CN110520475B

CN110520475B - Curable resin composition, dry film, cured product, electronic component, and printed wiring board

Info

Publication number: CN110520475B
Application number: CN201880023151.5A
Authority: CN
Inventors: 大川夏芽; 增田俊明; 张振兴; 宇敷滋; 三轮崇夫; 松野匠
Original assignee: Taiyo Holdings Co Ltd
Current assignee: Taiyo Holdings Co Ltd
Priority date: 2017-03-31
Filing date: 2018-03-29
Publication date: 2023-02-28
Anticipated expiration: 2038-03-29
Also published as: TW201903039A; JP7134166B2; JPWO2018181802A1; TWI768021B; CN110520475A; WO2018181802A1; KR20190127942A; KR102511228B1

Abstract

Provided are a curable resin composition which can provide a cured product that can maintain a low thermal expansion coefficient even in a high-temperature region during component mounting and has excellent various properties such as toughness, a dry film using the same, a cured product, and an electronic component. A curable resin composition comprising: a curable resin, a fine powder having at least one dimension of less than 100nm, and a filler other than the fine powder. A dry film, a cured product and an electronic component using the curable resin composition.

Description

Curable resin composition, dry film, cured product, electronic component, and printed wiring board

Technical Field

The invention relates to a curable resin composition, a dry film, a cured product and an electronic component. The present invention also relates to a curable resin composition, a cured product, and a printed wiring board.

Background

Examples of the electronic component include a wiring board, an active component fixed to the wiring board, and a passive component. In some wiring boards, wiring of a conductor is applied to an insulating base material to connect and fix active components, passive components, and the like, and depending on the application, the insulating layer and the conductor layer may be multilayered, or an insulating base material having flexibility may be used, and thus the wiring board is an important electronic component in an electronic device. In addition, wiring boards are also used for semiconductor packages, and curable resin compositions and dry films for wiring boards are used as outer layers after mounting of wiring boards and semiconductors. Examples of the active component and the passive component include a transistor, a diode, a resistor, a coil, and a capacitor.

In recent years, with miniaturization of electronic devices, required characteristics of electronic components have become strict. In wiring boards, higher density of wiring is required, and low thermal expansion is required for materials of wiring boards in order to ensure reliability of wiring and component connection portions. The active and passive components are also required to be miniaturized and highly integrated, and low thermal expansion is also required to ensure reliability.

As a method for achieving low thermal expansion, for example, patent document 1 proposes a method of obtaining a low thermal expansion coefficient by filling a resin with an inorganic filler.

As a means for achieving low thermal expansion of such a material, for example, a method of reinforcing with cellulose fibers to produce a fiber-reinforced composite material has been proposed (see patent document 2).

Furthermore, in recent years, with the miniaturization of electronic devices, low dielectric characteristics are required for electronic components in order to efficiently transmit high frequencies. As a method for achieving low dielectric characteristics, for example, non-patent document 1 proposes a method for reducing the relative dielectric constant and the dielectric loss tangent by using an epoxy resin having a dicyclopentadiene skeleton.

Further, in recent years, as electronic devices have been improved in performance, higher frequencies have been required than ever, and electronic components have been required to efficiently transmit high frequencies. As the high frequency characteristic, a skin effect can be cited. For example, non-patent document 2 describes that as the frequency increases, the current becomes able to pass only near the surface of the conductor.

In recent years, in order to cope with miniaturization and high functionality of devices including printed wiring boards, the printed wiring boards have been made thinner and smaller. Therefore, the conductor circuit of the printed circuit board is required to be further thinned and the mounting area to be reduced.

In contrast, the following methods are widely used in the manufacturing method of the printed wiring board: a method of filling a resin filler in a recess or a through hole such as a via hole or a through hole provided in a wiring board, curing the resin filler, polishing the cured resin filler to form a smooth surface, and then laminating an insulating layer and a conductor layer on the via hole or the through hole filled with the resin filler to form a multilayer.

As a resin filler used in such a technical method, a material excellent in various characteristics such as filling property into a concave portion and a through hole, polishing property of a cured product, and heat resistance is required, and a thermosetting resin composition as described in patent document 3 is proposed.

On the other hand, for the purpose of higher density, a technique of mounting a component by providing a wiring such as a conductor pad or via hole in a recess or through hole such as a via hole or a through hole filled with a resin filler has recently been employed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001-72834

Patent document 2: japanese patent laid-open publication No. 2011-001559

Patent document 3: japanese laid-open patent publication No. 2015-10146

Non-patent document

Non-patent document 1: "Journal of network Polymer" Vol.17, no.2 (1996) pp69

Non-patent document 2: "physical education" volume 61, no. 1 (2013), pages 18-20

Disclosure of Invention

Problems to be solved by the invention

However, the material described in patent document 1 requires a large amount of an inorganic filler to be filled in order to obtain a desired low thermal expansion coefficient, and has a problem that the physical properties of the cured product such as toughness are poor.

Furthermore, the present inventors have found that the material described in patent document 1 has a large thermal expansion coefficient in a temperature range exceeding 200 ℃.

Accordingly, a first object of the present invention is to provide a curable resin composition which can provide a cured product having excellent properties such as toughness while maintaining a low thermal expansion coefficient even in a high-temperature region when mounting components.

A first additional object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

It is true that, according to the material described in patent document 2, since fibers having an average fiber diameter of 4 to 200nm are dispersed in a matrix material, a composite material having low thermal expansion can be obtained.

However, in the method described in patent document 2, cellulose fibers are selected to further improve the low thermal expansion property, but the inventors have noticed that, when electronic components having a laminated structure are produced for the purpose of miniaturization, high density, and high integration, there is a new problem that, in particular, the insulation reliability between layers deteriorates.

Accordingly, a second object of the present invention is to provide a curable resin composition which has low thermal expansion and can give a cured product having excellent interlayer insulation reliability even when an electronic component having a laminated structure is produced for the purpose of miniaturization, high density, and high integration.

A second additional object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Furthermore, in order to increase the frequency of electronic components, it is important to be able to form not only low dielectric characteristics but also a high-definition circuit. In this regard, the present inventors have found that the insulating layer described in non-patent document 1 can obtain low dielectric characteristics, but cannot obtain adhesion strength with a high-definition circuit (copper plating).

Accordingly, a third object of the present invention is to provide a curable resin composition which can give a cured product having low dielectric characteristics and excellent adhesion between the cured product and copper plating.

A third object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Further, the skin effect is exhibited even in the wiring of the electronic component, and the high frequency passes only through the extreme surface of the wiring. Therefore, in order to efficiently transmit high frequencies, smoothing the interface between the wiring of the electronic component and the insulating material is considered.

However, such smoothing has a problem that the adhesion (peel strength) between the insulating material and the copper plating constituting the wiring is reduced.

On the other hand, in order to improve the adhesion of copper plating constituting the wiring, the surface of the insulating material is generally roughened while removing (desmearing) smear generated at the bottom when the insulating material is drilled with a laser.

However, if such roughening is performed, there is a problem that high frequency cannot be efficiently transmitted.

Therefore, a fourth main object of the present invention is to provide a curable resin composition which can remove the smear generated by laser processing in the desmear step and can obtain a cured product having a small surface roughness advantageous for high frequency transmission and also excellent peel strength.

It is a fourth object of the present invention to provide a dry film, a cured product and an electronic component using the curable resin composition.

Further, it is confirmed that the material described in patent document 2 can obtain a composite material having low thermal expansion properties because fibers having an average fiber diameter of 4 to 200nm are dispersed in a matrix material.

However, the present inventors have found that when the copper plating is applied to the material in a solid state, a new problem arises in that the copper plating expands due to the thermal history of component mounting or the like.

Accordingly, a fifth main object of the present invention is to provide a curable resin composition which has low thermal expansion and which can provide a cured product having excellent high-temperature resistance and no thermal expansion due to copper plating even when copper plating is applied for the purpose of producing wiring on the cured product of the composition and copper plating is formed into a solid shape for the purpose of shielding electromagnetic waves other than the wiring pattern.

A fifth object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Further, the material described in patent document 1 requires a large amount of an inorganic filler to obtain a desired low thermal expansion coefficient, and has a problem of poor physical properties of a cured product such as toughness.

Further, the present inventors have found that the material described in patent document 1 has a new problem that a large thermal expansion coefficient is formed in a temperature range exceeding 200 ℃ when mounting a component, and thus, there is no effect in order to ensure reliability.

Accordingly, a sixth object of the present invention is to provide a curable resin composition which can provide a cured product having excellent properties such as toughness and heat resistance while maintaining a low thermal expansion coefficient even in a high-temperature region during component mounting.

A sixth object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Further, in the above-mentioned technical method used in the method for manufacturing a printed wiring board, when the thermosetting resin composition as described in patent document 3 is used as a resin filler, there is a problem that: the metal wiring such as the via hole, the recess such as the through hole, and the conductor pad and the via hole filled with the resin filler expands in the high-temperature heating step at the time of mounting the component, and this expansion affects the reliability.

In addition, the thermosetting resin composition filled in the concave portion and the through hole (hereinafter, also simply referred to as "hole portion and the like") has a problem that a resin component melts and cures by heating, and therefore bleeds out around the hole portion and the like during curing. Since the exuded resin composition contains a thin filler component, the adhesive property thereof cannot be completely removed by polishing in the subsequent step and remains, which causes a problem of plating.

Furthermore, in the polishing step after curing of the thermosetting resin composition filled in the concave portion and the through hole, it is necessary to completely remove the bleeding of the resin filler around the hole portion and the like, and as a result, there is another problem that the hole portion and the like are depressed by excessive polishing and cannot be a completely smooth surface.

Accordingly, a seventh main object of the present invention is to provide a curable resin composition capable of solving the above problems, specifically, a curable resin composition comprising: even in a high-temperature heating process during component mounting, recesses such as via holes and through holes filled with a resin filler, and wirings such as conductor pads and via holes on the via holes do not swell, and furthermore, a thin resin composition containing the filler does not bleed out during curing, and dishing such as holes due to over-polishing for smoothing does not occur in a polishing process after curing.

A seventh object of the present invention is to provide a cured product of the curable resin composition, which can solve the above problems, and a printed wiring board in which a hole or the like is filled with the cured product.

Means for solving the problems

The present inventors have conducted intensive studies and as a result, have found that the above-mentioned problems can be solved unexpectedly by blending a filler such as silica, calcium carbonate, barium sulfate, talc or titanium oxide, which has been conventionally used as a filler for electronic component materials such as solder resists, interlayer insulating materials or pore-filling materials, with a fine powder having at least one dimension of less than 100nm (hereinafter, also referred to simply as "fine powder").

That is, the curable resin composition according to the first embodiment of the present invention includes: a curable resin, a fine powder having at least one dimension of less than 100nm, and a filler other than the fine powder.

In the present invention, as the fine powder, fine cellulose powder (hereinafter also referred to as "CNF") or cellulose nanocrystalline particles (hereinafter also referred to as "CNC") is preferably used. The mixing ratio of the fine powder to the filler other than the fine powder in the total filler is suitably 100: (0.04-30).

In the present invention, it is preferable that the curable resin contains at least 1 kind of cyclic ether compound having a naphthalene skeleton and an anthracene skeleton, or at least 1 kind selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton, or at least 1 kind selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton.

The dry film of the present invention is characterized by having a resin layer obtained by applying the curable resin composition to a film and drying the film.

The cured product of the present invention is obtained by curing the resin layer of the curable resin composition or the dry film.

The electronic component of the present invention is characterized by comprising the cured product.

Here, in the present invention, the cellulose nanocrystal particles are those obtained by hydrolyzing a cellulose raw material with a high-concentration inorganic acid (hydrochloric acid, sulfuric acid, hydrobromic acid, or the like) to remove an amorphous portion and separate only a crystalline portion. Specifically, the crystal is a crystal which is free from an amorphous portion and is obtained by hydrolysis at a concentration of 60wt% or more with a strong acid which is easily concentrated at 7wt% or more, preferably 9wt% or more, and more preferably a strong acid such as sulfuric acid.

The present inventors have further studied to solve the above problems, and as a result, have found that the above problems can be solved by using a curable resin composition in which a thermosetting component and a fine powder having at least one dimension of less than 100nm are dispersed as a filler for a via hole, a recess such as a through hole, or a through hole of a printed wiring board, and the present invention has been completed.

The curable resin composition according to the second embodiment of the present invention is a curable resin composition for filling at least one of a recess and a through hole of a printed wiring board, and is characterized by containing (a) a fine powder having at least one dimension of less than 100nm and (B) a thermosetting component.

The curable resin composition of the present invention preferably contains a cyclic ether compound containing an amine as a precursor as the (B) thermosetting component, and further preferably contains a bisphenol a type epoxy resin and a bisphenol F type epoxy resin.

The curable resin composition of the present invention preferably contains (C) a boric acid ester compound.

The curable composition of the present invention preferably contains (D) a filler other than the fine powder (a).

The cured product of the present invention is obtained by curing the curable resin composition.

The printed wiring board of the present invention is characterized in that at least one of the recess and the through hole of the printed wiring board is filled with the curable resin composition.

In the present invention, the shape of the fine powder is not particularly limited, and a fibrous shape, a flake shape, a granular shape, and the like can be used, and "at least one dimension less than 100nm" means that any of one dimension, two dimensions, and three dimensions is less than 100nm. For example, in the case of a fibrous fine powder, those having a two-dimensional size smaller than 100nm and having a surplus one-dimensional expansion, in the case of a scale-like fine powder, those having a one-dimensional size smaller than 100nm and having a surplus two-dimensional expansion, and in the case of a granular fine powder, those having a three-dimensional size smaller than 100nm are cited.

In the present invention, the size of the fine powder in one, two, and three dimensions can be measured by observing the fine powder with an SEM (Scanning Electron Microscope), a TEM (Transmission Electron Microscope), an AFM (Atomic Force Microscope), or the like.

For example, in the case of scale-like fine powder, the average value of the smallest one-dimensional thickness is measured, and the average thickness is set to less than 100nm. Specifically, 12 points were randomly drawn on a diagonal line of a photomicrograph near the fine powder where the thickness could be measured, and after the thickest fine powder and the thinnest fine powder were removed, the thickness of the remaining 10 points was measured and was set to be smaller than 100nm on the average.

In the case of fibrous fine powder, the average value of the smallest two-dimensional fiber diameters (hereinafter also simply referred to as "average fiber diameter") is measured, and the average fiber diameter is set to be smaller than 100nm. Specifically, 12 points were randomly drawn out from the fine powder located in the vicinity of the line drawn on the diagonal line of the photomicrograph, the fine powder having the thickest fiber diameter and the finest fiber diameter was removed, and the fiber diameters of the remaining 10 points were measured and set to have an average value smaller than 100nm.

In the case of a granular fine powder, the average particle size is measured and is less than 100nm. Specifically, 12 points were randomly drawn from the fine powder located in the vicinity of the diagonal line drawn on the photomicrograph, and after the fine powder having the maximum particle diameter and the minimum particle diameter was removed, the particle diameters of the remaining 10 points were measured and the average value was set to be less than 100nm.

The fine powder having a fibrous or scaly shape and other dimensions, for example, has a size of less than 1000nm, preferably less than 650nm, and more preferably less than 450nm. If the size of the extension is less than 1000nm, a reinforcing effect by the interaction between fine powders can be effectively obtained.

In the present invention, the fine cellulose powder is defined in the same manner as the above fine powder.

ADVANTAGEOUS EFFECTS OF INVENTION

First, the present invention can provide a curable resin composition that can provide a cured product that can maintain a low thermal expansion coefficient even in a high-temperature region during component mounting and has excellent properties such as toughness.

Further, the present invention can provide a dry film, a cured product, and an electronic component using the curable resin composition.

Secondly, the present invention can provide a curable resin composition that can provide a cured product having low thermal expansion and excellent interlayer insulation reliability even when an electronic component having a laminated structure is produced for the purpose of miniaturization, high density, and high integration.

Third, the present invention can provide a curable resin composition which can give a cured product having low dielectric characteristics and good adhesion between the cured product and copper plating.

Fourthly, according to the present invention, there can be provided a curable resin composition which can remove the smear generated by laser processing in the smear removal step and can obtain a cured product having a small surface roughness advantageous for high frequency transmission and also excellent peel strength.

Fifth, according to the present invention, there can be provided a curable resin composition which has low thermal expansion and which can provide a cured product having excellent high-temperature resistance and no thermal expansion even when copper plating is applied for the purpose of producing wiring on the cured product of the composition and copper plating is formed into a solid shape for the purpose of shielding electromagnetic waves other than the wiring pattern.

Sixth, the present invention can provide a curable resin composition which can provide a cured product that maintains a low thermal expansion coefficient even in a high-temperature region during component mounting and has excellent properties such as toughness and heat resistance, and has an excellent pot life.

Seventh, according to the present invention, there can be provided a curable resin composition which, in a printed wiring board having at least one of a recess and a through-hole, does not cause swelling of the recess such as a via hole or a through-hole filled with a resin filler, or a wiring such as a conductor pad or a via hole on the through-hole even in a high-temperature heating step at the time of component mounting, does not cause bleeding of a thin resin composition of the filler component at the time of curing, and does not cause dishing of a hole portion or the like due to excessive polishing for smoothing in a polishing step after curing.

Further, according to the present invention, a cured product of the curable resin composition capable of solving the above problems, and a printed wiring board in which a hole portion and the like are filled with the cured product can be provided.

Drawings

FIG. 1-1 is a graph showing the relationship between the amount of silica and fine cellulose powder mixed and the thermal expansion coefficient.

FIG. 1-2-1 is a graph showing the effect of reducing the thermal expansion coefficient by the combined use of fine cellulose powder.

Fig. 1-2-2 are graphs showing the effect of reducing the thermal expansion coefficient by the combined use of fine cellulose powder.

Fig. 1 to 3 are graphs showing the effect of improving elongation by the combined use of fine cellulose powder.

FIGS. 1 to 4 are explanatory views showing test substrates used in examples.

FIG. 2-1 is a partial cross-sectional view showing an example of the configuration of a multilayer printed wiring board as an electronic component of the present invention.

FIG. 2-2 is an explanatory view showing a test substrate used in examples.

FIGS. 2 to 3 are other explanatory views showing the test substrate used in the examples.

FIGS. 2 to 4 are another explanatory view showing a test substrate used in examples.

FIG. 3-1 is a partial cross-sectional view showing an example of a configuration of a multilayer printed wiring board as an electronic component of the present invention.

FIG. 3-2 is an explanatory view showing a test substrate used in examples.

FIG. 4-1 is a partial cross-sectional view showing an example of a configuration of a multilayer printed wiring board as an electronic component of the present invention.

FIG. 4-2 is an explanatory view showing a test substrate used in examples.

FIG. 5-1 is a partial cross-sectional view showing an example of the configuration of a multilayer printed wiring board as an electronic component of the present invention.

FIG. 5-2 is an explanatory view showing a test substrate used in examples.

FIG. 6-1 is a graph showing the relationship between the amounts of silica and cellulose nanocrystal particles and the thermal expansion coefficient.

Fig. 6-2-1 is a graph showing the effect of reducing the thermal expansion coefficient by using the cellulose nanocrystal particles in combination.

Fig. 6-2-2 is a graph showing the effect of reducing the thermal expansion coefficient by using the cellulose nanocrystal particles in combination.

Fig. 6 to 3 are graphs showing the effect of improving elongation by the combined use of cellulose nanocrystal particles.

FIGS. 6 to 4 are explanatory views showing test substrates used in examples.

FIG. 7-1 is a schematic sectional view showing an example of a method for producing a printed wiring board using the curable resin composition of the present invention.

Fig. 7-2 is a partial sectional view showing an example of a configuration of a multilayer printed wiring board as an example of the printed wiring board of the present invention.

Fig. 7-3 are partial sectional views showing one configuration example of a multilayer printed wiring board as an example of the printed wiring board of the present invention.

Fig. 7 to 4 are schematic cross-sectional views illustrating depressions such as holes generated in the polishing step.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail.

< first embodiment of the present invention >

The curable resin composition according to the first embodiment of the present invention is characterized in that the fine powder and a filler other than the fine powder are used in combination as a filler.

With such a configuration, the first object is to provide a cured product that maintains a low thermal expansion coefficient even in a temperature range exceeding 200 ℃ when mounting components and has excellent properties such as toughness.

[ Fine powder ]

The fine powder used in the present invention means a powder having at least one dimension of less than 100nm, and includes not only fine approximately spherical powder but also fibrous powder having a cross-sectional diameter of less than 100nm, flaky (scaly) powder having a thickness of less than 100nm, and the like, as described above. Compared with the case where any of the three dimensions is 100nm or more, the surface area per unit mass of such a fine powder is much larger, and the proportion of atoms exposed on the surface is increased. Therefore, it is considered that the reinforcing effect is exhibited by the interaction of the fine powders attracting each other, and the thermal expansion property is lowered.

The fine powder is not particularly limited as long as it is a particle having at least one dimension smaller than 100nm, and 2 or more kinds of fine powders can be used in combination. Examples of the fine powder include carbon-based powders such as graphite, graphene, fullerene, single-walled carbon nanotube and multi-walled carbon nanotube, inorganic powders such as silver, gold, iron, nickel, titanium oxide, cerium oxide, zinc oxide, silica and aluminum hydroxide, mineral-based powders such as clay, smectite and bentonite, fine cellulose powders obtained by fibrillating plant fibers, cellulose nanocrystal particles obtained by fibrillating only a crystal portion from a cellulose raw material, fine chitin obtained by fibrillating chitin obtained from crustacean or the like, and polymer-based powders such as fine chitosan obtained by further subjecting these fine powders to alkali treatment, and these can be processed into nanotubes, nanowires and nanosheets, or 2 or more kinds of them can be used in combination. Among these, examples of the hydrophilic fine powder include metal oxide fine particles such as titanium oxide, metal hydroxide fine particles such as aluminum hydroxide, mineral fine particles such as clay, fine cellulose fibers, fine chitin, and the like. Among such fine powders, fine cellulose powders are preferable from the viewpoint of particularly reinforcing effect and ease of handling, and from the viewpoint of improving adhesion to copper plating and ease of handling. In addition, cellulose nanocrystalline particles are also preferred.

The inventors paid attention to fine cellulose powder having at least one dimension smaller than 100nm, and compared the relationship between the amount of fine cellulose powder blended and the thermal expansion coefficient with silica and studied intensively, and as a result, found that a significant effect of reducing the thermal expansion coefficient can be obtained with a small amount of fine cellulose powder blended (see fig. 1-1).

Further, the inventors have made intensive studies focusing on the fact that a sufficient effect of reducing the thermal expansion coefficient can be obtained by blending a small amount of fine cellulose powder, and as a result, have found that the above-mentioned effects peculiar to the present invention can be obtained by blending a filler such as silica for ensuring various characteristics required for an insulating material for electronic components such as toughness and the like and using the fine cellulose powder in combination (see fig. 1-2 and 1-3).

When hydrophilic fine powder is used as the fine powder described above, it is preferable to subject the particles to a hydrophobization treatment, a surface treatment using a coupling agent, or the like. For this treatment, a known and conventional method suitable for fine powder can be used.

The amount of fine powder to be mixed in the present invention is preferably 0.04 to 64% by mass, more preferably 0.08 to 30% by mass, and still more preferably 0.1 to 10% by mass, based on the total amount of the composition excluding the solvent. When the amount of the fine powder is 0.04% by mass or more, the effect of reducing the linear expansion coefficient can be obtained favorably, and the effect of improving the adhesion to copper plating can be obtained favorably. On the other hand, when 64% by mass or less, the film formability is improved.

In the fine powder of the present invention, the fine cellulose powder can be obtained as follows, but is not limited thereto.

(Fine cellulose powder)

As a raw material of the fine cellulose powder, pulp obtained from natural plant fiber raw materials such as wood, hemp, bamboo, cotton, jute, kenaf, beet, agricultural waste, cloth, and the like, regenerated cellulose fibers such as rayon, cellophane, and the like can be used, and among them, pulp is particularly preferable. As the pulp, chemical pulp such as kraft pulp and sulfite pulp obtained by pulping a plant raw material chemically or mechanically or in combination of both, semichemical pulp, chemical mill pulp, chemimechanical pulp, thermomechanical pulp, chemithermomechanical pulp, refiner mechanical pulp, groundwood pulp, deinked waste paper pulp, magazine waste paper pulp, corrugated waste paper pulp, or the like containing these plant fibers as a main component can be used. Among them, various kraft pulps derived from needle-leaved trees, which have strong fiber strength, such as needle-leaved unbleached kraft pulp, needle-leaved unbleached kraft pulp subjected to oxygen exposure, and needle-leaved bleached kraft pulp, are particularly suitable.

The raw material mainly comprises cellulose, hemicellulose and lignin, and the content of lignin is usually about 0 to 40 mass%, particularly about 0 to 10 mass%. These raw materials may be subjected to lignin removal or bleaching treatment as needed to adjust the amount of lignin. The lignin content can be determined by the Klason method.

In the cell wall of a plant, cellulose molecules are not single molecules, but rather form microfibers (fine cellulose fibers) having crystallinity, which are regularly aggregated and aggregated in tens of numbers, and become basic skeleton substances of the plant. Therefore, in order to produce a fine cellulose powder from the above-mentioned raw material, a method of unraveling the fibers into a nanometer size can be used by subjecting the above-mentioned raw material to beating or pulverization treatment, high-temperature and high-pressure steam treatment, treatment with a phosphate or the like, treatment for oxidizing the cellulose fibers using an N-oxyl compound as an oxidation catalyst, or the like.

In the above-mentioned beating or pulverizing treatment, the fine cellulose powder is obtained by applying a direct force to the raw material such as the pulp and mechanically beating or pulverizing the raw material to thereby disentangle the fibers. More specifically, for example, a pulp or the like is mechanically treated with a high-pressure homogenizer or the like to prepare a cellulose fiber having a fiber diameter of about 0.1 to 10 μm into an aqueous suspension of about 0.1 to 3 mass%, and the suspension is repeatedly ground or crushed with a grinder or the like to obtain a fine cellulose powder having a fiber diameter of about 10 to 100 nm.

The above-mentioned grinding or melt-crushing treatment can be carried out using, for example, a grinder "Pure fire Mill" manufactured by chestnut machine manufacturers or the like. The mill is a stone mortar mill which pulverizes a raw material into ultrafine particles due to impact, centrifugal force, and shearing force generated when the raw material passes through a gap between upper and lower 2-piece mills, and can simultaneously perform shearing, grinding, micronization, dispersion, emulsification, and fibrillation. The grinding or melting treatment may be performed by using a Super Masscolloider manufactured by Zengh industries, ltd. Super masscoleloider is a mill that can be ultrafinely shattered to a degree beyond the mere pulverization area and is felt to melt. Super Masscolloider is a stone mortar type ultrafine particle grinding mill composed of upper and lower 2 pore-free grindstones with intervals freely adjustable, wherein the upper grindstone is fixed, and the lower grindstone rotates at high speed. The raw material charged into the hopper is fed into the gap between the upper and lower grindstones by centrifugal force, and the raw material is gradually ground and made into ultrafine particles by strong compression, shearing, rotational friction force, and the like generated thereby.

The high-temperature high-pressure steam treatment is a method of exposing the raw material such as pulp to high-temperature high-pressure steam to thereby loosen fibers, thereby obtaining a fine cellulose powder.

The treatment with phosphate or the like is a treatment method in which the surface of the raw material such as pulp is phosphated to weaken the bonding force between cellulose fibers, and then refined cellulose powder is obtained by disentangling the fibers by a refiner treatment. For example, the fine cellulose powder can be obtained by immersing a raw material such as the above pulp in a solution containing 50 mass% of urea and 32 mass% of phosphoric acid, sufficiently infiltrating the solution between cellulose fibers at 60 ℃, then heating at 180 ℃ to phosphorylate the solution, washing the phosphorylated product with water, hydrolyzing the product in a 3 mass% hydrochloric acid aqueous solution at 60 ℃ for 2 hours, washing the product with water again, further treating the product in a 3 mass% sodium carbonate aqueous solution at room temperature for about 20 minutes to complete the phosphorylating, and defibrating the treated product with a refiner.

The treatment of oxidizing cellulose fibers with the N-oxyl compound as an oxidation catalyst is a method of oxidizing the raw material such as pulp and then refining the oxidized raw material to obtain fine cellulose powder.

First, natural cellulose fibers are dispersed in water in an amount of about 10 to 1000 times (mass basis) the absolute dry basis by using a mixer or the like, thereby preparing an aqueous dispersion. Examples of the natural cellulose fibers which are raw materials of the fine cellulose fibers include wood pulp such as softwood pulp and hardwood pulp, nonwood pulp such as wheat straw pulp and bagasse pulp, cotton pulp such as cotton linter and cotton linter, and bacterial cellulose. These can be used alone in 1 kind, also can be combined with more than 2 kinds. In addition, in order to enlarge the surface area in advance, the natural cellulose fibers may be subjected to a treatment such as beating.

Next, the aqueous dispersion is subjected to oxidation treatment of the natural cellulose fibers using an N-oxyl compound as an oxidation catalyst. Examples of the N-oxyl compound include TEMPO derivatives having various functional groups at the C4 position, such as 4-carboxy-TEMPO, 4-acetamide-TEMPO, 4-amino-TEMPO, 4-dimethylamino-TEMPO, 4-phosphonooxy-TEMPO, 4-hydroxy-TEMPO, 4-oxy-TEMPO, 4-methoxy-TEMPO, 4- (2-bromoacetamide) -TEMPO, and 2-azaadamantane N-oxyl, in addition to TEMPO (2, 6-tetramethylpiperidine-N-oxyl). The amount of the N-oxyl compound added is sufficient as a catalyst, and is usually in the range of 0.1 to 10 mass% based on the absolute dry content with respect to the natural cellulose fiber.

In the oxidation treatment of the natural cellulose fibers, an oxidizing agent and a co-oxidizing agent are used in combination. Examples of the oxidizing agent include a hypohalous acid, perhalogenic acid, salts thereof, hydrogen peroxide, and per-organic acids, and among these, alkali metal hypohalites such as sodium hypochlorite and sodium hypobromite are suitable. As the co-oxidant, for example, an alkali metal bromide such as sodium bromide can be used. The amount of the oxidizing agent is usually in the range of about 1 to 100% by mass on an absolute dry basis with respect to the natural cellulose fibers, and the amount of the co-oxidizing agent is usually in the range of about 1 to 30% by mass on an absolute dry basis with respect to the natural cellulose fibers.

In the oxidation treatment of the natural cellulose fibers, the pH of the aqueous dispersion is preferably maintained in the range of 9 to 12 from the viewpoint of efficiently carrying out the oxidation reaction. The temperature of the aqueous dispersion during the oxidation treatment can be arbitrarily set in the range of 1 to 50 ℃ and the reaction can be carried out at room temperature without temperature control. The reaction time may be in the range of 1 to 240 minutes. In order to introduce more carboxyl groups into the fiber surface, a penetrant may be added to the aqueous dispersion in order to allow the chemical to penetrate into the natural cellulose fibers. Examples of the penetrant include anionic surfactants such as carboxylate, sulfate, sulfonate and phosphate, and nonionic surfactants such as polyethylene glycol and polyhydric alcohol.

After the oxidation treatment of the natural cellulose fibers and before the pulverization, a purification treatment for removing impurities such as unreacted oxidizing agents and various by-products contained in the aqueous dispersion is preferably performed. Specifically, for example, a method of repeatedly washing and filtering the oxidized natural cellulose fibers may be used. The natural cellulose fibers obtained after the refining treatment are usually subjected to the refining treatment in a state of being impregnated with an appropriate amount of water, and may be dried to be made into fibers or powder as necessary.

Next, the natural cellulose treatment is carried out in a state where the refined natural cellulose fibers are dispersed in a solvent such as water, if desired. As the solvent of the dispersion medium used for the micronization treatment, water is usually preferred, and if desired, water-soluble organic solvents such as alcohols (methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, ethylene glycol, glycerin, etc.), ethers (ethylene glycol dimethyl ether, 1, 4-dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide, etc.), etc., and mixtures thereof may be used. The solid content concentration of the natural cellulose fibers in the dispersion liquid of these solvents is preferably 50 mass% or less. When the solid content concentration of the natural cellulose fiber exceeds 50 mass%, extremely high energy is required for dispersion, which is not preferable. The natural cellulose may be treated to fine particles by using a dispersing apparatus such as a low-pressure homogenizer, a high-pressure homogenizer, a grinder, a chopper, a ball mill, a jet mill, a beater, a disintegrator, a short-screw extruder, a twin-screw extruder, an ultrasonic mixer, or a home juice mixer.

The fine cellulose powder obtained by the micronization treatment may be prepared into a suspension with a regulated solid content concentration or a dried powder, as desired. Here, when the dispersion is in the form of a suspension, water alone may be used as a dispersion medium, or a mixed solvent of water and another organic solvent, for example, an alcohol such as ethanol, a surfactant, an acid, an alkali, or the like may be used.

The oxidation treatment and the refining treatment of the natural cellulose fiber selectively oxidize the hydroxyl group at the C6 position of the constituent unit of the cellulose molecule into a carboxyl group via an aldehyde group, and a highly crystalline fine cellulose powder having the predetermined number average fiber diameter and formed of cellulose molecules having a carboxyl group content of 0.1 to 3mmol/g can be obtained. The highly crystalline fine cellulose powder has a cellulose I-type crystal structure. This means that the fine cellulose powder is obtained by surface oxidation and refinement of naturally-derived cellulose molecules having an I-type crystal structure. That is, natural cellulose fibers are fine cellulose powders obtained by subjecting fine fibers called microfibrils produced in the course of biosynthesis thereof to bunching to construct a high-order solid structure, weakening strong aggregation force (hydrogen bonding between surfaces) between microfibrils by introduction of aldehyde groups or carboxyl groups by oxidation treatment, and further subjecting the fibers to micronization treatment. The average fiber diameter, average fiber length, average aspect ratio, and the like of the fine cellulose powder can be controlled by adjusting the conditions of the oxidation treatment, increasing or decreasing the content of the carboxyl group, changing the polarity, or by electrostatic repulsion of the carboxyl group or micronization treatment.

The natural cellulose fiber has an I-type crystal structure, and can be identified by having typical peaks at two positions in the vicinity of 2 θ =14 to 17 ° and in the vicinity of 2 θ =22 to 23 ° in a diffraction pattern obtained by measurement of a wide-angle X-ray diffraction pattern thereof. The carboxyl group introduced into the cellulose molecule of the fine cellulose powder can be caused by the presence of carbonyl group-induced absorption (1608 cm) in the total reflection infrared spectroscopy (ATR) in the sample from which moisture has been completely removed ^-1 Nearby). In the case of carboxyl group (COOH), 1730cm in the above measurement ^-1 There is absorption.

Since the halogen atoms are attached or bonded to the oxidized natural cellulose fibers, dehalogenation treatment may be performed for the purpose of removing such residual halogen atoms. The dehalogenation treatment can be performed by immersing the natural cellulose fibers subjected to the oxidation treatment in a hydrogen peroxide solution or an ozone solution.

Specifically, for example, the natural cellulose fibers after oxidation treatment are mixed in a hydrogen peroxide solution having a concentration of 0.1 to 100g/L at a bath ratio of 1:5 to 1: about 100, preferably 1: 10-1: the dipping was carried out under the condition of about 60 (mass ratio). The concentration of the hydrogen peroxide solution in this case is preferably 1 to 50g/L, more preferably 5 to 20g/L. The hydrogen peroxide solution preferably has a pH of 8 to 11, more preferably 9.5 to 10.7.

The amount [ mmol/g ] of carboxyl groups in cellulose relative to the mass of the fine cellulose powder contained in the aqueous dispersion can be evaluated by the following method. Specifically, 60ml of a 0.5 to 1 mass% aqueous dispersion of a fine cellulose powder sample weighed out precisely for the dry mass was prepared, the pH was adjusted to about 2.5 with 0.1M hydrochloric acid aqueous solution, and then 0.05M sodium hydroxide aqueous solution was added dropwise until the pH became about 11, and the conductivity was measured. The amount of functional groups can be determined from the amount of sodium hydroxide (V) consumed in the neutralization stage of a weak acid whose change in conductivity is slow, using the following formula. The amount of the functional group indicates the amount of the carboxyl group.

Amount of functional group [ mmol/g ] = Vml ]. Times.0.05/fine cellulose powder sample [ g ]

In addition, the fine cellulose powder used in the present invention may be chemically modified and/or physically modified to provide functionality. Here, the chemical modification can be performed by the following method: addition of a functional group by acetalization, acetylation, cyanoethylation, etherification, isocyanation or the like, or complex or coating of an inorganic substance such as a silicate or titanate by a chemical reaction, a sol-gel method or the like. As a method of chemical modification, for example, a method of immersing a fine cellulose powder molded into a sheet shape in acetic anhydride and heating the same can be mentioned. In addition, there is a method of modifying an amine compound, a quaternary ammonium compound, or the like with an ionic bond or an amide bond with respect to a carboxyl group in a molecule of fine cellulose powder obtained by oxidizing cellulose fibers with an N-oxyl compound as an oxidation catalyst.

Examples of the physical modification method include a method of coating a metal or ceramic material with a physical vapor deposition method (PVD method) such as vacuum vapor deposition, ion plating, or sputtering, a chemical vapor deposition method (CVD method), a plating method such as chemical plating or electrolytic plating, or the like. These modifications may be made before or after the above-mentioned treatment.

When the fine cellulose powder used in the present invention is in a fibrous form, it is preferable that the average fiber diameter thereof is 3nm or more and less than 100nm. Since the minimum diameter of the fine cellulose fiber single fiber is 3nm, it is substantially impossible to produce the fine cellulose fiber single fiber with a diameter of less than 3 nm. When the average particle size is less than 100nm, the desired effect of the present invention can be obtained without excessively adding the compound, and the film formability is good. The average fiber diameter of the fine cellulose powder can be measured by the method for measuring the size of the fine powder.

(cellulose nanocrystalline particles)

The present inventors have further focused on the crystal form of fine cellulose powder and have intensively studied, and as a result, have found that the above problems can be solved unexpectedly by hydrolyzing a cellulose raw material to remove an amorphous portion and separating only cellulose nanocrystal particles of a crystalline portion, and a curable resin composition having an excellent pot life can be provided.

By using cellulose nanocrystalline particles, from which only the crystalline portion is separated from the cellulose raw material, and a filler other than the cellulose nanocrystalline particles in combination as a filler, a curable resin composition having an excellent pot life, which can provide a cured product that maintains a low thermal expansion coefficient even in a temperature range exceeding 200 ℃ when mounting a component and has excellent properties such as toughness and heat resistance, can be provided.

Further, the inventors focused on the separation of only the cellulose nanocrystal particles in the crystal part from the cellulose raw material, and conducted intensive studies comparing the relationship between the amount of the added cellulose nanocrystal particles and the thermal expansion coefficient with that of silica, and as a result, found that a significant effect of reducing the thermal expansion coefficient can be obtained with a small amount of the added cellulose nanocrystal particles (see fig. 6-1).

The inventors have also found that the above-mentioned effects peculiar to the present invention can be obtained by blending a filler such as silica for securing various characteristics required for an insulating material for electronic parts such as toughness and heat resistance, and by using the cellulose nanocrystal particles in combination (see fig. 6-2 and 6-3).

Further, the inventors have found that cellulose nanocrystal particles formed only from crystalline portions exert a specific effect that fine cellulose powder containing amorphous portions, such as a curable resin composition having an excellent pot life, can be provided.

In the present invention, the cellulose nanocrystal particles are any particles as long as the amorphous portion is removed by hydrolyzing a cellulose raw material with a high-concentration inorganic acid (hydrochloric acid, sulfuric acid, hydrobromic acid, or the like) and only the crystalline portion is separated. The size of the particles is preferably 3 to 70nm in average crystal width and 100 to 500nm in average crystal length, more preferably 3 to 50nm in average crystal width and 100 to 400nm in average crystal length, and still more preferably 3 to 10nm in average crystal width and 100 to 300nm in average crystal length. Here, the crystal width refers to the length of the short side of the particle, and the crystal length refers to the length of the long side of the particle. Such cellulose nanocrystal particles have a larger surface area per unit mass than particles having a larger width and length, and the proportion of atoms exposed on the surface increases. Therefore, it is considered that the cellulose nanocrystal particles exhibit a reinforcing effect by attracting each other and have a reduced thermal expansion property.

The size (average crystal width and average crystal length) of the cellulose nanocrystal particles can be measured by observation with SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), AFM (Atomic Force Microscope), and the like.

Specifically, 12 points were randomly drawn on a diagonal line of a micrograph of particles whose size was measurable and which were located in the vicinity of the line, the largest particles and the smallest particles were removed, and the sizes of the remaining 10 points (crystal width and crystal length) were measured, and the values averaged to obtain the average crystal width and average crystal length of the cellulose nanocrystal particles.

As the cellulose nanocrystal particles, 2 or more different types of raw material cellulose can be used in combination.

Such cellulose nanocrystal particles are preferably subjected to hydrophobization treatment, surface treatment using a coupling agent, or the like. Such treatment may be carried out by a known and customary method suitable for cellulose nanocrystal particles.

The amount of the cellulose nanocrystal particles to be blended in the present invention is preferably 0.04 to 30 mass%, more preferably 0.08 to 20 mass%, and still more preferably 0.1 to 10 mass% with respect to the total amount of the composition excluding the solvent. When the amount of the cellulose nanocrystal particles is 0.04% by mass or more, the effect of reducing the thermal expansion coefficient can be obtained well. On the other hand, when 30 mass% or less, the film forming property is improved.

The cellulose nanocrystal particle of the present invention can be obtained by hydrolyzing a cellulose raw material with a high-concentration inorganic acid (hydrochloric acid, sulfuric acid, hydrobromic acid, etc.) to remove an amorphous portion and separating only a crystalline portion.

Here, the cellulose raw material includes, but is not particularly limited to, paper making pulp, cotton-based pulp such as cotton linter and cotton linter, nonwood-based pulp such as hemp, wheat straw and bagasse, and cellulose separated from sea squirts, sea weeds, and the like. Among these, paper pulp is preferable in terms of availability, and cotton and sea squirt are preferable in terms of being able to produce CNC having more excellent heat resistance.

Examples of the paper-making pulp include hardwood kraft pulp, softwood kraft pulp, and the like.

Examples of the hardwood kraft pulp include bleached kraft pulp (LBKP), unbleached kraft pulp (LUKP), and oxygen bleached kraft pulp (LOKP).

Examples of the softwood kraft pulp include bleached kraft pulp (NBKP), unbleached kraft pulp (NUKP), and oxygen bleached kraft pulp (NOKP).

Further, chemical pulp, semichemical pulp, mechanical pulp, non-wood pulp, deinked pulp using waste paper as a raw material, and the like can be given. As the chemical pulp, sulfite Pulp (SP), soda pulp (AP), and the like are available. Examples of the semichemical pulp include semichemical pulp (SCP), chemically ground wood pulp (CGP), and the like. As the mechanical pulp, there are wood pulp (GP), thermomechanical pulp (TMP, BCTMP), and the like. Examples of the non-wood pulp include those obtained by using broussonetia papyrifera, edgeworthia chrysantha, hemp, kenaf, and the like as a raw material.

The cellulose raw material may be used alone in 1 kind, or may be used in combination of 2 or more kinds. Cellulose nanofibers (hereinafter also simply referred to as "CNF") produced by a mechanical defibration method, a phosphorylation method, a TEMPO oxidation method, or the like may be used as the cellulose raw material.

The hydrolysis of the cellulosic material as described above can then be carried out as follows: for example, an aqueous suspension or slurry containing the cellulose raw material is treated with sulfuric acid, hydrochloric acid, hydrobromic acid, or the like, or the cellulose raw material is directly suspended in an aqueous solution of sulfuric acid, hydrochloric acid, hydrobromic acid, or the like. In particular, when pulp is used as the cellulose raw material, it is preferable to perform hydrolysis after forming cotton-like fibers by a chopper, pin mill, or the like, and to perform uniform hydrolysis.

In the hydrolysis treatment, the temperature condition is not particularly limited, and may be, for example, 25 to 90 ℃. The conditions for the hydrolysis treatment time are not particularly limited, and may be, for example, 10 to 120 minutes.

The cellulose nanocrystal particles obtained by hydrolyzing the cellulose raw material in this manner can be neutralized with an alkali such as sodium hydroxide, for example.

The cellulose nanocrystal particles thus obtained may be subjected to micronization treatment as necessary. In the atomization treatment, the treatment apparatus and the treatment method are not particularly limited.

Examples of the micronization apparatus include a mill (a mortar-type pulverizer), a high-pressure homogenizer, an ultrahigh-pressure homogenizer, a high-pressure impact pulverizer, a ball mill, a bead mill, a disc refiner, a conical refiner, a twin-screw mixer, a vibration mill, a homomixer rotating at high speed, an ultrasonic disperser, and a beater.

In the microparticulation treatment, it is preferable to dilute the cellulose nanocrystal particles with water and an organic solvent alone or in combination to prepare a slurry, but there is no particular limitation. Preferable organic solvents include alcohols, ketones, ethers, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMAc). The number of the dispersion medium may be 1, or 2 or more. The dispersion medium may contain a solid component other than the cellulose nanocrystal particles, for example, urea having hydrogen bonding properties.

In addition, the cellulose nanocrystal particles used in the present invention may be chemically and/or physically modified to improve functionality. Here, the chemical modification can be performed by the following method: addition of functional groups by acetalization, acetylation, cyanoethylation, etherification, isocyanation, or the like, or composite or coating of inorganic substances such as silicates and titanates by chemical reaction, sol-gel method, or the like. The physical modification may be performed by plating or vapor deposition.

[ Filler other than Fine powder ]

The resin composition of the present invention further contains a filler other than the fine powder. Examples of such fillers include inorganic fillers such as barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, and titanium oxide. When the fine powder is cellulose nanocrystal particles, the fine powder may be an organic filler, and cellulose nanofibers may be used as the organic filler, with silica being preferred as the filler.

The average particle diameter of the filler is preferably 3 μm or less, more preferably 1 μm or less. The average particle size of the filler can be determined by a laser diffraction particle size distribution measuring apparatus.

The amount of the filler is 1 to 90% by mass, preferably 2 to 80% by mass, and more preferably 5 to 75% by mass of the total amount of the composition excluding the solvent. When the amount of the filler is within the above range, the coating performance of the cured product after curing can be satisfactorily ensured.

The mixing ratio of the filler other than the fine powder to the total filler of the fine powder is set by mass ratio (filler other than fine powder: fine powder) =100: (0.04 to 30), preferably 100: (0.1 to 20), more preferably 100: (0.2-10). By using the filler at such a blending ratio, it is possible to maintain a low thermal expansion coefficient and to satisfy various characteristics such as toughness and heat resistance required for an insulating material for electronic components.

The total amount of the filler to be blended in the curable resin composition is preferably a conventionally known amount as appropriate depending on the application of the curable resin composition, for example, the required characteristics of an insulating material such as an interlayer insulating material for electronic components.

< ingredients for compounding other than the fine powder and the filler other than the fine powder relating to the first and sixth objects >

In the first embodiment of the present invention, the components other than the fine powder and the filler other than the fine powder relating to the first and sixth objects are as follows.

[ curable resin ]

In the present invention, the curable resin is not particularly limited, and a known resin can be used, and for example, a material containing either a thermosetting component or a photocurable component is used, but a material containing a thermosetting component is preferable.

As the thermosetting component, any resin may be used as long as it can be cured by heating to exhibit electrical insulation properties, and examples thereof include known thermosetting resins such as compounds having a cyclic ether group such as epoxy compounds and oxetane compounds, melamine resins, silicone resins, benzoguanamine resins, melamine derivatives, and amino resins such as benzoguanamine derivatives, polyisocyanate compounds, blocked isocyanate compounds, cyclic carbonate compounds, episulfide resins, bismaleimides, carbodiimide resins, polyimide resins, polyamideimide resins, polyphenylene oxide resins, and polyphenylene sulfide resins. Particularly preferred are at least 1 kind of thermosetting resin having a plurality of cyclic ether groups and cyclic thioether groups (hereinafter, simply referred to as cyclic (thio) ether groups) in the molecule. Among these, epoxy compounds and oxetane compounds are preferable, and epoxy resins as epoxy compounds are more preferable.

Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol a type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol E type epoxy resins, bisphenol M type epoxy resins, bisphenol P type epoxy resins, bisphenol Z type epoxy resins, bisphenol a novolac type epoxy resins, phenol novolac type epoxy resins such as cresol novolac epoxy resins, biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, arylalkylene type epoxy resins, tetrahydroxyphenylethane type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, phenoxy type epoxy resins, dicyclopentadiene type epoxy resins, norbornene type epoxy resins, adamantane type epoxy resins, fluorene type epoxy resins, glycidyl methacrylate copolymer type epoxy resins, copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivatives, CTBN modified epoxy resins, trimethylolpropane polyglycidyl ether, phenyl-1, 3-diglycidyl ether, biphenyl-4, 4' -diglycidyl ether, 1, 6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, 2, 3-glycidyl (2, 3) triglycidyl ether, tris (glycidyl ether, 2, 3-glycidyl ether, tris (glycidyl ether) isocyanurate, etc.

Among them, it is preferable to use at least either one of a solid epoxy resin which is solid at 40 ℃ and a semisolid epoxy resin which is solid at 20 ℃ and liquid at 40 ℃ in combination with a liquid epoxy resin which is liquid at 20 ℃ in view of maintaining the effects of the present invention and further excellent crack resistance during a cold-hot cycle. Examples of the solid epoxy resin, the semi-solid epoxy resin, and the liquid epoxy resin include those described in Japanese patent application laid-open No. 2015-10232.

The thermosetting component is used together with a curing agent as needed. Examples of the curing agent include a phenol resin, a polycarboxylic acid and an acid anhydride thereof, a cyanate ester resin, an active ester resin in which a hydroxyl group is blocked by acetylation or the like, a cycloolefin polymer having a carboxyl group, a hydroxyl group, and an active ester structure in a side chain, and a curing agent having a substituent that reacts with a cyclic ether group having a hydroxyl group, a carboxyl group, and an active ester structure in a part of the curable resin, and 2 or more of these curing agents can be used alone or in combination.

As the phenol resin, conventionally known resins such as phenol novolac resin, alkylphenol novolac resin, bisphenol a novolac resin, dicyclopentadiene type phenol resin, xylok type phenol resin, terpene modified phenol resin, cresol/naphthol resin, polyvinyl phenol, phenol/naphthol resin, phenol resin containing an α -naphthol skeleton, and triazine-containing cresol novolac resin can be used.

The polycarboxylic acid and the anhydride thereof are compounds having 2 or more carboxyl groups in one molecule and anhydrides thereof, and examples thereof include copolymers of (meth) acrylic acid, copolymers of maleic anhydride, condensates of dibasic acid, and resins having a carboxylic acid terminal such as carboxylic acid terminal imide resins.

The cyanate ester resin is a compound having 2 or more cyanate groups (-OCN) in one molecule. Any of the cyanate ester resins known in the art can be used. Examples of the cyanate ester resin include phenol novolac type cyanate ester resin, alkylphenol novolac type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol a type cyanate ester resin, bisphenol F type cyanate ester resin, and bisphenol S type cyanate ester resin. In addition, a part of the prepolymer may be triazined.

The active ester resin is not particularly limited, and a resin having 2 or more active ester groups in one molecule is preferable. The active ester resin can be obtained by condensation reaction of 1 or more kinds of carboxylic acid compounds and thiocarboxylic acid compounds with 1 or more kinds of hydroxyl compounds and thiol compounds. Examples of the active ester resin include dicyclopentadiene diphenol ester compounds, bisphenol A diacetate, diphenyl phthalate, diphenyl terephthalate, bis [4- (methoxycarbonyl) phenyl ] terephthalate, and the like.

The active ester resin is suitable for obtaining an electronic component having a low dielectric constant and a low dielectric loss tangent.

Such thermosetting components, curing agents and the like are preferably blended in a conventional and known composition in accordance with the use of the thermosetting resin composition containing the thermosetting components as constituent components and the required characteristics of an insulating material such as an interlayer insulating material of an electronic component.

In the present invention, the thermosetting resin composition containing the thermosetting component may contain, in addition to the above components, a thermoplastic resin, an elastomer, a polymer resin such as rubber particles, a curing accelerator such as an imidazole compound, an amine compound, a hydrazine compound, a phosphorus compound, an s-triazine derivative, a flame retardant, a colorant, a diluent such as an organic solvent, and other additives.

Next, the photocurable component may be a resin which exhibits electrical insulation by curing with light irradiation, and examples thereof include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; mono-or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; polyhydric (meth) acrylates of polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol and trishydroxyethyl isocyanurate, or ethylene oxide or propylene oxide adducts thereof; (meth) acrylic acid esters of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylate and polyethoxy di (meth) acrylate of bisphenol A; (meth) acrylic acid esters of glycidyl ethers such as glycerol diglycidyl ether, trimethylolpropane triglycidyl ether and triglycidyl isocyanurate; and melamine (meth) acrylate.

The photocurable component is used together with a photoreaction initiator that generates 1 of a radical, a base, and an acid, if necessary. Examples of the photoreaction initiator include bisacylphosphine oxides such as bis- (2, 6-dichlorobenzoyl) phenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 5-dimethylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 4-trimethylpentylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 5-dimethylphenylphosphine oxide, bis- (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE 819, manufactured by BASF JPAN Co., ltd.); monoacyl phosphine oxides such as 2, 6-dimethoxybenzoyldiphenylphosphine oxide, 2, 6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4, 6-trimethylbenzoylphenylphosphinate, 2-methylbenzoyldiphenylphosphine oxide, isopropyl pivaloylphenylphosphinate, and 2,4, 6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF JAPAN corporation, DAROCURTPO); hydroxyacetophenones such as 1-hydroxy-cyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl ] phenyl } -2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzoyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, michler's ketone, methylbenzophenone, 4' -dichlorobenzophenone, and 4,4' -bisdiethylaminobenzophenone; acetophenones such as acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinyl phenyl) -1-butanone, and N, N-dimethylaminoacetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone and 2, 4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzoic acid esters such as ethyl 4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, and ethyl p-dimethylaminobenzoate; oxime esters such as {1- [4- (phenylthio) -2- (O-benzoyloxime) ] }1, 2-octanedione, 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -1- (O-acetyloxime) ethanone, and the like; titanocenes such as bis (. Eta.5-2, 4-cyclopentadien-1-yl) -bis (2, 6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2, 6-difluoro-3- (2- (1-pyrrol-1-yl) ethyl) phenyl ] titanium and the like; phenyl 2-nitrofluorene disulfide, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like. The above photoreaction initiators may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Such a photocurable component, a photoreaction initiator, and the like are preferably blended in a conventional and known composition in accordance with the use of the photocurable resin composition containing the components and the required characteristics of an insulating material such as an interlayer insulating material of an electronic component.

In the present invention, the photocurable resin composition containing the photocurable component may contain, in addition to the above components, a thermoplastic resin, an elastomer, a polymer resin such as rubber-like particles, a sensitizer, a flame retardant, a colorant, a diluent such as an organic solvent, and other additives.

When the curable resin composition of the present invention is used as an alkali-developable photosolder resist composition which can be developed with an aqueous alkali solution, it is preferable to use a carboxyl group-containing resin in addition to the thermosetting component and the photocurable component.

(carboxyl group-containing resin)

The carboxyl group-containing resin is not particularly limited, and any of a photosensitive carboxyl group-containing resin having 1 or more photosensitive unsaturated double bonds and a carboxyl group-containing resin having no photosensitive unsaturated double bonds can be used. As the carboxyl group-containing resin, the following resins can be particularly preferably used.

(1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid and a compound having an unsaturated double bond, and a carboxyl group-containing resin modified to adjust a molecular weight and an acid value.

(2) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth) acrylic copolymer resin with 1 molecule of a compound having an oxirane ring and an ethylenically unsaturated group.

(3) A photosensitive carboxyl group-containing resin obtained by reacting a copolymer of a compound having 1 epoxy group and an unsaturated double bond in each molecule and a compound having an unsaturated double bond with an unsaturated monocarboxylic acid and reacting a secondary hydroxyl group formed by the reaction with a saturated or unsaturated polybasic acid anhydride.

(4) A photosensitive hydroxyl group-and carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride and then reacting a carboxylic acid produced by the reaction with a compound having 1 epoxy group and 1 unsaturated double bond in each molecule.

(5) A photosensitive carboxyl group-containing resin obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a polybasic acid anhydride with part or all of secondary hydroxyl groups formed by the reaction.

(6) A carboxyl group-containing photosensitive resin is obtained by reacting a polyfunctional epoxy compound with 1 molecule of a compound having 2 or more hydroxyl groups and 1 reactive group other than a hydroxyl group which reacts with an epoxy group, with an unsaturated group-containing monocarboxylic acid, and reacting the resultant reaction product with a polybasic acid anhydride.

(7) A carboxyl group-containing photosensitive resin obtained by reacting a reaction product of a resin having a phenolic hydroxyl group and an alkylene oxide or a cyclic carbonate with an unsaturated group-containing monocarboxylic acid and reacting the resulting reaction product with a polybasic acid anhydride.

(8) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy compound with 1 molecule of a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group and an unsaturated group-containing monocarboxylic acid and reacting the alcoholic hydroxyl group of the resulting reaction product with an anhydride group of a polybasic acid anhydride.

The carboxyl group-containing resin is preferably blended in a known composition conventionally used in an alkali-developable curable resin composition such as a solder resist composition containing the resin as a component.

In the curable resin composition of the present invention described above, other conventional compounding ingredients may be further suitably compounded depending on the use thereof. Examples of the conventional other compounding ingredients include, as described above, thermoplastic resins, elastomers, high molecular weight resins such as rubber particles, curing accelerators, sensitizers, flame retardants, colorants, diluents such as organic solvents, and other additives, specifically, known and conventional additives such as antifoaming agents, leveling agents, thixotropic agents, thickeners, coupling agents, and dispersing agents.

In particular, as the colorant, conventionally known colorants such as red, blue, green, and yellow may be used, and any of pigments, dyes, and pigments may be used. However, from the viewpoint of reducing environmental load and influence on the human body, it is preferable that halogen is not contained.

Red colorant:

examples of the red colorant include monoazo colorants, diazo colorants, azo colorants, benzimidazolone colorants, perylene colorants, diketopyrrolopyrrole colorants, condensed azo colorants, anthraquinone colorants, quinacridone colorants, and the like.

Blue colorant, green colorant:

examples of The blue colorant and The green colorant include phthalocyanine-based colorants and anthraquinone-based colorants, and examples of The Pigment-based colorants include compounds classified as pigments (pigments), specifically, compounds having a color index (c.i.; issued by The Society of Dyers and Colourists). Further, a metal-substituted or unsubstituted phthalocyanine compound may also be used.

Yellow colorant:

examples of the yellow coloring agent include monoazo-based, diazo-based, condensed azo-based, benzimidazolone-based, isoindolinone-based, and anthraquinone-based coloring agents.

Further, for the purpose of adjusting the color tone, colorants such as violet, orange, brown, black, etc. may be added.

The specific blending ratio of the colorant can be adjusted as appropriate by the kind of the colorant used, the kind of other additives, and the like.

Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate, and esters of the above glycol ethers; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, solvent naphtha, and the like.

The curable resin composition of the present invention containing the components described above may be used as a dry film or may be used as it is in a liquid form. When used in the form of a liquid, the liquid may be 1-liquid type or 2-liquid type or more.

The curable resin composition of the present invention can also be used as a so-called prepreg in which a sheet-like fibrous substrate such as a glass cloth, a glass, or an aramid nonwoven fabric is coated or impregnated with the composition and then semi-cured.

The dry film of the present invention has a resin layer obtained by coating the curable resin composition of the present invention on a film (support film) and drying the coating.

Here, in forming a dry film, the curable resin composition of the present invention is first diluted with the organic solvent and adjusted to an appropriate viscosity, and then coated on a film with a uniform thickness using a comma coater, a knife coater, a lip coater, a bar coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like. Thereafter, the coated composition is dried at a temperature of usually 40 to 130 ℃ for 1 to 30 minutes, whereby a resin layer can be formed. The coating film thickness is not particularly limited, and is usually selected appropriately in the range of 3 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

As the film (support film), a resin film can be used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the film is not particularly limited, and is usually suitably selected within the range of 10 to 150. Mu.m. More preferably in the range of 15 to 130 μm.

In the film having the resin layer formed from the curable resin composition of the present invention, a peelable film (protective film) is preferably further laminated on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer.

The peelable film may be any film having a smaller adhesion to the resin layer than to the support film at the time of peeling, and examples thereof include a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, and surface-treated paper.

The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer in the dry film of the present invention. The cured product of the present invention can be suitably used as an electronic component material such as a solder resist, an interlayer insulating material, and a via filling material, which require insulation reliability.

The electronic component of the present invention includes the cured product of the present invention, and specifically includes a printed wiring board and the like. In particular, a multilayer printed wiring board using the curable resin composition of the present invention as an interlayer insulating material can have good interlayer insulation reliability.

< ingredients for compounding other than the fine powder and the filler other than the fine powder for the second to fifth objects >

In the first embodiment of the present invention, the components other than the fine powder and the filler other than the fine powder relating to the second to fifth objects are as follows.

In the second object of the present invention, the curable resin composition of the present invention preferably contains, as the curable resin, a cyclic ether compound having at least 1 of a naphthalene skeleton and an anthracene skeleton.

In this manner, when an electronic component having a laminated structure is produced by using a cyclic ether compound having at least either one of a naphthalene skeleton and an anthracene skeleton, interlayer migration can be suppressed, and thus good interlayer insulation reliability can be obtained. In particular, the present invention is useful in that the surface of the insulating layer roughened by desmear treatment is likely to migrate, and in this case, the insulation reliability between layers is easily ensured.

In addition, the effect of reducing the thermal expansion property by blending the fine powder also remarkably manifests hydrophilicity in the fine powder. Since such fine powder has a large quantum effect on optical, electrical, and magnetic properties, physical properties such as reactivity and electrical properties may be changed, which may cause unexpected changes. This is considered to be the reason why the insulation reliability between layers is poor when the electronic component having such a laminated structure is manufactured. When the fine powder is hydrophilic particles such as fine cellulose fibers, the interlayer migration is particularly poor. This problem can be solved by using a cyclic ether compound having at least either a naphthalene skeleton or an anthracene skeleton.

[ Cyclic ether Compound having at least 1 of naphthalene skeleton and anthracene skeleton ]

The cyclic ether compound having a naphthalene skeleton is a compound having a naphthalene skeleton or a structure derived from a naphthalene skeleton and having a cyclic ether. The cyclic ether compound having a naphthalene skeleton is not particularly limited, and a compound having 2 or more cyclic ethers in 1 molecule is preferable. The cyclic ether may be a cyclic thioether.

Commercially available products include Epiclon HP-4032, HP-4032D, HP-4700, HP-4770, HP-5000 (both DIC Co., ltd.), NC-7000L, NC-7300L, NC-7700L (both Nippon Kagaku K.K.), ZX-1355, ESN-155, ESN-185V, ESN-175, ESN-355, ESN-375, ESN-475V, and ESN-485 (both Nippon Ciki Kagaku K.K.), and the like.

The cyclic ether compound having an anthracene skeleton is a compound having an anthracene skeleton or a structure derived from an anthracene skeleton and having a cyclic ether. The cyclic ether compound having an anthracene skeleton is not particularly limited, and a compound having 2 or more cyclic ethers in 1 molecule is preferable. The cyclic ether may be a cyclic thioether.

Examples of commercially available products include YX-8800 (manufactured by Mitsubishi chemical Co., ltd.).

The amount of the cyclic ether compound having at least either one of a naphthalene skeleton and an anthracene skeleton is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and further preferably 1.5% by mass or more and 30% by mass or less, with respect to the total amount of the composition from which the solvent is removed. When the amount of the cyclic ether compound is 0.5% by mass or more, the deterioration of insulation reliability between layers due to the fine cellulose fibers can be prevented. On the other hand, when it is 80% by mass or less, the curability is improved.

In the present invention, the cyclic ether compound having at least one of the naphthalene skeleton and the anthracene skeleton has a function as a curable resin, and the cyclic ether compound having the naphthalene skeleton and the cyclic ether compound having the anthracene skeleton may be used alone or in combination.

In the present invention, a curable resin such as a thermosetting resin or a photocurable resin other than the cyclic ether compound having at least 1 of the naphthalene skeleton and the anthracene skeleton can be used in combination as desired.

With respect to the third object of the present invention, the curable resin composition of the present invention preferably contains at least 1 selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton as the curable resin.

In this manner, by using at least 1 kind selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton, the relative permittivity and the dielectric loss tangent can be reduced, and an electronic component having low dielectric characteristics can be obtained. On the other hand, by using the fine powder, adhesion between the cured product and the copper plating can be ensured, and a high-definition circuit can be formed.

In addition, the fine powder used in the present invention can obtain very high adhesion to copper plating by blending a curable resin having a dicyclopentadiene skeleton with low adhesion to copper plating, and a cured product of a composition containing the curable resin. In addition, this effect can be obtained without lowering the dielectric characteristics derived from the dicyclopentadiene skeleton.

[ Cyclic ether Compound having Dicyclopentadiene skeleton and phenol resin having Dicyclopentadiene skeleton ]

The cyclic ether compound having a dicyclopentadiene skeleton is a compound having a dicyclopentadiene skeleton or a structure derived from a dicyclopentadiene skeleton and having a cyclic ether. The cyclic ether compound having a dicyclopentadiene skeleton is not particularly limited, and those having 2 or more cyclic ethers in 1 molecule are preferable. The cyclic ether may be a cyclic thioether.

Commercially available products include Epiclon HP-7200, HP-7200H, HP-7200L (both available from DIC Co., ltd.), XD-1000-1L, XD-1000-2L (both available from Nippon Kagaku Co., ltd.), tactix558 and Tactix756 (both available from Huntsman Advanced Materials Co., ltd.).

The phenol resin having a dicyclopentadiene skeleton is a compound having a dicyclopentadiene skeleton or a structure derived from a dicyclopentadiene skeleton and having a phenolic hydroxyl group. The phenol resin having a dicyclopentadiene skeleton is not particularly limited, and those having 2 or more phenolic hydroxyl groups in 1 molecule are preferable. Examples of commercially available products include Resitop GDP-6085, resitop GDP-6095LR, resitop GDP-6095HR, resitop GDP-6115L, resitop GDP-6115H, resitop GDP-6140 (all manufactured by Younoho chemical Co., ltd.), J-DPP-95, and J-DPP-115 (all manufactured by JFE chemical Co., ltd.).

The amount of at least 1 selected from the group consisting of cyclic ether compounds having a dicyclopentadiene skeleton and phenol resins having a dicyclopentadiene skeleton is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and further preferably 1.5% by mass or more and 30% by mass or less, relative to the total amount of the composition from which the solvent has been removed. When the amount of at least 1 selected from the group consisting of cyclic ether compounds having a dicyclopentadiene skeleton and phenol resins having a dicyclopentadiene skeleton is 0.5% by mass or more, good low dielectric characteristics can be obtained. On the other hand, when the amount is 80% by mass or less, the curability is improved.

In the present invention, at least 1 kind selected from the group consisting of the cyclic ether compound having a dicyclopentadiene skeleton and the phenol resin having a dicyclopentadiene skeleton has a function as a curable resin, and the cyclic ether compound having a dicyclopentadiene skeleton and the phenol resin having a dicyclopentadiene skeleton may be used alone or in combination.

In the present invention, a curable resin such as a thermosetting resin or a photocurable resin other than at least 1 selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton can be used in combination as desired.

With respect to the fourth object of the present invention, the curable resin composition of the present invention preferably contains a phenoxy resin as the curable resin.

By using the phenoxy resin and the fine powder in this manner, the smear can be removed in a short time in the desmear step, and the surface roughness of the cured product can be suppressed to a small level, so that high frequency transmission can be performed efficiently. On the other hand, even if the surface roughness is small, adhesion between the cured product and the copper plating can be secured, and thus a high-definition circuit can be formed.

Further, by using the fine powder of the present invention, the cured product of the composition containing the fine powder can easily remove the smear, and the adhesion to the copper plating can be secured while suppressing the surface roughness of the cured product from being small. This effect is exhibited by combination with a phenoxy resin described later. In addition, this effect can be remarkably exhibited even by a hydrophilic substance in the fine powder.

[ phenoxy resin ]

Phenoxy resins are generally synthesized from bisphenols and epichlorohydrin. The bisphenols used include bisphenol A, bisphenol F, bisphenol S, biphenyl, bisphenol acetophenone, fluorene, trimethylcyclohexane, and terpene, and 2 or more kinds of these are copolymerized. The phenoxy resin is not particularly limited, and is desirably of a terminal epoxy type in the case of a photocurable composition. Commercially available products include 1256, 4250, 4275, YX8100, YX6954, YL7213, YL7290, YL7482 (all manufactured by Mitsubishi chemical Co., ltd.), FX280, FX293, YP50S, YP55, YP70, YPB-43C (all manufactured by Nissan chemical Co., ltd.), PKHB, PKHC, PKHH, PKHJ, PKFE, PKHP-200, and PKCP-80 (all manufactured by InChem).

The amount of the phenoxy resin blended is preferably 0.1% by mass or more and 50% by mass or less, more preferably 0.3% by mass or more and 30% by mass or less, and further preferably 0.5% by mass or more and 10% by mass or less, relative to the total amount of the composition from which the solvent is removed. When the amount of the phenoxy resin is 0.1 mass% or more, removability of the smear due to the fine powder and adhesion of the conductor are improved. On the other hand, when it is 50 parts by mass or less, the curability is improved.

In the present invention, a curable resin such as a thermosetting resin or a photocurable resin other than the phenoxy resin may be used in combination as desired.

As for the fifth object of the present invention, the curable resin composition of the present invention preferably contains at least 1 selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton as the curable resin.

In this way, when the solid copper plating is formed on the cured product by using at least 1 selected from the group consisting of the cyclic ether compound having a biphenyl skeleton and the phenol resin having a biphenyl skeleton, the occurrence of swelling of the copper plating due to thermal history such as component mounting can be suppressed.

Further, even a hydrophilic substance in the fine powder is remarkably expressed by the effect of reducing the thermal expansion property by blending the fine powder. On the other hand, when the fine powder is hydrophilic particles such as fine cellulose fibers, the application of the present invention is useful in consideration of the fact that the solid copper plating is likely to expand at high temperature.

[ at least 1 selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton ]

The cyclic ether compound having a biphenyl skeleton is a compound having a biphenyl skeleton or a structure derived from a biphenyl skeleton and having a cyclic ether. The cyclic ether compound having a biphenyl skeleton is not particularly limited, and a compound having 2 or more cyclic ethers in 1 molecule is preferable. The cyclic ether may be a cyclic thioether.

Examples of commercially available products include NC-3000H, NC-3000L, NC-3100 (all manufactured by Nippon Kagaku Co., ltd.), YX-4000, YX4000H, YL-6121 (all manufactured by Mitsubishi chemical Co., ltd.), denacol EX-412 (manufactured by Nagase ChemteX Co., ltd.), and the like.

The amount of the cyclic ether compound having a biphenyl skeleton blended is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and further preferably 1.5% by mass or more and 30% by mass or less, with respect to the total amount of the solvent removed. When the amount of the compound is 0.5% by mass or more, swelling due to copper plating of fine particles can be prevented. On the other hand, when the amount is 80% by mass or less, the curability is improved.

The phenolic resin having a biphenyl skeleton is a compound having a biphenyl skeleton or a structure derived from a biphenyl skeleton and having a phenolic hydroxyl group. The phenolic resin having a biphenyl skeleton is not particularly limited, and those having 2 or more phenolic hydroxyl groups in 1 molecule are preferable. Commercially available products include GPH-65, GPH-103 (manufactured by Nippon Kabushiki Kaisha), MEH-7851SS, MEH-7851M, MEH-7851-4H, MEH-7851-3H (manufactured by Minghe Kaisha), HE200 (manufactured by Air Water Co., ltd.), and the like.

The amount of the phenolic resin having a biphenyl skeleton blended is preferably 0.5% by mass or more and 60% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and further preferably 1.5% by mass or more and 20% by mass or less, with respect to the total amount of the solvent removed. When the amount of the compound is 0.5% by mass or more, swelling due to copper plating of fine particles can be prevented. On the other hand, when it is 60% by mass or less, the curability is improved.

In the present invention, at least 1 kind selected from the group consisting of the cyclic ether compound having a biphenyl skeleton and the phenol resin having a biphenyl skeleton has a function as a curable resin, and the cyclic ether compound having a biphenyl skeleton and the phenol resin having a biphenyl skeleton may be used alone or in combination.

In the present invention, a curable resin such as a thermosetting resin or a photocurable resin other than at least 1 selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton may be used in combination as desired.

(thermosetting resin)

The thermosetting resin may be any resin that exhibits electrical insulation properties by being cured by heating, examples thereof include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, bisphenol E-type epoxy resin, bisphenol M-type epoxy resin, bisphenol P-type epoxy resin, bisphenol Z-type epoxy resin and the like bisphenol-type epoxy resin, bisphenol A novolak-type epoxy resin, phenol novolak-type epoxy resin, cresol novolak-type epoxy resin and the like novolak-type epoxy resin, biphenyl aralkyl-type epoxy resin, arylalkylene-type epoxy resin, tetrahydroxyethylene-type epoxy resin, phenoxy-type epoxy resin, dicyclopentadiene-type epoxy resin, norbornene-type epoxy resin, adamantane-type epoxy resin, fluorene-type epoxy resin, glycidyl methacrylate copolymer-based epoxy resin, epoxy resin copolymer of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1, 3-diglycidyl ether, biphenyl-4, 4' -diglycidyl ether, 1, 6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A-type epoxy resin modified with 2-stage phenol-modified novolac resin, phenol-modified with 2-glycidyl isocyanurate, phenol-novolac resin, phenol-modified with epoxy novolac resin, cresol novolac (E) and the like novolak-type epoxy resin, phenol novolac modified with epoxy novolac, phenol-2-modified with cresol novolac, phenol-novolac, phenol-novolac-type novolac resin, phenol-modified with epoxy-novolac, phenol-novolac-type novolac, phenol-modified with epoxy resin, phenol-novolac, etc., and active ester compounds such as phenoxy resins, urea (urea) resins, triazine ring-containing resins such as melamine resins, unsaturated polyester resins, bismaleimide resins, diallyl phthalate resins, silicone resins, resins having a benzoxazine ring, norbornene resins, cyanate resins, isocyanate resins, urethane resins, benzocyclobutene resins, maleimide resins, bismaleimide triazine resins, polyimide resins, thermosetting polyimides, dicyclopentadiene diphenol ester compounds, bisphenol a diacetate, diphenyl phthalate, diphenyl terephthalate, bis [4- (methoxycarbonyl) phenyl ] terephthalate, and the like. Among these, the use of an active ester compound is preferable because thermal expansion in a high temperature region can be reduced and a low thermal expansion coefficient can be ensured.

(Photocurable resin (radical polymerization))

The photocurable resin may be any resin that can be cured by irradiation with an active energy ray to exhibit electrical insulation, and in particular, a compound having 1 or more ethylenically unsaturated bonds in the molecule is preferably used. As the compound having an ethylenically unsaturated bond, a known and conventional photopolymerizable oligomer, a photopolymerizable vinyl monomer, or the like can be used.

Examples of the photopolymerizable oligomer include unsaturated polyester oligomers and (meth) acrylate oligomers. Examples of the (meth) acrylate-based oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, and bisphenol epoxy (meth) acrylate, urethane (meth) acrylate, epoxy urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, and polybutadiene-modified (meth) acrylate. In the present specification, the term (meth) acrylate is a term generically referring to acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

Examples of the photopolymerizable vinyl monomer include known and customary ones, and examples thereof include styrene derivatives such as styrene, chlorostyrene, and α -methylstyrene; vinyl esters such as vinyl acetate, vinyl caseinate, and vinyl benzoate; vinyl ethers such as vinyl isobutyl ether, vinyl n-butyl ether, vinyl tert-butyl ether, vinyl n-pentyl ether, vinyl isoamyl ether, vinyl n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, and triethylene glycol monomethyl vinyl ether; (meth) acrylamides such as acrylamide, methacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymmethacrylamide, N-ethoxymethacrylamide and N-butoxymethacrylamide; allyl compounds such as triallyl isocyanurate, diallyl phthalate, and diallyl isophthalate; esters of (meth) acrylic acid such as 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, and phenoxyethyl (meth) acrylate; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and pentaerythritol tri (meth) acrylate; alkoxyalkylene glycol mono (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; alkylene polyol poly (meth) acrylates such as ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like; polyoxyalkylene glycol poly (meth) acrylates such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane tri (meth) acrylate; poly (meth) acrylates such as hydroxypivalyl hydroxypivalate di (meth) acrylate; and isocyanurate type poly (meth) acrylates such as tris [ (meth) acryloyloxyethyl ] isocyanurate.

(Photocurable resin (cationic polymerization))

As the photocurable resin, an alicyclic epoxy compound, an oxetane compound, a vinyl ether compound, or the like can be suitably used. Among them, examples of the alicyclic epoxy compound include alicyclic epoxy compounds having an epoxy group such as 3,4,3',4' -diepoxybicyclohexyl, 2-bis (3, 4-epoxycyclohexyl) propane, 2-bis (3, 4-epoxycyclohexyl) -1, 3-hexafluoropropane, bis (3, 4-epoxycyclohexyl) methane, 1- [1, 1-bis (3, 4-epoxycyclohexyl) ] ethylbenzene, bis (3, 4-epoxycyclohexyl) adipate, 3, 4-epoxycyclohexylmethyl (3, 4-epoxy) cyclohexanecarboxylate, (3, 4-epoxy-6-methylcyclohexyl) methyl-3 ',4' -epoxy-6-methylcyclohexanecarboxylate, ethylene-1, 2-bis (3, 4-epoxycyclohexanecarboxylate), epoxycyclohexane, 3, 4-epoxycyclohexylmethyl alcohol, and 3, 4-epoxycyclohexylethyltrimethoxysilane. Examples of commercially available products include Celloxide 2000, celloxide 2021, celloxide 3000, EHPE3150, manufactured by Daicel chemical industries, ltd; eponic VG-3101, manufactured by mitsui chemical corporation; E-1031S, manufactured by oiled Shell Epoxy Co., ltd; TETRAD-X and TETRAD-C available from Mitsubishi gas chemical; EPB-13 and EPB-27 available from Nippon Caoda corporation.

Examples of the oxetane compound include polyfunctional oxetanes such as bis [ (3-methyl-3-oxetanylmethoxy) methyl ] ether, bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ether, 1, 4-bis [ (3-methyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, 3-methyl-3-oxetanyl methyl acrylate, (3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, and oligomers or copolymers thereof, and copolymers of oxetanol with hydroxyl group-containing resins such as novolak resins, poly (p-hydroxystyrene), cardo-type bisphenols, calixarene, or silsesquioxanes, and compounds such as etherates of unsaturated monomers having an oxetane ring and (meth) acrylic acid alkyl esters. Examples of commercially available products include Eternacoll OXBP, OXMA, OXBP, EHO, xylylene dioxirane manufactured by Utsumadiki, inc., and Aron oxyethane OXT-101, OXT-201, OXT-211, OXT-221, OXT-212, OXT-610, PNOX-1009 manufactured by Toyawa Kabushiki Kaisha, inc.

Examples of the vinyl ether compound include cyclic ether type vinyl ethers such as isosorbide divinyl ether and oxanorbornene divinyl ether (vinyl ethers having a cyclic ether group such as an oxirane ring, an oxetane ring and an oxolane); aryl vinyl ethers such as phenyl vinyl ether; alkyl vinyl ethers such as n-butyl vinyl ether and octyl vinyl ether; cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; polyfunctional vinyl ethers such as hydroquinone divinyl ether, 1, 4-butanediol divinyl ether, cyclohexane divinyl ether and cyclohexanedimethanol divinyl ether, and vinyl ether compounds having a substituent such as an alkyl group or an allyl group at the α -and/or β -position. Examples of commercially available products include 2-hydroxyethyl vinyl ether (HEVE), diethylene glycol monovinyl ether (DEGV), 2-hydroxybutyl vinyl ether (HBVE), and triethylene glycol divinyl ether manufactured by PELLENTHONIC DENKO K.K.

In addition, when the curable resin composition of the present invention is used as an alkali-developable photosolder resist capable of developing in an alkaline aqueous solution, a carboxyl group-containing resin is also preferably used.

(carboxyl group-containing resin)

(8) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy compound with a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group in 1 molecule and an unsaturated group-containing monocarboxylic acid and reacting the alcoholic hydroxyl group of the resulting reaction product with the anhydride group of a polybasic acid anhydride.

[ Filler ]

The curable resin composition of the present invention preferably further contains a filler other than the fine powder. Examples of the filler include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, and aluminum nitride. Among these fillers, silica, particularly spherical silica, is preferable because of its small specific gravity, high compounding ratio in the composition, and excellent low thermal expansion properties. The average particle diameter of the filler is preferably 3 μm or less, more preferably 1 μm or less. The average particle size of the filler can be determined by a laser diffraction particle size distribution measuring apparatus.

The amount of the filler added is 1 to 90% by mass, preferably 2 to 80% by mass, and more preferably 5 to 75% by mass of the total amount of the solvent removed. When the amount of the filler is within the above range, the coating performance of the cured product after curing can be satisfactorily ensured.

In the curable resin composition of the present invention, other conventional compounding ingredients may be further appropriately compounded depending on the use. Examples of the conventional other compounding ingredients include a curing catalyst, a photopolymerization initiator, a colorant, an organic solvent, and the like.

Examples of the curing catalyst include phenol compounds; imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, and 4-methyl-N, N-dimethylbenzylamine, and hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine, and the like. Further, as commercially available products, there may be mentioned 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Kasei chemical Co., ltd.), U-CAT3503N, U-CAT3502T, DBU, DBN, U-CATA SA102, U-CAT5002 (manufactured by San Apro Co., ltd.), and the like, and 2 or more thereof may be used singly or in combination. In addition, in the same manner, an s-triazine derivative such as guanamine, acetoguanamine, benzoguanamine, melamine, 2, 4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-2, 4-diamino-s-triazine, 2-vinyl-4, 6-diamino-s-triazine isocyanuric acid adduct, or 2, 4-diamino-6-methacryloyloxyethyl-s-triazine isocyanuric acid adduct can be used.

In the present invention, a phenol compound is particularly preferably used. The phenol compound may be used singly or in combination of 2 or more kinds of known and conventional phenol compounds such as phenol novolak resin, alkylphenol novolak resin, triazine structure-containing novolak resin, bisphenol a novolak resin, dicyclopentadiene type phenol resin, xylock type phenol resin, copna resin, terpene-modified phenol resin, polyvinyl phenol resin, naphthalene-based curing agent, fluorene-based curing agent, and the like. <xnotran> , Air Water HE-610C, 620C, DIC TD-2131, TD-2106, TD-2093, TD-2091, TD-2090, VH-4150, VH-4170, KH-6021, KA-1160, KA-1163, KA-1165, TD-2093-60M, TD-2090-60M, LF-6161, LF-4871, LA-7052, LA-7054, LA-7751, LA-1356, LA-3018-50P, EXB-9854, SN-170, SN180, SN190, SN475, SN485, SN495, SN375, SN395, JX DPP, HF-1M, HF-3M, HF-4M, H-4, DL-92, MEH-7500, MEH-7600-4H, MEH-7800, MEH-7851, MEH-7851-4H, MEH-8000H, MEH-8005, XL, XLC, RN, RS, RX , . </xnotran> These phenol compounds may be used singly or in combination of 2 or more.

The amount of the curing catalyst used in the present invention is sufficient in a proportion that is usually used, and is, for example, 1 to 150 parts by mass, preferably 5 to 100 parts by mass, and more preferably 10 to 50 parts by mass in the case of a phenol compound, and 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass in the case of another curing catalyst, based on 100 parts by mass of the thermosetting resin.

The photopolymerization initiator is used for curing a photocurable resin in a curable resin, and may be a photo radical polymerization initiator or a photo cation polymerization initiator.

Examples of the photo-radical polymerization initiator include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenones such as acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone and 1, 1-dichloroacetophenone; aminoalkylbenzones such as 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, and 2- (dimethylamino) -2- [ (4-methylphenyl) methyl ] -1- [4- (4-morpholino) phenyl ] -1-butanone; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone and 1-chloroanthraquinone; thioxanthones such as 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone and 2, 4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzophenones such as benzophenone; or xanthones; phosphine oxides such as (2, 6-dimethoxybenzoyl) -2, 4-pentylphosphine oxide, bis (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide, ethyl-2, 4, 6-trimethylbenzoyl phenylphosphinate, etc.; various peroxides, titanocene-based initiators, and the like. These compounds can be used in combination with photosensitizers such as ethyl N, N-dimethylaminobenzoate, isoamyl N, N-dimethylaminobenzoate, amyl 4-dimethylaminobenzoate, triethylamine, triethanolamine and other tertiary amines.

Examples of the photo cation polymerization initiator include onium salts such as diazonium salts, iodonium salts, bromonium salts, chloronium salts, sulfonium salts, selenium salts, pyrylium salts, thiopyrylium salts, and pyridinium salts; halogenated compounds such as tris (trihalomethyl) -s-triazine and derivatives thereof; 2-nitrobenzyl esters of sulfonic acids; an imine disulfonate salt; 1-oxo-2-diazonaphthoquinone-4-sulfonate derivatives; n-hydroxyimide = sulfonate; tris (methanesulfonyloxy) benzene derivatives; bis-sulfonyl diazomethanes; sulfonyl carbonyl alkanes; sulfonyl carbonyl diazepines; disulfone compounds, and the like.

These photopolymerization initiators may be used alone or in combination of 2 or more.

The amount of the photopolymerization initiator to be blended is, for example, 0.05 to 10 parts by mass, preferably 0.1 to 8 parts by mass, and more preferably 0.3 to 6 parts by mass, in terms of solid content, relative to 100 parts by mass of the photocurable resin. When the photopolymerization initiator is blended in this range, photocurability on copper becomes sufficient, the coating film has good curability, and coating film characteristics such as chemical resistance are improved, and further, deep-part curability is also improved.

As the colorant, conventionally known colorants such as red, blue, green and yellow may be used, and any of pigments, dyes and pigments may be used. However, from the viewpoint of reducing environmental load and influence on the human body, it is preferable that no halogen is contained.

Blue colorant:

examples of The blue colorant include phthalocyanine-based and anthraquinone-based colorants, and examples of The Pigment-based colorant include compounds classified as pigments (pigments), and specifically include compounds having a color index (c.i.; issued by The Society of dyeing and colorists and Colourists) number as follows: pigment Blue 15, pigment Blue 15: 1. fragment Blue 15: 2. fragment Blue 15: 3. fragment Blue 15: 4. fragment Blue 15: 6. pigment Blue 16, pigment Blue 60.

As the dye system, solvent Blue 35, solvent Blue 63, solvent Blue 68, solvent Blue 70, solvent Blue 83, solvent Blue 87, solvent Blue 94, solvent Blue 97, solvent Blue 122, solvent Blue 136, solvent Blue 67, solvent Blue 70 and the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds may be used.

Green colorant:

the Green colorant may be phthalocyanine-based or anthraquinone-based, and specifically, pigment Green 7, pigment Green 36, solvent Green 3, solvent Green 5, solvent Green20, solvent Green 28, or the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds may be used.

Yellow colorant:

examples of the yellow coloring agent include monoazo-based, diazo-based, condensed azo-based, benzimidazolone-based, isoindolinone-based, and anthraquinone-based coloring agents, and specific examples thereof include the following coloring agents.

Anthraquinone series: solvent Yellow 163, pigment Yellow 24, pigment Yellow 108, pigment Yellow 193, pigment Yellow 147, pigment Yellow 199, pigment Yellow 202.

Isoindolinone systems: pigment Yellow 110, pigment Yellow 109, pigment Yellow 139, pigment Yellow 179, pigment Yellow 185.

Condensation azo system: pigment Yellow 93, pigment Yellow 94, pigment Yellow 95, pigment Yellow 128, pigment Yellow 155, pigment Yellow 166, pigment Yellow 180.

Benzimidazolone series: pigment Yellow 120, pigment Yellow 151, pigment Yellow 154, pigment Yellow 156, pigment Yellow 175, and Pigment Yellow 181.

Mono-azo series:

pigment Yellow

1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62: 1. 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183.

Diazo system: pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

Red colorant:

the red colorant includes monoazo-based, diazo-based, azo lake-based, benzimidazolone-based, perylene-based, diketopyrrolopyrrole-based, condensed azo-based, anthraquinone-based, quinacridone-based colorants, and the like, and specific examples thereof include the following colorants.

Mono-azo series: pigment Red1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.

Diazo system: fragment Red 37, 38, 41.

Monoazo lake system: fragment Red 48: 1. 48: 2. 48: 3. 48: 4. 49: 1. 49: 2. 50: 1. 52: 1. 52: 2. 53: 1. 53: 2. 57: 1. 58: 4. 63: 1. 63: 2. 64: 1. 68.

Benzimidazolone series: segment Red 171, segment Red 175, segment Red 176, segment Red 185, segment Red 208.

Perylene series: solvent Red 135, solvent Red 179, pigment Red 123, pigment Red149, pigment Red 166, pigment Red 178, pigment Red 179, pigment Red 190, pigment Red 194, pigment Red 224.

Diketopyrrolopyrrole series: segment Red 254, segment Red 255, segment Red 264, segment Red 270, segment Red 272.

Condensed azo system: fragment Red 220, fragment Red 144, fragment Red 166, fragment Red 214, fragment Red 220, fragment Red 221, fragment Red 242.

Anthraquinone series: pigment Red 168, pigment Red 177, pigment Red 216, solvent Red 149, solvent Red 150, solvent Red 52, solvent Red 207.

Quinacridone series: fragment Red 122, fragment Red 202, fragment Red 206, fragment Red 207, fragment Red 209.

Further, for the purpose of adjusting the color tone, a coloring agent such as violet, orange, brown, black, or the like may be added.

Specifically, examples of the Pigment include Pigment Violet 19, 23, 29, 32, 36, 38, 42, solvent Violet 13, 36, c.i. Pigment orange 1, c.i. Pigment orange 5, c.i. Pigment orange 13, c.i. Pigment orange 14, c.i. Pigment orange 16, c.i. Pigment orange 17, c.i. Pigment orange 24, c.i. Pigment orange 34, c.i. Pigment orange 36, c.i. Pigment orange 38, c.i. Pigment orange 40, c.i. Pigment orange 43, c.i. Pigment orange 46, c.i. Pigment orange 49, c.i. Pigment orange 51, c.i. Pigment orange 61, c.i. Pigment orange 63, c.i. Pigment orange 64, c.i. Pigment orange 71, c.i. Pigment orange 73, c.i. Pigment brown 23, c.i. Pigment brown 25, c.i. Pigment orange 1, and c.i. Pigment black 7.

The specific blending ratio of the colorant can be appropriately adjusted depending on the kind of the colorant used, the kind of other additives, and the like.

Further, if necessary, known and conventional additives such as an antifoaming agent, a leveling agent, a thixotropic agent, a thickener, a coupling agent, a dispersant, and a flame retardant may be contained.

The curable resin composition of the present invention may be used in the form of a dry film or in the form of a liquid. The curable resin composition of the present invention can also be used as a prepreg obtained by coating or impregnating a sheet-like fibrous substrate such as a glass cloth, a glass or an aramid nonwoven fabric with the composition and then semi-curing the substrate. When used in the form of a liquid, the liquid may be 1-liquid, or 2-liquid or more. The 2-pack composition may be prepared, for example, as follows: fine cellulose fibers; and at least 1 selected from the group consisting of a cyclic ether compound having a naphthalene skeleton and a cyclic ether compound having an anthracene skeleton, at least 1 selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton, a phenoxy resin, or at least 1 selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton.

The dry film of the present invention has a resin layer obtained by coating the curable resin composition of the present invention on a carrier film and drying. In the case of forming a dry film, the curable resin composition of the present invention is first diluted with the organic solvent and adjusted to an appropriate viscosity, and then coated on a carrier film in a uniform thickness using a comma coater, a knife coater, a lip coater, a bar coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like. Thereafter, the coated composition is dried at a temperature of usually 40 to 130 ℃ for 1 to 30 minutes, whereby a resin layer can be formed. The coating film thickness is not particularly limited, and is usually appropriately selected in the range of 3 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

As the carrier film, a plastic film can be used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, and is usually appropriately selected within a range of 10 to 150 μm. More preferably in the range of 15 to 130 μm.

After forming a resin layer made of the curable resin composition of the present invention on a carrier film, a releasable cover film is preferably further laminated on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. The cover film may be one having a smaller adhesive force with the resin layer than with the carrier film when the cover film is peeled off.

In the present invention, the curable resin composition of the present invention is applied to the cover film and dried to form a resin layer, and a carrier film is laminated on the surface of the resin layer. That is, in the case of producing a dry film in the present invention, any of a carrier film and a cover film may be used as a film to which the curable resin composition of the present invention is applied.

The cured product of the present invention may be obtained by curing the curable resin composition of the present invention or the resin layer in the dry film of the present invention.

The electronic component of the present invention includes the cured product of the present invention, and specifically, a printed wiring board and the like can be given. The cured product of the present invention can be suitably used for electronic components requiring interlayer insulation reliability. In particular, by forming a multilayer printed wiring board using the curable resin composition of the present invention as an interlayer insulating material, it is possible to have good interlayer insulation reliability.

FIG. 2-1 (FIG. 3-1, FIG. 4-1, and FIG. 5-1) is a partial cross-sectional view showing an example of the structure of a multilayer printed wiring board as an example of the electronic component of the present invention. The illustrated multilayer printed circuit board can be manufactured, for example, as follows. First, a through hole is formed in the core substrate 2 on which the conductor pattern 1 is formed. The through-hole can be formed by an appropriate means such as a drill, a die punch, or a laser. After that, roughening treatment is performed using a roughening agent. In general, roughening treatment is performed by swelling with an organic solvent such as N-methyl-2-pyrrolidone, N-dimethylformamide, or methoxypropanol, or an alkaline aqueous solution such as caustic soda or caustic potash, and using an oxidizing agent such as dichromate, permanganate, ozone, hydrogen peroxide/sulfuric acid, or nitric acid.

Next, the conductor pattern 3 is formed by a combination of electroless plating, electrolytic plating, or the like. The step of forming the conductor layer by electroless plating is a step of immersing the conductor layer in an aqueous solution containing a plating catalyst to adsorb the catalyst, and then immersing the conductor layer in a plating solution to deposit a plated layer. A predetermined circuit pattern is formed on the conductor layer on the surface of the core substrate 2 by a conventional method (a subtractive method, a semi-additive method, etc.), and conductor patterns 3 are formed on both sides as shown in the drawing. At this time, a plating layer is also formed in the through hole, and as a result, the connection portion 4 of the conductor pattern 3 and the connection portion 1a of the conductor pattern 1 of the multilayer printed circuit board are electrically connected to each other, thereby forming the through hole 5.

Next, the interlayer insulating layer 6 is formed by applying a thermosetting composition by an appropriate method such as a screen printing method, a spray coating method, or a curtain coating method, and then heating and curing the composition. When a dry film or a prepreg is used, the interlayer insulating layer 6 is formed by laminating or heating and curing under pressure on a hot plate. Next, via holes 7 for electrically connecting the connection portions of the conductor layers are formed by an appropriate means such as laser light, and conductor patterns 8 are formed by the same method as that of the conductor patterns 3. Further, the interlayer insulating layer 9, the via hole 10, and the conductor pattern 11 are formed in the same manner. After that, the solder resist layer 12 is formed on the outermost layer, whereby a multilayer printed wiring board is manufactured. In the above description, the example of forming the interlayer insulating layer and the conductor layer on the laminated substrate has been described, and a single-sided substrate or a double-sided substrate may be used instead of the laminated substrate.

< second embodiment of the present invention >

A curable resin composition according to a second embodiment of the present invention is characterized by containing: (A) A fine powder having at least one dimension of less than 100nm, and (B) a thermosetting component.

According to the characteristic configuration of the second embodiment of the present invention, the following effects unique to the present invention can be exhibited: in a printed circuit board having at least one of a recess and a through hole, the recess such as a via hole or a through hole filled with a resin filler, and the wiring such as a conductor pad or a via hole on the through hole do not swell even when heated at high temperature during component mounting.

The detailed mechanism of the expansion of the wiring during the high-temperature heating is not clear, and it is considered that the reason is that the difference between the thermal expansion coefficients of the via hole and the through hole formed of copper and the resin filler at a high temperature is large.

Generally, a method of blending a large amount of an inorganic filler is known in order to reduce the thermal expansion coefficient of an organic material such as a resin to be close to that of a metal. According to this method, although the thermal expansion coefficient in the vicinity of normal temperature can be surely made close to that of metal, the thermal expansion coefficient is still much larger than that of metal even if a large amount of filler is contained in the material during high-temperature heating such as component mounting. Therefore, the resin filler is considered to expand, for example, above and below the through-hole when heated at a high temperature. In addition, the wall surface of the through hole and the bottom of the via hole, which are prevented from swelling, are subject to a decrease in reliability such as disconnection due to pressure application.

This is because, according to the present invention, since fine powders such as fine cellulose fibers are dispersed in the resin filler, the fine powders mutually attract each other to interact with each other, thereby exhibiting a reinforcing effect, and an increase in the thermal expansion coefficient can be suppressed even when heated at a high temperature, and as a result, a unique effect that expansion of the wiring does not occur under high-temperature heating can be obtained.

In addition, according to the characteristic configuration of the second embodiment of the present invention, in the method for manufacturing a printed wiring board having at least one of the concave portion and the through hole, the effect unique to the present invention can be exhibited in which a thin resin composition of the filler component does not bleed out when the curable resin composition filled in the concave portion and the through hole is cured.

The mechanism of bleeding of the thin resin component of the filler component during curing is not clear, but it is considered to be caused by the fact that a liquid must be used as the resin component in order to adjust the viscosity. It is desirable that the resin filler filled in the recesses and through holes such as via holes and through holes should use as little solvent as possible as a volatile component, and when such a liquid resin component is used, the viscosity of the resin component decreases before the curing reaction occurs when heating for curing, and the resin component seeps out along the contour of the copper foil due to capillary phenomenon.

This is because, according to the second embodiment of the present invention, since fine powders such as fine cellulose fibers are dispersed in the resin filler, the interaction between the fine powders exhibits a reinforcing effect, and the viscosity at the time of standing can be maintained even by heating at a high temperature, and therefore, a unique effect that the resin component is cured before the copper foil bleeds out can be obtained.

In addition, according to the characteristic configuration of the present invention, in the printed wiring board having at least one of the concave portion and the through hole, the characteristic effect of the present invention can be exhibited in which the depression of the hole portion or the like due to the excessive polishing for smoothing is not generated in the polishing step after the curing of the curable resin composition filled in the concave portion and the through hole.

The detailed mechanism of the recess and the depression of the through hole in the polishing step is not clear, but the resin filler is used so as to completely fill the recess and the through hole such as a via hole and a through hole, and therefore, for example, the resin filler is filled so as to seep out around the through hole and over the through hole (fig. 7 to 4 (a)), and after thermosetting, unnecessary portions are scraped off by a polishing roll or the like in the polishing step. However, such a thermosetting resin filler is deformed when pressure is applied thereto, and thus a cutting residue is likely to be generated (fig. 7-4 (b)). In this case, if the polishing is performed under such severe conditions that no cutting residue is generated, the resin filler is excessively cut, and thus a recess is generated in the through hole (fig. 7-4 (c)).

This is considered that, according to the second embodiment of the present invention, since fine powders such as fine cellulose fibers are dispersed in the resin filler, the interaction between the fine powders exhibits a reinforcing effect, and the strength of the resin is increased, so that a unique effect of reducing the pressure strain and uniformly polishing can be obtained.

Hereinafter, an embodiment of a second embodiment of the present invention will be described in detail.

[ (A) Fine powder ]

As the fine powder used in the second embodiment of the present invention, the same substances as those described in the first embodiment can be used. By using such fine powder, when a curable resin composition containing the fine powder is used as a resin filler for filling holes or the like, an interaction in which the fine powder attracts each other is obtained, and a reinforcing effect is exhibited, so that as described above, expansion after heating at a high temperature and bleeding of a resin component are less likely to occur, and a cured product in which a depression of the filler filled in a hole or the like is less likely to occur in a polishing step can be formed. In addition, this effect is also remarkably exhibited by hydrophilic substances in the fine powder.

[ (B) thermosetting component ]

The thermosetting component is not particularly limited, but is preferably a compound having 2 or more cyclic ethers in 1 molecule. The cyclic ether may be a cyclic thioether. The cyclic ether compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds. Among such cyclic ether compounds, epoxy resins and oxetane resins are preferable, and epoxy resins are particularly preferable.

As the epoxy resin, a known epoxy resin can be used. Examples of the thermosetting resin include resins that are cured by heating and exhibit electrical insulation properties, and examples thereof include bisphenol epoxy resins such as bisphenol a type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol Z type epoxy resin, bisphenol a novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolac epoxy resin, etc., novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, tetrahydroxyphenyl ethane type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin, glycidyl methacrylate copolymer type epoxy resin, copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivatives, CTBN modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1, 3-diglycidyl ether, 4-diglycidyl ether, 2, 4' -diglycidyl glycol, 2, 3-ethylene glycol, 2, 3-propylene glycol, 2, 3-diglycidyl ether, 2, 3-ethylene glycol, 2, and 2, 3-propylene glycol.

The curable resin composition of the present invention can improve the dispersibility of fine powder such as fine cellulose fibers by mixing an epoxy resin containing an amine as a precursor as the epoxy resin. Specifically, in the production of a fine powder dispersion, the fluidity is increased and the viscosity can be lowered, so that the workability is improved and the viscosity of the composition is lowered, and therefore the fine powder can be easily mixed or blended without a solvent.

Examples of the epoxy resin containing an amine as a precursor include tetraglycidyldiaminodiphenylmethane, glycidyl compounds of xylylenediamine, triglycidylaminophenol, and glycidyl aniline, which are substituted with an alkyl group or a halogen, each having a positional isomer. Examples of commercially available products of tetraglycidyl diaminodiphenylmethane include sumiooxy ELM434, (manufactured by sumitomo chemical co., ltd.), araldite MY720, MY721, MY9512, MY9612, MY9634, MY9663 (manufactured by Huntsman Advanced Materials), and JER604 (manufactured by mitsubishi chemical co., ltd.). Commercially available products of triglycidyl aminophenol include, for example, JER630 (manufactured by mitsubishi chemical corporation), araldite MY0500, MY0510 (manufactured by Huntsman Advanced Materials), and ELM100 (manufactured by sumitomo chemical corporation). Examples of commercially available glycidylanilines include GAN and GOT (manufactured by japan chemical co., ltd.).

In addition, as the curable resin composition of the present invention, when fine powder such as fine cellulose fiber is mixed or blended to obtain low viscosity, a decrease in heat resistance is observed, and in order to improve this phenomenon, when a component for improving heat resistance is blended, a tendency to increase viscosity is generated, and by blending a bisphenol a type epoxy resin and a bisphenol F type epoxy resin in combination, the above problem can be solved.

Further, an alkyl glycidyl ether such as 1, 6-hexanediol diglycidyl ether is desirably used as a diluent or for viscosity adjustment when the viscosity of the composition is high because of its low viscosity.

In the present invention, as the thermosetting component (B), a thermosetting resin other than the cyclic ether compound may be used as desired. The thermosetting resin other than the cyclic ether compound may be a resin which is cured by heating, and examples thereof include a phenol resin such as a novolak phenol resin such as a phenol novolak resin, a cresol novolak resin, or a bisphenol a novolak resin, an unmodified resol resin, a resol resin such as an oil-modified resol resin modified with tung oil, linseed oil, or walnut oil, a phenolic resin such as a resol resin, a phenoxy resin, a urea (urea) resin, or a triazine ring-containing resin such as a melamine resin, an unsaturated polyester resin, a bismaleimide resin, a diallyl phthalate resin, a silicone resin, a resin having a benzoxazine ring, a norbornene resin, a cyanate resin, an isocyanate resin, a urethane resin, a benzocyclobutene resin, a maleimide resin, a bismaleimide triazine resin, a polyimide resin, a thermosetting polyimide, a dicyclopentadiene diphenol ester compound, bisphenol a diacetate, a phthalic acid diphenyl ester, a terephthalic acid diphenyl ester, a bis [4- (methoxycarbonyl) phenyl terephthalate, and the like active ester compound.

(B) The amount of the thermosetting component blended is preferably 10 to 70% by mass based on the total amount of the composition. When the content is 10% by mass or more, the workability of printing or the like is excellent. When the amount is 70% by mass or less, the thermal expansion becomes lower. More preferably 20 to 60% by mass.

[ curing agent ]

The curable resin composition of the present invention preferably uses a curing agent as desired.

As the curing agent of the present invention, for example, an imidazole compound can be used. Examples of the imidazole compound include imidazole derivatives such as 2-methylimidazole, 4-methyl-2-ethylimidazole, 2-phenylimidazole, 4-methyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-undecylimidazole.

Further, as the imidazole compound, an imidazole compound containing a triazine structure may be mentioned. Examples of the imidazole compound having a triazine structure include 2, 4-diamino-6- [2' -methylimidazolyl- (1 ') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -undecylimidazolyl- (1 ') ] -ethyl-s-triazine, and 2, 4-diamino-6- [2' -ethyl-4 ' -methylimidazolyl- (1 ') ] -ethyl-s-triazine. Examples of commercially available products thereof include 2MZ-A, 2MZ-AP, 2MZA-PW, C11Z-A, and 2E4MZ-A (manufactured by four national chemical industries, ltd.).

Among the imidazole compounds, 2, 4-diamino-6- [2' -methylimidazolyl- (1 ') ] -ethyl-s-triazine and 2, 4-diamino-6- [2' -ethyl-4 ' -methylimidazolyl- (1 ') ] -ethyl-s-triazine are preferable. This provides a curable resin composition having excellent storage stability and a cured product which is not cracked by short-time curing.

As the curing agent, compounds other than imidazole compounds can be used, for example, dicyandiamide and its derivatives, melamine and its derivatives, diaminomaleonitrile and its derivatives, diethylenetriamine, triethylenetetramine, tetramethylenepentamine, bis (hexamethylene) triamine, triethanolamine, diaminodiphenylmethane, benzyldimethylamine, amines such as 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, adipic acid dihydrazide, sebacic acid dihydrazide and other organic acid hydrazides, 1, 8-diazabicyclo [5.4.0] undecene-7, 3, 9-bis (3-aminopropyl) -2,4,8, 10-tetraoxaspiro [5.5] undecane, or organic phosphine compounds such as triphenylphosphine, tricyclohexylphosphine, tributylphosphine, and methyl diphenylphosphine, phenol compounds and the like can be used. Further, examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Kagaku Kogyo Co., ltd.), ATU (manufactured by Kagaku K.K.), U-CAT3503N, U-CAT3502T, DBU, DBN, U-CATA SA102, and U-CAT5002 (manufactured by San Apro Co., ltd.). Guanamines such as dicyandiamide, melamine, acetoguanamine, benzoguanamine, and 3, 9-bis [2- (3, 5-diamino-2, 4, 6-triazabenzyl) ethyl ] -2,4,8, 10-tetraoxaspiro [5.5] undecane, and derivatives thereof, and organic acid salts and epoxy adducts thereof are known to have adhesion to copper and rust resistance, and to function not only as a curing agent for epoxy resins but also to contribute to the prevention of copper discoloration in printed wiring boards.

As the above-mentioned phenol compound, for example, the following can be used alone or in combination of 2 or more: phenol compounds such as phenol novolac resins, alkylphenol novolac resins, triazine structure-containing novolac resins, bisphenol a novolac resins, dicyclopentadiene type phenol resins, xylock type phenol resins, copna resins, terpene-modified phenol resins, polyvinyl phenols, naphthalene-based curing agents, fluorene-based curing agents, and the like are known and commonly used. <xnotran> , Air Water HE-610C, 620C, DIC TD-2131, TD-2106, TD-2093, TD-2091, TD-2090, VH-4150, VH-4170, KH-6021, KA-1160, KA-1163, KA-1165, TD-2093-60M, TD-2090-60M, LF-6161, LF-4871, LA-7052, LA-7054, LA-7751, LA-1356, LA-3018-50P, EXB-9854, SN-170, SN180, SN190, SN475, SN485, SN495, SN375, SN395, JX DPP, HF-1M, HF-3M, HF-4M, H-4, DL-92, MEH-7500, MEH-7600-4H, MEH-7800, MEH-7851, MEH-7851-4H, MEH-8000H, MEH-8005, XL, XLC, RN, RS, RX , . </xnotran>

The curing agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The amount of the curing agent to be blended may be a known and conventional amount relative to the thermosetting component, and is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the epoxy resin, for example. When the curing agent is a phenol compound, it is preferably 1 to 150 parts by mass per 100 parts by mass of the epoxy resin.

[ (C) Borate Compound ]

The curable resin composition of the present invention may contain a borate ester compound. The borate ester compound has an effect of further improving the storage stability of the resin composition, and therefore it is desirable to use it. It is considered that the borate ester compound acts by modifying the surface of the latent curing agent to encapsulate by reacting with the surface of the latent curing accelerator. Examples of the borate ester compound include trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris (2-ethylhexyloxy) borane, bis (1, 4,7, 10-tetraoxaundecyl) (1, 4,7,10, 13-pentaoxatetradecyl) (1, 4, 7-trioxaundecyl) borane, tribenzyl borate, triphenylborate, tri-o-tolyl borate, tri-m-tolyl borate, and triethanolamine borate. These can be purchased as reagents. Further, examples of commercially available products include Cureduct L-07N and L-07E (manufactured by Shikoku Kogyo Co., ltd.) which are blended products of an epoxy resin and a phenol novolac resin.

The borate ester compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The amount of the borate compound to be blended is preferably 0.01 to 3 parts by mass per 100 parts by mass of the thermosetting component. When the amount is 0.01 parts by mass or more, the storage stability is good. When the amount is 3 parts by mass or less, the curability is good.

[ (D) Filler ]

The curable resin composition of the present invention may further contain a filler other than the fine powder (a). As the filler other than the fine powder (a), an organic filler or an inorganic filler may be used, and an inorganic filler is more preferably used, as long as it is suitable and commonly known filler in accordance with the required characteristics of the curable resin composition of the present invention.

Examples of the inorganic filler include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, mica powder, noniberg silica, silicon nitride, and aluminum nitride. Among the inorganic fillers, calcium carbonate is preferable.

The shape of the filler may be spherical, acicular, plate-like, scaly, hollow, amorphous, hexagonal, cubic, or flaky, and spherical is preferable from the viewpoint of high filling property.

The filler may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The amount of the filler blended is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, based on the total amount of the composition. When the content is 10% by mass or more, the workability of printing or the like is excellent. If the amount is 70% by mass or less, the thermal expansion becomes lower.

[ other ingredients ]

In the curable resin composition of the present invention, an organic solvent is not necessarily used, but may be added to the extent that voids are not generated in order to adjust the viscosity of the composition and the like.

Further, the curable resin composition of the present invention may contain, as necessary, known and conventional colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black, and in order to impart storage stability during storage, known and conventional thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol, and phenothiazine, known and conventional thickeners or thixotropic agents such as clay, kaolin, organobentonite, and montmorillonite, adhesion-imparting agents such as silicone-based, fluorine-based, and polymer-based antifoaming agents and/or leveling agents, adhesiveness-imparting agents such as imidazole-based, thiazole-based, triazole-based, and silane-coupling agents, and known and conventional additives such as photopolymerization initiators, dispersants, and flame retardants.

The curable resin composition of the present invention may be 1-pack type or 2-pack type or more.

The curable resin composition of the present invention obtained as described above can be easily filled into holes such as via holes and through holes of a printed wiring board by a conventionally used method such as screen printing, roll coating, die coating, or the like.

Therefore, the viscosity of the curable resin composition of the present invention is preferably in the range of 100 to 1000 dPas, more preferably 200 to 900 dPas, and particularly preferably 300 to 800 dPas at 25. + -. 1 ℃. By setting the range, the hole portion can be easily filled, and the recess portion and the through hole can be satisfactorily filled without generating voids and the like.

The glass transition temperature (Tg) of the curable resin composition of the present invention is preferably 150 ℃ or higher, and more preferably 160 ℃ or higher. When the Tg is 150 ℃ or higher, the occurrence of delamination can be suppressed.

The cured product of the present invention is obtained by curing the curable resin composition according to the second embodiment of the present invention.

The printed wiring board of the present invention is obtained by filling at least one of the concave portion and the through hole with a cured product of the curable resin composition of the second embodiment of the present invention.

Hereinafter, a curable resin composition of the present invention is filled in recesses and through holes such as via holes and through holes provided in a wiring board, and pads and wirings are formed thereon, and an example of a method for manufacturing a printed wiring board formed in this manner will be described with reference to fig. 7-1.

(1) Hole filling

First, as shown in fig. 7-1 (a), the curable resin composition of the present invention is filled in a through hole 103 (a recess such as a via hole in addition to a through hole when a multilayer printed wiring board is used as a core substrate) provided in a wiring board 101 having a through hole 103 and a conductor circuit layer 104 formed on a substrate 102, as shown in fig. 7-1 (b). For example, a mask having an opening in a through hole portion is placed on a substrate and filled in the through hole by a printing method, a dot printing method, or the like.

Here, as the wiring substrate 101, the following wiring substrate can be suitably used: a wiring board comprising a copper foil laminated on a glass epoxy substrate, a polyimide resin substrate, a bismaleimide-triazine resin substrate, a fluororesin substrate or other resin substrate, a ceramic substrate, a metal substrate or other substrate 102, through-holes are formed by drilling, and the wall surfaces of the through-holes and the surfaces of the copper foil are subjected to electroless plating or electrolytic plating to form through-holes 103 and a conductor circuit layer 104. As the plating, copper plating is generally used.

(2) Grinding

Subsequently, the filled curable resin composition is pre-cured by heating at about 90 to 130 ℃ for about 30 to 90 minutes. Since the hardness of the cured product 105 thus pre-cured is relatively low, unnecessary portions that have oozed from the substrate surface can be easily removed by physical polishing, and a flat surface can be formed. Thereafter, the mixture is heated again at about 140 to 180 ℃ for about 30 to 90 minutes to perform main curing (complete curing).

The term "precured" or "precured" as used herein generally means a state in which the reaction rate of epoxy is 80% to 97%. The hardness of the precured article can be controlled by changing the heating time and heating temperature of the precured article. Thereafter, as shown in FIG. 7-1 (c), unnecessary portions of the cured product 105 that have oozed out from the through-holes are removed by polishing and planarized. The grinding may be performed by a belt sander, a polishing grinder, or the like.

(3) Formation of conductor circuit layer

As shown in fig. 7-1 (d), a plating film is formed on the surface of the substrate on which the via hole is filled. Thereafter, a resist is formed, and etching is performed on the resist non-formation portion (not shown). Subsequently, the resist is removed, whereby the conductor circuit layer 106 is formed as shown in FIG. 7-1 (e).

As described above, the curable resin composition of the present invention can be suitably used as a resin filler for through holes provided in a printed wiring board as shown in fig. 7-1, and further as a resin filler for through holes and via holes provided in a multilayer printed wiring board as shown in fig. 7-2 and 7-3.

Examples

The present invention will be described in more detail below with reference to examples.

< first embodiment >

[ preparation of fibrous Fine cellulose powder ]

Production example 1 (CNF 1)

Bleached kraft pulp fibers of coniferous trees (Machenzie CSF650ml, manufactured by Fletcher Challenge Canada Co., ltd.) were thoroughly stirred in 9900g of ion-exchanged water, and then 1.25 mass% of TEMPO (2, 6-tetramethylpiperidine 1-oxyl radical, manufactured by ALDRICH Co., ltd.) was added to 100g of the pulp, 12.5 mass% of sodium bromide, and 28.4 mass% of sodium hypochlorite were added in this order. Using pH-stat, 0.5M sodium hydroxide was added dropwise and the pH was maintained at 10.5. After the reaction was carried out for 120 minutes (20 ℃ C.), the dropwise addition of sodium hydroxide was stopped to obtain oxidized pulp. The oxidized pulp obtained was thoroughly washed with ion-exchanged water, followed by dehydration treatment. Then, 3.9g of the oxidized pulp and 296.1g of ion-exchanged water were subjected to micronization treatment at 245MPa for 2 times using a high-pressure homogenizer ((Starburst Lab HJP-25005, manufactured by Sugino machine Co., ltd.) to obtain a dispersion of a carboxyl group-containing fine cellulose powder (solid content concentration: 1.3 mass%).

Subsequently, 4088.75g of the resulting dispersion of the carboxyl group-containing fine cellulose powder was placed in a beaker, 4085g of ion-exchanged water was added to prepare a 0.5 mass% aqueous solution, and the mixture was stirred with a mechanical stirrer at room temperature (25 ℃) for 30 minutes. Next, 245g of 1M aqueous hydrochloric acid solution was poured into the flask, and the mixture was reacted at room temperature for 1 hour. After the reaction, the mixture was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added thereto and filtration was carried out to obtain a dispersion of acetone-containing acid-type cellulose powder (solid content concentration 5.0 mass%) in a state where the carboxyl-containing fine cellulose powder was swollen with acetone. After the reaction, the reaction mixture was filtered, and then washed with ion-exchanged water to remove hydrochloric acid and salts. After solvent substitution with acetone, solvent substitution was performed with DMF to obtain a DMF-containing acid-type cellulose powder dispersion (average fiber diameter 3.3nm, solid content concentration 5.0 mass%) in a state in which the carboxyl-containing fine cellulose powder was swollen.

Production example 2 (CNF 2)

40g of the DMF-containing acid-form cellulose powder dispersion obtained in production example 1 and 0.3g of hexylamine were placed in a beaker equipped with a magnetic stirrer and a stirrer, and dissolved in 300g of ethanol. The reaction mixture was allowed to react at room temperature (25 ℃ C.) for 6 hours. After completion of the reaction, filtration was performed, and washing and solvent substitution were performed with DMF to obtain a dispersion of the fine cellulose powder in which amine was ionically bonded to the fine cellulose powder (solid content concentration 5.0 mass%).

The CNF2 produced by the method of production example 2 has particularly good dispersibility, and can be dispersed by a usual method without using a special dispersing machine such as a high-pressure homogenizer.

Production example 3 (CNF 3)

This replacement operation was repeated 3 times, and carbitol acetate (20 times the mass of the filtrate) was added to prepare a dispersion of fine cellulose powder (solid content concentration: 5.0 mass%) by dehydrating and filtering 10 mass% of fibrous fine cellulose powder (BiNFi-s manufactured by Sugino machine, average fiber diameter: 80 nm), adding carbitol acetate (10 times the mass of the filtrate), stirring for 30 minutes, and filtering.

[ preparation of cellulose nanocrystal particles ]

Production example 4 (CNC 1)

The dried pieces of bleached kraft pulp of coniferous trees are processed by a shredder and a pin crusher to produce cotton-like fibers. The cotton-like fibers were taken out in an absolute dry mass of 100g, suspended in 2L of a 64% aqueous sulfuric acid solution, and hydrolyzed at 45 ℃ for 45 minutes.

The suspension thus obtained was filtered, and then 10L of ion-exchanged water was injected and stirred to uniformly disperse the solution, thereby obtaining a dispersion. Subsequently, the procedure of filtering and dehydrating the dispersion was repeated 3 times to obtain a dehydrated sheet. Subsequently, the obtained dehydrated sheet was diluted with 10L of ion-exchanged water, and a 1N aqueous solution of sodium hydroxide was added little by little with stirring to adjust the pH to about 12. Then, the suspension was filtered and dehydrated, 10L of ion-exchanged water was added thereto, and the filtration and dehydration were carried out with stirring, and this step was repeated 2 times.

Subsequently, ion-exchanged water was added to the obtained dehydrated tablet to prepare a 2% suspension. This suspension was passed through a wet micronizer ("Ultimaizer" manufactured by Sugino machine) 10 times at a pressure of 245MPa to obtain an aqueous dispersion of cellulose nanocrystal particles.

After that, acetone was used for solvent substitution, and then DMF was used for solvent substitution, thereby obtaining a DMF dispersion (solid content concentration 5.0 mass%) of cellulose nanocrystal particles in a swollen state. The cellulose nanocrystal particles in the obtained dispersion were observed and measured by AFM, and as a result, the average crystal width was 10nm and the average crystal length was 200nm.

Production example 5 (CNC 2)

The same procedure was carried out except that the cellulose raw material of production example 4 was changed to absorbent cotton (manufactured by Baikui Co., ltd.), thereby obtaining a DMF dispersion (solid content concentration: 5.0 mass%) in a state in which the cellulose nanocrystal particles were swollen. The cellulose nanocrystal particles in the obtained dispersion were observed and measured by AFM, and as a result, the average crystal width was 7nm and the average crystal length was 150nm.

(examples 1-1 to 1-15 and comparative examples 1-1 to 1-8)

Each composition was prepared by mixing and stirring the components as described in tables 1 to 3 below, and dispersing the mixture by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian machinery industry. The numerical values in tables 1 to 3 represent parts by mass.

The compositions obtained in examples and comparative examples were evaluated for thermal expansion coefficient, soldering heat resistance, insulation properties, and toughness (elongation). The evaluation method is as follows.

[ thermal expansion Rate ]

Each composition was applied to a 38 μm thick PET film using an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the composition was laminated on a copper foil 18 μm thick for 60 seconds using a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the resin layer of each composition was peeled off from the PET film. Then, the composition was heated in a hot air circulation type drying oven at 180 ℃ for 30 minutes to cure the composition and peeled from the copper foil, thereby obtaining film samples formed of cured products of the respective compositions. The obtained film sample was cut into a 3mm wide by 30mm long to prepare a test piece for measuring thermal expansion coefficient. The test piece was heated from 20 ℃ to 250 ℃ at 5 ℃/min under a nitrogen atmosphere with a load of 30mN between chucks in a tensile mode using TMA (thermal Analysis) Q400 manufactured by TA Instrument Co., ltd, and then cooled from 250 ℃ to 20 ℃ at 5 ℃/min, and thermal expansion coefficients α 1 and α 2 (ppm/K) were measured. The measurement results are shown in tables 1 to 3.

[ solder Heat resistance ]

Each composition was screen-printed on an FR-4 copper-clad laminate having a size of 150mm × 95mm and a thickness of 1.6mm using an 80-mesh Diterlon (Tetron) bias plate, and the whole was coated, dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes, and then cured by heating at 180 ℃ for 30 minutes to obtain a test substrate on which a resin layer containing a cured product of each composition was formed. The surface of the resin layer of the test substrate was coated with rosin flux, and the resin layer was fluidized at 260 ℃ for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then with ethanol. The test substrates after cleaning were visually observed for swelling, peeling, and changes in surface state of the resin layer, and the solder heat resistance was evaluated. As evaluation criteria, a case where abnormality due to swelling, peeling, dissolution, softening, or the like of the surface was observed in the resin layer was taken as x, and a case where the abnormality was not observed was taken as o. The evaluation results are shown in tables 1 to 3.

[ insulating Property ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, on a TEST piece A of IPC MULTI-PURPOSE TEST BOARDB-25 formed on a FR-4 substrate having a thickness of 1.6mm and a copper thickness of 35 μm, a vacuum laminator was used to press-bond the TEST piece A for 60 seconds at 60 ℃ and a pressure of 0.5MPa, the resin layers of the respective compositions were laminated, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace. Next, the lower end of the IPC Multi-PURPOSE TEST BOARDB-25 is cut to form an electrically independent terminal (cut in the broken line of FIGS. 1-4). Then, the insulation resistance value was measured and evaluated by applying a bias of DC500V to the test piece A with the upper part serving as a cathode and the lower part serving as an anode.

As evaluation criteria, the case where the insulation resistance value is 100G Ω or more is indicated by o, and the case where the insulation resistance value is less than 100G Ω is indicated by x. The evaluation results are shown in tables 1 to 3.

[ toughness ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 200 μm, and dried at 90 ℃ for 20 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, an electrolytic copper foil having a thickness of 18 μm with its glossy surface facing upward was fixed to an FR-4 copper-clad laminate having a thickness of 1.6mm using an adhesive tape, the dry film was pressed in a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, the resin layers of the respective compositions were laminated on the electrolytic copper foil, and then the PET film was peeled off, and the resin layer was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace. Then, the fixed tape was peeled off, and further, the electrolytic copper foil was peeled off, to obtain a film sample containing a resin layer. Subsequently, the film sample was cut into a predetermined size in accordance with JIS K7127 to prepare a test piece for evaluation. The test piece was subjected to stress [ MPa ] and strain [% ] at a tensile rate of 10 mm/min using a bench-top testing machine EZ-SX manufactured by Shimadzu corporation. The strain [% ] at this time is the elongation at break of the test piece, and the toughness can be evaluated from the strain [% ] because the toughness is higher as the strain is larger.

For the evaluation criteria, the case of strain [% ] being less than 2.0% is taken as poor, and the case of 2.0% or more is taken as good. The evaluation results are shown in tables 1 to 3.

[ Table 1]

* 1-1) thermosetting resin 1-1: cyclohexanone varnish (cyclic ether compound having naphthalene skeleton) having a solid content of 50% by mass, manufactured by Epiclon HP-4032 DIC corporation

* 1-2) thermosetting resin 1-2: NC-7300L Cyclohexanone varnish (Cyclic ether Compound having a naphthalene skeleton) having a solid content of 50% by mass, manufactured by Nippon chemical Co., ltd

* 1-3) thermosetting resin 1-3: cyclohexanone varnish (cyclic ether compound having anthracene skeleton) having a solid content of 50% by mass, manufactured by YX-8800 Mitsubishi chemical Co., ltd

* 1-4) thermosetting resin 1-4: epiclon HP-7200 Cyclohexanone varnish (Cyclic Ether Compound having Dicyclopentadiene skeleton) having a solid content of 50% by mass

* 1-5) thermosetting resin 1-5: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by NC-3000H Nippon Chemicals K.K

* 1-6) thermosetting resin 1-6: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by YX-4000 Mitsubishi chemical corporation

* 1-7) thermosetting resin 1-7: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 1-8) thermosetting resin 1-8: epiclon 830 DIC manufactured by Epiclon 830

* 1-9) thermosetting resin 1-9: JER827 Mitsubishi chemical corporation

* 1-10) phenoxy resin 1-1: cyclohexanone varnish having a solid content of 30% by mass, manufactured by YX6954 Mitsubishi chemical corporation

* 1-11) curing agent 1-1: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 1-12) curing agent 1-2: bisphenol A diacetate Tokyo chemical industry Co., ltd. (active ester)

* 1-13) curing catalyst 1-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Sizhou chemical industry Co., ltd

* 1-14) filler 1-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 1-15) organic solvent 1-1: dimethyl formamide

* 1-16) defoaming agent 1-1: BYK-352 BYK Chemie JAPAN Co

[ Table 2]

* 1-17) Filler 1-2: b-30 Sakai barium sulfate made by chemical industry Co., ltd

* 1-18) filler 1-3: aluminum oxide produced by DAW-07 Denka corporation

* 1-19) dispersant 1-1: DISPERBYK-111 BYK Chemie

[ Table 3]

As is clear from the results shown in tables 1 to 3, by using a combination of a fine cellulose powder and a filler other than a fine cellulose powder, a cured product having excellent properties such as toughness and a low thermal expansion coefficient can be obtained not only at room temperature but also in a high temperature region at the time of component mounting. The evaluation results of the solder heat resistance confirmed that the compositions of examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards. Further, it was confirmed that the use of an active ester as a curing agent reduced the relative dielectric constant and the dielectric loss tangent.

< second embodiment >

The same production examples 1 to 5 as in the first example were used as the fine cellulose fibers CNF1 to CNF3 and the cellulose nanocrystalline particles CNC1 and CNC 2.

Synthesis example 1 (varnish 1)

900g of diethylene glycol dimethyl ether as a solvent and 21.4g of tert-butyl peroxy-2-ethylhexanoate (trade name: perbutyl O, manufactured by Nichikoku Co., ltd.) as a polymerization initiator were charged into a 2-liter separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube, and heated to 90 ℃. After heating, 309.9g of methacrylic acid, 116.4g of methyl methacrylate, and 109.8g of lactone-modified 2-hydroxyethyl methacrylate (product name, manufactured by Daicel, ltd.; placcel FM 1) were added dropwise over 3 hours together with 21.4g of bis (4-t-butylcyclohexyl) peroxydicarbonate (product name, manufactured by Nichikura, ltd.; peroyl TCP) as a polymerization initiator. Further, the resin was aged for 6 hours to obtain a carboxyl group-containing copolymer resin. These reactions were carried out under a nitrogen atmosphere.

Then, 363.9g of 3, 4-epoxycyclohexyl methacrylate (trade name; cyclomer A200, manufactured by Daicel Co., ltd.), 3.6g of dimethylbenzylamine as a ring-opening catalyst, and 1.80g of hydroquinone monomethyl ether as a polymerization inhibitor were added to the obtained carboxyl group-containing copolymer resin, and the mixture was heated to 100 ℃ and stirred to conduct a ring-opening addition reaction of the epoxy resin. After 16 hours, a solution containing 53.8 mass% (nonvolatile content) of a carboxyl group-containing resin having an acid value of 108.9mgKOH/g and a mass average molecular weight of 25,000 as a solid content was obtained.

Synthesis example 2 (varnish 2)

In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, diethylene glycol monoethyl ether acetate as a solvent and azobisisobutyronitrile as a catalyst were charged, and heated to 80 ℃ under a nitrogen atmosphere, and methacrylic acid and methyl methacrylate were added dropwise in a ratio of 0.40:0.60 mole ratio of mixed monomers. Further, after stirring for 1 hour, the temperature was raised to 115 ℃ to deactivate it to obtain a resin solution.

After cooling the resin solution, butyl glycidyl ether was added to the resin solution at a molar ratio of 0.40 using tetrabutylammonium bromide as a catalyst at 95 to 105 ℃ for 30 hours in an equivalent amount to the carboxyl groups of the resin obtained, and the resulting solution was cooled.

Further, tetrahydrophthalic anhydride was added to the OH groups of the resin obtained above at a molar ratio of 0.26 at 95 to 105 ℃ for 8 hours. After cooling, the reaction mixture was taken out to obtain a solution containing a solid content of 50 mass% (non-volatile content) of a carboxyl group-containing resin having an acid value of 78.1mgKOH/g and a mass average molecular weight of 35,000.

Synthesis example 3 (varnish 3)

In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, 210g of cresol novolak type epoxy resin (product of DIC corporation, epiclon N-680, epoxy equivalent = 210) and 96.4g of carbitol acetate as a solvent were charged and dissolved by heating. Next, 0.1g of hydroquinone as a polymerization inhibitor and 2.0g of triphenylphosphine as a reaction catalyst were added thereto. The mixture was heated to 95 to 105 ℃ and 72g of acrylic acid was slowly added dropwise thereto to react for 16 hours until the acid value became 3.0mgKOH/g or less. After cooling the reaction product to 80-90 ℃, 76.1g of tetrahydrophthalic anhydride was added and the absorption peak of the anhydride (1780 cm) was determined by infrared spectroscopic analysis ^-1 ) Until disappeared, the reaction was allowed to proceed for about 6 hours. To the sameTo the reaction solution, 96.4g of an aromatic solvent Ipouzolu #150, manufactured by Shikino corporation, was added, and the mixture was diluted and taken out. The nonvolatile content of the thus obtained carboxyl group-containing photosensitive polymer solution was 65% by mass, and the acid value of the solid content was 78mgKOH/g.

Each composition was prepared by mixing and stirring the components as described in tables 4 to 12 below, and dispersing the mixture by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian machinery industry. The numerical values in tables 4 to 12 represent parts by mass.

[ reliability of interlayer insulation ]

(thermosetting composition)

The compositions shown in tables 4 to 6 were applied to a PET film having a thickness of 38 μm with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain dry films having resin layers of the compositions. Then, on a TEST piece A of IPC Multi-PURPOSE TEST BOARD B-25 (the part indicated by the arrow in FIGS. 2-2: the right side of the comb pattern in the lower part of the figure) formed on a FR-4 substrate of 1.6mm thickness and having a copper thickness of 35 μm, a resin layer of each composition was laminated by pressing for 60 seconds at 60 ℃ and a pressure of 0.5MPa using a vacuum laminator, and the PET film was peeled off, and then cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the treatment was carried out in the order of desmear with permanganic Acid (ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries, ltd.), and electrolytic copper plating, and copper plating was carried out to a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. Then, an acid-resistant tape formed into a circle having a diameter of 1cm was attached to the copper plating so as to be the center of the test piece a, and the copper plating except the acid-resistant tape portion on the cured resin was removed by etching with a 40 mass% aqueous solution of ferric chloride at 40 ℃. The test substrate in this case was as follows: on the A TEST piece of IPC Multi-PURPOSE TEST BOARD B-25, a cured product of each composition was formed as a coating film, and a circular copper plating having a diameter of 1cm was formed thereon (see FIGS. 2 to 3). Then, the wire is attached to the circular copper plating with wire solder and soldering iron Similarly, the wire of the IPC Multi-PURPOSE TEST BOARD was wired, and a voltage of 3.3V was applied to the wire with the circular shape as the anode and the wire as the cathode, and the TEST was carried out at 130 ℃ for 200 hours in an environment of 85%. 10 test pieces were prepared for each composition. In this case, the insulation resistance was measured at all times and was set to 1X 10 ⁶ The time at Ω or less is NG. All the NG-free persons were evaluated as very good, 1 to 4 NG persons as good, 5 to 9 NG persons as Δ, and all the NG-free persons as x. The evaluation results are shown in tables 4 to 6.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 7 to 12 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, on a TEST piece A of IPC Multi-PURPOSE TEST BOARDB-25 formed on a FR-4 substrate with a thickness of 1.6mm and a copper thickness of 35 μm, a resin layer of each composition was laminated by pressure bonding for 60 seconds at 60 ℃ under a pressure of 0.5MPa in a vacuum laminator, and a metal halide lamp exposure machine for a printed circuit board was used at 700mJ/cm ² After full-face exposure, the PET film was peeled off, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to be cured. Next, the treatment was carried out in the order of desmear with permanganic acid (manufactured by ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries), and electrolytic copper plating treatment to thereby carry out copper plating treatment with a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. Then, an acid-resistant tape formed into a circle having a diameter of 1cm was attached to the copper plating so as to be the center of the test piece A, and the copper plating except for the acid-resistant tape portion on the cured resin was removed by etching with a 40 mass% aqueous solution of ferric chloride at 40 ℃. Then, an electric wire was attached to the circular copper plating with wire solder and soldering iron, and the wire was attached to the wiring of IPC Multi-PURPOSE TEST BOARD in the same manner, and 3.3V was applied to the circular copper plating with the circular shape as the anode and the wiring as the cathodeVoltage, the test was carried out at 130 ℃ under 85% atmosphere for 200 hours. 10 test pieces were prepared for each composition. In this case, the insulation resistance was measured at all times and was set to 1X 10 ⁶ The time at Ω or less was evaluated as NG. All the NG-free samples were evaluated as very good, 1 to 4 NG samples were evaluated as good, 5 to 9 NG samples were evaluated as "Δ", and all the NG samples were evaluated as "x". The evaluation results are shown in tables 7 to 12.

[ reliability of comb-shaped electrode insulation ]

(thermosetting composition)

The compositions shown in tables 4 to 6 were applied to a PET film having a thickness of 38 μm with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain dry films having resin layers of the compositions. Then, on a TEST piece A of IPC MULTI-PURPOSE TEST BOARD B-25 formed of an FR-4 substrate of 1.6mm thickness and having a copper thickness of 35 μm, a vacuum laminator was used to bond the bonded members for 60 seconds at 60 ℃ and a pressure of 0.5MPa, the resin layers of the respective compositions were laminated, the PET film was peeled off, and the resultant was heated in a hot air circulation type drying oven at 180 ℃ for 30 minutes to cure the resin layers. Next, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut to form an electrically independent terminal (cut in the broken line portion in FIGS. 2 to 4). Then, a voltage of 50V was applied to the test piece A with the upper part of the test piece A serving as a cathode and the lower part serving as an anode, and the test was carried out at 130 ℃ for 200 hours in an atmosphere of 85%. 10 test pieces were prepared for each composition. In this case, the insulation resistance is often measured. Becomes 1 × 10 ⁶ The time at Ω or less is NG. All the NG-free persons were evaluated as very good, 1 to 4 NG-free persons were evaluated as good, 5 to 9 NG-free persons were evaluated as Δ, and all the NG-free persons were evaluated as "poor". The evaluation results are shown in tables 4 to 6.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 7 to 12 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, on a TEST piece A of IPC Multi-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate having a thickness of 1.6mm and a copper thickness of 35 μm, a strip was laminated at 60 ℃ and a pressure of 0.5MPa using a vacuum laminatorThe members were pressed for 60 seconds, and the resin layers of the respective compositions were laminated and exposed to light at 700mJ/cm using a metal halide lamp exposure machine for a printed wiring board ² After the whole surface exposure, the PET film was peeled off, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to be cured. Then, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut off as an electrically independent terminal. Then, a voltage of 50V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the test was carried out at 130 ℃ and 85% for 200 hours. 10 test pieces were prepared for each composition. In this case, the insulation resistance was measured constantly to be 1X 10 ⁶ The time at Ω or less is NG. All the NG-free persons were evaluated as very good, 1 to 4 NG persons as good, 5 to 9 NG persons as Δ, and all the NG-free persons as x. The evaluation results are shown in tables 7 to 12.

[ solder Heat resistance ]

(thermosetting composition)

Each composition was screen-printed on an FR-4 copper-clad laminate having a size of 150mm X95 mm and a thickness of 1.6mm using an 80-mesh Ditelon offset plate to form a solid pattern on the whole surface, dried at 80 ℃ for 30 minutes in a hot air circulation type drying oven, and then cured by heating at 180 ℃ for 30 minutes to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and change in surface state of the coating film. The case where the coating film had observed abnormalities such as swelling, peeling, and surface dissolution and softening was evaluated as "x", and the case where no such abnormalities were observed was evaluated as "o". The evaluation results are shown in tables 4 to 6.

(Photocurable thermosetting composition)

Printing the composition on FR-4 copper-clad laminate with size of 150mm × 95mm and thickness of 1.6mm by screen printing with 80 mesh Ditelon offset plate to form solid pattern, drying in hot air circulation type drying oven at 80 deg.C for 30 min, and printing with metal for circuit boardThe halide lamp exposure machine is 700mJ/cm ² Subjecting to full-face exposure using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated and cured at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and washed with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where the coating film had observed abnormalities such as swelling, peeling, and surface dissolution and softening was evaluated as "x", and the case where no such abnormalities were observed was evaluated as "o". The evaluation results are shown in tables 7 to 12.

[ preparation of sample for measuring thermal expansion ]

(thermosetting resin composition)

Each of the compositions shown in tables 4 to 6 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the film was pressed against a copper foil 18 μm thick for 60 seconds at 60 ℃ and 0.5MPa using a vacuum laminator, and the resin layers of the respective compositions were laminated to peel off the PET film. Subsequently, the film was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace, and the copper foil was peeled off to obtain a sample of a cured film.

(Photocurable thermosetting resin composition)

A copper foil 18 μm in thickness was attached to an FR-4 copper-clad laminate 1.6mm in thickness, and each of the compositions shown in tables 7 to 12 was applied with an applicator having a gap of 120 μm, and dried in a hot air circulating drying oven at 90 ℃ for 10 minutes. Then, a negative mask having a pattern of 3mm in width by 30mm in length was closely attached, and the mask was exposed to light at 700mJ/cm using a metal halide lamp exposure machine for a printed circuit board ² And (6) carrying out exposure. Then, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the film was heated in a hot air circulation type drying furnace at 150 ℃ for 60 minutes to be cured, and the copper foil was peeled off to obtain a sample of a cured film.

[ measurement of thermal expansion Rate ]

(thermosetting resin composition)

The prepared sample for measuring thermal expansion was cut into a size of 3mm in width by 30mm in length. The test piece was heated from 20 ℃ to 250 ℃ at 5 ℃/min in a tensile mode under a nitrogen atmosphere with a load of 30mN between chucks and a tensile mode using TMA (thermal Analysis) Q400 manufactured by TA Instrument Co., ltd, and then was cooled from 250 ℃ to 20 ℃ at 5 ℃/min. The average thermal expansion coefficient alpha 1 from 30 ℃ to 100 ℃ and the average thermal expansion coefficient alpha 2 from 200 ℃ to 230 ℃ at the time of temperature reduction were determined. The results are shown in tables 4 to 6.

(Photocurable thermosetting resin composition)

The procedure was carried out in the same manner as for the thermosetting resin composition except that the prepared sample was used as it is. The results are shown in tables 7 to 12.

[ Table 4]

* 2-1) thermosetting resin 2-1: cyclohexanone varnish (cyclic ether compound having naphthalene skeleton) having a solid content of 50% by mass, manufactured by Epiclon HP-4032DIC corporation

* 2-2) thermosetting resin 2-2: NC-7300L Cyclohexanone varnish (Cyclic ether Compound having a naphthalene skeleton) having a solid content of 50% by mass, manufactured by Nippon chemical Co., ltd

* 2-3) thermosetting resin 2-3: cyclohexanone varnish (cyclic ether compound having anthracene skeleton) having a solid content of 50% by mass, manufactured by YX-8800 Mitsubishi chemical Co., ltd

* 2-4) thermosetting resin 2-4: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 2-5) thermosetting resin 2-5: epiclon 830 DIC manufactured by Epiclon 830

* 2-6) thermosetting resin 2-6: JER827 Mitsubishi chemical corporation

* 2-7) thermosetting resin 2-7: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 2-8) curing catalyst 2-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Kasei Kogyo Kabushiki Kaisha

* 2-9) Filler 2-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 2-10) organic solvent 2-1: dimethyl formamide

* 2-11) defoaming agent 2-1: BYK-352 BYK Chemie JAPAN, inc

[ Table 5]

[ Table 6]

* 2-18) Filler 2-2: b-30 Sakai barium sulfate made by chemical industry Co., ltd

* 2-19) filler 2-3: aluminum oxide produced by DAW-07Denka corporation

* 2-20) dispersant 2-1: DISPERBYK-111 BYK Chemie

[ Table 7]

* 2-12) curing catalyst 2-2: micro-pulverized melamine Nissan chemical Co., ltd

* 2-13) curing catalyst 2-3: dicyandiamide

* 2-14) photopolymerization initiator 2-1: irgacure 907BASF corporation

* 2-15) photocurable resin 2-1: dipentaerythritol tetraacrylate

* 2-16) thermosetting resin 2-8: TEPIC-H (triglycidyl isocyanurate) Nissan chemical Co., ltd

2-17) colorant 2-1: phthalocyanine blue

[ Table 8]

[ Table 9]

[ Table 10]

[ Table 11]

[ Table 12]

As is clear from the results shown in tables 4 to 12, it was confirmed that a curable resin composition having excellent insulation reliability between layers and between electrodes, particularly excellent insulation reliability between layers, and a low thermal expansion coefficient can be obtained by including a fine powder such as a fine cellulose fiber and a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton. The evaluation results of the solder heat resistance confirmed that the compositions of the examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards.

< third embodiment >

The same production examples 1 to 5 as in the first example were used as the fine cellulose fibers CNF1 to CNF3 and the cellulose nanocrystalline particles CNC1 and CNC2, and the same synthesis examples 1 to 3 as in the second example were used as the varnishes 1 to 3.

Each composition was prepared by mixing and stirring the components as described in tables 13 to 21, and dispersing the components by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian industries. The numerical values in tables 13 to 21 represent parts by mass.

[ peeling Strength of copper plating ]

(thermosetting composition)

Each of the compositions shown in tables 13 to 15 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, the resulting resin layer was laminated on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150mm X100 mm for 60 seconds by a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the treatment was carried out in the order of desmear with permanganic acid (manufactured by ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries), and electrolytic copper plating treatment to thereby carry out copper plating treatment with a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, to obtain a test substrate subjected to copper plating treatment. The test substrate was cut out to have a width of 1cm and a length of 7cm or more, and the peel strength of peeling at an angle of 90 degrees was determined using a 90-degree printing peeling jig using a bench-top testing machine EZ-SX manufactured by Shimadzu corporation. For the evaluation, those with a value of 4.5N/m or more were evaluated as "O", those with a value of 2.5N/m or more and less than 4.5N/m were evaluated as "Δ", and those with a value of less than 2.5N/m were evaluated as "X". The results are shown in tables 13 to 15. It is considered that, when the peel strength is 4.5N/m or more, there is no problem of peeling even in a high-definition circuit. This reference is a rather strict evaluation condition.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 16 to 21 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resulting laminate was pressed in a vacuum laminator at 60 ℃ and 0.5MPa for 60 seconds on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150mm X100 mm, and the resin layer of each composition was laminated thereon to obtain a printed wiring boardExposing machine for metal halide lamp at 700mJ/cm ² After full-face exposure, the PET film was peeled off, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated in a hot air circulation type drying furnace at 150 ℃ for 60 minutes to be cured. Next, the treatment was carried out in the order of desmear with permanganic Acid (ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries, ltd.), and electrolytic copper plating, and copper plating was carried out to a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. The test substrate was cut out at a width of 1cm and a length of 7cm or more, and the peel strength of the test substrate peeled at an angle of 90 degrees was determined using a 90-degree printing peel jig using a bench-top tester EZ-SX manufactured by Shimadzu corporation. For the evaluation, the value of 4.5N/m or more is "O", the value of 2.5N/m or more and less than 4.5N/m is "Delta", and the value of less than 2.5N/m is "X". The results are shown in tables 16 to 21.

[ solder Heat resistance ]

(thermosetting composition)

Each of the compositions shown in tables 13 to 15 was screen-printed on an FR-4 copper-clad laminate having a size of 150 mm. Times.95 mm and a thickness of 1.6mm by an 80-mesh Ditelon bias plate to form a solid pattern on the whole surface, and the solid pattern was dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes and then cured by heating at 180 ℃ for 30 minutes to obtain a test piece. The rosin flux was applied to the cured product side of the composition of this test piece, flowed through the solder layer at 260 ℃ for 60 seconds, and washed with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where the coating film was observed to swell, peel off, or have abnormality due to dissolution, softening, or the like of the surface was evaluated as "x", and the case where the above-mentioned abnormality was not observed was evaluated as "o". The evaluation results are shown in tables 13 to 15.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 16 to 21 was screen-printed on an FR-4 copper-clad laminate having a size of 150mm × 95mm and a thickness of 1.6mm using an 80-mesh Ditelon offset plate to form a solid pattern on the whole surface, and the solid pattern was heated with hot airDrying in a circulating drying furnace at 80 deg.C for 30 min, exposing with a metal halide lamp exposure machine for printed circuit board at 700mJ/cm ² Subjecting to full face exposure using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the resultant was cured by heating at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where an abnormality due to swelling, peeling, dissolution, softening, or the like of the surface was observed in the coating film was evaluated as "x", and the case where the above-described abnormality was not observed was evaluated as "o". The evaluation results are shown in tables 16 to 21.

[ insulating Property ]

(thermosetting composition)

Each of the compositions shown in tables 13 to 15 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, the A TEST piece of IPC Multi-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate having a thickness of 1.6mm and a copper thickness of 35 μm was pressed in a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, the resin layers of the respective compositions were laminated, the PET film was peeled off, and the laminate was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 is cut off as an electrically independent terminal (cut off with the broken line portion in FIG. 3-2). Then, a bias of DC500V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was regarded as o, and the case where the insulation resistance value was less than 100G Ω was regarded as x. The results are shown in tables 13 to 15.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 16 to 21 was applied to a 38 μm thick PET film by means of an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a film having each compositionDry film of the resin layer of the article. Then, the A TEST piece of IPC Multi-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate with a thickness of 1.6mm and a copper thickness of 35 μm was pressed in a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, the resin layers of the respective compositions were laminated, and the exposure was carried out by a metal halide lamp exposure machine for a printed circuit BOARD at 700mJ/cm ² After the whole surface exposure, the PET film was peeled, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulating drying furnace to be cured. Then, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut off as an electrically independent terminal. Then, a bias of DC500V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was regarded as o, and the case where the insulation resistance value was less than 100G Ω was regarded as x. The results are shown in tables 16 to 21.

[ relative dielectric constant, dielectric loss tangent ]

(thermosetting composition)

Each of the compositions shown in tables 13 to 15 was applied to a PET film having a thickness of 38 μm with an applicator having a gap of 200 μm, and dried in a heated air circulation type drying oven at 90 ℃ for 20 minutes to obtain a dry film having a resin layer of each composition. Then, the glossy surface of the electrolytic copper foil having a thickness of 18 μm was faced upward, and the resultant was fixed to an FR-4 copper-clad laminate having a thickness of 1.6mm with an adhesive tape, and the resulting substrate was pressed against the substrate with a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, and the resin layers of the respective compositions were laminated, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Then, the fixed tape was peeled off, the electrolytic copper foil was peeled off, and a size of 1.7mm × 100mm was cut out as a sample for evaluation. The measurements were carried out using a cavity resonator (5 GHz) manufactured by Kanto electronic applications development Co., ltd., network analyzer E-507 manufactured by Keysight Technologies Co., ltd. For the evaluation of the relative dielectric constant, the case where the average value of 3 measurements was less than 2.8 was regarded as ≈ g, the case where the average value was not less than 2.8 and less than 3.0 was regarded as Δ, and the case where the average value was not less than 3.0 was regarded as ×. For the evaluation of the dielectric loss tangent, the value obtained by measuring 3 times and averaging the values was rated as 0.02 and rated as 0.02 or more. The results are shown in tables 13 to 15.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 16 to 21 was applied to a 38 μm thick PET film with a 200 μm gap applicator, and dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes to obtain a dry film having a resin layer of each composition. Then, the glossy surface of the electrolytic copper foil 18 μm thick was faced up, and the resultant was fixed with an adhesive tape to an FR-4 copper-clad laminate 1.6mm thick, and the resulting substrate was pressed against the resin layer of each composition for 60 seconds at 60 ℃ and 0.5MPa in a vacuum laminator, and the resin layer was laminated on the substrate, and the substrate was exposed to 700mJ/cm by a metal halide lamp exposure machine for printed wiring board using an opening mask of 1.7 mm. Times.100 mm ² After exposure, the PET film was peeled off, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated in a hot air circulation type drying furnace at 150 ℃ for 60 minutes to be cured. Then, the fixed tape was peeled off, and the electrolytic copper foil was peeled off as a sample for evaluation. The measurement was carried out using a cavity resonator (5 GHz) manufactured by Kanto electronic application development Co., ltd., network analyzer E-507 manufactured by Keysight Technologies Co., ltd. For the evaluation of the relative dielectric constant, the case where the average value of 3 measurements was less than 3.0 was regarded as ≈ g, the case where the average value was 3.0 or more and less than 3.2 was regarded as Δ, and the case where the average value was 3.2 or more was regarded as ×. For the evaluation of the dielectric loss tangent, the value obtained by measuring 3 times and averaging the values was rated as 0.02 and rated as 0.02 or more. The results are shown in tables 16 to 21.

[ Table 13]

* 3-1) thermosetting resin 3-1: epiclon HP-7200 Cyclohexanone varnish (cyclic ether compound having dicyclopentadiene skeleton) having a solid content of 50% by mass

* 3-2) thermosetting resin 3-2: tactix756 Cyclohexanone varnish (cyclic ether compound having dicyclopentadiene skeleton) having a solid content of 50% by mass

* 3-3) thermosetting resin 3-3: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 3-4) thermosetting resin 3-4: product of Epiclon 830 DIC Kabushiki Kaisha

* 3-5) thermosetting resin 3-5: JER827 Mitsubishi chemical corporation

* 3-6) thermosetting resin 3-6: resitop GDP-6085 solid content 60% by mass Cyclohexanone varnish (phenol resin having dicyclopentadiene skeleton)

* 3-7) thermosetting resin 3-7: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 3-8) curing catalyst 3-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Sizhou chemical industry Co., ltd

* 3-9) filler 3-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 3-10) organic solvent 3-1: dimethyl formamide

* 3-11) defoaming agent 3-1: BYK-352BYK Chemie JAPAN, inc

[ Table 14]

[ Table 15]

* 3-18) Filler 3-2: b-30 Sakai chemical industry Co., ltd., made barium sulfate

* 3-19) filler 3-3: aluminum oxide produced by DAW-07 Denka corporation

* 3-20) dispersant 3-1: DISPERBYK-111BYK Chemie Ltd

[ Table 16]

* 3-12) curing catalyst 3-2: micro-pulverized product of Nissan chemical Co Ltd of Melamine

* 3-13) curing catalyst 3-3: dicyandiamide

* 3-14) photopolymerization initiator 3-1: irgacure 907 BASF corporation

* 3-15) photocurable resin 3-1: dipentaerythritol tetraacrylate

* 3-16) thermosetting resin 3-8: TEPIC-H (triglycidyl isocyanurate) Nissan chemical Co., ltd

* 3-17) colorant 3-1: phthalocyanine blue

[ Table 17]

[ Table 18]

[ Table 19]

[ Table 20]

[ Table 21]

As is clear from the results shown in tables 13 to 21, it was confirmed that a curable resin composition having excellent insulation reliability, low dielectric characteristics, and good adhesion between a cured product and copper plating can be obtained by containing fine powder such as fine cellulose fiber and at least 1 selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton. Further, the evaluation results of the solder heat resistance confirmed that the compositions of examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards.

< fourth embodiment >

Each composition was prepared by mixing and stirring the components as described in tables 22 to 30 below, and dispersing the components by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian industries. The numerical values in tables 22 to 30 represent parts by mass.

[ solder Heat resistance ]

(thermosetting composition)

Each of the compositions shown in tables 22 to 25 was screen-printed on an FR-4 copper-clad laminate having a size of 150 mm. Times.95 mm and a thickness of 1.6mm by an 80-mesh Ditelon bias plate to form a solid pattern on the whole surface, and the solid pattern was dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes and then cured by heating at 180 ℃ for 30 minutes to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where an abnormality due to swelling, peeling, dissolution, softening, or the like of the surface was observed in the coating film was evaluated as "x", and the case where no abnormality was observed was evaluated as "o". The evaluation results are shown in tables 22 to 25.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 26 to 30 was screen-printed on an FR-4 copper-clad laminate having a size of 150mm × 95mm and a thickness of 1.6mm by an 80-mesh Ditelon bias plate to form a solid pattern on the whole surface, dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes, and exposed to 700mJ/cm by a metal halide lamp exposure machine for a printed circuit board ² Subjecting to full face exposure using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the resultant was cured by heating at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where an abnormality due to swelling, peeling, dissolution, softening, or the like of the surface was observed in the coating film was evaluated as "x", and the case where the above-described abnormality was not observed was evaluated as "o". The evaluation results are shown in tables 26 to 30.

[ insulating Property ]

(thermosetting composition)

Each of the compositions shown in tables 22 to 25 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried at 90 ℃ for 10 minutes in a heated air circulation type drying oven to obtain a dry film having a resin layer of each composition. Then, the resin layers of the compositions were laminated on a TEST piece A of IPC Multi-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate having a thickness of 1.6mm and a copper thickness of 35 μm by pressure bonding for 60 seconds using a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut to form an electrically independent terminal (cut in the broken line portion of FIG. 4-2). Then, a bias of DC500V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was regarded as o, and the case where the insulation resistance value was less than 100G Ω was regarded as x. The results are shown in tables 22 to 25.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 26 to 30 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a heated air circulating drying oven to obtain a dry film having a resin layer of each composition. Thereafter, IPC Multi-PURPOSE TEST BOARD B-25 was formed in a copper thickness of 35 μm on a 1.6mm thick FR-4 substrateA test piece was pressed by a vacuum laminator at 60 ℃ and 0.5MPa for 60 seconds, the resin layers of the respective compositions were laminated, and the printed wiring board was exposed to light by a metal halide lamp at 700mJ/cm ² After the whole surface exposure, the PET film was peeled, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to be cured. Then, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut off as an electrically independent terminal. Then, a bias of DC500V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was defined as o, and the case where the insulation resistance value was less than 100G Ω was defined as x. The results are shown in tables 26 to 30.

[ removability of smeared residue ]

(thermosetting resin composition)

Each of the compositions shown in tables 22 to 25 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried in a heated air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resin layers of the respective compositions were laminated on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm in a size of 150mm X100 mm by pressure-bonding for 60 seconds at 60 ℃ under a pressure of 0.5MPa in a vacuum laminator, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven to obtain a test piece.

The test piece was drilled with a carbon dioxide laser drill LC-2K212 (manufactured by Hitachi Via mechanics Co., ltd.) to a beam diameter of 100. Mu.m. Next, the residue was removed by using permanganic acid (manufactured by ATOTECH). The standard steps for desmear were a swelling step (60 ℃ C. For 5 minutes), a permanganate etching step (80 ℃ C. For 20 minutes), and a neutralization step (40 ℃ C. For 5 minutes), but the permanganate etching step was conducted in 3 stages of 10 minutes, 15 minutes, and 20 minutes.

Then, the drilled part was observed at a magnification of 3500 times using a scanning electron microscope JSM-6610LV (manufactured by Nippon electronics Co., ltd.), and the presence or absence of the smear on the copper surface was confirmed. For the evaluation, the case where the permanganate etching was performed for 10 minutes without smear was evaluated as "o", the case where the permanganate etching was performed for 15 minutes without smear was evaluated as "Δ", and the case where the permanganate etching was performed for 20 minutes without smear was evaluated as "x". The results are shown in tables 22 to 25.

(Photocurable thermosetting resin composition)

Each of the compositions shown in tables 26 to 30 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resulting laminate was pressed in a vacuum laminator at 60 ℃ and 0.5MPa for 60 seconds to form a resin layer of each composition on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150mm X100 mm, and the resin layer was exposed to light with a metal halide lamp exposure machine for a printed circuit board at 700mJ/cm ² After the whole surface exposure, the PET film was peeled, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the resultant was heated at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to be cured, thereby obtaining a test piece.

The test piece was drilled with a carbon dioxide laser drill LC-2K212 (manufactured by Hitachi Via mechanics Co., ltd.) to a beam diameter of 100. Mu.m. Next, the permanganate etching step was conducted in 3 stages of 10 minutes, 15 minutes, and 20 minutes using the desmear of permanganic acid (manufactured by ATOTECH corporation).

Then, the drilled part was observed at a magnification of 3500 times using a scanning electron microscope JSM-6610LV (manufactured by Nippon electronics Co., ltd.), and the presence or absence of the smear on the copper surface was confirmed. For the evaluation, the case where no smear was left in the permanganate etching for 10 minutes was regarded as "o", the case where no smear was left in 15 minutes was regarded as "Δ", and the case where no smear was left after 20 minutes was regarded as "x". The results are shown in tables 26 to 30.

[ measurement of peeling Strength and Ra ]

(thermosetting resin composition)

Each of the compositions shown in tables 22 to 25 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resin layers of the respective compositions were laminated on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150 mm. Times.100 mm by pressure bonding for 60 seconds at 60 ℃ and a pressure of 0.5MPa using a vacuum laminator, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulating type drying oven. Next, using the desmear of permanganic acid (manufactured by ato ech corporation), only 10 minutes of the sample was prepared in the example, and 10 minutes and 20 minutes 2 stages of the sample were prepared in the comparative example. As the roughness measurement of the surface of the sample, ra (arithmetic mean roughness) was measured using an optical coherence microscope (contiger GT, manufactured by BRUKER). Ra represents an arithmetic average roughness, and a line drawn at the center of the cross-sectional curve is a value obtained by dividing the total area on the curve obtained through the center line by the length, and the larger the value is, the larger the roughness is, the smaller the value is, the higher the smoothness is. Ra is defined in JIS B0031: 2003. The results are shown in tables 22 to 25.

Subsequently, the test piece from which the desmear had been completed was subjected to electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries, ltd.) and electrolytic copper plating in this order, and copper plating was performed to a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. The test substrate was cut out to have a width of 1cm and a length of 7cm or more, and the peel strength of peeling at an angle of 90 degrees was determined using a 90-degree printing peeling jig using a bench-top testing machine EZ-SX manufactured by Shimadzu corporation. For the evaluation, the case of 4.5N/m or more was regarded as. Smallcircle,. DELTA.2.5N/m or more and less than 4.5N/m was regarded as. Smallcircle, and the case of less than 2.5N/m was regarded as. Smallcircle. The results are shown in tables 22 to 25.

(Photocurable thermosetting resin composition)

Each of the compositions shown in tables 26 to 30 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resulting laminate was pressed in a vacuum laminator at 60 ℃ and 0.5MPa for 60 seconds on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150mm X100 mm, and the resin layers of the respective compositions were laminated on the laminate to obtain a printed wiring board Exposing with a metal halide lamp at 700mJ/cm ² After the whole surface exposure, the PET film was peeled, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulating drying furnace to be cured. Next, using the desmear of permanganic acid (manufactured by ato ech corporation), only 10 minutes of the sample was prepared in the example, and 10 minutes and 20 minutes 2 stages of the sample were prepared in the comparative example. As the roughness measurement of the surface of the sample, ra was measured using an optical coherence microscope (contiger GT, manufactured by BRUKER). The results are shown in tables 26 to 30.

Next, the test piece from which the smear was removed was subjected to electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries, ltd.) and electrolytic copper plating in this order, and copper plating was performed to a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. The test substrate was cut out at a width of 1cm and a length of 7cm or more, and the peel strength of the test substrate peeled at an angle of 90 degrees was determined using a 90-degree printing peel jig using a bench-top tester EZ-SX manufactured by Shimadzu corporation. For the evaluation, the case of 4.5N/m or more was regarded as ≈ and the case of 2.5N/m or more and less than 4.5N/m was regarded as Δ, and the case of less than 2.5N/m was regarded as x. The results are shown in tables 26 to 30.

[ Table 22]

* 4-1) phenoxy resin 4-1: cyclohexanone varnish having a solid content of 30% by mass, manufactured by YX6954 Mitsubishi chemical corporation

* 4-2) phenoxy resin 4-2: cyclohexanone varnish having a solid content of 30% by mass, manufactured by 1256 Mitsubishi chemical corporation

* 4-3) phenoxy resin 4-3:4250 Cyclohexanone varnish having a solid content of 30% by mass, manufactured by Mitsubishi chemical corporation

* 4-4) thermosetting resin 4-1: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 4-5) thermosetting resin 4-2: product of Epiclon 830 DIC Kabushiki Kaisha

* 4-6) thermosetting resin 4-3: JER827 Mitsubishi chemical corporation

* 4-7) thermosetting resin 4-4: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 4-8) curing catalyst 4-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Sizhou chemical industry Co., ltd

* 4-9) filler 4-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 4-10) organic solvent 4-1: dimethyl formamide

* 4-11) defoaming agent 4-1: BYK-352 BYK Chemie JAPAN Co

[ Table 23]

[ Table 24]

* 4-18) filler 4-2: b-30 Sakai barium sulfate made by chemical industry Co., ltd

* 4-19) filler 4-3: aluminum oxide production by DAW-07 Denka corporation

* 4-20) dispersant 4-1: DISPERBYK-111 BYK Chemie

[ Table 25]

* 4-12) curing catalyst 4-2: micro-pulverized melamine Nissan chemical Co., ltd

* 4-13) curing catalyst 4-3: dicyandiamide

* 4-14) photopolymerization initiator 4-1: irgacure 907 BASF corporation

* 4-15) photocurable resin 4-1: dipentaerythritol tetraacrylate

* 4-16) thermosetting resin 4-5: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan chemical Co., ltd

* 4-17) colorant 4-1: phthalocyanine blue

[ Table 26]

[ Table 27]

[ Table 28]

[ Table 29]

[ Table 30]

As is clear from the results shown in tables 22 to 30, it was confirmed that a curable resin composition which can remove the smear generated by laser processing in the smear removal step, has a small surface roughness advantageous for high-frequency transmission, and has excellent peel strength can be obtained by including a fine powder such as a fine cellulose fiber and a phenoxy resin. The evaluation results of the solder heat resistance confirmed that the compositions of the examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards.

< fifth embodiment >

Each composition was prepared by mixing and stirring the components as described in tables 31 to 39 below, and dispersing the mixture by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian machinery industry. The numerical values in tables 31 to 39 represent parts by mass.

[ swelling of copper plating ]

(thermosetting composition)

Each of the compositions shown in tables 31 to 33 was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resulting resin layer was laminated on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a thickness of 1.6mm and a size of 150mm X100 mm for 60 seconds by a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the treatment was carried out in the order of desmear with permanganic acid (manufactured by ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries), and electrolytic copper plating treatment to thereby carry out copper plating treatment with a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. Then, after passing 3 times in a reflow furnace at a peak temperature of 265 ℃, the copper plating was visually evaluated for swelling. The value obtained when no swelling was observed in the test substrate 10 was "o", the value obtained when swelling was observed in 1 or less of the test substrate 10 was "Δ", and the value obtained when swelling was observed in 2 or more of the test substrate 10 was "x". The results are shown in tables 31 to 33.

(Photocurable thermosetting composition)

Each of the compositions shown in tables 34 to 39 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried in a hot air circulating drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the thickness of the film was set to be 1.6 mm by 150mm X100 mmThe FR-4 copper-clad laminate (copper thickness 18 μm) having a thickness of about mm was laminated with the resin layers of the respective compositions by a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, and exposed to light at 700mJ/cm with a metal halide lamp exposure machine for a printed circuit board ² After full-face exposure, the PET film was peeled off, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (3) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to be cured. Next, the treatment was carried out in the order of desmear with permanganic acid (manufactured by ATOTECH), electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries), and electrolytic copper plating treatment to thereby carry out copper plating treatment with a copper thickness of 25 μm. Subsequently, annealing treatment was performed at 190 ℃ for 60 minutes in a hot air circulation type drying furnace, and a test substrate subjected to copper plating treatment was obtained. Then, after passing 3 times in a reflow furnace at a peak temperature of 265 ℃, the copper plating was visually evaluated for swelling. The value obtained when no swelling was observed in the test substrate 10 was "o", the value obtained when swelling was observed in 1 or less of the test substrate 10 was "Δ", and the value obtained when swelling was observed in 2 or more of the test substrate 10 was "x". The results are shown in tables 34 to 39.

[ solder Heat resistance ]

(thermosetting composition)

Each of the compositions shown in tables 31 to 33 was screen-printed on an FR-4 copper-clad laminate having a size of 150 mm. Times.95 mm and a thickness of 1.6mm by an 80-mesh Ditelon bias plate to form solid patterns on the whole surface, and the solid patterns were dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes and then cured by heating at 180 ℃ for 30 minutes to obtain test pieces. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and changes in the surface state of the coating film. The case where the coating film was observed to have swelling, peeling, surface dissolution, softening, and other abnormalities was evaluated as x, and the case where no such abnormalities were observed was evaluated as o. The evaluation results are shown in tables 31 to 33.

(Photocurable thermosetting composition)

FR-4 copper clad layer with the size of 150mm multiplied by 95mm and the thickness of 1.6mmOn the laminate, each of the compositions shown in tables 34 to 39 was screen-printed by an 80-mesh Ditelon bias plate to form a solid pattern on the whole surface, dried in a hot air circulating drying furnace at 80 ℃ for 30 minutes, and exposed to light at 700mJ/cm by a metal halide lamp exposure machine for printed circuit boards ² Subjecting to full-face exposure using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the resultant was cured by heating at 150 ℃ for 60 minutes in a hot air circulation type drying furnace to obtain a test piece. The cured product of the composition of this test piece was coated with rosin flux, flowed on the solder layer at 260 ℃ for 60 seconds, and then cleaned with propylene glycol monomethyl ether acetate and then with ethanol. The test piece was visually observed for swelling, peeling, and change in surface state of the coating film. The case where an abnormality due to swelling, peeling, dissolution, softening, or the like of the surface was observed in the coating film was evaluated as "x", and the case where the above-described abnormality was not observed was evaluated as "o". The evaluation results are shown in tables 34 to 39.

[ insulating Property ]

(thermosetting composition)

Each of the compositions shown in tables 31 to 33 was applied to a 38 μm thick PET film with a 120 μm gap applicator, and dried at 90 ℃ for 10 minutes in a heated air circulation type drying oven to obtain a dry film having a resin layer of each composition. Then, the resin layers of the compositions were laminated on a TEST piece A of IPC Multi-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate having a thickness of 1.6mm and a copper thickness of 35 μm by pressure bonding for 60 seconds using a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the PET film was peeled off and cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying oven. Next, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut to form an electrically independent terminal (cut in the broken line portion of FIG. 5-2). Then, a bias of DC500V was applied to test piece A with the upper part of the test piece A serving as a cathode and the lower part serving as an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was regarded as o, and the case where the insulation resistance value was less than 100G Ω was regarded as x. The results are shown in tables 31 to 33.

(Photocurable thermosetting composition)

Applicator with gap 120 μm on 38 μm thick PET filmThe compositions shown in tables 34 to 39 were applied and dried at 90 ℃ for 10 minutes in a hot air circulation type drying oven to obtain dry films having resin layers of the compositions. Then, on a TEST piece A of IPC MULTI-PURPOSE TEST BOARD B-25 formed on a FR-4 substrate with a thickness of 1.6mm and a copper thickness of 35 μm, a vacuum laminator was used to press bond the TEST piece at 60 ℃ and a pressure of 0.5MPa for 60 seconds, resin layers of the respective compositions were laminated, and a metal halide lamp exposure machine for a printed circuit BOARD was used to expose 700mJ/cm ² After the whole surface exposure, the PET film was peeled, and the content of Na was 1wt% at 30 DEG C ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the mixture was heated at 150 ℃ for 60 minutes in a hot air circulating drying furnace to be cured. Next, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut off as an electrically independent terminal. Then, a bias of DC500V was applied to the test piece A with the upper part thereof being a cathode and the lower part thereof being an anode, and the insulation resistance value was measured. For the evaluation, the case where the insulation resistance value was 100G Ω or more was defined as o, and the case where the insulation resistance value was less than 100G Ω was defined as x. The results are shown in tables 34 to 39.

[ preparation of sample for measuring thermal expansion ]

(thermosetting resin composition)

Each of the compositions shown in tables 31 to 33 was applied to a PET film 38 μm in thickness with an applicator having a gap of 120 μm, and dried in a hot air circulating drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the film was pressed against a copper foil 18 μm thick for 60 seconds at 60 ℃ and 0.5MPa using a vacuum laminator, and the resin layers of the respective compositions were laminated to peel off the PET film. Subsequently, the film was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace, and the copper foil was peeled off to obtain a sample of a cured film.

(Photocurable thermosetting resin composition)

A copper foil 18 μm in thickness was attached to an FR-4 copper-clad laminate 1.6mm in thickness, and each of the compositions shown in tables 34 to 39 was applied with an applicator having a gap of 120 μm, and dried in a hot air circulating drying oven at 90 ℃ for 10 minutes. Then, a negative mask having a pattern of 3mm in width by 30mm in length was closely attached, and the mask was exposed to light at 700mJ/cm using a metal halide lamp exposure machine for a printed circuit board ² And (6) exposing. Then, using 1wt% Na at 30 ℃ ₂ CO ₃ The developer of (4) was developed for 60 seconds by a developing machine. Thereafter, the film was heated in a hot air circulation type drying furnace at 150 ℃ for 60 minutes to be cured, and the copper foil was peeled off to obtain a sample of a cured film.

[ measurement of thermal expansion Rate ]

(thermosetting resin composition)

The prepared sample for measuring thermal expansion was cut into a 3mm width by 30mm length. The test piece was measured in a tensile mode using TMA (thermal Analysis) Q400 manufactured by TA Instrument corporation, under a nitrogen atmosphere with a load of 30mN between chucks and a load of 16mm, at a temperature of from 20 ℃ to 250 ℃ at 5 ℃/min, and then at a temperature of from 250 ℃ to 20 ℃ at 5 ℃/min. The average thermal expansion coefficient alpha 1 of 30 ℃ to 100 ℃ and the average thermal expansion coefficient alpha 2 of 200 ℃ to 230 ℃ at the time of temperature reduction were determined. Further, evaluation was performed from the values. Those with α 1 less than 25ppm were indicated as "O", those with α less than 35ppm were indicated as "Δ", and those with α 1 more than 35ppm were indicated as "X". Those with α 2 less than 75ppm are indicated by "O", those with α less than 95ppm are indicated by "Delta", and those with α 2 more than 95ppm are indicated by "X". The results are shown in tables 31 to 33.

(Photocurable thermosetting resin composition)

The same method as that for the thermosetting resin composition was carried out except that the prepared sample was used as it is. The results are shown in tables 34 to 39.

[ Table 31]

* 5-1) thermosetting resin 5-1: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by NC-3000H Nippon chemical Co., ltd

* 5-2) thermosetting resin 5-2: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by YX-4000 Mitsubishi chemical corporation

* 5-3) thermosetting resin 5-3: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 5-4) thermosetting resin 5-4: epiclon 830 DIC manufactured by Epiclon 830

* 5-5) thermosetting resin 5-5: JER827 Mitsubishi chemical corporation

* 5-6) thermosetting resin 5-6: GPH-103 Nippon chemical Co., ltd. (phenol resin having biphenyl skeleton) Cyclohexanone varnish (solid content: 60 mass%)

* 5-7) thermosetting resin 5-7: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 5-8) curing catalyst 5-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Sizhou chemical industry Co., ltd

* 5-9) filler 5-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 5-10) organic solvent 5-1: dimethyl formamide

* 5-11) defoaming agent 5-1: BYK-352BYK Chemie JAPAN Co

[ Table 32]

* 5-18) thermosetting resin 5-8: bisphenol A diacetate Tokyo chemical Co., ltd. (active ester compound)

[ Table 33]

* 5-19) filler 5-2: b-30 Sakai chemical industry Co., ltd., made barium sulfate

* 5-20) filler 5-3: aluminum oxide produced by DAW-07 Denka corporation

* 5-21) dispersant 5-1: DISPERBYK-111 BYK Chemie

[ Table 34]

* 5-12) curing catalyst 5-2: micro-pulverized melamine Nissan chemical Co., ltd

* 5-13) curing catalyst 5-3: dicyandiamide

* 5-14) photopolymerization initiator 5-1: irgacure 907 BASF corporation

* 5-15) photocurable resin 5-1: dipentaerythritol tetraacrylate

* 5-16) thermosetting resin 5-9: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan chemical Co., ltd

* 5-17) colorant 5-1: phthalocyanine blue

[ Table 35]

[ Table 36]

[ Table 37]

[ Table 38]

[ Table 39]

As is clear from the results shown in tables 31 to 39, it was confirmed that a curable resin composition which has low thermal expansion and which gives a cured product that does not expand due to thermal history even when copper plating is formed in a solid state on a cured product of the composition can be obtained by including fine powder such as fine cellulose fibers and at least 1 selected from the group consisting of cyclic ether compounds having a biphenyl skeleton and phenolic resins having a biphenyl skeleton. The evaluation results of the solder heat resistance confirmed that the compositions of examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards.

< sixth embodiment >

As the cellulose nanocrystal particles CNC1 and CNC2, the same manufacturing examples 4 and 5 as the first example were used.

Each composition was prepared by mixing and stirring the components as described in tables 40 and 41 below, and dispersing the components by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 available from Jitian industries. The numerical values in tables 40 and 41 represent parts by mass.

The compositions obtained in examples and comparative examples were evaluated for thermal expansion coefficient, heat resistance, insulation properties, toughness (elongation), and pot life. The evaluation method is as follows.

[ thermal expansion Rate ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the resin layer of each composition was laminated on a copper foil 18 μm thick by pressure bonding using a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, and the PET film was peeled. Then, the film was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace, and peeled from the copper foil to obtain film samples each containing a cured product of each composition. The obtained film sample was cut into a size of 3mm in width × 30mm in length to obtain a test piece for measuring thermal expansion coefficient. The test piece was measured for thermal expansion coefficients α 1 and α 2 (ppm/K) in a tensile mode using TMA (thermal Analysis) Q400 manufactured by TA Instrument corporation, with a 16mm distance between chucks and a load of 30mN, under a nitrogen atmosphere, and then, with a temperature rise from 20 ℃ to 250 ℃ at 5 ℃/min, and then, with a temperature drop from 250 ℃ to 20 ℃ at 5 ℃/min. The measurement results are shown in tables 40 and 41.

[ Heat resistance ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 10 minutes to obtain a dry film having a resin layer of each composition. Then, the film was pressed against a copper foil 18 μm thick for 60 seconds using a vacuum laminator at 60 ℃ and a pressure of 0.5MPa, and the resin layers of the respective compositions were laminated to peel off the PET film. Then, the composition was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace, and peeled from the copper foil to obtain film samples containing cured products of the respective compositions. The obtained film sample was pulverized in an agate mortar, and then the 3 wt% heating weight loss temperature was confirmed from a TG curve measured under a nitrogen stream at a temperature increase rate of 10 ℃/min in accordance with JIS-K-7120 and evaluated. As evaluation criteria, those having a 3 wt% heating weight loss temperature of less than 300 ℃ were evaluated as "x", those having a temperature of 300 ℃ or more and less than 310 ℃ were evaluated as "Δ", and those having a temperature of 310 ℃ or more were evaluated as good.

[ insulating Property ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 120 μm, and dried at 90 ℃ for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Then, on a TEST piece A of IPC MULTI-PURPOSE TEST BOARD B-25 formed of an FR-4 substrate of 1.6mm thickness and a copper thickness of 35 μm, a vacuum laminator was used to bond the TEST piece A for 60 seconds at 60 ℃ and a pressure of 0.5MPa, the resin layers of the respective compositions were laminated, the PET film was peeled off, and the laminate was cured by heating at 180 ℃ for 30 minutes in a hot air circulation type drying furnace. Next, the lower end of the IPC Multi-PURPOSE TEST BOARD B-25 is cut to form an electrically independent terminal (cut in the broken line portion of FIGS. 6-4). Then, a bias of DC500V was applied with the upper part of the test piece a as a cathode and the lower part as an anode, and the insulation resistance value was measured and evaluated.

For the evaluation criteria, a value having an insulation resistance value of 100G Ω or more is represented by "o", and a value having an insulation resistance value of less than 100G Ω is represented by "x". The evaluation results are shown in tables 40 and 41.

[ toughness ]

Each composition was applied to a 38 μm thick PET film with an applicator having a gap of 200 μm, and dried in a hot air circulation type drying oven at 90 ℃ for 20 minutes to obtain a dry film having a resin layer of each composition. Then, an electrolytic copper foil having a thickness of 18 μm with its glossy surface facing upward was fixed to an FR-4 copper-clad laminate having a thickness of 1.6mm by means of an adhesive tape, the dry film was pressed in a vacuum laminator at 60 ℃ and a pressure of 0.5MPa for 60 seconds, the resin layers of the respective compositions were laminated on the electrolytic copper foil, and then the PET film was peeled off and heated in a hot air circulation type drying oven at 180 ℃ for 30 minutes to cure the resin layers. Then, the fixed tape was peeled off, and further the electrolytic copper foil was peeled off, to obtain a film sample including a resin layer. Subsequently, the film sample was cut into a predetermined size in accordance with JIS K7127 to prepare a test piece for evaluation. The test piece was subjected to stress [ MPa ] and strain [% ] at a tensile rate of 10 mm/min using a bench-top testing machine EZ-SX manufactured by Shimadzu corporation. The strain [% ] at this time is the elongation at break of the test piece, and the toughness can be evaluated from the strain [% ] because the toughness is higher as the strain is larger.

For the evaluation criteria, the case where the strain [% ] is less than 2.0% is taken as x, and the case where the strain [% ] is 2.0% or more is taken as good. The evaluation results are shown in tables 40 and 41.

[ pot life ]

The viscosity of each composition after dispersion was measured as an initial viscosity by using a cone and plate viscometer TPE-100-H manufactured by Toyobo industries. Thereafter, the mixture was placed in a hermetically sealable container and placed at a temperature of 23 ℃, and the viscosity was measured and evaluated after 48 hours and after 96 hours. As evaluation criteria, those having an increase rate of viscosity of 30% or less after 96 hours were evaluated as good, those having an increase rate of 30% or less after 48 hours were evaluated as Δ, and those having an increase rate of 30% or more after 48 hours were evaluated as x. The usable time of x is short, so that when a liquid or film-like person is stored from low temperature to room temperature, there is a possibility that a problem will occur unless the next step is performed at an early stage, but the usable time of a person with good quality is long, and therefore, the handling is easy in both liquid and film-like.

[ Table 40]

* 6-1) thermosetting resin 6-1: cyclohexanone varnish (cyclic ether compound having naphthalene skeleton) having a solid content of 50% by mass, manufactured by Epiclon HP-4032 DIC corporation

* 6-2) thermosetting resin 6-2: cyclohexanone varnish (cyclic ether compound having naphthalene skeleton) having a solid content of 50 mass%, manufactured by NC-7300L Nippon Chemicals K.K

* 6-3) thermosetting resin 6-3: cyclohexanone varnish (cyclic ether compound having anthracene skeleton) having a solid content of 50 mass% manufactured by YX-8800 Mitsubishi chemical Co., ltd

* 6-4) thermosetting resin 6-4: epiclon HP-7200 Cyclohexanone varnish (cyclic ether compound having dicyclopentadiene skeleton) having a solid content of 50% by mass

* 6-5) thermosetting resin 6-5: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by NC-3000H Nippon chemical Co., ltd

* 6-6) thermosetting resin 6-6: cyclohexanone varnish (cyclic ether compound having a biphenyl skeleton) having a solid content of 50 mass%, manufactured by YX-4000 Mitsubishi chemical corporation

* 6-7) thermosetting resin 6-7: cyclohexanone varnish having a solid content of 50% by mass, manufactured by Epiclon N-740 DIC corporation

* 6-8) thermosetting resin 6-8: epiclon 830 DIC manufactured by Epiclon 830

* 6-9) thermosetting resin 6-9: JER827 Mitsubishi chemical corporation

* 6-10) phenoxy resin 6-1: cyclohexanone varnish having a solid content of 30% by mass, manufactured by YX6954 Mitsubishi chemical corporation

* 6-11) curing agent 6-1: cyclohexanone varnish having a solid content of 60% by mass, manufactured by HF-1 Minghem chemical Co., ltd

* 6-12) curing agent 6-2: bisphenol A diacetate Tokyo chemical industry Co., ltd. (active ester)

* 6-13) curing catalyst 6-1:2E4MZ (2-ethyl-4-methylimidazole) manufactured by Sizhou chemical industry Co., ltd

* 6-14) filler 6-1: manufactured by Admatech SO-C2, admatechs (silicon dioxide)

* 6-15) organic solvent 6-1: dimethyl formamide

* 6-16) defoaming agent 6-1: BYK-352BYK Chemie JAPAN Co

* 6-17) cellulose powder: NP fiber W-06MG (average particle diameter 6 μm) made of Japanese paper

[ Table 41]

As is clear from the results shown in tables 40 and 41, by using the cellulose nanocrystal particles and the filler other than the cellulose nanocrystal particles in combination, it is possible to obtain a curable resin composition having an excellent pot life, and a cured product having excellent properties such as toughness and heat resistance, while maintaining a low thermal expansion coefficient not only at room temperature but also in a high temperature region at the time of mounting the component. It was also confirmed that the use of an active ester as a curing agent reduced the relative dielectric constant and dielectric loss tangent, although not shown in tables 40 and 41.

< seventh embodiment >

[ production of Fine cellulose fiber ]

Production example 6 (CNF Dispersion 1)

Bleached kraft pulp fibers of coniferous trees (Machenzie CSF650ml, manufactured by Fletcher Challenge Canada Co., ltd.) were thoroughly stirred in 9900g of ion-exchanged water, and then 1.25 mass% of TEMPO (2, 6-tetramethylpiperidine 1-oxyl radical, manufactured by ALDRICH Co., ltd.) was added to 100g of the pulp, 12.5 mass% of sodium bromide, and 28.4 mass% of sodium hypochlorite were added in this order. Using pH-stat, 0.5M sodium hydroxide was added dropwise and the pH was maintained at 10.5. After the reaction was carried out for 120 minutes (20 ℃ C.), the dropwise addition of sodium hydroxide was stopped to obtain oxidized pulp. The obtained oxidized pulp was sufficiently washed with ion-exchanged water, and then subjected to dehydration treatment. Then, 3.9g of the oxidized pulp and 296.1g of ion-exchanged water were subjected to micronization treatment at 245MPa using a high-pressure homogenizer ((Starburst LabHJP25005, manufactured by Sugino machine Co., ltd.) to obtain a carboxyl group-containing fine cellulose fiber dispersion liquid (solid content concentration, 1.3 mass%).

Subsequently, 4088.75g of the carboxyl group-containing fine cellulose fiber dispersion obtained was placed in a beaker, 4085g of ion-exchanged water was added thereto to prepare a 0.5 mass% aqueous solution, and the mixture was stirred with a mechanical stirrer at room temperature (25 ℃ C.) for 30 minutes. Next, 245g of 1M aqueous hydrochloric acid solution was poured into the flask, and the mixture was reacted at room temperature for 1 hour. After the reaction, the mixture was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added thereto and filtered to obtain an acetone-containing acid cellulose fiber dispersion (solid content concentration 5.0 mass%) in a state where the carboxyl-containing fine cellulose fibers were swollen with acetone. After the reaction, the reaction mixture was filtered, and then washed with ion-exchanged water to remove hydrochloric acid and salts. Then, the solvent was replaced with acetone to obtain a dispersion liquid containing 5.0 mass% of a solid content. Then, 250g of Epiclon 830 DIC (bisphenol F epoxy resin) and 100g of JER827 Mitsubishi chemical corporation (bisphenol A epoxy resin) were mixed with 1000g of a dispersion prepared by ELM100 Sumitomo chemical industries, inc. (epoxy resin containing amine as a precursor: triglycidyl aminophenol) and solvent-substituted with the above acetone to adjust the solid content to 5.0 mass%, and after stirring, the acetone was removed by an evaporator to obtain an epoxy resin-containing acid cellulose fiber dispersion (average fiber diameter 3.3nm, CNF concentration 7.7 mass%).

Production example 7 (CNF Dispersion 2)

Bleached kraft pulp fibers of coniferous trees (Machenzie CSF650ml, manufactured by Fletcher Challenge Canada Co., ltd.) were thoroughly stirred in 9900g of ion-exchanged water, and then 1.25 mass% of TEMPO (2, 6-tetramethylpiperidine 1-oxyl radical, manufactured by ALDRICH Co., ltd.) was added to 100g of the pulp, 12.5 mass% of sodium bromide, and 28.4 mass% of sodium hypochlorite were added in this order. Using pH-stat, 0.5M sodium hydroxide was added dropwise and the pH was maintained at 10.5. After the reaction was carried out for 120 minutes (20 ℃ C.), dropping of sodium hydroxide was stopped to obtain oxidized pulp. The oxidized pulp obtained was thoroughly washed with ion-exchanged water, followed by dehydration treatment. Then, 3.9g of the oxidized pulp and 296.1g of ion-exchanged water were subjected to micronization treatment at 245MPa using a high-pressure homogenizer ((Starburst LabHJP25005, manufactured by Sugino machine Co., ltd.) to obtain a carboxyl group-containing fine cellulose fiber dispersion liquid (solid content concentration, 1.3 mass%).

Next, 4088.75g of the carboxyl group-containing fine cellulose fiber dispersion obtained was placed in a beaker, 4085g of ion-exchanged water was added to prepare a 0.5 mass% aqueous solution, and the mixture was stirred with a mechanical stirrer at room temperature (25 ℃ C.) for 30 minutes. Next, 245g of 1M aqueous hydrochloric acid solution was poured in, and the reaction was carried out at room temperature for 1 hour. After the reaction, the mixture was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added thereto and filtration was performed to obtain an acetone-containing acid cellulose fiber dispersion (solid content concentration 5.0 mass%) in a state in which the carboxyl-containing fine cellulose fibers were swollen with acetone. After the reaction, the reaction mixture was filtered and washed with ion-exchanged water to remove hydrochloric acid and salts. After the solvent substitution with acetone, the solvent substitution was carried out with DMF to obtain a DMF-containing fine cellulose fiber-swollen acid-type cellulose fiber dispersion (average fiber diameter 3.3nm, solid content concentration 5.0 mass%).

400g of the DMF-containing acid cellulose fiber dispersion and 3g of hexylamine were placed in a beaker equipped with a magnetic stirrer and a stirrer, and dissolved in 3000g of ethanol. The reaction mixture was reacted at room temperature (25 ℃ C.) for 6 hours. After the reaction, the reaction mixture was filtered, washed with DMF and replaced with a solvent to obtain a fine cellulose fiber composite (solid content concentration 5.0 mass%) in which amine was connected to fine cellulose fibers via ionic bonds. Then, 25g of Epiclon 830 DIC (bisphenol F epoxy resin) and 10g of JER827 Mitsubishi chemical corporation (bisphenol A epoxy resin) were mixed with 25g of a fine cellulose fiber composite in which amine was bonded to the fine cellulose fibers via an ionic bond (ELM 100 Sumitomo chemical industries, ltd.) (epoxy resin containing an amine as a precursor: triglycidyl aminophenol) and 200g of a fine cellulose fiber composite in which amine was bonded to the fine cellulose fibers via an ionic bond were mixed, and after stirring, DMF was removed by an evaporator to obtain a fine cellulose fiber composite in which amine containing an epoxy resin was bonded to the fine cellulose fibers via an ionic bond (CNF concentration 15.4 mass%).

The CNF produced by the method of production example 7 was particularly excellent in dispersibility, and dispersion could be carried out by a usual method without using a special dispersing machine such as a high-pressure homogenizer.

Production example 8 (CNF Dispersion 3)

10% by mass of fine cellulose fibers (BiNFi-s manufactured by Sugino machine, average fiber diameter 80 nm) were subjected to dehydration filtration, acetone was added in an amount 10 times the mass of the filtrate, the mixture was stirred for 30 minutes and then filtered, and the substitution operation was repeated 3 times, and acetone was added in an amount 20 times the mass of the filtrate to prepare a fine cellulose fiber dispersion (solid content concentration: 5.0% by mass). Next, 250g of Epiclon 830 DIC (bisphenol F-type epoxy resin), 100g of JER827 Mitsubishi chemical corporation (bisphenol A-type epoxy resin), and 1000g of ELM100 Sumitomo chemical industry Co., ltd. (epoxy resin containing amine as a precursor: triglycidyl aminophenol) were mixed, and after stirring, the acetone was removed by an evaporator to obtain an epoxy resin-containing cellulose fiber dispersion (CNF concentration: 7.7% by mass%).

Production example 9 (CNC Dispersion 1)

The dried pieces of bleached softwood kraft pulp were processed by a chopper and pin mill to produce cotton-like fibers. 100g of the cotton-like fibers were taken out in an absolute dry mass, suspended in 2L of a 64% aqueous sulfuric acid solution, and hydrolyzed at 45 ℃ for 45 minutes.

The suspension thus obtained was filtered, 10L of ion-exchanged water was poured, and the mixture was uniformly dispersed by stirring to obtain a dispersion. Subsequently, the procedure of filtering and dehydrating the dispersion was repeated 3 times to obtain a dehydrated sheet. Subsequently, the obtained dehydrated sheet was diluted with 10L of ion-exchanged water, and a 1N aqueous solution of sodium hydroxide was added little by little with stirring to adjust the pH to about 12. Then, the suspension was filtered and dehydrated, 10L of ion-exchanged water was added thereto, and the filtration and dehydration were performed by stirring, and this step was repeated 2 times.

Subsequently, ion-exchanged water was added to the obtained dehydrated sheet to prepare a 2% suspension. The suspension was passed through a wet micronizer ("Ultimaizer" manufactured by Sugino machine) 10 times under a pressure of 245MPa to obtain an aqueous dispersion of cellulose nanocrystal particles.

Thereafter, the solvent was replaced with acetone to obtain an acetone dispersion (solid content concentration 5.0 mass%) in a state where the cellulose nanocrystal particles were swollen. The cellulose nanocrystal particles in the obtained dispersion were observed and measured by AFM, and as a result, the average crystal width was 10nm and the average crystal length was 200nm.

Then, 50g of epoxy resin (bisphenol F type) manufactured by Epiclon 830 DIC corporation, 20g of epoxy resin (bisphenol A type) manufactured by JER827 Mitsubishi chemical corporation, 50g of epoxy resin (amine type as precursor: triglycidyl aminophenol) manufactured by ELM100 Sumitomo chemical industries, and 200g of the acetone dispersion were mixed, and after stirring, the acetone was removed by an evaporator to obtain an epoxy resin-containing acid cellulose fiber dispersion.

PRODUCTION EXAMPLE 10 (CNC Dispersion 2)

Absorbent cotton (manufactured by white cross corporation) 100g was taken out in an absolute dry mass, suspended in 2L of a 64% sulfuric acid aqueous solution, and hydrolyzed at 45 ℃ for 45 minutes.

The suspension thus obtained was filtered, 10L of ion-exchanged water was poured, and the mixture was uniformly dispersed by stirring to obtain a dispersion. Subsequently, the procedure of filtering and dehydrating the dispersion was repeated 3 times to obtain a dehydrated sheet. Subsequently, the obtained dehydrated sheet was diluted with 10L of ion-exchanged water, and a 1N aqueous solution of sodium hydroxide was added little by little with stirring to adjust the pH to about 12. Then, the suspension was filtered and dehydrated, 10L of ion-exchanged water was added thereto, and the filtration and dehydration were carried out while stirring, and this step was repeated 2 times.

Thereafter, the solvent was replaced with acetone to obtain an acetone dispersion (solid content concentration 5.0 mass%) in a state where the cellulose nanocrystal particles were swollen. The cellulose nanocrystal particles in the obtained dispersion were observed and measured by AFM, and as a result, the average crystal width was 7nm and the average crystal length was 150nm.

Each composition was prepared by mixing and stirring the components as described in tables 42 and 43 below, and dispersing the mixture by repeating 6 times using a high pressure homogenizer Nanovater NVL-ES008 manufactured by Jitian industries. The numerical values in tables 42 and 43 represent parts by mass.

[ bleeding out of the periphery of the through-hole ]

A test substrate was prepared by performing electroless copper plating and electrolytic copper plating treatments in this order on an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150mm × 100mm and a thickness of 1.6mm, using a 0.8mm diameter drill to form 3 rows and 10 columns of holes at 30, and applying a copper plating treatment having a copper thickness of 25 μm to the surface of the copper-clad laminate. After polishing and grinding the test substrate, each composition was filled into the through-hole by screen printing using a plate having a hole portion with a circular opening portion having a diameter of 0.9mm, and then, after filling, the through-hole was placed in a hot air circulation type drying oven and pre-cured at 120 ℃ for 1 hour to obtain a test piece. The test piece was observed with a magnifying glass to evaluate the bleeding state of the cured product. As evaluation criteria, those in which no bleeding was observed at all were evaluated as good, those in which bleeding did not occur in a spelt shape but due to size enlargement of the plate were evaluated as Δ, and those in which bleeding occurred only in a resin bleeding along polishing marks of polishing were evaluated as poor. The results are shown in tables 42 and 43.

[ abrasiveness ]

The test piece in which the bleeding around the through-hole was evaluated for the grindability by lapping (# 320). In observation with a magnifying glass, the one whose cured product was completely removed 1 time was evaluated as good, and the one whose cured product was completely removed 2 times or more was evaluated as poor. The results are shown in tables 42 and 43.

[ swelling marks on through-holes ]

The test piece for which the polishing property was evaluated was treated in the order of electroless copper plating (Thru-Cup PEA, manufactured by Shanmura industries, ltd.) and electrolytic copper plating (copper thickness: 10 μm). Next, after passing 3 times in a reflow furnace at a peak temperature of 265 ℃, the portion on the hole was visually evaluated. The case where no expansion mark was observed in 15 through holes was indicated by "o", the case where expansion marks were observed in 1 to 5 through holes was indicated by "Δ", and the case where expansion marks were observed in 6 or more through holes was indicated by "x". The results are shown in tables 42 and 43.

[ Table 42]

Examples 7-1 to 7-4 contained thermosetting resins 7-1 to 7-3 in the CNF dispersion, and therefore the resin components of the examples and comparative examples were almost the same.

* 7-1) thermosetting resin 7-1: epiclon 830 DIC (bisphenol F epoxy resin)

* 7-2) thermosetting resin 7-2: JER827 Mitsubishi chemical corporation (bisphenol A epoxy resin)

* 7-3) thermosetting resin 7-3: sumiepoxy ELM100 Sumitomo chemical Co., ltd. (epoxy resin containing amine as a precursor: triglycidyl aminophenol)

* 7-4) thermosetting resin 7-4: denacol EX-212 Nagase ChemteX (1, 6 hexanediol diglycidyl ether)

* 7-5) curing agent 7-1:2MZA-PW four-kingdom chemical industry Co., ltd. (2, 4-diamino-6- [2 '-methylimidazolyl- (1') ] -ethyl-s-triazine)

* 7-6) storage stabilizer 7-1: cureduct L-07N manufactured by Kasei Kogyo Co., ltd. (5% by mass of boric acid ester, and a blended product of epoxy resin and novolac resin)

* 7-7) inorganic filler 7-1: softon 1800 Beibei powdered Industrial Co., ltd (calcium carbonate)

* 7-8) defoaming agent 7-1: KS-66 shin-Etsu chemical Co., ltd

[ Table 43]

As is clear from the results shown in tables 42 and 43, by using a curable resin composition in which fine powder such as fine cellulose fiber is dispersed in a resin filler, a hole-filling material can be obtained which does not cause swelling in the hole to be filled even when heated at the time of component mounting, does not cause bleeding of the resin component, and does not cause dishing of the hole portion even in the polishing step.

Description of the reference numerals

1,3,8,11 conductor pattern

2. Core substrate

1a,4 connecting part

5. Through-hole

6,9 interlayer insulating layer

7,10 via hole

12. Solder mask

101. Wiring board

102. Base material

103. Plated through hole

104. Conductor circuit layer

105. Pre-cured product or main cured product of curable resin composition

106. Conductor circuit layer

107. Multilayer printed circuit board having laminated layers on core substrate

108. Layer upon layer

109. Conductor circuit layer

110. Multilayer printed wiring board in which via holes are formed in holes and filled with cured product of curable resin composition when forming build-up layers

111. Via hole filled with cured product of curable resin composition

112. Residue at the peripheral part of the hole which may be generated in the polishing process

113. Dishing of hole portions that may occur during a polishing process

Claims

1. A curable resin composition characterized by comprising: a curable resin, a fine powder having at least one dimension of less than 100nm, and a filler other than the fine powder,

the fine powder is a fine cellulose powder having a carboxyl group in a molecule and chemically modified with an amine compound or quaternary ammonium,

the curable resin includes a phenolic resin and a cyclic ether compound having at least 1 of a naphthalene skeleton and an anthracene skeleton.

2. The curable resin composition according to claim 1, wherein the fine powder is cellulose nanocrystal particles.

3. The curable resin composition according to claim 1, wherein the mixing ratio of the fine powder to the filler other than the fine powder in all the fillers is, in terms of mass ratio, filler other than fine powder: fine powder =100: (0.04-30).

4. The curable resin composition according to any one of claims 1 to 3, wherein the curable resin contains at least 1 selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton.

5. The curable resin composition according to any one of claims 1 to 3, wherein the curable resin comprises a phenoxy resin.

6. The curable resin composition according to any one of claims 1 to 3, wherein the curable resin contains at least 1 selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton.

7. A dry film comprising a resin layer obtained by applying the curable resin composition according to claim 1 to a film and drying the applied film.

8. A cured product obtained by curing the curable resin composition according to claim 1 or the resin layer of the dry film according to claim 7.

9. An electronic component comprising the cured product according to claim 8.