CN109206902B

CN109206902B - Resin sheet, laminate, and method for producing resin sheet

Info

Publication number: CN109206902B
Application number: CN201810612200.0A
Authority: CN
Inventors: 柄泽泰纪
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2017-06-30
Filing date: 2018-06-14
Publication date: 2022-07-12
Anticipated expiration: 2038-06-14
Also published as: TW201906902A; KR102504892B1; TWI765028B; CN109206902A; KR20190003344A

Abstract

The resin sheet of the present invention is a resin sheet containing a resin composition, wherein the resin composition contains (a) a thermosetting component containing (a1) a maleimide resin, and (B) an adhesive component, and the radius R of hansen-soluble spheres of the (a1) maleimide resin is calculated from hansen solubility parameter values_HSPIs 3.0 to 15.0 inclusive.

Description

Resin sheet, laminate, and method for producing resin sheet

Technical Field

The present invention relates to a resin sheet, a laminate, and a method for producing a resin sheet.

Background

As a sealing material for power semiconductors and the like, a resin composition having high heat resistance can be used.

In conventional Si power semiconductor devices, as a semiconductor sealing material, a material composed of a cured product of an epoxy resin composition as a main material is generally used from the viewpoints of adhesiveness, electrical stability, and the like. However, the semiconductor sealing material obtained by using the epoxy resin composition cannot be said to have sufficient heat resistance. Therefore, studies have been made on using a cured product of a resin composition containing bismaleimide and an allyl compound as a semiconductor encapsulating material in place of an epoxy resin composition. For example, document 1 (jp 2015-147849 a) discloses a resin composition containing a maleimide compound, a compound having at least one of an allyl group and an epoxy group, an amine compound, and a radical generator containing at least 1 of an acetophenone derivative and a tetraphenylethane derivative.

On the other hand, in recent years, sheet-shaped sealing materials have been proposed as shapes of sealing materials instead of flat plate-shaped or liquid sealing materials. The sheet-like sealing material can be produced, for example, by wet coating in which a varnish prepared by dissolving or dispersing the respective components in an organic solvent or the like is applied to form a sheet.

However, since maleimide compounds are generally difficult to dissolve in organic solvents, there is a problem that processing by wet coating is difficult. In addition, the resin composition described in document 1 has the following problems: when the varnish is dissolved or dispersed in an organic solvent and applied to form a sheet, the film-forming property is poor, and a uniform coating film cannot be obtained, and the sheet cannot be formed.

Disclosure of Invention

The purpose of the present invention is to provide a resin sheet, a laminate, and a method for producing a resin sheet, which achieve both sheet formability and heat resistance.

The resin sheet according to one embodiment of the present invention is a resin sheet containing a resin composition, wherein the resin composition contains (a) a thermosetting component containing (a1) a maleimide resin, and (B) an adhesive component, and the radius R of hansen-soluble spheres of the (a1) maleimide resin is calculated from a hansen solubility parameter value_HSPIs 3.0 to 15.0 inclusive.

In the resin sheet according to one embodiment of the present invention, the resin composition preferably further contains (C) an inorganic filler.

In the resin sheet according to one embodiment of the present invention, the complex viscosity η (complex viscosensitivity) of the resin composition before curing at 30 ℃ is preferably 5.0 × 10⁶Pa · s or more and 5.0X 10⁹Pa · s or less.

The resin sheet according to one embodiment of the present invention is preferably used for encapsulating a power semiconductor element or for sandwiching the power semiconductor element and another electronic component.

The resin sheet according to one embodiment of the present invention is preferably used for encapsulating a semiconductor element using any one of 1 or more types of silicon carbide and gallium nitride, or for sandwiching the semiconductor element using any one of 1 or more types of silicon carbide and gallium nitride and another electronic component.

In the resin sheet according to one embodiment of the present invention, the binder component (B) is preferably at least one resin selected from the group consisting of a phenoxy resin, a polyamideimide resin, and a wholly aromatic polyester resin.

In the resin sheet according to one embodiment of the present invention, the resin composition preferably has a storage modulus E' of 1.0 × 10 at 250 ℃ after curing²2.0X 10 MPa or more³MPa or less.

In the resin sheet according to one embodiment of the present invention, the weight average molecular weight of the adhesive component (B) is preferably 1 to 10 ten thousand.

In the resin sheet according to one embodiment of the present invention, the content of the binder component (B) in the resin composition is preferably 0.1 mass% or more and 50 mass% or less based on the total amount of solid components in the resin composition.

In the resin sheet according to one embodiment of the present invention, the thickness of the resin sheet is preferably 10 μm or more and 500 μm or less.

The laminate according to one embodiment of the present invention preferably includes a support sheet and a resin sheet formed on the support sheet.

In the laminate according to one aspect of the present invention, it is preferable that the support sheet is a first release material, and the resin sheet further includes a second release material.

A method for producing a resin sheet according to an embodiment of the present invention includes: a step (1) for dissolving the resin composition in a solvent to prepare a resin composition solution; a step (2) of applying the resin composition solution to a support sheet; and (3) drying the resin composition solution after coating to form a resin sheet, wherein the resin composition contains (A) a thermosetting component and (B) a binder component, the thermosetting component (A) contains (A1) a maleimide resin, and the radius R of the Hansen dissolving sphere calculated according to the Hansen solubility parameter value of the maleimide resin (A1)_HSPIs 3.0 to 15.0 inclusive.

In the method for producing a resin sheet according to one embodiment of the present invention, the support sheet is preferably a first release material, and the method further includes a step (4) of bonding a second release material to the resin sheet.

In the method for producing a resin sheet according to one embodiment of the present invention, the solvent is preferably methyl ethyl ketone, cyclohexanone, or a mixed solvent thereof.

According to the present invention, a resin sheet, a laminate, and a method for producing a resin sheet can be provided, which have both sheet formability and heat resistance.

Drawings

Fig. 1 is a schematic cross-sectional view of a laminate according to an embodiment.

Detailed Description

[ resin sheet ]

The resin sheet of the present embodiment contains a resin composition.

The resin sheet of the present embodiment can be obtained by forming the resin composition of the present embodiment into a sheet. By forming the resin composition into a sheet shape, the application to an adherend becomes easy, and particularly, the application to an adherend having a large area becomes easy. If the resin composition is in the form of a sheet, it can be formed into a shape that conforms to the shape after the sealing step to some extent, and therefore, a sealing material that maintains a certain degree of uniformity can be supplied by application alone. Further, since no fluidity is present, the workability is excellent.

The method for sheeting the resin composition is not particularly limited, and conventionally known sheeting methods can be used. For example, the resin sheet of the present embodiment can be obtained as a laminate in which a resin composition is formed on a support sheet. The resin sheet of the present embodiment may be a strip-shaped sheet, or may be provided in a rolled state. The resin sheet of the present embodiment wound in a roll shape can be fed from the roll and cut into a desired size.

The thickness of the resin sheet of the present embodiment is preferably 10 μm or more, and more preferably 20 μm or more, for example. The thickness is preferably 500 μm or less, more preferably 400 μm or less, and still more preferably 300 μm or less.

The resin sheet of the present embodiment is preferably applied to a plurality of semiconductor elements at one time. For example, when the resin composition is in a sheet form, it can be used for a so-called Panel Level Package (Panel Level Package) in which a resin sheet is applied to a structure in which a semiconductor element is disposed in each gap of a frame provided with a plurality of gaps, and the frame and the semiconductor element are packaged at once.

From the viewpoint of fluidity of the resin sheet before curing, the complex viscosity η of the resin sheet of the embodiment at 30 ℃ before curing is preferably 5.0 × 10⁶Pa · s or more and 5.0X 10⁹Pa · s or less, more preferably 6.0X 10⁶Pa · s or more and 1.0X 10⁹Pa · s or less, more preferably 1.0X 10⁷Pa · s or more and 5.0X 10⁸Pa · s or less.

The resin sheet before curing has a complex viscosity eta of more than 5.0X 10 at 30 DEG C⁹Pa · s is not preferable because the resin becomes too hard and the workability is deteriorated. On the other hand, in the case where the complex viscosity eta is less than 5.0X 10⁶Pa · s is not preferable because the resin is too soft and the workability is deteriorated.

The elastic modulus G' of the resin sheet of the present embodiment before curing at 30 ℃ is preferably 5.0 × 10 from the viewpoint of fluidity of the resin sheet before curing⁶Pa or more and 5.0X 10¹⁰Pa · s or less.

The resin sheet before curing has an elastic modulus G' of more than 5.0X 10 at 30 DEG C¹⁰Pa is not preferable because the resin becomes too hard and the workability is deteriorated. On the other hand, in the case where the complex viscosity eta is less than 5.0X 10⁶Pa is not preferable because the resin is too soft and the workability is deteriorated.

The complex viscosity η of the resin sheet of the present embodiment can be adjusted to the above range by adjusting the components or the blending amount used in the resin composition, for example.

The complex viscosity η in the present specification is a value obtained by applying a resin composition and drying the resin composition to prepare a resin sheet, and measuring the complex viscosity (unit: Pa · s) of the resin sheet at 30 ℃.

[ resin composition ]

The resin composition of the resin sheet of the present embodiment contains (a) a thermosetting component and (B) an adhesive component.

((A) thermosetting component)

(A) The thermosetting component (hereinafter, sometimes simply referred to as "component (a)") forms a three-dimensional network when heated, and has a property of firmly adhering to an adherend. The thermosetting component (a) of the present embodiment contains a maleimide resin (a 1).

((A1) Maleimide resin)

The maleimide compound is a compound having a maleimide group, and is one of the components contained in the resin composition.

By including the maleimide compound in the resin composition, a resin sheet containing the resin composition exhibits excellent heat resistance after curing.

The radius of the Hansen Solubility spheres (hereinafter, sometimes referred to as R) calculated from the Hansen Solubility Parameters (hereinafter, sometimes referred to as HSP values) value of the maleimide resin contained in the thermosetting component (a) (a1)_HSP) Is 3.0 to 15.0 inclusive. From the viewpoint of sheet formation, R calculated from the HSP value_HSPThe value is preferably 4.0 or more, more preferably 5.0 or more, further preferably 6.0 or more, and particularly preferably 7.0 or more. R_HSPIf the value is less than 3.0, the solubility of the solvent is low, and a uniform coating liquid cannot be formed, and the sheet-like shape is difficult to form.

For HSP values and R_HSPA method of calculating a value is described in "technique for adhesion (next technique)" (vol.34no.3(2014)116, p.1-8).

Here, the HSP value is considered to be 3 kinds of main interaction forces, i.e., (1) London dispersion force, (2) dipole-dipole interaction force, and (3) hydrogen bond force, among interaction forces constituting the cohesive energy of the substance, and is a value for evaluating the solubility of the solute in the solvent.

The HSP value has values corresponding to the London (London) dispersion force term, the dipole interaction force term, and the hydrogen bond force term. London dispersion force term in δ_dExpressed in terms of the dipole-dipole interaction force in delta_pExpressed by the hydrogen bond force term δ_hIndicating that the substances each have a unique 1 coordinate on the 3D chart.

In general, the solubility evaluation using the HSP value can be performed on a 3D graph by the value of the distance between the coordinates of each substance.

HSP value as beingThe case of a substance determined by a physical property value or a molecular group contribution method (for example, a polymer, a natural polymer, a fullerene particle, a nanoparticle, and TiO)₂Microparticles, etc.), a hansen sphere method determined from the target substance and dissolution tests for various pure solvents has been newly proposed. The radius R of the Hansen dissolving spheres can be calculated according to the Hansen sphere method_HSP。

Radius R of Hansen-dissolved sphere of maleimide resin of the present invention_HSPCan be determined by conducting a dissolution test of the maleimide resin using a pure solvent whose HSP value is known. Specifically, the results of the dissolution test were plotted on a hansen 3D graph, and the smallest sphere was set such that the HSP values of all solvents determined to be good solvents were the inside of the sphere and the HSP values of all solvents determined to be poor solvents were the outside of the sphere, and in this case, the center of the sphere was taken as the HSP value of the maleimide resin, and the radius of the sphere was taken as R_HSP。

In general, R_HSPThe higher the solubility of the solvent, and the higher the solubility of the solvent, the higher the solubility of the solvent.

By including such a maleimide resin in the resin composition, the resin composition can be easily dissolved in a solvent, and a uniform resin sheet can be obtained by wet coating.

The maleimide resin (a1) of the present embodiment is not particularly limited as long as it has a maleimide group in 1 molecule, and is preferably a maleimide resin containing 2 or more maleimide groups in 1 molecule, for example.

From the viewpoint of heat resistance, the maleimide resin (a1) of the present embodiment preferably contains a benzene ring, for example, and more preferably has a maleimide group bonded to the benzene ring. The maleimide compound preferably has a structure in which 2 or more maleimide groups are bonded to benzene rings.

In addition, in the case of the (a1) maleimide resin of the present embodiment, the radius R of the hansen-dissolved sphere to be calculated from the hansen solubility parameter value is calculated from the hansen-dissolved sphere_HSPWithin the above range and increase in the amount of the solventFrom the viewpoint of solubility of (b), the compound preferably has a substituent. As the substituent, there may be mentioned: alkyl, alkylene, and the like.

In view of these, examples of the maleimide resin (a1) of the present embodiment include, for example, a maleimide resin (hereinafter, may be simply referred to as "biphenyl maleimide resin") containing 2 or more maleimide groups and 1 or more biphenyl skeletons in 1 molecule. From the radius R of the Hansen dissolving spheres to be calculated from the Hansen solubility parameter values_HSPFrom the viewpoint of increasing the solubility in a solvent and improving the sheet formability within the above range, the biphenyl skeleton may have a substituent. Examples of the substituent include: alkyl groups such as methyl and ethyl, and alkylene groups.

The maleimide resin (a1) of the present embodiment includes a maleimide resin containing 2 or more maleimide groups and 2 or more phenylene groups in 1 molecule. From the radius R of the Hansen solubility sphere to be calculated from the Hansen solubility parameter value_HSPIn view of the above range, increasing the solubility in a solvent, and improving the sheet formability, it is preferable that the phenylene group has a substituent. Examples of the substituent include: alkyl groups such as methyl and ethyl, and alkylene groups. In addition, the maleimide resin (a1) of the present embodiment is preferably a maleimide resin having an ether bond between a maleimide group and a phenylene group, from the viewpoint of sheet formability.

Examples of the maleimide resin containing 2 or more maleimide groups and 2 or more phenylene groups in 1 molecule include compounds represented by the following general formula (1).

In the above general formula (1), R¹～R⁴Each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L¹Is an alkylene group having 1 to 6 carbon atoms, L²And L³Each independently an alkylene group of 1 to 6 carbon atoms or a C6 to E10, p and q are each independently 0 or 1.

The maleimide resin represented by the above general formula (1) of the present embodiment may specifically be a compound represented by the following general formula (2) or the following general formula (3), for example.

In the above general formulae (2) and (3), L¹Is an alkylene group having 1 to 6 carbon atoms.

In the above general formula (2), R¹～R⁴Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Specifically, the (a1) maleimide resin of the present embodiment is preferably bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, N' -1, 3-phenylenedimaleimide, 4-methyl-1, 3-phenylenedimaleimide, polyphenylmethanemaleimide, or 2, 2-bis [4- (4-maleimidophenoxy) phenyl ] propane, from the viewpoint of obtaining a cured product having high sheet formability and heat resistance, and more preferably bis (3-ethyl-5-methyl-4-maleimidophenyl) methane from the viewpoint of sheet formability.

Examples of the maleimide resin having a biphenyl skeleton include compounds represented by the following general formula (4).

In the general formula (4), k is an integer of 1 or more, and the average value of k is preferably 1 or more and 10 or less; m1 and m2 are each independently an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1; n1 and n2 are each independently an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0; r⁵And R⁶Each independently an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.

Specific examples of the maleimide resin represented by the above general formula (4) include compounds represented by the following general formula (5) or the following general formula (6).

In the general formulae (5) and (6), k is the same as that of the general formula (4). In the above general formula (5), n1, n2 and R⁵And R⁶And n1, n2 and R in the general formula (4)⁵And R⁶The same is true.

Examples of commercially available maleimide resins represented by the above general formula (3) include "MIR-3000-70 MT" manufactured by Nippon Kagaku K.K.

(A) The thermosetting component may contain (a1) a maleimide resin and at least one of an allyl resin and an epoxy resin.

By containing at least one of an allyl resin and an epoxy resin, a polymerization reaction between the maleimide resin and at least one of the allyl resin and the epoxy resin can form a dense network, and the cured resin sheet can exhibit excellent heat resistance.

The allyl resin of the present embodiment is not particularly limited as long as it has an allyl group, and is preferably an allyl resin containing 2 or more allyl groups in 1 molecule. The allyl resin may have other functional groups than allyl groups, such as epoxy groups and hydroxyl groups.

The allyl resin of the present embodiment is more preferably represented by the following general formula (7).

In the above general formula (7), R⁷And R⁸Each independently an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably an alkyl group selected from a methyl group and an ethyl group.

Specific examples of the allyl resin in the present embodiment include diallyl bisphenol a.

The epoxy resin in the present embodiment is not particularly limited as long as it is an epoxy compound having 2 or more epoxy groups in 1 molecule. The epoxy resin may be liquid or solid at normal temperature, and an epoxy resin which is liquid at normal temperature and an epoxy resin which is solid at normal temperature may be used in combination.

The thermosetting component (a) of the present embodiment may contain (a1) a thermosetting resin other than the maleimide resin, the allyl resin and the epoxy resin component, as long as the object of the present invention is not impaired.

As such a thermosetting resin, any thermosetting resin having high heat resistance may be used, and examples thereof include: maleimide resin other than the component (A1), and benzene

And oxazine resins, cyanate resins, and melamine resins. These thermosetting resins may be used alone in 1 kind, or in combination in 2 or more kinds.

The thermosetting component (a) of the present embodiment may contain a curing agent as long as the object of the present invention is not impaired. Examples of the curing agent include: resins such as phenol resins and resins having a C ═ C double bond, and amines, acid anhydrides, and formaldehyde. These curing agents can be used alone in 1, or in combination with more than 2.

The content of the (a1) maleimide resin is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, based on the total amount of the solid components of the (a) thermosetting component (i.e., when all the solid components of the (a) thermosetting component other than the solvent are taken as 100 mass%. When the content of the (a1) maleimide resin is in the above range, the heat resistance of the resin sheet can be improved.

Since a uniform coating liquid can be prepared by using the maleimide resin (a1) of the present embodiment, a uniform resin sheet can be obtained by using the resin composition even when the content of the maleimide resin (a1) in the thermosetting component (a) is large. Specifically, the content of the (a1) maleimide resin may be 75% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass based on the total amount of the solid components of the (a) thermosetting component (that is, when all the solid components of the (a) thermosetting component other than the solvent are taken as 100% by mass). The thermosetting component (a) may not contain an allyl resin. In the present embodiment, the combination of the thermosetting component (a) and the binder component (B) may be a combination other than the combination of bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, diallyl bisphenol a, and the BisA/BisF mixed phenoxy resin.

In the present embodiment, the content of the thermosetting component (a) in the resin composition is preferably 2% by mass or more and 75% by mass or less, and more preferably 5% by mass or more and 70% by mass or less, based on the total amount of solid components in the resin composition (that is, when all solid components except the solvent are taken as 100% by mass). When the content of the thermosetting component (a) is within the above range, the workability, sheet formability, and heat resistance of the resin sheet can be improved.

In the present embodiment, (a) the thermosetting component may contain a curing accelerator.

Examples of the curing accelerator include imidazole compounds (e.g., 2-ethyl-4-methylimidazole).

The content of the curing accelerator in the resin composition is preferably 0.005 mass% or more and 12 mass% or less, and more preferably 0.01 mass% or more and 10 mass% or less, based on the total amount of the resin composition (that is, when all solid components except the solvent are taken as 100 mass%).

((B) adhesive component)

In the present embodiment, the resin composition preferably contains (B) a binder component (hereinafter, may be simply referred to as "component (B)") in addition to the component (a). The resin composition of the present embodiment can be provided with film-forming properties by further containing (B) a binder component, and the resin composition can be easily molded into a sheet shape.

The adhesive component (B) of the present embodiment is a resin component other than the component (a), and has a function of bonding the component (a) or other components. (B) The binder component is preferably a thermoplastic resin or the like. (B) The component (b) may have a functional group. In the case where the (B) binder component has a functional group as described above, even if the (B) binder component can participate in the curing of the resin composition by heat, the (B) binder component is distinguished from the (a) thermosetting component in the present invention.

The binder component (B) can be selected from a wide range of components, whether aliphatic or aromatic. (B) The binder component is preferably at least one resin selected from, for example, phenoxy resins, acrylic resins, methacrylic resins, polyester resins, urethane resins, and polyamideimide resins, and more preferably at least one resin selected from phenoxy resins, polyamideimide resins, and polyester resins, from the viewpoint of heat resistance. The polyester resin is preferably a wholly aromatic polyester resin. (B) The binder component may be used alone in 1 kind, or in combination of 2 or more kinds.

The phenoxy resin is preferably a phenoxy resin having 1 or more kinds of skeletons selected from a bisphenol a skeleton (hereinafter, bisphenol a may be referred to as "BisA"), a bisphenol F skeleton (hereinafter, bisphenol F may be referred to as "BisF"), a biphenyl skeleton and a naphthalene skeleton, and more preferably a phenoxy resin having a bisphenol a skeleton and a bisphenol F skeleton.

From the viewpoint of easily adjusting the complex viscosity of the resin composition before curing of the resin sheet to a desired range, the weight average molecular weight (Mw) of the (B) binder component is preferably 100 or more and 100 ten thousand or less, more preferably 1000 or more and 80 ten thousand or less, and the properties are preferably 1 ten thousand or more and 10 ten thousand or less. The weight average molecular weight in the present specification is a value measured by a Gel Permeation Chromatography (GPC) method and converted to standard polystyrene.

In the present embodiment, the content of the binder component (B) in the resin composition is preferably 0.1 mass% or more and 50 mass% or less, and more preferably 1 mass% or more and 40 mass% or less, based on the total amount of solid components of the resin composition (that is, when all solid components except the solvent are taken as 100 mass%). By setting the content of the binder component (B) in the resin composition to the above range, the complex viscosity of the resin composition before curing of the resin sheet can be easily adjusted to a desired range, and the workability and sheet formability of the resin sheet can be improved.

In the present embodiment, the content of the component (a1) is preferably 20 mass% or more and 80 mass% or less based on the total amount of the solid content of the components (a) and (B) (that is, when the total solid content of the components (a) and (B) excluding the solvent is 100 mass%). (A1) When the content of the component (b) is 20% by mass or more, the heat resistance of the resin composition can be further improved. On the other hand, when the content of the component (a1) is 80 mass% or less, the resin composition can be easily molded into a sheet shape.

(C) inorganic Filler)

In the present embodiment, the resin composition preferably contains (C) an inorganic filler (hereinafter, may be simply referred to as "component (C)") in addition to the component (a) and the component (B). The component (C) can lower the linear expansion coefficient of the resin composition and can increase the storage modulus of the resin composition.

Examples of the (C) inorganic filler include: silica filler, alumina filler, boron nitride filler, and the like. Among them, silica fillers are preferable.

Examples of silica fillers include: fused silica, spherical silica, and the like.

(C) The inorganic filler may be used alone in 1 kind, or in combination of 2 or more kinds. In addition, (C) the inorganic filler may be surface-treated.

(C) The average particle diameter of the inorganic filler is not particularly limited. The average particle diameter of the (C) inorganic filler is preferably 0.1nm or more and 100 μm or less, more preferably 10nm or more and 10 μm or less, as determined by a typical particle size distribution tester. The average particle diameter of the inorganic filler (C) in the present specification is a value measured by a dynamic light scattering method using a particle size distribution measuring apparatus (product name "nanosrack Wave-UT 151" manufactured by japanese unexamined patent publication).

The content of the inorganic filler (C) in the resin composition is preferably 10 mass% or more and 90 mass% or less, and more preferably 20 mass% or more and 80 mass% or less, based on the total amount of solid content of the resin composition (that is, when all solid content except the solvent is taken as 100 mass%).

An example of the resin sheet of the present embodiment is a resin sheet formed of a resin composition containing only (a) a thermosetting component, (B) a binder component, and (C) an inorganic filler.

As another example of the resin sheet of the present embodiment, a resin sheet formed of a resin composition containing (a) a thermosetting component, (B) a binder component, (C) an inorganic filler, and components other than the components (a) to (C) is mentioned below.

(other Components)

In the present embodiment, the resin composition may further contain at least one component selected from a coupling agent, a crosslinking agent, a pigment, a dye, an antifoaming agent, a leveling agent, an ultraviolet absorber, a foaming agent, an antioxidant, a flame retardant, and an ion scavenger.

For example, the resin composition may contain a coupling agent.

Silanes (silane coupling agents) are preferred as the coupling agent because of their versatility, cost advantage, and the like. These may be used alone in 1 kind, or in combination of 2 or more kinds.

In addition, the resin composition may further contain a crosslinking agent in order to adjust initial adhesiveness and cohesiveness before curing.

Examples of the crosslinking agent include: organic polyisocyanate compounds and organic polyimine compounds. These crosslinking agents may be used alone in 1 kind, or in combination with 2 or more kinds.

Examples of the organic polyisocyanate compound include: aromatic polyisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, and trimer of these polyisocyanate compounds, and isocyanate-terminated urethane prepolymers obtained by reacting these polyisocyanate compounds with polyol compounds.

As more specific examples of the organic polyisocyanate compound, there may be mentioned, for example: 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, 1, 3-xylylene diisocyanate, 1, 4-xylylene diisocyanate, diphenylmethane-4, 4 '-diisocyanate, diphenylmethane-2, 4' -diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4, 4 '-diisocyanate, dicyclohexylmethane-2, 4' -diisocyanate, lysine isocyanate, and the like.

Specific examples of the organic polyimine compound include, for example: n, N ' -diphenylmethane-4, 4 ' -bis (1-aziridinecarboxamide), trimethylolpropane tris (. beta. -aziridinyl) propionate, tetramethylolmethane tris (. beta. -aziridinyl) propionate, and N, N ' -toluene-2, 4-bis (1-aziridinylcarboxamide) triethylenemelamine.

The crosslinking agent is usually blended in a proportion of 0.01 to 12 parts by mass, preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the binder component (B).

The excellent heat resistance of the resin sheet of the present embodiment can be expressed, for example, by measuring the storage modulus E' after curing. The storage modulus E' of the resin sheet of the present embodiment after curing is preferably 1.0 × 10 at a temperature of 250 ℃²MPa or more, more preferably 2.0X 10²Is more than MPa. It is considered that if the storage modulus E' at a temperature of 250 ℃ is in the above range, the reliability of the package can be improved even in the case of a package or the like preferably used for a GaN or SiC-based power semiconductor element which is operated at a high temperature of 200 ℃ or higher without excessively softening a cured product in applications used at a high temperature. The upper limit of the storage modulus E' at a temperature of 250 ℃ after curing is not particularly limited, but is preferably 2.0X 10³MPa or less, more preferably 1.0X 10³MPa or less, more preferably 0.8X 10³MPa or less.

The storage modulus E' of the resin sheet after curing can be measured by the method described in examples.

The storage modulus E' after curing can be brought to the above range by, for example, preparing the components or compounding amounts for the resin composition.

The resin sheet of the present embodiment is preferably used for a semiconductor element. Specifically, the resin sheet of the present embodiment is preferably used for encapsulating a semiconductor element. The resin sheet of the present embodiment is preferably used to be sandwiched between a semiconductor element and another electronic component.

The semiconductor element is preferably a power semiconductor.

The resin sheet of the present embodiment is preferably used for encapsulating a semiconductor element using any 1 or more of silicon carbide and gallium nitride, or for sandwiching between a semiconductor element using any 1 or more of silicon carbide and gallium nitride and another electronic component.

Examples of other electronic components include: printed wiring boards, lead frames, and the like.

[ laminate ]

The laminate includes a support sheet, and the resin sheet of the present embodiment is provided on the support sheet.

The laminate preferably has a resin sheet formed between the first support sheet and the second support sheet.

The support sheet is preferably a release material. The first support sheet and the second support sheet may be used to improve the workability in conveying the resin sheet or to prevent foreign matter from being mixed in during operations such as slitting or punching performed while being in close contact with one surface of the resin.

Fig. 1 shows a schematic cross-sectional view of a laminate 1 of the present embodiment.

The laminate 1 of the present embodiment includes a first release material 2, a second release material 4, and a resin sheet 3 of the present embodiment provided between the first release material 2 and the second release material 4.

The first release material 2 and the second release material 4 preferably have releasability, and the peel force of the first release material 2 to the resin sheet 3 is different from the peel force of the second release material 4 to the resin sheet 3. The material of the first release member 2 and the second release member 4 is not particularly limited. The ratio (P2/P1) of the peel force P2 of the second release material 4 to the peel force P1 of the first release material 2 is preferably 0.02. ltoreq. P2/P1 < 1 or 1 < P2/P1. ltoreq.50.

The first release material 2 and the second release material 4 may be, for example, members having releasability of the release material itself, members subjected to a release treatment, or members having a release agent layer laminated thereon. When the first release liner 2 and the second release liner 4 are not subjected to the release treatment, examples of the material include an olefin resin and a fluororesin.

The first release material 2 and the second release material 4 may be release materials each including a release base material and a release agent layer formed by applying a release agent to the release base material. By forming the release material having the release base and the release agent layer, handling is facilitated. The first release material 2 and the second release material 4 may have a release agent layer only on one surface of the release base material, or may have release agent layers on both surfaces of the release base material.

Examples of the release substrate include: a paper substrate, a laminated paper in which a thermoplastic resin such as polyethylene is laminated on the paper substrate, and a plastic film. Examples of the paper substrate include: cellophane, coated paper, cast-coated paper, and the like. Examples of the plastic film include: polyester films (e.g., polyethylene terephthalate, polybutylene naphthalate, etc.), polyolefin films (e.g., polypropylene, polyethylene, etc.), and the like. Among them, a polyester film is preferable.

Examples of the release agent include: a silicone release agent composed of a silicone resin; long-chain alkyl group-containing compound-based release agents composed of long-chain alkyl group-containing compounds such as polyvinyl urethane and alkylurea derivatives; alkyd resin-based release agents composed of alkyd resins (e.g., non-convertible alkyd resins, etc.); olefin resin-based release agents composed of olefin resins (for example, crystalline polypropylene resins such as polyethylene (for example, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and the like), propylene homopolymers having an isotactic structure or a syndiotactic structure, and propylene- α -olefin copolymers); rubber-based release agents composed of rubbers such as natural rubber and synthetic rubber (for example, butadiene rubber, isoprene rubber, styrene-butadiene rubber, methyl methacrylate-butadiene rubber, and nitrile rubber); and various release agents such as acrylic resin release agents composed of an acrylic resin such as a (meth) acrylate copolymer, and these release agents may be used alone in 1 kind or in combination in 2 or more kinds. Among them, silicone-based release agents are preferable.

The resin sheet 3 of the present embodiment has low viscosity at normal temperature, and it is difficult to control the peeling force of the first peeling member 2 and the second peeling member 4. In order to easily control the ratio of the peeling force P2 of the second release material 4 to the peeling force P1 of the first release material 2 (P2/P1) in the above range, for example, the first release material 2 preferably includes a release base and a release agent layer formed by applying a silicone-based release agent to the release base, and the second release material 4 preferably includes a release base and a release agent layer formed by applying an alkyd-based release agent to the release base.

The thicknesses of the first release material 2 and the second release material 4 are not particularly limited. Usually 1 to 500 μm, preferably 3 to 100 μm.

The thickness of the release agent layer is not particularly limited. When a solution containing a release agent is applied to form a release agent layer, the thickness of the release agent layer is preferably 0.01 μm or more and 3 μm or less, and more preferably 0.03 μm or more and 1 μm or less.

[ method for producing resin sheet ]

The method for producing a resin sheet according to the present embodiment is a method for producing the resin sheet 3, and includes the steps of: a step (1) of dissolving a resin composition in a solvent to prepare a resin composition solution; a step (2) of applying the resin composition solution to a support sheet; and a step (3) of drying the applied resin composition solution to produce a resin sheet 3.

Preferably, the support sheet is the first release material 2, and the method further includes a step (4) of bonding the second release material 4 to the resin sheet 3.

In the step (1), a resin composition solution is prepared by dissolving the resin composition in a solvent.

The solvent used here is not particularly limited as long as it is a solvent that uniformly dissolves the resin composition, and from the viewpoint of volatility and solubility of the maleimide resin, methyl ethyl ketone, cyclohexanone, a mixed solvent thereof, or the like is preferable.

In the step (2), the resin composition solution is applied to the first surface of the first release material 2.

The coating method is not particularly limited, and examples thereof include: a bar coating method, a reverse roll coating method, a blade coating method, a roll blade coating method, a gravure coating method, an air knife coating method, a blade coating method, and the like.

Preferably for a given time after application. The standing time at this time is preferably about 300 seconds at maximum.

In step (3), the resin composition solution applied is dried to produce a resin sheet 3.

The drying conditions are not particularly limited, and vary depending on the solvent used. For example, the drying temperature is preferably 80 ℃ or higher and 120 ℃ or lower. The drying time is preferably 10 seconds to 10 minutes.

The thickness of the resin sheet 3 after drying is not particularly limited, but is usually preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 400 μm or less, and further preferably 300 μm or less.

In the step (4), the second release material 4 is bonded to the resin sheet 3. This makes it possible to produce the laminate 1 including the resin sheet 3 of the present embodiment.

[ semiconductor device ]

The semiconductor device of the present embodiment includes a semiconductor element encapsulated with the resin sheet of the present embodiment.

The semiconductor element package using the resin sheet of the present embodiment can be performed, for example, as follows. The semiconductor element is encapsulated by placing a resin sheet so as to cover the semiconductor element and pressure-bonding the resin sheet by a vacuum lamination method.

In the case of using the laminate 1 of the present embodiment, after one release material of the laminate 1 is peeled, a resin sheet is placed so as to cover the semiconductor element. Then, another release material is peeled off. Then, the semiconductor element is sealed by pressure bonding by a vacuum lamination method.

The semiconductor element using the resin sheet of the present embodiment can be bonded to another electronic component as follows, for example. After a resin sheet is placed on another electronic component and a semiconductor element is further placed on the resin sheet, the resin composition and the semiconductor element are temporarily pressed against each other and heated to be cured. Thus, the resin composition is sandwiched between the semiconductor element and another electronic component, and the semiconductor element and the other electronic component are bonded.

[ Effect of the embodiment ]

According to the resin sheet and the method for producing the resin sheet of the present embodiment, both sheet formability and heat resistance can be achieved.

In the semiconductor device of the present embodiment, the semiconductor element is preferably a power semiconductor element. The power semiconductor element is supposed to operate at a high temperature of 200 ℃. Materials used in semiconductor devices having power semiconductor elements are required to have heat resistance. The resin sheet of the present embodiment has excellent heat resistance, and can be preferably used for covering a power semiconductor element or sandwiching the power semiconductor element and another member in a semiconductor device.

As described above, the resin composition of the present embodiment can be preferably used for a power semiconductor element. In other words, in the semiconductor device of the present embodiment, the semiconductor element is preferably a power semiconductor element. The power semiconductor element is supposed to operate at a high temperature of 200 ℃. Materials used in semiconductor devices having power semiconductor elements are required to have heat resistance. The resin composition and the resin sheet of the present embodiment have excellent heat resistance, and can be preferably used for covering a power semiconductor element or sandwiching the power semiconductor element and another member in a semiconductor device.

As described above, the resin composition of the present embodiment can be preferably used for a semiconductor device using 1 or more kinds of silicon carbide and gallium nitride. In other words, in the semiconductor device of the present embodiment, the semiconductor element preferably uses 1 or more kinds of semiconductor elements selected from silicon carbide and gallium nitride. Since a semiconductor element using 1 or more of silicon carbide and gallium nitride has characteristics different from those of an organic silicon semiconductor, the semiconductor element can be preferably used for applications such as a power semiconductor, a high-output power device for a base station, a sensor, a detector, and a schottky barrier diode. In these applications, the resin composition and the resin sheet of the present embodiment are excellent in heat resistance in view of the heat resistance of the semiconductor element using any 1 or more of silicon carbide and gallium nitride, and therefore can be preferably used in combination with the semiconductor element using any 1 or more of silicon carbide and gallium nitride.

[ variation of embodiment ]

The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a range in which the object of the present invention can be achieved are also included in the present invention.

In the above embodiment, the description has been given of the laminate having the first release material, the second release material, and the resin sheet provided between the first release material and the second release material, and the laminate may have the release material only on one surface of the resin sheet.

In addition, although the above embodiment has been described for the semiconductor package application, the resin sheet of the present invention may be used as an insulating material for a circuit board (for example, a hard printed wiring board material, a material for a flexible wiring board, an interlayer insulating material for a build-up (build-up) board, and the like), an adhesive film for a build-up, an adhesive, and the like.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

[ R of Maleimide resin_HSPCalculation of values]

R of the following maleimide resin was calculated_HSPThe value is obtained.

BMI resin-1: bis (3-ethyl-5-methyl-4-maleimidophenyl) methane

BMI resin-2: 2, 2-bis [4- (4-maleimidophenoxy) phenyl ] propane

BMI resin-3: polyphenyl methane maleimide

BMI resin-4: 4, 4' -diphenylmethane bismaleimide

First, 20 mass% solutions of the above maleimide resins were prepared for the 25 solvents shown in table 1. After the solution was allowed to stand for 6 hours, it was classified into a solvent capable of dissolving the maleimide resin (of the BMI resin) and a solvent incapable of dissolving the maleimide resin. In table 1, a case where BMI resin can be dissolved is referred to as "a", and a solvent in which BMI resin cannot be dissolved is referred to as "B".

[ Table 1]

Based on the results of Table 1 above, R of the maleimide resin was calculated_HSPThe values are shown in Table 2. R_HSPThe HSP calculation software "HSPiP ver 4.0" was used for the calculation of the values.

Specifically, the above-described dissolution test results of the maleimide resin were inputted into the software, and hansen-dissolved spheres of the maleimide resin were plotted on a 3D graph. The center of the Hansen-dissolved sphere is HSP value of maleimide resin, and the radius of the sphere is R_HSPIs derived from the form of (c).

[ Table 2]

	BMI resin-1	BMI resin-2	BMI resin-3	BMI resin-4
					R_HSP	8.0	7.8	10.0	2.3

From the above results, R in BMI resin-1, BMI resin-2 and BMI resin-3 was found_HSPThe value was higher than that of BMI resin-4.

[ preparation of resin composition ]

Resin compositions of examples 1 to 7 and comparative examples 1 to 2 were prepared at the blending ratios (mass% (ratio in terms of solid content)) shown in table 3.

The materials used for the preparation of the resin composition are as follows.

(thermosetting component)

BMI resin-1: bis (3-ethyl-5-methyl-4-maleimidophenyl) methane ("BMI-70" manufactured by K.I Chemical Industry Co.)

BMI resin-2: 2, 2-bis [4- (4-maleimidophenoxy) phenyl ] propane ("BMI-80" manufactured by K.I Chemical Industry Co.)

BMI resin-3: phenylmethanemaleimides (BMI-2300, manufactured by Dahe Kasei Kogyo Co., Ltd.)

BMI resin-4: 4, 4' -Diphenylmethanebismaleimide ("BMI-1000" manufactured by K.I Chemical Industry Co.)

Allyl resin: diallyl bisphenol A ("DABPA" manufactured by Dahe chemical industry Co., Ltd.)

(Binder component)

Phenoxy resin: BisA/BisF mixed phenoxy resin ("ZX-1356-2" manufactured by Nippon Tekken chemical Co., Ltd., weight average molecular weight 65,000)

Polyamideimide resin: polyamideimide resin of Main skeleton ("ACX-2" manufactured by Toyo Boseki Co., Ltd., weight-average molecular weight 10,000)

(inorganic Filler)

Silica filler: fused silica (modified with epoxy silane, average particle diameter 0.5 μm, maximum particle diameter 2.0 μm) ("SC 2050 MA" manufactured by Admatechs Co., Ltd.)

[ production of resin sheet ]

A resin varnish (coating solution prepared by dissolving a resin composition in methyl ethyl ketone at a solid content concentration of 40 mass%) was applied to a first release material (polyethylene terephthalate having a release layer formed from an alkyd resin-based release agent and having a thickness of 38 μm) by a die coater so that the thickness of a resin sheet formed from the dried resin composition was 20 μm, and the resin sheet was dried at 100 ℃ for 2 minutes. Immediately after being taken out from the drying oven, the resin sheet formed of the dried resin composition was bonded to a second release material (polyethylene terephthalate provided with a release layer formed of a silicone-based release agent, having a thickness of 38 μm) at room temperature, to prepare a laminate in which the first release material, the resin sheet formed of the resin composition, and the second release material were laminated in this order.

As the solvent for the resin varnish, a mixed solvent of 80 mass%/20 mass% of methyl ethyl ketone/cyclohexanone was used in examples 2, 3 and 4, and a methyl ethyl ketone solvent was used in examples 1, 5, 6 and 7.

< evaluation of resin composition before curing >

[ film Forming Property ]

In the production of the above-described resin sheet, the obtained resin varnish was applied to the first release material so as to be 20 μm, and whether or not the film could be formed by appropriately spreading the resin varnish on the first release material with wetting. The case where a uniform film of 20 μm was formed was evaluated as "A", and the case where the film could not be formed due to insufficient solubility in a solvent or the like was evaluated as "B".

[ Complex viscosity and elastic modulus ]

The obtained resin composition was applied to a release material and dried at 100 ℃ for 2 minutes to prepare a resin sheet having a thickness of 20 μm. 2 sheets of the resin sheets were laminated to prepare a 40 μm thick resin sheet laminate. Further, 2 sheets of the resin sheet laminate were laminated to prepare an 80 μm resin sheet laminate, and this procedure was repeated to prepare a measurement sample having a thickness of 1280 μm. The complex viscosity (unit: pas) and the elastic modulus G' (unit · Pa) at 30 ℃ of the measurement sample were measured by the following measurement instrument and under the measurement conditions. The obtained results are shown in table 3.

The measurement instrument: viscoelasticity measuring apparatus, "MCR 301", manufactured by Anton Paar "

Measurement conditions: the frequency is 1Hz, the temperature range is 30-150 ℃, and the heating speed is 5 ℃/min

< evaluation of the resin composition after curing > [ storage modulus E' ]

The obtained resin composition was applied to a release material and dried at 100 ℃ for 2 minutes to prepare a resin sheet having a thickness of 20 μm. 10 pieces of the resin sheet were laminated to a thickness of 200 μm, and then peeled from the release material to prepare a sample. The sample was cured under the above-mentioned thermosetting conditions (temperature 200 ℃ C., 4 hours) to prepare a sample for measurement. The storage modulus E' (unit: MPa) at 250 ℃ was measured using "DMA Q800" manufactured by TAInstructions corporation under conditions of a temperature rise rate of 3 ℃/min, a temperature range of 30 to 300 ℃ and a frequency of 11 Hz. The obtained results are shown in table 3. The resin compositions of comparative examples 1 and 2 could not be measured because a film could not be formed.

It was confirmed that the resin sheets of examples 1 to 7 have both sheet formability and heat resistance. On the other hand, the resin compositions of comparative examples 1 and 2 had poor sheet formability, and a resin sheet could not be produced. The resin compositions of examples 1 to 7 have high storage modulus and good heat resistance after thermosetting, and thus are considered to be suitable for the production of power modules.

Claims

1. A resin sheet comprising a resin composition, wherein,

the resin composition contains (A) a thermosetting component and (B) a binder component,

the thermosetting component (A) contains a maleimide resin (A1),

the radius R of the Hansen solubility sphere of the (A1) maleimide resin calculated from the Hansen solubility parameter value_HSPIs 3.0 to 15.0 inclusive,

the binder component (B) is at least one resin selected from the group consisting of phenoxy resins, polyamideimide resins, and wholly aromatic polyester resins.

2. The resin sheet according to claim 1, wherein the resin composition further contains (C) an inorganic filler.

3. The resin sheet according to claim 1, wherein the resin composition has a complex viscosity η of 5.0 x 10 at 30 ℃ before curing⁶Pa · s or more and 5.0X 10⁹Pa · s or less.

4. The resin sheet according to claim 1, which is used for encapsulating a power semiconductor element, or is sandwiched between the power semiconductor element and other electronic components.

5. The resin sheet according to claim 1, wherein the resin sheet is used for encapsulating a semiconductor element using any one or more of silicon carbide and gallium nitride, or is sandwiched between the semiconductor element using any one or more of silicon carbide and gallium nitride and another electronic component.

6. The resin sheet according to claim 1, wherein the resin composition is curedThe storage modulus E' at 250 ℃ is then 1.0X 10²2.0X 10 MPa or more³MPa or less.

7. The resin sheet according to claim 1, wherein the weight average molecular weight of the (B) adhesive component is 1 ten thousand or more and 10 ten thousand or less.

8. The resin sheet according to claim 1, wherein the content of the binder component (B) in the resin composition is 0.1 mass% or more and 50 mass% or less based on the total amount of solid components in the resin composition.

9. The resin sheet according to any one of claims 1 to 8, wherein the thickness of the resin sheet is 10 μm or more and 500 μm or less.

10. A laminate, comprising:

a support sheet, and

the resin sheet according to any one of claims 1 to 9 formed on the support sheet.

11. The laminate according to claim 10, wherein,

the support sheet is a first release material,

the resin sheet is further provided with a second release material.

12. A method for producing a resin sheet containing a resin composition, the method comprising:

a step (1) for dissolving the resin composition in a solvent to prepare a resin composition solution;

a step (2) of applying the resin composition solution to a support sheet;

a step (3) of drying the resin composition solution after coating to produce a resin sheet,

the thermosetting component (A) contains a maleimide resin (A1),

13. The method of manufacturing a resin sheet according to claim 12, wherein,

the support sheet is a first release material,

the method further comprises a step (4) of bonding a second release material to the resin sheet.

14. The method of manufacturing a resin sheet according to claim 12 or claim 13, wherein,

the solvent is methyl ethyl ketone, cyclohexanone or a mixed solvent thereof.