CN113795560A

CN113795560A - Adhesive for semiconductor, method for manufacturing semiconductor device, and semiconductor device

Info

Publication number: CN113795560A
Application number: CN202080023019.1A
Authority: CN
Inventors: 茶花幸一; 秋吉利泰; 林出明子; 佐藤慎
Original assignee: Showa Denko KK
Current assignee: Resonac Holdings Corp
Priority date: 2019-03-26
Filing date: 2020-03-23
Publication date: 2021-12-14
Also published as: WO2020196430A1; TW202039760A; JPWO2020196430A1; KR20210143720A

Abstract

The invention provides an adhesive for a semiconductor, which contains resin with the weight average molecular weight less than 10000, a curing agent, an inorganic filler and a silicone rubber filler.

Description

Adhesive for semiconductor, method for manufacturing semiconductor device, and semiconductor device

Technical Field

The present invention relates to an adhesive for a semiconductor, a method for manufacturing a semiconductor device, and a semiconductor device.

Background

Conventionally, wire bonding (wire bonding) methods using a thin metal wire such as a gold wire have been widely used for connecting a semiconductor chip (chip) and a substrate. On the other hand, in response to demands for higher functionality, higher integration, higher speed, and the like of semiconductor devices, a flip chip connection method (FC connection method) has been developed in which conductive bumps called bumps (bumps) are formed on a semiconductor chip or a substrate to directly connect the semiconductor chip and the substrate.

As an FC connection method, a method of metal-bonding a connection portion using solder, tin, gold, silver, copper, or the like is known; a method of applying ultrasonic vibration to metal-bond the connection portion; and a method of maintaining mechanical contact by a contraction force of the resin. However, from the viewpoint of reliability of the connection portion, a method of metal-bonding the connection portion using solder, tin, gold, silver, copper, or the like is generally employed.

For example, as for the connection between a semiconductor Chip and a substrate, a Chip On Board (COB) type connection method widely used in BGA (Ball grid Array) and CSP (Chip Size Package) is also equivalent to the FC connection method. The FC connection method is also widely used for a COC (Chip On Chip) type connection method in which a connection portion (bump or wiring) is formed On a semiconductor Chip to connect semiconductor chips (for example, refer to patent document 1).

Further, among the packages strongly required to be further miniaturized, thinned and highly functional, a chip stack Package, a POP (Package On Package), a TSV (Through-Silicon Via), and the like, in which the above connection systems are laminated and multilayered, have also come into wide use. Since the semiconductor chips and the like are three-dimensionally arranged by such a lamination/multilayer technique, the package size can be reduced as compared with a method of two-dimensionally arranging them. Such a lamination/multilayer technique is effective for improving the performance of semiconductors, reducing noise, reducing the mounting area, and saving power, and therefore has attracted attention as a next-generation semiconductor wiring technique.

In addition, from the viewpoint of improving productivity, attention is paid to COW (Chip On Wafer) in which semiconductor chips are bonded (connected) to a semiconductor Wafer and then singulated to produce a semiconductor package, and WOW (Wafer On Wafer) in which semiconductor wafers are bonded (connected) to each other and then singulated to produce a semiconductor package. From the same viewpoint, a multi-terminal bonding (gan bonding) method is also attracting attention, in which a plurality of semiconductor chips are aligned on a semiconductor wafer or a mapping substrate and temporarily bonded, and then the plurality of semiconductor chips are collectively and formally bonded to ensure connection.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2008-294382

Disclosure of Invention

Technical problem to be solved by the invention

In flip chip packaging, stress may be generated due to a difference in thermal expansion coefficient between the adhesive for semiconductor and the semiconductor chip and between the semiconductor chip and the substrate, and warpage may occur in the packaging. With the film formation of semiconductor chips and semiconductor wafers, warpage of the package is more likely to occur.

In the stacked and multilayered chip stack package, warpage tends to increase compared to a chip stack package of one layer.

Due to the warpage of the package, problems such as failure of secondary molding (overmolding) and occurrence of poor connection of the package are likely to occur. Therefore, low warpage of the package is strongly demanded.

Here, as a method for reducing warpage of a package, it is conceivable to reduce elasticity of an adhesive for a semiconductor. As a method for lowering the elasticity of the adhesive for a semiconductor, a method of lowering the glass transition temperature of the polymer component, a method of reducing the addition amount of the inorganic filler, a method of increasing the addition amount of the organic filler, and the like can be considered. However, when the adhesive for a semiconductor is made less elastic by these methods, it is difficult to deteriorate the workability of the adhesive for a semiconductor and to appropriately change the melt viscosity, and it is difficult to achieve both of these characteristics and the reduction of warpage of the package.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an adhesive for a semiconductor, a method for manufacturing a semiconductor device using the adhesive for a semiconductor, and a semiconductor device, which can suppress a decrease in adhesion and reliability and can reduce warpage of the obtained package.

Means for solving the technical problem

In order to achieve the above object, the present invention provides an adhesive for a semiconductor, which contains a resin having a weight average molecular weight of less than 10000, a curing agent, an inorganic filler and a silicone rubber filler. According to the adhesive for a semiconductor, by using an inorganic filler and a silicone rubber filler in combination as fillers, it is possible to suppress a decrease in adhesion and reliability and to reduce warpage of the obtained package. In particular, by using a silicone rubber filler as an organic filler in combination with an inorganic filler, warpage of the resulting package can be greatly reduced.

The average particle diameter of the silicone rubber filler may be 30 μm or less. In this case, the warpage of the resulting package can be further reduced while more sufficiently suppressing the decrease in adhesion and reliability.

The inorganic filler may contain a silica filler. In this case, the adhesive force and reliability can be further improved. Further, the inorganic filler and the silicone rubber filler are more easily and uniformly dispersed, and good adhesion and reliability can be achieved at a higher level, and the warpage of the resulting package can be reduced.

The adhesive for semiconductors may contain a polymer component having a weight average molecular weight of 10000 or more. In this case, the adhesive for a semiconductor can have improved heat resistance and film formability.

The weight average molecular weight of the polymer component may be 30000 or more. The glass transition temperature of the polymer component may be 100 ℃ or lower. When the weight average molecular weight is 30000 or more, film formability is improved. When the glass transition temperature is 100 ℃ or lower, the adhesiveness to the substrate and the semiconductor chip becomes good.

The adhesive for semiconductor may be in the form of a film. In this case, the handling property of the adhesive for a semiconductor can be improved, and the workability and productivity in manufacturing a package can be improved.

The content of the silicone rubber filler in the adhesive for a semiconductor may be 0.1 to 20% by mass based on the total solid content of the adhesive for a semiconductor. In this case, good adhesion and reliability can be achieved at a higher level, and the resulting package can be reduced in warpage.

In the adhesive for a semiconductor, a mass ratio of the content of the silicone rubber filler to the content of the inorganic filler (mass of silicone rubber filler/mass of inorganic filler) may be 0.05 to 0.5. In this case, good adhesion and reliability can be achieved at a higher level, and the resulting package can be reduced in warpage.

Further, the present invention provides a method for manufacturing a semiconductor device in which connection portions of a semiconductor chip and a printed circuit board are electrically connected to each other, or a semiconductor device in which connection portions of a plurality of semiconductor chips are electrically connected to each other, the method comprising: and sealing at least a part of the connection portion with the adhesive for semiconductor. According to the above manufacturing method, a semiconductor device having excellent adhesion between the semiconductor chip and the printed circuit board or the semiconductor chip, excellent reliability, and reduced warpage can be obtained.

Further, the present invention provides a semiconductor device including: a connection structure in which respective connection portions of the semiconductor chip and the printed circuit board are electrically connected to each other, or a connection structure in which respective connection portions of the plurality of semiconductor chips are electrically connected to each other; and an adhesive material for sealing at least a part of the connection portion, the adhesive material being formed of a cured product of the adhesive for a semiconductor. The semiconductor device is excellent in adhesion between the semiconductor chip and the printed circuit board or the semiconductor chip, reliability, and reduced in warpage.

Effects of the invention

According to the present invention, it is possible to provide an adhesive for a semiconductor, which can realize a low warpage of the obtained package while suppressing a decrease in adhesion and reliability, and a method for manufacturing a semiconductor device and a semiconductor device using the adhesive for a semiconductor.

Drawings

Fig. 1 is a schematic cross-sectional view showing one embodiment of a semiconductor device of the present invention.

Fig. 2 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention.

Fig. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings as appropriate.

In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted. Unless otherwise specified, the positional relationship such as vertical, horizontal, and the like is based on the positional relationship shown in the drawings.

The dimensional ratios in the drawings are not limited to the illustrated ratios.

In the present specification, a numerical range represented by "to" means a range in which numerical values before and after "to" are included as a minimum value and a maximum value, respectively. In the numerical ranges recited in the present specification, the upper limit or the lower limit of the numerical range in one stage may be arbitrarily combined with the upper limit or the lower limit of the numerical range in another stage. In the numerical ranges described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples. The term "a" or "B" may include both a and B, as long as both a and B are included. Unless otherwise specified, the materials mentioned in the present specification may be used singly or in combination of two or more. In the present specification, "(meth) acrylic acid" means acrylic acid or methacrylic acid corresponding thereto.

< adhesive for semiconductor >

The binder for a semiconductor of the present embodiment contains a resin having a weight average molecular weight of less than 10000 (hereinafter referred to as "component (a)" in some cases), a curing agent (hereinafter referred to as "component (b)" in some cases), an inorganic filler (hereinafter referred to as "component (e)" in some cases), and an organic filler (hereinafter referred to as "component (f)" in some cases). The adhesive for semiconductors of the present embodiment contains a silicone rubber filler as an organic filler. The adhesive for a semiconductor of the present embodiment contains a polymer compound having a weight average molecular weight of 10000 or more (hereinafter referred to as "component (c)" in some cases) and/or a flux (hereinafter referred to as "component (d)" in some cases) as necessary. Hereinafter, each component will be described.

(a) Resin with weight average molecular weight less than 10000

The component (a) is not particularly limited, but is preferably a component that reacts with the curing agent of the component (b) from the viewpoint of heat resistance. The component (a) preferably has two or more reactive groups in the molecule. Examples of the component (a) include: epoxy resin, phenol resin, imide resin, urea resin, melamine resin, silicone resin, (meth) acrylic compound, vinyl compound. Among them, from the viewpoint of excellent heat resistance and storage stability, epoxy resins, phenol resins, and imide resins are preferable, and epoxy resins and imide resins are more preferable. These components (a) may be used alone or as a mixture or copolymer of two or more kinds.

The epoxy resin is not particularly limited as long as it has two or more epoxy groups in the molecule, and examples thereof include: epoxy resins such as bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type, and dicyclopentadiene type, and various polyfunctional epoxy resins. The epoxy resin may be used singly or in combination of two or more. Among them, bisphenol F type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, and triphenylmethane type epoxy resins are preferable from the viewpoint of heat resistance and workability.

The imide resin is not particularly limited as long as it has two or more imide groups in the molecule, and examples thereof include: naphthalene diimide resins, allyl naphthalene diimide resins, maleimide resins, amide imide resins, imide acrylate resins, various polyfunctional imide resins, and various polyimide resins. The imide resin may be used singly or in combination of two or more.

From the viewpoint of suppressing generation of volatile components due to decomposition at the time of connection at a high temperature, when the temperature at the time of connection is 250 ℃, it is preferable to use a resin having a thermal weight loss rate of 5% or less at 250 ℃ as the component (a), and when the temperature at the time of connection is 300 ℃, it is preferable to use a resin having a thermal weight loss rate of 5% or less at 300 ℃.

When an epoxy resin is used as the component (a), the 1% heat weight loss temperature of a bisphenol a type or bisphenol F type liquid epoxy resin is 250 ℃ or lower, and therefore, the epoxy resin may be decomposed and volatile components may be generated when heated at high temperatures. Therefore, an epoxy resin which is solid at room temperature (1 atmosphere, 25 ℃) is preferably used. When a liquid epoxy resin is used, it is preferably used in combination with a solid epoxy resin.

(a) The weight average molecular weight of the component (b) is less than 10000, but is preferably less than 10000 from the viewpoint of film formation, and is preferably 100 or more from the viewpoint of optimization of melt viscosity.

Therefore, the weight average molecular weight of the component (a) is preferably 100 or more and less than 10000, more preferably 300 or more and 8000 or less, and further preferably 300 or more and 5000 or less.

The content of the component (a) is, for example, 5 to 75 mass%, preferably 15 to 60 mass%, and more preferably 30 to 50 mass% based on the total solid content of the adhesive for a semiconductor. When the content of the component (a) is 5% by mass or more, the adhesive force and reliability are excellent, and when the content is 75% by mass or less, the cured product is prevented from becoming too hard, and warpage of the package is easily reduced.

(b) Curing agent

Examples of the curing agent (b) include: a phenolic resin curing agent, an acid anhydride curing agent, an amine curing agent, an imidazole curing agent, and a phosphine curing agent. When the component (b) contains a phenolic hydroxyl group, an acid anhydride, an amine or an imidazole, the fluxing activity for suppressing the formation of an oxide film in the connecting portion is exhibited, and the connection reliability and the insulation reliability can be improved. The curing agents are described below.

(b-i) phenolic resin curing agent

The phenolic resin curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule, and it can be used: phenol novolac resins, cresol novolac resins, phenol aralkyl resins, cresol naphthol formaldehyde condensation polymers, triphenylmethane type multifunctional phenol resins, various multifunctional phenol resins, and the like. These can be used alone or as a mixture of two or more. Further, since the liquid phenol resin may be decomposed to generate volatile components when heated at high temperature, it is preferable to use a phenol resin which is solid at room temperature (1 atm, 25 ℃).

The equivalent ratio of the phenolic resin curing agent (b-i) to the component (a) (the molar ratio of phenolic hydroxyl groups/(reactive groups of the component (a)) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of improving curability, adhesion, storage stability, and the like. When the equivalent ratio is 0.3 or more, curability tends to be improved and adhesive force tends to be improved, and when it is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively, water absorption is suppressed to be low, and insulation reliability tends to be improved. Since the phenolic hydroxyl group shows fluxing activity without an oxide film, the phenolic resin-based curing agent is contained in the binder for a semiconductor, whereby the connectivity and reliability can be improved.

(b-ii) acid anhydride curing agent

Examples of the acid anhydride curing agent include: methylcyclohexane tetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride ester, and the like. These can be used alone or as a mixture of two or more. Further, since liquid acid anhydride may be decomposed to generate volatile components when heated at high temperature, it is preferable to use acid anhydride which is solid at room temperature (1 atm, 25 ℃).

The equivalent ratio of the (b-ii) acid anhydride curing agent to the component (a) (the molar ratio of acid anhydride groups/(reactive groups of the component (a)) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of improving curability, adhesion, storage stability, and the like. When the equivalent ratio is 0.3 or more, curability tends to be improved and adhesive force tends to be improved, and when it is 1.5 or less, unreacted acid anhydride does not excessively remain, water absorption is suppressed to be low, and insulation reliability tends to be improved. Since the acid anhydride exhibits fluxing activity without an oxide film, the adhesive for a semiconductor can have improved connectivity and reliability by containing an acid anhydride-based curing agent.

(b-iii) amine-based curing agent

As the amine-based curing agent, dicyanodiamine and the like can be used. Further, since liquid amine may be decomposed to generate volatile components when heated at high temperature, it is preferable to use amine which is solid at room temperature (1 atm, 25 ℃).

The equivalent ratio of the (b-iii) amine-based curing agent to the component (a) (the molar ratio of amine/(reactive groups of the component (a)) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and still more preferably 0.5 to 1.0, from the viewpoint of improving curability, adhesion, storage stability, and the like. When the equivalent ratio is 0.3 or more, curability tends to be improved and adhesive force tends to be improved, and when it is 1.5 or less, unreacted amine does not excessively remain, water absorption is suppressed to be low, and insulation reliability tends to be improved. Since the amine-based adhesive exhibits fluxing activity without an oxide film, the adhesive for a semiconductor can have improved connectivity and reliability by containing an amine-based curing agent.

(b-iv) imidazole-based curing agent (wherein the nitrogen atom contained therein is a tertiary nitrogen atom)

Examples of the imidazole-based curing agent include: 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-diamino-6- [2' -methylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -undecylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -ethyl-4 ' -methylimidazolyl- (1') ] -ethyl-s-triazine, and mixtures thereof, 2, 4-diamino-6- [2 '-methylimidazolyl- (1') ] -ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, and adduct of epoxy resin and imidazole system. Among them, from the viewpoint of satisfactory curability, adhesion, storage stability and the like, preferred are 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-diamino-6- [2' -methylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -ethyl-4 ' -methylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -methylimidazolyl- (1') ] -ethyl-s-triazine isocyanurate, and an adduct of these compounds, 2-phenylimidazole isocyanurate adduct. These can be used alone, or two or more kinds can be used in combination. In addition, a latent curing agent having enhanced latent properties by microencapsulating the above-mentioned components can also be used.

The content of the imidazole curing agent (b-iv) is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the component (a). When the content is 0.1 parts by mass or more, curability tends to be improved, and when the content is 20 parts by mass or less, the adhesive for a semiconductor does not cure before metal bonding is formed, and poor connection tends to be less likely to occur. The imidazole-based curing agent may be used alone as the curing agent (b), or may be used together with the curing agents (b-i) to (b-iii) as a curing accelerator.

(b-v) phosphine-based curing agent

Examples of the phosphine-based curing agent include: triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrakis (4-methylphenyl) borate, tetraphenylphosphonium (4-fluorophenyl) borate, etc.

The content of the (b-v) phosphine-based curing agent is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the component (a). When the content of the phosphine-based curing agent is 0.1 parts by mass or more, curability tends to be improved, and when it is 10 parts by mass or less, the film-like adhesive does not cure before the metal joint is formed, and poor connection tends to be less likely to occur.

The phenolic resin curing agent, the acid anhydride curing agent and the amine curing agent may be used singly or as a mixture of two or more kinds. The imidazole-based curing agent and the phosphine-based curing agent may be used alone or in combination with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

(c) A polymer component having a weight average molecular weight of 10000 or more

Examples of (c) the polymer component having a weight average molecular weight of 10000 or more include: phenoxy resins, polyimide resins, polyamide resins, polycarbodiimide resins, cyanate ester resins, acrylic resins, polyester resins, polyethylene resins, polyethersulfone resins, polyetherimide resins, polyvinyl acetal resins, polyurethane resins, acrylic rubbers, and the like. Among them, phenoxy resins, polyimide resins, acrylic rubbers, cyanate ester resins, polycarbodiimide resins, and the like are preferable, phenoxy resins, polyimide resins, and acrylic rubbers are more preferable, and phenoxy resins are even more preferable, from the viewpoint of excellent heat resistance and film formability. These polymer components may be used alone or as a mixture or copolymer of two or more kinds.

(c) The mass ratio of the component (a) to the component (b) is not particularly limited, and from the viewpoint of improving film formability and film formability by spin coating or the like, the total mass of the component (a) and the component (b) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and still more preferably 0.1 to 3 parts by mass, relative to 1 part by mass of the component (c). When the mass ratio is 0.01 parts by mass or more, the adhesive for a semiconductor tends to be inhibited from lowering in curability and from lowering in adhesive force, and when the mass ratio is 5 parts by mass or less, the adhesive tends to be excellent in film formability and film formability.

The polyimide resin used as the component (c) can be obtained by, for example, a condensation reaction of tetracarboxylic dianhydride and diamine by a known method. More specifically, the tetracarboxylic dianhydride and the diamine are mixed in an equimolar or approximately equimolar amount (the order of addition of the components is arbitrary) in the organic solvent, and the addition reaction is carried out at a reaction temperature of 80 ℃ or less, preferably 0 to 60 ℃. As the reaction proceeds, the viscosity of the reaction solution gradually increases, and polyamic acid as a precursor of polyimide is produced. In order to suppress the deterioration of various properties of the adhesive for semiconductors, the tetracarboxylic dianhydride is preferably subjected to a recrystallization purification treatment with acetic anhydride.

The polyamic acid can also be depolymerized by heating at a temperature of 50 to 80 ℃ to adjust its molecular weight.

The polyimide resin can be obtained by dehydration ring closure of the reaction product (polyamic acid). The dehydration ring closure can be performed by a thermal ring closure method in which heat treatment is performed or a chemical ring closure method using a dehydrating agent.

The glass transition temperature (Tg) of the component (c) is preferably 100 ℃ or lower, more preferably 75 ℃ or lower, from the viewpoint of improving the adhesion to the substrate and the semiconductor chip. When Tg is 100 ℃ or lower, it is easy to fill the irregularities such as bumps formed on a semiconductor chip or electrodes or wiring patterns formed on a substrate with a semiconductor adhesive, and it is likely that the generation of voids (void) can be suppressed by preventing the remaining of bubbles. The Tg was measured by using a differential scanning calorimeter (Perkinelmer, Inc., DSC-7 type) under conditions of a sample amount of 10mg, a temperature increase rate of 5 ℃/min, and a measurement atmosphere: tg when measured under air conditions.

(c) The weight average molecular weight of the component (a) is 10000 or more in terms of polystyrene, but is preferably 20000 or more, more preferably 30000 or more, and still more preferably 40000 or more in order to exhibit good film formability alone. When the weight average molecular weight is less than 10000, film formation properties may be reduced. In view of fluidity, the weight average molecular weight of the component (c) is, for example, 100 ten thousand or less, preferably 50 ten thousand or less.

In the present specification, the weight average molecular weight means a weight average molecular weight when measured in terms of polystyrene using high performance liquid chromatography (C-R4A manufactured by Shimadzu corporation on).

(c) The content ratio of the component (a) to the component (a) is not particularly limited, and from the viewpoint of maintaining the film shape well, the component (a) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 2 parts by mass, relative to 1 part by mass of the component (c). When the content ratio is 0.01 parts by mass or more, the adhesive for a semiconductor tends to be inhibited from lowering in curability and from lowering in adhesive force, and when the content ratio is 5 parts by mass or less, the adhesive tends to be excellent in film formability and film formability.

(d) Fluxing agent

The adhesive for a semiconductor can contain (d) a flux, that is, a flux activator which is a compound exhibiting flux activity (activity of removing an oxide and impurities). Examples of the flux include: nitrogen-containing compounds having a non-covalent electron pair such as imidazole-based compounds and amine-based compounds, carboxylic acids, phenols and alcohols. In addition, organic acids such as carboxylic acids exhibit a stronger fluxing activity than alcohols, and are likely to improve the connectivity.

The content of the component (d) is preferably 0.1 to 5% by mass, more preferably 1 to 5% by mass, based on the total solid content of the adhesive for a semiconductor, from the viewpoint of exhibiting flux activity and improving connectivity.

(e) Inorganic filler

The adhesive for semiconductors of the present embodiment contains an inorganic filler as the component (e). By containing the component (e), the viscosity of the adhesive for a semiconductor and the physical properties of the cured product can be controlled, and generation of voids and moisture absorption rate at the time of connecting the semiconductor chip and the substrate can be suppressed. Further, by containing the component (e), the adhesive for a semiconductor can obtain excellent adhesive force and can improve reliability such as reflow resistance and moisture resistance.

Examples of the component (e) include insulating inorganic fillers and whiskers. Examples of the material of the insulating inorganic filler include: glass, silica, alumina, silica-alumina, titanium oxide, mica, boron nitride and the like, among which silica, alumina, silica-alumina, titanium oxide, boron nitride and the like are preferable, silica, alumina, boron nitride are more preferable, and silica is further preferable. Examples of the material of the whisker include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, boron nitride, and the like.

The component (e) is preferably a surface-treated filler from the viewpoint of improving dispersibility and adhesive force. Examples of the surface treatment include glycidyl group-based (epoxy group-based), amine-based, phenyl group-based, aniline-based, acrylic group-based, and vinyl group-based.

As the surface treatment, silane treatment using a silane compound such as an epoxysilane-based, aminosilane-based, or acrylate-based silane compound is preferable in terms of easiness of the surface treatment. As the surface treatment agent, glycidyl group-based, aniline group-based, and (meth) acrylic compounds are preferable from the viewpoint of excellent dispersibility and fluidity and further improvement in adhesive force. As the surface treatment agent, a phenyl-based or (meth) acrylic-based compound is preferable from the viewpoint of storage stability.

The particle size of the component (e) is preferably 1.5 μm or less in average particle size from the viewpoint of preventing biting at the time of flip-chip connection, and more preferably 1.0 μm or less in average particle size from the viewpoint of visibility (transparency). (e) The average particle diameter of the component can be measured by, for example, a wet-dry particle size distribution measuring apparatus (manufactured by Beckman Coulter, inc., LS 13320).

These components (e) may be used alone or as a mixture of two or more kinds. The shape of the component (e) is not particularly limited.

The content of the component (e) is preferably 20 to 60% by mass, more preferably 30 to 50% by mass, based on the total solid content of the adhesive for a semiconductor. When the content is 20 mass% or more, particularly 30 mass% or more, generation of voids and moisture absorption rate can be further suppressed, and reliability such as adhesion, reflow resistance, moisture resistance and the like can be further improved. On the other hand, if the content is 60 mass% or less, particularly 50 mass% or less, the warpage of the obtained package tends to be reduced easily, and biting in flip chip connection tends to be prevented easily.

(f) Organic filler

The adhesive for semiconductors of the present embodiment contains an organic filler as the component (f). By containing the component (f), the viscosity of the adhesive for a semiconductor and the physical properties of the cured product can be controlled, and generation of voids and moisture absorption rate at the time of connecting the semiconductor chip and the substrate can be suppressed.

Examples of the material of the organic filler include polyurethane, polyimide, silicone, methyl methacrylate resin, and methyl methacrylate-Butadiene-Styrene copolymer resin (MBS). (f) Component (c) is suitable for improving reflow resistance and temperature cycle resistance because it can impart flexibility to the adhesive for a semiconductor and the cured product thereof at a high temperature such as 260 ℃. Further, since flexibility is imparted, it is also effective in improving film formability.

These components (f) may be used alone or as a mixture of two or more kinds. The shape of the component (f) is not particularly limited.

The adhesive for semiconductors of the present embodiment contains a silicone rubber filler as the component (f). By containing the silicone rubber filler in the adhesive for a semiconductor, the warpage of the resulting package can be reduced.

The silicone rubber filler may be a filler containing only a silicone rubber, or may be a filler compounded with other components, as long as the filler contains a silicone rubber as a constituent component of the filler. The silicone rubber filler may be particles having a core-shell type structure. The core-shell structure includes a structure having a core layer (core material) and a shell layer (surface layer) provided so as to cover the core layer. The core layer and the shell layer may have the same or different compositions. In addition, the core layer and the shell layer may not have a definite boundary. As the silicone rubber filler, for example, composite particles in which the core layer is composed of silicone rubber particles and the shell layer is composed of components other than silicone rubber particles can be used. As such composite particles, silicone composite powder in which the core layer is composed of silicone rubber particles and the shell layer is composed of silicone resin having a higher glass transition temperature and higher elastic coefficient than those of the silicone rubber particles of the core layer can be preferably cited. In this silicone composite powder, the shell layer can prevent the silicone rubber particles in the core layer from swelling with a solvent or a constituent material of a binder for a semiconductor and forming aggregates between the silicone rubber particles.

The average particle diameter of the silicone rubber filler is preferably 0.1 to 50 μm, more preferably 0.1 to 30 μm, and still more preferably 0.1 to 10 μm. When the average particle diameter is 50 μm or less, the connectivity at the time of mounting tends to be good. The average particle diameter of the silicone rubber filler can be measured, for example, by a wet-dry particle size distribution measuring apparatus (manufactured by Beckman Coulter, inc., LS 13320).

The content of the silicone rubber filler is preferably 0.1 to 20% by mass, more preferably 1 to 18% by mass, and still more preferably 3 to 15% by mass, based on the total solid content of the adhesive for semiconductors. When the content is 0.1% by mass or more, the elasticity tends to be low, and when the content is 20% by mass or less, the melt viscosity tends to be appropriate.

From the viewpoint of more sufficiently obtaining the effects of the present invention, the proportion of the content of the silicone rubber filler in the component (f) is preferably 50 mass% or more, and more preferably 80 mass% or more, based on the total amount of the component (f). The content of the silicone rubber filler may be 100% by mass.

The mass ratio of the content of the silicone rubber filler to the content of the component (e) (mass of silicone rubber filler/mass of inorganic filler) is preferably 0.05 to 0.5, more preferably 0.08 to 0.4, and still more preferably 0.1 to 0.3. By setting the mass ratio within the above range, it is possible to achieve both good adhesion and reliability and low warpage of the resulting package at a higher level.

The total content of the component (e) and the component (f) is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, based on the entire solid content of the adhesive for a semiconductor. When the content is 30% by mass or more, the adhesive force tends to be more sufficiently improved. When the content is 90% by mass or less, the viscosity is increased, and the lowering of the fluidity of the adhesive for semiconductor and the biting (trapping) of the filler into the connecting portion can be suppressed, and good connection reliability tends to be obtained.

From the viewpoint of insulation reliability, the filler is preferably insulating. The adhesive for semiconductors preferably does not contain conductive metal fillers such as silver fillers and solder fillers. An adhesive for a semiconductor (circuit connecting material) containing no Conductive filler (Conductive particles) is also sometimes called NCF (Non-Conductive-FILM) or NCP (Non-Conductive-Paste). The adhesive for a semiconductor according to the present embodiment can be suitably used as NCF or NCP.

The adhesive for semiconductors may further contain an ion trap, an antioxidant, a silane coupling agent, a titanium coupling agent, a leveling agent, and the like. These may be used alone or in combination of two or more. These amounts of blending may be adjusted as appropriate to exhibit the effects of the respective additives.

The adhesive for a semiconductor of the present embodiment can be formed into a film shape. An example of a method for producing a film-like adhesive using the adhesive for a semiconductor of the present embodiment is described below.

First, the components (a) to (f) and the essential components of the additives are added to an organic solvent, and dissolved or dispersed by stirring, mixing, kneading or the like to prepare a resin varnish. Then, after the resin varnish is applied to the substrate film subjected to the release treatment using a blade coater, a roll coater, an applicator, or the like, the organic solvent is removed by heating, whereby a film-like adhesive can be formed on the substrate film.

The thickness of the film-like adhesive is not particularly limited, and is, for example, preferably 0.5 to 1.5 times, more preferably 0.6 to 1.3 times, and still more preferably 0.7 to 1.2 times the height of the bump before connection.

If the thickness of the film-like adhesive is 0.5 times or more the height of the bump, generation of voids due to non-filling of the adhesive can be sufficiently suppressed, and connection reliability can be further improved. Further, if the thickness is 1.5 times or less, the amount of the adhesive pushed out from the chip connection region at the time of connection can be sufficiently suppressed, and therefore adhesion of the adhesive to an unnecessary portion can be sufficiently prevented. If the film-like adhesive has a thickness of more than 1.5 times, a large amount of the adhesive must be excluded from the bump, and poor conduction is likely to occur. Further, weakening of the bump (miniaturization of the bump diameter) by narrowing the pitch and widening the stitch length is not preferable because the removal of a large amount of resin increases the damage to the bump.

In general, the thickness of the film-like adhesive is preferably 2.5 to 150 μm, more preferably 3.5 to 120 μm, from the viewpoint that the height of the bump is 5 to 100 μm.

The organic solvent used for the preparation of the resin varnish preferably has a property of uniformly dissolving or dispersing each component, and examples thereof include: dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. These organic solvents may be used alone, or two or more of them may be used in combination. The stirring, mixing and kneading in the preparation of the resin varnish may be carried out using, for example, a stirrer, an attritor, a three-roll mill, a ball mill, a bead mill or a homogenizer.

The substrate film is not particularly limited as long as it has heat resistance capable of withstanding heating conditions when the organic solvent is volatilized, and examples thereof include: polyolefin films such as polypropylene films and polymethylpentene films; polyester films such as polyethylene terephthalate films and polyethylene naphthalate films; polyimide films and polyetherimide films. The substrate film is not limited to a single-layer film including these films, and may be a multilayer film including two or more materials.

The drying condition for volatilizing the organic solvent from the resin varnish applied to the base film is preferably a condition under which the organic solvent is sufficiently volatilized, and specifically, heating at 50 to 200 ℃ for 0.1 to 90 minutes is preferably performed. The organic solvent is preferably removed to 1.5 mass% or less with respect to the total amount of the film-like binder.

The adhesive for a semiconductor of the present embodiment may be formed directly on a wafer. Specifically, for example, the resin varnish may be directly spin-coated on a wafer to form a film, and then the organic solvent may be removed to directly form the adhesive for a semiconductor on the wafer.

< semiconductor device >

The semiconductor device according to the present embodiment will be described below with reference to fig. 1 and 2. Fig. 1 is a schematic cross-sectional view showing one embodiment of a semiconductor device of the present invention. As shown in fig. 1 (a), the semiconductor device 100 includes: the semiconductor device includes a semiconductor chip 10 and a substrate (printed circuit board) 20 facing each other, wires 15 respectively disposed on the facing surfaces of the semiconductor chip 10 and the substrate 20, connection bumps 30 connecting the wires 15 of the semiconductor chip 10 and the substrate 20 to each other, and an adhesive material 40 filled in a gap between the semiconductor chip 10 and the substrate 20 without a gap. The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wires 15 and the connection bumps 30. The wiring 15 and the connection bump 30 are sealed from the external environment by the adhesive material 40.

As shown in fig. 1 (b), the semiconductor device 200 includes: the semiconductor device includes a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 respectively disposed on the facing surfaces of the semiconductor chip 10 and the substrate 20, and a bonding material 40 filled in the gap between the semiconductor chip 10 and the substrate 20 without a gap. The semiconductor chip 10 and the substrate 20 are connected to each other by the opposing bumps 32 and flip chip connected. The bump 32 is sealed from the external environment by the adhesive material 40. The adhesive material 40 is a cured product of the adhesive for a semiconductor of the present embodiment.

Fig. 2 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention. As shown in fig. 2 (a), the semiconductor device 300 is the same as the semiconductor device 100 except that two semiconductor chips 10 are flip-chip connected by the wires 15 and the connection bumps 30. As shown in fig. 2 (b), the semiconductor device 400 is the same as the semiconductor device 200 except that two semiconductor chips 10 are flip-chip connected by bumps 32.

The semiconductor chip 10 is not particularly limited, and an element semiconductor composed of one kind of element such as silicon or germanium; gallium arsenide, indium phosphide, and the like.

The substrate 20 is not particularly limited as long as it is a circuit substrate, and it is possible to use: a circuit board having a wiring (wiring pattern) 15 formed by etching and removing an unnecessary portion of a metal film on a surface of an insulating substrate mainly composed of glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, or the like; a circuit board having a wiring 15 formed on a surface of the insulating substrate by metal plating or the like; and a circuit board having wiring 15 formed by printing a conductive material on the surface of the insulating substrate.

The connection portions such as the wiring 15 and the bump 32 contain gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), nickel, tin, lead, and the like as main components, and may contain a plurality of metals.

Among the metals, gold, silver, and copper are preferable, and silver and copper are more preferable, from the viewpoint of forming a package in which the electrical conductivity and thermal conductivity of the connection portion are excellent. From the viewpoint of forming a package with reduced cost, silver, copper, and solder are preferred, copper and solder are more preferred, and solder is even more preferred, because of low cost. Since the productivity may be lowered and the cost may be increased when the oxide film is formed on the surface of the metal at room temperature, gold, silver, copper, and solder are preferable, gold, silver, and solder are more preferable, and gold and silver are even more preferable, from the viewpoint of suppressing the formation of the oxide film.

A metal layer containing gold, silver, copper, solder (mainly containing tin-silver, tin-lead, tin-bismuth, and tin-copper), tin, nickel, or the like as a main component may be formed on the surfaces of the wiring 15 and the bump 32 by plating, for example. The metal layer may contain only a single component or may contain a plurality of components. The metal layer may have a single layer or a structure in which a plurality of metal layers are stacked.

In fig. 1 (b), the bump 32 provided on the surface of the semiconductor chip 10 may have a multilayer structure including a copper pillar portion and a solder portion. In this case, it is preferable that the copper pillar portion is disposed on the semiconductor chip 10 side and the solder portion is provided at an end portion of the copper pillar portion.

In the semiconductor device of the present embodiment, a plurality of structures (packages) shown in the semiconductor devices 100 to 400 may be stacked. In this case, the semiconductor devices 100 to 400 may be electrically connected to each other by bumps or wirings containing gold, silver, copper, solder (the main component is, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin, nickel, or the like.

As a method of stacking a plurality of semiconductor devices, for example, a TSV (through-Silicon Via) technique is given as shown in fig. 3. Fig. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present invention, and is a semiconductor device using the TSV technology. In the semiconductor device 500 shown in fig. 3, the wirings 15 formed on the interposer (interposer)50 are connected to the wirings 15 of the semiconductor chip 10 via the connection bumps 30, whereby the semiconductor chip 10 and the interposer 50 are flip-chip connected. In the gap between the semiconductor chip 10 and the interposer 50, the adhesive material 40 is filled without a gap. The semiconductor chip 10 is repeatedly laminated on the surface of the semiconductor chip 10 opposite to the interposer 50 through the wiring 15, the connection bump 30, and the adhesive material 40. The wirings 15 on the front and back pattern surfaces of the semiconductor chip 10 are connected to each other by the through electrodes 34 filled in the holes penetrating the semiconductor chip 10. As a material of the through electrode 34, copper, aluminum, or the like can be used.

With such TSV technology, signals can also be acquired from the back surface of a semiconductor chip that is not normally used. Furthermore, since the through electrode 34 vertically penetrates the semiconductor chips 10, the distance between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 can be shortened, and flexible connection can be achieved. In the TSV technology, the adhesive for a semiconductor of the present embodiment can be applied as an adhesive for a semiconductor between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50.

In a bump forming method with a high degree of freedom, such as an area bump (area bump) chip technique, a semiconductor chip can be directly packaged on a motherboard (motherboard) without an interposer. The adhesive for a semiconductor of the present embodiment can be applied also to the case where a semiconductor chip is directly packaged on a motherboard. The adhesive for a semiconductor of the present embodiment can also be used when sealing a gap between two wiring circuit boards when the boards are stacked.

< method for manufacturing semiconductor device >

Next, a method for manufacturing the semiconductor device of the present embodiment will be described.

First, a film-like adhesive is attached to a substrate or a semiconductor chip. The film-like adhesive can be attached by heat pressing, roll lamination, vacuum lamination, or the like. The supply area and thickness of the film-like adhesive are appropriately set according to the size of the semiconductor chip or substrate and the height of the connection bumps. The film-like adhesive may be attached to a semiconductor chip, or may be cut into individual semiconductor chips after being attached to a semiconductor wafer, thereby producing a semiconductor chip with the film-like adhesive attached thereto.

After the film-like adhesive is attached to the substrate or the semiconductor chip, the connection bumps (solder bumps, etc.) of the semiconductor chip and the wirings (copper wirings, etc.) of the substrate are aligned using a connection device such as a flip chip bonder. Then, the semiconductor chip and the substrate are connected by heating at a temperature not lower than the melting point of the connection bump and pressure-bonding the semiconductor chip and the substrate, and the gap between the semiconductor chip and the substrate is sealed and filled with a film-like adhesive. The semiconductor device is obtained as described above.

The connection load can be set in consideration of variations in the number and height of the connection bumps, and deformation of the connection bumps or the wiring receiving the bumps of the connection portion due to pressurization. The connection temperature is preferably a temperature equal to or higher than the melting point of the connection bump, but may be a temperature at which metal bonding of each connection portion (bump or wiring) can be formed. In the case where the connection bump is a solder bump, the connection temperature may be about 220 ℃.

The connection time at the time of connection differs depending on the constituent metal of the connection portion, but from the viewpoint of improvement in productivity, the shorter the time, the better. When the connection bump is a solder bump, the connection time is preferably 20 seconds or less, more preferably 10 seconds or less, and further preferably 5 seconds or less. In the case of performing connection in a short time by using a solder bump, the connection time is preferably 4 seconds or less, more preferably 3 seconds or less, and further preferably 2 seconds or less. By performing the connection in a short time in this manner, more packages with high reliability can be manufactured. Here, the connection time refers to a time when the connection temperature is applied to the connection bump. In the case of a copper-copper or copper-gold metal connection, the connection time is preferably 60 seconds or less. When the connection bump is a solder bump, it is preferable that the solder is melted at the time of connection, and impurities on the oxide film and the surface are removed to form metal bonding at the connection portion.

In the method of manufacturing a semiconductor device according to the present embodiment, after the positioning, the semiconductor chip and the substrate may be connected to each other by temporarily fixing the semiconductor chip (with the adhesive for semiconductor interposed therebetween) and performing a heat treatment in a reflow furnace to melt the connection bumps. Since the metal bond is not necessarily formed in the temporary fixing step, the pressure bonding can be performed at a low load, a short time, and a low temperature, as compared with the above-described method of performing the pressure bonding while heating, and the productivity can be improved and the deterioration of the connection portion can be suppressed.

Further, after the semiconductor chip and the substrate are connected, heat treatment may be performed in an oven or the like to further improve the connection reliability and insulation reliability. The heating temperature is preferably a temperature at which the film-like adhesive is cured, and more preferably a temperature at which the adhesive is completely cured. The heating temperature and the heating time can be appropriately set.

In the method of manufacturing a semiconductor device according to the present embodiment, a paste-like adhesive for a semiconductor may be supplied to a substrate or a semiconductor chip instead of the film-like adhesive. The adhesive for semiconductor can be supplied by a coating method such as spin coating.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

Examples

The present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

The compounds used in the examples and comparative examples are as follows.

(a) The components: resin with weight average molecular weight less than 10000

(a-1): polyfunctional epoxy resin having a triphenylol methane skeleton (product name "EP 1032H 60" manufactured by Mitsubishi Chemical corporation; weight average molecular weight: 800 to 2000)

(a-2): bisphenol F type liquid epoxy resin (product name "YL 983U" manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: about 340)

(a-3): flexible semi-solid epoxy resin (product name "YX 7110B 60" manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: about 1000 to 5000)

(b) The components: curing agent: 2, 4-diamino-6- [2 '-methylimidazole- (1') ] -ethyl-s-triazine isocyanurate adduct (product name "2 MAOK-PW" from Shikoku Chemicals Corp)

(c) The components: a high molecular compound having a weight average molecular weight of 10000 or more: phenoxy resin (TohtoKasei Co., Ltd., product name "ZX 1356", Tg: about 71 ℃, weight average molecular weight: about 63000)

(d) The components: flux (carboxylic acid): glutaric acid (melting point: about 95 ℃ C.)

(e) The components: inorganic filler

(e-1) silica Filler (manufactured by Admatechs Co., Ltd., trade name "SE 2050", average particle diameter: 0.5 μm)

(e-2) methacrylic acid surface-treated nanosilica filler (manufactured by Admatechs Co., Ltd., trade name "YA 050C-SM", average particle diameter: about 50nm)

(f) The components: organic filler

(f-1): silicone composite powder (Shin-Etsu Chemical Co., Ltd., trade name "KMP-602", average particle diameter: 30 μm, spherical powder in which the surface of spherical silicone rubber powder is coated with silicone resin)

(f-2): silicone composite powder (Shin-Etsu Chemical Co., Ltd., trade name "KMP-600", average particle diameter: 5 μm, spherical powder in which the surface of spherical silicone rubber powder is coated with silicone resin)

(f-3): silicone composite powder (Shin-Etsu Chemical Co., Ltd., trade name "KMP-605", average particle diameter: 2 μm, spherical powder in which the surface of spherical silicone rubber powder is coated with silicone resin)

(f-4): silicone composite powder (spherical powder manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-52-7030", average particle diameter: 0.8 μm, surface of spherical silicone rubber powder coated with silicone resin)

(f-5): core-shell type organic fine particles (product name "EXL-2655" manufactured by Rohm and Haas Japan, core part: butadiene/styrene copolymer, shell part: PMMA/styrene copolymer)

(examples 1 to 4 and comparative examples 1 to 2)

< preparation of film-like adhesive >

The amounts shown in Table 1 were adjusted (singly)Bit: component (a), component (b), component (c), component (d), component (e), and component (f) in parts by mass are expressed as NV value ([ mass of paint component after drying ]]/[ quality of coating Components before drying]X 100) was added to the organic solvent (methyl ethyl ketone) so as to become 60 mass%. Then, the same mass as the total amount of the components (a) to (f) and the organic solvent is added

The zirconia beads (2) were stirred for 30 minutes by means of a ball mill (Fritsch Japan Co., Ltd., planetary type micro mill P-7). After stirring, the zirconia beads were removed by filtration to prepare a coating varnish.

The obtained coating varnish was coated with a bench coater (Hirano Kinzoku co., ltd.) and dried at 80 ℃ for 5 minutes, thereby obtaining a film-like adhesive having a film thickness of 20 μm.

The film-like adhesives obtained in examples and comparative examples were evaluated for adhesion and reliability, and for warpage of semiconductor devices fabricated using the same, by the evaluation methods described below. The evaluation results are shown in table 1.

< measurement of adhesive force >

A film-like adhesive was cut into a predetermined size (3.2 mm in length × 3.2mm in width × 0.02mm in thickness), attached to a silicon chip (3 mm in length × 3mm in width × 0.725mm in thickness) at 70 ℃, and pressure-bonded to another silicon chip (5 mm in length × 5mm in width × 0.725mm in thickness) using a thermocompression bonding machine (Hitac hi Chemical technology Plant Co., Ltd., manufactured by Ltd.) (pressure-bonding conditions: pressure-bonding at a pressure-bonding head temperature of 190 ℃ for 5 seconds, pressure-bonding at a pressure-bonding head temperature of 240 ℃ for 5 seconds, load of 0.5 MPa). Then, curing (175 ℃, 2 hours) was performed in a clean oven (Tabai Espec co., ltd.) to obtain a test sample.

The test sample was placed in a constant temperature and humidity chamber (Tabai Espec Co., Ltd.) having a temperature of 85 ℃ and a relative humidity of 85% for 24 hours, and after taking out, the adhesion force (the adhesion force at 250 ℃ after moisture absorption) was measured on a hot plate at 250 ℃ under conditions of a tool height of 0.05mm from the upper surface of the lower silicon chip and a tool speed of 0.05mm/s using an adhesion force measuring apparatus (Dage Arctek Co., Ltd.).

< evaluation of reflow resistance >

A film-like adhesive was cut into predetermined dimensions (7.3 mm in length: 7.3mm in width: 0.04mm in thickness), attached to a bump-side surface of a semiconductor chip with solder bumps (chip size: 7.3mm in length: 7.3mm in width: 0.15mm in thickness: metal of a connection portion: copper pillar + solder, bump height (total height of copper pillar + solder): about 45 μm), mounted by a flip chip mounting apparatus "FCB 3" (mounting condition: after temporary pressure bonding at 100 ℃/0.5MPa/1s, temperature was raised to 180 ℃/0.5MPa/2s, and then formal pressure bonding was performed at 260 ℃/0.5MPa/5 s) on a glass epoxy substrate (thickness of glass epoxy substrate: 0.42mm, thickness of copper wiring: 9 μm), to obtain a semiconductor device. The film-like adhesive is formed by laminating two sheets of adhesive having a film thickness of 20 μm so that the film thickness becomes 40 μm. The stage temperature for placing the substrate during the press bonding was 80 ℃. The semiconductor device was molded using a sealing material (manufactured by hitachi chemical co., ltd., trade name "CEL 9750ZHF 10") under conditions of 180 ℃, 6.75MPa, and 90 seconds, and cured (175 ℃, 2 hours) in a clean oven (manufactured by Tabai Espec co., ltd.), thereby obtaining a test sample.

Next, the above test sample was passed through a reflow furnace (manufactured by Tamura Corporation) 3 times (up to a temperature of 260 ℃ C.) after being treated under a condition of JEDEC (Joint Electron Device Engineering Council) grade 2. The connection resistance values of the packages before and after reflow were measured using a multimeter (manufactured by Custom co., ltd.). The case where the change amount of the connection resistance value before and after reflow was 5 Ω or less was regarded as evaluation "a", and the case where the change amount exceeded 5 Ω or the connection was defective was regarded as evaluation "B".

< evaluation of warpage >

A semiconductor device was produced by the same method as the evaluation of reflow resistance, and this was used as a test sample. For the above test samples, the shapes of both sides in the diagonal direction when the chip was observed from above were measured using a noncontact shape measuring device (manufactured by Sony Group Corporation). The difference between the maximum value and the minimum value of the irregularities on each side was defined as the warpage amount (μm), and the warpage amount was evaluated by the average value of both sides. The case where the warpage amount is 70 μm or less was referred to as "A" and the case where the warpage amount exceeds 70 μm was referred to as "B".

[ Table 1]

From the results shown in table 1, it is understood that the adhesives for semiconductors of examples 1 to 4 containing an inorganic filler and a silicone rubber filler are superior in adhesion and reflow resistance and achieve low warpage compared to the adhesives for semiconductors of comparative examples 1 to 2.

Description of the symbols

10 semiconductor chip

15 distribution (connecting part)

20 substrate (printed circuit board)

30 connecting projection

32 convex block (connecting part)

34 penetration electrode

4 adhesive material

50 interposer

100. 200, 300, 400, 500 semiconductor devices.

Claims

1. An adhesive for semiconductors, comprising:

resin with weight average molecular weight less than 10000, curing agent, inorganic filler and silicone rubber filler.

2. The adhesive for semiconductors according to claim 1, wherein,

the silicone rubber filler has an average particle diameter of 30 [ mu ] m or less.

3. The adhesive for semiconductors according to claim 1 or 2, wherein,

the inorganic filler contains a silica filler.

4. The adhesive for semiconductors according to any one of claims 1 to 3, further comprising:

a polymer component having a weight average molecular weight of 10000 or more.

5. The adhesive for semiconductors according to claim 4, wherein,

the weight average molecular weight of the polymer component is 30000 or more, and the glass transition temperature of the polymer component is 100 ℃ or less.

6. The adhesive for semiconductors according to any one of claims 1 to 5, which is in the form of a film.

7. The adhesive for semiconductors according to any one of claims 1 to 6, wherein,

the content of the silicone rubber filler is 0.1 to 20% by mass based on the total solid content of the adhesive for semiconductors.

8. The adhesive for semiconductors according to any one of claims 1 to 7, wherein,

the mass ratio of the content of the silicone rubber filler to the content of the inorganic filler is 0.05 to 0.5.

9. A method of manufacturing a semiconductor device in which connection portions of a semiconductor chip and a printed circuit board are electrically connected to each other, or in which connection portions of a plurality of semiconductor chips are electrically connected to each other, the method comprising:

a step of sealing at least a part of the connection portion using the adhesive for a semiconductor according to any one of claims 1 to 8.

10. A semiconductor device includes:

a connection structure in which respective connection portions of the semiconductor chip and the printed circuit board are electrically connected to each other, or a connection structure in which respective connection portions of the plurality of semiconductor chips are electrically connected to each other; and

an adhesive material sealing at least a portion of the connection portion,

the adhesive material is formed from a cured product of the adhesive for semiconductors according to any one of claims 1 to 8.