JP7683597B2 - Adhesive for semiconductors, and semiconductor device and manufacturing method thereof - Google Patents

Description

The present disclosure relates to an adhesive for semiconductors, as well as a semiconductor device and a method for manufacturing the same.

Traditionally, wire bonding, which uses thin metal wires such as gold wires, has been widely used to connect semiconductor chips and substrates. However, in order to meet the demands for higher performance, higher integration, and faster speeds for semiconductor devices, the flip-chip connection method (FC connection method), in which conductive protrusions called bumps are formed on the semiconductor chip or substrate to directly connect the semiconductor chip to the substrate, is becoming more widespread.

Known flip chip connection methods include metal bonding using solder, tin, gold, silver, copper, etc., metal bonding by applying ultrasonic vibrations, and maintaining mechanical contact using the contraction force of resin. From the standpoint of reliability of the connection, however, metal bonding using solder, tin, gold, silver, copper, etc. is more commonly used.

For example, in the connection between a semiconductor chip and a substrate, the COB (Chip On Board) type connection method that is widely used for BGA (Ball Grid Array) and CSP (Chip Size Package) is also a flip chip connection method. The flip chip connection method is also widely used in the COC (Chip On Chip) type connection method in which bumps or wiring are formed on a semiconductor chip to connect between semiconductor chips (for example, see Patent Document 1 below).

In the case of packages that are required to be even smaller, thinner, and more functional, chip-stack packages that use the above-mentioned connection methods in multiple layers, such as POP (Package On Package) and TSV (Through-Silicon Via), are becoming more widespread. These technologies are widely used because they can make packages smaller by arranging them in a three-dimensional rather than flat form. They are also effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, and are attracting attention as the next-generation semiconductor wiring technology.

JP 2008-294382 A

In the above-mentioned flip chip connection method, the flip chip connection may be performed via a semiconductor adhesive for the purpose of protecting the metal bond at the connection part, etc.

In recent years, flip chip packages have become more highly functional and integrated. However, as these packages become more highly integrated and integrated, the pitch between the wiring becomes narrower, which increases the amount of heat generated by the package. If heat builds up in the package, the semiconductor chip will become too hot, which can lead to malfunctions. For this reason, semiconductor adhesives are required to have better heat dissipation properties than ever before.

Therefore, the present disclosure aims to provide a semiconductor adhesive with excellent heat dissipation properties. The present disclosure also aims to provide a semiconductor device using such a semiconductor adhesive and a method for manufacturing the same.

One aspect of the present disclosure provides a semiconductor adhesive used to seal connections in a semiconductor device having a connection structure in which the respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the respective connection portions of a plurality of semiconductor chips are electrically connected to each other, the semiconductor adhesive comprising a curable resin component, a fluxing agent, and an inorganic filler, the content of the inorganic filler being 60 to 95 mass % based on the total amount of the semiconductor adhesive, and the semiconductor adhesive having a thermal conductivity of 1.5 W/mK or more after curing.

The inorganic filler may include polyhedral alumina.

The inorganic filler may contain at least one selected from the group consisting of silicon carbide, boron nitride, diamond, silica, and aluminum nitride.

The inorganic filler may have peaks in the ranges of 0.1 to 4.5 μm and 5 to 20 μm in the volume-based particle size distribution.

The semiconductor adhesive may contain, as an inorganic filler, polyhedral alumina having a volume-based average particle diameter _r1 of 5 to 20 μm and polyhedral alumina having a volume-based average particle diameter _r2 of 0.1 to 4.5 μm.

The difference (r ₁ -r ₂ ) between the average particle diameter r ₁ and the average particle diameter r ₂ may be 4 to 10 μm.

The above semiconductor adhesive may have a thermal conductivity of 3.0 W/mK or more after curing.

The fluxing agent may be a carboxylic acid.

The curable resin component may include a thermosetting resin, a curing agent, and a thermoplastic resin.

Another aspect of the present disclosure provides a method for manufacturing a semiconductor device having a connection structure in which the respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the respective connection portions of a plurality of semiconductor chips are electrically connected to each other, the method comprising a step of sealing at least a portion of the connection portion using the above-mentioned semiconductor adhesive.

Another aspect of the present disclosure provides a semiconductor device comprising a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other, and a sealing material that seals at least a portion of the connection portions, the sealing material including a cured product of the semiconductor adhesive described above.

According to the present disclosure, it is possible to provide a semiconductor adhesive having excellent heat dissipation properties. Furthermore, according to the present disclosure, it is possible to provide a semiconductor device using such a semiconductor adhesive and a method for manufacturing the same.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device according to the present disclosure. FIG. 11 is a schematic cross-sectional view showing another embodiment of a semiconductor device according to the present disclosure. FIG. 11 is a schematic cross-sectional view showing another embodiment of a semiconductor device according to the present disclosure. 4A to 4C are schematic cross-sectional views showing an example of a method for manufacturing the semiconductor device shown in FIG. 3. FIG. 11 is a schematic cross-sectional view showing another embodiment of a semiconductor device according to the present disclosure.

Hereinafter, the embodiments for carrying out the present disclosure will be described in detail, with reference to the drawings where necessary. However, the present disclosure is not limited to the following embodiments. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)acrylate" means acrylate or the corresponding methacrylate. "A or B" may contain either A or B, or may contain both.

In addition, in this specification, a numerical range indicated using "~" indicates a range that includes the numerical values before and after "~" as the minimum and maximum values, respectively. Furthermore, in a numerical range described in stages in this specification, the upper limit or lower limit of a numerical range of a certain stage may be replaced with the upper limit or lower limit of a numerical range of another stage. Furthermore, in a numerical range described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in an example.

<Semiconductor adhesive>
The semiconductor adhesive of this embodiment is a semiconductor adhesive used to seal connections in a semiconductor device having a connection structure in which the respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the respective connection portions of a plurality of semiconductor chips are electrically connected to each other, and contains a curable resin component, a flux agent, and an inorganic filler, in which the content of the inorganic filler is 60 to 95 mass % based on the total amount of the semiconductor adhesive, and the thermal conductivity of the semiconductor adhesive after curing is 1.5 W/mK or more.

(Curable resin component)
The curable resin component may contain (a) a thermosetting resin, (b) a curing agent, and (c) a thermoplastic resin.

((a) Thermosetting resin)
Examples of the thermosetting resin include epoxy resin, urea resin, melamine resin, and phenol resin. The thermosetting resin may be an epoxy resin from the viewpoint of good curability and excellent adhesiveness. The thermosetting resin may be used alone or in combination of two or more kinds.

Epoxy resins include, for example, epoxy resins having two or more epoxy groups in the molecule, such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, naphthalene type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, phenol aralkyl type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, dicyclopentadiene type epoxy resins, and various polyfunctional epoxy resins. These epoxy resins can be used alone or in combination of two or more types.

The epoxy resin content may be 40 parts by mass or more or 50 parts by mass or more per 100 parts by mass of the hardener resin component. The epoxy resin content may be 90 parts by mass or less or 80 parts by mass or less per 100 parts by mass of the hardener resin component.

The epoxy resin content may be 10 parts by mass or more, or 20 parts by mass or more, per 100 parts by mass of the semiconductor adhesive. The epoxy resin content may be 50 parts by mass or less, or 40 parts by mass or less, per 100 parts by mass of the semiconductor adhesive. The epoxy resin content may be 10 to 50 parts by mass, per 100 parts by mass of the semiconductor adhesive.

((b) Curing Agent)
Examples of the curing agent include phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, and phosphine-based curing agents. When the curing agent contains a phenolic hydroxyl group, acid anhydride, amines, or imidazoles, it is likely to exhibit flux activity that suppresses the generation of an oxide film at the connection portion, and connection reliability and insulation reliability can be easily improved.

Examples of phenolic resin-based hardeners include hardeners having two or more phenolic hydroxyl groups in the molecule, such as phenol novolac, cresol novolac, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane-type polyfunctional phenol, and various polyfunctional phenol resins. The phenolic resin-based hardeners can be used alone or in combination of two or more.

When the curable resin component contains an epoxy resin, the equivalent ratio of the phenolic resin-based curing agent to the epoxy resin (phenolic hydroxyl group/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0, from the viewpoint of good curability, excellent adhesion, and storage stability. An equivalent ratio of 0.3 or more tends to improve curability and adhesion, and an equivalent ratio of 1.5 or less tends to prevent excessive unreacted phenolic hydroxyl groups from remaining, suppress water absorption to a low level, and further improve insulation reliability.

Examples of acid anhydride curing agents include methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. The acid anhydride curing agents can be used alone or in combination of two or more.

When the curable resin component contains an epoxy resin, the equivalent ratio of the acid anhydride curing agent to the epoxy resin (acid anhydride group/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0, from the viewpoint of good curability, excellent adhesion, and storage stability. An equivalent ratio of 0.3 or more tends to improve curability and adhesion, and an equivalent ratio of 1.5 or less tends to prevent excess unreacted acid anhydride from remaining, suppress water absorption to a low level, and further improve insulation reliability.

An example of an amine-based curing agent is dicyandiamide.

When the curable resin component contains an epoxy resin, the equivalent ratio of the amine-based curing agent to the epoxy resin (amine/epoxy group, molar ratio) may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0, from the viewpoint of good curability, excellent adhesion, and storage stability. An equivalent ratio of 0.3 or more tends to improve curability and adhesion, and an equivalent ratio of 1.5 or less tends to prevent excessive unreacted amine from remaining, further improving insulation reliability.

Examples of imidazole-based curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino- Examples of the compound include 6-[2'-undecylimidazolyl-(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 isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles. Among these, from the viewpoint of being more excellent in curing property, storage stability and connection reliability, the imidazole-based curing agent is preferably 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole 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 isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. The imidazole-based curing agent may be used alone or in combination of two or more. These may also be microencapsulated to form a latent curing agent.

The content of the imidazole-based curing agent may be 0.1 to 20 parts by mass, 0.1 to 10 parts by mass, 0.1 to 5 parts by mass, or 0.5 to 5 parts by mass, relative to 100 parts by mass of the curable resin component. When the content of the imidazole-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and when the content is 20 parts by mass or less, the adhesive composition does not harden before a metal bond is formed, and connection failures tend not to occur.

Examples of phosphine-based curing agents include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

The content of the phosphine-based curing agent may be 0.1 to 10 parts by mass, or 0.1 to 5 parts by mass, per 100 parts by mass of the curable resin component. When the content of the phosphine-based curing agent is 0.1 parts by mass or more, the curability tends to be improved, and when the content is 10 parts by mass or less, the semiconductor adhesive does not harden before the metal bond is formed, and connection failures tend to be less likely to occur.

The phenolic resin-based hardener, the acid anhydride-based hardener, and the amine-based hardener can each be used alone or in combination of two or more. The imidazole-based hardener and the phosphine-based hardener can each be used alone or together with the phenolic resin-based hardener, the acid anhydride-based hardener, or the amine-based hardener.

As for the hardener, from the viewpoint of excellent hardening properties, a combination of a phenol resin hardener and an imidazole hardener, a combination of an acid anhydride hardener and an imidazole hardener, a combination of an amine hardener and an imidazole hardener, or an imidazole hardener alone may be used. Since productivity improves when connecting in a short time, an imidazole hardener with excellent fast hardening properties may be used alone. In this case, since hardening in a short time can suppress volatile components such as low molecular weight components, the occurrence of voids can also be easily suppressed.

The content of the curing agent may be 0.1 to 20 parts by mass, or 0.1 to 10 parts by mass, per 100 parts by mass of the curable resin component.

((c) Thermoplastic resin)
Examples of the thermoplastic resin include phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, (meth)acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, acrylic rubber, etc. From the viewpoint of excellent heat resistance and film formability, the thermoplastic resin may be phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber, cyanate ester resin, polycarbodiimide resin, etc., or may be phenoxy resin, polyimide resin, (meth)acrylic resin, or acrylic rubber. The thermoplastic resin may be used alone or in combination of two or more kinds.

Examples of phenoxy resins include ZX1356-2 and FX-293 manufactured by Nippon Steel Chemical & Material Co., Ltd. Examples of urethane resins include T-8175N manufactured by DIC Covestro Polymer Co., Ltd., which is a polyurethane. Examples of (meth)acrylic resins include acrylic block copolymers, which are block copolymers of at least one compound of (meth)acrylate compounds, such as (meth)acrylic acid and (meth)acrylic acid esters such as methyl (meth)acrylate. Examples of acrylic block copolymers include LA4285, LA2330, and LA2140 (all manufactured by Kuraray Co., Ltd.), which are block copolymers of methyl methacrylate and butyl acrylate. The thermoplastic resin may be a phenoxy resin having a structure that is likely to form a crystalline structure (a structure with many aromatic rings) from the viewpoint of excellent high heat dissipation.

The glass transition temperature (Tg) of the thermoplastic resin may be 120°C or less, 100°C or less, or 85°C or less, from the viewpoint of excellent adhesion of the semiconductor adhesive to the substrate and chip. When the semiconductor adhesive contains a thermoplastic resin having a Tg of 120°C or less, the curing reaction can be suppressed, and the adhesive is easily embedded in the bumps formed on the semiconductor chip, the electrodes formed on the substrate, and the unevenness of the wiring pattern, etc., so that air bubbles are less likely to remain and the occurrence of voids tends to be easily suppressed. In addition, when the semiconductor adhesive contains a thermoplastic resin having a Tg of room temperature (25°C) or more, the semiconductor adhesive is easily formed into a film or membrane.

In this specification, the Tg of a thermoplastic resin means the Tg measured using differential scanning calorimetry (DSC, PerkinElmer DSC-7 model) under the following conditions: a sample weight of 10 mg, a heating rate of 10°C/min, and a measurement atmosphere of air.

The weight average molecular weight of the thermoplastic resin may be 10,000 or more, 30,000 or more, 40,000 or more, or 50,000 or more, from the viewpoint of excellent film-forming properties of the semiconductor adhesive. The weight average molecular weight of the thermoplastic resin may be 1,000,000 or less, or 500,000 or less, from the viewpoint of excellent film processability of the semiconductor adhesive.

In this specification, weight average molecular weight means the weight average molecular weight measured in polystyrene equivalent terms using high performance liquid chromatography (Shimadzu Corporation C-R4A).

When the curable resin component contains an epoxy resin and a thermoplastic resin, the content of the epoxy resin may be 1 part by mass or more, 5 parts by mass or more, or 10 parts by mass or more, and may be 500 parts by mass or less, 400 parts by mass or less, or 300 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin. The content of the epoxy resin may be 1 to 500 parts by mass, 5 to 400 parts by mass, or 10 to 300 parts by mass, relative to 100 parts by mass of the thermoplastic resin. When the content of the epoxy resin is within these ranges, the semiconductor adhesive has sufficient curability, excellent adhesive strength, and the semiconductor adhesive can be easily formed into a film or membrane.

The content of the thermoplastic resin may be 0.1 parts by mass or more, 1 part by mass or more, or 10 parts by mass or more, and may be 50 parts by mass or less, or 40 parts by mass or less, relative to 100 parts by mass of the curable resin component. The content of the thermoplastic resin may be 0.1 to 50 parts by mass, 1 to 50 parts by mass, or 10 to 40 parts by mass, relative to 100 parts by mass of the curable resin component.

The content of the curable resin component may be 10% by mass or more or 30% by mass or more, and may be 70% by mass or less or 50% by mass or less, based on the total amount of the semiconductor adhesive. The content of the curable resin component may be 10 to 70% by mass, 10 to 50% by mass, or 30 to 50% by mass, based on the total amount of the semiconductor adhesive.

(Flux agent)
The semiconductor adhesive according to this embodiment may further contain a fluxing agent (i.e., a flux activator exhibiting flux activity (activity to remove oxides, impurities, etc.)). Examples of fluxing agents include nitrogen-containing compounds having unshared electron pairs (imidazoles, amines, etc.), carboxylic acids, phenols, alcohols, etc.

The flux agent may contain an organic acid that reacts with the epoxy resin, as this has stronger flux activity than alcohols and makes it easier to improve connectivity.

When the curable resin component contains an epoxy resin, it may contain an organic acid or a carboxylic acid, since it reacts with the epoxy resin and does not exist in a free state in the cured semiconductor adhesive, thereby preventing a decrease in insulation reliability.

Examples of carboxylic acids include saturated fatty carboxylic acids such as ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, and octadecanoic acid; unsaturated fatty carboxylic acids such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, and eicosapentaenoic acid; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, hemimellitic acid, pyromellitic acid, pentanecarboxylic acid, and mesic acid; maleic acid, and fumaric acid. Examples of carboxylic acids having a hydroxyl group include lactic acid, malic acid, citric acid, and salicylic acid.

The carboxylic acid may be a dicarboxylic acid. Dicarboxylic acids tend to be less volatile than monocarboxylic acids, and therefore tend to be able to suppress voids. Also, dicarboxylic acids tend to be less reactive than tricarboxylic acids at low temperatures (below bonding temperatures, e.g., 100°C or lower) during film formation, lamination, preheating, etc., and therefore tend not to cause excessive viscosity and to suppress poor connections.

The carboxylic acid may be a carboxylic acid having one or more alkyl groups at the second or third position from the carboxyl group. Examples of carboxylic acids having such alkyl groups include 2-methylglutaric acid and 3-methylglutaric acid.

The fluxing agent content may be 0.5 parts by mass or more, 1 part by mass or more, or 1.5 parts by mass or more, per 100 parts by mass of the semiconductor adhesive. The fluxing agent content may be 10 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of the semiconductor adhesive. The fluxing agent content may be 0.5 to 10 parts by mass, or 0.5 to 5 parts by mass, per 100 parts by mass of the semiconductor adhesive.

(Inorganic filler)
The adhesive for semiconductors of the present embodiment contains an inorganic filler. The content of the inorganic filler is 60 to 95 mass% based on the total amount of the adhesive for semiconductors. If the content of the inorganic filler is within the above range, it is possible to impart excellent heat dissipation properties to the adhesive for semiconductors.

Examples of inorganic fillers include alumina (Al ₂ O ₃ ), magnesium oxide, silicon carbide, boron nitride, diamond, and aluminum nitride. From the viewpoint of thermal conductivity of the semiconductor adhesive, the inorganic filler may contain at least one selected from the group consisting of alumina, silicon carbide, boron nitride, diamond, and aluminum nitride.

When the inorganic filler is a particle containing alumina (hereinafter also referred to as "alumina filler"), the alumina may be α-alumina. From the viewpoint of excellent heat dissipation properties of the semiconductor adhesive, the purity of the alumina in the alumina filler may be 99.0 mass% or more, 99.5 mass% or more, or 99.9 mass% or more. The purity of the alumina filler may be such that it is substantially composed of alumina (100 mass% of the alumina filler is substantially alumina).

The shape of the alumina filler is not particularly limited, but examples include a sphere, an approximately sphere, a polyhedron, a needle, and a plate. Among these, from the viewpoint of excellent heat dissipation of the semiconductor adhesive, a sphere or a polyhedron may be used, and a polyhedron may also be used. In this specification, a "polyhedron" refers to a solid having multiple planes as constituent parts of the surface. The multiple planes may each intersect via a curved surface (the corners may be rounded). A polyhedron may have, for example, 4 to 100 planes as constituent parts of the surface.

It is not entirely clear why the use of polyhedral alumina as the alumina filler gives the semiconductor adhesive excellent heat dissipation properties, but the inventors believe that because the alumina filler is polyhedral, the fillers come into contact with each other through their faces, increasing the heat transfer area and improving heat transfer.

The average particle diameter of the inorganic filler may be 20 μm or less, 15 μm or less, or 10 μm or less from the viewpoint of improving the film-forming properties when the semiconductor adhesive is formed into a film. The average particle diameter of the inorganic filler may be 0.1 μm or more, 0.5 μm or more, or 1 μm or more from the viewpoint of dispersibility of the inorganic filler.

In this specification, "average particle size" refers to the particle size at the point corresponding to 50% volume when the cumulative frequency distribution curve of particle size is calculated assuming the total volume of the particles to be 100%, and can be measured using a particle size distribution measuring device using a laser diffraction scattering method.

The alumina filler may be alumina whose surface has been treated in order to improve visibility, dispersibility, and adhesive strength. Examples of surface treatment agents include glycidyl (epoxy) compounds, amine compounds, phenyl compounds, phenylamino compounds, (meth)acrylic compounds (e.g., compounds having a structure represented by the following general formula (1)), vinyl compounds having a structure represented by the following general formula (2), etc.

［Ｒ^１１は、水素原子又はアルキル基を示し、Ｒ^１２は、アルキレン基を示す。］

[R ¹¹ represents a hydrogen atom or an alkyl group, and R ¹² represents an alkylene group.]

Examples of the filler surface-treated with a compound having ^a structure represented by formula (1) include an acrylic surface-treated filler in which R ¹¹ is a hydrogen atom, a methacrylic surface-treated filler in which R ¹¹ is a methyl group, and an ethacrylic surface-treated filler in which R 11 is an ethyl group. From the viewpoint of reactivity with the resin contained in the semiconductor adhesive and the surface of the semiconductor substrate, and bond formation, R ¹¹ may be a hydrogen atom or a methyl group that is a non-bulky substituent. The surface-treated filler may be an acrylic surface-treated filler or a methacrylic surface-treated filler. There is no particular restriction on the alkylene group of R ¹² , but from the viewpoint of reducing volatile components, it may be one with a high weight average molecular weight.

［Ｒ^２１、Ｒ^２２及びＲ^２３は、それぞれ独立に水素原子又はアルキル基を示し、Ｒ^２４は、アルキレン基を示す。］

[R ²¹ , R ²² and R ²³ each independently represent a hydrogen atom or an alkyl group, and R ²⁴ represents an alkylene group.]

R ²¹ , R ²² and R ²³ may be a non-bulky substituent from the viewpoint of not lowering reactivity. Also, it may be a substituent that improves the reactivity of the vinyl group in formula (2). R ²⁴ is not particularly limited, but may be a high weight average molecular weight from the viewpoint of making it difficult to volatilize and reducing voids. Also, R ²¹ , R ²² , R ²³ and R ²⁴ may be selected based on the ease of surface treatment. For example, R ²¹ , R ²² and R ²³ may be a hydrogen atom or a methyl group.

The surface treatment agent may be a silane compound such as an epoxy silane, an amino silane, a (meth)acrylic silane, or a vinyl silane, from the viewpoint of ease of surface treatment. In addition, from the viewpoint of more excellent transparency of the semiconductor adhesive, the alumina filler may be an alumina surface that has been silane-treated. The surface treatment agent may be a glycidyl-, phenylamino-, (meth)acrylic, or vinyl-based silane compound, from the viewpoint of excellent dispersibility, fluidity, and adhesive strength. The surface treatment agent may be a vinyl-, phenylamino-, or (meth)acrylic-based silane compound, from the viewpoint of excellent storage stability.

The inorganic filler may be used alone or in combination of two or more different types. The inorganic fillers used in combination may be two or more different types of inorganic fillers, such as a combination of alumina filler and silicon carbide. The inorganic fillers used in combination may also be two or more types of the same type of inorganic filler that are different in shape, average particle size, surface treatment, etc.

The inorganic fillers used in combination may be two or more of the same type of inorganic fillers, two or more types of alumina fillers, two or more types of polyhedral alumina, or two or more types of polyhedral alumina with different average particle sizes, from the viewpoint of better heat dissipation properties.

When two or more types of inorganic fillers are used, from the viewpoint of better heat dissipation, the inorganic fillers may have multiple peaks in the volumetric particle size distribution, and may have peaks in the ranges of 0.1 to 4.5 μm and 5 to 20 μm. In this specification, "peak" means the maximum value of the number frequency in the volumetric particle size distribution.

One of the multiple peaks (first peak) may be at 5 to 15 μm, 5 to 10 μm, or 5 to 8 μm, from the viewpoint of better heat dissipation. One of the multiple peaks (second peak) may be at 0.1 to 3.0 μm, 0.1 to 2.0 μm, or 0.1 to 1.5 μm, from the viewpoint of better heat dissipation.

From the viewpoint of better heat dissipation, the difference in peak position between the first peak and the second peak may be 4 μm or more or 5 μm or more, and may be 10 μm or less, 8 μm or less, or 7 μm or less. The difference in peak position between the first peak and the second peak may be 4 to 10 μm, 4 to 8 μm, or 5 to 7 μm.

An inorganic filler having multiple peaks in the volumetric particle size distribution can be obtained by using two or more types of inorganic fillers with different mode diameters or average particle diameters in combination. The inorganic fillers used in combination may be, for example, an inorganic filler with a mode diameter or average particle diameter of 5 to 20 μm and an inorganic filler with a mode diameter or average particle diameter of 0.1 to 4.5 μm.

From the viewpoint of achieving better heat dissipation, the semiconductor adhesive may be blended with a first inorganic filler having a mode diameter or average particle diameter of 5 to 20 μm and a second inorganic filler having a mode diameter or average particle diameter of 0.1 to 4.5 μm. The mode diameter or average particle diameter of the first inorganic filler may be 5 to 15 μm, 5 to 10 μm, or 5 to 8 μm. The mode diameter or average particle diameter of the second inorganic filler may be 0.1 to 3.0 μm, 0.1 to 2.0 μm, or 0.1 to 1.5 μm.

From the viewpoint of more excellent heat dissipation, the adhesive for semiconductors may be blended with a first polyhedral alumina having an average particle size _r1 of 5 to 20 μm and a second polyhedral alumina having an average particle size _r2 of 0.1 to 4.5 μm. The average particle size _r1 of the first polyhedral alumina may be 5 to 15 μm, 5 to 10 μm, or 5 to 8 μm. The average particle size _r2 of the second polyhedral alumina may be 0.1 to 3.0 μm, 0.1 to 2.0 μm, or 0.1 to 1.5 μm.

From the viewpoint of more excellent heat dissipation properties, the difference (r ₁ -r ₂ ) between the average particle size r ₁ of the first polyhedral alumina and the average particle size r ₂ of the second polyhedral alumina may be 4 to 10 μm, 4 to 8 μm, or 5 to 7 μm.

The blending amount of the first polyhedral alumina and the second polyhedral alumina may be 10 to 70 parts by mass, 10 to 50 parts by mass, or 10 to 30 parts by mass of the second polyhedral alumina per 100 parts by mass of the first polyhedral alumina.

From the viewpoint of achieving better heat dissipation, the content of the first polyhedral alumina in the semiconductor adhesive may be 60% by mass or more or 70% by mass or more, and may be 90% by mass or less or 85% by mass or less, based on the total amount of the semiconductor adhesive. The content of the first polyhedral alumina in the semiconductor adhesive may be 60 to 90% by mass, or 70 to 85% by mass, based on the total amount of the semiconductor adhesive.

From the viewpoint of achieving better heat dissipation, the content of the second polyhedral alumina in the semiconductor adhesive may be 10 mass% or more or 15 mass% or more, and may be 30 mass% or less or 20 mass% or less, based on the total amount of the semiconductor adhesive. The content of the second polyhedral alumina in the semiconductor adhesive may be 10 to 30 mass%, or 15 to 20 mass%, based on the total amount of the semiconductor adhesive.

From the viewpoint of achieving better heat dissipation, the content of the inorganic filler may be 75% by mass or more or 85% by mass or more based on the total amount of the semiconductor adhesive. When the inorganic filler is two or more types of inorganic filler, the content of the inorganic filler means the total amount of all the inorganic fillers.

When the inorganic filler is an alumina filler, the content of the alumina filler may be 75% by mass or more or 85% by mass or more based on the total amount of the semiconductor adhesive, from the viewpoint of better heat dissipation. When the inorganic filler is two or more types of alumina filler, the content of the alumina filler means the total amount of all the alumina fillers.

When the inorganic filler is a mixture of two or more types of alumina filler having different average particle diameters or mode diameters, the content of the alumina filler having the largest average particle diameter or mode diameter may be 60 to 90 mass % or 70 to 85 mass % based on the total amount of the semiconductor adhesive, from the viewpoint of better heat dissipation properties.

(others)
The semiconductor adhesive of this embodiment may further contain additives such as organic filler (resin filler), antioxidant, silane coupling agent (excluding compounds corresponding to fluxing agents), titanium coupling agent, leveling agent, etc. These additives may be used alone or in combination of two or more. The content of these additives may be appropriately adjusted so that the effect of each additive is exerted.

Polyurethane, polyimide, etc. can be used as the material for the organic filler. Compared to inorganic fillers, resin fillers can impart flexibility at high temperatures such as 260°C, which is effective in improving film formability.

(Thermal Conductivity)
The adhesive for a semiconductor according to this embodiment has a thermal conductivity of 1.5 W/mK or more after curing. When the adhesive for a semiconductor has a thermal conductivity of 1.5 W/mK or more after curing, an adhesive for a semiconductor having excellent heat dissipation properties can be provided.

The thermal conductivity of the semiconductor adhesive after curing may be 2.0 W/mK or more, 2.5 W/mK or more, 3.0 W/mK or more, 3.5 W/mK or more, or 4.0 W/mK or more, in order to provide better heat dissipation properties.

The thermal conductivity of the semiconductor adhesive after curing can be calculated by measuring the thermal diffusivity using the laser flash method (Xe-flash method) and multiplying the thermal diffusivity by the specific heat and density. Specifically, the thermal conductivity can be obtained by the method described in the examples below.

The semiconductor adhesive can be cured by heating at 240°C for 1 hour, and specifically, the cured semiconductor adhesive can be obtained by the method described in the examples below.

The semiconductor adhesive of this embodiment can be formed into a film or membrane. The thickness of the film or membrane semiconductor adhesive (film adhesive) may be, for example, 100 μm or less, 80 μm or less, or 50 μm or less. There is no particular limit to the lower limit of the thickness of the film adhesive, but it may be 1 μm or more or 5 μm or more.

<Method of producing semiconductor adhesive>
A film-like or membrane-like semiconductor adhesive can be obtained by the following method. First, the above-mentioned curable resin component, fluxing agent, inorganic filler, and other components are added to an organic solvent, and then dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a resin varnish. Then, the resin varnish is applied to a substrate film that has been subjected to a release treatment using a knife coater, roll coater, applicator, die coater, comma coater, etc., and the organic solvent is reduced by heating to form a semiconductor adhesive on the substrate film. In addition, before reducing the organic solvent by heating, the resin varnish may be spin-coated on a wafer or the like to form a film, and then the solvent may be dried to form a semiconductor adhesive on the wafer.

There are no particular limitations on the substrate film, so long as it has heat resistance sufficient to withstand the heating conditions used when volatilizing the organic solvent, and examples of the substrate film include polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, polyether naphthalate film, methylpentene film, etc. The substrate film is not limited to a single layer film made of one of these films, but may be a multilayer film made of two or more types of films.

Specific conditions for volatilizing the organic solvent from the applied resin varnish may include heating at 50 to 200°C for 0.1 to 90 minutes. Conditions may be such that the organic solvent volatilizes to 1.5% or less, provided that this does not affect voids or viscosity adjustment after mounting.

<Semiconductor Device>
A semiconductor device manufactured using the semiconductor adhesive according to this embodiment will be described. The semiconductor device according to this embodiment includes a connection structure in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the connection parts of a plurality of semiconductor chips are electrically connected to each other, and a sealant that seals at least a part of the connection parts, and the sealant includes a cured product of the semiconductor adhesive according to this embodiment. The connection parts in the semiconductor device may be either a metal bond between a bump and a wiring, or a metal bond between a bump and another bump. In the semiconductor device according to this embodiment, for example, a flip chip connection that obtains an electrical connection via the semiconductor adhesive can be used.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device (a COB-type connection between a semiconductor chip and a substrate). As shown in FIG. 1(a), the semiconductor device 100 has a semiconductor chip 10 and a substrate (circuit wiring substrate) 20 facing each other, wiring 15 arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, connection bumps 30 connecting the wiring 15 of the semiconductor chip 10 and the substrate 20 to each other, and a sealant 40 filled without gaps in the gap between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wiring 15 and the connection bumps 30. The wiring 15 and the connection bumps 30 are sealed by the sealant 40 and are isolated from the external environment. The sealant 40 contains a cured product of the semiconductor adhesive according to this embodiment.

As shown in Figure 1 (b), the semiconductor device 200 has a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 arranged on the facing surfaces of the semiconductor chip 10 and the substrate 20, respectively, and a sealing material 40 that fills the gap between the semiconductor chip 10 and the substrate 20 without any gaps. The semiconductor chip 10 and the substrate 20 are flip-chip connected by connecting the facing bumps 32 to each other. The bumps 32 are sealed by the sealing material 40 and are isolated from the external environment.

Figure 2 is a schematic cross-sectional view showing another embodiment of a semiconductor device (COC type connection between semiconductor chips). As shown in Figure 2(a), semiconductor device 300 is similar to semiconductor device 100 except that two semiconductor chips 10 are flip-chip connected by wiring 15 and connection bumps 30. As shown in Figure 2(b), semiconductor device 400 is similar to semiconductor device 200 except that two semiconductor chips 10 are flip-chip connected by bumps 32.

There are no particular limitations on the semiconductor chip 10, and various types of semiconductors can be used, such as elemental semiconductors composed of the same type of element, such as silicon and germanium, and compound semiconductors, such as gallium arsenide and indium phosphide.

The substrate 20 is not particularly limited as long as it is a wired circuit board, and examples thereof include a circuit board in which wiring (wiring pattern) is formed by etching away unnecessary parts of a metal layer formed on the surface of an insulating substrate whose main components are glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, polyimide, etc., a circuit board in which wiring (wiring pattern) is formed on the surface of the insulating substrate by metal plating, etc., and a circuit board in which wiring (wiring pattern) is formed by printing a conductive material on the surface of the insulating substrate.

The connection parts such as wiring 15 and bumps 32 contain gold, silver, copper, solder (the main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), nickel, tin, lead, etc. as main components, and may contain multiple metals.

A metal layer mainly composed of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. may be formed on the surface of the wiring (wiring pattern). This metal layer may be composed of only a single component, or may be composed of multiple components. It may also have a structure in which multiple metal layers are laminated. The metal layer may be copper or solder, which are inexpensive and commonly used, but flux activation is required due to the presence of oxides and impurities.

The materials used for the conductive protrusions called bumps are mainly gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc., and may be composed of only a single component or multiple components. These metals may also be formed to form a laminated structure. The bumps may be formed on a semiconductor chip or substrate. The bumps may be copper or solder, as they are inexpensive and commonly used, but flux activation is required due to the presence of oxides and impurities.

Also, semiconductor devices (packages) such as those shown in Figure 1 or Figure 2 may be stacked and electrically connected with gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel, etc. The connections may be with copper or solder, as these are inexpensive and commonly used, but flux activation is required due to the presence of oxides and impurities. For example, as seen in TSV technology, semiconductor adhesive may be interposed between semiconductor chips, for flip-chip connection or stacking, and holes that penetrate the semiconductor chips may be formed to connect to the electrodes on the pattern surface.

3 is a schematic cross-sectional view showing another embodiment of the semiconductor device (semiconductor chip stacking type embodiment (TSV)). In the semiconductor device 500 shown in FIG. 3, the wiring 15 formed on the interposer 50 is connected to the wiring 15 of the semiconductor chip 10 via the connection bump 30, so that the semiconductor chip 10 and the interposer 50 are flip-chip connected. The gap between the semiconductor chip 10 and the interposer 50 is filled with the sealing material 40 without any gaps. On the surface of the semiconductor chip 10 opposite the interposer 50, the semiconductor chips 10 are repeatedly stacked via the wiring 15, the connection bump 30 and the sealing material 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 10 are connected to each other by the through electrodes 34 filled in the holes that penetrate the inside of the semiconductor chip 10. The material of the through electrodes 34 can be copper, aluminum, etc.

Such TSV technology makes it possible to obtain signals from the back surface of the semiconductor chip, which is not normally used. Furthermore, because the through electrodes 34 are passed vertically through the semiconductor chip 10, the distance between opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 can be shortened, allowing for flexible connections. The semiconductor adhesive according to this embodiment can be used as a sealing material between opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 in such TSV technology.

In addition, with highly flexible bump formation methods such as area bump chip technology, a semiconductor chip can be mounted directly to a motherboard without using an interposer. The semiconductor adhesive of this embodiment can also be applied when mounting such a semiconductor chip directly to a motherboard. The semiconductor adhesive of this embodiment can also be applied when sealing the gap between two wiring circuit boards when stacking the boards.

Figure 5 is a schematic cross-sectional view showing another embodiment of a semiconductor device (a COB-type connection between a semiconductor chip and a substrate). In the semiconductor device 600 shown in Figure 5, a substrate (glass epoxy substrate) 60 having wiring (copper wiring) 15 and a semiconductor chip 10 having wiring (copper pillar, copper post) 15 are connected to each other via a sealing material 40. The wiring 15 of the semiconductor chip 10 and the wiring 15 of the substrate 60 are electrically connected by a connection bump (solder bump) 30. A solder resist 70 is arranged on the surface of the substrate 60 on which the wiring 15 is formed, except for the position where the connection bump 30 is formed. The semiconductor chip 10 may have a through electrode.

<Method of Manufacturing Semiconductor Device>
The method for manufacturing a semiconductor device according to this embodiment is a method for manufacturing a semiconductor device having a connection structure in which the respective connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which the respective connection portions of a plurality of semiconductor chips are electrically connected to each other, and includes a step of sealing at least a portion of the connection portion using a semiconductor adhesive according to this embodiment.

The above process can be carried out by connecting a semiconductor chip and a wiring circuit board, or multiple semiconductor chips together, using the semiconductor adhesive according to this embodiment. In this case, the method for manufacturing a semiconductor device according to this embodiment may include, for example, a step of connecting a semiconductor chip and a wiring circuit board together via a semiconductor adhesive and electrically connecting the respective connection portions of the semiconductor chip and the wiring circuit board together, and/or a step of connecting multiple semiconductor chips together via a semiconductor adhesive and electrically connecting the respective connection portions of the multiple semiconductor chips together.

In the method for manufacturing a semiconductor device according to this embodiment, the connection parts can be connected to each other by metal bonding. That is, the connection parts of the semiconductor chip and the wiring circuit board can be connected to each other by metal bonding, or the connection parts of the multiple semiconductor chips can be connected to each other by metal bonding.

As an example of a method for manufacturing a semiconductor device according to this embodiment, a method for manufacturing a semiconductor device 500 shown in FIG. 3 will be described. In the semiconductor device 500, the wiring (copper wiring) 15 formed on the interposer 50 is connected to the wiring (copper pillar, copper post) 15 of the semiconductor chip 10 via the connection bump (solder bump) 30, so that the semiconductor chip 10 and the interposer 50 are flip-chip connected. The gap between the semiconductor chip 10 and the interposer 50 is filled with the sealing material 40 without any gaps. On the surface of the semiconductor chip 10 opposite the interposer 50, the semiconductor chip 10 is repeatedly stacked via the wiring 15, the connection bump 30, and the sealing material 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 10 are connected to each other by the through electrodes 34 filled in the holes that penetrate the inside of the semiconductor chip 10.

4 is a diagram for explaining an example of a method for manufacturing the semiconductor device shown in FIG. 3. FIG. 4(a) shows a step of pressing a stacked chip having a semiconductor adhesive on the main surface of the semiconductor chip and another semiconductor chip via a semiconductor adhesive. The stacked chip (semiconductor chips to be stacked) 700 includes a semiconductor chip 10 and a semiconductor adhesive 42 provided on the main surface of the semiconductor chip 10. The semiconductor chip 10 includes a through electrode 34 filled in a hole penetrating the inside of the semiconductor chip 10, a wiring 15 arranged on one surface of the semiconductor chip 10, and a connection bump 30 arranged on the wiring 15. The semiconductor adhesive 42 is provided so as to embed the wiring 15 and the connection bump 30, but may cover at least a part of the surface of the semiconductor chip 10, the wiring 15, and the connection bump 30.

The laminated chip 700 can be produced by applying a semiconductor adhesive 42 to a semiconductor wafer having wiring 15 and connection bumps 30, or by applying the semiconductor adhesive 42 in the form of a film, and then dicing the semiconductor wafer into individual semiconductor chips 10. The film-like semiconductor adhesive can be applied by hot pressing, roll lamination, vacuum lamination, or the like.

The bonding of the stacked chip 700 to another semiconductor chip can be performed, for example, by aligning the connection bumps 30 of the stacked chip 700 so as to electrically connect with the through electrodes 34 filled in the holes penetrating the interior of the other semiconductor chip 10, and by using a bonding tool 90 while heating the stacked chip 700 and the semiconductor chip 10 at a temperature equal to or higher than the melting point of the connection bumps 30 (if solder is used for the connection, the temperature applied to the solder portion may be 240°C or higher). This allows the stacked chip 700 and the semiconductor chip 10 to be connected, and the connection portion to be sealed with a hardened product of the semiconductor adhesive.

The connection load depends on the number of bumps, but is set taking into consideration the absorption of bump height variations and the control of bump deformation amount. The connection time may be short from the viewpoint of improving productivity. The connection time may be the time required to melt the solder, remove the oxide film and surface impurities, and form a metal bond at the connection. A short connection time (pressure bonding time) means that the time during which the connection is subjected to a temperature of 240°C or higher during connection formation (main pressure bonding) (for example, the time when solder is used) is 10 seconds or less. The connection time may be 5 seconds or less or 3 seconds or less. A similar method can be applied to the connection between the interposer 50 having the wiring 15 and the stacked chip 700.

By repeating the above steps, the semiconductor device 500 shown in FIG. 4(b) can be manufactured. The semiconductor device 500 may also be manufactured by repeatedly aligning and stacking (temporarily fixing) the stacked chip 700 and the semiconductor chip 10, obtaining a temporarily fixed multi-stage stack, and then performing a heat treatment in a reflow furnace to melt the solder bumps and connect the semiconductor chips together. Since the temporary fixing does not require a significant need to form a metal bond, it may be performed with a lower load, in a shorter time, and at a lower temperature than the above-mentioned full pressure bonding, and has the advantages of improved productivity and prevention of deterioration of the connection. After connecting the semiconductor chip and the substrate, the semiconductor adhesive may be hardened by performing a heat treatment in an oven or the like. The heating temperature may be a temperature at which the semiconductor sealing adhesive hardens and is completely hardened. The heating temperature and heating time may be set appropriately.

The present disclosure will be explained below using examples, but the present disclosure is not limited to these.

<Preparation of semiconductor adhesive>
The compounds used in the preparation of the semiconductor adhesive are shown below.

(Curable resin component)
((a) Epoxy Resin)
- Triphenolmethane skeleton-containing multifunctional solid epoxy (manufactured by Japan Epoxy Resins Co., Ltd., product name "EP1032H60")
- Bisphenol F type liquid epoxy (manufactured by Japan Epoxy Resins Co., Ltd., product name "YL983U")
- Flexible epoxy (product name "YL7175" manufactured by Japan Epoxy Resin Co., Ltd.)

((b) Curing Agent)
2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Kasei Co., Ltd., product name "2MAOK-PW")

((c) Thermoplastic resin)
Phenoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., product name "ZX1356-2", Tg: about 71°C, Mw: about 63,000)

(Inorganic filler)
Polyhedral Alumina 1 (Sumitomo Chemical Co., Ltd., AA-04, average particle size: 0.41 μm)
Polyhedral alumina 2 (Sumitomo Chemical Co., Ltd., AA-07, average particle size: 0.83 μm)
Polyhedral Alumina 3 (Sumitomo Chemical Co., Ltd., AA-1.5, average particle size: 1.6 μm)
Polyhedral Alumina 4 (Sumitomo Chemical Co., Ltd., AA-3, average particle size: 3.7 μm)
Polyhedral Alumina 5 (Sumitomo Chemical Co., Ltd., AA-5, average particle size: 6.6 μm)
Polyhedral Alumina 6 (Sumitomo Chemical Co., Ltd., AA-10, average particle size: 14.5 μm)
Silicon carbide 1 (Tomoe Engineering Co., Ltd., αSiC2500N, average particle size: 0.87 μm)
Silicon carbide 2 (Tomoe Engineering Co., Ltd., βSiC2500N, average particle size: 0.82 μm)
Boron nitride 1 (Momentive, PT132, average particle size: 5.1 μm)
Boron nitride 2 (Momentive, AC6041, average particle size: 5.4 μm)
Boron nitride 3 (Momentive, TECO20191251, average particle size: 4.5 μm)
・Diamond (Tomei Diamond, CMM2-4, average particle size: 2.4 μm)

(Fila)
Inorganic silica filler (Admatechs Co., Ltd., SE2050, average particle size: 500 nm)

(Flux agent)
Glutaric acid (Wako Pure Chemical Industries, Ltd., Wako special grade, melting point: about 95°C)

Example 1
Thermosetting resin ("EP1032H60" 45 parts by mass, "YL983U" 15 parts by mass, "YL7175" 5 parts by mass), 2 parts by mass of curing agent, inorganic filler (amount listed in Table 1, unit: mass% (based on the total amount of semiconductor adhesive)), 10 parts by mass of organic filler, and 4 parts by mass of fluxing agent were added to an organic solvent (cyclohexanone) so that the NV (non-volatile content concentration) was 55% by mass. Then, Φ1.0 mm beads and Φ2.0 mm beads were added in the same mass as the solid content, and the mixture was stirred for 30 minutes with a bead mill (Fritsch Japan Co., Ltd., planetary fine grinder P-7). Then, 30 parts by mass of phenoxy resin was added as a thermoplastic resin, and the mixture was stirred again with a bead mill for 30 minutes. The beads used for stirring were removed by filtration. The prepared varnish was coated using a small precision coating device (manufactured by Yasui Seiki Co., Ltd.) and dried (100°C/10 minutes) in a clean oven (manufactured by ESPEC Corporation) to obtain a film-like adhesive (semiconductor adhesive) with a thickness of 400 µm.

(Examples 2 to 21, Comparative Example 1)
A film-like adhesive (semiconductor adhesive) was obtained in the same manner as in Example 1, except that the type and content of the inorganic filler were changed as shown in Tables 1 to 4. The difference in average particle size between Tables 3 and 4 was calculated from the absolute value of the difference in average particle size of the inorganic filler used in combination.

<Evaluation>
(1) Thermal Conductivity Measurement The prepared film-like adhesive was cut into 1 cm x 1 cm pieces, which were cured in a clean oven (manufactured by ESPEC Corporation) at 240 ° C for 1 hour to obtain a cured product. Both sides of the obtained cured product were blackened with graphite spray, and the thermal diffusivity in the thickness direction was measured. The thermal diffusivity was measured by the laser flash method (Xe-flash method) (manufactured by NETZSCH, LFA447 nanoflash). Pulse light irradiation was performed under conditions of a pulse width of 0.1 (ms) and an applied voltage of 236 V. The measurement was performed at an ambient temperature of 25 ° C ± 1 ° C. Next, the thermal conductivity value was obtained by multiplying the specific heat and density by the thermal diffusivity using the following formula (I). The results are shown in Tables 1 to 4.
λ = α × Cp × ρ Formula (I)
[In formula (I), λ is thermal conductivity (W/mK), α is thermal diffusivity (m ² /s), Cp is specific heat (J/kg·K), and ρ is density (g/cm ³ ).]
The specific heat (J/kg·K) was measured using differential scanning calorimetry (DSC) according to the following procedure. The semiconductor adhesive was weighed out into an aluminum pan, and measured at 10° C./min from room temperature (25° C.) to 60° C. using a differential scanning calorimeter (Pyris1, manufactured by Perkin-Elmer Japan Co., Ltd.). Sapphire was used as a reference. The specific heat of the sample at 25° C. was calculated using the known specific heat of sapphire.
The density (g/cm ³ ) was measured at a water temperature of 25° C. using an electronic specific gravity meter (SD-200L, manufactured by Alpha Mirage Co., Ltd.).

In the examples, it was confirmed that excellent heat dissipation was achieved. In the comparative example 1, it was confirmed that sufficient heat dissipation was not achieved.

10...semiconductor chip, 15...wiring, 20, 60...substrate, 30...connection bump, 32...bump, 34...through electrode, 40...sealant, 42...semiconductor adhesive, 50...interposer, 70...solder resist, 90...compression tool, 100, 200, 300, 400, 500, 600...semiconductor device, 700...laminated chip.

Claims (9)

A semiconductor adhesive used to seal a connection portion in a semiconductor device having a connection structure in which connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which connection portions of a plurality of semiconductor chips are electrically connected to each other,
Contains a curable resin component, a flux agent, and an inorganic filler;
The content of the inorganic filler is 60 to 95 mass% based on the total amount of the adhesive for semiconductors,
The inorganic filler is a mixture of polyhedral alumina having a volume-based average particle size r1 of 5 to 20 μm and polyhedral alumina having a volume-based average particle size r2 of 0.1 to _4.5 μm _,
the difference (r ₁ -r ₂ ) between the average particle diameter r ₁ and the average particle diameter r ₂ is 4 to 10 μm;
The adhesive for semiconductors has a thermal conductivity of 1.5 W/mK or more after curing. The semiconductor adhesive according to claim 1, wherein the inorganic filler comprises polyhedral alumina. The semiconductor adhesive according to claim 1 or 2, wherein the inorganic filler contains at least one selected from the group consisting of silicon carbide, boron nitride, diamond, and aluminum nitride. The adhesive for semiconductors according to any one of claims 1 to 3, wherein the inorganic filler has peaks in the ranges of 0.1 to 4.5 μm and 5 to 20 μm in the volume-based particle size distribution. The adhesive for semiconductors according to any one of claims 1 to 4 , which has a thermal conductivity after curing of 3.0 W/mK or more. The adhesive for semiconductors according to any one of claims 1 to 5 , wherein the fluxing agent is a carboxylic acid. The adhesive for a semiconductor according to claim 1 , wherein the curable resin component comprises a thermosetting resin, a curing agent, and a thermoplastic resin. A method for manufacturing a semiconductor device having a connection structure in which connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which connection portions of a plurality of semiconductor chips are electrically connected to each other, comprising:
A method for manufacturing a semiconductor device, comprising the step of sealing at least a part of the connection portion with the adhesive for semiconductor according to any one of claims 1 to 7 . a connection structure in which connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and/or a connection structure in which connection portions of a plurality of semiconductor chips are electrically connected to each other;
a sealant that seals at least a portion of the connection portion,
A semiconductor device, wherein the sealing material comprises a cured product of the adhesive for semiconductors according to any one of claims 1 to 7 .

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