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

Abstract

Provided is an adhesive for a semiconductor, the adhesive being used to seal connection portions in a semiconductor device having: a connection structure in which connection portions of semiconductor chips 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. The adhesive for a semiconductor contains a curable resin component, a flux agent, and an inorganic filler, wherein the content of the inorganic filler is 60-95 mass% with respect to the total amount of said adhesive, and the thermal conductivity of said adhesive after curing is at least 1.5 W / mK.

Description

Technical Field

[0001] The present disclosure relates to an adhesive for semiconductors, as well as a semiconductor device and a method for manufacturing the same.

Background Art

[0002] Conventionally, a wire bonding method using a fine metal wire such as a gold wire has been widely applied to connect a semiconductor chip and a substrate. However, in order to meet the requirements for high functionality, high integration, high speed, etc. of semiconductor devices, a flip chip connection method (FC connection method) in which conductive protrusions called bumps are formed on a semiconductor chip or a substrate and directly connected between the semiconductor chip and the substrate is becoming widespread.

[0003] As the flip chip connection method, methods such as a method of metal bonding using solder, tin, gold, silver, copper, etc., a method of metal bonding by applying ultrasonic vibration, and a method of maintaining mechanical contact by the shrinkage force of resin are known. However, from the viewpoint of the reliability of the connection portion, a method of metal bonding using solder, tin, gold, silver, copper, etc. is common.

[0004] For example, in the connection between a semiconductor chip and a substrate, a COB (Chip On Board) type connection method that is widely used in BGA (Ball Grid Array), CSP (Chip Size Package), etc. is also a flip chip connection method. Further, the flip chip connection method is also widely used in a COC (Chip On Chip) type connection method in which bumps or wirings are formed on a semiconductor chip and connected between the semiconductor chips (see, for example, Patent Document 1 below).

[0005] In packages where further miniaturization, thinning, and high functionality are strongly demanded, chip stack packages, POP (Package On Package), TSV (Through-Silicon Via), etc., which are formed by stacking and multi-staging the above-described connection methods, have also begun to spread widely. Since the package can be made smaller by arranging it in a three-dimensional shape rather than a planar shape, these technologies are frequently used and are also effective in improving the performance of semiconductors, reducing noise, reducing the mounting area, and saving power, and are attracting attention as next-generation semiconductor wiring technologies.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, in the flip chip connection method described above, flip chip connection may be performed via a semiconductor adhesive for the purpose of protecting the metal bonding of the connection portion.

[0008] In flip chip packages, in recent years, high functionality and high integration have been progressing. However, as the functionality and integration increase, the pitch between wirings becomes narrower, resulting in an increase in the heat generation amount of the package. When heat accumulates in the package, the semiconductor chip becomes hot, which may cause malfunction. Therefore, the semiconductor adhesive is required to have better heat dissipation performance than in the past.

[0009] Therefore, an object of the present disclosure is to provide a semiconductor adhesive having excellent heat dissipation performance. Another object of the present disclosure is to provide a semiconductor device using such a semiconductor adhesive and a method for manufacturing the same.

Means for Solving the Problems

[0010] One aspect of the present disclosure provides an adhesive for semiconductors used for sealing connection portions in a semiconductor device including 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, the adhesive for semiconductors containing a curable resin component, a fluxing agent, and an inorganic filler, the content of the inorganic filler being 60 to 95% by mass based on the total amount of the adhesive for semiconductors, and the thermal conductivity of the adhesive for semiconductors after curing being 1.5 W / mK or more.

[0011] The inorganic filler may include polyhedral alumina.

[0012] The inorganic filler may include at least one selected from the group consisting of silicon carbide, boron nitride, diamond, silica, and aluminum nitride.

[0013] The inorganic filler may have peaks in respective ranges of 0.1 to 4.5 μm and 5 to 20 μm in a particle size distribution based on volume.

[0014] The adhesive for semiconductors contains, as the inorganic filler, polyhedral alumina having an average particle size r 1 of 5 to 20 μm based on volume and polyhedral alumina having an average particle size r 2 of 0.1 to 4.5 μm based on volume.

[0015] The average particle size r 1 and the average particle size r 2 The difference (r 1 -r 2 ) may be 4 to 10 μm.

[0016] The adhesive for semiconductors may have a thermal conductivity of 3.0 W / mK or more after curing.

[0017] The fluxing agent may be a carboxylic acid.

[0018] The above curable resin component may contain a thermosetting resin, a curing agent, and a thermoplastic resin.

[0019] Another aspect of the present disclosure provides a method for manufacturing a semiconductor device including 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, the method including a step of sealing at least a part of the connection portion using the above-described semiconductor adhesive.

[0020] Another aspect of the present disclosure provides a semiconductor device including 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, and a sealing material for sealing at least a part of the connection portion, the sealing material including a cured product of the above-described semiconductor adhesive.

Advantages of the Invention

[0021] According to the present disclosure, a semiconductor adhesive excellent in heat dissipation can be provided. Further, according to the present disclosure, a semiconductor device using such a semiconductor adhesive and a method for manufacturing the same can be provided.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments for implementing the present disclosure will be described in detail with reference to the drawings as appropriate. 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” means that either A or B may be included, or both may be included.

[0024] Also, in this specification, a numerical range indicated using “~” indicates a range including the numerical values described before and after “~” as the minimum value and the maximum value, respectively. Further, in the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value of a numerical range at a certain step may be replaced with the upper limit value or the lower limit value of a numerical range at another step. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0025] <Adhesive for semiconductor> The adhesive for semiconductor according to this embodiment is an adhesive for semiconductor used for sealing 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, and contains a curable resin component, a fluxing agent, and an inorganic filler. The content of the inorganic filler is 60 to 95% by mass based on the total amount of the adhesive for semiconductor, and the thermal conductivity after curing of the adhesive for semiconductor is 1.5 W / mK or more.

[0026] (Curable resin component) The curable resin component may contain (a) a thermosetting resin, (b) a curing agent, and (c) a thermoplastic resin.

[0027] ((a) Thermosetting resin) Examples of the thermosetting resin include, for example, epoxy resin, urea resin, melamine resin, and phenol resin. From the viewpoint of good curability and excellent adhesiveness, the thermosetting resin may be an epoxy resin. The thermosetting resin can be used alone or in combination of two or more.

[0028] Examples of the epoxy resin include, for example, an epoxy resin having two or more epoxy groups in the molecule, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin, and various polyfunctional epoxy resins. These epoxy resins can be used alone or in combination of two or more.

[0029] The content of the epoxy resin may be 40 parts by mass or more, or 50 parts by mass or more, based on 100 parts by mass of the curing agent resin component. The content of the epoxy resin may be 90 parts by mass or less, or 80 parts by mass or less, based on 100 parts by mass of the curing agent resin component.

[0030] The content of the epoxy resin may be 10 parts by mass or more, or 20 parts by mass or more, based on 100 parts by mass of the semiconductor adhesive. The content of the epoxy resin may be 50 parts by mass or less, or 40 parts by mass or less, based on 100 parts by mass of the semiconductor adhesive. The content of the epoxy resin may be 10 to 50 parts by mass, based on 100 parts by mass of the semiconductor adhesive.

[0031] ((b) Curing agent) Examples of the curing agent include, for example, phenol 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 phenolic hydroxyl groups, acid anhydrides, amines, or imidazoles, it is likely to exhibit flux activity that suppresses the formation of an oxide film at the connection part, and the connection reliability and insulation reliability can be easily improved.

[0032] Examples of phenolic resin curing agents include curing agents having two or more phenolic hydroxyl groups in the molecule, and phenolic novolac, cresol novolac, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenol, various polyfunctional phenolic resins, etc. can be used. The phenolic resin curing agent can be used alone or in combination of two or more.

[0033] When the curable resin component contains an epoxy resin, the equivalent ratio (phenolic hydroxyl group / epoxy group, molar ratio) of the phenolic resin curing agent to the epoxy resin may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoint of excellent curability, adhesiveness, and storage stability. When the equivalent ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve. When it is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively, the water absorption rate is kept low, and the insulation reliability tends to be further improved.

[0034] Examples of acid anhydride curing agents include methylcyclohexane tetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. The acid anhydride curing agent can be used alone or in combination of two or more.

[0035] When the curable resin component contains an epoxy resin, the equivalent ratio (acid anhydride group / epoxy group, molar ratio) of the acid anhydride curing agent to the epoxy resin may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoint of excellent curability, adhesiveness, and storage stability. When the equivalent ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve. When it is 1.5 or less, unreacted acid anhydrides do not remain excessively, the water absorption rate is kept low, and the insulation reliability tends to be further improved.

[0036] Examples of amine curing agents include dicyandiamide.

[0037] When the curable resin component contains an epoxy resin, the equivalent ratio (amine / epoxy group, molar ratio) of the amine-based curing agent to the epoxy resin may be 0.3 to 1.5, 0.4 to 1.0, or 0.5 to 1.0 from the viewpoints of excellent curability, adhesiveness, and storage stability. When the equivalent ratio is 0.3 or more, the curability tends to improve and the adhesive strength tends to improve. When it is 1.5 or less, unreacted amine does not remain excessively, and the insulation reliability tends to further improve.

[0038] 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-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 isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles. Among these imidazole-based curing agents, 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 isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole may be used from the viewpoint of further excellent curability, storage stability, and connection reliability. The imidazole-based curing agent can be used alone or in combination of two or more. Further, they may be used as latent curing agents encapsulated in microcapsules.

[0039] 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 with respect to 100 parts by mass of the curable resin component. When the content of the imidazole-based curing agent is 0.1 part by mass or more, the curability tends to improve. When it is 20 parts by mass or less, the adhesive composition does not cure before the metal bond is formed, and connection failures are less likely to occur.

[0040] Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium (4-fluorophenyl)borate.

[0041] 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 with respect to 100 parts by mass of the curable resin component. When the content of the phosphine-based curing agent is 0.1 part by mass or more, the curability tends to improve. When it is 10 parts by mass or less, the semiconductor adhesive does not cure before the metal bond is formed, and connection failures are less likely to occur.

[0042] The phenolic resin-based curing agent, acid anhydride-based curing agent, and amine-based curing agent can each be used alone or in combination of two or more. The imidazole-based curing agent and the phosphine-based curing agent may each be used alone, or may be used together with the phenolic resin-based curing agent, acid anhydride-based curing agent, or amine-based curing agent.

[0043] From the viewpoint of excellent curability, the curing agent may be a combination of a phenolic resin-based curing agent and an imidazole-based curing agent, a combination of an acid anhydride-based curing agent and an imidazole-based curing agent, a combination of an amine-based curing agent and an imidazole-based curing agent, or the sole use of an imidazole-based curing agent. Since productivity is improved when connecting in a short time, the sole use of an imidazole-based curing agent with excellent rapid curability may be used. In this case, since volatiles such as low molecular components can be suppressed when curing in a short time, the generation of voids can also be easily suppressed.

[0044] The content of the curing agent may be 0.1 to 20 parts by mass, or 0.1 to 10 parts by mass with respect to 100 parts by mass of the curable resin component.

[0045] ((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-forming property, the thermoplastic resin may be phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber, cyanate ester resin, polycarbodiimide resin, etc., and may be phenoxy resin, polyimide resin, (meth)acrylic resin, acrylic rubber. The thermoplastic resin can be used alone or in combination of two or more.

[0046] Examples of the phenoxy resin include ZX1356-2 and FX-293 manufactured by Nippon Steel Chemical & Material Co., Ltd. As the urethane resin, for example, T-8175N manufactured by DIC Covestro Polymer Co., Ltd., which is polyurethane, can be used. As the (meth)acrylic resin, for example, an acrylic block copolymer which is a block copolymer of at least one compound such as (meth)acrylate compounds such as (meth)acrylic acid and methyl (meth)acrylate can be used. Examples of the acrylic block copolymer include LA4285, LA2330, and LA2140 (all manufactured by Kuraray Co., Ltd.), which are block copolymers of methyl methacrylate and butyl acrylate. From the viewpoint of excellent high heat dissipation property, the thermoplastic resin may be a phenoxy resin having a structure (a structure with many aromatic rings) that is likely to take a crystal structure.

[0047] The glass transition temperature (Tg) of the thermoplastic resin may be 120°C or lower, 100°C or lower, or 85°C or lower from the viewpoint of excellent adhesiveness to the substrate and the chip of the semiconductor adhesive. By containing a thermoplastic resin having a Tg of 120°C or lower in the semiconductor adhesive, the curing reaction can be suppressed. Therefore, it is likely to be embedded in the unevenness such as bumps formed on the semiconductor chip, electrodes formed on the substrate, and wiring patterns, etc., so that air bubbles are less likely to remain, and the generation of voids tends to be suppressed. Also, by containing a thermoplastic resin having a Tg of room temperature (25°C) or higher in the semiconductor adhesive, it becomes easier to form the semiconductor adhesive into a film shape or a membrane shape.

[0048] In this specification, the Tg of the thermoplastic resin means the Tg measured under the conditions of a sample amount of 10 mg, a heating rate of 10°C / min, and a measurement atmosphere: air using differential scanning calorimetry (DSC, DSC-7 type manufactured by PerkinElmer).

[0049] The weight average molecular weight of the thermoplastic resin may be 10,000 or higher, 30,000 or higher, 40,000 or higher, or 50,000 or higher 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 lower, or 500,000 or lower from the viewpoint of excellent film processability of the semiconductor adhesive.

[0050] In this specification, the weight average molecular weight means the weight average molecular weight measured in terms of polystyrene using high performance liquid chromatography (C-R4A manufactured by Shimadzu Corporation).

[0051] 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, based on 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, based on 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 is easily formed into a film or sheet shape.

[0052] The content of the thermoplastic resin may be 0.1 part 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, based on 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, based on 100 parts by mass of the curable resin component.

[0053] 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.

[0054] (Flux agent) The semiconductor adhesive according to this embodiment may further contain a flux agent (that is, a flux activator that exhibits flux activity (activity for removing oxides, impurities, etc.)). Examples of the flux agent include nitrogen-containing compounds having unshared electron pairs (imidazoles, amines, etc.), carboxylic acids, phenols, alcohols, and the like.

[0055] From the viewpoint that the flux agent exhibits stronger flux activity than alcohols and is likely to improve connectivity, it may contain an organic acid that reacts with the epoxy resin.

[0056] When the curable resin component contains an epoxy resin, it reacts with the epoxy resin and does not exist in a free state in the cured product of the semiconductor adhesive, so it is possible to prevent a decrease in insulation reliability. Therefore, it may contain an organic acid or may contain a carboxylic acid.

[0057] Examples of carboxylic acids include fatty saturated carboxylic acids such as acetic 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, octadecanoic acid; fatty unsaturated carboxylic acids such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid; fatty dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, 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, mesitylenic acid; maleic acid and fumaric acid. Further, examples of carboxylic acids having a hydroxyl group include lactic acid, malic acid, citric acid, salicylic acid, etc.

[0058] The carboxylic acid may be a dicarboxylic acid. Since dicarboxylic acids are relatively less volatile than monocarboxylic acids, there is a tendency to suppress voids. Also, dicarboxylic acids are less likely to react at low temperatures (temperatures below bonding, for example, 100 °C or lower) in film formation, lamination, preheating, etc. than tricarboxylic acids, so the viscosity does not become too high and there is a tendency to suppress connection failures.

[0059] The carboxylic acid may be a carboxylic acid having one or more alkyl groups at the 2-position or 3-position from the carboxyl group. Examples of such carboxylic acids having an alkyl group include 2-methylglutaric acid, 3-methylglutaric acid, etc.

[0060] The content of the fluxing agent may be 0.5 part by mass or more, 1 part by mass or more, or 1.5 part by mass or more with respect to 100 parts by mass of the semiconductor adhesive. The content of the fluxing agent may be 10 parts by mass or less, or 5 parts by mass or less with respect to 100 parts by mass of the semiconductor adhesive. The content of the fluxing agent may be 0.5 to 10 parts by mass, or 0.5 to 5 parts by mass with respect to 100 parts by mass of the semiconductor adhesive.

[0061] (Inorganic filler) The semiconductor adhesive of the present embodiment contains an inorganic filler. The content of the inorganic filler is 60 to 95% by mass based on the total amount of the semiconductor adhesive. If the content of the inorganic filler is within the above range, excellent heat dissipation properties can be imparted to the semiconductor adhesive.

[0062] Examples of the inorganic filler include alumina (Al 2 O 3 ), magnesium oxide, silicon carbide, boron nitride, diamond, and aluminum nitride. The inorganic filler may contain at least one selected from the group consisting of alumina, silicon carbide, boron nitride, diamond, and aluminum nitride from the viewpoint of the thermal conductivity of the semiconductor adhesive.

[0063] When the inorganic filler is particles containing alumina (hereinafter also referred to as "alumina filler"), the alumina may be α-alumina. The purity of alumina in the alumina filler may be 99.0% by mass or more, 99.5% by mass or more, or 99.9% by mass or more from the viewpoint of excellent heat dissipation properties of the semiconductor adhesive. The purity of the alumina filler may be in a mode that consists substantially of alumina (100% by mass of the alumina filler is substantially alumina).

[0064] The shape of the alumina filler is not particularly limited, and examples thereof include spherical, substantially spherical, polyhedral, needle-like, and plate-like shapes. Among these, from the viewpoint of excellent heat dissipation of the semiconductor adhesive, it may be spherical or polyhedral, and may be polyhedral. In the present specification, the "polyhedron" refers to a solid having a plurality of planes as constituent parts of the surface. The plurality of existing planes may intersect through curved surfaces (the shape may have rounded corners). The polyhedron may have, for example, 4 to 100 planes as constituent parts of the surface.

[0065] The reason why the heat dissipation of the semiconductor adhesive is excellent by using polyhedral alumina as the alumina filler is not necessarily clear, but the inventors of the present invention believe that when the alumina filler is polyhedral, the fillers come into contact with each other on the surface, and the heat transfer area increases, thereby improving heat transfer.

[0066] From the viewpoint of improving the film-forming property when the semiconductor adhesive is formed into a film, 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 the dispersibility of the inorganic filler, 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.

[0067] In the present specification, the "average particle diameter" is the particle diameter at the point corresponding to 50% by volume when a cumulative frequency distribution curve by particle diameter is obtained with the total volume of the particles being 100%, and can be measured with a particle size distribution measuring device using the laser diffraction scattering method or the like.

[0068] From the viewpoint of further improving visibility, dispersibility, and adhesive strength, the alumina filler may be one having its alumina surface treated. Examples of the surface treatment agent include glycidyl-based (epoxy-based) compounds, amine-based compounds, phenyl-based compounds, phenylamino-based compounds, (meth)acrylic-based compounds (for example, compounds having a structure represented by the following general formula (1)), vinyl-based compounds having a structure represented by the following general formula (2), and the like.

[0069]

Chemical formula

[0070] Examples of the filler surface-treated with the compound having the 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, an ethacrylic surface-treated filler in which R 11 is an ethyl group, and the like. From the viewpoints of the reactivity between 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, which 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 limitation on the alkylene group of R 12 , but from the viewpoint of reducing volatile components, it may have a high weight-average molecular weight.

[0071] [Chemical formula] [R 21 , R 22 and R 23 each independently represent a hydrogen atom or an alkyl group, and R 24 represents an alkylene group.]

[0072] R 21 , R 22 and R 23 may be non-bulky substituents from the viewpoint of not reducing reactivity. Further, they may be substituents that improve the reactivity of the vinyl group in formula (2). There is no particular limitation on R 24 , but from the viewpoint of making it difficult to volatilize and reducing voids, it may have a high weight-average molecular weight. Further, 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 R23 It may be a hydrogen atom or a methyl group.

[0073] As the surface treatment agent, from the viewpoint of ease of surface treatment, it may be a silane compound such as an epoxy-based silane, an amino-based silane, a (meth)acrylic-based silane, or a vinyl-based silane. Further, from the viewpoint of better transparency of the adhesive for semiconductors, the alumina filler may be one obtained by subjecting the alumina surface to silane treatment. As the surface treatment agent, from the viewpoints of excellent dispersibility, fluidity, and adhesive strength, it may be a glycidyl-based, phenylamino-based, (meth)acrylic, or vinyl-based silane compound. As the surface treatment agent, from the viewpoint of excellent storage stability, it may be a vinyl-based, phenylamino-based, or (meth)acrylic-based silane compound.

[0074] The inorganic filler can be used alone or in combination of two or more different types. The inorganic fillers used in combination may be, for example, two or more different types of inorganic fillers such as the combination of alumina filler and silicon carbide. Also, the inorganic fillers used in combination may be two or more of the same type of inorganic fillers having different shapes, average particle diameters, surface treatments, etc.

[0075] From the viewpoint of better heat dissipation, the inorganic fillers used in combination may be two or more of the same type of inorganic fillers, two or more alumina fillers, two or more polyhedral aluminas, or two or more polyhedral aluminas having different average particle diameters.

[0076] When using two or more types of inorganic fillers, from the viewpoint of better heat dissipation, the inorganic fillers may have multiple peaks in the particle size distribution based on volume, and may have peaks in the respective 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 particle size distribution based on volume.

[0077] One of the plurality of peaks (the first peak) may be in the range of 5 to 15 μm, 5 to 10 μm, or 5 to 8 μm from the viewpoint of better heat dissipation. One of the plurality of peaks (the second peak) may be in the range of 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.

[0078] The difference in peak positions 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 from the viewpoint of better heat dissipation. The difference in peak positions between the first peak and the second peak may be 4 to 10 μm, 4 to 8 μm, or 5 to 7 μm.

[0079] The inorganic filler having a plurality of peaks in the volume-based particle size distribution can be obtained by using in combination two or more kinds of inorganic fillers having different mode diameters or average particle diameters. The inorganic fillers to be used in combination may be, for example, an inorganic filler having a mode diameter or an average particle diameter of 5 to 20 μm and an inorganic filler having a mode diameter or an average particle diameter of 0.1 to 4.5 μm.

[0080] The adhesive for a semiconductor may be blended with a first inorganic filler having a mode diameter or an average particle diameter of 5 to 20 μm and a second inorganic filler having a mode diameter or an average particle diameter of 0.1 to 4.5 μm from the viewpoint of better heat dissipation. The mode diameter or the 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 the 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.

[0081] The adhesive for a semiconductor, from the viewpoint of better heat dissipation, 1 a first polyhedral alumina having an average particle diameter r 2 of 5 to 20 μm and a second polyhedral alumina having an average particle diameter r 1 of 0.1 to 4.5 μm may be blended. The average particle diameter r of the first polyhedral alumina2 may be 0.1 to 3.0 μm, 0.1 to 2.0 μm, or 0.1 to 1.5 μm.

[0082] The average particle diameter r of the first polyhedral alumina 1 and the average particle diameter r of the second polyhedral alumina 2 The difference (r 1 - r 2 ) may be 4 to 10 μm, 4 to 8 μm, or 5 to 7 μm from the viewpoint of better heat dissipation.

[0083] 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 with respect to 100 parts by mass of the first polyhedral alumina.

[0084] 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 from the viewpoint of better heat dissipation. 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.

[0085] The content of the second polyhedral alumina in the semiconductor adhesive may be 10% by mass or more or 15% by mass or more, and may be 30% by mass or less or 20% by mass or less based on the total amount of the semiconductor adhesive from the viewpoint of better heat dissipation. The content of the second polyhedral alumina in the semiconductor adhesive may be 10 to 30% by mass, or 15 to 20% by mass based on the total amount of the semiconductor adhesive.

[0086] 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 from the viewpoint of better heat dissipation. When the inorganic filler is two or more types of inorganic fillers, the content of the inorganic filler means the total amount of all the inorganic fillers.

[0087] When the inorganic filler is 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 fillers, the content of the alumina filler means the total amount of all the alumina fillers.

[0088] When the inorganic filler is a mixture of two or more types of alumina fillers with different average particle diameters or mode diameters, the content of the alumina filler with the largest average particle diameter or mode diameter 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 better heat dissipation.

[0089] (Others) The semiconductor adhesive of the present embodiment may further contain additives such as organic fillers (resin fillers), antioxidants, silane coupling agents (excluding compounds corresponding to flux agents), titanium coupling agents, and leveling agents. These additives can be used alone or in combination of two or more. The content of these additives may be appropriately adjusted so that the effects of each additive are exhibited.

[0090] As the material of the organic filler, polyurethane, polyimide, etc. can be used. Since the resin filler can impart flexibility at a high temperature such as 260°C compared to the inorganic filler, it is effective in improving film formability.

[0091] (Thermal conductivity) The semiconductor adhesive according to the present embodiment has a thermal conductivity after curing of 1.5 W / mK or more. By having a thermal conductivity after curing of the semiconductor adhesive of 1.5 W / mK or more, a semiconductor adhesive with excellent heat dissipation can be provided.

[0092] From the viewpoint of better heat dissipation, the thermal conductivity after curing of the semiconductor adhesive 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.

[0093] The thermal conductivity after curing of the adhesive for semiconductors can be calculated by measuring the thermal diffusivity by the laser flash method (Xe-flash method) and multiplying the specific heat and density by the thermal diffusivity. Specifically, the thermal conductivity can be obtained by the method described in the examples below.

[0094] The adhesive for semiconductors can be cured by heating at 240°C for 1 hour. Specifically, the cured adhesive for semiconductors can be obtained by the method described in the examples below.

[0095] The adhesive for semiconductors of this embodiment can be formed in a film shape or a membrane shape. The thickness of the film-shaped or membrane-shaped adhesive for semiconductors (film-shaped adhesive) may be, for example, 100 μm or less, 80 μm or less, or 50 μm or less. There is no particular limitation on the lower limit of the thickness of the film-shaped adhesive, but it may be 1 μm or more or 5 μm or more.

[0096] <Method for producing an adhesive for semiconductors> The film-shaped or membrane-shaped adhesive for semiconductors can be obtained by the following method. First, the above-described curable resin component, fluxing agent, inorganic filler, and other components are added to an organic solvent, and then dissolved or dispersed by stirring, kneading, etc. to prepare a resin varnish. Then, the resin varnish is applied onto a base film subjected to a release treatment using a knife coater, roll coater, applicator, die coater, comma coater, etc., and then the organic solvent is reduced by heating to form an adhesive for semiconductors on the base film. Also, before reducing the organic solvent by heating, the resin varnish may be spin-coated onto a wafer or the like to form a film, and then the adhesive for semiconductors may be formed on the wafer by a method of performing solvent drying.

[0097] The base film is not particularly limited as long as it has heat resistance capable of withstanding the heating conditions when the organic solvent is volatilized, and examples include polyester film, polypropylene film, polyethylene terephthalate film, polyimide film, polyetherimide film, polyether naphthalate film, methyl pentene film, etc. The base film is not limited to a single-layer film composed of one of these films, and may be a multilayer film composed of two or more films.

[0098] Specifically, as the conditions for volatilizing the organic solvent from the resin varnish after coating, heating may be performed at 50 to 200 °C for 0.1 to 90 minutes. As long as there is no influence on voids after mounting, viscosity adjustment, etc., conditions under which the organic solvent volatilizes to 1.5% or less may also be used.

[0099] <Semiconductor device> A semiconductor device manufactured using the semiconductor adhesive according to this embodiment will be described. The semiconductor device according to this embodiment has a connection structure in which the connection portions of the semiconductor chip and the 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 part of the connection portion. The sealing material contains a cured product of the semiconductor adhesive according to this embodiment. The connection portion in the semiconductor device may be either a metal bond between a bump and a wiring or a metal bond between bumps. In the semiconductor device according to this embodiment, for example, flip chip connection for obtaining an electrical connection through a semiconductor adhesive can be used.

[0100] FIG. 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device (COB type connection mode of a semiconductor chip and a substrate). As shown in FIG. 1(a), the semiconductor device 100 includes a semiconductor chip 10 and a substrate (circuit wiring board) 20 facing each other, wirings 15 respectively disposed on the opposing surfaces of the semiconductor chip 10 and the substrate 20, connection bumps 30 connecting the wirings 15 of the semiconductor chip 10 and the substrate 20 to each other, and a sealing material 40 filling the gap between the semiconductor chip 10 and the substrate 20 without any gap. The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wirings 15 and the connection bumps 30. The wirings 15 and the connection bumps 30 are sealed by the sealing material 40 and are blocked from the external environment. The sealing material 40 includes a cured product of an adhesive for semiconductors according to the present embodiment.

[0101] As shown in FIG. 1(b), the semiconductor device 200 includes a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 respectively disposed on the opposing surfaces of the semiconductor chip 10 and the substrate 20, and a sealing material 40 filling the gap between the semiconductor chip 10 and the substrate 20 without any gap. The semiconductor chip 10 and the substrate 20 are flip-chip connected by connecting the opposing bumps 32 to each other. The bumps 32 are sealed by the sealing material 40 and are blocked from the external environment.

[0102] FIG. 2 is a schematic cross-sectional view showing another embodiment of a semiconductor device (COC type connection mode between semiconductor chips). 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 wirings 15 and 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.

[0103] The semiconductor chip 10 is not particularly limited, and various semiconductors such as elemental semiconductors composed of the same kind of elements such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphide can be used.

[0104] The substrate 20 is not particularly limited as long as it is a wiring circuit board. For example, it can be a circuit board formed by etching away unnecessary portions of a metal layer formed on the surface of an insulating substrate mainly composed of glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine, polyimide, etc. to form wiring (wiring pattern); a circuit board with wiring (wiring pattern) formed on the surface of the above insulating substrate by metal plating or the like; a circuit board with wiring (wiring pattern) formed by printing a conductive substance on the surface of the above insulating substrate, etc.

[0105] The connection parts such as the wiring 15 and the bump 32 contain, as main components, gold, silver, copper, solder (the main components are, for example, tin - silver, tin - lead, tin - bismuth, tin - copper), nickel, tin, lead, etc., and may contain a plurality of metals.

[0106] On the surface of the wiring (wiring pattern), a metal layer mainly composed of gold, silver, copper, solder (the main components are, for example, tin - silver, tin - lead, tin - bismuth, tin - copper), tin, nickel, etc. may be formed. This metal layer may be composed of only a single component, or may be composed of a plurality of components. Also, a structure in which a plurality of metal layers are laminated may be formed. Since it is inexpensive and commonly used, the metal layer may be copper or solder, but due to the presence of oxides and impurities, flux activity is required.

[0107] As the material of the conductive protrusion called a bump, as main components, gold, silver, copper, solder (the main components are, for example, tin - silver, tin - lead, tin - bismuth, tin - copper), tin, nickel, etc. are used, and it may be composed of only a single component, or may be composed of a plurality of components. Also, it may be formed so as to have a structure in which these metals are laminated. The bump may be formed on the semiconductor chip or the substrate. Since it is inexpensive and commonly used, the bump may be copper or solder, but due to the presence of oxides and impurities, flux activity is required.

[0108] Alternatively, semiconductor devices (packages) as shown in FIG. 1 or FIG. 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. Since it is inexpensive and commonly used, the connection may be made of copper or solder. However, due to the presence of oxides and impurities, flux activity is required. For example, a semiconductor adhesive may be interposed between semiconductor chips through the TSV technology, flip-chip connection or stacking may be performed, holes penetrating the semiconductor chips may be formed, and the electrodes on the pattern surface may be connected.

[0109] FIG. 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device (a 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 bumps 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 to the interposer 50, the semiconductor chips 10 are repeatedly stacked via the wiring 15, the connection bumps 30, and the sealing material 40. The wirings 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 penetrating the inside of the semiconductor chip 10. Note that, as the material of the through electrodes 34, copper, aluminum, etc. can be used.

[0110] With such TSV technology, signals can be obtained from the back surface of a semiconductor chip that is not normally used. Furthermore, since the through electrodes 34 are vertically passed through the semiconductor chip 10, the distance between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 can be shortened, enabling flexible connection. The semiconductor adhesive according to this embodiment can be applied as a sealing material between the opposing semiconductor chips 10 or between the semiconductor chip 10 and the interposer 50 in such TSV technology.

[0111] In addition, in a bump formation method with a high degree of freedom such as area bump chip technology, the semiconductor chip can be directly mounted on the mother board without going through an interposer. The adhesive for semiconductor according to the present embodiment can also be applied when such a semiconductor chip is directly mounted on the mother board. Note that the adhesive for semiconductor according to the present embodiment can also be applied when sealing the gap between the substrates when two wiring circuit boards are laminated.

[0112] FIG. 5 is a schematic cross-sectional view showing another embodiment of a semiconductor device (COB type connection mode of a semiconductor chip and a substrate). In the semiconductor device 600 shown in FIG. 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 disposed on the surface of the substrate 60 where the wiring 15 is formed, except for the formation position of the connection bump 30. The semiconductor chip 10 may have a through electrode.

[0113] <Manufacturing method of semiconductor device> The manufacturing method of the semiconductor device according to the present embodiment is a manufacturing method of a semiconductor device including a connection structure in which the connection portions of the semiconductor chip and the 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 includes a step of sealing at least a part of the connection portion using the adhesive for semiconductor according to the present embodiment.

[0114] The above process can be carried out by connecting a semiconductor chip and a wiring circuit board, or a plurality of semiconductor chips to each other using the adhesive for semiconductors according to the present embodiment. In this case, the method for manufacturing a semiconductor device according to the present embodiment may include, for example, steps of connecting a semiconductor chip and a wiring circuit board to each other via an adhesive for semiconductors and electrically connecting the respective connection portions of the semiconductor chip and the wiring circuit board to each other, and / or steps of connecting a plurality of semiconductor chips to each other via an adhesive for semiconductors and electrically connecting the respective connection portions of the plurality of semiconductor chips to each other.

[0115] In the method for manufacturing a semiconductor device according to the present embodiment, the connection portions can be connected to each other by metal bonding. That is, the respective connection portions of the semiconductor chip and the wiring circuit board can be connected to each other by metal bonding, or the respective connection portions of the plurality of semiconductor chips can be connected to each other by metal bonding.

[0116] As an example of the method for manufacturing a semiconductor device according to the present embodiment, the method for manufacturing the 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 gap. On the surface of the semiconductor chip 10 opposite to the interposer 50, the semiconductor chips 10 are repeatedly stacked via the wiring 15, the connection bumps 30, and the sealing material 40. The wirings 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 penetrating the inside of the semiconductor chip 10.

[0117] FIG. 4 is a diagram for explaining an example of a method for manufacturing the semiconductor device shown in FIG. 3. (a) of FIG. 4 shows a step of pressing a stacked chip in which a semiconductor adhesive is provided on the main surface of a semiconductor chip and another semiconductor chip via the semiconductor adhesive. The stacked chip (stacked semiconductor chip) 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 is provided with a through electrode 34 filled in a hole penetrating the inside of the semiconductor chip 10, a wiring 15 disposed on one surface of the semiconductor chip 10, and a connection bump 30 disposed 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.

[0118] The stacked chip 700 can be manufactured by dicing a semiconductor wafer having the wiring 15 and the connection bump 30 after applying the semiconductor adhesive 42 or after pasting the semiconductor adhesive 42 in a film form and then separating it into individual semiconductor chips 10. The pasting of the film-like semiconductor adhesive can be performed by heat pressing, roll lamination, vacuum lamination, or the like.

[0119] The pressing of the stacked chip 700 and another semiconductor chip can be performed, for example, by aligning the connection bump 30 of the stacked chip 700 so as to be electrically connected to a through electrode 34 filled in a hole penetrating the inside of the other semiconductor chip 10, and using a pressing 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 bump 30 (when solder is used for the connection part, the temperature applied to the solder part may be 240° C. or higher). Thereby, the stacked chip 700 and the semiconductor chip 10 can be connected, and the connection part can be sealed with a cured product of the semiconductor adhesive.

[0120] The connection load depends on the number of bumps, but is set in consideration of absorbing the height variation of the bumps, controlling the amount of bump deformation, etc. The connection time may be short from the viewpoint of improving productivity. The connection time may be a time sufficient to melt the solder, remove the oxide film, surface impurities, etc., and form a metal bond at the connection portion. The short connection time (crimping time) means that the time during which a temperature of 240°C or higher is applied to the connection portion during connection formation (main crimping) (for example, the time when using solder) is 10 seconds or less. The connection time may be 5 seconds or less, or 3 seconds or less. The same method can also be applied to the connection between the interposer 50 having the wiring 15 and the stacked chip 700.

[0121] By repeating the above steps, the semiconductor device 500 shown in FIG. 4(b) can be manufactured. Further, the semiconductor device 500 may be manufactured by repeatedly aligning and stacking (temporarily fixing) the stacked chip 700 and the semiconductor chip 10, obtaining a temporarily fixed multi-stage stacked body, and then performing heat treatment in a reflow furnace to melt the solder bumps and connect the semiconductor chips together all at once. Since the need to form a metal bond is not significantly required for temporary fixing, it may be at a lower load, shorter time, and lower temperature than the above-described main crimping, and merits such as improved productivity and prevention of deterioration of the connection portion occur. After connecting the semiconductor chip and the substrate, heat treatment may be performed in an oven or the like to cure the semiconductor adhesive. The heating temperature may be a temperature at which the curing of the semiconductor encapsulation adhesive proceeds and is completely cured. The heating temperature and heating time may be set as appropriate.

Example

[0122] Hereinafter, the present disclosure will be described using examples, but the present disclosure is not limited thereto.

[0123] <Fabrication of Semiconductor Adhesive> The compounds used for the fabrication of the semiconductor adhesive are shown below.

[0124] (Curable Resin Component) ((a) Epoxy Resin) · Polyfunctional solid epoxy containing a triphenol methane skeleton (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 (manufactured by Japan Epoxy Resins Co., Ltd., product name "YL7175")

[0125] ((b) Curing agent) 2,4 - Diamino - 6 - [2’ - methylimidazolyl - (1’)] - ethyl - s - triazine isocyanurate adduct (manufactured by Shikoku Chemicals Corporation, product name "2MAOK - PW")

[0126] ((c) Thermoplastic resin) Phenoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., product name "ZX1356 - 2", Tg: about 71°C, Mw: about 63000)

[0127] (Inorganic filler) · Polyhedral alumina 1 (Sumitomo Chemical Co., Ltd., AA - 04, average particle size: 0.41μm) · Polyhedral alumina 2 (Sumitomo Chemical Co., Ltd., AA - 07, average particle size: 0.83μm) · Polyhedral alumina 3 (Sumitomo Chemical Co., Ltd., AA - 1.5, average particle size: 1.6μm) · Polyhedral alumina 4 (Sumitomo Chemical Co., Ltd., AA - 3, average particle size: 3.7μm) · Polyhedral alumina 5 (Sumitomo Chemical Co., Ltd., AA - 5, average particle size: 6.6μm) · Polyhedral alumina 6 (Sumitomo Chemical Co., Ltd., AA - 10, average particle size: 14.5μm) · Silicon carbide 1 (Bar Industrial Co., Ltd., αSiC2500N, average particle size: 0.87μm) · Silicon carbide 2 (Bar Industrial Co., Ltd., βSiC2500N, average particle size: 0.82μm) · Boron nitride 1 (Momentive, PT132, average particle size: 5.1μm) · Boron nitride 2 (Momentive, AC6041, average particle size: 5.4μm) · Boron nitride 3 (Momentive, TECO20191251, average particle diameter: 4.5 μm) · Diamond (Tomei Diamond, CMM2-4, average particle diameter: 2.4 μm)

[0128] (Filler) · Inorganic silica filler (Admatechs Co., Ltd., SE2050, average particle diameter: 500 nm)

[0129] (Flux agent) Glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd., Wako special grade, melting point: about 95 °C)

[0130] (Example 1) Thermosetting resin (45 parts by mass of "EP1032H60", 15 parts by mass of "YL983U", 5 parts by mass of "YL7175"), 2 parts by mass of curing agent, inorganic filler (the amounts shown in Table 1, unit: mass% based on the total amount of the semiconductor adhesive), 10 parts by mass of organic filler, and 4 parts by mass of flux agent were added to an organic solvent (cyclohexanone) so that the NV (non-volatile content concentration) became 55% by mass. Then, beads with a diameter of Φ1.0 mm and beads with a diameter of Φ2.0 mm were added in the same mass as the solid content, and stirred for 30 minutes with a bead mill (manufactured by Fritsch Japan Co., Ltd., planetary type fine grinder P-7). Then, 30 parts by mass of phenoxy resin was added as a thermoplastic resin, and stirred again with a bead mill for 30 minutes. The beads used for stirring were removed by filtration. The prepared varnish was applied with a small precision coating device (manufactured by Renkei Seiki Co., Ltd.) and dried in a clean oven (manufactured by ESPEC Corporation) (100 °C / 10 minutes) to obtain a film-shaped adhesive (semiconductor adhesive) with a thickness of 400 μm.

[0131] (Examples 2 to 21, Comparative Example 1) A film-shaped 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 the average particle diameter in Tables 3 and 4 was calculated from the absolute value of the difference in the average particle diameter of the combined inorganic fillers.

[0132] (Evaluation) (1) Thermal conductivity measurement The prepared film-shaped adhesive was cut into 1 cm × 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 by graphite spraying, 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). The pulsed light irradiation was performed under the conditions of a pulse width of 0.1 (ms) and an applied voltage of 236 V. The measurement was carried out at an ambient temperature of 25 °C ± 1 °C. Next, the value of the thermal conductivity 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 the thermal conductivity (W / mK), α is the thermal diffusivity (m 2 / s), Cp is the specific heat (J / kg·K), and ρ is the density (g / cm 3 ).] The specific heat (J / kg·K) was measured by the following procedure using differential scanning calorimetry (DSC). The semiconductor adhesive was weighed into an aluminum pan, and using a differential scanning calorimeter (manufactured by Perkin-Elmer Japan Co., Ltd., Pyris1), it was measured from room temperature (25 °C) to 60 °C at 10 °C / min. 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 (manufactured by Alpha Mirage Co., Ltd., SD-200L).

[0133]

Table 1

[0134]

Table 2

[0135]

Table 3

[0136]

Table 4

[0137] In the examples, it was confirmed that excellent heat dissipation was obtained. In Comparative Example 1, it was confirmed that sufficient heat dissipation could not be obtained.

Explanation of Reference Signs

[0138] 10…semiconductor chip, 15…wiring, 20, 60…substrate, 30…connection bump, 32…bump, 34…through electrode, 40…sealing material, 42…adhesive for semiconductor, 50…interposer, 70…solder resist, 90…crimping tool, 100, 200, 300, 400, 500, 600…semiconductor device, 700…stacked chip.

Claims

1. A semiconductor adhesive used for sealing a connection portion in a semiconductor device including 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, the semiconductor adhesive containing: a curable resin component, a fluxing agent, and an inorganic filler; wherein the content of the inorganic filler is 60 to 95% by mass based on the total amount of the semiconductor adhesive; wherein the inorganic filler is blended with polyhedral alumina having an average particle diameter r1 of 5 to 20 μm on a volume basis and polyhedral alumina having an average particle diameter r2 of 0.1 to 4.5 μm on a volume basis; wherein the difference (r1 - r2) between the average particle diameter r1 and the average particle diameter r2 is 4 to 10 μm; and wherein the thermal conductivity of the semiconductor adhesive after curing is 1.5 W / mK or more.

2. The semiconductor adhesive according to claim 1, wherein the inorganic filler contains polyhedral alumina.

3. 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.

4. The semiconductor adhesive 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 a particle size distribution on a volume basis.

5. The semiconductor adhesive according to any one of claims 1 to 4, wherein the thermal conductivity after curing is 3.0 W / mK or more.

6. The semiconductor adhesive according to any one of claims 1 to 5, wherein the fluxing agent is a carboxylic acid.

7. The semiconductor adhesive according to any one of claims 1 to 6, wherein the curable resin component includes a thermosetting resin, a curing agent, and a thermoplastic resin.

8. A method for manufacturing a semiconductor device including 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, the method comprising: a step of sealing at least a part of the connection portion with the semiconductor adhesive according to any one of claims 1 to 7.

9. 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 sealing material for sealing at least a part of the connection portion, The semiconductor device, wherein the sealing material includes a cured product of the semiconductor adhesive according to any one of claims 1 to 7.

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