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

Abstract

This semiconductor adhesive is used to seal connection units in a semiconductor device that is provided with connection structures where connection units of a semiconductor chip and a wiring board are connected together electrically, and / or connection structures where connection units of multiple semiconductor chips are connected together electrically, wherein the semiconductor adhesive contains a curable resin component and an alumina filler with an average particle diameter of 15μm or less, the content of the alumina filler is 35-75 mass% of the total amount of the semiconductor adhesive, and the thermal conductivity of the semiconductor adhesive after curing is 0.5-1.5 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, in order to connect a semiconductor chip and a substrate, a wire bonding method using a fine metal wire such as a gold wire has been widely applied. 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 metal bonding using solder, tin, gold, silver, copper, etc., methods of applying ultrasonic vibration to perform metal bonding, and methods 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 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 that are strongly required to be further miniaturized, thinner, and more highly functional, chip stack packages, POP (Package On Package), TSV (Through-Silicon Via), etc., in which the above-described connection method is laminated and multi-staged, have also begun to spread widely. Since the package can be made smaller by arranging it in a three-dimensional shape instead of 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, for the purpose of protecting the metal bonding of the connection part, flip chip connection may be performed via a semiconductor adhesive.

[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. If 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 before.

[0009] Also, in the connection process in the manufacture of flip chip packages, alignment is usually performed using alignment marks provided on the substrate or semiconductor chip as a guide. When performing flip chip connection via a semiconductor adhesive, the semiconductor chip or substrate provided with the semiconductor adhesive is aligned. Therefore, the semiconductor adhesive is required to have visibility that allows the covered alignment marks to be visually recognized.

[0010] Therefore, an object of the present disclosure is to provide an adhesive for a semiconductor that has excellent heat dissipation properties and sufficient visibility. Another object of the present disclosure is to provide a semiconductor device using such an adhesive for a semiconductor and a method for manufacturing the same.

Means for Solving the Problems

[0011] One aspect of the present disclosure is an adhesive for a semiconductor used for sealing a connection portion in a semiconductor device in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which the connection portions of a plurality of semiconductor chips are electrically connected to each other, the adhesive for a semiconductor containing a curable resin component and alumina filler having an average particle diameter of 15 μm or less, the content of the alumina filler being 35 to 75% by mass based on the total amount of the adhesive for a semiconductor, and the thermal conductivity of the adhesive for a semiconductor after curing being 0.5 to 1.5 W / mK.

[0012] The above adhesive for a semiconductor may further contain a fluxing agent.

[0013] The above fluxing agent may be a carboxylic acid.

[0014] The above alumina filler may be one obtained by subjecting the alumina surface to a silane treatment.

[0015] The average particle diameter of the above alumina filler may be 0.5 μm or less.

[0016] The above adhesive for a semiconductor may be an adhesive for a semiconductor having a light transmittance of 0.5% or more with respect to light having a wavelength of 550 nm.

[0017] The above curable resin component may include a thermosetting resin, a curing agent, and a thermoplastic resin.

[0018] 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.

[0019] The above step may include a step of pressing an alignment mark-equipped semiconductor chip having alignment marks on a main surface and having a semiconductor adhesive provided on the main surface and another semiconductor chip against each other via the semiconductor adhesive, and / or a step of pressing an alignment mark-equipped semiconductor chip having alignment marks on a main surface and having a semiconductor adhesive provided on the main surface and a wiring circuit board against each other via the semiconductor adhesive.

[0020] The alignment mark-equipped semiconductor chip may be obtained by singulating a semiconductor adhesive-coated wafer including a wafer having alignment marks on a main surface and a semiconductor adhesive provided on the main surface.

[0021] 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 semiconductor adhesive according to the present disclosure.

Advantages of the Invention

[0022] According to the present disclosure, it is possible to provide a semiconductor adhesive having excellent heat dissipation and sufficient visibility. Further, 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.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments for carrying out 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.

[0025] 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 certain step's numerical range may be replaced with the upper limit value or the lower limit value of another step's numerical range. 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.

[0026] <Adhesive for Semiconductors> The adhesive for semiconductors according to one embodiment of the present disclosure contains a curable resin component and alumina filler with an average particle diameter of 15 μm or less, the content of the alumina filler is 35 to 75% by mass based on the total amount of the adhesive for semiconductors, and the thermal conductivity after curing of the adhesive for semiconductors is 0.5 to 1.5 W / mK.

[0027] The adhesive for semiconductors can be used for sealing the connection parts in a semiconductor device in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a semiconductor device in which the connection parts of a plurality of semiconductor chips are electrically connected to each other.

[0028] (Curable resin component) The curable resin component may contain (a) a thermosetting resin, (b) a curing agent, and (c) a thermoplastic resin.

[0029] ((a) Thermosetting resin) Examples of the thermosetting resin include epoxy resin, urea resin, melamine resin, and phenol resin. The thermosetting resin may contain an epoxy resin from the viewpoints of good curability and excellent adhesiveness. The thermosetting resin can be used alone or in combination of two or more.

[0030] The epoxy resin may be, for example, an epoxy resin having two or more epoxy groups in the molecule, and examples thereof include 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.

[0031] The content of the epoxy resin may be 40 parts by mass or more, and may also be 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, and may also be 80 parts by mass or less, based on 100 parts by mass of the curing agent resin component.

[0032] The content of the epoxy resin may be 10 parts by mass or more, and may also be 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, and may also be 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.

[0033] ((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. Since the curing agent containing phenolic hydroxyl groups, acid anhydrides, amines or imidazoles is likely to exhibit flux activity that suppresses the formation of an oxide film at the connection part, the connection reliability and insulation reliability can be easily improved.

[0034] The phenolic resin-based curing agent may be, for example, a curing agent having two or more phenolic hydroxyl groups in the molecule, and examples thereof include phenol novolac, cresol novolac, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenol, and various polyfunctional phenolic resins. The phenolic resin-based 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 (phenolic hydroxyl group / epoxy group, molar ratio) of the phenolic resin-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 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 in excess, the water absorption rate is kept low, and the insulation reliability tends to further improve.

[0036] Examples of the acid anhydride-based curing agent include methylcyclohexane tetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. The acid anhydride-based curing agent can be used alone or in combination of two or more.

[0037] When the curable resin component contains an epoxy resin, the equivalent ratio (acid anhydride group / epoxy group, molar ratio) of the acid anhydride-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 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 in excess, the water absorption rate is kept low, and the insulation reliability tends to further improve.

[0038] Examples of the amine-based curing agent include dicyandiamide.

[0039] 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 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 amines do not remain in excess, and the insulation reliability tends to further improve.

[0040] 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, from the viewpoint of further excellent curability, storage stability, and connection reliability, 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, or 2-phenyl-4-methyl-5-hydroxymethylimidazole may be used. The imidazole-based curing agent can be used alone or in combination of two or more. Also, it may be a latent curing agent in which these are microencapsulated.

[0041] 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.

[0042] Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium (4-fluorophenyl)borate.

[0043] 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.

[0044] 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, amine-based curing agent, etc.

[0045] 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. From the viewpoint of improving productivity 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.

[0046] 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.

[0047] ((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.

[0048] As the phenoxy resin, for example, ZX1356-2 and FX-293 manufactured by Nippon Steel Chemical & Material Co., Ltd. can be used. 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. As the acrylic block copolymer, for example, LA4285, LA2330, LA2140 (all manufactured by Kuraray Co., Ltd.), which are block copolymers of methyl methacrylate and butyl acrylate, can be used. 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 adopt a crystal structure.

[0049] 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 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 easily embedded in 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 is likely to be suppressed. Further, by containing a thermoplastic resin having a Tg of room temperature (25°C) or higher in the semiconductor adhesive, it becomes easy to form the semiconductor adhesive in a film shape or a membrane shape.

[0050] 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).

[0051] 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 formability 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.

[0052] 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).

[0053] When the curable resin component contains an epoxy resin and a 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 with respect 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 it becomes easy to form the semiconductor adhesive in a film shape or a membrane shape.

[0054] 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 with respect to 100 parts by mass of the curable resin component.

[0055] 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.

[0056] (Flux agent) The semiconductor adhesive according to this embodiment may further contain a flux agent (that is, a flux activator showing 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, and alcohols.

[0057] The flux agent may contain an organic acid that reacts with the epoxy resin. From the viewpoint that the flux agent exhibits stronger flux activity than alcohols and is likely to improve connectivity, it may be an organic acid.

[0058] When the curable resin component contains an epoxy resin, since it reacts with the epoxy resin and does not exist in a free state in the cured product of the semiconductor adhesive, it is possible to prevent a decrease in insulation reliability. Therefore, the flux agent may contain an organic acid or may contain a carboxylic acid.

[0059] Examples of carboxylic acids include aliphatic 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, and octadecanoic acid; aliphatic unsaturated carboxylic acids such as oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, and eicosapentaenoic acid; aliphatic 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 mesitylenic acid; and maleic acid and fumaric acid. Examples of carboxylic acids having a hydroxyl group include lactic acid, malic acid, citric acid, and salicylic acid.

[0060] Among the carboxylic acids, it may be a dicarboxylic acid. Since dicarboxylic acids are relatively less volatile than monocarboxylic acids, voids can be suppressed. Also, dicarboxylic acids react less easily at low temperatures (temperatures below the bonding temperature, for example, 100 °C or lower) in film formation, lamination, preheating, etc. than tricarboxylic acids, so the viscosity does not become too high and poor connection can be suppressed.

[0061] 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 and 3-methylglutaric acid.

[0062] 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. It may be 10 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, or 2 parts by mass or less with respect to 100 parts by mass of the semiconductor adhesive. The content of the flux compound may be, for example, 0.5 to 10 parts by mass or 0.5 to 5 parts by mass based on the amount of the semiconductor adhesive.

[0063] (alumina filler) The adhesive for semiconductor of the present embodiment contains alumina fillers with an average particle diameter of 15 μm or less. The content of the alumina fillers is 35 to 75% by mass based on the total amount of the adhesive for semiconductor. If the content of the alumina fillers is within the above range, excellent heat dissipation and sufficient visibility can be imparted to the adhesive for semiconductor.

[0064] The alumina fillers are particles containing alumina (Al 2 O 3 ), and specifically, α-alumina fillers can be mentioned. The purity of alumina in the alumina fillers 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 of the adhesive for semiconductor. The purity of the alumina fillers may be in a mode that consists substantially of alumina (100% by mass of the alumina fillers is substantially alumina).

[0065] The shape of the alumina fillers is not particularly limited, and examples include spherical, substantially spherical, polyhedral, needle-like, plate-like, etc. Among these, from the viewpoint of excellent heat dissipation of the adhesive for semiconductor, it may be spherical or polyhedral, and from the viewpoint of excellent transparency of the adhesive for semiconductor, it may be spherical. In this specification, "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 corners may have a rounded shape). The polyhedron may have, for example, 4 to 100 planes as constituent parts of the surface.

[0066] The reason why the heat dissipation of the adhesive for semiconductor is excellent by using polyhedral alumina as the alumina fillers is not necessarily clear, but the inventors believe that when the alumina fillers are polyhedral, the fillers come into contact with each other on the surface, and the heat transfer area increases, thereby improving heat transfer.

[0067] The average particle size of the alumina filler may be 15 μm or less, 10 μm or less, 5 μm or less, 1 μm or less, 0.5 μm or less, 0.25 μm or less, or 0.2 μm or less from the viewpoints of excellent transparency of the semiconductor adhesive, improvement in film-forming properties when the semiconductor adhesive is formed into a film, and ease of thinning when the semiconductor adhesive is formed into a film. Further, when the average particle size of the alumina filler is 0.25 μm or less, it is possible to suitably suppress the occurrence of conduction failure due to the filler biting into the bump and the wiring. The average particle size of the alumina filler may be 0.01 μm or more, or 0.1 μm or more from the viewpoint of excellent thermal conductivity of the semiconductor adhesive.

[0068] In this specification, the "average particle size" is the particle size at the point corresponding to 50% by volume when a cumulative frequency distribution curve by particle size 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.

[0069] The alumina filler may be one obtained by treating the alumina surface from the viewpoints of improved visibility, dispersibility, and adhesive strength. By using the surface-treated alumina filler, the dispersibility of the alumina filler is improved, and the light transmittance tends to be more excellent. 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.

[0070] [Chemical formula] [R 11 represents a hydrogen atom or an alkyl group, and R 12 represents an alkylene group.]

[0071] Examples of the filler surface-treated with the compound having a structure represented by the formula (1) include an acrylic surface-treated filler in which R 11 is a hydrogen atom, and R 11A methacrylic surface-treated filler where R is a methyl group 11 Examples thereof include an ethacrylic surface-treated filler where R is an ethyl group. 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. R 12 There is no particular limitation on the alkylene group of R, but from the viewpoint of reducing volatile components, it may have a high weight average molecular weight.

[0072] [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.]

[0073] R 21 , R 22 and R 23 may be non-bulky substituents from the viewpoint of not reducing reactivity. Also, they may be substituents that improve the reactivity of the vinyl group in formula (2). R 24 There is no particular limitation, but from the viewpoints of being difficult to volatilize and reducing voids, it may have a high weight average molecular weight. 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.

[0074] As the surface treatment agent, silane compounds such as epoxy-based silane, amino-based silane, (meth)acrylic-based silane, and vinyl-based silane may be used from the viewpoint of ease of surface treatment. 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, glycidyl-based, phenylamino-based, (meth)acrylic, and vinyl-based silane compounds may be used from the viewpoints of excellent dispersibility, fluidity, and adhesive strength. As the surface treatment agent, vinyl-based, phenylamino-based, and (meth)acrylic-based silane compounds may be used from the viewpoint of excellent storage stability.

[0075] The alumina filler can be used alone or in combination of two or more having different shapes, average particle diameters, surface treatments, etc.

[0076] From the viewpoint of better heat dissipation, the content of the alumina filler may be 45% by mass or more, 50% by mass or more, or 55% by mass or more based on the total amount of the adhesive for semiconductors. From the viewpoints of better visibility, excellent film-forming property of the film, excellent dispersibility of the alumina filler, and suppressing the occurrence of resin residue due to the decrease in the fluidity of the resin and preventing the decrease in connection reliability, the content of the alumina filler may be 70% by mass or less or 65% by mass or less based on the total amount of the adhesive for semiconductors.

[0077] (Other components) The adhesive for semiconductors of this embodiment may contain inorganic fillers other than the alumina filler. Examples of the inorganic filler include silica, magnesium oxide, silicon carbide, boron nitride, and aluminum nitride. From the viewpoint of handleability (shape uniformity), the inorganic filler may be silica, boron nitride, or aluminum nitride.

[0078] The adhesive for semiconductors of the present embodiment may further contain additives such as organic fillers (resin fillers), antioxidants, silane coupling agents (excluding compounds corresponding to fluxing 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 can be appropriately adjusted so that the effects of each additive are manifested.

[0079] As the material of the organic filler, polyurethane, polyimide, etc. can be used. Since the organic filler can impart flexibility at a high temperature such as 260°C as compared with the inorganic filler, the film-forming property can be improved.

[0080] (Thermal conductivity) The adhesive for semiconductors according to the present embodiment has a thermal conductivity of 0.5 to 1.5 W / mK after curing. By having a thermal conductivity of 0.5 W / mK or more after curing of the adhesive for semiconductors, an adhesive for semiconductors with excellent heat dissipation properties can be provided.

[0081] From the viewpoint of more excellent heat dissipation properties, the thermal conductivity of the adhesive for semiconductors after curing may be 0.7 W / mK or more, 0.9 W / mK or more, or 1.0 W / mK or more.

[0082] The thermal conductivity of the adhesive for semiconductors after curing 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.

[0083] The adhesive for semiconductors can be cured by heating at 240°C for 1 hour. Specifically, the adhesive for semiconductors after curing can be obtained by the method described in the examples below.

[0084] (Light transmittance) The adhesive for semiconductor according to this embodiment may have a light transmittance of 0.5% or more with respect to light having a wavelength of 550 nm. From the viewpoint of better visibility, the light transmittance of the adhesive for semiconductor with respect to light having a wavelength of 550 nm may be 1.0% or more, 1.5% or more, 2.0% or more, 3.0% or more, 4.0% or more, 5.0% or more, 8.0% or more, 10% or more, 12% or more, 15% or more, or 20% or more. If the light transmittance with respect to light having a wavelength of 550 nm is 1.0% or more, there is a tendency that the alignment mark can be automatically identified by the image processing system. If the light transmittance with respect to light having a wavelength of 550 nm is 10% or more, it is possible to further suppress the occurrence of misalignment when the alignment mark is automatically identified by the image processing system.

[0085] When the adhesive for semiconductor of this embodiment is in the form of a film or a membrane, the light transmittance with respect to light having a wavelength of 550 nm measured in the thickness direction of the adhesive for semiconductor may satisfy the above conditions.

[0086] The light transmittance of the adhesive for semiconductor with respect to light having a wavelength of 550 nm can be measured using a spectrophotometer. Specifically, the light transmittance can be measured in the same manner as the method described in the examples below.

[0087] The adhesive for semiconductor of this embodiment may satisfy the above conditions in terms of the light transmittance with respect to light having a wavelength of 550 nm when formed into a film of 20 μm or 16 μm. That is, from the viewpoint of better visibility, the light transmittance per 20 μm or per 16 μm in thickness with respect to light having a wavelength of 550 nm of the adhesive for semiconductor of this embodiment may be 0.5% or more, 1.0% or more, 1.5% or more, 2.0% or more, 3.0% or more, 4.0% or more, 5.0% or more, 8.0% or more, 10% or more, 12% or more, 15% or more, or 20% or more.

[0088] The adhesive for semiconductors in this embodiment may be in the form of a film or a membrane. The thickness of the film or membrane adhesive for semiconductors (film adhesive) may be, for example, 100 μm or less, 80 μm or less, 50 μm or less, 30 μm or less, 20 μm or less, 16 μm or less, or 12 μm or less. There is no particular limitation on the lower limit of the thickness of the film adhesive, but it may be 1 μm or more or 5 μm or more.

[0089] <Method for producing an adhesive for semiconductors> The film or membrane adhesive for semiconductors can be obtained by the following method. First, after adding the above-described curable resin component, alumina filler, and other components into an organic solvent, they are 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, a roll coater, an applicator, a die coater, a 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 drying the solvent.

[0090] The base film is not particularly limited as long as it has heat resistance capable of withstanding the heating conditions when volatilizing the organic solvent, and examples thereof include a polyester film, a polypropylene film, a polyethylene terephthalate film, a polyimide film, a polyetherimide film, a polyether naphthalate film, a methylpentene film, etc. The base film is not limited to a single-layer one composed of one of these films, and may be a multilayer film composed of two or more films.

[0091] 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. The conditions for volatilizing the organic solvent may be conditions under which the organic solvent volatilizes to 1.5% or less as long as there is no influence on voids after mounting, viscosity adjustment, etc.

[0092] <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.

[0093] 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 shielded from the external environment. The sealing material 40 contains a cured product of the semiconductor adhesive according to this embodiment.

[0094] 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 the opposing bumps 32 being connected to each other. The bumps 32 are sealed by the sealing material 40 and are shielded from the external environment.

[0095] FIG. 2 is a schematic cross-sectional view showing another embodiment of the 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.

[0096] There is no particular limitation on the semiconductor chip 10, 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.

[0097] There is no particular limitation on the substrate 20 as long as it is a wiring circuit board. For example, a circuit board in which 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. are etched away to form wirings (wiring patterns), a circuit board in which wirings (wiring patterns) are formed on the surface of the above insulating substrate by metal plating or the like, a circuit board in which a conductive substance is printed on the surface of the above insulating substrate to form wirings (wiring patterns), etc. can be used.

[0098] The connection portions such as the wirings 15 and the 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 a plurality of metals.

[0099] 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.

[0100] As the material of the conductive protrusions called bumps, gold, silver, copper, solder (the main components are, for example, tin - silver, tin - lead, tin - bismuth, tin - copper), tin, nickel, etc. are mainly used as components, 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 bumps may be formed on a semiconductor chip or a substrate. Since it is inexpensive and commonly used, the metal layer may be copper or solder, but due to the presence of oxides, impurities, etc., flux activity is required.

[0101] Also, semiconductor devices (packages) such as those shown in FIG. 1 or FIG. 2 may be laminated and electrically connected with gold, silver, copper, solder (the main components are, for example, tin - silver, tin - lead, tin - bismuth, tin - copper), tin, nickel, etc. Since it is inexpensive and commonly used, the metal layer may be copper or solder, but due to the presence of oxides, impurities, etc., flux activity is required. For example, a semiconductor adhesive as seen in TSV technology may be interposed between semiconductor chips for flip - chip connection or lamination, holes may be formed through the semiconductor chips, and connected to the electrodes on the pattern surface.

[0102] FIG. 3 is a schematic cross-sectional view showing another embodiment of a semiconductor device (a semiconductor chip stacking type aspect (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. As the material of the through electrode 34, copper, aluminum, etc. can be used.

[0103] With such TSV technology, signals can be acquired 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.

[0104] Also, in a highly flexible bump formation method such as the area bump chip technology, the semiconductor chip can be directly mounted on the mother board without going through the interposer. The semiconductor adhesive according to this embodiment can also be applied when such a semiconductor chip is directly mounted on the mother board. Note that the semiconductor adhesive according to this embodiment can also be applied when sealing the gap between the substrates when two wiring circuit boards are stacked.

[0105] <Method for manufacturing a 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 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 includes a step of sealing at least a part of the connection portion using the semiconductor adhesive according to the present embodiment.

[0106] The above step can be performed by connecting the semiconductor chip and the wiring circuit board, or a plurality of semiconductor chips to each other using the semiconductor adhesive according to the present embodiment. In this case, the manufacturing method of the semiconductor device according to the present embodiment may include, for example, a step of connecting the semiconductor chip and the wiring circuit board to each other via the semiconductor adhesive and electrically connecting the respective connection portions of the semiconductor chip and the wiring circuit board to each other, and / or a step of connecting a plurality of semiconductor chips to each other via the semiconductor adhesive and electrically connecting the respective connection portions of the plurality of semiconductor chips to each other.

[0107] Further, the above step may include a step of pressing a semiconductor chip with an alignment mark on a main surface, on which a semiconductor adhesive is provided, and another semiconductor chip via the semiconductor adhesive, and / or a step of pressing a semiconductor chip with an alignment mark on a main surface, on which a semiconductor adhesive is provided, and a wiring circuit board via the semiconductor adhesive. Since the semiconductor adhesive of the present embodiment has sufficient visibility, even if the semiconductor adhesive is provided so as to cover the alignment mark, alignment can be performed with sufficient accuracy.

[0108] The semiconductor chip with an alignment mark can be obtained by singulating a wafer with a semiconductor adhesive provided on a main surface having an alignment mark on the main surface.

[0109] 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 connection portions of the semiconductor chip and the wiring circuit board can be connected to each other by metal bonding, or the connection portions of the plurality of semiconductor chips can be connected to each other by metal bonding.

[0110] As an example of the method for manufacturing a semiconductor device according to the present embodiment, a 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 bumps (solder 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 encapsulant 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 encapsulant 40. The wirings 15 on the patterned 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.

[0111] FIG. 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 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. Since the semiconductor adhesive 42 has sufficient visibility, it may cover an alignment mark (not shown) provided on the surface of the semiconductor chip 10.

[0112] The stacked chip 700 can be manufactured by dicing the 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 to form 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.

[0113] 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 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 using solder at the connection portion, the temperature applied to the solder portion may be 240° C. or higher. Thereby, the stacked chip 700 and the semiconductor chip 10 can be connected, and the connection portion can be sealed with a cured product of the semiconductor adhesive.

[0114] The connection load depends on the number of bumps, but can be set considering absorption of bump height variations, control of bump deformation amounts, etc. The connection time may be short from the perspective of productivity improvement. 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. A 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 be applied to the connection between the interposer 50 having the wiring 15 and the stacked chip 700.

[0115] By repeating the above steps, the semiconductor device 500 shown in FIG. 4(b) can be manufactured. Also, the semiconductor device 500 may be manufactured by repeatedly aligning and stacking (temporarily fixing) the stacked chip 700 and the semiconductor chip 10 to obtain a temporarily fixed multi-stage stacked body, and then heat-treating 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 compared to the above-described main crimping, resulting in advantages such as productivity improvement and prevention of deterioration of the connection portion. 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 may be a temperature at which complete curing occurs. The heating temperature and heating time may be set as appropriate.

[0116] As another example of the manufacturing method of the semiconductor device according to this embodiment, a manufacturing method of the semiconductor device 600 shown in FIG. 5 will be described. The semiconductor device 600 includes a substrate (glass epoxy substrate) 60 having wiring (copper wiring) 15 and a semiconductor chip 10 having wiring (copper pillars, copper posts) 15, which 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 connection bumps (solder bumps) 30. A solder resist 70 is disposed on the surface of the substrate 60 where the wiring 15 is formed, except for the formation positions of the connection bumps 30.

[0117] FIG. 6 is a diagram showing an example of the manufacturing method of the semiconductor device 600. FIGS. 6(a) and (b) show steps of pressing a stacked chip provided with a semiconductor adhesive on the main surface of a semiconductor chip and a wiring circuit board via the semiconductor adhesive. The stacked chip (stacked semiconductor chips) 800 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 wiring 15 disposed on one surface of the semiconductor chip 10, connection bumps 30 disposed on the wiring 15, and alignment marks 80 provided on the same surface as the surface on which the wiring 15 is disposed. The semiconductor adhesive 42 is provided so as to embed the wiring 15 and the connection bumps 30, but may cover at least a part of the surface of the semiconductor chip 10, the wiring 15, and the connection bumps 30.

[0118] The semiconductor chip 10 may have through electrodes. The stacked chip 800 can be manufactured in the same manner as the stacked chip 700.

[0119] Since the alignment marks 80 covered by the semiconductor adhesive 42 can be sufficiently recognized, as shown in FIG. 6(a), by capturing the position information obtained by imaging the alignment marks 80 with an imaging device 85 and taking it into an image processing system, the position of the stacked chip 800 can be corrected and alignment can be performed.

[0120] The crimping of the stacked chip 800 and the wiring circuit board can be performed, for example, as shown in FIG. 6(b), by aligning the connection bumps 30 of the stacked chip 800 to be electrically connected to the wiring 15 not covered by the solder resist 70 on the substrate 60, and using a crimping tool 90 while heating the stacked chip 800 and the wiring 15 on the substrate 60 at a temperature equal to or higher than the melting point of the connection bumps 30. When using solder for the connection part, the temperature applied to the solder part may be 240° C. or higher. Thereby, the stacked chip 800 and the substrate 60 can be connected, and the connection part can be sealed with a cured product of a semiconductor adhesive.

[0121] The connection load depends on the number of bumps, but can be 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 part. The short connection time (crimping time) means that the time during which a temperature of 240° C. or higher is applied to the connection part 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.

[0122] The semiconductor device 600 may be manufactured by connecting the semiconductor chip 10 after applying the semiconductor adhesive 42 on the substrate 60 on which the solder resist 70 is formed, or after pasting the semiconductor adhesive 42 in the form of a film. The semiconductor manufacturing 600 may be manufactured by heat treatment in a reflow furnace, similar to the semiconductor manufacturing 500.

Example

[0123] Hereinafter, the present disclosure will be described using examples, but the present disclosure is not limited thereto.

[0124] <Preparation of semiconductor adhesive> The compounds used for the preparation of the semiconductor adhesive are shown below.

[0125] (Curable resin component) ((a) Epoxy resin) · Polyfunctional solid epoxy containing a triphenolmethane skeleton (manufactured by Japan Epoxy Resin Co., Ltd., product name "EP1032H60") · Bisphenol F type liquid epoxy (manufactured by Japan Epoxy Resin Co., Ltd., product name "YL983U") · Flexible epoxy (manufactured by Japan Epoxy Resin Co., Ltd., product name "YL7175") · Flexible epoxy (manufactured by Japan Epoxy Resin Co., Ltd., product name "YX7110B80")

[0126] ((b) Hardening agent) 2,4 - Diamino - 6 - [2’ - methylimidazolyl - (1’)] - ethyl - s - tri azine isocyanurate adduct (manufactured by Shikoku Kasei Co., Ltd., product name "2MAOK - PW")

[0127] ((c) Thermoplastic resin) Phenoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., product name "ZX1356 - 2", Tg: about 71°C, Mw: about 63000)

[0128] (Alumina filler) · Alumina filler 1 (manufactured by Sumitomo Chemical Co., Ltd., product name "AA - 04", polyhedral alumina, average particle size: 0.5μm) · Alumina filler 2 (manufactured by Sumitomo Chemical Co., Ltd., product name "AA - 3", polyhedral alumina, average particle size: 3.2μm) · Alumina filler 3 (manufactured by Admatechs Co., Ltd., product name "AO - 502", average particle size: 0.2μm) · Alumina filler 4 (manufactured by Admatechs Co., Ltd., product name "AC2000 - SML", alumina surface treated with methacryl silane, average particle size: 0.2μm) · Alumina filler 5 (spherical alumina, product name A2 - SX - C8, alumina surface treated with phenylamino silane, average particle size: 0.2μm) · Alumina filler 6 (spherical alumina, product name A2 - SV - C2, alumina surface treated with vinyl silane, average particle size: 0.2μm) · Alumina filler 7 (spherical alumina, product name A2-SM-C4, alumina surface treated with methacryl silane, average particle size: 0.2 μm) · Alumina filler 8 (manufactured by Admatechs Co., Ltd., product name "AC2050-SI", spherical alumina, average particle size: 0.2 μm)

[0129] (Fillers other than alumina) · Inorganic silica filler (manufactured by Admatechs Co., Ltd., product name "SE2050", average particle size: 500 nm) · Organic filler (manufactured by Rohm and Haas Japan Co., Ltd., product name "EXL-2655", resin filler: core-shell type organic fine particles)

[0130] (Flux agent) · Glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd., Wako special grade, melting point: about 95 °C) · 2-Methylglutaric acid

[0131] (Example 1) The thermosetting resin, curing agent, alumina filler, inorganic filler, organic filler, and flux agent in the blending amounts shown in Table 1 (unit: parts by mass) 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 with a bead mill (manufactured by Fritsch Japan Co., Ltd., planetary type fine grinder P-7) for 30 minutes. Then, as the thermoplastic resin, a phenoxy resin in the blending amount shown in Table 1 (unit: parts by mass) was added, and stirred again with the 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-like adhesive (adhesive for semiconductors) with a thickness of 400 μm.

[0132] (Examples 2 to 10, Comparative Examples 1 and 2) A film-like adhesive (adhesive for semiconductors) was obtained in the same manner as in Example 1, except that the materials used were changed as shown in Table 1.

[0133] (Example 11) A thermosetting resin, a curing agent, alumina filler, an organic filler, and a fluxing agent in the amounts shown in Table 2 (unit: parts by mass) were added to an organic solvent (cyclohexanone) so that the NV (non-volatile content concentration) was 55% by mass. Then, beads with a diameter of Φ1.0 mm were added in the same mass as the solid content, and stirring was carried out for 30 minutes using a bead mill (manufactured by RETSCH Co., Ltd., trade name "Planetary Ball Mill PM400"). Then, as a thermoplastic resin, a phenoxy resin in the amount shown in Table 1 (unit: parts by mass) was added, and stirring was carried out again with the bead mill for 30 minutes. In order to remove the aggregates of the beads and alumina filler used for stirring, filtration was carried out using a nylon mesh with an opening of 10 μm. The varnish obtained after filtration was coated 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 (adhesive for semiconductors) with a thickness of 20 μm.

[0134] (Examples 12 to 21) A film-shaped adhesive (adhesive for semiconductors) was obtained in the same manner as in Example 11, except that the materials used were changed as shown in Table 2.

[0135] <Evaluation> (1) Measurement of thermal conductivity A film-shaped adhesive (1 cm × 1 cm, thickness 400 μm) was prepared, and this was cured in a clean oven (manufactured by ESPEC Corporation) at 240 °C for 1 hour to obtain a cured product. The obtained cured product was blackened on both sides 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 carried out 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. Then, 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 and 2. 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 / cm3 ) are each shown. The specific heat (J / kg·K) was measured using differential scanning calorimetry (DSC) according to the following procedure. An adhesive for semiconductors was weighed into an aluminum pan, and using a differential scanning calorimeter (Pyris1, manufactured by Perkin-Elmer Japan Co., Ltd.), the measurement was carried out at 10 °C / min from room temperature (25 °C) to 60 °C. Sapphire was used as a reference. The specific heat at 25 °C of the sample was calculated using the known specific heat of sapphire. 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.).

[0136] (2) Measurement of light transmittance For Examples 1 to 10 and Comparative Examples 1 and 2, as measurement samples, sheets (film-like adhesive sheets) in which a 20-μm-thick film-like adhesive (adhesive for semiconductors) was formed on a PET separator film were obtained. After cutting the obtained film-like adhesive sheets and the PET separator film alone into sizes of 30 mm × 30 mm each, the film-like adhesive sheet was placed in the sample mounting part of a spectrophotometer (U-3310, manufactured by Hitachi High-Technologies Corporation), and the PET separator film alone was placed in the reference mounting part, and the light transmittance was measured at a scan speed of 300 nm / min in the wavelength range of 400 to 800 nm. The light transmittance with respect to light having a wavelength of 550 nm was taken as the measured value. The results are shown in Table 1. For Examples 11 to 21, as measurement samples, sheets (film-like adhesive sheets) in which a 16-μm-thick film-like adhesive (adhesive for semiconductors) was formed on a PET separator film were obtained, and the light transmittance was measured in the same manner as above. The results are shown in Table 2.

[0137] (3) Evaluation of connection reliability A film adhesive (7.3 mm × 7.3 mm, thickness 0.045 mm) was fabricated and attached onto a semiconductor chip with solder bumps (chip size: 7.3 mm × 7.3 mm, thickness 0.15 mm, bump height: copper pillar + solder approximately 45 μm, number of bumps 328, pitch 80 μm). Next, it was mounted on a glass epoxy substrate (glass epoxy base material: thickness 420 μm, copper wiring: thickness 9 μm) using a flip chip bonder (manufactured by Panasonic Corporation, FCB3) (mounting conditions: crimping head temperature 350 °C / 5 s / 0.5 MPa), and a semiconductor device similar to that in Fig. 5 was obtained. The stage temperature was set at 80 °C. After mounting the above glass epoxy substrate and the semiconductor chip with solder bumps (in daisy chain connection) using FCB3, the initial conductivity was measured using a multimeter (manufactured by ADVANTEST, R6871E). When the initial connection resistance value was 10.0 Ω or more and 13.5 Ω or less, it was evaluated as "A", and when it was more than 13.5 Ω and 20 Ω or less, it was evaluated as "B". The results are shown in Tables 1 and 2.

[0138] (4) Visibility evaluation In the above connection reliability evaluation, when crimping, the visibility of the alignment marks on the chip was evaluated through the semiconductor adhesive using the above FCB3. When the automatic recognition of the alignment marks by the image processing system was possible, it was evaluated as "A", when the alignment marks could be confirmed visually, it was evaluated as "B", and when neither the image processing system nor visual confirmation was possible, it was evaluated as "C". The results are shown in Tables 1 and 2.

[0139] (5) Film forming property evaluation A film adhesive (200 mm × 200 mm, thickness 20 μm) was fabricated, and the appearance and handleability of the obtained film adhesive after drying were confirmed. Those with a uniform coating surface visually, no streaks due to aggregation, no non-uniformity of the coating surface due to insufficient thermoplastic resin, and no film cracking when the film was cut were evaluated as "A", and those not evaluated as "A" were evaluated as "B". The results are shown in Table 2.

[0140]

Table 1

[0141]

Table 2

[0142] In the examples, it was confirmed that a thermal conductivity of 0.5 to 1.5 W / mK, excellent connection reliability, and visibility were obtained. In Comparative Example 1, sufficient heat dissipation could not be obtained, and in Comparative Example 2, it was confirmed that sufficient connection reliability and visibility could not be obtained.

[0143] In Examples 11 to 15, it was confirmed that a thermal conductivity of 0.7 W / mK or more, a high light transmittance, and excellent film formability of the film could be achieved simultaneously. Regarding the film formability of Example 17, the film tended to crack easily, and this result is considered to be due to the low resin content. Also, regarding the film formability of Example 18, streaks tended to occur due to the aggregation of alumina fillers.

Description of Reference Numerals

[0144] 10… semiconductor chip, 15… wiring, 20, 60… substrate, 30… connection bump, 32… bump, 34… through electrode, 40… encapsulant, 42… semiconductor adhesive, 50… interposer, 70… solder resist, 80… alignment mark, 85… imaging device, 90… crimping tool, 100, 200, 300, 400, 500, 600… semiconductor device.

Claims

1. A semiconductor adhesive used for sealing the connection parts in a semiconductor device comprising 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, the semiconductor adhesive containing: a curable resin component and alumina filler having an average particle diameter of 0.5 μm or less; wherein the content of the alumina filler is 35 to 75% by mass based on the total amount of the semiconductor adhesive; the thermal conductivity of the semiconductor adhesive after curing is 0.5 to 1.5 W / mK; and the light transmittance with respect to light having a wavelength of 550 nm is 0.5% or more.

2. The semiconductor adhesive according to claim 1, further containing a fluxing agent.

3. The semiconductor adhesive according to claim 2, wherein the fluxing agent is a carboxylic acid.

4. The semiconductor adhesive according to any one of claims 1 to 3, wherein the alumina filler is obtained by subjecting the alumina surface to silane treatment.

5. The semiconductor adhesive according to any one of claims 1 to 4, wherein the curable resin component includes a thermosetting resin, a curing agent, and a thermoplastic resin.

6. A method for manufacturing a semiconductor device comprising 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, the method including: a step of sealing at least a part of the connection parts using the semiconductor adhesive according to any one of claims 1 to 5.

7. The method for manufacturing a semiconductor device according to claim 6, wherein the step includes a step of pressing a semiconductor chip with an alignment mark provided on a main surface and having the semiconductor adhesive provided on the main surface and another semiconductor chip through the semiconductor adhesive, and / or a step of pressing a semiconductor chip with an alignment mark provided on a main surface and having the semiconductor adhesive provided on the main surface and a wiring circuit board through the semiconductor adhesive.

8. The method for manufacturing a semiconductor device according to claim 7, wherein the semiconductor chip with an alignment mark is obtained by singulating a wafer with an alignment mark provided on a main surface and having the semiconductor adhesive provided on the main surface.

9. 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 sealing material for sealing at least a part of the connection part, comprising a semiconductor device. The sealing material contains a cured product of the semiconductor adhesive according to any one of claims 1 to 5.

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