TWI868207B - Heat-conductive composition and semiconductor device - Google Patents

Abstract

A thermally conductive composition comprising metal-containing particles and a thermosetting component comprising at least one selected from the group consisting of polymers, oligomers and monomers, wherein the metal-containing particles are sintered by heat treatment to form a particle connection structure. The thermally conductive composition is heated from 30°C to 180°C at a constant rate for 60 minutes and then heated at 180°C for 2 hours to obtain a cured film having a thermal conductivity λ in the thickness direction at 25°C of 25 W/m•K or more. In addition, the storage elastic modulus E' obtained by measuring the viscoelasticity of the cured film under the conditions of 25°C, tensile mode, and frequency of 1 Hz was 10000 MPa or less. The cured film was obtained by heating the thermal conductive composition from 30°C to 180°C at a constant rate for 60 minutes and then heating at 180°C for 2 hours.

Description

Thermally conductive composition and semiconductor device

The present invention relates to a thermally conductive composition and a semiconductor device. More specifically, it relates to a thermally conductive composition and a semiconductor device including a component obtained by heat treating the thermally conductive composition.

A technology for manufacturing semiconductor devices using a thermosetting resin composition containing metal particles in order to improve the heat dissipation of semiconductor devices is known. By making the thermosetting resin composition contain metal particles having a greater thermal conductivity than the resin, the thermal conductivity of the cured product can be improved. As a specific example applicable to semiconductor devices, as shown in the following patent documents 1 and 2, a technology for bonding/joining semiconductor elements and substrates (supporting members) using a thermosetting resin composition containing metal particles is known.

Patent document 1 describes a semiconductor bonding thermosetting resin composition containing a (meth)acrylate compound, a radical initiator, silver particles, silver powder, and a solvent (technical solution 1, etc.). The document also describes that the semiconductor element and the metal substrate can be bonded by heating to 200°C (paragraphs 0001, 0007, etc.).

Patent document 2 describes a resin paste composition containing an epoxy resin, a hardener, a hardening accelerator, a diluent, and silver powder (Table 1, etc.). It describes that the resin paste composition can be hardened at 150°C, and a semiconductor element and a supporting member can be bonded by a hardened material such as an epoxy resin (Paragraph 0038, etc.). Prior art documents Patent document

[Patent document 1] Japanese Patent Publication No. 2014-74132 [Patent document 2] Japanese Patent Publication No. 2000-239616

Thermosetting resin compositions containing metal particles can be classified into several types depending on the behavior of the metal particles during thermosetting. For example, there are "sintering type" resin compositions that form a particle-connected structure by sintering during heat treatment, and types that do not undergo sintering.

The inventors of the present invention have found that when a semiconductor device and a substrate are bonded together using a conventional sintered resin composition, peeling may sometimes occur due to thermal cycling (repeated heating-cooling).

The present invention is made in view of the above circumstances. One of the objects of the present invention is to provide a thermally conductive composition which is suitable for use, for example, in bonding a semiconductor device and a substrate and which has little peeling caused by thermal cycling.

As a result of in-depth research, the inventors have completed the invention provided below and solved the above-mentioned problems.

According to the present invention, a thermally conductive composition is provided, which contains metal-containing particles and a thermosetting component containing at least one selected from the group consisting of polymers, oligomers and monomers, and the metal-containing particles are sintered by heat treatment to form a particle connection structure, and the thermally conductive composition is heated from 30°C to 180°C at a constant rate for 60 minutes, and then heated at 180°C for 2 hours to obtain a hard The thermal conductivity λ of the cured film in the thickness direction at 25°C is 25W/m•K or more, and the storage elastic modulus E' obtained by viscoelastic measurement of the cured film at 25°C, tensile mode, and frequency 1Hz is less than 10000MPa. The cured film is obtained by heating the thermally conductive composition from 30°C to 180°C at a constant rate for 60 minutes and then heating at 180°C for 2 hours.

Furthermore, according to the present invention, a semiconductor device is provided, which comprises: a substrate; and a semiconductor element, which is mounted on the substrate via a bonding layer obtained by heat treating the thermally conductive composition. [Effect of the invention]

According to the present invention, a thermally conductive composition is provided, which is suitable for use, for example, in bonding a semiconductor device and a substrate and which is less likely to peel off due to thermal cycling.

The following is a detailed description of the embodiments of the present invention with reference to the drawings. In all drawings, the same components are labeled with the same symbols, and the description is omitted as appropriate. In order to avoid complication, (i) when there are multiple identical components in the same drawing, sometimes only one of them is labeled with a symbol instead of all components, or (ii) especially in the drawings after FIG. 2, sometimes the same components as FIG. 1 are not re-labeled with symbols. All drawings are for explanation only. The shapes and size ratios of the components in the drawings do not necessarily correspond to the actual items.

In this specification, unless otherwise specified, the notation "a to b" in the description of a numerical range means a or more and b or less. For example, "1 to 5 mass %" means "1 mass % or more and 5 mass % or less."

In the notation of groups (atomic groups) in this specification, the notation notating substitution or unsubstituted includes both those without substitution and those with substitution. For example, "alkyl" includes not only those without substitution (unsubstituted alkyl) but also those with substitution (substituted alkyl). The notation "(meth)acrylic acid" in this specification means the concept including both acrylic acid (-CO-CH=CH ₂ ) and methacrylic acid (-CO-C(CH ₃ )=CH ₂ ). The same applies to similar notations such as "(meth)acrylate".

<Thermal Conductive Composition> The thermal conductive composition of this embodiment is a thermal conductive composition containing metal-containing particles and a thermosetting component containing at least one selected from the group consisting of polymers, oligomers and monomers, and the metal-containing particles are sintered by heat treatment to form a particle connection structure. The thermal conductive composition of this embodiment is heated from 30°C to 180°C at a constant rate for 60 minutes, and then heated at 180°C for 2 hours. The thermal conductivity λ in the thickness direction at 25°C of the cured film is 25W/m•K or more. The storage elastic modulus E' obtained by viscoelastic measurement of the cured film under the conditions of 25°C, tensile mode, and frequency of 1 Hz was 10000 MPa or less. The cured film was obtained by heating the thermal conductive composition of this embodiment from 30°C to 180°C at a constant rate for 60 minutes and then heating at 180°C for 2 hours.

Hereinafter, "a thermosetting component containing at least one selected from the group consisting of a polymer, an oligomer, and a monomer" is also simply recorded as "a thermosetting component". In addition, a cured film obtained by heat curing under the above-mentioned heating conditions is sometimes recorded as a "specific cured film".

The inventors of the present invention have studied the cause of peeling when a sintered thermally conductive composition is applied and then subjected to thermal cycling (repeated heating-cooling).

The inventors of the present invention believe that the reason for the peeling is that (1) the heating temperature when hardening the composition/sintering the metal particles in the composition is too high, so stress caused by thermal contraction is generated in the hardened material after cooling, or (2) expansion-contraction caused by thermal cycles also generates stress, etc.

From the viewpoint of (1) above, the inventors of the present invention believe that it is sufficient to design a composition that can be hardened even when heated at a certain low temperature (when the metal-containing particles are sintered, the sintering forms a heat conduction path). This is because it is believed that if the temperature required for hardening the composition/sintering the metal-containing particles is low, the degree of thermal contraction caused by cooling after hardening/sintering can be reduced, and the stress generated by thermal contraction can be reduced (thus suppressing the reduction of adhesion). Furthermore, from the perspective of (2) above, it is believed that if the composition is designed so that the "elastic modulus" of the cured product is relatively small (so that the cured product has a certain degree of "flexibility"), the cured product will absorb the stress generated by the thermal cycle and suppress the reduction in adhesion.

Therefore, as one of the indices for designing a thermally conductive composition, the inventors set the thermal conductivity λ in the thickness direction at 25°C of the cured film obtained by heating the thermally conductive composition at "180°C" (the details of the heating conditions are as described above). In addition, it is considered that if a thermally conductive composition with a sufficiently large λ is designed, a decrease in adhesion can be suppressed (since λ is related to the degree of sintering of metal-containing particles, a large λ roughly corresponds to "easy sintering at a low temperature (180°C)").

Furthermore, as another index for designing a thermally conductive composition, the inventors set a storage modulus E' obtained by measuring the viscoelasticity of a cured film obtained by heating the thermally conductive composition at 180°C under the conditions of 25°C, tensile mode, and frequency of 1 Hz (the details of the heating conditions are as described above). Furthermore, it is believed that if a thermally conductive composition with a suitably small E' is designed, a decrease in adhesion can be suppressed (this is because it is believed that if the cured product has a certain degree of "flexibility", the cured product can easily absorb the stress generated by the thermal cycle).

The inventors designed a thermally conductive composition based on these two indicators. Furthermore, by newly designing a thermally conductive composition with λ of 25 W/m•K or more and E' of 10000 MPa or less, the decrease in adhesion due to thermal cycles was reduced.

In this embodiment, by appropriately selecting the type and amount of materials, the preparation method of the composition, etc., a thermally conductive composition having a λ of 25 W/m•K or more and an E' of 10000 MPa or less can be obtained. For example, by using the metal coating resin particles described below as part or all of the metal-containing particles, a thermally conductive composition having appropriate values of λ and E' can be obtained. The following will provide a more specific description of the materials and preparation methods that can be used.

It is hereby reminded that the present invention shall not be interpreted in a limited manner by the above-mentioned contents.

Hereinafter, the components, physical properties, characteristics, etc. of the thermally conductive composition of this embodiment will be described in detail.

(Metal-containing particles) The thermally conductive composition of this embodiment contains metal-containing particles. Typically, the metal-containing particles can be sintered by appropriate heat treatment to form a particle-connected structure (sintered structure).

The "metal" in the metal-containing particles can be any metal. From the perspective of good thermal conductivity, easy sintering, and applicability to semiconductor devices, a preferred metal is, for example, at least one selected from the group consisting of gold, silver, copper, nickel, and tin. A more preferred metal is at least one selected from the group consisting of silver, gold, and copper. The metal-containing particles can contain only one metal or more than two metals (that is, the metal-containing particles can also be alloy-containing particles). In addition, the core part and the surface part of the metal-containing particles can be composed of different types of metals. In particular, by including silver particles (especially, silver particles having a relatively small particle size and a relatively large specific surface area) in the thermally conductive composition, a sintered structure can be easily formed even when heat-treated at a relatively low temperature (about 180°C). The preferred particle size will be described later.

The shape of the metal-containing particles is not particularly limited. The preferred shape is spherical, but it can also be a non-spherical shape, such as an ellipse, a flat shape, a plate, a flake, a needle, etc. ("Spherical" is not limited to a perfect sphere, but also includes shapes with slight bumps on the surface. The same applies to the following in this manual.)

The metal-containing particles may be (i) particles substantially composed of metal only, or (ii) particles composed of metal and components other than metal. In addition, the metal-containing particles may be used in combination with (i) and (ii).

In this embodiment, the metal-containing particles include metal-coated resin particles in which the surface of the resin particles is coated with metal, which is particularly preferred. This makes it easy to prepare a thermally conductive composition with λ of 25 W/m•K or more and E' of 10000 MPa or less. The metal-coated resin particles have a metal surface and a resin inside, so they are considered to have good thermal conductivity and are soft (compared to particles composed only of metal). Therefore, it is considered that by using metal-coated resin particles, it is easy to design λ and E' to appropriate values. In general, in order to increase λ, it is considered to increase the amount of metal-containing particles. However, in general, since metal is "hard", if the amount of metal-containing particles is too large, the elastic modulus after sintering sometimes becomes too large. By making a part or all of the metal-containing particles metal-coated resin particles, it is easy to design a thermally conductive composition with λ of 25 W/m•K or more and E' of 10000 MPa or less.

In the metal-coated resin particles, the metal layer only needs to cover at least a part of the surface of the resin particles. Of course, the metal can also cover the entire surface of the resin particles. Specifically, in the metal-coated resin particles, it is preferred that the metal layer covers more than 50% of the surface of the resin particles, more preferably more than 75%, and further preferably more than 90%. In the metal-coated resin particles, it is particularly preferred that the metal layer substantially covers the entire surface of the resin particles. From another point of view, when the metal-coated resin particles are cut with a certain cross section, it is preferred that the metal layer can be confirmed all around the cross section. From another viewpoint, the mass ratio of resin/metal in the metal coating resin particles is, for example, 90/10 to 10/90, preferably 80/20 to 20/80, and more preferably 70/30 to 30/70.

The "metal" in the metal-coated resin particles is as described above. In particular, silver is preferred. As the "resin" in the metal-coated resin particles, for example, silicone resin, (meth) acrylic resin, phenol resin, polystyrene resin, melamine resin, polyamide resin, polytetrafluoroethylene resin, etc. can be cited. Of course, other resins can also be used. In addition, the resin can be only one type, or two or more resins can be used in combination. From the perspective of elastic properties and heat resistance, the resin is preferably silicone resin or (meth) acrylic resin.

The polysilicone resin may be particles composed of an organic polysiloxane obtained by polymerizing an organic chlorosilane such as methylchlorosilane, trimethyltrichlorosilane, or dimethyldichlorosilane. Alternatively, the polysilicone resin may be a polysilicone resin having a structure formed by further three-dimensionally crosslinking the organic polysiloxane as a basic skeleton. The (meth)acrylic resin may be a resin obtained by polymerizing a monomer containing (meth)acrylate as a main component (50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more). As (meth)acrylate, for example, at least one compound selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-propyl (meth)acrylate, chloro-2-hydroxyethyl (meth)acrylate, diethylene glycol mono(meth)acrylate, methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate and isoborneol (meth)acrylate can be cited. In addition, the monomer component of the acrylic resin can contain a small amount of other monomers. As such other monomer components, for example, styrene monomers can be cited. Regarding the metal coating (meth) acrylic resin, you can also refer to the description of Japanese Patent Publication No. 2017-126463. Various functional groups can be introduced into the polysilicone resin or the (meth) acrylic resin. The functional groups that can be introduced are not particularly limited. For example, epoxy groups, amino groups, methoxy groups, phenyl groups, carboxyl groups, hydroxyl groups, alkyl groups, vinyl groups, hydroxyl groups, etc. can be cited.

The resin particle portion of the metal coating resin particle may contain various additives, such as a low stress modifier. Examples of the low stress modifier include butadiene styrene rubber, butadiene acrylonitrile rubber, polyurethane rubber, polyisoprene rubber, acrylic rubber, fluororubber, liquid organic polysiloxane, liquid polybutadiene and other liquid synthetic rubbers. In particular, when the resin particle portion contains a polysilicone resin, the inclusion of a low stress modifier can improve the elastic properties of the metal coating resin particle.

The shape of the resin particles in the metal coating resin particles is not particularly limited. The preferred shape is spherical, but it may be a different shape other than spherical, such as flat, plate-like, needle-like, etc. When the metal coating resin particles are formed into a spherical shape, the shape of the resin particles used is preferably spherical.

The specific gravity of the metal coating resin particles is not particularly limited, and the lower limit is, for example, 2 or more, preferably 2.5 or more, and more preferably 3 or more. The upper limit of the specific gravity is, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. An appropriate specific gravity is preferred in terms of the dispersibility of the metal coating resin particles themselves and the uniformity when the metal coating resin particles and other metal-containing particles are used together.

When metal-coated resin particles are used, the ratio of metal-coated resin particles in the entire metal-containing particles is preferably 1 to 50 mass%, more preferably 3 to 45 mass%, and further preferably 5 to 40 mass%. By appropriately adjusting the ratio, it is possible to further improve heat dissipation while suppressing the reduction in adhesion due to thermal cycles. Incidentally, when the ratio of metal-coated resin particles in the entire metal-containing particles is not 100 mass%, the metal-containing particles other than the metal-coated resin particles are, for example, particles substantially composed only of metal.

The median particle size _D50 of the metal-containing particles (in the case of using a plurality of metal-containing particles together, the median particle size D50 is, for example, 0.001 to 1000 μm, preferably 0.01 to 100 μm, and more preferably 0.1 to 20 μm. By setting _D50 to an appropriate value, it is easy to maintain a balance among thermal conductivity, sintering properties, and resistance to thermal cycles. In addition, by setting _D50 to an appropriate value, coating/joining workability can sometimes be improved. The particle size distribution of the metal-containing particles (horizontal axis: particle size, vertical axis: frequency) can be unimodal or multimodal.

The median particle size _D50 of the particles substantially composed only of metal is, for example, 0.8 μm or more, preferably 1.0 μm or more, and more preferably 1.2 μm or more. This can further improve thermal conductivity. In addition, the median particle size _D50 of the particles substantially composed only of metal is, for example, 7.0 μm or less, preferably 5.0 μm or less, and more preferably 4.0 μm or less. This can further improve sinterability and sintering uniformity.

The median particle size D ₅₀ of the metal coating resin particles is, for example, 0.5 μm or more, preferably 1.5 μm or more, and more preferably 2.0 μm or more. This makes it easy to set the storage elastic modulus E' to an appropriate value. In addition, the median particle size D ₅₀ of the metal coating resin particles is, for example, 20 μm or less, preferably 15 μm or less, and more preferably 10 μm or less. This makes it easy to fully improve thermal conductivity.

The median particle size _D50 of the metal-containing particles can be determined, for example, by measuring particle images using a flow particle image analyzer FPIA (registered trademark)-3000 manufactured by Sysmex Corporation. More specifically, the particle size of the metal particles can be determined by measuring the median particle size based on volume in a wet manner using the device.

The ratio of the metal-containing particles in the entire thermally conductive composition (the total of the metal-containing particles when a plurality of metal-containing particles are used) is, for example, 1 to 98 mass%, preferably 30 to 95 mass%, and more preferably 50 to 90 mass%. By setting the ratio of the metal-containing particles to 1 mass% or more, thermal conductivity can be easily improved. By setting the ratio of the metal-containing particles to 98 mass% or less, coating/attachment workability can be improved.

Among the metal-containing particles, particles consisting essentially of only metal can be obtained from, for example, DOWA HIGHTECH CO., LTD., Fukuda Metal Foil & Powder Co., Ltd., etc. Moreover, metal-coated resin particles can be obtained from, for example, Mitsubishi Materials Corporation, SEKISUI CHEMICAL CO., LTD., SANNO Co., Ltd., etc.

(Thermosetting component) The thermally conductive composition of this embodiment contains at least one thermosetting component selected from the group consisting of polymers, oligomers and monomers. Thermosetting components usually contain a group that polymerizes/crosslinks by allowing active chemical substances such as free radicals to act and/or a chemical structure that reacts with a curing agent described below. Thermosetting components contain, for example, one or more of an epoxy group, an oxycyclobutane group, a group containing an ethylenic carbon-carbon double bond, a hydroxyl group, an isocyanate group, a succinimidyl group, and the like.

The thermosetting component preferably contains at least one selected from the group consisting of epoxy-containing compounds and (meth)acryl-containing compounds.

The epoxy group-containing compound may be a compound having only one epoxy group in one molecule, or may be a compound having two or more epoxy groups in one molecule.

As the epoxy group-containing compound, specifically, known epoxy resins can be cited. As epoxy resins, for example, bifunctional or crystalline epoxy resins such as biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, distyrene type epoxy resins, and hydroquinone type epoxy resins; phenolic varnish type epoxy resins such as cresol novolac type epoxy resins, phenolic varnish type epoxy resins, and naphthol novolac type epoxy resins; phenolic aralkyl type epoxy resins containing a phenylene skeleton, and phenolic aralkyl type epoxy resins containing a phenylene skeleton; Phenol aralkyl epoxy resins such as phenyl-containing skeleton-containing phenol aralkyl epoxy resins and phenyl-containing skeleton-containing naphthol aralkyl epoxy resins; trifunctional epoxy resins such as trisphenol methane epoxy resins and alkyl-modified trisphenol methane epoxy resins; modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins and terpene-modified phenol-type epoxy resins; epoxy resins containing heterocyclic rings such as tris-nucleus-containing epoxy resins, etc.

Examples of the epoxy group-containing compound include monofunctional epoxy group-containing compounds such as 4-tert-butylphenyl epoxypropyl ether, m-cresyl epoxypropyl ether, p-cresyl epoxypropyl ether, phenyl epoxypropyl ether, and cresyl epoxypropyl ether.

Examples of compounds containing a (meth)acryl group include a monofunctional (meth)acrylic monomer having only one (meth)acrylic group in one molecule and a polyfunctional (meth)acrylic monomer having two or more (meth)acrylic groups in one molecule. Typically, a polyfunctional (meth)acrylic monomer has 2 to 6 (meth)acrylic groups in one molecule, preferably 2 to 4 (meth)acrylic groups in one molecule.

As the monofunctional (meth)acrylic monomer, specifically, there can be mentioned 2-phenoxyethyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-tridecyl (meth)acrylate, n-stearyl (meth)acrylate, Isostearyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydi Ethylene glycol (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, nonylphenol ethylene oxide modified (meth)acrylate, phenylphenol ethylene oxide modified (meth)acrylate, isoborneol (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate quaternary compound, glycidyl (meth)acrylate, neopentyl glycol (meth)acrylate benzoate, 1,4-cyclohexane Alkyl dimethanol mono(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, 2-(meth)acryloyloxyethylphthalic acid, 2-(meth)acryloyloxyethyl-2-hydroxyethylphthalic acid, 2-(meth)acryloyloxyethyl acid phosphate, etc.

Specific examples of the multifunctional (meth)acrylic monomer include ethylene glycol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, hexane-1,6-diol bis(2-(meth)acrylate methyl ester), 4,4'-isopropylidene diphenol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,6-bis((meth)acryloyloxy)-2,2,3,3 ,4,4,5,5-octafluorohexane, 1,4-bis((meth)acryloxy)butane, 1,6-bis((meth)acryloxy)hexane, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, N,N’-di(meth)acrylethylenediamine, N,N’-(1,2-dihydroxyethylene)bis(meth)acrylamide or 1,4-bis((meth)acryl)piperidinium, etc.

Furthermore, as a type of (meth)acrylic monomer, a (meth)acrylamide monomer can also be mentioned. Specifically, (meth)acrylamide, diethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-dimethylmethacrylamide, N,N-diethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N'-methylenebis (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, diacetone (meth)acrylamide, (meth)acrylamide Phylin, etc.

As the (meth)acrylic monomer, a monofunctional (meth)acrylic monomer or a polyfunctional (meth)acrylic monomer may be used alone, or a monofunctional (meth)acrylic monomer and a polyfunctional (meth)acrylic monomer may be used in combination. As the (meth)acrylic monomer, it is preferred to use a polyfunctional acrylic monomer alone. As the (meth)acrylic monomer, for example, the "LIGHT ESTER" series sold by Kyoeisha Chemical Co., Ltd. may be used.

The thermally conductive composition of this embodiment may contain only one thermosetting component or may contain two or more thermosetting components. In this embodiment, it is preferred to use epoxy resin and (meth)acryl-containing compound in combination as thermosetting components. The ratio (mass ratio) of epoxy resin and (meth)acryl-containing compound in combination is not particularly limited, for example, epoxy resin/(meth)acryl-containing compound = 95/5 to 50/50, preferably epoxy resin/(meth)acryl-containing compound = 90/10 to 60/40.

In particular, preferred examples of epoxy resins include bisphenol A type epoxy resins and bisphenol F type epoxy resins. Furthermore, preferred (meth)acryl group-containing compounds include polyfunctional (meth)acrylic monomers, and more preferred bifunctional (meth)acrylic monomers.

The amount of the thermosetting component in the thermally conductive composition of the present embodiment is, for example, 5 to 25 mass %, preferably 10 to 20 mass %, based on all non-volatile components.

(Hardener) The thermally conductive composition of this embodiment may contain a hardener. As the hardener, there may be cited those having a reactive group that reacts with the thermosetting component. The hardener, for example, contains a reactive group that reacts with functional groups such as an epoxy group, a succinimidyl group, and a hydroxyl group contained in the thermosetting component.

The curing agent preferably contains a phenolic curing agent and/or an imidazole curing agent, and these curing agents are particularly preferred when the thermosetting component contains an epoxy group.

The phenolic hardener may be a low molecular weight compound or a high molecular weight compound (ie, a phenolic resin).

Examples of low molecular weight phenolic curing agents include bisphenol A, bisphenol F (dihydroxybenzhydryl) and other bisphenol compounds (phenol resins having a bisphenol F skeleton); and compounds having a biphenyl skeleton such as 4,4'-bisphenol.

Specifically, the phenol resins include novolac-type phenol resins such as phenolic novolac resins, cresol novolac resins, bisphenol novolac resins, and phenol-biphenyl novolac resins; polyfunctional phenol resins such as polyvinylphenol and triphenylmethane-type phenol resins; modified phenol resins such as terpene-modified phenol resins and dicyclopentadiene-modified phenol resins; phenol aralkyl-type phenol resins such as phenol aralkyl resins having a phenyl-extension skeleton and/or a biphenyl-extension skeleton, and naphthol aralkyl resins having a phenyl-extension skeleton and/or a biphenyl-extension skeleton.

When a hardener is used, only one type may be used or two or more types may be used in combination. When the thermally conductive composition of the present embodiment contains a hardener, when the amount of the thermosetting component is set to 100 parts by mass, the amount is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass.

(Hardening accelerator) The thermally conductive composition of this embodiment may contain a hardening accelerator. Typically, the hardening accelerator is a accelerator that accelerates the reaction between the thermosetting component and the hardener.

Specifically, the curing accelerator includes: compounds containing phosphorus atoms, such as organic phosphines, tetrasubstituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds; amidine groups and tertiary amines, such as dicyandiamide, 1,8-diazabicyclo[5.4.0]undecene-7, and benzyldimethylamine; and compounds containing nitrogen atoms, such as quaternary ammonium salts of the above amidine groups or the above tertiary amines.

When using a hardening accelerator, only one type may be used or two or more types may be used in combination. When the thermally conductive composition of the present embodiment contains a hardening accelerator, when the amount of the thermosetting component is set to 100 parts by mass, the amount is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass.

(Silane coupling agent) The thermally conductive composition of this embodiment may contain a silane coupling agent. This can further improve the adhesion.

As the silane coupling agent, known silane coupling agents can be cited. Specifically, the following silane coupling agents can be cited. Vinyl silanes such as vinyl trimethoxysilane and vinyl triethoxysilane; Epoxy silanes such as 2-(3,4-epoxyhexyl)ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, and 3-glycidoxypropyl triethoxysilane; Styrene silanes such as p-styrene trimethoxysilane; Methacryl silanes such as 3-methacryloyloxypropyl methyl dimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyl methyl diethoxysilane, 3-methacryloyloxypropyl triethoxysilane; Methacryl silanes such as 3-(trimethoxysilyl)propyl methacrylate and 3-acryloyloxypropyl trimethoxysilane; N-2-(aminoethyl)-3-aminopropyl methyl dimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl- =Aminosilanes such as butylene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane; Trimeric isocyanate silanes; Alkylsilanes; Urea silanes such as 3-ureidopropyltrialkoxysilane; Alkylsilanes such as 3-butylenepropylmethyldimethoxysilane and 3-butylenepropyltrimethoxysilane; Isocyanate silanes such as 3-isocyanatepropyltriethoxysilane, etc.

When using a silane coupling agent, only one type may be used, or two or more types may be used in combination. When the thermally conductive composition of the present embodiment contains a silane coupling agent, when the amount of the thermosetting component is set to 100 parts by mass, the amount is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass.

(Plasticizer) The thermally conductive composition of this embodiment may contain a plasticizer. This makes it easy to design E' to a small value. Also, it is easy to further suppress the reduction in adhesion due to thermal cycles.

Specific examples of the plasticizer include polyester compounds, silicone oils, silicone rubbers and other polysilicone compounds, polybutadiene compounds such as polybutadiene maleic anhydride adducts, and acrylonitrile-butadiene copolymer compounds.

When a plasticizer is used, only one type may be used or two or more types may be used in combination. When the thermally conductive composition of the present embodiment contains a plasticizer, when the amount of the thermosetting component is set to 100 parts by mass, the amount is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass.

(Free radical initiator) The thermally conductive composition of this embodiment may contain a free radical initiator. This may, for example, suppress insufficient curing, allow the curing reaction to proceed sufficiently at a relatively low temperature (e.g., 180°C), or further improve adhesion.

As the free radical initiator, peroxides, azo compounds and the like can be cited.

Examples of peroxides include organic peroxides such as diacyl peroxide, dialkyl peroxide, and peroxyketal. More specifically, the following peroxides are exemplified. Ketone peroxides such as methyl ethyl ketone peroxide and cyclohexane peroxide; peroxy ketones such as 1,1-di(tertiary butyl peroxy)cyclohexane and 2,2-di(4,4-di(tertiary butyl peroxy)cyclohexyl)propane; Hydroperoxides such as p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, isopropylbenzene hydroperoxide, and tertiary butyl hydroperoxide; Di(2-tertiary butyl peroxyisopropyl)benzene, diisophenylpropyl peroxide, 2,5-dimethyl-2,5-di(tertiary butyl peroxy)hexane, tertiary butyl isopropyl =Dialkyl peroxides such as phenyl peroxide, di-tertiary hexyl peroxide, 2,5-dimethyl-2,5-di(tertiary butyl peroxy)hexyne-3, di-tertiary butyl peroxide; Diacyl peroxides such as dibenzoyl peroxide and di(4-methylbenzoyl) peroxide; Peroxydicarbonates such as di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate; Peroxyesters such as 2,5-dimethyl-2,5-di(benzoyl peroxy)hexane, tertiary hexyl peroxybenzoate, tertiary butyl peroxybenzoate, and tertiary butyl peroxy 2-ethylhexanoate.

Examples of the azo compound include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile).

When a free radical initiator is used, only one type may be used or two or more types may be used in combination. When the thermally conductive composition of the present embodiment contains a free radical initiator, when the amount of the thermosetting component is set to 100 parts by mass, the amount is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass.

(Solvent) The thermally conductive composition of this embodiment may contain a solvent. This can, for example, adjust the fluidity of the thermally conductive composition and improve workability when forming an adhesive layer on a substrate.

Typically, the solvent is an organic solvent. Specific examples of the organic solvent include the following.

Methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, methyl methoxybutanol, α-terpineol, β-terpineol, hexylene glycol, benzyl alcohol, 2-phenylethyl alcohol, isopalmitol, isostearyl alcohol, lauryl alcohol, ethylene glycol, propylene glycol, butylglycerol, glycerol and other alcohols;

Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophorone (3,5,5-trimethyl-2-cyclohexene-1-one), and diisobutyl ketone (2,6-dimethyl-4-heptanone);

Ethyl acetate, butyl acetate, diethyl phthalate, dibutyl phthalate, acetoxyethane, methyl butyrate, methyl caproate, methyl octanoate, methyl decanoate, methyl cellulose acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 1,2-diethoxyethane, tributyl phosphate, tricresyl phosphate, tripentyl phosphate and other esters;

Ethers such as tetrahydrofuran, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, ethoxyethyl ether, 1,2-bis(2-diethoxy)ethane, 1,2-bis(2-methoxyethoxy)ethane, etc.

Ethers such as 2-(2-butoxyethoxy)ethane acetate; Ether alcohols such as 2-(2-methoxyethoxy)ethanol; Hydrocarbons such as toluene, xylene, normal alkanes, isoalkanes, dodecylbenzene, turpentine, kerosene, and light oil; Nitriles such as acetonitrile or propionitrile; Amides such as acetamide and N,N-dimethylformamide; Silicone oils such as low molecular weight volatile silicone oils and volatile organic modified silicone oils, etc.

When a solvent is used, only one solvent may be used, or two or more solvents may be used in combination. When a solvent is used, the amount is not particularly limited. The amount used may be appropriately adjusted based on the desired fluidity, etc. As an example, the solvent is used in an amount such that the concentration of the non-volatile component of the thermally conductive composition becomes 50 to 90 mass %.

(Properties of the composition) The thermally conductive composition of this embodiment is preferably in a paste state at 20°C. That is, the thermally conductive composition of this embodiment can be preferably applied to a substrate, etc., like a paste at 20°C. Thereby, the thermally conductive composition of this embodiment can be preferably used as an adhesive for semiconductor elements, etc. Of course, depending on the applicable process, etc., the thermally conductive composition of this embodiment can also be in a relatively low-viscosity varnish state, etc.

(Supplement to λ) As described above, the thermal conductivity λ of the specific cured film in the thickness direction at 25°C is 25 W/m•K or more. λ is preferably 30 W/m•K or more, and more preferably 50 W/m•K or more. A large λ value itself means good heat dissipation. That is, a large λ value means that the thermally conductive composition of this embodiment can be preferably applied to semiconductor devices. From the perspective of practical design, λ is, for example, 200 W/m•K or less, and preferably 150 W/m•K or less.

(Supplement to E’) As described above, the storage elastic modulus E’ of the specific cured film obtained by viscoelastic measurement at 25°C, tensile mode, and frequency 1 Hz is 10000 MPa or less. E’ is preferably 8000 MPa or less, and more preferably 6000 MPa or less. By making the E’ value appropriately small, it is easy to further absorb the stress generated by the thermal cycle. On the other hand, E’ is preferably 500 MPa or more, and more preferably 1000 MPa or more. By making the E’ value appropriately large, the mechanical strength of the cured product can be improved. That is, damage caused by physical impact, etc. can be suppressed.

<Semiconductor device> Semiconductor devices can be manufactured using the above-mentioned thermally conductive composition. For example, semiconductor devices can be manufactured by using the above-mentioned thermally conductive composition as a "bonding agent" between a substrate and a semiconductor element. In other words, the semiconductor device of this embodiment has, for example: a substrate; and a semiconductor element, which is mounted on the substrate by a bonding layer obtained by heat-treating the above-mentioned thermally conductive composition. In the semiconductor device of this embodiment, the adhesion of the bonding layer is not easily reduced by heat cycles. That is, the reliability of the semiconductor device of this embodiment is high.

Examples of semiconductor components include ICs, LSIs, power semiconductor components (power semiconductors), and other various components. Examples of substrates include various semiconductor wafers, lead frames, BGA substrates, mounting substrates, heat spreaders, heat sinks, and the like.

Hereinafter, an example of a semiconductor device will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a semiconductor device. The semiconductor device 100 comprises: a substrate 30; and a semiconductor element 20, which is mounted on the substrate 30 via an adhesive layer 10 (chip adhesive material) which is a heat-treated body of a thermally conductive composition. The semiconductor element 20 and the substrate 30 are electrically connected, for example, via a bonding wire (bonding wire) 40. In addition, the semiconductor element 20 is sealed, for example, by a sealing resin 50.

The thickness of the connecting layer 10 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. This can improve the stress absorption capacity of the thermally conductive composition and improve the heat cycle resistance. The thickness of the connecting layer 10 is, for example, 100 μm or less, preferably 50 μm or less.

In FIG. 1 , the substrate 30 is, for example, a lead frame. At this time, the semiconductor element 20 is mounted on the chip pad 32 or the substrate 30 via the bonding layer 10. In addition, the semiconductor element 20 is electrically connected to the outer lead 34 (substrate 30) via, for example, a bonding wire 40. The substrate 30 as a lead frame is composed of, for example, a 42 alloy or a Cu frame.

The substrate 30 can be an organic substrate or a ceramic substrate. As an organic substrate, for example, one composed of epoxy resin, cyanate resin, butylene diimide resin, etc. can be cited. The surface of the substrate 30 can be covered with a metal such as silver or gold. Thereby, the adhesion between the bonding layer 10 and the substrate 30 is improved.

FIG. 2 is a cross-sectional view showing an example of a semiconductor device 100 different from FIG. 1 . In the semiconductor device 100 of FIG. 2 , the substrate 30 is, for example, an interposer. A plurality of solder balls 52 are formed on the surface of the substrate 30 serving as the interposer, which is opposite to the surface on which the semiconductor element 20 is mounted. At this time, the semiconductor device 100 is connected to other wiring substrates via the solder balls 52.

An example of a method for manufacturing a semiconductor device is described. First, a thermally conductive composition is applied to a substrate 30, and then a semiconductor element 20 is arranged thereon. That is, the substrate 30, the thermally conductive composition, and the semiconductor element 20 are layered in sequence. The method for applying the thermally conductive composition is not particularly limited. Specifically, dispensing, printing, inkjet, etc. can be cited. Next, the thermally conductive composition is thermally cured. Thermal curing is preferably performed by pre-curing and post-curing. By thermal curing, the thermally conductive composition becomes a heat-treated body (hardened body). By thermal curing (heat treatment), the metal-containing particles in the thermally conductive composition are agglomerated, and a structure in which the interfaces between a plurality of metal-containing particles disappear is formed in the bonding layer 10. Thus, the substrate 30 and the semiconductor element 20 are bonded via the bonding layer 10. Then, the semiconductor element 20 and the substrate 30 are electrically connected using the bonding wire 40. Then, the semiconductor element 20 is sealed with the sealing resin 50. In this way, a semiconductor device can be manufactured.

The above describes the embodiments of the present invention, but these are only examples of the present invention, and various structures other than the above can also be adopted. In addition, the present invention is not limited to the above embodiments, and modifications and improvements within the scope of the purpose of the present invention are included in the present invention. [Example]

The embodiments of the present invention are described in detail based on the embodiments and comparative examples. The present invention is not limited to the embodiments.

<Preparation of thermally conductive composition> First, the raw material components are mixed according to the blending amount shown in Table 1 described below to obtain a varnish. Then, the obtained varnish, solvent and metal-containing particles (including metal coating resin particles) are blended according to the blending amount shown in Table 1 described below and kneaded using a three-roll mill at room temperature. In this way, a paste-like thermally conductive composition is prepared.

The information of the raw material components in Table 1 is shown below.

(Thermosetting component) • Epoxy resin 1: Bisphenol F type liquid epoxy resin (Nippon Kayaku Co., Ltd., RE-303S) • Acrylic monomer 1: (Meth) acrylic monomer (ethylene glycol dimethacrylate, Kyoeisha Chemical Co., Ltd., LIGHT ESTER EG) • Acrylic monomer 2: (Meth) acrylic monomer (phenoxyethyl methacrylate, Kyoeisha Chemical Co., Ltd., LIGHT ESTER PO) • Acrylic monomer 3: (Meth) acrylic monomer (1,4-cyclohexanedimethanol monoacrylate, Mitsubishi Chemical Corporation., CHDMMA)

(Hardener) •Hardener 1: Phenolic resin with a bisphenol F skeleton (solid at room temperature 25°C, manufactured by DIC Corporation, DIC-BPF)

(Acrylic particles) •Acrylic particles 1: Isobutyl = methacrylate • Methyl = methacrylate polymer (Sekisui Kasei Co., Ltd., IBM-2, particle size 0.1 to 0.8 mm)

(Plasticizer) •Plasticizer 1: Allyl resin (manufactured by KANTO CHEMICAL CO., INC., a polymer of 1,2-cyclohexanedicarboxylic acid bis(2-propenyl) and propane-1,2-diol, a polyester compound with the following chemical structure, R is a methyl group)

(Silane coupling agent) •Silane coupling agent 1: 3-(trimethoxysilyl)propyl methacrylate (manufactured by Shin-Etsu Chemica.Co.,Ltd., KBM-503P) •Silane coupling agent 2: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemica.Co.,Ltd., KBM-403E)

(Hardening accelerator) • Imidazole hardener 1: 2-phenyl-1H-imidazole-4,5-dimethanol (manufactured by SHIKOKU CHEMICALS CORPORATION., 2PHZ-PW)

(Polymerization initiator) • Radical polymerization initiator 1: diisopropyl peroxide (manufactured by Kayaku Akzo Corporation, Perkadox BC)

(Solvent) •Solvent 1: Butyl propylene glycol (BFTG)

(Particles containing metal) •Silver Particle 1: Silver powder (AG-DSB-114 manufactured by DOWA HIGHTECH CO., LTD., spherical, D ₅₀ : 1μm) •Silver Particle 2: Silver powder (HKD-16 manufactured by Fukuda Metal Foil & Powder Co., Ltd., flake, D ₅₀ : 2μm) •Silver-coated resin particle 1: Silver-coated silicone resin particle (Mitsubishi Materials Corporation, heat-resistant/surface-treated 10μm product, spherical, D ₅₀ : 10μm, specific gravity: 2.3, weight ratio of silver is 50wt%, weight ratio of resin is 50wt%) •Silver-coated resin particle 2: Silver-coated acrylic resin particle (SANNO Co., Ltd., SANSILVER-8D, spherical, D ₅₀ : 8 μm, monodisperse particles, specific gravity: 2.4, weight ratio of silver is 50wt%, weight ratio of resin is 50wt%)

<Measurement of thermal conductivity λ in the thickness direction at 25°C> The obtained thermally conductive composition was applied to a Teflon plate, and the temperature was raised from 30°C to 180°C in 60 minutes, and then heat treated at 180°C for 120 minutes. In this way, a heat-treated body of the thermally conductive composition with a thickness of 1 mm was obtained ("Teflon" is a registered trademark for fluororesin). Then, the heat diffusion coefficient α in the thickness direction of the heat-treated body was measured using the laser flash method. The measurement temperature was 25°C. In addition, the specific heat Cp was measured using differential scanning calorimetry (DSC). Furthermore, the density ρ was measured in accordance with JIS K 6911. Using these values, the thermal conductivity λ is calculated based on the following formula. Thermal conductivity λ[W/(m•K)]=α[m ² /sec]×Cp[J/kg•K]×ρ[g/cm ³ ]

<Measurement of storage elastic modulus E’ at 25°C> The obtained thermally conductive composition was applied to a Teflon plate, and the temperature was raised from 30°C to 180°C over 60 minutes, and then heat-treated at 180°C for 120 minutes. Thus, a heat-treated body of the thermally conductive composition having a thickness of 0.3 mm was obtained. The heat-treated body obtained was peeled off the Teflon plate and placed on a measuring device (DMS6100 manufactured by High-Tech Science Corporation.), and dynamic viscoelasticity measurement (DMA) was performed in the tensile mode at a frequency of 1 Hz. Thus, the storage elastic modulus E’ (MPa) at 25°C was measured.

<Confirmation of sintering> The heat-treated body (hardened film) used for the measurement of λ and E' was ground with an automatic grinder, and its ground surface was observed with a SEM (scanning electron microscope). The observation results confirmed that: in all heat-treated bodies made using the compositions of Examples 1 to 3, the metal-containing particles were sintered by heating to form a connection structure of the metal-containing particles. In particular, in the connection structure of the metal-containing particles, the metal on the surface of the particles consisting of metal and the metal coating resin particles was sintered to form a connection structure.

<Thermal cycle test/evaluation of peeling> A thermally conductive composition was applied to a silver-plated substrate to form a coating, and a 3.5×3.5 mm silicon wafer (only the surface was silver-plated in Comparative Example 2, and the rest was not coated) was placed on the coating. The reason for using a silver-plated silicon wafer in Comparative Example 2 is that the silicon wafer is not bonded to the substrate at all when it is not coated. Afterwards, the temperature was raised from 30°C to 180°C over 60 minutes, and then heat treated at 180°C for 120 minutes. This hardened the thermally conductive composition and bonded the silicon wafer to the substrate. The bonded silicon wafer substrates were sealed with sealing material EME-G700ML-C (manufactured by Sumitomo Bakelite Co., Ltd.) and used as samples for the temperature cycle test.

The sample was placed in a high temperature and high humidity tank at 85°C/60%RH for 168 hours, and then reflowed at 260°C. The sample after reflow was placed in a temperature cycle tester TSA-72ES (manufactured by ESPEC CORP.) and cycled 2,000 times, with (i) 150°C/10 minutes, (ii) 25°C/10 minutes, (iii) -65°C/10 minutes, and (iv) 25°C/10 minutes as one cycle. Afterwards, the presence of peeling was checked using SAT (ultrasonic flaw detection). Those without peeling were rated as ○ (good), and those with peeling were rated as × (bad).

The composition of the thermally conductive composition, thermal conductivity λ, storage elastic modulus E', and the results of the thermal cycle test are summarized and shown in Table 1. In Table 1, the unit of the amount of each component is part by mass.

[Table 1]

As shown in Table 1, in the heat cycle test using the thermally conductive compositions of Examples 1 to 3 (λ is 25 W/m•K or more and E' is 10000 MPa or less), no peeling occurred. On the other hand, in the heat cycle test using the thermally conductive compositions of Comparative Examples 1 and 2 (E' is greater than 10000 MPa), peeling occurred.

This application claims priority based on Japanese Tokugan Application No. 2019-161766 filed on September 5, 2019, and all the contents disclosed therein are incorporated herein by reference.

100: semiconductor device 10: bonding layer 20: semiconductor element 30: substrate 32: chip pad 34: external lead 40: bonding wire 50: sealing resin 52: solder ball

[Fig. 1] is a cross-sectional view schematically showing an example of a semiconductor device. [Fig. 2] is a cross-sectional view schematically showing an example of a semiconductor device.

100:Semiconductor devices

10: Next layer

20: Semiconductor components

30: Base material

32: Chip pad

34: External lead wire

40:Joining line

50: Sealing resin

Claims (12)

A thermally conductive composition comprising metal-containing particles and a thermosetting component comprising at least one selected from the group consisting of a polymer, an oligomer and a monomer, wherein the metal-containing particles are sintered by heat treatment to form a particle connection structure, wherein the metal-containing particles comprise metal-coated resin particles having a resin/metal mass ratio of 90/10 to 10/90, and the thermally conductive composition is heated at a constant rate from 30°C to 180°C for 60 minutes. The thermal conductivity λ of the cured film in the thickness direction at 25°C obtained by heating at 180°C for 2 hours is 25W/m˙K or more, and the storage elastic modulus E' obtained by viscoelastic measurement of the cured film at 25°C, tensile mode, and frequency 1Hz is less than 10000MPa. The cured film is obtained by heating the thermal conductive composition from 30°C to 180°C at a constant rate for 60 minutes and then heating at 180°C for 2 hours. The thermally conductive composition of claim 1, wherein the metal-containing particles include particles containing at least one selected from the group consisting of silver, gold and copper. The thermally conductive composition of claim 1 or 2, wherein the metal-containing particles include metal-coated resin particles whose surfaces are coated with metal. The thermally conductive composition of claim 1 or 2, wherein the thermosetting component contains at least one selected from the group consisting of epoxy-containing compounds and (meth)acryl-containing compounds. The thermally conductive composition of claim 1 or 2 further contains a hardener. As in claim 5, the thermally conductive composition, wherein the aforementioned hardener contains a phenolic hardener and/or an imidazole hardener. The thermally conductive composition of claim 1 or 2 further contains a silane coupling agent. The thermally conductive composition of claim 1 or 2 further contains a plasticizer. The thermally conductive composition of claim 1 or 2 further contains a free radical initiator. The thermally conductive composition of claim 1 or 2 further contains a solvent. The thermally conductive composition of claim 1 or 2 is in a paste state at 25°C. A semiconductor device comprising: a substrate; and a semiconductor element, wherein a bonding layer obtained by heat treating a thermally conductive composition according to any one of claims 1 to 11 is mounted on the substrate.