CN114341288B

CN114341288B - Thermally conductive composition and semiconductor device

Info

Publication number: CN114341288B
Application number: CN202080062341.5A
Authority: CN
Inventors: 渡部直辉; 高本真
Original assignee: Sumitomo Bakelite Co Ltd
Current assignee: Sumitomo Bakelite Co Ltd
Priority date: 2019-09-05
Filing date: 2020-08-26
Publication date: 2023-07-28
Anticipated expiration: 2040-08-26
Also published as: CN114341288A; KR20220058923A; JP2022027775A; TW202115216A; JP6981580B2; JP7264211B2; JPWO2021044915A1; KR102576953B1; WO2021044915A1

Abstract

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 a heat treatment to form a particle-bonded structure. The thermal conductive composition is heated from 30 ℃ to 180 ℃ at a constant speed over 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film having a thermal conductivity lambda of 25W/mK or more in the thickness direction at 25 ℃. The heat conductive composition is heated from 30 ℃ to 180 ℃ at a constant rate over 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film, and the cured film has a storage modulus E' of 10000MPa or less, which is obtained by measuring viscoelasticity under conditions of 25 ℃ and a stretching mode and a frequency of 1 Hz.

Description

Thermally conductive composition and semiconductor device

Technical Field

The present invention relates to a thermally conductive composition and a semiconductor device. And more particularly, to a thermally conductive composition and a semiconductor device including a member obtained by heat-treating the thermally conductive composition.

Background

In order to improve heat dissipation of a semiconductor device, a technique for manufacturing a semiconductor device using a thermosetting resin composition containing metal particles is known. The thermosetting resin composition contains metal particles having a thermal conductivity greater than that of the resin, so that the thermal conductivity of the cured product can be improved.

As specific examples applied to a semiconductor device, as in the following patent documents 1 and 2, a technique of bonding/joining a semiconductor element to a substrate (supporting member) using a thermosetting resin composition containing metal particles is known.

Patent document 1 describes a thermosetting resin composition for semiconductor bonding containing a (meth) acrylate compound, a radical initiator, silver particles, silver powder, and a solvent (claim 1 and the like). This document also describes that bonding of a semiconductor element to a metal substrate can be achieved by heating to 200 ℃ (paragraphs 0001 and 0007, etc.).

Patent document 2 describes a resin paste composition containing an epoxy resin, a curing agent, a curing accelerator, a diluent, and silver powder (table 1, etc.). It is described that the resin paste composition is cured at 150 ℃ to bond the semiconductor element to the support member by using a cured product such as an epoxy resin (paragraph 0038, etc.).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2014-74132

Patent document 2: japanese patent laid-open No. 2000-239616

Disclosure of Invention

Technical problem to be solved by the invention

Thermosetting resin compositions containing metal particles can be classified into several types according to the characteristics of the metal particles at the time of thermosetting. For example, there are a "sintered type" resin composition which is sintered by heat treatment to form a particle-connected structure, a resin composition of a type which is not sintered, and the like.

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

The present invention has been made in view of such circumstances. An object of the present invention is to provide a thermally conductive composition which is less likely to be peeled off by thermal cycle when applied to, for example, bonding a semiconductor element to a substrate.

Means for solving the technical problems

The present inventors have conducted intensive studies and as a result, have completed the invention provided below, and have achieved the above-mentioned problems.

According to the present invention, there is provided a thermally conductive composition comprising metal-containing particles and a thermosetting component, wherein the thermosetting component comprises at least one selected from the group consisting of a polymer, an oligomer and a monomer, and wherein the metal-containing particles are sintered by a heat treatment to form a particle-connected structure,

the heat conductive composition is heated from 30 ℃ to 180 ℃ at a constant speed for 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film, the heat conductivity coefficient lambda in the thickness direction at 25 ℃ is more than 25W/m.K,

the thermal conductive composition is heated from 30 ℃ to 180 ℃ at a constant speed over 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film, and the cured film has a storage modulus E' of 10000MPa or less, which is obtained by measuring viscoelasticity under conditions of 25 ℃ and a stretching mode and a frequency of 1 Hz.

Also, according to the present invention, there is provided a semiconductor device including:

a substrate; and

and a semiconductor element having an adhesive layer formed by heat-treating the thermally conductive composition, which is mounted on the substrate.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a thermally conductive composition which is less likely to be peeled off by thermal cycle when applied to, for example, bonding a semiconductor element to a substrate.

Drawings

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 the semiconductor device.

Detailed Description

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

In all the drawings, the same constituent elements are denoted by the same reference numerals, and description thereof is omitted as appropriate.

In order to avoid complication, (i) in the case where a plurality of identical constituent elements exist in the same drawing, (ii) in particular, in the drawings subsequent to fig. 2, the same constituent elements as those in fig. 1 are not denoted by the same reference numerals in some cases.

All figures are for illustration only. The shapes, dimensional ratios, etc. of the respective parts in the drawings do not necessarily correspond to actual articles.

In the present specification, unless otherwise specified, the numerals "a to b" in the description of the numerical ranges denote a to b. For example, "1 to 5 mass%" means "1 mass% or more and 5 mass% or less".

In the labeling of a group (atomic group) in the present specification, an unsubstituted or unsubstituted label includes both the case of having no substituent and the case of having a substituent. For example, "alkyl" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

The term "(meth) acrylic" as used herein is meant to include acrylic (-CO-ch=ch) ₂ ) And methacrylic acid (-CO-C (CH) ₃ )＝CH ₂ ) Both concepts. The same applies to "(meth) acrylate" and the like.

< thermally conductive composition >

The heat conductive composition of the present embodiment is a heat conductive composition containing metal-containing particles and a thermosetting component containing at least one selected from a polymer, an oligomer, and a monomer, and the metal-containing particles are sintered by a heat treatment to form a particle-connected structure.

The thermal conductive composition of the present embodiment is heated from 30 ℃ to 180 ℃ at a constant rate over 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film having a thermal conductivity λ of 25W/m·k or more in the thickness direction at 25 ℃.

The heat conductive composition of the present embodiment is heated from 30 ℃ to 180 ℃ at a constant rate over 60 minutes, and then heated at 180 ℃ for 2 hours to obtain a cured film, and the cured film has a storage modulus E' of 10000MPa or less, which is obtained by measuring the viscoelasticity under conditions of 25 ℃, stretching mode, and frequency of 1 Hz.

Hereinafter, the "thermosetting component containing at least one selected from the group consisting of a polymer, an oligomer, and a monomer" will also be simply referred to as "thermosetting component".

The cured film obtained by heat curing under the above-described heating conditions is sometimes referred to as a "specific cured film".

The inventors of the present invention studied the cause of peeling due to thermal cycling (repeated heating-cooling) when the sintered heat conductive composition is applied to bonding.

The inventors of the present invention considered that the cause of the peeling is (1) that stress due to thermal shrinkage is generated in the solidified product after cooling due to an excessively high heating temperature at the time of solidifying the composition and sintering the metal particles in the composition, and (2) that stress and the like are also generated due to expansion-shrinkage due to thermal cycling.

From the viewpoint of the above (1), the inventors of the present invention considered that: it is sufficient to design a composition which cures even when heated at a low temperature to a certain extent (in the case where sintering of metal-containing particles occurs, sintering forms a heat conduction path). This is considered to be because, if the temperature required for solidification of the composition and sintering of the metal-containing particles is low, the degree of thermal shrinkage due to cooling after solidification and sintering can be reduced, and stress due to thermal shrinkage can be reduced (further, the decrease in adhesion force can be suppressed).

From the viewpoint of (2) above, it is considered that when the composition is designed so that the "elastic modulus" of the cured product is small (the cured product has a certain degree of "softness"), the cured product absorbs stress due to thermal cycling, and the decrease in adhesive force can be suppressed.

Therefore, as one of the indexes for designing the thermally conductive composition, the inventors of the present invention set the thermal conductivity coefficient λ in the thickness direction at 25 ℃ of the cured film obtained by heating the thermally conductive composition at "180 ℃ (the heating condition is as detailed above). Further, it is considered that if a thermally conductive composition having a sufficiently large λ is designed, it is possible to suppress the decrease in adhesion (since λ is related to the degree of sintering of the metal-containing particles, λ substantially corresponds to "easy sintering at low temperature (180 ℃)).

Further, as another index for designing the thermally conductive composition, the inventors of the present invention set a storage modulus E' obtained by measuring the viscoelasticity of a cured film obtained by heating the thermally conductive composition at 180 ℃ (the heating condition is as described above in detail) under conditions of 25 ℃, stretching mode, and frequency of 1 Hz. Further, it is considered that if the heat conductive composition E' is designed to be appropriately small, the decrease in adhesion can be suppressed (it is considered that this is because if the cured product has a certain degree of "flexibility", the cured product is likely to absorb stress due to thermal cycling).

The inventors of the present invention devised a thermally conductive composition based on these two indices. Further, by newly designing the thermally conductive composition having a λ of 25W/m·k or more and an E' of 10000MPa or less, the decrease in adhesion due to thermal cycling can be reduced.

In this embodiment, by appropriately selecting the type and amount of the raw materials, the method of producing the composition, and the like, a thermally conductive composition having a λ of 25W/m·k or more and an E' of 10000MPa or less can be obtained. For example, by using metal-coated resin particles described later as part or all of the metal-containing particles, a thermally conductive composition in which λ and E' are appropriate values can be obtained. Hereinafter, usable materials, production methods, and the like will be described in more detail.

The present invention should not be construed as limited to the above description.

The components, physical properties, and the like contained in the thermally conductive composition of the present embodiment will be described in detail below.

(containing Metal particles)

The thermally conductive composition of the present embodiment contains metal-containing particles.

Typically, the metal-containing particles can be sintered (sinterable) by a suitable heat treatment to form a particle-bonded structure (sintered structure).

The "metal" in the metal-containing particles may be any metal. The preferred metal is, for example, at least one selected from gold, silver, copper, nickel, and tin from the viewpoints of good thermal conductivity, easy sintering property, applicability to semiconductor devices, and the like. More preferred metals are at least any one selected from silver, gold and copper.

The metal-containing particles may contain only one metal or two or more metals (i.e., the metal-containing particles may be alloy-containing particles). Also, the core portion and the surface layer portion containing the metal particles may be composed of different kinds of metals.

In particular, when silver-containing particles, particularly silver particles having a small particle diameter and a large specific surface area are contained in the thermally conductive composition, a sintered structure is easily formed even by heat treatment at a relatively low temperature (about 180 ℃). The preferred particle size is described later.

The shape of the metal-containing particles is not particularly limited. The preferred shape is spherical, but may be a non-spherical shape, such as ellipsoidal, flat, plate-like, sheet (flag), needle-like, or the like.

( The "spherical shape" is not limited to a perfect sphere, but includes a shape with a slight irregularity on the surface, and the like. Hereinafter, the same applies to the present specification. )

The metal-containing particles may be (i) particles substantially composed of only a metal, or (ii) particles composed of a metal and a component other than the metal. Further, as the metal-containing particles, (i) and (ii) may be used in combination.

In the present embodiment, particularly preferred are metal-coated resin particles in which the surfaces of the metal-containing particles containing resin particles are metal-coated. Thus, a thermally conductive composition having a lambda of 25W/mK or more and an E' of 10000MPa or less can be easily produced.

The metal-coated resin particles are considered to have good thermal conductivity and are soft (compared with particles composed of only metal) because the surface is metal and the interior is resin. Therefore, it is considered that λ and E' are easily designed to appropriate values by using metal-coated resin particles.

Generally, in order to increase λ, it is considered to increase the amount of the metal-containing particles. However, since metals are generally "hard", there are cases where the elastic modulus after sintering becomes too large once the amount of metal-containing particles is excessive. By forming part or all of the metal-containing particles as metal-coated resin particles, it is easy to design a thermally conductive composition having a lambda of 25W/mK or more and an E' of 10000MPa or less.

In the metal-coated resin particle, it is sufficient that the metal layer covers at least a part of the area of the surface of the resin particle. Of course, the metal may cover the entire surface of the resin particles.

Specifically, in the metal-coated resin particles, the metal layer preferably covers 50% or more, more preferably 75% or more, and still more preferably 90% or more of the surface of the resin particles. Particularly preferably, in the metal-coated resin particles, the metal layer covers substantially the entire surface of the resin particles.

As another point of view, when the resin particles are coated with a certain section cut metal, it is preferable that the metal layer is confirmed around the section.

As yet another aspect, the mass ratio of resin/metal in the metal-coated resin particles is, for example, 90/10 to 10/90, preferably 80/20 to 20/80, more preferably 70/30 to 30/70.

The "metal" in the metal-coated resin particles is as described above. Silver is particularly preferred.

Examples of the "resin" in the metal-coated resin particles include silicone resins, (meth) acrylic resins, phenolic resins, polystyrene resins, melamine resins, polyamide resins, polytetrafluoroethylene resins, and the like. Of course, other resins may be used. The resin may be one kind only, or two or more kinds may be used in combination.

From the viewpoints of elastic properties and heat resistance, the resin is preferably a silicone resin or a (meth) acrylic resin.

The silicone resin may be particles composed of organopolysiloxane obtained by polymerizing organochlorosilanes such as methylchlorosilane, trimethyltrichlorosilane, dimethyldichlorosilane, and the like. The silicone resin may have a basic skeleton structure obtained by further three-dimensionally crosslinking an organopolysiloxane.

The (meth) acrylic resin may be a resin obtained by polymerizing a monomer containing a (meth) acrylate as a main component (50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more). Examples of the (meth) acrylic acid ester include 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, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and isobornyl (meth) acrylate. The monomer component of the acrylic resin may contain a small amount of other monomers. Examples of such other monomer components include styrene monomers. For the metal-coated (meth) acrylic resin, reference may also be made to the description of Japanese patent application laid-open No. 2017-126463, and the like.

Various functional groups may be introduced into the silicone resin or the (meth) acrylic resin. The functional group that can be introduced is not particularly limited. Examples thereof include an epoxy group, an amino group, a methoxy group, a phenyl group, a carboxyl group, a hydroxyl group, an alkyl group, a vinyl group, and a mercapto group.

The portion of the resin particles in the metal-coated resin particles may contain various additive components, such as a low-stress modifier and the like. Examples of the low stress modifier include liquid synthetic rubbers such as butadiene styrene rubber, butadiene acrylonitrile rubber, urethane rubber, polyisoprene rubber, acrylic rubber, fluororubber, liquid organopolysiloxane, and liquid polybutadiene. In particular, when the silicone resin is contained in the resin particles, the elastic properties of the metal-coated resin particles can be improved by containing the low-stress modifier.

The shape of the portion of the resin particles in the metal-coated resin particles is not particularly limited. The shape is preferably spherical, but may be a different shape other than spherical, for example, flat, plate-like, needle-like, or the like. In the case where the metal-coated resin particles are formed into a spherical shape, the shape of the resin particles used is also preferably spherical.

The specific gravity of the metal-coated 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. The specific gravity is preferably appropriate from the viewpoints of dispersibility of the metal-coated resin particles themselves, uniformity when the metal-coated resin particles are used in combination with other metal-containing particles, and the like.

When the metal-coated resin particles are used, the proportion of the metal-coated resin particles in the whole metal-containing particles is preferably 1 to 50% by mass, more preferably 3 to 45% by mass, and still more preferably 5 to 40% by mass. By properly adjusting the ratio, the decrease in adhesion due to thermal cycling can be suppressed, and the heat dissipation can be further improved.

When the proportion of the metal-coated resin particles in the whole metal-containing particles is not 100% by mass, the metal-containing particles other than the metal-coated resin particles are, for example, particles substantially composed of only metal.

Median particle diameter D of metal-containing particles (bulk in the case of the combination of multiple metal-containing particles) ₅₀ For example, 0.001 to 1000. Mu.m, preferably 0.01 to 100. Mu.m, more preferably 0.1 to 20. Mu.m. By combining D ₅₀ When the value is set to an appropriate value, it is easy to balance the heat conductivity, sinterability, resistance to thermal cycling, and the like. And by combining D ₅₀ When the value is set to an appropriate value, the coating/bonding operability may be improved.

The particle size distribution (horizontal axis: particle diameter, vertical axis: frequency) of the metal-containing particles may be unimodal or multimodal.

Median diameter D of particles consisting essentially of metal only ₅₀ For example, 0.8 μm or more, preferably 1.0 μm or more, more preferablyIs selected to be more than 1.2 mu m. This can further improve the thermal conductivity.

And, the median diameter D of the particles consisting essentially of only metal ₅₀ For example, the particle size is 7.0 μm or less, preferably 5.0 μm or less, and more preferably 4.0 μm or less. Thus, further improvement in the easiness of sintering, improvement in the uniformity of sintering, and the like can be achieved.

Median particle diameter D of Metal-coated resin particles ₅₀ For example, the particle size is 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 modulus E' to an appropriate value.

And, median particle diameter D of the metal-coated resin particles ₅₀ For example, 20 μm or less, preferably 15 μm or less, and more preferably 10 μm or less. This makes it easy to sufficiently improve the thermal conductivity.

Median particle diameter D of Metal-containing particles ₅₀ For example, the particle image can be obtained by performing particle image measurement using a Sysmex Corporation flow-type particle image analyzer FPIA (registered trademark) -3000. More specifically, the particle diameter of the metal particles can be determined by using the device to measure the median particle diameter on a volume basis in a wet manner.

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

The metal-containing particles are made of only metal, and are commercially available from DOWA high tech co, ltd, fofield metal foil powder industry, inc. The metal-coated resin particles are commercially available from Mitsubishi composite Co., ltd., water chemical industry Co., ltd., mountain king, etc.

(thermosetting component)

The thermally conductive composition of the present embodiment contains a thermosetting component selected from at least any one of a polymer, an oligomer, and a monomer.

The thermosetting component generally contains groups that polymerize/crosslink by the action of reactive chemicals such as radicals, and/or chemical structures that react with a curing agent described below. The thermosetting component includes, for example, one or two or more of an epoxy group, an oxetane group, a group containing an olefinic carbon-carbon double bond, a hydroxyl group, an isocyanate group, a maleimide structure, and the like.

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

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.

Specific examples of the epoxy group-containing compound include known epoxy resins.

Examples of the epoxy resin include: 2-functional or crystalline epoxy resins such as biphenyl type epoxy resins, bisphenol a type epoxy resins, bisphenol F type epoxy resins, stilbene type epoxy resins, and hydroquinone type epoxy resins; novolac type epoxy resins such as cresol novolac type epoxy resin, phenol novolac type epoxy resin, naphthol novolac type epoxy resin and the like; phenol aralkyl type epoxy resins such as phenol aralkyl type epoxy resins having a phenylene skeleton, phenol aralkyl type epoxy resins having a biphenylene skeleton, and naphthol aralkyl type epoxy resins having a phenylene skeleton; 3-functional epoxy resins such as triphenol methane-type epoxy resins and alkyl-modified triphenol methane-type epoxy resins; modified phenolic epoxy resins such as dicyclopentadiene modified phenolic epoxy resins and terpene modified phenolic epoxy resins; and heterocyclic epoxy resins such as triazine nucleus-containing epoxy resins.

Examples of the epoxy group-containing compound include monofunctional epoxy group-containing compounds such as 4-t-butylphenyl glycidyl ether, m-tolyl glycidyl ether, p-tolyl glycidyl ether, phenyl glycidyl ether, and tolyl glycidyl ether.

Examples of the (meth) acryl-containing compound include a monofunctional (meth) acrylic monomer having only one (meth) acrylic group in one molecule, and a multifunctional (meth) acrylic monomer having two or more (meth) acrylic groups in one molecule.

The polyfunctional (meth) acrylic monomer typically has 2 to 6 (meth) acrylic groups in one molecule, preferably 2 to 4 (meth) acrylic groups in one molecule.

Specific examples of the monofunctional (meth) acrylic monomer include 2-phenoxyethyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-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, ethoxydiglycol (meth) acrylate, butoxydiglycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-ethylhexyl diglycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiglycol (meth) acrylate, phenoxypolyethylene (meth) acrylate, nonylphenol ethylene oxide modified (meth) acrylate, phenylphenol ethylene oxide modified (meth) acrylate, isobornyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate quaternary ammonium, glycidyl (meth) acrylate, neopentyl glycol (meth) acrylate, 1, 4-cyclohexanedimethanol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalic acid, 2- (meth) acryloyloxyethyl acid phosphate (2- (meth) acryloyloxy ethyl acid phosphate), and the like.

As the polyfunctional (meth) acrylic monomer, specific examples thereof include ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, hexane-1, 6-diol bis (2-methyl (meth) acrylate), 4' -isopropylidenediphenol di (meth) acrylate, 1, 3-butanediol di (meth) acrylate 1, 6-bis ((meth) acryloyloxy) -2, 3,4, 5-octafluorohexane, 1, 4-bis ((meth) acryloyloxy) butane, 1, 6-bis ((meth) acryloyloxy) hexane, triethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, N, N ' -bis (meth) acryloylethylenediamine, N ' - (1, 2-dihydroxyethylene) bis (meth) acrylamide, 1, 4-bis ((meth) acryloylpiperazine, and the like.

Further, as one of the (meth) acrylic monomers, a (meth) acrylamide monomer may be mentioned. Specific examples thereof include (meth) acrylamide, diethyl (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N, N' -methylenebis (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, diacetone (meth) acrylamide, (meth) acryloylmorpholine, and the like.

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, a polyfunctional acrylic monomer alone is preferably used.

As the (meth) acrylic monomer, for example, "LIGHT ESTER" series sold by Kagaku Co., ltd.

The heat conductive composition of the present embodiment may contain only one kind of thermosetting component, or may contain two or more kinds.

In the present embodiment, as the thermosetting component, it is preferable to use an epoxy resin and a (meth) acryl-containing compound in combination. The ratio (mass ratio) of the epoxy resin to the (meth) acryl-containing compound is not particularly limited, and 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.

The epoxy resin is particularly preferably bisphenol a type epoxy resin, bisphenol F type epoxy resin, or the like. In addition, as the (meth) acryl-containing compound, a polyfunctional (meth) acrylic monomer is preferable, and a 2-functional (meth) acrylic monomer is more preferable.

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

(curing agent)

The thermally conductive composition of the present embodiment may contain a curing agent.

As the curing agent, a substance having a reactive group that reacts with the thermosetting component can be mentioned.

The curing agent contains, for example, a reactive group that reacts with a functional group such as an epoxy group, a maleimide group, a hydroxyl group, or the like contained in the thermosetting component.

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

The phenolic curing agent may be a low-molecular compound or a high-molecular compound (i.e., a phenolic resin).

Examples of the phenolic curing agent of the low molecular compound include: bisphenol compounds (phenol resins having a bisphenol F skeleton) such as bisphenol a and bisphenol F (dihydroxydiphenylmethane); and compounds having a biphenylene skeleton such as 4,4' -biphenol.

Specific examples of the phenolic resin include novolak type phenolic resins such as phenol novolak type resins, cresol novolak type resins, bisphenol novolak type resins, and phenol-biphenyl novolak type resins; polyvinyl phenol; multifunctional phenolic resins such as triphenylmethane type phenolic resins; modified phenolic resins such as terpene-modified phenolic resins and dicyclopentadiene-modified phenolic resins; phenol aralkyl type phenolic resins such as phenol aralkyl resins having a phenylene skeleton and/or a biphenylene skeleton and naphthol aralkyl resins having a phenylene and/or biphenylene skeleton.

In the case of using a curing agent, only one kind may be used, or two or more kinds may be used in combination.

When the thermally conductive composition of the present embodiment contains a curing agent, the amount of the curing agent is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass, based on 100 parts by mass of the thermosetting component.

(curing accelerator)

The thermally conductive composition of the present embodiment may contain a curing accelerator.

The curing accelerator is typically a component that promotes the reaction of the thermosetting component with the curing agent.

Specific examples of the curing accelerator include: phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaines (phosphobetaines) compounds, adducts of phosphine compounds with quinone compounds, adducts of phosphonium compounds with silane compounds, and the like; amidines or tertiary amines such as dicyandiamide, 1, 8-diazabicyclo [5.4.0] undecene-7, and benzyldimethylamine; and nitrogen atom-containing compounds such as quaternary ammonium salts of the above amidines and the above tertiary amines.

In the case of using a curing accelerator, only one kind may be used, or two or more kinds may be used in combination.

When the thermally conductive composition of the present embodiment contains a curing accelerator, the amount of the curing accelerator is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the thermosetting component.

(silane coupling agent)

The thermally conductive composition of the present embodiment may contain a silane coupling agent. This can further improve the adhesion.

The silane coupling agent may be a known silane coupling agent. Specific examples of the silane coupling agent include the following.

Vinyl silanes such as vinyl trimethoxy silane and vinyl triethoxy silane;

epoxysilanes such as 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, and 3-epoxypropoxypropyltriethoxysilane;

styrylsilanes such as p-styryltrimethoxysilane;

methacrylic silanes such as 3-methacryloxypropyl methyl dimethoxy silane, 3-methacryloxypropyl trimethoxy silane, 3-methacryloxypropyl methyl diethoxy silane, and 3-methacryloxypropyl triethoxy silane;

acrylic silanes such as 3- (trimethoxysilyl) propyl methacrylate and 3-acryloxypropyl trimethoxysilane;

aminosilanes such as N-2- (aminoethyl) -3-aminopropyl methyldimethoxy silane, N-2- (aminoethyl) -3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane, 3-triethoxysilyl-N- (1, 3-dimethyl-butylene) propylamine, and N-phenyl-gamma-aminopropyl trimethoxy silane;

Trimeric isocyanate silanes;

an alkylsilane;

ureidosilanes such as 3-ureidopropyltrialkoxysilane;

mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane;

isocyanate silanes such as 3-isocyanate propyltriethoxysilane.

In the case of using a silane coupling agent, only one kind may be used, or two or more kinds may be used in combination.

When the thermally conductive composition of the present embodiment contains a silane coupling agent, the amount of the silane coupling agent is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the thermosetting component.

(plasticizer)

The thermally conductive composition of the present embodiment may contain a plasticizer. Thus, E' is easily designed to a small value. Further, the decrease in adhesion caused by thermal cycling is easily suppressed.

Specific examples of the plasticizer include polyester compounds, silicone oils, silicone rubber and other organosilicon compounds, polybutadiene compounds such as polybutadiene maleic anhydride adducts, acrylonitrile butadiene copolymer compounds and the like.

In the case of using a plasticizer, only one kind may be used, or two or more kinds may be used in combination.

When the thermally conductive composition of the present embodiment contains a plasticizer, the amount of the plasticizer is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass, based on 100 parts by mass of the thermosetting component.

(radical initiator)

The thermally conductive composition of the present embodiment may contain a radical initiator. This can prevent insufficient curing, allow a curing reaction at a relatively low temperature (for example, 180 ℃) to proceed sufficiently, and further improve the adhesive strength, for example.

Examples of the radical initiator include peroxides and azo compounds.

Examples of the peroxide 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 cyclohexanone peroxide; peroxyketals such as 1, 1-bis (t-butylperoxy) cyclohexane, 2-bis (4, 4-bis (t-butylperoxy) cyclohexyl) propane, and the like;

hydrogen peroxide such as p-menthane hydroperoxide, dicumyl hydroperoxide, 1, 3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide and the like;

dialkyl peroxides such as di (2-t-butylperoxyisopropyl) benzene, diisopropylbenzene peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, and di-t-butyl peroxide;

Diacyl peroxides such as dibenzoyl peroxide and bis (4-methylbenzoyl) peroxide;

peroxydicarbonates such as di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate;

peroxy esters such as 2, 5-dimethyl-2, 5-di (benzoyl peroxide) hexane, t-hexyl peroxybenzoate, t-butyl peroxybenzoate, and t-butyl peroxy-2-ethylhexanoate.

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

In the case of using a radical initiator, only one kind may be used, or two or more kinds may be used in combination.

When the thermally conductive composition of the present embodiment contains a radical initiator, the amount of the radical initiator is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the thermosetting component.

(solvent)

The thermally conductive composition of the present embodiment may contain a solvent. This can, for example, adjust the fluidity of the thermally conductive composition and improve the operability in forming the adhesive layer on the substrate.

The solvent is typically an organic solvent. Specific examples of the organic solvent include the following.

Alcohols such as 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-phenethyl alcohol, isopalmitol, isostearyl alcohol, lauryl alcohol, ethylene glycol, propylene glycol, butyl tripropylene glycol (butylpropylene triglycol), and glycerin;

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

esters such as ethyl acetate, butyl acetate, diethyl phthalate, dibutyl phthalate, acetoxyethane, methyl butyrate, methyl caproate, methyl caprylate, methyl caprate, methyl cellosolve acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 1, 2-diacetoxyethane, tributyl phosphate, tricresyl phosphate, and tripentyl phosphate;

ethers such as tetrahydrofuran, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, ethoxydiethyl ether, 1, 2-bis (2-diethoxy) ethane, and 1, 2-bis (2-methoxyethoxy) ethane;

Ester ethers such as acetic acid-2- (2-butoxyethoxy) ethane;

ether alcohols such as 2- (2-methoxyethoxy) ethanol;

hydrocarbons such as toluene, xylene, n-alkane, isoalkane, dodecylbenzene, turpentine, kerosene, and light oil;

nitriles such as acetonitrile and propionitrile;

amides such as acetamide and N, N-dimethylformamide;

low molecular weight volatile silicone oils, volatile organic modified silicone oils, and the like.

In the case of using a solvent, only one solvent may be used, or two or more solvents may be used in combination.

In the case of using a solvent, the amount thereof is not particularly limited. The amount to be used may be appropriately adjusted based on the desired fluidity or the like. As an example, the solvent is used in an amount such that the concentration of the non-volatile component of the thermally conductive composition is 50 to 90 mass%.

(Properties of the composition)

The thermally conductive composition of the present embodiment is preferably pasty at 20 ℃. That is, the thermally conductive composition of the present embodiment can be preferably applied to a substrate or the like as a paste at 20 ℃. Thus, the thermally conductive composition of the present embodiment is suitable for use as an adhesive for semiconductor elements or the like.

Of course, the thermally conductive composition of the present embodiment may be in the form of a varnish having a low viscosity, depending on the process or the like to be applied.

(supplement to lambda)

As described above, the specific cured film has a thermal conductivity λ of 25W/mK or more in the thickness direction at 25 ℃. Lambda is preferably 30W/mK or more, more preferably 50W/mK or more. A large lambda value itself means good heat dissipation. That is, a large λ value means that the thermally conductive composition of the present embodiment is suitable for a semiconductor device.

From the practical design point of view, λ is, for example, 200W/mK or less, preferably 150W/mK or less.

(supplementation of E')

As described above, the storage modulus E' of the specific cured film was 10000MPa or less, which was obtained by measuring the viscoelasticity at 25 ℃ in the stretching mode at a frequency of 1 Hz. E' is preferably 8000MPa or less, more preferably 6000MPa or less. By properly decreasing the E' value, it is easy to further absorb stress due to thermal cycling.

On the other hand, E' is preferably 500MPa or more, more preferably 1000MPa or more. When the E' value is appropriately large, the mechanical strength of the cured product is improved. That is, breakage due to physical impact or the like can be suppressed.

Semiconductor device

The use of the thermally conductive composition enables the manufacture of a semiconductor device. For example, a semiconductor device can be manufactured by using the thermally conductive composition as an "adhesive" between a substrate and a semiconductor element.

In other words, the semiconductor device of the present embodiment includes, for example: a substrate; and a semiconductor element mounted on the substrate via an adhesive layer obtained by heat-treating the thermally conductive composition.

In the semiconductor device of the present embodiment, adhesion of the adhesive layer and the like are not easily reduced even by thermal cycling. That is, the semiconductor device of the present embodiment has high reliability.

Examples of the semiconductor element include an IC, an LSI, a power semiconductor element (power semiconductor), and other various elements.

Examples of the substrate include various semiconductor chips, lead frames, BGA substrates, mounting substrates, heat sinks (heat spreader), heat sinks (heat sink), and the like.

An example of the semiconductor device will be described below with reference to the drawings.

Fig. 1 is a cross-sectional view showing an example of a semiconductor device.

The semiconductor device 100 includes: a base material 30; and a semiconductor element 20 mounted on the substrate 30 via an adhesive layer 10 (wafer bonding material) which is a heat-treated body of the heat-conductive composition.

The semiconductor element 20 and the substrate 30 are electrically connected via, for example, bonding wire 40 or the like. The semiconductor element 20 is sealed with, for example, a sealing resin 50.

The thickness of the adhesive layer 10 is preferably 5 μm or more, more preferably 10 μm or more, and still more preferably 20 μm or more. This improves the stress absorbing ability of the thermally conductive composition, and can improve the thermal cycle resistance.

The thickness of the adhesive 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 die pad 32 or the base material 30 via the adhesive layer 10. The semiconductor element 20 is electrically connected to the outer leads 34 (the base material 30) via, for example, bonding wires 40. The base material 30 as a lead frame is composed of, for example, 42 alloy, cu frame, or the like.

The substrate 30 may be an organic substrate or a ceramic substrate. Examples of the organic substrate include organic substrates made of epoxy resin, cyanate resin, maleimide resin, and the like.

The surface of the substrate 30 may be covered with a metal such as silver or gold. This improves the adhesion between the adhesive layer 10 and the base material 30.

Fig. 2 is a cross-sectional view showing an example of the semiconductor device 100 different from fig. 1.

In the semiconductor device 100 of fig. 2, the substrate 30 is, for example, an interposer (interposer). In the base material 30 as the interposer, for example, a plurality of solder balls 52 are formed on a surface opposite to the surface on which the semiconductor element 20 is mounted. At this time, the semiconductor device 100 is connected to another wiring board via the solder balls 52.

An example of a method for manufacturing a semiconductor device is described.

First, a thermally conductive composition is coated on a substrate 30, and then, a semiconductor element 20 is disposed thereon. That is, the base material 30, the thermally conductive composition, and the semiconductor element 20 are laminated in this order.

The method of coating the thermally conductive composition is not particularly limited. Specifically, a dispensing method (dispensing), a printing method, an inkjet method, and the like can be cited.

Next, the thermally conductive composition is thermally cured. The thermal curing is preferably carried out by means of pre-curing and post-curing. The thermally conductive composition is thermally cured to form a thermally treated body (cured product). By the heat curing (heat treatment), the metal-containing particles in the heat conductive composition aggregate, and a structure in which the interfaces of the plurality of metal-containing particles with each other disappear is formed in the adhesive layer 10. Thereby, the substrate 30 and the semiconductor element 20 are bonded via the adhesive layer 10. Next, the semiconductor element 20 and the substrate 30 are electrically connected using the bonding wire 40. Next, the semiconductor element 20 is sealed with the sealing resin 50. This enables the manufacture of a semiconductor device.

While the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than the above may be adopted. The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a range that can achieve the object of the present invention are included in the present invention.

Examples

Embodiments of the present invention will be described in detail based on examples and comparative examples. The present invention is not limited to the examples.

Preparation of thermally conductive composition

First, each raw material component was mixed according to the mixing amounts shown in table 1 below to obtain a varnish.

Next, the obtained varnish, solvent and metal-containing particles (including metal-coated resin particles) were blended in the blending amounts shown in Table 1 below, and kneaded at normal temperature using a three-roll mill. Thus, a paste-like thermally conductive composition was produced.

The information on the raw material components in table 1 is shown below.

(thermosetting component)

Epoxy resin 1: bisphenol F type liquid epoxy resin (RE-303S, manufactured by Japanese chemical Co., ltd.)

Acrylic monomer 1: (meth) acrylic acid monomer (ethylene glycol dimethacrylate, manufactured by co-Rong Chemie Co., ltd., LIGHT ESTER EG)

Acrylic monomer 2: (meth) acrylic acid monomer (phenoxyethyl methacrylate, manufactured by Kyowa Kagaku Co., ltd., LIGHT ESTER PO)

Acrylic monomer 3: (meth) acrylic acid monomer (1, 4-cyclohexanedimethanol monoacrylate, CHDMMA, mitsubishi chemical Co., ltd.)

(curing agent)

Curing agent 1: phenolic resin having bisphenol F skeleton (DIC-BPF, manufactured by DIC Corporation, solid at 25 ℃ C.)

(acrylic particles)

Acrylic particles 1: isobutyl=methacrylate-methyl=methacrylate polymer (IBM-2, manufactured by Seisakusho Kagaku Co., ltd., particle size 0.1 to 0.8 mm)

(plasticizer)

Plasticizer 1: allyl resin (polymer of bis (2-propenyl) 1, 2-cyclohexanedicarboxylate and propane-1, 2-diol, manufactured by Kato chemical Co., ltd., polyester compound of the following chemical structure, R is methyl)

(silane coupling agent)

Silane coupling agent 1: 3- (trimethoxysilyl) propyl methacrylate (KBM-503P, manufactured by Xinyue chemical industries Co., ltd.)

Silane coupling agent 2: 3-epoxypropoxypropyltrimethoxysilane (KBM-403E, from Xinyue chemical Co., ltd.)

(curing accelerator)

Imidazole hardener 1: 2-phenyl-1H-imidazole-4, 5-dimethanol (2 PHZ-PW manufactured by Sichuang chemical industry Co., ltd.)

(polymerization initiator)

Radical polymerization initiator 1: diisopropylbenzene-based peroxide (Kayaku Akzo Corporation, perkadox BC)

(solvent)

Solvent 1: butyl tripropylene glycol (butyl propylene triglycol, BFTG)

(containing Metal particles)

Silver particles 1: silver powder (DOWA HIGHTECH CO., LTD. Manufactured by AG-DSB-114, spherical, D) ₅₀ ：1μm)

Silver particles 2: silver powder (HKD-16, flake, D, manufactured by Futian Metal foil powder Co., ltd.) ₅₀ ：2μm)

Silver coated resin particles 1: silver-plated silicone resin particles (Heat-resistant/surface-treated 10 μm product, spherical, manufactured by Mitsubishi Integrated materials Co., ltd., D) ₅₀ :10 μm, specific gravity: 2.3, silver 50wt%, resin 50 wt%)

Silver coated resin particles 2: silver-plated acrylic resin particles (Kagaku Kogyo mountain Wang Zhi, SANSILVER-8D, spherical, D) ₅₀ :8 μm, monodisperse particles, specific gravity: 2.4, silver 50wt%, resin 50 wt%)

Measurement of thermal conductivity coefficient λ in thickness direction at 25

The obtained thermally conductive composition was coated on a teflon plate, and heated from 30 to 180 ℃ over 60 minutes, followed by heat treatment at 180 ℃ for 120 minutes. Thus, a heat-treated body of the thermally conductive composition having a thickness of 1mm was obtained ("Teflon" is a registered trademark with respect to fluorine resins).

Next, the thermal diffusivity α in the thickness direction of the heat-treated body was measured by a laser flash method. The measured temperature was 25 ℃.

The specific heat Cp was measured by differential scanning calorimetric (Differential scanning calorimetry: DSC) measurement.

And the density ρ was measured in accordance with JIS K6911.

Using these values, the thermal conductivity λ is calculated based on the following equation.

Thermal conductivity lambda W/(m.K)]＝α[m ² /sec]×Cp[J/kg·K]×ρ[g/cm ³ ]

< measurement of storage modulus E' at 25 >

The obtained thermally conductive composition was coated on a teflon plate, and heated from 30 to 180 ℃ over 60 minutes, followed by heat treatment at 180 ℃ for 120 minutes. Thus, a heat-treated body of the heat-conductive composition having a thickness of 0.3mm was obtained.

The obtained heat-treated body was peeled off from the teflon plate, and mounted on a measuring apparatus (DMS 6100, hitachi high technology, ltd.) to perform dynamic viscoelasticity measurement (DMA) under conditions of a stretching mode and a frequency of 1 Hz. Thus, the storage modulus E' (MPa) at 25℃was measured.

< sintering confirmation >

The above heat-treated body (cured film) for measurement of λ and E' was polished by an automatic polishing machine, and the polished surface thereof was observed by SEM (scanning electron microscope).

The observed results confirm: in all the heat-treated bodies produced using the compositions of examples 1 to 3, the metal-containing particles were sintered by heating, and a bonded structure of the metal-containing particles was formed. In particular, in the bonding structure containing metal particles, the bonding structure is formed by sintering only the particles made of metal and the metal on the surface of the metal-coated resin particles.

< evaluation of thermal cycle test/Peel-off

The thermally conductive composition was applied to a surface-plated substrate to form a coating film, and a silicon chip of 3.5x3.5 mm was placed on the coating film (only comparative example 2 was surface-plated but not plated). The reason why the surface-silver-plated silicon chip was used in comparative example 2 is that the silicon chip was not bonded to the substrate at all in the case of no plating.

Thereafter, the temperature was raised from 30℃to 180℃over 60 minutes, followed by heat treatment at 180℃for 120 minutes. Thereby, the thermally conductive composition is cured, and the silicon chip is bonded to the substrate.

The bonded silicon chip-substrate was sealed with a sealing material EME-G700ML-C (manufactured by Sumitomo electric Co., ltd.). This was used as a sample for a temperature cycle test.

The sample was placed in a high temperature and high humidity tank at 85 c/60% rh for 168 hours, after which a reflow treatment at 260 c was performed.

The sample after the reflow treatment was put into a temperature cycle tester TSA-72ES (manufactured by ESPEC CORP.) and subjected to 2000 cycles of (i) 150 ℃/10 minutes, (ii) 25 ℃/10 minutes, (iii) -65 ℃/10 minutes, and (iv) 25 ℃/10 minutes as 1 cycle.

Thereafter, the presence or absence of delamination was confirmed by SAT (ultrasonic flaw detection). The evaluation of absence of peeling was evaluated as o (good), and the evaluation of presence of peeling was evaluated as x (bad).

Table 1 summarizes the composition of the thermally conductive composition, the thermal conductivity λ, the storage modulus E', and the results of the thermal cycle test. In table 1, the unit of the amounts of the respective components is parts by mass.

As shown in table 1, in the thermal cycle test using the thermally conductive compositions of examples 1 to 3 (λ is 25W/m·k or more and E' is 10000MPa or less), peeling did not occur.

In the thermal cycle test using the thermally conductive compositions (E' exceeding 10000 MPa) of comparative examples 1 and 2, peeling occurred.

The present application claims priority based on japanese application publication No. 2019-161766, filed on 5 of 9 in 2019, and the entire disclosure thereof is incorporated herein.

Description of the reference numerals

100: semiconductor device, 10: adhesive layer, 20: semiconductor element, 30: substrate, 32: chip pad, 34: outer lead, 40: bonding wire, 50: sealing resin, 52: and (5) welding balls.

Claims

1. A thermally conductive composition, characterized in that,

comprising metal-containing particles and a thermosetting component comprising at least any one selected from the group consisting of polymers and monomers, the metal-containing particles being sintered by a heat treatment to form a particle-bonded structure,

the metal-containing particles include metal-coated resin particles obtained by coating the surface of the resin particles with at least any one metal selected from the group consisting of silver, copper, nickel and tin,

2. A thermally conductive composition as claimed in claim 1, wherein,

the metal-containing particles include particles containing at least any one selected from silver, gold, and copper.

3. A thermally conductive composition as claimed in claim 1 or 2, wherein,

the thermosetting component includes at least any one selected from the group consisting of an epoxy group-containing compound and a (meth) acryl group-containing compound.

4. A thermally conductive composition as claimed in claim 1 or 2, wherein,

and further contains a curing agent.

5. A thermally conductive composition as claimed in claim 4, wherein,

the curing agent comprises a phenolic curing agent and/or an imidazole curing agent.

6. A thermally conductive composition as claimed in claim 1 or 2, wherein,

and also contains a silane coupling agent.

7. A thermally conductive composition as claimed in claim 1 or 2, wherein,

and also contains plasticizer.

8. A thermally conductive composition as claimed in claim 1 or 2, wherein,

And also contains a free radical initiator.

9. A thermally conductive composition as claimed in claim 1 or 2, wherein,

and further comprises a solvent.

10. A thermally conductive composition as claimed in claim 1 or 2, wherein,

the thermally conductive composition is pasty at 25 ℃.

11. A thermally conductive composition as claimed in claim 1 or 2, wherein,

the polymer contained in the thermosetting component is an oligomer.

12. A semiconductor device, comprising:

a substrate; and

a semiconductor device having an adhesive layer obtained by heat-treating the thermally conductive composition according to any one of claims 1 to 11, mounted on the substrate.