Resin composition, thermosetting film using same, cured product of thermosetting film, and semiconductor device

Abstract

The present invention provides a resin composition that has excellent adhesive strength at room temperature and excellent wire bonding properties in a temperature range suitable for Cu wire bonding. This resin composition contains: (A) a phenoxy resin having a glass transition temperature Tg1 of 50°C or less; (B) a curing agent; (C) a filler; and (D) at least one resin selected from the group consisting of a phenoxy resin having a glass transition temperature Tg2 of 100°C or more, a trifunctional or higher epoxy resin, and a naphthalene-type epoxy resin. The resin composition has a glass transition temperature Tg3 of 130°C or more, and the cured product thereof has a modulus of elasticity of 0.5 GPa or more at 200°C.

Description

Resin composition, thermosetting film using the same, cured product of thermosetting film, and semiconductor device

[0001] The present invention relates to a resin composition, a thermosetting film using the same, a cured product of the thermosetting film, and a semiconductor device.

[0002] Conventionally, Au wire bonding using gold wire has been used to bond semiconductor elements to lead frames, etc. in the mounting of semiconductor devices, but in recent years, a switch to Cu wire bonding using copper wire has been considered from a cost perspective. Hereinafter, Au wire bonding using gold wire will also be referred to as "AuWB," and Cu wire bonding using copper wire will also be referred to as "CuWB."

[0003] In semiconductor devices mounted by wire bonding, an interlayer insulating film made of a resin composition is sometimes used to form an interlayer insulating layer between a substrate and a lead frame, etc. As an insulating sheet used as such an interlayer insulating film, for example, an insulating sheet used to bond a thermal conductor having a thermal conductivity of 10 W / m·K or more to a conductive layer has been proposed (see, for example, Patent Document 1). The insulating sheet described in Patent Document 1 contains a polymer having a weight-average molecular weight of 10,000 or more, a curable compound having a molecular weight of 1,200 or less and containing an epoxy group or an oxetanyl group, a curing agent, and an inorganic filler.

[0004] International Publication No. 2012 / 073360

[0005] As mentioned above, when changing the wire bonding method from AuWB to CuWB, it is necessary not only to change the metal material of the wire but also to change the bonding temperature due to the difference in the melting points of the metals. That is, the bonding temperature suitable for AuWB is about 140°C, while the bonding temperature suitable for CuWB is about 200°C. Therefore, in order to perform CuWB, the bonding temperature must be higher than that for AuWB.

[0006] Therefore, when changing from AuWB to CuWB, the interlayer insulating film used is required to have heat resistance capable of withstanding the higher bonding temperature (for example, 200° C.) due to the increase in bonding temperature mentioned above.

[0007] However, the insulating sheet described in Patent Document 1 has a problem in that it does not have heat resistance sufficient to withstand CuWB. Therefore, when the insulating sheet described in Patent Document 1 is applied as an interlayer insulating film to CuWB, which is bonded at higher temperatures, the film softens during wire bonding and sinks, resulting in insufficient adhesive strength between the wire and a lead frame or the like located on the interlayer insulating layer.

[0008] In order to improve the insufficient adhesive strength of the bonding described above, it is necessary to provide the film with heat resistance. Specifically, a high modulus of elasticity is required in a temperature range suitable for CuWB (e.g., around 200°C). For example, one method for achieving a high modulus of elasticity at high temperatures is to blend a resin with a high glass transition temperature into the resin composition used for the film. However, simply blending a resin with a high glass transition temperature into the resin composition creates a new problem: the adhesive strength of the film at room temperature decreases.

[0009] For this reason, there is a strong demand for the development of an adhesive film that not only has excellent wire bonding properties in Cu wire bonding but also has excellent adhesive strength at room temperature.

[0010] The present invention has been made in consideration of the problems of the prior art. The present invention provides a resin composition used as an adhesive film that has excellent adhesive strength at room temperature and also excellent wire bonding properties in a temperature range suitable for Cu wire bonding. The present invention also provides a thermosetting film, a cured product of the thermosetting film, and a semiconductor device using the above-mentioned resin composition.

[0011] According to the present invention, there are provided a resin composition, a thermosetting film using the same, a cured product of the thermosetting film, and a semiconductor device, all of which are shown below.

[0012] [1] A resin composition comprising: (A) a phenoxy resin having a glass transition temperature Tg1 of 50°C or lower; (B) a curing agent; (C) a filler; and (D) at least one resin selected from the group consisting of a phenoxy resin, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin, having a glass transition temperature Tg2 of 100°C or higher; wherein the resin composition has a glass transition temperature Tg3 of 130°C or higher, and a modulus of elasticity of the cured product at 200°C of 0.5 GPa or higher.

[0013] [2] A resin composition comprising: (A) a phenoxy resin having a glass transition temperature Tg1 of 50°C or lower; (B) a curing agent; (C) a filler; and (D) at least one selected from the group consisting of a phenoxy resin, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin having a glass transition temperature Tg2 of 100°C or higher, wherein the content of the component (A) is 3 to 200 parts by mass per 100 parts by mass of the component (D).

[0014] [3] The resin composition according to [1] or [2], wherein the component (D) contains at least two or more selected from the group consisting of a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin.

[0015] [4] The resin composition according to any one of [1] to [3], wherein the component (D) contains at least a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher.

[0016] [5] The resin composition according to any one of [1] to [4], wherein the component (C) contains a thermally conductive filler having a thermal conductivity of 5 W / (m·K) or more.

[0017] [6] The content of the (C) component is 50 to 95 mass% when the non-volatile components in the resin composition are 100 mass%. The resin composition according to any one of [1] to [5].

[0018] [7] A thermosetting film comprising the resin composition according to any one of [1] to [6].

[0019] [8] The thermosetting film according to [7] above, which is used for joining a copper wire to a semiconductor element or a lead frame.

[0020] [9] A cured product of the thermosetting film according to [7] or [8].

[0021]

[10] A semiconductor device comprising a cured product of the thermosetting film according to [9] above.

[0022]

[11] A semiconductor device comprising a configuration in which a heat dissipation member, a cured product of the thermosetting film described in [9] above, and a lead frame are laminated in this order.

[0023] The resin composition of the present invention can be suitably used as a film for interlayer bonding between substrates of a semiconductor device. The film has excellent adhesive strength at room temperature and excellent wire bonding properties in a temperature range suitable for Cu wire bonding using copper wire. Therefore, the resin composition of the present invention can be suitably used as an interlayer insulating film used in Cu wire bonding. That is, when used as an interlayer insulating film as described above, the resin composition of the present invention effectively suppresses a decrease in adhesive strength between a copper wire and a semiconductor element or lead frame, thereby achieving highly reliable wire bonding. Furthermore, the thermosetting film, cured product of the thermosetting film, and semiconductor device of the present invention contain the above-mentioned resin composition of the present invention and enjoy the effects of the present invention described so far.

[0024] While the present invention will be described below with reference to exemplary embodiments, it should be understood that the present invention is not limited to the following exemplary embodiments. Therefore, it should be understood that modifications and improvements to the following exemplary embodiments, based on the ordinary knowledge of those skilled in the art, are also within the scope of the present invention, provided that they do not deviate from the spirit of the present invention.

[0025] [Resin Composition (First Embodiment)] A first embodiment of the resin composition of the present invention is a resin composition comprising: (A) a phenoxy resin having a glass transition temperature Tg1 of 50° C. or lower, (B) a curing agent, (C) a filler, and (D) at least one resin selected from the group consisting of a phenoxy resin, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin, having a glass transition temperature Tg2 of 100° C. or higher. The resin composition of this embodiment has a glass transition temperature Tg3 of 130° C. or higher, and a cured product having an elastic modulus of 0.5 GPa or higher at 200° C.

[0026] The resin composition of this embodiment can be suitably used as a film for interlayer bonding between substrates of a semiconductor device. The film has excellent adhesive strength at room temperature and also excellent wire bonding properties in a temperature range suitable for Cu wire bonding using copper wire. Therefore, the resin composition of this embodiment can be suitably used as an interlayer insulating film used in Cu wire bonding. That is, when used as an interlayer insulating film as described above, the resin composition of this embodiment effectively suppresses a decrease in adhesive strength between the copper wire and the semiconductor element or lead frame, thereby achieving highly reliable wire bonding.

[0027] Hereinafter, the (A) phenoxy resin having a glass transition temperature Tg1 of 50°C or lower contained in the resin composition of this embodiment may be referred to as component (A). Similarly, the (B) curing agent may be referred to as component (B), and the (C) filler may be referred to as component (C). Furthermore, at least one resin selected from the group consisting of (D) a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin may be referred to as component (D). Components (A) to (D) contained in the resin composition of this embodiment will be described in more detail below.

[0028] [Component (A)] Component (A) is a phenoxy resin having a glass transition temperature Tg1 of 50°C or less. By including component (A) in the resin composition, adhesion to an adherend at room temperature can be effectively ensured when the resin composition is formed into a film. Although the reason for this is unclear, it is thought that a film formed using a resin composition containing component (A) can have appropriate flexibility after curing, and this flexibility contributes to the development of adhesiveness at room temperature. Commercially available phenoxy resins having a glass transition temperature Tg1 of 50°C or less include, for example, YX7180BH40 manufactured by Mitsubishi Chemical Corporation.

[0029] The phenoxy resin as component (A) is not particularly limited as long as it has a glass transition temperature Tg1 of 50°C or less, but examples include those having one or more skeletons selected from a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenolacetophenone skeleton, a novolac skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, and a norbornene skeleton.

[0030] The phenoxy resin having a glass transition temperature Tg1 of 50° C. or less as the component (A) may be used alone or in combination of two or more.

[0031] The glass transition temperature Tg1 of the phenoxy resin as component (A) may be 50°C or lower, but from the viewpoint of adhesiveness at room temperature, for example, the glass transition temperature Tg1 is preferably 40°C or lower, and more preferably 30°C or lower. There is no specific limit on the lower limit of the glass transition temperature Tg1 of the phenoxy resin as component (A). For example, the lower limit of the glass transition temperature Tg1 may be -50°C, 0°C, or 10°C. Therefore, the glass transition temperature Tg1 of the phenoxy resin as component (A) may be -50 to 50°C, preferably 0 to 40°C, and more preferably 10 to 30°C.

[0032] There are no particular restrictions on the content of component (A) in the resin composition. For example, when the nonvolatile components in the resin composition are taken as 100% by mass, the content of component (A) is preferably 0.5 to 30% by mass, more preferably 1.0 to 20% by mass, and even more preferably 1.5 to 15% by mass. Hereinafter, the "content (% by mass) of each component when the nonvolatile components in the resin composition are taken as 100% by mass" may be referred to as the "content of each component relative to the entire resin composition." Here, nonvolatile components refer to solid or liquid components that do not volatilize at the curing temperature of the resin composition (e.g., 170°C). If the content of component (A) relative to the entire resin composition is less than 0.5% by mass, sufficient adhesive strength at room temperature may not be achieved.

[0033] There are no particular restrictions on the weight average molecular weight (Mw) of the phenoxy resin as component (A), but it is preferably 5,000 to 100,000, more preferably 10,000 to 60,000, and even more preferably 30,000 to 45,000.

[0034] There are no particular limitations on the method for measuring the glass transition temperature Tg1 of the phenoxy resin of component (A), but it can be measured, for example, according to JIS K7121.

[0035] [Component (B)] Component (B) is a curing agent. Examples of curing agents include known curing agents such as imidazole-based curing agents, amine-based curing agents, phosphorus-based curing agents, and phenol-based curing agents, and they can be used without any particular restrictions. From the viewpoint of curability, it is preferable to use at least an imidazole-based curing agent. The content of the curing agent is not particularly limited, but is preferably 0.5 to 10 parts by mass per 100 parts by mass of the total of components (A) and (D). Only one type of curing agent may be used, or two or more types may be used in combination. In this specification, the term "curing agent" includes not only curing agents in the narrow sense, but also compounds known as curing catalysts and curing accelerators.

[0036] Examples of imidazole curing agents include imidazole compounds such as 2-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-imidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, and 2-phenyl-4-methylimidazole. Among these, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, and 1-cyanoethyl-2-ethyl-4-imidazole are preferred. Modified imidazole curing agents can also be used as imidazole curing agents, such as epoxy-imidazole adduct compounds and acrylate-imidazole adduct compounds. Commercially available epoxy-imidazole adduct compounds include Amicure PN-23 and Amicure PN-40 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Novacure HX-3721 (manufactured by Asahi Kasei E-materials Co., Ltd.), and Fujicure FX-1000 (manufactured by Fuji Chemical Industry Co., Ltd.). Commercially available acrylate-imidazole adduct compounds include EH2021 (manufactured by ADEKA Corporation).

[0037] Examples of the amine curing agent include triazine compounds such as 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, and tertiary amine compounds such as 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), triethylenediamine, benzyldimethylamine, and triethanolamine. Of these, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine is preferred.

[0038] Examples of the phosphorus-based curing agent include triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, and tri(nonylphenyl)phosphine.

[0039] As the phenolic curing agent, known phenolic resins can be used, for example, resol-type or novolac-type phenolic resins, such as alkyl resol-type, alkyl novolac-type, and aralkyl novolac-type phenolic resins, xylene resins, and allyl phenolic resins. Of these, novolac-type phenolic resins are preferred, and examples of commercially available products include TD-2131 (manufactured by DIC Corporation).

[0040] [Component (C)] Component (C) is a filler. Known fillers can be used. The filler of component (C) is preferably, for example, an inorganic filler. The inorganic filler is not particularly limited, but examples include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. These may be used alone or in combination of two or more. Of these, silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina, aluminum nitride, and boron nitride are preferred from the viewpoint of improving thermal conductivity. For example, from the viewpoint of maintaining insulating properties, the filler of component (C) may be a thermally conductive filler having a thermal conductivity of 5 W / (m K) or more. Examples of thermally conductive fillers having a thermal conductivity of 5 W / (m K) or more include alumina, magnesium oxide, boron nitride, aluminum nitride, and titanium oxide.

[0041] There are no particular restrictions on the content of the filler in component (C). For example, the content of the filler in component (C) is 50 to 95% by mass, more preferably 60 to 90% by mass, and even more preferably 70 to 90% by mass, when the nonvolatile components in the resin composition are taken as 100% by mass. For example, if the filler content is less than 50% by mass, the proportion of the resin component becomes relatively high, which may make it difficult to form the resin composition into a film. On the other hand, if the filler content exceeds 95% by mass, there is a concern that sufficient adhesiveness may not be obtained.

[0042] For example, when an inorganic filler is used as component (C), the upper and lower limits of the average particle size of the inorganic filler are not particularly limited, but are preferably 0.01 to 50 μm, more preferably 0.03 to 30 μm, and even more preferably 0.1 to 10 μm. If the average particle size of the inorganic filler exceeds 50 μm, there is a concern that the insulating properties may be reduced. If the average particle size of the inorganic filler is less than 0.01 μm, there is a concern that the adhesive properties may be reduced.

[0043] [Component (D)] The component (D) contains at least one resin selected from the group consisting of a phenoxy resin having a glass transition temperature Tg2 of 100° C. or higher, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin. By containing such component (D), the resin composition of the present embodiment can increase the high-temperature elastic modulus and achieve excellent wire bondability in a temperature range suitable for Cu wire bonding (CuWB).

[0044] Component (D) is not particularly limited as long as it contains a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, a tri- or higher functional epoxy resin, or a naphthalene-type epoxy resin. However, it preferably contains at least two or more selected from the group consisting of a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin, and more preferably contains at least a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher. By containing a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, the film-forming properties can be improved, making the film easier to handle. Commercially available phenoxy resins having a glass transition temperature Tg2 of 100°C or higher include YX8100BH30 and YX7200B35 manufactured by Mitsubishi Chemical Corporation.

[0045] To distinguish between the "phenoxy resin with a glass transition temperature Tg2 of 100°C or higher" of component (D) and the "phenoxy resin with a glass transition temperature Tg1 of 50°C or lower" of component (A), hereinafter, the "phenoxy resin with a glass transition temperature Tg2 of 100°C or higher" of component (D) may be referred to as the "phenoxy resin with a high glass transition temperature." Also, the "phenoxy resin with a glass transition temperature Tg1 of 50°C or lower" of component (A) may be referred to as the "phenoxy resin with a low glass transition temperature."

[0046] There are no particular restrictions on the content of component (D) in the resin composition. Component (D) is a component that contributes to improving the high-temperature elastic modulus of the resin composition. Therefore, component (D) is preferably contained in the resin composition so that the elastic modulus of the cured resin composition at 200°C is 0.5 GPa or more. For example, although not particularly limited, from the viewpoint of more easily obtaining a high high-temperature elastic modulus, the content of component (D) is preferably 3 to 30 mass%, more preferably 5 to 20 mass%, and even more preferably 5 to 17 mass%, when the non-volatile components in the resin composition are taken as 100 mass%. From the same viewpoint, the content of component (D) is preferably 50 to 1000 mass%, more preferably 70 to 900 mass%, and even more preferably 100 to 800 mass%, relative to 100 mass% of component (A). By configuring in this manner, excellent wire bondability can be effectively achieved in a temperature range suitable for Cu wire bonding (CuWB).

[0047] The phenoxy resin having a glass transition temperature Tg2 of 100°C or higher as component (D) is not particularly limited, but examples thereof include those having one or more skeletons selected from a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenolacetophenone skeleton, a novolac skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, and a norbornene skeleton.

[0048] The phenoxy resin having a glass transition temperature Tg2 of 100° C. or higher as component (D) may be used alone or in combination of two or more.

[0049] The glass transition temperature Tg2 of the phenoxy resin as component (D) may be 100° C. or higher, but from the viewpoint of realizing excellent wire bondability in a temperature range suitable for Cu wire bonding (CuWB), the glass transition temperature Tg2 is preferably 100 to 200° C., and more preferably 130 to 180° C. There are no particular restrictions on the method for measuring the glass transition temperature Tg2 of the phenoxy resin as component (D), and it can be measured using the same method as for the glass transition temperature Tg1 of the phenoxy resin as component (A).

[0050] There are no particular restrictions on the weight average molecular weight (Mw) of the phenoxy resin as component (D), but it is preferably 5,000 to 100,000, more preferably 10,000 to 60,000, and even more preferably 30,000 to 45,000.

[0051] The tri- or higher functional epoxy resin as component (D) refers to an epoxy resin having three or more epoxy groups. Examples of tri- or higher functional epoxy resins include polyfunctional glycidyl ether epoxy resins such as phenol novolac, orthocresol novolac, trishydroxyphenylmethane, and tetraphenylolethane, and glycidyl amine epoxy resins such as tetraglycidyldiaminodiphenylmethane, tetraglycidyl-m-xylylenediamine, triglycidyl-p-aminophenol, and triglycidyl-m-aminophenol.

[0052] Examples of tri- or higher functional epoxy resins include jER152, jER154, and jER630 manufactured by Mitsubishi Chemical Corporation, and D.E.N.431 and D.E.N.432 manufactured by Dow Chemical Company. 438, EPICLON N-730, N-770, N-865 manufactured by DIC Corporation, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000 manufactured by Nippon Kayaku Co., Ltd., Sumiepoxy ESCN-195X, ESCN-220 manufactured by Sumitomo Chemical Co., Ltd., YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-701, YDCN-704, YDCN-704A manufactured by Nippon Steel Chemical & Material Co., Ltd., EPICLON manufactured by DIC Corporation Novolac type epoxy resins such as N-680, N-690, and N-695 (all trade names); glycidylamine type epoxy resins such as jER604 manufactured by Mitsubishi Chemical Corporation, Epotohto YH-434 manufactured by Nippon Steel Chemical & Material Co., Ltd., and Sumiepoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (all trade names); trihydroxyphenylmethane type epoxy resins such as YL-933 manufactured by Mitsubishi Chemical Corporation and EPPN-501H, EPPN-501HY, and EPPN-502H manufactured by Nippon Kayaku Co., Ltd. (all trade names); bisphenol A novolac type epoxy resins such as jER157S (trade name) manufactured by Mitsubishi Chemical Corporation; tetraphenylolethane type epoxy resins such as jERYL-931 manufactured by Mitsubishi Chemical Corporation (all trade names); heterocyclic epoxy resins such as TEPIC-S manufactured by Nissan Chemical Industries, Ltd. epoxy resins; tetraglycidylxylenoylethane resins such as ZX-1063 manufactured by Nippon Steel Chemical & Material Co., Ltd.; naphthalene group-containing epoxy resins such as ESN-185 and ESN-365 manufactured by Nippon Steel Chemical & Material Co., Ltd.; epoxy resins having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC Corporation; glycidyl methacrylate copolymer epoxy resins such as CP-50S and CP-50M manufactured by NOF Corporation; further, copolymer epoxy resins of cyclohexylmaleimide and glycidyl methacrylate; CTBN-modified epoxy resins such as YR-102 and YR-450 manufactured by Nippon Steel Chemical & Material Co., Ltd.; and trifunctional epoxy resins having a triphenol skeleton such as VG3101L manufactured by Printec Co., Ltd., but are not limited to these.

[0053] The naphthalene-type epoxy resin as component (D) refers to an epoxy resin having a skeleton containing at least one naphthalene ring per molecule. Examples of the naphthalene-type epoxy resin include naphthol-based and naphthalenediol-based epoxy resins.

[0054] Examples of naphthalene type epoxy resins include 1,3-diglycidyl ether naphthalene, 1,4-diglycidyl ether naphthalene, 1,5-diglycidyl ether naphthalene, 1,6-diglycidyl ether naphthalene, 2,6-diglycidyl ether naphthalene, 2,7-diglycidyl ether naphthalene, 1,3-diglycidyl ester naphthalene, 1,4-diglycidyl ester naphthalene, 1,5-diglycidyl ester naphthalene, and 1,6-diglycidyl ester naphthalene. Examples of naphthalene-type epoxy resins include naphthalene-type epoxy resins such as tetraglycidyl ester naphthalene, 2,6-diglycidyl ester naphthalene, 2,7-diglycidyl ester naphthalene, 1,3-tetraglycidylamine naphthalene, 1,4-tetraglycidylamine naphthalene, 1,5-tetraglycidylamine naphthalene, 1,6-tetraglycidylamine naphthalene, 1,8-tetraglycidylamine naphthalene, 2,6-tetraglycidylamine naphthalene, and 2,7-tetraglycidylamine naphthalene. Commercially available naphthalene-type epoxy resins include HP4032D and HP4710 (both trade names) manufactured by DIC.

[0055] [Other Components] In addition to the components (A), (B), (C), and (D) described above, the resin composition may further contain other components as needed, as long as the object of the present invention is not impaired. For example, other components include additives such as solvents, coupling agents, ion trapping agents, leveling agents, antioxidants, antifoaming agents, flame retardants, colorants, and reactive diluents. The types and amounts of each of these additives are the same as in conventional methods.

[0056] [Characteristics of Resin Composition] The resin composition of this embodiment is characterized in that the cured product has an elastic modulus of 0.5 GPa or more at 200°C. Having an elastic modulus of 0.5 GPa or more at 200°C prevents the film from softening in the temperature range for Cu wire bonding, thereby enabling excellent adhesive strength to be obtained in Cu wire bonding. From the viewpoint of ensuring better wire bonding properties, the elastic modulus at 200°C is preferably 0.6 GPa or more, more preferably 0.7 GPa or more, even more preferably 0.8 GPa or more, and particularly preferably 1.0 GPa or more. The upper limit of the elastic modulus at 200°C is not particularly limited, but from a practical viewpoint, it may be 30 GPa, 20 GPa, or 15 GPa. From the viewpoint of ensuring better wire bonding properties, the elastic modulus at 200°C is preferably 0.5 to 30 GPa, more preferably 0.5 to 20 GPa, even more preferably 0.5 to 15 GPa, and particularly preferably 0.6 to 15 GPa.

[0057] The elastic modulus of the cured product at 200°C can be measured by the following method. First, the resin composition is applied to a release-treated polyethylene terephthalate film (hereinafter referred to as "PET film"), which serves as a support, using a knife. The resin composition applied to the PET film is then dried in a drying oven heated to 120°C to produce an uncured film with a thickness of 50 μm. Next, the produced uncured film is thermally cured in a press. The thermal curing conditions in the press are 170°C, 120 minutes, and 1 MPa. The thermally cured film is cut into a size of 1 cm x 4 cm to prepare a test specimen for measurement. The elastic modulus of the produced test specimen is measured using a viscoelasticity measuring device (model number: DMS7100) manufactured by Hitachi High-Tech Science Corporation. The measurement conditions for measuring the elastic modulus are a temperature range of 25 to 350°C, a heating rate of 5°C / min, and a frequency of 10 Hz in air. The storage modulus (E') of the data obtained by the measurement at a measurement temperature of 200°C is taken as the modulus at 200°C.

[0058] The resin composition of this embodiment has a glass transition temperature Tg3 of 130°C or higher. A resin with a high glass transition temperature, such as component (D), is blended into the resin composition to ensure that the elastic modulus of the cured product at 200°C falls within the above-mentioned range. On the other hand, a resin with a relatively low glass transition temperature, such as component (A), is also blended into the resin composition to obtain adhesive strength at room temperature. Therefore, the resin composition of this embodiment has a glass transition temperature Tg3 of 130°C or higher due to the combined use of components (A) and (D). Of course, the glass transition temperature Tg3 (°C) of a resin composition and the elastic modulus (GPa) of the cured product of the resin composition at 200°C are independent physical properties. Therefore, even if the elastic modulus of the cured product is 0.5 GPa or higher, this does not necessarily mean that the glass transition temperature Tg3 of the resin composition is 130°C or higher. Conversely, even if a resin composition has a glass transition temperature Tg3 of 130°C or higher, the elastic modulus of the cured product at 200°C may be less than 0.5 GPa.

[0059] The glass transition temperature Tg3 of the resin composition may be 130°C or higher, may be 140°C or higher, may be 145°C or higher, or may be 150°C or higher. There is no particular upper limit to the glass transition temperature Tg3 of the resin composition, but it may be, for example, 300°C or lower, 290°C or lower, or 280°C or lower. For example, the glass transition temperature Tg3 of the resin composition may be 130 to 300°C, 140 to 300°C, 145 to 290°C, or 145 to 280°C.

[0060] The glass transition temperature Tg3 of the resin composition can be measured by the following method. First, the resin composition is applied to a release-treated PET film, which serves as a support, using a knife. Then, the resin composition applied to the PET film is dried in a drying oven heated to 120°C to produce an uncured film with a thickness of 50 μm. Next, the produced uncured film is heat-cured using the same method as the above-mentioned elastic modulus measurement method, and a test specimen measuring 1 cm x 4 cm is cut from the heat-cured film to prepare a test specimen for measurement. The loss modulus (E") and storage modulus (E') of the produced test specimen are measured using a viscoelasticity measuring device (model: DMS7100) manufactured by Hitachi High-Tech Science Corporation under the same conditions as those for measuring the elastic modulus. The temperature showing the maximum value of the loss tangent tanδ (E" / E'), which is the ratio of the loss modulus (E") to the storage modulus (E') obtained by the measurement, is defined as the glass transition temperature Tg3 of the resin composition.

[0061] [Resin Composition (Second Embodiment)] Next, a second embodiment of the resin composition of the present invention will be described. Similar to the first embodiment of the resin composition described above, the resin composition of this embodiment is a resin composition comprising, as component (A), a phenoxy resin having a glass transition temperature Tg1 of 50°C or lower, as component (B), a curing agent, as component (C), a filler, as component (C), and at least one resin selected from the group consisting of a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin, as component (D).

[0062] The resin composition of this embodiment contains 3 to 200 parts by mass of component (A) per 100 parts by mass of component (D). This configuration allows the resin composition to be suitably used as a film for interlayer bonding between substrates in a semiconductor device, and the film has excellent adhesive strength at room temperature and also excellent wire bonding properties in a temperature range suitable for CuWB.

[0063] The contents of the (D) and (A) components in the resin composition may be 3 to 200 parts by mass of the (A) component per 100 parts by mass of the (D) component. If the content of the (A) component per 100 parts by mass of the (D) component is less than 3 parts by mass, it becomes difficult to achieve adhesive strength at room temperature. On the other hand, if the content of the (A) component per 100 parts by mass of the (D) component is more than 200 parts by mass, the modulus of elasticity at high temperatures decreases, which may result in a decrease in Cu wire bonding properties.

[0064] The amount of component (A) per 100 parts by mass of component (D) is preferably 5 to 150 parts by mass, and more preferably 10 to 130 parts by mass.

[0065] In the resin composition of this embodiment, as long as the content of component (A) relative to 100 parts by mass of component (D) is 3 to 200 parts by mass, the other components are preferably configured in the same manner as in the first embodiment described above. Therefore, with regard to components (A), (B), (C), (D), and other components contained in the resin composition, explanations of parts that overlap with those in the first embodiment will be omitted as appropriate. In addition, the properties of the resin composition are preferably configured in the same manner as in the first embodiment.

[0066] [Method for preparing resin composition] The resin composition can be prepared by a conventional method, for example, by mixing the components described above using a mortar and pestle mixer, a pot mill, a three-roll mill, a rotary mixer, a twin-screw mixer, or the like.

[0067] [Uses of Resin Composition] The resin composition can be suitably used as a resin composition for adhesive films used in electronic components. The resin composition can also be suitably used as a thermosetting film as an interlayer insulating film for multilayer substrates, and in particular, can be suitably used as an interlayer insulating film used to bond copper wires to semiconductor elements or lead frames, etc.

[0068] When the resin composition of the present embodiment is used for various applications for electronic components, there are no particular limitations on the electronic components to be bonded, and examples include ceramic substrates, organic substrates, semiconductor chips, and semiconductor devices.

[0069] Adhesive films, interlayer bonding sheets, interlayer adhesives, etc. using the resin composition of this embodiment are contained as cured products of the resin composition in laminates and semiconductor devices that constitute electronic components, etc. Therefore, laminates and semiconductor devices that constitute electronic components, etc. preferably contain a cured product of the resin composition of this embodiment.

[0070] [Thermosetting Film] Next, an embodiment of the thermosetting film of the present invention will be described. The thermosetting film of this embodiment is formed from the resin composition described above. Specifically, the thermosetting film is obtained by applying the resin composition to at least one surface of a desired support and then drying it.

[0071] The support used when forming the thermosetting film is appropriately selected depending on the desired form in the method for producing the thermosetting film and is not particularly limited, and examples thereof include metal foils such as copper and aluminum foils, and carrier films of resins such as PET, polyester, and polyethylene. When the thermosetting film is provided in the form of a film peeled from the support, the support may be subjected to a release treatment with a release agent such as a silicone compound.

[0072] The thermosetting film is suitable for adhesive films and interlayer adhesive films for electrical and electronic applications, particularly for applications where the environment may be subject to high temperatures. It is particularly suitable for use as an interlayer insulating film used to bond copper wires to semiconductor elements or lead frames. The thermosetting film is included as a cured product in laminates and semiconductor devices that constitute electronic components, etc.

[0073] [Semiconductor Device] Next, an embodiment of the semiconductor device of the present invention will be described. The semiconductor device of this embodiment includes a cured product of a thermosetting film. In particular, the semiconductor device of this embodiment is preferably a semiconductor device including a configuration in which a heat dissipation member such as a substrate, a cured product of a thermosetting film, and a lead frame are stacked in this order. Note that any known heat dissipation member can be used without particular limitation. Examples of semiconductor devices include power modules and inverter modules.

[0074] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0075] (Examples 1 to 9, Comparative Examples 1 to 4) [Preparation of Resin Compositions] After weighing out each component to obtain the blending ratio (parts by mass) shown in Tables 1 and 2 below, the components were dissolved and dispersed in a mixed solvent of methyl ethyl ketone and anone (cyclohexanone) to prepare solutions containing the resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4.

[0076] The raw materials used in preparing the solutions containing the resin compositions in Examples 1 to 9 and Comparative Examples 1 to 4 are as follows.

[0077] [Component (A): Phenoxy resin having a glass transition temperature of 50° C. or lower] Low Tg phenoxy resin: manufactured by Mitsubishi Chemical Corporation, trade name "YX7180BH40", glass transition temperature (Tg) = 25° C., molecular weight Mw = 40,000.

[0078] [Component (B): Curing Agent] Imidazole: ADEKA Corporation, trade name "EH2021" Phenol novolak: DIC Corporation, trade name "TD-2131".

[0079] [Component (C): Filler] Alumina filler 1: Denka Company, trade name "DAW0735", average particle size 7 μm. Alumina filler 2: Denka Company, trade name "ASFP20", average particle size 0.2 to 0.3 μm. Silica filler 1: Denka Company, trade name "FB300MDX", average particle size 3 μm. Silica filler 2: Admatechs Co., Ltd., trade name "SC4050", average particle size 1 μm. AlN (aluminum nitride) filler 1: Tokuyama Corporation, trade name "HF-10C", average particle size 8 μm. AlN (aluminum nitride) filler 2: Tokuyama Corporation, trade name "HF-01DC", average particle size 0.9 μm. BN (boron nitride) filler 1: Tomoe Engineering Co., Ltd., trade name "PTX60", spherical agglomerates, average particle size 55 to 65 μm. BN (boron nitride) filler 2: manufactured by JFE Corporation, trade name "HP-40", spherical agglomerate (HP-40MF100), average particle size 36 μm.

[0080] [Component (D): Phenoxy resin with a glass transition temperature Tg2 of 100°C or higher, tri- or higher functional epoxy resin, naphthalene-type epoxy resin] High Tg phenoxy resin: Mitsubishi Chemical Corporation, trade name "YX8100BH30", glass transition temperature (Tg) = 150°C, molecular weight Mw = 38,000. Multifunctional epoxy: Nippon Kayaku Co., Ltd., trade name "EPPN-501HY", glass transition temperature (Tg) = 233°C, trihydroxyphenylmethane-type epoxy. Naphthalene-type epoxy 1: DIC Corporation, trade name "HP4710", glass transition temperature (Tg) = 253°C. Multifunctional liquid epoxy: Mitsubishi Chemical Corporation, trade name "jER 630", aminophenol-type epoxy. Naphthalene-type epoxy 2: DIC Corporation, trade name "HP4032D".

[0081] [Other components (optional components)] Carbon black: Orion Engineered Carbons, trade name "Special Black 4". Antioxidant: ADEKA, trade name "AO 80". Coupling agent: Shin-Etsu Silicones, trade name "KBM 403".

[0082] [Preparation of Uncured Films] Using the solutions containing the resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4 obtained as described above, uncured films made of the resin compositions were prepared by the following method. First, the solution containing the resin composition was applied to a release-treated PET film using a knife. Then, the solution of the resin composition applied to the PET film was dried in a drying oven heated to 120°C to prepare an uncured film with a thickness of 50 μm.

[0083] [Measurement of Physical Properties] The glass transition temperature Tg3 (°C) and modulus of elasticity after curing (GPa) were measured by the following method for the uncured films prepared using the solutions containing the resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4. The results are shown in Tables 1 and 2.

[0084] [Glass Transition Temperature Tg3 (°C)] First, the prepared uncured film was heat-cured in a press at 170°C, 120 minutes, and 1 MPa. The heat-cured film was then cut into 1 cm x 4 cm pieces to prepare test specimens for measurement. The loss modulus (E") and storage modulus (E') of the test specimens were measured using a viscoelasticity measuring device (model: DMS7100) manufactured by Hitachi High-Tech Science Corporation. The measurement conditions were a temperature range of 25 to 350°C, a heating rate of 5°C / min, and a frequency of 10 Hz in air. The temperature showing the maximum value of the loss tangent tanδ (E" / E'), which is the ratio of the loss modulus (E") to the storage modulus (E'), obtained by the measurement, was taken as the glass transition temperature Tg3.

[0085] [Elastic modulus after curing (GPa)] First, the prepared uncured film was thermally cured in a press under conditions of 170°C, 120 minutes, and 1 MPa. The thermally cured film was then cut into a size of 1 cm x 4 cm to prepare a test specimen for measurement. The storage modulus (E') of the test specimen was measured using a viscoelasticity measuring device (model number: DMS7100) manufactured by Hitachi High-Tech Science Corporation. The measurement conditions were a temperature range of 25 to 350°C, a heating rate of 5°C / min in air, and a frequency of 10 Hz. The storage modulus (E') value at a measurement temperature of 200°C of the data obtained by the measurement was taken as the elastic modulus at 200°C.

[0086] [Evaluation of Adhesion Strength, Wire Bonding (WB) Shear Strength, and Film-Forming Ability] For the uncured films prepared using solutions containing the resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4, "adhesion strength (N / cm)," "wire bonding (WB) shear strength (gf)," and "film-forming ability" were measured by the following methods, and the measurement results were evaluated. The results are shown in Tables 1 and 2.

[0087] [Adhesive Strength (N / cm)] The glossy side of an 18 μm thick electrolytic copper foil "CF-T9FZ-SV" (manufactured by Fukuda Metal Foil & Powder Co., Ltd.) was laminated to both sides of the uncured film, and the film was cured by thermocompression bonding using a press. The thermocompression bonding conditions using the press were 170°C, 120 minutes, and 1 MPa. The cured film was cut to a width of 10 mm, and the electrolytic copper foil was peeled off at 180°C using an autograph manufactured by Shimadzu Science Tohnihon Co., Ltd., to measure the peel strength (N / cm). The measured peel strength (N / cm) was used as the adhesive strength (N / cm) of the film made of each resin composition of Examples 1 to 9 and Comparative Examples 1 to 4. An adhesive strength (N / cm) of 1.5 N / cm or more was considered acceptable.

[0088] [Wire Bonding (WB) Shear Strength (gf)] An Al substrate is attached to one side (one side) of the uncured film. Then, a lead frame with a soldered chip is thermocompression bonded to the other side of the uncured film. The uncured film with the Al substrate and lead frame attached is heated in an oven at 160°C for 4 hours to cure the uncured film. Then, a copper wire with a diameter of 50 μm is bonded to the chip on the lead frame at 200°C. The shear strength (gf) of the bonded portion where the Cu wire was bonded is measured using a bonding tester "PTR1102" (manufactured by Rhesca Corporation). The measured shear strength (gf) is shown in the "WB Shear Strength (gf)" column in Tables 1 and 2. A WB shear strength (gf) of 150 gf or more was considered acceptable.

[0089] [Film-forming properties] The state of the uncured film was visually inspected after manually peeling the PET film from the uncured film made of each of the resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4. After peeling the PET film, films that were in an intact state were rated "A," and films that had chips or wrinkles in some areas but were practically acceptable were rated "B."

[0090]

[0091]

[0092] [Results] As shown in Tables 1 and 2, the resin compositions of Examples 1 to 9 showed good results in both the adhesive strength (N / cm) and WB shear strength (gf) measurements. In particular, the resin compositions of Examples 1 to 3 and 5 to 8 also had excellent film-forming properties. On the other hand, resin compositions such as those of Examples 4 and 9 that did not contain a phenoxy resin with a glass transition temperature Tg2 of 100°C or higher as component (D) tended to have poor film-forming properties.

[0093] On the other hand, the resin composition of Comparative Example 1 had an excessive content of component (A) relative to the content of component (D), and the cured product exhibited a very low elastic modulus of 0.091 GPa at 200°C, as well as a low glass transition temperature Tg3. The resin composition of Comparative Example 1 also had a low WB shear strength (gf), making it unsuitable for Cu wire bonding. The resin compositions of Comparative Examples 2 and 3 did not contain a phenoxy resin (A) whose glass transition temperature Tg1 was 50°C or lower, and therefore did not provide sufficient adhesive strength at room temperature. In particular, the resin composition of Comparative Example 3 did not exhibit any adhesive strength at room temperature, making it impossible to measure or evaluate the WB shear strength (gf). The resin composition of Comparative Example 4 exhibited a low elastic modulus at 200°C, as well as a low glass transition temperature Tg3. The resin composition of Comparative Example 4 also had a low WB shear strength (gf), making it unsuitable for Cu wire bonding.

[0094] The resin composition of the present invention and the thermosetting film using the same can be used, for example, as a film for interlayer bonding between substrates of a semiconductor device, and can be particularly suitably used as an interlayer insulating film used in Cu wire bonding. The semiconductor device of the present invention can also be used, for example, in various electronic devices.

Claims

1. A resin composition comprising: (A) a phenoxy resin having a glass transition temperature Tg1 of 50°C or lower; (B) a curing agent; (C) a filler; and (D) at least one resin selected from the group consisting of a phenoxy resin, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin, having a glass transition temperature Tg2 of 100°C or higher; wherein the resin composition has a glass transition temperature Tg3 of 130°C or higher and a modulus of elasticity of the cured product at 200°C of 0.5 GPa or higher.

2. A resin composition comprising: (A) a phenoxy resin having a glass transition temperature Tg1 of 50°C or lower; (B) a curing agent; (C) a filler; and (D) at least one member selected from the group consisting of a phenoxy resin, a tri- or higher functional epoxy resin, and a naphthalene-type epoxy resin having a glass transition temperature Tg2 of 100°C or higher, wherein the content of the (A) component is 3 to 200 parts by mass per 100 parts by mass of the (D) component.

3. A resin composition according to claim 1 or 2, wherein component (D) comprises at least two or more members selected from the group consisting of phenoxy resins having a glass transition temperature Tg2 of 100°C or higher, tri- or higher functional epoxy resins, and naphthalene-type epoxy resins.

4. The resin composition according to any one of claims 1 to 3, wherein the component (D) contains at least a phenoxy resin having a glass transition temperature Tg2 of 100°C or higher.

5. A resin composition according to any one of claims 1 to 4, wherein component (C) contains a thermally conductive filler having a thermal conductivity of 5 W / (m·K) or more.

6. A resin composition according to any one of claims 1 to 5, wherein the content of component (C) is 50 to 95 mass % when the non-volatile components in the resin composition are 100 mass %.

7. A thermosetting film comprising the resin composition according to any one of claims 1 to 6.

8. The thermosetting film according to claim 7, which is used to bond copper wire to a semiconductor element or a lead frame.

9. A cured product of the thermosetting film according to claim 7 or 8.

10. A semiconductor device comprising a cured product of the thermosetting film according to claim 9.

11. A semiconductor device comprising a heat dissipation member, a cured product of the thermosetting film according to claim 9, and a lead frame stacked in this order.

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