WO2019017053A1 - Resin composition for sealing sheet, sealing sheet and semiconductor device - Google Patents

Abstract

A sealant resin composition which comprises (A) a crystalline epoxy resin and / or a liquid epoxy resin, (B) a phenolic resin curing agent, (C) a cure accelerator, (D) ) an inorganic filler material and (E) a silane compound comprising a ketimine group.

Description

Resin composition for sealing sheet, sealing sheet and semiconductor device

The present invention relates to a resin composition for a sealing sheet, a sealing sheet and a semiconductor device.

As an electronic component used for an electronic device, there is a semiconductor package obtained by resin-sealing a semiconductor element. Conventionally, this semiconductor package is generally manufactured by transfer molding using a solid epoxy resin sealing material. On the other hand, in recent years, with the miniaturization and weight reduction of electronic devices, high-density mounting of electronic components on a wiring substrate has been required, and miniaturization, thickness reduction, and weight reduction have been promoted also in semiconductor packages. .
Specifically, semiconductor packages such as a lead on chip (LOC), a quad flat package (QFP), a chip size package (CSP), and a ball grid array (BGA) have been developed. Furthermore, recently, so-called face-down type package flip chip, wafer level CSP and the like have been developed in which the circuit surface of the semiconductor element is mounted on the wiring substrate side.

As described above, with the progress of miniaturization and thinning of semiconductor packages, there have been cases where conventional transfer molding can not cope. That is, when the semiconductor package becomes thinner, the proportion of the inorganic filler blended in the encapsulant may be increased in consideration of the characteristics after curing and the like. However, when the proportion of the inorganic filler is increased, the melt viscosity of the sealing material at the time of transfer molding is increased, and the filling property of the sealing material is reduced. As a result, filling defects, residual voids in the molded product, wire flow (deformation and breakage of the bonding wire), increase in stage shift and the like occur, and the quality of the molded product is degraded.

Then, application of a compression (compression) molding method is examined as a sealing method instead of transfer molding, and various sheet-like sealing materials used for this are proposed. For example, in Patent Document 1, a sealing resin sheet obtained by laminating a plurality of resin sheets made of an epoxy resin composition containing an epoxy resin, a curing agent, a curing catalyst or a curing accelerator, and an inorganic filler It is disclosed. Further, Patent Document 2 discloses a sheet-like sealing material having a thickness of 3.0 mm or less, which is made of a thermosetting resin composition which softens or melts at 70 to 150 ° C.

Japanese Patent Application Laid-Open No. 8-73621 JP, 2006-216899, A

However, the resin sheet for sealing of patent document 1 has a problem that curvature will generate | occur | produce in a molded article, when package or a wafer size becomes large. The problem can be ameliorated by, for example, blending a large amount of an inorganic filler such as silica, but in this case, the melt viscosity increases, and the above-mentioned problems such as filling defects occur. On the other hand, although the sheet-like sealing material of Patent Document 2 can sufficiently cope with a large size package and the like, it is easily broken when the sheet thickness is reduced to about 0.5 mm in order to further reduce the thickness. There are problems in handling, such as difficulty in loading into the mold.

The present invention has been made to solve the above-mentioned problems of the prior art, and has excellent handleability and moldability even when the thickness is reduced, and flexibility is maintained over a long period, and excellent adhesion A sealing sheet capable of sealing the semiconductor element efficiently and favorably by a compression molding method, a resin composition for a sealing sheet to be a forming material of the sealing sheet, and a seal using the sealing sheet An object of the present invention is to provide a high quality, high reliability resin-sealed semiconductor device.

The inventors of the present invention conducted intensive studies to achieve the above object, and as a result, by using a ketimine compound in combination with a crystalline epoxy resin and / or a liquid epoxy resin, the handling property and the molding are obtained even if the thickness is reduced. It has been found that a sealing sheet having excellent properties and having flexibility maintained for a long time and having excellent adhesion can be obtained, and the present invention has been completed.

That is, the present invention provides the following [1] to [4].
[1] (A) crystalline epoxy resin and / or liquid epoxy resin, (B) phenol resin curing agent, (C) curing accelerator, (D) inorganic filler, and (E) ketimine group-containing silane compound Resin composition for sealing sheet to be
[2] The resin composition for a sealing sheet according to the above [1], wherein the (D) inorganic filler is a silica powder, and 70 to 95% by mass is contained in the entire resin composition for a sealing sheet.
[3] A sealing sheet comprising the resin composition for a sealing sheet according to the above [1] or [2].
[4] A semiconductor device comprising an element sealed by the sealing sheet according to the above [3].

According to the present invention, even when the thickness is reduced, the handling property and the moldability are good, and the flexibility is maintained for a long period, and the adhesive strength is excellent, and the semiconductor element can be efficiently formed by the compression molding method. And a sealing sheet capable of sealing well, a resin composition for sealing sheet to be a forming material of the sealing sheet, and a semiconductor with high quality and high reliability sealed using the sealing sheet An apparatus can be provided.

Hereinafter, the resin composition for sealing sheets which is one Embodiment of this invention, a sealing sheet, and a semiconductor device are demonstrated in detail.
[Resin composition for sealing sheet]
The resin composition for sealing sheet of this embodiment includes (A) crystalline epoxy resin and / or liquid epoxy resin, (B) phenol resin curing agent, (C) curing accelerator, (D) inorganic filler, and (E) A ketimine group-containing silane compound is contained.
First, each component of the resin composition for sealing sheets of this embodiment (Hereinafter, it is also only called a resin composition.) Is demonstrated.

The epoxy resin of the component (A) used in the present embodiment is a crystalline epoxy resin and / or a liquid epoxy resin. The crystalline epoxy resin is an epoxy resin which is solid at normal temperature (25 ° C.) and shows a crystalline state, and has a property that the viscosity is largely reduced at the time of melting. The melting point of the crystalline epoxy resin is preferably 80 to 150 ° C., more preferably 90 to 130 ° C. Moreover, a liquid epoxy resin means the epoxy resin of a liquid or semisolid state at normal temperature (25 degreeC), for example, the epoxy resin which has fluidity | liquidity at normal temperature (25 degreeC) is mentioned. The viscosity at 25 ° C. of the liquid epoxy resin is preferably 10,000 mPa · s or less, more preferably 1,000 to 6,000 mPa · s.
The melting point of the crystalline epoxy resin can be measured by the endothermic peak of DSC. The viscosity at 25 ° C. of the liquid epoxy resin can be measured by a rotational viscometer.

The crystalline epoxy resin of the component (A) and the liquid epoxy resin (hereinafter, also simply referred to as an epoxy resin of the component (A)) can be used without being restricted by the molecular structure, molecular weight, etc. Biphenyl type epoxy resin, bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable. These may use 1 type and may mix and use 2 or more types.
The biphenyl type epoxy resin is an epoxy resin having a biphenyl skeleton, but the biphenyl skeleton in the present embodiment also includes one obtained by hydrogenating at least one aromatic ring of the biphenyl ring.
Specific examples of the biphenyl type epoxy resin include, for example, 4,4′-bis (2,3-epoxypropoxy) biphenyl, 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5, Epoxy obtained by reacting 5'-tetramethylbiphenyl, epichlorohydrin and 4,4'-biphenol or a biphenol compound such as 4,4 '-(3,3', 5,5'-tetramethyl) biphenol Resin etc. are mentioned. Among these, 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl, 4,4 ′-(3,3 ′, 5,5′- The glycidyl ether of tetramethyl) biphenyl is preferred. 1 type may be used for a biphenyl type epoxy resin, and 2 or more types may be mixed and used.

For example, YX-4000 (epoxy equivalent 185, melting point 105 ° C.), YX-4000 K (epoxy equivalent 185, melting point 105 ° C.), manufactured by Mitsubishi Chemical Corporation, is exemplified as a commercial product used as a biphenyl type epoxy resin. Examples thereof include YX-4000H (epoxy equivalent 193, melting point 105 ° C.), and YL-6121H (epoxy equivalent 175, melting point 125 ° C.) (all are trade names).
Further, specific examples of the bisphenol A epoxy resin include EXA-850 CRP (epoxy equivalent 173, viscosity at 25 ° C. 4500 mPa · s) manufactured by DIC Corporation. Specific examples of the bisphenol F-type epoxy resin include YDF-8170C (epoxy equivalent 160, viscosity 1250 mPa · s at 25 ° C.) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and the like.

In addition to the epoxy resin of the component (A), an epoxy resin used as a sealing material can be used in combination as long as the effects of the present invention are not impaired.
In addition, when using together epoxy resin other than the said crystalline epoxy resin and liquid epoxy resin, it is preferable to set it as 30 mass parts or less with respect to 100 mass parts of epoxy resin of (A) component, and 20 mass parts. It is more preferable to set it as the following, and it is still more preferable to set it as 10 mass parts or less.

The phenol resin curing agent of the component (B) used in this embodiment is particularly limited as long as it has two or more phenolic hydroxyl groups capable of reacting with the epoxy group in the epoxy resin of the component (A). It can be used without being Specifically, novolac type phenol resins such as phenol novolac resin and cresol novolac resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, these novolac type phenol resins are epoxidized or butylated Modified novolac type phenol resin, dicyclopentadiene modified phenol resin, paraxylene modified phenol resin, phenol aralkyl resin, naphthol aralkyl resin, triphenol alkane type phenol resin, polyfunctional phenol resin and the like. Among them, novolac type phenol resin and triphenol alkane type phenol resin are preferably used. These may use 1 type and may mix and use 2 or more types.

The compounding amount of the phenol resin curing agent of the component (B) is the number of phenolic hydroxyl groups (b) possessed by the phenol resin curing agent of the component (B) with respect to the number of epoxy groups (a) possessed by the epoxy resin of the component (A). The range in which the ratio [(b) / (a)] is 0.3 or more and 1.5 or less is preferable, and the range in which 0.5 or more and 1.2 or less is more preferable. If the ratio [(b) / (a)] is 0.3 or more, the moisture resistance reliability of the cured product can be improved, and if it is 1.5 or less, the strength of the cured product can be increased.

The curing accelerator of the component (C) used in the present embodiment is a component that promotes the curing reaction between the epoxy resin of the component (A) and the phenol resin curing agent of the component (B). As the curing accelerator for the component (C), any known curing accelerator can be used without particular limitation as long as it exerts the above-mentioned action.
Specific examples of the curing accelerator for component (C) include 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-undecylimidazole, 1,2-dimethylimidazole and 2,4-dimethylimidazole. Imidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 4-methylimidazole, 4-ethylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2 -Methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2 -Phenylimidazo Imidazoles such as 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, etc .; 8-Diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonene, 5,6-dibutylamino-1,8-diazabicyclo [5.4.0] Diazabicyclo compounds such as undecene-7 and salts thereof; tertiary amines such as triethylamine, triethylenediamine, benzyldimethylamine, α-methylbenzyldimethylamine, triethanolamine, dimethylaminoethanol and tris (dimethylaminomethyl) phenol; Trimethylphosphine, triethyl Phosphine, tributyl phosphine, diphenyl phosphine, triphenyl phosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, methyl diphenyl phosphine, dibutyl phenyl phosphine, tricyclohexyl phosphine, bis (diphenyl phosphino) methane, And organic phosphine compounds such as 2-bis (diphenylphosphino) ethane. Among these, imidazoles are preferable, and 2-phenyl-4-methyl-5-hydroxymethylimidazole is more preferable, from the viewpoint of good fluidity and moldability. These may use 1 type and may mix and use 2 or more types.

The content of the curing accelerator as the component (C) is preferably in the range of 0.1 to 5% by mass, and more preferably in the range of 0.2 to 1% by mass, based on the entire resin composition. If the compounding amount of the component (C) is 0.1% by mass or more, the curing promoting effect can be sufficiently obtained, and if 5% by mass or less, the moisture resistance reliability of the molded article can be improved.

The inorganic filler of the component (D) used in the present embodiment is filled in the resin composition to adjust the viscosity of the resin composition and to improve the handleability and the formability of the sealing sheet to be described later. It is. As the inorganic filler of the component (D), any known inorganic filler generally used in this type of resin composition can be used without particular limitation.
Specifically, the inorganic filler of the component (D) is, for example, oxide powder such as fused silica, crystalline silica, crushed silica, synthetic silica, alumina, titanium oxide, magnesium oxide, etc .; aluminum hydroxide, magnesium hydroxide And hydroxide powders, and nitride powders such as boron nitride, aluminum nitride, and silicon nitride. These inorganic fillers may be used alone or in combination of two or more.

Among the exemplified inorganic fillers of the component (D) from the viewpoint of enhancing the handleability and formability of the sealing sheet, silica powder is preferable among the above-exemplified examples, fused silica is more preferable, and spherical fused silica is particularly preferable. Moreover, fused silica and silica other than fused silica can be used together, and in that case, it is preferable to make the ratio of silica other than fused silica less than 30 mass% of the whole silica powder.

The inorganic filler of the component (D) preferably has an average particle diameter of 0.5 to 40 μm, more preferably 1 to 30 μm, and still more preferably 5 to 30 μm. Further, the maximum particle size of the inorganic filler of the component (D) is more preferably 105 μm or less.
If the average particle diameter is 0.5 μm or more, it is possible to suppress the decrease in the fluidity of the resin composition and to improve the moldability. In addition, when the average particle diameter is 40 μm or less, warpage of a molded product obtained by curing the resin composition can be suppressed, and deterioration in dimensional accuracy can be prevented. If the maximum particle size is 105 μm or less, the moldability of the resin composition can be improved.
In the present specification, the average particle size of the inorganic filler of the component (D) can be determined, for example, by a laser diffraction type particle size distribution measuring apparatus, and the average particle size is the particle size distribution measured by the same apparatus. The particle size (d50) is 50% of the cumulative volume.

The content of the inorganic filler as the component (D) is preferably 70 to 95% by mass, more preferably 75 to 90% by mass, with respect to the entire resin composition. If the blending amount of the inorganic filler is 70% by mass or more, the increase in the linear expansion coefficient of the resin composition can be suppressed, and the dimensional accuracy, the moisture resistance, the mechanical strength and the like of the molded article can be enhanced. When the blending amount of the inorganic filler is 95% by mass or less, the increase in the melt viscosity of the resin composition can be suppressed, and the decrease in the fluidity can be suppressed, and the moldability can be enhanced. Moreover, the sealing sheet obtained by shape | molding this resin composition can be made hard to be cracked.

The ketimine group-containing silane compound of the component (E) used in this embodiment is a compound having a ketimine group and an alkoxy group in one molecule, and is cured by containing the component (E) in the resin composition. The adhesion of objects can be enhanced.
The ketimine group-containing silane compound of the component (E) is not particularly limited as long as it has a ketimine group and an alkoxy group in one molecule, but from the viewpoint of enhancing the adhesion of a cured product, it is represented by the following general formula (1) It is preferred that the compound be

In the above general formula (1), R ¹ to R ⁴ each independently represent an alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group Groups, isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups and the like can be mentioned. Among them, methyl group, ethyl group, propyl group and butyl group are preferable from the viewpoint of market availability.
R ⁵ represents an alkylene group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. The alkylene group may be linear or branched, and examples thereof include a methylene group, an ethylene group, a propylene group, a trimethylene group, a butylene group and a pentylene group. Among them, ethylene and trimethylene are preferable.

A represents an integer of 0 to 2, preferably 0.

The ketimine group-containing silane compound of the component (E) is easily hydrolyzed under high temperature conditions at the time of molding to form a primary amine. Although water necessary for hydrolysis is sufficient for water adsorbed on the silica surface, it may be mixed with pure water in advance. Also, they may be used alone or in combination with other silane coupling agents.

Specific examples of the ketimine group-containing silane compound represented by the general formula (1) include N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine and N- (1,3-dimethyl) Butylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3 -(Methyldiethoxysilyl) -1-propanamine, N- (1,3-dimethylbutylidene) -3- (methyldiethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3 -(Methyldiethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (ethyldiethoxysilyl) -1-propanamine, N- (1,3-diethyl) Tylbutylidene) -3- (ethyldiethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (ethyldiethoxysilyl) -1-propanamine, N- (1-methylethylidene)- 3- (Methyldimethoxysilyl) -1-propanamine, N- (1,3-dimethylbutylidene) -3- (methyldimethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (Methyldimethoxysilyl) -1-propanamine, N- (1-methylethylidene) -2- (triethoxysilyl) -1-ethanamine, N- (1,3-dimethylbutylidene) -2- (triethoxysilyl) ) -Ethanamine, N- (1-methylpropylidene) -2- (triethoxysilyl) -1-ethanamine, N- (1-methylethyene) Den) -2- (methyldiethoxysilyl) -1-ethanamine, N- (1,3-dimethylbutylidene) -2- (methyldiethoxysilyl) -1-ethanamine, N- (1-methylpropylidene) -2- (methyldiethoxysilyl) -1-ethanamine, N- (1-methylethylidene) -2- (ethyldiethoxysilyl) -1-ethanamine, N- (1,3-dimethylbutylidene) -2- (Ethyldiethoxysilyl) -1-ethanamine, N- (1-methylpropylidene) -2- (ethyldiethoxysilyl) -1-ethanamine, N- (1-methylethylidene) -2- (methyldimethoxysilyl) -1-ethanamine, N- (1,3-dimethylbutylidene) -2- (methyldimethoxysilyl) -1-ethanamine, N- (1-methylpropylide) And 2- (methyldimethoxysilyl) -1-ethanamine. Among them, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine is preferable from the viewpoint of market availability.
These ketimine group-containing silane compounds may be used alone or in combination of two or more.

The ketimine group-containing silane compound of the component (E) is easily hydrolyzed under high temperature conditions during molding to form a primary amine and to form a silanol group. The primary amine reacts with the epoxy resin of the component (A), and the silanol group causes a condensation reaction with the hydroxy group present on the surface of the inorganic filler of the component (D), whereby the cured resin and the inorganic filler The bond with is strong. As a result, when the resin composition of the present embodiment is used as a sealing material for a semiconductor device, the cured product has strong adhesion to a silicon chip or the like.

The content of the ketimine group-containing silane compound of the component (E) with respect to the total amount of the resin composition is from the viewpoint of improving the adhesion of the cured product to the silicon chip etc., suppressing molding defects such as voids, and balance of economy. Preferably, it is selected in the range of 0.5 to 2.0% by mass, more preferably 0.8 to 1.5% by mass.

A commercially available product used as the ketimine group-containing silane compound of the above component (E) can be exemplified, for example, as N- (1,3-dimethylidene) -3- (triethoxysilyl) -1-propanamine Examples thereof include KBE-9103 manufactured by Silicone Co., Ltd., Sira Ace S340 manufactured by JNC Co., Ltd., Z-6860 manufactured by Toray Dow Corning Co., Ltd., and the like.

In the resin composition of the present embodiment, in addition to the above-described components, components generally compounded in this kind of resin composition, to the extent that the effects of the present embodiment are not inhibited, such as coupling agents; Mold release agents such as natural waxes, higher fatty acids, metal salts of higher fatty acids; coloring agents such as carbon black and cobalt blue; low stress imparting agents such as silicone oil and silicone rubber; hydrotalcites; can do.

Examples of the coupling agent include coupling agents such as epoxysilane type, aminosilane type, ureidosilane type, vinylsilane type, alkylsilane type, organic titanate type and aluminum alcoholate type. One of these may be used, or two or more may be mixed and used.
As the above-mentioned coupling agent, an aminosilane type coupling agent is preferable from the viewpoint of moldability, flame retardancy, curability, etc., and in particular, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-amino Propylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, (N-phenyl-γ-aminopropyl) trimethoxysilane and the like are preferable.

When using a coupling agent, the range which becomes the 0.01 mass% or more and 3.0 mass% or less of the whole resin composition is preferable, and the range which becomes 0.1 mass% or more and 1 mass% or less is more preferable preferable. If the compounding amount of the coupling agent is 0.01% by mass or more, the formability can be improved, and if it is 3.0% by mass or less, the occurrence of foaming is suppressed at the time of molding, and voids or surface swelling in the molded product It can suppress that etc. occur.

The resin composition of the present embodiment includes (A) crystalline epoxy resin and / or liquid epoxy resin, (B) phenolic resin curing agent, (C) curing accelerator, (D) inorganic filler, (E) ketimine group After thoroughly mixing (dry blending) the contained silane compound and the various components to be blended according to the above-mentioned necessity with a mixer etc., it is melt-kneaded by a kneading apparatus such as a heat roll or kneader, and after cooling, it has an appropriate size. Crush to. The grinding method is not particularly limited, and a common grinder such as a speed mill, a cutting mill, a ball mill, a cyclone mill, a hammer mill, a vibration mill, a cutter mill, a grinder mill, etc. can be used. Among them, a speed mill is preferably used. The pulverized material can then be adjusted to a particle assembly having a predetermined particle size distribution by sieve classification, air classification or the like.

[Sealing sheet]
Next, the sealing sheet of this embodiment is demonstrated.
The sealing sheet of this embodiment is a sheet-like molded object obtained by using the above-mentioned resin composition for sealing sheets as a material, and shape | molding this to a sheet form. The sealing sheet is obtained, for example, by heating, melting and compressing the resin composition of the present embodiment between pressure members, and forming it into a sheet. More specifically, the above resin composition is supplied on a heat resistant release film such as a polyester film so as to have a substantially uniform thickness to form a resin layer, and then the resin layer is heated and softened to form a roll. And rolling by heat press. At that time, a heat resistant film such as a polyester film is disposed also on the resin layer. Thus, after rolling the resin layer to a desired thickness, it is solidified by cooling, and the heat resistant film is peeled off, and further cut into a desired size and shape as required. Thereby, the sealing sheet of arbitrary sizes is obtained.
The heating temperature for softening the resin layer is usually about 80 to 150 ° C. When the heating temperature is less than 80 ° C., the melt mixing becomes insufficient, and when the heating temperature exceeds 150 ° C., the curing reaction proceeds too much, and the moldability may be deteriorated at the time of heat curing.

The sealing sheet of the present embodiment has a melt viscosity of 2 to 50 Pa · s measured by a heightening type flow tester under conditions of a temperature of 175 ° C. and a load of 10 kg (shear stress 1.23 × 10 ⁵ Pa). Is preferable, and 3 to 20 Pa · s is more preferable. When the melt viscosity is 2 Pa · s or more, the generation of burrs can be suppressed, and when the melt viscosity is 50 Pa · s or less, the filling property is improved, and the generation of voids and unfilled portions can be suppressed.

The sealing sheet of the present embodiment is suitable for sealing components such as semiconductor elements, and is provided by appropriately adjusting the size according to the size and the like of the component to be sealed. The size of the sealing sheet can be arbitrarily made, but for example, 200 × 200 mm to 600 × 600 mm is preferable. The sealing sheet preferably has a thickness of 0.1 to 2.0 mm. If the thickness is 0.1 mm or more, there is no fear of cracking, the handling property is excellent, and the loading into the compression molding die can be easily performed without any problem. Moreover, if thickness is 2.0 mm or less, melting of the sealing sheet in a metal mold | die will be delayed at the time of semiconductor sealing, and shaping | molding will not become defective.

[Semiconductor device]
The semiconductor device of this embodiment is provided with the element sealed by the above-mentioned sealing sheet. The semiconductor device can be manufactured by sealing the semiconductor element fixed on the substrate by compression molding using the above sealing sheet. Hereinafter, an example of the method will be described.
First, the sealing sheet is covered on the semiconductor element so as to be sandwiched between the two sealing sheets on the substrate on which the semiconductor element is mounted, and placed at a predetermined position in the cavity of the compression molding die. And compression molding at a predetermined pressure. The molding conditions are preferably a temperature of 100 to 190 ° C. and a pressure of 4 to 12 MPa. After molding, post curing is performed at a temperature of 130 to 190 ° C. for about 2 to 8 hours. By this heat curing, the sealing sheet adheres to the semiconductor element and is cured, and a resin-sealed semiconductor device sealed so that the semiconductor element is not in contact with the external atmosphere can be manufactured.

The semiconductor device obtained in this manner is sealed by compression molding using a sealing sheet that is easy to handle even if it is thin and has excellent formability, so it has high quality and high reliability even if it is thin. can do.
The semiconductor element sealed in the semiconductor device of the present embodiment is not particularly limited because it may be a known semiconductor element, and, for example, IC (Integrated Circuit), LSI (Large Scale Integration), A diode, a thyristor, a transistor or the like can be exemplified. In particular, in the case of a semiconductor element having a thickness of 0.1 to 1.5 mm after sealing, which is difficult to seal with a conventional sealing material, a semiconductor device using the above sealing sheet The method of manufacture is particularly useful.

EXAMPLES The present invention will next be described by way of examples, which should not be construed as limiting the invention in any way. The materials used in the following examples and comparative examples are as shown in Table 1.

(Examples 1 to 6, Comparative Examples 1 to 3)
Each raw material was mixed at normal temperature (25.degree. C.) so as to obtain the composition shown in Table 2, and then heat-kneaded at 80 to 130.degree. C. using a heat roll. After cooling, it was pulverized using a speed mill to prepare a resin composition for encapsulating sheet.
The obtained resin composition for sealing sheet is sandwiched between mold release films made of polyester, placed between hot plates at 80 ° C., heated and pressurized at a pressure of 10 MPa for 1 minute, and sealed with a thickness of 0.5 mm A sheet was made.
Furthermore, the semiconductor chip was sealed using the obtained sealing sheet. That is, first, a 150 mm × 30 mm sheet was cut out from the obtained sealing sheet. The cut-out sealing sheet is placed in a compression molding mold, a substrate on which a semiconductor chip is mounted is stacked thereon, and the sealing sheet is further stacked thereon, and 30 at a temperature of 175 ° C. under a pressure of 8.0 MPa. Compression molding was performed for 1 minute. Thereafter, post curing was performed at 175 ° C. for 4 hours to manufacture a semiconductor device.

Various characteristics were evaluated by the method shown below about the resin composition for sealing sheets obtained by said each Example and comparative example, a sealing sheet, and a semiconductor device (product). The results are shown in Table 2 together. In Table 2, blanks indicate no blending.

＊１：目開き７５μｍの篩を用いて分級した。

* 1: Classification was performed using a sieve with an aperture of 75 μm.

<Resin composition>
(1) Spiral flow It measured by transfer molding at a temperature of 175 ° C. and a pressure of 9.8 MPa using a mold conforming to the EMMI standard.

(2) Gel time About 1 g of the resin composition for a sealing sheet is applied on a hot plate at 175 ° C. according to the gelation time A method defined in 7.5.1 of JIS C 2161, and the stirring bar is used. The time until it became gel-like and could not be stirred was measured.

(3) Enhanced flow viscosity Using a flow property evaluation device (manufactured by Shimadzu Corporation, product name: Flow Tester CFT-500), the environment at a temperature of 175 ° C. and a load of 10 kg (shear stress: 1.23 × 10 ⁵ Pa) The melt viscosity in the lower) was measured.

<Sealing sheet>
(1) Flexibility A sealing sheet of 10 mm in width, 50 mm in length and 0.5 mm in thickness is cut out, and a portion of 15 mm is clamped from one end, and set at a height of 18 mm on a gantry. The time to contact the upper surface of the gantry was measured (initial).
Separately from this, a sealing sheet with a width of 10 mm, a length of 50 mm and a thickness of 0.5 mm is cut out and left at 25 ° C. for 168 hours, and similarly, a portion of 15 mm from one end is clamped. The height was set to 18 mm, and the time it took for one end of the sheet to come in contact with the upper surface of the mount by its own weight was measured.

<Cured product>
(1) Glass transition point (Tg)
A stick-like sample is prepared from a cured product obtained by curing by heating at 175 ° C. for 3 minutes, and the temperature is raised by a thermal analyzer (TMA) (product name: TMA SS-150, manufactured by Seiko Instruments Inc.) The temperature was raised under the conditions of a speed of 10 ° C./min to measure the TMA chart, and it was obtained from the intersection of two tangents.

(2) Bending strength and flexural modulus The samples produced in the same manner as in (1) above were measured at a temperature of 25 ° C. in accordance with JIS K 6911.

(3) Water absorption: compression molded at 175 ° C. for 2 minutes under pressure of 12 MPa, followed by post curing at 175 ° C. for 8 hours to obtain a disc-shaped cured product having a diameter of 50 mm and a thickness of 3 mm. The The cured product was allowed to stand in saturated steam at 127 ° C. and 0.25 MPa for 24 hours, and the increased mass before and after the treatment was determined and calculated from the following equation.
Water absorption (%) = increased mass (g) / initial mass of cured product (g)

(4) Adhesive Strength to Silicon Chip A sealing sheet was transfer molded on a silicon chip into a square shape of 2 mm on a side at a molding temperature of 150 ° C. and a molding pressure of 100 kg / cm ² for 10 minutes. A shear force was applied to the obtained molded article, and the shear force at break was taken as the adhesive force.

<Product (semiconductor device)>
(1) Reflow resistance (MSL test)
A test (MSL test: Level 3) of heating the semiconductor device at 85 ° C. and 85% RH for 72 hours and then heating it in an infrared reflow furnace at 240 ° C. for 90 seconds is performed. The incidence was examined (number of samples = 20).

(2) Moisture resistance reliability (Pressure cooker test: PCT)
After the semiconductor device was allowed to absorb water for 72 hours at 127 ° C. and 0.25 MPa in a pressure cooker, vapor reflow was performed at 240 ° C. for 90 seconds, and the incidence of defects (open defects) was examined (sample Number = 20).

(3) High temperature storage reliability (Highly accelerated life test: HAST)
The semiconductor device was left in a thermostat at 180 ° C. for 1000 hours, and the incidence of defects (open defects) was examined (the number of samples = 20).

As apparent from Table 2, the sealing sheet of the present embodiment has flexibility even when left at normal temperature for a long time, has good handling properties, and has good adhesion to silicon chips. Met.
In addition, semiconductor devices manufactured using the sealing sheet show good results in any of the MSL test, pressure cooker test, and advanced accelerated life test, and are high as a resin-sealed semiconductor device. It could be confirmed that it was reliable.

The sealing sheet of the present invention is excellent in handleability and moldability even when the thickness is reduced. Therefore, it is useful as a sealing material for compression molding of a thinned semiconductor element, and a high-quality, highly reliable resin-sealed semiconductor device can be manufactured.
Moreover, it can use as a sealing sheet which seals components etc. so that it may not expose to external environment besides a semiconductor element.

Claims (4)

(A) Crystalline epoxy resin and / or liquid epoxy resin, (B) phenolic resin curing agent, (C) curing accelerator, (D) inorganic filler, and (E) ketimine group-containing silane compound Resin composition for sheets. The resin composition for a sealing sheet according to claim 1, wherein the (D) inorganic filler is a silica powder, and 70 to 95% by mass is contained in the entire resin composition for a sealing sheet. A sealing sheet comprising the resin composition for a sealing sheet according to claim 1 or 2. The semiconductor device provided with the element sealed by the sealing sheet of Claim 3.