JP2007045884A - Resin composition for sealing and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for sealing exhibiting good mold-releasability from a mold for molding to enable successive molding without obstacle; and to provide a semiconductor device sealed with such the resin composition for the sealing. <P>SOLUTION: The resin composition for the sealing comprises (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) an inorganic filler and (D) a silicone, satisfying the relation of (θ<SB>0</SB>-θ<SB>100</SB>)/θ<SB>0</SB>≤0.1 (wherein, θ<SB>100</SB>is a contact angle of water on the metal plate surface obtained by repeating 100 times of processes comprising subjecting the resin composition for the sealing to transfer molding on a metal plate under a condition of 175°C and 2 min, and pealing the resultant molded product therefrom; and θ<SB>0</SB>is a contact angle of the water on the metal plate before the transfer molding). The semiconductor device is obtained by sealing a semiconductor element with the cured product of the resin composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sealing resin composition used as a sealing material for a semiconductor device or the like and a semiconductor device using the same, and in particular, a sealing resin composition having improved releasability from a molding die. And a semiconductor device using the same.

  Conventionally, sealing with a thermosetting resin has been widely performed in order to protect semiconductor integrated circuits and the like from mechanical and chemical effects. As a sealing resin material, a composition in which an epoxy resin is used as a base and a curing agent, a curing accelerator, an inorganic filler such as silica powder, or a pigment is blended, is reliable and moldable. It is often used from the point of.

  Incidentally, in recent years, the mounting method of a semiconductor device such as a semiconductor integrated circuit has been shifted from a conventional pin insertion type to a surface mounting type, and high-temperature mounting using a high melting point solder has become common. The shift to the surface mounting type is to cope with the recent high density mounting of semiconductor devices and the automation of the assembly process. In addition, the use of high melting point solder is because there is a strong demand for the removal of lead, which is harmful to the human body, due to the recent increase in interest in the environment. This is because many of the solders that can be used in the semiconductor field have a higher melting point than conventional solders.

  In the surface mounting type mounting method, when soldering a lead portion of a semiconductor package to a substrate, a method is used in which cream solder on the substrate is heated with infrared rays or fluorocarbon vapor to be connected to the lead. In such a mounting method, since the package itself is also heated when the solder is heated, the sealing resin is required to have high reflow resistance. When a high melting point solder as described above is used as the solder, the reflow temperature becomes even higher, so the sealing resin is required to have higher reflow resistance.

Accordingly, various sealing resin materials having high reflow resistance that can withstand such surface mounting and high melting point solder have been developed (see, for example, Patent Documents 1 and 2). However, many of them are excellent in reflow resistance, but have a problem of poor mold release from a molding die and often cause molding defects during continuous molding.
JP 7-82343 A JP-A-8-277356

  As described above, a sealing resin material having excellent reflow resistance has been developed along with the transition from the pin insertion type of the mounting method to the surface mounting type and the use of high melting point solder not using lead. However, these have a problem that they are poor in releasability from the molding die and are difficult to be continuously formed.

  The present invention has been made in view of such a conventional situation, and has a good mold release property from a molding die, and a sealing resin composition capable of performing continuous molding without hindrance, and such It aims at providing the semiconductor device sealed with the resin composition for sealing.

  As a result of intensive studies to achieve the above object, the present inventors have found that the interaction force between the inner surface of the mold and the cured resin composition for sealing is such that distilled water, organic solvent, liquid form on the inner surface of the mold. Correlation with cos θ of contact angle θ when silicone or the like is dropped, and fluctuation of contact angle θ with water on the inner surface of the mold when molding and peeling are repeated using the sealing resin composition, It has been found that the sealing resin composition serves as an index showing the releasability from the mold for molding, and the present invention has been completed.

That is, the sealing resin composition according to claim 1 of the present application is a sealing containing (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) a filler, and (D) silicone. A liquid on the inner surface of the mold after repeating the molding of the sealing resin composition under predetermined conditions and releasing the molded body from the mold for molding 100 times. the contact angle and theta ₁₀₀ and, when the contact angle between the liquid of the mold inner surface of the front the transfer molding was theta _0, that is _{0 ≦ 0.1 (θ 0 -θ 100} ) / θ Features.

  The invention according to claim 2 is the sealing resin composition according to claim 1, wherein (A) the epoxy resin is 1.0 to 15.0% by weight and (B) the phenol resin-based curing agent is 1.0. -15.0 wt%, (C) 60.0-93.0 wt% filler, and (D) 0.1-2.0 wt% silicone.

  The invention according to claim 3 is the sealing resin composition according to claim 1 or 2, wherein the component (D) is a silicone having an alkyl group in the side chain.

  The invention according to claim 4 is the sealing resin composition according to any one of claims 1 to 3, wherein the component (A) includes a biphenyl novolac type epoxy resin, and the component (B) And an aralkyl-type phenol resin.

Further, the semiconductor device according to claim 5 of the present application is a resin composition for sealing containing (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) an inorganic filler, and (D) silicone. Contact with the liquid on the inner surface of the mold after 100 times repeating the molding of the sealing resin composition under predetermined conditions and releasing the molded body from the molding mold the angle and theta _100, wherein when the contact angle between the liquid of the mold inner surface of the front transfer molding was _{θ 0, (θ 0 -θ 100} ) / θ encapsulating resin composition is ₀ ≦ 0.1 The semiconductor element is sealed with a cured product.

  INDUSTRIAL APPLICABILITY According to the present invention, a sealing resin composition having good releasability from a molding die and capable of continuous molding without hindrance, and a semiconductor device sealed with such a sealing resin composition Can be obtained.

  Hereinafter, the present invention will be described in detail.

The sealing resin composition of the present invention is obtained by transfer molding the sealing resin composition using a molding die under predetermined curing conditions, for example, at 175 ° C. for 2 minutes, Contact angle with the liquid on the inner surface of the mold, for example, distilled water, organic solvent, liquid silicone, etc. after 100 times of releasing from the mold (hereinafter referred to as “contact angle after 100 shots”). was a theta _100, the contact angle between the liquid of the mold inner surface of the front transfer molding (hereinafter, referred to as "initial contact angle".) when the a _{θ 0, (θ 0 -θ 100} ) / θ 0 ≦ 0.1. When (θ ₀ −θ ₁₀₀ ) / θ ₀ exceeds 0.1, that is, (θ ₀ −θ ₁₀₀ ) / θ ₀ > 0.1, the releasability from the molding die is reduced, Continuous molding becomes difficult.

  Next, each component which comprises the resin composition for sealing of this invention is demonstrated.

（式中、ｎは０以上の整数を表す） As the epoxy resin which is the component (A) of the sealing resin composition of the present invention, as long as it has two or more epoxy groups in one molecule, it is generally not limited by molecular structure, molecular weight, etc. Widely used ones can be used. Specifically, biphenyl novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus represented by the following general formula (1) Containing epoxy resin, dicyclopentadiene type epoxy resin, stilbene type epoxy resin, biphenyl type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, condensed ring aromatic hydrocarbon modified epoxy resin, fat Examples thereof include a ring type epoxy resin. These epoxy resins may be used individually by 1 type, and 2 or more types may be mixed and used for them.

(In the formula, n represents an integer of 0 or more)

  In order to provide releasability from a mold for molding and reflow resistance sufficient for surface mounting and high temperature mounting, the use of a biphenyl novolac type epoxy resin represented by the general formula (1) is particularly important. Preferably, when another epoxy resin is used in combination, it is preferably 20% by weight or less of the total component (A).

  The epoxy resin as the component (A) is preferably blended in an amount of 1.0 to 15.0% by weight, more preferably 1.0 to 7.0% by weight in the entire composition. If the blending amount is less than 1.0%, the mechanical strength after curing may decrease, and if it exceeds 15.0% by weight, the composition may be uncured.

（式中、ｎは０以上の整数を表す） The phenol resin-based curing agent that is the component (B) of the sealing resin composition of the present invention has two or more phenolic hydroxyl groups in the molecule that can react with the epoxy group of the epoxy resin of the component (A). If it is, it will be used without any particular limitation. Specifically, novolak-type phenol resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, such as phenol novolac resins and cresol novolac resins, these modified resins such as epoxidized or butylated Novolak-type phenol resins, dicyclopentadiene-modified phenol resins, para-xylene-modified phenol resins, condensates of phenols with benzaldehyde, naphthyl aldehyde, etc., for example, aralkyl-type phenol resins represented by the following general formula (2) Examples include methane compounds and polyfunctional phenol resins. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.

(In the formula, n represents an integer of 0 or more)

  In order to provide releasability from a mold for molding and reflow resistance sufficient for surface mounting and high temperature mounting, it is particularly preferable to use an aralkyl type phenol resin represented by the general formula (2). When using in combination with other phenolic resin-based curing agents, it is preferably 20% by weight or less of the total component (B).

  The blending amount of the (B) component phenolic resin curing agent is the number of epoxy groups (a) possessed by the epoxy resin (A) and the number of phenolic hydroxyl groups (b) possessed by the phenolic resin curing agent (B). The ratio (a) / (b) is preferably in the range of 0.5 to 1.0, more preferably in the range of 0.6 to 0.8. If (a) / (b) is less than 0.5, the curing reaction may not occur sufficiently. Conversely, if it exceeds 1.0, fluidity is impaired and filling becomes difficult.

  Examples of the filler that is the component (C) of the sealing resin composition of the present invention include metal oxides such as fused silica, crystalline silica, alumina, bengara, titanium white, talc, calcium carbonate, silicon carbide, boron nitride, and the like. And inorganic fillers such as beads, spheroidized beads, single crystal fibers, and glass fibers, and organic fillers such as silicone resin powder. These can be used alone or in admixture of two or more. In the present invention, among these, use of silica powder, alumina powder, titanium white powder, and silicone resin powder is preferable, and silica powder is particularly preferable. Moreover, about the particle size, it is preferable that an average particle diameter is 5-100 micrometers, and it is more preferable in it being 10-30 micrometers. When the average particle size is less than 5 μm or exceeds 100 μm, the fluidity of the composition is lowered, the moldability becomes poor and practical use becomes difficult.

  The blending amount of the filler of the component (D) is preferably in the range of 60.0 to 93.0% by weight, more preferably in the range of 70.0 to 93.0% by weight, and 80. The range of 0 to 93.0% by weight is even more preferable. When the blending amount is less than 60.0% by weight, heat resistance and moisture resistance are lowered. On the other hand, if the blending amount exceeds 93.0% by weight, the fluidity of the composition is lowered and practical use becomes difficult.

  The silicone of component (D) in the encapsulating resin composition of the present invention has the effect of improving the releasability from the molding die of the composition of the present invention. The component is preferably a liquid or powdery silicone having an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group in the side chain. Specific examples thereof include XF-42-334 and TSF-433 (trade names) manufactured by GE Toshiba Silicone.

  The amount of silicone of component (D) is preferably in the range of 0.1 to 2.0% by weight of the total composition, more preferably in the range of 0.1 to 0.8% by weight, More preferably, it is in the range of -0.5 wt%. If the blending amount is less than 0.1% by weight, it is difficult to sufficiently improve the releasability from the molding die. Conversely, if it exceeds 2.0% by weight, mold stains are likely to occur.

  In the sealing resin composition of the present invention, in addition to the components described above, a curing accelerator, a coupling agent, and a synthetic wax that are generally blended in this type of composition as long as the effects of the present invention are not impaired. Natural wax, linear aliphatic metal salts, release agents such as acid amides and esters, colorants such as carbon black and cobalt blue, low stress imparting agents and the like can be blended.

  Curing accelerators include trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, methyldiphenylphosphine, dibutylphenylphosphine, tricyclohexylphosphine, bis (diphenyl). Organic phosphine compounds such as phosphino) methane, 1,2-bis (diphenylphosphino) ethane, tetraphenylphosphonium tetraphenylborate, triphenylphosphinetetraphenylborate, triphenylphosphinetriphenylborane; 1,8-diazabicyclo [5 , 4, 0] Undecene-7 (DBU) and other diazabicycloalkene compounds; triethylamine, triethylenediamine, benzyldimethylamine Tertiary amine compounds such as α-methylbenzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; 2-heptadecylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 4-methylimidazole, 4-ethylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-enyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2-phenyl Imidazole compounds such as 2-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole; tetraphenyls such as 2-ethyl-4-methylimidazole and tetraphenylborate Examples thereof include a phenylboron salt. These can be used alone or in admixture of two or more.

  As the coupling agent, a silane coupling agent is preferable, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (methacrylopropyl) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyl Dimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ -Mercaptopropylmethyldimethoxysila , Bis (3-triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, and the like. These can be used alone or in admixture of two or more.

  In preparing the sealing resin composition of the present invention as a molding material, (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) a filler, (D) silicone, and Various components to be blended as necessary may be sufficiently mixed with a mixer or the like, then melt-kneaded with a hot roll or a kneader, and pulverized to an appropriate size after cooling.

  The semiconductor device of this invention can be manufactured by sealing a semiconductor element using said sealing resin composition. As a sealing method, a low-pressure transfer method is generally used, but sealing by injection molding, compression molding or the like is also possible. After sealing with the sealing resin composition, the semiconductor device is finally heated and cured, and finally sealed with the cured product. The heating temperature for post-curing is preferably 150 ° C. or higher. Note that examples of the semiconductor device for sealing include an integrated circuit, a large-scale integrated circuit, a diode, a transistor, and a thyristor, but the semiconductor device is not particularly limited thereto.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples at all.

Examples 1-7, Comparative Examples 1-6
Epoxy resin, phenol resin curing agent and silicone shown below, fused silica powder (trade name MSR-2212 manufactured by Tatsumori Co., Ltd.) as filler, carbon black (MA-600 manufactured by Mitsubishi Chemical Corporation), curing acceleration 2-methylimidazole (trade name 2MZP manufactured by Shikoku Kasei Co., Ltd.) as the agent, carbana wax (trade name Carnabar No. 1 manufactured by Toyo Petlite Co., Ltd.) as the mold release agent, and γ-glycidoxypropyltrimethoxysilane (product name: Carnauba No. 1 manufactured by Toyo Petlite Co., Ltd.) The resin composition for sealing was manufactured by the mixing | blending ratio shown in Table 1 and Table 2 using Nippon Unicar Co., Ltd. brand name A-187).
That is, each component was mixed (dry blended) at room temperature, then heat-kneaded using a heating roll at 90 to 95 ° C., cooled, and pulverized to produce a sealing resin composition.

Epoxy resin A: biphenyl novolac type epoxy resin (trade name NC-3000, epoxy equivalent 276 manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin B: o-cresol novolac type epoxy resin (trade name CNE-200ELB, epoxy equivalent 198 manufactured by Changchun Artificial Resin Co., Ltd.)
Phenolic resin-based curing agent: Aralkyl type phenolic resin (trade name BRG-556, hydroxyl group equivalent 198 manufactured by Showa Polymer Co., Ltd.)
Silicone A: Silicone oil (trade name XF-42-334 manufactured by GE Toshiba Silicones)
Silicone B: Silicone oil (trade name TSF-433, manufactured by GE Toshiba Silicones)
Silicone C: Silicone oil (trade name SF-8421 manufactured by Toray Dow Corning)

For the sealing resin compositions obtained in the above Examples and Comparative Examples, “adhesion strength” was measured, and “initial contact angle θ ₀ ”, “contact angle θ ₁₀₀ after 100 shots”, and “acceleration” After contact angle θ _ac ”is measured, the rate of decrease of“ contact angle θ ₁₀₀ after 100 shots ”from“ initial contact angle θ ₀ ”[(θ ₀ −θ ₁₀₀ ) / θ ₀ ] and“ after acceleration ” The reduction rate [(θ ₀ −θ _ac ) / θ ₀ ] of the contact angle θ _ac ”of the contact angle was calculated. In addition, a continuous molding test was performed to evaluate the continuous molding workability. The measurement method will be described below. The measurement results are shown in the lower column of Tables 1 and 2.

[Adhesion]
After molding a 2 mm square test piece on a copper frame using a sealing resin composition, the test piece was peeled off from the copper frame by applying a shear with a bond tester manufactured by SEISHIN TRADING. The load of was measured.
[Initial contact angle θ ₀ ]
Using a mold for transfer molding, mold-fitting material (trade name M-96, manufactured by Kyocera Chemical Co., Ltd., containing 0.7% by weight of wax) was shot in two shots, and then 20 μL of distilled water was added dropwise to the inner surface of the mold at room temperature (20 The contact angle between the inner surface of the mold and water was measured with a contact angle meter manufactured by Elma Optical Co., Ltd.
[Contact angle θ ₁₀₀ after 100 shots]
A silicon chip is bonded onto a frame made of 42 alloy alloy using a silver paste, and the sealing resin composition is injected into the mold after the initial contact angle θ ₀ measurement heated to 175 ° C. is transferred for 2 minutes. After molding, the molded body was peeled off from the mold. After repeating this 100 shots, 20 μL of distilled water was dropped onto the peeled surface, and the contact angle between the peeled surface and water was measured at room temperature with a contact angle meter manufactured by Elma Optical Co., Ltd.
[Contact angle θ _ac after acceleration]
After measuring the contact angle θ ₁₀₀ after 100 shots, the inner surface of the mold (peeling surface) is rubbed with a brush to almost remove the wax adhering to the surface, and then 20 μL of distilled water is dropped onto the surface, and at room temperature, The contact angle between the peeled surface and water was measured with a contact angle meter manufactured by Elma Optical Co., Ltd.
[Continuous molding test]
After bonding a silicon chip onto a frame made of 42 alloy alloy using a silver paste, a sealing resin composition was injected into a mold heated to 175 ° C., and transfer molding was performed for 2 minutes. This was continuously performed, and the number of shots until a molding defect such as unfilling occurred was examined.

  As is clear from Tables 1 and 2, the sealing resin compositions of the examples had high adhesion and good continuous molding workability.

Claims (5)

A sealing resin composition containing (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) a filler, and (D) silicone,
The sealing resin composition is transfer molded under predetermined conditions, and the contact angle with the liquid on the inner surface of the mold after 100 times of releasing the molded body from the molding mold is set to θ _100. , when said contact angle between the liquid of the mold inner surface of the front transfer molding was _{θ 0, (θ 0 -θ 100} ) / θ resin for sealing, which is a ₀ ≦ 0.1 object.   (A) 1.0-15.0 wt% of epoxy resin, (B) 1.0-15.0 wt% of phenol resin curing agent, (C) 60.0-93.0 wt% of filler, (D) Silicone is contained 0.1 to 2.0 weight%, The sealing resin composition of Claim 1 characterized by the above-mentioned.   (D) Component is silicone which has an alkyl group in a side chain, The resin composition for sealing of Claim 1 or 2 characterized by the above-mentioned.   The resin composition for sealing according to any one of claims 1 to 3, wherein the component (A) includes a biphenyl novolac type epoxy resin, and the component (B) includes an aralkyl type phenol resin. object. A sealing resin composition containing (A) an epoxy resin, (B) a phenol resin-based curing agent, (C) a filler, and (D) silicone, wherein the sealing resin composition is subjected to predetermined conditions. and transfer molding, the contact angle with a liquid of the mold inner surface after repeating 100 times to release the molded article from the mold and theta _100, the of the mold inner surface of the front the transfer molding when the contact angle with a liquid and a theta _0, characterized by being sealed with the cured product, the semiconductor device of (θ ₀ -θ _{100) /} θ encapsulating resin composition is ₀ ≦ 0.1 A semiconductor device.