JP2006299128A - Epoxy resin composition for semiconductor encapsulation and semiconductor device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for semiconductor encapsulation which can suppress the generation of a burr without hardly affecting the moldability, and to provide a semiconductor device using it. <P>SOLUTION: The composition contains as the essential components a polymer having a siloxane bond whose average particle size is in the range of 5-200 nm, an epoxy resin, a curing agent and an inorganic filler. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an epoxy resin composition for encapsulating semiconductors used for encapsulating semiconductors in electrical / electronic components, general-purpose semiconductor devices, optical semiconductor devices, and the like, and sealing using the epoxy resin composition for encapsulating semiconductors. The present invention relates to a stopped semiconductor device.

  Conventionally, as sealing methods for electrical / electronic components, general-purpose semiconductor devices, optical semiconductor devices, etc., sealing methods using epoxy resin compositions, silicon resin compositions, etc., and hermetic sealing methods using glass, metals, ceramics, etc. It has been known. Epoxy resins are superior in terms of adhesion, moisture resistance, electrical insulation, heat resistance, transparency, etc., and moreover can be mass-produced and have cost advantages. Is the mainstream. As such an epoxy resin composition, for example, an organopolysiloxane compound is contained in order to improve flame retardancy (see, for example, Patent Document 1), semiconductors are encapsulated, and semiconductors are used at high temperature and high humidity. An epoxy resin composition containing a silicone / acrylic composite rubber-based graft copolymer in order to reduce the stress applied to the element (for example, see Patent Document 2) has been reported.

  When a package is molded using the epoxy resin composition as described above, for example, it is a problem to suppress the amount of burr generated from the parting surface of the mold. If burrs occur, it takes time to remove them, and if they remain attached to the lead frame without completely removing burrs, the lead frame will be misaligned when transported. Yields deteriorated, for example, the line stopped, or burrs dropped onto the mold, resulting in poor molding. For this reason, as a method for reducing the generation of burrs, a method in which silica having a small particle size is contained in the epoxy resin composition has been proposed.

However, according to the above method, the specific surface area increases as the silica particle size decreases, and the contact area with the epoxy resin increases to increase the viscosity, which adversely affects the moldability of the epoxy resin composition. There was a problem.
JP-A-10-195179 JP 2003-55533 A

  This invention makes it a subject to provide the epoxy resin composition for semiconductor sealing which can suppress generation | occurrence | production of a burr | flash with little influence on a moldability, and a semiconductor device using the same from the background as mentioned above. Yes.

  In order to solve the above-mentioned problems, the present invention first includes a polymer having a siloxane bond having an average particle size in the range of 5 to 200 nm as an essential component together with an epoxy resin, a curing agent, and an inorganic filler. It is characterized by that.

  Secondly, in the above epoxy resin composition for semiconductor encapsulation, the polymer having a siloxane bond is coated with an acrylic polymer, and third, the polymer having a siloxane bond is It contains in the range of 0.5-10 mass% with respect to the whole epoxy resin composition for semiconductor sealing.

  Furthermore, the invention of the present application is characterized in that, as a semiconductor device, a semiconductor element is encapsulated with any one of the above epoxy resin compositions for encapsulating a semiconductor.

  According to the first invention as described above, a polymer having a siloxane bond having an average particle size in the range of 5 to 200 nm is contained as an essential component together with an epoxy resin, a curing agent, and an inorganic filler. It is possible to suppress the occurrence of burrs with almost no effect on sex.

  According to said 2nd invention, since the polymer which has a siloxane bond is coated with the acrylic polymer, compatibility with an epoxy resin improves and the influence on a moldability can be made still smaller.

  Moreover, according to said 3rd invention, when the polymer which has a siloxane bond contains in the range of 0.5-10 mass% with respect to the whole epoxy resin composition for semiconductor sealing, 1st In addition to the effects of the second invention, the occurrence of burrs can be suppressed without impairing the properties of the cured product such as bending strength and bending elastic modulus.

  The remarkable effects as described above are actually realized greatly as the semiconductor device of the fourth invention.

  The present invention has the above-described features, and the best mode for carrying out the invention will be described below.

  In the epoxy resin composition for semiconductor encapsulation of the present invention, as described above, a polymer having a siloxane bond having an average particle size of 5 to 200 nm is contained as an essential component together with an epoxy resin, a curing agent, and an inorganic filler. It is.

  The polymer having a siloxane bond in the present invention is not particularly limited as long as the average particle diameter is in the range of 5 to 200 nm, and may be a silicone rubber or a silicone elastomer having a siloxane bond in the main chain. For example, such a silicone rubber is a linear polymer having a degree of polymerization of about 5000 to 10000, a millable type silicone rubber such as dimethyl silicone, methyl vinyl silicone, and methyl phenyl vinyl silicone, or a degree of polymerization of about 100 to 2000. A liquid silicone rubber that is a linear polymer is considered.

  A smaller average particle size of the polymer is preferable because it does not adversely affect the physical properties, but the lower limit is set to 5 nm at a practical level in production. When the average particle diameter exceeds 200 nm, physical properties such as Tg are adversely affected, and the generation of burrs cannot be suppressed without affecting the moldability.

  The polymer having a siloxane bond in the present invention may be coated with an acrylic polymer on the surface. Thereby, the compatibility with the epoxy resin is improved, and the influence on the moldability can be reduced.

  Examples of the acrylic polymer include polymethyl methacrylate (PMMA) and polyglycidyl methacrylate (PGMA). Then, in consideration of the average particle diameter of the polymer having a siloxane bond to be used and the compatibility with the epoxy resin, it is preferable to coat the film so that the film thickness is in the range of 50 to 100 μm, for example.

  The polymer having a siloxane bond in the present invention is preferably contained in a range of 0.5 to 10% by mass, particularly preferably in a range of 1 to 3% by mass with respect to the entire epoxy resin composition for semiconductor encapsulation. It is. If it is less than 0.5% by mass, the occurrence of burrs may not be sufficiently suppressed. If it exceeds 10% by mass, Tg may be reduced, and the cured product may be impaired in properties such as bending strength and flexural modulus. Therefore, it is not preferable.

  As an epoxy resin in this invention, if it has two or more epoxy groups in 1 molecule, it can be used without being restrict | limited especially. For example, o-cresol novolac type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, bisphenol type epoxy resin, bromine-containing epoxy resin and the like can be exemplified, and these may be used alone or in combination of plural kinds. . In addition, an epoxy resin can be mix | blended in 7-35 mass% with respect to the whole epoxy resin composition for semiconductor sealing.

  Any curing agent can be used without particular limitation as long as it has two or more phenolic hydroxyl groups in one molecule and can cure the above epoxy resin. For example, a phenolic curing agent, an amine curing agent, an acid anhydride curing agent, and the like can be used, but a phenolic curing agent is used to make a highly reliable epoxy resin composition with a low moisture absorption rate. preferable. Examples of the phenolic curing agent include various phenols such as phenol aralkyl, phenol novolak, cresol novolak, curing agent having triphenylmethane skeleton, curing agent having dicyclo skeleton, curing agent having paraxylylene skeleton, and naphthol aralkyl. A compound or a naphthol compound can be used. These may be used alone or in combination. The blending amount in the case of using a phenolic curing agent is preferably set so that the epoxy equivalent of the epoxy resin / phenol equivalent = 0.5 to 1.5, and preferably 0.8 to 1.2. Set as follows.

  As the inorganic filler, various inorganic fillers such as amorphous silica (fused silica), crystalline silica, alumina, silicon nitride and the like can be used, and they may be used alone or in combination. Considering the fluidity of the epoxy resin composition for semiconductor encapsulation, it is particularly preferable to use fused silica or crystalline silica among these. The blending amount of the inorganic filler is preferably set in the range of 60 to 93% by mass with respect to the total amount of the epoxy resin composition for semiconductor encapsulation. When the blending amount of the inorganic filler is less than 60% by mass with respect to the total amount of the epoxy resin composition for semiconductor encapsulation, the low linear expansion coefficient and the low moisture absorption necessary as a sealing molded body of the epoxy resin composition for semiconductor encapsulation It is not preferable because performance such as high reliability and solder resistance cannot be obtained sufficiently. When it exceeds 93 mass%, since the fluidity | liquidity at the time of shaping | molding of the epoxy resin composition for semiconductor sealing falls and a moldability may deteriorate, it is unpreferable.

  The present invention may be used in combination with a curing accelerator, and is not particularly limited as long as it has an action of promoting the reaction between the epoxy resin and the curing agent. For example, imidazoles such as 2-methylimidazole and 2-phenylimidazole, organic phosphines such as triphenylphosphine, tributylphosphine, and trimethylphosphine, 1,8-diazabicyclo (5,4,0) undecene-7 (DBU), Tertiary amines such as triethanolamine and benzyldimethylamine can be used. These may be used alone or in combination.

  Moreover, this invention can mix | blend a coupling agent. Coupling agents include mercaptosilanes such as γ-mercaptopropyltrimethoxysilane, glycidoxysilanes such as γ-glycidoxypropyltrimethoxysilane, silane coupling agents such as aminosilane, and epoxy / polyether groups. A coupling agent such as polysiloxane can be used. These may be used alone or in combination. The molecular weight and functional group equivalent of the epoxy group / polyether group-containing polysiloxane are not particularly limited.

  The present invention further includes a colorant such as carbon black, a mold release WAX such as carnauba wax, a flame retardant such as a silicone flexible agent, a brominated epoxy resin, and a flame retardant aid such as antimony trioxide. An agent or the like can be added.

  The epoxy resin composition for semiconductor encapsulation of the present invention comprises a polymer having a siloxane bond having an average particle size in the range of 5 to 200 nm, an epoxy resin, a curing agent, an inorganic filler, and other materials as required. It can be prepared by uniformly mixing with a kneader or blender and then heating and mixing with a kneader or roll. In addition, after heating and mixing, it may be cooled and solidified as necessary, pulverized and used as a powder, or may be used after being formed into a tablet or a stick.

  And a semiconductor device can be produced by sealing-molding the epoxy resin composition for semiconductor sealing prepared as mentioned above. For example, a semiconductor device in which a semiconductor element is encapsulated with an encapsulating resin by the above epoxy resin composition for encapsulating a semiconductor by setting a lead frame on which a semiconductor element such as an IC is mounted in a transfer molding die and performing transfer molding Can be produced.

  Hereinafter, examples will be shown and described in more detail. Of course, the present invention is not limited by the following examples.

<Examples 1 to 5 and Comparative Example>
The blend shown in Table 1 (the unit of blending amount is mass%) is mixed with a blender for 30 minutes, homogenized, kneaded and melted with a kneader heated to 80 ° C., extruded, cooled, and then ground to a predetermined particle size with a grinder. And the epoxy resin composition for semiconductor sealing of Examples 1-5 and a comparative example was obtained as a granular material. About these epoxy resin compositions for semiconductor sealing, fluidity | liquidity, the grade of burr | flash generation, bending strength, bending elastic modulus, and Tg were evaluated.

In addition, as a compounding material of the epoxy resin composition for semiconductor sealing in Table 1, the following were used.
o-Cresol novolac type epoxy resin: "ESCN195XL" epoxy equivalent 195 manufactured by Sumitomo Chemical Co., Ltd.
Phenol novolac resin: “Tamanol 752” hydroxyl equivalent 104 manufactured by Arakawa Chemical Industries, Ltd.
Silica: “FB820” manufactured by Denki Kagaku Kogyo Co., Ltd.
γ-glycidoxypropyltrimethoxysilane: “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.
Epoxy group / polyether group-containing polysiloxane: “SF8421” manufactured by Toray Dow Corning Silicone Co., Ltd.
Carbon black: “40B” manufactured by Mitsubishi Chemical Corporation
Curing accelerator: “TPP” manufactured by Hokuko Chemical Industry Co., Ltd.
Carnauba wax: “F1-100” manufactured by Dainichi Chemical
Brominated epoxy resin: “ESB400T” (epoxy equivalent 400) manufactured by Sumitomo Chemical Co., Ltd.
Antimony trioxide: “NT3” manufactured by Toko Sangyo Co., Ltd.
Polymer having a siloxane bond: “Silicon Particle Modifier” manufactured by Asahi Kasei Wacker Silicone Co., Ltd. (particle size distribution in the range of 5 to 200 nm)
(Evaluation of epoxy resin composition for semiconductor encapsulation)
Flowability: Using a spiral flow measurement mold, molding was performed at a mold temperature of 175 ° C. and an injection pressure of 6.86 MPa (70 kgf / cm ² ) in a curing time of 100 seconds, and the flow distance was measured to evaluate the fluidity.

    Degree of burr generation: A burr evaluation mold in which gaps of 10, 20, 30, 50, and 100 μm were designed was molded under the same conditions as the spiral flow, and the burr length was measured.

    Bending strength and flexural modulus: The flexural strength and flexural modulus were measured according to JIS K6911. As a tester, an autograph AG-5000D manufactured by Shimadzu Corporation was used.

    Tg: Measured using a linear expansion coefficient tester manufactured by Tokyo Kogyo Co., Ltd.

  The results are shown in Table 1.

表１の結果より、実施例１〜５では、平均粒径５〜２００ｎｍの範囲のシロキサン結合をもつポリマーが含有されていることで、成形性にほとんど影響を与えずにバリの発生を抑えることができることが確認された。また、シロキサン結合をもつポリマーが半導体封止用エポキシ樹脂組成物全体に対して０．５〜１０質量％の範囲で含有されていることにより（実施例１，３，４）、Ｔｇがほとんど低下せず、曲げ強度や曲げ弾性率を損なうことなくバリの発生を抑えることができることが確認された。比較例では、平均粒径５〜２００ｎｍの範囲のシロキサン結合をもつポリマーが含有されていないことにより、バリの発生が低減されていないことが確認された。

From the results of Table 1, in Examples 1 to 5, the polymer having a siloxane bond with an average particle size in the range of 5 to 200 nm is contained, thereby suppressing the occurrence of burrs with almost no influence on the moldability. It was confirmed that In addition, since the polymer having a siloxane bond is contained in the range of 0.5 to 10% by mass with respect to the entire epoxy resin composition for semiconductor encapsulation (Examples 1, 3, and 4), Tg is almost reduced. Thus, it was confirmed that the generation of burrs can be suppressed without impairing the bending strength and the bending elastic modulus. In the comparative example, it was confirmed that the generation of burrs was not reduced because the polymer having a siloxane bond having an average particle size in the range of 5 to 200 nm was not contained.

Claims (4)

  An epoxy resin composition for encapsulating a semiconductor, wherein a polymer having a siloxane bond having an average particle size in the range of 5 to 200 nm is contained as an essential component together with an epoxy resin, a curing agent, and an inorganic filler.   The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the polymer having a siloxane bond is coated with an acrylic polymer.   The polymer having a siloxane bond is contained in a range of 0.5 to 10% by mass with respect to the entire epoxy resin composition for semiconductor encapsulation. Epoxy resin composition.   A semiconductor device comprising a semiconductor element sealed with the epoxy resin composition for sealing a semiconductor according to claim 1.