JP4111865B2 - Epoxy resin composition and hollow package for housing semiconductor device using the same - Google Patents

Description

【００４１】
【発明の効果】
本発明のエポキシ樹脂組成物は、これまで問題とされていた、吸湿剤として配合している粒子同士の凝集がなく、また成形体の透湿性が小さく、成形性にも優れているため、信頼性の高いＣＣＤやＣＭＯＳ等の固体撮像素子を収納するための樹脂製中空パッケージに好適に用いることができる。
【図面の簡単な説明】
【図１】本発明のエポキシ樹脂組成物によって成形された中空パッケージの一例を示す断面図である。
【符号の説明】
１ 中空パッケージ
２ 蓋材
３ 接着剤
４ アイランド
５ 外部リード部
６ 内部リード部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin composition having low moisture permeability and excellent moldability for a hollow package for housing a semiconductor element, and a hollow package for housing a semiconductor element comprising the resin composition.
[0002]
[Prior art]
Conventionally, in addition to ceramics, inexpensive resin packages are used as hollow packages for housing solid-state imaging devices such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor).
[0003]
Generally, a resin-made hollow package such as an epoxy resin is integrated with a resin molding by insert molding, and a lead frame whose both ends are open to the inside and outside of the package, and fixed to the center of the package with an adhesive. The semiconductor element is electrically connected by a bonding wire. Further, the upper surface of the resin molded body has a hermetic sealing structure in which a cover material such as a transparent synthetic resin plate or glass plate is fixed with an adhesive.
[0004]
However, a resin package made of an epoxy resin composition absorbs moisture when exposed to humidification conditions, and in particular, applications that require airtightness and waterproofness such as a solid-state image sensor are long in high-temperature and high-humidity environments. When exposed to time, the molded body gradually absorbs moisture, and moisture may eventually condense in the hollow portions that are kept airtight, thereby degrading the function of the image sensor itself.
[0005]
Therefore, in the epoxy resin composition used for the hollow package, it has been a problem how to reduce moisture permeation. Conventionally, an inorganic hygroscopic agent is added to the epoxy resin composition to allow the moisture permeation from the outside of the molded body. Techniques for adsorbing moist water have been proposed.
[0006]
In the specification of Japanese Patent No. 2846551, the density measured using 1-butanol as a medium in the epoxy resin composition is less than 2.10 g / cm ³ , the moisture absorption is 3% or more, and the average particle size is 0.1 μm. The technique of the epoxy resin composition characterized by containing the silica below 3 micrometers above is described.
[0007]
As described above, in the prior art, inorganic substances such as silica powder have been often used as the hygroscopic agent, but these inorganic hygroscopic agents are preferably in a state where the shape and particle diameter are almost uniform from the viewpoint of moldability. On the other hand, if the particles are too fine, the particles tend to aggregate.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide an epoxy resin composition having a low moisture permeability and a good moldability as a molded body in order to solve the above-mentioned problems, and using this, a solid-state imaging device such as a CCD or CMOS can be accommodated. Therefore, an object of the present invention is to provide a resin-made hollow package having excellent airtightness and waterproofness.
[0009]
[Means for Solving the Problems]
As a result of various studies to solve the above problems, the present inventors have completed the present invention. That is, in the present invention,
(1) An epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and porous carbon having a specific surface area of 0.5 m ² / g to 30 m ² / g and an average particle diameter of 3 μm to 50 μm The epoxy resin composition characterized by containing is provided.
[0010]
(2) The epoxy resin assembly as described in (1) above, wherein the porous carbon content is 2% by mass or more and 30% by mass or less of the total amount of the epoxy resin composition, It is an aspect.
[0011]
(3) The epoxy resin composition according to (1) or (2) above, wherein the molded product has a boiling water absorption of 0.55% by mass or more after a boiling water absorption test for 168 hours. This is a preferred embodiment of the invention.
[0012]
In the present invention,
(4) Provided is an epoxy resin composition for a hollow package for housing semiconductor elements, characterized by comprising the epoxy resin composition described in (1) to (3) above.
[0013]
further,
(5) Provided is a hollow package for housing semiconductor elements, characterized in that it is molded from the epoxy resin composition described in (1) to (3) above.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The epoxy resin composition of the present invention is an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator and an inorganic filler, and additionally containing porous carbon. Each component will be described in detail.
[0015]
<Epoxy resin>
As the epoxy resin of the present invention, bisphenol A type, bisphenol F type, bisphenol AD type epoxy resins, phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, naphthalene skeleton-containing epoxy resins, and biphenyl skeleton-containing epoxy resins are suitable. Any one of these may be used alone, or two or more may be used in an appropriate ratio.
The epoxy equivalent of these epoxy resins is preferably 300 (g / eq) or less, more preferably 300 (g / eq) or less and 100 (g / eq) or more.
[0016]
In the present invention, the blending amount of the epoxy resin in the total resin composition is usually 2% by mass or more and 30% by mass or less, and particularly preferably 3% by mass or more and 15% by mass or less.
[0017]
<Curing agent>
The curing agent used in the present invention can be used without particular limitation as long as it is capable of curing reaction with the above epoxy resin. Among them, a phenol resin is preferable, and specifically, a phenol novolak resin and an aralkyl phenol resin. Is mentioned. In addition, amines such as diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, acid anhydrides such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, acid dihydrazides such as isophthalic acid dihydrazide, adipic acid dihydrazide, Dicyandiamide, boron trifluoride and the like are preferable.
[0018]
From the viewpoint of moisture resistance and mechanical properties, the compounding amount of the curing agent is preferably such that the chemical equivalent ratio of the epoxy resin to the epoxy group is in the range of 0.5 to 1.5, and more preferably 0.7 to 1. Is preferably in the range of.
[0019]
<Curing accelerator>
As a hardening accelerator used by this invention, what accelerates | stimulates the crosslinking reaction of the said epoxy resin and a hardening | curing agent is used.
Specific examples thereof include imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole azine; triphenylphosphine, tri (p-methylphenyl) phosphine and the like. Organic phosphines; 1,8-diazacyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) DBU derivatives such as phenol salts, phenol novolak salts, carbonates; formula Ar—NH—CO—NR ₂ , Ar And urea derivatives represented by — (NH—CO—NR ₂ ) ₂ (Ar is a substituted or unsubstituted aryl group, R is the same or different substituted or unsubstituted alkyl group).
[0020]
The curing accelerator is preferably blended in an amount of 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 0.3 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin. It is preferable.
[0021]
<Inorganic filler>
Examples of the inorganic filler used in the present invention include crystalline silica pulverized by a ball mill, crushed fused silica obtained by melting with a flame, spherical fused silica, alumina, boron nitride, mica, clay, talc, titanium oxide, Examples thereof include calcium carbonate, aluminum nitride, and silicon nitride. These may be used singly or in combination of two or more at an appropriate ratio.
[0022]
The total amount of the inorganic filler used is 100 parts by mass or more and 1000 parts by mass or less, preferably 300 parts by mass or more and 1000 parts by mass or less, with respect to 100 parts by mass of the total amount of the epoxy resin and the curing agent.
[0023]
<Porous carbon>
In general, carbon blacks such as acetylene black, channel black, furnace black, etc., as described in the Chemical Dictionary of Kyoritsu Publishing Co., Ltd. and the Ultra Fine Particle Handbook published by Fuji Techno System Co., Ltd., It is produced by a method such as an impact method or a furnace method, and has properties such as a specific surface area of about 30 to 460 m ² / g and an average particle size of about 0.005 to 0.1 μm. The quality carbon is produced by appropriately selecting conditions, and it is preferable to use carbon having the following properties.
[0024]
That is, the porous carbon used in the present invention has a specific surface area of 0.5 m ² / g or more and 30 m ² / g or less. In the present invention, the specific surface area was measured using a three-sample fully automatic gas adsorption amount measuring device Autosorb 3B type manufactured by Cantachrome, using nitrogen as the adsorption gas.
[0025]
The average particle size of the porous carbon is 3 μm or more and 50 μm or less. In the present invention, the average particle size was measured using a laser diffraction scattering particle size distribution analyzer X-100 manufactured by Lees & Notrup.
[0026]
By using such porous carbon, the epoxy resin composition is molded to reduce moisture permeability of the resin hollow package, and has moisture resistance against the penetration of moisture in the atmosphere into the package. .
[0027]
The content of the porous carbon in the entire composition is preferably 2% by mass or more and 30% by mass or less, and more preferably 2% by mass or more and 20% by mass or less.
[0028]
<Other ingredients>
In the present invention, if necessary, ferrite, aluminum hydroxide, and the like can be blended as other inorganic fillers as long as the object of the present invention is not impaired. As release agents, ester waxes of higher fatty acids such as montanic acid, stearic acid, behenic acid, oleic acid; carnauba wax (carnauba wax); zinc behenate, zinc oleate, magnesium stearate, barium stearate, stearin Metal salts of higher fatty acids such as aluminum acid; metal soaps such as zinc stearate can be blended. These may be used alone or in combination.
[0029]
In addition, as long as it does not impair the purpose of the present invention for the resin composition, a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide, a colorant such as carbon black and phthalocyanine, A low stress agent may be added.
[0030]
The following method is mentioned as an example of the preferable manufacturing method of the epoxy resin composition for hollow packages for semiconductor element accommodation of this invention. First, all materials are dry blended with a commonly used mixer such as a Henschel mixer, then heated and melt-kneaded with a two-roll, kneader, twin-screw extruder, etc., followed by cooling and pulverization to achieve the desired epoxy resin composition Get things.
[0031]
This epoxy resin composition has excellent suitability for a hollow package for housing a solid-state imaging device such as a CCD or CMOS, but semiconductor sealing and electronic parts in which the epoxy resin composition is generally used Of course, it can also be used.
[0032]
<Hollow package>
As shown in FIG. 1, the hollow package molded by the epoxy resin composition of the present invention is usually composed of a box-shaped hollow package 1 having an upper opening, and the upper surface thereof is a lid 2 made of glass or transparent plastic. Is sealed through the adhesive 3. Further, an island 4 is provided in the center of the package, and the lead frame is integrally formed by insert molding at the time of package molding, and the external lead portion 5 and the internal lead portion 6 are connected via leads enclosed in the package. .
[0033]
The hollow package for housing a semiconductor element of the present invention is molded by an arbitrary molding method such as an injection molding method or a transfer molding method using the above epoxy resin composition, and a transfer molding method is preferably employed. In the case of the transfer molding method, molding is preferably performed under molding conditions of pressure 1 × 10 ⁶ to 50 × 10 ⁶ Pa (10 to 500 kg / cm ² ), mold temperature 150 to 200 ° C., and time 0.5 to 5 minutes. .
[0034]
【Example】
Hereinafter, the excellent effect of the present invention will be described with reference to examples, but the present invention is not limited to the examples.
[0035]
[Examples 1-2]
Raw materials shown in Table 1,
Orthocresol novolac epoxy resin: Nippon Kayaku Co., Ltd., EOCN-102S, epoxy equivalent = 210 g / eq,
Phenol novolak resin (curing agent): manufactured by Meiwa Kasei Co., Ltd., H-1, softening point = 84 ° C.
Brominated epoxy resin (flame retardant): Nippon Kayaku Co., Ltd., BREN-S, epoxy equivalent = 285 g / eq,
Fused spherical silica (inorganic filler): manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size (measured by laser diffraction particle size distribution meter MODEL920 manufactured by CILAS) 26.0 μm, density (pycnometer method) 2.21 g / cm ³ ,
Porous carbon: specific surface area 4.5 m ² / g, average particle size 13.6 μm,
Antimony trioxide: manufactured by Nippon Seiko Co., Ltd., PATOX-M,
Silane coupling agent: Shin-Etsu Chemical Co., Ltd., KBM-403,
Imidazole (curing accelerator): manufactured by Shikoku Kasei Co., Ltd., 2E4MZ-AZINE, montanic acid wax: manufactured by Clariant Japan Co., Ltd., Rico Wax (registered trademark),
After mixing with a Henschel mixer at a ratio of parts by weight (in the parentheses are% by weight in the composition) described in the table, the mixture is heated and kneaded with two rolls at a temperature of 90 to 110 ° C., then cooled and pulverized to obtain an epoxy resin A composition was obtained.
Using this composition, physical properties were determined by the following evaluation methods. The results are shown in Table 1.
<Evaluation method>
(1) Spiral flow Using a mold having a spiral inside conforming to the EMMI1-66 standard, the mold temperature is 150 ° C., the effective pressure is 6.9 × 10 ⁶ Pa (70 kgf / cm ² ) by transfer molding. The length of fluidization in the mold when it was molded and cured for 180 seconds was measured.
[0036]
(2) Boiling water absorption rate The epoxy resin composition prepared as described above is formed by transfer molding at a thickness of 4 mm under molding conditions of a pressure of 30 × 10 ⁶ Pa (300 kg / cm ² ), a temperature of 180 ° C., and a time of 3 minutes. A test piece having a size of 30 mm × 30 mm was formed. This test piece is dried at 50 ° C. for 12 hours, and the mass at this time is defined as W ₀ . Then immersing the specimen in boiling water, measure the weight W ₁ after 168 hours was determined boiling water absorption rate by the following equation.
Boiling water absorption (%) = {(W ₁ −W ₀ ) / W ₀ } × 100
[0037]
(3) Moisture resistance The epoxy resin composition prepared as described above was subjected to transfer molding by the molding conditions of a pressure of 7 × 10 ⁶ Pa (70 kg / cm ² ), a temperature of 180 ° C., and a time of 2 minutes. (Outer dimensions: 10 mm x 10 mm x thickness 2 mm, hollow dimensions 7.3 mm x 7.3 mm x depth 1.2 mm, lead thickness 1.5 mm). Next, in order to hermetically seal the hollow part, a lid “a” is prepared by applying a UV curable adhesive (sealant 8723K8L manufactured by Kyoritsu Chemical Industry Co., Ltd.) to the glass plate, and the adhesive application side is placed below “A”. The cured “a” is placed and UV cured under predetermined conditions. Thus, a hermetically sealed hollow test body was obtained, and the moisture resistance was evaluated by measuring the amount of water entering the hollow portion.
[0038]
For the measurement, the method described in “Journal of Television Society 42 (9), 959 (1988)” was referred to. That is, the specimen was placed in a pressure cooker tester and exposed for 10 hours in a moist heat environment at a temperature of 121 ° C. and a humidity of 100% RH. Next, the glass surface was forcibly cooled, and it was examined whether moisture in the hollow portion was condensed. The forced cooling was performed under the condition of heating for 10 seconds at 100 ± 1 ° C. using a hot plate and then cooling for 7 seconds using an electronic cooler of 23 ± 1 ° C. In the evaluation, a case where no dew condensation was visually observed was indicated as ◯, and a case where condensation was recognized was indicated as ×.
[0039]
(4) Acetone-insoluble aggregate 300 g of the epoxy resin composition prepared as described above was placed in a 2-liter Erlenmeyer flask, and then 900 g of acetone was added and dissolved for 30 minutes. The container was filtered and dried with a 60-mesh wire mesh, and the presence or absence of aggregates remaining on the wire mesh was examined using a stereomicroscope.
[0040]
[Table 1]

[0041]
【The invention's effect】
The epoxy resin composition of the present invention is reliable because there is no aggregation of particles blended as a hygroscopic agent, which has been a problem until now, and the molded article has low moisture permeability and excellent moldability. It can be suitably used for a resin-made hollow package for housing a solid-state image pickup device such as a high-performance CCD or CMOS.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a hollow package molded with the epoxy resin composition of the present invention.
[Explanation of symbols]
1 Hollow Package 2 Lid 3 Adhesive 4 Island 5 External Lead 6 Internal Lead

Claims (5)

An epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and porous carbon having a specific surface area of 0.5 m ² / g to 30 m ² / g and an average particle size of 3 μm to 50 μm An epoxy resin composition characterized by the above. 2. The epoxy resin composition according to claim 1, wherein the content of the porous carbon is 2% by mass or more and 30% by mass or less of the total amount of the epoxy resin composition. The epoxy resin composition according to claim 1 or 2, wherein the molded product has a boiling water absorption of 0.55% by mass or more after a boiling water absorption test for 168 hours. An epoxy resin composition for a hollow package for housing semiconductor elements, comprising the epoxy resin composition according to claim 1. A hollow package for housing a semiconductor element, which is molded from the epoxy resin composition according to any one of claims 1 to 3.

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