JP2004331920A - Epoxy resin composition and hollow package for housing semiconductor element by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition having a less moisture permeability as its molded material and a good molding property, and a hollow package made from the resin for housing a solid image-picking up element, excellent in airtightness and waterproof property by using the same. <P>SOLUTION: This epoxy resin composition is characterized by containing an epoxy resin, a curing agent, a curing accelerator, an inorganic filler and porous carbon having ≥0.5 m<SP>2</SP>/g and ≤30 m<SP>2</SP>/g specific surface area, and ≥3 μm and ≤50 μm mean particle diameter. The content of the porous carbon is preferably ≥2 mass % and ≤30 mass % based on the total amount of the epoxy resin composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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]
TECHNICAL FIELD 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 semiconductor element housing hollow package made of the resin composition.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an inexpensive resin package other than ceramic is used for a hollow package for accommodating a solid-state imaging device such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).
[0003]
Generally, a hollow package made of resin such as epoxy resin is integrated with a resin molded body by insert molding, and both ends are opened to the inside and outside of the package, and a lead frame is fixed to the center of the package with an adhesive. The semiconductor element is electrically connected by a bonding wire. The upper surface of the resin molded body has a hermetically sealed structure in which a cover material such as a transparent synthetic resin plate or a 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 particularly in applications requiring airtightness and waterproofness, such as solid-state imaging devices, are difficult to operate in a high-temperature and high-humidity environment. If the molded article is exposed for a long time, the molded article gradually absorbs moisture, and eventually moisture is condensed in the airtight hollow part, which may reduce the function of the image sensor itself.
[0005]
Therefore, in epoxy resin compositions used for hollow packages, it has been an issue how to reduce the moisture permeability. Conventionally, an inorganic hygroscopic agent is added to the epoxy resin composition, and the epoxy resin composition is permeable from outside the molded product. Techniques for adsorbing moist water have been proposed.
[0006]
In the specification of Japanese Patent No. 2846551, a density measured using 1-butanol as a medium is less than 2.10 g / cm ³ , a moisture absorption rate is 3% or more, and an average particle size is 0.1 μm in the epoxy resin composition. A technique of an epoxy resin composition characterized by containing silica having a particle size of less than 3 μm is described.
[0007]
As described above, in the related art, inorganic materials such as silica powder have been often used as a moisture absorbent. However, from the viewpoint of moldability, these inorganic moisture absorbents desirably have shapes and particle diameters that are close to uniform. On the other hand, if the particles are too fine, the particles tend to aggregate easily.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide an epoxy resin composition having low moisture permeability and good moldability as a molded article, and using the same to house a solid-state imaging device such as a CCD or CMOS. It is an object of the present invention to provide a resin hollow package excellent in airtightness and waterproofness.
[0009]
[Means for Solving the Problems]
The present inventors have conducted various studies in order to solve the above problems, and as a result, completed the present invention. That is, in the present invention,
{Circle around (1)} An epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and a porous carbon having a specific surface area of 0.5 m ² / g or more and 30 m ² / g or less and an average particle diameter of 3 μm or more and 50 μm or less. An epoxy resin composition characterized by comprising:
[0010]
(2) The epoxy resin assembly according to (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. It is an aspect.
[0011]
(3) The epoxy resin composition according to (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. This is a preferred embodiment of the present invention.
[0012]
In the present invention,
(4) An epoxy resin composition for a hollow package for housing a semiconductor element, comprising the epoxy resin composition described in (1) to (3).
[0013]
further,
(5) A hollow package for housing a semiconductor element, which is formed from the epoxy resin composition described in (1) to (3).
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
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 further comprising 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 resin, phenol novolak type epoxy resin, orthocresol novolak type epoxy resin, naphthalene skeleton-containing epoxy resin, and biphenyl skeleton-containing epoxy resin are preferable. Any one of these may be used alone, or two or more of them 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 compounding amount of the epoxy resin in the entire 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>
As the curing agent used in the present invention, any one can be used without particular limitation as long as it reacts with the epoxy resin described above. Among them, a phenol resin is preferable, and specifically, a phenol novolak resin and an aralkyl phenol resin are used. Is mentioned. Further, diaminodiphenylmethane, diaminodiphenylsulfone, amines such as m-phenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, acid anhydrides such as hexahydrophthalic anhydride, isophthalic dihydrazide, acid dihydrazide such as adipic dihydrazide, Preference is given to dicyandiamide, boron trifluoride and the like.
[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 to the epoxy group of the epoxy resin is in the range of 0.5 to 1.5, and more preferably 0.7 to 1 .2.
[0019]
<Curing accelerator>
As the curing accelerator used in the present invention, one that promotes a crosslinking reaction between the epoxy resin and the curing agent is used.
Specific examples thereof include imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-ethyl-4-methylimidazoleazine; and triphenylphosphine and tri (p-methylphenyl) phosphine. 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; and the formulas Ar-NH-CO-NR ₂ , Ar A urea derivative represented by — (NH—CO—NR ₂ ) ₂ (Ar is a substituted or unsubstituted aryl group, and R is a substituted or unsubstituted alkyl group which may be the same or different).
[0020]
The curing accelerator is preferably blended in an amount of 0.1 to 20 parts by mass, more preferably 0.3 to 15 parts by mass, based on 100 parts by mass of the epoxy resin. Is preferred.
[0021]
<Inorganic filler>
As the inorganic filler used in the present invention, crystalline silica pulverized by a ball mill or the like, crushed fused silica or spherical fused silica obtained by flame fusion, alumina, boron nitride, mica, clay, talc, titanium oxide, Examples thereof include calcium carbonate, aluminum nitride, and silicon nitride. These may be used alone or in combination of two or more at an appropriate ratio.
[0022]
The total use amount of such an inorganic filler 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, and furnace black are described in Chemical Dictionary, published by Kyoritsu Shuppan Co., Ltd., and ultrafine particle handbooks, published by Fuji Techno System Co., Ltd. It is made 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 high quality carbon is manufactured 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 apparatus, Autosorb 3B, manufactured by Cantachrome, using nitrogen as the adsorbed gas.
[0025]
The porous carbon has an average particle diameter of 3 μm or more and 50 μm or less. In the present invention, the average particle diameter was measured using a laser diffraction scattering particle size distribution analyzer X-100 manufactured by Leeds & Notrup.
[0026]
By using such a porous carbon, the epoxy resin composition is molded and the moisture permeability of the resin hollow package is reduced, and the resin has moisture resistance against intrusion of atmospheric moisture into the package. .
[0027]
The content of the porous carbon in the whole composition is preferably from 2% by mass to 30% by mass, and more preferably from 2% by mass to 20% by mass.
[0028]
<Other compounding agents>
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 a releasing agent, ester waxes of higher fatty acids such as montanic acid, stearic acid, behenic acid and oleic acid; carnauba wax (carnauba wax); zinc behenate, zinc oleate, magnesium stearate, barium stearate, stearin Metal salts of higher fatty acids such as aluminum phosphate; metal soaps such as zinc stearate can be added. These may be used alone or as a mixture.
[0029]
Further, within the range not impairing the object of the present invention for the present resin composition, a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide, a carbon black, a coloring agent such as phthalocyanine, if necessary, A low stress agent may be added.
[0030]
Preferred examples of the method for producing the epoxy resin composition for a hollow package for housing a semiconductor element of the present invention include the following methods. First, all the materials are dry-blended by a commonly used mixer such as a Henschel mixer, and then heated and melt-kneaded with a two-roll, kneader, twin-screw extruder, etc., and then cooled and pulverized to obtain the desired epoxy resin composition. Get things.
[0031]
This epoxy resin composition has excellent suitability for a hollow package for accommodating a solid-state imaging device such as a CCD or a CMOS. However, the epoxy resin composition is generally used for semiconductor encapsulation and electronic parts. Of course, it can also be used for other purposes.
[0032]
<Hollow package>
The hollow package formed by the epoxy resin composition of the present invention usually comprises a box-shaped hollow package 1 having an open top as shown in FIG. Is sealed through the adhesive 3. Further, an island 4 is provided at the center of the package, and the lead frame is integrally formed by insert molding at the time of molding the package, and the external lead 5 and the internal lead 6 are connected via a lead sealed in the package. .
[0033]
The hollow package for housing a semiconductor element of the present invention is molded by any molding method such as an injection molding method or a transfer molding method using the above-mentioned epoxy resin composition, and the transfer molding method is preferably employed. In the case of the transfer molding method, molding is preferably performed under molding conditions of a pressure of 1 × 10 ⁶ to 50 × 10 ⁶ Pa (10 to 500 kg / cm ² ), a mold temperature of 150 to 200 ° C., and a time of 0.5 to 5 minutes. .
[0034]
【Example】
Hereinafter, the excellent effects of the present invention will be described with reference to examples, but the present invention is not limited to the examples.
[0035]
[Examples 1 and 2]
Raw materials shown in Table 1,
Orthocresol novolak 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): BREN-S, manufactured by Nippon Kayaku Co., Ltd., 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 analyzer 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: Nippon Seiko Co., Ltd., PATOX-M,
Silane coupling agent: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.
Imidazole (curing accelerator): 2E4MZ-AZINE, manufactured by Shikoku Chemicals Co., Ltd.
Montanic acid wax: manufactured by Clariant Japan Co., Ltd., Licowax (registered trademark),
Was mixed by a Henschel mixer at a ratio of parts by weight (in parentheses,% by weight in the composition) described in the table, heated and kneaded with two rolls at a temperature of 90 to 110 ° C., and 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 according to the EMMI1-66 standard, transfer molding, mold temperature 150 ° C, effective pressure 6.9 × 10 ⁶ Pa (70 kgf / cm ² ) , And the length of flow in the mold when cured for 180 seconds was measured.
[0036]
(2) Boiling water absorption The epoxy resin composition prepared as described above was subjected to transfer molding at a pressure of 30 × 10 ⁶ Pa (300 kg / cm ² ), a temperature of 180 ° C., and a thickness of 4 mm under molding conditions of 3 minutes in time. A test piece having a size of 30 mm × 30 mm was formed. The test piece was dried at 50 ° C. 12 h, the mass at this time it is 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 to form a hollow package “A” under the conditions of a pressure of 7 × 10 ⁶ Pa (70 kg / cm ² ), a temperature of 180 ° C. and a time of 2 minutes. (External dimensions: 10 mm × 10 mm × thickness 2 mm, hollow section dimensions 7.3 mm × 7.3 mm × depth 1.2 mm, lead thickness 1.5 mm). Next, a lid material “a” prepared by applying a UV curing adhesive (sealing agent 8723K8L manufactured by Kyoritsu Chemical Industry Co., Ltd.) to the glass plate to hermetically seal the hollow portion is prepared, and the adhesive application side is placed below “A”. The "a" is placed on the substrate 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]
The measurement referred to the method described in "The Journal of the Institute of Television Engineers of Japan 42 (9), 959 (1988)". That is, the test 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 or not moisture in the hollow portion was condensed. The forced cooling was performed under the conditions of heating at 100 ± 1 ° C. for 10 seconds with a hot plate and then cooling for 7 seconds with an electronic cooler at 23 ± 1 ° C. The evaluation was indicated by ○ when no dew condensation was visually observed, and x when the dew condensation was observed.
[0039]
(4) Acetone-insoluble aggregates 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. This 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 stereoscopic microscope.
[0040]
[Table 1]

[0041]
【The invention's effect】
The epoxy resin composition of the present invention has been considered to be a problem because there is no agglomeration of particles blended as a hygroscopic agent, and the molded article has low moisture permeability and excellent moldability. It can be suitably used for a resin hollow package for accommodating a solid-state imaging device such as a CCD or a CMOS having high performance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a hollow package formed using the epoxy resin composition of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hollow package 2 Lid material 3 Adhesive 4 Island 5 External lead part 6 Internal lead part

Claims (5)

It contains 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 or more and 30 m ² / g or less and an average particle diameter of 3 μm or more and 50 μm or less. The epoxy resin composition characterized by the above-mentioned. 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 a semiconductor device, comprising the epoxy resin composition according to claim 1. A hollow package for housing a semiconductor element, formed from the epoxy resin composition according to claim 1.

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