JPH09165498A - Resin composition for sealing of electronic component part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. for sealing of an electronic component part which has excellent dimensional stability, effect of preventing water penetration or the like by incorporating a curing agent, a curing accelerator, an inorg. filler, a particular zeolite, and silica gel into an epoxy resin. SOLUTION: An epoxy resin (A) (e.g. a bisphenol type epoxy resin), a phenolic resin curing agent (B) (e.g. phenol novolak resin), a curing accelerator (C) (e.g. 2-methylimidazole), an inorg. filler (D) (e.g. silica), a zeolite (E) in an amt. of 3 to 30wt.% based on the whole composition, the zeolite having a compsn. represented by the formula (wherein (x)=0.1 to 2; (y)=1 to 200; (z)=0 to 100; M represents an alkali metal or an alkaline earth metal; and (n) is a valency of the metal) and a max. particle diameter of not more than 200μm, and a silica gel (E) in an amt. of 3 to 30wt.% based on the whole compsn., the silica gel having a max. particle diameter of not more than 200μm are used as indispensable components to obtain a resin compsn. for sealing of an electronic component part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for encapsulating an electronic component with a window such as a solid-state image sensor, which has excellent dimensional stability and has a problem of infiltration of moisture from the outside.

[0002]

2. Description of the Related Art Transistors, ICs, capacitors,
As a method of sealing electronic parts such as diodes, the method of transfer molding of epoxy resin is widely used because it is suitable for low-cost mass production, and the conventional metal and ceramic sealing has been replaced by resin sealing. There is.
With the recent progress in multimedia, it has become necessary to capture images and images in a personal computer and instantly send them to a remote place, and a small-sized, lightweight, low-cost solid-state imaging device has been required. Conventionally, a solid-state image sensor is mounted in a ceramic case and a glass window is adhered, but it is expensive although it has high performance. Therefore, to reduce costs, a method of mounting an element in a case molded with epoxy resin and attaching a window of glass or acrylic resin has been adopted, but the dimensional accuracy is worse than that of ceramic and moisture entering from outside is epoxy resin. It penetrated through the inside and eventually formed condensation in the case, causing deterioration of characteristics. Generally, in order to prevent water infiltration, a means of highly filling an inorganic filler with low hygroscopicity such as silica into the resin composition is taken, but this is not sufficient for this application and water diffuses into the resin over a long period of time. Then, it reached the internal element. Therefore, hygroscopic agents such as water-absorbent polymers are being studied to fix water in order to prevent diffusion in the resin, but when organic hygroscopic agents are used, swelling occurs and problems occur with dimensional stability and appearance of the product. It was

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a resin composition for encapsulating electronic parts, which has dramatically improved dimensional stability and the ability to block moisture invading from the outside.

[0004]

The present invention provides an epoxy resin, a phenol resin curing agent, a curing accelerator, an inorganic filler,
Zeolite and silica gel are essential components, the structure of the zeolite is represented by the formula (1), the maximum particle size is 200 μm or less, the content of zeolite in the entire composition is 3 to 30% by weight, and the maximum particle size of the silica gel is A resin composition for encapsulating an electronic component, which has a diameter of 200 μm or less and a content of silica gel in the entire composition of 3 to 30% by weight. _{xM 2 / n O · Al 2} O 3 · ySiO 2 · zH 2 O (1) ( where, x = 0.1~2.0, y = 1.0~200 ,
z = 0 to 100, M is an alkali metal or alkaline earth metal, and n is its valence. )

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin used in the present invention is not particularly limited as long as it contains two or more epoxy groups. For example, cresol novolac type epoxy resin, trifunctional epoxy resin, biphenyl type epoxy resin,
Examples thereof include dicyclopentadiene type epoxy resin, bisphenol type epoxy resin, brominated epoxy resin and the like.
These epoxy resins may be used alone or as a mixture. The phenol resin curing agent is not particularly limited as long as it contains two or more hydroxyl groups. Examples thereof include phenol novolac type, cresol novolac type, phenol aralkyl type, dicyclopentadiene type triphenylmethane type, and modified resins thereof. These phenol resin curing agents may be used alone or in combination. The amount of these curing agents is preferably such that the number of epoxy groups in the epoxy resin matches the number of hydroxyl groups in the curing agent. Examples of the curing accelerator include imidazole, organic phosphine, tertiary amine, and 1,8-diazabicycloundecene, but are not particularly limited. These may be used alone or in combination.

The zeolite of the formula (1) used in the present invention is
It has a maximum particle size of 200 μm or less, has a crystal structure, and has a large number of pores with a diameter of 3 to 20 Å in the crystal particles by its nature, so that water can be adsorbed and held. Silica gel also has a diameter of 50 ~
It has an innumerable number of pores of about 300 Å and can absorb and hold water. When these hygroscopic agents were blended in an epoxy resin composition and studied earnestly, it was found that by using zeolite and silica gel together, a stable moisture adsorption capacity for a long time, which could not be achieved by a single blending, could be obtained. Zeolite has a maximum particle size of 200 μm or less, and if the maximum particle size is exceeded, the packing property becomes poor. The average particle size is not particularly limited, but is 5 to 3
A range of 0 μm is preferred. If the content in the entire composition is less than 3% by weight, the hygroscopic performance is low, and if it exceeds 30% by weight, the fluidity is deteriorated and molding failure occurs. The shape of the zeolite particles may be a crushed shape, a spherical shape, a dice shape, or the like, but is not particularly limited. If the maximum particle size of the silica gel particles exceeds 200 μm, the filling property will be poor. The average particle size is not particularly limited, but is 5 to 30.
The range of μm is preferred. Content in the total composition is 3% by weight
If it is less than 40% by weight, the hygroscopicity is low, and if it exceeds 30% by weight, the fluidity is deteriorated to cause defective molding. The silica gel particles may have a crushed shape, a spherical shape, or the like, but are not particularly limited. Zeolite and silica gel are required to be used in combination, and the combination ratio is not particularly limited. preferable.

As the inorganic filler, silica, alumina,
Clay, calcium carbonate, aluminum nitride, silicon nitride and the like are available, and silica is preferred among these. As the silica, fused silica is preferably crushed or spherical and has an average particle size of 10 to 30 μm and a maximum particle size of 150 μm, but other particle sizes may be used, and two or more kinds of these may be used in combination. . The silica used in the present invention must be contained in an amount of 40% by weight or more in the total composition, and the total amount of zeolite, silica gel and silica must be 75 to 90% by weight. If the silica content is less than 40% by weight, the reliability, moldability, and dimensional stability are poor. When the total amount of zeolite, silica gel and silica is 75 to 90% by weight, the dimensional stability and hygroscopicity are particularly excellent, and the formability is poor outside this range.

The encapsulating resin composition of the present invention has a coefficient of thermal expansion of 1.5 × 10 ⁻⁵ 1 / ° C. or less and a molding shrinkage of 0.3%.
It is also necessary to be below, and within this range, excellent dimensional stability can be obtained. Further, the moisture absorption rate of the sealing resin composition,
85 ° C., relative humidity 85%, 0.3% after moisture absorption treatment for 336 hours.
It must be 4% by weight or more. If it is less than 0.4% by weight, the moisture adsorption capacity is insufficient, and it is not possible to prevent the infiltration of moisture into the internal elements. The method of measuring the coefficient of thermal expansion and the coefficient of moisture absorption in the present invention will be described in the section of Examples.

In the present invention, an epoxy resin, a phenol resin curing agent, a curing accelerator, an inorganic filler, zeolite and silica gel are essential components, but in addition to these, a surface treatment agent such as a silane coupling agent, Flame retardants such as antimony acid, colorants such as carbon black and red iron oxide,
Release agents such as natural wax and synthetic wax, low-stress additives such as silicone oil and rubber, and various other additives may be appropriately blended. Further, in order to produce the electronic component sealing resin composition of the present invention as a molding material, an epoxy resin, a phenol resin curing agent, a curing accelerator, an inorganic filler, zeolite and silica gel, and other additives are mixed with a mixer or the like. After sufficiently uniformly mixing, the mixture can be further melt-kneaded with a hot roll or a kneader, cooled and pulverized to obtain a sealing material.

[0010]

The present invention will be specifically described below with reference to examples. << Example 1 >> Biphenyl type epoxy resin: [Yukasei Shell Co., Ltd., YX4000H, epoxy equivalent 190, melting point 170 ° C.] 90 parts by weight Brominated epoxy resin: Dainippon Ink and Chemicals, Epicron 152, Epoxy equivalent 360, softening point 65 ° C.] 8 parts by weight Phenol novolac resin: [Sumitomo Dures Co., Ltd., hydroxyl equivalent 105, softening point 70 ° C.] 52 parts by weight 2-methylimidazole: 1 part by weight Zeolite: [ Tosoh Corporation, Zeolum A-3] 100 parts by weight Silica gel: [Tokai Chemical Industry Co., Ltd., maximum particle size 200 microns] 100 parts by weight Crushed fused silica: [Average particle size 15 microns, maximum particle size 100 microns] 100 parts by weight-Spherical fused silica: [average particle size 23 microns, maximum particle size 74 microns] 500 parts by weight-γ-glycidoxypropylto Methoxysilane 6 parts by weight Antimony trioxide 8 parts by weight Hoechst wax S 3 parts by weight Carbon black 2 parts by weight are sufficiently mixed at room temperature and then kneaded at 80 to 110 ° C. using a biaxial heating roll and cooled. It was pulverized to obtain a resin composition for sealing electronic parts.

<< Examples 2 and 3 >> Using the formulations shown in Table 1, the resin composition for sealing electronic parts was obtained in the same manner as in Example 1. << Comparative Examples 1 to 3 >> Resin compositions for electronic component encapsulation were obtained in the same manner as in Example 1 with the formulations shown in Table 1. The resin compositions of Examples and Comparative Examples were heated at a temperature of 17 using a transfer molding machine.
175 after molding at 5 ° C. and injection pressure of 120 kg / cm ^2.
Post-cure treatment was performed at 8 ° C. for 8 hours to obtain a test piece.

<Evaluation Method> Spiral flow: Measured at a temperature of 175 ° C. and an injection pressure of 70 kg / cm ² using a mold conforming to EMMI-I-66.・ Thermal expansion coefficient: 15 × 4 × 4 mm test piece 17
Molded by curing at 5 ℃ for 90 seconds, post cure, TMA
The value at 60 ° C. was obtained using [manufactured by Seiko Instruments Inc.]. Temperature rising speed is 5 ° C / min, unit is × 10
^-5 1 / ° C. Molding shrinkage rate: A disk test piece was molded by curing at 175 ° C. for 90 seconds according to JIS K-6911, and was determined from the dimensions after the post cure treatment. Units%.・ Moisture absorption rate: A disk with a thickness of 50φ x 3 mm is formed at 85 ° C,
After treatment for 336 hours in a thermo-hygrostat having a relative humidity of 85%, the weight increase rate was measured after cooling to room temperature in a desiccator. -Dimensional stability: A disc having a diameter of 50 mm and a thickness of 3 mm was treated for 336 hours in a thermo-hygrostat at 85 ° C. and a relative humidity of 85%. ○
Indicates that the surface is smooth, and × indicates that there are irregularities. Moisture trapping property: Phosphorus pentoxide was placed in a cylindrical glass container having an open top, and the resin composition was preliminarily heated to 175 ° C. and 50φ ×
After molding to a size of 1 mm (thickness) and sealing the glass container with the above-mentioned molded product using an adhesive, the sealed glass container is placed in a thermo-hygrostat at 85 ° C and a relative humidity of 85%. 1
After standing for 00 hours and 300 hours, the weight increase rate of phosphorus pentoxide inside was measured. ○: 0.3% or less, ×: 0.3
Table 1 shows the evaluation results of not less than%.

Table 1 Example Comparative Example 1 2 3 1 2 3 4 Compounding (parts by weight) Biphenyl type epoxy resin 90 90 90 90 90 90 Cresol-runo-volak type epoxy resin 95 Brominated epoxy resin 8 8 8 8 8 8 8 Phenol novolac Resin 52 52 52 52 52 52 52 2-Methylimidazole 1 0.7 1 1 1 1 1, 1, 8-Diazabicycloundecene 1.2 Zeolite 100 150 50 200 400 Silica gel 100 120 80 200 400 Crushed fused silica 100 100 100 100 200 Spherical fused Silica 500 550 600 500 500 600 γ-glycidoxypropyltrimethoxysilane 6 6 6 6 6 6 6 antimony trioxide 8 8 8 8 8 8 8 Hoechst wax S 3 3 3 3 3 3 3 carbon black 2 2 2 2 2 2 2 Characteristics Sparal flow (cm) 100 60 95 90 90 120 0 Thermal expansion coefficient (× 10 ^-5 1 / ℃) 1.4 1.4 1.3 1.4 1.4 1.2 ∧ Molding shrinkage (%) 0.26 0.24 0.23 0.26 0.25 0.20 Moisture absorption (%) ) 0.80 1.23 0.56 0.60 0.59 0.32 Dimensions Qualitative ○ ○ ○ ○ ○ ○ non moisture trapping after 100 hours ○ ○ ○ ○ ○ × friendly after 300 hours ○ ○ ○ × × × ∨

[0014]

EFFECTS OF THE INVENTION By using the resin composition of the present invention, the dimensional stability is excellent and the intrusion of moisture from the outside can be prevented, and it is particularly suitable for windowed electronic parts such as solid-state image pickup devices.

Claims (4)

[Claims] An epoxy resin, a phenol resin curing agent,
A curing accelerator, an inorganic filler, zeolite, and silica gel are essential components, the structure of the zeolite is represented by the formula (1), the maximum particle size is 200 μm or less, and the content of the zeolite in the entire composition is 3 to 30. %, The maximum particle size of the silica gel is 200 μm or less, and the content of silica gel in the total composition is 3 to 30% by weight. _{xM 2 / n O · Al 2} O 3 · ySiO 2 · zH 2 O (1) ( where, x = 0.1~2.0, y = 1.0~200 ,
z = 0 to 100, M is an alkali metal or alkaline earth metal, and n is its valence. ) 2. A resin for encapsulating electronic parts, which contains 40% by weight or more of silica as an inorganic filler in the total composition, and the total amount of zeolite, silica gel and silica is 75 to 90% by weight of the total composition. Composition. 3. The resin composition for encapsulating electronic components according to claim 1, which has a molding shrinkage of 0.3% or less and a thermal expansion coefficient of 1.5 ×.
A resin composition for encapsulating electronic components, having a temperature of 10 ^-5 1 / ° C or less. 4. A resin composition for encapsulating electronic components, wherein the resin composition for encapsulating electronic components according to claim 1 has a moisture absorption rate of 85 ° C., relative humidity of 85%, and 0.4% by weight or more after 336 hours of treatment. Stuff.