JPH02233715A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition consisting essentially of specific epoxy resin, phenol resin and inorganic filler, having higher heat resistance and plasticity and useful for semiconductor sealing. CONSTITUTION:The aimed composition obtained by blending (A) an epoxy resin containing 50-10wt.% (based on the total epoxy resin) random copolymer silicone-modified polyfunctional epoxy resin obtained by reacting a polyfunctional epoxy resin of random copolymer expressed by formula I (n is integer of 0-10; X is mixture of random copolymer existing at a ratio of formula II/formula III of <=1/2) organopolysiloxane with (B) a phenol resin (e.g. phenol novolak), (C) an inorganic filler (e.g. crystalline silica) and curing accelerator, mold releasing agent, etc., used as other components.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an epoxy resin composition for semiconductor encapsulation that has excellent soldering heat resistance and thermal shock resistance. [Conventional technology] Semiconductor-related technology has progressed in the direction of increasing packaging density in response to the recent trend toward lighter, thinner, and smaller devices. To this end, the degree of memory integration is increasing and the mounting method is moving from through-hole mounting to surface mounting. The following package is a traditional DrP
The type has changed to small and thin flat packages for surface mounting, SOP, and SOJSPLCC.
There are problems such as the occurrence of puff cage cranks due to stress and a decrease in moisture resistance due to these cranks.

In particular, when soldering leads in the surface mounting process, the package is subject to rapid temperature changes, and the problem of cracks occurring in the pan cage due to this has been attracting a lot of attention.

To solve these problems, thermoplastic oligomers were added to alleviate the thermal shock during soldering (Japanese Patent Laid-Open No. 62
-115849) and addition of various silicone compounds (JP-A-62-115850, 62-11665)
4, 62-128162) and silicone modification (Japanese Patent Application Laid-open No. 62-136860), but all of these techniques cause cranks to occur in the pan cage during soldering, which has resulted in poor reliability. However, it has not been possible to obtain an excellent epoxy resin composition for encapsulating semiconductors.

On the other hand, in order to obtain a heat-resistant epoxy resin composition with excellent solder stress resistance, the use of a polyfunctional epoxy resin as a resin system (Japanese Patent Application Laid-open No. 168620/1983) has been considered; The use of resin increases the crosslinking density and improves heat resistance, but the solder stress resistance is insufficient especially when exposed to high temperatures such as 200°C to 300°C, and the thermal shock resistance becomes hard and brittle. The quality was extremely unsatisfactory. In order to solve these problems, the present inventors have developed an epoxy resin composition in which a polyfunctional epoxy resin is blended with a random copolymerized silicone-modified epoxy resin, a random copolymerized silicone-modified phenol resin, and furthermore, the above-mentioned epoxy resin composition. We have already proposed an epoxy resin composition containing an additive type low-stress agent, and have found that these can significantly improve soldering heat resistance and thermal shock resistance.

However, as packages are becoming thinner and chips are becoming larger rapidly, the required properties for epoxy resin compositions for semiconductor encapsulation are becoming increasingly strict, and the requirements for soldering heat resistance and thermal shock resistance are becoming greater than ever. There is a growing demand for superior resins.

[Problem to be solved by the invention]

The purpose is to provide an epoxy resin composition for semiconductor encapsulation that has good soldering heat resistance and thermal shock resistance. [Means for Solving the Problems] The present inventors conducted intensive studies to obtain a well-balanced and excellent epoxy resin composition for semiconductor encapsulation, which could not be overcome using conventional techniques. A polyfunctional epoxy resin represented by the formula (]) which has the effect of improving soldering heat resistance and (n is an integer from O to 1O, and X in the chemical structural formula is (A) is 2, while (B) (a mixture of random copolymers in which a mixture of random copolymers is present in a proportion of 0 to 1).

Random copolymerized silicone-modified polyfunctional epoxy resin made by reacting with organopolysiloxane which has the effect of imparting toughness and low elasticity to the total epoxy resin
The present inventors have discovered that both solder heat resistance and thermal shock resistance are significantly improved by blending 100% to 100% by weight, and have completed the present invention.

The random copolymerized silicone-modified polyfunctional epoxy resin used in the present invention is an extremely important component that has the effect of improving both solder heat resistance and thermal shock resistance.

The organopolysiloxane used as a raw material for these random copolymerized silicone-modified multifunctional epoxy resins has functional groups such as alkoxy groups, hydroxyl groups, amino groups, and hydrosilyl groups, and the organopolysiloxane molecules The structure may be either linear or branched.

Formula (1) to be reacted with these organopolysiloxanes
The polyfunctional epoxy resin with the structure shown has three or more epoxy groups in one molecule, and has the function of improving soldering heat resistance. Further, X in the formula is preferably a random copolymer in which (A) is present in a ratio of 2 to (B) in a ratio of 0 to 1; in this case, when (A) is 2, (B) is When it is larger than 1, water absorption increases, thermal shock during solder immersion becomes large, and soldering heat resistance tends to deteriorate. Also 2
If the epoxy resin is less than functional, the crosslinking density will not increase, the heat resistance will be poor, and the effect of soldering heat resistance will not be obtained. Also, the value of n is 0
A range from 10 to 10 is preferred. In this case, the value of n is IO
If it is larger, fluidity tends to decrease and moldability tends to deteriorate.

The reaction method of the random copolymerized silicone-modified polyfunctional epoxy resin obtained using these raw materials is not particularly limited, but for example, the reaction method of the random copolymerized silicone-modified polyfunctional epoxy resin obtained using these raw materials is not particularly limited. Epoquine groups are directly reacted to form a random copolymer, or an alkenyl group-containing Epoquine resin obtained by reacting orthoallylphenol to a part of the evoquino group and organoporin loxane having two or more hydrosilyl groups are used. There are methods such as reacting to obtain a random copolymer. The random copolymerized soricone-modified multifunctional epoxy resin of the present invention is a product in which olkali polysiloxane and a multifunctional epoxy resin are randomly copolymerized, and the silicone domains are more uniformly dispersed than those obtained by simple Bronok copolymerization. It has excellent moldability, imprintability, heat resistance, and thermal shock resistance, and since the silicone domain part is composed of a copolymer of silicone and a multifunctional epoxy resin with good heat resistance, it is suitable for multifunctional epoxy resins. , when a silicone-modified epoxy resin whose silicone domain is composed of a copolymer of a normal epoxy resin and silicone, and a silicone-modified phenol resin whose silicone domain is composed of a copolymer of a phenol resin and silicone are blended. Soldering heat resistance is significantly improved compared to .

A silicone-modified polyfunctional epoxy resin may be mixed with a conventional epoxy resin, but in these mixed systems, it is necessary to blend the silicone-modified polyfunctional epoxy resin in an amount of 50% or more by weight based on the total amount of epoxy resin. be.

If the blending amount is less than 50% by weight, both solder heat resistance and thermal shock resistance will decrease, making it unsatisfactory.

The conventional epoxy resin referred to herein may be any resin having two or more epoxy groups in one molecule, such as bisphenol A type epoxy resin,
Examples include bisphenol F type epoxy resin, phenol novolank type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, and modified resins thereof, and these epoxy resins may be used singly or in combination of two or more types. You can also do it. Among these epoxy resins, Evoquine equivalent is 150~
250, a softening point of 60 to 130°C, and Na'
, CI, etc. are preferably contained as little as possible.

The phenolic resin used in the present invention functions as a curing agent. Examples of these phenolic resins include phenol novolak, cresol nopolanc, and modified resins thereof, and these may be used alone or in combination of two or more. The phenol resin used has a hydroxyl equivalent of 80 to 150
It is preferable that the softening point is 60 to 120°C and that the content of ionic impurities such as NaCl is as small as possible. Examples of the inorganic filler used in the present invention include crystalline silica, fused silica, alumina, calcium carbonate, Kuruk, Myriki, and glass fiber, and these may be used singly or in combination of two or more. Among these, crystalline silica or fused silica is particularly preferably used. In addition, as necessary components other than these, curing of tertiary amines such as BDMA, imidazoles, organic phosphorus compounds such as 1.8 diazabisic (5, 4, O) undense 7, triphenylphosphine, etc. Accelerators, mold release agents such as natural waxes and synthetic waxes, flame retardants such as hexabromobenzene, decaprom biphenyl ether, and antimony dioxide, colorants such as carpon branok and red iron, silane coupling agents, and other thermoplastic resins. It can be added and blended as appropriate. A general method for manufacturing the epoxy resin composition for semiconductor encapsulation of the present invention is to mix raw materials with a predetermined composition ratio sufficiently uniformly using a mixer, etc., and then melt-mix using a roll, a 21-glue, etc. This can be easily carried out by processing, cooling, solidifying, and pulverizing into an appropriate size.

4. Examples Example 1 Random copolymerized silicone-modified polyfunctional epoxy resin (a
) 90 parts by weight Brominated bisphenol A type epoxo resin lO parts by weight (epoxy equivalent 370, softening point 65°C, bromine content 3)
7%) Phenol novolac resin 50 parts by weight (OH
Fused silica 490 parts by weight Antimony trioxide 25 parts by weight Silane Canopling agent 2 parts by weight Carnauba wax 3 parts by weight Carbon black
Three parts by weight were thoroughly mixed at room temperature, further kneaded at 95 to 100°C, cooled, and then crushed to form tablets to obtain the epoxy resin composition for semiconductor encapsulation of the present invention.

This material was molded using transfer molding i (molding conditions: mold temperature 175°C, curing time 2 minutes), and the resulting molded product was post-cured at 175'C for 8 hours to improve thermal shock resistance and Solder heat resistance was evaluated. The results are shown in Table 1.

Example 2 In Example 1, 90 parts by weight of the random copolymerized silicone-modified polyfunctional epoxy resin (a) was changed to 60 parts by weight,
A resin composition for semiconductor encapsulation was obtained in the same manner as in Example 1 except that 30 parts by weight of a cresol novolac epoxy resin was further blended.

This material was molded using a transfer molding machine (molding conditions 2: mold temperature 175°C, curing time 2 minutes), and the resulting molded product was post-cured at 175°C for 8 hours to achieve thermal shock resistance and soldering heat resistance. was evaluated. The results are shown in Table 1. Examples 3 to 4 Epoxy resin compositions for semiconductor encapsulation having the compositions shown in Table 1 were obtained in the same manner. The evaluation results of this epoxy resin composition for semiconductor encapsulation are also shown in Table 1. Comparative Examples 1 to 4 Epoxy resin compositions for semiconductor encapsulation having the compositions shown in Table 1 were obtained in the same manner. The evaluation results of this epoxy resin composition for semiconductor encapsulation are also shown in Table 1. *1) Random copolymerized silicone-modified polyfunctional epoxy resin (aJ formula (It)
Tris(hydrocoxyalkylphenyl)methane triglycine compound (when n-2, m=0 is 6; when n=5, m=
Random copolymerized polyfunctional epoxy resin (mixed with compound 1 in a ratio of 4) and orthoallylphenol and organopolysiloxane represented by formula ([1)] are mixed into random copolymerized polyfunctional epoxy resin/ Random copolymerized silicone-modified polyfunctional epoxy resin made by reacting organopolysiloxane at a ratio of 100/20 (weight ratio)
Epoxy equivalent weight 260, softening point 75°C).

*2) Random copolymerized silicone-modified polyfunctional epoxy resin (b) Tris(hydroxyalkylphenyl)methantriglycidyl ether indicated by 2 (■) (when n = 2, m = 0
A random copolymerized polyfunctional epoxy resin with bisphenol A and an organopolysiloxane represented by the formula (IV). A random copolymerized silicone-modified polyfunctional epoxy resin (epoxy equivalent: 258, softening point: 72"C) made by reacting a random copolymerized polyfunctional epoxo resin/organopolysiloxane at a ratio of 100/20 (weight ratio). Polymerized silicone-modified polyfunctional epoxy resin (c) Random copolymerized polyfunctional epoxy resin of tris(hydroxyalkylphenyl)methantriglucidyl ether represented by formula (V) and orthoallylphenol and formula (II)
Random copolymerization of polyfunctional epoxy resin/organopolysiloxane with organopolysiloxane represented by I)
0/20 (weight ratio) random copolymerized silicone-modified polyfunctional epoxy resin (epoxy equivalent: 26
4. Softening point 80℃). 84) Random copolymerization silicone-modified polyfunctional epoxy resin (d) A random copolymerization polyfunctional epoxy resin of tris(hydroxyalkylphenyl)methantriglycidyl ether represented by formula (V) and bisphenol A and formula (rV) Randomly copolymerized polyfunctional epoxy resin/organopolysiloxane with the indicated organopolysiloxane 10072
Random copolymerized silicone-modified polyfunctional epoxy resin reacted at 0 (weight ratio) (epoxy equivalent: 262, softening point: 7)
9'C).

*5) Random copolymerized silicone-modified multifunctional epoxy resin (e) Epoxy resin represented by formula (Vr) and bisphenol A
A random copolymerized silicone-modified epoxy resin (random copolymerized epoxy resin/organopolysiloxane, which is made by reacting a random copolymerized epoxy resin with an organopolysiloxane indicated by 2 (■) in a 100/20 (weight ratio) Epoxy equivalent: 260, softening point: 75°C) However, m/n+m-0.05 *6) Tris(hydroxyalkylphenyl)methantriglucidyl ether represented by formula (V) *7) Phenol novolak resin (OH, itllO, Softening point 95℃)
and the organopolysiloxane represented by the formula (■), and the phenol novolac resin/organopolysiloxane in 1
Random copolymerized silicone-modified phenol resin reacted at 00/20 (weight ratio) (1127 per OH, softening point 9)
7℃) 8B) 20 molded products (chip size 36III1!) (post-curing 175℃8H) were subjected to a temperature cycle test (15℃).
0 to -65℃), and was subjected to 500 cycles of testing and determined by the number of molded products that developed cracks. The table shows the number of molded products with cranks out of 20 molded products. *9) Molded products (chip size 90m+++”) 20 pieces (
Post-cured 175'C8H) was subjected to temperature shock test (-19
6°C to +150'c), 500 cycles of testing were performed, and judgment was made based on the number of molded products in which cranking occurred. The table shows the number of molded products in which cranking occurred out of 20 molded products.

*10) 20 molded products (chip size 36+nn+”) (post-cured 175°C8H) were treated at 85°C under 85% steam for 72 hours, then immersed in a 260°C solder bath for 10 seconds, and moldings with cranks were removed. Judgment is based on the number of molded products. The table shows the number of molded products in which cranking occurred out of 16 molded products. *11) 20 molded products (chip size 90mm") (post-curing 175°C 8 hours) at 85°C 85 % water vapor for 72 hours, immersed in a 260°C solder bath for 10 seconds,
Determined by the number of molded products where cranking occurred. The table shows the number of molded products with cracks out of 16 molded products.

[Effects of the Invention] According to the present invention, it is possible to obtain an epoxy resin composition that has a high degree of heat resistance and plasticity that could not be obtained using conventional techniques, so it is possible to obtain an epoxy resin composition that has a high degree of heat resistance and plasticity that could not be obtained using conventional techniques. Due to its excellent crank resistance and thermal shock resistance when subjected to shock, it is used for sealing electronic and electrical components, coating insulation, etc., especially for highly integrated large chip ICs mounted on surface-mounted path cages. Suitable for products where authenticity is highly required.

Claims (1)

[Claims] (1), (A) A random copolymerized silicone-modified polyfunctional epoxy resin obtained by reacting a polyfunctional epoxy resin having a structure represented by the following formula (I) with an organopolysiloxane in an amount of 50 to 50% based on the total amount of epoxy resin. Epoxy resin containing 100% by weight▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) ) (n is an integer from 0 to 10, and X in chemical structural formula (I) is a mixture of random copolymers in which (B)/(A) is present in a ratio of 1/2 or less). (B) A phenolic resin (C) An epoxy resin composition containing an inorganic filler as an essential component.