JPH0324115A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain a semiconductor sealing epoxy resin composition excellent in soldering-heat resistance, humidity resistance and heat cycling resistance by mixing an epoxy resin, a specified phenol novolac resin curing agent and an inorganic filler. CONSTITUTION:A liquid epoxy resin composition useful for semiconductor sealing is obtained by mixing an epoxy resin (desirably one which is liquid at 10 deg.C or higher and has an epoxy equivalent of 120-250, e.g. bisphenol A epoxy resin) with a curing agent comprising 50-90wt.% acid anhydride (e.g. methylhexahydrophthalic anhydride) and 10-50wt.% phenol novolac resin (containing at least 35wt.% total of at least 20wt.% binuclear phenol of formula I and trinuclear phenol of formula II) and an inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to resin compositions. More specifically, the present invention relates to a liquid epoxy resin composition particularly useful for encapsulating semiconductors.

2. Description of the Related Art In recent years, with the development of hybrid ICs and the like, the number of systems in which paired chips are directly mounted on a substrate has increased.

It is well known that a liquid epoxy resin composition is used to seal this bare chip.

However, the liquid epoxy resin compositions conventionally used are not satisfactory in terms of quality and have various problems. Among these, a particular problem is that it has excellent heat resistance during soldering processing and does not have sufficient moisture resistance and heat cycle resistance.

Generally, epoxy resins with a high glass transition temperature are used to improve the heat resistance during soldering, but in this case, the crosslinking density of the cured product increases, making it hard and brittle. Internal stress is also large or sudden 1.
Due to thermal changes, knocking occurs and the wiring is likely to break.

, a substance that imparts flexibility for example acrylonitrinolebutadiene rubber (which has a carboxyl group at the end)
The occurrence of cracks can be prevented by adding rubber-like resins such as CTBN), silicone resin, and UVP resin. However, in this case, the chemical resistance and moisture resistance tend to deteriorate, so it is preferable that the color be red.

Problems to be Solved by the Invention As mentioned above, there is a desire to develop an epoxy resin composition for semiconductor encapsulation that has excellent heat resistance during soldering, moisture resistance, and heat cycle resistance.

Means for Solving the Problems We have arrived at the present invention as a result of extensive research into solving the above-mentioned problems. That is, the present invention is characterized in that the content of a) an epoxy resin b) an acid anhydride of 50 to 90% (weight ratio) and a component represented by the following general formula (1) is 20% or more (weight ratio), and 10 to 50% (weight ratio) of a phenol novolac resin whose sum with the components represented by the following general formula (2) is 35% or more (weight ratio) (In formulas (1) and (2), R is hydrogen or An epoxy resin silk composition is provided, characterized in that the curing agent is C) an inorganic noiler.

The epoxy resin used in the present invention is preferably an epoxy resin that is liquid at a temperature of 10° C. or higher.Specific examples include bisphenol A epoxy resin, bisphenol F epoxy resin, resorcinol diglycidyl ether resin, and lucidyl ether resin,
Examples include epoxy resins comprising one or more types of butyl phenyl glycidyl ether resins. Further, a fluor novolac resin or a cresol novolak resin, which is solid at room temperature, may be partially dissolved in these liquid epoxy resins and used. The epoxy resin used in the present invention has an epoxy equivalent of 120 to 25.
0 is preferred.

Next, the curing agent used in the present invention will be explained.

The curing agent used in the present invention is a mixture of an acid anhydride and a specific phenol novolac resin, and specific examples of acid anhydrides include hexahydrophthalic anhydride, methyl hexahydro-phthalic anhydride, and methyl tel-a-hydro. Examples include phthalic anhydride and methyl hymic anhydride. In addition, unlike ordinary phenol novolak resins, which are conventionally used as curing agents for epoxy resins, phenol novolac resins are dinuclear bodies (two 7-enyl nuclei in one molecule) represented by the general formula (1). (so-called dinuclear body containing), general formula (2
) It is a mixture with a phenol novolak resin containing a large amount of trinuclear bodies shown in (). While the cured products of epoxy resins using other phenol novolac resins as curing agents are hard and brittle, the cured products of epoxy resins using the phenol novolak resin used in the present invention are Excellent flexibility.

By the way, in the phenol novolac resin that is usually used as a curing agent for epoxy resin, the content of the dinuclear substance represented by the general formula (1) is at most 15% or less, and the content of the dinuclear substance represented by the general formula (2) is at most 15% or less. The sum of the trinuclear bodies represented by is 25% or less, and it contains a large amount of high molecular weight components of trinuclear bodies or more.

The phenol novolac resin used in the present invention can be produced by reacting excess phenol and formalin in the presence of an acid catalyst and then recovering unreacted phenol, and is produced by formula (1) and ( A product having a total content of 35 to 80% of the components shown in 2) is obtained.

The blending ratio of the acid anhydride and the phenol novolac resin used in the present invention is in the range of 50% to 90% (weight ratio) of the acid anhydride and 10 to 50% (weight ratio) of the phenol novolak resin.

When the amount of acid anhydride used is more than 90% (weight ratio), cracks often occur during heat cycles.
% (weight ratio) or less, the viscosity of the epoxy resin composition becomes too high and the heat resistance decreases, which is undesirable.

The amount of the curing agent of the present invention used was epoxy resin.The cured product of the epoxy resin using the curing agent of the present invention exhibited excellent heat resistance during soldering, and was also excellent in moisture resistance and crack resistance.

Next, specific examples of the inorganic filler used in the present invention include silica, calcium carbonate, aluminum hydroxide, etc. The amount used is arbitrary, but usually 100% of the epoxy resin is used.
200 to 600 parts by weight, preferably 300 to 600 parts by weight
It is 500 parts by weight. The particle size of the inorganic filler used is not particularly limited, but it is usually preferable to use a particle size of 3 to 50 microns.

The epoxy resin compositions of the present invention are typically cured using accelerators. As the accelerator that can be used, those used for curing ordinary epoxy resins can be used, such as trisdimethylaminomethylphenol,
imidazoles, 1,8-diazapicyclo(5,4.
0) undecene-7 (DBU), }rifenylphosphine, etc., and the amount used is arbitrary, but is usually used in an amount of 0.05 to 5 parts by weight. Furthermore, the Q epoxy resin composition of the present invention may contain a desired amount of a coloring agent, a flow control agent, a coupling agent, etc., if necessary.

The epoxy resin composition of the present invention includes the above-mentioned epoxy resin,
It can be easily manufactured by uniformly mixing a curing agent, an inorganic filler, and other additives as necessary in a vacuum incubator.

The curing of the epoxy resin composition of the present invention is usually 80 to 190
Cure for 20 minutes to 8 hours.

Example The present invention will be explained in more detail with reference to Examples below.

Example 1. Bisphenol A type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.; 25
℃ viscosity 12000 cps, epoxy equivalent 1
80) 100 g. Methylhexahydrophthalic anhydride (Rikacid MH-700, manufactured by Shin Nihon Rika Co., Ltd.) 3
3 g. The compound represented by the general formula (1) (R=H
') content is 50.5% by weight, and the sum of the components represented by the general formula (2) (R=H) is 77% by weight (manufactured by Nippon Kayaku Co., Ltd.; softening point, room temperature Add 33 g of 2.4-diamino-6 [ 2'
-undecylimidazole (l)] monoethyl-S-triazine 2 g, silica powder (Fuse Rex rtD-8
, manufactured by Tatsumori Co., Ltd.; average particle size 25μ), and further added 0.2 g of carbon plaque as a coloring agent and γ-glycidoxypropyl trimethoxysilane Ig as a coupling agent, and mixed uniformly in a vacuum incubator. 479.2 g of a liquid epoxy resin composition of the present invention was obtained.

The viscosity, hardness, and durability test results of the obtained epoxy resin composition are shown in Table 1.

Example 2. Bisphenol A type epoxy resin used in Example 1
Instead of OOg, 95 g of bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., viscosity at 25°C 4100 cps, epoxy equivalent 170) was added to 2,4-diamino-6[2'-undecylimidazole (1)]-ethyl-S - The liquid of the present invention was prepared in the same manner as in Example 1, except that 2,4-diasomino 6 {2-methylimidazo also ru(1)} ethyl-S - triazine/isocyanuric acid adduct 3 g was used instead of 2 g of triazine. 475.2 g of an epoxy resin composition was obtained.

Table 1 shows the viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test.

Example 3. Bisfunol A type epoxy resin used in Example 1
In place of 00 g, 30 g of bisphenol A type epoxy resin used in Example 1, resorcinol diglycidyl ether resin (manufactured by Nippon Kayaku Co., Ltd.; viscosity at 25°C: 4
10CpS, epoxy equivalent 121) was used, and 2,4-diamino-6[2-undecylimidazole (
1') ]-ethyl-s-}U Instead of 2 g of azine, 2,4-diamino-6{2-methylimidazolyl(
l)}Ethyl-S-}Liquid epoxy resin composition of the present invention 4 in the same manner as in Example 1 except that 3 g of riazine-isocyanuric acid adduct was used. 2 g was obtained.

Table 1 shows the viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test.

Example 4. In place of 33 g of Fusnol novolac resin used in Example 1, a compound represented by the general formula (1) (R.=H
) is 22 weight 1-%, and the sum of the components represented by the general formula (2) (R=H) is 38 weight % (manufactured by Nippon Kayaku Co., Ltd.; softening point, 72°C, 33g
) 479.2 g of the liquid epoxy resin silk composition of the present invention was obtained in the same manner as in Example 1, except that 33 g of the liquid epoxy resin silk composition of the present invention was used.

The viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test are shown in Table 1.

Example 5. 22.5 g of bisphenol A type epoxy resin used in Example 1, 52.5 g of resorcinol diglycidyl ether resin used in Example 3, and 62.2 g of methylhexahydrophthalic anhydride used in Example 1. , 478.0 g of the liquid epoxy resin composition of the present invention was obtained in the same manner as in Example 1 except that 27 g of the phenol novolak resin used in Example 1 was used.

The viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test are shown in Table 1.

Example 6 Methylhexahydrophthalic anhydride 3 used in Example 1
481.8 g of a liquid epoxy resin composition was obtained in the same manner as in Example 1 except that 35.6 g of methyl hymic anhydride was used instead of 3 g.

Table 1 shows the viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test.

Example 7.

Methylhexahydrophthalic anhydride 62 used in Example 5
．． Methyltetrahydrophthalic anhydride 62 instead of 2g
A liquid epoxy resin composition was prepared in the same manner as in Example 5 except that g was used. 8 g was obtained.

Table 1 shows the viscosity of the obtained liquid epoxy resin composition, the physical properties of the cured product, and the results of the durability test.

Comparative example 1. Methyl hexahydride phthalic anhydride 33 used in Example 1
A liquid epoxy resin composition of 496.2 g was prepared in the same manner as in Example 1, except that 83 g of methylhexahydrophthalic anhydride was used instead of 33 g of the phenol novolak resin.
I got g.

The viscosity of the obtained liquid epoxy resin silk composition, the physical properties of the cured product, and the results of the durability test are shown in Table 1.

Note that the moisture resistance test and heat cycle resistance test were conducted under the following conditions.

Moisture resistance test: A silicon chip printed with an aluminum wiring width of 4μ, thickness of 03μ, and wiring spacing of 4μ is mounted on an alumina ceramic substrate, and a test board is wire-bonded with 25μl of gold wire using a dispenser. After trotting the epoxy resin of the invention and curing it at 160°C for 3 hours, PCT was applied at a temperature of 120°C and a humidity of 85%.
(pressure cooker test).

Heat cycle test After sealing and curing using the same test piece as in the humidity test, a potato cycle test was performed at a temperature range of -40 to 85°C to check for breakage of the gold wire due to cracks. .

Effects of the Invention It is possible to provide a liquid epoxy resin composition with excellent heat resistance, moisture resistance, and heat cycle resistance.Using this liquid epoxy resin composition improves the reliability of electrical and electronic parts. did.

Claims (1)

[Claims] 1. a) epoxy resin b) 50 to 90% (weight ratio) of acid anhydride and the following general formula (
The content of the component represented by 1) is 20% (weight ratio) or more, and the sum of the content of the component represented by the following general formula (2) is 35%
% (weight ratio) or more (weight ratio) Phenol novolak resin 10-50% (weight ratio) , (2) in which R represents hydrogen or a methyl group); c) an epoxy resin composition comprising an inorganic filler;