JP2885289B2 - Epoxy resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition. More particularly, the present invention relates to a liquid epoxy resin composition particularly useful for sealing semiconductors.

2. Description of the Related Art In recent years, with the development of hybrid ICs and the like, a method of directly mounting a bare chip on a substrate has increased. It is well known that a liquid epoxy resin composition is used for sealing the bare chip. However, conventionally used liquid epoxy resin compositions are not satisfactory in quality and have various problems. Among them, a particular problem is that they have excellent heat resistance at the time of soldering and cannot sufficiently cope with moisture resistance and heat cycle resistance.

Generally, in order to improve the heat resistance during soldering, an epoxy resin having a high glass transition temperature is used, but in this case, the cross-linking density of the cured product becomes high, and it becomes hard and brittle. The internal stress also increases, causing a crack due to a rapid thermal change, and the disconnection of the wiring is likely to occur. For this reason, cracks are prevented by adding a substance which imparts flexibility, for example, a rubber-like resin such as acrylonitrile-butadiene rubber (CTBN) having a carboxyl group at a terminal, a silicone resin, or a urethane resin. However, in this case, chemical resistance and moisture resistance tend to deteriorate, which is not preferable.

Problems to be Solved by the Invention As described above, development of an epoxy resin composition for semiconductor encapsulation that is excellent in heat resistance during soldering, and excellent in moisture resistance and heat cycle resistance is desired.

Means for Solving the Problems We have conducted intensive studies to solve the problems described above, and as a result, have reached the present invention. That is, the present invention a) resorcinol diglycidyl ether resin and bisphenol A type epoxy resin b) 50 to 90% (weight ratio) of acid anhydride and the following general formula (1)
The phenol novolak resin having a content of at least 20% (weight ratio) and a sum of the components represented by the following general formula (2) of at least 35% (weight ratio) is 10 to 50% (weight). ratio) (In the formulas (1) and (2), R represents hydrogen or a methyl group.) C) An inorganic filler is provided. The present invention provides a liquid epoxy resin composition for semiconductor encapsulation.

In the present invention, a resorcinol diglycidyl ether resin and a bisphenol A type epoxy resin are used as the epoxy resin, and another epoxy resin which is liquid at 10 ° C. or more can be used in combination. A specific example is bisphenol F
Epoxy resin, phenyl glycidyl ether resin,
One or two or more epoxy resins such as tertiary butyl phenyl glycidyl ether resin can be used. Further, a phenol novolak resin or a cresol novolak resin which is solid at room temperature may be partially dissolved in these liquid epoxy resins and used. The liquid epoxy resin used in the present invention preferably has an epoxy equivalent of 120 to 250.

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

The curing agent used in the present invention is a mixture of an acid anhydride and a specific phenol novolak resin, and specific examples of the acid anhydride include hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, Methyl hymic anhydride and the like. The phenol novolak resin is different from a usual phenol novolak resin conventionally used as a curing agent for an epoxy resin, and is a binuclear compound represented by the general formula (1) (a so-called dinuclear structure containing two phenyl nuclei in one molecule). Is a mixture with a phenol novolak resin containing a large amount of a trinuclear compound represented by the general formula (2). A cured product of an epoxy resin using a phenol novolak resin used as the curing agent of the present invention is hard and brittle, whereas a cured product of an epoxy resin using a phenol novolak resin used in the present invention has flexibility. Is excellent. Incidentally, the phenol novolak resin which is usually used as a curing agent for epoxy resin has a binuclear content represented by the general formula (1):
It is at most 15% or less, and the sum with the trinuclear compound represented by the general formula (2) is 25% or less, and contains a large amount of a high molecular weight component equal to or more than the trinuclear compound.

The phenol novolak 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 represented by the general formulas (1) and (2). ) Are obtained having a content of 35 to 80%.

The compounding ratio of the acid anhydride and the phenol novolak 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.

If the amount of acid anhydride used is more than 90% (weight ratio), cracks in the heat cycle will increase and 50%
If the ratio is less than (weight ratio), the viscosity of the epoxy resin composition becomes too high and the heat resistance is lowered, which is not preferable.

The amount of the curing agent used in the present invention is preferably 0.7 to 1.1 mol, and more preferably 0.8 to 0.95 mol, per mol of the 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 excellent in moisture resistance and crack resistance.

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

The epoxy resin composition of the present invention is usually cured using an accelerator. As the accelerator which can be used, an accelerator which is usually used for curing an epoxy resin can be used. Examples thereof include trisdimethylaminomethylphenol, imidazoles, 1,8-diaza-bicyclo (5,4,0 )
Undecene-7 (DBU), triphenylphosphine, and the like can be used.
5 parts by weight are used. In the epoxy resin composition of the present invention, if necessary, a colorant, a flow regulator, a coupling agent and the like may be used in desired amounts.

The epoxy resin composition of the present invention can be easily produced by uniformly mixing the epoxy resin, the curing agent, the inorganic filler, and other additives as necessary with a vacuum kneader. The epoxy resin composition of the present invention is usually cured at 80 to 190 ° C. for 20 minutes to 8 hours.

Examples Hereinafter, the present invention will be described in more detail with reference to Examples.

Reference Example 1. Bisphenol A type epoxy resin (Nippon Kayaku Co., Ltd .; 25
The viscosity of 12000 cps at 100 ° C., epoxy equivalent 180) 100 g, methylhexahydrophthalic anhydride (Ricacid MH-700, manufactured by Shin Nippon Rika Co., Ltd.) 33 g, and the content of the compound represented by the general formula (1) (R = H) are as follows: 33 g of a phenol novolak resin (manufactured by Nippon Kayaku Co., Ltd .; softening point, semi-solid at room temperature) containing 50.5% by weight and a total of 77% by weight of a component represented by the general formula (2) (R = H), and added at 60 ° C. The mixture was cooled to room temperature, and then cooled to room temperature. Then, 2,4-diamino-6 [2'-undecylimidazole (1)]-ethyl-s-triazine (2 g), silica powder (Hughex RD-8, Made by Tatsumori; average particle size 25μ) 310g, and carbon black 0.
1 g of γ-glycidoxypropyltrimethoxysilane was added as a 2 g coupling agent and uniformly mixed by a vacuum kneader to obtain 479.2 g of a liquid epoxy resin composition of the present invention.

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

Reference Example 2. Bisphenol A epoxy resin used in Reference Example 1.
95 g of bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co .; viscosity 4100 cps at 25 ° C., epoxy equivalent 170) instead of 100 g
Is replaced with 2,2-diamino-6 [2′-undecylimidazole (1) ′]-ethyl-s-triazine in place of 2 g.
4-diamino-6 ｛2'-methylimidazolyl-
(1) 475.2 g of a liquid epoxy resin composition of the present invention was obtained in the same manner as in Reference Example 1 except that 3 g of '｝ -ethyl-s-triazine / isocyanuric acid adduct was used. 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. Bisphenol A type epoxy resin used in Reference Example 1
Bisphenol A used in Reference Example 1 instead of 100 g
Using 30 g of a type epoxy resin, 47 g of a resorcinol diglycidyl ether resin (manufactured by Nippon Kayaku Co., Ltd., viscosity: 410 cps at 25 ° C., epoxy equivalent: 121), and 2,4-diamino-6 [2′-
Instead of 2 g of undecylimidazole (1) ']-ethyl-s-triazine, 3 g of 2,4-diamino-6−2'-methylimidazolyl- (1)'｝ ethyl-s-triazine isocyanuric acid adduct was used. Except for using the same procedure as in Reference Example 1, 467.2 g of a liquid epoxy resin composition of the present invention 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.

Reference Example 4. The compound represented by the above general formula (1) (R = H) instead of 33 g of the phenol novolak resin used in Reference Example 1.
Is 22% by weight, and the component represented by the general formula (2) (R
= H) and the liquid epoxy resin composition of the present invention in the same manner as in Reference Example 1 except that 33 g of a phenol novolak resin (manufactured by Nippon Kayaku Co., Ltd .; softening point, 72 ° C., 33 g) having a sum of 38% by weight was used. 479.2 g of the product were 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 5. Bisphenol A type epoxy resin used in Reference Example 1
Reference Example 1 except that 22.5 g, 52.5 g of resorcinol diglycidyl ether resin used in Example 3, 62.2 g of methylhexahydrophthalic anhydride used in Reference Example 1, and 27 g of phenol novolak resin used in Reference Example 1 were used. In the same manner as in the above, 478.0 g of the liquid epoxy resin composition of the present invention 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.

Reference Example 6. Methyl hexahydrophthalic anhydride used in Reference Example 1
A liquid epoxy resin composition 48 was prepared in the same manner as in Reference Example 1 except that 35.6 g of methylhymic anhydride was used instead of 33 g.
1.8 g were 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 7. Methyl hexahydrophthalic anhydride 6 used in Reference Example 5
477.8 g of a liquid epoxy resin composition was obtained in the same manner as in Example 5 except that 62 g of methyltetrahydrophthalic anhydride was used instead of 2.2 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.

Comparative Example 1. Methyl hexahydrophthalic anhydride 33 used in Reference Example 1
496.2 g of a liquid epoxy resin composition was obtained in the same manner as in Reference Example 1 except that 83 g of methylhexahydrophthalic anhydride was used instead of g and 33 g of the phenol novolak resin.

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.

The humidity test and the heat cycle test were performed under the following conditions.

Moisture resistance test A silicon chip printed and printed with an aluminum wiring width of 4μ, a thickness of 0.3μ, and a wiring interval of 4μ was mounted on an alumina ceramic substrate, and this was mounted on a test substrate wire-bonded with a 25μφ gold wire using a dispenser. After dropping the epoxy resin of the invention and curing it at 160 ° C. for 3 hours, a PCT (pressure cooker test) was performed under the conditions of a temperature of 120 ° C. and a humidity of 85%.

Heat cycle test A test piece similar to the moisture test was used, sealed and cured in the same manner as in the humidity test, and then subjected to a heat cycle test at a temperature range of -40 to 85 ° C to check the breaking of the gold wire due to cracks.

Effect of the Invention It is possible to provide a liquid epoxy resin composition having excellent heat resistance, humidity resistance and heat cycle resistance, and the reliability of electric and electronic parts is improved by using this liquid epoxy resin composition.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiko Uemura 2-333-8, 3-409 Harayama, Urawa City, Saitama Prefecture (56) References JP-A-60-190418 (JP, A) JP-A 48-48 55241 (JP, A) JP-A-58-47051 (JP, A) JP-A-63-83035 (JP, A)

Claims (1)

(57) [Claims] (1) a) a resorcinol diglycidyl ether resin and a bisphenol A type epoxy resin; (b) an acid anhydride of 50 to 90% (weight ratio);
The phenol novolak resin having a content of at least 20% (weight ratio) and a sum of the components represented by the following general formula (2) of at least 35% (weight ratio) is 10 to 50% (weight). ratio) (Wherein R represents hydrogen or a methyl group in the formulas (1) and (2)) c) a liquid epoxy resin composition for semiconductor encapsulation comprising an inorganic filler