JPS5943062B2 - Epoxy resin composition for encapsulating semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition for encapsulating a semiconductor device, and an object thereof is to provide a resin-encapsulated semiconductor device with excellent moisture resistance. be.

Recent semiconductor devices such as IC, LSI transistor,
Diodes and the like are produced using a resin encapsulation method, which is advantageous in terms of mass productivity and rationalization of the production process, and can yield products at low cost, compared to ceramic and can encapsulation types.

However, resin-sealed semiconductor devices are
The airtightness is slightly inferior to that of the can-sealed type, and in fact, the problem of poor moisture resistance has occurred in resin-sealed semiconductor products (TRS, IC, LSI, etc.). Therefore, in order to prevent such poor moisture resistance of resin-sealed semiconductor products, various improvements have been made here and there. Examples of these improvement methods include a method of undercoating the semiconductor element itself with an organic compound such as silicone resin or polyimide resin and then sealing it with resin, and Methods include removing ionic substances, adding additives that trap ionic substances, and adding metal oxides to reduce the moisture resistance and moisture absorption of the sealant itself. There is. In addition to this, various improvement methods have been considered and are being studied. The present inventors investigated ways to improve the moisture resistance of an epoxy resin composition as a sealing material in order to obtain a resin-sealed semiconductor product with good moisture resistance.

In addition to the methods described above, it is generally known to use a coupling agent as a means for improving the moisture resistance of the sealing material. Therefore, we conducted various studies on coupling agents, especially silane coupling agents. Then, various silane coupling agents were added to the epoxy resin composition, which has an epoxy resin, a curing agent, and a curing accelerator as essential components, and the moisture resistance of the cured products was investigated. transfer mold,
The product was also tested for moisture resistance. As a result, among silane coupling agents, epoxy resin compositions in which a silane coupling agent having an epoxy group and a silane coupling agent having a mercapto group are used together have a cured product with a moisture resistance that is lower than that of a silane coupling agent alone. It was found that the moisture resistance of MOS type 1C was significantly improved, although the moisture resistance of the cured product added in combination was almost the same as that of the cured product. A feature of the present invention is that in an epoxy resin composition for semiconductor device encapsulation comprising an epoxy resin having two or more oxirane rings in the molecule, a curing agent, and a curing accelerator, a silane coupling agent is used. Epoxysilane and mercaptosilane are used together in a ratio of 0.01 to 1 part of the latter to 1 part of the former, and the total amount is blended in a range of 0.1 to 5 parts to 100 parts of the epoxy resin.

If the blending amount of these epoxy silane and mercaptosilane coupling agents is less than 0.1 part by weight with respect to 100 parts by weight of the epoxy resin, the effect of improving moisture resistance will not be seen much. If it exceeds this, the glass transition point of the cured product will become low, which is not preferable.

Further, the optimum blending amount is preferably in the range of 0.5 to 3.0 parts by weight. The epoxy resin targeted by the present invention is
There are no particular limitations, and a wide variety of known epoxy compounds can be used.

For example, glycidyl ethers of phenols such as bisphenol A1 bisphenol F1 resorcinol, phenol novolak, and cresol novolak, glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol, phthalic acid, isophthalic acid, and tetrahydrophthalic acid. Glycidyl-type (including methylglycidyl-type) epoxy resins, such as glycidyl esters of carboxylic acids such as aniline and isocyanuric acid, in which the active hydrogen bonded to the nitrogen atom is replaced with a glycidyl group, Vinyl cyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate obtained by epoxidation with acid etc.
So-called alicyclic epoxides such as 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane and m-dioxane are used. Further, as the curing agent, a known curing agent for epoxy resins can be used. To name a few, for example, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, tetrachlorophthalic anhydride. Acids, so-called acid anhydrides such as endo dichloromethylenetetrachlorophthalic anhydride, tetrabromophthalic anhydride, trimellitic anhydride, cyclopentanetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride Curing agent, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, benzidine, dianisidine, phenylenediamine, methylenebis(0-chloroaniline), 3,3'-dicarboxylbenzidine, 3
, 3'-dicarboxyldiaminodiphenylmethane and other aromatic amines, phenol novolac, cresol novolac, condensates of phenol, cresol, etc. and paraxylylene dimethoxide, phenol, cresol, etc. and diphenyl ether, formaldehyde. There are so-called phenolic curing agents having polyhydric phenolic hydroxyl groups such as condensates with. Furthermore, isocyanates that react with epoxy resins to form oxatritone rings and harden, and also trimerize and polymerize themselves;
For example, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexane-1,6-diisocyanate, naphthalene diisocyanate, polymethylene polyphenylene polyisocyanate, and dimerized or trimerized products of the above isocyanates. There is. In addition, maleimides synthesized from amines such as diaminodiphenylmethane and polymethylene polyphenylene polyamine and maleic anhydride not only polymerize themselves, but also react with the amic acid remaining in the molecule with the epoxy resin. It hardens,
It can be used as a curing agent for epoxy resins. Furthermore, adducts of the above maleimides and polyamines can also be used as curing agents for epoxy resins. As the curing accelerator, all known ones useful for epoxy resins can be used. In particular, compounds with excellent latent properties include tetra-substituted phosphonium/tetra-substituted borate, tetra-substituted arsonium/tetra-substituted borate, tetra-substituted ammonium/tetra-substituted borate, borate compounds of various imidazole compounds, and reaction products of dimethylaminoethanol and anhydride. It is preferable to use In addition, various imidazole compounds and their derivatives are also effective. Furthermore, two or more of these curing accelerators may be used in combination. Further, it is preferable to mix an inorganic filler into the epoxy resin composition of the present invention in order to transfer mold semiconductor devices such as transistors, ICs, and LSIs. Examples of inorganic fillers include calcium carbonate, silica powder,
Zirconium silicate, calcium silicate, quartz glass powder, talc, clay, mica, glass fiber powder, etc. are useful, and two or more of these may be used in combination, if necessary. In addition, other additives such as a mold release agent, a coloring agent, a surface coupling agent, and a flame retardant aid may be added. In preparing the epoxy resin composition of the present invention into a molding material, each of the solid component materials is ground and thoroughly mixed in a desired ratio.

For mixing, conventional mixing machines such as mixing roll machines, kneaders, ribbon mixers, and ball mills can be used.
The obtained mixture can be directly applied to transfer molding. Below, the present invention will be described using examples and comparative examples.
This will be explained in detail.

Example 1 [Composition] Components (a) to (g) above were heated to 50 to 80°C.
Melt and knead on an inch mixing roll for 3 to 10 minutes,
Thereafter, it was cooled and pulverized to prepare an epoxy resin composition.

Comparative Examples 1 to 2 Epoxy resin compositions were prepared by changing the curing agent in Example 1 to phenol novolac resin (molecular weight approximately 800) and blending the silane coupling agent shown in Table 1 with this system.

Example 2 [Composition] Components (a) to (1) above were heated to 50 to 60°C.
An epoxy resin composition was prepared by melt-kneading for 5 to 10 minutes using an inch-inch mixing roll, then cooling and pulverizing.

Comparative Example 3 An epoxy resin composition containing the silane coupling agent of Example 2 in the amount shown in Table 2 was prepared.

For each sample of Examples 1 and 2 and Comparative Examples 1 to 3, the moisture resistance of the cured product, the glass transition point, and the moisture resistance of the MOSIC molded product were examined. The results are shown in Tables 1 and 2. The moisture resistance of the cured product was determined using a disk test piece with a thickness of 2 m, 71 L, and a diameter of 100 mm, which was transfer-molded under the conditions of a molding temperature of 170°C, a molding pressure of 50 kg/Cd, and a molding time of 3 to 5 minutes, and was cured at 1700C for 15 hours. After, 120
The sample was left in water vapor at 0C and 2 atmospheres for 100 hours, and the moisture absorption rate at that time was determined.

The glass transition point of the cured product is 10 m in diameter, 7 fL, and 100 m in length when transfer molded under the same molding conditions as above.
After post-curing at 170° C. for 5 hours using a round bar test piece of mm, measurement was performed using an apparatus according to ASTM-D696.

Comparative Example 4 An epoxy resin composition having the composition of Example 1 but not containing a silane coupling agent was prepared.

Then, a MOS type 1C was molded and its moisture resistance was examined. Next, the MOS type IC obtained in the above examples and comparative examples
The figure shows the moisture resistance of The moisture resistance and properties of the MOS type 1C were determined by transfer molding under the same molding conditions as described above.
After post-curing at 0°C for 5 hours, it was left in water vapor at 120°C and 2 atm, and the occurrence of moisture resistance defects was investigated. In the figure, curve A is Example 1, Sample 3, curve B is Comparative Example 2, Sample 10, curve C is Comparative Example 2, Sample 11, curve D is Comparative Example 4 (no coupling agent), curve E curve F shows the moisture resistance of the MOS type IC of Comparative Example 1 and Sample Taki 8. As detailed above, it can be seen that the combined use of mercaptosilane and epoxysilane as silane coupling agents significantly improves the moisture resistance of MOSIC.

Furthermore, the ratio of the combined use of mercaptosilane and epoxysilane is 1:1 of epoxysilane and 0.0:0 of mercaptosilane.
It can be seen that a range of 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin is best for the glass transition point and moisture resistance of the cured product.

[Brief explanation of the drawing]

The figure is a graph showing the moisture resistance of MOS type 1C.

Claims (1)

[Claims] 1. In an epoxy resin composition for encapsulating semiconductor devices comprising an epoxy resin having two or more oxirane rings in the molecule, a curing agent, and a curing accelerator, the former 1 contains epoxylan and mercaptosilane as a silane coupling agent. for the latter 0
．． An epoxy resin composition for encapsulating a semiconductor device, which is used in combination in the range of 0.01 to 1 and the total amount thereof is in the range of 0.1 to 5 parts by weight based on 100 parts by weight of the epoxy resin.