JPS61197624A - Epoxy resin composition for sealing semiconductor device - Google Patents

Abstract

PURPOSE:The titled composition which can give a cured product good in balance among moisture, corrosion and cracking resistances, comprising an epoxy resin, a novolak epoxy resin, a novolak phenolic resin, a polyvinyl acetal compound and a liquid epoxy compound. CONSTITUTION:100-125pts.wt. epoxy resin having at least two epoxy groups in the molecule (e.g., bisphenol A diglycidyl ether), a softening point of 60-100 deg.C and an epoxy equivalent of 100-300 is mixed with 40-65pts.wt. novolak phenolic resin having a softening point of 60-120 deg.C and a hydroxyl equivalent of 100-150, 1-10pts.wt. polyvinyl acetal compound (e.g., polyvinyl formal resin) of a degree of acetalization of 35-85mol% and 1-10pts.wt. liquid epoxy compound having one epoxy group in the molecule (e.g., propylene oxide), and the obtained mixture is melt-kneaded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an epoxy resin composition for encapsulating a semiconductor device,
More specifically, the present invention relates to an epoxy resin composition for encapsulating semiconductor devices in which the obtained cured product has a good balance of temperature resistance, corrosion resistance, and crack resistance.

[Technical background of the invention and its problems] In recent years, with the miniaturization and thinning of electronic components and the increase in chip size, semiconductor device encapsulation that has high reliability and reduces stress on the chip has become necessary. The development of epoxy resin compositions for use is desired.

Conventionally, as this sealing resin, for example, a resin composition containing a phenol novolac resin as a curing agent has been used. However, when parts sealed using this composition are used, cracks occur in the sealing resin, cracks occur in the aluminum (All) wiring protective film, and 11 wiring layers are moved, resulting in electronic parts. This has had problems such as a decrease in reliability or the occurrence of defects.

As a solution to these problems, resin compositions using rubber or silicone as a compounding component have been proposed, but the resulting cured product must have a balance between sufficient reliability and crack resistance. A well-equipped resin composition has not yet been obtained, and together with the stress reduction technology described above,
In order to ensure high moisture resistance of the resulting encapsulating resin, it is also important to apply high-purity technology to lower the concentration of hydrolyzable chlorine in the epoxy resin composition for encapsulating semiconductor devices. ing.

[Object of the Invention] The object of the present invention is to solve the above-mentioned problems, and to provide an epoxy resin composition for encapsulating semiconductor devices in which the resulting cured product has good moisture resistance, corrosion resistance, and crack resistance in a well-balanced manner. The goal is to provide the following.

[Summary of the Invention] The epoxy resin composition for encapsulating a semiconductor device of the present invention comprises: (a) 100 to 125 parts by weight of an epoxy resin having at least two epoxy groups in one molecule; (b) 40 to 65 parts by weight of a novolac type phenol resin. Part by weight (c) 1 to 10 parts by weight of a polyvinyl acetal compound having an acetalization rate of 35 to 85 mol% (d) 1 to 10 parts by weight of a liquid epoxy compound having one epoxy group in one molecule It is characterized by containing.

The epoxy resin (a) according to the present invention may be any resin as long as it has at least two epoxy groups in one molecule, such as diglycidyl ether of bisphenol A, butadiene diepoxide, 3. 4-Epoxycyclohexylmethyl-(3,4-epoxy)cyclohexanecarboxylate, vinylcyclohexane dioxide, 4.4°-di(1,2-epoxyethyl)diphenyl ether, 4.4'-(1,2-epoxyethyl) ) biphenyl.

2.2-bis(3,4-epoxycyclohexyl)propane, glycidyl ether of resorcinol, diglycidyl ether of phloroglucin, diglycidyl ether of methylphloroglucin, bis-(2,3-epoxycyclopentyl)ether, 2-( 3,4-epoxy)cyclohexane-5,5-spiro (3,4-epoxy)
-Cyclohane-m-dioxane, bis-(3,4-
Akin-8-methylcyclohexyl) adipate,
N,N'-m-phenylenebis (4,5-epoxy-
Bifunctional epoxy compounds such as 1,2-'y cyclohexanedicarboximide, triglycidyl ether of paraamine phenol, polyallyl glycidyl ether,
1,3,5-tri(l,2-epoxyethyl)benzene, 2,2°,4.4°-tetraglycidoxybenzophenone, polyglycidyl ether of phenol formaldehyde novolac, triglycidyl ether of glycerin, trimethylolpropane An epoxy compound having three or more functionalities such as triglycidyl ether is used. The above compounds can also be used in combination of two or more types depending on the purpose. Specific examples of these epoxy resins include EOCN-1025 (Nippon Kayaku ■, softening point 74°C).
, epoxy amount 215), ECN-1273 (Ciba Geigy, softening point 73°C, epoxy equivalent 230), EPP
N-201 (Nippon Kayaku ■, softening point 65°C, epoxy equivalent 181), Epicoat 1001 (Shell Chemical, softening point 70°C, epoxy equivalent 475), Chissonox 201
(Chisso stock, viscosity 1800cps (25℃), epoxy equivalent 154), Chissonox 289 (Chisso ■, viscosity 8-0cps (25℃), epoxy ethyl 219)
can be mentioned. Among the above epoxy resins, the softening point is 80.
Those having a temperature of ~100°C are preferred.

Particularly preferred is one having a temperature of 70 to 85°C. Moreover, those having an epoxy equivalent of 100 to 300 are preferable, and those having an epoxy equivalent of 175 to 220 are particularly preferable.

The blending ratio of component (a) is usually 100 to 12
5 parts by weight, component (a) contains 100 parts of epoxy resin.
It is constructed by adding flame retardant epoxy resin in an amount of 0 to 25 parts by weight, based on the overlapped part. If the blending ratio of the flame-retardant epoxy resin exceeds 25 parts by weight, there is a risk that the moisture resistance and reliability of the sealing resin will be reduced.

Examples of the novolak type phenolic resin (b) according to the present invention include those having two or more phenolic hydroxyl groups, such as phenol novolak resin and cresol novolak resin. Among the novolac type phenolic resins, those having a softening point of 60 to 120°C are preferable, and those having a softening point of 80 to 100°C are particularly preferable. Furthermore, those having a hydroxyl equivalent of 100 to 150 are preferred, and those having a hydroxyl equivalent of 100 to 110 are particularly preferred.

The blending ratio of component (b) is usually 40 to 85 parts by weight, preferably 45 to 55 parts by weight. If the blending ratio is less than 40 parts by weight, the strength of the cured resin product will be weakened, which is undesirable. On the other hand, if it exceeds 65 parts by weight, the moisture resistance of the sealing resin will decrease, which is not preferred.

The polyvinyl acetal compound (c) according to the present invention may be any compound having an acetal group with an acetalization rate of 35 to 85 mol%, such as polyvinyl formal resin, polyvinyl acetoacetal,
Examples include polyvinyl propional resin, polyvinyl butyral resin, and polyvinyl hexylal resin. The acetalization rate (mol%) above refers to the number of moles of all seven
It is a value expressed in mol% of the ratio of the number of moles of a monomer having an acetal group when OO is used.

The blending ratio of this polyvinyl acetal compound is 1-10
It is preferably 2 to 8 parts by weight. If this blending ratio is less than 1 part by weight, it will be difficult to obtain sufficient thermal cycle element characteristics, and if it exceeds 10 parts by weight, moldability will deteriorate, especially mold releasability and mold staining. The type of polyvinyl acetal compound that is likely to cause problems such as oxidation can be selected in consideration of the compatibility of the liquid epoxy compound and the workability of the solution.

The liquid epoxy compound (d) having one epoxy group in one molecule according to the present invention is not particularly limited, but propylene oxide, epichlorohydrin, n-butyl glycidyl ether, octylene oxide, phenyl glycidyl ether, styrene oxide, allyl An example is glycidyl ether. These are selected in consideration of compatibility with the polyvinyl acetal compound. These components (d) may be used alone or in combination of two or more as appropriate.The blending amount of the liquid epoxy compound having one epoxy group in one molecule is as follows. 1~
The amount is 10 parts by weight, preferably 3 to 8 parts by weight.

If the blending ratio is less than 1 part by weight, it will be difficult to obtain sufficient thermal cycle element characteristics, and if it exceeds 10 parts by weight, there is a risk that the glass transition point and moldability will decrease.

The composition of the present invention may optionally contain a curing accelerator such as imidazole or a derivative thereof, a tertiary amine derivative, a phosphine derivative, a cycloamidine derivative; zircon, silica, fused silica glass, alumina, aluminum hydroxide. , glass, quartz glass, calcium silicate, gypsum, calcium carbonate, magnesite, clay, kaolin, talc, iron powder, copper powder, mica, asbestos, silicon carbide, boron nitride, molybdenum dioxide, lead compounds.

Fillers such as lead oxide, zinc white, titanium white, carbon black; mold release agents such as higher fatty acids and waxes; epoxy silane, vinyl silane, amino silane, poran compounds,
Coupling agents such as alkoxy titanate compounds and aluminum chelate compounds; known flame retardants containing antimony, phosphorus compounds, bromine and chlorine may be blended in appropriate amounts.

The composition of the present invention can be prepared by melt-mixing the above-mentioned components using a heating roll, melt-kneading using a kneader, melt-mixing using an extruder, mixing with a special mixer after pulverization, or an appropriate combination of these methods. It can be easily manufactured. However, during production, the polyvinyl acetal compound stands out on the surface of the molded product due to the compatibility of the resin system, resulting in poor appearance of the molded product. In addition, for the reason of improving the dispersibility of the polyvinyl acetal compound, the above (c) and (
d) It is preferable to dissolve and mix the components in advance and then blend the remaining components. Furthermore, sealing of a semiconductor device with the composition of the present invention can be carried out according to a conventional method.

[Effects of the Invention] According to the epoxy resin composition for semiconductor device enclosure of the present invention, the obtained cured product has good moisture resistance, corrosion resistance, and crack resistance in a well-balanced manner, and has excellent moldability. I also have it. Furthermore, the composition of the present invention does not have the appearance defects seen in materials imparted with crack resistance, and therefore has great industrial value as a semiconductor sealing material.

EXAMPLES Below, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

In addition, in Examples and Comparative Examples, all "1 part" indicates "part by weight."

[Examples of the invention] Example 1 Polyvinyl butyral resin (70 mol% of butyral groups)
3 parts of phenyl glycidyl ether were dissolved and blended in 5 parts of phenyl glycidyl ether. Then, to the above formulation, an ortho-cresol novolac type epoxy resin (softening point 71"C, epoxy equivalent weight 21B) was added.
100 parts, brominated phenol nopolac epoxy resin (bromine content 30%, softening point 87°C, epoxy equivalent 2
7G) 14 parts and 50 parts of phenol novolac resin (ortho conversion rate 25%, softening point 95°C, hydroxyl equivalent 104),
and triphenylphosphine as a curing accelerator 1.
5 parts, 1.2 parts of carna/hewax as a mold release agent and 1.8 parts of carbon powder, 4 parts of fused silica powder as a filler.
Part 05! 11 parts of antimony trioxide powder and 2.4 parts of a filler-resin coupling agent were blended as a refueling agent. The mixture thus obtained was heated at 70-110°C.
The mixture was kneaded with a two-wheeled roll, cooled and pulverized, and then tableted to prepare an epoxy resin composition for encapsulating a semiconductor device of the present invention. This obtained composition was heated at 175°C and 180°C.
Transfer molding was performed under conditions of 2 seconds to obtain a semiconductor element sealed product (chip size: 8 mm square).

The obtained semiconductor element encapsulated product was subjected to a thermal cycle test (~65~b), a bias application pressure puller test (applied voltage 1
8V, 2.5 atm). Defects in the characteristics of the semiconductor elements were checked by a thermal cycle test, and then the sealed elements were opened using fuming nitric acid, and the presence or absence of PSGS Thiclaf was observed. Furthermore, the appearance of the molded product was also observed.

The above test and observation results are shown in the table.

Example? Polyvinyl butyral resin (butyral group 63 mol%)
3 parts were dissolved and blended in 5 parts of n-butyl glycidyl ether. Thereafter, in the same manner as in Example 1, an epoxy resin composition for encapsulating a semiconductor device of the present invention was prepared.

A semiconductor element encapsulated product was prepared in the same manner as in Example 1 using the above-obtained composition, and the same tests, observations, and measurements as in Example 1 were carried out. The results are shown in the table.

Example 3 Polyvinyl butyral resin (butyral group 83 mol%)
2 parts were dissolved and blended in 5 parts of n-butyl glycidyl ether. Thereafter, in the same manner as in Example 1, an epoxy resin composition for encapsulating a semiconductor device of the present invention was prepared.

A semiconductor element encapsulated product was prepared in the same manner as in Example 1 using the above-obtained composition, and the same tests, observations, and measurements as in Example 1 were carried out. The results are shown in the table.

Example 4 Polyvinyl butyral resin (72 mol% of butyral groups)
2 parts were dissolved and blended in 5 parts of phenyl glycidyl ether. Thereafter, in the same manner as in Example 1, an epoxy resin composition for encapsulating a semiconductor device of the present invention was prepared.

A semiconductor element encapsulated product was prepared in the same manner as in Example 1 using the above-obtained composition, and the same tests, observations, and measurements as in Example 1 were carried out. The results are shown in the table.

Example 5 Polyvinyl formal resin (formal group 85 mol%)
3 parts dissolved in 7 parts of phenyl glycidyl ether,
Thereafter, in the same manner as in Example 1, an epoxy resin composition for encapsulating a semiconductor device of the present invention was prepared.

A semiconductor element encapsulated product was prepared in the same manner as in Example 1 using the obtained composition, and the same tests, observations, and measurements as in Example 1 were carried out. The results are shown in the table.

Comparative Example 1 A comparative composition was prepared in the same manner as in Example 1 except that 3 parts of fused silica powder was added in place of 3 parts of polyvinyl butyral resin in Example 1, and a semiconductor device was encapsulated from this composition. A product was prepared and subjected to the same evaluation test. The results are shown in the table.

Comparative Example 2 Example 1 A comparative composition was prepared in the same manner as in Example 1 by blending polyvinyl butyral resin with phenyl glycidyl ether without dissolving it, and a semiconductor device seal made from this composition was prepared. The finished product was subjected to the same evaluation test. The results are shown in the table.

Comparative Example 3 A comparative composition was prepared in the same manner as in Example 5 except that 7 parts of fused silica powder was added in place of 7 parts of phenyl glycidyl ether in Example 5, and a semiconductor was produced from this composition. The device-sealed product was subjected to similar evaluation tests.

Claims (1)

Scope of Claims: (a) 100 to 125 parts by weight of an epoxy resin having at least two epoxy groups in one molecule (b) 40 to 65 parts by weight of a novolac type phenol resin (c) Acetalization rate 35 to 85 mol% (d) 1 to 10 parts by weight of a polyvinyl acetal compound having an acetal group (d) 1 to 10 parts by weight of a liquid epoxy compound having one epoxy group per molecule; Resin composition.