JPH0196241A - Epoxy resin composition for sealing semiconductor device - Google Patents

Abstract

PURPOSE:To provide a composition for the sealing of a semiconductor device and giving a cured product having excellent heat-shock resistance and moisture resistance by compounding an epoxy resin, a novolak phenolic resin, a polyether and preferably a phenolic aralkyl resin. CONSTITUTION:The objective epoxy resin composition for the sealing of a semiconductor device can be produced by compounding (A) 100pts.wt. of an epoxy resin preferably having a softening point of 60-100 deg.C and an epoxy equivalent of 100-300, (B) (B1) 40-65pts.wt. of a novolak phenolic resin preferably having a softening point of 60-120 deg.C and a hydroxyl equivalent of 100-150 and preferably (B2) 20-40pts.wt. of a phenolic aralkyl resin (the sum of B1 and B2 being 50-90pts.wt.) and (C) 1-40pts.wt. of a polyether [preferably poly(2,6-dimethylphenylene-1,4-ether)] containing the recurring unit of formula (Ar is bivalent aromatic group) and having a number-average mol.wt. of 1,000-10,000.

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 that provides a cured product having excellent thermal shock resistance and moisture resistance.

[Technical background of the invention and its problems] In recent years, in the field of encapsulation of semiconductor devices, with the increasing integration of semiconductor devices, various functional units on the device have become smaller and the device pellet itself has become larger. It's progressing rapidly.

Due to these changes in element pellets, conventional sealing resins are no longer able to satisfy requirements such as thermal shock resistance. Epoxy resin compositions cured with phenol novolac resins, which have been conventionally used as sealing resins for semiconductor devices, have excellent hygroscopicity, high-temperature electrical properties, moldability, etc., and have become the mainstream resin for molding.

However, when this type of resin composition is used to seal a large device pellet with a fine surface structure, phosphosilicate glass, which is a coating material to protect the aluminum (All) pattern on the surface of the device pellet, is sealed. PSG) film or silicon nitride (SiN) film, or the element pellet may be cracked. In particular, when a thermal cycle test is carried out, this tendency is very large, resulting in defects in element characteristics due to pellet cracks and defects due to corrosion of the Al pattern due to cracks in the protective film.

As a countermeasure, it is necessary to reduce the stress on the internal encapsulation of the sealing resin, and to reduce the stress on the sealing resin and the PSG film or S f film on the element.
It is necessary to increase the adhesion with the glass film such as NII. Furthermore, in order to prevent corrosion of the Al pattern on the element surface as much as possible, the cured product must contain a low concentration of hydrolyzable halogen compounds, especially chlorine, and maintain a high level of electrical insulation performance during moisture absorption and high temperatures. There is a need.

[Object of the Invention] An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an epoxy resin composition for encapsulating a semiconductor device that provides a cured product having excellent thermal shock resistance and moisture resistance.

[Summary of the Invention] The epoxy resin composition for encapsulating a semiconductor device of the present invention includes: (1) (a) 100 parts by weight of epoxy resin (b) 40 to 65 parts by weight of novolac type phenol resin (c) Formula: ■Ar- O■ ...[Contains 1 to 40 parts by weight of polyether having a repeating unit represented by Al (in the formula, Ar represents a divalent aromatic group) and having a number average molecular weight of 1000 to 1oooo Features.

Epoxy resin (a) which is one component in the composition according to the present invention
) are, for example, bisphenol A epoxy resins, novolac epoxy resins, alicyclic epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, etc. Examples include epoxy resins having two or more epoxy groups in one molecule, such as epoxy resins and halogenated epoxy resins. These epoxy resins may be used alone or in a mixed system of two or more.

Among the above epoxy resins, those having a softening point of 60 to 100°C are preferred, and those having a softening point of 70 to 85°C are particularly preferred. In addition, the epoxy equivalent is 100 to 300
is preferable, particularly preferably 175 to 22
0.

This CB,) component preferably contains epoxy resin 10
It is constructed by adding up to 30% by weight of a flame-retardant epoxy resin to 0 parts by weight.

The novolac type phenolic resin (b) according to the present invention is (a
) It acts as a curing agent for the epoxy resin component, and examples include those having 2 (1 g or more) phenolic hydroxyl groups such as phenol novolac resin and cresol novolak resin. Among the novolac type phenolic resins, softening point Those having a temperature of 60 to 120°C are preferable, particularly preferably those having a temperature of 80 to 100°C, and those having a hydroxyl equivalent of 100 to 150 are preferable, and those having a hydroxyl equivalent of 100 to 110 are particularly preferable.

If the blending ratio of component (b) is less than 40 parts by weight, sufficient hardness of the molded article will not be obtained, and if it exceeds 65 parts by weight, sufficient moisture resistance will not be obtained. Preferably, it is 45 to 55 parts by weight.

In the present invention, it is preferable that a phenol aralkyl resin (b') is further blended to improve moisture resistance and thermal shock resistance against PSG cracks and aluminum slides.

This phenol aralkyl resin (b') is a resin obtained by reacting an aralkyl ether with phenol using a free-sol fluorine catalyst, and is also called a free-sol fluorine resin. A condensation polymer compound of α, α゛-dimethoxy p-xylene and phenol is well known (Plastics 3
4, No. 2, p. 85), specifically XL-225 (Mitsui Toatsu Chemical Co., Ltd., softening point: 85-105°C), XYLOK
-225 (Albright Andilson ■, Softening point:
85°C to 105°C). Among these phenol aralkyl resins, those having a softening point of 80°C to 120°C are preferred, particularly preferably 85°C to 105°C.
℃, and preferably has a hydroxyl equivalent of 195 to 235.

If the blending ratio of component (b') is less than 10 parts by weight, it is difficult to obtain sufficient thermal shock resistance, and if it exceeds 50 parts by weight, the viscosity increases and moldability deteriorates. Preferably it is 20 to 40 parts by weight. The blending ratio of component (b) and component (b') is such that the total amount of component (b) and (b') is 10% of component (a).
It is preferable to add in an amount of 50 to 90 parts by weight relative to 0 parts by weight. If the total blending ratio is less than 50 parts by weight, the strength of the cured resin product will be weakened, and if it exceeds 90 parts by weight, the moisture resistance of the sealing resin will decrease.

The polyether (e) used in the present invention is a polymer represented by the above-mentioned formula [A]. If the number average molecular weight of this polymer is less than 100, sufficient thermal shock resistance cannot be obtained,
When it exceeds 10,000, peeling from the epoxy resin tends to occur and moisture resistance decreases. Preferably 2000-80
It is 00. Furthermore, one end of this polymer is a hydroxyl group, but the other end may be a hydrogen atom, a hydroxyl group, or another group.As a specific example of this polyphenylene ether, poly(2,6-silane Methylphenylene-1
．． 4-ether), poly(2-methyl-6-ethylphenylene-1,4-ether), poly(2,6-diethylphenylene-1,4-ether), poly(2,6-cyclophenylene ether) ), poly(2-chloro-6-methylphenylene-1,4-ether), poly(2,6-
phenylphenylene-1,4-ether), poly(2-
Methyl-6-n-propylphenylene-1,4-ether) and poly(phenylene-1,3-ether). Among these, poly(2,6-dimethylphenylene-1,4-ether) is preferred, and these may be used alone or in a mixed system of two or more. In addition, the component (c) is usually one having a sieve r3 diameter of 2oou or less in view of its compatibility with the resin, which is another component.

Preferably it is 1007 m or less.

If the blending ratio of component (c) is less than 1 part by weight, sufficient thermal shock resistance cannot be obtained, and if it exceeds 40 parts by weight, the viscosity will increase significantly and the properties will deteriorate. Preferably 3-30
Parts by weight.

The composition of the present invention may optionally contain a curing accelerator such as imidazole or a derivative thereof, a tertiary amine conductor, 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, lead oxides,
Fillers such as zinc white, titanium white, and carbon black; Mold release agents such as high-grade fats and waxes; Epoxy silane,
Coupling agents such as vinylsilane, aminosilane, poran compounds, alkoxytitanate compounds, and aluminum chelate compounds; known flame retardants containing antimony, phosphorus compounds, bromine, and chlorine may also be blended. Furthermore, various improvers such as silicone oil may be added for the purpose of improving thermal shock resistance and the like.

The epoxy resin composition for encapsulating semiconductor devices of the present invention exhibits excellent effects when applied to, for example, encapsulating integrated circuits, large-scale integrated circuits, transistors, thyristors, and diodes.

Next, a method for producing the epoxy resin composition for encapsulating a semiconductor device of the present invention will be described.

The composition of the present invention can be easily produced by melt mixing the above-mentioned components using a heating roll, melt mixing using a Nigu, melt mixing using an extruder, mixing using a special mixer after pulverization, or an appropriate combination of these methods. can be manufactured. In addition, the method for blending polyphenylene ether (c) is either a method in which it is homogeneously dissolved in part or all of the epoxy resin (5L), or a method in which the component (c) is pulverized and added. Good too.

Note that a resin-sealed semiconductor device encapsulated using the composition of the present invention can be easily manufactured using a commonly used method. The most common method for this sealing is low-pressure transfer molding, but sealing by injection molding, compression molding, casting, etc. is also possible. The epoxy resin composition is cured by heating during sealing, and a resin-sealed semiconductor device can finally be obtained by encapsulating the cured product of this composition. When curing, 150
It is desirable to heat it to a temperature above ℃.

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] 1-7 1-2 As epoxy resins, octocresol novolac type epoxy resin (softening point 71°C, epoxy equivalent 210), and brominated phenol novolac epoxy resin (bromine content 30%, softening point 87°C) , epoxy equivalent 1280), phenol novolac resin (softening point 90°C, hydroxyl equivalent 104) as a novolak type phenolic resin, XL-225 (Mitsui Toatsu Chemical ■,
softening point 90°C, hydroxyl equivalent 19B), 200-pass poly[2,6-dimethylphenylene-1,4-ether] (a average molecular weight 15000) and 105-pass poly[2,6-ether] as polyethers. -dimethylphenylene-1,4-ether] (number average molecular weight: 5,000), and 105-pass poly [2,6-dimethylphenylene-1,4-ether] (number average molecular weight: 5,000)
, further contains triphenylphosphine as a curing accelerator, carnauba wax as a mold release agent, carbon powder as a coloring agent, fused silica powder as a filler, antimony trioxide powder as a flame retardant aid, and a coupling agent between the filler and the resin. The compositions shown in Table 1 were blended using the following ingredients, and the mixture was kneaded with a twin-screw roll at 70-100°C.

The mixture was cooled and crushed and tableted to obtain an epoxy resin composition for encapsulating a semiconductor device of the present invention and a comparative composition.

Using the obtained composition, a low pressure transfer molding machine (
A large pellet evaluation sample element (8 mm) with a PSG film on the surface was
X 8 +w+s) was sealed. In addition, sealing was performed using an element of the same pellet size with an An wiring layer exposed on the surface without a passivation film.

The following tests were conducted to evaluate the thermal shock resistance and moisture resistance of the obtained sample element. The results are shown in the table.

Thermal shock resistance test: Samples were subjected to cooling and heating cycles from -65°C to 150°C, and property defects were measured. After the measurement, the element having the P2O layer and the hybridization line layer element molded product on the surface were melted off using fuming nitric acid, and the presence or absence of cracks in the PSG film and the A9. The amount of movement was observed using a microscope.

Humidity deterioration test: A9. 2 sealed products for wiring corrosion measurement elements
．． It was exposed to saturated steam at 5 atm for each test period, and pass/fail was judged based on disconnection due to Al corrosion.

In addition, as other structural characteristics, tests were conducted on volume resistivity, glass transition point, and flexural modulus.

Volume resistivity: 175℃ according to JIS K-6911
After 3 minutes of transfer molding, after-cure (1
The test was carried out using a sample treated at 75°C for 8 hours. The measurement conditions were DC500V applied, 1 minute value and measurement temperature 150V.
The value of volume resistivity in °C is shown.

Glass transition point: A 5ma+X2Os+s square prism was cut out from a sample that had been subjected to the same molding and processing as described above, and the glass transition point was measured at a temperature increase of 5 using a thermal dilatometer.

Flexural modulus: Performed according to JIS K-6911 using the same molded and treated samples described above.

[Effects of the Invention] As detailed above, the epoxy resin composition for encapsulating semiconductor devices of the present invention provides a cured product having excellent thermal shock resistance and moisture resistance, so its industrial value is extremely large. .

Claims (2)

[Claims] (1) (a) 100 parts by weight of epoxy resin (b) 40 to 65 parts by weight of novolac type phenolic resin (c) Formula: ■Ar-O■ (In the formula, Ar represents a divalent aromatic group) and a number average molecular weight of 10
An epoxy resin composition for encapsulating a semiconductor device, characterized in that it comprises 1 to 40 parts by weight of a polyether having a molecular weight of 0.00 to 10,000. (2) The epoxy resin composition for encapsulating a semiconductor device according to claim 1, further comprising a phenol aralkyl resin.