JPS6272714A - Epoxy resin composition for sealing semiconductor device - Google Patents

Abstract

PURPOSE:The titled composition providing a cured material having improved thermal shock resistance, comprising an epoxy resin, a novolak phenolic resin, a phenol aralkyl resin and a dihydroxy-terminated polyester having a specific molecular weight in a specific ratio. CONSTITUTION:The aimed composition comprising (A) 100pts.wt. epoxy resin (e.g., preferably having at least two epoxy groups in one molecule such as bisphenol A type epoxy resin, etc., having 70-85 deg.C softening point, preferably having 175-200 epoxy equivalent), (B) 10-50pts.wt. novolak type phenolic resin (preferably having 80-100 deg.C softening point and 100-110 hydroxyl group equivalent), (C) 10-50pts.wt. phenolic aralkyl resin (resin having preferably 85-105 deg.C softening point and 195-235 hydroxyl group obtained by reacting aralkyl ether with phenol in the presence of Friedel-Crafts catalyst) in the total amounts of the components B+C of 50-90pts.wt. and (D) 2-40pts.wt. dihydroxy-terminated polyester having 2,500-50,000 number-average molecular weight.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an epoxy resin composition for encapsulating semiconductor devices,
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.

[Technical background of the invention and its problems]

In recent years, in the field of encapsulation of semiconductor devices, as semiconductor elements have become highly integrated, various functional units on the elements have become finer and the element pellets themselves have become larger.

Due to these changes in the element pellets, the conventional sealing +h resins are no longer able to satisfy the requirements for thermal shock resistance and the like.

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 element pellet with a fine surface structure, aluminum (AM) on the surface of the element pellet (> phosphosilicate glass, which is a coating material for protecting the pattern) ( PSG) film or silicon nitride (SiN) film, or the element pellet may be cracked.

This tendency is particularly significant when a thermal cycle test is performed. As a result, defects such as defects in element characteristics due to pellet cracks and defects due to corrosion of the AM pattern occur due to cracks in the protective film.

Therefore, as a countermeasure to this problem, it is necessary to reduce the stress on the internal sealing resin and to increase the adhesion between the sealing resin and the glass film such as the PSG film or SiN film on the element. be. Moreover.

Regarding the cured product, in order to prevent corrosion of the Ai pattern on the surface of the element as much as possible, we use hydrolyzable /\rogen compounds, especially to keep the chlorine concentration low, and to have a high level of electrical insulation performance when absorbing moisture or at high temperatures. need to be kept.

Japanese Patent Publication No. 5B-48135 describes a sealing resin consisting of an epoxy resin, an acid anhydride, and a specific terminal dihydroxy polyester, which has sufficient heat resistance for sealing semiconductor devices. It had no moisture resistance.

[Object of the Invention] An object of the present invention is to provide an epoxy vAIIIvi composition for encapsulating semiconductor devices that can eliminate the above-mentioned drawbacks or satisfy the above-mentioned countermeasures, and can produce a cured product having excellent thermal shock resistance. There is a particular thing.

[Summary of the invention]

As a result of intensive research aimed at improving the reliability of resin-encapsulated semiconductor devices, the inventors of the present invention have found that the components of the resin composition include phenol aralkyl resin and a number-average molecular i of 2500~
The present inventors have discovered that the composition can provide a cured product having excellent thermal shock resistance by using a terminal dihydroxy polyester having a molecular weight of 50,000, and have completed the present invention.

That is, the epoxy resin composition for encapsulating a semiconductor device of the present invention.

a) Epoxy resin 100 parts by weight b)
Novolac type phenolic resin 10-50% C) Phenol aralkyl resin 10-50ffi
1 part and the total amount of (b) + (c) is 50 to 90
Weight part d) Terminal dihydroxy polyester having a number average molecular weight of 2,500 to 50,000 2 to 40 parts by weight.

Epoxy resin (a) which is one component in the composition according to the present invention
) may be of any type as long as it has at least two epoxy groups in one molecule; for example, bisphenol A type epoxy resin, novolac type epoxy resin, alicyclic type epoxy resin, glycidyl ester type epoxy resin. Can be mentioned. Moreover, you may use these in combination suitably. Specific examples of these epoxy resins include EOGN-102S (Nippon Kayaku ■, softening point 74°C, epoxy fi 215), ESCN-195XL (equipment chemistry ■, softening point 71°C, epoxy 5 immersion 19B), EC
M-1273 (Ciba Geigy, softening point 3°C, epoxy equivalent 230), EPPN-201 (T) Honkayaku, softening point 65°C, epoxy equivalent 181), Epicote +00
1 (Shell Chemical, softening point 70℃, epoxy 1475
), Chissonox 201 (Chisso ■, viscosity 18 (lG)
cps (25°C), epoxy equivalent 154), Chissonox 289 (Chisso stock, viscosity 870cps (25°C),
Epoxy 1a1219) and the like. Among the above epoxy resins, those having a softening point of 80 to 100°C are preferred, and those having a softening point of 70 to 85°C are particularly preferred. Moreover, those having an epoxy value of a too much to 300 are preferable, and those having an epoxy value of from 175 to 220 are particularly preferable.

This component (a) preferably contains epoxy resin 10
It is constructed by adding up to 30 parts 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 of the component, and examples thereof include those having two or more phenolic hydroxyl groups such as phenol novolac resin and cresol novolak resin. Among the novolac type phenolic resins, those having a softening point of 60 to 120°C are preferred, particularly those having a softening point of 80 to 100°C, and those having a hydroxyl equivalent of 100 to 150 are preferred,
Particularly preferably, it has a value of 100 to 110.

The phenol aralkyl resin (c) according to the present invention is a resin obtained by reacting an aralkyl ether and phenol with a free-sol Tarafluor catalyst, and is also called a Friedel-Kraf type resin. The condensed heavy metal compound of α, α′-dimethoxy P−+silene and phenol monomer is well known (Plastics VoL 34. No. 2. PO2).
Specifically, XL-225 (Mitsui Toatsu Chemical ■, softening point 8
5℃~105℃), XYLOK-225 (Albright & Wilson■, Softening point 85℃~105
℃), etc. Among these phenol aralkyl resins, those having a softening point of 80°C to 120°C are preferred, particularly those having a softening point of 85°C to 105°C, and those having a hydroxyl equivalent of 195°C to 235°C are preferred.

The amounts added in (b) and (c) above are (b) + (c)
The total amount is 5 parts per 100 parts by weight of epoxy resin (a).
It is necessary to add it in a range of 0 to 90 parts by weight. If this blending ratio is less than 50 parts by weight, the strength of the cured resin product will be weakened, which is undesirable. On the other hand, if it exceeds 90 parts by weight, the moisture resistance of the sealing resin will decrease, which is undesirable. The amounts of the phenol resin and the phenol aralkyl resin to be added can be selected within a range that satisfies the above conditions and within a range of 10 to 50 parts by weight, respectively.

If the phenolic resin is less than 10 parts by weight, sufficient hardness of the molded product cannot be obtained;
Sufficient thermal shock resistance cannot be obtained if the thickness is less than tunkube.

In addition, if the phenol resin is more than 50 parts of heavy acid,
Sufficient moisture resistance cannot be obtained, and on the other hand, if the amount of phenol aralkyl resin is more than 50 parts of heavy acid, the viscosity will be high and the molded product will be poor.

The terminal dihydroxy polyester (d) of the present invention has a number average molecular weight IL of 2,500 to 50,000, and may be any polyester that is generally known as a polyester having two hydroxyl groups at the end of the polymer. If the above-mentioned average molecular weight is less than 2,500, it will cause a decrease in the heat deformation part and mechanical properties of the obtained cured product, and if it exceeds 50,000, the moldability will decrease due to an increase in viscosity. Not preferable, preferably 5
000 to 30000. Polyester like this (
d) is ethylene glycol, propylene glycol,
Neopentyl glycol, 1,3-butanediol, 1
．． It can be easily obtained by condensation polymerization of dihydric alcohols such as 8-hexanediol and dicarboxylic acids such as isophthalic acid, terephthalic acid, adipic acid, and sebacic acid; (-) and lactones such as caprolactone. Specific examples of useful products include Byron 103 (trade name, Toyobo ■, molecular weight 18,000-20,000), Byron 200 (trade name, Toyobo ■, molecular weight 15,000).
-20,000), Byron 300 (trade name, Toyobo Co., Ltd., molecular weight 20,000-25,000), Byron 500 (
Product name, Toyobo Co., Ltd., Molecule 1i 20000-2500
0), Byron 30P (trade name, Toyobo &! Mari, molecular weight 18,000 to 20,000), and PH-10073 (trade name, Ube Industries, Ltd., molecular weight about 10,000). Among these, Byron 200, PH-10073
is preferred.

The blending method for this terminal dihydroxy polyester is as follows:
It may be selected appropriately depending on the softness or hardness of the polyester used. That is, if it is soft, it may be dispersed by heating and melting it together with the epoxy resin in advance; if it is hard, it may be made into a powder and used by directly adding it when mixing the composition. The particle size of this powder is 300 g, preferably 150 g or less, from the viewpoint of moldability.

The blending ratio of component (d) is usually 2 to 40 parts by weight, preferably 5 to 30 parts by weight. This mixing ratio is 2
If the amount is less than 40 parts by weight, the improved curing of thermal shock resistance will not be sufficient, and if it exceeds 40 parts by weight, the moldability of the resin will deteriorate, which is not preferable.

Next, a method for manufacturing the epoxy resin composition for semiconductor resin encapsulation of the present invention will be described.

The composition of the present invention can be prepared by melt-kneading the above-mentioned components using heated rolls, 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.

The composition of the present invention may optionally contain a curing accelerator such as imidazole or its derivatives, tertiary amine derivatives, phosphine derivatives, and cycloamidine derivatives; zircon, silica, fused silica glass, alumina, and hydroxide. aluminum, glass.

Quartz glass, calcium silicate, gypsum, calcium carbonate, magnesite, clay, kaolin, Riruku, iron powder,
Fillers such as copper powder, mica, asbestos, silicon carbide, boron nitride, molybdenum dioxide, lead compounds, lead oxide, zinc white, titanium white, and carbon black; Repellents such as higher fatty acids and waxes; Epoxy silane, vinyl silane,
Coupling agents such as aminosilane, poran compounds, alkoxy titanate compounds, aluminum chelate compounds, etc. Known flame retardants containing antimony, phosphorus compounds, bromine and chlorine may be blended, and thermal shock resistance etc. Various improvers such as silicone oil may be added for the purpose of improving.

[Effects of the Invention] As detailed above, the cured product of the epoxy resin composition for encapsulating semiconductor devices of the present invention has excellent thermal shock resistance, and is suitable for applications such as highly integrated semiconductor devices. The practical value of this can be said to be extremely large.

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 "parts" indicate "heavy seam parts."

[Embodiments of the invention]

100 parts of ortho-cresol nopolar-2 type epoxy resin (softening point 76°C, equivalent weight 20B), brominated phenol novolak type epoxy resin (bromine content 30%).

Softening point: 87°C, epoxy equivalent: 270) 15 parts, phenol novolac resin (softening point: 95°C, hydroxyl equivalent: 104)
36 parts, phenol aralkyl resin (XL-225: Mitsui Toatsu v4) (softening point 90°C, hydroxyl equivalent 19B) 38
Vyron 200 (Toyobo ka@, terminal dihydroxy polyester, molecular weight 15,000-20,000)
In addition, 1.5 parts of tolphenylphosphine as a hardening accelerator, 1 part of carnauba wax as an M-type agent, 1.8 parts of carbon powder as a coloring agent, 500 parts of fused silica powder as a filler, and 3 parts as a flame retardant aid. 15 parts of antimony oxide powder and 2.4 parts of an epoxy silane coupling agent are blended and kneaded with a twin-screw roll at 70 to 100°C. The resulting kneaded product is cooled and crushed, and then tableted to form the semiconductor of the present invention. An epoxy resin composition for device sealing was obtained.

Using the obtained composition, a low pressure transfer molding machine (
Toa Seiki 50 ton press) 175℃, 80Kg
/ cm, for 120 seconds, a large pellet evaluation sample element (8 mm X am layer) having a PSG layer on the surface was sealed.

In order to evaluate the thermal shock resistance, mechanical properties (flexural modulus 1 bending strength), and thermal properties (glass transition point, coefficient of thermal expansion) of the obtained sample element, various tests described below were conducted.

Thermal shock resistance test - one test using 20 sample elements obtained
Rapid heating for the number of cycles shown in the table in the range of ℃ to 150℃,
It was rapidly cooled and tested for thermal shock resistance to determine whether or not cracks occurred. The presence or absence of cracks was confirmed by dissolving the molding resin using fuming nitric acid and using a microscope.

The flexural modulus was measured according to JISK-6911.

Bending strength was measured according to JISK-Ei911.

The glass transition point was determined from the inflection point of the thermal expansion curve using a thermal dilatometer manufactured by Shinku Riko.

Thermal] expansion coefficient was measured using a thermal dilatometer manufactured by Shinku Riko.

The results are shown in the table.

"Support 1" 24 parts of Byron 200 from Example 1, 4 parts of fused silica powder
A composition of the present invention was obtained in the same manner as in Example 1, except that the composition was changed to 88 parts, and the same evaluation test was conducted.

The results are shown in the table.

Byron 200 of Example 1 was mixed with PH-10073 (Ube Industries, terminal dihydroxy polyester, molecular weight approximately 10.
A composition of the present invention was obtained in the same manner as in Example 1, except that the composition was changed to 000), and the same evaluation test was conducted.

The results are shown in the table.

A composition of the present invention was obtained in the same manner as in Example 1, except that 50 parts of the phenol novolac resin of Example 1 and 20 parts of the phenol aralkyl resin were used, and the same evaluation tests were conducted. The results are shown in the table.

Instead of using 36 parts of phenol aralkyl resin and 12 parts of Vylon 2001 in Example 1, the amount of phenol novolac resin was increased to 55 parts, and in order to keep the filler filling amount constant, fused silica powder was added to 480 parts. Example 1 except that
A comparative composition was obtained in the same manner as above, and the same evaluation test was conducted. The results are shown in the table.

A comparative composition was obtained in the same manner as in Example 1, except that 491 parts of fused silica powder was used instead of using 12 parts of Vylon 200 in Example 1, and the same evaluation test was conducted. .

The results are shown in the table.

Without using 36 parts of the phenol aralkyl resin of Example 1,
A comparative composition was obtained in the same manner as in Example 1, except that the phenol novolac resin was changed to 55 parts and the fused silica powder was changed to 488 parts, and the same evaluation test was conducted. The results are shown in the table.

The reaction components were 5.5 moles of propylene glycol, 6 moles of 1,6-hexanediol, and 10 moles of adipic acid.
An esterification reaction was carried out to obtain a terminal dihydroxy polyester (A) having a molecular weight of about 2,200.

A comparative composition was obtained in the same manner as in Example 1, except that the terminal dihydroxypolyester (A) obtained above was used in place of Vylon 200 in Example 1, and the same evaluation test was conducted. The results are shown in the table.

Claims (1)

[Scope of Claims] (a) 100 parts by weight of epoxy resin (b) 10 to 50 parts by weight of novolac type phenolic resin (
c) 10 to 50 parts by weight of a phenolic aralkyl resin, in which the total amount of (b) + (c) is 50 to 90 parts by weight; (d) 2 to 40 parts by weight of a terminal dihydroxy polyester having a number average molecular weight of 2,500 to 50,000; An epoxy resin composition for encapsulating a semiconductor device, characterized in that: