JPS62209126A - Epoxy resin composition for sealing semiconductor device - Google Patents

Abstract

PURPOSE:The titled composition capable of providing a cured material having improved thermal shock resistance, containing an epoxy resin, a novolak phenolic resin, silica powder, a dimethyl-siloxane oil and a surface active agent in a specific ratio. CONSTITUTION:The aimed composition consisting of (A) 100pts.wt. epoxy resin (preferably containing at least two epoxy groups in one molecule), (B) 30-70pts. wt. novolak type phenolic resin (preferably one having 80-100 deg.C softening point and 100-110 OH equivalents) as a curing agent, (C) 300-550pts.wt. silica powder (preferably one having 5-30mu average particle diameter) as a filler, (D) 0.2-20pts.wt. dimethylsiloxane oil (preferably one having 50,000-500,000cps at 20 deg.C) and (E) 0.2-20pts.wt., preferably 1-10pts.wt. fluorine type and/or silicone type surface active agent.

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, a gap has been occurring due to the shift to four-pack semiconductor packages. When mounting a thinner flat package with JFJ, 1Unlike normal DIP.

High-temperature soldering (for example, 260° C.) is performed from the resin package side. Therefore, with conventional resins, resin flags may occur due to thermal shock, and subsequent accelerated moisture resistance tests (PUT
) can't stand it.

Therefore, as a countermeasure for such problems, improvements have been made from the frame design and the structure, but no sufficient countermeasures have been found. For example, as a countermeasure for resin 1-, there are attempts to lower the glass transition of the resin by 12.1 degrees and soften the resin to absorb the thermal shock when exposed to solder. This is undesirable because other defects such as open wires occur frequently. Heat resistance: The objective is to provide an epoxy resin composition for semiconductor 4Aa sealing that provides a cured product with impact resistance.

[Key points of invention]

As a result of intensive research aimed at improving the reliability and properties of low-fat encapsulated semiconductor devices, the present inventors discovered that dimethylsiloxane oil and fluorine-based and/or silicone-based interfaces were used as components of the resin composition. The present invention was completed based on the discovery that the composition can provide a cured product having excellent thermal shock resistance when used in combination with an activator.

That is, the epoxy resin composition for encapsulating a semiconductor device of the present invention includes: a) 100 parts by weight of an epoxy resin; b) a novolac type phenol resin.

30-70 parts by weight C) Silica powder 300-550'! Volume part d)
Dimethylsiloxa/oil 0.2-20 parts by weight e) Fluorine-based and/or silicone-based surfactant
It is characterized by comprising 0.2 to 20 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.

Examples include bisphenol A-based epoxy resins, novolak-type epoxy resins, alicyclic-type epoxy resins, and glycidyl ester-type epoxy resins.

Moreover, you may use these in combination suitably.

Specific examples of these epoxy resins include l! 30CN
-1028 (Nippon Kayaku Co., Ltd., softening point 74°C, epoxy equivalent 215), ESCN-195XL (Sumitomo Chemical Co., Ltd.)
, softening point 71°C, epoxy equivalent weight 198), ECN-12
73 (Ciba Geigy, softening point 3℃, epoxy 11
230) EPPN-201 (Nippon Kayaku (Tue, Softening Point 65
℃, epoxy equivalent 181), Epicote 1001 (Shell Chemical, softening point 70℃, epoxy equivalent! 1t475),
Chisson Knox 201 (Chisso c force, viscosity 1800 c
ps (25°C), epoxy 2154), Chissonox 289 (Chisso 0 stock) viscosity 870cps (25°C)
, epoxy 121q), etc. 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. Moreover, those having an epoxy weight of 1-100 to 300 are preferable, and those having an epoxy weight of 1-175 to 220 are particularly preferable.

This (at acid component is preferably an epoxy resin 100%
It is constructed by adding up to 30 parts by weight of a flame retardant epoxy resin to the heavy part.

The novolac type phenolic resin (b) according to the present invention is (a
) Dust 1 that acts as a hardening agent for epoxy resins with K content, for example, phenol novolac resins.

Examples include those having two or more phenolic hydrogen groups such as bresol novolak resin. A specific example is B-M-558 (Showa Union Synthetic Chemical Co., Ltd., softening point 97).
°C, QH current approximately 104 m, BR, M-557 (Showa Union Synthetic Chemical (a), softening point 86°C, OH current approximately 10
4) etc. Among the novolac type phenolic resins, those having a softening point of 60 to 120°C are preferred,
Particularly preferred are those having a temperature of 80 to 100°C, and those having a hydroxyl equivalent of 100 to 150, particularly preferably 100 to 110.

The amount of the phenol resin added is preferably 30 to 70 parts by weight, because if it is less than 30 parts, sufficient strength cannot be obtained, while if it is more than 70 parts, the moisture resistance will deteriorate.

The filler as component (c) of this invention reduces the linear expansion coefficient of the sealing material to prevent peeling of the sealing resin and the element or frame, and as a result, the semiconductor device This is to improve the moisture resistance of.

As a specific example, fused silica powder or crystalline silica powder having a shape such as a crushed spherical shape can be conveniently used.

The average particle size of the powder is preferably 5 to 30 μm.

In addition, the filling bond is preferably 300 to 550 parts by weight.
The reason is that below 300 needles, the coefficient of thermal expansion becomes large and defects due to wire open tend to occur. On the other hand, if it is above 550 degrees, the viscosity during molding becomes high and moldability deteriorates.

Silicone oil fdl according to the invention.

Any compound with a viscosity of 0.1.
) approx. 10,000 cpS), TSF-451-10M (Toshiba silicone + m s deadback (20°C) approx. IQOOOO
cps), TSF-451-50M (Toshiba Silicone ■
, viscosity (20°C) approximately 5oooo.

cps), 5H-200-5000 (Toshi Silicone fi@, viscosity (20°C) approximately 5000 cps), and the like.

However, among silicone oils, the viscosity (20℃) is 500.
It is preferable to have an M of 1,000,000 cps, and particularly preferably 500 to 500,000 cps.

The blending ratio of component (d) is usually 0.2 to 20 parts, preferably 1 to 10 parts. If this blending ratio is less than 0.2 parts, the effect of improving thermal shock resistance will not be sufficient (if it exceeds 20 parts + i parts, the surface of the cured product will become dirty due to silicone oil embossment). do not have.

fe) Fluorine surfactants used in the method of the present invention include 1, for example, the nonionic surfactant FC-430°FC.
-431, FC-176 (trade name, both manufactured by 3M Corporation), etc. Silicone surfactants include 1, for example, nonionic surfactants 5H-3746, 5
Examples include glycol-modified silicone surfactants such as t(-3749, 5F-8421, 5F-8410 (trade names, all manufactured by Toshi Silicone Tsuji).

The blending ratio of this component (fe) is usually 0.2 to 20 parts by weight, preferably 1-10 parts by weight. If this blending ratio is less than 0.2 parts, the improved curing of thermal shock resistance will not be sufficient (if it exceeds 2 parts mt, the bottom shape of the resin will deteriorate, which is not preferred).

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 is prepared by melting and mixing the above-mentioned components using a heated roll and a kneader.

It can be easily produced by melt blending using an extruder, mixing using a special mixer after fine crushing, or an appropriate combination of these methods.

Note that the composition of the present invention may optionally contain a curing accelerator such as imidazole or its derivative, a tertiary amine derivative, a phosphine derivative, a cycloamidine derivative; a mold release agent such as a higher fatty acid or wax; and an epoxy. Coupling agents such as silanes, vinylsilanes, aminosilanes, borane compounds, alkoxytitanate compounds, and aluminum chelate compounds; known flame retardants containing anti-sulfur compounds, phosphorus compounds, bromine, and chlorine may be blended.

[Embodiments of the invention]

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

In the Examples and Comparative Examples, "Miyako" μ all indicate "straight wrinkles".

Example 1 Orthocresol novolac type epoxy resin (softening point 7
6℃, 1206) 1009. Brominated phenol novolag type epoxy resin (certain raw material M1130%, softening point 87
50 parts of phenol novolak resin (softening point 95°C, hydroxyl equivalent 104), bath-fused silica powder (average particle size 18 μm) as optical filler 42
0 parts, TSF-451 as dimethylsiloxane oil
-1 part M (Toshiba silicon ■) 3s, fluorine-based surfactant a
agent FC-430 (Order 3M ■) 1.5 ml, and as a hardening accelerator, tolphenylphosphine 1.5 ml,
1 fIs of carnauba wax as a female mold agent, 1.8 parts of carbon powder as a coloring agent, #! After treating 15 parts of antimony trioxide powder as a combustion aid in one thread of antimony powder with an epoxy silane coupling agent,
Dimethylsiloxane oil and fluorosurfactant were added and mixed, and finally the remaining materials were added to form a mixture for crosstalk.

After that, it is kneaded with twin screw rolls at 70 to 100°C.

The obtained kneaded product was cooled, crushed, and tableted to obtain an epoxy ridge resin composition for encapsulating a semiconductor device of the present invention.

Using the obtained composition, a low pressure transfer molding machine (
Toa Seiki 50 ton press), 175℃, 80k
g/cm”, 120 seconds, heat resistance 1# washing property test, test element of size 3mm x 3mm was 2mm
It was sealed in a 24-bottle flat package.

The obtained sample element was molded into a molded product to evaluate thermal shock resistance, mechanical properties (flexural modulus 1 bending strength), and thermal customization (glass transition point, coefficient of thermal expansion), and various tests described below were conducted. did.

All resin molded products were post-cured at 175°C for 4 hours. Thermal Shock Resistance Test - After performing solder immersion at 260°C for 10 seconds using 20 sample elements obtained, a 7IO rapid moisture resistance test (PCT, 25 atm, 127°C) was performed.
) to check for defects.

The flexural modulus was measured in accordance with JISK-6911.

Bending strength was measured according to JISK-6911.

The glass transition point was measured using a heat 1 tension meter manufactured by Shinku Riko.

It was determined from the inflection point of the thermal expansion curve.

The coefficient of thermal expansion was measured using a thermal J dilatometer manufactured by Shinku Riko. II was determined.

Example 2 A composition of the present invention was prepared in the same manner as in Example 1, except that 81 parts of the dimethylsiloxane oil and 3.5 parts of the fluorine-based surfactant were used in Example 1.

Example 3 A composition of the present invention was obtained in the same manner as in Example 1, except that the fluorine-based surfactant in Example 1 was replaced with silicone-based surfactant 8F-8421 (Toshi Silicone ■).

Example 4 Dimethylsiloxane oil (TsF-451) of Example 1
A composition of the present invention was obtained in the same manner as in Example 1, except that TSF-451-IM, which had a low viscosity, was used instead of TSF-451-IM.

Comparative Example 1 Comparison was made in the same manner as in Example 1, except that the dimethylsiloxane oil and fluorine-based surfactant of Example 1 were not used, and 1 m fused silica powder was changed to 424.5 parts in order to increase the amount of filler. A composition was obtained.

Comparative Example 2 Except for changing the dimethylsiloxane oil to 4.5 parts without using 1.5 parts of the fluorosurfactant in Example 1,
A comparative composition was obtained in the same manner as in Example 1.

Ratio ei column 3 A comparative composition was obtained in the same manner as in Example 1, except that the dimethylsiloxane oil 3.0ii of Example 1 was not used and the fluorosurfactant was changed to 4.5 parts.

A test similar to that in Example 1 was conducted using the above composition. The evaluation results are shown in the table. The following margins [Effects of the Invention] As detailed above, the epoxy resin composition for encapsulating semiconductor devices of the present invention has excellent moisture resistance and heat resistance S
It has s-characteristics, and its practical value in applications such as direct use of semiconductor devices can be said to be excellent.

Agent Patent Attorney Norihiro Chika Same Bamboo Flower Kikuo

Claims (1)

[Scope of Claims] (a) 100 parts by weight of epoxy resin (b) 30 to 70 parts by weight of novolac type phenolic resin (
c) 300 to 550 parts by weight of silica powder (d) 0.2 to 20 parts by weight of dimethylsiloxane oil (
e) Fluorine and/or silicone surfactant 0.2
An epoxy resin composition for encapsulating a semiconductor device, characterized in that the composition contains 20 parts by weight.