JPH08259666A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE: To obtain a thermosetting resin composition comprising an epoxy resin, a curing agent, an inorganic filler, a thermoplastic resin and a specific organic silicon compound in a specific ratio, low in viscosity on molding, excellent in adhesivity and the warping resistance of packages after cured, and useful as a sealing material for semiconductor devices, etc. CONSTITUTION: This composition comprises (A) an epoxy resin such as a bisphenol A type epoxy resin or a cresol novolack epoxy resin, (B) a curing agent, (C) an inorganic filler, (D) a thermoplastic resin such as methyl methacrylate-butadiene-styrene copolymer or styrene-ethylene-butylene-styrene copolymer, and (E) an organic silicon compound having a SH group or a group producing the SH group and a hydrolyzable group, wherein the contents of the components C, D and E are 100-1000 pts.wt., 0.5-20 pts.wt. and 0.1-5 pts.wt., respectively, per 100 pts.wt. of A+B.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a thermosetting resin composition which is excellent in adhesiveness to a gold-plated surface and a solder resist and is particularly suitable for use as a single-sided molding semiconductor package sealing resin such as a BGA package. Regarding

[0002]

2. Description of the Related Art A thermosetting resin composition containing an epoxy resin, a phenol resin as a curing agent for the epoxy resin, and an inorganic filler has been used for a semiconductor package. .

Further, in recent years, with the increase in the number of pins of semiconductor packages, semiconductor chips are mounted on an organic resin substrate having solder bumps called BGA (ball grid array), and one surface thereof is sealed with an epoxy resin sealing material. A package to stop is being developed. Despite the increase in the number of pins, this package has a tendency to expand its applications because it is easy to solder, several semiconductor chips can be mounted, and the manufacturing cost is low.

However, in the above BGA package, the materials forming the BGA package have different expansion coefficients, so that the package is easily warped after the molding of the package, which causes a fatal problem that it cannot be connected to a printed circuit board. .

In addition, since the BGA package is large in size and has a large number of pins, the number of gold wires connecting the semiconductor chip and the wiring on the substrate is large and the length thereof is also long. Therefore, when a sealing material having a high viscosity at the time of molding is used, problems such as bending of the gold wires and contact between the gold wires are likely to occur.

Further, the adhesiveness with the solder mask and the gold-plated portion on the substrate is also an important factor for improving the reliability of the BGA package. Particularly in a single-sided package such as BGA, if the adhesion to the solder mask or the gold-plated portion is insufficient, there is a problem that the solder mask and the gold-plated portion are easily separated from each other during solder reflow, and the package is cracked. It has been pointed out.

In order to solve the above problems, in the semiconductor industry, as a sealing resin for a BGA package, the resin viscosity at the time of molding is low, the adhesiveness with a solder mask or gold plating is excellent, and the warpage of the package is also reduced. There is a demand for the development of a thermosetting resin composition that can be used.

In order to improve the above problems, the present inventor proposes a resin composition capable of preventing warpage of a single-sided molded package in Japanese Patent Publication Nos. 5-77686 and 6-17458. However, it was difficult to say that this composition was sufficiently effective in preventing warpage when the package size was 25 cm square or more.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a thermosetting resin composition suitable for semiconductor encapsulation, which has a low viscosity during molding and gives a cured product excellent in adhesiveness to a solder mask or gold plating and which can reduce warpage of a package. And

[0010]

Means and Actions for Solving the Problems As a result of extensive studies conducted by the present inventor in order to achieve the above object, a thermosetting resin composition containing an epoxy resin, a curing agent and an inorganic filler, When a thermoplastic resin and an organosilicon compound having a mercapto group or a group that generates a mercapto group by decomposition and a hydrolyzable group are used in combination in the following specific ranges, the viscosity at the time of molding is low, and the bending of gold wires and gold wires A cured product that does not cause contact and that has excellent adhesion to both the base material of the gold plating and the solder mask can be sufficiently reduced in warping of the package, and semiconductor encapsulation for BGA packages can be achieved. It can be preferably used as a material, that is, an organic silicon compound containing a thermoplastic resin or a mercapto group or a group that produces a mercapto group by decomposition and a hydrolyzable group is used alone. Despite the low adhesion with the gold plating when use, the combined use of these two components, the adhesion of the gold unexpectedly has found that significantly improved,
The present invention has been made.

Therefore, according to the present invention, 100 parts by weight of (A) epoxy resin and curing agent, and (B) inorganic fillers 100 to 1 are used.
000 parts by weight, (C) 0.5 to 20 parts by weight of a thermoplastic resin, and (D) 0.1 to 5 parts by weight of an organosilicon compound having a mercapto group or a group that produces a mercapto group by decomposition and a hydrolyzable group. Provided is a thermosetting resin composition characterized by containing the same.

The present invention will be described in more detail below. The thermosetting resin composition according to the present invention contains an epoxy resin, a curing agent, an inorganic filler and the like.

As the epoxy resin used in the present invention, any epoxy resin having at least two epoxy groups in one molecule can be used. Specific examples of the epoxy resin include bisphenol-
A type epoxy resin, novolac type epoxy resin, alicyclic epoxy resin, glycidyl type epoxy resin, and epoxy resin represented by the following structural formula are exemplified, and one of these is used alone or two or more of them are used in combination. Can be used.

[0014]

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[0015]

Embedded image (However, tBu represents a t-butyl group, and n is 0 or an integer of 1 to 10.)

In the present invention, among these epoxy resins, the above-mentioned bisphenol A type epoxy resin, cresol novolac type epoxy resin, phenyl group, alkyl group having 1 to 6 carbon atoms such as n-butyl group, and other monovalent carbonization. It is preferable to use a polyfunctional epoxy resin having a hydrogen group in order to improve adhesion with gold plating.

These epoxy resins have a softening point of 50 to 50.
It is desirable that the epoxy equivalent is 100 to 400 at 100 ° C.

In addition to the above, a brominated epoxy resin may be used as the epoxy resin for flame retardancy.

Next, a phenol resin is preferably used as the curing agent, specifically, a phenol resin having two or more phenolic hydroxyl groups such as phenol novolac resin, cresol novolac resin, and triphenol methane. Is exemplified. Among such phenolic resins, the softening point is 60 to 120 ° C. and the hydroxyl group equivalent is 90 to 1
Those of 50 are preferably used.

The amount of the phenol resin used as the curing agent may be any amount as long as the equivalent ratio of the epoxy groups in the epoxy resin to the hydroxyl groups in the phenol resin is in the range of 0.5 to 2, but is usually Epoxy resin 100 parts (weight part,
The same applies hereinafter), and a range of 30 to 100 parts, particularly 40 to 70 parts is preferable. If the amount of the phenolic resin used is less than 30 parts, sufficient strength may not be obtained, and if it exceeds 100 parts, unreacted phenolic resin may remain to lower the moisture resistance.

The inorganic filler used in the present invention is to reduce the expansion coefficient of the encapsulant and to reduce the stress applied to the semiconductor element. As a specific example, fused silica having a crushed or spherical shape, crystalline silica, or the like is mainly used, and in addition, alumina, silicon nitride, aluminum nitride, or the like can also be used. The average particle size of the inorganic filler is preferably in the range of 5 to 20 μm. Further, the shape is not particularly limited, and various shapes such as spherical shape and crushed shape can be used, but in order to achieve both low expansion of the cured product and moldability, a blend of spherical and crushed products, or a spherical product It is better to use only. This type of inorganic filler can be used after being surface-treated with a silane coupling agent in advance.

The filling amount of the inorganic filler is preferably 100 to 1000 parts with respect to 100 parts of the total amount of the epoxy resin and the curing agent, and if it is less than 100 parts, the expansion coefficient becomes large and B
In addition to the large warpage of the GA package, the stress applied to the semiconductor element may increase, which may lead to deterioration of element characteristics.
If it exceeds 1000 parts, the viscosity at the time of molding becomes high and the moldability may deteriorate.

Next, as the thermoplastic resin which is an important component in the present invention, for example, styrene-ethylene-butylene-styrene copolymer (SEBS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin). Polymers such as Methyl Methacrylate-Butadiene-Styrene Copolymer (MB
S resin) is more preferably used.

Further, as the MBS resin, butadiene.
Styrene copolymer rubber was prepared by emulsion polymerization, and after styrene / methyl methacrylate was graft-polymerized,
It is effective to use a powder that is solidified and dried.

When the above-mentioned thermoplastic resin is mixed with the epoxy resin composition, it is added as fine powder as possible.
Alternatively, it is desirable to add it after previously melt-mixing with an epoxy resin or a phenol resin.

The organosilicon compound having a hydrolyzable group and a mercapto group that improves adhesiveness when used together with a thermoplastic resin or a group that decomposes to form a mercapto group is represented by the following structural formula. Such compounds can be mentioned as typical examples. Examples of the hydrolyzable group include alkoxy groups having 1 to 5 carbon atoms.

[0027]

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Further, examples of the compound which decomposes to generate a mercapto group include the following. _{(CH 3 O) 3 SiCH 2} CH 2 CH 2 SSCH 2 CH 2 CH 2
Si (OCH ₃ ) ₃

The blending amount of the thermoplastic resin is 0.5 to 20 with respect to 100 parts of the total amount of the epoxy resin and the curing agent.
Parts, preferably 2 to 10 parts. If the blending amount of the thermoplastic resin is less than 0.5 part, sufficient adhesiveness cannot be obtained, and if it exceeds 20 parts, the viscosity of the epoxy resin composition increases and the fluidity decreases, and the mechanical strength becomes weak. Such a problem occurs.

The amount of the organosilicon compound having a mercapto group and a hydrolyzable group is 0.1 to 5 parts, preferably 0.2 to 5 parts, based on 100 parts of the total amount of the epoxy resin and the curing agent. 2 copies. If the blending amount of the above organosilicon compound is less than 0.1 part, sufficient adhesive force cannot be obtained, and in some cases, semiconductor characteristics are deteriorated.
If it exceeds 5 parts, the semiconductor characteristics deteriorate.

Further, the mixing ratio of the thermoplastic resin and the organosilicon compound having a mercapto group and a hydrolyzable group is
The weight ratio of the organic silicon compound to the thermoplastic resin 1 is 0.01 to 0.5, particularly 0.01 to 0.3.
It is desirable to be within the range. If the compounding ratio of the above organosilicon compound to the thermoplastic resin 1 is less than 0.01, sufficient adhesion may not be obtained, and if it exceeds 0.5, the semiconductor properties may deteriorate.

In the present invention, it is preferable to add a curing catalyst in addition to the above components. Typical examples of the curing catalyst include imidazole or a derivative thereof, a phosphine derivative, and a cycloamidine derivative, and 2P4MHZ and 2PHZ represented by the following structural formulas are particularly preferably used.

[0033]

[Chemical 4]

The amount of the curing catalyst used may be a catalytic amount, but 0.001 to 10 parts, particularly 0.1 to 4 parts is suitable for 100 parts of the total amount of the epoxy resin and the curing agent. is there. If it is less than 0.001 part, it may not be possible to cure in a short time, and if it exceeds 10 parts, the curing rate may be too fast to obtain a good molded product.

A silicone-based flexibility-imparting agent may be added to the composition of the present invention to reduce stress. Examples of the silicone-based flexibility imparting agent include silicone rubber powder, silicone gel, block polymers of organic resin and silicone polymer, and the like. The surface of the inorganic filler may be treated with a two-component type silicone rubber or silicone gel.

Usually, the amount of this type of stress reducing agent used is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the whole composition. May not be imparted, and if it exceeds 10% by weight, mechanical strength may be insufficient.

In the composition of the present invention, if necessary, a releasing agent such as carnauba wax, higher fatty acid or synthetic wax, silane coupling agent having no mercapto group, antimony oxide, phosphorus compound, etc. May be blended.

The composition of the present invention can be produced by melt-kneading the above-mentioned components by melt-kneading with a heating roll, melt-kneading with a kneader, melt-kneading with a continuous extruder, or the like. The curing conditions are not particularly limited, but post-curing at 165 to 185 ° C. for 2 to 8 hours is desirable.

[0039]

EFFECT OF THE INVENTION The thermosetting resin composition of the present invention provides a cured product having a low resin viscosity at the time of molding and excellent adhesiveness with a solder mask or gold plating, and can reduce the warpage of the package. Therefore, it can be suitably used as a sealing material for a single-sided semiconductor package such as a BGA package.

[0040]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. All parts in each example are parts by weight.

[Examples and Comparative Examples] According to the blending composition shown in Table 1, the raw materials were uniformly mixed and then set to 90 ° C.
A thermosetting resin composition was obtained by uniformly melt-mixing with this roll.

The following various properties were measured for these thermosetting resin compositions. The results are shown in Table 1. (A) Spiral flow 175 ° C, 70k using a mold conforming to EMMI standard
It was measured under the condition of g / cm ² . (B) Melt viscosity It was measured at 175 ° C. using a Shimadzu Koka type flow tester. (C) Mechanical strength (flexural strength and flexural modulus) 175 ° C., 70 kg / cm according to JIS-K6911
^{2. A} bending bar of 10 × 100 × 4 mm was molded under the condition of a molding time of 2 minutes, and post-cured at 180 ° C. for 4 hours, and then measured. (C) Glass transition temperature, expansion coefficient 175 ° C., 70 kg / cm ² , molding time 2 minutes 4
It was measured by molding a test piece of × 4 × 15 mm, post-curing at 180 ° C. for 4 hours, and raising the temperature at 5 ° C./min with a delight meter. (F) Adhesiveness A gold-plated 42 alloy plate with a diameter of 15 mm and a height of 5 mm
The cylindrical molded article was molded under the conditions of 175 ° C., 70 kg / cm ² and a molding time of 2 minutes, post-cured at 180 ° C. for 4 hours, and the adhesiveness between the molded product and gold plating was measured with a push-pull gauge. Average of n = 5.

[0043]

[Table 1]

[0044]

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From the results shown in Table 1, when the thermoplastic resin and the mercapto group-containing organosilicon compound are used in combination, a cured product having excellent adhesion to gold plating is obtained. It is recognized that when each of these is used alone (Comparative Examples 2 and 3), the adhesive strength to gold plating is poor. Further, when a large amount of a thermoplastic resin is blended (Comparative Example 1), the viscosity becomes high, the spiral flow is lowered, and the bending strength and bending elastic modulus are also inferior.

[Procedure amendment]

[Submission date] February 21, 1996

[Procedure Amendment 1]

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[0014]

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[0015]

Embedded image (However, tBu represents a t-butyl group, and n is 0 or an integer of 1 to 10.)

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[0044]

Embedded image Tuftec M1943: Styrene-ethylene-butylene-styrene copolymer (manufactured by Asahi Kasei) M901: Methyl methacrylate-styrene-butadiene copolymer (manufactured by Kanegafuchi Chemical Co., Ltd.)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08L 101: 00) (72) Inventor Taharu Ikeda 1 Hitomi, Osamu Matsuida-cho, Usui District, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory

Claims (3)

[Claims] 1. (A) 100 parts by weight of an epoxy resin and a curing agent, (B) 100 to 1000 parts by weight of an inorganic filler,
(C) 0.5 to 20 parts by weight of a thermoplastic resin, and (D) 0.1 to 5 parts by weight of an organosilicon compound having a mercapto group or a group that generates a mercapto group by decomposition and a hydrolyzable group. A thermosetting resin composition comprising: 2. The thermoplastic resin is methyl methacrylate-butadiene-styrene copolymer or styrene-ethylene-
The thermosetting resin composition according to claim 1, which is a butylene-styrene copolymer. 3. An epoxy resin selected from a bisphenol A type epoxy resin, a cresol novolac type epoxy resin and a polyfunctional type epoxy resin having a monovalent hydrocarbon group in a phenyl group. Thermosetting resin composition.