JPH069754A - Resin composition for sealing semiconductor and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:To obtain a resin composition for sealing semiconductor which is excellent in fluidity and adhesion and can give a cured product excellent in cracking resistance after absorption of humidity by mixing an epoxy resin with a phenolic resin, a mixed resin prepared by dispersing a specified copolymer resin in a specified epoxy resin, and an inorganic filler. CONSTITUTION:The resin composition essentially consists of an epoxy resin [e.g. a resin of formula I (wherein R<4> is H or 1-5C alkyl; OG is a group of formula II; k is 0-5; j is 0-3; m is 0-2; and s is 1 or 2), a phenolic resin] (e.g. a resin of formula III), a mixed resin prepared by dispersing a methyl methacrylate/butadiene/styrene copolymer resin in an epoxy resin of formula IV (wherein R<1> is H, halogen or 1-5C alkyl; m is 0-2; and q is 0-5) and an inorganic filler. This composition is excellent in fluidity and adhesion and can give a cured product excellent in cracking resistance after absorption of humidity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for semiconductor encapsulation and a semiconductor device which gives a cured product having good fluidity, good adhesion and excellent crack resistance after moisture absorption.

[0002]

2. Description of the Related Art In recent years,
Various problems have occurred as semiconductor packages have become thinner. For example, when mounting a flat package on a printed circuit board, the package is immersed in a high-temperature solder bath, so that the conventional epoxy resin composition has a problem that the package is cracked by thermal shock. More recently, it has been pointed out that when the package absorbs moisture before being mounted on a printed circuit board, when it is immersed in a high-temperature solder bath, steam explosion occurs in the package and cracks occur.

However, as measures against this kind of problem, improvements have been studied from both sides of the frame and the epoxy resin composition, but few are satisfactory, and particularly, the thermal shock resistance and adhesiveness of the epoxy resin composition There is a demand for improvement in terms of this aspect.

The present invention has been made in view of the above circumstances.
With good fluidity, high thermal shock resistance, excellent crack resistance after moisture absorption, and a resin composition for semiconductor encapsulation that gives a cured product having excellent adhesiveness and sealed with the cured product. It is an object of the present invention to provide a semiconductor device.

[0005]

Means for Solving the Problems The present inventor has conducted extensive studies to achieve the above object, and as a result, an epoxy resin composition containing an epoxy resin, a phenol resin, and an inorganic filler has the following general formula ( By blending a mixed resin in which a methyl methacrylate / butadiene / styrene copolymer resin is dispersed in the epoxy resin represented by I), the thermal shock resistance is high and the crack resistance after moisture absorption is excellent.
It has also been found that a cured product having excellent adhesiveness is provided.

A semiconductor device encapsulated with such a cured product has high reliability even after thermal shock during surface mounting. Therefore, the epoxy resin composition has the SOP type and SO type.
It has been found that it can be used for encapsulation of any type of semiconductor device such as J type, TSOP type, TQFP type, etc., and in particular has very excellent characteristics as an encapsulating material for a surface mounting semiconductor device.

[0007]

[Chemical 2] (Wherein R ¹ is a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, m is an integer of 0 to 2, and q is 0.
Is an integer of ~ 5. )

That is, as a method of dispersing a methylmethacrylate / butadiene / styrene copolymer resin in an epoxy resin, a method described in Japanese Patent Laid-Open No. 225617/1988 is known. When the methacrylate / butadiene / styrene copolymer resin is mixed, the methyl methacrylate / butadiene / styrene copolymer resin is not sufficiently dispersed in the epoxy resin, and the methyl methacrylate / butadiene / styrene copolymer resin is dispersed in the epoxy resin matrix. Particle size of coalescing resin is 3
There was a problem that it becomes 0 μm or more. On the other hand, when the methyl methacrylate / butadiene / styrene copolymer resin is dispersed in the epoxy resin of the above formula (I), surprisingly, the copolymer resin becomes fine particles of 5 μm or less and uniformly. When the mixed resin is further dispersed in the epoxy resin composition, the methyl methacrylate / butadiene / styrene copolymer resin is present as phase-separated particles of 5 μm or less in the epoxy resin matrix, and has a fine sea-island structure. It has been found that the cured product is effective in improving crack resistance and adhesiveness after moisture absorption because it is in a dispersed state.

Therefore, the present invention provides (1) an epoxy resin,
(2) Phenolic resin, (3) Mixed resin in which methyl methacrylate / butadiene / styrene copolymer resin is dispersed in the epoxy resin represented by the general formula (I),
(4) To provide a resin composition for semiconductor encapsulation containing an inorganic filler as an essential component, and a semiconductor device encapsulated with a cured product of this resin composition.

The present invention will be described in more detail below. The epoxy resin which is the first essential component of the present invention may be any one 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 epoxy resin, glycidyl type epoxy resin, etc. may be mentioned.
Further, these epoxy resins can be used alone or in combination of two or more kinds.

Among these epoxy resins, the epoxy resin represented by the following formula is preferable.

[0012]

[Chemical 3]

Further, as the epoxy resin, an epoxy resin represented by the following general formula (I), which is used in a mixed resin described later, can also be used.

[0014]

[Chemical 4] (However, in the formula, R ¹ is a hydrogen atom, a halogen atom or a monovalent hydrocarbon group having 1 to 5 carbon atoms, and q is an integer of 0 to 5.)

Further, as the epoxy resin, a brominated epoxy resin can be used for flame retardancy.

The phenolic resin which is the second essential component of the present invention acts as a curing agent for the epoxy resin which is the first component, for example phenolic hydroxyl groups such as phenol novolac resin, cresol novolac resin and triphenol methane. Those having two or more are preferably used. Specifically, the following compounds are exemplified.

[0017]

[Chemical 5] (In the above formula, R ⁴ , k, j and m have the same meanings as above.)

In the present invention, among the phenolic resins, those having a softening point of 60 to 120 ° C. are preferable,
The hydroxyl equivalent is preferably 90 to 150.

The amount of the above-mentioned phenol resin used is such that the equivalent ratio of the epoxy groups of the epoxy resin to the hydroxyl groups of the phenol resin is in the range of 0.5 to 2, especially 0.7 to 1.5. Preferably, it is usually 30 to 100 parts, especially 40 to 100 parts (parts by weight, the same below) of epoxy resin.
It is preferably about 70 parts. If the amount of the phenol resin used is less than 30 parts, sufficient strength may not be obtained, and if it exceeds 100 parts, unreacted phenol resin may remain and the moisture resistance may decrease.

Next, in the present invention, a mixed resin prepared by dispersing a methyl methacrylate / butadiene / styrene copolymer resin in an epoxy resin represented by the following general formula (I) is compounded as a third essential component.

[0021]

[Chemical 6] (Wherein R ¹ is a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, for example, a hydrogen atom, a chlorine atom, a bromine atom, a methyl group or an ethyl group, and m is an integer of 0 to 4, q is an integer of 0 to 5.)

Specific examples of the epoxy resin of the formula (I) include the following compounds.

[0023]

[Chemical 7]

Here, the mixing ratio of the epoxy resin of the formula (I) and the methyl methacrylate / butadiene / styrene copolymer resin is 100 parts by weight of the epoxy resin of the formula (I). The amount of the polymer resin is preferably 1 to 80 parts, particularly preferably 5 to 60 parts, and if it is less than 1 part, the crack resistance and adhesiveness of the cured product may not be improved satisfactorily, and if it exceeds 80 parts, it is mixed. In some cases, the softening point of the resin is increased, making uniform dispersion difficult.

A method of dispersing and mixing the methylmethacrylate / butadiene / styrene copolymer resin in the epoxy resin of the above formula (I) is, for example, in an organic solvent such as toluene, acetone or methyl isobutyl ketone, of the formula (I). 50 to 15 by dissolving epoxy resin and adding methylmethacrylate / butadiene / styrene copolymer resin
Examples include a method of dissolving and mixing at 0 ° C. and then distilling a solvent under reduced pressure, a method of heating and melting an epoxy resin of the formula (I), and then adding a methyl methacrylate / butadiene / styrene copolymer resin to the mixture and melting and mixing. To be A catalyst such as triphenylphosphine may be added in a catalytic amount when the two resins are mixed.

The mixed resin thus obtained is a resin in which the methyl methacrylate / butadiene / styrene copolymer resin is uniformly dispersed as fine particles of usually 5 μm or less in the epoxy resin.

The addition amount of the mixed resin of the third essential component is 1 to 60 parts, and particularly 2 to 40 parts based on 100 parts of the total amount of the epoxy resin of the first component and the phenol resin of the second component. It is preferable. In addition, the total amount of resin components (epoxy resin + phenol resin + mixed resin) in the composition is 10
The amount of methylmethacrylate / butadiene / styrene copolymer resin in the mixed resin is 0.5 to 15 parts with respect to 0 parts,
It is particularly preferable that the amount is 2 to 10 parts. If the amount of methyl methacrylate / butadiene / styrene copolymer resin is less than 0.5 parts, the effect of improving the crack resistance and adhesiveness of the cured product may be reduced, and if it exceeds 15 parts, the mechanical strength will decrease. May cause

The inorganic filler, which is the fourth essential component of the present invention, can reduce the expansion coefficient of the encapsulant and reduce the stress applied to the semiconductor element. Specifically, it is crushed or spherical. Shaped fused silica and crystalline silica are mainly used, and in addition to these, alumina, silicon nitride, aluminum nitride and the like can also be used. In the present invention, in order to achieve both low expansion of the cured product and moldability, it is preferable to use a blend of spherical and crushed products or only spherical products as the inorganic filler.

The inorganic filler is preferably surface-treated with a silane coupling agent before use.

Further, as the inorganic filler, those having an average particle diameter of 5 to 30 μm are preferably used.

The filling amount of the inorganic filler is 300 to 90 with respect to 100 parts of the total amount of the resin components (the above first to third components).
0 part is preferable, and if it is less than 300 parts, the expansion coefficient increases and the stress applied to the semiconductor element increases, which may lead to deterioration of element characteristics. If it exceeds 900 parts, the viscosity at the time of molding increases and molding There is a case where the sex becomes worse.

In the present invention, it is preferable to further add a curing catalyst. Examples of the curing catalyst include imidazole or its derivative, phosphine derivative, cycloamidine derivative and the like.

The amount of the curing catalyst used is not particularly limited, but is 0.00 per 100 parts of the first component epoxy resin.
1 to 5 parts, particularly preferably 0.1 to 2 parts,
If it is less than 0.001 part, it may not be possible to cure in a short time, and if it exceeds 5 parts, the curing rate may be too fast to obtain a good molded product.

Further, in the present invention, in addition to the above-mentioned essential components, it is preferable to add a silicone-based flexibility-imparting agent for reducing stress. Examples of the flexibility-imparting agent include silicone rubber powder, silicone gel, block polymers of organic resin and silicone polymer, and the like. Instead of adding such a flexibility-imparting agent, the surface of the inorganic filler may be treated with a two-component type silicone rubber or silicone gel.

The amount of the flexibility-imparting agent used is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the whole composition. If the amount is less than 0.5% by weight. It may not give sufficient impact resistance, and if it exceeds 10% by weight, mechanical strength may become insufficient.

If desired, the resin composition for semiconductor encapsulation of the present invention may contain other optional components within a range that does not impair the effects of the present invention.

Examples of such optional components include mold release agents such as carnauba wax, higher fatty acids and synthetic waxes, silane coupling agents, antimony oxide, phosphorus compounds and the like.

In the production of the resin composition for semiconductor encapsulation of the present invention, the predetermined amounts of the above-mentioned components are uniformly stirred and mixed, and the kneader, roll, and extruded are heated to 70 to 95 ° C. in advance. It can be obtained by a method such as kneading with a ruder, cooling, and pulverization. There is no particular limitation on the order of mixing the components.

As described above, the resin composition for semiconductor encapsulation of the present invention is used for ICs, LSIs, transistors, thyristors,
It can be preferably used for encapsulating a semiconductor device such as a diode, and can be effectively used for manufacturing a printed circuit board.

Here, when the semiconductor device is sealed,
It can be carried out by adopting conventionally used molding methods such as transfer molding, injection molding, and casting method. In this case, the molding temperature of the resin composition for semiconductor encapsulation is 150 to 180 ° C., and the post cure is 150 to 180 ° C.
It is preferable to carry out at 180 ° C. for 2 to 16 hours.

[0041]

EFFECT OF THE INVENTION The resin composition for semiconductor encapsulation of the present invention gives a cured product having good fluidity, high thermal shock resistance, excellent crack resistance after moisture absorption, and excellent adhesiveness. ,
Therefore, it does not cause the problems associated with the recent thinning of semiconductor packages, and is useful as a resin for sealing semiconductors. Furthermore, the semiconductor device sealed with the cured product of the composition of the present invention has high reliability.

[0042]

EXAMPLES Hereinafter, production examples, examples and comparative examples will be described.
The present invention will be specifically described, but the present invention is not limited to the following examples. In the following examples, all parts are parts by weight.

[Production Example 1] Reflux condenser,
To a 2 liter flask equipped with a thermometer and a sample introduction tube, put 500 ml of toluene and add 20 parts of epoxy resin of the following formula.
After the addition of 0 g, the flask was heated to dissolve the epoxy resin under reflux conditions.

[0044]

[Chemical 8]

Then, after cooling to room temperature, 40 g of a methylmethacrylate / butadiene / styrene copolymer was added, heated again and mixed under reflux for 30 minutes. afterwards,
When toluene was distilled off under reduced pressure, a cloudy white mixed resin (I) (epoxy equivalent 291) was obtained.

The particle diameter of the methyl methacrylate / butadiene / styrene copolymer in this mixed resin (I) was measured by an electron microscope and found to be 1 μm.

[Production Example 2] Reflux condenser,
200 g of an epoxy resin represented by the following formula was placed in a 1 liter flask equipped with a thermometer, a nitrogen introducing tube and a sample introducing tube, and heated and melted at 130 ° C. under a nitrogen stream.

[0048]

[Chemical 9]

To this, 100 g of methyl methacrylate / butadiene / styrene copolymer was added,
Mix at 60 ° C. for 60 minutes. It was a transparent resin immediately after tapping, but when cooled at room temperature for 12 hours, a cloudy white mixed resin (II) (epoxy equivalent: 288) was obtained.

The particle diameter of the methyl methacrylate / butadiene / styrene copolymer in this mixed resin (II) is 2 μm.
It was m.

[Production Example 3] A cresol novolak resin (EOCN1020-65, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 200, softening point: 65 ° C) was used as the epoxy resin. The mixed resin (III) of was obtained. .

The particle diameter of the methyl methacrylate / butadiene / styrene copolymer in this mixed resin (III) is 3
It was 5 μm.

[Examples 1 to 9 and Comparative Examples 1 to 5] Tables 1 and 2
The composition obtained by adding 10 parts of antimony trioxide, 1.5 parts of γ-glycidoxypropyltrimethoxysilane, 1.0 part of carbon black, and 0.8 parts of triphenylphosphine to the composition shown in FIG. The two rolls were uniformly melt mixed to obtain 14 kinds of epoxy resin compositions.

The following various characteristics (a) to (e) of these epoxy resin compositions were measured. The results are shown in Tables 1 and 2.
Also described in. (A) Spiral flow 175 ° C, 70k using a mold conforming to EMMI standard
It was measured under the condition of g / cm ² . (B) Mechanical strength (flexural strength, flexural modulus) 175 ° C, 70 kg / c according to JISK6911
Measurement was performed on a 10 × 100 × 4 mm bending bar molded under the conditions of m ² and a molding time of 2 minutes and post-cured at 180 ° C. for 4 hours. (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 dilatometer. (D) Solder crack resistance and moisture resistance after moisture absorption A semiconductor device for moisture resistance test for aluminum wiring corrosion measurement is sealed in a 14 × 20 × 20 mm flat package under the conditions of 175 ° C., 70 kg / cm ² , and molding time of 2 minutes. Stop,
Post cure was performed at 180 ° C. for 4 hours. The package was allowed to stand in an atmosphere of 85 ° C./65% RH for 72 hours for moisture absorption treatment, and then immersed in a solder bath at 260 ° C. for 10 seconds. After confirming the number of package cracks generated at this time, only non-defective products were left in a saturated steam atmosphere at 120 ° C. for 500 hours, and the defect occurrence rate was examined. (E) Adhesiveness A cylindrical molded product having a diameter of 15 mm and a height of 5 mm is molded on a 42 alloy plate under the conditions of 175 ° C., 75 kg / cm ² and a molding time of 2 minutes, and post-cured at 180 ° C. for 4 hours, and then a push pre-gauge. The peeling force between the molded product and the 42 alloy plate was measured with.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Chemical 10]

[0058]

[Chemical 11] (Note 3) Mixed resins (I) to (III): those obtained in Production Examples (I) to (III), respectively (Note 4) MBS resin: Methyl methacrylate / butadiene / styrene polymer (Note 5) Average fused silica Spherical silica with a particle size of 18 μm, maximum diameter of 75 μm (Note 6) E-5: 10 ^-5

From the results shown in Tables 1 and 2, the epoxy resin composition containing the mixed resin according to the present invention (Example) was superior in adhesiveness to the epoxy resin composition containing no mixed resin (Comparative Example).
It was also confirmed that it gives a cured product having high thermal shock resistance and excellent crack resistance after moisture absorption.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number in the agency FI Technical indication location H01L 23/31 (72) Inventor Takayuki Aoki 1 Hitomi, Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Industry Silicone Electronic Materials Technology Laboratory

Claims (2)

[Claims] 1. A mixed resin comprising (1) an epoxy resin, (2) a phenol resin, and (3) an epoxy resin represented by the following general formula (I), in which a methyl methacrylate / butadiene / styrene copolymer resin is dispersed. , [Chemical 1] (Wherein R ¹ is a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms, m is an integer of 0 to 2, and q is 0.
Is an integer of ~ 5. (4) A resin composition for semiconductor encapsulation, comprising an inorganic filler as an essential component. 2. A semiconductor device encapsulated with the cured product of the resin composition according to claim 1.