JPH06136268A - Resin composition for sealing semiconductor element - Google Patents

Abstract

PURPOSE:To provide a resin composition for sealing a semiconductor element containing a specific aromatic polysulfone resin, a polyphenylene sulfide resin and an inorganic filler at specific ratios and having excellent thermal shock resistance, heat-resistance and moldability. CONSTITUTION:The resin composition contains (A) 1-50wt.% of an aromatic polysulfone resin containing the recurring unit of formula and having a reduced viscosity of 0.35-0.60dl/g measured in DMF at 30 deg.C at a concentration of 1g/dl, (B) 99-50wt.% of a polyphenylene sulfide resin and (C) 20-250 pts.wt. (based on 100 pts.wt. of A+B) of an inorganic filler such as fused silica.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition for encapsulating a semiconductor element.

[0002]

2. Description of the Related Art Conventionally, thermosetting resins such as silicon resins and epoxy resins have been used as sealing materials for semiconductor elements such as ICs and LSIs. However, thermosetting resins have drawbacks such as long molding time, long post-curing, and poor resin yield. In order to solve these problems, it has been considered to seal the semiconductor element with a thermoplastic resin. Among them, polyphenylene sulfide (hereinafter abbreviated as PPS) resin has been attracting attention because it can withstand heat applied by solder dip during soldering and is relatively inexpensive among engineering plastics.
However, the semiconductor element sealed with PPS resin has a temperature of -65 ° C.
When the thermal cycle test is performed at up to 200 ° C., cracks are likely to occur in the resin and the thermal shock resistance is low, which is a problem. Therefore, as an attempt to improve the thermal shock resistance, Japanese Patent Application Laid-Open No. 61-21635 discloses a method in which a polysulfone resin is added to a PPS resin, but it has not been sufficiently improved and a recent semiconductor The performance required by the element sealing resin has not been achieved sufficiently.

[0003]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and an object thereof is to:
In addition to the excellent heat resistance originally possessed by PPS resin, a resin composition for encapsulating a semiconductor element, which has thermal shock resistance (in this specification, refers to crack resistance during heating and after cooling) and has good moldability. To provide things.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems. As a result, by blending a PPS resin and a specific aromatic polysulfone resin, various kinds of respective resins can be obtained. In addition to the excellent properties of PPS
It was found that a resin composition having improved resin crack resistance and excellent heat resistance and moldability was obtained, and the present invention was completed. The resin composition for encapsulating a semiconductor device of the present invention comprises 1 to 50% by weight of an aromatic polysulfone resin having a repeating unit represented by the following formula (I) and a PPS resin 99 to 5:
20 to 250 parts by weight of an inorganic filler is included with respect to 100 parts by weight of a resin composed of 0% by weight, and the reduced viscosity of the aromatic polysulfone is 1 g / concentration in dimethylformamide.
0.35 when measured under conditions of dl and temperature of 30 ° C.
~ 0.6 dl / g.

[0005]

[Chemical 2]

The aromatic polysulfone resin of the present invention has a repeating unit represented by the above formula (I). Preferably, the aromatic polysulfone resin has the above formula (I) and the following formula (II)
It may be a copolymer with the repeating unit represented by (XVII). The aromatic polysulfone copolymer has the repeating unit of the above formula (I) of 50 mol% or more and the following formulas (II) to (XVII).
It is preferable that at least one kind of repeating unit selected from the group consisting of repeating units represented by The aromatic polysulfone resin is
It is more preferable that the repeating unit (II) is contained in an amount of 5 to 30 mol%.

[0007]

[Chemical 3]

[0008]

[Chemical 4]

When the above aromatic polysulfone resin contains the repeating unit (II) in a proportion of 5 to 30 mol%, the heat resistance of the resin composition of the present invention is improved. When the content of the repeating unit exceeds 30 mol%, the melt viscosity increases and the processability decreases. The molecular weight of the aromatic polysulfone can be based on the reduced viscosity, and the reduced viscosity is
When measured in dimethylformamide at 30 ° C. at a concentration of 1 g / dl, 0.35-0.6 dl / g is required. When the reduced viscosity is less than 0.35 dl / g, the thermal shock resistance of the sealing body using the obtained resin composition is poor, and
When it exceeds 6 dl / g, the moldability becomes low.

The method for producing the aromatic polysulfone resin used in the present invention is not particularly limited, but a preferred method is to prepare a monomer having a hydroxyl group and a halogen group in a polar solvent in the presence of an alkali metal salt. A nucleophilic substitution polycondensation method of polymerizing a monomer having (at least one of these has a sulfonyl group) (a monomer having a hydroxyl group and a halogen group may be used) is used,
For example, there is a method of polymerizing these monomers in an aprotic polar solvent in the presence of an alkali metal carbonate.

The above-mentioned alkali metal carbonate has the above formula (I),
Alternatively, it is capable of forming an alkali metal salt by reacting with a monomer having a hydroxyl group among the above monomers for forming the repeating units represented by (I) and (II) to (XVII). Examples thereof include sodium, potassium carbonate, rubidium carbonate and cesium carbonate. Particularly preferred is potassium carbonate or sodium carbonate. Further, potassium bicarbonate or sodium bicarbonate can also be used for producing carbonate by the thermal decomposition reaction represented by the following formula.

[0012]

[Chemical 5]

(In the formula, M is an alkali metal.) The amount of the alkali metal carbonate used is in order to obtain a polymer having a high molecular weight and to increase the polymerization reaction rate, based on the total molar amount of the monomers having a hydroxyl group. On the other hand, an excess molar amount is preferable. When the amount of the alkali metal carbonate used is small, it is not preferable because a large amount of free hydroxyl groups are present and only a low molecular weight product is obtained.

In the polymerization, the composition of the monomers capable of forming the repeating units of the formulas (I) to (XVII) (the above-mentioned monomer having a hydroxyl group and monomer having a halogen group) is
It is preferable to carry out in a range such that the halogen groups of all the monomers are 90 to 110 mol% with respect to the hydroxyl groups of all the monomers. In order to obtain a higher polymer, it is preferably used within the range of 95 to 105 mol%.

To prepare an aromatic polysulfone resin having the above formula (II) as a partial structure, 4,4 "-dihydroxy-p-terphenyl, 4,4"'is used as a monomer capable of forming this part. The polymer is prepared by including -dihydroxy-p-quaterphenyl.4.
4 ′ ″-Dihydroxy-p-quaterphenyl can be synthesized, for example, according to the method described in Journal of Chemical Society 1379-85 (1940).

As the polar solvent, sulfone solvents such as sulfolane, diphenyl sulfone and dimethyl sulfone, or amide solvents such as dimethylacetamide and dimethylimidazoline are preferably used.

In the production of the above-mentioned polymer, the polymerization reaction temperature is usually 80 to 400 ° C., preferably 100 to 350 ° C., though it varies depending on the reaction raw materials, the types of components, the type of polymerization reaction and the like. Be implemented. When the reaction temperature is lower than the above temperature range, the desired polymerization reaction does not proceed at a speed that can be practically used, and it is difficult to obtain a polymer having a required molecular weight. On the other hand, when the reaction temperature is higher than the above range, side reactions other than the intended polymerization reaction cannot be ignored, and the resulting polymer is significantly colored.

Next, the polyphenylene sulfide (PPS) resin used in the present invention will be described. The PPS resin used in the present invention is represented by the following general formula.

[0019]

[Chemical 6]

Here, -ph- is a structure corresponding to a phenylene derivative, for example, the following formulas (XVIII) to (X
XII) is included.

[0021]

[Chemical 7]

Here, Q is F, Cl, Br or CH ₃ and m is an integer of 1 to 3.

A typical PPS resin has the general formula —C ₆ H ₄ —
It is designated by S- and is marketed under the trade name of "Ryton" by Philippe Petroleum Company, USA.

The method for producing the PPS resin used in the present invention is disclosed in, for example, US Pat. No. 3,354,129 and Japanese Patent Publication No. 45-3368 corresponding thereto. According to this method, the PPS resin "Ryton" is prepared by subjecting resins having various degrees of polymerization to a post heat treatment step.
A resin having no cross-linking to one having a partial cross-linking can be freely produced, and a resin having appropriate melt viscosity characteristics at the time of melt blending with other components can be arbitrarily selected.

The composition of the present invention comprises 1 to 50% by weight of aromatic polysulfone and PPS resin 99 to 5 as described above.
Contains 0% by weight. Aromatic polysulfone content is 1
If it is less than 50% by weight, thermal shock resistance is not improved, and if it exceeds 50% by weight, moldability is poor.

Examples of the inorganic filler used in the present invention include fused silica, talc calcium silicate, zirconium silicate, calcium carbonate, clay, alumina, glass fiber, carbon fiber and barium sulfate powder. These may be used alone or in a mixture.
The inorganic filler is the aromatic polysulfone resin and PP.
20 to 250 parts by weight, preferably 30 to 230 parts by weight, may be added to 100 parts by weight of the S resin in total. When the compounding ratio of the inorganic filler is less than 20 parts by weight, the thermal shock resistance is insufficient, and when it exceeds 250 parts by weight, the fluidity is low.

Further, in order to improve the reliability under high humidity, at least one organic tertiary phosphine compound such as triphenylphosphine, tri-p-tolylphosphine, tri-m-tolylphosphine and methyldiphenylphosphine is used. Can be added. This organic third phosphine compound is in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the total amount of the aromatic polysulfone resin and the PPS resin,
It is preferably blended in a proportion within the range of 0.1 to 3 parts by weight. If it is 0.01 part by weight or less, the reliability under high humidity is not improved, and if it is 5 parts by weight or more, the thermal shock resistance is adversely affected.

Further, various additives may be added to the composition of the present invention within a range not impairing the effects of the present invention. For example, one or more of an antioxidant, a heat stabilizer, an ultraviolet absorber, a release agent, a colorant, a crystal nucleating agent may be contained.

The means for mixing the above components of the composition of the present invention is not particularly limited. The aromatic polysulfone resin and PPS resin can be separately supplied to the melt mixer, and these raw materials are preliminarily mixed using a mortar, a Henschel mixer, a ball mill, a ribbon blender, etc. It can also be fed to a melt mixer. When manufacturing a molded article using an injection molding machine equipped with a screw cylinder having excellent melt blending performance, it is not necessary to separately prepare a uniform melt blending composition in advance, and the aromatic polysulfone and PPS resin can be directly added. It is possible to produce molded articles of uniform composition in one step by feeding them separately or just dry blended into a screw hopper.

The resin composition thus obtained is
It is preferably used as a sealing material for semiconductor elements such as C and LSI.

[0031]

The present invention will be described below with reference to examples, but these are merely examples and the present invention is not limited to these.

Example 1 [Production of Aromatic Polysulfone Resin] 4-Chloro-4 ′-(p) was placed in a reaction vessel equipped with a stirrer, a gas inlet tube, a thermometer and a condenser with a receiver at the tip. -Hydroxyphenyl) diphenyl sulfone 100 parts by weight, anhydrous potassium carbonate 22.1 parts by weight, sulfolane 290 parts by weight were charged,
Nitrogen substitution was performed. Then, stirring and temperature increase are started under a nitrogen atmosphere, and the system temperature is 220 ° C. for 1 hour and 230 ° C.
The reaction was carried out by holding for 30 minutes at 240 ° C. for 3 hours. After completion of the reaction, the reaction solution was cooled to room temperature, potassium chloride precipitated in the reaction solution was removed by filtration, and the filtrate was poured into a large amount of methanol to precipitate a polymer powder.
The reduced viscosity of the obtained polymer was 0.40 dl / g (30
C., 1 g / dl in dimethylformamide).

[Mixing of Resin and Preparation of Test Piece] Aromatic polysulfone resin obtained by the above method and PPS resin (“Ryton P-4” manufactured by Philip Petroleum Co., Ltd.)
(Trade name)) and fused silica glass powder (“DENKA Fused Silica FS-15” (trade name) manufactured by Denki Kagaku Kogyo Co., Ltd.) are shown in Table 1.
4 with a screw after dry blending with the composition
It was extruded while being melt-kneaded with a 00 mm extruder to obtain a uniform blended pellet. Then, using the ordinary injection molding machine, the uniform blended pellets obtained above were used at a cylinder temperature of 340 to 360.
C, mold temperature 150-200 C, injection pressure 70-100
A resin test piece was obtained by injection molding under a condition of kg / cm ² using a mold into which an integrated circuit board was inserted.

With respect to the 20 test pieces obtained, a thermal shock tester (manufactured by Tabai Co., Ltd.) was used to perform a heat cycle test in the range of −65 to 220 ° C. for 50 cycles to measure the number of cracks. This was used as the standard for evaluation of thermal shock resistance. Further, the heat distortion temperature was measured as a measure of moldability. The results are shown in Table 1.

(Comparative Example 1) PPS resin ("Ryton P-4" (trade name) manufactured by Philip Petroleum Co., Ltd.) and fused silica glass powder ("DENKA Fused" manufactured by Denki Kagaku Kogyo Co., Ltd.) were used without adding aromatic polysulfone. Example 1 except that only Silica FS-15 "(trade name) was used in the composition of Table 1.
A test piece was prepared in the same manner as in.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 1. The results are shown in Table 1.

(Examples 2 to 5) The same aromatic polysulfone as in Example 1, PPS resin ("Ryton P-4" (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass powder (Electrochemical Industry) "DENKA Fused Silica FS-"
15 "(trade name) was used in the composition shown in Table 1, and a test piece was obtained in the same manner as in Example 1.

The thermal shock resistance and moldability of the obtained test piece were examined in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2) The same aromatic polysulfone as in Example 1, PPS resin ("Ryton P-4" (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass powder (manufactured by Denki Kagaku Kogyo Co., Ltd.) "Denka Fused Silica FS-1
5 "(trade name) was used in the composition shown in Table 1, and a test piece was obtained in the same manner as in Example 1.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 1. The results are shown in Table 1.

(Examples 6 to 10) [Production of aromatic polysulfone resin] 4-chloro, 4'-
(P-hydroxyphenyl) diphenyl sulfone 100
Parts by weight, 4,4 ′ ″-dihydroxy-p-quaterphenyl 32.8 parts by weight, 4,4′-dichlorodiphenyl sulfone 27.9 parts by weight, anhydrous potassium carbonate 33 parts by weight, and sulfolane 290 parts by weight. Polymerization was carried out in the same manner as in Example 1 to obtain aromatic polysulfone. The reduced viscosity of the obtained polymer was 0.40 dl / g (30 ° C., 1 g / dl in dimethylformamide).

[Mixing of Resin and Preparation of Test Piece] Aromatic polysulfone obtained by the above method, PPS resin (“Ryton P-4” (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass Powder (“DENKA Fused Silica FS-15” (trade name) manufactured by Denki Kagaku Kogyo Co., Ltd.) was used in the composition shown in Table 1, and a resin composition was obtained in the same manner as in Example 1.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3) The same aromatic polysulfone as in Example 6, PPS resin ("Ryton P-4" (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass powder (manufactured by Denki Kagaku Kogyo Co., Ltd.) "Denka Fused Silica FS-1
5 "(trade name) was used in the composition shown in Table 1, and a test piece was obtained by the same method as in Example 6.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 6. The results are shown in Table 1.

Examples 11 to 15 [Mixing of resin and preparation of test piece] 4-chloro, 4'-
(P-hydroxyphenyl) diphenyl sulfone 100
Parts by weight, 4chloro, 4'-hydroxydiphenyl sulfone 77.9 parts by weight, anhydrous potassium carbonate 44.1 parts by weight,
And 290 parts by weight of sulfolane were polymerized in the same manner as in Example 1 to obtain an aromatic polysulfone. The reduced viscosity of the obtained polymer was 0.42 dl / g (30 ° C., 1 g / dl in dimethylformamide).

[Mixing of Resin and Preparation of Test Piece] Aromatic polysulfone obtained by the above method, PPS resin (“Ryton P-4” (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass powder (Denka Fused Silica FS-15 (trade name) manufactured by Denki Kagaku Kogyo Co., Ltd.) was used in the composition shown in Table 1, and a test piece was obtained in the same manner as in Example 1.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 4) The same aromatic polysulfone as in Example 11, PPS resin ("Ryton P-4" (trade name) manufactured by Philip Petroleum Co., Ltd.), and fused silica glass powder (manufactured by Denki Kagaku Kogyo Co., Ltd.) "Denka Fused Silica FS-1
5 "(trade name)) was used in the composition shown in Table 1, and a test piece was obtained in the same manner as in Example 11.

The test pieces thus obtained were examined for thermal shock resistance and moldability in the same manner as in Example 11. The results are shown in Table 1.

[0051]

[Table 1]

A: 4-chloro-4 '(p-hydroxyphenyl) diphenyl sulfone mole fraction b: 4,4'"-dihydroxy-p-quarterphenyl mole fraction c: 4,4'-dichlorophenyl Molar Fraction of Sulfone d: 4-Chloro, 4'-Hydroxyphenyl Sulfone Molar Fraction e: Weight Fraction of Ryton P-4 f: Weight Fraction of Aromatic Polysulfone (Polysulfone of a to d) g: Inorganic Filler Part by weight of fused silica glass powder 1) The heat distortion temperature is measured according to ASTM D-648 with a load of 18.6 kg. When the heat distortion temperature is 270 ° C or less, the moldability is excellent.
Below ℃ was good, below 310 ℃ was acceptable, and above that was not acceptable.

2) A cooling / heating cycle test was performed to check the number of cracks in 20 samples.

[0054]

According to the present invention, the thermal shock resistance (crack resistance) of the PPS resin is improved by blending the PPS resin with the specific aromatic polysulfone resin and the inorganic filler, and further, in high humidity. A resin composition having excellent reliability, heat resistance, and moldability can be obtained. This composition is preferably used for sealing semiconductor devices.

Claims (1)

[Claims] 1. An inorganic filler 20 to 100 parts by weight of a resin composed of 1 to 50% by weight of an aromatic polysulfone resin having a repeating unit represented by the following formula (I) and 99 to 50% by weight of a polyphenylene sulfide resin. A resin composition for encapsulating a semiconductor element, containing 250 parts by weight to 250 parts by weight, wherein the reduced viscosity of the aromatic polysulfone is 0, when measured in dimethylformamide at a concentration of 1 g / dl and a temperature of 30 ° C. A resin composition for encapsulating a semiconductor element, which has a density of 35 to 0.6 dl / g. [Chemical 1]