JPH11349813A - Polyarylene sulfide resin composition for sealing electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyarylene sulfide resin (PAS) composition especially suitable as a material for sealing electronic components, which satisfies the contradictory requirements, i.e., having high bending strength and suitable melt viscosity as well as many good properties inherent in a PAS resin and has besides a small coefficient of linear expansion. SOLUTION: There is provided a polyarylene sulfide resin composition for sealing electronic components, comprising (A) 20-35 wt.% substantially linear polyarylene sulfide resin, (B) 65-75 wt.% fused silica (being in the form of spheres having a particle diameter of 10-50 μm), and (C) 3-5 wt.% elastomer and having a bending strength of 80 MPa or above and a melt viscosity of 1,000 Pa.s (at 310 deg.C and 1,200 sec<-1> ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyarylene sulfide resin composition for sealing electronic parts. For more information,
Particularly, the present invention relates to a polyarylene sulfide (hereinafter sometimes referred to as PAS) resin composition suitable for sealing a semiconductor such as an IC.

[0002]

2. Description of the Related Art Polyarylene sulfide resin is an engineering plastic having excellent heat resistance, flame retardancy, electrical properties and various mechanical properties. It is known that it is widely used as a stopping material (for example, JP-A-61-266461, JP-A-61-2960).
No. 62, JP-A-62-150752, JP-A-02-45560, JP-A-05-202245, etc.). However, in these, there was a problem that the operation reliability after the heat cycle was not sufficient.

[0003] Electronic components to be sealed are generally formed of a silicon chip, a lead frame, and the like, and the lead wires are connected to an aluminum circuit by bonding wires so as to be able to conduct electricity. When sealing such an electronic component using a resin such as PAS, a silicon chip is usually inserted in a mold in advance, and then,
For example, a method of supplying resin pellets to a screw in-line type injection molding machine and performing sealing molding has been adopted.

[0004] Materials required for sealing such electronic components include, as properties particularly required, a low linear expansion coefficient, a high bending strength, and an appropriate melt viscosity. That is, when the coefficient of linear expansion is large, there is a possibility that separation occurs at the interface between the electronic component and the chip, the lead frame or the bonding wire. If the bending strength is low, the package may be damaged, or the adhesion between the lead frame and the package may be reduced. Further, if the melt viscosity is too low, the bending strength is reduced, and if the melt viscosity is too high, the bending strength is increased, but the bonding wire may be deformed or cut during injection molding.

[0005] Looking at the prior art, it has been found that none satisfying all of these basic properties has yet been obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it has been found that the PAS resin itself has good flexural strength and a suitable melt viscosity while maintaining the good various properties of the PAS resin itself. Meet conflicting demands, and
It is an object of the present invention to provide a PAS resin composition having a small linear expansion coefficient and particularly suitable as an electronic component sealing material.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by using a polyarylene sulfide resin composition having a specific composition. That is, the present invention provides the following inventions. (1) (A) 20 to 35% by weight of a substantially linear polyarylene sulfide resin, (B) an average particle diameter of 10 to 50
A polyarylene sulfide resin composition for sealing electronic components, comprising 65 to 75% by weight of fused silica having a spherical shape of μm and 3 to 5% by weight of an elastomer (C). (2) The elastomer (C) is a copolymer of ethylene, an α, β-unsaturated carboxylic acid alkyl ester and maleic anhydride, each having a repeating unit content of 5%.
The polyarylene sulfide resin composition for electronic component sealing according to the above (1), which is an ethylene copolymer in an amount of 0 to 90% by weight, 5 to 49% by weight, and 0.5 to 10% by weight. (3) The bending strength is 80 MPa or more, 310 ° C., 1
The polyarylene sulfide resin composition for electronic component sealing according to the above (1) or (2), wherein the melt viscosity at 200 sec ^-1 is 1,000 Pa · s or less.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. 1. Each component of the PAS resin composition according to the present invention (A) Polyarylene sulfide resin The polyarylene sulfide (PA) used in the present invention
S) and (A) are polymers containing a repeating unit represented by the structural formula -Ar-S- (where Ar is an arylene group) in an amount of 70 mol% or more, and a typical substance is the following structural formula (I)

[0009]

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(Wherein R ¹ is an alkyl group having 6 or less carbon atoms, an alkoxy group, a phenyl group, a carboxylic acid / metal salt,
A substituent selected from an amino group, a nitro group, a halogen atom such as fluorine, chlorine, and bromine, and m is an integer of 0 to 4. N is an average degree of polymerization and is in the range of 1.3 to 30), and is a polyphenylene sulfide having a repeating unit of 70 mol% or more (hereinafter, may be referred to as PPS).

The PAS is generally known to have a substantially linear, molecular structure having no branched or crosslinked structure and a structure having a branched or crosslinked structure according to the production method. It must be linear in the upper part. In the case of only having a branched or crosslinked structure, the strength may be insufficient. As a preferred PAS for use in the present invention, a paraphenylene sulfide unit as a repeating unit is 70 mol% or more, more preferably 80 mol% or more.
Homopolymers or copolymers containing at least mol% are exemplified. If this repeating unit is less than 70 mol%, the original crystallinity, which is a characteristic of a crystalline polymer, tends to be low, and sufficient mechanical properties tend not to be obtained, which is not preferable. Examples of the copolymerizable structural unit include a metaphenylene sulfide unit, an orthophenylene sulfide unit,
p, p'-diphenylene ketone sulfide unit, p,
p′-diphenylene sulfone sulfide unit, p, p ′
-Biphenylene sulfide unit, p, p'-diphenylene ether sulfide unit, p, p'-diphenylene methylene sulfide unit, p, p'-diphenylene cumenyl sulfide unit, naphthyl sulfide unit and the like.

The PAS resin can be obtained, for example, by subjecting a dihalo aromatic compound and a sulfur source to a polycondensation reaction in a polar organic solvent by a method known per se. The melt viscosity of the PAS resin used in the present invention is not particularly limited, but is preferably in the range of 10 to 100 Pa · s at 300 ° C. and 200 sec ⁻¹ . (B) Fused Silica Fused silica is used for the purpose of improving the adhesion to chips, lead frames and bonding wires in electronic components because of its small coefficient of linear expansion.

[0013] The fused silica has an average particle size of 10 to 50 µm.
And those having a spherical shape of 20 to 40 μm are preferred. When the particle size is 10 μm or less, a sufficient bending strength may not be obtained, which is not desirable. Also,
In the case of an amorphous material such as crushed silica, there is a problem that the melt viscosity tends to increase. (C) Elastomer The elastomer used in the present invention includes, for example, olefins having a functional group such as a carboxyl group or a salt thereof, an acid anhydride group, an amino group, a hydroxyl group, and a mercapto group; Elastomers may be mentioned. More specifically, the monomer component is ethylene,
A copolymer of an α, β-unsaturated carboxylic acid alkyl ester and maleic anhydride, each having a repeating unit content of 50 to 90% by weight, 5 to 49% by weight, 0.5 to 0.5% by weight.
10% by weight, preferably 60-85% by weight, 7-45%
% By weight, 1 to 8% by weight of an ethylene copolymer.

Further, there may be mentioned hydrogenated styrene-butadiene copolymer (SEBS) and acid-modified products thereof, specifically, olefin-based elastomers containing maleic anhydride-modified SEBS, fumaric acid-modified SEBS, and the like. (D) Other components In addition to the above components, the PAS resin composition according to the present invention may further include, as necessary, a range that does not impair the object of the present invention.
Other components may be added and blended. Other components include, for example, silane coupling agents, inorganic fillers,
Various additives such as antioxidants, heat stabilizers, lubricants, coloring agents, plasticizers, conductivity-imparting agents, polyamides, epoxy resins,
Silicone resin, silicone oil, silicone oil with various functional groups introduced, thermoplastic resin and / or thermosetting resin such as polyolefin, polyether sulfone, polyphenylene ether, hydrogenated SBS, hydrogenated NBR, silicone rubber, fluorine Rubbers such as rubber,
Pigments and the like can be mentioned.

Among them, a silane coupling agent, especially an epoxy silane coupling agent, is preferably added for the purpose of improving the wettability of silica. The amount of addition is usually 0.5 with respect to 100 parts by weight of the total amount of the above components (A) to (C).
The amount is preferably from 1.2 to 1.2 parts by weight, more preferably from 0.6 to 0.9 parts by weight. The method of addition is not particularly limited, and examples thereof include an integral blend, a method of treating silica surface in advance, and a combination thereof. Examples of the silane compound include those having an epoxy group, a mercapto group, a vinyl group, an isocyanate group, a sulfide group, and an amino group.
Among them, one or more epoxy groups in one molecule and Si-
A silane compound having one or more OR groups (R represents an alkyl group) is preferable. Here, R has 1 carbon atom.
To 20 alkyl groups, among which those having 1 to 1 carbon atoms.
0 is preferred. Specific examples include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like.

Various inorganic fillers such as granules and powders are used. For example, the granular or powdery materials include, for example, talc, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, which do not fall under the component (C) in the present invention. Examples include oxysulfate, tin oxide, alumina, kaolin, silicon carbide, glass powder, glass flake, glass beads, and the like.

Further, as the inorganic filler, a material which has been subjected to a surface treatment with a coupling agent or the like in order to improve the adhesiveness with the resin may be used. As the coupling agent, a silane coupling agent, a titanium coupling agent, or any conventionally known coupling agent can be arbitrarily selected and used. The content of other components can be appropriately selected within a range that does not impair the purpose of the present invention. 2. Properties of the polyarylene sulfide resin composition according to the present invention The PAS resin composition according to the present invention desirably has the following properties. (1) The bending strength is 80 MPa or more.

If the pressure is less than 80 MPa, the strength is insufficient.
Therefore, the package may be damaged, or the adhesion between the lead frame and the package may be reduced. (2) The melt viscosity at 310 ° C. and 1200 sec ⁻¹ is 10
00 Pa · s or less. If the melt viscosity exceeds 1000, the bending strength increases, but the bonding wire may be deformed or cut during injection molding. 3. Mixing ratio of each component of PAS resin composition according to the present invention Mixing ratio of each component of PAS resin composition according to the present invention is as follows. That is, (A) 20 to 35% by weight, preferably 24 to 26% by weight of a substantially linear polyarylene sulfide resin, and (B) fused silica 65 to 7
5% by weight, preferably 68-72% by weight, (C) 3-5% by weight of elastomer, preferably 3.5-5% by weight. (A) When the content of the substantially linear polyarylene sulfide resin is less than 20% by weight, the performance as a PAS resin may not be exhibited. There is a possibility that various requirements for parts sealing may not be satisfied. (B) 6 fused silica
If the content is less than 5% by weight, the coefficient of linear expansion does not decrease, so that thermal deformation increases and separation from a chip, a lead frame or the like easily occurs. On the other hand, if it exceeds 75% by weight, the viscosity of the resin composition may increase, and kneading may be difficult. If the content of the elastomer (C) is less than 3% by weight, the adhesion to the lead frame may be insufficient, and peeling may occur. If it exceeds 5% by weight, the strength may be reduced. 4. Preparation of PAS Resin Composition The PAS resin composition can be prepared by blending each of the above components with other components selected as necessary, and then, for example, melt-kneading them.

The above-mentioned melt-kneading can be carried out by a commonly known method. In any case, the above-mentioned components are uniformly mixed and dispersed in a resin to obtain a predetermined resin composition. I do. For the melt-kneading, a twin-screw extruder, a single-screw extruder or the like can usually be suitably used. There are no particular restrictions on the conditions for melt kneading, but it is preferable to avoid extremely high temperatures and extremely long residence times in order to limit the decomposition or foaming of other components added as needed. The specific temperature is usually 280-3
It is 50 degreeC, and 285-330 degreeC is preferable.

The PAS resin composition thus prepared is usually granulated or cut into a shape and size suitable as a material for secondary processing such as pellets, and then subjected to molding, especially injection molding. 5. Applications for Sealing Electronic Components The PAS resin composition according to the present invention is suitably used for sealing electronic components. Here, the type of the electronic component is not particularly limited, and examples thereof include a connector and a relay. The whole or a part of the current-carrying portion of the electronic component is placed on the plate-like body formed by molding the PAS resin according to the present invention, but the size and shape of this plate-like body are not particularly limited. It is appropriately selected according to the use to be used.

[0021]

EXAMPLES Hereinafter, the PAS resin composition according to the present invention will be described more specifically with reference to examples. [Examples 1 to 13, Comparative Examples 1 to 13, Reference Examples 1 and 2] Using a twin-screw extruder (TEM35, manufactured by Toshiba Machine Co., Ltd.), the following components were mixed in the proportions shown in Tables 1 and 2. After uniformly mixing using a Henschel mixer, the cylinder temperature was reduced to 3
The mixture was melt-kneaded at a temperature of 10 to 350 ° C. to produce pellets.

The mixing ratios in the table are as follows:
The component (C) is a percentage by weight and the other components are parts by weight based on 100 parts by weight of the total amount of the components (A) to (C). A blank portion indicates 0. <Each component> (A) component ・ PPS-1 Hydrous sodium sulfide (Na ₂ S) was placed in a polymerization tank equipped with a stirrer.
5H ₂ O) 833 mol lithium chloride (LiCl) 830
145 ° C under reduced pressure
, And dehydrated for 1 hour. Then, set the reaction system to 4
After cooling to 5 ° C., 905 mol of dichlorobenzene (DCB) was added, and polymerization was carried out at 260 ° C. for 3 hours. 5 contents with hot water
Times, N-methyl-2-pyrrolidone (NMP) at 170 ° C
And once with water three times, and dried at 185 ° C. to obtain PPS-1.

The melt viscosity at 300 ° C. and 200 sec ⁻¹ was 15 Pa · s. -PPS-2, PPS-3 In the preparation of PPS-1, PPS-2 and PPS-3 were prepared by changing the polymerization time and the number of washings. The melt viscosity at 300 ° C and 200 sec- ¹ is PP
S-2 was 40 Pa · s, and PPS-3 was 100 Pa · s. PPS-4 PPS-1 is obtained by heat-treating PPS-1 at 120 ° C. for 6 hours in a hot-air dryer to form a crosslink. (B) Ingredients ・ Fused silica 1: FB74, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size: 31.5 μm ・ Fused Silica 2: FB6D, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size: 6 μmφ ・ Fused Silica 3: Admatex SO, manufactured by Admatechs Co., Ltd. -C2 particle size 0.5 μmφ ・ crushed silica 4: FS-200 manufactured by Denki Kagaku Kogyo Co., Ltd.
Average particle size 27 μm Surface-treated silica A: The above fused silica 1 was previously surface-treated with epoxysilane.

Surface-treated silica B: fused silica 1
Is previously surface-treated with vinylsilane. Component (C) C-1 (AX8390) Copolymer of ethylene-ethyl acrylate-maleic anhydride, trade name: Bondyne AX8390, manufactured by Sumitomo Chemical Co., Ltd. (ethylene 68% by weight, ethyl acrylate 30% by weight,
Maleic anhydride 2% by weight) C-2 (SEBS) hydrogenated styrene-butadiene copolymer (SEBS) manufactured by Asahi Kasei Corporation, trade name: Tuftec H1041 <Other components> Talc: Talc FFR manufactured by Asada Flour Milling Co., Ltd. (FT591) JAFT591 manufactured by Asahi Fiber Glass Co., Ltd. • Epoxysilane γ-glycidoxypropyltrimethoxysilane Toray Dow Corning Silicone SH6040 • Mercaptosilane γ-mercaptopropyltrimethoxysilane Toray Dow Corning Silicone SH6062 • Chlorosilane γ -Chloropropyltrimethoxysilane SH6076 manufactured by Dow Corning Toray Silicone Co., Ltd. <Physical property evaluation method> Melt viscosity (unit: Pa · s) Viscosity at a resin temperature of 310 ° C. and a shear rate of 1200 s ⁻¹ using a capillary viscometer. Indicates the degree. Flexural strength (unit: MPa) According to ASTM D790. Wire deformation The wire deformation rate when insert molding a chip in which a 150 mm-diameter aluminum bonding wire was arranged perpendicular to the resin flow direction was evaluated. A sample having a deformation rate of less than 10% was evaluated as ○, and a sample having no deformation rate was evaluated as ×. Package destruction This was performed according to the tensile test method in JIS C-5035. Stress was applied until breakage occurred, and the broken portion was evaluated as x when the package was broken, and the lead frame was evaluated as ○. PCT failure rate This test was performed in accordance with JIS C 5030. In a pressure vessel, the temperature was 121 ° C, the relative humidity was 100%, and the pressure was 2.02.
The defective product occurrence rate (%) after performing the steam heating and pressurizing treatment under the conditions of atm for 100 hours is shown. TCT failure rate This was performed according to JIS C 5030, and was 130
The percentage of defective products (%) after 100 times of a heat treatment cycle of heating at ℃ for 1 hour and then cooling at −40 ° C. for 1 hour is shown. <Evaluation Results> The evaluation results are shown in Table 1.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

As described above, the bending strength is high while maintaining the good properties of the PAS resin itself.
In addition, it is possible to provide a PAS resin composition which satisfies the contradictory requirements of an appropriate melt viscosity and has a small linear expansion coefficient and is particularly suitable as a material for electronic component sealing.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 21:00 23:08 33:06 35:00)

Claims (3)

[Claims] (A) 20 to 35% by weight of a substantially linear polyarylene sulfide resin, and (B) an average particle diameter of 1
65 to 75% by weight of spherical fused silica of 0 to 50 μm,
(C) An electronic component sealing polyarylene sulfide resin composition comprising 3 to 5% by weight of an elastomer. (C) The elastomer is ethylene, α,
A copolymer of a β-unsaturated carboxylic acid alkyl ester and maleic anhydride, wherein the content of the repeating unit is 50 to 90% by weight, 5 to 49% by weight, 0.5 to 10% by weight, respectively.
The polyarylene sulfide resin composition for electronic component sealing according to claim 1, which is an ethylene-based copolymer in an amount of 1% by weight. 3. The bending strength is 80 MPa or more, and 31
The melt viscosity at 0 ° C and 1200 sec- ¹ is 1000 Pa
The polyarylene sulfide resin composition for sealing electronic parts according to claim 1 or 2, which is not more than s.