JPH075836B2 - Resin composition for electronic component encapsulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for encapsulating electronic components, which is made of polyphenylene sulfide resin having excellent moisture resistance and molding processability, and is used for ICs, transistors, capacitors, Resistors, diodes, triodes, thyristors, coils, varistors, connectors, capacitors,
Transducer, crystal oscillator, fuse, rectifier,
It can be used for sealing various electronic parts such as power supplies, switches, sensors, relays, and composite parts thereof.

(Prior arts and problems to be solved by the invention) The above-mentioned electronic components such as ICs, transistors, capacitors, and resistors have electrical insulation retention, mechanical protection,
Sealing with a synthetic resin is widely performed for the purpose of preventing characteristic changes due to the external atmosphere. Conventionally, thermosetting resins such as epoxy resin and silicone resin have been mainly used as synthetic resins, but when encapsulating electronic parts using these thermosetting resins, the molding cycle is long and burrs appear. It has the drawbacks that it is easy, the storability of the resin itself is not sufficient, and the difference in sprue runner cannot be utilized.

On the other hand, polyphenylene sulfide resin has excellent heat resistance, flame retardancy, chemical resistance, and since it is a thermoplastic resin, it does not have the drawbacks found in the above thermosetting resins and has the advantage of high productivity. Therefore, in recent years, it has attracted attention as a resin for sealing electronic parts.

However, when encapsulating with polyphenylene sulfide resin, the melt viscosity at the time of encapsulation is higher than that of epoxy resin, and the reliability of the electronic component is poor due to the poor adhesion with the metal lead used in the electronic component. It has problems such as inferiority.

(Means for Solving Problems) As a result of intensive studies to eliminate such disadvantages or defects, the present inventors have found that an inorganic filler having an aspect ratio (length / diameter) of 9 or less with respect to the polyphenylene sulfide resin. High moisture resistance that can reduce the melt viscosity at the time of encapsulation, reduce the wear of the molding machine and the mold, and improve the reliability of electronic parts by using silane and using unmodified and / or modified silicone oil. It was found that a resin composition for encapsulating an electronic component having the above can be obtained, and the present invention has been completed.

The polyphenylene sulfide resin (A) of the present invention has the general formula A copolymer resin having a repeating unit of ## STR3 ## can be used within a range not departing from the object of the present invention. The polyphenylene sulfide resin is ASTM D 1238-74 (316 ° C, 5k
Melt flow rate measured by g load) is 10,000 to 10,000
It is preferably in the range of g / 10 minutes, and an appropriate melt flow rate can be selected depending on the type of electronic component. Particularly, the preferable melt flow rate of polyphenylene sulfide is 3000 to 10000 g / 10 minutes. The polyphenylene sulfide includes non-crosslinked polymers, oxygen, sulfur, trifunctional monomer crosslinked polymers and mixtures thereof.

The inorganic filler (B) having an aspect ratio of 9 or less in the present invention is, for example, silica, diatomaceous acid, alumina, titanium oxide, iron oxide, zinc oxide, antimony oxide, pumice stone, calcium carbonate, magnesium carbonate, potassium titanate, calcium sulfate. , Calcium sulfite, barium sulfate, talc, clay, mica, asbestos, glass, calcium silicate,
Montmorillonite, bentonite, wollastonite,
Examples thereof include granular or fibrous shaped or amorphous shaped substances such as silicon carbide and a mixture thereof. Particularly preferable inorganic filler (B) is silica, glass fiber, glass such as glass beads, silicic acid represented by wollastonite, or silicate.

The inorganic filler is used in an amount of 25 to 400 parts by weight, preferably 80.
Used up to 300 parts by weight. If it is less than 25 parts by weight, the heat resistance and wet heat resistance will be poor, and if it is more than 400 parts by weight, the melt viscosity will be high and the moldability will be poor, such being undesirable. The aspect ratio of the inorganic filler is 9 or less, preferably 8 or less. When the average aspect ratio is larger than 9, not only is the melt viscosity of the composition of the present invention increased, which is disadvantageous for the sealing of electronic parts, but also the moisture resistance tends to be reduced, which is not preferable, but the effect of the present invention is impaired. Unless otherwise specified, it does not prevent mixing of an inorganic filler having an aspect ratio of 9 or more.

The organic silane used in the present invention is generally known as a silane coupling agent, and includes various types such as vinylsilane, methacryloxysilane, epoxysilane, aminosilane, and mercaptosilane, for example, vinyltrichlorosilane, Vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β- (aminoethyl) -γ
-Aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane,
N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,
γ-chloropropyltrimethoxysilane and the like are exemplified, but the present invention is not limited thereto.

Further, as the unmodified and / or modified silicone oil (C) used in the present invention, various known silicone oils and modified products thereof can be used. The unmodified silicone oil is typified by polydimethylsiloxane and polymethylphenylsiloxane, and the latter includes, for example, polydimethyl-diphenylsiloxane copolymer, polydimethyl-phenylmethylsiloxane copolymer and polymethylphenyl-diphenylsiloxane copolymer. On the other hand, the modified silicone oil is obtained by modifying a part of the above-mentioned unmodified silicone oil with a functional group, and preferable functional groups are hydroxyl group, amino group, carboxyl group, epoxy group, methacryloxy group, mercapto group and the like. Is.
Specific examples thereof include terminal silanol polydimethyl siloxane, terminal silanol dimethyl diphenyl siloxane, terminal carbinol polydimethyl siloxane, terminal hydroxypropyl dimethyl siloxane, polydimethyl hydroxy alkylene oxide methyl siloxane, terminal acetoxy polydimethyl siloxane, terminal dimethyl amino poly Dimethylsiloxane, terminal ethoxypolydimethylsiloxane, terminal stearoxypolydimethylsiloxane, terminal aminopropylpolydimethylsiloxane, aminoalkyl-containing T structure polydimethylsiloxane, terminal carboxypropylpolydimethylsiloxane, carboxypropyl-containing T structure polydimethylsiloxane, terminal grease Sidoxypropyl polydimethylsiloxane, T structure containing glycidoxypropyl Polydimethylsiloxane, polyglycidoxypropylmethylsiloxane, polyglycidoxypropylmethyl-dimethylsiloxane copolymer, terminal methacryloxypropyl polydimethylsiloxane, methacryloxypropyl-containing T-structure polydimethylsiloxane, polydimethyl-methacryloxypropylmethylsiloxane, Examples thereof include mercaptopropyl-containing T-structure polydimethylsiloxane and polymercaptopropylmethylsiloxane. The viscosity of the above unmodified and / or modified silicone oil is not particularly limited within the range of 10 ctsk to 5,000,000 ctsk at 25 ° C., but high viscosity is more preferable.

The organic silane and the unmodified and / or modified silicone oil (C) used in the present invention are used in an amount of 0.2 to 25 parts by weight per 100 parts by weight of the polyphenylene sulfide resin as the component (A). Moisture resistance of the composition and fluidity at the time of sealing are deteriorated, and the adhesiveness with the leads of electronic parts is impaired, which is not preferable. On the other hand, if it is 25 parts by weight or more, increase of volatile components at the time of sealing, and sealing A problem such as bleeding on the surface of the molded product is not preferable, which is not preferable. Further, the quantitative ratio of the organic silane to the unmodified and / or modified silicone oil is preferably 95: 5 to 5:95 (weight ratio), and when the ratio exceeds 95: 5, the amount of the organic silane is large and the unmodified and modified silicone is large. When the amount of oil is reduced, the effect of the modified silicone oil is apt to be impaired, and problems such as deterioration of fluidity at the time of sealing, deterioration of adhesion with the leads of electronic parts, abrasion of a molding machine and a mold are likely to occur. On the other hand, if the ratio exceeds 5:95 and the amount of the organic silane is small and the amount of unmodified and / or modified silicone oil is large, the effect of the organic silane is likely to be impaired and the moisture resistance of the present composition is likely to be deteriorated, which is not preferable.

The composition of the present invention comprises a polyphenylene sulfide resin (A), an inorganic filler having an aspect ratio of 9 or less (B), an organic silane, an unmodified and / or modified silicone oil (C).
Can be obtained by melt-kneading with a known kneader such as an extruder or a Banbury mixer. The respective components may be mixed by, for example, adhering an organic silane, unmodified and / or modified silicone oil to an inorganic filler in advance, and then mixing them with a polyphenylene sulfide resin, or mixing all the components at the same time. The melt-kneading temperature in the kneader is preferably 280 to 400 ° C. Further, the composition of the present invention is
Other polymers such as polyolefins, polysulfones, polyimides, polyamideimides, epoxies, polyphenylene ethers, polyamides, unhydrogenated or hydrogenated styrene butadiene rubber, EPDM without departing from the object of the present invention.
Rubber and polybutene can be added.

Further, the composition of the present invention is a known additive such as an antioxidant,
Heat stabilizers, corrosion inhibitors, lubricants, colorants can be added.

The sealing of electronic components in the present invention is not particularly limited, but generally electronic components, for example, IC. Transistor, diode, coil, capacitor, resistor, varistor, connector, various sensors, converter, A switch, a resistor, a thyristor, a crystal oscillator, a fuse, a rectifier, a power relay, a transducer, etc. or a hybridized part of these are encapsulated with a resin composition to provide mechanical protection, electrical insulation retention, and characteristics change due to the external atmosphere. What is done for the purpose of prevention.

(Effects of the Invention) The resin composition for encapsulating electronic parts, which comprises the polyphenylene sulfide resin of the present invention, has excellent moisture resistance and molding processability. Have.

(Examples) Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

Examples 1 to 7 and Comparative Example 7 100 parts by weight of a polyphenine sulfide resin having a melt flow rate of 5000, various inorganic fillers, organic silane, and unmodified silicone oil were melt-kneaded and pelletized by using a 65 mmφ extruder at 320 ° C. did. The obtained pellets were used as an injection molding machine to prepare a test piece for measuring physical properties at a resin temperature of 320 ° C. and a mold temperature of 150 °, and the results shown in the following table were obtained.

For the adhesion to metal, the 16-pin ID lead frame shown in Fig. 1 is sealed, the molded product is immersed in red ink at 121 ° C and 2 atm for 24 hours, and the red ink permeates the metal surface. The degree was observed. IC leads were made of silver-plated copper alloy.

Examples 8 to 13 and Comparative Examples 2 and 3 The same experiment was conducted using various modified silicone oils instead of the unmodified silicone oils in Examples 1 to 7, and the results in Table 2 were obtained.

[Brief description of drawings]

FIG. 1 is a diagram specifically showing only the upper right portion of a 6.2 mm × 19.0 mm IC encapsulation-molded product, and the numerals in the figures 1 to 3 indicate the degree of penetration of red ink on the lead metal surface.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08L 83:04)

Claims (3)

[Claims] 1. A polyphenylene sulfide resin (A) 10
Resin for encapsulating electronic parts, comprising 25 to 400 parts by weight of (B) an inorganic filler having an aspect ratio of 9 or less and (C) 0.2 to 25 parts by weight of an unmodified and / or modified silicone oil with respect to 0 parts by weight. Composition. 2. The ratio of the addition amount of the organic silane to the unmodified and / or modified silicone oil (C) is 95: 5 to 5:95 (weight ratio). The resin composition for encapsulating an electronic component of. 3. The modified silicone oil is a hydroxyl group,
A silicone oil modified with a functional group arbitrarily selected from an amino group, a carboxyl group, an epoxy group, a methacryloxy group, and a mercapto group, and the electronic component encapsulation according to claim 1 or 2, characterized in that Stopping resin composition.