JPH02292362A - Resin composition and electronic component - Google Patents

Abstract

PURPOSE:To obtain an electronic component with few voids in a molded item, excellent adhesiveness with a metal, a silicon chip, etc., and moisture resistance and excellent reliability as a packaging material by incorporating polyarylene sulfide with a specified flaky substance as an essential component. CONSTITUTION:Polyarylene sulfide (A) (pref. polyphenylene sulfide contg. 70mol% or more p-phenylene sulfide units) is incorporated with a flaky substance (B) (a glass flake, a silica flake, a synthetic mica, etc., 5wt.% or more substance with a ratio of the length to thickness of 3 or larger and 20wt.% or more substance with a length of 300mum or longer are incorporated in the compsn.), if necessary, an inorg. filler such as a silica powder or a glass fiber with an aspect ratio of 50 or larger to prepare a compsn. with a melt viscosity of 3,000P or smaller (at 350 deg.C and shear velocity of 1,000/sec), which is a resin compsn. useful as a package material for electronic components.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is made of polyarylene sulfide and a flake-like substance, and has extremely low voids in the molded product, which has excellent adhesion to metals, silicon chips, etc., and moisture resistance. The present invention relates to an excellent resin composition, and also to an electronic component having excellent reliability using the composition as a packaging material.

(Prior Art) Polyarylene sulfide resin (hereinafter referred to as PAS) is known as an engineering plastic with excellent chemical resistance, heat resistance, flame retardance, and electrical properties, and is widely used in various fields. In general, thick-walled molded products made from PAS are prone to voids, and in recent years, there has been an increasing demand for lower viscosity resin materials when applied to sealing materials for precision parts and electronic parts. This situation is becoming more likely to occur. Furthermore, when used as a encapsulating material for electronic components, voids are more likely to occur because they are usually molded at low pressure, and the voids that occur can cause a decrease in strength and poor adhesion with leads and encapsulation elements. As a result, moisture resistance deteriorates, and shrinkage occurs unevenly, causing increased damage to the sealing element, resulting in a significant decrease in the reliability of electronic components.

In general, PAS has poor ductility and is brittle, so improvements in physical properties such as strength, rigidity, and toughness are attempted by incorporating fibrous reinforcing materials such as glass fiber.

However, when a large amount of fibrous reinforcing material with a relatively long fiber length is blended into PAS, these physical properties can be improved and voids can be reduced, but the viscosity of such a composition increases significantly. It was found that the molded product's surface smoothness was impaired, and it could not have the properties required for a sealing material, such as low viscosity and good adhesion to leads and elements.

(Problems to be Solved by the Invention) The present invention provides a PAS molding material that has extremely few voids in molded products, excellent adhesion to metals, silicone chips, etc. and moisture resistance, and low melt viscosity, and a package using the same. We provide high quality electronic components.

(Means for Solving the Problems) The present inventors have developed a composition in which PAS and a specific flake-like substance are essential components, and if necessary, an inorganic filler and a fibrous reinforcing material of a limited length are blended. Despite the low viscosity of the composition, there are very few voids in the molded product, and it has excellent adhesion to metals, silicon chips, etc. and moisture resistance, and the reliability of electronic parts sealed with this composition is also excellent. This discovery led to the present invention.

That is, the present invention provides (A) P A S and/or (
B) Contains one or more flake-like substances selected from glass flakes, silica flakes, and synthetic fibers, and the flake-like substances have a length/thickness ratio (hereinafter referred to as aspect ratio). 5% by weight or more (in the composition) of 3 or more, and 20% by weight or less of length 300 μm or more (in the composition)
&fl composition) and has a melt viscosity of 3000 poise or less at 350°C (shear rate 10'see-').

The PAS used in the present invention includes uncrosslinked or partially crosslinked PAS, mixtures or modified products thereof, and Bg p
The melt flow rate of AS is ASTM D1238-7
4 (360°C, 5 kg load) 2 to 60,000
g/10 min, especially the general formula XφΣS-
Polyphenylene sulfide (hereinafter referred to as PPS) containing 70 mol % or more of the structural unit represented by is preferable because it provides a composition with excellent properties. PPS polymerization methods include polymerizing P-dichlorobenzene in the presence of sulfur and sodium carbonate, and polymerizing PPS in the presence of sodium sulfide, sodium bisulfide and sodium hydroxide, or hydrogen sulfide and sodium hydroxide in a polar solvent. Polymerization methods include self-condensation of p-chlorothiophenol, but N
- A method in which sodium sulfide and p-dichlorobenzene are reacted in an amide solvent such as methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane is suitable. At this time, in order to adjust the degree of polymerization, it is a preferable method to add an alkali metal salt of carboxylic acid or sulfonic acid, or to add alkali hydroxide. If it is less than 30 mol% as a copolymerization component, the meta bond K (indicates phenyl, alkoxy, carboxylic acid, or a metal base of carboxylic acid), trifunctional phenyl sulfate is used as a block copolymer within a range that does not significantly affect the crystallinity of the polymer. Alternatively, it may be contained as a random copolymer, but preferably the copolymerization component is 10 mol% or less. In particular, when trifunctional or higher functional phenyl, biphenyl, naphthyl sulfide bonds, etc. are selected for copolymerization, the amount is preferably 3 mol% or less, more preferably 1 mol% or less.

Such PPS can be produced by common manufacturing methods, such as (1) reaction of a halogen-substituted aromatic compound with an alkali sulfide (see U.S. Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671 and Japanese Patent Publication No. 45-3368) (2) ) Condensation reaction of thiophenols in the presence of an alkali catalyst or copper salt (US Patent No. 3,274,165, British Patent No. 11)
60660) (3) Condensation reaction of aromatic compounds with sulfur chloride in the presence of a Lewis acid catalyst
No. 27255, Belgian Patent No. 29437), etc., and can be arbitrarily selected depending on the purpose.

The glass flakes and silica flakes used in the present invention are scaly glass and fused silica, respectively, and the glass is particularly preferably made of E glass.

The synthetic Mairikyo used in the present invention is crystallized water (O
It has a structure in which H) is replaced with fluorine (F), and can be synthesized by melting predetermined blended raw materials, and specifically has the general formula ×. ．． 5~,. . ■2~3Z401. For example, although not limited to the following, KMgi(A f SizO+o)Ft+KM
g,. %(Si.0,.)h, KMgzLi(Sin
O+. )F8,KMg3(Aj2GeiO+o)Fz+
KMgz. s(Ge401o)Fz+KshiJgzshi:
“Non-swellable synthetic mica” such as +Li”z3 (S1401.)F2 is used. However, so-called "Eiwa swelling synthetic mica", which swells by absorbing water, is not preferred. Furthermore, the use of natural minerals is not preferable because it reduces moisture resistance and reduces the reliability of electronic components.

The flaky substance used in the present invention has a length/thickness (aspect ratio) of 3 or more in an amount of 5% by weight or more, and a length of 30% by weight.
It is desirable that the content of particles with a diameter of 0 μm or more is 20% by weight or less. 5% by weight of items with an aspect ratio of 3 or more
Otherwise, the effect of reducing voids will be small, and the length is 30 mm.
If there are many particles larger than 0 μm, this is effective in reducing voids, but it is not preferable because the particle size becomes high and the smoothness with the interface with the lead etc. is lost, resulting in poor adhesion. In addition, it is more preferable that the flaky substance has a thickness of 30 μm or less. Further, the length of the aspect ratio is the longer one, and if it is elliptical, it corresponds to the major axis.

Compositions of the invention can include mineral fillers.

The inorganic filler mentioned here preferably has a powder-like (pulverized material), bead-like, or balloon-like shape, and specific examples of the filler include the following, which may be used alone or in combination. It is not necessarily limited to these.

For example, silica, diatomaceous earth, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, antimonic acid, antimony oxide, barium ferrite, strontium ferrite, beryllium oxide, pumice, pumice balloon, lead oxide, bismuth oxide, zirconium oxide, manganese dioxide,
Oxides such as tin dioxide, barium oxide, iron sesquioxide,
Hydroxides such as aluminum hydroxide, magnesium hydroxide, and basic magnesium carbonate; carbonates such as calcium carbonate, magnesium carbonate, dolomite, and dawsonite;
Sulfuric acid or sulfites such as calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, sulfides such as zinc sulfide, calcium sulfide, strontium sulfide, dominium sulfide, barium sulfide, talc, clay, sulfur,
Glass balloons, glass beads, calcium silicate, montmorillonite, bentonite and other silicates, carbon black, graphite, molybdenum sulfide,
Examples include boron, silicon carbide, lead zirconate titanate, zinc borate, barium metaborate, calcium borate, sodium borate, etc., but preferably non-quality or crystalline silicate or glass powder. (pulverized products), beads, and balloons, particularly preferably those made of amorphous silica, E glass, or high silicate glass.

The composition of the present invention may further contain a fibrous reinforcing material, but if the composition has an aspect ratio of 50 or more,
It is required that the amount is not more than 15% by weight, preferably not more than 15% by weight. If a large amount of long fibers are present, the number of voids will be reduced, but this is not preferable because it will increase the viscosity and reduce the adhesion to the lead. Examples of fiber reinforcing materials include glass fiber, wollastonite, potassium titanate fiber, aramid fiber, silica fiber, alumina fiber, silica/alumina fiber, zirconia fiber, boron nitride fiber,
Examples include silicon nitride fibers, boron fibers, gypsum fibers, polyester fibers, polyethylene fibers, polyacrylic fibers, fluorine fibers, phenol fibers, processed mineral fibers, and glass fibers, wollastonite, and silica/alumina fibers are particularly preferred. .

In the present invention, it is preferable to add an organic silane, usually called a silane coupling agent, for the purpose of improving moisture resistance and strength properties, such as vinyl silane, acrylic silane, amino silane, epoxy silane, mercapto silane, and halo silane. Examples include. The appropriate amount of the silane coupling agent added is 0.01 to 5% by weight in the composition. Furthermore, titanate-based, zirconate-based, zircoaluminate-based, and aluminum chelate compound-based coupling agents can also be added as required.

In the present invention, in order to further improve adhesion, unmodified and/or modified silicone oil, copolyamide, hydrogenated polymer of conjugated diene, and/or hydrogenated polymer of conjugated diene and aromatic vinyl hydrocarbon, / Or modified products in which unsaturated carboxylic acids or derivatives thereof are grafted onto the hydrogenated polymer, amide compounds such as bis fatty acids and bis aromatic amides, fatty acid lower alcohol esters, etc.
Esters such as fatty acid polyhydric alcohol esters, esters, and waxes can be added.

The composition of the present invention may also contain other polymers such as polysulfone, polyallylsulfone,
Polyether sulfone, polyester, polyolefin, polystyrene, polymethylbentene, polycarbonate, polyphenylene oxide, polyarylate, phenoxy resin, polytetrafluoroethylene, silicone rubber, silicone resin, fluororubber, nitrile rubber, polymethylbentene, Epoxy resin, liquid crystal polymer, etc. may also be added. Furthermore, known additives such as heat stabilizers, antioxidants, corrosion inhibitors, fluidity improvers, lubricants, mold release agents,
Appropriate amounts of colorants, epoxy compounds, etc. can be added. Alkali metal carbonates, hydroxides, as corrosion inhibitors
For example, it is preferable to add 0.1 to 10% by weight of sodium carbonate, lithium carbonate, lithium hydroxide, zinc oxide, lead oxide, magnesium oxide, barium oxide, dolomite, T-alumina, hydrotalcites, and the like. In particular, zinc oxide, γ-alumina, and dolomite are preferable in terms of increasing the credibility of the packaging material.

The composition of the present invention is heated at 350°C (shear rate 103 sec).
It is preferable that the melt viscosity at 3,000 poise or less is low for use as a sealing material for electronic components.

The PAS composition of the present invention can be molded into various molded products mainly by methods such as injection molding, transfer molding, compression molding, and dipping, and is particularly preferred as a packaging material for electronic parts. Examples of such electronic components include ICs, hybrid ICs, transistors, diodes, capacitors, resistors, thyristors, coils, varistors, connectors, transducers, crystal oscillators, fuses, rectifiers, power supplies, switches, various sensor relays,
These include surge absorbers, pin grid arrays, leadless chip carriers, leaded chip carriers, and composite parts thereof.

These electronic components encapsulated with the composition of the present invention have excellent adhesion to metal and silicon chips, and have increased reliability because the intrusion of water from the interface between the leads and the resin is reduced. Since voids tend to occur in thick parts, 0. 3
In the case of a part having a wall thickness greater than or equal to RTM, it can be particularly suitably used.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

<Examples 1 to 9, Comparative Examples 1 to 6> ASTM D123B-74 (360°C, 5k
Melt flow rate measured at 4000g/g load)
After blending and mixing flaky substances, inorganic fillers, and fibrous substances in the proportions shown in Table 1, PPS having a 10-minute heating time was heated at 320°C (Examples 1 to 6) using a 50 mm extruder.
, Comparative Examples 1 to 6) or 355°C (other examples), and then pelletized using a 1-ounce injection molding machine at the same cylinder temperature as extrusion pelletizing, and at the mold temperature of 1. The 16-pin IC was sealed at 80'C. The sealed tC was photographed using a TYPE-CMB manufactured by SOFTHX, and the presence or absence of gold wire breakage and the occurrence of voids were observed. Furthermore, as a reliability test, it was kept at 121°C and 2 atm for 500 hours. A pressure cooker test (PCT) was conducted to check for leaks and open conditions, and the defect rate was evaluated.

In calculating the defective rate, those with broken gold wire were excluded from the number of samples tested.

Further, the melt-kneaded pellets were baked at 800° C. for 2 hours, and the resulting residue was observed under a microscope to determine the fiber length distribution of the fibrous material.

The above results are shown in Table-1. It should be noted that the IC sealed with the composition of the present invention has no voids or broken gold wires, and the PC
Good reliability was also shown in T, but it was clear that voids occurred and the gold wires were cut in other cases, and the defective rate was high even in PCT.

The symbols in Table 11 are as follows.

1) Glass flakes: CEF-325, manufactured by Nippon Sheet Glass Co., Ltd., thickness 2-3 μm
, particle size of 300 μm or more, approximately 60% 2) Synthetic mica; PDM-7-325, manufactured by Topie Industries, synthetic phlogopite KM
g3(AISi301o)Fz, thickness 3-4 μm
, about 70% particle size 6 to 100 μm, about 30% below 6 μm 3) Glass flakes: CEF-48, manufactured by Nippon Sheet Glass Co., Ltd., thickness 2 to 3 μm, about 65% particle size 6 to 90 μm, about 35% particle size below 6 μm %4)? Fused silica: Glass grain GR-80, manufactured by Toshiba Ceramics Co., Ltd., length 44 μm or less, 70% or less 5) Glass beads: EGB-731, manufactured by Toshiba Barotii Co., Ltd., average particle size 3
0 μm 6) Silica flakes: thickness 3-4 μm, particle size 6-100
μm approximately 70%, particle size 6 μm or less approximately 30% by weight 7) Milled glass: MP-B, manufactured by Asahi Fiberglass Co., Ltd., diameter 10 μm, length 210 ± 35 μm 8) Glass fiber: Glasslon 03JA-404, Asahi Fiberglass, Chopped glass with a length of 3 ram, diameter 10 μm 9) Milled glass: NYADG, manufactured by NYCO, MP-A, Asahi 77 Everglass, diameter 10 μm, length 60 ± 15 μm 10) Wollastonite: Average aspect ratio 14, 200 mesh sieve Residue rate 3
0% or less 11) Natural mica: Susolite Mica 325H, MI? 12) Organosilane made by one company: Aminosilane, KBE903, made by Shin-Etsu Chemical Co., Ltd. (Effects of the invention) The present invention has extremely few voids in the molded product, excellent moisture resistance and adhesion to metals, and low melt viscosity. The composition and high quality electronic components packaged therewith can be produced.

teenager Reason Man

Claims (7)

[Claims] 1. Contains (A) polyarylene sulfide and (B) one or more flake-like substances selected from galac flakes, silica flakes, and synthetic mica, and the flake-like substance has a length/thickness ratio of 3 or more. 5% or more by weight (
(in the composition) and 20% by weight or less (in the composition) of 300 μm or more in length, and the melt viscosity of the composition at 350°C (shear rate 10^3sec^-^1) is 3000 poise A resin composition characterized by: 2. The resin composition according to claim 1, which contains an inorganic filler other than glass flakes, silica flakes, and synthetic mica. 3. 3. The resin composition according to claim 2, wherein the inorganic filler is one or more selected from silica powder, glass powder, silica beads, glass beads, silica balloons, and glass balloons. 4. 3. The resin composition according to claim 2, wherein the inorganic filler is a fibrous reinforcing material, and the fibrous reinforcing material contains 20% by weight or less (in the composition) of a material having an aspect ratio of 50 or more. 5. 5. The resin composition according to claim 4, wherein the fibrous reinforcing material is glass fiber and/or wollastonite. 6. The resin composition according to any one of claims 1 to 5, which contains an organic silane. 7. An electronic component comprising the resin composition according to any one of claims 1 to 6 as a packaging material.