JPS6253009B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a liquid epoxy resin composition that has extremely excellent moisture resistance and a significantly long pot life, and is suitable for use in electronic parts and electronic devices. Epoxy resins have excellent electrical properties, mechanical properties, etc., and are therefore widely used for sealing, impregnation, etc. of electronic components and devices such as semiconductor devices. However, conventional epoxy resin compositions, especially liquid types, have insufficient moisture resistance, so electronic components sealed with them may lose their insulation properties and increase leakage current as they are used. A major drawback is that the wiring can corrode and break. As a result of intensive research aimed at solving the above-mentioned drawbacks, the present inventor has found that moisture resistance can be significantly improved by using a reaction product of a specific aromatic diamine and a specific quaternary phosphionium salt in a specific ratio as a curing agent. The present inventors have discovered that the present invention is improved and has a significantly longer pot life. That is, the present invention provides at least one of (1) a liquid epoxy resin, (2) diaminodiphenylmethane, diaminodiphenyl sulfone, and 2,6-diaminopyridine.
100 parts by weight of an aromatic diamine and at least one of tetrabutylphosphonium acetate, tetrabutylphosphonium chloride, methyltriphenylphosphonium dimethylphosphate, and methyltrioctylphosphonium dimethylphosphate. A liquid epoxy resin composition containing as essential components a curing agent which is a reaction product with 1 to 100 parts by weight of a certain quaternary phosphonium salt, (3) a flame retardant, and (4) an inorganic filler. Pertains to. The liquid epoxy resin in the present invention is not particularly limited, and any known ones can be used, such as phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin.
type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, epoxy resin derived by epoxidation of olefin bond, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic type Epoxy resin, halogenated epoxy resin, polybutadiene modified epoxy resin, acrylonitrile-butadiene copolymer rubber modified epoxy resin,
Examples include those having two or more epoxy groups in one molecule, such as epoxy resins derived from acrolein, phenol and epichlorohydrin, and epoxy resins derived from benzaldehyde, phenol and epichlorohydrin. At least one of the above is used. In the present invention, as a curing agent, 100 parts by weight of an aromatic diamine which is at least one of diaminodiphenylmethane, diaminodiphenyl sulfone and 2,6-diaminopyridine, tetrabutylphosphonium acetate, and tetrabutylphosphonium chloride are used. , 1 to 100 parts by weight of a quaternary phosphonium salt, which is at least one of methyltriphenylphosphonium dimethylphosphate and methyltrioctylphosphonium dimethylphosphate.
The reaction product is a curing agent newly developed by the present inventor, and its use significantly improves moisture resistance and significantly lengthens pot life. The reaction product usually contains 1 to 100 parts of quaternary phosphionium salt per 100 parts by weight of aromatic diamine.
Use about part by weight and heat for 10 minutes at a temperature of about 100 to 150℃.
It is prepared by reacting for about 5 hours.
This reaction is preferably carried out under a nitrogen atmosphere, but may also be carried out in the atmosphere. If the amount of the quaternary phosphonium salt used is less than 1 part by weight, the pot life cannot be extended, and if it exceeds 100 parts by weight, the cost will increase, which is not preferable. The amount of the reaction product of the aromatic diamine and the quaternary phosphonium salt used is 0.1 to 30 parts by weight based on 100 parts by weight of the epoxy resin. If it is less than 0.1 part by weight, the moisture resistance will not improve, and if it exceeds 30 parts by weight, the pot life will be shortened. In the present invention, a curing accelerator may be used in combination in order to adjust the curing speed or to ensure sufficient curing. Examples of the curing accelerator include benzyldimethylamine, triethanolamine, dimethylaminomethylphenol, tris(dimethylaminomethyl)phenol, triethyltetramine, 3,9-bis(3-aminopropyl)-2,
4,8,10-tetraoxaspiro(5,5)undecane, 1,8-diazabicyclo(5,4,
0) Tertiary amines such as undecene-7 or its phenol or organic acid derivatives, 1,2,3-
Triazoles such as benzotriazole and 5-methyltriazole, 2-phenylimidazole,
2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,
4-dimethylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 1-
Vinyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2
-Phenyl-4-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-
Methylimidazole, 2,4-diamino-6-
[2′-Methylimidazolyl-(1)′-ethyl]-sym
-triazine or its isocyanuric acid adduct,
imidazoles such as 2,4-diamino-6-[2'-undecylimidazolyl-(1)'-ethyl]-sym-triazine or its isocyanuric acid adduct;
Acetylacetonates of metals such as aluminum, titanium, zinc, zircon, nickel, iron, lead, cerium, manganese, magnesium, cobalt, copper, chromium, vanadium, uranium, thorium, strontium, sodium, potassium, beryllium, etc., or derivatives thereof, etc. At least one of these is used. When these curing accelerators are used in combination, the appropriate amount is about 10 parts by weight or less per 100 parts by weight of the epoxy resin. If it exceeds 10 parts by weight, storage stability will be poor (pot life will be short). As the flame retardant used in the present invention, a wide variety of known flame retardants can be used, such as hexabromobenzene, antimony trioxide, tetrabromobisphenol A, hexabromobiphenyl, decachlorobiphenyl, red phosphorus, etc. , at least one of these is used. The appropriate amount of flame retardant to be used is 3 to 150 parts by weight per 100 parts by weight of the epoxy resin. If the amount is less than 3 parts by weight, no flame retardant effect can be expected. In addition, in the present invention, a wide variety of known inorganic fillers can be used to improve moisture resistance, reduce the coefficient of expansion, improve thermal conductivity, etc., such as quartz glass, crystalline silica, and fused silica. , glass fiber, talc, alumina, hydrated alumina, calcium silicate, calcium carbonate, barium sulfate, magnesium, zirconium silicate, clay, mica, etc., and at least one of these is used. These inorganic fillers are preferably used in powder form. The appropriate amount of the inorganic filler to be used is 20 to 450 parts by weight per 100 parts by weight of the epoxy resin. If it is less than 20 parts by weight, no reduction in the expansion coefficient can be expected. Moreover, if it exceeds 450 parts by weight, the viscosity becomes extremely high, making it difficult to use. Furthermore, in the present invention, in addition to the above-mentioned components, additives commonly used in this type of composition, such as colorants such as carbon black, red iron oxide, and phthalocyanine green, silane coupling agents,
A moisture resistance and adhesion improver such as a titanium-based coupling agent, a thixotropic agent (thickener) such as finely powdered silica or finely powdered calcium carbonate, an antifoaming agent such as a silicone oil type, etc. may be added in combination. The liquid epoxy resin composition of the present invention is prepared using the above-mentioned components according to a conventional method. In addition, its use is not particularly limited and can be applied to a wide range of areas, but it is particularly suitable for sealing electronic parts and electronic equipment, and the molding method for this type of composition is Conventionally known methods such as casting, potting, encapsulation, injection molding, compression molding, hot press molding, sealing, pressure and heat molding,
Heat roll molding, transfer molding, far infrared curing molding, etc. can all be applied depending on the purpose. In addition to sealing, the composition of the present invention can also be used for coating, insulation, adhesion, etc. Furthermore, the composition of the present invention can be used for impregnation by dissolving it in a suitable solvent such as methyl ethyl ketone, styrene monomer, butyl carbinol, etc. You can also do that. The liquid epoxy resin composition of the present invention has extremely excellent moisture resistance and has an extremely long pot life due to the use of the specific curing agent. Moreover, since it is a liquid type, it becomes possible to automate the production line. Advantages include complete defoaming, no loss due to runners, culls, etc., and no defects due to deformation of lead wires of electronic parts, etc. The liquid epoxy resin composition of the present invention can be applied to a wide range of electronic components and devices without particular limitation, such as integrated circuits (IC), large-scale integrated circuits (LSI, VLSI),
Examples include hybrid ICs (HICs), transistors, thyristors, diodes, optical semiconductor devices (LEDs), capacitors, coils, transformers, resistors, insulators, sockets, cases, connectors, and varistors. In addition to electronic applications, it can also be applied to optical fiber adhesion, various other mechanical parts, various containers, etc. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1 to 5 and Comparative Examples 1 to 4 100 parts by weight of diaminophenylmethane and 50 parts by weight of tetrabutyl phosphonium acetate were reacted at 120°C for 1 hour in a nitrogen atmosphere, and then cooled to produce a pale yellow reaction product. I got item A. Further, 100 parts by weight of diaminodiphenylmethane and 40 parts by weight of tetrabutylphosphonium chloride were reacted at 120° C. for 1 hour in a nitrogen atmosphere, and then cooled to obtain a reaction product B. Further, 100 parts by weight of diaminodiphenylsulfone and 25 parts by weight of methyltriphenylphosphonium dimethylphosphonate were reacted at 130° C. for 2 hours in a nitrogen atmosphere, and then cooled to obtain a reaction product C. Further, 100 parts by weight of 2,6-diaminopyridine and 10 parts by weight of methyl trioctyl phosphonium dimethyl phosphate were reacted at 110° C. for 1 hour in a nitrogen atmosphere, and then cooled to obtain a reaction product D. The present invention using the above reaction products A, B, C or D or diaminodiphenylmethane, diaminodiphenyl sulfone, 2,6-diaminopyridine or phenol novolak resin as a curing agent and having the composition shown in Table 1 below. A comparative liquid epoxy resin composition (only Comparative Example 4 was in solid form) was prepared.

[Table] Next, each component was stirred in vacuum using a planetary mixer at 30°C, then taken out, and an integrated circuit component was cast onto a ceramic substrate using a dispenser, and then heated at 100°C for 1 hour. The resin-sealed semiconductor device was obtained by curing at 150° C. for 3 hours. However, only in the case of Comparative Example 4, the molding was performed by transfer molding at 170° C. under a pressure of 80 kg/cm ² for 2 minutes, and then cured at 150° C. for 5 hours to obtain a resin-sealed semiconductor device. Next, the gelation time, pot life, and yield of each of the compositions obtained above, as well as the moisture resistance of each resin-sealed semiconductor device, deformation of lead wires, and generation of bubbles were investigated. The test method is shown below. Γ gelation time...Place 1 g of sample on a hot plate at 150°C and stir with a metal rod. The time (seconds) until stirring became impossible due to gelation was measured, and this was taken as the gelation time. ΓPot life: When stored in a sealed container at a temperature of 23℃ and a humidity of 60% or less, the time (in days) until the gelation time at 150℃ becomes 1/2 of the initial value. was taken as the pot life. Γ yield...calculated using the following formula. Amount of the composition used in the product/amount of the entire composition used ×100=yield (%) Γ Moisture resistance: Evaluated by Pressure-Jakkutsker test (PCT). That is, 30 resin-sealed semiconductor devices each were examined for disconnection due to corrosion of the aluminum wiring when 20V was applied for 1000 hours under high-pressure steam at 120°C. Deformation of Γ lead wire...30 each for each resin-sealed semiconductor device
The deformation of the lead wire was examined using X-rays. Generation of Γ bubbles: Thirty resin-sealed semiconductor devices were examined for the generation of bubbles by external appearance and X-rays. The results of each test are shown in Table 2 below.

【table】

Claims (1)

[Claims] 1 (1) Liquid epoxy resin, (2) Diaminodiphenylmethane, Diaminodiphenyl sulfone and 2,6
- 100 parts by weight of an aromatic diamine which is at least one type of diaminopyridine, tetrabutylphosphonium acetate, tetrabutylphosphonium chloride, methyltriphenylphosphonium dimethylphosphate, and methyltrioctylphosphonium dimethylphosph (3) a curing agent which is a reaction product with 1 to 100 parts by weight of a quaternary phosphonium salt which is at least one type of ate;
A liquid epoxy resin composition characterized by containing a flame retardant and (4) an inorganic filler as essential components.