JPH0278238A - Sealing method for electronic part - Google Patents

Abstract

PURPOSE:To improve the tight adhesiveness between an electronic part and polyaryene lsulfide resin and to improve reliability by a method wherein triazine thiol is provided on the interface between the electronic part and the polyarylene sulfide resin. CONSTITUTION:After a 16-pin IC lead frame, consisting of a copper alloy, has been dipped into the methanol solution of sodium salt of dimethylaminotriazinediol, the lead frame is pulled up, methanol solution is evaporated, and a traizimethiol treatment is conducted. On the other hand, after glass fiber has been mixed to polyarylene sulfide, polyarylene sulfide resin is melted, kneaded, and pelletized. The lead frame, which is triazinthiol- treated using said polyarylene sulfide resin, is sealed. Through these procedures, the tight adhesiveness of the lead frame and the polyarylene sulfide resin can be improved, and reliability can also be improved.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a new and improved method for encapsulating electronic components, and more specifically, the present invention relates to a new and improved method for encapsulating electronic components, and more specifically, by interposing triazine thiol at the interface between electronic components and polyarylene sulfide resin. The present invention relates to a method of improving the adhesion between an electronic component and a polyarylene sulfide resin and providing an electronic component with increased reliability. Examples of such electronic components include:
I.C.

Hybrid IC,) Lanso Star, Diode.

Triode, cano 4 jitter, resistor, thyristor, coil, varistor, filter, transformer, surge absorber, motor, connector, transducer, photocoupler, Hall element, crystal oscillator, sensor, fuse, rectifier, power switch, etc. and composite parts thereof, but are not necessarily limited to these.

(Prior art and problems to be solved by the invention) For electronic components such as ICs, diodes, capacitors, resistors, etc., the purpose is to protect them, maintain electrical insulation, and prevent characteristic deterioration due to external atmosphere. It is widely practiced to seal electronic components with synthetic resin. Thermosetting resins such as epoxy resins and silicone resins are used as synthetic resins in this case, but these thermosetting resins require a long molding time, need for post-curing to be covered, and have problems with Paris. It's easy.

Disadvantages include that scraps such as snails and runners cannot be reused, and that the material itself is not easy to handle.

Therefore, in order to eliminate the drawbacks of these thermosetting resins, it has been proposed to seal with polyarylene sulfide resin, which is a thermoplastic resin. Basic performance as a sealing material for electronic components is required to be excellent in moisture resistance, and in the case of polyarylene sulfide resin TJ, the sealing material itself can be improved by blending a silane coupling agent with an inorganic filler. Moisture resistance can be improved.

The reliability of electronic components depends not only on water entering from the sealing material itself, but also on water entering from the interface between the external lead and the sealing material. Adhesion between the lead and the lead is important.

However, the adhesion of polyarylene sulfide resin to leads is significantly inferior to that of epoxy resin.
This is a major drawback.

(Means for Solving the Problems) In view of the above-mentioned circumstances, the inventors of the present invention have made intensive studies to obtain electronic components with improved adhesion between polyarylene sulfide resin and electronic components, especially leads. It has been found that the above problems can be solved by interposing triazinethiol at the interface between the arylene sulfide resin and the electronic component, and the present invention has been achieved.

The polyarylene sulfide resin of the present invention is an uncrosslinked or partially crosslinked polyarylene sulfide resin, and examples of its copolymerization include random and block copolymers.

R is an alkyl group, a nitro group, a phenyl group, a carboxyl group, a metal base of carboxylic acid, or an alkoxy group.

The polyarylene sulfide resin used has a different molecular weight depending on the type of target electronic component, and there is no particular restriction, but it is usually ASTM D1238-34 (316 ° C.
,,5kl? 2 in the melt flow rate measured at
A range of 0 to 30,000.9/10 minutes is used. The preferred range is 200 to 20,000 II/10 minutes.

The triazinethiol of the present invention has at least one
A triazine compound having thiol groups, preferably (where M is a hydrogen atom or an alkali metal, and X is, for example, -8H, -8M, -OH, -OR, -NH2゜-NR2, -NHR (R is a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms.) This is a triazine compound having at least two thiol groups in the molecule. Specific examples of the 6-position substituted 1,3.5-triazine-2,4-dithiol represented by the above general formula include -8H, -8Na, etc. as the 6-position substituent.
, -OH, -0C4H5, -0C4H,.

-NH2, -NH-CH,, -NHC2H5, -NHC
4H,, -NHC12H25゜-NHC1sHs y
I -NHC6H11t -NHC6H5r -Nl(
CH2C6H51-zu・03H6・N(CH,)2. −
NHC8H,6CH=CI(C8H,,.

-N(CH5)2. -N(C2H5)2. -N(04H
,)2. -N(C8H1,)2゜-N(C10H21)
2, -N(C12H25)2' NCCH2CH2
)2'-N(CH2CH=CH2)2,-N(CH
2CH2)20, -N(CH2CH20H)2, etc., and 6-position substitutions having these substituents 1.
．． 3. Monoalkali metal salt of 5-triazine-2,4-dithiol (typical examples of alkali metals include Na, K)
, Li) are included.

In order to intervene at the interface between the triazine thiol-containing component and the polyarylene sulfide resin, the surface of the electronic component is treated with triazine thiol and then sealed with a polyarylene sulfide resin, or a polyester containing triazine thiol is There is one method of sealing electronic components with arylene sulfide resin. The former method is preferable in terms of effectiveness, but the latter method is simpler in terms of operation. Specifically, the former method involves diluting triazinethiol with an organic solvent or water to a concentration of, for example, 0.01 to 3%, and then immersing electronic components in the diluted solution, or spraying or brushing the diluted solution. Thereafter, the surface of the electronic component can be treated with trianonethiol by evaporating the diluting medium. - The latter method is achieved by preparing a polyarylene sulfide resin composition containing 0.01 to 10% by weight of trianonethiol.

The electronic component used in the present invention usually has a lead portion. The metal of the lead part is not particularly limited, but the most preferred are copper, copper alloy, lead, and lead alloy, and nickel,
Also included are zinc, iron, silver, aluminum, and alloys thereof.

In the present invention, known inorganic or organic fillers can be used, and although there are no particular limitations, specific examples are as follows.

Examples of inorganic fillers are silica, diatomaceous earth, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, antimony oxide, and nomaritum ferrite.

Sutro/titanium ferrite, beryllium oxide, pumice, pumice balloon, alumina fiber, silica fiber.

Oxides such as silica peas; water-dispersed aluminum.

Hydroxides such as magnesium hydroxide and basic magnesium carbonate; carbonates such as calcium carbonate, magnesium carbonate, dolomite, and dawsonite; calcium sulfate, barium sulfate, and ammonium sulfate.

()Sulfites such as calcium sulfite; talc.

Clay, mica, asbestos, glass fiber, glass balloon, glass beads, calcium silicate.

Silicates such as montmorillonite and bentonite, carbon such as carmen black, graphite, carbon fiber, and carbon hollow spheres; and iron powder, copper powder, lead powder, aluminum powder, molybdenum sulfide, boron fiber, silicon carbide fiber, brass fiber, Potassium titanate, lead zirconate titanate, zinc borate, nitrium metapho'7ate, calcium borate, sodium borate, etc.

An example of an organic filler is aromatic polyamide fibers.

Examples include aromatic polyester fibers.

The amount of the filler added is usually 0 to 100 parts by weight per 100 parts by weight of the polyarylene sulfide resin. A suitable range can be selected depending on the application.

The polyarylene sulfide resin used in the present invention can be obtained by mixing the polyarylene sulfide resin with optionally a predetermined amount of filler and triazinethiol, and melting and kneading the mixture using a known kneader such as an extruder or a Banbury mixer. Additionally, other polymers such as polyolefins, polycarbonates, polyesters, polyethersulfones, polysulfones, liquid crystal polymers, polyetheretherketones, polyimides may be used without departing from the scope of the invention.

Polyamideimide, epoxy, polyphenylene ether, ytelyamide, unhydrogenated or hydrogenated styrene butadiene rubber, EPDM rubber, polybutene polyisoptylene, polyisoprene, silicone rubber, etc. can all be added.

In addition, the composition of the present invention may contain known additives such as coupling agents (7ran, titanate, etc.), antioxidants, heat stabilizers,
Corrosion inhibitors, lubricants, colorants, and crystal nucleating agents can be added.

Electronic components are encapsulated with polyarylene sulfide resin using a resin encapsulation molding machine such as a press, a transfer molding machine, or an elbow molding machine, at a resin temperature of 260 to 400°C.
It can be carried out at a mold temperature of 20 to 220°C.

(Effects of the Invention) According to the method for sealing an electronic component of the present invention, the adhesion between the electronic component and the polyarylene sulfide resin is improved, and an electronic component having increased reliability can be obtained.

(Example) The present invention will be explained below with reference to Examples and Comparative Examples.

Example 1 A 16 pin IC lead frame (made of prepared alloy) shown in Fig. 1 was placed in a methanol solution of 1% monosodium salt of 6-nomethylamino-1.3.5-triazine-2,4-dithiol at 60°C for 30 minutes. After immersion, the lead frame was pulled up, methanol was evaporated, and triazinethiol treatment was performed. On the other hand, the polyarylene sulfide resin was prepared by mixing 40 parts by weight of glass fiber and 110 parts by weight of silica with 42,100 parts by weight of polyarylene sulfide having a melt flow rate of 8,000 and F/10 minutes.
The mixture was melt-kneaded at 300° C. using an M extruder to form pellets. The polyarylene sulfide resin was used to seal the triazone thiol-treated lead frame prepared above, and a red ink penetration test was conducted to examine the adhesion between the lead and the polyarylene sulfide resin. The degree of penetration was less than 5%.

Red ink penetration test A sealed molded product of the lead 16 pin IC lead frame was boiled in red ink at 120°C for 48 hours, and the percentage of red ink penetration was determined for the longest lead portion sealed with the resin composition. was evaluated in (a).

100 inches: All intrusion 0%: No intrusion at all Comparative Example 1 A red ink penetration test was carried out in the same manner as in Example 1 except that a lead frame not treated with triazinethiol was used.

The degree of red ink penetration was 100 inches.

Example 2 The copper alloy lead frame of Example 1 was Pb/8n=p6
In the case of a lead frame manufactured by 42 ALLOY which was subjected to solder plating of the composition, the degree of red ink penetration was 5% or less.

Comparative Example 2 The same procedure as in Example 2 was carried out except that a lead frame not treated with triazinethiol was used. The degree of red ink penetration was 100 inches.

Example 3 In Example 1, polyarylene sulfide m't
-, polyarylene sulfide (melt flow rate 5
When the composition was 100 parts by weight (00.9/10 minutes) and 30 parts by weight of glass fiber, the degree of red ink penetration was 5%.

Example 4 When 0.2% by weight of epoxysilane was added to the polyarylene sulfide resin composition in Example 1, the degree of red ink penetration was 5% or less.

Examples 5 to 9 Table 1 shows the results of experiments conducted in the same manner as in Example 1, except for using other triazinethiols.

Table-1 Example 10 Polyarylene sulfide (Melt Flow Ray) 15
000.9/10 minutes) 100 parts by weight, 50 glass peas
i parts by weight, 50 parts by weight of follastonite, 3% by weight of monosodium salt of 6-dimethylamine-1.3.5-) riazine-2,4-dithiol were mixed and melted at 290°C using a 50W extruder. It was kneaded and made into one let. When an untreated copper alloy lead frame was sealed using the polyarylene sulfide resin and the adhesion between the lead and the polyarylene sulfide resin was examined, the degree of red ink penetration was 20 inches.

Comparative Example 3 In the polyarylene sulfide resin of Example 10, 6
-dimethyl-amino1,3#5-)rianone-2,4
- When the same experiment was conducted except for the monosodium salt of dithiol, the degree of penetration of red ink was 100%◎ Patent attorney Katsutoshi Takahashi

Claims (1)

[Claims] A method for sealing an electronic component, characterized by interposing triazinethiol at the interface between the electronic component and a polyarylene sulfide resin.