JPH06134802A - Injection molded article - Google Patents

Abstract

PURPOSE:To obtain a novel injection molded article remarkably improved in resistance to water absorption from a boundary between a primary injection molded item and a secondary injection molded item. CONSTITUTION:In an injection molded article formed by conducting an injection molding twice, i.e., a primary molding and a secondary molding, a polyphenylene sulfide resin (PPS resin) is used as a material to be primarily and secondarily molded. The polyphenylene sulfide resin (PPS resin) is injection molded into a primary molded item around a lead frame 3. An electrical part 4 is connected to the ends of the lead frame 3 of the primary molded items by soldering or spot welding. A range of the connecting part over the primary molded items 8 is covered with the same polyphenylene sulfide resin (PPS resin) as the material of the primary molded item 8 by secondary injection molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article, and more particularly to an injection molded article using an engineering plastic.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings.
4 and 5 are cross-sectional views showing an example of a two-time injection molded product. That is, FIG. 4 shows two pieces formed around the lead frame 3 by primary injection molding of a molding material such as vinyl, polyethylene, polycarbonate (PC), polybutylene terephthalate (PBT), ABS resin, polyamide (PA). The electrical components 4 are soldered or spot-welded to the respective ends of the lead frame of the primary molded product of No. 1 and connected in a straight line, and the above-mentioned 1
A secondary molded product 2 is formed by performing secondary injection molding with the same material as that of the next molded product and covered. And the primary molded product and 2
Insulation tape 5 of vinyl adhesive tape to prevent water or moisture from entering from the adhesive surface (boundary) between the next molded product
Is wrapped with tape to form a more complete waterproof structure.

FIG. 5 is a primary molding in which molding materials such as vinyl, polyethylene, polycarbonate (PC), polybutylene terephthalate (PBT), ABS resin, polyamide (PA), etc. are subjected to primary injection molding like FIG. After the lead frame 3 of the product is connected to each other by soldering or spot welding, the secondary molded product 2 of the same material is injection-molded to form the secondary molded product 2.
It is formed by applying an adhesive agent 7 such as a vinyl paint or an epoxy resin in order to prevent water or moisture from entering from the bonding surface of the boundary surface between the secondary molded product 1 and the secondary molded product 2.

[0004]

As described above, in the case of the application requiring particularly the water absorption resistance, as shown in FIG. 4 and FIG. 5, in the molded article injection-molded with the above-mentioned molding material such as vinyl, Since sufficient adhesion cannot be obtained on the bonding surface of the primary molded product and the secondary molded product, it is necessary to wrap the boundary with insulating tape or apply adhesive to reinforce it to prevent water and moisture absorption. was there. In addition, these materials also have a drawback that heat resistance is insufficient and product reliability is poor. Further, since the molding process is performed, the price is increased and the process is performed manually, so that there is a problem that uniform reliability cannot be obtained.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to greatly improve the water absorption resistance from the boundary between the primary injection molded product and the secondary injection molded product. To provide.

[0006]

SUMMARY OF THE INVENTION The present invention provides an injection-molded article formed by two injection molding processes, a primary molding process and a secondary molding process, wherein a polyphenylene sulfide resin (PPS) is used as the material for the primary molding process and the secondary molding process. ) Is used to form an injection-molded article.

[0007]

[Function] Since polyphenylene sulfide resin (PPS) is used as a material for the primary molding and the secondary molding,
The secondary molded product and the secondary molded product had good adhesion and strong adhesion, and the water absorption from the boundary between the primary molded product and the secondary molded product could be greatly improved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of an injection-molded product according to an embodiment. That is, primary injection molding is performed around the lead frame 3 using polyphenylene sulfide resin (PPS) to form a primary molded product 8. Next, the electrical components 4 are linearly connected between the lead frames 3 of the primary molded product 8 by soldering or spot welding. Then, the lead frame 3 is formed around the connected electrical component 4.
The secondary injection molding is performed using polyphenylene sulfide resin (PPS) so as to cover the primary molded product 8 extending over the entire length, to form an integrated secondary molded product 9.

At this time, the temperature of the molding die is 50 to 110 ° C. for the primary injection molding, and the temperature of the molding die is 130 to 160 ° C. for the secondary injection molding. As a result, the adhesiveness at the boundary between the primary molded product 8 and the secondary molded product 9 became extremely strong, and the water absorption test was carried out by immersing the molded product in normal temperature water for 1000 hours. . Also,
5 cycles of 30 minutes at -55 ° C and 30 minutes at + 125 ° C
After carrying out a thermal shock test repeatedly performed 00 times, the product was immersed in water and subjected to a withstand voltage test of 1000 V. As a result, no abnormality was found in the product.

FIG. 2 is a transverse sectional view showing another embodiment.
Also in the case of this example, primary injection molding is performed around the lead frame 3 using polyphenylene sulfide resin (PPS) to form a primary molded product 8. These are opposed to each other, and the end portions of the lead frame 3 are connected by the solder 6.
Secondary injection molding is performed using a polyphenylene sulfide resin (PPS) so as to cover this connection portion over the primary molded product 8 to form an integrated secondary molded product 9.

Also in this case, as in the above example, 1
As a result of water absorption test after immersion for 000 hours, 1000
Passed the V withstand voltage test. Also, at -55 ° C for 30 minutes, +
After conducting a thermal shock test in which a cycle of 30 minutes at 125 ° C. was repeated 500 times, the product was immersed in water and subjected to a withstand voltage test of 1000 V. As a result, no abnormality was found in the product.

Next, a modification will be described with reference to FIG.
Primary injection molding is performed by using a general-purpose resin around the lead frame 3 to form a primary molded product 1. Next, the polyphenylene sulfide resin (PP
Secondary injection molding is performed using S) to form a secondary molded product 8. Next, the electrical components 4 are connected between the lead frames 3 of the secondary molded product 8 by soldering or spot welding. Subsequently, a tertiary injection molding was performed using a polyphenylene sulfide resin (PPS) so as to cover the connected electrical components 4 up to the primary molded product 8 around the lead frame 3, and integrated. The tertiary molded product 9 is formed.

[0013]

As described above, according to the injection-molded product of the present invention, the primary molded product obtained by the primary molding and the secondary molded product obtained by the secondary molding are in close contact with each other, and the high water resistance and moisture absorption resistance are obtained. Is an injection molded product. This is because the adhesion between polyphenylene sulfide resins (PPS) is extremely excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an injection-molded article according to an embodiment of the present invention,

FIG. 2 is a cross-sectional view showing the structure of an injection-molded article according to another embodiment of the present invention,

FIG. 3 is a cross-sectional view showing the structure of an injection-molded article according to a modified example of the present invention,

FIG. 4 is a cross-sectional view showing an example of a conventional injection molded product,

FIG. 5 is a cross-sectional view showing another example of a conventional injection molded product.

[Explanation of symbols]

 1 General-purpose resin primary molded product 2 General-purpose resin secondary molded product 3 Lead frame 4 Electrical component 5 Insulating tape 6 Soldering 7 Adhesive 8 PPS primary molded product 9 PPS secondary molded product

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Claims (3)

[Claims] 1. An injection-molded article formed by two injection-molding steps of primary molding and secondary molding, using a polyphenylene sulfide resin (PPS resin) as the material for the primary molding and secondary molding. An injection molded product characterized by the following. 2. An electrical component is mutually soldered or spot-welded to an end of a lead frame of a primary molded product in which a polyphenylene sulfide resin (PPS resin) is injection-molded around the lead frame, and this connecting portion is connected. An injection-molded product, characterized by being formed by secondary injection-molding and coating the same polyphenylene sulfide resin (PPS resin) as the primary-molded product over the primary-molded product. 3. The lead frame ends of a primary molded product obtained by injection molding a polyphenylene sulfide resin (PPS resin) around the lead frame are connected to each other by soldering or spot welding, and this connecting part is primary molded. 1 across items
Polyphenylene sulfide resin (PP same as the next molded product
An injection-molded article characterized by being formed by secondary injection molding with S resin) and coating.