JPH07164478A - Injection molded circuit part - Google Patents

Abstract

PURPOSE:To provide injection molded circuit parts having good strength and environmental resistance, high peel strength between an electric conductor film and a resin compound, and high reliability as electric circuit parts. CONSTITUTION:A primary injection molded article 1 is formed with a resin 7 mixed with a catalyst for electroless plating. The surface of the article 1 is roughened by sand blasting, and a resin 5 not containing the catalyst for electroless plating is injection molded secondarily on the surface so that a part of the article 1 is exposed on the surface as a pattern part of an electric circuit, thereby forming an electric conductor film 8 on the surface of the resin 7 having a shape corresponding to the pattern part of the injection molded article.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to circuit components, and more particularly to injection molded circuit components.

[0002]

[Prior art]

(1) As shown in FIG. 4, a conventional injection molded circuit component is
After forming a primary injection molded body 10 by performing a primary injection molding of a compounded resin containing a catalyst for electroless plating, a part of the primary injection molded body 10 is exposed as a pattern portion 11 of an electric circuit. As shown in FIG. 3, a non-blended resin 12 not containing a catalyst for electroless plating is subjected to secondary injection molding to mold an injection molded article 13, and the pattern portion 11 of the injection molded article 13 (of the blended resin It is obtained by forming an electric conductor coating on the exposed surface) by electroless plating. The electroless plating process includes a step of roughening the exposed surface of the compounded resin, that is, the surface of the pattern portion with a chemical to increase the exposure frequency of the catalyst and improve the adhesion between the electric conductor coating and the resin. ing.

(2) For injection molded circuit parts, after the primary injection molding of the compounded resin, the surface of the primary injection molded body is roughened with chemicals, washed with water and dried, and then subjected to electroless plating. After coating and drying the catalyst on the primary injection molded body,
This is placed in a mold and a non-blended resin is subjected to secondary injection molding so that a part of the injection molded body is exposed as a pattern portion of an electric circuit. It is obtained by forming an electric conductor film by an electrolytic plating method.

[0004]

By the way, the above-mentioned injection-molded circuit parts have the following problems.

In the case of (1), when the surface of the pattern portion formed of the compounded resin is roughened by the chemical agent in the electroless plating process, the resin not roughened by the chemical agent is replaced with the non-compounded resin. Had to be selected as. The reason is that the surface of the compounded resin is covered with an electric conductor coating, but when the non-compounded resin is roughened, it remains roughened and the surface area becomes large due to roughening, so it is environmentally resistant. This is because there is a problem in terms of. Further, if the surface is still roughened, there are many defects and the strength is lowered. However, on the contrary, when the non-blended resin is not roughened, the affinity between the blended resin and the non-blended resin is poor, peeling occurs at the interface between the two resins due to the difference in external force and the coefficient of thermal expansion, and the strength is not only lowered. However, there is a problem that water and various environmental substances easily enter the interface between both resins.

In the case of (2), the adhesiveness at the interface between the compounded resin and the non-compounded resin is better than that of (1), but after the surface of the primary injection molded body is roughened, the secondary injection molding is performed. During the process, the roughened surface is in contact with the surface of the mold, so that the roughened surface is crushed or soiled, and the peel strength of the electric conductor coating film is lowered. In addition, since the catalyst applied to the surface of the primary injection-molded body after surface roughening adheres to the surface of the mold and diffuses, an electric conductor coating is formed at an unnecessary portion, and the defective rate in terms of production is high. There was a problem.

The object of the present invention is to solve the above-mentioned problems of the prior art, to have good strength and environmental resistance, high peel strength from the resin mixture of the electric conductor coating, and high reliability as an electric circuit component. To provide injection molded circuit parts.

[0008]

In order to achieve the above object, the injection molded circuit component of the present invention is a primary injection molded article formed by primary injection molding a compounded resin containing a catalyst for electroless plating, After roughening the surface layer of the primary injection-molded product by a sandblasting method, a catalyst for electroless plating is not added so that a part of the molded product is exposed on the surface as a pattern part of an electric circuit. A compound resin is subjected to secondary injection molding, and an electric conductor film is formed on the surface of the compound resin having a shape corresponding to the pattern portion of the injection molded product by electroless plating.

In the case of injection-molded circuit parts, soldering is required for electrical connection with other electric parts. Therefore, as a compounded resin and a non-compounded resin, the soldering temperature and the soldering temperature are used. It is required that the resin is not deformed or deteriorated during the specified time. In other words, if it is an amorphous resin, it is necessary to use a resin having a glass transition temperature of 180 ° C. or higher. For example, there are polysulfone, polyether sulfone, polyallyl sulfone, polyetherimide, epoxy resin, and those in which an inorganic filler is mixed, but the invention is not limited thereto. If it is a crystalline resin, it is necessary to use a resin having a crystal melting point of 180 ° C or higher. For example, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, nylon 6, nylon 66, polyoxybenzoic acid-based resin, and those obtained by blending an inorganic filler with these are not particularly limited.

As the compounding resin, an epoxy resin which is not deformed or deteriorated even if it is immersed in a molten solder bath at 260 ° C. for 30 seconds, and a polyoxybenzoic acid resin which can form a liquid crystal structure in the surface layer of a molded article are particularly suitable . As a non-blended resin, 26
Polyphenylene sulfide, which does not deform even when immersed in a molten solder bath for 30 seconds at 0 ° C. and is not easily exposed to chemicals, is particularly suitable.

The sandblasting method is a processing method in which abrasive particles are sprayed on the surface of an object and shaving, and in this case, the diameter of the abrasive particles for sandblasting is the width of the portion of the pattern portion of the primary injection-molded body where the electric conductor film is formed. , It must be smaller than the distance between the parts forming the electric conductor coating. The reason is that if the diameter of the abrasive grains is larger than the above-mentioned size, the pattern portion of the primary injection-molded article may be significantly damaged by sandblasting, which may result in deterioration of the performance of the finally formed electric circuit. Is.

The primary and secondary injection molding can be performed by using a mold, for example.

[0013]

[Function] Since the primary injection-molded product of the compounded resin is roughened by the sandblast method and the non-compounded resin is injection-molded, the adhesion between the primary injection-molded product of the compounded resin and the non-compounded resin is improved. The bending strength of the injection molded product is improved. In addition, the resin A roughened by the sandblasting method with the chemicals in the electroless plating method
By further roughening the surface, the surface irregularities become large, and the peel strength between the electric conductor coating formed by the electroless plating method and the compounded resin is improved. Therefore, strength,
It is possible to obtain an injection-molded circuit component having improved environmental resistance and high peel strength from the resin mixture of the electric conductor coating, and high reliability as an electric circuit component.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

First, a mixed resin containing a catalyst for electroless plating is subjected to primary injection molding using a mold or the like to form a primary injection molded body 1 having the shape shown in FIG. 1, for example. In this primary injection molded body 1, a plurality of through holes 2 that form an electric conductor coating film are formed, and a through hole 3 is also formed separately from these through holes 2. The through hole 3 is for fixing the resin to be subjected to the secondary injection molding.

The surface layer of the primary injection-molded body 1 is roughened by a sandblast method, and after roughening, this is mounted in a mold so that a part of the molded body 1 is exposed on the surface as a pattern portion 4 of an electric circuit. Thus, as shown in FIG. 2, the non-blended resin 5 containing no electroless plating catalyst was subjected to the secondary injection molding to form the injection molded product 6.

The pattern portion 4 of this injection-molded product 6
As shown in FIG. 3, a copper plating film was formed as an electric conductor film 8 on the surface of the compounded resin 7 having a shape corresponding to the above by electroless plating.

Specifically, in FIGS. 1 to 3, the width d of the portion of the pattern portion 4 where the electric conductor coating is formed is 0.5 mm, and the interval e between the portions where the electric conductor coating 8 is formed is narrow. It is 0.6 mm. As the abrasive grains for sandblasting, alumina-based abrasive grains having an average diameter of 0.03 mm were used. In addition, the compounding resin 7 contains 0.1% by weight of palladium on the inorganic filler.
The adsorbed catalyst was used as a catalyst for electroless plating with 10% by weight added. The electric conductor film 8 was an electroless copper plating film and had an average film pressure of 0.05 mm. Other conditions (blended resin (resin A), non-blended resin (resin B), presence / absence of sandblast, and chemical rough chemistry in electroless plating process) are as shown in Table 1, and the results of Examples 1 to 4 and conventional Eight injection molded circuit components of Examples 1 to 4 were prototyped. Bending strength and peeling strength of the injection-molded circuit parts prototyped based on these examples were evaluated. The results are also shown in Table 1.

In the conventional example, the injection molded body shown in FIG. 1 was used without sandblasting, and the other steps were the same as those of the example. The performances of the examples and the conventional examples were evaluated by the bending strength and the peeling strength of the electroless copper-plated film when an external force was applied to the injection-molded article shown in FIG. 2 from the direction perpendicular to the paper surface. Further, in Table 1, when both the bending strength and the peeling strength are assumed to be the conventional example 1, the examples show relative values of how many times the conventional example is.

[0020]

[Table 1]

As is apparent from Table 1, it was found that in Examples 1 to 4 according to the present invention, the bending strength and the peel strength were improved.

Therefore, the primary injection-molded body 1 of the compounded resin 7 is roughened by the sandblasting method, and then the non-compounded resin 5 is injection-molded. Since the adhesiveness at the interface is improved, the bending strength of the injection molded circuit component made of both resins 7 and 5 can be improved. In addition, after shaving the surface layer of the injection molded body 1 of the compounded resin 7 by the sand blast method,
Since the surface is roughened by the chemicals in the electroless plating process, the unevenness of the surface becomes large, and the peel strength between the electric conductor coating 8 formed by the electroless plating method and the compound resin 7 can be improved. . by this,
It is possible to obtain an injection-molded circuit component having improved reliability as an electric circuit component because the strength and the environment resistance are improved and the peeling strength of the electric conductor coating film 8 from the compounded resin 7 is high.

In this embodiment, the primary injection-molded body was directly roughened by the sandblasting method. However, the inner surface of the mold for molding the primary injection-molded body is roughened by the sandblasting method or another method, and the roughened surface is You may make it transfer to a primary injection molded body. In this case, as compared with the roughened surface layer in the case of directly roughening the primary injection molded body by the sandblast method, the amount of the catalyst for electroless plating of the surface layer is slightly smaller, so it takes time to form the electroless copper plating film. However, the same effects as those of the above-described first to fourth embodiments can be obtained.

[0024]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the strength and the environmental resistance are improved, and the peeling strength of the electric conductor coating from the compounded resin is high, and the injection molding is highly reliable as an electric circuit component Circuit parts can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a primary injection-molded article of the present invention.

FIG. 2 is a plan view showing an injection-molded article obtained after performing secondary injection molding of a non-blended resin on the primary injection-molded article shown in FIG.

3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a plan view showing an example of a primary injection molded body obtained by primary injection molding a compounded resin.

FIG. 5 is a plan view showing an example of an injection molded product obtained after secondary injection molding of a non-blended resin.

[Explanation of symbols]

 1 Primary injection molded product 4 Pattern part 5 Non-compounded resin 6 Injection molded product 7 Compounded resin 8 Electrical conductor coating

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryo Sato 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Power Systems Co., Ltd.

Claims (2)

[Claims] 1. A primary resin injection molded article is formed by subjecting a compounded resin containing an electroless plating catalyst to a primary injection molding, and the surface layer of the primary injection molded article is roughened by a sand blast method, and then molded. A shape corresponding to the pattern part of the injection-molded product obtained by secondary injection molding of a non-blended resin that does not contain the electroless plating catalyst so that a part of the body is exposed on the surface as the pattern part of the electric circuit. An injection-molded circuit component, characterized in that an electric conductor film is formed on the surface of the compounded resin by electroless plating. 2. One type of resin selected from the group of epoxy type injection molding resin as the compounded resin and polyoxybenzoic acid type resin capable of forming a liquid crystal structure in the surface layer of the molded product is used as the non-compounded resin. The injection molded circuit component according to claim 1, wherein polyphenylene sulfide is used.