JPH10193387A - Manufacture of electronic part or the like and electronic part manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost to a large extent by molding inte grally a molded product in which a moving body is housed rotatably and mova bly without being divided into a plurality of sections. SOLUTION: A core for injection molding provided with the structure of forming a cylindrical moving body with a hollow shaft section and embedding the moving body in a manner of encircling the outer periphery of the hollow shaft section is molded by using oxyalkylene group-containing polyvinyl alcohol resin, and the core is inserted in a manner of exposing a part of the core, and an easy platable liquid crystal polymer is injected into the cavity to mold a secondary molded product having the inserted core and a central shaft running through the inside of the hollow shaft. A non-platable liquid crystal polymer is so injected as to expose a protruded face on the secondary molded produce surface to mold a third molded product, which is heated in hot water to elute the core into the hot water, etched and plated to form conductive circuits on the protruded face, the inner peripheral face and the outer peripheral face of the central shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a connector, for example,
The present invention relates to a method of manufacturing a synthetic resin electronic component having a dense and complicated inner surface shape, such as a bottom plate of an outer case of a switch, a mobile phone, a video camera, or the like, and an electronic component manufactured by the method.

[0002]

2. Description of the Related Art Conventionally, electronic parts made of synthetic resin having a dense and complicated inner surface shape are injection-molded in a shape divided into a plurality of portions, and then these portions are gathered to generate heat or high frequency. To form one electronic component.

However, according to such a manufacturing method, a mold for each part is required, so that the cost of the mold is increased, the number of manufacturing steps is increased, and the parts must be joined after being formed. Not only is the number of steps to be increased increased and the process is complicated, but also there are many problems such as the strength of the joint part being inferior and it is difficult to make the strength of the entire electronic component uniform.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned problems and has solved the above-described problems. It can be molded by injection molding without being divided. Accordingly, it is an object of the present invention to significantly reduce the manufacturing cost by manufacturing with a small number of molds and a small number of steps, and to provide a high-quality electronic component by eliminating the joint.

[0005]

In order to achieve the above object, the present invention according to claim 1 of the present invention provides a component forming step for forming a cylindrical moving body, and a hollow shaft having a hollow shaft portion. A first molding step of molding an injection molding core having a structure in which the moving body is embedded so as to surround an outer periphery of a shaft portion with an oxyalkylene group-containing polyvinyl alcohol resin, and formed on a surface of an electronic component; The portion of the circuit pattern becomes a ridge, and the injection molding core is inserted into a cavity having a shape conforming to the external shape in which a part of the injection molding core is exposed, and a catalyst containing the catalyst is inserted into the cavity. Injecting a highly heat-resistant thermoplastic material that is easy to be plated, a secondary molding step of molding a secondary molded product having a central axis through which the injection molding core is inserted and penetrating the hollow shaft portion,
In the cavity of the shape that matches the external shape of the electronic component,
Inserting the secondary molded product, injecting a non-plating highly heat-resistant thermoplastic material into the cavity, molding a tertiary molded product in which the surface of the ridge of the secondary molded product is exposed. A tertiary molding step, an elution step of heating the tertiary molded article in hot water to elute the injection molding core into the hot water, and the circuit pattern exposed on the surface of the tertiary molded article after the elution step Forming a conductive circuit by roughening the surface and then plating it.

[0006] Since the core for injection molding molded in the first molding step is eluted in the elution step after the third molding step, it has a lower melting point than the plastic material from which the electronic component is to be molded. Further, a material that is water-soluble and can be easily eluted is desirable. The oxyalkylene group-containing polyvinyl alcohol-based resin used in the present invention is, for example, trade name “Ecomaty AX” manufactured by Nippon Synthetic Chemical Industry Co., Ltd. and is suitable for injection molding because it has excellent melt moldability. Since it has a melting point of 190-200 ° C. and is water-soluble, it is suitable for the elution step, and since it is biodegradable, it is extremely desirable in that it is naturally reduced without polluting the environment.

[0007] A secondary molded product in which an injection molding core molded in the secondary molding step is inserted must be able to be molded without melting the core. Furthermore, the use of electronic components generally requires solder heat resistance that can withstand solder reflow. Generally, the furnace temperature is 240-280.
Since it is exposed to an atmosphere of 10 ° C. for 10 to 30 seconds, it is a highly heat-resistant thermoplastic material capable of withstanding the same and capable of forming a circuit, and an easily-plated highly heat-resistant thermoplastic material containing a catalyst is used. Examples of the aromatic polyester liquid crystal polymer (hereinafter referred to as “liquid crystal polymer”) include C810 of trade name “VECTRA” manufactured by Polyplastics Co., Ltd. and polyphenylene sulfide (PPS) which is a high heat-resistant thermoplastic material. Those mixed with electroless plating catalysts such as precious metals such as palladium, gold and silver,
For example, PPS mixed with 0.1 wt% of palladium is used.

When a liquid crystal polymer is used, injection molding at a resin temperature of 290 to 350 ° C., which is far higher than the melting point of 190 to 200 ° C. of the polyvinyl alcohol resin as a core,
The core is excellent in that the surface of the core does not show melting, deformation, fusion or the like, and a precise shape can be obtained as a secondary molded product. Although this is an inference, the liquid crystal polymer exhibits crystalline properties while in a molten state, further exhibits an elongated molecular structure in the flow direction during molding, and its surface exhibits a unique structure called a skin layer. In addition, since the cooling and solidifying speed is much faster than that of a general resin and the fluidity is very high, the injection filling speed is high. It seems to be a unique interaction generated from the result of such a combination.

[0009] A tertiary molded product formed by the tertiary molding step and having an exposed convex ridge surface is required to have solder heat resistance similarly to the secondary molded product, and at the same time, has a non-plating property. Required. As an example, among the aromatic polyester liquid crystal polymers (hereinafter referred to as “liquid crystal polymer”), LCX3 of trade name “VECTRA” manufactured by Polyplastics Co., Ltd
64 or polyphenylene sulfide (PPS).

Further, since the elution step is carried out in hot water to elute the core for injection molding, the elution is not only easy, but also "Ecomaty AX" is biodegradable and does not pollute the environment. It is very desirable because it can be reduced naturally.

Further, when plating the surface of the tertiary molded article after the elution step after roughening the surface, a portion to be a circuit pattern and an inner peripheral surface are parts formed by the secondary molding step, so that a catalyst can be easily contained. Although it is platable, the other parts are non-plating, so that etching and plating can be easily applied only to desired locations.

According to a second aspect of the present invention, in the above-described first molding step, the first molding step is performed in a cavity having a shape that conforms to the complicated inner surface shape of the electronic component and having a shaft portion penetrating the center. In addition, the movable body is inserted so as to be fitted to the shaft portion, and the material is injected into the cavity to form the injection molding core, thereby facilitating the production of the injection molding core. To

In the electronic component according to the third aspect of the present invention, since a circuit is formed on the surface of a high-quality component in which a complicated inner surface shape is precisely formed, an electronic component excellent in reliability is provided. It is suitable for providing parts at low cost.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic component 1 according to the present invention shown in FIG.
Will be described in detail for each of the steps shown in FIGS.

Embodiment 1 (a) First, as a first step, a part forming step, in which a cylindrical moving body 2 is formed. This may be cylindrical as shown in FIG. 4 or rectangular. As the material, various materials such as metal, ferrite, and thermosetting synthetic resin can be used, and any material can be used as long as it can withstand molding of the injection molding core in the next second step.

(B) Next, as a second step, FIG. 1 shows an injection molding core 3, which is formed by a first molding step. The core 3 has a shape conforming to the inner surface shape of the electronic component 1 as a final product. The core 3 has a hollow shaft portion 3a, and the moving body 2 previously formed so as to surround the outer periphery of the hollow shaft portion is embedded. Of structure. At the time of molding, a cavity having a shape that matches the complex inner surface shape of the electronic component and has a shaft portion that passes through the center is formed on the opposing surfaces of the normal upper and lower molds (not shown). The movable body 2 is inserted into the shaft portion so as to be fitted, and then, an oxyalkylene group-containing polyvinyl alcohol-based resin (trade name “Ecomaty AX” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is injected into the cavity by a predetermined injection. Molded by injection with pressure. An example of the injection molding conditions in this step is shown below.

[0017] "Eco-Mati AX" is injected at a cylinder temperature of 210 ° C, a mold temperature of 25 ° C, an injection pressure of 900 kg / cm ² , and a cooling time of 20 seconds.

(C) Next, as a third step, FIG. 2 shows a secondary molded product 4 into which the injection molding core 3 is inserted, which is formed by the secondary molding step. is there. Although not shown, the secondary molded article 4 has convex portions 4a and 4a on the opposing surfaces of the normal upper and lower molds, and the portions of the circuit pattern formed on the surface of the electronic component 1 are formed as protrusions 4a and 4a.
Are formed to have a shape conforming to the external shape having a window hole 4b.
The injection molding core 3 was inserted, and a plating-grade liquid crystal polymer ("Vectra" C810) containing a catalyst was injected into the cavity around the injection molding core 3 at a predetermined injection pressure to be molded. Things. By this molding, the injection molding core 3 in which the moving body 2 is embedded is inserted, and the secondary molded product 4 in which the central shaft 4c passes through the hollow shaft portion 3a can be molded. An example of the injection molding conditions in this step is shown below.

“VECTRA” C810 was injected at a cylinder temperature of 320 ° C., a mold temperature of 110 ° C., an injection pressure of 1200 kg / cm ² , and a cooling time of 15 seconds.

(D) Next, as a fourth step, FIG. 3 shows a tertiary molded product 5, which is formed by a tertiary molding step. The tertiary molded product 5 has a cavity (not shown) having a shape conforming to the outer shape of the electronic component formed on the opposing surfaces of the normal upper and lower molds, and the secondary molded product 4 is inserted into the cavity. The non-plating liquid crystal polymer (“VECTRA” LCX364) is injected into the cavity around the next molded product 4 at a predetermined injection pressure and molded. The injection molding core 3 in which the moving body 2 is embedded is inserted by this molding, and the hollow shaft portion 3a is inserted.
A secondary molded product 4 having a central shaft 4c penetrating therethrough is inserted, and a tertiary molded product 5 in which the protruding ridge surface 4a of the secondary molded product 4 is exposed and the other outer peripheral surface is covered can be molded. An example of the injection molding conditions in this step is shown below.

[0021] "Vectra" LCX 364 is injected at a cylinder temperature of 300 ° C, a mold temperature of 100 ° C, and an injection pressure of 600 kg / cm ² , and the cooling time is 15 seconds.

(E) Next, the fifth step is an elution step. FIG. 4 shows a molded product after the injection molding core 3 is eluted. The tertiary molded product 5 molded in the third molding step is put in hot water and heated to 80 to 100 ° C. Liquid crystal polymer trade name "VECTRA" LCX364, C81
0 means that the heat deformation temperature is 200 ° C.
By heating to the above-mentioned 80 to 100 ° C., the core 3 formed by “Eco-Mati AX” can be eluted into the hot water through the window holes 4 b. As shown in FIG. 4, as shown in FIG.
A molded product having a shape exposing the entire inner peripheral surface 4d and the central axis 4c made of a plating grade liquid crystal polymer is obtained.

(F) Finally, as a sixth step, the molded article after the elution step shown in FIG. 5 is subjected to a surface roughening (etching) treatment, and a conductive circuit is formed by a plating treatment shown in FIG. A process for manufacturing the component 1 will be described. As an example of the etching process, an alkaline aqueous solution in which caustic soda or potassium hydroxide is dissolved at a predetermined concentration is heated to a predetermined temperature, for example, 5 ° C.
Heating is performed at 0 to 90 ° C., and the molded article after the elution step in FIG. By this processing, the ridge surfaces 4a, 4a, the entire inner peripheral surface 4d, and the outer peripheral surface of the central axis 4c which become the circuit pattern are etched and roughened as shown in an exaggerated manner in FIG. The surface of the molded article 5 is not etched and remains smooth. Next, as an example of the plating process, chemical copper plating or chemical nickel plating is performed.
The material used in the secondary molding contains a catalyst, and the surface of the ridges 4a, 4a, the entire inner peripheral surface 4d, and the outer peripheral surface of the central shaft 4c, which are the circuit patterns, are all exposed and roughened. ,
As shown in an exaggerated manner in FIG. 5, the surface is easily plated to form a conductive film 1b on the conductive circuits 1a, 1a and the entire inner peripheral surface 4d and the outer peripheral surface of the central shaft 4c. Lastly, the step of forming a conductive circuit by performing a heat treatment to remove the internal moisture is completed.

Embodiment 2 FIG. 7 shows another example of the first molding step for molding the injection molding core. In this step, the injection molding core is divided into upper and lower parts and molded using the same material as described in the first embodiment. A hollow shaft portion 31a is formed in the upper core 31. The lower core 32 has a hollow shaft portion 32a and a concave groove 32b into which the moving body 2 is fitted so as to surround the outer periphery of the hollow shaft portion. And the concave groove 32b of the core 32
The moving body 2 is inserted into the inside, and the core 31 is
2a are aligned so as to be concentric and continuous, and are joined at their opposing surfaces. Thus, an injection molding core having the same shape as that of FIG. 1 can be formed. The first and third steps are the same as those described in the first embodiment.

According to such a manufacturing method, an electronic component 1 having a complicated shape having a conductive circuit on the surface and a rotatable / movable body accommodated therein can be integrally manufactured. And it is easy to mount the electronic device on the circuit by soldering.

[0026]

The present invention uses an oxyalkylene group-containing polyvinyl alcohol resin as a material for an injection molding core, and uses a non-plating highly heat-resistant thermoplastic material as a material for an electronic component and an easy plating property containing a catalyst. The use of a high heat-resistant thermoplastic material makes it possible to integrally mold electronic components without melting the core, safely elute the core for injection molding, and allow the moving body to rotate and move inside. It is extremely excellent for producing housed complex-shaped injection molded products.

Since the moving body is buried in the core for injection molding and the central shaft portion penetrating the moving body is provided, only the moving body remains inside the electronic component after the core is eluted, and can be rotationally moved. An electronic component having a certain structure can be integrally formed, which has a remarkable effect.

Since the core for injection molding is eluted in hot water,
In addition to being easy to dissolve, this material is extremely excellent in that it is biodegradable and can be naturally reduced without polluting the environment.

Since the surface is roughened and a conductive circuit is formed on the surface containing the catalyst which is exposed on the surface and the inner peripheral surface, the circuit can be easily formed only on a desired portion and is a material having high heat resistance. In addition, heat treatment for forming a circuit can be performed safely.

The electronic component manufactured by this manufacturing method is a high-quality and highly-reliable component having a complicated shape, and it is easy to mount the electronic device on a circuit by soldering, and the cost is low. Can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an injection molding core formed by a first step of a manufacturing method of the present invention.

FIG. 2 is a perspective view showing a secondary molded product into which an injection molding core molded in a second step is inserted.

FIG. 3 is a perspective view showing a tertiary molded product in which a surface of a ridge serving as a circuit pattern of the secondary molded product is exposed.

FIG. 4 is a perspective view showing a molded article after an elution step.

FIG. 5 is a cross-sectional view showing a state where a portion to be a circuit is etched.

FIG. 6 is a cross-sectional view showing a state where a conductive circuit is formed on the surface of the electronic component.

FIG. 7 shows another embodiment of molding of a core for injection molding,
(A) is a perspective view showing an upper core, and (b) is a lower core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component 1a, 1b Conductive circuit 2 Moving body 3 Core for injection molding 3a Hollow shaft part 4 Secondary molded product 4a Protrusions which become a circuit pattern 4c Central axis 5 Tertiary molded product

Claims (3)

[Claims] 1. A component forming step of forming a cylindrical moving body, and an injection molding core having a hollow shaft portion and having the moving body embedded so as to surround an outer periphery of the hollow shaft portion. A primary molding step of molding with an oxyalkylene group-containing polyvinyl alcohol-based resin, and a portion of a circuit pattern formed on the surface of the electronic component has a convex shape, and has an outer shape in which a part of the injection molding core is exposed. Into the cavity of the matching shape, insert the core for injection molding, inject a highly heat-resistant thermoplastic material containing a catalyst into the cavity, and insert the core for injection molding. And a secondary molding step of molding a secondary molded article having a central axis penetrating through the hollow shaft portion, and in a cavity having a shape matching the external shape of the electronic component,
Inserting the secondary molded product, injecting a non-plating highly heat-resistant thermoplastic material into the cavity, and forming a tertiary molded product in which the ridge surface of the secondary molded product is exposed. A tertiary molding step, an elution step of heating the tertiary molded article in hot water and eluting the injection molding core into the hot water, and the circuit pattern exposed on the surface of the tertiary molded article after the elution step Forming a conductive circuit by roughening the surface and the inner peripheral surface and then plating to form a conductive circuit. 2. The first molding step according to claim 1, wherein the moving body is placed in a cavity having a shape conforming to a complicated inner surface shape of the electronic component and having a shaft portion penetrating a central portion. A method for manufacturing an electronic component or the like, characterized in that an insert is fitted to the shaft portion, the material is injected into the cavity, and the injection molding core is molded. 3. An electronic component manufactured by the manufacturing method according to claim 1.