JPH10193389A - Manufacture of electronic part or the like and electronic part manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the reduction of a cost and the improvement of quality by molding an electronic part, which is required to be separately molded into a plurality of parts as an integrated part in which the parts are fixedly pro vided. SOLUTION: Polyvinyl alcohol resin containing oxyalkylene group is fed into a cavity of the shape for forming parts for conforming to the inner face shape of an electronic part and having a shaft section forming a through-hole for inserting the parts to mold a core for injection molding, and the parts are inserted into the through-hole in a manner of protruding the ends of the parts, and the core for injection molding is inserted into the cavity conforming to the outer shape of the electronic part. An aromatic polyester liquid crystal polymer is fed into the cavity to mold a secondary molded product into which the core for injection molding is inserted, and the secondary molded product is heated in hot water, and the core for injection molding is eluted into the hot water to manufacture the electronic part having the parts fixedly provided in the internal space.

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 for manufacturing a synthetic resin electronic component having a complicated internal space and an opening on the outer periphery, 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 complicated internal space and an opening on the outer periphery cannot be integrally formed at one time. After that, these parts are collected and joined by 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 to solve the above-mentioned problems and to divide an electronic component having a complicated internal space and an opening on the outer periphery into a plurality of parts. Instead, it can be molded by injection molding. 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, according to the first aspect of the present invention, there is provided a component forming step of forming a component fixedly provided in an internal space of an electronic component, An oxyalkylene group-containing polyvinyl alcohol-based resin is injected into a cavity having a shape that matches the inner surface shape of the electronic component and has a shaft portion to form a through-hole into which the component is inserted, thereby forming an injection molding core. A primary molding step of molding, an insertion step of inserting the component into the through hole of the injection molding core so that at least one end thereof projects, and a part of the injection molding core being exposed Into the cavity of the shape that matches the external shape of the electronic component, insert the injection molding core into which the component has been inserted,
A second molding step of injecting the aromatic polyester liquid crystal polymer into the cavity and molding a secondary molded product in which the injection molding core is inserted, and heating the secondary molded product in hot water And dissolving the injection molding core into hot water.

[0006] Since the core for injection molding molded in the primary molding step is eluted in the elution step after the secondary 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 molded by the secondary molding process and having the injection molding core into which the parts have been inserted must be molded without melting the core. Furthermore, the use of electronic components generally requires solder heat resistance that can withstand solder reflow. In general, an aromatic polyester liquid crystal polymer (hereinafter, referred to as a “liquid crystal polymer”) is often used as a thermoplastic resin which can be exposed to an atmosphere having a furnace temperature of 240 to 280 ° C. for 10 to 30 seconds. .

Therefore, in the present invention, the use of a liquid crystal polymer in the second molding step was considered. However, the problem here is that the melting point of the polyvinyl alcohol-based resin as the core is far from 190 to 200 ° C. Resin temperature above 29
With the injection at 0-350 ° C, the core surface is fused, deformed or fused with the liquid crystal polymer, and as a result, it is expected that a precise shape cannot be obtained as a secondary molded product. It was to have been.

However, as a result of various experiments by the present inventors,
Melting, deformation and fusion were not found contrary to such a prediction, and it was found that the method was sufficiently practical. 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.

The present inventor paid attention to this point, and decided to use this liquid crystal polymer in the secondary molding step, so that the inserted injection molding core can be molded without melting and deforming, and precise injection can be performed. It is excellent for making molded products, and even in the step of eluting the core for injection molding inserted after the secondary molding step, it has excellent mold releasability with the core for injection molding due to the presence of the skin layer It is highly desirable in that respect.

Furthermore, since the elution step is performed 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.

According to a second aspect of the present invention, at least one of the parts has a large-diameter portion formed in an intermediate portion, and the first forming step includes the step of forming the intermediate portion. The injection molding core is formed by inserting a part having a large diameter portion into the core. In this way,
Parts that are difficult to insert into the through-holes of the injection molding core are insert-molded, and parts that can be easily inserted are inserted only after the first molding step.

The third aspect of the present invention is characterized in that a plating-grade liquid crystal polymer is used as the resin in the second molding step, and a conductive circuit is formed on the surface after the elution step. . For this reason, it can withstand heat treatment at the time of forming a conductive circuit, can safely pass through a high-temperature furnace, and can easily form a conductive circuit on the surface.

The electronic component according to the fourth aspect of the present invention is of a high quality in which the component is fixedly provided in the internal space, and has excellent reliability by forming a circuit on its surface. It is suitable for providing electronic components at low cost.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 An embodiment of the present invention will be described in detail for a method of manufacturing the electronic component 1 shown in FIG.

(A) The first step is a part forming step, in which the parts 11, 12 and 13 shown in FIG. 1 are formed. FIG.
The component 11 shown in (a) is a long and thin plate shape, and has concave portions 11a for retaining at both ends. FIG. 1 (b)
The component 12 shown in FIG. 1 is a columnar shaft, and has concave portions 12a for retaining at both ends. The component 13 shown in FIG. 1C is a ring and has an inner diameter that can be fitted to the component 12. FIG. 1D shows a state in which the ring 13 is fitted to the shaft 12 to form a component having a large-diameter portion at an intermediate portion. Various materials such as metal, ferrite, and thermosetting synthetic resin can be used as materials for these components 11, 12, and 13. When molding the injection molding core by inserting the components in the next second step. In this case, a material that can withstand this molding is selected. When a part is inserted after molding the core for injection molding to form a secondary molded product, a material that can withstand this molding is selected.

(B) The next second step is a primary molding step in which the core 2 for injection molding is molded as shown in FIG. The above-mentioned components are inserted into the core 2. Although not shown, the cavities formed on the opposing surfaces of the normal upper and lower molds have a shape matching the inner surface shape of the electronic component 1 as a final product. In this cavity, there is provided a shaft portion for forming the through holes 2a. As shown in FIG. 1D, the part 13 is fitted into the middle part of one part 12 to form a large-diameter part. Both ends (or one end) are inserted so that they protrude from the core 2. Then, an oxyalkylene group-containing polyvinyl alcohol-based resin (trade name “Ecomaty AX” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is injected and molded at a predetermined injection pressure in a cavity around the inserted component. is there. An example of the injection molding conditions is as follows.

“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) The third step is an insertion step.
As shown in FIG. 3, the component 11 is inserted into the through hole 2a of the core 2.
Insert Since the component 11 is longer than the through hole, both end portions (at least one end portion) protrude.

(D) Next, the fourth step is a secondary molding step, in which a secondary molded product 3 into which the injection molding core 2 is inserted is molded as shown in FIG. This secondary molded product 3
Although not shown, the core 2
A cavity having a window hole 3a from which a part of the electronic component 1 is exposed and having a shape conforming to the outer shape of the electronic component 1 is formed, and the injection molding core 2 into which the components 11, 12, and 13 are inserted is formed in the cavity. A liquid crystal polymer (grade C810 of trade name "VECTRA" manufactured by Polyplastics Co., Ltd.) is injected into a cavity around the injection molding core 2 at a predetermined injection pressure and molded. Both ends of the parts 11, 12 protruding from the injection molding core 2 are embedded in the secondary molded product 3, so that the parts are fixedly provided in the internal space of the electronic part. . An example of the injection molding conditions is shown below.

The liquid crystal polymer is injected with 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.

(E) Next, the fifth step is an elution step,
FIG. 5 shows the electronic component 1 after the core 2 for injection molding has been eluted. The secondary molded article 3 molded in the secondary molding step is put in hot water and heated to 80 to 100 ° C. Since the above-mentioned liquid crystal polymer has a heat distortion temperature of 200 ° C. or more, “Ecomaty AX” can be eluted in hot water by heating to the above-mentioned 80 to 100 ° C. Without any change,
The electronic component 1 in which the components 11, 12, 13 are fixedly provided in the internal space can be manufactured.

FIG. 6 is a sectional view of the electronic component 1. By projecting both ends of the parts 11 and 12 from the injection molding core, the recesses 11a and 12a formed at the both ends (the recess 11a is not shown) are formed.
It is buried in the opposite wall surface of the secondary molded article made of a liquid crystal polymer so as not to come off.

Example 2 In this example, a conductive circuit was formed on the surface. For this purpose, a plating grade liquid crystal polymer was used in the above-mentioned secondary molding step. The electronic component 1 having a complicated shape as shown in FIG.
After the molding of No. 0, a conductive circuit 20 was formed on the surface as shown in FIG.

As an example of a process for forming the conductive circuit 20, a catalyst applying process is performed after an etching process, electroless copper plating is performed thereon, and pattern processing is performed by irradiating the upper surface with a laser or the like. After this processing, electrolytic copper plating is further applied, and unnecessary portions that do not become circuits are removed by etching to form circuits. Thereafter, electrolytic nickel plating is performed, and heat treatment for hardening nickel is performed. Next, after surface plating is performed, finally, heat treatment is performed to remove moisture inside, and the conductive circuit process is completed.

According to such a manufacturing method, a component is fixedly provided in an internal space, an electronic component can be integrally manufactured in a highly accurate shape, and an electronic component having a complicated shape having a conductive circuit on its surface. Can be manufactured integrally, so that the device can be of high quality and the electronic device can be easily mounted on the circuit by soldering.

[0027]

The present invention uses an oxyalkylene group-containing polyvinyl alcohol resin as a material for an injection molding core and an aromatic polyester liquid crystal polymer as a material for an electronic component, so that the core is melted. An electronic component can be integrally molded without any need. On the surface of the liquid crystal polymer,
Since a strong alignment layer in the flow direction is generated, molding with high precision is possible, and it is excellent in mold releasability with the core for injection molding, hardly generates burrs, and has excellent heat resistance, so injection molding The core can be safely eluted, and the components inserted into the injection molding core are fixedly provided in the internal space of the electronic component, so it can be used as various precision electronic components such as relays, switches, and optical pickups. There are effects that can be used.

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.

Furthermore, if a plating grade aromatic polyester liquid crystal polymer is used, heat treatment for forming a conductive circuit on the surface of an electronic component can be performed safely.

The electronic component manufactured by this manufacturing method is a high-quality and highly reliable component having a precise and complicated shape, and can be provided at a low cost.

[Brief description of the drawings]

1A, 1B, and 1C show components fixedly provided in an internal space of an electronic component of the present invention, and FIG. 1A is a perspective view, a front view, a plan view, and a right side view. , (B)
(C) is a perspective view, a front view, and a right side view, respectively, and (d) is a perspective view, a front view, and a right side in a state where two parts are fitted to form a part having a large-diameter part in an intermediate part. FIG.

FIG. 2 is a partially cutaway perspective view showing an injection molding core formed by a first forming step of the manufacturing method of the present invention.

FIG. 3 is a partially cutaway perspective view showing a state where components are inserted into an injection molding core.

FIG. 4 is a partially cutaway perspective view showing a secondary molded product in which a core for injection molding in which components are inserted is inserted.

FIG. 5 is a partially cutaway perspective view showing the electronic component after an elution step.

FIG. 6 is an enlarged sectional view of the electronic component of FIG.

FIG. 7 is a cross-sectional view showing an electronic component having a conductive circuit formed on the surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 10 Electronic component 11, 12, 13 Component 2 Core for injection molding 3 Secondary molded product 20 Conductive circuit

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Claims (4)

[Claims] 1. A component forming step of forming a component that is fixedly provided in an internal space of an electronic component, and a through hole into which the component is inserted having a shape matching the inner surface shape of the electronic component. In a cavity having a shaft portion, a primary molding step of injecting an oxyalkylene group-containing polyvinyl alcohol-based resin to mold an injection molding core, and in the through-hole of the injection molding core, An insertion step of inserting at least one end thereof in a protruding state, and the injection wherein the part is inserted into a cavity having a part of the injection molding core exposed and conforming to the outer shape of the electronic part. Insert a molding core, inject the aromatic polyester liquid crystal polymer into the cavity,
A secondary molding step of molding a secondary molded product in which the injection molding core is inserted, and elution in which the secondary molded product is heated in hot water to elute the injection molding core in the hot water. And a method for manufacturing an electronic component. 2. The component according to claim 1, wherein at least one of the parts has a large-diameter part formed in an intermediate part, and the first molding step includes a part having a large-diameter part in the intermediate part. A method for manufacturing an electronic component or the like, characterized in that the core for injection molding is molded by inserting a core. 3. The resin of claim 1 or 2, wherein the resin in the second molding step is a plating grade aromatic polyester liquid crystal polymer, and a conductive circuit is formed on the surface after the elution step. A method of manufacturing an electronic component or the like. 4. An electronic component manufactured by the manufacturing method according to claim 1.