JP3014801B2 - Electronic component manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electronic component having a capacitor function.

[0002]

2. Description of the Related Art Assuming that the area of an electrode plate is S, the dielectric constant of a dielectric sandwiched between both electrode plates is ε, and the thickness of the dielectric, that is, the distance between the electrode plates is d, the capacitance C The general formula is C = ε × S / d. As can be seen from this general formula, in order to obtain a larger capacitance C while keeping the dielectric constant ε constant, either increase the area S of the electrode plate or shorten the distance d. .

[0003] Conventionally, as an electronic component having a large capacitance, a pair of pins made of a metal wire is inserted into a dielectric made of a plastic molding material so that the distance between the pins constituting the electrodes is reduced. Proposed. In this method of manufacturing an electronic component, a pair of pins is set at predetermined intervals in a cavity of a mold, and thereafter, a liquid plastic molding material is injected into the cavity and molded.

[0004]

In the conventional electronic component, since the gap between the pins is very narrow, there is a possibility that the gap between the pins is not sufficiently filled with the plastic molding material during injection molding. In order to solve this problem, if the injection pressure of the molding material is increased to fill the gap, a new problem that the pin is bent or broken by the pressure occurs, and the production of electronic components is easy. Did not. In addition, since a metal pin is used to increase the capacitance, the weight of the pin is added to the weight of the molding material that is the component body, and the weight of the entire electronic component increases. Since the pins protrude from the component body only in a portion necessary for attachment to the circuit board, it becomes an obstacle to make the component thin by the length of the protruding portion.

[0005] It is an object of the present invention to facilitate manufacture and to reduce the weight and thickness of this electronic component.

[0006]

A feature of the method for manufacturing an electronic component according to the present invention is that a conductive body is formed at least at two places on a dielectric body, and a through hole is provided in the middle of each conductive circuit. In a method of manufacturing an electronic component in which a capacitor function is generated between opposing through holes, a primary molded component having a conductive circuit portion projection and at least two through holes is molded by a mold, and The surface of the primary molded part (including the inner peripheral surface of the through hole) is etched to apply a catalyst to the roughened surface of the primary molded part. The surface of the protruding portion for the conductive circuit portion exposed from the surface of the secondary molded part and the surface of each of the above-mentioned parts are covered with a molding material except for the surface of the part and the inner peripheral surface of each through hole. Through hole The inner circumferential surface is to form a conductive circuit portion by plating. Plastic is used as the molding material of the primary molded part and the secondary molded part. The molding material of the primary molded part and the molding material of the secondary molded part may be the same type of plastic, or may be different types. Often, a plating-incompatible material, such as a liquid crystal resin, is used as a molding material for the secondary molded component.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 5, a main body 1 of an electronic component is formed in a front rectangular shape using a dielectric plastic as a molding material. A pair of through holes 2 and 3 are formed in the center of the main body 1 in the left-right direction in FIG. The through holes 2 and 3 are opposed to each other on the upper and lower sides with the boundary 4 therebetween. The shape of the through holes 2 and 3 is substantially semicircular, and the inner peripheral surface of the through hole at the boundary 4 side is a flat surface 2a,
3a.

The main body 1 of the electronic component has a pair of legs 5, 5a, 6, 6 on the upper and lower sides of its rear surface (right side in FIG. 2).
a is formed integrally with the main body.

On the main body 1 of the electronic component, there are formed conductive circuit portions 7 and 8 connected to the front surface, a part of the inner peripheral surface of the through holes 2 and 3, and the back surface. The conductive circuit section 7 and the conductive circuit section 8 are arranged vertically symmetrically with respect to the through holes 2 and 3. The structure of the conductive circuit portion 7 is such that the leg 5a on the right side in FIG. 3 showing the back surface of the main body 1 goes down from the left side in FIG. 2 to the rear surface of the main body through the inner peripheral surface of FIG. The other conductive circuit section 8
Is substantially the same as that of the conductive circuit section 7. As shown in FIGS. 1 and 5, a part of the conductive circuit portions 7 and 8 is provided on the inner peripheral surfaces of the through holes 2 and 3. A capacitor function is generated between the holes.

The body 1 has through holes 2a, 3a
The ring-shaped magnetic body 9 is embedded so as to surround the magnetic material.

Therefore, a method for molding an electronic component according to the present invention will be described.

First, a primary molded part 1a as shown in FIGS. 6 to 11 is molded using a mold. Primary molded part 1
a has an inner frame 1a1 at the center and an outer frame 1a2 having a rectangular front surface so as to surround the inner frame. Through holes 2a and 3a penetrate through the inner frame 1a1, and these through holes oppose each other with the boundary portion 4 interposed therebetween. The protruding portions 7a, 8a for the conductive circuit portion are formed on the front, back and upper and lower sides of the primary molded part 1a. 1a2. A pair of legs 5, 5a, 6, 6a are integrally formed on the upper and lower sides of the back surface (the right side surface in FIG. 7) of the primary molded component 1a with the conductive circuit portion projections 7a, 8a. Inner frame 1a1
The ring-shaped magnetic body 9 is held by the outer frame 1a2.

Next, the primary molded part 1a is immersed in a tank containing an etchant to make the surface of the primary molded part 1a rough, and then a catalyst is applied to the surface of the primary molded part 1a. .

After the etching step and the catalyst application step are completed, the primary molded part 1a is set in a mold, filled with a liquid coating plastic b1 having a plating incompatible property, and the primary molded part is coated with this plastic. Thus, a secondary molded part 1b shown in FIG. 12 is formed. The structure of the secondary molded part 1b is the same as the structure of the main body 1 shown in FIG. 1 except that the conductive circuit portions 7 and 8 are not formed. Secondary molded part 1
b, the inner frame 1a1 of the primary molded part 1a
, Only the inner peripheral surfaces of the through holes 2a, 3a, the protruding portions 7a, 8a for the conductive circuit portion and the legs 5, 5a, 6, 6a are exposed.

Thereafter, the surface of the secondary molded part 1b is plated by placing it in a plating solution. As a result, as shown in FIG. 1, the inner peripheral surfaces of the exposed through holes 2a and 3a, the protruding portions 7a and 8a for the conductive circuit portion, and the legs 5, 5a, 6, and 6a are plated, and the stippling of FIG. Conductive circuit parts 7, 8 indicated by
Is formed. As shown in FIG. 13, the primary molded part 1a and the secondary molded part 1b are partially enlarged so that the surface of the primary molded part has an uneven surface, so that the coupling between the two is strengthened. Will be.

The shape of the through holes 2 and 3 is not limited to the example shown in FIG. In order to secure a large electrode surface area, it is desirable that the inner peripheral surfaces of the through holes opposed to each other are flat surfaces. In addition to the shape of FIG. 1, for example, as shown in FIG.
3 may be oval. 12a and 13a are flat surfaces;
Reference numeral 18 denotes a conductive circuit unit. Further, as shown in FIG. 15, the through holes 22, 23 may be triangular. 22a,
23a is a flat surface, and 27 and 28 are conductive circuit portions. Further, the number of through holes is not limited to two. For example, in FIG. 16, four through holes 32 and 33 are shown. In this example, through holes 32 and 33 are provided between the upper and lower conductive circuit sections 37 and 38. 32a and 33a are flat surfaces.

The magnetic material 9 is not always necessary depending on the use of the electronic component.

The illustrated electronic components are a portable radio telephone,
Although it is used as a transmission main control power detector such as a digital cordless telephone and a transceiver, the application range of the electronic component according to the present invention is not limited to the above detector.

[0019]

According to the manufacturing method of the present invention, since the primary and secondary molded parts are formed by the mold and the conductive circuit portion is formed by electroless plating, it is possible to easily manufacture electronic parts having a complicated shape. Can be. According to the electronic component manufactured by the present invention, the conductive circuit portion is formed on the surface of the dielectric body,
In addition, since a through hole is interposed in the conductive circuit portion, a large capacitance can be secured without depending on the pin, and the manufacturing is easy. As a result, parts can be made lighter and thinner. By making the inner peripheral surfaces of the opposed through holes flat, a large electrode area can be obtained, and a large capacitance can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of an electronic component manufactured according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a rear view of FIG. 1;

FIG. 4 is a plan view of FIG. 1;

FIG. 5 is a sectional view taken along line BB in FIG. 1;

FIG. 6 is a front view of a primary molded part.

FIG. 7 is a sectional view taken along the line CC in FIG. 6;

FIG. 8 is a rear view of FIG. 6;

FIG. 9 is a plan view of FIG. 6;

FIG. 10 is a sectional view taken along the line DD in FIG. 6;

FIG. 11 is a perspective view of a primary molded part.

FIG. 12 is a front view of a secondary molded part.

FIG. 13 is a sectional view taken along line EE of FIG. 6;

FIG. 14 is a front view of another embodiment of the through hole.

FIG. 15 is a front view of still another through hole embodiment.

FIG. 16 is a front view of still another through hole embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric (body) 1a Primary molded part 1b Secondary molded part 1b1 Coated plastic 2 Through hole 2a Flat surface 3 Through hole 3a Flat surface 4 Boundary part 7 Conductive circuit part 7a Projecting part for conductive circuit part 8 Conductive circuit part 8a Projecting portion for conductive circuit portion 12 Through hole 12a Flat surface 13 Through hole 13a Flat surface 17 Conductive circuit portion 18 Conductive circuit portion 22 Through hole 22a Flat surface 27 Conductive circuit portion 28 Conductive circuit portion 33 Through hole 33a Flat surface 37 Conductive circuit portion 38 Conductive circuit

Claims (1)

(57) [Claims] 1. The method according to claim 1, wherein the dielectric body is guided to at least two places.
Form an electric circuit part and a through hole in the middle of each conductive circuit part
To provide a capacitor function between opposing through holes.
A method of manufacturing an electronic component, characterized in that to generate the primary molded part are provided with through holes to the conductive circuit portion for collision detection section and at least two places is molded by a die,
The surface of the primary molded part after molding is etched, the catalyst was applied to the surface became rough primary molded part, the surface and the respective through conductive circuit portion for impact detection section of the primary molded part after the catalyst application The inner surface of the hole is left covered with the molding material, leaving 2
To form the next molded part, and forming a conductive circuit portion inner peripheral surface by plating collision detecting section surface and each of the through holes of the conductive circuit portion exposed from the secondary molded part surface Manufacturing method of electronic components.