JPH0399414A - Manufacture of feedthrough capacitor - Google Patents

Abstract

PURPOSE:To cut down the manufacturing cost of an earthing terminal plate and an external electrode by a method wherein the earthing terminal plate is separated into first and second parts, and the section which is formed as an external electrode terminal, is formed with the first part and the second part which are separated with each other. CONSTITUTION:First, a sheet of metal plate is punched out, and an earthing terminal plate string 24, in which an earthing terminal 23 consisting of a first part 21 and a second part 22 are series-connected, is formed. The part 21a, which is bent in U-shape by turning back at a connection part 25, of the first part 21 and the second part 22 of each earthing terminal is engaged to the U-curved part 22a of the second part 22, and the so-called side-seaming is conducted. Then, after through type terminals 28 and 29 have been inserted into the aperture located at one end of the external electrode terminals, a composite dielectric 31 is filled in the external electrode terminals 26 and 27 in the state wherein the through type terminals 28 and 29 are retained at each center position of the external electrode terminals 26 and 27 using an insert- molding method, for example, and the composite dielectric 31 is hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a feedthrough capacitor used in a filter circuit or the like that prevents microwaves generated by a magnetron of a microwave oven from leaking to the outside.

[Prior Art] Generally, a filter circuit is inserted into a magnetron such as a microwave oven in order to prevent microwaves from leaking as noise from the power line supplied to the magnetron.

As a feed-through capacitor used in this type of filter circuit, the applicant of the present application has proposed in Japanese Patent Application No. 1-96031 a composite dielectric material in which the dielectric material is a composite dielectric material of a resin material and a dielectric material powder mixed therein. We proposed a feedthrough capacitor l having the configuration shown in Figure 3.

The feedthrough capacitor l has two feedthrough terminals 2.3, and a cylindrical electrode 4.5 which serves as an external electrode of the feedthrough capacitor l, and these two feedthrough terminals 2.3 pass through their respective axial positions.
These cylindrical electrodes 4.5 are each filled with a composite dielectric 6, a ground terminal plate 7, and an insulating case 8.9.

The cylindrical electrodes 4 and 5 are both made of cylindrical pipes, and are fitted into fixing holes 7a and 7b formed in the ground terminal plate 7, respectively, as shown by arrow A in FIG. , is electrically conductively fixed to the ground terminal plate 7 by welding or soldering. The ground terminal plate 7 is made of a metal plate such as aluminum, and is a rectangular plate with holes 11 formed at each of its four corners for mounting the feedthrough capacitor l to a magnetron case (not shown), etc. . An extruded portion 12 is formed in the ground terminal plate 7 by extrusion molding, and the fixing hole 7 is formed in this extruded portion 12.
a and 7b are formed.

As shown in FIG. 3, the through terminals 2 and 3 are inserted into the cylindrical electrode 4.5 through an opening at one end thereof, and then the through terminals 2.3 are inserted into the cylindrical electrode by insert molding, for example. While the electrodes 4 and 5 are held at their axial center positions, the cylindrical electrode 4.5 is filled with the composite dielectric 6 and hardened.

A cylindrical insulating case 8 made of a resin such as polybutylene terephthalate is attached to one side of the ground terminal plate 7 so as to fit over the extruded portion 12 . Further, on the other side of the ground terminal plate 7, another cylindrical insulating case 9 made of the same resin material as the insulating case 8 is attached by fitting into the extruded portion 12. Insulating resin 15 such as epoxy resin is placed inside the two insulating cases 8.9.
is filled.

Capacitance is generated between the through terminals 2, 3 and the cylindrical electrode 4.5 using the composite dielectric 6 as a dielectric.

[Problems to be Solved by the Invention] In the feedthrough capacitor shown in FIG. 3 above, the composite dielectric 6 is filled in the cylindrical electrode 4.5 and the dielectric is formed by hardening. - It has the advantage of being easier to manufacture and lower cost than conventional feedthrough capacitors that use ceramic dielectric blocks as dielectrics, which require processes such as firing and electrode formation. However, in the feedthrough capacitor shown in FIG. 3, the cylindrical electrodes 4.5 are fitted into fixing holes 7a and 7b formed in the ground terminal plate 7, respectively, and are electrically conductive to the ground terminal plate 7 by welding or soldering. This poses a problem in that the number of parts increases and man-hours are required for fixing the cylindrical electrodes 4 and 5 to the ground terminal plate 7.

Furthermore, in the feedthrough capacitor l shown in FIG. 3, it is also possible to form the cylindrical electrode 4.5 integrally with the ground terminal plate 7 by press drawing to reduce the number of parts. However, in order to obtain a feedthrough capacitor having a capacitance above a certain level, a large protruding length of the cylindrical electrode 4.5 is required. Moreover, as devices in which feedthrough capacitors are incorporated have recently been required to be more compact, the cylindrical electrode 4.5
The spacing between them should also be as small as possible. Under such restrictions, even if the cylindrical electrodes 4.5 are press-drawn integrally with the ground terminal plate 7, the cylindrical electrodes 4.5 between adjacent cylindrical electrodes 4.5 will form a ground terminal. Since the absolute volume of the material of the plate 7 is small, there is a problem in that the wall thickness of the opposing portions of the adjacent cylindrical electrodes 4 and 5 becomes extremely thin, making it impossible to mold them.

An object of the present invention is to provide a method for manufacturing a feedthrough capacitor with low manufacturing costs for a ground terminal plate and an external electrode.

[Means for Solving the Problems] Therefore, in the first invention of the present application, each capacitor element includes a through-hole terminal, a cylindrical external electrode terminal surrounding the through-hole terminal, and a dielectric material present between the through-hole terminals. , a method for manufacturing a feedthrough capacitor in which the external electrode terminal protrudes from a ground terminal plate, and a plurality of capacitor elements are connected by the ground terminal plate, the ground terminal plate having a first portion and a second portion. The first part and the second part are connected to each other and connected in series with another ground terminal board,
The external electrode terminals protrude in opposite directions from each other to form a grounding terminal plate series, and the connecting portion between the first and second parts of each grounding terminal plate forms a first The part is folded back and a part of the first part is overlapped with a part of the second part, and the first part and the second part are connected at the overlapping part, and a dielectric is inserted into each external electrode terminal. After accommodating the body and supporting the through terminal, adjacent ground terminal plates of the series of ground terminal plates are separated.

Further, the second invention of the present application provides that each capacitor element has a through terminal, a cylindrical external electrode terminal surrounding the through terminal,
and a dielectric material existing between them, the external electrode terminal protrudes from a ground terminal plate, and a plurality of capacitor elements are coupled by the ground terminal plate, the method of manufacturing a feedthrough capacitor, wherein the external electrode terminal is A grounding terminal board formed integrally with a hole formed at an adjacent position is connected in series with another grounding terminal board to form a grounding terminal board series, and each ground terminal board of this grounding terminal board series is After attaching the external electrode terminals formed separately from the grounding terminal board to the holes of the terminal board and supporting the through terminals by accommodating the dielectric inside each external electrode terminal, the adjacent grounding terminal boards are separated. It is a feature.

[Effect of the invention 1] According to the first invention of the present application, the ground terminal plate is separated into a first part and a second part, and each part formed as an external electrode terminal is separated from the other part. 1st part and 2nd part
Since each external electrode terminal is molded from the parts of can.

Further, according to the second invention of the present application, the external electrode terminal adjacent to the external electrode terminal that is molded integrally with the ground terminal plate is molded separately from the external electrode terminal that is molded integrally with the ground terminal plate. However, since the number of parts is reduced by the number of external electrodes molded integrally with the ground terminal plate, the number of assembly steps is reduced and a feedthrough capacitor can be obtained at low cost.

[Example 1 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

An embodiment of the method for manufacturing a feedthrough capacitor according to the present invention will be described with reference to FIGS. 1(a) to 1(d).

First, punch out a piece of metal plate (not shown) and punch it out as shown in Figure 1 (
a) and FIG. 1(b), the first part 21
The ground terminal plates 23 consisting of the first and second portions 22 are connected in series to form a series of ground terminal plates 24.

The first portion 21 and the second portion 22 of each ground terminal plate 23 have a rectangular shape. The first part 21 and the second part 22 are connected by a connecting part 25 near their respective corners.

The first portion 21 and the second portion of each ground terminal plate 23
In the portion 22, cylindrical external electrode terminals 26 and 27 are connected to these first portions 21 and tj by press drawing.
The portions 22 of s2 are integrally formed so as to protrude in opposite directions.

Next, the first portion 21 and the second portion 22 for forming each ground terminal plate 23 of the ground terminal plate series 24 are folded back by folding the first portion 21 at the connecting portion 25. Before overlapping and bonding a portion 21a of the first portion 21 to a portion 22a of the second portion 22, they are bent into a U-shape as shown in FIG. 1(c). Note that since the part 21a of the first part 21 overlaps the part 22a of the second part 22, the part 21a of the first part 21 overlaps with the part 21a of the first part 21 by the thickness of the first part 21. It is molded to be lower than the rest of the body.

Then, as shown in FIG. 1(d), each ground terminal plate 23
The first part 21 and the second part 22 are formed by folding back the first part 21 at the connecting part 25.
The U-shaped curved portion 21a of the first portion is connected to the second portion 22.
The U-shaped curved portion 22a is engaged to perform a so-called seam connection. As a result, the first portion 21 and the second portion 22 of each ground terminal plate 23 are combined, and a single ground terminal plate 23 is formed in which the external electrode terminals 26 and 27 protrude in the same direction.

Next, as shown in FIG. 1(6), external electrode terminal 26.
27, the through terminals 28 and 29 were inserted through the opening at each end thereof, and then these through terminals 28 and 29 were held at the respective axial center positions of the external electrode terminals 26 and 27 by, for example, an insert molding method. state, the external electrode terminal 26.2
Composite dielectric material 31 is filled in 7 and hardened.

A cylindrical insulating case 32 made of resin such as polybutylene terephthalate is attached to one side of the ground terminal plate 23.

The insulating case 32 is filled with an insulating resin 33 such as epoxy resin.

Finally, each ground terminal plate 24 of the ground terminal plate series 24 is separated at the joint portion 34 thereof.

In this way, the ground terminal plate 23 is separated into the first part 21 and the second part 22, and the external electrode terminal 26.
The parts molded as 27 each have a first part separated from each other.
It is molded from a part 21 and a second part 22. Therefore, the volume of the material of the first portion 21 and the second portion 22, which will become each external electrode terminal 26.27, is approximately the same, and the wall thickness of each external electrode terminal 26.27 is approximately the same. Become something. This allows the external electrode terminals 26, 27 and the ground terminal plate 23 to be integrated.

Another embodiment of the method for manufacturing a feedthrough capacitor according to the present invention is shown in FIGS. 2(a) to 2(c).

First, punch out a piece of metal plate (not shown) and punch it out as shown in Figure 2 (
As shown in a), a ground terminal plate series 42 in which square-shaped ground terminal plates 41 are connected in series by a connecting portion 46.
form.

An external electrode terminal 43 is integrally formed on each ground terminal plate 41 of the ground terminal plate series 42, and a hole 44 is formed at a position adjacent to the external electrode terminal 43.

In this hole 44, as shown in FIG. 2(b), an external electrode terminal 4 is formed separately from the ground terminal plate 41.
5 and solder or weld.

After that, as shown in FIG. 2(c), the external electrode terminal 43
．． 45 has through terminals 29 and 28 extending from the opening at one end thereof.
After passing through the external electrode terminals 43.45, the through terminals 29.28 are held at respective axial center positions of the external electrode terminals 43.45 by insert molding, for example.
Composite dielectric material 31 is filled in 45 and hardened.

A cylindrical insulating case 32 made of resin such as polybutylene terephthalate is attached to one side of the ground terminal plate 41, as shown in FIG. 2(C).

The insulation case 32 is filled with an insulation resin 33 such as epoxy resin and hardened.

Then, each ground terminal plate 41 of the ground terminal plate series 42 is separated at the connecting portion 46 thereof.

Even in this case, the external electrode terminal 45 adjacent to the external electrode terminal 43 formed integrally with the ground terminal plate 41 is molded separately from the external electrode terminal 43 formed integrally with the ground terminal plate 41. Therefore, the wall thicknesses of the external electrode terminals 43 and 45 can be set to predetermined values. As a result, the number of parts is reduced by the number of external electrode terminals 43 integrally formed with the ground terminal plate 41.

In the above embodiment, an embodiment in which the present invention is applied to the production of two feedthrough capacitors has been described.
It can also be applied to feed-through capacitors with more than one series.

[Brief explanation of drawings]

Figure 1(a), Figure 1(b), Figure 1(C), Figure 1(
d) and FIG. 1(e) are explanatory diagrams of the manufacturing process of an embodiment of the method for manufacturing a feedthrough capacitor according to the present invention, and FIG. 2(a), FIG. 2(b), and FIG. ) are explanatory diagrams of the manufacturing process of another embodiment of the method for manufacturing a feedthrough capacitor according to the present invention, FIG. 3 is a longitudinal cross-sectional view showing the structure of a feedthrough capacitor manufactured by a conventional manufacturing method, and FIG. FIG. 4 is an explanatory diagram of the assembly of the ground terminal plate and the cylindrical electrode of the through-hole correductor shown in FIG. 3; 21...first part, 21a...part of the first part. 22... second part, 22a... part of the second part. 23...Grounding terminal board, 24...Grounding terminal board series. 25... Connection portion, 26.27... External electrode terminal. 28.29...Through terminal, 31...Composite dielectric material. 32... Insulating case, 33... Insulating resin. 34...Connection part, 41...Grounding terminal board. 42...Ground terminal board connection, 43...External electrode terminal. 44... Hole, 45... External electrode terminal, 46... Connection part. Agent for Murata Manufacturing Co., Ltd.

Claims (2)

[Claims] (1) Each capacitor element consists of a through terminal, a cylindrical external electrode terminal surrounding the through terminal, and a dielectric between them, and the external electrode terminal protrudes from the ground terminal plate, and a plurality of capacitors A method for manufacturing a feedthrough capacitor in which elements are connected by the ground terminal plate, the ground terminal plate being separated into a first part and a second part, and the first part and the second part being separated. are connected to each other and connected in series with other ground terminal boards, and the first
The external electrode terminals protrude in opposite directions from each other to form a grounding terminal plate series, and the connecting portion between the first and second parts of each grounding terminal plate forms a first The part is folded back and a part of the first part is overlapped with a part of the second part, and the first part and the second part are connected at the overlapping part, and a dielectric is inserted into each external electrode terminal. 1. A method for manufacturing a feedthrough capacitor, comprising: accommodating a body to support the feedthrough terminal, and then separating adjacent ground terminal plates of a series of ground terminal plates. (2) Each capacitor element consists of a through terminal, a cylindrical external electrode terminal surrounding the through terminal, and a dielectric between them, and the external electrode terminal protrudes from the ground terminal plate, and a plurality of capacitors A method for manufacturing a feedthrough capacitor in which elements are connected by the above-mentioned grounding terminal plate, wherein an external electrode terminal is integrally formed, and a grounding terminal plate having a hole formed at a position adjacent to the external electrode terminal is connected to another grounding terminal. A ground terminal plate series is formed by connecting the ground terminal plate in series, and external electrode terminals formed separately from the ground terminal plate are attached to the holes of each ground terminal plate of this ground terminal plate series, and inside each external electrode terminal. A method for manufacturing a feedthrough capacitor, comprising: supporting the feedthrough terminal by accommodating a dielectric therein, and then separating adjacent ground terminal plates.