JPH0219953Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The invention is a ceramic capacitor with an internal electrode structure.
In particular, it relates to feed-through ceramic capacitors.

<Prior Art> As a through-type ceramic capacitor with an internal electrode structure, the one shown in FIG. 1 is known. In the conventional example shown in FIG. 1, dielectric ceramic layers 101 to 105 are formed inside a ceramic base 1 formed in an annular shape with a through hole 5 penetrating in the thickness direction along the direction of the thickness t. Through the plurality of internal electrodes 20
1 to 205 are buried in a layered manner, and the internal electrodes 201 to 206 are pulled out every interval to the outer circumferential surface of the ceramic base 1 and the inner circumferential surface of the through hole 5, and the drawn-out end is connected to the inner circumferential surface of the ceramic base 1. It has a structure in which it is electrically connected to an outer circumferential electrode 3 and an inner circumferential electrode 4 which are formed on the outer circumferential surface and the inner circumferential surface of the through hole 5, respectively.

<Problem to be solved by the invention> As described above, in the conventional internal electrode structure type ceramic capacitor, the lead-out ends of the internal electrodes 201 to 206 are connected to the inner circumferential surface of the through hole provided in the ceramic base 1 and Since it was drawn out at the same position as the outer peripheral surface, the dielectric ceramic base 1 and the internal electrodes 201 to 206
Due to the difference in shrinkage ratio between the inner electrode 20 and
The lead-out ends of Nos. 1 to 206 are buried inside the dielectric ceramic base 1 and cannot be electrically connected to the inner circumferential electrode 3 and the inner circumferential electrode 4, which tends to cause variations in capacitance or a drop in capacitance. As a means to solve this problem, conventionally, means such as barrel polishing or sandblasting polishing have been employed to draw out the ends of the internal electrodes 201 to 206 to the end surface of the porcelain base 1.

However, in feed-through ceramic capacitors,
Unlike a general flat ceramic capacitor, it has a through hole 5, and it is necessary to draw out an internal electrode to the inner peripheral surface of the through hole 5. The inner circumferential surface of the through hole 5 cannot be polished by barrel polishing, sandblasting, etc., and must be manually polished using a tool or the like. For this reason, polishing work requires a great deal of time and labor costs, leading to a significant increase in costs.

Therefore, the object of the present invention is to solve the above-mentioned conventional problems and to easily and reliably draw out the internal electrodes to the outside, especially to draw out the internal electrodes on the inner peripheral surface side. The goal is to provide the following.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a ceramic capacitor in which internal electrodes are embedded inside a ceramic base, in which the ceramic base is arranged in a direction perpendicular to the plane of the internal electrodes. The internal electrode has a through hole penetrating therethrough and a flange projecting in the radial direction from one end in the axial direction, and the lead-out end of the internal electrode is connected to the inner circumferential surface of the through hole and the outer circumference of the porcelain base. It is made to protrude outward from a surface, and the said lead-out end part of the said internal electrode of the lowest layer among the said internal electrodes is led out to the surface of the said flange part, It is characterized by the above-mentioned.

<Function> Since the lead-out end of the internal electrode protrudes outward from the inner circumferential surface of the through hole and the outer circumferential surface of the porcelain base,
The drawn-out ends of the internal electrodes do not become buried inside the porcelain base due to the difference in shrinkage ratio during firing on both the inner circumferential side and the outer circumferential side. Therefore, it is possible to obtain a feedthrough ceramic capacitor that is free from variations in capacitance, loss of capacitance, etc. due to buried internal electrodes.

Moreover, since the structure is such that the lead-out ends of the internal electrodes protrude from the inner circumferential surface of the through-hole, manual polishing using a tool, which was conventionally essential, is no longer necessary, and manufacturing efficiency is significantly improved.

Since the porcelain base has a radially protruding flange on one end in the axial direction, in a through-type porcelain capacitor whose support base area tends to decrease due to the through hole, the base area can be increased. Can be stably supported.

<Example> FIG. 2 is a front sectional view of a ceramic capacitor according to the present invention. This example shows an example of a laminated ceramic capacitor similar to that shown in FIG. It has a structure in which it is formed to protrude from the inner circumferential surface of the through hole 5. The lead-out ends A and B of the internal electrodes 201 to 206 are conductors of the same composition extending from the internal electrodes 201 to 206. One end in the axial direction has a flange 111 that protrudes in the radial direction intersecting the axis, and among the internal electrodes 201 to 206, the internal electrode 206 located at the lowest layer is led out to the surface of the flange 111. has been done.

To form internal electrodes with such a structure, as shown in FIG. 3, a dielectric magnetic paste is applied to a predetermined thickness by means such as screen printing, and then a dielectric ceramic sheet 1 is coated with the dielectric magnetic paste to a predetermined thickness. After forming the
An electrode paste is applied thereon, and one end of the electrode pattern 2, which becomes the internal electrode, is exposed to the outside of the outer peripheral surface of the dielectric ceramic sheet 1 or the inner peripheral surface of the through hole 5. It can be easily formed by repeating the steps of forming the dielectric paste and electrode paste, leaving the lead-out terminal portions A or B above.

As described above, if the lead-out ends A and B of the internal electrodes 201 to 206 are conductors of the same composition extending from the internal electrodes 201 to 206 and protrude outward from the end surface of the ceramic base 1, the internal electrodes 201
The drawer end portions A and B of 206 to 206 do not become buried inside the porcelain base 1 due to the difference in shrinkage ratio during firing.
Therefore, it is possible to obtain a ceramic capacitor that is free from variations in capacitance, loss of capacitance, etc. due to burying of the internal electrodes 201 to 206.

In particular, an internal electrode 20 is provided on the inner circumferential surface of the through hole 5.
By adopting a structure in which the drawer end portions 1, 203, and 205 protrude, manual polishing using a tool, which was conventionally essential, for exposing the drawer end portions RO is no longer necessary, and manufacturing efficiency is significantly improved.

Furthermore, since one end in the axial direction has a flange 111 that protrudes in the radial direction intersecting the axis, the through-type porcelain capacitor is likely to have a reduced support base area due to the through hole 5. It is possible to increase the bottom area and improve support stability and installation stability.

FIG. 4 shows an application example of the magnetic capacitor shown in FIG. 2, in which a through conductor 6 is fitted inside a through hole 5 and then housed in an external metal fitting 7. Among the internal electrodes 201 to 206, the internal electrodes 201, 203, and 205 are electrically connected to the through conductor 6 within the through hole 5, and the internal electrodes 202, 204, and 2
06 is electrically connected to the inner peripheral surface of the external metal fitting 7. 8 is internal electrodes 201, 203 and 205 and through conductor 6
Solder 9 connects and fixes the internal electrode 20
Solders 10 and 11 that connect and fix between 2, 204, and 406 and the external metal fitting 7 are insulating resin.

<Effects of the invention> As described above, according to the present invention, the following effects can be obtained.

(a) The porcelain base has a through hole that penetrates in a direction perpendicular to the surface of the internal electrode, and the lead-out end of the internal electrode is located outside of the inner circumferential surface of the through hole and the outer circumferential surface of the porcelain base. Since the inner electrodes are protruded, it is possible to provide a through-type ceramic capacitor with an inner electrode structure that allows the inner electrodes to be easily and reliably drawn out.

(b) Since the lead-out end of the internal electrode is projected outward from the inner peripheral surface of the through hole, manual polishing using a tool, which was conventionally essential, is not necessary, and a through-type ceramic capacitor with high manufacturing efficiency can be provided.

(c) Since the porcelain base has a radially protruding flange on one end in the axial direction, the bottom area of the through-type porcelain capacitor tends to be reduced due to the through hole. It is possible to provide a feedthrough ceramic capacitor with increased support stability.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a conventional feed-through type multilayer ceramic capacitor, FIG. 2 is a front cross-sectional view of a feed-through type multilayer ceramic capacitor according to the present invention, and FIG.
This figure is a diagram showing the manufacturing process of the magnetic capacitor shown in FIG. 2, and FIG. 4 is a sectional view showing an application example of the magnetic capacitor shown in FIG. 2. 1... Porcelain base, 201-206... Internal electrodes, A, B... Drawer end.

Claims (1)

[Claims for Utility Model Registration] A ceramic capacitor in which internal electrodes are embedded inside a ceramic base, the ceramic base having a through hole penetrating in a direction perpendicular to the surface of the internal electrode, and an axial It has a flange portion that projects in the radial direction on one end side of the direction, and the drawn-out end portion of the internal electrode projects outward from the inner circumferential surface of the through hole and the outer circumferential surface of the porcelain base. Features: Porcelain capacitors.