JPS5911448Y2 - Feedthrough capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feed-through type capacitor used as a noise filter for high-frequency, high-power equipment, such as microwave ovens, magnetrons for broadcasting equipment, or X-ray tubes.

Recently, high-power electromagnetic waves such as UHF and VHF have come to be used not only in industrial equipment such as broadcasters and X-ray medical equipment, but also in consumer equipment such as microwave ovens, and as their usage increases. , Noise pollution caused by electromagnetic waves leaking from these devices has come to be highlighted as a major social problem.

In order to prevent such noise pollution, various noise filters have been proposed.

Figures 1A and 1B show conventional examples of feedthrough capacitors as this type of noise filter, with one electrode 1 on both sides.
Then, the flat dielectric ceramics 4, 4 each provided with two divided electrodes 2, 3 are faced so that the divided electrodes 2, 3 face each other, and the divided electrodes 2, 2, 3, 3 are The through terminals 5 and 6 are sandwiched between the dielectric ceramics 4 and 4 are pasted together using conductive paste or solder paste, and the blocks of dielectric ceramics 4 and 4 are fitted onto the external terminals 7, and the whole is assembled. It had a structure covered with an insulating resin 8 such as epoxy resin.

However, the above-described structure has the disadvantage that the gap g1 separating the electrodes 2 and 3 is small, and a high breakdown voltage cannot be achieved.

In addition, the cylindrical through terminals 5 and 6 are replaced with the planar electrodes 2 and 3.
Since the structure is such that the penetrating terminals 5 and 6 are sandwiched between the terminals, the holding stability of the through terminals 5 and 6 is poor, and there is also the drawback that assembly work is difficult and reliability is lowered.

Furthermore, the whole is made of dielectric ceramics 4, 4, metal electrodes 1,
2, 3. Since the structure was such that the epoxy resin 8 was coated with a significantly different coefficient of linear expansion from that of the through terminals 5, 6 and the external terminal 7, when the epoxy resin 8 cured and shrunk, the difference in the coefficient of linear expansion of each part, etc. Due to the residual stress or adhesive force generated based on this, gaps or cracks may occur due to peeling between the epoxy resin 8 and the dielectric ceramic 4, the through terminals 5 and 6, or the external terminal 7. Ta.

Further, since the difference in linear expansion coefficient between the epoxy resin 9 and the dielectric ceramic 4 is large, a heat shock occurs due to residual stress during a heat cycle test, and the dielectric ceramic 4 cracks.

When such gaps and cracks occur, water and moisture enter there, resulting in a decrease in dielectric strength characteristics and a loss of reliability.

Particularly recently, products that combine a microwave oven and a steam oven have been commercialized, and feed-through capacitors have been used in high temperature and humid environments, causing gaps and cracks as mentioned above to occur. It is necessary to suppress the occurrence of this as much as possible, and to improve the dielectric strength characteristics to several times or more than the conventional one.

The present invention solves the above-mentioned problems, does not generate gaps or cracks due to residual stress, has very high dielectric strength, has a small number of parts, is easy to assemble, and is cost-effective. Our goal is to provide capacitors.

In order to achieve the above object, the feedthrough type capacitor according to the present invention includes a flat ceramic capacitor with electrodes formed on both sides of an insulator in which internal terminals are embedded on both sides, and one of the electrodes is formed on both sides of the insulator. The terminal is characterized in that the terminals overlapped so as to be in contact with the internal terminals are enlarged in the through-holes of the external terminals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically explained in detail below with reference to the accompanying drawings, which are examples.

FIG. 2 is a perspective view of a through-type container according to the present invention, FIG. 3 is a sectional view taken along the line C--C in FIG. 2, and FIG. 4 is an exploded perspective view of the main parts.

In this embodiment, a flat porcelain container 1 is placed on both sides of a flat insulator 9 with internal terminals 10 and 11 in between.
2 and 13 are stacked one on top of the other and are enlarged in the through hole 15 of the external terminal 14.

The insulator 9 is made of insulating porcelain such as alumina, forsterite, or stearite, and grooves 16.17 reaching both edges are provided at intervals d1 on both sides facing the ceramic capacitor 12.13. At the same time, a recess 18 extending in the width direction is provided in the middle of the grooves 16 and 17.

The internal terminal 10.11 is shaped into a flat plate by flattening a pipe or punching a plate, and its width, thickness, and shape are matched to the grooves 16.17 of the insulator 9. and is embedded in the groove 16.17.

In this case, the protrusions 10a, lla of the internal terminal 10.11
However, since the locking portions are fitted into the recesses 18 of the grooves 16 and 17, it is impossible for the internal terminals 10, 11 to come out in the longitudinal direction.

Further, on both sides of the ceramic capacitor 12.13, there is a gap g2 between the outer periphery and the electrodes 12a, 12
b, 13a, and 13b are provided.

These ceramic capacitors 12.13 have electrodes 12 b
, 13a are superimposed on both sides of the insulator 9 such that they are in contact with the internal terminals 10, 11, respectively.

What is assembled in this way is compressed into the through hole 15 of the external terminal 14 and the whole is crimped and fixed.
Protruding pieces 15 a and 15 b having spring properties are provided on opposing inner edges of the through hole 15 .
, 15 b, the insulator 9 and internal terminal 10
．． 11 and the magnetic capacitors 12 and 13 are crimped and fixed, and the projecting pieces 15 a and 15 b are connected to the electrodes 12 a and 13 b located outside the magnetic capacitors 12 and 13.
By bringing them into pressure contact with each other, electrical continuity between the electrodes 12 a and 13 b and the external terminal 14 is ensured.

Therefore, in the assembled state, as shown in FIGS. 2 and 3, the opposing electrodes 12b,
13a and the internal terminals 10.11, an insulation gap is formed by the insulator 9, so that the dielectric strength is significantly improved compared to the conventional one.

Moreover, during assembly, internal terminals 10 are placed on both sides of the insulator 9.
, 11, It is only necessary to press fit the stacked ceramic capacitors 12 and 13 into the through hole 15 of the external terminal 14, and the assembly is very easy, resulting in a product with high mechanical strength after assembly. can.

In addition, internal terminals 10 and 11 are embedded in both sides of the insulator 9,
Since the insulator 9 and the ceramic containers 12 and 13 are in surface contact, the overall assembly stability is improved.

Furthermore, the structure is such that the entire structure is compressed and elastically supported within the through hole 15 of the external terminal 14, the insulator 9 acts as a buffer, and the overall assembly strength and stability are extremely high. Even when coated with insulating resin, residual stress is absorbed, and even if residual stress remains, it has a large resistance to it, effectively preventing the occurrence of cracks in various parts due to residual stress, and improving temperature resistance. The withstand voltage characteristics are improved.

Furthermore, since a locking portion is formed between the internal terminal 10.11 and the insulation 9 to prevent the internal terminal 10.11 from slipping out in the length direction, the mounting strength of the internal terminal 10.11 is high. Become.

As mentioned above, the feedthrough capacitor according to the present invention is
A flat ceramic capacitor with electrodes on both sides is superimposed on both sides of an insulator with internal terminals embedded on both sides, with one of the electrodes facing the internal terminal, and an external terminal is formed. It is characterized by a large pressure inside the through hole, so it does not create gaps or cracks due to residual stress, has very high dielectric strength, has a small number of parts, is easy to assemble, and is cost effective. It is possible to provide an advantageous feedthrough capacitor.

Therefore, according to the present invention, a highly reliable penetration filter that exhibits sufficient temperature resistance and breakdown voltage resistance even in a high temperature and humidity environment, such as a magnetron filter for a microwave oven equipped with a steam oven, etc. The company will be providing capacitors of this type.

[Brief explanation of the drawing]

Figure 1A is a plan view of a conventional feedthrough capacitor, Figure 1B
is a sectional view taken along the line B-B of FIG. 1A, FIG. 2 is a perspective view of the feedthrough capacitor according to the present invention, and FIG. 3 is FIG. 2C.
The sectional view taken along the line -C and FIG. 4 are similarly exploded perspective views of the main parts. 9... Insulator, 10.11... Internal terminal, 12.13... Magnetic capacitor, 14...
...External terminal, 15...Through hole.

Claims (1)

[Scope of utility model registration request] A flat ceramic capacitor with electrodes formed on both sides is superimposed on both sides of an insulator with internal terminals embedded on both sides, with one of the electrodes facing the internal terminal, and the external A feed-through capacitor characterized by a large pressure inside the through-hole of the terminal.