JPS595964Y2 - LC feedthrough capacitor - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an LC feedthrough capacitor.

FIG. 1 shows an example of a conventional LC feedthrough capacitor, in which a porcelain dielectric 2 shaped like a disk is soldered 3 on the bottom inner surface of a stepped cylindrical external fitting 1, and the porcelain The through terminal 4 passed through the through hole 2C provided in the center of the dielectric 2 is soldered 5 to the electrode 2b provided on the other surface of the ceramic dielectric 2, and is then filled inside the external fitting 1. some resin 6
It has a structure in which magnetic beads 7 are embedded inside the through terminal 4 so as to go around the through terminal 4 in a circular manner.

8 is a synthetic resin.

By the way, the resins 6 and 8 are absolutely necessary to ensure moisture proofing and insulation properties for the porcelain dielectric material 2, and at the same time to support the magnetic beads 7. Using a certain liquid insulating paint instead of resin,
This must be injected into the external fitting 1.

However, it is extremely difficult to accurately inject the required amount of insulating paint, and in some cases, the amount injected is too large and overflows from the cylinder 1a or 1b, and in other cases, the amount injected is too small. This causes problems such as insufficient insulation and insufficient holding power of the magnetic beads 7.

Furthermore, since the inside of the external fitting 1 is partitioned by the porcelain dielectric 2, it is not possible to simultaneously inject into the upper cylinder 1a and the lower cylinder 1b. After fixing the beads 7, two steps are required: inverting the LC feedthrough capacitor to open the lower cylinder body 1b upward, and injecting the insulating paint again, which has the drawback of increasing costs due to increased man-hours. .

Moreover, when inverting, it is necessary to allow at least enough time for the injected insulating paint to harden so that it does not flow, which has the disadvantage of decreasing productivity.

In addition, a step of drying and curing the injected insulating paint at high temperature is required, which increases costs due to increased man-hours and reduces productivity. The solder that had fixed the external metal fittings 1 to each other melts and flows again, causing problems such as eccentricity of the through terminal 4 and increased silver migration of the electrode silver.

Furthermore, according to the above-described insulating paint injection method, the edges of the insulators 6 and 8 almost coincide with each other, so when an external component such as a lead wire is connected to the through terminal 4 as shown in FIG.
The molten solder flows and diffuses on the insulator 6 in the direction of the external fitting 1, generating a solder bridge 9, and the through terminal 4 and the external fitting 1 are electrically short-circuited to each other, and the function as a capacitor is lost. This was often the case.

The present invention aims to eliminate the above-mentioned conventional drawbacks, and provide a highly reliable LC feed-through capacitor that is easy to assemble, has high productivity, and is free from short-circuit accidents caused by solder flow. purpose.

In order to achieve the above object, the present invention provides an LC feed-through type capacitor in which one side of two opposing surfaces with through holes are fixed on the stepped part in a stepped cylindrical external metal fitting. A porcelain dielectric body having a through-hole terminal fixed thereto that passes through the through-hole in the axial direction of the external fitting is built into the surface, and the through-hole terminal is penetrated into the cavity from at least one end of the external fitting. It is characterized by a pressed insulating block with a ring-shaped magnetic material.

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. 3 shows a sectional view of the LC feedthrough capacitor according to the present invention.

In the figure, the same reference numerals as in FIG. 1 indicate the same structural parts.

As shown in the figure, in the present invention, an insulating block 10 with a through terminal 4 inserted therein is press-fitted into the inside of the upper cylindrical body 1a of the external fitting 1 by its own elastic force, and is also inserted into the inside of the lower cylindrical body 1b. has a structure in which an insulating block 11 having an annular magnetic body 12 in a cavity R is enlarged.

In this embodiment, the insulating block 10.11 has a bottomed cylindrical shape having an outer diameter that is approximately the same as the inner diameter of the upper cylinder 1a and the upper cylinder 1b, and has a bottom cylindrical shape.
A center hole 10b, llb having an inner diameter approximately the same as the diameter of the through terminal 4 is bored in the hole 11a.

The annular magnetic body 7 has a diameter slightly smaller than the inner diameter of the insulating block 11, and is supported by being placed on the bottom 11a of the insulating block 11.

With the above structure, the insulation blocks 10 and 11 can be inserted into the upper cylinder 1a and the lower cylinder 1b respectively while inserting the through terminals 4 into the center holes 10b and llb, and the connection to the ceramic dielectric 2 can be made. Since the magnetic body 12 serving as an inductor is attached at the same time as the insulating layer is formed, assembly becomes very simple and easy.

The height of the insulating blocks 10.11 is determined so that they protrude outward from the edges of the upper cylinder 1a and the lower cylinder 1b when press-fitted.

With such a structure, the insulating block 10 or 1
1, the creepage distance from the through terminal 4 to the upper cylindrical body 1a or the lower cylindrical body 1b is long and the path is curved, so even when a lead wire or the like is soldered to the through terminal 4, molten solder does not reach the through terminal 4. The probability of flowing and diffusing from the through terminal 4 to the upper cylindrical body 1a or the lower cylindrical body 1b becomes extremely small, which helps prevent short circuits due to solder bridges.

Moreover, this LC feedthrough capacitor, as shown in Fig. 4,
While inserting the lower cylinder 1b into the pre-provided through hole 13a,
The outer circumferential surface of the stepped portion is attached to the button 14 of the board 13 by soldering, but in the present invention, the insulating block 10.11 is press-fitted inside the upper cylinder 1a or the lower cylinder 1b. Therefore, it does not become an obstacle during soldering.

In the embodiment, insulating blocks 10.11 are pressed into both the upper cylinder 1a and the lower cylinder 1b, but as shown in FIG. 5, a cavity R is formed in only one of the lower cylinders 1b. The structure may be such that an insulating block 11 having a magnetic material 12 is press-fitted into the cavity R, and a conventional insulating paint is filled in the upper cylinder 1a.

Plastic, insulating paper, etc. can be used as the material for the insulating block 10.11, but insulating paper, such as paper made of asbestos impregnated with silicone varnish, kraft paper, etc. is desirable.

．． As described above, in the LC feed-through capacitor according to the present invention, one surface of the two opposing surfaces having the through-holes is fixed to the step part of the external metal fitting within the stepped cylindrical external metal fitting, and the other surface is fixed to the stepped part of the external metal fitting. an annular body having a built-in porcelain dielectric body fixed with a through terminal passing through the through hole in the axial direction of the external fitting, and having the through terminal penetrate into a cavity from at least one end of the external fitting; Since it is characterized by press-fitting an insulating block with a magnetic material, it has the following effects.

(1) Since the time required to form the insulating layer is significantly shortened and the process becomes simpler, mass production costs can be reduced.

(2) Short circuit accidents caused by soldering between the through terminal and the external metal fitting can be prevented, and reliability can be improved.

(3) Since the insulating block can be made of insulating paper or the like, material costs and processing costs can be reduced, and costs can be reduced.

(4) High-quality, highly reliable LC feed-through type because eccentricity of the feed-through terminal due to solder melt movement and increase of silver migration of electrode silver, which conventionally occurred during resin injection and heating drying processes, can be almost prevented. A capacitor is obtained.

[Brief explanation of the drawings] Fig. 1 is a sectional view of a conventional LC feedthrough capacitor, Fig. 2 is a diagram explaining its handling, and Fig. 3 is a sectional view of a conventional LC feedthrough capacitor.
FIG. 4 is a sectional view of the C feedthrough capacitor, and FIG. 4 is an installation view thereof, and FIG. 5 is a sectional view of another embodiment. 1... External metal fittings, 2... Ceramic dielectric material,
4...Through terminal, 10.11...Insulating block, 12...Magnetic material, R...Cavity.

Claims (1)

[Scope of utility model registration request] In a stepped cylindrical external fitting, one side of two opposing surfaces with through holes opened is fixed onto the stepped portion of the external fitting, and the other side is provided with a hole extending through the through hole in the axial direction of the external fitting. A porcelain dielectric body to which a through-hole terminal is fixed is built-in, and an insulating block having an annular magnetic body is press-fitted from at least one end of the external metal fitting into the cavity to allow the through-hole terminal to penetrate therethrough. LC feedthrough capacitor.