JPH0662531U - Feedthrough filter - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the occurrence of damage to the soldered parts of the capacitor and the through terminal caused by the difference in expansion and contraction rate due to heat between the metal case and the through terminal. [Structure] A capacitor 12 is provided on both ends of the metal case 11,
12 is housed, and the through terminal 14 has both capacitors 12, 12
And penetrates the inside of the metal case 11 along the axis, and solders the outer electrodes 16 of both capacitors 12 and 12 to the metal case 11 and the inner electrode 17 to the through terminal 14, respectively, and
A portion of the through terminal 14 located between the capacitors 12 and 12 is formed into a bent shape 18, and the bent shape 18 absorbs and relaxes a difference in shrinkage due to heat between the metal case 11 and the through terminal 14.
The occurrence of damage to the soldered portion with the capacitors 12 and 12 due to contraction of the through terminal 14 is prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a through-type LC filter.

[0002]

[Prior art]

 FIG. 2 shows a conventional through-type LC filter, in which both inner ends of a tubular metal case 1 are formed to have large diameters, and the multilayer capacitors 2 and 2 are brought into contact with the inner diameter stepped portions 3 and 3 in both ends of this large diameter. So that the penetrating terminal 4 penetrating along the axis of the metal case 1 penetrates both the multilayer capacitors 2 and 2 and the ferrite is located in the metal case 1 between the two capacitors 2 and 2 of the penetrating terminal 4. It has a structure in which the beads 5 are externally fitted and inserted.

The metal case 1 is formed of steel because strength is required, and the penetrating terminal 4 is generally formed of copper to increase a current value during energization. The outer electrodes 6 on the outer circumference of the capacitors 2 and 2 are soldered to the metal case 1, and the inner electrodes 7 of the inner circumference are soldered to the through terminals 4.

[0004]

[Problems to be solved by the device]

 By the way, when the capacitors 2 and 2 are soldered to the metal case 1 and the through terminal 4, a high temperature is applied to the metal case 1 and the through terminal 4, but the metal case 1 made of steel and the through terminal 4 made of copper are connected to each other. Has a large difference in the coefficient of thermal expansion, and the expansion and contraction of the through terminal 4 is particularly large. Therefore, during the soldering work of the capacitors 2 and 2, the through terminal 4 expands more than the metal case 1, and the room temperature after soldering When returning to, it will shrink more than metal case 1. When used in a cryogenic environment, this difference becomes even larger.

As described above, when there is a difference in the contraction amount between the metal case 1 and the through terminal 4, the through terminal 4 exerts an inward force on the capacitors 2 and 2 fixed to the metal case 1. Since all of this force is supported by the soldered portion, this force pulls the inner electrodes 7 of the capacitors 2 and 2 off, and the soldered portions of the capacitors 2 and 2 and the through terminal 4 are soldered. Has the problem of being damaged.

Therefore, in order to solve the above-mentioned problems, the present invention absorbs the difference in contraction between the metal case and the through terminal by the through terminal itself, and the inner electrode of the capacitor and the half-finished portion of the through terminal. It is an object of the present invention to provide a feedthrough filter that can prevent breakage.

[0007]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a feedthrough filter in which capacitors are housed at both ends in a metal case, and through-hole terminals pass through both capacitors and the metal case along the axis. The portion of the through terminal located between both capacitors is formed in a bent shape.

[0008]

[Action]

 The bent shape that is formed between the through-hole terminals and between the capacitors is the part that absorbs the expansion and contraction of the through-hole terminals, and mainly when the capacitors return to room temperature after being soldered to the metal case and the through-hole terminals, and at extremely low temperatures. When used in an environment, the bent shape absorbs and relaxes the difference in contraction of the through-hole terminal with respect to the metal case, which prevents the inner electrode of the capacitor and the soldered portion of the through-hole from being subjected to force, and It can be prevented from peeling off and being damaged.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. 1 of the accompanying drawings.

In FIG. 1, the feed-through filter has a cylindrical metal case 11 made of steel with both inner ends formed to have large diameters, and washer-shaped multilayer capacitors 12 and 12 having inner diameter stepped portions formed therein. A through terminal 14 that is housed so as to abut on the metal case 13 and penetrates along the axis of the metal case 11 penetrates both the multilayer capacitors 12 and 12, and both capacitors 12 and 12 of the through terminal 14 in the metal case 11 are inserted. A ferrite bead 15 is externally fitted and inserted in a portion located between them, and the outer electrodes 16 of both capacitors 12 and 12 are soldered to the metal case 11 and the inner electrode 17 to the through terminal 14, respectively. The capacitors 12 and 12 are not limited to the laminated structure as shown in the figure, but may be any capacitors such as those having capacitor electrodes on both sides.

The through terminal 14 is made of copper in order to increase the current value during energization, and the portion located between the capacitors 12 and 12 is bent in a dogleg shape at both ends and the center. The shape 18 is formed.

Since the bent shape 18 is formed between the capacitors 12 of the through terminal 14, the ferrite beads 15 are divided into two parts on both sides, but one or three or more may be used. Good.

The through-type filter of the present invention has the above-mentioned configuration, and when the capacitors 12 and 12 are soldered to the metal case 11 and the through terminal 14, heat is transferred to the metal case 11 and the through terminal 14. Although the respective stretches occur, the stretch of the portion of the through terminal 14 between the capacitors 12 and 12 can be absorbed by the bending of the bent shape 18.

When the temperature returns to normal temperature after soldering, and when it is used in an extremely low temperature environment, both the metal case 11 and the through terminal 14 contract, but in the through terminal 14 with a large contraction amount, it is between the capacitors 12 and 12. Since the formed bent shape portion 18 relaxes the contraction, the inward force applied to the capacitors 12 and 12 is reduced, and the inner electrode 17 is peeled off to solder the capacitors 12 and 12 to the through terminal 14. It is possible to reliably prevent the part from being damaged.

The through-type filter may be repeatedly subjected to thermal shock with a large temperature difference due to mounting on the circuit board. Even in this case, the difference in contraction between the metal case 11 and the through terminal 14 is bent. This can be mitigated by 18, and the occurrence of damage to the soldered portions of the capacitors 12 and 12 and the through terminal 14 can be prevented.

[0016]

[Effect of device]

 As described above, according to the present invention, since the portion of the through-hole terminal penetrating the inside of the capacitor and the metal case, which is located between both capacitors, is formed in a bent shape, the difference in expansion / contraction rate due to heat between the metal case and the through-terminal is reduced. The bent portion can absorb and relax, and the force applied to the inner electrode part of the capacitor during expansion and contraction of the through terminal after soldering the through terminal to the capacitor and the metal case can be relaxed by the bent shape, resulting in peeling of the inner electrode. It is possible to prevent damage to the soldered parts of the capacitor and the through terminal, and improve the reliability of the through filter.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a feedthrough filter according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a conventional feedthrough filter.

[Explanation of symbols]

 11 Metal Case 12 Capacitor 14 Through Terminal 16 Outer Electrode 17 Inner Electrode 18 Bent Shape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Sakamoto 2 26-10 Tenjin Tenjin, Nagaokakyo, Kyoto Murata Manufacturing Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A feed-through filter, wherein capacitors are housed at both ends in a metal case, and a through terminal penetrates through both capacitors and the metal case along an axis, and is located between both capacitors of the through terminal. A through-type filter having a bent portion.