JPH0662625U - 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
Fixing the stoppers 18, 18 that come into contact with the outer surfaces of the capacitors 12, 12 on both ends of the through terminal 14 to fix the metal case 1
The difference between the contraction of 1 and the through terminal 14 due to heat is
18 and the capacitors 12, 12 are supported by the metal case 11 and the capacitors 12, 1
Prevents the occurrence of damage to the soldered part with 2.

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 problems, the present invention is designed such that an inward force due to a difference in contraction between the metal case and the through terminal is received by the metal case via the capacitor, It is an object of the present invention to provide a feedthrough filter that can prevent the occurrence of damage to the soldered portion of the inner electrode and the feedthrough terminal.

[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 stoppers that contact the outer surfaces of both capacitors are fixed to both ends of the through terminal.

[0008]

[Action]

 Since the stoppers that contact the outer surfaces of both capacitors are fixed to both ends of the through-hole terminal, when the capacitors are returned to room temperature after being soldered to the metal case and the through-hole capacitor, and when used in a cryogenic environment The force generated by the contraction of the through-hole terminal with respect to the case is transmitted to the capacitor by the stopper, and the capacitor is supported by the metal case at the inner diameter step, so it is supported by the metal case via the stopper and the capacitor. It is possible to prevent a force from being applied to the soldered portion of the inner electrode and the through terminal, and to prevent the inner electrode from peeling 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 formed with a large diameter at both inner ends, and washer-shaped multilayer capacitors 12, 12 are provided in the both ends of the large diameter. 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 stoppers 18 and 18 which come into contact with the outer surfaces of both capacitors 12 and 12 are fixed to both ends of the through terminal 14 so that the outside of both capacitors 12 and 12 is fixed. The electrode 16 is soldered to the metal case 11, and the inner electrode 17 is soldered to the through terminal 14. The capacitors 12 and 12 are not limited to the laminated structure shown in the figure, and any capacitor such as one having capacitor electrodes on both sides may be used.

The through-terminal 14 is made of copper in order to increase the current value during energization, and the stoppers 18, 18 fixed to both ends of the through-terminal 14 are made of metal or synthetic resin. On the other hand, it is fixed by means of screwing, caulking, soldering, adhesion or the like.

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. Each of them expands and returns to room temperature after soldering, and when used in an extremely low temperature environment, both the metal case 11 and the through terminal 14 contract.

The penetration terminal 14 has a larger contraction amount than the metal case 11, but the force at the time of contraction is transmitted to both capacitors 12, 12 by the stoppers 18, 18 fixed to both ends, so that both capacitors 12, 12 are connected. Is received by the inner diameter step portion 13 of the metal case 11, so that the force generated by the contraction of the through terminal 14 is supported by the metal case 11 via the stopper 18 and the capacitor 12 as a result, and the through terminal 14 and the capacitor 12 are connected. It is possible to prevent a force from being applied to the soldered portion of the inner electrode 17 of.

Therefore, it is possible to reliably prevent the inner electrodes 17 from peeling off and damaging the soldered portions of the capacitors 12 and 12 and the through terminal 14 due to the contraction of the through terminal 14.

Further, the feedthrough filter may be repeatedly subjected to thermal shock having 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 feedthrough terminal 14 is stopped. It is possible to prevent damage to the soldered portions of the capacitors 12 and 12 and the through terminal 14 by supporting them with the metal case 11 via the capacitors 18 and 18 and the capacitors 12 and 12.

[0016]

[Effect of device]

 As described above, according to the present invention, the stoppers that abut the outer surface of the capacitor are fixed to both ends of the penetration terminal that penetrates the capacitor and the metal case. The contraction force of the through-hole terminal due to the difference in the ratio can be supported by the metal case through the stopper and the capacitor, and when the through-hole terminal contracts after soldering the capacitor and the through-hole to the metal case, the inner electrode of the capacitor It is possible to disperse the force applied to the part, prevent damage to the soldered part of the capacitor and the through terminal due to peeling of the inner electrode, 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 Stopper

 ─────────────────────────────────────────────────── ─── 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 through-type filter having a capacitor housed in both ends of a metal case, and a through-terminal penetrating both capacitors and the metal case along an axial center thereof. A through-type filter having a stopper that abuts the outer surface of the filter.