JPS5841653Y2 - airtight terminal - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an airtight terminal having a soldering part.

Figures 1 and 2 are used as stems for power transistors.
There is an airtight terminal with the structure shown in the figure.

In the figure, 1 is a copper stem board with 2 parts near the center.
Through-holes 2, 2 are drilled, and lead wires 4 made of iron/nickel alloy are inserted through glasses 3, 3 into these through-holes 2, 2.
, 4 are hermetically and insulatively sealed and fitted with an iron eyelet 5.5, a brazing material 6 is placed in the corner formed by the stem substrate 1 and the eyelets 5, 5, and the brazing material 6 is heated and melted. do,
The stem substrate 1 and the eyelets 5, 5 are brazed to each other in an airtight manner.

However, in such a configuration, the molten brazing material 6 often flows onto the surface of the glass 3, causing glass cracks, or the corners formed by the inner wall surface of the through hole 2 of the stem substrate 1 and the upper end surface of the eyelet 5. 6 wax materials have accumulated in
Therefore, since the brazing material does not flow into the gap between the stem substrate 1 and the eyelet 5, brazing the stem substrate 1 and the eyelet 5 has problems such as insufficient strength and poor airtightness.

This invention was proposed to solve these problems, and is characterized by forming a recess on the end face of the first metal member to which glass is sealed and on the side opposite to the glass.

Examples of this invention will be described below with reference to the drawings.

First, the soldering of the first embodiment in which this idea was applied to the power transistor shown in Fig. 1 is shown in Fig. 3.
The state after soldering is shown in FIG. 4.

In the drawings, the same or corresponding parts as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

The feature of this embodiment is that an eyelet 5, which is a first metal member formed by sealing a lead wire 4 through a glass 3 in an airtight and insulating manner, is provided with a recess, as an example, on the upper end surface and on the side opposite to the glass 3. A ring-shaped brazing material 6 is arranged at a corner of a triangular cross section formed by the tapered part 5a and the inner wall surface of the through hole 2 of the stem substrate 1.
This brazing material 6 is heated and melted to braze the stem substrate 1 and the eyelet 5.

If the tapered portion 5a is formed in the eyelet 5 and the brazing material 6 is placed and heated and melted in this way, the melted brazing material 6 will never flow toward the glass 3, and no glass cracks will occur. Instead, it flows smoothly into the gap between the stem substrate 1 and the eyelet 5 guided by the tapered portion 5a, so that the stem substrate 1 and the eyelet 5 are brazed together to obtain a stem with high strength and airtightness.

FIG. 5 shows a plan view of a power transistor according to a second embodiment of the present invention, and FIG. 6 shows an enlarged vertical cross-sectional view of a main part taken along line VIVI in FIG.

In the figure, reference numeral 10 denotes an iron stem substrate as a first metal member, and two cylindrical parts 11 are formed by drawing near the center.
．． 11 integrally.

A lead wire 13.13 made of an iron-nickel alloy is hermetically and insulatively sealed to this cylindrical portion 11.11 through a glass 12.12, and the lead wire 13. Chamfered taper part 11 as an example of a part placed on the part
a, 11a are formed.

Reference numeral 14 denotes a circular copper heat sink serving as a second metal member, and has two through holes 15.15 into which the cylindrical portion 11.11 is fitted.

16 is a tapered portion 11a, 1 of the cylindrical portion 11.11.
1a and the inner wall surfaces of the through holes 15, 15 of the heat dissipation plate 14, the brazing material is placed in a corner of a triangular cross section and is heated and melted.

In this embodiment as well, effects similar to those described above can be obtained.

FIG. 7 is a bottom view of a cap for a semiconductor rectifier according to a third embodiment of the invention, and FIG. 8 is a longitudinal cross-sectional view taken along the line ■--■ in FIG.

In the figure, 20 is a thick-walled iron ring as a first metal member, and a pipe lead 22 made of an iron-nickel alloy is hermetically and insulatively sealed with a glass 21 interposed therebetween.

A chamfered tapered portion 20 a, which is an example of four portions, is formed on the upper end surface of the ring 20 and on the opposite side from the glass 21 .

Reference numeral 23 denotes a thin-walled cap body formed by drawing an iron plate, and the ring 20 is placed on the inner folded portion 24 of the cap body.

Reference numeral 25 denotes a brazing material which is placed at a corner of the triangular cross section formed by the tapered portion 20a and the inner wall surface of the cap body 23 and is heated and melted.

This embodiment also provides the same effects as the previous embodiment.

In each of the above embodiments, the eyelet 5. is used as the first metal member. A chamfered tapered portion 5a is formed as a recess formed in the cylindrical portion 11 and ring 20 of the stem substrate 10.
, lla, and 20a are shown, but a stepped portion or the like may be used.

Further, in the above embodiment, the eyelet 5 as the first metal member. The upper end surfaces of the glasses 3, 12, and 21 are slightly lower than the cylindrical portion 11 of the stem substrate 10 and one inner end of the ring 20, but this is because the tapered portion 5a,
By forming the eyelets 5.lla and 20a. This is to prevent the compressive stress applied to the glasses 3.degree. 12 and 21 from decreasing as a result of the decrease in the wall thickness of the cylindrical portion 11a and the upper end of the ring 21.

However, even if the tapered portion is formed, if the thickness of the upper end portion is sufficiently large, there is no need to do this.

Also, in the case of a matched seal type in which the first metal member is made of an iron-nickel-cobalt alloy called Kovar and the glass is made of borosilicate glass called Kovar glass, it is not necessary to do this.

In addition to the embodiments described above, this invention can be applied to various types of airtight terminals having soldered parts.

As described above, this invention involves forming a recess on the end face of the first metal member with the lead hermetically and insulatively sealed through the glass and on the opposite side from the glass, and placing the brazing material in the recess. Because it is heated and melted and brazed to the second metal member, the molten brazing material does not flow onto the glass surface and cause glass cracks, and the gap between the first metal member and the second metal member is reliably and sufficiently filled. The brazing material flows into the terminal, and brazing has the effect of providing an airtight terminal with high strength and airtightness.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a power transistor that is the premise of this invention, Fig. 2 is an enlarged longitudinal sectional view of the main part along line II-II in Fig. 1, and Fig. 3 is a diagram of the first embodiment of this invention. Fig. 4 is an enlarged vertical cross-sectional view of the main part before soldering, Fig. 5 is a plan view of the power transistor of the second embodiment of this invention, and Fig. 6 is a longitudinal sectional view of the main part after brazing. 5 is an enlarged vertical cross-sectional view of the main part along line VI-VI, FIG. 7 is a bottom view of the rectifier cap of the third embodiment of this invention, and FIG. 8 is a -
It is a longitudinal cross-sectional view along the line. 1... Second metal member (stem board), 3, 12
．． 21...Glass, 4,13.22...
・Lead, 5...First metal member (eyelet)
, 5 a , 11 a , 20 a ... recess (
Taper part), 6, 16.25... Brazing material, 1
0...First metal member (stem board), 11...
... Cylindrical part, 14 ... Second metal member (heat sink), 20 ... First metal member (ring), 23
...Second metal member (cap body).

Claims (1)

[Scope of utility model registration request] In an airtight terminal formed by brazing a first metal member and a second metal member with leads hermetically and insulatively sealed via glass, a recess is formed on the side of the first metal member opposite to the glass; An airtight terminal characterized in that a brazing material is placed in the recess and heated and melted to braze the first metal member and the second metal member.