JPS5827487Y2 - airtight terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airtight terminal suitable for a cap for a semiconductor rectifier.

Airtight terminals used as caps for semiconductor rectifiers are
As shown in FIG.
A metal inner ring 3 made of an iron-nickel alloy is sealed in an airtight and insulating manner via a metal inner ring 3, and a copper pipe lead 4 whose one end is pinch-sealed is brazed to the metal inner ring 3.

However, as shown in FIG. 2, the airtight terminal with such a structure is mounted on a stud 6 on which a semiconductor element 5 is mounted, and a lead wire 7 from the semiconductor element 5 is inserted into the pipe lead 4. When the pipe lead 4 is pinched, the stress applied in the length direction of the lead wire 7 causes the lead wire 7 to
is bent in the right angle direction, the distance between the lead wire 7 and the metal outer ring 1 decreases, and the withstand voltage between them deteriorates.

In addition, since the heat capacity of the metal inner ring 3 is small, if the heat generation of the pipe lead 4 is large, leakage may occur at the soldering part between the metal inner ring 3 and the pipe lead 4 or at the sealing interface between the metal inner ring 3 and the glass 2. Accidents are likely to occur.

Furthermore, there were various problems such as difficulty in inserting the lead wire 7 from the semiconductor element 5 into the pipe lead 4.

The present invention has been proposed to solve these problems, and is characterized by providing a tapered portion at the inner opening of the metal inner ring.Examples of the invention will be described below with reference to the drawings.

In FIG. 3, the same reference numerals are given to the same or corresponding parts as in FIG. 1, so the explanation thereof will be omitted. The tapered portion 31 is formed at the inner opening end.

According to such a configuration, even if the lead wire from the semiconductor element is inserted into the pipe lead 4 and tries to bend in the right angle direction due to stress when pinched, the lead wire will not fit into the tapered portion 31 of the metal inner ring 30. As a result, the distance between the lead wire and the metal outer ring 1 does not decrease, and therefore the withstand voltage between the two does not deteriorate.

In addition, since the metal inner ring 30 has a large heat capacity, the heat generated by the pipe lead 4 may cause leakage accidents from the soldering part between the pipe lead 4 and the metal inner ring 30 or from the sealing interface between the metal inner ring 30 and the glass 2. disappears.

Furthermore, when inserting the lead wire from the semiconductor element into the pipe lead 4, the tapered part 31 of the metal inner ring 30 serves as a guide part, which has the advantage that the insertion work can be carried out smoothly.

FIG. 4 shows another embodiment, in which the metal outer ring 10 is composed of a thin-walled metal cylinder 11 made of iron and a thick-walled metal ring 12 made of iron, both of which are brazed together. The pipe lead 40 is the same as that shown in FIG. 3 except that the pipe lead 40 is formed of a cylindrical body having a partition wall 41 in the middle.

According to this embodiment, in addition to producing the same effects as the embodiment shown in FIG. 3, it also has the following advantages.

That is, in the case of a compression sealing wall that applies compressive stress to the glass 2 with the metal outer ring 1 or 10, the metal outer ring 1 or 10
The thickness of the portion in contact with the glass 2 is required to be at least a certain value in order to apply a predetermined compressive stress to the glass 2.

It is difficult to manufacture such thick-walled parts by pressing a cylindrical body, so generally a steel bar is cut and the third
Manufactured in one piece as shown in the figure.

However, since cutting the steel bar is complicated, not only does the airtight terminal become expensive, but the steel bar often has whiskers in the axial direction, which may result in a terminal with poor airtightness and reliability.

However, as shown in FIG. 4, if the metal outer ring 10 is formed by brazing the thin metal cylinder 11 and the thick metal ring 12, the metal cylinder 11 and the metal ring 12 can be manufactured by press molding, and the brazing of both can be done using glass 2.
Since the sealing can be carried out simultaneously with the sealing, it is possible to obtain an airtight terminal that is not only easy to manufacture but also has high airtightness and reliability.

In addition, the cylindrical pipe lead 40 has lead wires from the semiconductor element inserted into the lower hole 42, and external lead wires inserted into the upper hole 43.
It is convenient because it can be easily connected by inserting it into the holder and pinching it.

In addition, the above embodiment describes a compression-sealed airtight terminal in which the metal outer ring 1 or 10 is made of iron, the metal inner ring 30 is made of iron-nickel alloy, and the glass 2 is made of soda lime glass or soda barium glass. However, it can also be applied to a matched seal type hermetic terminal in which the metal outer ring and the metal inner ring are made of an iron-nickel-cobalt alloy, and the glass is made of borosilicate glass.

Further, the present invention can also be applied to configurations other than those shown in the above embodiments.

As described above, this invention has a tapered part in the inner opening of the metal inner ring, so the stress when pinching the lead wire inserted into the pipe lead causes the lead wire to bend in the right angle direction. The distance between the metal outer ring and the metal outer ring is reduced and the withstand voltage between them does not deteriorate, and the heat capacity of the metal inner ring is large, so there is no risk of leaks caused by heat generated by the pipe lead. It has various effects such as acting as a guide and making it easier to insert the lead wire into the pipe lead.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the airtight terminal that is the premise of the present invention, Figure 2
The figure is a longitudinal cross-sectional view of a main part for explaining the problem of the semiconductor rectifier using the airtight terminal shown in Fig. 1, and FIGS. 3 and 4 are longitudinal cross-sectional views of airtight terminals of different embodiments of the present invention. . 1.10...Metal outer ring, 2...Glass, 4.40...Six-piece lead, 30...
・Metal inner ring, 31...Tapered part.

Claims (1)

[Scope of utility model registration request] In an airtight terminal in which a metal inner ring is hermetically and insulatively sealed to one end of the metal outer ring via glass and a pipe lead is brazed to the metal inner ring, the inner opening of the metal inner ring is tapered. An airtight terminal characterized by having a section.