JPS5920763Y2 - airtight terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an airtight terminal, and more particularly to a small, high-current airtight terminal used as an airtight cap for a gated semiconductor device such as an SCR or TRIAC.

As shown in Figures 1 and 2, airtight terminals used in SCRs, TR1ACs, etc. for power use of medium or higher power include a metal outer ring 1 made of iron or low carbon steel and soda barium glass or soda lime glass. There is a structure in which a relatively large-diameter pipe lead 3 made of an iron-nickel alloy and a relatively small-diameter pipe lead 4 are hermetically and insulatively sealed via a sealing glass 2 such as the above.

In the case of SCR, the pipe node 3 becomes a cathode lead, and the pipe lead 4 becomes a gate lead.

Therefore, if it is desired to increase the current capacity, the thickness of the pipe lead 3 may be increased.

However, if the wall thickness of the pipe lead 3 is simply increased, the distance g1 between the metal outer ring 1 and the pipe lead 3 and the distance g2 between the pipe lead 3 and the pipe lead 4 shown in FIG. There is a problem that the withstand voltage or insulation resistance between the two is reduced.

In order to prevent a decrease in the withstand voltage or insulation resistance between the two, there is a problem in that the metal outer ring 1 must be made larger.

This idea was proposed in consideration of these points,
The present invention is characterized in that at least the outer shape of the relatively large pipe lead is formed into an elliptical cross-sectional shape, and the short axis direction thereof is opposed to the relatively small pipe lead.

Below, an embodiment of this invention will be explained with reference to the drawings.
In the figures and in FIG. 4, the same parts as in FIG.

The feature of this embodiment is that the larger pipe node 30 is
The outer shape has an elliptical cross-sectional shape and the inner shape has a circular cross-sectional shape, and is sealed so that the short axis direction thereof faces the small diameter pipe lead 4.

With this configuration, the cross-sectional area of the pipe lead 30 is increased by an amount corresponding to the mesh portion shown in FIG. 3, compared to the conventional pipe lead 3 having a circular cross section with the same inner diameter, and the current capacity is increased accordingly. can be made larger.

Moreover, the distance G1 between the metal outer ring 1 and the pipe lead 30
The distance G2 between the pipe lead 30 and the pipe node 4 can be made as large as that of the conventional pipe lead 3 having a circular cross section, so there is no problem of deterioration of withstand voltage or insulation resistance between the two, and the metal Ring 1 does not become large.

As a practical matter, the pipe lead 30 with an elliptical outer cross-sectional shape and a circular inner cross-sectional shape as shown in FIG. 3 is difficult to handle manually, so the following implementation is required. Examples may be used.

That is, FIG. 5 is a plan view of another embodiment of this invention.
The same parts as in FIGS. 3 and 4 are designated by the same reference numerals.

A feature of this embodiment is that the larger pipe lead 31 has an elliptical cross-sectional shape both inside and outside, and has a uniform wall thickness over the entire circumference.

In this embodiment as well, the same effects as in the previous embodiment can be obtained.

However, in this embodiment, although the increase in cross-sectional area is not as large as in the case of the previous embodiment, it has the advantage that it can be easily implemented by purchasing a commercially available circular pipe member and press-molding it into a flat shape.

In addition, when using the pipe lead 31 having an elliptical cross-sectional shape both inside and outside, the upper portion may be pinch-molded as shown in FIG.

According to this embodiment, the internal shape of the upper portion of the pipe lead 31 is similar to that of the pipe lead 30 in FIG. It has the advantage of being easy to do.

Further, in all of the above embodiments, the metal outer ring 1 is made of iron or low carbon steel, the pipe leads 30, 31 and 4 are made of an iron-nickel alloy, and these are made of soda barium glass, soda lime glass, etc. The description has been made of a compression-sealed type in which the metal outer ring 1 and the pipe nodes 30, 31 and 4 are sealed through the sealing glass 2, but the metal outer ring 1 and the pipe nodes 30, 31 and 4 are formed of an iron-nickel-cobalt alloy, and these are made of borosilicate. The same method can also be applied to a matched sealing type in which the glass 2 is used for sealing.

As described above, this invention forms a relatively large pipe node with at least an elliptical cross-sectional shape, and makes the short axis direction face a relatively small pipe lead. This has the effect that the current capacity of the pipe leads can be increased without sacrificing the withstand voltage or insulation resistance between the metal outer ring and the pipe leads or between the pipe leads.

[Brief explanation of the drawing]

Figure 1 is a plan view of the airtight terminal which is the background of this invention, Figure 2
The figure is a sectional view taken along the line ■■-■■ in Fig. 1, Fig. 3 is a plan view of an airtight terminal according to an embodiment of this invention, and Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3. , FIG. 5 is a plan view of a hermetic terminal according to another embodiment of this invention, and FIG. 6 is a plan view of a hermetic terminal according to still another embodiment of this invention. 1...Metal outer ring, 2...Glass, 4.
30.31...Pipe lead do.

Claims (1)

[Scope of utility model registration request] In an airtight terminal in which a relatively large pipe lead and a relatively small pipe lead are hermetically and insulatively sealed within a metal outer ring via glass, the relatively large pipe lead is formed at least in an elliptical cross-sectional shape. An airtight terminal characterized in that the short diameter direction of the terminal is opposed to the relatively small pipe lead and sealed.