JPS5937550B2 - Manufacturing method for airtight terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an airtight terminal having a pipe lead with a terminal plate used as a cap for a semiconductor device.

As a semiconductor rectifier, for example, as shown in FIGS. 1 and 2, a semiconductor element 3 is fixed to a stud 2 integrally formed with a mounting bolt 1, and an airtight terminal 4 is placed on the stud 2.
Some are resistance welded.

This airtight terminal 4 has a pipe lead 5 for leading the electrode of the semiconductor element 3 to the outside, and is sealed to a metal outer ring 6 with glass 7, thereby airtightly sealing the inside. The outer end of the pipe lead 5 is provided with a terminal plate 8 for closing the hole of the pipe lead 5 and for connecting an external line. Further, one end of the internal lead wire 9 connected to the electrode of the semiconductor element 3 is inserted into the inside of the pipe lead 5, and is fixed by pinching and caulking the pipe lead 5 at the part indicated by the arrow. Note that the terminal plate 8 is formed by press-shaping one end of the pipe lead 5, or by brazing a separate member. By the way, this airtight terminal 4
Conventionally, it was manufactured as follows1. First, the third
As shown in the figure, a concave hole 10 into which the metal outer ring 6 fits, a slit-shaped concave hole 11 into which the terminal plate 8 fits into the bottom surface 10' of this concave hole 10, and a round hole 12 into which the pipe lead 5 fits. A sealing jig 13 made of graphite is prepared.

Then, as shown in FIG. 4, the pipe lead 5 to which the terminal plate 8 is brazed is inserted into the slit-shaped concave hole 11 and the round hole 12 with the terminal plate 8 facing downward.
Furthermore, a glass tablet 14 formed by pressing glass powder into a ring shape and a metal outer ring 6 are placed concentrically in the concave hole 10.

Then, it is placed in a heating furnace to melt the glass tablet 14 and seal the pipe lead 5 and the metal outer ring 6 through the glass 7 in an airtight and insulating manner. Then, when the glass cools and solidifies,
In the compression sealing type, the metal outer ring 6 tightens the glass due to the difference in thermal expansion coefficient between the metal outer ring 6 and the glass, thereby achieving high airtightness. However, the concave hole 11 for fitting the terminal plate 1 of the sealing jig 13 used in this glass sealing process has a slit shape because it is necessary to allow the flat terminal plate 8 to pass through, and the pipe lead 5 is inserted into the round hole 12. When inserted, hollow portions 15, 15 are formed that extend to the left and right.

When the glass tablet 14 melts, it sag into the hollow parts 15, 15 located below, and the glass 7 tends to get wet along the pipe lead 5. Therefore, the sealed airtight terminal has a rising part r of glass along the pipe lead 5 as shown in FIG. The distance h becomes shorter, making it difficult to pinch and fix the internal lead wire 9.
In addition, cracks are likely to occur from the rising portion γ of the glass, causing deterioration of airtightness and electrical characteristics. Furthermore, even when brazing the terminal plate 8 to the pipe lead 5 after sealing the pipe lead 5 to the metal outer ring 6 with the glass 7 in an airtight and insulating manner, the working temperature of the brazing material used is such that the glass 7 softens. If it is higher than the point, the glass 7
A climbing portion 7' is formed along the pipe lead 5, and
Similar problems arise. Therefore, in view of the above-mentioned drawbacks, the present invention improves this by inserting an auxiliary jig made of graphite into the hollow part of the jig for passing the terminal plate 8, which causes glass to creep up onto the pipe lead. By supporting the lower surface of the glass, the glass is prevented from creeping up along the pipe lead.

Hereinafter, the present invention will be described in detail with reference to examples. 6th
In the figure, 16 is a sealing jig made of graphite, which has poor wettability with glass, and round holes 17, 17 for fitting auxiliary sealing jig are provided on both sides of the round hole 12 into which the pipe lead 5 is fitted. The sealing jig 12 is similar to the conventional sealing jig 12 shown in FIG. 3, and the same parts are given the same reference numerals and the explanation thereof will be omitted.

Then, as shown in FIG. 7, the pipe lead 5 with the terminal plate 8 brazed thereon is inserted into the slit-shaped recessed hole 11 and round hole 12 provided in the sealing jig 16 with the terminal plate 8 facing downward. match. Next, the auxiliary sealing jigs 18, 1 are inserted into the two round holes 17, 17 formed on the left and right sides of the round hole 12 for fitting the pipe lead 5.
8 from above as shown in FIG. The auxiliary sealing jigs 18, 18 are made of graphite, and the cross-sectional shape does not necessarily have to be circular, but may be square, for example. Then, the glass tablet 14 and the metal outer ring 6 are inserted and arranged in a predetermined positional relationship, and the sealing jig 16 is placed in a neutral or weakly reducing heating furnace. When heated at about 1000°C, the glass tablet r melts, and the metal outer ring 6 and the pipe lead 5 are sealed in an airtight and insulating manner by the glass 7. Wearing jig 18,
18, the molten glass 7 is blocked by the auxiliary sealing jigs 18, 18, and the glass 7 does not creep up onto the pipe bleed 5. After sealing, if the cooled airtight terminal 4 is taken out from the sealing jig 16, the two auxiliary sealing jigs 18, 18 can also be taken out laterally and reused. As shown in FIG. 9, in the airtight terminal obtained by such a manufacturing method, the distance h between the lower end of the terminal plate 8 of the pipe lead 5 and the sealing glass 7 is sufficiently long as designed.
Pinch connections of the internal lead wires 9 can be easily made, and glass cracks at the time of pitching, which conventionally occur at creeping portions, do not occur. Further, in the above description, an airtight terminal used in a semiconductor rectifier has been described, but the present invention can similarly be applied to an airtight terminal having a structure in which a pipe lead having a terminal plate is sealed with glass. For example, in the case of a semiconductor device with a gate such as a reverse blocking three-terminal thyristor or a bidirectional three-terminal thyristor, in addition to the pipe lead 5 with the terminal plate 8, the pipe lead 19 for the gate is made of metal as shown in FIG. ring 6
However, in this case as well, an auxiliary sealing jig 18'', 1 of an appropriate shape is installed adjacent to the pipe lead 5''.
8' may be inserted and arranged. In the above embodiment, the case where the pipe lead 5 to which the terminal plate 8 is brazed is used has been described, but it is also possible to use a pipe lead that integrally includes a terminal plate formed by crushing and sealing one end of a metal pipe. can also be implemented in the same way.

Further, in the above embodiment, a terminal plate 8 is brazed to the pipe lead 5, and the pipe lead 5 with the terminal plate and the metal outer rings 6, 6! Although the case where the metal outer rings 6, 6'' and the pipe leads 5, 19 without terminal plates are sealed with the glass 7 has been described, for example, an airtight sealing structure in which the metal outer rings 6, 6'' and the pipe leads 5, 19 without terminal plates are sealed with the glass 7 is manufactured in advance. Even when brazing the terminal plate 8 to the pipe lead 5 of this hermetically sealed structure, if the brazing temperature is higher than the softening point of the glass 7, the pipe lead 5 may be attached to the glass 7 in the same way. Since a creeping portion 7'' is formed along the glass 7, the creeping portion r of the glass 7 can be prevented by performing the brazing operation using the same sealing jig 16 as described above.

Furthermore, if the sealing temperature of the glass 7 and the brazing temperature of the pipe lead 5 and the terminal plate 8 are similar, the metal outer ring 6, 6'' and the pipe without a terminal plate may be used. It is also possible to seal the leads 5 and 19 with the glass 7 and at the same time braze the terminal plate 8 to the pipe lead 5 without a terminal plate, and the present invention can also be carried out in such a case. .

Furthermore, in the above embodiment, a case was explained in which the slit-shaped recesses 11 were continuously formed for convenience of processing in the sealing jig 16 for manufacturing a large number of airtight terminals at the same time. The recessed holes 11 may be formed independently.

As explained above, according to the present invention, in an airtight terminal having a pipe lead with a terminal plate, an auxiliary jig with a simple rod-like structure is installed adjacent to the pipe lead during glass sealing and/or brazing work. Just by placing it, you can reliably prevent glass from climbing up into the pipe lead. Therefore, the internal lead can be easily connected to the pipe lead by pinching, and the occurrence of glass cracks can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a semiconductor rectifier using airtight terminals, which is the background of this invention, FIG. 2 is a top view thereof, and FIG.
The figure is a perspective view of a conventional sealing jig for manufacturing airtight terminals, FIG. 4 is a cross-sectional view illustrating a conventional method of manufacturing airtight terminals using the sealing jig shown in FIG. 6 is a perspective view of an example of a sealing jig for manufacturing an airtight terminal of the present invention, and FIG. 8 is an enlarged perspective view of the main part of FIG. 5, and FIG. 9 is an enlarged sectional view of the main part of the airtight terminal manufactured by the method of the invention. , FIG. 10 is a plan view showing a method of manufacturing an airtight terminal according to another embodiment of the present invention. 4...Airtight terminal, 5...Pipe lead, 6...Metal outer ring, 7...Sealing glass, 8...Terminal Plate, 10... Concave hole, 10
″...Bottom surface of the recess, 11...Slit-shaped recess for fitting the terminal plate, 12...Rounded for fitting the pipe lead 14... glass tablet, 1
5, 15...Cavity hole 16...Sealing jig, 17,17...Round hole for fitting auxiliary sealing jig, 18,18... ...Auxiliary sealing jig, 19...
... Pipe lead for gate terminal.

Claims (1)

[Scope of Claims] 1. A jig having a recessed hole into which a metal outer ring and a glass are fitted, a slit-like recessed hole into which a terminal plate is fitted into the bottom of the recessed hole, and a round hole into which a pipe lead is fitted; In the step of fitting a terminal plate and a pipe lead into a slit-shaped recessed hole and a round hole with the terminal plate facing down, and also fitting a metal outer ring and a glass into the recessed hole and heating them, the left and right sides of the pipe lead are heated. A method for manufacturing an airtight terminal, comprising the step of fitting a rod-shaped auxiliary jig in contact with the pipe lead into a cavity formed in the pipe lead to support the lower surface of the glass. 2. The method according to claim 1, wherein the heating step is a step of glass-sealing the metal outer ring and the pipe lead with a terminal plate, and the glass fitted into the recessed hole is a glass tablet. Method of manufacturing airtight terminals. 3. The method of manufacturing an airtight terminal according to claim 1, wherein the heating step is a step of brazing the pipe lead and the terminal plate. 4. The method of manufacturing an airtight terminal according to claim 1, wherein the heating step is a step of glass-sealing the metal outer ring and the pipe lead and brazing the pipe lead and the terminal plate. 5. The method of manufacturing an airtight terminal according to claim 1, wherein the auxiliary jig is a round bar having a diameter larger than the width of the slit-like recessed hole.