JPH0766929B2 - Flat semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a container including at least a semiconductor substrate in a container formed of an insulating side wall and electrode bodies flexibly coupled to both end surfaces thereof. The present invention relates to a flat semiconductor device that is regulated and housed in the center, and is electrically and thermally connected by contact between an electrode body and internal housing parts and mutual internal housing parts due to pressure from the outside.

[Conventional technology]

An example of a conventional semiconductor device of this type is shown in FIG. Second
The figure shows a schematic cross-sectional view of a container housing structure of a power flat diode. This structure is a semiconductor substrate 1 with one PN junction.
As shown in FIG. 3, a substantially annular insulating member 3 having a notch 31 in a part of its circumference is used so that the inner electrode plate 2 which is in pressure contact therewith does not move laterally. The position of the inner wall of the ceramic side wall 4 is regulated at the center of the container. The annular ceramic side wall 4 forms an airtight container 7 together with the external electrode bodies 51, 52 and the flanges 61, 62, and the semiconductor substrate 1 and the internal electrode plate 2 are sandwiched between the external electrode bodies 51, 52, and Are pressed together by the force of to form an electrical and thermal conduction path.

[Problems to be solved by the invention]

In such a structure, the central position regulating member 3 needs to position the semiconductor substrate 1 and the internal electrode plate 2 at the center of the airtight container 7 with the inner surface of the side wall 4 as a reference. The flanges 61 and 62 are required to be rigid and flexibly connect the external electrode bodies 51 and 52.
Brazing accuracy with ceramic side wall 4 and flange
Welding accuracy with 61, 62 is also required. Notch 3 in regulating member 3
In the case of a thyristor, 1 also serves as a passage for the gate electrode lead, and is provided so as to be able to follow a slight dimensional error of the side wall 4, the base body 1, and the internal electrode plate 2. May be deformed, which may make it difficult to regulate the position.

An object of the present invention is to solve the above-mentioned problems and to perform position regulation of a member containing at least a semiconductor substrate housed in a container by a member that is difficult to deform, and yet does not require strictness in dimensional accuracy of the inner surface of the container. To provide a device.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a container including at least a semiconductor substrate in a container composed of an insulating side wall and electrode bodies that are flexibly coupled to both end surfaces thereof. In a flat semiconductor device in which the inside is evacuated and replaced with an inert gas, one electrode body is formed with a large-diameter side surface on the outer side and a small-diameter side surface on the inner side via an annular step surface. An insulative annular center position restricting member capable of contacting the annular step surface, the small diameter side surface of the body, and the outer peripheral surface of the internal housing member, and a part of the contact surface of the central position restricting member with the electrode body annular step surface. It is assumed that a countersunk portion is formed and a plurality of ventilation holes are radially formed in a part of the contact surface of the central position regulating member with the semiconductor substrate.

[Action]

The central position regulating member is based on an annular stepped surface and a small diameter side surface that are easy to machine with high dimensional accuracy compared to the inner surface of the insulating side wall of the container, and since it has no notch, it may become unusable due to deformation. Absent. Furthermore, this center position regulating member serves as a passage for control leads such as thyristors when a counterbore or a ventilation hole for complete gas replacement is provided, and also facilitates support of the member when inserted into the container. In addition, it also has a role of absorbing dimensional changes during thermal expansion and contraction of the electrode body and the internal containing member.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and the same parts as those in FIG. 2 are designated by the same reference numerals. As is clear from the figure, the central position regulating member 3 for preventing the lateral movement of the semiconductor substrate 1 and the internal electrode plate 2 is not in contact with the ceramic side wall 4 of the container 7, but is based on the upper electrode body 51. . Therefore, the position regulating member 3 comes into contact with the stepped surface 81 and the small-diameter side surface 82 of the electrode body 51 having a convex cross section, and at the same time, comes into contact with the outer peripheral surfaces of the internal electrode plate 2 and the semiconductor substrate 1 as in the case of FIG. Then, it is positioned at the center of the container concentric with the electrode body 51.

4 (a) and 4 (b) are detailed views of the central position regulating member 3 used when the semiconductor device is a thyristor, and FIG. 4 (a) shows the position regulating member 3 in the state of FIG. 1 from below. 2B is a cross-sectional view taken along the line AA of FIG. This member 3 is made of a heat resistant resin such as polytetrafluoroethylene, but has no notch unlike the member shown in FIG. As a passage for the gate lead, a square groove-shaped counterbore portion 32 is provided on the side in contact with the step surface of the electrode body 1. In the process of assembling the thyristor using this member 3, first, the electrode body 51 and the side wall 4 are joined by brazing and welding by the flange 61, while the member 3 has the internal electrode plate 2 and the thyristor inside in the posture shown in FIG. Substrate 1 is inserted, in which case the gate lead has a counterbore 32
Through the member 3 through. Then, with the electrode body 51 facing down, the member 3 and the internal electrode plate 2 and the thyristor substrate 1 are lowered from above while passing the gate lead through a gate lead extraction tube (not shown) of the side wall 4, and the member 3 is stepped surface 81, Contact the side surface 82. The electrode body 52 having the flange 62 joined thereto is put down on the housing member whose position is thus regulated, and the flange 62 and the flange portion brazed to the side wall 4 are welded together. After that, the inside of the container is evacuated by using the gate lead drawing tube and replaced with an inert gas to seal the drawing tube. At this time, a plurality of ventilation holes 33 are radially formed in the member 3 so that the gas replacement is completely performed.

The counterbore 32 not only serves as a passage for the gate lead, but also serves as a hooking place for the jig when the member 3 is inserted, and also serves to absorb dimensional changes due to temperature fluctuations as described above, so that it is not a single place. It may be provided at a plurality of places, and therefore it is effective to provide the counterbore portion 32 even in a semiconductor device such as a diode that does not have a lead extending to the outside. When the semiconductor substrate and the electrode body are directly contacted with each other without the internal electrode plate, the member 3 has an L-shaped cross section.

〔The invention's effect〕

According to the present invention, since the insulating annular member for positioning the container inner accommodating member of the pressure contact flat semiconductor device in the container center is brought into contact with the step surface and the small diameter side wall of one electrode body, Eliminates the need for dimensional precision machining of the side wall of an insulating container unlike the conventional center position regulation member,
It is possible to obtain a highly reliable flat semiconductor device having a simple structure. Further, although the central position restricting member according to the present invention is annular and does not deform, a dimensional change due to a temperature change of the electrode body or the containing member is absorbed by forming a counterbore or a vent hole on the contact surface to the electrode body. It can also be used for pulling out control leads such as thyristors and transistors. Then, by providing a plurality of ventilation holes radially in the central position regulating member, the replacement with the inert gas in the container can be performed completely.

[Brief description of drawings]

FIG. 1 is a sectional view of a flat semiconductor device according to an embodiment of the present invention,
2 is a cross-sectional view of a conventional flat semiconductor device, FIG. 3 is a plan view of a central position regulating member used therein, FIG. 4 (a),
(B) is a central position regulating member used in the thyristor of one embodiment of the present invention, (a) is a plan view, (b) is A- of (a).
It is an A line sectional view. 1: semiconductor substrate, 2: internal electrode body, 3: central position regulating member, 3
2: Counterbore part, 4: Insulating container side wall, 51, 52: Electrode body, 7: Container.

Claims (1)

[Claims] 1. A container including at least a semiconductor substrate is housed between both electrode bodies in a container composed of an insulating side wall and electrode bodies flexibly coupled to both end surfaces thereof, and the inside of the container is evacuated to be inactive. In the one that has been replaced with gas, one electrode body is formed with a large-diameter side surface on the outer side and a small-diameter side surface on the inner side via an annular step surface, and the annular step surface of the electrode body,
An insulative annular center position regulating member that can contact the small diameter side surface and the outer peripheral surface of the inner housing member is provided, and a counterbore is formed on a part of the contact surface of the center position regulating member with the annular step surface of the electrode body. A flat semiconductor device, wherein a plurality of ventilation holes are radially formed in a part of a contact surface of the central position regulating member with the semiconductor substrate.