JPH07118532B2 - Light-driven semiconductor device - Google Patents

Description

The present invention relates to an optically driven semiconductor device such as an optical trigger thyristor, and more particularly to a highly reliable hermetically sealing structure for an envelope. The present invention relates to an optically driven semiconductor device used for a high voltage conversion device such as a DC power transmission device and a reactive power compensation device.

(Prior Art) A semiconductor device such as a thyristor is widely used as a control element of a device for electric power or electric equipment.

Among these, an optical drive type semiconductor device such as an optical trigger thyristor transmits an optical signal using a light guide and controls the operation of the semiconductor device by the transmitted optical signal.
Since it has advantages such as excellent electrical insulation between the main circuit and the control signal generation circuit, it is particularly used for high voltage converters such as DC power transmission and reactive power compensators. FIG. 4 is a cross-sectional view of an example of a typical optical trigger thyristor in which an optical signal introducing direction forms an angle of about 90 degrees with a main current conducting direction. Reference numeral 1 is a semiconductor element in which a pnpn layer of a thyristor is formed, and its n-layer side main surface is pressure-welded with a copper electrode 2 via an aluminum electrode 3, and the p-layer side main surface is a brazing material 4 and a thermal buffer plate 5.
It is pressure-welded with the copper electrode 2'through. A cathode is led out from the copper electrode 2 and an anode is led out from the copper electrode 2 '.

Signal light is applied to the light receiving portion 6 at the center of the main surface on the cathode side. An optical fiber is used for the internal light guide 7 for guiding the signal light to be applied, and one end face 7a thereof is arranged to face the light receiving portion 6 (6a is a positioning jig) of the element 1, and from there An internal light guide 7 extends along the copper electrode 2 parallel to the semiconductor main surface toward the side surface of the envelope 8,
The other end 7b of the inner light guide 7 passes through an opening 9 penetrating the peripheral side surface of the envelope 8, and the end face 7b is an optical transmissive body 10 (also referred to as a light receiving window 10) provided in the envelope 8. ) Is arranged so as to face. FIG. 5 is a partially enlarged sectional view of the vicinity of the opening 9. The optical transmissive body 10 is hermetically sealed by the metal members 11 and 12.

In such a light-driven semiconductor device, a part of the light entering from the optical transmission plate 10 is not received in the internal light guide 7 and leaks through the gap between the internal light guide 7 and the metal member 11. Will end up. Therefore, there is a problem that the light coupling (transmission) efficiency cannot be improved.

(Problems to be Solved by the Invention) An object of the present invention is to provide a light-driven semiconductor device in which light coupling efficiency is improved.

[Structure of Invention]

(Means for Solving Problems) The present invention is directed to a semiconductor element driven by an optical signal, a light guide for guiding light to a light receiving portion of the semiconductor element, and an optical element facing the light receiving end portion of the light guide. In a light-driven semiconductor device having a light guide and an envelope that hermetically accommodates the light guide and the semiconductor element, in a state in which light does not leak between the light receiving region of the light guide and the optically transparent body. It is an optical drive type semiconductor device characterized by being directly connected by a light reflection tube.

Here, the light reflecting cylinder may be formed by extending a metal member existing between the light guide and the envelope in the direction of the optical transmitting body, or by holding the optical transmitting body. It may be formed by increasing the thickness of the portion between the optically transparent body of the metal member and the light receiving area of the light guide. Alternatively, a light reflecting tube may be provided by providing a tube body that surrounds the vicinity of the light receiving area of the light guide and has an end portion extending toward the optically transparent body.

(Operation) According to the optically driven semiconductor device of the present invention, since the light reflecting tube is provided between the light receiving region of the light guide and the optically transparent body in a state in which light does not leak, the optically transparent body is provided. It is possible to efficiently supply the light entering from the light guide to the light guide and increase the light coupling efficiency.

(Example) Hereinafter, the Example of this invention is described with reference to drawings. FIG. 1 is an explanatory diagram of a main part of an embodiment of the present invention. The same parts as those of the conventional one shown in FIGS. 4 and 5 are designated by the same reference numerals, and the description of the structure of the same part will be replaced with that of the conventional example. As shown in FIG. 1, the inner light guide 7 which is inserted through the outer envelope 8 and has one end led out to the outside is surrounded by a metal member 11 existing between the outer envelope 8 and the inner light guide 7. One end of the metal member 11 extends to the vicinity of the optical transmissive body 10 opposite to the light receiving region 20 of the internal light guide 7 to form a light reflecting cylinder 21. The optical transmission body 10 is fixed to a metal member 12 attached to the outer surface of the envelope 8.

According to the light-driven semiconductor device 30 configured as above,
A light reflection tube between the internal light guide 7 and the optical transmission body 10.
21 is provided so that light does not leak between the light receiving region 20 and the optical transmission body 10 and is effectively guided to the light receiving region 20. Therefore, the light coupling efficiency can be improved.

In addition, as another embodiment of the present invention, as shown in FIG. 2, an optical transmissive body of a metal member 12 holding an optical transmissive body 10.
The light reflecting cylinder 22 may be configured by increasing the thickness of the portion between the light receiving region 20 and the light receiving region 20 so that light does not leak. Further, as shown in FIG. 3, the inner light guide 7 surrounds the vicinity of the light receiving area, and the end of the inner light guide 7 is extended toward the optically transparent body 10 to form the light reflecting cylinder 23. 24 may be provided. Incidentally, 25 in FIG. 3 is a cylindrical body 24.
Is an O-ring that fixes the other end of the.

〔The invention's effect〕

As described above, the light-driven semiconductor device according to the present invention can improve the light coupling efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of an embodiment of the present invention, FIGS. 2 and 3 are explanatory views of a main part of another embodiment of the present invention, and FIG.
FIG. 5 is an explanatory diagram showing a schematic configuration of a conventional light-driven semiconductor device, and FIG. 5 is an explanatory diagram of a main part of the conventional semiconductor device. DESCRIPTION OF SYMBOLS 1 ... Semiconductor element, 2, 2 '... Copper electrode, 6 ... Light receiving part, 7 ... Internal light guide, 8 ... Envelope, 9 ... Opening part, 10 ... Optical transmissive body (light receiving window), 11, 12 ... Metal member, 20 ... Light receiving area, 2
1,22,23 ... Light reflecting cylinder, 24 ... Cylinder, 25 ... O-ring, 30,31,3
2 ... Optical drive type semiconductor device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Kubota No. 1 Komukai Toshiba-cho, Kouki-ku, Kawasaki-shi, Kanagawa Inside the Tama River Factory, Toshiba Corporation (56) Reference JP-A-59-34662 (JP, A) Kai 61-141410 (JP, A) Unexamined Japanese Patent Sho 54-9952 (JP, A) Actual Sho 56-53371 (JP, U) Actual Sho 61-85813 (JP, U) Actual Sho 61-206906 ( JP, U)

Claims (1)

[Claims] 1. A semiconductor element driven by an optical signal, an envelope for hermetically housing the semiconductor element, a through hole provided in a wall of the envelope, and a light emitting end face of the semiconductor element for receiving light. And a light guide formed of an optical fiber arranged so that the vicinity of the light receiving end surface thereof projects through the through hole to the outside of the envelope, and extends around the projecting portion of the light guide and surrounds the through hole. A metal cylindrical body for airtightly fixed to the light-receiving part, and an optical transmission fixed to the open end of the metal cylindrical body airtightly and facing the light-receiving end face of the light guide. And a light receiving window made of a body,
In a light driven semiconductor device for guiding a light driving signal supplied from the outside through the light receiving window to the light receiving portion of the semiconductor element through the light guide, the light is provided inside the metal tubular body for protecting the light receiving portion. A light reflecting tube is provided which surrounds the protruding part of the guide and extends beyond the light receiving end surface of the light guide to the optical transmitting body, and the inner surface of the light reflecting tube is surface-finished so as to obtain sufficient light reflection. By so doing, the optical drive type semiconductor device characterized in that the optical signal incident from the light receiving window is efficiently supplied to the light receiving end face of the light guide.