JPH0334674B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a stem for an optical semiconductor device, and more particularly to a stem for a light receiver for optical communication.

BACKGROUND ART In optical communication, a light emitter is placed at one end of an optical transmission line made of an optical fiber, and a light receiver is placed at the other end.

A conventional general light receiver has a structure shown in FIG. 1, for example. In the figure, reference numeral 1 denotes a stem, and lead wires 5, 5 are hermetically and insulated sealed in through holes 3, 3 of a stem substrate 2 via glasses 4, 4. A light-receiving element 6 is fixed to the center of the upper surface of the stem substrate 2 of the stem 1, and electrodes of the light-receiving element 6 are connected to the lead wires 5, 5 by thin connecting wires 7, 7. 8 is a cap, and a window glass 11 is hermetically fixed to a through hole 10 of a cap body 9.

In the above configuration, input light 12 projected from an optical fiber (not shown) passes through window glass 11 and is irradiated onto light receiving element 6 . However, as shown in the figure, when the surfaces of the window glass 10 and the light receiving element 6 are perpendicular to the path of the input light 12, some of the reflected light reflected from the surface of the light receiving element 6 13 is reflected by the lower surface of the window glass 11 and enters the light receiving element 6 again, or returns through the window glass 11 into the optical fiber, causing noise.

Therefore, in order to prevent noise caused by such reflected light, a light receiver as shown in FIG. 2 has been considered. The figure is the same as FIG. 2 except for the following points, and the same parts are given the same reference numerals. The difference from FIG. 1 is that a lead wire 5' is provided in addition to the lead wires 5, 5, and a light-receiving element support plate 14, which is inclined with respect to the plate surface of the window glass 11, is attached to this lead wire 5'. This support plate 14
The light receiving element 6 is fixed on top.

With such a structure, the input light 12 projected from the optical fiber passes through the window glass 11 and is irradiated onto the light receiving element, but a part of the reflected light 13 reflected from the surface of the light receiving element 6 is reflected from the input light 12. Since the light is re-reflected or transmitted in a direction different from that of the light 13, the above-described problem of noise caused by unnecessary reflected light is solved. However, it is complicated to fix the light receiving element support plate 14 to the lead wire 5', and when fixing the light receiving element 6 on the support plate 14, the support plate 14 must be fixed so that it does not move. , support plate 14
Due to this deformation, there were problems such as the mounting angle of the light receiving element 6 changing and the need for another lead wire 5' on the stem 1.

For this reason, a stem 20 as shown in FIG. 3 can be considered. This stem 20 has through holes 22, 22 formed in a stem substrate 21, and a light receiving element mounting surface 23 whose upper surface is inclined with respect to the remaining surface of the stem substrate 21. The lead wires 25, 25 are hermetically and insulatedly sealed via glasses 24, 24. With this structure, the problems of the light receiving element support plate 14 fixed to the lead wire 5' as shown in FIG. 2 can be eliminated.

However, although the light-receiving element mounting surface 23 is formed at the same time as the stem substrate 21 is press-molded,
Since the height H of the light-receiving element mounting surface 23 is large, a considerably large pressing pressure is required and the flatness tends to be low.

DISCLOSURE OF THE INVENTION [Objective] Therefore, it is an object of the present invention to provide a stem for an optical semiconductor device, which allows a stem substrate to be manufactured with a lower press pressure and has a high flatness of a light-receiving element mounting surface.

〔composition〕

To summarize, the present invention is characterized in that a part of the inclined light-receiving element mounting surface is recessed from the upper surface of the stem substrate.

〔effect〕

In this invention, as described above, since the light receiving element mounting surface is formed on the stem substrate by press working, the second
As shown in the figure, a lead wire 5' is provided and a light receiving element support plate 14 is fixed to this lead wire 5'. Not only is it unnecessary to hold the support plate 14 when fixing the light-receiving element, but the mounting angle of the light-receiving element does not change as the support plate 14 is deformed, and the lead wire 5' is also unnecessary. Moreover, even though the light-receiving element mounting surface is formed by press working, a part of the mounting surface is recessed from the top surface of the stem board, so as shown in FIG. Compared to the case where the entire light-receiving element mounting surface is formed protrudingly on the stem substrate by processing,
The height of the convex part on the light-receiving element mounting surface is reduced, and the meat of the recessed part forms the convex part from the top surface of the stem board on the light-receiving element mounting surface, so the amount of meat flowing is small, and the meat is thinner. As a result of the smooth flow of
The convex portion can be easily formed with a press pressure lower than that of the conventional method, and the flatness of the light-receiving element mounting surface can be increased.

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the present invention will be described below with reference to the drawings.

FIG. 4 shows a stem 30 for an optical semiconductor device of the present invention.
A perspective view of the figure is shown. The figure is the same as FIG. 3 except for the following points, so the same parts as in FIG. 3 are given the same reference numerals. The difference from FIG. 3 is that a part of the light-receiving element mounting surface 26 is formed within a recess 27 and is recessed further than the upper surface of the stem substrate 21.

According to the above configuration, due to the movement of the meat in the recess 27,
Since the convex portion 28 of the light-receiving element mounting surface 26 is formed from the upper surface of the stem substrate 21, the height h of the convex portion 28 becomes small, the pressing pressure of the stem substrate 21 can be reduced, and the flat surface of the light-receiving element mounting surface 26 is reduced. The degree can be increased.

In addition, in this invention, the volume of the concave portion 27 and the convex portion 28
Although it is desirable that the volumes of

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional light receiver. FIG. 2 is a sectional view of a light receiver that solves the drawbacks of the light receiver of FIG. FIG. 3 is a perspective view of a stem for an optical semiconductor device, which is the background of the present invention. FIG. 4 is a perspective view of a stem for an optical semiconductor device according to an embodiment of the present invention. 21... Stem substrate, 22... Through hole, 24...
Glass, 25... Lead wire, 26... Light receiving element mounting surface, 27... Concave portion, 28... Convex portion.

Claims (1)

[Scope of Claims] 1. A lead wire is hermetically and insulated sealed in a through hole of a stem substrate through a glass, and a light receiving element mounting surface is formed on the stem substrate at an angle with respect to the upper surface of the stem substrate. In the stem for an optical semiconductor device, the light-receiving element mounting surface is formed by press working, and a portion of the mounting surface is recessed relative to the upper surface of the stem substrate. Stem for optical semiconductor devices. 2. The stem for an optical semiconductor device according to claim 1, wherein the volume of the concave portion is approximately the same as the volume of the convex portion.