JPS62139366A - Semiconductor device for optical communications - Google Patents

Abstract

PURPOSE:To improve the assembling properties by providing a circular step portion of the same outer diameter as that of the stem flange portion in the neighborhood of the airtight seal fixing portion of the cap, thereby providing a construction to allow the beads to escape which are generated at the time of airtight seal fixing, eliminating the need for the optical axis adjustment between the respective devices. CONSTITUTION:A circular step portion 5 of the cap is processed to the same outer diameter as that of the circular flange of a stem 1, and supports the circular flange of the stem when performing the optical axis adjustment of the outgoing parallel lights with the axis center of the cap's outer periphery or when adjusting the light receiving surface position of a photo detector to the focal position of the entering parallel lights. And the step portion 5 is the portion to which a laser light is applied or the brazing portion when performing laser welding as the airtight seal for securing the reliability of an optical device, and it is to be in a size relationship that it does not become larger than the cap's outer size even in the occurrence of a gap between the cap step and the stem flange involved in the adjustment of the optical axis or focal point, or in the occurrence of raised deposit of the beads which are generated at the time of laser welding or brazing. With this, the need for the optical axis adjustment between the respective optical semiconductor devices is eliminated, enabling them to be mounted on the substrate without any adjustment.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a wavelength division multiplexing optical communication device in which a light emitting/receiving semiconductor device and an optical multiplexing/demultiplexing device are mounted on a substrate, and particularly, The present invention relates to a semiconductor device for optical communication that is suitable for mounting and assembly without adjusting the optical axis of light.

[Background of the invention]

In conventional semiconductor devices for optical communication, a cap supporting a window glass or an optical lens or optical fiber for collimating human-emitted light to protect the optical element, and a stem carrying the optical element are connected by electrical resistance welding or Hermetically sealed with solder. In this manufacturing method, the outer dimensions of the cap are formed to have smaller outer dimensions than the outer dimensions of the stem flange. For this reason, in a wavelength multiplexing optical communication device that multiplexes or demultiplexes light in a direction parallel to the component mounting surface of the board, it is impossible to directly mount the semiconductor device having a light emitting/receiving element on the board. No consideration was given to the fact that it is necessary to mount and assemble the semiconductor devices while mutually adjusting the optical axes of the semiconductor devices through mechanical parts for axis adjustment, resulting in very poor assembly work efficiency. A related example of this type of semiconductor device for optical communication includes, for example, Japanese Patent Application Laid-open No. 59-69986.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve problems related to assembly workability in the prior art and to provide a semiconductor device for optical communication that can be directly mounted on a substrate and does not require adjustment of the optical axis of input and output parallel light.

[Summary of the invention]

In the present invention, a flange (flange) having an optical element is provided.
e) a stem having a circularly shaped portion, and a cap having external dimensions larger than the flange of the stem,
In order to use its outer periphery as a reference surface when mounting the board, its cross-sectional shape is precisely machined into a circular or regular polygonal shape, and the emitted light from the light emitting element is frimated into parallel light and placed at a position coaxial with the axis of the cross section. In addition to fixing the optical lens in an airtight seal, the contact area with the stem flange has the same outer diameter as the stem flange in order to release misalignment that occurs when adjusting the optical axis of the emitted parallel light and beads that occur due to laser welding or brazing. and a cap with a circular step, and the outer periphery of the camp is used as a reference surface when mounting a board.

[Embodiments of the invention]

EMBODIMENT OF THE INVENTION Hereinafter, the semiconductor device for optical communication of this invention will be explained in detail based on the Example shown in drawing. FIGS. 1 and 2 are cross-sectional views of an embodiment of a semiconductor device for optical communication that implements the present invention. In the figure, 1 is a circular flange stem for mounting an optical semiconductor element 2, 2 is an optical semiconductor element, and 3 is a circular flange stem for mounting an optical semiconductor element 2.
is a cap whose cross section is precisely machined to have a circular or regular polygonal shape, and is located at a position coaxial with the axis of the outer periphery where the emitted light from the light emitting element is collimated into parallel light, or where incident parallel light coaxial with the axis is received. An optical lens 4°4I is hermetically fixed so that the light-receiving surface of the element is at the focal point. 5 is a circular step on the cap machined to have the same outer diameter as the circular flange of stem 1, and is used to adjust the optical axis of the output parallel light with the axis of the outer periphery of the cap, or to align the light receiving surface of the light receiving element to the focal position of the incident parallel light. The part that is irradiated with laser light or soldered during laser welding is used to support the circular flange of the stem during adjustment and to ensure the reliability of the optical element. Even if there is a misalignment between the cap step and the stem flange, and bead accretion that sometimes occurs during laser welding or brazing, the dimensional relationship is such that the cap does not become larger than the outer dimensions of the cap.

Since the semiconductor device for optical communication of the present invention is configured as described above, the optical multiplexing/demultiplexing device on the substrate and the optical multiplexing/demultiplexing device on the substrate can be mounted at once on the substrate by being supported on a jig that can accurately position the mounting position on the substrate. There is no need to adjust the optical axis between each optical semiconductor device during mounting, and it becomes possible to mount the optical semiconductor device on the board without any adjustment.

FIG. 3 shows a semiconductor device 9 for optical communication according to the present invention on a substrate 12.
In FIG. 3, which is a perspective view of the device installed, 10 is an optical multiplexer/demultiplexer, and 11 is a common boat.

〔Effect of the invention〕

As described above, according to the present invention, when mounting an optical communication semiconductor device on a substrate, there is no need to adjust the optical axis between each device, and the ease of assembly is greatly improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view in the optical axis direction showing an embodiment of the present invention using a ball lens, FIG. 2 is a cross-sectional view of an embodiment of the present invention using a squared index distribution rod lens, FIG. 3 is a perspective view showing an embodiment of the present invention mounted on a board. DESCRIPTION OF SYMBOLS 1...Circular flange stem, 2...Optical semiconductor element, 6...Cap, 4...
・Spherical lens, 4'...squared refractive index distribution type 6
゛°°Bead 5...Step, Rokudo lens, 7...Lead, 8a, 8b...
Ray trajectory. τ

Claims (1)

[Claims] a stem having an optical element and having a circular flange;
The cap has external dimensions larger than the flange of the stem, and its outer periphery is processed into a circular or regular polygonal shape in order to use it as a reference surface when mounting the board, and the emitted light from the light emitting element is A semiconductor device for optical communication, comprising a cap having an optical lens hermetically fixed at a position collimated by parallel light and coaxial with the central axis of the outer periphery, the cap having an optical lens hermetically fixed in a position near the hermetically sealed fixing part of the cap. A semiconductor device for optical communication, characterized in that a circular stepped portion having the same outer diameter as the stem flange portion is provided to allow a bead generated during the hermetically sealed fixation to escape.