JPH02296388A - Mounting of semiconductor light-emitting element - Google Patents

Abstract

PURPOSE:To contrive the improvement of the light-receiving efficiency of a semiconductor light-emitting element by a photodiode having a small light- receiving area by a method wherein emitted light reflect by an inclined part for reflecting light emitted from the rear of the element is directed to the photodiode. CONSTITUTION:An inclined part 103 for reflecting light emitted from the rear of a semiconductor laser 102 is provided on the part of a supporting body 101 and a silicon substrate 113 for directing emitted light l2 reflected by the part 103 to a photodiode 104 is provided. Accordingly, the laser 102 and the diode 104 can be arranged in such a way that their main surfaces 11 and 10 become parallel to each other. Moreover, the distance between the laser 102 and the diode 104 can be made short. Thereby, the improvement of the light-receiving efficiency of the laser is enhanced by the photodiode having a small light- receiving area.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for mounting semiconductor light emitting devices such as semiconductor lasers used in optical discs, optical communications, and the like.

2. Description of the Related Art Semiconductor lasers are widely used in consumer and industrial equipment as light sources for optical discs, laser printers, bar code readers, etc., or as light sources for optical communications.

In general, semiconductor lasers have a conversion efficiency (
quantum efficiency) is high. However, the oscillation threshold current value for laser oscillation changes with changes in the surrounding temperature, so it is difficult to obtain a stable and constant optical output simply by connecting a constant current source to the semiconductor laser. The light output is monitored by a photodiode to ensure a constant light output.

FIG. 2 shows a conventional method for mounting a semiconductor laser equipped with a photodiode for monitoring optical output.

In FIG. 2, 201 is a support (stem) for bonding a semiconductor laser and a photodiode, and 202
203 is a semiconductor laser chip, and 203 is a photodiode chip. As shown in FIG. 2, light is emitted from the semiconductor laser 202 from both front and rear end faces. The light emitted from the rear end facet of the semiconductor laser 202 is transmitted to the photodiode 2.
03 and is converted into an electrical signal. When the light reflected by the photodiode 203 enters the semiconductor laser 202, the noise of the semiconductor laser 202 increases.
The main surface of the semiconductor laser 202 is formed to be inclined at an angle other than 900 to prevent the light from entering the semiconductor laser 202 again. Semiconductor laser 202 and photodiode 203
Wires (Au) 20B and 207 are bonded from the electrodes to lead wires 204 and 20F5, respectively.

[Problems to be Solved by the Invention] In a conventional method for mounting two series of semiconductor lasers, a semiconductor laser 202 and a photodiode 203 are bonded to a support 201 at angles that differ from each other by approximately 90'. Therefore, the semiconductor laser 202 and the photodiode 203
When bonding the chips, it was necessary to change the direction of the support 201 so that the chips could be easily bonded to each chip. Further, the bonding of the wires 206 and 207 was similar, and the work was complicated.

Furthermore, in the conventional semiconductor laser mounting method, it is difficult to make the distance between the semiconductor laser 202 and the photodiode 203 close, and in order to increase the light receiving efficiency of the photodiode 203, a photodiode with a large light receiving area is required.

Means for Solving the Problems The present invention has been made in order to solve the problems in the conventional semiconductor laser mounting method as described above. The device has a slope portion for reflecting light emitted from the rear of the semiconductor light emitting element, and means for causing the light reflected by the slope portion to enter a photodiode.

Effect: By using such means, the present invention has the effect that the semiconductor laser chip and the photodiode chip can be arranged so that their main surfaces are parallel to each other, thereby simplifying the process of adhering the chips and bonding the wires. exists.

Furthermore, since the distance between the semiconductor laser and the photodiode can be brought closer, high light-receiving efficiency can be obtained with a photodiode having a small light-receiving area.

EXAMPLES The present invention will be explained below with reference to Examples. FIG. 1 shows a method for mounting a semiconductor light emitting device according to an embodiment of the present invention. In FIG. 1(a), 101 is a support (stem) for bonding a semiconductor laser and a photodiode;
02 is a semiconductor laser chip, 104 is a photodiode chip, 105 and 106 are lead wires, and 107 and 108 are wires that connect the semiconductor laser chip 102 and the photodiode 104 to the lead wires 105 and 106, respectively. Figure 1 (b) shows A (Figure 1 (a)
) Semiconductor laser chip 1 viewed from the direction of the arrow
An enlarged view of the area around 02 is shown. As shown in FIG. 1(b), light 9. is emitted from the semiconductor laser 102 from both front and rear end faces. Q2 is emitted.

Light 21 emitted from the rear end facet of the semiconductor laser 102 is reflected by the inclined portion 103 provided at the rear of the semiconductor laser 102, and its optical path is bent. The light reflected by the inclined portion 103 enters the main surface (light receiving surface) 10 of the potodiode 104 as shown in the figure. The inclined part 103 is the support body 1
Although it is possible to form the silicon substrate 113 by cutting 01, for example, after etching the silicon substrate 113 with a thickness of 200 μm into a tapered shape, for example, Cr/Au is vapor-deposited on the surface, as shown in FIG. 1(b). It can be formed by adhering to the support 101 with solder. Photodiode 104
As shown in FIG. 1(b), a silicon substrate 113 is provided with a flat part or an inclined part of the support 101 so as to cover the inclined part 103 with the principal surface 10 serving as a light-receiving surface facing the inclined part 103. Glue on the flat part of the

As can be seen from the above description, according to the present invention, the main surface 11 of the semiconductor laser 102 and the main surface 1 of the photodiode 104
Since the semiconductor laser 102 and the photodiode 104 can be arranged so that they are parallel to each other, the semiconductor laser 102 and the photodiode 104 can be bonded to the support without rotating the support as in the conventional case.

Furthermore, wire 107.108 is lead wire 105.10.
Similarly, there is no need to change the orientation of the support 101 when connecting it to the support 101, which simplifies the assembly work.

In addition, by doing this, the distance between the semiconductor laser 102 and the photodiode 104 is reduced from about 3 mm in the conventional case to 1 mm.
Since they can be brought close to each other within a millimeter, the light-receiving area of the photodiode can be reduced, and since almost all of the light emitted from the rear can be incident on the photodiode, the light-receiving efficiency of the photodiode can also be improved.

FIG. 1C shows an enlarged view of the periphery of a semiconductor laser chip, showing another embodiment of the present invention in which the inclined portion is a concave mirror.

FIG. 1C shows an example in which the inclined portion and the submount to which the semiconductor laser 102 is bonded are integrated. The inclined portion is formed by etching a silicon substrate 123 having a thickness of 300 μm in a tapered shape, for example, and then coating the surface with Cr.
/ Au can be formed by vapor-depositing and adhering to the support 101 with solder as shown in FIG. 1(C). As shown in FIG. 1(C), the photodiode 104 is made of a silicon substrate 123 provided with an inclined part so as to cover the inclined part 103 with its main surface serving as a light-receiving surface facing the inclined part 103.
Glue on the flat part of the

When the curvature of the inclined portion 103 provided on the silicon substrate 123 is adjusted so that the light emitted from the rear of the semiconductor laser 102 is focused on the main surface (light receiving surface) of the photodiode 104, the light receiving efficiency of the photodiode becomes as shown in FIG. ) is even better than the embodiment of the present invention shown in FIG.

Also, if it is configured as shown in FIG. 1(C), the photodiode 104
Since the light is obliquely incident on the photodiode 104
The light reflected by the semiconductor laser 102 does not enter the semiconductor laser 102 and increase the noise of the semiconductor laser 102.

"Effects of the Invention" - As described above, the present invention has an inclined part for reflecting light output monitor light on a part of the support for adhering an edge-emitting semiconductor light emitting element, and the inclined part By making the monitor light reflected by the photodiode enter the photodiode, the semiconductor laser chip and the photodiode tip can be arranged so that their main surfaces are parallel to each other, making it easy to bond the chips and bond the wires. This has the effect of simplifying the process.

Furthermore, since the distance between the semiconductor laser and the photodiode can be brought closer, there is also the effect that high light receiving efficiency can be obtained with a photodiode having a small light receiving area.

[Brief explanation of drawings]

FIG. 1(a) is a schematic perspective view of a device using the semiconductor laser mounting method of the present invention, and FIG. 1(C) is a semiconductor laser mounting method of one embodiment and another embodiment of the present invention. FIG. 2 is a schematic perspective view of a device made by a conventional semiconductor laser mounting method. 101・Fist・Support body, 102・11φ semiconductor laser chip, 103... Slanted portion, 104-... Photodiode, 113, 123... Silicon substrate.

Claims (5)

[Claims] (1) A part of the support for adhering an edge-emitting type semiconductor light-emitting element has a sloped part for reflecting light emitted from the rear of the semiconductor light-emitting element, and the light emitted from the rear side of the semiconductor light-emitting element is reflected by the sloped part. A method for mounting a semiconductor light emitting device, characterized by making incident light incident on a photodiode. (2) A method for mounting a semiconductor light emitting device according to claim 1, wherein the main surfaces of the semiconductor light emitting device and the photodiode are mounted parallel to each other. (3) The method for mounting a semiconductor light emitting device according to claim 1, wherein the inclined portion is formed by etching a crystal. (4) A method for mounting a semiconductor light emitting device according to claim 4, characterized in that the main surface of the photodiode is bonded to the main surface of the crystal. (5) The method for mounting a semiconductor light emitting device according to claim 1, wherein the inclined portion forms a concave surface with curvature.