JPH0653597A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To secure an appropriate strength of bonding for the implementation of the long life, and at the same time, reduce the variation of the amount of received light by making the height of the leads, to which fine metal wires are connected, substantially equal to that of a semiconductor laser element, and by arranging the leads on the left-or right-side of the center line of the optical axis. CONSTITUTION:In a semiconductor laser device, a light receiving element 7 has surface electrodes 8 and 9 and a reverse side electrode 10, which are made of silicon crystal. These electrodes are fixed on a first lead 1 through a conductive bonding agent. Also, both ends of a semiconductor laser element 12 are cut open, and reflection films are formed on them. This element is fixed by soldering or the like on the surface electrode 8 of the light receiving element 7 so that the main surface of emission is positioned in front. A second lead 13 is provided in such a manner that it extends in the direction opposite to the direction of the main emission of the semiconductor laser element 12. In this case, however, the leading end of the second lead 13 is configured in the form of a crank. The surface of the leading end is substantially at the same height as the surface of the semiconductor laser element 12. Further, the surface is biased to the left or the right with respect to the center line of the optical axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device which has a long life and can easily secure a stable optical output monitor current.

[0002]

2. Description of the Related Art In recent years, many improvements have been made to semiconductor laser devices.
A semiconductor laser device filed in Japanese Patent No. 138696 is shown in FIG. In this figure, the light receiving element 4 is placed on the first lead 41.
2 is mounted, and the semiconductor laser element 43 is mounted thereon. The rear surface of the semiconductor laser element 43 and the light receiving element 42
The P type diffusion region 44 is covered with the transparent resin 45. The second lead 46 is provided separately from the first lead 41. A thin metal wire 47 is wired between the semiconductor laser element 43 and the second lead 46.

[0003]

However, the above-mentioned semiconductor laser device has the first drawback that the life of the semiconductor laser element 43 is shortened. The cause that the present inventor has investigated will be described. Since the position of the semiconductor laser element 43 is higher than the position of the second lead 46, when bonding with a wire bonder, the bonder is normally compressed at the position of the second lead 46 where the stroke of the bonder becomes long and the compression strength becomes small. The strength is set. Therefore, the second lead 46 secures a necessary and sufficient bonding strength. However, in the bonding with the semiconductor laser element 43, the stroke of the bonder is shortened, so that the semiconductor laser element 43 is excessively compressed. Therefore, the semiconductor laser element 43 is damaged at the time of bonding and the life is shortened.

The second drawback of this device is that since the second lead 46 is located directly below the optical axis center line 48, the sub-emitted light from the rear surface of the semiconductor laser device 43 is a thin metal wire 47.
Since the light enters the P-type diffusion region 44 in part, the amount of received light varies. Therefore, the present invention has been made in view of the above-mentioned conventional drawbacks, and provides a semiconductor laser device that secures an appropriate bonding strength, has a long life, and has a small variation in the amount of light received by the sub-emitted light. .

[0005]

In order to solve the above-mentioned problems, the present invention provides a light-receiving element mounted on a first lead having a positioning means, and a first light-receiving element on or in front of the light-receiving element. Provided is a semiconductor laser element which is mounted on a lead and which has an optical axis center line located at a position higher than the light receiving surface of the light receiving element and has a main emitting surface in the front. A transparent resin that covers the vicinity of the rear surface of the semiconductor laser element to the light receiving surface formed on the surface of the light receiving element, and a second lead that is arranged apart from the first lead are provided. An insulating frame formed around the first and second leads and a thin metal wire that connects the semiconductor laser element and the second lead are provided. And the second metal wire is connected
The height of the lead and the height of the semiconductor laser element are set to be substantially the same, and the second lead is arranged left or right with respect to the center line of the optical axis.

[0006]

According to the present invention, as described above, when the position of the semiconductor laser element and the position of the second lead are provided at substantially the same height, when bonding with a wire bonder, the strokes of the bonder at these two positions are It will be almost the same. Therefore, it is possible to set the compressive strength of bonding in each of the second lead and the semiconductor laser element to substantially the same and appropriate values. Further, according to the present invention, since the center line of the optical axis is provided at a position higher than the light receiving surface, the sub-emitted light sufficiently enters the light receiving surface. By arranging the second lead left or right with respect to the center line of the optical axis, it is possible to prevent the sub-emission light reflected by the metal thin wire or the end face of the second lead from entering the light receiving surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 is a side sectional view of a semiconductor laser device according to this embodiment, and FIG. 2 is a plan sectional view of the semiconductor laser device. In these figures, the first lead 1 is made of a metal material such as copper having a thickness of 0.2 to 1.0 mm and is composed of a rectangular portion 2, a notch portion 3 and a terminal portion 4. The first lead 1 has a positioning means 6 such as a V-shaped groove formed on the end face 5. In addition, the positioning means 6 may be a U-shaped groove, a concave portion having a substantially U-shaped cross section, or a convex portion having a V-shaped, U-shaped or substantially U-shaped cross section.

The light-receiving element 7 is, for example, a silicon crystal having a P-I-N structure provided with front electrodes 8 and 9 and a back electrode 10. The surface electrode 9 is formed in ohmic contact with the light receiving surface 11 formed of a P type diffusion region. The light receiving element 7 is fixed on the first lead 1 via a conductive adhesive such as silver paste.

The semiconductor laser device 12 is made of, for example, a GaAlAs light emitting layer including an active layer and a clad layer sandwiching the active layer. Both ends of the semiconductor laser element 12 are cleaved and a reflective film is formed on the cleaved surface. Semiconductor laser device 1
Reference numeral 2 is fixed on the surface electrode 8 of the light receiving element 7 via silver paste or solder so that the main emission surface is located in front. The semiconductor laser element 12 is formed so that the reflectance of the reflective film on the rear surface is higher than that on the front surface so that the secondary emission for monitoring is performed rearward. The optical axis center line 12a of the semiconductor laser element 12 is provided at a position higher than the light receiving surface 11 of the light receiving element 7.

The second and third leads 13 and 14 are made of a metal material such as copper, are located in the notch 3 of the first lead 1, and extend in the direction opposite to the main emission direction of the semiconductor laser device 12. . The second and third leads 13 and 14 are the optical axis center line 12a.
On the other hand, they are arranged so as to be divided into right and left respectively. Also, if necessary, the second and third leads 13, 1
4 may be arranged on the left and right respectively. The second lead 13 is formed into a crank shape by pressing,
The surface of the tip is positioned so as to be substantially the same height as the surface of the semiconductor laser device 12.

The thin metal wires 15 and the other thin metal wires 16 are both made of gold or the like, and are respectively between the semiconductor laser element 12 and the second lead 13 and between the surface electrode 9 and the third electrode of the light receiving element 7.
It is wired so as to connect to the lead 14 of the. The thin metal wires 15 and the other thin metal wires 16 are distributed to the right and left with respect to the optical axis center line 12a. Other thin metal wires 17
Are wired so as to connect between the surface electrode 8 of the light receiving element 7 and the first lead 1.

The transparent resin 18 is made of, for example, an epoxy resin, and the light receiving element 7 is provided from the vicinity of the rear surface of the semiconductor laser element 12.
Is formed so as to integrally cover the light receiving surface 11 of. The insulating frame 19 is made of, for example, a polycarbonate resin or an epoxy resin and has a substantially U-shaped plan view so as to expose the emission surface of the semiconductor laser element 12, and the first, second and third leads 1, 13 and 14 are formed. It is formed by transfer molding so as to sandwich each front surface and back surface. The insulating frame 19 is also formed below the crank-shaped tip of the second lead 13. This is to prevent the second lead 13 from deforming as a base of the second lead 13 during wire bonding. The semiconductor laser device 20 is composed of these components.

Then, the semiconductor laser device 20 supports the semiconductor laser device 20 so that the convex portion or the concave portion formed on the support 21 and the positioning means 6 formed on the end surface 5 of the first lead 1, that is, the concave portion or the convex portion are fitted to each other. It is fixed at 21. Optical components 22 such as a diffraction grating, a half mirror, and an objective lens are provided in the main emission direction of the semiconductor laser device 12.

Next, a second embodiment of the present invention will be described with reference to the sectional view of FIG. The first lead 23 is pressed,
It is partially formed in a crank shape, and the light receiving element 7 is fixed thereon. A semiconductor laser element 12 is provided on the light receiving element 7.
Is stuck. The surface of the second lead 24 is substantially flush with the surface of the semiconductor laser device 12, and has a flat plate shape. A thin metal wire 25 is wired so as to connect the semiconductor laser device 12 and the second lead 24. An insulating frame 26 is provided so as to integrally cover the first and second leads 23 and 24. The numbers in FIG. 3 and FIG.
The same parts as those in FIG. 2 indicate the same parts. As described above, in the first embodiment, the tips of the second leads are partially raised, but in the second embodiment, the first leads are partially lowered. Has been

Next, a third embodiment of the present invention will be described with reference to the sectional view of FIG. The first lead 1 is formed in a flat plate shape, and the light receiving element 7 and the semiconductor laser element 12 are sequentially mounted thereon. The flat plate-shaped second lead 27 is arranged at substantially the same height as the first lead 1. Submount 28
Is made of silicon to which boron or the like is added, and is fixed on the second lead 27. The surface of the submount 28 is provided so as to be substantially at the same height as the surface of the semiconductor laser device 12. Metal wire 29 is submount 28
The surface of the semiconductor laser device 12 and the surface of the semiconductor laser device 12 are connected to each other. The insulating frame 30 has the first and second leads 1 and 2.
It is provided so as to cover 7 integrally. Unlike the semiconductor laser devices of the first and second embodiments, the semiconductor laser device of the present embodiment does not require press work for forming a step on the lead, but it requires a submount to be mounted, which increases the cost.

A fourth embodiment of the present invention will be described with reference to the sectional view of FIG. The light receiving element 31 is, for example, a silicon crystal having a P-I-N structure provided with a front electrode 32 and a back electrode 33. The surface electrode 32 is formed in ohmic contact with the light receiving surface 34 formed of a P type diffusion region. The light receiving element 31 is fixed onto the first lead 1 via a conductive adhesive.

The submount 35 is made of silicon or the like and provided with a front surface electrode 36 and a back surface electrode (not shown), and is fixed on the first lead 1 by a conductive adhesive. The semiconductor laser device 12 is fixed by being alloyed with the surface electrode 36 of the submount 35. In this way, the semiconductor laser element 12 is mounted on the first lead 1 in front of the light receiving element 31 via the submount 35, and the optical axis center line 12 a thereof is located higher than the light receiving surface 34 and in front of the light receiving surface 34. It has a main exit surface.

The transparent resin 37 is formed so as to cover the vicinity of the rear surface of the semiconductor laser element 12 to the light receiving surface 34.
As described above, since the semiconductor laser device 12 and the light receiving device 31 are placed on the first lead 1 while being separated from each other, the temperature of the semiconductor laser device 12 does not rise so much. Therefore, the light receiving characteristic of the light receiving element 31 (the monitor current value with respect to the amount of received light) is stable, and the monitor current is also stable.

In addition to the present embodiment, a recess is formed in the lead, the light receiving element is placed on the recess, and the semiconductor laser element is placed directly on the first lead in front of the recess. May be provided at a position higher than the light receiving surface.

[0020]

According to the present invention, as described above, the center line of the optical axis is provided at a position higher than the light receiving surface, and the light receiving surface is covered with the transparent resin from the rear surface of the semiconductor laser element to the light receiving surface. A sufficient amount can be secured.

Further, according to the present invention, when bonding is performed by a wire bonder by arranging the position of the semiconductor laser element and the wiring position of the second lead at substantially the same height,
The stroke of the bonder at each point can be made approximately the same. Therefore, it is possible to set the compressive strength of bonding in each of the second lead and the semiconductor laser element to substantially the same value and to an appropriate value. Therefore, the bonding strength to the second lead and the semiconductor laser element can be ensured as necessary and sufficient, so that there is no fear that the thin metal wire will come off in the second lead and the semiconductor laser element.
Further, unlike the conventional case, excessive compressive strength is not applied to the semiconductor laser device having the active layer which is easily damaged near the surface, so that the semiconductor laser device is not damaged and the life is extended.

According to the present invention, the second lead is arranged to the left or right of the center line of the optical axis so that the sub-emitted light that propagates through the light-transmissive resin is thin metal wire or the end of the second lead. Since it is not reflected by the part, the reflected light does not penetrate the translucent resin again and enter the light receiving surface. Therefore, the amount of light received on the light receiving surface is stable and a stable monitor current can be obtained by the light receiving element, so that the output control of the semiconductor laser element becomes accurate.

Further, according to the present invention, by positioning the positioning means provided on the first lead of the semiconductor laser device and the convex portion or the concave portion of the supporting member, the positional deviation of the semiconductor laser device can be prevented, and the emitted beam and the optical component can be prevented. The relative position of can be held accurately.

[Brief description of drawings]

FIG. 1 is a side sectional view of a semiconductor laser according to a first embodiment of the present invention.

FIG. 2 is a plan sectional view of a semiconductor laser according to a first embodiment of the present invention.

FIG. 3 is a side sectional view of a semiconductor laser according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a semiconductor laser according to a third embodiment of the present invention.

FIG. 5 is a side sectional view of a semiconductor laser according to a fourth embodiment of the present invention.

FIG. 6 is a side sectional view of a conventional semiconductor laser device.

[Explanation of symbols]

 1, 23 First lead 6 Positioning means 7, 31 Light receiving element 11, 34 Light receiving surface 12 Semiconductor laser element 12a Optical axis center line 13, 24, 27 Second lead 15, 25, 29 Thin metal wire 18, 37 Light transmission Resin 19, 26, 30 Insulation frame

Claims (1)

[Claims] 1. A light receiving element mounted on a first lead having a positioning means, and a light receiving surface of the light receiving element mounted on the light receiving element or on the first lead in front of the light receiving element. A semiconductor laser element having an optical axis center line at a high position and having a main emission surface in the front, and a translucent resin covering from the vicinity of the rear surface of the semiconductor laser element to the light receiving surface formed on the surface of the light receiving element. A second lead arranged apart from the first lead, an insulating frame formed around the first and second leads, the semiconductor laser device and the second lead are connected to each other. A height of the second lead to which the metal thin wire is connected and a height of the semiconductor laser element are substantially the same, and the second lead is located with respect to the optical axis center line. Characterized by being placed on the left or right Semiconductor laser device.