JPH0983085A - Semiconductor laser device and assembling method thereof - Google Patents

Abstract

(57) Abstract: A semiconductor laser device and its assembly capable of easily realizing light shielding without adversely affecting a semiconductor laser element when a light shielding member is attached to a light receiving element so that reflected light from the outside does not enter. Get the way. A semiconductor laser device configured to control the intensity of front emission light 5 based on reception of rear emission light 7 of the semiconductor laser element 1 by a light receiving element 2 arranged on the rear end face side of the semiconductor laser element 1. In the above-mentioned semiconductor laser element 1, the semiconductor laser element 1 is covered with the longitudinal direction substantially orthogonal to the installation direction of the active layer 1a of the semiconductor laser element 1 and covers the light receiving element 2 from the outside. As a light-shielding member that shields the incidence of light, the ribbon wire 13 is thermocompression-bonded to the semiconductor laser element 1 on both sides thereof while avoiding the central portion where the active layer 1a of the semiconductor laser element 1 is present.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which the intensity of front emission light is controlled on the basis of the reception of rear emission light of the semiconductor laser element by a light receiving element arranged on the rear end face side of the semiconductor laser element. The present invention relates to a laser device and an assembling method thereof.

[0002]

2. Description of the Related Art FIGS. 7A and 7B are a perspective view and a sectional view showing a conventional semiconductor laser device. In FIG. 7, reference numeral 1 is a semiconductor laser element, 1 a is an active layer that exists in the substantially central portion of the semiconductor laser element 1, 2 is a light receiving element arranged on the rear end face side of the semiconductor laser element 1, and 3 is the semiconductor laser element 1. A heat sink for mounting, 4 is a wire for supplying power to the semiconductor laser element 1, 5 is front emission light of the semiconductor laser element 1, 6 is return light reflected from the outside, 7 is rear emission light of the semiconductor laser element 1, 8 Is a stem, and 9 is a mount for the light receiving element 2. The stem 8 and the mounting base 9 are omitted in the perspective view shown in FIG.

In the semiconductor laser device having the illustrated configuration, the semiconductor laser element 1 usually has two end faces, a front end face and a rear end face, because the end face is produced by cleavage. Therefore, when the semiconductor laser device 1 is driven,
Both the front emission light 5 and the rear emission light 7 are generated. Since the light receiving element 2 receives the rear surface emitted light 7, it detects the monitor current generated in the light receiving element 2 and allows the drive current to the semiconductor laser element 1 to flow while controlling the monitor current to be constant. For example, the intensity of the front emission light 5 is constantly controlled (Automatic Power Control: hereinafter, A
(PC control).

However, in general, the semiconductor laser device 1 is
It is often used as a structure for coupling with an external optical fiber, an optical disk, an object to be excited, etc. via an optical system, and in order to always control the intensity of the front emission light 5 at a constant level, the light receiving element 2 is a semiconductor laser. When placed on the rear side of element 1,
The reflected return light 6 from the outside enters the light receiving element 2, and only the rear surface emission light 7 of the semiconductor laser element 1 cannot be accurately detected. Therefore, in that case, the intensity of the front surface emission light 5 is accurately controlled. There was a problem that it could not be done.

Therefore, as shown in FIG. 8, a method of die-bonding the light-shielding member 10 for die-bonding to the upper portion of the semiconductor laser element 1 by soldering so that the reflected return light 6 from the outside does not enter the light-receiving element 2, or As shown in FIG. 9, a light shield is formed on the active layer 1a located at the center of the semiconductor laser device 1.
A method of thermocompression bonding the light shielding ribbon wire 11 connected to the power feeding ribbon wire fixing post 12 over the entire surface has been considered.

[0006]

However, in the method shown in FIGS. 8 and 9, extra heat stress is applied to the semiconductor laser element 1 by soldering or thermocompression bonding, which adversely affects the semiconductor laser element 1. Further, when a low melting point solder is used as the solder, there is a problem that there is a risk of a junction short circuit between the semiconductor laser element 1 and other members due to growth of whiskers (whisker-shaped protrusions) due to a change with time of the solder. was there.

The present invention has been made to solve the above-mentioned problems, and adversely affects the semiconductor laser element when the light shielding member is attached to the light receiving element so that reflected light from the outside does not enter. It is an object of the present invention to provide a semiconductor laser device and a method for assembling the same that can easily realize light shielding.

[0008]

A semiconductor laser device according to the present invention has an intensity of front emission light based on reception of rear emission light of the semiconductor laser element by a light receiving element arranged on the rear end face side of the semiconductor laser element. In the semiconductor laser device, the longitudinal direction of the semiconductor laser device is substantially perpendicular to the installation direction of the active layer of the semiconductor laser device. It is characterized in that a light blocking member for blocking the incidence of reflected return light from is provided.

Further, the light-shielding member is characterized in that both sides are pressure-bonded onto the semiconductor laser element while avoiding the central portion where the active layer of the semiconductor laser element is present.

Further, the present invention is characterized in that a ribbon wire for supplying power to the semiconductor laser element is also used as the light shielding member.

Further, the light shielding member is attached to a pair of bonding posts provided on both sides of a heat sink on which the semiconductor laser device is mounted.

Further, the light-shielding member is U-shaped, and both legs of the light-shielding member are erected on a heat sink on which the semiconductor laser device is mounted and die-bonded.

Further, in the method for assembling the semiconductor laser device according to the present invention, the stem connected to the heat sink for mounting the semiconductor laser device is provided with the light receiving device for receiving the rear surface emitted light of the semiconductor laser device, and the light receiving device is received. A step of wire-bonding an anode electrode to the element using a wire; a step of die-bonding the semiconductor laser element to a position on a heat sink that emits rear surface emission light to the light-receiving element by soldering; A step of providing a light-shielding member that covers the semiconductor laser element with the longitudinal direction substantially orthogonal to the installation direction of the active layer of the semiconductor laser element and shields the light-receiving element from the incidence of reflected return light from the outside, Bonding the anode electrode to the semiconductor laser element using a wire, and the semiconductor laser element The cap for sealing with a window on the output side of the front light emitted are those comprising a step of fixing to the stem, and a step of connecting an optical system in front of the window of the cap.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. 1A and 1B are a perspective view and a sectional view showing a semiconductor laser device according to the first embodiment.
In FIG. 1, the same parts as those of the conventional example shown in FIGS. 7A and 7B are designated by the same reference numerals, and the description thereof will be omitted. In the semiconductor laser device according to the first embodiment, when the front emission light 5 of the semiconductor laser element 1 is controlled by receiving the rear emission light 7 of the semiconductor laser element 1 by the light reception element 2, the semiconductor laser device 1 is externally connected to the light reception element 2. As a light-shielding member for shielding the reflected return light 6 from, let us cover the semiconductor laser element 1 with a ribbon wire 13 made of gold, for example, in a direction whose longitudinal direction is substantially orthogonal to the installation direction of the active layer of the semiconductor laser element 1. And then
It is fixed on the semiconductor laser element 1 while avoiding the central portion of the semiconductor laser element 1 having the active layer.

Gold as a material of the ribbon wire 13 is a soft material having a low Young's modulus, and is fixed to the semiconductor laser element 1 by avoiding the central portion of the semiconductor laser element 1 having the active layer 1a. Only both sides of the ribbon wire 13 are thermocompression bonded. By doing so, it is possible to prevent thermal stress from being applied to the vicinity of the active layer 1a of the semiconductor laser element 1, and to shield the reflected return light 6 from the outside without adversely affecting the semiconductor laser element 1. This can be easily realized, and the front emission light 5 of the semiconductor laser device 1 can be stably controlled.

In this case, the thickness of the ribbon wire 13 may be about several tens of μm to several hundreds of μm. Since the reflected return light 6 from the outside normally returns to the semiconductor laser device 1 via the lens 14 of the optical system, it is focused on a position slightly deviated from the active layer 1a of the semiconductor laser device 1. . Therefore, the thickness of the ribbon wire 13 fixed on the semiconductor laser device 1 as a light shielding member is several tens of μm.
If it is from m to several hundreds of μm, the reflected return light 6 incident on the light receiving element 2 from the outside can be sufficiently shielded.

Next, a method of assembling the semiconductor laser device having the above structure will be described in detail. 2A to 2F show a flow relating to the assembling process of the semiconductor laser device. First, as shown in FIG. 2A, the light receiving element 2 for receiving the rear surface emitted light of the semiconductor laser element 1 is attached to the mounting base 9 provided on the stem 8 connected to the heat sink 3, and the light receiving element 2 is attached to the light receiving element 2. The anode electrode 15 is wire-bonded using the wire 17. Here, as the light receiving element 2, the light receiving surface of the Si material has a rectangular shape of 500 × 500 μm. In the figure, 14 indicates an anode electrode of the semiconductor laser device 1, 16 indicates a cathode electrode of the semiconductor laser device 1 and a cathode electrode portion of the light receiving device 2.

Next, as shown in FIG. 2B, the semiconductor laser device 1 is placed at a position on the heat sink 3 which emits the rear emission light to the light receiving device 2 by using AuSn solder.
Die bonding at 0 ° C. This semiconductor laser device 1
As AlGa that emits output light in the 0.86 μm band
It is made of As / GaAs material and its chip width is 600
μm, chip thickness 100 μm, resonator length 750 μm
Therefore, there is an active layer 1a that emits laser light and guides it at a depth of 5 μm from the surface.

Then, as shown in FIG. 2C, a ribbon wire 13 made of gold is formed on the semiconductor laser element 1 as a light-shielding member that shields the reflected return light 6 incident on the light-receiving element 2 from the outside. With the longitudinal direction of the semiconductor laser device 1 substantially orthogonal to the installation direction of the active layer of the semiconductor laser device 1 so as to straddle the central portion of the semiconductor laser device 1 having the active layer (see FIG. 1A). Only the both sides of the ribbon wire 13 are thermocompression bonded while avoiding the central portion of the semiconductor laser device 1 having the layer 1a.

The ribbon wire 13 has a thickness of 100 μm, a width of 100 μm and a length of 600 μm, and the thermocompression bonding temperature to the semiconductor laser device 1 is 200 ° C. Gold as a material of the ribbon wire 13 is a soft material having a low Young's modulus, and is fixed to the semiconductor laser device 1 by avoiding the central portion of the semiconductor laser device 1 having an active layer. Since both sides are thermocompression bonded, it is possible to prevent thermal stress from being applied to the vicinity of the active layer 1a of the semiconductor laser element 1, and the semiconductor laser element 1 is not adversely affected.

After that, as shown in FIG. 2D, wire bonding is performed on the semiconductor laser element 1 to connect the anode electrode 14 to the wire 18 for supplying power. And FIG.
As shown in (e), a sealing cap 19 having a window 19a provided on the emission side of the front emission light 5 of the semiconductor laser element 1 is fixed to the stem 8 by welding, and further shown in FIG. 2 (f). As described above, the lens 14 is arranged on the front surface of the window 19a and is connected to the optical system.

Therefore, according to the first embodiment, the longitudinal direction of the semiconductor laser device 1 is set to be substantially orthogonal to the installation direction of the active layer 1a of the semiconductor laser device 1. A light-shielding member that shields the light-receiving element 2 from the incidence of reflected return light from the outside is pressed on both sides of the semiconductor laser element 1 while avoiding the central portion where the active layer 1a of the semiconductor laser element 1 is located. Since the semiconductor laser device 1 is provided in this manner, it is possible to prevent thermal stress from being applied to the vicinity of the active layer 1a of the semiconductor laser device 1, and the semiconductor laser device 1 is not adversely affected.
It is possible to easily realize the light shielding against the light and to stably control the front emission light 5 of the semiconductor laser device 1.

In the first embodiment, the semiconductor laser element 1 is made of AlGaAs / GaAs and the light receiving element 2 is made of Si. However, the semiconductor laser element 1 is made of InGaAsP / InP long-wave semiconductor laser. InGaAs / I as an element, an AlGaInP / GaInP-based visible light semiconductor laser element, and a light receiving element 2.
Of course, it can be applied to the case of using the nP type.

Embodiment 2. Next, FIG. 3 shows a second embodiment.
FIG. 3 is a perspective view showing a semiconductor laser device according to the present invention. In the semiconductor laser device according to the second embodiment, the gold pellet 20 is used as the light blocking member for blocking the reflected return light 6 from the outside that is incident on the light receiving element 2, and the gold pellet is used as in the first embodiment. The semiconductor laser device 1 is mounted on the semiconductor laser device 1 such that the longitudinal direction of the semiconductor laser device 20 is substantially orthogonal to the installation direction of the active layer of the semiconductor laser device 1 so as to straddle the central portion of the semiconductor laser device 1 having the active layer 1a. Only the both sides of the gold pellet 20 are thermocompression bonded or ultrasonic pressure bonded, avoiding the central part of the semiconductor laser device 1 having layers.

Here, the size of the gold pellet 20 used is such that the reflected return light 6 from the outside can be sufficiently shielded, the length in the longitudinal direction is equivalent to the width of the light receiving element 2, and the thickness is several. It may be about 10 to several hundreds. By doing so, similar to the first embodiment, it is possible to prevent thermal stress from being applied to the vicinity of the active layer 1a of the semiconductor laser device 1, and the semiconductor laser device 1 is not adversely affected.

Embodiment 3 FIG. Next, FIG. 4 shows a third embodiment.
FIG. 3 is a perspective view showing a semiconductor laser device according to the present invention. In the semiconductor laser device according to the third embodiment, a ribbon is provided on the pair of bonding posts 22, 22 provided on both sides of the heat sink 3 as a light blocking member for blocking the reflected return light 6 incident on the light receiving element 2 from the outside. Attach the wire 21. This ribbon wire 21 has the same structure as in the first embodiment.
The semiconductor laser device 1 is mounted on the semiconductor laser device 1 with its longitudinal direction substantially orthogonal to the installation direction of the active layer of the semiconductor laser device 1. The difference is that there is no need for thermocompression bonding.

Here, the width of the ribbon wire 21 used is
The width is such that the reflected light 6 reflected from the outside and incident on the light receiving element 2 can be shielded, and it may be about several tens to several hundreds although it varies depending on the size and arrangement of the light receiving element 2. By doing so, it is not necessary to directly thermocompression-bond the light shielding member on the semiconductor laser device 1 as in the first embodiment, so that no thermal stress is applied to the vicinity of the active layer 1a of the semiconductor laser device 1. Moreover, the semiconductor laser element 1 is not adversely affected by thermal stress.

Fourth Embodiment Next, FIG. 5 shows a fourth embodiment.
FIG. 3 is a perspective view showing a semiconductor laser device according to the present invention. In the semiconductor laser device according to the fourth embodiment, a U-shaped member 23 is used as a light-shielding member that shields the reflected return light 6 incident on the light-receiving element 2 from the outside.
In the same manner as in the first embodiment, the both legs are covered so that the longitudinal direction of the beam portion between the two legs is substantially orthogonal to the installation direction of the active layer 1a of the semiconductor laser device 1 so as to cover the semiconductor laser device 1. The semiconductor laser device 1 is die-bonded so as to stand upright on the heat sink 3.
The difference is that it does not need to be directly thermocompression bonded.

Here, a U-shaped member 23 as a light shielding member
For example, metal, ceramic or the like is used, but there is no particular problem as long as die bonding to the heat sink 3 is possible. Further, the gap between the semiconductor laser element 1 and the beam portion of the U-shaped member 23 is preferably as small as possible, but several μm to several tens μ so that a load is not applied to the semiconductor laser element 1.
It is preferably about m. By doing this,
Since it is not necessary to directly thermocompress the light shielding member on the semiconductor laser device 1 as in the third embodiment, no thermal stress is applied to the vicinity of the active layer 1a of the semiconductor laser device 1, and the semiconductor device is not affected by the thermal stress. There is no adverse effect on the laser element 1.

Embodiment 5 Next, FIG. 6 shows a fifth embodiment.
FIG. 3 is a perspective view showing a semiconductor laser device according to the present invention. In the semiconductor laser device according to the fifth embodiment, the ribbon wire 24 is used as a light shielding member that shields the reflected return light 6 incident on the light receiving element 2 from the outside. Is placed so as to cross the central portion of the semiconductor laser element 1 having the active layer 1a in a direction substantially orthogonal to the installation direction of the active layer of the semiconductor laser element 1, and the center of the semiconductor laser element 1 having the active layer 1a is placed. Only the both sides of the ribbon wire 24 are thermocompression bonded while avoiding the portion. Further, at this time, unlike the first embodiment, the ribbon wire 24 is also used as a power feeding wire without separately providing the power feeding wire 4 to the semiconductor laser element 1.

By doing so, the first embodiment
Similarly, it is possible to prevent thermal stress from being applied to the vicinity of the active layer 1a of the semiconductor laser element 1, and the semiconductor laser element 1 is not adversely affected. Further, since the ribbon wire 24 as the light shielding member is also used as the power feeding wire, the number of parts can be reduced.

As described above, according to the semiconductor laser device and the method of assembling the same according to the present invention, the longitudinal direction of the semiconductor laser device is set to be substantially orthogonal to the installation direction of the active layer of the semiconductor laser device. A light-shielding member that covers the semiconductor laser element and shields the reflected light from entering the light-receiving element from the outside, and presses both sides on the semiconductor laser element while avoiding the central portion where the active layer of the semiconductor laser element is present. Since it is provided in this way, it is possible to avoid applying thermal stress to the vicinity of the active layer of the semiconductor laser element, and it is possible to easily shield reflected light from the outside without adversely affecting the semiconductor laser element. In addition, the front emission light of the semiconductor laser device can be stably controlled, and its assembly becomes extremely easy.

Further, when a wire for supplying power to the semiconductor laser element is also used as a light shielding member for shielding the reflected return light from the outside which is incident on the light receiving element, the number of parts can be reduced.

Further, when the light shielding member is attached to a pair of bonding posts provided on both sides of a heat sink on which the semiconductor laser element is mounted, the light shielding member is U-shaped, and both legs are on the heat sink on which the semiconductor laser element is mounted. In the case of a light-shielding member that is erected and die-bonded, since it is not necessary to directly thermocompress the light-shielding member on the semiconductor laser element, no thermal stress is applied near the active layer of the semiconductor laser element, Semiconductor laser device 1 due to thermal stress
It has the effect of not adversely affecting.

[Brief description of drawings]

FIG. 1 is a perspective view and a sectional view showing a semiconductor laser device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an assembling method of the semiconductor laser device shown in FIG.

FIG. 3 is a perspective view showing a semiconductor laser device according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a semiconductor laser device according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing a semiconductor laser device according to a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a semiconductor laser device according to a fifth embodiment of the present invention.

FIG. 7 is a perspective view and a sectional view showing a semiconductor laser device according to a conventional example.

FIG. 8 is a perspective view showing a semiconductor laser device according to another conventional example.

FIG. 9 is a perspective view showing a semiconductor laser device according to still another conventional example.

[Explanation of symbols]

1 semiconductor laser device, 1a active layer, 2 light receiving device,
3 heat sink, 5 front emission light, 6 external reflection return light, 7 rear emission light, 8 stem, 13 ribbon wire (light shielding member), 14 semiconductor laser element 1 anode electrode, 18 wire, 19 cap, 19a
Window, 20 gold pallet (light blocking member), 21 ribbon wire (light blocking member), 22 bonding post, 23 U-shaped member (light blocking member), 24 ribbon wire (light blocking member).

Claims (6)

[Claims] 1. A semiconductor laser device in which the intensity of front emission light is controlled based on the reception of rear emission light of the semiconductor laser element by a light receiving element arranged on the rear end face side of the semiconductor laser element. On the laser element,
A light-shielding member is provided to cover the semiconductor laser element with its longitudinal direction substantially orthogonal to the installation direction of the active layer of the semiconductor laser element and to shield the light-receiving element from incident reflected return light from the outside. Characteristic semiconductor laser device. 2. The semiconductor laser device according to claim 1, wherein the light shielding member is formed by crimping both sides on the semiconductor laser element while avoiding a central portion where an active layer of the semiconductor laser element is provided. . 3. The semiconductor laser device according to claim 2, wherein a ribbon wire for supplying power to the semiconductor laser element is also used as the light shielding member. 4. The semiconductor laser device according to claim 1, wherein the light shielding member is attached to a pair of bonding posts provided on both sides of a heat sink on which the semiconductor laser element is mounted. 5. The semiconductor laser device according to claim 1, wherein the light-shielding member is U-shaped, and both legs of the light-shielding member are erected on a heat sink on which the semiconductor laser element is mounted and die-bonded. . 6. A light receiving element for receiving rear surface emitted light of the semiconductor laser element is attached to a stem connected to a heat sink for mounting the semiconductor laser element, and an anode electrode is wire-bonded to the light receiving element with a wire. A step of die-bonding a semiconductor laser element to a position on a heat sink that emits rear surface emission light with respect to the light receiving element using solder, and a longitudinal direction of the active layer of the semiconductor laser element on the semiconductor laser element. A step of providing a light shielding member for covering the semiconductor laser element in a direction substantially orthogonal to the installation direction and shielding the reflected light from the outside from entering the light receiving element; and using an anode electrode for the semiconductor laser element using a wire. A bonding cap and a sealing cap having a window on the emission side of the front emission light of the semiconductor laser device are attached. A method of assembling a semiconductor laser device, comprising the steps of fixing to the stem and connecting an optical system to the front surface of the window of the cap.