JP2006202955A - Semiconductor laser apparatus and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frame type semiconductor laser apparatus capable of receiving laser light emitted backward by a semiconductor laser chip on a monitoring light receiving element stably as much as possible. <P>SOLUTION: The semiconductor laser apparatus comprises a first lead including a plate shaped mounting part 1a; second leads 21, 22, 23 separated from the first lead 1; and a holder 3 consisting of an insulating material for integrally holding them. It further comprises a semiconductor laser chip 5 mounted at the front of the mounting part 1a for emitting laser light froward and backward. It furthermore comprises the monitoring light receiving element 15 disposed more behind than the semiconductor laser chip 5 in the mounting part 1a. It further comprises an optical reflector 16 disposed more behind than the monitoring light receiving element 15 in the mounting part 1a independently from the holder 3. The optical reflector 16 receives at least part of the laser light emitted backward from the semiconductor laser chip 5, and reflects it to the monitoring light receiving element 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor laser device and a manufacturing method thereof, and more particularly to a frame type semiconductor laser device and a manufacturing method thereof. Typically, this type of semiconductor laser device is used in an optical pickup device or the like that reads information recorded on an optical recording medium.

  In order to read information recorded on an information recording medium such as a CD-ROM (compact disk-read only memory) or an MD (mini disk), a semiconductor laser device is widely used as a component of an optical pickup device. Among the semiconductor laser devices, there is a frame type laser device as disclosed in Japanese Patent Application Laid-Open No. 2002-43679. This frame-type laser device includes a package in which a metal lead frame and a plurality of leads serving as electrodes are integrally formed of resin (envelope). A semiconductor laser chip is mounted on an element mounting portion (chip mounting portion) of the lead frame via a submount, and the semiconductor laser chip and the electrode lead are electrically connected by a wire. In the example of Patent Document 1 (Japanese Patent Laid-Open No. 2002-43679), the submount is made of a Si substrate with a monitor light receiving element built in, and a semiconductor laser chip is attached thereon by soldering or the like. During operation, the semiconductor laser chip emits laser light forward and also emits laser light backward. Part of the laser light emitted backward is incident on the monitor light receiving element, and the laser light emitted forward by the semiconductor laser chip is controlled based on the output of the monitor light receiving element.

  However, in this example, most of the laser light emitted backward from the semiconductor laser chip does not enter the light-receiving element for monitoring due to restrictions on the arrangement of the semiconductor laser chip and the submount. For this reason, the amount of light incident on the light-receiving element for monitoring is small, which may cause inconvenience in the control of the laser light emitted forward by the semiconductor laser chip.

  In the frame type semiconductor laser device described in Patent Document 2 (Japanese Patent Laid-Open No. 2003-31885), an envelope is provided that surrounds the periphery of the semiconductor laser chip and the light receiving element for monitoring, and a part of the inner surface of the envelope is provided. Is provided with a light reflecting surface. The laser light emitted backward from the semiconductor laser chip is reflected by the light reflecting surface, and most of the light is incident on the light receiving element for monitoring.

However, in the example of Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-31885), when a stress is applied to the envelope when the semiconductor laser device is mounted on an electronic device such as an optical pickup device, the light reflecting surface is distorted. . As a result, there arises a problem that the amount of light incident on the monitor light receiving element is not stable.
JP 2002-43679 A JP 2003-31885 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor laser device capable of receiving a laser beam emitted backward from a semiconductor laser chip in a light receiving element for monitoring stably and a manufacturing method thereof.

In order to solve the above problems, a semiconductor laser device of the present invention is
A first lead including a plate-shaped mounting portion;
A second lead separate from the first lead;
A holding portion made of an insulating material that holds the first lead and the second lead together;
A semiconductor laser chip mounted on the front part of the mounting part and emitting laser light forward and backward; and
A light receiving element for monitoring disposed behind the semiconductor laser chip in the mounting portion;
It is separate from the holding part and is arranged behind the monitoring light receiving element in the mounting part, and receives at least part of the laser light emitted backward from the semiconductor laser chip to the monitoring light receiving element. It is characterized by comprising a light reflector that reflects toward the screen.

  Here, the laser beam emitted forward by the semiconductor laser chip is used for the original application of the semiconductor laser device. For example, when the semiconductor laser device of the present invention is mounted on an optical pickup device, it is used for irradiating an optical disk.

  In the semiconductor laser device of the present invention, the light reflector receives at least part of the laser light emitted backward from the semiconductor laser chip and reflects it toward the light receiving element for monitoring. Therefore, the amount of light incident on the light receiving element for monitoring increases as compared with the case where no light reflector is provided. In addition, since the light reflector is separate from the holding portion, even if stress is applied to the holding portion when the semiconductor laser device is mounted on an electronic device such as an optical pickup device, the light reflector Will not be distorted. Therefore, the amount of light incident on the monitor light receiving element is stabilized. As a result, the laser beam emitted forward by the semiconductor laser chip is well controlled based on the output of the light receiving element for monitoring.

  The first lead is preferably made of metal, and the bottom surface of the mounting portion is preferably exposed from the lead fixing resin. In that case, the heat generated by the semiconductor laser chip during operation is efficiently radiated through the bottom surface of the mounting portion.

  In one embodiment of the semiconductor laser device, the light reflector is made of a white resin.

  In the semiconductor laser device of this embodiment, since the light reflector is white, the received light is reflected almost without being absorbed. Accordingly, the amount of light incident on the monitor light receiving element increases. Moreover, since the light reflector is made of resin, it is easily processed into a shape suitable for reflection.

  In one embodiment of the semiconductor laser device, the light reflector is made of a resin plated with metal.

  In the semiconductor laser device of this embodiment, since the light reflector has a metal plating, it reflects the received light with little absorption. Accordingly, the amount of light incident on the monitor light receiving element increases.

  In the semiconductor laser device of one embodiment, the light reflector is made of metal.

  In the semiconductor laser device of this embodiment, since the light reflector is made of metal, it reflects the received light with little absorption. Accordingly, the amount of light incident on the monitor light receiving element increases.

  In one embodiment, the light reflector is inclined with respect to the laser light emitting direction of the semiconductor laser chip so as to reflect the laser light from the semiconductor laser chip toward the light receiving element for monitoring. It is characterized by having a reflective surface.

  In the semiconductor laser device according to this embodiment, the light reflector reflects the laser light from the semiconductor laser chip toward the light receiving element for monitoring with respect to the laser light emitting direction of the semiconductor laser chip. It has an inclined reflective surface. Accordingly, the amount of light incident on the monitor light receiving element increases.

  In one embodiment, the semiconductor laser chip is mounted on the mounting portion via a plate-shaped submount, and the monitor is mounted on a portion of the submount that extends rearward from the semiconductor laser chip. The light receiving element for use is built in.

  In the semiconductor laser device of this embodiment, the semiconductor laser chip is mounted on the mounting portion via a plate-shaped submount, and the portion of the submount that extends rearward from the semiconductor laser chip is Built-in monitor light-receiving element. Accordingly, the number of parts is reduced as compared with the case where the submount and the light receiving element for monitoring are provided separately from each other.

  A method of manufacturing a semiconductor laser device according to the present invention is a method of manufacturing a semiconductor laser device for manufacturing the semiconductor laser device, wherein at least the light receiving element for monitoring and the light reflector are simultaneously bonded on the mounting portion. It is characterized by.

  In the method of manufacturing a semiconductor laser device according to the present invention, at least the monitoring light receiving element and the light reflector are simultaneously bonded onto the mounting portion, so that the semiconductor laser device is easily manufactured.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 shows a frame type semiconductor laser device 40 according to an embodiment of the present invention as viewed obliquely. 2A is a view of the semiconductor laser device 40 from above, FIG. 2B is a view of FIG. 2A viewed from the right side, and FIG. 2C is a view of FIG. 2A. Each is shown from the bottom. It should be noted that the vertical and horizontal directions of the semiconductor laser device 40 in this embodiment are for convenience of explanation.

  As shown in FIGS. 1 and 2A, this frame type semiconductor laser device 40 includes a first lead 1 having a mounting portion 1a on which a semiconductor laser chip 5 is mounted, and a plurality of second signals for signal input / output. Leads 21, 22 and 23, and resin part 3 as a holding part for holding first lead 1 and second leads 21, 22 and 23 together are provided.

  Specifically, the first lead 1 protrudes from the mounting portion 1a along a substantially rectangular plate-shaped mounting portion 1a, a lead portion 1b that extends and extends continuously from the mounting portion 1a, and a back surface 1c of the mounting portion 1a. Tie bar portions 6a and 6b. A semiconductor laser chip 5 is mounted on the mounting portion 1 a via a rectangular plate-shaped submount member 4. The semiconductor laser chip 5 has a rectangular parallelepiped shape elongated in the optical axis direction, and emits laser light toward the front (upward in FIG. 2A). The submount member 4 is made of metal in this example.

  A monitor light receiving element 15 separate from the submount member 4 is mounted at a position behind the semiconductor laser chip 5 on the mounting portion 1a. Further, a separate light reflector 16 is mounted on the monitor light receiving element 15 and the resin part 3 at a position behind the monitor light receiving element 15 on the mounting portion 1a.

  In this example, the monitor light receiving element 15 is formed of a substantially rectangular parallelepiped photodiode chip formed by diffusing impurities in a Si substrate.

  In this example, the light reflector 16 is made of a white resin formed in a substantially rectangular parallelepiped shape. The light reflector 16 is easily formed by resin molding using a mold. This light reflector 16 has a reflecting surface perpendicular to the laser light emitting direction of the semiconductor laser chip 5 (vertical direction in FIG. 2A), and a part of the laser light emitted backward from the semiconductor laser chip 5. Is received and reflected toward the light receiving element 15 for monitoring.

  In this example, the resin portion 3 is made of a black insulating resin material such as an epoxy resin. Therefore, the resin part 3 is easily formed by resin molding using a mold.

  As shown in FIG. 2C, the back surface 1 c of the mounting portion 1 a is exposed from the resin portion 3. Further, the second leads 21, 22, and 23 extend elongated along the lead portion 1 b of the first lead 1. As shown in FIG. 1, the inner ends 21 a, 22 a, and 23 a of the second leads 21, 22, and 23 are exposed in the resin portion 3 that is molded in a frame shape. A wire made of an Au wire (not shown) is wired from the semiconductor laser chip 5 and the monitoring light receiving element 15 to the inner ends 21a, 22a, 23a of the second leads 21, 22, 23.

  As shown in FIG. 1 and FIG. 2A, the first lead 1 has a recess 7 that is retracted so as to indicate the mounting position of the semiconductor laser chip 5 at the front edge 1e of the mounting portion 1a. This facilitates positioning of the submount member 4 and the semiconductor laser chip 5 when the submount member 4 and the semiconductor laser chip 5 are attached on the mounting portion 1a in the manufacturing stage. For example, the front edge of the submount member 4 may be aligned along the edge of the recess 7.

  As shown in FIG. 3, the laser light L <b> 1 emitted from the semiconductor laser chip 5 forward (upward in FIG. 3) is used for the original application of the semiconductor laser device 40. For example, when this semiconductor laser device 40 is incorporated in an optical pickup device (not shown), it is used for irradiating an optical disk.

  A part of the laser beam L2 emitted backward from the semiconductor laser chip 5 directly enters the light-receiving element 15 for monitoring. However, most of the laser beam L2 emitted backward from the semiconductor laser chip 5 enters the light reflector 16. The light reflector 16 reflects the incident laser light toward the monitoring light receiving element 15. Therefore, the amount of incident light on the monitor light receiving element 15 is increased as compared with the case where the light reflector 16 is not provided. In particular, in this example, since the light reflector 16 is white, the received light is reflected almost without being absorbed. Accordingly, the amount of light incident on the monitor light receiving element 15 is further increased. In addition, since the light reflector 16 is separate from the resin portion 3, for example, even if stress is applied to the resin portion 3 when the semiconductor laser device 40 is mounted on the optical pickup device, the light reflector 16 is distorted. There is nothing. Therefore, the amount of light incident on the monitor light receiving element 15 is stabilized. As a result, the laser beam L1 emitted forward by the semiconductor laser chip 5 is well controlled based on the output of the light receiving element 15 for monitoring.

  Even if the resin itself constituting the light reflector 16 is a color other than white (for example, black), if the surface thereof is plated with a metal such as silver, the light receiving element 15 for monitoring is provided in the same manner as described above. The amount of incident light can be increased and stabilized. Moreover, even if the light reflector 16 is made of metal, the same effect can be obtained.

  As described above, in the semiconductor laser device 40, the back surface 1c of the mounting portion 1a of the first lead 1 is exposed from the resin portion 3. Therefore, if the mounting portion 1a of the first lead 1 is brought into contact with the housing of the optical pickup device when the semiconductor laser device is mounted on the optical pickup device, for example, the mounting portion 1a is radiated during operation of the semiconductor laser chip 5. Work for. That is, the heat generated by the semiconductor laser chip 5 is radiated to the housing through the mounting portion 1a.

  The semiconductor laser device 40 is manufactured as follows.

  First, as shown in FIG. 4, a frame 90 made of Cu is prepared. In this frame 90, a plurality of sets of first leads 1 and second leads 21, 22, 23 for constituting the semiconductor laser device 40 are arranged in two rows along bars 91, 92 extending in the left-right direction in FIG. Are lined up. The bars 91 and 92 are connected by a connecting bar 93. Further, the mounting portions 1 a of the adjacent first leads 1 are connected via a tie bar 6. The resin portion 3 is provided for each set of the first lead 1 and the second leads 21, 22, and 23 by resin molding using a mold.

  In this state, the semiconductor laser chip 5 is mounted on the mounting portion 1a of the first lead 1 via the submount member 4, and the monitor light receiving element 15 and the light reflector 16 are mounted (die bonding step). ). In order to simplify the process, it is desirable that the submount member 4, the monitor light receiving element 15, and the light reflector 16 are simultaneously bonded onto the mounting portion 1 a.

  Next, wires made of Au wire are routed from the semiconductor laser chip 5 and the light receiving element 15 for monitoring to the inner ends 21a, 22a, 23a of the second leads 21, 22, 23 (wire bonding step).

  At this stage, it is desirable to provide a lid for protecting the semiconductor laser chip 5 on the resin portion 3.

  Next, the lead portion 1b of the first lead 1 and the portions near the bars 91 and 92 of the second leads 21, 22, and 23 and the tie bar 6 are cut to obtain individual semiconductor laser devices 40 (tie bar cutting step). .

  In this way, the semiconductor laser device 40 is easily manufactured.

  In the above example, the material of the holding portion is an insulating resin, but may be a ceramic. If the material of the holding part is ceramic, the heat dissipation can be further improved.

  FIG. 5 shows a semiconductor laser device 50 according to another embodiment in which the semiconductor laser device 40 is modified. In addition, the same code | symbol is attached | subjected to the component same as FIG. 1, and each description is abbreviate | omitted.

  The semiconductor laser device 50 is different from the semiconductor laser device 40 in that the monitoring light receiving element 18 is incorporated in a plate-like submount 19 made of Si, not as a single component. Specifically, the semiconductor laser chip 5 is mounted on the front portion of the submount 19, and the monitoring light receiving element 18 is formed on the surface of the portion of the submount 19 that extends rearward from the semiconductor laser chip 5. Such a light receiving element 18 is formed by diffusing impurities on the surface of the Si substrate by a known method.

  Even in this semiconductor laser device 50, the amount of light incident on the light-receiving element 18 for monitoring increases due to the light reflector 16. Moreover, since the light reflector 16 is separate from the resin portion 3, even if stress is applied to the resin portion 3 when the semiconductor laser device is mounted on the optical pickup device, for example, the light reflector 16 is distorted. The incident light quantity to the monitor light receiving element 18 is stabilized. As a result, the laser beam L1 emitted forward by the semiconductor laser chip 5 is favorably controlled based on the output of the light receiving element 18 for monitoring. In addition, the number of parts can be reduced as compared with the case where the submount and the light receiving element for monitoring are provided separately from each other.

  FIG. 6 shows still another semiconductor laser device 60 obtained by modifying the semiconductor laser device 50 of FIG.

  In the semiconductor laser device 60, the light reflector 16 reflects the laser light L2 from the semiconductor laser chip 5 toward the light receiving element 18 for monitoring, as compared with the semiconductor laser device 50 of FIG. 1 is different in that it has a reflecting surface 17 inclined with respect to the laser beam emission direction (vertical direction in FIG. 6). Thanks to this reflecting surface 17, the amount of incident light on the monitor light receiving element 18 can be increased. Further, the amount of light incident on the monitor light receiving element 18 can be adjusted according to the angle of inclination.

  FIG. 7 shows a modification 70 in which the silver paste 20 is used as an adhesive for adhering the light reflector 16 to the mounting portion 1a of the first lead 1 in the semiconductor laser device 60 of FIG. In this modified example 70, a plate-like submount 19 made of Si, in which the monitor light-receiving element 18 is incorporated and the semiconductor laser chip 5 is mounted, and the light reflector 16 are mounted via a layered silver paste 20. Bonded to the part 1a.

  According to this configuration, the submount 19 and the light reflector 16 can be simultaneously bonded to the mounting portion 1a. Specifically, in the die bonding process, a predetermined amount of silver paste 20 is applied to the mounting portion 1 a of the first lead 1 by a dispenser or the like, and the submount 19 and the light reflector 16 are placed on the silver paste 20. Thereafter, they are put in an oven or the like and heated to be cured simultaneously. In this case, the semiconductor laser device 70 can be easily manufactured as compared with the case where the submount 19 and the light reflector 16 are separately mounted on the mounting portion 1a.

1 is a perspective view showing a schematic configuration of a semiconductor laser device according to an embodiment of the present invention. (A), (b), (c) is the front view, side view, and bottom view of the semiconductor laser device of this invention, respectively. It is sectional drawing of the said semiconductor laser apparatus. It is a figure which shows the flame | frame of the resin molding state used for producing the said semiconductor laser apparatus. It is a figure which shows the semiconductor laser apparatus of another embodiment provided with the submount which incorporated the light receiving element. FIG. 6 is a diagram showing a modification in which the light reflector is provided with an inclined surface in the semiconductor laser device of FIG. 5. It is a figure which shows the further modification of the semiconductor laser apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lead 1a Mounting part 1b Lead part 21,22,23 2nd lead 3 Holding part 4,19 Submount 5 Semiconductor laser chip 15,18 Light receiving element for monitoring 16 Light reflector 17 Inclined reflecting surface

Claims (7)

A first lead including a plate-shaped mounting portion;
A second lead separate from the first lead;
A holding portion made of an insulating material that holds the first lead and the second lead together;
A semiconductor laser chip mounted on the front part of the mounting part and emitting laser light forward and backward; and
A light receiving element for monitoring disposed behind the semiconductor laser chip in the mounting portion;
It is separate from the holding part and is arranged behind the monitoring light receiving element in the mounting part, and receives at least part of the laser light emitted backward from the semiconductor laser chip to the monitoring light receiving element. A semiconductor laser device comprising a light reflector that reflects toward the surface. The semiconductor laser device according to claim 1,
A semiconductor laser device, wherein the light reflector is made of a white resin. The semiconductor laser device according to claim 1,
2. The semiconductor laser device according to claim 1, wherein the light reflector is made of a resin plated with metal. The semiconductor laser device according to claim 1,
A semiconductor laser device, wherein the light reflector is made of metal. The semiconductor laser device according to claim 1,
The light reflector has a reflecting surface inclined with respect to the laser light emitting direction of the semiconductor laser chip so as to reflect the laser light from the semiconductor laser chip toward the light receiving element for monitoring. Semiconductor laser device. The semiconductor laser device according to claim 1,
The semiconductor laser chip is mounted on the mounting portion via a plate-like submount, and the monitor light receiving element is built in a portion of the submount that extends rearward from the semiconductor laser chip. A semiconductor laser device. A manufacturing method of a semiconductor laser device for manufacturing the semiconductor laser device according to claim 1,
A manufacturing method of a semiconductor laser device, wherein at least the light receiving element for monitoring and the light reflector are simultaneously bonded on the mounting portion.

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