JP3048818B2 - Semiconductor laser device - Google Patents

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 can be used as a light source of an optical disk device, or a light source such as a displacement measuring device, a pointer, and an LD-excited solid-state laser.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor laser device, a semiconductor laser device having a structure including a laser diode and an output detecting photodiode for detecting an optical output thereof, and a signal detecting device for detecting a signal read from a medium in addition to this structure. Some have a built-in photodiode.

FIG. 4A shows a semiconductor laser device having a semiconductor laser and a photodiode as viewed from above, and FIG. 4A shows the semiconductor laser device as viewed from the side.
It is shown in (B). As shown in FIG. 4B, in this semiconductor laser device, a semiconductor laser chip 41 and a light output detection photodiode 42 are mounted on a stem 43 fixed to an outer package 47. As shown in FIG. 4A, a current injection terminal 44 is wire-bonded to the semiconductor laser chip 41, and the current injected from the current injection terminal 44 drives the semiconductor laser chip 41. 4
5 is an output terminal of the photodiode 42;
Is a common terminal common to the semiconductor laser chip 41 and the photodiode 42. FIG. 4C shows an equivalent circuit of this semiconductor laser device. A portion surrounded by a broken line shown in FIG. 4C is attached to the exterior package 47 to be integrated.

As shown in FIG. 5, the semiconductor laser device 51 is connected to a wiring board 54 by soldering.
The current injection terminal 44 of the semiconductor laser device 51 is connected to the wiring 60 of the wiring board 54 at the soldering section 55, the common terminal 46 is connected to the wiring 59 at the soldering section 56, and the output terminal 45 is connected to the wiring section 57 at the soldering section 57. Connected to wiring 58.

The semiconductor laser device 51 is connected to a drive circuit 53 connected to a wiring board 54 via wirings 58, 59 and 60. The drive circuit 53 supplies a drive current to the semiconductor laser device 51 via the wirings 59 and 60.

[0006] A surge absorbing capacitor 52 connected between wirings 59 and 60 connecting the drive circuit 53 and the semiconductor laser device 51 is disposed near the semiconductor laser device 51 and receives a signal from the drive circuit 53. The surge current is absorbed to prevent the surge current from being applied to the semiconductor laser device 51.

[0007]

However, in the above-described conventional semiconductor laser device, the capacitor 52 is provided separately from the semiconductor laser device 51 to absorb the surge current.
4, there is a problem that the number of parts is increased and the number of assembling steps is increased in order to prevent surge current.

An object of the present invention is to provide a semiconductor laser device capable of taking measures against surge current without increasing the number of parts and without increasing the number of assembling steps.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor laser device comprising: a ceramic capacitor chip including a dielectric portion, an electrode sandwiching the dielectric portion; and a semiconductor laser chip. The semiconductor laser chip is mounted on the one electrode surface so that one surface of the semiconductor laser chip that requires electrical connection is electrically connected to one electrode surface of the ceramic capacitor chip. The other surface of the semiconductor laser chip that requires electrical connection is electrically connected to the other electrode surface of the ceramic capacitor chip by wire bonding, and the one electrode surface for mounting the semiconductor laser chip, The other electrode surface on which the wire bonding is performed is parallel to the other electrode surface.

According to a second aspect of the present invention, in the semiconductor laser device according to the first aspect, the other electrode of the ceramic capacitor chip faces the dielectric portion and is insulated from each other. A photodiode chip that has split electrodes and receives laser light from the semiconductor laser chip is mounted on one electrode of the ceramic capacitor chip, and one surface of the photodiode chip that requires electrical connection is The photodiode chip is electrically connected to one of the electrodes, and the other surface of the photodiode chip that requires electrical connection is electrically connected to one of the two divided electrodes; The other surface that needs to be described above is electrically connected to the other of the two divided electrodes.

According to a third aspect of the present invention, in the semiconductor laser device of the first aspect, the semiconductor laser body including the ceramic capacitor chip and the semiconductor laser chip is housed in a package. .

According to a fourth aspect of the present invention, in the semiconductor laser device according to the second aspect, the semiconductor laser body including the ceramic capacitor chip, the semiconductor laser chip, and the photodiode chip is housed in a package. It is characterized by.

[0013]

According to a first aspect of the present invention, in the semiconductor laser device, the semiconductor laser chip is mounted on one electrode of the ceramic capacitor chip, and the semiconductor laser chip is integrated with the ceramic capacitor chip.
One surface of the semiconductor laser chip that requires electrical connection is electrically connected to the one electrode.

That is, the semiconductor laser chip is integrated with a ceramic capacitor chip and is also electrically connected.

The surge current flowing from the drive circuit toward the semiconductor laser chip is absorbed by the ceramic capacitor chip.

Therefore, according to the first aspect of the present invention, it is possible to take measures against surge absorption from the drive circuit without increasing the number of parts and without increasing the number of assembly steps. In addition, since one electrode surface of the ceramic capacitor chip on which the semiconductor laser chip is mounted and the other electrode surface on which wire bonding is performed are parallel, the mounting surface of the semiconductor laser chip on the ceramic capacitor chip and the wire bonding surface And the semiconductor laser chip and the ceramic capacitor chip can be integrated by a simple process, and the surge current to the semiconductor laser can be prevented.

According to a second aspect of the present invention, a semiconductor laser chip and a photodiode chip are mounted and electrically connected to one electrode of the ceramic capacitor chip, and are integrated.
The semiconductor laser chip and the photodiode chip are connected to the other and one split electrode of the other electrode of the ceramic capacitor chip which are insulated from each other.

That is, the semiconductor laser chip and the photodiode chip are integrated with a ceramic capacitor chip and are also electrically connected.

The surge current from the drive circuit toward the semiconductor laser chip is absorbed by the ceramic capacitor chip. Further, laser light from the semiconductor laser chip can be monitored by the photodiode chip.

Therefore, according to the second aspect of the present invention, it is possible to take measures against surge absorption from the drive circuit without increasing the number of parts and without increasing the number of assembling steps. Light can be monitored.

According to a third aspect of the present invention, there is provided a semiconductor laser device including the ceramic capacitor chip and the semiconductor laser chip of the semiconductor laser device of the first aspect housed in a package.

Therefore, according to the third aspect of the present invention, the semiconductor laser body can be protected.

According to a fourth aspect of the present invention, there is provided a semiconductor laser device according to the second aspect, wherein the semiconductor laser body including the ceramic capacitor chip, the semiconductor laser chip, and the photodiode chip is housed in a package. .

Therefore, according to the present invention, the semiconductor laser body can be protected.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

<First Embodiment> FIG. 1 shows a first embodiment of the semiconductor laser device of the present invention. The first embodiment includes a surge absorbing capacitor chip C1 having a ceramic dielectric 2 and two electrodes 3 and 4 sandwiching the dielectric 2. On the electrode 3 of this capacitor chip C1,
The semiconductor laser chip 1 is mounted and fixed via a silicon submount base 5. The surface facing the stacking direction of the semiconductor laser 1 is in close contact with the silicon submount base 5, and the other surface 1a facing the stacking direction of the semiconductor laser 1 is connected to the capacitor chip C.
One other electrode 4 is wire-bonded with a gold wire 6. FIG. 1E shows an equivalent circuit of this embodiment. The semiconductor laser 1 and the capacitor chip C1 are connected in parallel.

The electrode 3 of the capacitor chip C1 also serves as a common electrode of the semiconductor laser chip 1, and the electrode 4 of the capacitor chip C1 also serves as a drive current injection electrode of the semiconductor laser chip 1.

In this embodiment, a drive circuit composed of a drive IC is usually connected to the electrodes 4 and 3 of the capacitor chip C1, and a drive current is injected from the drive circuit into the semiconductor laser chip 1. Then, the laser light 7 is emitted from the light emission surface of the semiconductor laser chip 1.

When a surge current is output from the drive circuit, the capacitor chip C1 absorbs the surge current, and the semiconductor laser chip 1 is protected from the surge current.

In the above embodiment, since the semiconductor laser chip 1 is integrally fixed to the surge current absorbing capacitor chip C1, the number of parts and the number of parts are different from the conventional example in which a surge current absorbing capacitor must be provided as a separate component. The semiconductor laser chip can be protected from a surge current from the drive circuit without increasing the number of assembly steps.

<Second Embodiment> FIG. 2 shows a second embodiment of the semiconductor laser device of the present invention. In the second embodiment, a ceramic dielectric 22 and an electrode 23 sandwiching the dielectric 22 are used.
, And a capacitor chip C2 including 24A and 24B. The electrodes 24A and 24B sandwich the protrusion 22a of the dielectric 22. The semiconductor laser chip 21 is mounted and fixed on the electrode 23 of the capacitor chip C2 via a silicon submount base 25. The surface of the semiconductor laser chip 21 facing the stacking direction is in close contact with the silicon submount base 25, and the other surface 21a of the semiconductor laser chip 21 in the stacking direction is connected to the electrode 24A by a gold wire 26. Wire bonded. A photodiode chip 28 is mounted and fixed on the electrode 23 adjacent to the silicon submount base 25. The photodiode chip 28 is a photodiode for detecting the optical output of the semiconductor laser chip 21. The upper surface 28A of the photodiode chip 28 includes a light receiving surface and an output terminal 29. The output terminal 29 is wire-bonded to the electrode 24B with a gold wire 30.
FIG. 2B shows an equivalent circuit of the second embodiment. Capacitors are connected in parallel to the semiconductor laser chip 21 and the photodiode chip 28, respectively. The electrode 23 of the capacitor chip C2 of the second embodiment also serves as a common terminal of the semiconductor laser chip 21 and the photodiode chip 28, and the electrode 24A is
The electrode 24B also serves as the output terminal of the photodiode chip 28.

In the second embodiment, the equivalent circuit shown in FIG. 2B is realized by one integrated component.

In the second embodiment, the electrodes 23 and 24
When the semiconductor laser chip 21 is driven by connecting a drive circuit (not shown) between the semiconductor laser chip A and the semiconductor laser chip 24B, the semiconductor laser chip 21 emits laser light. Part of the laser light is incident on the light receiving surface of the photodiode chip 28, and the photodiode chip 28 outputs a current corresponding to the amount of the laser light from the electrode 23 serving as an output terminal. Further, when a surge current is output from the drive circuit, the surge current is absorbed by the capacitor chip C2, so that the semiconductor laser chip 21 can be protected from the surge current.

According to the second embodiment, the semiconductor laser chip 21 is integrally mounted on the capacitor chip C2 for absorbing the surge current, and the photodiode chip 28 is integrally mounted on the capacitor chip C2. 1 integrated with a semiconductor laser device having both protection function against surge current and monitoring function of laser light
It can be realized with individual components.

In general, it is rare that the laser diode alone is driven, and it is overwhelming that the laser diode and the light output detecting photodiode are used in combination and the light output of the laser diode is constantly controlled and used. Therefore, the second embodiment is practically excellent.

<Third Embodiment> FIG. 3 shows a third embodiment.
The third embodiment includes a capacitor chip C3 having a ceramic dielectric 32, electrodes 33 sandwiching the dielectric 32, and divided electrodes 34A and 34B. The semiconductor laser chip 31 is mounted and fixed on the electrode 33 of the capacitor chip C3 via a silicon submount base 35. The upper surface 31a of the semiconductor laser chip 31 facing in the laminating direction is wire-bonded to the divided electrode 34A of the capacitor chip C3 by a gold wire 36. Further, a photodiode chip 38 for light detection is provided adjacent to the semiconductor laser chip 31 and is connected to the silicon submount base 3.
5 and is fixed. The upper surface 38A including the light receiving surface of the photodiode chip 38 is wire-bonded to the divided electrode 34B by a gold wire 39. The semiconductor laser device body R shown in FIG. 3A is inserted into a cylindrical metal package P, housed in the metal package P, and fixed, as shown in FIG. 3B. The axial length of the metal package P is 4 to 5 mm, and the outer diameter is 3 mm.
mm. The axial direction of the metal package P forms a Z-axis direction perpendicular to the light emitting surface of the semiconductor laser chip 31, and extends perpendicular to the radial direction of the metal package P.
A plane including the axis and the Y axis is included in the light emitting plane.

Therefore, the semiconductor laser chip 31
The laser light 37A is emitted from the light emitting surface 31a of the metal package P to the outside of the metal package P and in the Z direction, and the laser light 37B emitted to the inside of the metal package P is received by the photodiode chip 38 for light detection.

In the third embodiment, the capacitor chip C3
And the semiconductor laser chip 31 and the photodetecting photodiode 38 as an integral component, and the semiconductor laser device body R, which is an integral component, is housed in a cylindrical metal package P, so that surge current can be absorbed, and The laser beam output can be detected, and the integrated components (semiconductor laser chip 31, photodiode chip 38, gold wire 36
Etc.) can be protected.

In the third embodiment, the semiconductor laser device main body R is housed in the metal package P, but may be housed in a plastic package. Further, the semiconductor laser device main body R may be resin-molded. The outer diameter of the metal package P may be selected in the range of φ2 to 4 mm.
Further, the dimensions of the metal package P need not be limited to the above values.

In the above embodiment, the semiconductor chip and the photodiode chip are wire-bonded with gold wires.
This wire bond is not limited to a gold wire, and another conductive wire having good conductivity may be used.

[0041]

As is clear from the above, the semiconductor laser device according to the first aspect of the present invention has a semiconductor laser chip mounted on one electrode of a ceramic capacitor chip.
The semiconductor laser chip is integrated with the ceramic capacitor chip, and one surface of the semiconductor laser chip that requires electrical connection is electrically connected to one electrode. That is, the semiconductor laser chip is integrated with the ceramic capacitor chip and is also electrically connected. Then, a surge current flowing from the drive circuit toward the semiconductor laser chip is absorbed by the ceramic capacitor chip.

Therefore, according to the first aspect of the present invention, it is possible to take measures against surge absorption from the drive circuit without increasing the number of parts and without increasing the number of assembly steps. In addition, since one electrode surface of the ceramic capacitor chip on which the semiconductor laser chip is mounted and the other electrode surface on which wire bonding is performed are parallel, the mounting surface of the semiconductor laser chip on the ceramic capacitor chip and the wire bonding surface And the semiconductor laser chip and the ceramic capacitor chip can be integrated by a simple process, and the surge current to the semiconductor laser can be prevented.

In the semiconductor laser device according to the present invention, the semiconductor laser chip and the photodiode chip are mounted and electrically connected to one electrode of the ceramic capacitor chip, and are integrated. The semiconductor laser chip and the photodiode chip are respectively connected to the other electrode and one split electrode of the other electrode of the ceramic capacitor chip which are insulated from each other. That is, the semiconductor laser chip and the photodiode chip are integrated with the ceramic capacitor chip and are also electrically connected. And
Surge current from the drive circuit toward the semiconductor laser chip is absorbed by the ceramic capacitor chip. Further, laser light from the semiconductor laser chip can be monitored by the photodiode chip.

Therefore, according to the second aspect of the present invention, it is possible to take measures against surge absorption from the drive circuit without increasing the number of parts and the number of assembling steps, and to reduce the laser beam from the semiconductor laser chip. Light can be monitored.

According to a third aspect of the present invention, there is provided a semiconductor laser device including the ceramic capacitor chip and the semiconductor laser chip of the semiconductor laser device of the first aspect housed in a package.

Therefore, according to the third aspect of the present invention, the semiconductor laser body can be protected.

According to a fourth aspect of the present invention, there is provided a semiconductor laser device according to the second aspect, wherein the semiconductor laser body including the ceramic capacitor chip, the semiconductor laser chip, and the photodiode chip is housed in a package. .

Therefore, according to the fourth aspect of the present invention, the semiconductor laser body can be protected.

As described above, according to the present invention, since the semiconductor laser and the surge absorbing capacitor are integrated and electrically connected, the semiconductor laser and the surge absorbing capacitor are separately mounted on the substrate. The disadvantage of the prior art, which must be connected in parallel, can be eliminated. That is, according to the present invention, a countermeasure against a surge current to the semiconductor laser can be performed with a smaller number of parts and a smaller number of assembling steps than in the related art.

[Brief description of the drawings]

FIG. 1A is a top view of a first embodiment of a semiconductor laser device according to the present invention, FIG. 1B is a front view of the first embodiment, and FIG. FIG. 1D is a side view of the first embodiment, and FIG. 1D is a perspective view of the first embodiment.
(E) is an equivalent circuit diagram of the first embodiment.

FIG. 2A is a perspective view of a second embodiment of the present invention, and FIG. 2B is an equivalent circuit diagram of the second embodiment.

FIG. 3A is a perspective view of a semiconductor laser device body according to a third embodiment of the present invention, and FIG. 3B is a perspective view of the third embodiment.

4 (A) is a top view of a conventional semiconductor laser device, FIG. 4 (B) is a side view of the conventional example, and FIG. 4 (C) is an equivalent circuit diagram of the conventional example.

FIG. 5 is a perspective view showing a structure for protecting a conventional semiconductor laser device from surge current.

[Explanation of symbols]

1, 21, 31 ... semiconductor laser chip, 2, 22, 32
... Dielectric part, 3,4,23,33 ... Electrode, 5,25,3
5. Silicon submount base, 6, 26, 30, 3
6, 39: gold wire, 7, 37A, 37B: laser beam, C
1, C2, C3 ... ceramic capacitor chip, 24
A, 34A, 24B, 34B: divided electrodes, P: metal package.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 5/00-5/50 H01L 33/00 H01L 27/04

Claims (4)

(57) [Claims] 1. A ceramic capacitor chip including a dielectric portion and an electrode sandwiching the dielectric portion, and a semiconductor laser chip, wherein one surface of the semiconductor laser chip that requires electrical connection is one of the ceramic capacitor chips. The semiconductor laser chip is mounted on the one electrode surface so that the semiconductor laser chip is electrically connected to the electrode surface of the ceramic capacitor chip. A semiconductor laser electrically connected to an electrode surface by wire bonding, wherein the one electrode surface on which the semiconductor laser chip is mounted and the other electrode surface on which the wire bonding is performed are parallel to each other; apparatus. 2. The semiconductor laser device according to claim 1, wherein the other electrode of the ceramic capacitor chip faces the dielectric portion and is insulated from each other.
A photodiode chip for receiving laser light from the semiconductor laser chip is mounted on one electrode of the ceramic capacitor chip, and one surface of the ceramic capacitor chip that requires electrical connection is The other surface of the photodiode chip, which is required to be electrically connected, is electrically connected to one of the two divided electrodes, and is electrically connected to the one electrode. A semiconductor laser device, wherein the other surface requiring connection is electrically connected to the other of the two divided electrodes. 3. The semiconductor laser device according to claim 1, wherein the semiconductor laser body including the ceramic capacitor chip and the semiconductor laser chip is housed in a package. 4. The semiconductor laser device according to claim 2, wherein the semiconductor laser body including the ceramic capacitor chip, the semiconductor laser chip, and the photodiode chip comprises:
A semiconductor laser device housed in a package.