JPS63144588A - Sub-mount for semiconductor chip laser - Google Patents

Abstract

PURPOSE:To change an inrush current region to a semiconductor laser chip, and to operate a semiconductor chip laser easily and stably by forming one or more of insulating sections having a required shape to a conductive chip bonding section on which the semiconductor laser chip is bonded. CONSTITUTION:A sub-mount body 1 is constituted of an insulating material having an excellent heat transfer coefficient such as beryllium oxide, silicon carbide, diamond, aluminum nitride, etc. Since insulating sections 4 are formed to one parts in a chip bonding section 2 disposed onto the body 1, both end surface sections of a chip 5 are not bonded when the chip 5 is bonded with the bonding section 2. Consequently, wires are stretched properly to the chip 5, a wire bonding section 3, a stem 6 and the chip bonding section 2, thus flowing currents through the chip 5, then acquiring laser beams from a light-emitting region 8. Since the end surface sections are not bonded with a conductor section for the bonding section 2, current concentration to the end surfaces is inhibited, and single mode oscillation by the control of grain distribution in the axial direction is facilitated, thus stably operating a semiconductor laser.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a submount used for assembling a high-output type semiconductor laser or a semiconductor laser emitting single mode.

(Prior Art) FIG. 3(a) shows an example of a commonly used conventional submount of this type. Further, FIG. 3(b) shows an example of an assembled state using a conventional submount.

In FIGS. 3(a) and (b), 1 is a submount body made of an insulator, 2 is a chip adhesive part formed on the submount body 1, and 5 is a semiconductor bonded to this chip adhesive part 2. Laser chip (hereinafter simply referred to as chip), 6
is a stem (or package), 7 is the stem 6,
This is solder for bonding the submount body 1 together.

In a conventional submount, a conductive chip bonding portion 2 is provided on a submount body 1 using a technique such as plating or vapor deposition. The chip 5 is assembled into the stem 6 via the submount body 1. When the chip 5 is directly assembled into the stem 6, mechanical strain is applied to the light emitting region of the chip 5 due to the difference in linear expansion coefficient between the chip 5 and the stem 6, causing deterioration. Since the submount uses a material with good thermal conductivity,
Heat dissipation does not deteriorate even if the submount is used.

One electrode surface of the chip 5 is completely bonded to the chip adhesive surface 2 on the submount by solder 7, so that current is uniformly injected into the chip 5.

[Problems to be Solved by the Invention] When a normal semiconductor laser is operated at high output, the temperature near the end face increases several times that of the inside of the active layer due to the concentration of current at the laser end face, resulting in end face deterioration. , is known to cause oxidation. Therefore, a non-injected region is provided near the end face of the laser to suppress the temperature rise near the end face. However, providing such a region inside the laser is technically difficult and has the problem of lowering yield. Further, in a single mode laser (for example, a DFB laser), more stable single wavelength emission can be expected when gain distribution is controlled in the axial direction of the active region. However, when using the conventional submount as described above, the adhesive surface of the chip 5 is completely made of conductive material, so the current flows uniformly within the chip 5, so that the injection is performed in the axial direction of the active region. There was a problem in that it was not possible to change the gain distribution by changing the current.

This invention was made in order to solve the above-mentioned problems. 2. It provides a submount for a semiconductor laser that can change the region of current injected into the chip and that can easily and stably operate the semiconductor laser. The purpose is to obtain.

[Means for solving problems]

The semiconductor chip laser submount according to the present invention includes:
The submount body is made of a material that has good thermal conductivity and is an electrical insulator, and the submount body has a conductive chip adhesive part that adheres the semiconductor laser chip to the surface of the submount body, and a conductive chip adhesive part that adheres the wire to the surface of the submount body. A conductive chip bonding portion to which the semiconductor laser chip is bonded has one or more insulating portions having a predetermined shape formed therein.

[Function] In the present invention, by forming one or more insulating portions in the conductive chip bonding portion that is bonded to the semiconductor laser chip, a current can be uniformly applied over the entire area of the semiconductor laser chip bonded to the chip bonding portion. The current will no longer flow, and the current will only flow through the part that is bonded to the chip bonding area.

〔Example〕

1(a) and 1(b) are views showing one embodiment of the present invention, FIG. 1(a) is a perspective view of a submount, and FIG. 1(b) is a diagram showing an embodiment of the present invention. ) is a diagram showing an assembled state of a semiconductor laser chip using a submount.

In FIG. 1, reference numeral 1 denotes a submount body made of an insulator, which is made of a material with good thermal conductivity. On this submount body 1, a chip bonding section 2 and a wire bonding section 3 are formed in an electrically insulated state. Reference numeral 4 denotes an insulating portion formed at one or more locations within the chip bonding portion 2. In addition, as the submount body 1, beryllium oxide (Bed), silicon carbide (S i C)
.

Insulators containing diamond, aluminum nitride (AJ!N), etc. are used.

Using the submount constructed in this way, the structure shown in Fig. 1 (
As shown in b), a semiconductor laser chip (hereinafter simply referred to as a chip) 5 is assembled. That is, the chip 5 is bonded onto the chip bonding portion 2 on the submount, and this submount is bonded onto the stem 6 with solder 7, thereby being assembled. 8 indicates a light emitting region of the chip 5. Note that although not shown in the figure, the chip bonding portion 2. Wire adhesive part 3. Predetermined wiring is provided between the chip 5 and the stem 6 using bonding wires.

FIGS. 2(a) and 2(b) show another embodiment of the present invention, in which the wire adhesive part 3 formed on the submount main body 1 is separated to form an insulating part 4, and the submount It is composed of Note that other configurations and assemblies are the same as those shown in FIG. 1, so explanations thereof will be omitted.

The embodiment shown in FIG. 1 relates to a submount and assembly method used for a high-output type chip 5. chip 5
is bonded to the chip bonding portion 2 on the submount with the substrate facing upward (with the light emitting region 8 downward). Since the submount is made of a material that has good thermal conductivity and has the same coefficient of linear expansion as the chip 5, it has a sufficient heat dissipation effect. Since the insulating portion 4 is formed in a part of the chip bonding portion 2, when the chip 5 is bonded to the chip bonding portion 2, both end face portions of the chip 5 are not bonded. By appropriately connecting wires to the chip 5, the wire bonding portion 3, the stem 6, and the chip bonding portion 2, current flows through the chip 5 and laser light can be obtained from the light emitting region 8. Normally, when a semiconductor laser is operated at high output, the temperature near the end face increases several times that of the inside of the active layer due to current concentration at the laser end face, causing end face deterioration. When used, since the end face portion is not bonded to the conductor portion of the chip bonding portion 2, current is less likely to concentrate on the end face, and temperature rise at the end face portion can be suppressed.

The embodiment of FIG. 2 is a single mode (e.g. DFB laser)
The present invention relates to a submount and an assembly method for use in a type of semiconductor laser chip. Since the insulating portion 4 is formed in the chip bonding portion 2, the bonding portion with the chip 5 is divided. By appropriately connecting wires to the chip 5, the wire bonding portion 3, the stem 6, and the chip bonding portion 2, a current flows through the chip 5, and laser light is obtained from the light emitting region.

When the chip 5 is completely bonded to the chip adhesive part 2, current flows uniformly within the chip 5, but since the bonded part is divided, the injected current flows in the axial direction of the active region of the chip 5. becomes uneven. By appropriately changing the length of the part to which the chip 5 is connected, it is possible to change the injection current and control the gain distribution in the axial direction of the active region. It becomes easier to oscillate in one mode. - In each of the above embodiments, the case where the submount main body 1 is directly bonded to the stem (or package) 6 has been described, but the submount main body 1 can also be bonded to the stem 6 via a conductor.

〔Effect of the invention〕

As explained above, the present invention is capable of bonding a conductive chip bonding portion for bonding a semiconductor laser chip and a wire onto a submount body made of an electrically insulating material with good thermal conductivity. A conductive wire bonding portion for bonding the semiconductor laser chip is provided, and one or more insulating portions having a desired shape are formed on the conductive chip bonding portion to which the semiconductor laser chip is bonded.
Current can be injected non-uniformly into the semiconductor laser chip, and in the case of high-output type semiconductor lasers, current concentration on the end face can be suppressed, and in the case of single mode types, the gain distribution in the axial direction can be injected non-uniformly. Single mode oscillation is facilitated by the control of , and the semiconductor laser can be operated stably.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are views showing one embodiment of the present invention, FIG. 1(a) is a perspective view of the submount structure, and FIG.
b) is a perspective view showing a schematic configuration using the submount of Fig. 1(a), and Figs. 2(a) and 2(b) are views showing other embodiments of the present invention. Figure 1 <a), <b
3 is a perspective view similar to <a> i.
<b> is a perspective view showing a conventional submount and an assembled state using this submount. In the figure, 1 is a submount body, 2 is a chip bonding part, 3 is a wire bonding part, 4 is an insulating part, 5 is a chip, 6 is a stem, 7 is solder, and 8 is a laser light emitting area. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 2 Figure 3

Claims (7)

[Claims] (1) A conductive chip adhesive part that adheres the semiconductor laser chip and a conductive wire adhesive that adheres the wire to the submount body, which is made of an electrically insulating material with good thermal conductivity. 1. A submount for a semiconductor chip laser, characterized in that an insulating part having a desired shape is formed at one or more places on a conductive chip bonding part to which the semiconductor laser chip is bonded. (2) a chip bonding part for bonding the semiconductor laser chip;
A submount for a semiconductor chip laser according to claim 1, wherein the wire bonding portion for bonding the wire is electrically isolated. (3) The submount for a semiconductor chip laser according to claim (1), wherein the insulator contains beryum oxide. (4) A submount for a semiconductor chip laser according to claim (1), wherein the insulator includes silicon carbide. (5) A submount for a semiconductor chip laser according to claim (1), wherein the insulator contains diamond. (6) A submount for a semiconductor chip laser according to claim (1), wherein the insulator contains aluminum nitride. (7) The submount for a semiconductor chip laser according to claim (1), wherein the submount is integrated with an electrical conductor.