JP2553069Y2 - Semiconductor laser stem - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a metal stem for fusing a semiconductor laser device.

[0002]

2. Description of the Related Art In recent years, there has been a demand for downsizing and cost reduction of a module using a semiconductor laser device, and accordingly, a downsizing and cost reduction of a semiconductor laser device have also been demanded. To satisfy this demand, it is important to reduce the size and cost of the stem used in the semiconductor laser device.

A conventional semiconductor laser stem is shown in FIG.
(A) As shown in FIG.
A copper projection (31) for fusing a semiconductor laser element was fused onto an iron circular portion (32) of mmΦ. The reason why the projection (31) is made of copper is that the thermal conductivity is better than that of iron and the thermal resistance of the semiconductor laser device can be reduced. However, in this stem, since the projections are fused, it takes a lot of man-hours to manufacture, and it is difficult to reduce the size and the cost.

On the other hand, in a semiconductor laser device for a CD (compact disk), FIG.
There are stems for semiconductor lasers as shown in FIGS. In this stem, a circular portion (42) having a terminal 47 and having a diameter of 5.6 mm and a projection (41) for fusing the semiconductor laser element were both integrally formed of iron.

[0005]

[Problems to be Solved by the Invention] The above-mentioned conventional CD
The stem (FIG. 4) used for the semiconductor laser device for (compact disk) is downsized from 9.0 mmΦ to 5.6 mmΦ, and the material of the projection (41) for fusing the semiconductor laser element is also iron. is made of. With such a stem, the heat capacity of the stem itself becomes small, and the thermal conductivity of iron, which is a material, is about 80 w / mk (room temperature) and the thermal conductivity of copper (about 400 w / mk (room temperature)). The thermal resistance is about 30% higher than that of the stem shown in Fig. 3. On the other hand, the temperature characteristics of the communication InP-based semiconductor laser device are worse than that of the GaAs-based semiconductor laser due to the material properties. In addition, the requirements for the operating temperature range are strict, and the temperature has recently been raised to 85 ° C. Therefore, the heat generated by the semiconductor laser element cannot be released to the outside of the stem having a large thermal resistance. There is a drawback that it is not suitable for use with.

[0006]

The semiconductor laser stem of the present invention has the following features. (1) The stem has a circular stem base, a projection for fusing the semiconductor laser element, and a circular portion ( The stem base) has a groove for fusing the monitor light detection photodiode. Further, the shape of the projection for fusing the semiconductor laser element spreads in a wing-like manner as it approaches the outer edge of the stem from the surface on which the semiconductor laser element is fused.

(2) The material of the circular portion of the stem and the projection for fusing the semiconductor laser element is an alloy containing copper as a main component. The part is made of iron. Has the following two features at the same time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a plan view (FIG. 1A) and a cross-sectional view taken along line AA '(FIG. 1B) of one embodiment of the present invention. In the present embodiment, a projection (1) for fusing a semiconductor laser element is integrally formed of the same copper / tungsten alloy as the stem base on the stem base of a 5.6 mmφ circular portion (2) having the terminal 7. . Further, the shape of the projection (1) for fusing the semiconductor laser element spreads like a wing closer to the outer edge of the stem than the surface 5 for fusing the conductor laser, thereby increasing the heat capacity of the projection. Further, an outer edge portion (3) of a surface having a protrusion for fusing the stem-based semiconductor laser element of the circular portion (2) of 5.6 mmΦ has a ring-shaped iron fused to the circular portion. This is because if the outer edge is integrally formed with a copper-tungsten alloy, the cap and the stem cannot be fused by the resistance heating method.

The thermal resistance of the semiconductor laser device using the stem of this embodiment is about 75 ° C./w, and the thermal resistance using the conventional stem as shown in FIG.
A reduction of about 20 ° C./w was achieved as compared with the case of using the same type of semiconductor laser device and the same assembling method.

FIG. 2 is a plan view of a second embodiment of the present invention (FIG. 2).
(A)) and a sectional view along the line BB '(FIG. 2 (b)).
In the second embodiment, in addition to the configuration similar to that of the first embodiment shown in FIG.
The shape of 1) is extended in a double wing shape at a position deeper than the surface where the semiconductor laser element is fused. This is because the heat capacity of the semiconductor laser element is easily increased by increasing the volume of the projection (21) so that the heat generated by the semiconductor laser element is easily absorbed by the projection (21). There is an advantage that the thermal resistance of the semiconductor laser device is further reduced as compared with the first embodiment.

[0011]

As described above, according to the present invention, the protrusion for fusing the semiconductor laser element on the circular stem base is spread in a wing shape deeper than the surface for fusing the semiconductor laser element, thereby increasing the volume. By doing so, the heat capacity is increased, and the heat generated from the semiconductor laser element is easily absorbed by the stem.
Further, the thermal conductivity is higher than that of iron by forming the above-mentioned protrusion and the circular portion below the protrusion with a copper-based alloy. This allows
CD (compact disk) that has both miniaturization and standardization
While using a stem having the same outer shape as the stem used in the semiconductor laser for manufacturing, the thermal resistance has been conventionally used at 9.0 m.
It is possible to lower the same degree as that of the stem of mΦ.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of a semiconductor laser stem according to the present invention, and FIG.

FIGS. 2A and 2B are a plan view and a cross-sectional view taken along line BB ′ of FIG. 2A of the second embodiment of the semiconductor laser stem of the present invention;

3A is a plan view of a conventional semiconductor laser stem, and FIG. 3B is a cross-sectional view taken along line CC ′ of FIG. 3A.

4A is a plan view of a conventional semiconductor laser stem, and FIG. 4B is a sectional view taken along line DD ′ of FIG.

[Explanation of symbols]

1, 21, 31, 41 Projection for fusing semiconductor laser element 2, 32, 42 Circular part 2 Upper surface part of outer edge of circular part 4 Groove for fusing monitor light detection photodiode 5 Fusing semiconductor laser element Surface on protrusion 7,37,47 Terminal

Claims (1)

(57) [Scope of request for utility model registration] 1. A metal stem for a semiconductor laser device having a semiconductor laser element and a photodiode for detecting a monitor light thereof, wherein the stem for a semiconductor laser satisfies the following two conditions at the same time. (1) The shape of the stem is
A projection for fusing the semiconductor laser element; and a groove for fusing the monitor light detection photodiode, and the shape of the projection is closer to a stem outer edge than a surface to which the semiconductor laser element is fused. It spreads like wings. (2) The material of the circular portion and the protrusion of the stem is an alloy mainly composed of copper, and the outer edge portion of the circular portion on the surface where the protrusion for fusing the semiconductor laser element is made of iron. I have.