JPS59172786A - Submounting device for semiconductor laser - Google Patents

Abstract

PURPOSE:To enable to conduct the Joule heat generated at a P-N junction to a heat sink member and at the same time to improve the heat dissipating effect caused by a micro uneven surface by a method wherein silicon is used as a submounting member, and many micro unevennesses are formed on the exposed surface around the junction of said member with a semiconductor laser element. CONSTITUTION:A semiconductor laser element 2 is brazed to a submounting member 6 with a solder 3, and a heat sink member 4 is brazed to said member 6 with a solder 5. Many micro unnevennesses 7 are formed around the junction of said member 6 with said element. As the heat sink member 4, a metal excellent in thermal conductivity such as Cu and Ag is used, and Si is used as the submounting member 6. E.g. In, Sn, and In-Sn alloy is used for the solders 5 and 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a submount device for a semiconductor laser device.

<Prior art> In order to make a semiconductor laser continuously oscillate at room temperature and improve its operating life, it is necessary to effectively dissipate the Joule heat generated during operation mainly at the p-n junction of the ζ semiconductor laser to the outside. be. For this reason, in the conventional mounting structure for a semiconductor laser device, as shown in FIG.
)JQ The p- A structure in which heat generated at the n-junction is dissipated to the outside has been common.

In such a structure, diamond, copper (Cu) is used as the material for the submount 1 and the heat sink material 4.
Semiconductor materials such as silver (Ag), silicon (Si), etc. are used.

Heat sink material 4 requires high thermal conductivity due to its intended use, but there are other issues such as the price of the heat sink material,
The material must be selected taking into account workability, etc., and copper is usually the most commonly used material.

The submount material 1 needs to have high thermal conductivity like the heat sink material 4, but in addition, the submount material 1 needs to have high thermal conductivity.
The material must be determined by taking into account the price of the material, the difference in thermal expansion coefficient from that of the semiconductor laser element, etc.

However, among the materials of the submount material 1, Diacent has the highest thermal conductivity near room temperature and exhibits excellent properties as a submount NJ material, but it is very expensive and is usually an insulator, so In order to use it as the sub-mount l-1fJf 1, it must be coated with a suitable metal 7V film to improve its compatibility with the brazing material 3, and in order to operate the semiconductor laser element, it must be in a state where it can be energized. It has the disadvantage of complicating the process. Copper and silver are relatively cheap and have high thermal conductivity (in this respect, they are excellent as submount materials, but on the other hand, compared to other materials, GaAs, which constitutes semiconductor laser devices), is relatively cheap and has high thermal conductivity.

There is a large difference in coefficient of thermal expansion from Ga1-xA#xAs, and there is a large risk that distortion will be introduced inside the semiconductor laser element when the heated brazing material is later cooled, but it will not adversely affect the operating life of the semiconductor laser element. result.

Additionally, although copper and silver have good workability, they also have the disadvantage that they are not suitable for high-precision mass production of submounts. Silicon is semiconductor laser material GaAs, Ga1-xAl
! Although it has the advantage of having a relatively similar expansion coefficient to xAs and reducing mounting strain, it has the disadvantage that it is considerably inferior to diamond, copper, and silver in terms of thermal conductivity.

<Object of the invention> The object of the invention is to use silicon as a submount material,
It is an object of the present invention to provide a semiconductor laser submount device with improved heat dissipation effect to compensate for the drawback of heat conduction.

(Structure of the Invention) The submount device of the present invention is a device in which a submount material is interposed between a semiconductor laser device and a heat sink material, in which silicon is used as the submount material and the semiconductor laser device is bonded to the submount material. It is characterized by a large number of minute irregularities formed on the exposed circumferential surface of the part.
/<Example> FIG. 2 shows an example of the present invention. The semiconductor laser element 2 and the submount material 6 are brazed with a brazing material 3,
The heat sink material 4 and the submount material 6 are brazed with a brazing material 5.

A large number of minute irregularities 7 are formed around the submount material 60 and the semiconductor laser element bonding portion.

As the heat sink material 4, a metal with good thermal conductivity such as copper or silver is used, and as the submount material 6, silicon is used. The brazing materials 3 and 5 include, for example, indium,
Tin and indium-tin alloys are used. Submount material 6
The size of the minute irregularities formed around the laser element junction is as follows: When the irregularities are striped, the depth of the groove is 10 μm.
m ~ 150 koku m (7) range, groove width 10 pm ~ 20
0 pm range, the width of the 6 places left between the grooves is 1o
Preferably, the thickness is in the range of μrn to 200 μm. Note that this minute unevenness is not limited to a cotton-like shape, but can be implemented in various shapes.

Next, a method of manufacturing the embodiment shown in FIG. 2 will be explained. S
A bottom resist is applied to the top surface of the Sf coated with the i02 film, and exposed with a cotton-like mask except for the part where the semiconductor laser element is mounted. After development, Sio
2 films are removed in stripes. Using the remaining cotton-like 5i02 film as an etching mask, KOH and H20(7) were added at a ratio of 1:1.
, etching is carried out using a solution at a temperature of 60°C to 100°C. This etching forms a large number of minute irregularities in which rectangular grooves are arranged in parallel.

<Effects of the Invention> According to the present invention, by using a silicon wafer that is relatively inexpensive and suitable for mass production, Joule heat generated at the p-n junction of a semiconductor laser element is conducted to the heat sink material, and at the same time, the heat is radiated from minute irregularities. Therefore, a semiconductor laser device with a long operating life can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged model diagram showing a conventional example, and FIG. 2 is an enlarged model diagram showing an embodiment of the present invention. 1 - Submount material 2 - Semiconductor laser element 4 - Heat sink material 7 - Minute irregularities

Claims (1)

[Claims] In a device in which a submount material is interposed between a semiconductor laser element and a heat sink material, silicon is used as the submount material, and a large number of minute irregularities are formed on the exposed surface of the submount material around the semiconductor laser element joint part. A semiconductor laser submount device characterized by: