JPS59172787A - 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 with good efficiency by a method wherein silicon is used as a submounting member, and many micro recesses are formed on the junction surface of the heat sink side of said member. 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. The many recesses 7 are previously formed on the junction surface of the heat sink side of the submounting member 6. 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 solder 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 semiconductor laser to the outside. be. For this reason, in the conventional mounting structure for a semiconductor laser device, as shown in FIG.
, 'The semiconductor laser element is mounted once through a brazing material 3 such as tin (Sn), and then further mounted on a heat sink material 4 through a brazing material 5 such as indium-tin alloy (1,n5n). A common structure was to dissipate heat generated at the p-n junction to the outside.

In such a structure, diamond, copper (C, u) 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.

The heat sink material 4 needs to have high thermal conductivity due to its intended use, but there are also other factors 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 the material is also determined by taking into account the price of the submount material, the difference in thermal expansion coefficient from the semiconductor laser element, etc. Must.

However, on the back of each abrasive material of submount material 1, diamond has the highest thermal conductivity near room temperature, and submount +A
Although it exhibits excellent properties as a material, it is very expensive and is usually an insulator. Therefore, in order to use it as the ζ submount material 1, it must be coated with a suitable thin metal film to make it compatible with the brazing material 3. In order to improve the performance and operate the semiconductor laser device, it has to be brought into a state where it can be energized, which is a disadvantage in that it involves a complicated 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 abrasive materials, they have a higher resistance to Ga S that constitutes a semiconductor laser element.

The difference in thermal expansion coefficient from Gal-XΔ#xAs is large,
There is a great risk that strain will be introduced into the semiconductor laser element during cooling after heating and waxing, but the result is that the operating life of the semiconductor laser element is not adversely affected.

In addition, 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 GaAsQ a 1-x, which is a semiconductor laser material.
Although it has the advantage of having a relatively similar expansion coefficient to AβXAS and reducing mounting strain, it has the disadvantage of being considerably inferior in thermal conductivity compared to diamond, copper, and silver.

<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 submount device for a semiconductor laser having a soldered &J structure that improves heat conduction, which is a drawback of the semiconductor laser.

<Structure of the Invention> The sub-mount device of the present invention is a device in which a sub-mount material is interposed between a semiconductor laser element and a heat sink material, in which silicon is used as the sub-mount material, and microscopic particles are formed on the bonding surface of the sub-mount material on the heat sink side. It is characterized by the formation of a large number of recesses.

<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 recesses 7 are formed in advance on the heat sink side bonding surface of the submount material 6.

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
When the recess is a striped groove, the size of the minute recess 7 formed in the joint surface of It is preferable that the width of the six places left between the grooves is in the range of 5 μm to 100 μm. Note that this minute recess 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. 3
A photoresist is applied to the top surface of the Si coated with the i02 film, exposed to light using a striped mask, and after development, the 5i02 film is removed in striped form using 1(F (hydrofluoric acid)).

Using the remaining cotton-like 5i02 film as an etching mask, K
OH and H20(7) ratio 1:1, temperature 60″C~100
Etching is carried out using a solution at °C.

By this etching, a large number of concave minute grooves are formed.

<Effects of the Invention> According to this QrlJ], a submount material that efficiently conducts Joule heat generated at the p-n junction of a semiconductor laser element to a heat sink material is created using a silicon wafer that is relatively inexpensive and suitable for mass production. Therefore, it is possible to manufacture a semiconductor laser device with a long operating life.

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. l - Submount material 2 - Semiconductor laser element 4 - Heat sink material 7 - Minute recess

Claims (1)

[Claims] A device in which a submount material is interposed between a semiconductor laser element and a heat sink material, characterized in that silicon is used as the submount material and many minute recesses are formed on the bonding surface of the submount material on the heat sink side. A submount device for semiconductor lasers.