JPH0222878A - Heat sink - Google Patents

Abstract

PURPOSE:To obtain a heat sink which can efficiently couple a front beam from a semiconductor laser element with an optical system and a rear beam with a photodetector by a method wherein a protruding part used to fix the semiconductor laser element is formed and a metal layer is formed on the surface of the protruding part in order to fix the element stably. CONSTITUTION:A heat sink 11 is composed of silicon whose resistance is low and whose thermal conductivity is high; a protruding part 12 used to fix a semiconductor laser element is formed on its surface. This protruding part 12 is formed accurately and, with high accuracy by a photoetching operation. In addition, Ti and Ni are evaporated on the whole surface of the protruding part 12; after that, a solder is plated and a metal layer 13 is formed. A semiconductor laser element 14 is positioned and fixed to the protruding part 12 by using the solder-plated metal layer 13. In addition, a height of the protruding part 12 is decided by measuring a far field pattern of the semiconductor laser element 14; when the height is mum or higher by an experiment, good coupling between a front beam 18 and an optical lens 20 as well as between a rear beam 19 and a photodetector 22 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat sink for mounting a semiconductor laser element.

(Prior Art) Recently, heat sinks for mounting semiconductor laser elements have been widely used in fields such as optical communication and optical measurement. Such a heat sink is known, for example, as described in Japanese Patent Laid-Open No. 59-98566.

FIG. 3 shows a state in which a semiconductor laser device 2 is mounted on a conventional heat sink 1. In the figure, 3 is an active region of the semiconductor laser device, 4 is a negative electrode application wire, and 5 is a positive electrode application wire. .

There are two methods for fixing the semiconductor laser device 2: an upside-down method in which the active region 3 of the semiconductor laser device 2 is close to the fixed portion, and an upside-up method in which the active region 3 is far from the fixed portion. Semiconductor laser element 2
An upside-up method is used to fix the package, taking into account grounding of the package and heat conduction.

(Problem to be Solved by the Invention) However, when fixing a semiconductor laser device using the above-mentioned upside-up method, the active region of the semiconductor laser device is located near the top surface of the heat sink. The emitted back light is reflected on the top surface of the heat sink and cannot be well coupled to the photodetector, and since the fixed position of the semiconductor laser element is not specified, the front light of the semiconductor laser element also enters the optical system. There was a problem in that good coupling of the semiconductor laser elements could not be obtained, and stable operation of the semiconductor laser device could not be achieved.

In view of the above points, the present invention allows the fixing position of a semiconductor laser element to be regulated and is stably fixed, and allows the front light from the semiconductor laser element to be transmitted to an optical system.

The present invention provides a heat sink that can couple back light to a light receiving element with high efficiency.

(Means for Solving the Problems) Therefore, the present invention provides a protrusion for fixing a semiconductor laser element,
The metal layer for fixing the laser element is formed on the upper surface of the convex portion.

(Function) Since the convex part for fixing the semiconductor laser element is provided and the fixing metal layer is provided on the upper surface thereof, the fixing position of the semiconductor laser element can be defined by fixing the semiconductor laser element to the fixing metal layer. The semiconductor laser element can be stably fixed to the metal, and by being fixed on the convex portion, the back light of the semiconductor laser element is well coupled to the light receiving element without being reflected on the upper surface of the heat sink.

Its front light is also well coupled into the optical system.

(Embodiment) Fig. 1 is a perspective view of an embodiment of the present invention showing a state in which a semiconductor laser element is mounted, Fig. 2 is a side view of the same including an optical system and a light receiving element system, and the heat sink 11 has a low resistance. It is made of silicon having a high thermal conductivity, and a convex portion 12 for fixing a semiconductor laser element is provided on its upper surface. This convex portion 12 is formed accurately and with high precision by photoetching. Further, a metal layer 13 is formed on the entire upper surface of the convex portion 12 by depositing Ti and Ni and then solder plating. 14 is a semiconductor laser device; 15 is an active region of the semiconductor laser device 14;

16 is a wire for the negative electrode, 17 is a wire for the positive electrode, 18 is the front light from the convex portion 12 for fixing the semiconductor laser element, 19 is the back light, 20 is the optical lens, 21 is the optical lens fixing stand, 2
2 is a light receiving element, and 23 is a light receiving element fixing base.

The semiconductor laser element 13 is positioned and fixed to the convex portion 12 by the metal layer 13 formed by soldering.

The height of the convex portion 12 is determined by measuring the far-field image of the semiconductor laser element 14, but according to an experiment, if it is 5#IIm or more, the front light 18 and the optical lens 20, the back light 19 and the light receiving element 22 are in good condition. A strong bond is obtained.

In the above embodiment, low-resistance silicon was used for the heat sink 11, but other materials with high thermal conductivity may be used, and solder plating was used for the metal layer 13 on the top surface of the convex portion 12. However, other metals may be used as long as the semiconductor laser element 14 can be stably fixed.

(Effects of the Invention) As described above, according to the present invention, the protrusion for fixing the semiconductor laser element is provided and the metal layer is formed on the upper surface of the protrusion, so that the fixing position of the semiconductor laser element is placed on the protrusion. regulated,
Moreover, stable metal fixation is possible, and the front light from the semiconductor laser element can be coupled to the optical system and the back light to the light receiving element with high efficiency by eliminating reflection from the surface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention showing a state in which a semiconductor laser device is fixed, FIG. 2 is a side view of the same including an optical system and a light receiving element system, and FIG. 3 is a state in which a semiconductor laser device is fixed. 1 is a perspective view of a conventional heat sink shown in FIG. DESCRIPTION OF SYMBOLS 11... Heat sink, 12... Convex part for fixing a semiconductor laser element, 13... Metal layer. 14... Semiconductor laser element. Patent Applicant: Matsushita Electric Industrial Co., Ltd. Figure 11°°° Heat sink, 13...Iku [1 12...Hiraba 1 Treig Rice 4r Tsuji Ryogei Convex 14...
Guidance - Boo Kuma 3 Figure

Claims (1)

[Claims] A heat sink characterized in that a convex part for fixing a semiconductor laser element is provided, and the metal layer for fixing the laser element is formed on the upper surface of the convex part.