JPH0511470U - Heat sink for semiconductor laser - Google Patents

Abstract

(57) [Abstract] [Purpose] Even when the semiconductor laser is mounted by the junction down, the light emitting portion formed on the side surface of the semiconductor laser can be soldered well without being hidden. [Configuration] A trapezoidal portion 23 is provided on one surface of the heat sink body 21.
And the striped groove 2 is formed on the top surface 23a of the trapezoidal portion 23.
4 is formed. A metallization layer is formed on the top surface 23a, and the semiconductor laser is soldered. At this time, the excess solder is poured into the groove 24, flows out from the end of the groove 24, and flows down the slope 23b of the trapezoidal portion 23, so that the solder does not rise to cover the side surface of the semiconductor laser.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a heat sink used for mounting a semiconductor laser and absorbing heat generated by the semiconductor laser.

[0002]

[Prior Art]

 In mounting a semiconductor laser on, for example, a submount, a method of mounting the semiconductor laser on a heat sink and mounting the heat sink on the submount is used in order to improve heat dissipation of the semiconductor laser. The conventional semiconductor laser heat sink 10 used in this manner has a structure as shown in FIG. The heat sink body 11 is made of a material having good thermal conductivity such as silicon or aluminum nitride and processed into a rectangular parallelepiped shape, and metallized layers 12 such as gold are formed on both upper and lower surfaces of the heat sink body 11. .

A semiconductor laser is soldered to one surface of the heat sink 10 on which the metallized layer 12 is formed, and the other surface is soldered to the submount. Due to the heat radiating action of the heat sink 10, the temperature rise of the semiconductor laser is suppressed, and stable and desired performance is emitted.

[0004]

[Problems to be solved by the device]

 By the way, the conventional heat sink 10 has a rectangular parallelepiped shape, and the surface on which the semiconductor laser is mounted is formed flat. Therefore, when the semiconductor laser is soldered to this surface, a swelling of the solder occurs around the semiconductor laser. . This is because, when soldering, the semiconductor laser is pressed against the melted solder on the heat sink 10, so that excess solder sticks out around the semiconductor laser.

The swelling of the solder generated around the semiconductor laser may cover the side surface of the semiconductor laser and hide the light emitting portion formed on the side surface, thereby making it impossible to emit light. In particular, when the semiconductor laser is junction down, that is, when the substrate side is placed on the heat sink 10 and the light emitting portion is located at a height of several μm from the mounting surface, a small amount of solder is used. Even if it rises, the light emission part will be hidden.

In view of the above problems, an object of the present invention is to prevent solder swelling and to solder a semiconductor laser favorably without hiding a light emitting portion even when the device is placed by a junk down. The purpose is to provide a structured heat sink for a semiconductor laser.

[0007]

[Means for Solving the Problems]

 In this invention, a semiconductor laser heat sink is constructed by forming a trapezoidal portion on which a semiconductor laser is mounted and forming a striped groove on the top surface of the trapezoidal portion.

[0008]

[Action]

 In the present invention configured as described above, when the semiconductor laser is pressed and soldered onto the solder that is heated and melted on the top surface of the trapezoidal portion, excess solder flows into the groove. Moreover, this groove serves as an outflow path for the solder, and excess solder flows out from the end of the groove. Since the solder that has flowed out flows down along the slope of the trapezoidal portion, the solder does not rise to cover the side surface of the semiconductor laser.

[0009]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a heat sink 20 for a semiconductor laser according to the present invention, and FIG. 2 shows the whole shape of a heat sink body 21 which is a base body thereof. The heat sink body 21 is made of a material having good thermal conductivity such as silicon or aluminum nitride, and a trapezoidal portion 23 is integrally formed on one surface 22a of the rectangular parallelepiped portion 22 so as to project from the surface 22a. Has a structure in which a plurality of grooves 24 are formed in stripes on the top surface 23a.

The size of the top surface 23a of the trapezoidal portion 23 is preferably set to be substantially equal to the size of the bottom surface of the semiconductor laser 25 mounted on the top surface 23a. In this embodiment, the stripe-shaped grooves 24 formed on the top surface 23a are formed in a lattice-stripe shape by forming three vertical stripe-shaped grooves 24a and three horizontal stripe-shaped grooves 24b orthogonal to each other. The top surface 23a is divided into 16 parts by the lattice-shaped grooves 24.

As shown in FIGS. 1 and 2, the groove 24 has a V-shape in the depth direction. This type of V-shaped groove 24 can be easily formed by using, for example, silicon as the material of the heat sink body 21 and subjecting this to anisotropic etching. The cross-sectional shape of the groove 24 is not limited to the V shape, but may be other shapes such as a square shape and a U shape.

Gold metallization layers 26 and 27 are formed on the upper and lower surfaces of the heat sink body 21 having the above-described structure, that is, the surface on which the trapezoidal portion 23 is formed and the surface opposite to the metallized layers 26 and 27 by electroless plating or vapor deposition, respectively. Then, the heat sink 20 is formed. The semiconductor laser 25 is soldered on the top surface 23a of the trapezoidal portion 23 on which the metallization layer 26 is formed of this heat sink 20, and the other surface on which the metallization layer 27 is formed is soldered to the submount. The semiconductor laser 25 is pressed and soldered on the solder which is heated and melted on the top surface 23 a, but the excess solder is pushed into the groove 24 by this pressing and further propagates through the groove 24. And is extruded from the peripheral edge of the top surface 23a which is the end of the groove 24. The extruded solder travels along the slope 23b of the trapezoidal portion 23, flows down onto the surface 22a of the rectangular parallelepiped portion 22, and deposits on this surface 22a.

That is, the heat sink 20 has a structure in which solder swelling does not occur on the top surface 23a of the trapezoidal portion 23 on which the semiconductor laser 25 is mounted. Therefore, the problem that the side surface 25a of the semiconductor laser 25 is covered with the solder does not occur. As one numerical example in which such action and effect are obtained, for example, when mounting the semiconductor laser 25 having an area of 300 μm × 300 μm on the heat sink 20, the protrusion of the trapezoidal portion 23 in the configuration of FIG. The height is about 20 μm, the depth of each groove 24a, 24b is about 10 μm, the width is about 30 μm, and the pitch of each groove 24a, 24b is about 80 μm. In this embodiment, three vertical stripe grooves 24a and three horizontal stripe grooves 24b are formed on the top surface 23a of the trapezoidal portion 23 of the heat sink body 21, but these grooves 24a and 24b are formed. Is not limited to three, and may be two, for example. Further, the groove 24 does not have to have such a grid stripe shape, and may have only the vertical stripe groove 24a as shown in FIG.

[0014]

[Effect of the device]

 As described above, according to the present invention, the portion of the heat sink on which the semiconductor laser is placed is trapezoidal, and the striped groove is formed on the top surface of this trapezoidal portion. When soldering to the semiconductor laser, the rise of the solder that covers the side surface of the semiconductor laser is prevented. Therefore, even when the semiconductor laser is placed by the junction down, the light emitting portion is not hidden and the soldering can be performed well.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor laser heat sink according to the present invention.

FIG. 2 is a perspective view showing a heat sink body used in an embodiment of a semiconductor laser heat sink according to the present invention.

FIG. 3 is a perspective view showing a heat sink body used in another embodiment of the semiconductor laser heat sink according to the present invention.

FIG. 4 is a perspective view showing a conventional heat sink for a semiconductor laser.

[Explanation of symbols]

 20 heat sink 21 heat sink main body 23 trapezoidal portion 23a top surface 24 groove 25 semiconductor laser 26, 27 metallized layer

Claims (1)

[Claims for utility model registration] [Claim 1] The portion on which the semiconductor laser is mounted has a trapezoidal shape, and a striped groove is formed on the top surface of the trapezoidal portion. Heat sink for semiconductor laser.