JPH04237179A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To provide a semiconductor laser for high-speed operation by eliminating wire bonding to avoid parasitic inductance ascribed to fine bonding wire. CONSTITUTION:A stepped part is provided to the side of a semiconductor laser pellet on its epitaxial layer side so as to come into contact with a substrate, an electrode is provided to the exposed part of the substrate and the surface of the epitaxial growth layer respectively, and the P electrode and the N electrode of the semiconductor laser pellet are connected to two electrodes provided to a heat sink provided with a stepped part as high as that of the semiconductor pellet to enable a semiconductor laser of this design to operate at a high speed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device, and more particularly to a semiconductor laser device suitable for high-speed operation for optical communications.

0002

2. Description of the Related Art A conventional semiconductor laser device has P and N electrodes on two opposing planes of a rectangular parallelepiped semiconductor laser pellet. One electrode is die-bonded to an electrode of a heat sink, and the other electrode is die-bonded to an electrode of a heat sink. The structure was such that it was connected to the lead terminals of the package through wire bonding.

A conventional semiconductor laser device will be explained with reference to the drawings. 6, 7, and 8 show a perspective view of a semiconductor laser pellet of a conventional semiconductor laser device, a perspective view of a heat sink, and a vertical cross-sectional view after die mounting and wire bonding. The semiconductor laser pellet 1 has an epitaxial growth layer 3 formed on a semiconductor substrate 2 with a thickness of 300 μm (
It is processed to a size of approximately W) x 300 μm (D) x 100 μm (H), and the electrodes include an n-(p) electrode 5 on the substrate side and a p-(n) electrode 4 on the epitaxial growth layer side. ing. The heat sink 7 has heat sink electrodes 12 and 14 made of gold or the like formed on two surfaces of a rectangular parallelepiped material such as silicon or diamond, and a semiconductor laser pellet is die-bonded thereon using a fusing agent. Furthermore, the electrode 14 on the lower side of the heat sink is die-bonded to the package using a fusing agent. The structure is such that the n-side electrode 5 of the semiconductor laser pellet and the package lead terminal are connected by wire bonding.

0004

[Problems to be Solved by the Invention] In the conventional semiconductor laser device described above, the wiring inside the package is done by wire bonding, and the gold or aluminum wire used is usually as thin as several tens of microns. There is a problem in that the response speed is likely to be restricted due to the large value.

[0005]

[Means for Solving the Problems] The semiconductor laser device of the present invention has a step reaching the substrate on the surface of the epitaxial layer side of the semiconductor laser pellet, and electrodes are formed on each of the exposed surfaces of the substrate and the epitaxial growth layer. It is characterized in that the P and N electrodes of the pellet are respectively connected to two electrode patterns on a heat sink having a step having the same height as the step of the pellet.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. 1, 2, and 3 show an embodiment of the present invention. FIG. 1 is a perspective view of a semiconductor laser pellet, FIG. 2 is a perspective view of a heat sink, and FIG. 3 is a cross-sectional view of the semiconductor laser pellet after die bonding to the heat sink, that is, a cross-sectional view of the semiconductor laser device. As shown in FIG. 1, the semiconductor laser pellet 1 consists of an n-(p) electrode 5 formed on the exposed substrate by removing part of the epitaxial layer 3 and the substrate 2, and a p-(n) electrode 5 formed on the epitaxial layer. It has an electrode 4. The heat sink 7 has a step having the same height as the semiconductor laser pellet described above, and further has two independent pattern electrodes 8 and 9, as shown in FIG. Figure 3
FIG. 2 is a cross-sectional view of the semiconductor laser pellet and heat sink of the present invention after die bonding. Two electrodes 4, 5 of the semiconductor laser pellet are independently connected to two electrodes 8, 9 of the heat sink.

FIGS. 4 and 5 show a second embodiment of the present invention. FIG. 4 is a longitudinal sectional view of the semiconductor laser pellet and the heat sink after die bonding, and FIG. 5 is a perspective view thereof. In this embodiment, the electrode patterns 8 and 9 on the heat sink are connected to the bottom surface via the side surface of the heat sink, as shown in FIG. Each electrode pattern further includes electrode patterns 10 and 1 formed on the package.
1, and is led to the signal input terminal of the package. According to the configuration of this embodiment, electrical connection is completed through the die bonding process without going through the wire bonding process, making it possible to keep manufacturing costs low, as well as keeping parasitic inductance low, making it suitable for high-speed response. A semiconductor laser device can be obtained.

[0008]

Effects of the Invention As explained above, the present invention provides a method for reducing the amount of P and N provided on the epitaxial growth layer side of a semiconductor laser pellet.
By bonding the electrode and two pattern electrodes provided on the surface of the heat sink with solder, there is no need for wire bonding, and the parasitic inductance caused by the thin wire of wire bonding is reduced, thereby providing a semiconductor laser suitable for high-speed operation. It is something.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a semiconductor laser pellet according to the present invention.

FIG. 2 is a perspective view of a heat sink according to the invention.

FIG. 3 is a sectional view of an embodiment of the semiconductor laser device of the present invention.

FIG. 4 is a sectional view of a second embodiment of the invention.

FIG. 5 is a perspective view of a second embodiment of the invention.

FIG. 6 is a perspective view of a conventional semiconductor laser pellet.

FIG. 7 is a perspective view of a conventional heat sink.

FIG. 8 is a cross-sectional view of a conventional semiconductor laser device.

[Explanation of symbols]

1 Semiconductor pellet 2 Semiconductor substrate 3 Epitaxial growth layer 4 p(n) electrode 5 n(p) electrode 7 Heat sink 8 n(p) side electrode 9 p(n) side electrode 10, 11 Package electrode 12, 14 Heat sink electrode

Claims (1)

[Claims] 1. A step reaching the substrate is provided on the epitaxial growth layer side of the semiconductor laser pellet, and both P and N electrodes are arranged on the epitaxial growth layer surface and the substrate surface exposed to the epitaxial growth layer side, and the height is the same as the step height. A semiconductor characterized in that two electrode patterns are provided on a heat sink having a step, and the P and N electrodes of the semiconductor laser pellet are connected to the two electrode patterns of the heat sink, respectively, by combining the steps of the semiconductor laser and the heat sink. laser equipment.