JP2003283037A - Package for optical semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the heat radiating property of a package for an optical semiconductor. <P>SOLUTION: In the package of the optical semiconductor, a supporting body 16 is electrically insulated from a lead plate 12 by an insulating material 13 while the lead plate 12 and the insulating material 13 form a hierarchical structure and lead plates for every stages are independent. The lead plate is constituted of Fe or a material whose principal constituent is Fe. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a package for mounting an optical semiconductor.

[0002]

2. Description of the Related Art An optical semiconductor package 10 has a structure in which an electrical signal lead 15 is passed through a through hole formed in an eyelet 11 and fixed by an insulating material 13. Further, the electric signal lead 15 may be directly welded to the eyelet 11. A portion 14 for mounting an optical semiconductor is installed on the upper surface of the eyelet 11.

In general, a semiconductor laser has a characteristic that a threshold value rises due to a temperature rise, and a light output is lowered in a low current drive. Therefore, in order to keep the driving temperature constant at a low temperature, a means for radiating heat is used by using the heat dissipation plate 21 installed on the outer circumference of the bottom surface of the stem shown in FIG.

[0004]

However, in the case of the conventional semiconductor laser package described above, the design is such that the contact area between the portion 14 on which the optical semiconductor is mounted and the heat radiating plate located directly below the portion 14 is not secured. ing. Therefore, in the case of a high-power semiconductor laser that requires watt-class power consumption, for example, the thermal resistance of the package cannot be ignored, and it is difficult to maintain reliability particularly in characteristics such as device life.

[0005]

The present invention has the following constitution in order to solve the problems described above. That is, the optical semiconductor package of the present invention includes the lead plate 12
Is sealed and electrically insulated by the insulating material 13 on the support 16 on which the optical semiconductor is mounted. For this reason, the support 16 and the lead plate 12 have a function of passing an electric signal, and the electric signal lead 15 penetrating the eyelet 11 is not necessary, and a sufficient contact area between the support 16 and the heat sink is secured. Is possible. This makes it possible to reduce the thermal resistance of the package and improve heat dissipation.

Further, the optical semiconductor package of the present invention is a package having a plurality of lead plates 12, whereby, for example, the support 16 is formed on the cathode electrodes of the semiconductor laser element and the light receiving element, and the two-layer lead plate 12. It is possible to distribute circuits necessary for controlling a plurality of elements such as an anode electrode of a semiconductor laser and an anode electrode of a photodiode (see FIGS. 7 and 8).

Further, the optical semiconductor package of the present invention comprises:
If iron or the like is used as the material of the lead plate 12, the cap 19
Since it is possible to perform resistance welding, the airtightness improves the reliability of the product.

Furthermore, the optical semiconductor package of the present invention uses glass, resin or plastic as the insulating material. Good moldability and improved product reliability.

The present invention is particularly effective for a laser that consumes a large amount of electricity.

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] FIG. 5 is a schematic view according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a conventional technique. In the prior art, the electric signal lead 15 penetrating the eyelet 11 is inserted into the hole provided in the heat sink and installed, so that the contact area between the eyelet and the heat sink cannot be sufficiently secured. In the present invention, since the electric signal lead penetrating the stem 12 is not provided, the contact area between the heat dissipation support 16 and the heat dissipation plate 23 can be sufficiently secured.

[0010]

EXAMPLE A thermal resistance was evaluated by mounting a nitride semiconductor laser having a particularly large amount of heat on the package thus formed.

The thermal resistance was evaluated by the temperature dependence of the voltage in the nitride semiconductor laser. Figure 6 shows the temperature dependence of voltage in nitride semiconductor lasers by PULS.
The results measured for E drive (Duty 1%) and CW drive are shown. This is a method used, for example, when investigating the temperature difference between the heat sink and the temperature of the light emitting point (heat source). For example, the temperature when the CW drive is performed at the heat sink temperature of 20 ° C. (point A in FIG. 6) and the voltage when the PULSE drive is the same (point B in FIG. 6) (the temperature in FIG. 6) C
Point) is equal to the temperature of the light emitting point (heat source) when driven by CW at a heat sink temperature of 25 ° C. As a result, the thermal resistance is given by thermal resistance = {light emitting point (heat source) temperature−heat sink temperature} / {input power−light output}. Here, the input power is C at point A in FIG.
This is the voltage when driven by W.

As a result of evaluating the thermal resistance by the temperature dependence of the voltage in the nitride semiconductor laser, the thermal resistance of the package of the present invention is one digit.
It was about [° C / W]. [Comparative Example] The thermal resistance of a nitride semiconductor laser formed in the same manner as in Example 1 using a conventional package was evaluated as a comparative example. The thermal resistance of the package was about 10 [° C / W].

[0013]

The contact area with the heat sink is sufficiently wide,
In addition, as a result that the distance between the element and the heat sink can be shortened, a package with excellent heat dissipation that can be used, for example, in a high power semiconductor laser can be obtained. Also, by using a conductive material in a hierarchical structure, it is possible to install a cap on the uppermost layer, and it is possible to provide a semiconductor laser that is not only heat-dissipative but also excellent in airtightness. Is improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a conventional technique.

FIG. 2 is a schematic cross-sectional view showing a conventional technique.

FIG. 3 is a schematic perspective view showing the technology of the present invention.

FIG. 4 is a disassembly diagram showing the technique of the present invention.

FIG. 5 is a schematic cross-sectional view showing the technique of the present invention.

FIG. 6 is a diagram illustrating a method of evaluating thermal resistance.

FIG. 7 is a schematic perspective view showing the technology of the present invention (insulating material omitted).

FIG. 8 is a disassembly diagram showing the technique of the present invention (insulating material omitted).

[Explanation of symbols]

10 Optical semiconductor packages 11 eyelets 12,12 'Lead plate 13 Insulation material 14 Section for mounting optical semiconductor elements 15 Electrical signal lead 16 Support 19 cap 20 heat sink 21 Fixing jig 22 screws 23 Heat sink 24 Fixing jig 25 insulation screw 26 PD (photodiode) 27 Optical semiconductor

Claims (4)

[Claims] 1. A support 1 in an optical semiconductor package.
6. An optical semiconductor package, wherein 6 and the lead plate 12 are electrically insulated by an insulating material 13. 2. The package for optical semiconductors according to claim 1, wherein in the package for optical semiconductors, the lead plate 12 and the insulating material 13 form a layered structure, and the lead plates for each layer are electrically independent. 3. The optical semiconductor package according to claim 1, wherein the lead plate is made of Fe or a material containing Fe as a main component. 4. The optical semiconductor package according to claim 1, wherein the insulating material is glass, resin, or plastic.