JP2959177B2 - Optical semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device with an optical fiber pigtail having a semiconductor laser element mounted thereon.
In particular, the present invention relates to an optical semiconductor device having a structure in which a cooling Peltier element is mounted on a dual in-line type (hereinafter abbreviated as DIP type) package.

[0002]

2. Description of the Related Art A conventional optical semiconductor device of this type will be described with reference to FIG. FIG. 3 is a longitudinal sectional view of a conventional optical semiconductor device. This device is briefly described below. A semiconductor laser element 1, a micro lens 2, an optical fiber pigtail 3, a cooling Peltier element 34, a lens holder 35, It comprises a DIP type package 38, a heat radiation flange 39, and a copper pedestal 40.

In a conventional optical semiconductor device (optical module) of this type, as shown in FIG. 3, a cooling Peltier element 34 is fixed toward a bottom surface of a DIP type package 38, as shown in FIG. An optical system (an optical system including a semiconductor laser element 1, a micro lens 2, and an optical fiber pigtail 3) is arranged on the cooling Peltier element 34. The optical system has a configuration in which a semiconductor laser element 1 is coupled to an optical fiber pigtail 3 by a microlens 2.

[0004]

In this type of optical semiconductor device (optical module), the quality of the cooling capability of the cooling Peltier element is an important point of the optical module performance. However, as shown in FIG.
Are disposed on the opposite side surface of the optical fiber pigtail 3, and thus have a disadvantage (disadvantage) that the heat radiation path of the cooling Peltier element 34 is long.

FIG. 4 is a view for explaining a heat radiation path of the cooling Peltier element 34 in the optical semiconductor device in which the heat radiation flange 39 is disposed on the side opposite to the optical fiber pigtail 3. There is a heat radiation path from the cooling Peltier element 34 as shown by the broken line in the figure.
Via the IP type package 38, the optical fiber pigtail
This leads to the heat dissipating flange 39 disposed on the opposite side surface of the shell 3 and has a disadvantage that this path is long.
In addition, the DIP type package 38 is made of a material having poor heat conduction, such as a cover, for example, in order to suppress shape distortion due to temperature change. The cooling capacity becomes disadvantageous. In FIG. 4, the route of heat from the surroundings is as shown by the broken line in FIG.

Therefore, in the above-mentioned conventional optical semiconductor device (optical module), as shown in FIG. 3, a copper pedestal 40 having good heat conduction is used, thereby securing an effective heat radiation path. It is devised to do so.

Referring to FIG. 5, FIG. 5 is a view for explaining a heat radiation path of the cooling Peltier element 34 in the conventional optical semiconductor device of FIG. The heat radiating path from the Peltier element 34 reaches the heat radiating flange 39 via the copper pedestal 40 as shown by a broken line in the figure, and even if the path is long,
The cooling capacity is improved because the heat does not pass through the DIP type package 38, which has poor heat conduction, but passes through the copper pedestal 40 having good heat conduction. However, this type of optical semiconductor device (optical module) has disadvantages such as a large number of components, a complicated configuration, and difficulty in downsizing.
In FIG. 5, the route of heat from the surroundings is
This is as shown by the broken line in FIG.

In principle, in order to minimize the heat radiation path of the cooling Peltier element, FIG. 6 (a diagram for explaining the heat radiation path in the optical semiconductor device in which the heat radiation path from the cooling Peltier element is shortened) is shown in FIG. As shown, the heat dissipating flange 39
The most efficient heat radiation can be expected by fixing the cooling Peltier element 34 to the side surface where the is disposed. However, a drawback of this device is that heat flows from the structure supporting the optical system from the bottom to the optical system itself, which is the heat absorbing side of the Peltier element 34, as shown by the thick dotted line in FIG. After all, the cooling capacity does not improve.

The present invention has been made to solve the above-mentioned drawbacks and the like, and has as its technical object.
The cooling capability of the built-in Peltier element of the IP type semiconductor laser module is improved, and an efficient, simple, and miniaturized, which could not be realized in a conventional module of this type. It is an object to provide a possible optical semiconductor device.

[0010]

According to the present invention, in order to achieve the above object, the heat radiation side of a cooling Peltier element is fixed to the side wall of a DIP type package or through a through hole in this side wall, and the heat absorption thereof is performed. The optical system has a cylindrical outer peripheral portion;
Fix a cylinder made of poor heat conduction material on the bottom or top of the
It is characterized in that the optical system cylindrical outer peripheral portion is supported by the contact point with the glass cylinder.

That is, in an optical semiconductor device in which an optical system in which a semiconductor laser element and an optical fiber pigtail are coupled by a lens is mounted on a dual in-line type package,
A radiation side of the cooling Peltier element is fixed to a side wall of the package or through a through hole in the side wall, and a heat absorption side is fixed to an optical system, and the optical system has a structure having a cylindrical outer peripheral portion, and An optical semiconductor device characterized in that a cylinder made of a material having poor heat conduction is fixed to the bottom or top surface of the package, and the cylinder and the optical system are supported by a contact point on the cylindrical outer peripheral portion. is there.

According to the present invention, in order to minimize the heat dissipation path of the cooling Peltier element, the Peltier element is arranged so as to be as close as possible to the heat dissipation flange. For this reason, the DIP provided with the heat dissipation flange is provided. Mold package
The structure is such that the heat radiation side of the cooling Peltier element is fixed to the side wall of the die. In order to further improve the heat dissipation efficiency of the cooling Peltier element, a hole may be formed in the side wall of the package, and the heat dissipation side of the cooling Peltier element may be directly fixed to the heat dissipation flange through this through hole. .

Further, in the present invention, the optical system has a cylindrical outer peripheral portion in order to minimize the reflux of heat to the optical system structure shown in FIG. As a means for supporting the cylindrical optical system, a column made of a material having poor heat conductivity, for example, a glass column, is fixed to the bottom or top surface of the DIP package, and the column and the outer peripheral portion of the cylinder are fixed. It is configured so as to be supported by a contact point, whereby a point contact is made, and heat flow can be minimized.

Since the optical semiconductor device of the present invention has the above-described structure, the cooling capability of the built-in Peltier element of the DIP type semiconductor laser module is improved, and the conventional semiconductor module of this type has the following advantages. It is possible to provide an efficient and simple optical semiconductor device which could not be realized and which can be downsized.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to FIGS. FIG. 1 is a longitudinal sectional view of an optical semiconductor device according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of an optical semiconductor device according to a second embodiment of the present invention.

(Embodiment 1) In the optical semiconductor device shown in FIG. 1, the optical system has the same structure as that of the conventional one, having a semiconductor laser element 1, a micro lens 2, and an optical fiber pigtail 3. The present invention is characterized in that the lens holder 5 for disposing the optical system has a cylindrical shape (φ3.2 mm), and the cylindrical holder is disposed. The subcarrier 6 of the semiconductor laser element 1 is welded to the lens holder 5 with a YAG laser, and the back surface of the subcarrier 6 is on one side of the cooling Peltier element 4 (heat absorbing side at high ambient temperature). The substrate is fixed with PbSn eutectic solder.

On the other hand, the other side (radiation side) of the Peltier element 4
The substrate is fixed to the side wall of the DIP package 18. The sidewall of the DIP package 18 is made of a copper-tungsten material in order to improve the heat conduction in the thickness direction. Further, the heat dissipation flange 19 uses a copper plate.

Further, the present invention is characterized in that the cylindrical lens holder 5 is supported. That is, as a supporting structure for the cylindrical lens holder 5, a chamfered glass cylinder 7 (1.5 mm in diameter) is packaged in a DIP type package 18.
Are arranged on the bottom surface of. Thereby, the lens holder-5
And the glass cylinder 7 are in point contact with each other, and the heat flow is minimized.

With this structure, the temperature difference ΔT between the ambient temperature and the mounting portion of the semiconductor laser element 1 achieves the same 45 ° C. as the conventional structure described above (see FIGS. 3 and 5), and at the same time, In contrast to the conventional optical semiconductor device shown in FIG. 3, a copper pedestal (40 in FIG. 3) and a Peltier element for cooling (34 in FIG. 3).
Is thinner by the amount arranged on the side wall, and can be made compact. Incidentally, the package height of the conventional optical semiconductor device shown in FIG. 3 is 12 mm, but in the optical semiconductor device of Example 1 shown in FIG.
7.5 mm. As for ΔT, the DIP package 38 in the optical semiconductor device of FIG.
When the package material is a cover, or as shown in FIG. 6, in an optical semiconductor device having a structure in which the cooling Peltier element 34 is fixed to the side surface of the heat radiation flange 39, the DIP type package 38 is used. In the case where heat flows from the bottom surface, only about 35 ° C. is obtained, and it becomes difficult to operate the semiconductor laser module for a long time in a high temperature environment.

(Embodiment 2) FIG. 2 is a longitudinal sectional view of an optical semiconductor device showing a second embodiment of the present invention.
The basic configuration is the same as that of the first embodiment. However, in order to further improve the heat radiation efficiency, a hole is made in the side wall of the DIP type package 28, and the hole is directly formed without passing through the side wall of the package 28. The heat radiation flange 29 has a structure in which the heat radiation side substrate of the cooling Peltier element 4 is fixed. With this,
T is improved up to 50 ° C.

[0021]

According to the present invention, as described in detail above, in order to minimize the heat radiation path of the cooling Peltier element, the Peltier element is arranged as close as possible to the heat radiation flange, and the cooling side of the Peltier element is cooled. The optical system is supported by a point contact with a glass column having poor heat conduction in order to minimize the heat return to the optical system structure disposed in the optical system, thereby cooling the semiconductor laser module. The remarkable effect that performance is improved and miniaturization and simplification can be realized is produced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an optical semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an optical semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a conventional optical semiconductor device.

FIG. 4 is a view for explaining a heat radiating path of a cooling Peltier element in an optical semiconductor device in which a heat radiating flange is disposed on a side opposite to an optical fiber pigtail.

5 is a view for explaining a heat radiation path of a cooling Peltier element in the conventional optical semiconductor device of FIG. 3 provided with a copper pedestal.

FIG. 6 is a view for explaining a heat radiation path in the optical semiconductor device in which the heat radiation path from the cooling Peltier element is shortened.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor laser element 2 microlens 3 optical fiber pigtail 4 cooling Peltier element 5 lens holder 6 semiconductor laser element submount 7 glass cylinder 18 DIP type package 19, heat radiation flange 28 DIP type package 29 Heat radiation flange 34 Peltier element for cooling 35 Lens holder 38 DIP type package 39 Heat radiation flange 40 Copper pedestal

Claims (1)

(57) [Claims] 1. A semiconductor laser device and an optical fiber piggy.
In an optical semiconductor device in which an optical system in which a lens and a lens are coupled by a lens is mounted on a dual in-line type package, the heat radiation side of the cooling Peltier element is fixed to the side wall of the package or through a through hole in the side wall. The heat absorption side is fixed to an optical system, the optical system has a cylindrical outer peripheral portion, and a column made of a material having poor heat conduction is fixed to the bottom or top surface of the package. An optical semiconductor device, wherein an optical system is supported by a contact at a cylindrical outer peripheral portion.