JP2834901B2 - Method for manufacturing stem for semiconductor laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stem constituting a can-seal type semiconductor laser device.

[0002]

2. Description of the Related Art A can-seal type semiconductor laser device 1 comprises:
As shown in JP-A-62-58066 and the like, and as shown in FIG. 7, a stem 2 is formed by projecting a block body 4 on a metal stem substrate 3 formed of a metal such as carbon steel into a disk shape.
A semiconductor laser chip 5 is die-bonded to a side surface of the block body 4 in the stem 2 via a semiconductor substrate 6, while the stem substrate 3 in the stem 2 is
A cap body 8 with a transparent plate 7 covering the block body 4
And a lead terminal 9 for the semiconductor laser chip 5 is fixed, so that the laser beam from the semiconductor laser chip 5 is emitted to the outside via the transparent plate 7.

Conventionally, as a means for manufacturing the stem 2, as shown in FIGS. 8 and 9, a brazing material 1 formed in a plate shape or a paste shape on an upper surface of a metal stem substrate 3 is used.
No. 0 is placed on the upper surface of the brazing material 10, and the metal block 4 is placed on the upper surface of the brazing material 10 and then heated to melt and solidify the brazing material 10. I was trying to attach it.

[0004]

According to the fixing by brazing, the lower surface of the block 4 is securely brought into close contact with the upper surface of the stem substrate 3 via the brazing material 10, so that the block 4 and the stem substrate 3 This has the advantage that the heat transfer performance between them is high, and the heat radiation performance of the heat generated in the semiconductor laser chip 5 is high.

[0005] On the other hand, however, the fixing method by brazing has a problem in that it takes a long time to melt and solidify the brazing material 10, so that the productivity is extremely low and the manufacturing cost is high. In addition, since the block body 4 can move between the time when the brazing material 10 is melted and the time when it is hardened, the block body 4 slides along the upper surface of the stem substrate 3 during brazing, and the position is shifted. For example, as shown by a dashed line in FIG. 9, the block body 4 is fixed to the stem substrate 3 in a state where its axis is inclined. After the semiconductor laser device 1 is assembled, the optical axis of the laser beam emitted from the semiconductor laser chip 5 is shifted or tilted from a predetermined state, and the quality of the semiconductor laser device 1 is reduced. Was also a problem.

An object of the present invention is to provide a method for manufacturing a stem for a semiconductor laser device with high accuracy and at extremely low cost.

[0007]

According to the present invention, there is provided a semiconductor laser device having a metal block body for fixing a semiconductor laser chip mounted on an upper surface of a metal stem substrate. A corner where the outer peripheral surface of the block body and the upper surface of the stem substrate are joined at substantially right angles to each other
A laser beam for welding is simultaneously applied to a plurality of places such as left and right sides sandwiching the block body, and at the same time, the outer peripheral surface of the block and the upper surface of the stem substrate
By irradiating toward both the block body and the stem substrate from the direction of Me oblique relative, it is characterized in that so as to weld the block body to the stem substrate. "
Things.

[0008]

The present invention is applicable to laser welding.
The outer peripheral surface of the block body and the upper surface of the stem substrate are substantially
The welding laser beam against the corners joining the corners, the
It is to irradiate both the block body and the stem substrate from a direction oblique to the outer peripheral surface of the block and the upper surface of the stem substrate, and by irradiating the welding laser beam, both the block body and the stem substrate are simultaneously In addition, since the welding can be instantaneously melted and welded, the time required for the welding should be significantly shorter than the case where the welding laser beam is applied to only one of the block body and the stem substrate. You can do it.

In addition, at least one of the corners where the outer peripheral surface of the block body and the upper surface of the stem substrate are joined at substantially right angles to each other.
Also, a plurality of places such as the left and right sides sandwiching the block body are simultaneously welded, and the block body is welded over its entire circumference, or the plurality of places are sequentially welded by one welding machine.
It is not necessary to move the laser beam irradiation position as in the case of welding at the turn, and the instantaneous irradiation of the laser beam to multiple welding points allows the block body to be attached to the stem substrate in a very short time. Since the stem can be fixed, the production efficiency of the stem can be significantly improved, and the production cost can be greatly reduced.

In the case where the block body is laser-welded to the stem substrate, stress is generated in the welded portion due to shrinkage deformation when the welded portion is melted and then solidified. To weld the block over its entire circumference, or when the laser welding machine is moved along the outer circumference of the block to weld a plurality of locations sequentially, the lower surface of the block and the stem Welding deformation will occur sequentially at corners where the upper surface of the board and the upper surface of the board are joined at right angles to each other. For this reason, a portion of the lower surface of the block opposite to the first welded portion is located on the stem substrate. A phenomenon occurs in which the block body is lifted from the upper surface of the substrate, and the fixing accuracy of the block body to the stem substrate is significantly reduced.

However, when the block body is welded to the stem substrate at a plurality of places such as the left and right sides of the block body at the same time as in the present invention, shrinkage deformation occurs simultaneously at each welded place. By doing so, the block body is attracted to the upper surface of the stem substrate with an even force over the entire lower surface thereof, and the block body is kept in close contact with the upper surface of the stem substrate. Can be fixed to the upper surface of the stem substrate with the
The heat transfer between the block body and the stem substrate is maintained in close contact, so that the heat dissipation performance of heat generated in the semiconductor laser chip can be prevented from being impaired.

Therefore, according to the present invention, there is an effect that a stem having both high accuracy and heat dissipation can be manufactured at extremely low cost.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment. In this embodiment, the block body 4 is formed in a rectangular shape in a plan view.
The block body 4 is placed at a predetermined position on the upper surface of the stem substrate 3, and the weight 11 is further placed on the upper surface of the block body 4 to hold the block body 4 in a positioned state. Among the corners where the outer peripheral surface of the block body 4 and the upper surface of the stem substrate 3 are joined at substantially right angles to each other, at four positions located at the lower end edges of each of the four side surfaces of the block body 4, a YAG laser welding machine ( The welding laser beam 12 is simultaneously applied to the
By irradiating both the block body 4 and the stem substrate 3 from a direction oblique to both the outer peripheral surface and the upper surface of the stem substrate 3, the block body 4 is attached to the substrate 3 at the lower end edges of the four side surfaces. Welding (welding location is indicated by reference numeral 13).

It is desirable that the irradiation angle of the laser beam 12 be about 30 to 60 ° with respect to the upper surface (horizontal plane) of the stem substrate 3. Means for holding the block body 4 in the positioning state include pressing the block body 4 downward with an elastic body such as a spring, or temporarily magnetizing the stem substrate 3 to magnetically attach the block body 4. Alternatively, other means may be adopted.

With this configuration, both the block body 4 and the stem substrate 4 can be melted and welded simultaneously and instantly by irradiating the welding laser beam, so that the time required for the welding is reduced. In addition, the length can be significantly reduced as compared with the case where only one of the block body and the stem substrate is irradiated with the welding laser beam.

Further, since the block body 4 is welded at a plurality of locations to the stem substrate 3 at the same time, it is necessary to move the irradiation position of the laser beam 12 as in the case where the block body 4 is welded over its entire circumference. Since there is no laser beam 12, the block body 4 can be welded to the stem substrate 3 by instantaneous irradiation of the laser beam 12, so that the production efficiency of the stem 2 is significantly improved and the production cost is greatly reduced. You can do it.

As shown by arrows in FIG. 3, a stress F pulling the block body 4 obliquely downward is simultaneously applied to each welded portion 13 by contraction deformation when solidifying from a molten state as shown in FIG. Then, the block body 3 is attracted to the upper surface of the stem substrate 2 with a uniform force over the entire area of the lower surface of the block body 3 by the downward component force F1 of the stress F at each welding portion 13, so that the block body 4 is attached to the upper surface of the stem substrate 2. And the block body 4
Can be fixed to the stem substrate 3 with high accuracy,
The heat transfer performance between the block body 4 and the stem substrate 3 can be maintained, and the heat radiation performance of the heat generated in the semiconductor laser chip 5 can be maintained.

FIG. 4 shows that the block body 4 is formed in a hexagonal shape in a plan view, and three of the side faces of the block body 3 are joined to every other side face and the upper surface of the stem substrate 3 is joined. The block body 4 is welded to the stem substrate 3 by simultaneously irradiating the welding laser beam 12. 5 and 6 show that the block body 4 is formed in a rectangular shape in a plan view, and two side surfaces of the upper surface of the stem substrate 3 which are located on opposite sides of the axis of the block body 4. A hole 14 is formed at a location, and a side surface of the block body 4 that does not overlap with the hole 14 of the stem substrate 3 and an upper surface of the stem substrate 3 are substantially perpendicular to each other.
By irradiating the welding laser beam 12 simultaneously to the joining corners so as to straddle both the block body 4 and the stem substrate 3 from an oblique direction, the block body 4 is temporarily applied to the stem substrate 3. After welding, the hole 14 of the stem substrate 3 is filled with a fixing material 15 such as silver braze formed in a powder or paste form, and this is heated and melted to form a block body at the position of the hole 14. 4 is permanently fixed to the substrate 2.

According to this method, the area where the block body 4 and the stem substrate 3 are integrated via the fixing material 15 is increased, and the fixing material 15 is in close contact with the lower surface of the block body 4. The force by which the block body 4 is pulled downward by the shrinkage when the fixing material 15 hardens increases,
Since the block body 4 adheres more strongly to the lower surface of the stem substrate 3, the heat transfer coefficient between the block body 4 and the stem substrate 3 is improved, and the heat radiation of the heat generated in the semiconductor laser chip 5 can be further ensured. Has advantages.

In the present invention, it goes without saying that the planar shape of the block body and the number of welding locations are not limited to those in the above embodiment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a plane showing a welding state.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a plan view showing another embodiment.

FIG. 5 is a plan view showing still another embodiment.

FIG. 6 is an enlarged sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a partially cutaway perspective view of the semiconductor laser device.

FIG. 8 is a diagram showing a conventional method.

FIG. 9 is a diagram showing a fixed state by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser apparatus 2 Stem 3 Stem board 4 Block body 5 Semiconductor laser chip 11 Weight 12 Laser beam for welding 13 Welding point 15 Adhesive material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H01S 3/18 H01L 33/00

Claims (1)

(57) [Claims] The upper surface of the metal stem substrate in 1. A semiconductor laser device, by placing a metal block member for fixing the semiconductor laser chip, and the upper surface of the outer peripheral surface and the stem substrate of the block body At the corners that are joined
At least the laser beam for welding to a plurality of places such as the left and right sides sandwiching at least the block body, at the same time,
And the outer peripheral surface of the block and the upper surface of the stem substrate
Both the block body and the stem substrate from the direction of Me oblique and
The method for manufacturing a stem for a semiconductor laser device, wherein the block body is welded to a stem substrate by irradiating the stem toward the stem substrate.