JP2823381B2 - 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 an improvement in a can-seal type semiconductor laser device in which a semiconductor laser chip is used as a light emitting element of a laser and the portion of the semiconductor laser chip is covered with a cap. It is about.

[0002]

2. Description of the Related Art In a can-seal type semiconductor laser device of this type, a semiconductor laser chip is mounted on a side surface of a projection provided on a metal stem, and a front cleavage plane serving as a laser beam emission surface is oriented in the projection direction of the projection. Thus, a cap having a window hole for emitting a laser beam is fitted on the projection, and the cap is fixed to the stem.

As means for emitting a laser beam to the outside in a state where the semiconductor laser chip is protected from moisture and dust in the air, conventionally, a means described in, for example, Japanese Utility Model Application Laid-Open No. 62-58066 is disclosed. As described above, while the cap body is fixed to the stem in a sealed state, a transparent plate made of glass, which covers the window hole, is sealed at the location of the window hole in the cap body with glass solder. By fixing, the inside of the cap body is kept confidential or the inside of the cap body is filled with a transparent synthetic resin.

[0004]

As in the former case, when a means for sealing the inside of the cap body with a transparent plate for closing the window hole is fixed to the cap body with glass solder, and the cap body is made of glass, Since the laser beam can be emitted through the smooth transparent plate, there is an advantage that high beam characteristics can be secured.

However, on the other hand, in order to fix the transparent plate to the cap body with glass solder, glass solder is manufactured in a ring shape, inserted between the transparent plate and the cap body, and then heated to a high temperature. In addition to the fact that the glass solder manufacturing process and the firing process require a lot of labor, the cap body that has been discolored by firing at a high temperature is pickled and then nickel-plated. Since a post-processing step of performing the application is required, there is a problem that the cost required for fixing the transparent plate to the cap body is increased, and the price of the semiconductor laser device is significantly increased.

Furthermore, a special metal having a coefficient of thermal expansion close to that of glass is used for the cap so that the glass solder does not crack due to a difference in the coefficient of thermal expansion between the glass solder and the cap. Not only must it be used, but strict process control is required to secure the cap body to the stem in a sealed state, so that the manufacturing cost is further increased.

On the other hand, the means for filling the inside of the cap body with a transparent synthetic resin, as in the latter, requires a glass solder manufacturing step, a high-temperature baking step, and a pickling and plating step as post-processing. A simple process of filling the cap with synthetic resin and curing it by drying etc. is sufficient, and it is not necessary to fix the cap to the stem in a completely sealed state, so the manufacturing cost is significantly reduced It has the advantage that it can be reduced.

However, on the other hand, synthetic resin is
There is a problem that it is difficult to form the outer surface into a smooth surface by curing by drying or the like, and it is difficult to obtain high beam characteristics because the outer surface is easily damaged. In addition, stress is applied to the synthetic resin due to thermal expansion of the cap body, and distortion occurs in the synthetic resin, so that the stability of beam characteristics is low.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inexpensive semiconductor laser device capable of stably maintaining high beam characteristics.

[0010]

In order to achieve the above object, the present invention provides a semiconductor device having a semiconductor laser chip mounted on a side surface of a projection provided on a stem such that an emission surface of a laser beam is directed in a projecting direction of the projection. A semiconductor laser having a cap body fixed to the stem and fixed to the stem, and a transparent plate disposed inside the cap body substantially parallel to a laser beam emission surface of the semiconductor laser chip; In the apparatus, the tip end surface of the projection on the stem may be connected to the semiconductor
The laser chip is approximately parallel to the exit surface of the laser beam.
Formed on a flat surface , the transparent plate is fixed to the tip surface with an adhesive in a non-contact state with the cap body, and a transparent synthetic resin is provided between the transparent plate and the side surface of the projection. The semiconductor laser chip is filled with the transparent synthetic resin so as to hermetically seal the semiconductor laser chip. ".

[0011]

According to this structure, the laser beam from the emission surface of the semiconductor laser chip passes through the transparent synthetic resin and is emitted from the transparent plate to the outside. Can be used, and thus high beam characteristics can be obtained.

Further, the semiconductor laser chip is reliably protected from moisture, dust, and the like by a transparent synthetic resin that seals the entire semiconductor laser chip, and the transparent plate is adhered to the projection, and The gap between the chip and the transparent plate and the posture of the transparent plate are maintained in a predetermined state, and even if the transparent plate or the transparent synthetic resin is in a non-contact state with the cap body, even if the cap body is thermally expanded. The combination of the fact that no distortion occurs in the transparent plate and the transparent synthetic resin enables stable maintenance of high beam characteristics without being affected by changes in the external environment such as temperature changes. Become.

Further, since the inner surface of the cap is not in contact with the transparent plate, an external impact acting on the cap is prevented from directly acting on the transparent plate and the semiconductor laser chip. The impact resistance of the chip device can also be improved. Since the cap body does not need to consider the adverse effects of thermal expansion, it is possible to use an inexpensive material such as a steel plate, and it is not necessary to fix the cap body to the stem in a sealed state. The cost required for manufacturing and mounting these cap bodies can be reduced, the transparent plate can be easily adhered to the projections with an adhesive, and the filling of the transparent synthetic resin is required. In addition, the manufacturing cost can be remarkably reduced in combination with the fact that it can be extremely easily performed by using a synthetic resin or a thermosetting synthetic resin which is cured by drying.

Therefore, according to the present invention, there is an effect that a semiconductor laser device which can maintain high beam characteristics without being affected by a change in environment and has improved impact resistance can be provided at low cost.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a semiconductor laser device including a disk-shaped stem 2 made of metal such as carbon steel, and a metal cap body 3 having a window hole formed at an upper end. A block-shaped projection 4 is integrally formed on the upper surface of the stem 2. A semiconductor substrate 5 is fixed to a side surface of the projection 4, and a semiconductor laser chip 6 is mounted on the semiconductor substrate 5. Die bonding is performed such that the cleavage plane 6a (the laser beam emission plane to the outside) faces the projection direction of the projection 4 and the rear cleavage plane 6b faces the monitoring photodiode (not shown) provided on the semiconductor substrate 5. .

Further, the upper surface of the projection 4 is placed on the semiconductor laser.
Front cleavage surface 6a of the laser chip 6 (external laser
(A beam exit surface) and a plane substantially parallel to the upper surface.
A transparent plate 7 made of glass or the like is
Adhering with a material adhesive 8 , the transparent plate 7 and the projection 4
The cap body 3 is fitted, the cap body 3 is fitted in a non-contact state, and the entire circumference of the outward flange portion 3b formed at the lower end of the cap body 3 is resistance to the upper surface of the stem 2. It is fixed to the stem 2 by welding.

A space between the lower surface of the transparent plate 7 and the side surface of the projection 4 is filled with a transparent and adhesive synthetic resin 9 of silicon or the like so as to seal the entire semiconductor laser chip 6. . As the transparent synthetic resin 9, a resin that is cured by drying, a thermosetting resin, a UV resin, or the like can be used.

One of the three lead terminals 10, 11, 11 for the semiconductor laser chip 6
Is fixed to the lower surface of the stem 2 by welding, and the other two lead terminals 11 are inserted into the inside of the cap body 3 through the through holes formed in the stem 2, and , And is fixed by bonding with glass solder or an adhesive.

With the above configuration, the laser beam from the front cleavage surface 6a of the semiconductor laser chip 6 passes through the transparent synthetic resin 9 and is emitted to the outside from the transparent plate 7 having a smooth surface. , High beam characteristics can be obtained. Further, the entire semiconductor laser chip 6 is sealed with a transparent synthetic resin 9 so that the semiconductor laser chip 6 is not affected by moisture or dust in the atmosphere, and the transparent plate 7 is adhered to the projections 4. The distance between the chip 6 and the transparent plate 7 and the posture of the transparent plate 7 can be kept constant, and the transparent plate 7 and the transparent synthetic resin 9 are in a non-contact state with the cap 3 and the cap 3 The transparent plate 7
And the transparent synthetic resin 9 is not distorted, so that high beam characteristics can be maintained without being affected by changes in the external environment such as temperature changes.

Further, since the transparent plate 7 is in a non-contact state with respect to the cap body 3, it is possible to prevent external shocks acting on the cap body 3 from directly acting on the transparent plate 7 and the semiconductor laser chip 6. Also, the impact resistance of the semiconductor laser chip device can be improved. The cap body 3 does not need to consider the adverse effects of its thermal expansion, so that an inexpensive material such as a steel plate can be used, and it is not necessary to fix the cap body 3 to the stem 2 in a sealed state. The time required for fixing to the stem 2 can be remarkably reduced.
The cost of manufacturing and mounting the cap body 3 can be reduced, the transparent plate 7 can be easily bonded to the protrusion 4 with an adhesive, and the covering of the semiconductor laser chip 6 with the transparent synthetic resin 9 By dropping a synthetic resin, a thermosetting synthetic resin, or the like which is cured by drying in a liquid state, it can be performed extremely easily, and the manufacturing cost can be remarkably reduced.

As shown by a dashed line in FIG. 1, an impermeable synthetic resin 12 such as a fluororesin may be applied to the surface of the transparent synthetic resin 9. Further, a transparent adhesive may be used as the adhesive 6 for adhering the transparent plate 7 to the projection 4. In this case, the adhesive 8 adheres to the front cleavage surface 6 a of the semiconductor laser chip 6. However, since the transparency of the laser beam is not impaired, there is no need to precisely apply the adhesive 8 when bonding the transparent plate 7, and there is an advantage that the manufacturing labor can be further reduced.

Further, the stem and the cap body are not limited to being formed of metal, but may be formed of other materials such as synthetic resin, respectively. Thus, both are made of synthetic resin. In this case, the cap body may be fixed to the stem by heat fusion. Alternatively, the stem may be formed of a metal plate, and the projection may be formed by cutting and raising.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a plan sectional view taken along the line III-III of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser device 2 Stem 3 Cap body 4 Projection 5 Semiconductor substrate 6 Semiconductor laser chip 6a Front cleavage surface (laser beam emission surface) 7 Transparent plate 8 Adhesive 9 Transparent synthetic resin

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-136684 (JP, A) JP-A-64-28882 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01S 3/18

Claims (1)

(57) [Claims] 1. A cap body fixed to a side surface of a projection provided on a stem such that an emission surface of a laser beam is directed to a projection direction of the projection, and a cap body fitted to the stem on the stem. the fixed, the transparent plate inside of the cap body, in a semiconductor laser device comprising disposed substantially parallel to the exit surface of the laser beam in the semiconductor laser chip, the tip surface of the projection in the stem, said semiconductor laser
On a plane approximately parallel to the laser beam exit surface of the chip
The transparent plate is fixed to the tip surface with an adhesive in a state of not contacting the cap body, and a transparent synthetic resin is provided between the transparent plate and the side surface of the projection. A semiconductor laser chip filled with a synthetic resin so as to seal the whole of the semiconductor laser chip.