JP2003023207A - Semiconductor laser assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser assembly which has good assembling workability and which can surely assure a conductivity between semiconductor laser arrays. SOLUTION: The semiconductor laser assembly 1 comprises a plurality of stages of semiconductor laser units 4 laminated in such a manner that the units 4 mount semiconductor laser arrays 3 and sub-mount bases 6 on heat sinks 2. The assembly 1 further comprises solder housing units 17 provided at positions opposed to upper surfaces of the adjacent bases 6 on lower surface sides of the sinks 2 of the units 4. The units 17 can be adopted by laminating and positioning the units 4 at the time of an assembling work, then heating solders 18 in the housing units 17, joining the bases 6 to the adjacent sinks 2, and simultaneously electrically connecting the bases 6 to the sinks 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser assembly used as a light source for pumping a fixed laser, fine processing, or the like.

[0002]

2. Description of the Related Art In this type of semiconductor laser assembly that has been generally used, a plurality of laser emission points are provided on the emission surface of a semiconductor laser array. The upper and lower surfaces of the semiconductor laser array are sandwiched by a pair of submount bases, and the semiconductor laser array is placed on the heat sink in this state. Further, for the purpose of condensing the laser light from the semiconductor laser array, a condensing lens made of a rod lens is fixed on the heat sink via an adhesive. As described above, the semiconductor laser unit is formed by sandwiching the semiconductor laser array between the submount bases on the heat sink, and by stacking the semiconductor laser units in multiple stages in the housing, a semiconductor laser assembly is formed.

[0003]

However, the above-mentioned conventional semiconductor laser assembly has the following problems. That is, when the semiconductor laser units are stacked in multiple stages at the time of assembly, the units are joined to each other via the conductive cushion material, but the assembly workability is poor and the conductivity between the semiconductor laser arrays must be ensured reliably. Was difficult.

The present invention has been made in order to solve the above-mentioned problems, and in particular, a semiconductor laser assembly is provided in which the assembling workability is improved and the conductivity between the semiconductor laser arrays is surely secured. The purpose is to provide.

[0005]

In the semiconductor laser assembly according to the present invention, a semiconductor laser array in which a plurality of laser emission points are arranged along the longitudinal direction of the front surface is brought into contact with the upper surface of the semiconductor laser array. A semiconductor laser assembly in which a plurality of semiconductor laser units each having a submount base and a heat sink having a semiconductor laser array arranged on the upper surface side are stacked, wherein the lower surface side of the heat sink faces the upper surface of the submount base. It is characterized in that a solder accommodating portion is provided at a position where the sub-mount base and the heat sink adjacent thereto are electrically connected by the solder in the solder accommodating portion.

This semiconductor laser assembly has a structure in which a plurality of semiconductor laser units are stacked in layers, and each semiconductor laser unit has a semiconductor laser array and a submount base mounted on a heat sink. . On the lower surface side of the heat sink of such a semiconductor laser unit, a solder accommodating portion is provided at a position facing the upper surface of the adjacent submount base.
When such a solder accommodating portion is adopted, during assembly work, the semiconductor laser units are stacked and positioned, and then the solder in the solder accommodating portion is heated to bond the submount base and the heat sink adjacent thereto. At the same time, it enables electrical conduction. Therefore, by providing the solder accommodating portion at such a position, it is possible to secure reliable conductivity between the semiconductor laser arrays using the solder and improve the assembly workability when stacking the semiconductor laser units in multiple stages. Try. This helps in the mass production of semiconductor laser assemblies.

Further, it is preferable that the semiconductor laser array is arranged on the front side of the heat sink and the corner portion on the lower surface of the heat sink is cut off to form the solder accommodating portion. By forming the solder accommodating portion at such a position, the solder can be easily accommodated in the solder accommodating portion in a state where the semiconductor laser units are stacked and positioned during assembly work. Therefore, the assembly work efficiency can be further improved.

Further, it is preferable that an electrically insulating member is arranged between the adjacent heat sinks, and the electrically insulating member is provided with an opening communicating with the inlet and the outlet of the medium passage formed inside the heat sink. is there. As a result of arranging the electrically insulating member between the heat sinks, direct electrical conduction between the heat sinks is avoided, and thus it becomes possible to efficiently pass an externally applied current to each semiconductor laser array.

Further, it is preferable that the semiconductor laser units are fixed to each other by the screw means penetrating the heat sinks in the laminated state. By employing the screw means, the semiconductor laser units can be securely fixed in a stacked state.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a semiconductor laser assembly according to the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, a semiconductor laser assembly 1
Is a semiconductor laser unit 4 having a flat semiconductor laser array 3 mounted on a heat sink 2 made of a material having excellent conductivity and thermal conductivity, which is stacked in a plurality of stages (two stages in this case). As shown in FIG. 2, on the front surface 5 of the semiconductor laser array 3, a large number of laser emission points 3a are arranged in a straight line along the longitudinal direction. Each semiconductor laser array 3 is made of a compound semiconductor such as GaAs, and has a light emitting region of 100 μm × 2.
It has a laser emission point 3a of about μm.

Further, the upper submount base (also known as "cover plate") 6 and the lower submount base 7 are sandwiched from above and below by the upper surface 3b and the lower surface 3c of one semiconductor laser array 3, respectively. Are joined to each. The upper and lower submount bases 6 and 7 are made of a material such as copper, copper tungsten, molybdenum, etc., which is excellent in electrical conductivity and thermal conductivity.

As shown in FIGS. 3 to 5, the semiconductor laser array 3 is mounted on the heat sink 2 by soldering the lower submount base 7 to the upper surface 2a of the heat sink 2. In addition, inside the heat sink 2, a medium passage 9 for cooling the semiconductor laser array 3 is provided.
The medium passage 9 extends in a U shape from the rear side to the front side inside the heat sink 2, and the inlet portion 10 and the outlet portion 11 of the medium passage 9 are formed on the upper surface 2a of the heat sink 2. Has been done. Therefore, by pumping a medium (for example, cooling water) from the external medium supply source (not shown) into the medium passage 9, the cooling water flows in each heat sink 2. As a result, each semiconductor laser array 3 is cooled.

Further, an electrically insulating member 12 is fixed to the upper surface 2a of the heat sink 2 so as to surround the inlet portion 10 and the outlet portion 11. Further, the electrically insulating member 12 is provided with a pair of left and right openings 13 that communicate with the inlet portion 10 and the outlet portion 11 of the medium passage 9. Then, the medium passages 9 in the adjacent heat sinks 2 are connected to each other by the openings 13, and the medium passages 9 are formed in series in the semiconductor laser assembly 1. In addition, as a result of disposing the electrically insulating member 12 between the adjacent heat sinks 2, direct electrical conduction between the heat sinks 2 is avoided, so that an externally applied current is applied in the stacking direction of the semiconductor laser arrays 3. It is designed to efficiently flow along.

The electrically insulating member 12 is composed of a spacer 14 made of polyimide or the like and an electrically insulating cushion material 15 made of silicon rubber, urethane rubber or the like loaded in the spacer 14, Has a pair of left and right openings 13 communicating with the inlet 10 and the outlet 11 of the medium passage 9. The cushion material 15 is in close contact with the heat sink 2 in order to prevent the medium flowing between the heat sinks 2 from leaking (see FIG. 1).

As shown in FIGS. 4 and 6, in the state where the semiconductor laser array 3 is arranged on the front side of the heat sink 2, the lower surface 2b side of the heat sink 2 faces the upper surface 6a of the adjacent submount base 6. The solder accommodating portion 17 is provided at the position. This solder container 1
7 is formed in a triangular prism shape by cutting the front corner portion 16 on the lower surface 2b of the heat sink 2 along the longitudinal direction of the submount base 6.

During the assembling work, the semiconductor laser units 4 are stacked with the electrically insulating member 12 sandwiched between the adjacent heat sinks 2 and the respective semiconductor laser units 4 are positioned, and then, inside the solder accommodating portion 17. From the front to the rod-shaped or spherical conductive solder 18
To load. The solder 18 has a lower melting point than the solder that joins the semiconductor laser array 3, the submount bases 6, 7 and the heat sink 2. Thereafter, the solder 18 in the solder accommodating portion 17 is externally heated to melt the solder 18, and the submount base 6 and the heat sink 2 adjacent thereto are joined by the solder 18 and at the same time electrically connected ( (See FIG. 1). As a result, reliable conductivity between the semiconductor laser arrays 3 using the solder 18 is achieved, and assembly workability when stacking the semiconductor laser units 4 in multiple stages is improved. This is to help mass production of the assembly 1.

Here, in order to securely fix the semiconductor laser units 4 stacked in the vertical direction to each other, as shown in FIGS. 3 and 7, screw means 20 is used. Each heat sink 2 has an inlet portion 10 and an outlet portion 11 of the medium passage 9.
A screw insertion hole 25 for inserting the male screw portion 26 of the screw means 20 is formed so as to pass through between. Then, the male screw portion 26 is inserted into the screw insertion hole 25, and the female screw portion 2 is attached to the tip of the male screw portion 26 exposed to the outside.
By screwing 7 into each other, the semiconductor laser unit 4 can be clamped from above and below by the screw means 20, and the semiconductor laser unit 4 can be securely fixed to each other.

Even when the semiconductor laser units 4 are integrated with each other by such screw means 20, a gap is generated between the electrically insulating member 12 and the heat sink 2, and the medium leaks to the outside through this gap. May occur (see arrow A in FIG. 6). Therefore, the spacer 14 of the electrically insulating member 12
In order to securely bond the heat sink 2 and the adjacent heat sink 2,
The electrically insulating member 12 is provided with three adhesive agent accommodating portions 21 arranged side by side in the longitudinal direction of the semiconductor laser array 3 so as to bridge between the adjacent heat sinks 2. In each adhesive accommodating portion 21, an adhesive flow hole 22 penetrating vertically is formed on the spacer 14 side, and an adhesive recess 23 is provided on the heat sink 2 side so as to correspond to the adhesive flow hole 22. There is.

Therefore, as shown in FIG. 7, at the time of assembling work, an electrically insulating and thermoplastic rod-shaped or spherical polyamide-based adhesive agent 24 of polyamide type is loaded in each adhesive agent accommodation section 21 and then the adjacent adhesive agent accommodation sections 21 are adjacent to each other. The semiconductor laser unit 4 is laminated such that the lower surface 2b of the heat sink 2 is pressed against the electrically insulating member 12. Then, the adhesive 24 in the adhesive container 21 is heated from the outside to melt the adhesive 24. As a result, the adhesive 24 flows in the adhesive container 21 and then solidifies the adhesive 24. as a result,
Each of the semiconductor laser units 4 has an electrically insulating member 12
The spacer 14 is securely bonded to the heat sink 2 in a pressed state, and the cushion material 15 is also securely pressed to the heat sink 2. That is, as a result of such joining, generation of a gap between the electrically insulating member 12 and the heat sink 2 during assembly is suppressed, and the medium is appropriately prevented from leaking to the outside.

As a result of adopting the thermoplastic adhesive 24, the assembling workability and the certainty of assembling when stacking the semiconductor laser units 4 in multiple stages are improved. The adhesive accommodating portion 21 as described above, together with the solder accommodating portion 17 described above, contributes to mass production of the semiconductor laser assembly 1. In addition, as a result of using the electrically insulating adhesive 24, the electrical conduction between the heat sinks 2 with the adhesive 24 interposed is avoided, and in cooperation with the electrically insulating member 12, the direct heat transfer between the adjacent heat sinks 2 is avoided. Proper electrical continuity is avoided.

It is also possible to make the adhesive accommodating portion 21 a single long hole. If the medium 24 can be sufficiently prevented from leaking with the adhesive 24 alone, the screw means 20 may not be employed.

The present invention is not limited to the above-described embodiment, but the heat sink 2A may be formed in a wedge shape as shown in FIG. 8, for example. Thereby, when the semiconductor laser units 4 are stacked, the laser light from each semiconductor laser array 3 can be focused on a predetermined place. Further, the semiconductor laser assembly 1 of the present invention is not limited to the case where the semiconductor laser units 4 are laminated in two stages, and may have three or more stages.

[0024]

Since the semiconductor laser assembly according to the present invention is constructed as described above, the following effects can be obtained. That is, a semiconductor laser array in which a plurality of laser emission points are arranged along the longitudinal direction of the front surface, a submount base in contact with the upper surface of the semiconductor laser array, and a heat sink in which the semiconductor laser array is arranged on the upper surface side. A semiconductor laser assembly in which a plurality of semiconductor laser units having a plurality of layers are stacked, wherein a lower surface side of the heat sink is provided with a solder accommodation portion at a position facing the upper surface of the submount base, and the solder in the solder accommodation portion is used to By electrically connecting the mount base and the heat sink adjacent to the mount base, the assembling workability is improved, and the conductivity between the semiconductor laser arrays is surely secured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor laser assembly according to the present invention.

FIG. 2 is a perspective view showing an assembled state of a semiconductor laser array and a submount base.

3 is a perspective view showing a spacer of a semiconductor laser unit applied to the semiconductor laser assembly shown in FIG.

4 is a perspective view showing a semiconductor laser unit applied to the semiconductor laser assembly shown in FIG. 1. FIG.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a cross-sectional view showing a state before the semiconductor laser units are stacked in two stages and fixed with solder.

FIG. 7 is a cross-sectional view showing a state in which semiconductor laser units are stacked in two stages and fixed by screw means.

FIG. 8 is a sectional view showing another embodiment of the semiconductor laser assembly according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser assembly, 2 ... Heat sink, 2a ... Heat sink upper surface, 2b ... Heat sink lower surface, 3 ... Semiconductor laser array, 3a ... Laser emission point, 3b ... Semiconductor laser array upper surface, 4 ... Semiconductor laser unit, 5 …
Front surface of semiconductor laser array, 6 ... Submount base,
6a ... Top surface of submount base, 9 ... Medium passage, 10
... inlet part, 11 ... exit part, 12 ... electrically insulating member, 13
... Opening part, 16 ... Corner part, 17 ... Solder receiving part, 1
8 ... Solder, 20 ... Screw means.

Claims (4)

[Claims] 1. A semiconductor laser array in which a plurality of laser emission points are arranged along a longitudinal direction of a front surface, and a submount base abutting on an upper surface of the semiconductor laser array,
A semiconductor laser assembly in which a plurality of semiconductor laser units having a heat sink having the semiconductor laser array arranged on the upper surface side are stacked, the lower surface side of the heat sink facing the upper surface of the submount base. A semiconductor laser assembly, wherein: a solder accommodating portion is provided in the sub-mount base and the heat sink adjacent to the sub-mount base is electrically conducted by the solder in the solder accommodating portion. 2. The semiconductor laser assembly according to claim 1, wherein the semiconductor laser array is arranged on the front side of the heat sink, and a corner portion on the lower surface of the heat sink is cut off to form the solder accommodating portion. Three-dimensional. 3. An electrically insulating member is arranged between the adjacent heat sinks, and the electrically insulating member is provided with an opening communicating with an inlet portion and an outlet portion of a medium passage formed inside the heat sink. The semiconductor laser assembly according to claim 1 or 2, wherein 4. The semiconductor laser units are fixed to each other by screw means penetrating the heat sinks in a laminated state.
4. The semiconductor laser assembly according to claim 3.