JP6573451B2 - Semiconductor laser unit and semiconductor laser device - Google Patents

Description

  The present invention relates to a semiconductor laser unit and a semiconductor laser device.

  As a technology in this type of field, for example, there is a semiconductor laser device described in Patent Document 1. This semiconductor laser device is formed by laminating a plurality of semiconductor laser units via spacers. The semiconductor laser unit is composed of a liquid-cooled heat sink having a fluid passage formed therein, and a semiconductor laser bar having an emission end face having a plurality of light emitting regions and fixed to an edge portion on one surface side of the heat sink. .

  Further, on the other surface side of the heat sink, a molybdenum reinforcing body having a smaller linear expansion coefficient than that of the heat sink is provided at a position facing the semiconductor laser bar. By this molybdenum reinforcing body, the overall rigidity of the semiconductor laser unit is improved, and bending of the semiconductor laser bar in the thickness direction due to the difference in linear expansion coefficient between the heat sink and the semiconductor laser bar is suppressed.

JP 2012-89584 A

  Until now, suppression of the curvature of the semiconductor laser bar due to the difference in linear expansion coefficient between the heat sink and the semiconductor laser bar has been studied in the thickness direction. However, in recent years, with the increase in output of the semiconductor laser bar, high melting point solder has been used for joining the semiconductor laser bar and the heat sink. Under such high-temperature bonding conditions, it is a new problem that the semiconductor laser bar cannot be overlooked in the direction of the optical axis when the semiconductor laser bar and the heat sink are bonded.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a semiconductor laser unit and a semiconductor laser device capable of suppressing the bending of the semiconductor laser bar in the optical axis direction.

  A semiconductor laser unit according to one aspect includes a plate-like heat sink having a fluid passage formed therein, and a semiconductor laser bar provided with an emission end face having a plurality of light emitting regions. It is arranged at the edge of one surface side of the heat sink via the submount so that it faces the one end surface side of the substrate, and the submount is made of a material having a smaller linear expansion coefficient and a larger Young's modulus than the substrate of the semiconductor laser bar. The support member is disposed at a position opposite to the emission end face.

  In this semiconductor laser unit, in the submount where the semiconductor laser bar is arranged, a support formed of a material having a smaller linear expansion coefficient and a higher Young's modulus than the semiconductor laser bar substrate at a position opposite to the emission end face of the semiconductor laser bar. The member is arranged. Due to the arrangement of the support member, when the semiconductor laser bar is bonded to the submount, a deformation opposite to the curve in the optical axis direction of the semiconductor laser bar due to the difference in linear expansion coefficient between the heat sink and the semiconductor laser bar acts on the semiconductor laser bar. . For this reason, the curvature of the semiconductor laser bar in the optical axis direction when the semiconductor laser bar is bonded to the heat sink is suppressed, and the emission end face can be flattened. Therefore, it is possible to position the light emitting region on the emission end face as designed.

  Further, the support member may be disposed apart from the semiconductor laser bar. In this case, the deformation of the semiconductor laser bar in the direction opposite to the curve in the optical axis direction due to the difference in the linear expansion coefficient between the heat sink and the semiconductor laser bar can be reliably applied by the semiconductor laser bar.

  A plurality of submounts may be arranged so as to sandwich the semiconductor laser bar and the support member. In this case, the heat generated in the semiconductor laser bar during use can be efficiently dissipated through the submount.

  Further, the semiconductor laser bar and the submount may be joined using gold-tin solder. With low melting point solder, solder migration may occur during use. In this case, if the solder moves to the emission end face of the semiconductor laser bar, the light emission characteristics may deteriorate and the reliability of the semiconductor laser unit may decrease. Therefore, the reliability of the semiconductor laser unit can be ensured by using gold-tin solder which is high melting point solder.

  A reinforcing member made of a material having a smaller linear expansion coefficient than that of the heat sink may be disposed on the other surface side of the heat sink at a position facing the semiconductor laser bar and the support member. Thereby, when joining a semiconductor laser bar to a heat sink, the curvature of the semiconductor laser bar in the thickness direction due to a difference in linear expansion coefficient between the heat sink and the semiconductor laser bar can be suppressed.

  A semiconductor laser device according to one aspect is formed by laminating a plurality of the semiconductor laser units in the thickness direction of the heat sink.

  In this semiconductor laser device, in the submount in which the semiconductor laser bar is disposed, a support formed of a material having a smaller linear expansion coefficient and a higher Young's modulus than the semiconductor laser bar substrate at a position opposite to the emission end face of the semiconductor laser bar. The member is arranged. Due to the arrangement of the support member, when the semiconductor laser bar is bonded to the submount, a deformation opposite to the curve in the optical axis direction of the semiconductor laser bar due to the difference in linear expansion coefficient between the heat sink and the semiconductor laser bar acts on the semiconductor laser bar. . For this reason, the curvature of the semiconductor laser bar in the optical axis direction when the semiconductor laser bar is bonded to the heat sink is suppressed, and the emission end face can be flattened. Therefore, it is possible to position the light emitting region on the emission end face as designed.

  According to the semiconductor laser unit and the semiconductor laser device, the bending of the semiconductor laser bar in the optical axis direction can be suppressed.

It is a perspective view showing one embodiment of a semiconductor laser device. It is a perspective view of the semiconductor laser unit which comprises the semiconductor laser apparatus shown in FIG. FIG. 3 is a plan view of the semiconductor laser unit shown in FIG. 2. FIG. 3 is a side view of the semiconductor laser unit shown in FIG. 2. It is a figure which shows the semiconductor laser unit which concerns on a comparative example, (a) is a side view which shows the structure, (b) is a figure which shows the mode of curvature of a semiconductor laser bar. It is a figure which shows the formation process of the laser module in the semiconductor laser unit which concerns on an Example, (a) is a side view, (b) is a top view. It is a figure which shows the assembly process of the laser module and reinforcement member in the semiconductor laser unit which concerns on an Example, (a) is a principal part expanded side view, (b) is a principal part enlarged plan view. It is a figure which shows the shape measurement result of the semiconductor laser bar in the formation process of a laser module, (a) is a comparative example, (b) and (c) is an Example. It is a figure which shows the shape measurement result of the semiconductor laser bar in the assembly process of a laser module and a reinforcement member, (a) is a comparative example, (b) and (c) is an Example.

  Hereinafter, preferred embodiments of a semiconductor laser unit and a semiconductor laser device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a semiconductor laser device. As shown in the figure, the semiconductor laser device 1 is configured by stacking a plurality of semiconductor laser units 2 in the thickness direction of a heat sink 11 described later. In FIG. 1, the semiconductor laser device 1 is configured by three semiconductor laser units 2, but the number of stacked semiconductor laser units 2 can be arbitrarily changed.

  Spacers 3 are used for stacking the semiconductor laser units 2. The spacer 3 is formed in a plate shape from a metal such as copper (Cu) or an insulator such as glass or ceramic. The spacer 3 is provided with a plurality of through holes 14 a and 14 b of the heat sink 11 and a plurality of through holes (not shown) communicating with the fluid passages inside the heat sink 11 in the thickness direction. The spacer 3 is disposed between the heat sinks 11 and 11 while being spaced apart from the laser module 12 and the reinforcing member 13 so as to fill a gap formed by a laser module 12 and a reinforcing member 13 described later between the semiconductor laser units 2 and 2. Is intervening.

  FIG. 2 is a perspective view of the semiconductor laser unit constituting the semiconductor laser device shown in FIG. FIG. 3 is a plan view of the semiconductor laser unit, and FIG. 4 is a side view thereof. As shown in FIGS. 2 to 4, the semiconductor laser unit 2 includes a heat sink 11, a laser module 12, and a reinforcing member 13.

  The heat sink 11 is a liquid-cooled heat sink in which a fluid passage is formed. The heat sink 11 is formed in a plate shape having a thickness similar to that of the spacer 3 by a material having high thermal conductivity such as copper (Cu). As shown in FIG. 3, the heat sink 11 is provided with a pair of through holes 14 a and 14 b corresponding to the through holes of the spacer 3. The cooling medium flowing from the through hole 14a on one side (laser module 12 side) flows through the fluid passage inside the heat sink 11 and is supplied to the laser module 12 side, and is discharged from the other through hole 14b. Yes.

  In addition, you may arrange | position an O-ring around the through-holes 14a and 14b as needed. A through hole 14c having a smaller diameter than the through holes 14a and 14b is provided between the pair of through holes 14a and 14b. The central through hole 14 c is a through hole used for stacking the semiconductor laser units 2. For example, a pillar for positioning the semiconductor laser unit 2 is inserted into the through hole 14c.

  As shown in FIG. 4, the laser module 12 is configured by laminating a first submount 21, a second submount 22, a semiconductor laser bar 23, and a support member 24, and one surface 11 a of the heat sink 11. At the edge on the side, the heat sink 11 is disposed flush with one end surface 11b in the longitudinal direction. The width of the laser module 12 is equal to or slightly smaller than the width of the heat sink 11.

  The first submount 21 and the second submount 22 are formed in a plate shape from a material having high electrical conductivity and heat resistance, such as copper tungsten (CuW). The first submount 21 is fixed to the edge of the one surface 11a of the heat sink 11 by, for example, gold tin (AuSn) solder. The second submount 22 is disposed so as to sandwich the semiconductor laser bar 23 and the support member 24 with the first submount 21. The second submount 22 is fixed to the semiconductor laser bar 23 and the support member 24 by, for example, gold tin solder. Other forming materials of the first submount 21 and the second submount 22 include molybdenum (Mo), tungsten (W), copper (Cu), copper molybdenum (MoCu), silicon carbide (SiC), and aluminum nitride. (AlN).

  The semiconductor laser bar 23 has a plate shape. One end surface side of the semiconductor laser bar 23 is an emission end surface 23a having a plurality of light emitting regions. The emission end face 23a is flush with the one end face 11b so as to face the one end face 11b side of the heat sink. The semiconductor laser bar 23 has a substrate made of a compound semiconductor, and an active layer is located at a position corresponding to the light emitting region, and a clad layer is located on both sides of the active layer. Examples of the substrate material include GaAs, GaN, AlGaAs, GaP, AlGaN, and InP. In this embodiment, for example, the main component of the substrate is GaAs, the active layer further contains In, and the cladding layer further contains Al.

  When the semiconductor laser bar 23 is driven, a drive current is supplied between the first submount 21 and the second submount 22. The semiconductor laser units 2 and 2 adjacent to each other in the vertical direction are stacked so that the second submount 22 and the reinforcing member 13 in the laser module 12 are in contact with each other (see FIG. 1). The submount 21 and the second submount 22 are electrically connected to each other via the reinforcing member 13.

  Therefore, by applying a driving voltage between the second submount 22 in the uppermost semiconductor laser unit 2 and the first submount 21 in the lowermost semiconductor laser unit 2, all the semiconductor laser bars 23 are applied. A drive current is supplied, and laser light can be emitted from each of the plurality of light emitting regions of the emission end face 23a.

The support member 24 is formed in a plate shape with a material having a smaller linear expansion coefficient and a higher Young's modulus than the substrate of the semiconductor laser bar 23. The material for forming the support member 24 is selected from materials having electrical insulation. Such materials silicon nitride (SiN), silicon carbide (SiC), cordierite _{(2MgO-2Al 2 O 3 -5SiO} 2), and the like quartz (SiO _2). As shown in FIGS. 3 and 4, the support member 24 is disposed at a position opposite to the emission end face 23 a and is fixed to the first submount 21 in a state of being separated from the other end face 23 b of the semiconductor laser bar 23. . Note that gold tin solder is used for fixing the semiconductor laser bar 23 and the support member 24 to the first submount 21.

  The reinforcing member 13 is formed in a plate shape from a material having a smaller linear expansion coefficient than the heat sink 11. An example of such a material is molybdenum (Mo). As shown in FIG. 4, the reinforcing member 13 is fixed at a position facing the laser module 12 on the other surface 11 c side of the heat sink 11.

  The length of the heat sink 11 in the longitudinal direction of the reinforcing member 13 is approximately the same as the length of the laser module 12 in the same direction, and the reinforcing member 13 faces the semiconductor laser bar 23 and the support member 24 with the heat sink 11 interposed therebetween. It is fixed at the position to be. For example, gold-tin solder is used to fix the reinforcing member 13 and the heat sink 11. In addition, although the forming material of the reinforcement member 13 has molybdenum as a main component, it may contain some impurities.

  Next, functions and effects of the semiconductor laser device 1 having the above-described configuration will be described.

  FIG. 5 is a diagram illustrating a semiconductor laser unit according to a comparative example. In the semiconductor laser unit 102 of the comparative example shown in FIG. 5A, no support member is disposed between the first submount 121 and the second submount 122, and the length of the heat sink 111 in the semiconductor laser bar 123 is long. The length in the direction is substantially the same as the length in the same direction in the first submount 121 and the second submount 122. The point that the reinforcing member 113 is disposed at the position facing the laser module 112 on the other surface side of the heat sink 111 is the same as in the present embodiment.

  However, in this semiconductor laser unit 102, for example, when the laser module 112 is joined to the edge portion on the one surface 111 a side of the heat sink 111 using gold tin solder, it is caused by a difference in linear expansion coefficient between the heat sink 111 and the semiconductor laser bar 123. The semiconductor laser bar 123 may be bent in the optical axis direction. In this case, the joining position of the semiconductor laser bar 123 is also affected by the edge on the one surface 111 a side of the heat sink 111, and as shown in FIG. It is pulled rearward (on the side of the surface 123b opposite to the emission end surface 123a) larger than the center side together with the one end surface 111b.

  Therefore, the semiconductor laser bar 123 is curved in an arch shape so that the emission end face 123a side is convex as a whole. When such a curvature of the emission end face 123a occurs, it becomes difficult to position the light emitting area of the emission end face 123a as designed, and the condensing property of the laser light emitted from the light emitting area is deteriorated or the light emission characteristics are deteriorated. There is a fear.

In contrast, in the semiconductor laser unit 2 according to this embodiment, as described above, the first submount 21 is formed of a material having a smaller linear expansion coefficient and a larger Young's modulus than the substrate of the semiconductor laser bar 23. The support member 24 is disposed at a position opposite to the emission end face 23a. In this semiconductor laser unit 2, as shown in FIG. 6A, a load of about 100 g is applied in an H ₂ atmosphere, and a semiconductor laser bar 23 and a supporting member are placed on the first submount 21 using gold tin solder. 24 is joined. Next, the second submount 22 is bonded onto the semiconductor laser bar 23 and the support member 24 using gold tin solder under the same conditions, and the semiconductor laser bar 23 and the second submount 22 are bonded to each other with the first submount 21 and the second submount 22. The laser module 12 is formed by sandwiching the support member 24.

  When the laser module 12 is formed, the support member 24 is disposed behind the semiconductor laser bar 23, so that the semiconductor laser bar 23 includes the heat sink 11 and the semiconductor laser bar 23 as shown in FIG. 6B. Deformation in the direction opposite to the curvature of the semiconductor laser bar 23 in the optical axis direction (see FIG. 5B) due to the difference in linear expansion coefficient occurs. That is, the center side in the width direction of the semiconductor laser bar 23 is pulled rearward (opposite to the emission end face 23a) than the edge side, and the semiconductor laser bar 23 is curved in an arch shape so that the emission end face 23a side is concave as a whole. To do.

Next, in the semiconductor laser unit 2, as shown in FIG. 7A, a load of about 50 g is applied in an H ₂ atmosphere, and the laser module 12 and the reinforcing member 13 are attached to the heat sink 11 using gold tin solder. Join. The laser module 12 and the reinforcing member 13 can be joined to the heat sink 11 at the same time using a predetermined jig. At this time, as in the comparative example, the semiconductor laser bar 23 is deformed in an arch shape so that the emission end face 23a side is convex as a whole due to the difference in linear expansion coefficient between the heat sink 11 and the semiconductor laser bar 23. Is about to occur.

  On the other hand, in the semiconductor laser bar 23, when the laser module 12 is formed, an arch-shaped deformation is generated in advance so that the emission end face 23a side is concave as a whole. Therefore, these deformations cancel each other, and as shown in FIG. 7B, in the laser module 12 bonded to the heat sink 11, the bending of the semiconductor laser bar 23 with respect to the optical axis direction of the emission end face 23a is suppressed, and the emission end face 23a is flattened. By flattening the emission end face 23a, the light emitting area of the emission end face 23a can be positioned as designed, and the light condensing property and emission characteristics of the laser light emitted from the light emitting area can be improved.

  In the semiconductor laser unit 2, the support member 24 is disposed away from the semiconductor laser bar 23. If the semiconductor laser bar 23 is in contact with the support member 24, it is considered that the deformation of the semiconductor laser bar 23 during the formation of the laser module 12 is hindered. Therefore, by disposing the support member 24 away from the semiconductor laser bar 23, the semiconductor laser bar 23 is deformed in the direction opposite to the curvature in the optical axis direction due to the difference in linear expansion coefficient between the heat sink 11 and the semiconductor laser bar 23. The laser bar 23 can act reliably.

  In the semiconductor laser unit 2, the semiconductor laser bar 23 and the support member 24 are sandwiched between the first submount 21 and the second submount 22. Thereby, the heat generated in the semiconductor laser bar 23 during use can be efficiently radiated through the first submount 21 and the second submount 22. In addition, when the semiconductor laser units 2 are stacked, a driving voltage can be easily applied to the semiconductor laser bar of each semiconductor laser unit 2 via the first submount 21 and the second submount 22.

  In the semiconductor laser unit 2, the semiconductor laser bar 23 and the support member 24 are bonded to the first submount 21, the semiconductor laser bar 23 and the support member 24 are bonded to the second submount 22, and the first submount 21. Gold-tin solder, which is high-melting-point solder, is used for joining the heat sink 11 and the reinforcing member 13 to the heat sink 11. With low melting point solder, solder migration may occur during use. In this case, if the solder moves to the emission end face 23a of the semiconductor laser bar 23, the light emission characteristics may be deteriorated and the reliability of the semiconductor laser unit 2 may be reduced. Therefore, the reliability of the semiconductor laser unit 2 can be ensured by using gold-tin solder, which is a high melting point solder, for bonding.

  In the semiconductor laser unit 2, the reinforcing member 13 made of a material having a smaller linear expansion coefficient than the heat sink 11 is disposed on the other surface 11 b side of the heat sink 11 at a position facing the semiconductor laser bar 23 and the support member 24. ing. Thereby, when the semiconductor laser bar 23 is joined to the heat sink 11, it is possible to suppress the bending in the thickness direction of the semiconductor laser bar 23 due to the difference in linear expansion coefficient between the heat sink 11 and the semiconductor laser bar 23.

  Examples of the semiconductor laser unit will be described below.

In the example, each component in the semiconductor laser unit was formed with the following dimensions and materials. The notation of the dimensions is width (length in the width direction of the heat sink) × length (length in the length direction of the heat sink) × thickness.
Heat sink (Cu: linear expansion coefficient 16.8 × 10 ⁻⁶ / ° C., Young's modulus 98 GPa) / 12 mm × 30 mm × 1.1 mm
・ Semiconductor laser bar (GaAs substrate: linear expansion coefficient 5.9 × 10 ⁻⁶ / ° C., Young's modulus 98 GPa) / 10 mm × 2 mm × 0.14 mm
First and second submounts (CuW: linear expansion coefficient 6.5 × 10 ⁻⁶ / ° C., Young's modulus 330 GPa) / 10 mm × 4 mm × 0.15 mm, Ni plating 2 μm to 3 μm / Au plating 0. 1 μm to 0.3 μm
Support member (SiN: linear expansion coefficient 2.6 × 10 ⁻⁶ / ° C., Young's modulus 290 GPa) / 10 mm × 1.5 mm × 0.14 mm
・ Reinforcing member (Mo: linear expansion coefficient 5.1 × 10 ⁻⁶ / ° C., Young's modulus 329 GPa) / 10 mm × 4 mm × 0.15 mm
Bonding surface / gold tin solder, between the semiconductor laser bar and the supporting member and the first and second submounts: thickness 5 μm, between the first submount and heat sink: thickness 20 μm, heat sink and reinforcing member Between: thickness 20 μm, thermocompression bonding temperature 300 ° C.

  The length of the semiconductor laser bar and the support member (the length in the longitudinal direction of the heat sink) may be appropriately changed within a range that does not protrude from the submount. When changing the length of the support member within a range of 2 mm to 4 mm, for example, the length of the first and second submounts is changed within a range of 4 mm to 12 mm, for example, and the length of the semiconductor laser bar is set to 1 mm to 5 mm, for example. The range may be changed.

  FIG. 8 is a diagram showing the shape measurement result of the semiconductor laser bar in the laser module forming process. In this shape measurement, when the forming material of the support member is changed, the shape of the emission end face of the semiconductor laser bar at the time of forming the laser module is measured with a laser microscope.

As shown in FIG. 8A, when zirconia (ZrO ₂ : linear expansion coefficient 10.5 × 10 ⁻⁶ / ° C., Young's modulus 210 GPa) is used as a comparative example of the forming material of the support member, Curved in an arch so as to be convex forward. In this case, the amount of curvature of the exit end face (the amount of protrusion relative to the straight line connecting both ends of the exit end face) was about 1.5 μm. On the other hand, as shown in FIG. 8B, when silicon carbide (SiC: linear expansion coefficient 4.5 × 10 ⁻⁶ / ° C., Young's modulus 360 GPa) is used as an example of the forming material of the support member, Compared to the case of zirconia, the amount of curvature of the exit end face was reduced, and it was almost flat.

Further, as shown in FIG. 8C, when silicon nitride (SiN: linear expansion coefficient 2.6 × 10 ⁻⁶ / ° C., Young's modulus 290 GPa) is used as an example of the material for forming the support member, the emission end face The direction of the curve was reversed, and the emission end face was curved in an arch shape so as to be concave forward. In this case, the amount of curvature of the exit end face was about −1.5 μm.

  FIG. 9 is a diagram showing the shape measurement result of the semiconductor laser bar in the assembly process of the laser module and the reinforcing member. As shown in FIG. 9A, when zirconia is used as a comparative example of the forming material of the support member, the amount of curvature of the exit end surface is curved in an arch shape so as to be more convex forward than when the laser module is formed. The amount of bending increased to about 3.0 μm. On the other hand, as shown in FIG. 9B, when silicon carbide is used as an example of the material for forming the support member, the amount of bending of the emission end face is reduced compared to the case of zirconia, and the amount of bending is It was suppressed to about 1.8 μm. In addition, as shown in FIG. 9C, when silicon nitride was used as an example of the material for forming the support member, the amount of bending of the exit end face was further reduced, and the amount of bending was suppressed to about 1.0 μm. .

From the above results, by using a support member made of a material having a smaller linear expansion coefficient and a larger Young's modulus than the substrate of the semiconductor laser bar at a position opposite to the emission end face of the semiconductor laser bar in the submount, the semiconductor laser bar can be used. It was confirmed that the bending in the optical axis direction was suppressed. For a semiconductor laser bar having a GaAs substrate, a quartz (SiO _2: linear expansion coefficient of 0.5 × ^{10 -6} / ℃, Young's modulus 70 GPa), and cordierite _{(2MgO-2Al 2 O 3 -5SiO} 2: linear expansion The condition is also satisfied for the coefficient <0.1 × 10 ⁻⁶ / ° C., Young's modulus 140 GPa). Therefore, a certain amount of bending suppression effect is exhibited.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser apparatus, 2 ... Semiconductor laser unit, 11 ... Heat sink, 11a ... One surface, 11b ... One end surface, 11c ... Other surface, 13 ... Reinforcement member, 21 ... 1st submount, 22 ... 2nd submount 23 ... Semiconductor laser bar, 23a ... Emission end face, 24 ... Supporting member.

Claims (6)

A plate-like heat sink with a fluid passage formed therein;
A semiconductor laser bar provided with an emission end face having a plurality of light emitting regions, and
The semiconductor laser bar is disposed on the edge of the one surface side of the heat sink via a submount so that the emission end surface faces the one end surface side of the heat sink,
In the submount, a support member made of a material having a smaller linear expansion coefficient and a larger Young's modulus than the substrate of the semiconductor laser bar is disposed away from the heat sink at a position opposite to the emission end face. And
The support member is a semiconductor laser unit formed of a material excluding BN, SiC, AlN, diamond, and BeO . The semiconductor laser unit according to claim 1 , wherein the support member is disposed apart from the semiconductor laser bar. The semiconductor laser unit according to claim 1, wherein a plurality of the submounts are arranged so as to sandwich the semiconductor laser bar and the support member. The semiconductor laser bar and the said submount, the semiconductor laser device according to any one of claims 1 to 3 which is joined with the Kimusuzu solder. On the other side of the heat sink, the semiconductor laser bar and at a position facing the supporting member, any claim 1-4 linear expansion coefficient than the heat sink reinforcing member formed by a material having a low is located the semiconductor laser device according to an item or. The semiconductor laser device formed by laminating a plurality of semiconductor laser unit in a thickness direction of the heat sink according to any one of claims 1-5.

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