JP2012222130A - Semiconductor laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser device that efficiently radiates waste heat from a high-power laser.SOLUTION: A semiconductor laser device comprises: a plurality of light-emitting elements; a semiconductor laser bar 10 that is perpendicular to the resonator direction of the light-emitting elements and has a first connection surface and a second connection surface for supplying power to the light-emitting elements facing to each other; a first water-cooled heat sink 11a that has a first electrode-side connection surface electrically and thermally bonded to the first connection surface, serves also as a first electrode, and has a minute flow channel located adjacent to the semiconductor laser bar; a first conductive support member that has a second electrode connection surface electrically and thermally connected to the second connection surface and serves also as a heat spreader; a metal foil 12 that is electrically and thermally connected to the conductive support member on the surface opposite to the second electrode connection surface and has flexibility; an insulating plate that is bonded between the first water-cooled heat sink and the metal foil; and a second water-cooled heat sink 11b that is bonded to the metal foil, serves also as a second electrode, and has a minute flow channel.

Description

  The present invention relates to a semiconductor laser device used in a laser annealing device or the like and having a mechanism for efficiently dissipating exhaust heat of a high-power laser.

  Semiconductor lasers are widely used for optical storage and the like. For example, in optical pickups and the like, high output and high reliability of semiconductor lasers are required in response to high-density recording typified by recent Blu-ray discs. . By the way, when the output of the semiconductor laser device is increased, the amount of heat generated is inevitably increased. However, since the semiconductor laser element is easily affected by deterioration due to heat released by itself, the heat generated as the output increases is increased. This is a serious problem for improving the performance of semiconductor lasers. In particular, it is known that an instantaneous optical damage phenomenon (COD) occurs in a semiconductor laser. This is because when the laser beam comes near the end face where the interface state is large and the band gap is reduced, the light energy changes into heat in the process of light absorption → non-radiative recombination, and the end face temperature rises. As the output rises, the band gap at the end face is further reduced and light absorption (heat generation) increases, resulting in a positive circulation, which eventually destroys the end face. The semiconductor laser device is highly reliable in a high output state. It is an obstructive factor for obtaining sex. Therefore, it is generally required to increase the COD level by efficiently performing exhaust heat.

  In semiconductor laser devices, in addition to the above-mentioned catastrophic breakdown damage, temperature rise has a large effect on light output, current characteristics, wavelength, noise, and life, and all basic characteristics shift in the direction of deterioration due to heat generation during operation. It is known to do.

  In addition, in a semiconductor laser device using a laser bar having a plurality of light emitting points, a laser element having uniform optical characteristics by suppressing relative differences in the characteristics of beams from each laser element such as wavelength, light emission efficiency, and light output. Therefore, it is important to reduce the thermal stress during mounting and to reduce the relative difference in strain applied to the light emitting portion.

  In an example of a conventional semiconductor laser device, a plurality of bumps are formed on the electrode surface of the semiconductor laser bar, and the space between the bumps is filled with a conductive paste (Ag) or the like to improve the thermal contact area. . The upper surface of the semiconductor laser bar and the lower surface of the extraction electrode are electrically and thermally connected to each other via the bump and the paste, and heat is exhausted upward in the semiconductor laser bar during laser output (Patent Document) 1).

JP 2003-88683 A

  In Patent Document 1, a laser bar and a lead electrode are connected via a protruding terminal called a bump and a paste filled in a gap. In the connection using bumps, the gap distance between the element and the extraction electrode is determined by the size of the bump. Therefore, if the bump size is reduced and the density is increased in order to suppress the connection thermal resistance, the gap distance becomes narrower but the filler. There is a problem that the occurrence of unfilled paste and voids (voids) increases.

  In addition, by reducing the bump size, stress concentration occurs at the joint, so that when solder is used as a material, the frequency of occurrence of cracks increases.

  Furthermore, since the connection part is a composite structure of multiple materials such as bumps and paste or solder, the thermal expansion coefficients are different from each other, and by repeating the exhaust heat cycle from the semiconductor laser bar, the thermal stress applied to the joint surface causes the stress from the electrode surface. Separation occurs, the thermal resistance increases, and a normal circulation occurs in which the thermal stress becomes larger and larger. Finally, the electrical connection is canceled and an open failure occurs.

  The present invention has been made in order to solve the above-described problems, and efficiently dissipates exhaust heat generated when the laser bar is oscillated at a high output, and also generates thermal stress generated when the laser bar is mounted. An object of the present invention is to provide a semiconductor laser device that can be reduced and obtain stable characteristics.

  In order to solve the above problems, a semiconductor laser device according to the present invention supplies power to a plurality of light emitting elements for laser output and the light emitting elements facing each other perpendicular to the resonator direction of the light emitting elements. A semiconductor laser bar having a first connection surface and a second connection surface, a first electrode side connection surface electrically and thermally bonded to the first connection surface of the semiconductor laser bar, and also serving as a first electrode, A heat spreader having a first water-cooled heat sink having a micro-channel (microchannel) at a position close to the semiconductor laser bar; a second electrode connection surface electrically and thermally connected to the second connection surface of the semiconductor laser bar; A metal foil having flexibility which is electrically and thermally connected to the conductive support member on a surface facing the second electrode connection surface, and the water-cooled heat A second water-cooled heat sink having an insulating plate disposed between the sink and the metal foil and mechanically bonded, and a microchannel serving as a second electrode electrically and thermally bonded to the metal foil Consists of

  According to the present invention, in addition to the above-described configuration, the first connection surface has an electrode connection surface electrically and thermally bonded to the first connection surface of the semiconductor laser bar, and the heat sink connection surface facing the electrode connection surface By providing the second conductive support member that also serves as a heat spreader that is electrically and thermally connected to the water-cooled heat sink, heat dissipation can be improved, and thermal stress generated particularly during mounting can be reduced.

  Furthermore, the invention described in the dependent claims defines a specific semiconductor laser device according to the present invention.

  According to the present invention, a semiconductor laser device capable of efficiently dissipating exhaust heat generated when a laser bar oscillates at a high output and reducing thermal stress generated when the laser bar is mounted, etc., and obtaining stable characteristics. Can be realized.

1 is an exploded perspective view showing the overall configuration of a semiconductor laser device according to an embodiment of the present invention. 1 is a sectional view of a semiconductor laser device according to a first embodiment of the present invention, and is an enlarged view in the vicinity of a laser beam emitting end. 1 is a front view of a semiconductor laser device according to a first embodiment of the present invention, and is an enlarged view in the vicinity of a laser beam emitting end. It is sectional drawing of the semiconductor laser apparatus in Embodiment 2 of this invention, and is an enlarged view near a laser beam emission end It is a front view of the semiconductor laser apparatus in Embodiment 2 of this invention, and is an enlarged view near the laser beam emission end

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view showing the entire configuration of a semiconductor laser device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the semiconductor laser device of the present invention, and is an enlarged view of the vicinity of the laser beam emitting end. FIG. 3 is a front view of the semiconductor laser device of the present invention, and is an enlarged view of the vicinity of the laser beam emitting end.

  In the figure, a semiconductor laser bar 10 is a blue-violet laser having a semiconductor layer made of a gallium nitride (GaN) based semiconductor having an oscillation wavelength of about 405 nm, for example. The semiconductor laser bar 10 is a laser diode bar in which a plurality of laser diode elements (not shown) are arranged in parallel, and the dimensions thereof are, for example, a length of about 3 mm, a resonator length of about 0.8 mm, and a thickness of about 0.1 mm. . The semiconductor laser bar 10 has a thermal expansion coefficient of about 4.5 ppm / K and a thermal conductivity of 130 W / (m · K).

  An n-type semiconductor of a laser diode element is arranged on the lower surface side inside the semiconductor laser bar 10, and further, a lower surface of the semiconductor laser bar is a first connection surface for supplying power to the n-type semiconductor, for example, A metal layer having a structure in which a titanium (Ti) layer, a platinum (Pt) layer, and an Au layer are sequentially laminated so that the surface becomes a gold (Au) layer is provided.

  The p-type semiconductor of the laser diode element is arranged on the upper surface side inside the semiconductor laser bar 10, and the upper surface of the semiconductor laser bar is a second connection surface for supplying power to the p-type semiconductor. For example, a metal layer having a structure in which a titanium (Ti) layer, a platinum (Pt) layer, and an Au layer are sequentially laminated so that the outermost surface is a gold (Au) layer is provided.

  The first water-cooled heat sink 11a has a copper (Cu, thermal conductivity of 398 W / (m · K)) thin plate and molybdenum (Mo, thermal conductivity) provided with a micro flow channel (micro channel) in front (laser beam emission end side). Is formed by laminating 140 W / (m · K) thin plates and has a thermal expansion coefficient of 8 ppm / K. Furthermore, the surface and the internal flow path are subjected to Au plating. The dimensions of the first water-cooled heat sink 11a are, for example, a width of about 10.8 mm, a depth of about 27 mm, and a thickness of about 1.55 mm. Further, a gold tin (AuSn) solder layer having a thickness of about 5 μm is formed in a portion of about 3 mm in front of the first water-cooled heat sink 11a.

  The second water-cooled heat sink 11b is formed by laminating a copper (Cu) thin plate and a molybdenum (Mo) thin plate provided with a micro flow channel (micro channel) on the front side (laser beam emission end side), and has a heat of 8 ppm / K. Has an expansion coefficient. Furthermore, the surface and the internal flow path are subjected to Au plating. The dimensions of the second water-cooled heat sink 11b are, for example, a width of about 10.8 mm, a depth of about 27 mm, and a thickness of about 1.55 mm.

  The flexible metal foil 12 is made of, for example, Cu having a thickness of about 50 μm, and the surface is subjected to Au plating. The overall planar shape is a convex shape with a narrow front, and a convex portion with a width of about 4 mm protrudes from a flat plate with a width of about 10.8 mm and a depth of about 25 mm with a length of about 2 mm. Furthermore, holes having substantially the same diameter are formed in portions that overlap the cooling water inlet, the cooling water discharge port, and the fixing through hole of the water cooling heat sink. The heat conduction of the flexible metal foil 12 is usually equivalent to about 125 Au wires having a diameter of 50 μm used for electrical and thermal connection of the upper electrode, even if the convex portion has the smallest cross-sectional area.

  The conductive support member 21a is made of, for example, a composite material (thermal conductivity is 200 W / (m · K)) of Cu (about 20%) and W (about 80%) having a thermal expansion coefficient of about 8 ppm / K, Is Au plated. The dimensions of the conductive support member 21a are, for example, a length of about 5 mm, a depth of about 1.5 mm, and a thickness of about 0.3 mm. Further, an AuSn solder layer having a thickness of about 2.5 μm is formed on the upper and lower surfaces of the conductive support member 21a.

  The conductive support member may be composed of a composite material of Cu (about 30%) and Mo (about 70%) (thermal expansion coefficient is about 8 ppm / K, thermal conductivity is 200 W / (m · K)). By setting the thermal expansion coefficient to substantially the same value as that of the water-cooled heat sink 11a, it is possible to reduce the thermal stress particularly generated during mounting.

  The insulating plate 13 is composed of polyimide (PI) having a thickness of 40 μm and an adhesive layer (about 10 μm on both top and bottom) sandwiching PI from above and below, and has a total thickness of about 60 μm. The overall planar shape is about 10.8 mm in width and about 25 mm in depth. Rectangle. Furthermore, holes having substantially the same diameter are formed in portions that overlap the cooling water inlet, the cooling water discharge port, and the fixing through hole of the water cooling heat sink.

  The spacer 13, the holding plate 14 that also serves as the upper electrode take-out part, and the cooling water flow path base part 15 that also serves as the lower electrode take-out part are made of Cu, and the surface and the internal flow path are subjected to Au plating.

  The semiconductor laser device of the present invention can be manufactured, for example, as follows.

  First, a semiconductor layer made of a GaN-based semiconductor is formed on a substrate made of GaN, for example, by a metal organic chemical vapor deposition (MOCVD) method or the like, and the metal layers are formed on the upper and lower surfaces. Subsequently, a GaN substrate is formed to a predetermined dimension. As a result, the semiconductor laser bar 10 shown in the figure is formed.

  Subsequently, the first water-cooled heat sink 11a is prepared, the AuSn solder layer at the tip and the first connection surface at the lower part of the semiconductor laser bar 10 are opposed to each other, and the semiconductor laser bar 10 is subjected to the first water-cooling after being aligned with high accuracy. Place on heat sink.

  Further, a conductive support member 21a is prepared, the AuSn solder layer on the lower surface and the second connection surface on the top of the semiconductor laser bar 10 are opposed to each other, and the conductive support member 21a is aligned with high accuracy. Put it on top.

  Furthermore, the metal foil 12 is prepared, and after aligning with high precision on the AuSn solder layer on the upper surface of the conductive support member 21a, the convex portion of the metal foil 12 is placed.

  Subsequently, a downward force of about 0.6 N is applied to the convex portion of the metal foil 12 via a flat jig, and the first water-cooled heat sink 11a is subjected to heat treatment, whereby the convex portion of the metal foil 12 and the conductive property are obtained. The support member 21a, the semiconductor laser bar 10, and the first water-cooled heat sink 11a are welded.

  Further, an insulating plate 13 is prepared and bonded to the first water-cooled heat sink 11a via a lower adhesive layer. Subsequently, the portion of the convex portion of the metal foil 12 that is not fixed to the conductive support member 21a is bent as shown in FIG. In addition, the flat plate portion of the metal foil 12 is bonded onto the insulating plate 13 via the adhesive layer on the insulating plate 13.

  Through the above steps, a member in which the semiconductor laser bar 10, the conductive support member 21a, the insulating plate 13, and the flexible metal foil 12 are fixed on the first water-cooled heat sink 11a is completed.

  By mounting the semiconductor laser bar 10 between the conductive support member 21a having the same thermal expansion coefficient as that of the laser bar and the first water-cooled heat sink 11a, the thermal expansion coefficient of both the upper surface and the lower surface of the semiconductor laser bar 10 is increased. As a result, the thermal stress generated during mounting can be reduced, and the warpage of the semiconductor laser bar 10 can be suppressed.

  Here, the member is placed on the cooling water passage base 15 with an O-ring 1 (not shown) interposed therebetween. Subsequently, the second water-cooled heat sink 11b is placed on the member with an O-ring 2 and a spacer 13 (not shown) interposed therebetween. Further, the holding plate 14 is placed on the second water-cooled heat sink 11b with an O-ring 3 (not shown) interposed therebetween. All the members are fixed to the cooling water channel base 15 using insulating set screws 16 a to 16 c (for example, made of alumina ceramic (Al 2 O 3)).

  Next, the operation will be described. A positive pole of a driving power supply device (not shown) is electrically connected to a screw hole at the rear end of the pressing plate 14 via a terminal and a conductive wire. The current from the positive electrode flows to the semiconductor laser bar 10 through the pressing plate 14, the second water-cooled heat sink 11b, the spacer 13, the metal foil 12, and the conductive support member 21a. The current is injected into the pn junction inside the semiconductor laser bar 10, and the laser beam is output in the laser beam emission direction in the figure. The current flowing through the pn junction passes through the first water-cooling heat sink 11a and the cooling water passage base portion 15 and is minus of the driving power supply device connected to the screw hole on the rear upper surface of the cooling water passage base portion 15 via a terminal and a lead wire. Return to the pole.

  Next, the heat flow at the time of laser beam output will be described. The heat generated in the pn junction portion is first diffused to the conductive support member 21a in the upward direction, and then is transferred to the flat plate portion via the convex portion of the metal foil 12, to the spacer 13 and the second water-cooled heat sink 11b. Spread. The heat transmitted to the second water-cooled heat sink 11b is in the microchannel portion, and the heat is taken away by the cooling water flowing into the microchannel portion from the cooling water circulation device (not shown) via the cooling water channel base portion 15. The cooling water is discharged from the cooling water channel base 15 and returns to the cooling water circulation device. On the other hand, in the downward direction, the heat is diffused and transmitted to the first water-cooled heat sink 11a, and the cooling water is deprived of heat by the microchannel portion in the first water-cooled heat sink 11a provided immediately below the semiconductor laser bar 10. As in the upward direction, the cooling water is discharged from the cooling water channel base and returns to the cooling water circulation device.

  As described above, in the semiconductor laser device according to the present invention, the exhaust heat is efficiently dissipated into the cooling water from both the upper and lower directions of the semiconductor laser bar through the highly heat conductive member, so that the laser light with stable characteristics and high output can be obtained. Can be output.

(Embodiment 2)
FIG. 1 is an exploded perspective view showing the entire configuration of a semiconductor laser device according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of the semiconductor laser device of the present invention, and is an enlarged view of the vicinity of the laser beam emitting end. FIG. 5 is a front view of the semiconductor laser device of the present invention, and is an enlarged view of the vicinity of the laser beam emitting end.

  In the figure, a semiconductor laser bar 10 is a blue-violet laser having a semiconductor layer made of a gallium nitride (GaN) based semiconductor having an oscillation wavelength of about 405 nm, for example. The semiconductor laser bar 10 is a laser diode bar in which a plurality of laser diode elements (not shown) are arranged in parallel, and the dimensions thereof are, for example, a length of about 3 mm, a resonator length of about 0.8 mm, and a thickness of about 0.1 mm. . The thermal expansion coefficient of the semiconductor laser bar 10 is about 4.5 ppm / K.

  An n-type semiconductor of a laser diode element is arranged on the lower surface side inside the semiconductor laser bar 10, and further, a lower surface of the semiconductor laser bar is a first connection surface for supplying power to the n-type semiconductor, for example, A metal layer having a structure in which a titanium (Ti) layer, a platinum (Pt) layer, and an Au layer are sequentially laminated so that the surface becomes a gold (Au) layer is provided.

  The p-type semiconductor of the laser diode element is arranged on the upper surface side inside the semiconductor laser bar 10, and the upper surface of the semiconductor laser bar is a second connection surface for supplying power to the p-type semiconductor. For example, a metal layer having a structure in which a titanium (Ti) layer, a platinum (Pt) layer, and an Au layer are sequentially laminated so that the outermost surface is a gold (Au) layer is provided.

  The first water-cooled heat sink 11a is formed by laminating a copper (Cu) thin plate and a molybdenum (Mo) thin plate provided with a micro flow channel (micro channel) on the front side (laser beam emission end side), and heat of 8 ppm / K. Has an expansion coefficient. Furthermore, the surface and the internal flow path are subjected to Au plating. The dimensions of the first water-cooled heat sink 11a are, for example, a width of about 10.8 mm, a depth of about 27 mm, and a thickness of about 1.55 mm.

  The second water-cooled heat sink 11b is formed by laminating a copper (Cu) thin plate and a molybdenum (Mo) thin plate provided with a micro flow channel (micro channel) on the front side (laser beam emission end side), and has a heat of 8 ppm / K. Has an expansion coefficient. Furthermore, the surface and the internal flow path are subjected to Au plating. The dimensions of the second water-cooled heat sink 11b are, for example, a width of about 10.8 mm, a depth of about 27 mm, and a thickness of about 1.55 mm.

  The flexible metal foil 12 is made of, for example, Cu having a thickness of about 50 μm, and the surface is subjected to Au plating. The overall planar shape is a convex shape with a narrow front, and a convex portion with a width of about 4 mm protrudes from a flat plate with a width of about 10.8 mm and a depth of about 25 mm with a length of about 2 mm. Furthermore, holes having substantially the same diameter are formed in portions that overlap the cooling water inlet, the cooling water discharge port, and the fixing through hole of the water cooling heat sink. The heat conduction of the flexible metal foil 12 is usually equivalent to about 125 Au wires having a diameter of 50 μm used for electrical and thermal connection of the upper electrode, even if the convex portion has the smallest cross-sectional area.

  For example, the conductive support members 21a and 21b are made of diamond having a thermal expansion coefficient of about 2.3 ppm / K and a thermal conductivity of> 1000 W / (m · K), and a Ti layer (0.06 μm), Pt on the surface. A metal layer having a structure in which a layer (0.2 μm) and an Au layer (2 μm) are sequentially laminated is formed. The dimensions of the conductive support member 21a are, for example, a length of about 5 mm, a depth of about 1.5 mm, and a thickness of about 0.2 mm. Further, an AuSn solder layer having a thickness of about 2.5 μm is formed on the upper and lower surfaces of the conductive support members 21a and 21b.

  The conductive support members 21a and 21b are a composite material of diamond (about 40%) and Cu (about 60%) with an Au plating layer formed on the surface (thermal expansion coefficient is about 6 ppm / K, thermal conductivity is 550 W / (m A structure in which an AuSn solder layer having a thickness of about 2.5 μm is formed on the upper surface and the lower surface is also possible.

  The insulating plate 22 is composed of polyimide (PI) having a thickness of 40 μm and an adhesive layer (about 10 μm on both top and bottom) sandwiching PI from above and below, and has a total thickness of about 60 μm. The overall planar shape is about 10.8 mm in width and about 25 mm in depth. Rectangle. Furthermore, holes having substantially the same diameter are formed in portions that overlap the cooling water inlet, the cooling water discharge port, and the fixing through hole of the water cooling heat sink.

  The spacer 13, the holding plate 14 that also serves as the upper electrode take-out part, and the cooling water flow path base part 15 that also serves as the lower electrode take-out part are made of Cu, and the surface and the internal flow path are subjected to Au plating.

  The semiconductor laser device of the present invention can be manufactured, for example, as follows.

  First, a semiconductor layer made of a GaN-based semiconductor is formed on a substrate made of GaN, for example, by a metal organic chemical vapor deposition (MOCVD) method or the like, and the metal layers are formed on the upper and lower surfaces. Subsequently, a GaN substrate is formed to a predetermined dimension. As a result, the semiconductor laser bar 10 shown in the figure is formed.

  Subsequently, the first water-cooled heat sink 11a and the conductive support member 21a are prepared, and after aligning with high precision, the conductive support member 21a is placed on the first water-cooled heat sink.

  Further, the AuSn solder layer on the upper surface of the conductive support member 21a and the first connection surface below the semiconductor laser bar 10 are opposed to each other, and after positioning with high precision, the semiconductor laser bar 10 is placed on the conductive support member 21a.

  In addition, the conductive support member 21b is prepared, the AuSn solder layer on the lower surface and the second connection surface on the upper portion of the semiconductor laser bar 10 are opposed to each other, and the conductive support member 21b is attached to the semiconductor laser bar with high accuracy. 10 on top.

  Furthermore, the metal foil 12 is prepared, and after aligning with high precision on the AuSn solder layer on the upper surface of the conductive support member 21b, the convex portion of the metal foil 12 is placed.

  Subsequently, a downward force of about 0.6 N is applied to the convex portion of the metal foil 12 via a flat jig, and the first water-cooled heat sink 11a is subjected to heat treatment, whereby the convex portion of the metal foil 12 and the conductive property are obtained. The support member 21b, the semiconductor laser bar 10, the conductive support member 21a, and the first water-cooled heat sink 11a are welded.

  Further, an insulating plate 22 is prepared and bonded to the first water-cooled heat sink 11a via a lower adhesive layer. Subsequently, the portion of the metal foil 12 convex portion not fixed to the conductive support member 21b is bent as shown in FIG. In addition, the flat plate portion of the metal foil 12 is bonded onto the insulating plate 22 via the adhesive layer on the insulating plate 22.

  A member in which the conductive support member 21a, the semiconductor laser bar 10, the conductive support member 21b, the insulating plate 22, and the flexible metal foil 12 are fixed on the first water-cooled heat sink 11a is completed through the above steps.

  By mounting the semiconductor laser bar 10 between the conductive support members 21a and 21b having a thermal expansion coefficient close to that of the same laser bar, the thermal expansion coefficient can be balanced on both the upper surface and the lower surface of the semiconductor laser bar 10, Thermal stress generated during mounting can be reduced, and warpage of the semiconductor laser bar 10 can be suppressed. Furthermore, the heat generated by the laser bar can be quickly diffused by configuring the conductive support member with a material having very high thermal conductivity.

  Here, the member is placed on the cooling water passage base 15 with an O-ring 1 (not shown) interposed therebetween. Subsequently, the second water-cooled heat sink 11b is placed on the member with an O-ring 2 and a spacer 13 (not shown) interposed therebetween. Further, the holding plate 14 is placed on the second water-cooled heat sink 11b with an O-ring 3 (not shown) interposed therebetween. All the members are fixed to the cooling water channel base 15 using insulating set screws 16 a to 16 c (for example, made of alumina ceramic (Al 2 O 3)).

  Next, the operation will be described. A positive pole of a driving power supply device (not shown) is electrically connected to a screw hole at the rear end of the pressing plate 14 via a terminal and a conductive wire. The current from the positive electrode flows to the semiconductor laser bar 10 through the pressing plate 14, the second water-cooled heat sink 11b, the spacer 13, the metal foil 12, and the conductive support member 21b. The current is injected into the pn junction inside the semiconductor laser bar 10, and the laser beam is output in the laser beam emission direction in the figure. The current flowing through the pn junction passes through the conductive support member 21b, the first water-cooled heat sink 11a, and the cooling water channel base 15 and is connected to the screw hole at the rear of the upper surface of the cooling water channel base 15 via a terminal and a conductor. Return to the negative pole of the drive power supply.

  Next, the heat flow at the time of laser beam output will be described. The heat generated in the pn junction portion is first diffused to the conductive support member 21b in the upward direction, and then is transferred to the flat plate portion via the convex portion of the metal foil 12, and then to the spacer 13 and the second water-cooled heat sink 11b. Spread. The heat transmitted to the second water-cooled heat sink 11b is in the microchannel portion, and the heat is taken away by the cooling water flowing into the microchannel portion from the cooling water circulation device (not shown) via the cooling water channel base portion 15. The cooling water is discharged from the cooling water channel base 15 and returns to the cooling water circulation device. On the other hand, in the downward direction, the heat is first diffused to the conductive support member 21a, then transferred to the first water-cooled heat sink 11a, and the cooling water in the microchannel portion in the first water-cooled heat sink 11a provided immediately below the semiconductor laser bar 10. Deprived of heat. As in the upward direction, the cooling water is discharged from the cooling water channel base and returns to the cooling water circulation device.

  As described above, in the semiconductor laser device according to the present invention, the exhaust heat is efficiently dissipated into the cooling water from both the upper and lower directions of the semiconductor laser bar through the highly heat conductive member, so that the laser light with stable characteristics and high output can be obtained. Can be output.

DESCRIPTION OF SYMBOLS 10 Semiconductor laser bar 11a, 11b Water cooling heat sink 12 Metal foil 13 Spacer 14 Holding plate 15 Cooling water flow path base part 21a, 21b Conductive support member 22 Insulating plate

Claims (7)

A plurality of light emitting elements for laser output;
A semiconductor laser bar having a first connection surface and a second connection surface for supplying power to the light emitting elements facing each other perpendicular to the resonator direction of the light emitting elements;
A first channel-side connection surface that is electrically and thermally joined to the first connection surface of the semiconductor laser bar, and also serves as a first electrode, and a microchannel (microchannel) is provided in the vicinity of the semiconductor laser bar. A first water-cooled heat sink having,
A first conductive support member having a second electrode connection surface electrically and thermally connected to the second connection surface of the semiconductor laser bar, and also serving as a heat spreader;
A flexible metal foil electrically and thermally connected to the conductive support member on a surface facing the second electrode connection surface;
A second electrode having an insulating plate disposed between the water-cooled heat sink and the metal foil and mechanically joined thereto, and a microchannel serving as a second electrode electrically and thermally joined to the metal foil. A semiconductor laser device comprising a water-cooled heat sink. An electrode connection surface electrically and thermally bonded to the first connection surface of the semiconductor laser bar, and electrically and thermally connected to the first water-cooled heat sink at a heat sink connection surface facing the electrode connection surface; 2. The semiconductor laser device according to claim 1, further comprising a second conductive support member that also serves as a heat spreader. 3. The semiconductor laser device according to claim 1, wherein the semiconductor laser bar has a semiconductor layer made of a GaN-based semiconductor having an oscillation wavelength of about 405 nm. 4. The semiconductor laser device according to claim 1, wherein the first water-cooled heat sink is a laminated structure of copper and molybdenum and has a thermal expansion coefficient close to that of the semiconductor laser element. 5. The conductive support member is made of a composite material of copper and tungsten or copper and molybdenum, and has substantially the same thermal expansion coefficient as that of the first water-cooled heat sink made of the laminated structure of copper and molybdenum. The semiconductor laser device described. 5. The semiconductor laser device according to claim 4, wherein the conductive support member has a metal coating layer having a laminated structure having a thickness of 2 [mu] m or more on a surface of a main body portion made of diamond. 5. The semiconductor laser device according to claim 4, wherein the conductive support member is made of a composite material of diamond and copper.

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