Cooler and laser module including the same

Abstract

To provide a cooler having a simple shape and being easy to manufacture.SOLUTION: A cooler 30 includes at least a first water passage block 40, a second water passage block 50, and a plate-shaped heat dissipation plate 60. The first and second water passage blocks 40 are each cylindrical with a bottom, and have bottom walls 41, 51, peripheral walls 42, 52, and openings 43, 53. The second water passage block 50 is disposed so as to accommodate the first water passage block 40 inside. The first water passage block 40 has a plurality of ejection holes 45. The second water passage block 50 has a through opening 54 penetrating the bottom wall 51 and a plurality of protrusions 56 provided at intervals along the inner peripheral surface of the peripheral wall 42. The heat dissipation plate 60 is disposed on the upper surface 51a of the bottom wall 51 so as to cover the through opening 54 from the outside.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a cooler and a laser module including the same. [Background technology]

[0002] In recent years, expectations for laser processing have been rising for various materials such as copper, gold, and resin. For example, in the automobile industry, motorization, miniaturization, high rigidity, improved design freedom, and improved productivity are required, and expectations for laser processing are high. To achieve highly productive processing, a laser light source that can obtain a high-efficiency, high-power laser light is required. A semiconductor laser element is known as a laser light source suitable for this requirement. In addition, to increase the output of laser light, a laser diode bar having a plurality of emitters that each emit laser light is useful. Note that the semiconductor laser element and the laser diode bar are usually used in a state where they are mounted on a submount. The submount is a component that mechanically supports the semiconductor laser element and the laser diode bar.

[0003] Typically, a large current of several amperes to several tens of amperes is passed through the laser diode bar to operate it. However, in this case, the temperature of the laser diode bar rises due to Joule heat. It is known that such a temperature rise reduces the output of the laser light and the operational reliability of the laser diode bar.

[0004] Therefore, conventionally, laser modules equipped with a cooler for cooling the laser diode bar during operation have been proposed. For example, Patent Document 1 discloses a laser module equipped with a cooler having a cooling water passage therein, a submount mounted on the surface of the cooler, and a laser diode bar mounted on the surface of the submount.

[0005] The cooler has a bottom cooler having an opening, and an upper cooler which is a lid material covering the opening. The space partitioned by the upper cooler and the bottom cooler is configured as a cooling water passage through which cooling water flows to cool the laser diode bar. It is also disclosed that the upper cooler has a back surface formed with a plurality of protrusions protruding toward the bottom cooler. It is also disclosed that the bottom cooler has a bottom wall facing the back surface of the upper cooler with a plurality of nozzles protruding toward the upper cooler. It is also disclosed that cooling water is sprayed from the plurality of nozzles toward the back surface of the upper cooler. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2021 / 028596 Summary of the Invention [Problem to be solved by the invention]

[0007] The conventional configuration disclosed in Patent Document 1 allows efficient cooling of the laser diode bar. However, this configuration has the following problems.

[0008] The top surface of the cooler comes into contact with the laser diode bar and the submount that supports it. On the other hand, in order to obtain high-power laser light, it is necessary to pass a large current through the laser diode bar and the submount. For this reason, it is necessary to prevent leakage to the outside through the cooling water, and the cooler is made of an insulator made of a nonmetallic material such as ceramic.

[0009] However, the conventional cooler disclosed in Patent Document 1 has a complex shape. Therefore, when the cooler is manufactured by injection molding using ceramic powder, it is difficult to improve the dimensional accuracy. In addition, because the shape is complex, there is a risk of cracks and voids occurring during molding. If voids and cracks exist in the cooler, there is a risk of cooling water leaking from them, and ultimately, electric leakage. As a result, there is a risk that the operational safety of the laser module equipped with the laser diode bar and the cooler cannot be ensured.

[0010] The present disclosure has been made in view of the above points, and has an object to provide a cooler that has a simple shape and is easy to manufacture, and a laser module including the same. [Means for solving the problem]

[0011] In order to achieve the above object, a cooler according to the present disclosure is a cooler for a laser diode bar, comprising at least a first member, a second member, and a third member, wherein the first member is cylindrical with a bottom and has a first bottom wall, a first annular peripheral wall continuous with the first bottom wall, and a first opening facing the first bottom wall, and the second member is cylindrical with a bottom and has a second bottom wall, a second annular peripheral wall continuous with the second bottom wall, and a second opening facing the second bottom wall, and the second member is disposed at a first interval from the first member so as to accommodate the first member therein, The material has a plurality of ejection holes penetrating the first bottom wall, the second member has a through opening penetrating the second bottom wall and a plurality of second protrusions spaced apart from one another along the inner circumferential surface of the second peripheral wall and each protruding inwardly from the inner circumferential surface, the second protrusions being continuous with the inner surface of the second bottom wall and forming a first groove between adjacent second protrusions, and the third member is a plate-shaped member having a third surface and a fourth surface opposite the third surface and is disposed on the second surface of the second bottom wall so as to cover the through opening from the outside.

[0012] The laser module according to the present disclosure is characterized by comprising at least the cooler, a submount mounted on the third surface of the third member, and the laser diode bar mounted on the submount. Effect of the Invention

[0013] The cooler of the present disclosure can be easily manufactured because its shape can be simplified. The laser module of the present disclosure can suppress the temperature rise of the laser diode bar and reduce defects in the shape of the cooler. This allows a safe and highly reliable laser module to be realized. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view of a laser module according to an embodiment; [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. [Figure 4A] FIG. 4 is a perspective view of a first water passage block as viewed from above. [Figure 4B] 4 is a perspective view of the first water passage block as viewed from below. FIG. [Figure 5A] 11 is a perspective view of a second water-passing block as viewed from above. FIG. [Figure 5B] 11 is a perspective view of a second water-passing block as viewed from above. FIG. [Figure 6A] FIG. 2 is a perspective view of the manifold as viewed from above. [Figure 6B] FIG. 6B is a cross-sectional view taken along line VIB-VIB in FIG. 6A. [Figure 7] FIG. 4 is a schematic cross-sectional view of a cooler according to a comparative example. [Figure 8] FIG. 11 is an exploded perspective view of a cooler according to a modified example. [Figure 9] FIG. 11 is a perspective view of a first water passage block according to a modified example, as viewed from above. [Figure 10] 13 is a perspective view of a first water passage block according to a modified example, seen from below. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its application, or its uses.

[0016] (Embodiment) [Laser module configuration] FIG. 1 is a perspective view of a laser module according to this embodiment, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

[0017] In the following description, the longitudinal direction of the laser diode bar 10 is called the X direction (first direction), and the direction in which the laser diode bar 10, the submount 20, and the cooler 30 are stacked is called the Y direction (second direction). The Y direction is also the direction in which the first water passage block (first member) 40 and the second water passage block (second member) 50 are stacked. The Y direction is also the extension direction of the ejection holes 45 (see Figs. 4A and 4B) provided in the first water passage block 40. The direction perpendicular to the X direction and the Y direction is called the Z direction. The Z direction (third direction) is the longitudinal direction of the emitter 11, and is also the optical axis direction of the laser light (not shown) emitted from each of the multiple emitters 11.

[0018] In the Y direction, the side where the laser diode bar 10 is arranged is called the top or upper side, and the side where the cooler 30 is arranged is called the bottom or lower side. In the Z direction, the side where the laser light emission end face 10a of the laser diode bar 10 is arranged is called the front or front side, and the side where the end face (rear end face) opposite to the emission end face 10a is arranged is called the rear or rear side.

[0019] As shown in FIG. 1, the laser module 100 is configured by stacking a cooler 30, a submount 20, and a laser diode bar 10 in this order from the bottom.

[0020] As shown in Fig. 1, the laser diode bar 10 has a plurality of emitters 11 and is a rectangular member in a plan view, with the long side in the X direction and the short side in the Z direction. The plurality of emitters 11 are separated by separation grooves. Note that the shapes of the laser diode bar 10 and the emitters 11 are illustrated in simplified form in Figs. 1 and 2. Also, the number of emitters 11 differs from the actual number.

[0021] The laser diode bar 10 shown in this embodiment is a so-called junction-up type in which the light emitting point of the emitter 11 is on the upper surface side far from the submount 20, but is not particularly limited to this. It may also be a so-called junction-down type in which the light emitting point of the emitter 11 is on the lower surface side close to the submount 20.

[0022] Each emitter 11 in the laser diode bar 10 of this embodiment emits laser light in a blue wavelength range. The "blue wavelength range" refers to a wavelength range of 350 nm or more and 450 nm or less. The main semiconductor material constituting the laser diode bar 10 is a nitride semiconductor (GaN-based semiconductor). However, the configuration of the laser diode bar 10 is not particularly limited thereto. For example, the main semiconductor material constituting the laser diode bar 10 may be a GaAs-based semiconductor or an InP-based semiconductor. Each emitter 11 may emit laser light in an infrared wavelength range, for example, a wavelength of about 960 nm.

[0023] The submount 20 is a conductive member having a rectangular plate shape in a plan view, and is made of, for example, a composite of diamond and metal. However, the material of the submount 20 is not particularly limited to this, and may be, for example, a composite of copper and tungsten (W). In addition, it is preferable that the submount 20 has a linear expansion coefficient close to that of the main semiconductor material constituting the laser diode bar 10 and a high Young's modulus. The submount 20 is fixed to the upper surface (third surface) 61 of the heat sink (third member) 60 by an adhesive (not shown) having high thermal conductivity, for example, metal solder.

[0024] The cooler 30 has a first water passage block 40, a second water passage block 50, a heat sink 60, and a manifold (fourth member) 70. As shown in FIG. 2, the first water passage block 40 and the second water passage block 50 are installed on an upper surface (fifth surface) 70a of the manifold 70. The heat sink 60 is disposed on an upper surface (second surface) 51a of a bottom wall (second bottom wall) 51 (see FIGS. 6A and 6B) of the second water passage block 50. The second water passage block 50 is disposed so as to accommodate the first water passage block 40 therein and at a distance D1 (first distance D1) from the first water passage block 40. The configurations and functions of the components constituting the cooler 30 will be described in detail later.

[0025] [Cooler configuration] FIG. 3 is an exploded perspective view of the cooler. FIG. 4A is a perspective view of the first water passage block seen from above. FIG. 4B is a perspective view of the first water passage block seen from below. FIG. 5A is a perspective view of the second water passage block seen from above. FIG. 5B is a perspective view of the second water passage block seen from above. FIG. 6A is a perspective view of the manifold seen from above. FIG. 6B is a cross-sectional view taken along line VIB-VIB in FIG. 6A.

[0026] 2, 3, 4A, and 4B, the first water passage block 40 is a cylindrical member with a bottom, and has a bottom wall 41 and a peripheral wall (first peripheral wall) 42 continuous with the bottom wall 41. The first water passage block 40 also has an opening (first opening) 43 facing the bottom wall 41 in the Y direction. As shown in FIGS. 2 and 3, the first water passage block 40 is disposed on the upper surface 70a of the manifold 70, with the bottom wall 41 on the upper side and the opening 43 on the lower side.

[0027] The bottom wall 41 is provided with a plurality of nozzles 44 protruding upward from an upper surface (first surface) 41a of the bottom wall 41. Each of the plurality of nozzles 44 is provided with a plurality of ejection holes 45. The ejection holes 45 penetrate the bottom wall 41. As will be described later, the cooling water supplied from the opening 43 passes through each of the plurality of ejection holes 45 and is ejected upward from the upper surface 41a of the bottom wall 41.

[0028] The first water passage block 40 is made of insulating ceramic, for example, alumina. The material of the first water passage block 40 is not particularly limited, but since cooling water flows inside, it needs to be a highly corrosion-resistant material, for example, an insulating non-metallic material. In addition, since it is necessary to form a plurality of nozzles 44, it is preferable that the material is easy to process, such as by injection molding.

[0029] 2, 3 and 5A and 5B, the second water passage block 50 is a cylindrical member with a bottom, and has a bottom wall (second bottom wall) 51 and a peripheral wall (second peripheral wall) 52 continuous with the bottom wall 51. The second water passage block 50 also has an opening (second opening) 53 facing the bottom wall 51 in the Y direction. As shown in FIGS. 2 and 3, the second water passage block 50 is disposed on the upper surface 70a of the manifold 70, with the bottom wall 51 on the upper side and the opening 53 on the lower side.

[0030] The bottom wall 51 is provided with a through opening penetrating the bottom wall 51 in the Y direction. Further, a step 55 is provided in front of the through opening on an upper surface (second surface) 51a of the bottom wall 51.

[0031] The second water-permeable block 50 has a plurality of projections (second projections) 56 that are spaced apart from one another along the inner circumferential surface of the peripheral wall 52 and each protrude inward from the inner circumferential surface. Each of the projections 56 is continuous with the inner surface of the bottom wall, in this case the lower surface. A groove (first groove) 57 is formed between adjacent projections 56.

[0032] The material of the second water passage block 50 is the same as the material of the first water passage block 40. That is, the second water passage block 50 is made of insulating ceramic, for example, alumina. The material of the second water passage block 50 needs to be a highly corrosion-resistant material, for example, an insulating non-metallic material. In addition, it is preferable that the material be easy to process, such as by injection molding.

[0033] The heat sink 60 is a plate-like member having an upper surface 61 and an opposing lower surface (fourth surface) 62. The heat sink 60 is disposed on the upper surface 51a of the bottom wall 51 so as to cover the through opening 54 from the outside. An adhesive (not shown) is provided between the heat sink 60 and the upper surface 51a of the bottom wall 51 of the second water passage block 50, and the heat sink 60 is attached and fixed to the second water passage block 50 by the adhesive. This adhesive is preferably highly water resistant and insulating.

[0034] As described above, the submount 20 on which the laser diode bar 10 is mounted is mounted on the upper surface 61 of the heat sink 60. In other words, the heat sink 60 is a supporting component that supports the laser diode bar 10 and the submount 20.

[0035] In addition, since the cooling water is applied to the lower surface 62 of the heat sink 60, the material of the heat sink 60 needs to be a material with high corrosion resistance, for example, a nonmetallic material, like the first water passage block 40 and the second water passage block 50. However, unlike the first water passage block 40 and the second water passage block 50, it is preferable that the material has high thermal conductivity. It is more preferable that the heat sink 60 has the same thermal conductivity as the submount 20. This is because the heat sink 60 also functions as a heat dissipation component that further discharges the heat generated in the laser diode bar 10 and propagated to the submount 20 to the outside. For example, the heat sink 60 is a plate material made of silicon carbide (SiC).

[0036] Further, a front side surface (first side surface) 60a of the heat sink 60 is provided parallel to a step 55 provided on an upper surface 51a of the bottom wall 51 of the second water passage block 50 and is provided with a predetermined distance therebetween.

[0037] The manifold 70 is a component for supplying cooling water to the first water passage block 40 and the heat sink 60, and for collecting the cooling water sprayed onto the lower surface 62 of the heat sink 60 and discharging it to the outside. The material of the manifold 70 is insulating ceramic, similar to the first water passage block 40 and the second water passage block 50. However, the material of the manifold 70 may be metal as long as the inner surface of the supply path 71, 71a (hereinafter simply referred to as the supply path 71, 72a) of the cooling water and the inner surface of the discharge path 72, 72a (hereinafter simply referred to as the supply path 71, 72a) of the cooling water are insulated. For example, the material of the manifold 70 may be stainless steel. In the following description, the supply path 71 may be referred to as the first flow path 71, and the discharge path 72 may be referred to as the second flow path 72.

[0038] As shown in FIGS. 2 and 6B, the manifold 70 has therein supply passages 71, 71a and discharge passages 72, 72a.

[0039] When viewed from the Y direction, the supply passage 71 is disposed at a position overlapping with the multiple nozzles 44 and the ejection holes 45. The supply passage 71 extends in the Y direction from inside the manifold 70 to reach the upper surface 70a of the manifold 70. Furthermore, at the upper surface 70a of the manifold 70, the supply passage 71 communicates with the opening 43 of the first water passage block 40. The supply passage 71a extends in the Z direction from the lower end of the supply passage 71 and reaches the rear side surface of the manifold 70.

[0040] The discharge path 72 is disposed outside the supply path 71 with a distance D2 (second distance D2) therebetween. The discharge path 72 extends in the Y direction from inside the manifold 70 to reach the upper surface 70a of the manifold 70. Furthermore, at the upper surface 70a of the manifold 70, the discharge path 72 communicates with a space S (hereinafter simply referred to as space S) between the first water passage block 40 and the second water passage block 50. The discharge path 72a extends in the Z direction from the lower end of the discharge path 72 and reaches the rear side surface of the manifold 70.

[0041] The extension directions of the supply path 71a and the discharge path 72a are not particularly limited to those shown in Fig. 2 and 6B. For example, the extension direction of each of the supply path 71a and the discharge path 72a may be the X direction, or one of the supply path 71a and the discharge path 72a may extend in the Z direction and the other in the X direction.

[0042] Further, an upper surface 70a of the manifold 70 is provided with a first groove 75 and a second groove 76, each of which has an annular shape. The second groove 76 is disposed outside the first groove 75 at a distance D3 (third distance D3; D3>D1) from the first groove 75. Further, when viewed from the X direction and the Y direction, the discharge passage 72 is disposed between the first groove 75 and the second groove 76.

[0043] 2 and 6B, the first groove 75 accommodates a first seal material 81, and the second groove 76 accommodates a second seal material 82. The first seal material 81 and the second seal material 82 are each a resin O-ring. In addition, with the first seal material 81 accommodated in the first groove 75 and the second seal material 82 accommodated in the second groove 76, the second seal material 82 is disposed outside the first seal material 81 with a distance D3 between them.

[0044] In this state, the first seal material 81 is interposed between the first water passage block 40 and the upper surface 70a of the manifold 70, and the second seal material 82 is interposed between the second water passage block 50 and the upper surface 70a of the manifold 70. In this manner, the cooling water flowing through the supply path 71 is prevented from flowing into the discharge path 72. In addition, the cooling water flowing through the space S and the discharge path 72 is prevented from leaking out of the cooler 30.

[0045] Additionally, the first groove 75 and the second groove 76 are coaxially arranged on the upper surface 70a of the manifold 70. The first water passage block 40 and the second water passage block 50 are coaxially arranged on the upper surface 70a of the manifold 70. Note that being coaxially arranged means that, when a virtual line (not shown) that passes through the center of the supply path 71 and extends in the Y direction is taken as the center line, the centers of the multiple members are arranged so as to overlap with the above-mentioned center line.

[0046] [Laser module cooling procedure during operation] When the laser module 100 is operated, a predetermined current is applied from an external power source (not shown) to the laser diode bar 10 to cause each of the multiple emitters 11 to emit laser light. Prior to this, cooling water is supplied to the cooler 30. Specifically, cooling water is supplied from the outside to a cooling water supply port 73 formed on the rear side surface of the manifold 70. The supplied cooling water flows into the supply path 71 through the supply path 71a. The cooling water passes through the opening 43 of the first water passage block 40 that is connected to the supply path 71 and reaches the multiple nozzles 44. The cooling water further passes through the multiple ejection holes 45 and is sprayed onto the lower surface 62 of the heat sink 60. This causes the heat sink 60 to be cooled by the cooling water. In addition, the submount 20 and the laser diode bar 10 mounted on the upper surface 61 of the heat sink 60 are cooled.

[0047] The cooling water sprayed onto the lower surface 62 of the heat sink 60 further passes through the grooves 57 and the space S provided in the second water passage block 50, and reaches the opening 53 of the second water passage block 50. The cooling water is discharged into the discharge path 72 communicating with the space S, and further passes from the discharge path 72 through the discharge path 72a and the cooling water discharge port 74 to the outside of the cooler 30.

[0048] If the cooling water supply equipment (not shown) is a cooling water circulation mechanism such as a chiller, the cooling water supplied from the supply port 73 receives the heat generated by the laser diode bar 10 and is discharged to the outside of the cooler 30 from the exhaust port 74, and after being cooled to a predetermined temperature in the supply equipment, is supplied again into the inside of the cooler 30 from the supply port 73.

[0049] [Effects, etc.] As described above, the cooler 30 of this embodiment includes a first water passage block (first member) 40, a second water passage block (second member) 50, a heat sink (third member) 60, and a manifold (fourth member) 70.

[0050] The first water-passing block 40 is cylindrical with a bottom, and has a bottom wall (first bottom wall) 41, a ring-shaped peripheral wall (first peripheral wall) 42 continuous with the bottom wall 41, and an opening (first opening) 43 facing the bottom wall 41.

[0051] The second water-passing block 50 is cylindrical with a bottom, and has a bottom wall (second bottom wall) 51, a ring-shaped peripheral wall (second peripheral wall) 52 continuous with the bottom wall 51, and an opening (second opening) 53 facing the bottom wall 51.

[0052] The second water-passage block 50 is disposed so as to house the first water-passage block 40 inside and at a distance (first distance) D1 from the first water-passage block 40. More specifically, the second water-passage block 50 and the first water-passage block 40 are disposed coaxially.

[0053] The first water passage block 40 has a plurality of nozzles 44 and a plurality of ejection holes 45 that are provided in each of the plurality of nozzles 44 and penetrate the bottom wall 41 .

[0054] The second water-permeable block 50 has a through opening 54 penetrating the bottom wall 51, and a plurality of protrusions (second protrusions) 56 that are spaced apart from one another along the inner circumferential surface of the peripheral wall 52 and each protrude inward from the inner circumferential surface. The plurality of protrusions 56 are continuous with the inner surface of the bottom wall, in this case the lower surface, and a groove (first groove) 57 is formed between adjacent protrusions 56.

[0055] The heat sink 60 is a plate-like member having an upper surface (third surface) 61 and a lower surface (fourth surface) 62 opposite to the upper surface 61. The heat sink 60 is disposed on the upper surface (second surface) 51a of the bottom wall 51 so as to cover the through opening 54 from the outside.

[0056] At least the first water passage block 40, the second water passage block 50 and the heat sink 60 are each made of a non-metallic material, more specifically, an insulating ceramic.

[0057] According to this embodiment, the first water passage block 40 and the second water passage block 50 are each shaped like a cylinder with a bottom, and the heat sink 60 is shaped like a plate. In other words, these components made of insulating ceramics have a general simple shape. This allows the cooler 30 to be easily manufactured by processing such as injection molding. This will be further explained with reference to FIG. 7.

[0058] FIG. 7 is a schematic cross-sectional view of a cooler according to a comparative example, and the cooler 30 includes a member 40A and a member 90. The member 40A corresponds to the heat sink 60 shown in FIGS. 1 and 2, and is made of the same material as the heat sink 60. That is, although not shown, the submount 20 on which the laser diode bar 10 is mounted is mounted on the upper surface 40A1 of the member 40A. However, a plurality of protrusions 40A3 are provided on the lower surface 40A2 of the member 40A. In this way, the surface area of ​​the lower surface 40A2 is increased, and the cooling efficiency by the cooling water is improved. The protrusions 40A3 are formed by processing such as dicing.

[0059] The member 90 has a first recess 91 recessed downward from an upper surface 90a and a second recess 92 recessed upward from a lower surface 90b. The material of the second member 50 is the same as that of the first water-passing block 40 and the second water-passing block 50.

[0060] A plurality of nozzles 93 are provided between the first recess 91 and the second recess 92. When the member 40A is attached to the member 90, each of the plurality of nozzles 93 faces the lower surface 40A2 of the member 40A. Cooling water is introduced into the second recess 92 from the outside of the cooler 30, and passes through each of the plurality of nozzles 93 to be sprayed onto the lower surface 40A2 of the member 40A.

[0061] 7 is configured by attaching the member 40A to the member 90 so as to cover the first recess 91. The member 40A is fixed to the member 90 by an insulating adhesive material 80 provided on an upper surface 90a of the member 90 so as to surround the periphery of the first recess 91. The insulating adhesive material 80 also seals the gap between the member 40A and the member 90.

[0062] The space defined by the lower surface 40A2 of the member 40A and the first recess 91 is configured as a cooling water supply path 95 through which the cooling water sprayed from the multiple nozzles 93 flows. In addition, a cooling water discharge path 94 is connected to the cooling water supply path 95, and the cooling water sprayed onto the member 40A is discharged to the outside of the cooler 30 through the discharge path 94.

[0063] 7, the heat generated in the laser diode bars 10 can be efficiently discharged to the outside of the cooler 30 via the cooling water. That is, the temperature rise of the laser diode bars 10 is suppressed, and the deterioration of the characteristics of the laser light can be suppressed.

[0064] 7, however, the shape of the member 90 is complex. For example, the discharge passage 94 extends obliquely inside the member 90. The shapes of the multiple nozzles 93 arranged at the end of the discharge passage 94 are also complex.

[0065] Because the shape of the member 90 is thus complex, it is difficult to manufacture the member 90 by, for example, injection molding using ceramic powder, and there is a high possibility that cracks and voids will be formed.

[0066] On the other hand, the first water passage block 40 and the second water passage block 50 each have a simple shape. This allows them to be easily manufactured by processing such as injection molding, and therefore allows the cooler 30 to be easily manufactured.

[0067] In addition, by providing multiple protrusions 56 and grooves 57 on the inner surface of the second water-passing block 50, the cooling water sprayed onto the underside 62 of the heat sink 60 can be reliably discharged into the space S through the supply passage 71, the opening 43, and the multiple outlet holes 45, respectively.

[0068] In order to reliably discharge the cooling water to the discharge path 72 through the interior of the space S, it is preferable that the first water passage block 40 and the second water passage block 50 are arranged coaxially on the upper surface 70a of the manifold 70. However, this is not particularly limited, and the first water passage block 40 and the second water passage block 50 do not have to be arranged coaxially. In addition, the interval D1 may vary along the circumferential direction of the first water passage block 40 and the second water passage block 50. It is sufficient that the cooling water is discharged to the discharge path 72 through the interior of the space S.

[0069] A step 55 may be provided on the upper surface 51a of the bottom wall 51 of the second water passage block 50. In this case, the step 55 is provided parallel to the front side surface (first side surface) 60a of the heat sink 60 and at a predetermined interval from the front side surface 60a.

[0070] In this manner, the laser light emitted from each of the multiple emitters 11 of the laser diode bar 10 is emitted forward without being eclipsed by the second water passage block 50.

[0071] When viewed from the Y direction, the manifold 70 has a supply passage (first flow path) 71 at a position overlapping with the multiple nozzle holes 45, and has a discharge passage (second flow path) 72 arranged outside the supply passage 71 at a distance D2 (second distance D2) from the supply passage 71.

[0072] The supply path 71 communicates with the opening 43 of the first water-passage block 40. The discharge path 72 communicates with the space S between the first water-passage block 40 and the second water-passage block 50.

[0073] By configuring the manifold 70 in this manner, it is possible to reliably supply cooling water to the multiple ejection holes 45 provided in the first water passage block 40. In addition, the cooling water that is sprayed onto the lower surface 62 of the heat sink 60 and flows downward along the inner circumferential surface of the second water passage block 50 can be reliably collected in the discharge path 72 and discharged to the outside of the cooler 30.

[0074] The first water passage block 40 and the second water passage block 50 are disposed on an upper surface (fifth surface) 70a of the manifold 70.

[0075] A first seal material 81 is interposed between the upper surface 70a of the manifold 70 and the first water passage block 40, and a second seal material 82 is interposed between the upper surface 70a of the manifold 70 and the second water passage block 50.

[0076] The second sealant 82 is disposed outside the first sealant 81 with a distance D3 (third distance D3) therebetween.

[0077] In providing the first seal material 81 and the second seal material 82 on the upper surface 70a of the manifold 70, a first groove 75 and a second groove 76 are provided in the upper surface 70a of the manifold 70.

[0078] The first groove 75 accommodates a first sealant 81, and the second groove 76 accommodates a second sealant 82. The second groove 76 is disposed outside the first groove 75 with a distance D3 between them. Note that the distance D3 is larger than the distance D1.

[0079] By providing the first groove 75 in the upper surface 70a of the manifold 70, the first seal material 81 for preventing water leakage can be reliably interposed between the upper surface 70a of the manifold 70 and the first water passage block 40. Furthermore, by providing the second groove 76 in the upper surface 70a of the manifold 70, the second seal material 82 for preventing water leakage can be reliably interposed between the upper surface 70a of the manifold 70 and the second water passage block 50.

[0080] Moreover, when viewed from the Y direction, the discharge path 72 is disposed between the first groove 75 and the second groove 76. This makes it possible to reduce the area in which the discharge path 72 is disposed, thereby enabling the miniaturization of the manifold 70. As is clear from Fig. 2, it is necessary to ensure that the distance D3 is larger than the distance D1 with a certain margin.

[0081] The laser module 100 according to this embodiment includes at least a cooler 30, a submount 20 mounted on the upper surface of a heat sink 60, and a laser diode bar 10 mounted on the submount 20.

[0082] By configuring the laser module 100 in this manner, the temperature rise of the laser diode bar is suppressed by the cooling water passing through the cooler 30. Also, as described above, the shape of each component constituting the cooler 30 can be simplified, so that the shape defects of each part of the cooler 30 can be reduced. As a result, a safe and highly reliable laser module 100 can be realized.

[0083] In addition, the cooling water that flows into the supply path 71 passes through the opening 43 of the first water passage block 40 and is sprayed onto the underside 62 of the heat sink 60 from multiple outlet holes, thereby cooling the heat sink 60, the submount 20, and the laser diode bar 10.

[0084] The cooling water sprayed onto the underside 62 of the heat sink 60 passes through multiple grooves 57, the space S, and the opening 53 provided in the second water passage block 50, and is discharged into the discharge path 72, and then further through the discharge path 72 to the outside of the cooler 30.

[0085] According to this embodiment, the heat sink 60 supporting the laser diode bar 10, which is a heat generating portion, can be reliably cooled by cooling water. At the same time, the cooling water with an increased temperature can be reliably discharged to the outside of the cooler 30. This makes it possible to prevent the temperature of the laser diode bar 10 from increasing above a predetermined level during operation, and to stabilize the characteristics of the laser light. In addition, it is possible to prevent the operational reliability of the laser diode bar 10 from decreasing.

[0086] In the cooler 30, the manifold 70 is not necessarily required and can be omitted. However, even in this case, a support component for supporting the first water passage block 40 and the second water passage block 50 is required. In this case, a supply pipe for cooling water may be directly connected to the opening 43 of the first water passage block 40. Also, a discharge pipe for cooling water may be directly connected so as to communicate with the space S.

[0087] That is, the cooler 30 of this embodiment may include at least the first water passage block 40, the second water passage block 50, and the heat sink 60. In the laser module 100 of this embodiment, the cooling water flowing into the opening 43 of the first water passage block 40 may be sprayed from a plurality of ejection holes onto the lower surface 62 of the heat sink 60, thereby cooling the heat sink 60, the submount 20, and the laser diode bar 10.

[0088] The cooling water sprayed onto the lower surface 62 of the heat sink 60 may be discharged to the outside of the cooler 30 through the multiple grooves 57 provided in the second water passage block 50, the space S, and the opening 53.

[0089] <Modification> Fig. 8 is an exploded perspective view of a cooler according to a modified example. Fig. 9 is a perspective view of a first water passage block according to a modified example, as viewed from above. Fig. 10 is a perspective view of a first water passage block according to a modified example, as viewed from below.

[0090] 8 to 10, for the sake of convenience, the same parts as those in the embodiment are denoted by the same reference numerals and detailed description thereof will be omitted. The cooler 30 of this modified example shown in Figure 8 differs from the cooler 30 of the embodiment shown in Figures 1 and 2 in that a protrusion (first protrusion) 46 protruding upward toward the bottom wall 51 of the second water passage block 50 is provided on the upper surface (first surface) 41a of the bottom wall 41 of the first water passage block 40.

[0091] Although not shown, the first water-passage block 40 and the second water-passage block 50 are arranged so that the protrusion 46 shown in FIGS.

[0092] In this way, the first water passage block 40 and the second water passage block 50 can be positioned relative to each other. In particular, rotation between the two can be prevented on the XZ plane. The XZ plane is a virtual plane (not shown) that includes the X and Z directions within its surface.

[0093] 4A and 8, when the first water passage block 40 rotates from a predetermined position relative to the second water passage block 50, the arrangement direction of the ejection holes 45 relative to the heat sink 60 changes. In this case, the spatial distribution of the amount of cooling water ejected onto the lower surface 62 of the heat sink 60 changes, and if the amount of rotation exceeds an allowable value, this may adversely affect the cooling efficiency of the laser diode bar 10.

[0094] 8 and 9, a protrusion 46 is provided on the upper surface 41a of the bottom wall 41 of the first water passage block 40, and the protrusion 46 is fitted into the groove 57 of the second water passage block 50, thereby preventing the first water passage block 40 from rotating in the XZ plane relative to the second water passage block 50. This allows the laser module 100 to operate without changing the cooling efficiency of the laser diode bar 10. In addition, by preventing the first water passage block 40 from rotating in the XZ plane relative to the second water passage block 50, it is possible to prevent the first seal material 81 from deforming and the cooling water from leaking.

[0095] In addition, the configuration for preventing rotation in the XZ plane between the first water passage block 40 and the second water passage block 50 is not limited to those shown in Figs. 8 and 9. For example, as shown in Fig. 10, another protrusion (third protrusion) 58 continuing from the protrusion 56 may be provided on the inner peripheral surface of the peripheral wall 52 of the second water passage block 50. In this case, the first water passage block 40 and the second water passage block 50 are arranged so that the tip of the protrusion 58 contacts the outer peripheral surface of the peripheral wall 52 of the first water passage block 40. In this case, it is possible to prevent the second water passage block 50 from rotating in the XZ plane relative to the first water passage block 40. This allows the laser module 100 to operate without changing the cooling efficiency of the laser diode bar 10. In addition, by preventing the second water passage block 50 from rotating in the XZ plane relative to the first water passage block 40, it is possible to prevent the second seal material 82 from deforming and the cooling water from leaking.

[0096] 8 and 9, two protrusions 46 are provided, but the number of protrusions 56 may be one or three or more. Also, in Fig. 10, two protrusions 58 are provided, but the number of protrusions 58 may be one or three or more. However, from the viewpoint of preventing rotation, it is preferable that the number of protrusions 58 is two or more.

[0097] Furthermore, in order to prevent rotation in the XZ plane between the first water-passage block 40 and the second water-passage block 50, it is sufficient to provide a protrusion 46 on the first water-passage block or a protrusion 58 on the second water-passage block 50, and it is not necessary to provide both.

[0098] (Other embodiments) In the present specification, the first water passage block 40 and the second water passage block 50 are cylindrical with a bottom, but are not particularly limited thereto. For example, the first water passage block 40 and the second water passage block 50 may each be an n-gon (n is an integer of 3 or more) as viewed from the Y direction. The first water passage block 40 may be an m-gon and the second water passage block 50 may be an o-gon (o is an integer of 3 or more and m≠o). One of the first water passage block 40 and the second water passage block 50 may be a circle and the other may be an n-gon as viewed from the Y direction. It is sufficient that the first water passage block 40 is accommodated inside the second water passage block 50 and a predetermined non-zero interval is provided between them.

[0099] 7 may be formed on the lower surface of the heat sink 60. This increases the surface area of ​​the lower surface 62 onto which the cooling water is sprayed, thereby improving the cooling efficiency of the laser diode bar 10 by the cooling water. [Industrial Applicability]

[0100] The cooler of the present disclosure can be easily manufactured since its shape can be simplified, and is useful as a cooler for high-power laser diode bars. [Explanation of symbols]

[0101] 10 Laser Diode Bar 11 Emitter 20 Submount 30 Cooler 40 First water-permeable block (first member) 41 Bottom wall (first bottom wall) 41a: Upper surface (first surface) of the bottom wall 41 42 Perimeter Wall (First Perimeter Wall) 43 Aperture (First Aperture) 44 Nozzle 45 Spout hole 46 Protrusion (First Protrusion) 40A Parts 40A1 Top 40A2 Bottom 40A3 protrusion 50 Second water-permeable block (second member) 51 Bottom wall (second bottom wall) 51a: Upper surface (second surface) of the bottom wall 51 52 Perimeter Wall (Second Perimeter Wall) 53 Aperture (Second Aperture) 54 Through hole 55 Steps 56 Protrusion (Second Protrusion) 57 Groove (First Groove) 58 Protrusion (third protrusion) 60 Heat sink 60a Front side (first side) 61 Top (third surface) 62 Bottom surface (fourth surface) 70 Manifold (fourth component) 70a Top surface (5th surface) 71 Cooling water supply passage (first passage) 71a Cooling water supply line 72 Cooling water discharge passage (second flow passage) 72a Cooling water drain 73 Cooling water supply port 74 Cooling water outlet 75 First Groove 76 Second Groove 80 Insulating adhesive 81 First sealing material 82 Second sealing material 90 Materials 90a top side 90b Bottom side 91 First recess 92 Second recess 93 Nozzle 94 Cooling water drain 95 Cooling water supply line 100 Laser Module

Claims

1. 1. A laser diode bar cooler comprising: The device includes at least a first member, a second member, and a third member, the first member is a cylindrical member having a bottom, and includes a first bottom wall, a first annular peripheral wall continuous with the first bottom wall, and a first opening facing the first bottom wall; the second member is a cylindrical member having a bottom, and includes a second bottom wall, a second annular peripheral wall continuous with the second bottom wall, and a second opening facing the second bottom wall, the second member is disposed so as to house the first member therein and to be spaced a first distance from the first member; The first member has a plurality of ejection holes penetrating the first bottom wall, The second member includes: a through opening penetrating the second bottom wall; a plurality of second protrusions provided along an inner circumferential surface of the second peripheral wall at intervals from one another and each protruding inwardly from the inner circumferential surface; the second projections are continuous with an inner surface of the second bottom wall, and a first groove is formed between adjacent second projections; The third member is a plate-shaped member having a third surface and a fourth surface opposite to the third surface, and is arranged on the second surface of the second bottom wall so as to cover the through opening from the outside.

2. 2. The cooling device according to claim 1, a step is provided on the second surface of the second bottom wall, A cooler, characterized in that the step is provided parallel to a first side surface of the third member and at a predetermined distance from the first side surface.

3. 2. The cooling device according to claim 1, At least one first protrusion is provided on a first surface of the first bottom wall and protrudes toward the second peripheral wall, the first surface is a surface close to the second bottom wall, A cooler, characterized in that the first member and the second member are arranged so that the first protrusion fits into the first groove.

4. The cooler according to claim 3, At least one third projection continuous with the second projection is provided on the inner circumferential surface of the second peripheral wall, A cooler, characterized in that the first member and the second member are arranged so that a tip end of the third projection is in contact with an outer peripheral surface of the first peripheral wall.

5. 2. The cooling device according to claim 1, A cooler according to claim 1, wherein the first member, the second member, and the third member are all made of a non-metallic material.

6. 2. The cooling device according to claim 1, Further comprising a fourth member for supplying and discharging cooling water; When the extension direction of the nozzle hole is a second direction, When viewed from the second direction, the fourth member has a first flow path at a position overlapping with the plurality of ejection holes, and has a second flow path disposed outside the first flow path at a second interval from the first flow path, The first flow passage communicates with the first opening of the first member. The cooler, wherein the second flow path is in communication with a space between the first member and the second member.

7. 7. The cooler according to claim 6, the first member and the second member are disposed on a fifth surface of the fourth member; a first sealant is interposed between the fifth surface of the fourth member and the first member; a second sealant is interposed between the fifth surface of the fourth member and the second member; The cooler according to claim 1, wherein the second sealant is disposed outside the first sealant at a third distance from the first sealant.

8. The cooler according to claim 7, a first groove for accommodating the first sealant and a second groove for accommodating the second sealant are provided on the fifth surface of the fourth member; A cooler, characterized in that the second groove is disposed outside the first groove at a third interval from the first groove.

9. 9. The cooler according to claim 8, A cooler, characterized in that, when viewed from the second direction, the second flow passage is disposed between the first groove and the second groove.

10. A cooler according to any one of claims 1 to 9; a submount mounted on the third surface of the third member; the laser diode bar mounted on the submount.

11. 11. The laser module according to claim 10, the cooling water flowing in from the first opening is sprayed from the plurality of spray holes onto the fourth surface of the third member, thereby cooling the third member, the submount, and the laser diode bar; A laser module characterized in that the cooling water sprayed onto the fourth surface of the third member passes through the plurality of first grooves and a space between the first member and the second member, and is discharged to the outside of the cooler through the second opening.

12. A cooler according to any one of claims 6 to 9; a submount mounted on the third surface; the laser diode bar mounted on the submount; the cooling water that has flowed into the first flow path passes through the first opening and is sprayed from the plurality of spray holes onto the fourth surface of the third member, thereby cooling the third member, the submount, and the laser diode bar; A laser module characterized in that the cooling water sprayed onto the fourth surface of the third member passes through the plurality of first grooves, the space between the first member and the second member, and the second opening, and is discharged into the second flow path, and further discharged from the second flow path to the outside of the cooler.

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