Cooler, cooling device, and method for manufacturing cooling device

Abstract

To provide a cooler or the like that can be manufactured at low cost.SOLUTION: A cooler includes a concave first member and a second member that covers the opening of the first member, and cools an object to be cooled by circulating a refrigerant inside, and the first member or the second member and the object to be cooled are joined by irradiating them with laser light.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a cooler, a cooling device, and a method for manufacturing a cooling device. [Background technology]

[0002] For example, the cooler described in Patent Document 1 is formed by accommodating a fin unit inside a base composed of a first base-forming member and a second base-forming member. An internal region through which a heat transfer medium flows is formed inside the base. The surface of the first base-forming member opposite the internal region is a first surface to which a power module serving as a heat generating element is bonded. The surface of the second base-forming member opposite the internal region is a second surface to which the power module is bonded. The fin unit is formed by forming cylindrical fins on both sides of a flat substrate. The fin unit is formed by integrally molding the substrate and fins. Specifically, the fin unit is formed by hot forging an aluminum plate or a copper plate using a forging die formed to match the shape of the fin unit. Then, a brazing filler metal is applied to the surfaces of the first and second base-forming members facing the internal region, and the tip surfaces of the fins in the fin unit are brazed together to the first and second base-forming members in contact with the brazing filler metal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-239675 Summary of the Invention [Problem to be solved by the invention]

[0004] The cooler of Patent Document 1 has room for further improvement in terms of low cost manufacturing. An object of the present invention is to provide a cooler or the like that can be manufactured at low cost. [Means for solving the problem]

[0005] The present invention, which was completed with this objective in mind, is a cooler that has a concave first member and a second member that covers the opening of the first member, and cools an object to be cooled by circulating a refrigerant inside the cooler, and in which the first member or the second member and the object to be cooled are joined by irradiating them with laser light. Here, the first member may have a plurality of protrusions protruding from a bottom surface, and the laser light may be irradiated between the plurality of protrusions. Also, from another perspective, the present invention is a cooling device having two coolers, each having a concave first member and a second member covering an opening of the first member, through which a refrigerant can flow, arranged symmetrically with respect to an object to be cooled, wherein the first member of one of the two coolers and the object to be cooled are joined by irradiating it with laser light, and the first member of the other of the two coolers and the object to be cooled are joined by irradiating it with laser light. Here, the first member may have a plurality of protrusions protruding from a bottom surface, and the laser light may be irradiated between the plurality of protrusions. From another perspective, the present invention is a method for manufacturing a cooling device having two coolers, each having a concave first member and a second member covering an opening of the first member, and capable of circulating a refrigerant therethrough, arranged symmetrically with respect to an object to be cooled, in which the first member of one of the two coolers is joined to the object to be cooled by irradiating it with laser light, and then the first member of the other of the two coolers is joined to the object to be cooled by irradiating it with laser light. Here, it is also possible to join the first member of one of the coolers and the second member of the one of the coolers by irradiating them with laser light, and to join the first member of the other of the coolers and the second member of the other of the coolers by irradiating them with laser light. The joining may be achieved by welding or soldering by irradiating the laser light. Furthermore, when the joining is by soldering, the surface of the first member that faces the object to be cooled and that is joined to the object to be cooled may be plated at the portion to be soldered. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a cooler or the like that can be manufactured at low cost. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of the appearance of a cooling device according to a first embodiment. [Figure 2] 2 is an example of an exploded view of components constituting the cooling device according to the first embodiment. FIG. [Figure 3] 1 is a diagram illustrating an example of a cross section of a cooling device according to a first embodiment. [Figure 4] 1(a) is a diagram showing an example of a plane of a first member of a first cooler, and FIG. 1(b) is a diagram showing an example of a cross section taken along line IVb-IVb of FIG. [Figure 5] FIG. 4 is an enlarged view of a joint portion between a first member of the first cooler and a connecting member. [Figure 6] FIG. 4 is a diagram for explaining the joining of the first member and the second member of the first cooler. [Figure 7] (a) is an example of a perspective view of a connecting member, (b) is a diagram for explaining the joining of the second member of the first cooler and the connecting member, and (c) is a diagram for explaining the joining of the connecting member and the first member of the second cooler. [Figure 8] FIG. 10 is a diagram illustrating an example of the appearance of a cooling device according to a third embodiment. [Figure 9] 10A to 10C are diagrams illustrating an example of a method for manufacturing a cooling device according to a third embodiment. [Figure 10] 10A and 10B are diagrams schematically showing an example of a method for joining a first member and a heating element by irradiating them with laser light. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. First Embodiment FIG. 1 is a diagram showing an example of the appearance of a cooling device 1 according to the first embodiment. FIG. 2 is an example of an exploded view of components constituting the cooling device 1 according to the first embodiment. 3 is a diagram showing an example of a cross section of the cooling device 1 according to the first embodiment, taken along line III-III in FIG. Fig. 4(a) is a diagram showing an example of a plane of the first member 11 of the first cooler 10. Fig. 4(b) is a diagram showing an example of a cross section taken along line IVb-IVb of Fig. 4(a). The cooling device 1 according to the first embodiment includes a first cooler 10, a second cooler 20, and a third cooler 30, which are coolers capable of circulating a refrigerant therethrough. The cooling device 1 also includes a connecting member 40 arranged between the first cooler 10 and the third cooler 30, and a connecting member 50 arranged between the first cooler 10 and the second cooler 20. The cooling device 1 also includes a support member 60 that supports the first cooler 10, the second cooler 20, and the third cooler 30. The cooling device 1 also includes a pressing member 70 that presses the heat generating element 100 arranged between the first cooler 10 and the second cooler 20 so that the surfaces of the first cooler 10 and the second cooler 20 come into contact with the heat generating element 100 arranged between the first cooler 10 and the third cooler 30, and so that the surfaces of the first cooler 10 and the third cooler 30 come into contact with the heat generating element 100 arranged between the first cooler 10 and the third cooler 30. The cooling device 1 also includes a connecting member 80 disposed between the third cooler 30 and the pressing member .

[0009] 1 and 2, the cooling device 1 is a stacked type cooling device in which a first cooler 10, a second cooler 20, and a third cooler 30 are stacked. Hereinafter, the direction in which the first cooler 10, the second cooler 20, and the third cooler 30 are stacked may be referred to as the "vertical direction." The materials of the first cooler 10, the second cooler 20, the third cooler 30, the connecting member 40, the connecting member 50, the support member 60, and the connecting member 80 can be, for example, aluminum or an aluminum material such as an aluminum alloy, or copper. The heat generating element 100 can be exemplified as a card-type power module.

[0010] (1st cooler 10) The first cooler 10 includes a case 13 formed by joining a first member 11 having a concave shape and a plurality of protruding portions 11b protruding from a bottom surface 11a and a second member 12 having a concave shape and a plurality of protruding portions 12b protruding from a bottom surface 12a such that the tips of the protruding portions 11b and the tips of the protruding portions 12b face each other. The case 13 is a generally rectangular parallelepiped member, and a space S1 through which a refrigerant flows is formed inside the case 13. In the following description, the longitudinal direction of the case 13 may be simply referred to as the "longitudinal direction," and the lateral direction of the case 13 may be simply referred to as the "lateral direction." The protruding portions 11b and 12b may be cylindrical or rectangular prism-shaped, for example. Alternatively, the protruding portions 11b and 12b may be flat plates extending in the longitudinal direction. Furthermore, when the protrusions 11b and 12b are flat, they may be parallel to the longitudinal direction, or may be wavy with portions inclined in the longitudinal direction.

[0011] The first member 11 has a first communication hole 11c formed at one longitudinal end of the bottom surface 11a, which connects the space S1 to the outside of the case 13, and a second communication hole 11d formed at the other longitudinal end of the bottom surface 11a, which connects the space S1 to the outside of the case 13. The first communication hole 11c is an elongated hole whose short side direction is the longitudinal direction of the first member 11 and whose long side direction is the short side direction of the first member 11. The second communication hole 11d can be, for example, the same shape as the first communication hole 11c. The first member 11 also has a side wall 11e extending from the outer periphery of the bottom surface 11a in a direction perpendicular to the bottom surface 11a, and a flange 11f protruding outward from the tip of the side wall 11e in a direction parallel to the bottom surface 11a. The bottom surface 11a and the side wall 11e form a recess, and a flange 11f is formed around the recess.

[0012] The plurality of protrusions 11b provided on the first member 11 are divided into three regions in the longitudinal direction: a first region 11g, a second region 11h, and a third region 11j. A plurality of (two in this embodiment) protrusions 11k protruding from the bottom surface 11a are provided in the lateral direction between the first region 11g and the second region 11h, and a plurality of (two in this embodiment) protrusions 11m protruding from the bottom surface 11a are provided in the lateral direction between the second region 11h and the third region 11j. These plurality of protrusions 11b, the plurality of protrusions 11k, and the plurality of protrusions 11m are provided on the recessed portion side, in other words, on the space S1 side of the case 13. On the other hand, on the side opposite the recessed portion of the first member 11, in other words, on the outer surface side of the case 13, the portion where the plurality of protrusions 11b are provided forms a flat outer surface 11p. A recess 11r recessed from the outer surface 11p is provided in the portion where the plurality of protrusions 11k and the plurality of protrusions 11m are provided. That is, the portions where the protrusions 11k and 11m are provided are recessed from the outer surface 11p to form recesses 11r with a thickness equal to the thickness between the bottom surface 11a and the outer surface 11p. However, the thickness around recesses 11r does not have to be equal to the thickness between the bottom surface 11a and the outer surface 11p.

[0013] The tips of the flange 11f, the protrusion 11k, and the protrusion 11m are molded to be on the same plane. The first outer surface 11s, which is the outer surface 11p corresponding to the first region 11g, the second outer surface 11t, which is the outer surface 11p corresponding to the second region 11h, and the third outer surface 11u, which is the outer surface 11p corresponding to the third region 11j, are surfaces that come into contact with the heating element 100 and are all formed to have the same area. A plurality of recesses 11r (two in this embodiment) are provided in the lateral direction between the first outer surface 11s and the second outer surface 11t. A plurality of recesses 11r (two in this embodiment) are provided in the lateral direction between the second outer surface 11t and the third outer surface 11u.

[0014] The plurality of protrusions 11b are provided in a first region 11g, a second region 11h, and a third region 11j as an example of a first region where the heating element 100 is disposed so as to be in contact with the first member 11, a surrounding region 11v as an example of a second region around the first communicating hole 11c, and a surrounding region 11w as an example of a second region around the second communicating hole 11d. The plurality of protrusions 11b are not provided between the surrounding region 11v and the first region 11g, or between the surrounding region 11w and the third region 11j. The side wall 11e does not have to extend from the outer periphery of the bottom surface 11a in a direction perpendicular to the bottom surface 11a, and may extend in a direction inclined relative to the perpendicular direction.

[0015] The second member 12 can be exemplified as having the same shape as the first member 11. That is, the second member 12 has a first communication hole (not shown) formed at one longitudinal end of the bottom surface 12a, which connects the space S1 to the outside of the case 13, and a second communication hole (not shown) formed at the other longitudinal end of the bottom surface 12a, which connects the space S1 to the outside of the case 13. The second member 12 also has a side wall 12e extending from the outer periphery of the bottom surface 12a in a direction perpendicular to the bottom surface 12a, and a flange 12f protruding outward from the tip of the side wall 12e in a direction parallel to the bottom surface 12a. The bottom surface 12a and the side wall 12e form a recess, and the flange 12f is formed around this recess.

[0016] The plurality of protrusions 12b provided on the second member 12 are divided into three regions in the longitudinal direction: a first region (not shown), a second region (not shown), and a third region (not shown). A plurality of (two in this embodiment) protrusions (not shown) protruding from the bottom surface 12a are provided in the lateral direction between the first region (not shown) and the second region (not shown). A plurality of (two in this embodiment) protrusions (not shown) protruding from the bottom surface 12a are provided in the lateral direction between the second region (not shown) and the third region (not shown). These plurality of protrusions 12b are provided on the recessed portion side, in other words, on the space S1 side of the case 13. On the other hand, on the opposite side of the recessed portion of the second member 12, in other words, on the outer surface side of the case 13, the portion where the plurality of protrusions 12b are provided forms an outer surface 12p. A recessed portion (not shown) recessed from the outer surface 12p is provided in the portion where the plurality of protrusions are provided. That is, the portion where the protrusion is provided is recessed from the outer surface 12p to form a recess so that the thickness is the same as the thickness between the bottom surface 12a and the outer surface 12p. However, the thickness around the recess does not have to be the same as the thickness between the bottom surface 12a and the outer surface 12p.

[0017] The flange 12f and the tips of the protrusions are molded to be on the same plane. The first outer surface (not shown), which is the outer surface 12p corresponding to the first region, the second outer surface (not shown), which is the outer surface 12p corresponding to the second region, and the third outer surface (not shown), which is the outer surface 12p corresponding to the third region, are surfaces that come into contact with the heating element 100 and are all formed to have the same area. A plurality of recesses (two in this embodiment) are provided in the lateral direction between the first and second outer surfaces. A plurality of recesses (two in this embodiment) are provided in the lateral direction between the second and third outer surfaces.

[0018] Since the first member 11 and the second member 12 have the same shape, it is possible to reduce the number of types of parts that make up the cooling device 1.

[0019] The first member 11 and the second member 12 are joined by laser welding in a state in which flanges 11f and 12f, tips of the plurality of convex portions 11b and tips of the plurality of convex portions 12b, tips of protrusions 11m and tips of protrusions (not shown), and tips of protrusions 11m and tips of protrusions (not shown) are in contact with each other. Laser welding is performed by irradiating one of the first member 11 or the second member 12 with laser light from the outside. The laser light is irradiated to the overlapping portions of flanges 11f and 12f, the overlapping portion of protrusions 11k and (not shown), and the overlapping portion of protrusions 11m and (not shown). For example, the overlapping portion of flange 11f and flange 12f is irradiated with laser light from the outside along the entire circumference of flange 11f of the first member 11. Furthermore, the overlapping portions of the projections 11k and 11m (not shown) and the overlapping portions of the projections 11m and 11m (not shown) are irradiated with spot laser light, for example, from the outside of the first member 11 toward the bottom of the recess 11r. Then, in both portions, the laser light is irradiated so that both the first member 11 and the second member 12 melt and solidify to form molten portions. As a result, laser welding is performed on the entire periphery of the space S in the case 13 and the portion inside the periphery of the space S, in other words, within the space S1.

[0020] The first cooler 10 is arranged so that the first member 11 is on the pressing member 70 side and the second member 12 is on the support member 60 side. The first communication hole formed in the second member 12 functions as an inlet for allowing the refrigerant to flow into the space S1, and the second communication hole formed in the second member 12 functions as an outlet for allowing the refrigerant to flow out of the space S1.

[0021] (2nd cooler 20) The second cooler 20 includes a case 23 in which a first member 21 is concave and has a plurality of protruding portions 21b protruding from a bottom surface 21a, and a flat second member 22 that covers the opening of the first member 21, the case 23 being joined together such that the tips of the protruding portions 21b face the second member 22. The case 23 is a member having a generally rectangular parallelepiped shape, and a space S2 through which the refrigerant flows is formed inside. The protruding portions 21b can be, for example, cylindrical or rectangular prism-shaped. Alternatively, the protruding portions 21b can be, for example, flat plate-shaped extending in the longitudinal direction. Furthermore, when the protruding portions 21b are flat, they may be parallel to the longitudinal direction or may be wavy with portions inclined in the longitudinal direction.

[0022] The first member 21 has the same shape as the first member 11 of the first cooler 10, and has a first communication hole (not shown), a second communication hole (not shown), a side wall 21e, and a flange 21f, which correspond to the first communication hole 11c, the second communication hole 11d, the side wall 11e, and the flange 11f, respectively. The first member 21 also has a protrusion (not shown), a protrusion (not shown), a recess (not shown), a first outer surface (not shown), a second outer surface (not shown), and a third outer surface (not shown), which correspond to the protrusion 11k, the protrusion 11m, the recess 11r, the first outer surface 11s, the second outer surface 11t, and the third outer surface 11u of the first member 11, respectively. The second member 22 is a flat plate-like member whose outer circumferential shape is the same as that of the flange 21f of the first member 21. The second member 22 has a first communication hole (not shown) formed in a position facing the first communication hole of the first member 21, and a second communication hole (not shown) formed in a position facing the second communication hole of the first member 21.

[0023] The first member 21 and the second member 22 are joined by laser welding with the flange 21f, the tips of the multiple convex portions 21b, and the tips of the multiple protrusions in contact with the second member 22. Laser welding is performed by irradiating the second member 22 with laser light from the outside. The areas irradiated with the laser light are the overlapping areas between the flange 21f and the second member 22 and the overlapping areas between the protrusions and the second member 22. The overlapping areas between the flange 21f and the second member 22 are irradiated with laser light from the second member 22 side, for example, so as to follow the shape of the entire circumference of the flange 21f of the first member 21. Furthermore, the overlapping areas between the protrusions and the second member 22 are irradiated with laser light from the outside of the second member 22 in a spot manner at areas corresponding to the protrusions. Then, the laser light is irradiated at both areas so that both the first member 21 and the second member 22 melt and solidify, thereby forming molten zones. As a result, laser welding is performed on the entire periphery of the space S2 in the case 23 and on the inner portion of the periphery of the space S2, in other words, inside the space S2. The second cooler 20 configured as above is arranged so that the first member 21 is on the pressing member 70 side and the second member 22 is on the support member 60 side. The first communication hole formed in the second member 22 functions as an inlet for allowing the refrigerant to flow into the space S2, and the second communication hole formed in the second member 22 functions as an outlet for allowing the refrigerant to flow out of the space S2.

[0024] (Third cooler 30) The third cooler 30 has a case 33 in which a first member 31 identical to the first member 21 of the second cooler 20 and a second member 32 corresponding to the second member 22 of the second cooler 20 are joined together. The case 33 is a member having a roughly rectangular parallelepiped shape, and has a space S3 formed therein through which the refrigerant flows. The third cooler 30 is arranged so that the first member 31 is on the support member 60 side and the second member 32 is on the pressing member 70 side. The first member 31 is formed with a first communication hole that functions as an inlet for allowing the refrigerant to flow into the space S3, and a second communication hole that functions as an outlet for allowing the refrigerant to flow out of the space S3. On the other hand, the second member 32 does not have any communication holes corresponding to the first and second communication holes of the second member 22.

[0025] (Connecting member 40) The connecting member 40 is an elliptical cylindrical member whose minor axis corresponds to the longitudinal direction of the case 13 and whose major axis corresponds to the lateral direction of the case 13. An elongated through-hole 41 is formed in the center of the connecting member 40, whose major axis corresponds to the longitudinal direction and whose minor axis corresponds to the lateral direction. The through-hole 41 has the same shape as the first communication hole 11c of the first member 11 of the first cooler 10. Grooves 42 into which O-rings 45 are fitted are formed around the through-hole 41 on both sides of the connecting member 40. The connecting member 40 also has cylindrical protrusions 43 protruding from one surface on both sides of the groove 42 in the longitudinal direction. A cylindrical through-hole 44 is formed in the center of the protrusion 43. The vertical size of the central part of connecting member 40 is the same as the vertical size of heating element 100, which is the thickness of heating element 100. In addition, the vertical size of protruding portion 43 of connecting member 40 is the same as the vertical size of case 13, which is the thickness of case 13.

[0026] (Connecting member 50) The connecting member 50 differs from the connecting member 40 in that the vertical size of a protrusion 53 corresponding to the protrusion 43 is smaller than the vertical size of the protrusion 43. That is, the connecting member 50 is an elliptical cylindrical member whose minor axis corresponds to the longitudinal direction of the case 13 and whose major axis corresponds to the lateral direction of the case 13. An elongated through-hole 51 is formed in the center of the connecting member 50, whose major axis corresponds to the longitudinal direction and whose minor axis corresponds to the lateral direction. The through-hole 51 has the same shape as the first communication hole 11c of the first member 11 of the first cooler 10. Grooves 52 into which O-rings 55 are fitted are formed around the through-hole 51 on both sides of the connecting member 50. The connecting member 50 also has cylindrical protrusions 53 protruding from one surface on both sides of the groove 52 in the longitudinal direction. A cylindrical through-hole 54 is formed in the center of the protrusion 53. The vertical size of the central part of the connecting member 50 is the same as the vertical size of the heating element 100. In addition, the vertical size of the protruding part 53 of the connecting member 50 is the same as the vertical size of the case 23, which is the thickness of the case 23. However, the connecting member 50 may have the same shape as the connecting member 40.

[0027] (support member 60) The support member 60 has a first space 61 recessed from the top surface at one end in the longitudinal direction and a second space 62 recessed from the top surface at the other end in the longitudinal direction. An opening 61a on the top surface of the first space 61 has the same shape as the first communicating hole 11c of the first member 11. An opening 62a on the top surface of the second space 62 has the same shape as the second communicating hole 11d of the first member 11. A groove 61b into which an O-ring 65 is fitted is formed around the opening 61a in the support member 60. A groove 62b into which an O-ring 66 is fitted is formed around the opening 62a in the support member 60. Furthermore, the support member 60 has female threads 61c formed on both outer sides of the groove 61b in the longitudinal direction. Furthermore, the support member 60 has female threads 62c formed on both outer sides of the groove 62b in the longitudinal direction.

[0028] A communication hole is formed in the support member 60, connecting the first space 61 with the outside in a direction perpendicular to the up-down direction (the short direction in FIGS. 1 and 2), and a first joint 63 is fitted into this communication hole. Further, a communication hole is formed in the support member 60, connecting the second space 62 with the outside in a direction perpendicular to the up-down direction, and a second joint 64 is fitted into this communication hole.

[0029] (Pressing member 70) The pressing member 70 includes a plurality of disc springs 71 (three in this embodiment) and a plate 72 that holds the plurality of disc springs 71. The disc spring 71 is a member made of a disk-shaped plate with a hole in the center that has been formed into a cone shape, and is arranged so that the smaller diameter side faces the plate 72 and the larger diameter side faces the third cooler 30. The disc springs 71 are attached to the plate 72 at positions corresponding to the three heat generating elements 100 arranged between the coolers. The plate 72 is a flat member and has, in its center, a holding portion 72a that holds the disc spring 71. The plate 72 also has, at both longitudinal ends of the holding portion 72a, cover portions 72b that cover the upper surface of the connecting member 80. Two through holes 72c for passing the bolts 90 are formed in each cover portion 72b. The disc spring 71 may be made of steel, and the plate 72 may be made of steel, iron, aluminum, or copper.

[0030] (Connecting member 80) Connecting member 80 differs from connecting member 50 in that it does not have through-hole 51 or groove 52. In other words, connecting member 80 is an elliptical cylindrical member whose minor axis direction is the longitudinal direction of case 13 and whose major axis direction is the short-side direction of case 13. Connecting member 80 also has cylindrical protrusions 83 that protrude from one surface at each end in the major axis direction. A cylindrical through-hole 84 is formed in the center of protrusion 83. The vertical size of protrusion 83 is the same as the vertical size of case 33.

[0031] In the cooling device 1 configured as described above, the second cooler 20 is arranged on the support member 60, the first cooler 10 is arranged on the second cooler 20, the third cooler 30 is arranged on the first cooler 10, and the pressing member 70 is arranged on the third cooler 30. In addition, a heat generating element 100 as an example of three objects to be cooled is arranged between the second cooler 20 and the first cooler 10. In addition, three heat generating elements 100 are arranged between the first cooler 10 and the third cooler 30. In addition, two connecting members 50 are arranged between the second cooler 20 and the first cooler 10, two connecting members 40 are arranged between the first cooler 10 and the third cooler 30, and two connecting members 80 are arranged between the third cooler 30 and the pressing member 70. The connecting member 50 disposed between the second cooler 20 and the first cooler 10 is arranged so that the lower surface of the protruding portion 53 contacts the support member 60, and the connecting member 40 disposed between the first cooler 10 and the third cooler 30 is arranged so that the lower surface of the protruding portion 43 contacts the connecting member 50. Furthermore, the connecting member 80 disposed between the third cooler 30 and the pressing member 70 is arranged so that the lower surface of the protruding portion 83 contacts the connecting member 40. At each of both longitudinal ends, the male threads of bolts 90 are passed from the upper side of the pressing member 70 through the through holes 72c of the plate 72, the through holes 84 of the connecting member 80, the through holes 44 of the connecting member 40, and the through holes 54 of the connecting member 50, and are tightened into the female threads 61c and 62c formed in the support member 60, thereby supporting the first cooler 10, the second cooler 20, the third cooler 30, and the heating element 100 on the support member 60.

[0032] (Manufacturing method of cooling device 1) The cooling device 1 configured as above is manufactured as follows. FIG. 5 is an enlarged view of the joint portion between the first member 11 of the first cooler 10 and the connecting member 40. As shown in FIG. The first member 11 and the connecting member 40 of the first cooler 10 are joined by laser welding. During laser welding, the first member 11 is placed on the connecting member 40, and the first member 11 and the connecting member 40 are overlapped so that the through hole 41 and the first communicating hole 11c are aligned. Then, laser light L is irradiated from the laser head 151 of the laser device 150 toward the first member 11 at the overlapping portion, and the laser head 151 is moved along the shape of the first communicating hole 11c to continuously irradiate the periphery of the first communicating hole 11c with the laser light L. The laser source of the laser device 150 is not particularly limited. Examples include a YAG laser, a CO2 laser, a fiber laser, a disk laser, and a semiconductor laser. The irradiation direction of the laser light L may be perpendicular to the bottom surface 11a of the first member 11 at the overlapping portion, or may be inclined relative to the perpendicular direction. Although FIG. 5 shows one end in the longitudinal direction, the first member 11 and the connecting member 40 are similarly joined by laser welding at the other end in the longitudinal direction.

[0033] FIG. 6 is a diagram for explaining the joining of the first member 11 and the second member 12 of the first cooler 10. As shown in FIG. Next, the first member 11 and the second member 12 are overlapped with each other so that the flange 11f of the first member 11 is placed on the flange 11f of the second member 12. Then, the laser head 151 of the laser device 150 irradiates the flange 12f with laser light L from the outside of the second member 12 toward the flange 12f while moving the laser head 151 along the shape of the flange 12f, thereby continuously irradiating the flange 12f with the laser light L. Furthermore, the laser light L is irradiated in a spot manner from the outside of the second member 12 to the overlapping portion between the protrusion 11k of the first member 11 and the protrusion (not shown) of the second member 12, and the overlapping portion between the protrusion 11m of the first member 11 and the protrusion (not shown) of the second member 12, for example, toward the bottom of the recess 12r. In this manner, the first member 11 and the second member 12 are joined by laser welding.

[0034] The first member 21 of the second cooler 20 and the connecting member 50 are joined by laser welding in the same manner as described with reference to Fig. 5. Thereafter, the first member 21 of the second cooler 20 and the second member 22 are joined by laser welding in the same manner as described with reference to Fig. 6. Furthermore, the second member 32 of the third cooling device 30 and the connecting member 80 are joined by laser welding in the same manner as described with reference to Fig. 5. Thereafter, the first member 31 and the second member 32 of the third cooling device 30 are joined by laser welding in the same manner as described with reference to Fig. 6.

[0035] Thereafter, the second cooler 20 to which the connecting member 50 is joined is placed on the support member 60. In other words, the connecting member 50 to which the second cooler 20 is joined is placed on the support member 60. Thereafter, the first cooler 10 to which the connecting member 40 is joined is placed on the second cooler 20. In other words, the connecting member 40 to which the first cooler 10 is joined is placed on the connecting member 50. At this time, three heat generating elements 100 are arranged between the first cooler 10 and the second cooler 20. More specifically, the heat generating elements 100 are arranged between the first outer surface of the first member 21 of the second cooler 20 and the first outer surface of the second member 12 of the first cooler 10, the heat generating elements 100 are arranged between the second outer surface of the first member 21 and the second outer surface of the second member 12, and the heat generating elements 100 are arranged between the third outer surface of the first member 21 and the third outer surface of the second member 12.

[0036] Thereafter, the third cooler 30 to which the connecting member 80 is joined is placed on the first cooler 10. In other words, the connecting member 80 to which the third cooler 30 is joined is placed on the connecting member 40. At this time, three heat generating elements 100 are arranged between the first cooler 10 and the third cooler 30. More specifically, the heat generating elements 100 are arranged between the first outer surface 11s of the first member 11 of the first cooler 10 and the first outer surface of the first member 31 of the third cooler 30, the heat generating elements 100 are arranged between the second outer surface 11t of the first member 11 and the second outer surface of the first member 31, and the heat generating elements 100 are arranged between the third outer surface 11u of the first member 11 and the third outer surface of the first member 31.

[0037] Thereafter, the pressing member 70 is placed on the third cooler 30. In other words, the plate 72 of the pressing member 70 is placed on the connecting member 80. Then, at one end in the longitudinal direction, a bolt 90 is passed from above the pressing member 70 through the through hole 72c of the plate 72, the through hole 84 of the connecting member 80, the through hole 44 of the connecting member 40, and the through hole 54 of the connecting member 50, and the male screw is tightened into the female screw 61c formed in the support member 60. Furthermore, at the other end in the longitudinal direction, a bolt 90 is passed from above the pressing member 70 through the through hole 72c of the plate 72, the through hole 84 of the connecting member 80, the through hole 44 of the connecting member 40, and the through hole 54 of the connecting member 50, and the male screw is tightened into the female screw 62c formed in the support member 60.

[0038] In the cooling device 1 configured as described above, the refrigerant that has flowed into the first space 61 from the first joint 63 of the support member 60 passes through the opening 61a and the first communication hole formed in one longitudinal end of the second member 22 of the second cooler 20, and then flows into the space S2 between the first member 21 and the second member 22 of the second cooler 20. Then, part of the refrigerant that has flowed into the space S2 advances in the longitudinal direction within the space S2, and flows out of the second cooler 20 through the second communication hole formed in the other longitudinal end of the second member 22.

[0039] Furthermore, part of the refrigerant that has flowed into the space S2 passes through a first communication hole formed at one end in the longitudinal direction of the first member 21 of the second cooler 20, flows out of the second cooler 20, passes through the through-hole 51 of the connecting member 50 and a first communication hole formed at one end in the longitudinal direction of the second member 12 of the first cooler 10, and flows into the space S1 between the first member 11 and the second member 12 of the first cooler 10. Then, part of the refrigerant that has flowed into the space S1 advances in the longitudinal direction within the space S1, and flows out of the first cooler 10 through a second communication hole formed at the other end in the longitudinal direction of the second member 12.

[0040] Furthermore, a portion of the refrigerant that has flowed into the space S1 passes through the first communication hole 11c formed at one end in the longitudinal direction of the first member 11 of the first cooler 10, flows out of the first cooler 10, passes through the through-hole 41 of the connecting member 40 and the first communication hole formed at one end in the longitudinal direction of the first member 31 of the third cooler 30, and flows into the space S3 between the first member 31 and the second member 32 of the third cooler 30. Then, the refrigerant that has flowed into the space S3 advances in the longitudinal direction within the space S3, and flows out of the third cooler 30 through the second communication hole formed at the other end in the longitudinal direction of the first member 31.

[0041] The refrigerant that has flowed out of the third cooler 30 passes through the through-hole 41 of the connecting member 40, the second communication hole 11d of the first member 11 of the first cooler 10, and the second communication hole of the second member 12, and then flows out of the first cooler 10. The refrigerant that has flowed out of the first cooler 10 passes through the through-hole 51 of the connecting member 50, and the second communication hole of the first member 21 of the second cooler 20 and the second communication hole of the second member 22, and then flows out of the second cooler 20. The refrigerant that has flowed out of the second cooler 20 then enters the second space 62 through the opening 62a formed in the support member 60, and flows out of the second joint 64.

[0042] In this way, while the refrigerant flows through the space S1 of the first cooler 10 and the space S2 of the second cooler 20, it cools the heat generating element 100 arranged between the first cooler 10 and the second cooler 20. Also, while the refrigerant flows through the space S1 of the first cooler 10 and the space S3 of the third cooler 30, it cools the heat generating element 100 arranged between the first cooler 10 and the third cooler 30.

[0043] Furthermore, at one end of the longitudinal direction, an O-ring 65 fitted into a groove 61b of the support member 60 seals the gap between the support member 60 and the second cooler 20, thereby preventing the refrigerant attempting to flow into the space S2 of the second cooler 20 through the opening 61a of the support member 60 from flowing out of the cooling device 1 through this gap. In addition, the O-ring 55 fitted into the groove 52 of the connecting member 50 seals the gap between the connecting member 50 and the first cooler 10, thereby preventing the refrigerant attempting to flow into the space S1 of the first cooler 10 through the through hole 51 of the connecting member 50 from flowing out of the cooling device 1 through this gap. In addition, the O-ring 45 fitted into the groove 42 of the connecting member 40 seals the gap between the connecting member 40 and the third cooler 30, thereby preventing the refrigerant attempting to flow into the space S3 of the third cooler 30 through the through hole 41 of the connecting member 40 from flowing out of the cooling device 1 through this gap.

[0044] Furthermore, at the other longitudinal end, an O-ring 45 fitted into the groove 42 of the connecting member 40 seals the gap between the connecting member 40 and the third cooler 30, thereby preventing the refrigerant attempting to flow into the space S1 of the first cooler 10 through the through hole 41 of the connecting member 40 from flowing out of the cooling device 1 through this gap. In addition, the O-ring 55 fitted into the groove 52 of the connecting member 50 seals the gap between the connecting member 50 and the first cooler 10, thereby preventing the refrigerant attempting to flow into the space S2 of the second cooler 20 through the through hole 51 of the connecting member 50 from flowing out of the cooling device 1 through this gap. In addition, the O-ring 66 fitted into the groove 62b of the support member 60 seals the gap between the support member 60 and the second cooler 20, thereby preventing the refrigerant attempting to flow into the second space 62 of the support member 60 through the opening 62a of the support member 60 from flowing out of the cooling device 1 through this gap.

[0045] As described above, the first cooler 10 has a case 13 in which a first member 11 that is concave and has a plurality of protrusions 11b protruding from a bottom surface 11a and a second member 12 that is concave and has a plurality of protrusions 12b protruding from a bottom surface 12a are joined together so that the tips of the protrusions 11b and the tips of the protrusions 12b face each other. In the first cooler 10 configured as described above, the convex portion 11b protrudes from the bottom surface 11a of the first member 11, and the convex portion 12b protrudes from the bottom surface 12a of the second member 12. Therefore, compared to a configuration in which a convex portion having a size equal to the sum of the vertical dimensions of the convex portion 11b and the convex portion 12b protrudes from one of the members (the first member 11 or the second member 12), the vertical dimensions of the convex portions 11b and 12b are smaller. Therefore, the first member 11 and the second member 12 can be formed by progressive press working using a press die configured to arrange multiple processes within a single press die and to perform each process continuously while the coil-shaped workpiece remains connected. As a result, the first member 11 and the second member 12 can be manufactured more inexpensively than, for example, hot forging. Furthermore, since the first member 11 and the second member 12 are concave and joined together to form a space S1 within the case 13, the surface area of ​​the multiple protrusions 11b and 12b within the case 13 is larger than the surface area of ​​the multiple protrusions 21b within the case 23 formed by the concave first member 21 and the flat second member 22. As a result, the cooling performance of the first cooler 10 can be improved more than the cooling performance of the second cooler 20. Furthermore, since the case 13 is joined so that the tip of the protrusion 11b faces the tip of the protrusion 12b, it is possible to prevent the case 13 from deforming in the up-down direction even when pressed by the pressing member 70.

[0046] The first member 11 and the second member 12 are joined by laser welding. The first member 11 and the second member 12 may be joined by brazing or soldering, but by joining by laser welding, the joining can be performed easily and with high accuracy. Furthermore, the longitudinal dimension of the case 13, which is an example of a refrigerant flow direction from an inlet through which the refrigerant flows into the case 13 to an outlet through which the refrigerant flows out of the case 13, is larger than the lateral dimension, which is an example of a direction perpendicular to the flow direction. Laser welding is performed on the entire periphery of the flange 11f and the flange 12f, which is an example of the entire outer periphery of the case 13, and on the overlapping portion between the protrusion 11k of the first member 11 and the protrusion of the second member 12 and the overlapping portion between the protrusion 11m of the first member 11 and the protrusion of the second member 12, which are examples of inner portions of the outer periphery. Therefore, even if the longitudinal dimension of the case 13 is large, deformation of the case 13 in the vertical direction can be suppressed. Furthermore, even if the pressure inside the case 13 increases, expansion of the case 13 can be suppressed. Furthermore, laser welding can be performed by moving the laser head 151 in a direction along the surface of the flange 12f without moving the laser head 151 in the vertical direction, which is easier than moving the laser head 151 in the vertical direction.

[0047] The overlapping portions of the projections 11k of the first member 11 and the projections of the second member 12, and the overlapping portions of the projections 11m of the first member 11 and the projections of the second member 12, which are laser welded, are preferably portions that divide the longitudinal size into equal intervals, thereby making it possible to make the case 13 less susceptible to deformation over the entire longitudinal area. Furthermore, in the first cooler 10, the first member 11 and the second member 12 have the same shape, so the number of types of parts can be reduced, making it easier to manage parts.

[0048] As described above, the cooling device 1 includes a first member (e.g., first member 11, first member 31) that is concave and has a plurality of protrusions (e.g., protrusions 11b, protrusions 31b) protruding from a bottom surface (e.g., bottom surface 11a, bottom surface 31a), and a second member (e.g., second member 12, second member 32) that covers openings of the first member, and includes a plurality of coolers (e.g., first cooler 10, third cooler 30) through which a refrigerant can circulate. The cooling device 1 also includes a connecting member (e.g., connecting member 40) that connects one of the plurality of coolers (e.g., first cooler 10) to another cooler (e.g., third cooler 30) so as to ensure a predetermined space between the one cooler and the other cooler, and the first member (e.g., first member 11) and the connecting member (e.g., connecting member 40) are joined by laser welding. This eliminates the need for space required for joining the first cooler 10 and the connecting member 40 compared to joining the first cooler 10, for example, outside the first cooler 10, thereby realizing space saving. Therefore, the size of the cooling device 1 can be reduced, and the cooling device 1 can be manufactured at low cost. Note that the predetermined space can be exemplified as a space in which a card-type power module, as an example of the heat generating body 100, can be placed between the first cooler 10 and the third cooler 30.

[0049] Here, it is preferable to irradiate the bottom surface (for example, bottom surface 11a) with the laser light L from the side where the convex portion (for example, convex portion 11b) is formed. This allows the laser head 151 to be moved in a direction along the bottom surface (for example, bottom surface 11a) without moving the laser head 151 in the vertical direction, which is easier than moving the laser head 151 in the vertical direction.

[0050] The plurality of protrusions (e.g., protrusion 11b) of the first member (e.g., first member 11) of the cooler (e.g., first cooler 10) are provided in a first portion (e.g., first region 11g) where the heat generating element 100 is disposed so as to be in contact with the first member, and in a second portion (e.g., peripheral region 11v) around the portion irradiated with laser light L, but are not provided between the first portion and the second portion. By providing the protrusions (e.g., protrusion 11b) in the first portion where the heat generating element 100 is disposed, the performance of cooling the heat generating element 100 can be improved. Furthermore, by providing the protrusions (e.g., protrusion 11b) in the second portion (e.g., peripheral region 11v), the rigidity around the first communication hole (e.g., first communication hole 11c) can be increased, and the sealing performance of an O-ring (e.g., O-ring 45) that seals between the connecting member (e.g., connecting member 40) and the cooler (e.g., third cooler 30) can be improved. Furthermore, since no heat exchanger is provided between the first and second portions, flow resistance of the refrigerant flowing inside the case (for example, case 13) can be reduced.

[0051] The cooling device 1 also includes a plurality of elongated coolers (e.g., first cooler 10, second cooler 20, third cooler 30), connecting members (e.g., connecting members 40, 50, and 80) provided at both ends of the coolers and having holes through which bolts are passed, a support member 60 that supports the plurality of coolers by fastening the plurality of coolers together via bolts 90, a heat generating element 100 that is disposed between the coolers between the connecting members provided at both ends, and a pressing member 70 as an example of a member that presses the coolers so that the surfaces of the coolers come into contact. This makes it possible to easily assemble the cooling device 1 made up of multiple parts, while more reliably cooling the heat generating element 100.

[0052] Here, the cooler (for example, the first cooler 10) and the connecting member (for example, the connecting member 40) are joined together before being fastened to the support member 60. This allows the coolers (for example, the first cooler 10, the second cooler 20, and the third cooler 30) to be stacked together with the coolers (for example, the first cooler 10) and the connecting member (for example, the connecting member 40) joined together, making assembly easier.

[0053] Furthermore, the first cooler 10, which is one of the multiple coolers and has the heating element 100 arranged on both sides, is joined so that the convex portion 11b and the convex portion 12b face each other to form a case 13 through which a refrigerant circulates, and the second cooler 20, which is another of the multiple coolers and has the heating element 100 arranged on one side, is joined to a first member 21 as an example of a third member that is concave and has multiple convex portions 21b protruding from the bottom surface 21a at the portion where the heating element 100 comes into contact, and a second member 22 as an example of a cover that covers the opening of the first member 21 to form a case 23 through which a refrigerant circulates. Furthermore, the third cooler 30, which is a cooler on one side of which the heat generating element 100 is arranged, comprises a first member 31 that is concave and has multiple protrusions 31b protruding from a bottom surface 31a where the heat generating element 100 comes into contact, and a second member 32 that covers the opening of the first member 31, joined together to form a case 33 through which a refrigerant flows. This allows the volume of the space S1 of the case 13 on both sides of which the heat generating element 100 is arranged to be larger than the volumes of the space S2 of the case 23 on one side of which the heat generating element 100 is arranged and the space S3 of the case 33, so that cooling performance does not decrease even in a configuration in which the heat generating element 100 is arranged on both sides. In other words, the required amount of refrigerant can be supplied to each of the multiple coolers so that the multiple heat generating elements 100 can be cooled uniformly in a balanced manner.

[0054] In the cooling device 1 described above, three heat generating elements 100 are arranged between the first cooler 10 and the second cooler 20, and between the first cooler 10 and the third cooler 30, respectively, but the number is not particularly limited to three. For example, there may be one, or two, four, or more. Depending on the number of heat generating elements 100 arranged between the coolers, it is preferable to change the longitudinal lengths of the first member (e.g., first member 11) and second member (e.g., second member 12) constituting the cooler (e.g., first cooler 10). Furthermore, although the heat generating elements 100 are arranged in two vertical stages, the number of stages is not limited to two. For example, one stage is acceptable, or three or more stages are also acceptable. When three or more stages are used, the number of first coolers 10 in the cooling device 1 may be increased. For example, when there are three stages, two first coolers 10 joined with a connecting member 40 may be stacked between the second cooler 20 and the third cooler 30.

[0055] Furthermore, in the cooling device 1 described above, the cooler (e.g., the first cooler 10) and the connecting member (e.g., the connecting member 40) are joined by laser welding, but they do not necessarily have to be joined. For example, if the first cooler 10 and the connecting member 40 are not joined by laser welding, it is preferable to seal the gap between the first cooler 10 and the connecting member 40 with an O-ring.

[0056] <Second embodiment> The cooling device 2 according to the second embodiment differs from the cooling device 1 according to the first embodiment in that the second member 12 of the first cooler 10 and a connecting member 250 corresponding to the connecting member 50 are joined by laser welding. The differences from the first embodiment will be described below. In the first and second embodiments, parts having the same shape and function are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0057] Fig. 7(a) is an example of a perspective view of the connecting member 250. Fig. 7(b) is a diagram for explaining the joining between the second member 12 of the first cooler 10 and the connecting member 250. Fig. 7(c) is a diagram for explaining the joining between the connecting member 250 and the first member 21 of the second cooler 20. A connecting member 250 according to the second embodiment differs from the connecting member 50 according to the first embodiment in the shape of a through hole 251 corresponding to the through hole 51. As shown in FIG. 7( a), the through hole 251 is composed of two holes of different sizes: a first through hole 251a having a smaller diameter and a second through hole 251b having a larger diameter. The shape of the first through hole 251a when viewed in the vertical direction is the same as the shape of the through hole 51 of the connecting member 50. The second through hole 251b is formed on the side where the protrusion 53 is provided relative to the first through hole 251a. The connecting member 250 has a step portion 254 provided around the first through hole 251a. Therefore, when viewed in the vertical direction from the protrusion 53 side, the step portion 254 can be seen at the back of the second through hole 251b.

[0058] (Manufacturing method of cooling device 2) The manufacturing method of the cooling device 2 differs from the manufacturing method of the cooling device 1 in that when the first member 21 of the second cooler 20 and the connecting member 250 are joined by laser welding, the connecting member 250 and the second member 12 of the first cooler 10 are also joined by laser welding. That is, first, using the method described with reference to Figures 5 and 6, the first member 11 of the first cooler 10 and the connecting member 40 are joined by laser welding, and the first member 11 and the second member 12 are joined by laser welding.

[0059] 7(b), the connecting member 250 is placed on the second member 12 of the first cooler 10 to which the connecting member 40 has been joined, and the second member 12 and the connecting member 250 are overlapped so that the first communication hole of the second member 12 and the first through-hole 251a of the connecting member 250 are aligned. Furthermore, the first member 21 of the second cooler 20 is placed on the connecting member 250, and the connecting member 250 and the first member 21 are overlapped so that the hole center of the second through-hole 251b of the connecting member 250 is aligned with the hole center of the first communication hole 21c of the first member 21. At this time, three heat generating elements 100 are arranged between the second member 12 of the first cooler 10 and the first member 21 of the second cooler 20. Then, laser light L is irradiated toward the step portion 254 of the connecting member 250, and the laser head 151 is moved along the shape of the first through hole 251a, thereby continuously irradiating the periphery of the first through hole 251a with laser light L, and joining the first cooler 10 and the connecting member 250. Furthermore, laser light L is irradiated toward the periphery of the first communication hole 21c in the first member 21, and the laser head 151 is moved along the shape of the first communication hole 21c, thereby continuously irradiating the periphery of the first communication hole 21c with laser light L, and joining the connecting member 250 and the first member 21.

[0060] Thereafter, the first member 21 and the second member 22 of the second cooler 20 are joined by laser welding in the same manner as described with reference to FIG. The rest of the manufacturing method is the same as that of the cooling device 1, so detailed description will be omitted.

[0061] As described above, the manufacturing method is a method for manufacturing a cooling device 2 including a first member (e.g., first member 11, first member 21) that is concave and has a plurality of convex portions (e.g., convex portion 11b, convex portion 21b) protruding from a bottom surface (e.g., bottom surface 11a, bottom surface 21a), a second member (e.g., second member 12, second member 22) that covers an opening of the first member, a plurality of coolers (e.g., first cooler 10, second cooler 20) that can circulate a refrigerant therethrough, and a plurality of connecting members (e.g., connecting member 40, connecting member 250) that connect one cooler (e.g., first cooler 10) to another cooler (e.g., second cooler 20) among the plurality of coolers so as to secure a predetermined space between the one cooler and the other cooler. Then, in the above manufacturing method, the first member (e.g., first member 11) of one cooler (e.g., first cooler 10) is joined to one connecting member (e.g., connecting member 40) of the plurality of connecting members by laser welding, and then the first member is joined to the second member (e.g., first member 12) of the one cooler by laser welding.

[0062] Then, the second member (e.g., first member 12) of one cooler (e.g., first cooler 10) is joined by laser welding to another connecting member (e.g., connecting member 250) among a plurality of connecting members arranged between the one cooler and another cooler (e.g., second cooler 20). Then, another connecting member (e.g., connecting member 250) is placed on one cooler (e.g., first cooler 10), and a first member (e.g., first member 21) of another cooler (e.g., second cooler 20) is placed on the other connecting member. In this state, the second member (e.g., first member 12) of the one cooler is joined to the other connecting member (e.g., connecting member 250) by laser welding, and then the other connecting member is joined to the first member of the other cooler by laser welding. In this way, by consecutively joining the one cooler (e.g., first cooler 10) to the other connecting member (e.g., connecting member 250) and joining the other connecting member (e.g., connecting member 250) to the first member (e.g., first member 21) of the other cooler (e.g., second cooler 20), manufacturing efficiency is improved.

[0063] Furthermore, by joining the first cooler 10 and the connecting member 250, it is possible to prevent the refrigerant from leaking to the outside from between the connecting member 250 and the first cooler 10, even without providing an O-ring 55. Note that the connecting member 250 may be placed on the second member 12 of the first cooler 10 to which the connecting member 40 has been joined, and the second member 12 and the connecting member 250 may be overlapped, and then the second member 12 and the connecting member 250 may be joined by laser welding before the connecting member 250 and the first member 21 are overlapped. Then, the connecting member 250 and the first member 21 may be overlapped, and the connecting member 250 and the first member 21 may be joined by laser welding.

[0064] Similarly, a step portion (not shown) corresponding to the step portion 254 of the connecting member 250 may be provided in the connecting member 40, and before joining the first member 11 of the first cooler 10 and the connecting member 40, laser light L may be irradiated onto this step portion to join the connecting member 40 and the first member 31 of the third cooler 30 to which the connecting member 80 is joined by laser welding. This makes it possible to prevent the refrigerant from leaking to the outside from between the connecting member 40 and the third cooler 30, even without providing the O-ring 45.

[0065] <Third embodiment> The cooling device 3 according to the third embodiment differs from the cooling device 1 according to the first embodiment in that it does not include the first cooler 10 and the connecting member 40, and instead cools three heat generating elements 100 using the second cooler 20 and the third cooler 30. The cooling device 3 also differs from the cooling device 1 in that it does not include the pressing member 70. The following describes the differences from the first embodiment. In the first and third embodiments, parts having the same shape and function are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0066] FIG. 8 is a diagram showing an example of the appearance of the cooling device 3 according to the third embodiment. The cooling device 3 includes a second cooler 20, a third cooler 30, a connecting member 50 disposed between the second cooler 20 and the third cooler 30, and a support member 60.

[0067] (Manufacturing method of cooling device 3) FIG. 9 is a diagram showing an example of a method for manufacturing the cooling device 3 according to the third embodiment. First, as shown in FIG. 9(a), the first member 21 of the second cooler 20 and the connecting member 50 are joined by laser welding in the same manner as described with reference to FIG. Thereafter, the first member 21 of the second cooling device 20 and the heat generating element 100 are joined together by irradiating them with laser light L, thereby forming a joined body as shown in FIG. 9(b).

[0068] FIG. 10 is a diagram schematically showing an example of a method for joining the first member 21 and the heating element 100 by irradiating them with laser light L. In FIG. Assuming that the heating element 100 is a card-type power module 110 (hereinafter, sometimes referred to as "module 110"), a method for joining the module 110 and the first member 21 by irradiating them with laser light L will be described in detail below. With solder 120 applied to copper exposed portions 111 where copper is exposed in the module 110, the first member 21 is placed on the module 110. When placing the first member 21 on the module 110, the copper exposed portions 111 and the first outer surface of the first member 21 are in contact with each other via the solder 120. Then, laser light L is irradiated onto the bottom surface 21a between the convex portions 21b of the first member 21. The laser light L is irradiated so as to melt only the solder 120 between the metals, i.e., the copper of both the first member 21 and the module 110, without melting them. In other words, the laser light L is irradiated to heat the first member 21 so that the temperature of the bottom surface 21a of the first member 21 is equal to or higher than the temperature at which the solder 120 melts and lower than the temperature at which the first member 21 melts.

[0069] The laser light L may be irradiated onto the bottom surface 21a of the first member 21 continuously by moving the laser head 151, or may be irradiated in a spot manner. Furthermore, when the first member 21 is made of aluminum, it is preferable to apply plating 25 to the surface of the first member 21 facing the module 110, that is, at least the first outer surface, second outer surface, and third outer surface on which the module 110 is disposed. This is because the solder 120 does not adhere to the aluminum base. Examples of plating include nickel plating, gold plating, and silver plating.

[0070] After joining the first member 21 and the heating element 100, as shown in Fig. 9(c), the first member 31 of the third cooling device 30 is placed on the heating element 100, and as shown in Fig. 9(d), the heating element 100 and the first member 31 of the third cooling device 30 are joined by irradiating them with laser light L. The method of joining the heating element 100 and the first member 31 by irradiating them with laser light L is the same as the method of joining the first member 21 and the heating element 100 described using Fig. 10, so a detailed description will be omitted. Furthermore, the first member 31 and the connecting member 50 are joined by laser welding using a method similar to that described using Fig. 5.

[0071] Thereafter, as shown in Fig. 9(e), the first member 21 of the second cooler 20 is covered with the second member 22, and as shown in Fig. 9(f), the two members are joined together in the same manner as described with reference to Fig. 6. Furthermore, as shown in Fig. 9(e), the first member 31 of the third cooler 30 is covered with the second member 32, and as shown in Fig. 9(e), the two members are joined together in the same manner as described with reference to Fig. 6. Then, the second cooler 20, the third cooler 30 and the connecting member 50 joined as described above are joined together by tightening the male thread of the bolt 90 passed through the through hole 54 of the connecting member 50 to the female threads 61c and 62c formed on the support member 60, thereby completing the cooling device 3.

[0072] As described above, the manufacturing method is a method for manufacturing a cooling device 3 in which the second cooler 20 and the third cooler 30, which are an example of two coolers capable of circulating a refrigerant therethrough, have a concave first member (e.g., first member 21, first member 31) and a second member (e.g., second member 22, second member 32) that covers the opening of the first member, and are arranged symmetrically with respect to the heat generating element 100, which is an example of an object to be cooled. In the manufacturing method, the first member 21 of the second cooler 20, which is an example of one of the second coolers 20 and the third cooler 30, is joined to the heat generating element 100 by irradiating it with laser light L, and then the first member 31 of the third cooler 30, which is an example of the other cooler, is joined to the heat generating element 100 by irradiating it with laser light L.

[0073] Furthermore, in the above manufacturing method, the first member 21 and the second member 22 of the second cooler 20 are joined by irradiating them with laser light, and the first member 31 and the second member 32 of the third cooler 30 are joined by irradiating them with laser light. In the above manufacturing method, the first member 21 and the heating element 100 and the first member 31 and the heating element 100 are joined by soldering through irradiation with laser light L. However, the method of joining the first member 21 and the heating element 100 and the method of joining the first member 31 and the heating element 100 are not limited to the method of joining by melting the solder 120 described with reference to Fig. 10. For example, the first member 21, the first member 31, and the copper of the copper exposed portion 111 of the module 110 may be joined by irradiating with laser light L to melt them without using the solder 120.

[0074] The second cooler 20 described above is a cooler that includes a concave first member 21 and a second member 22 that covers the opening of the first member 21, and cools the heat generating element 100 by circulating a refrigerant therethrough, and the first member 21 and the heat generating element 100 are joined together by irradiating them with laser light L. The first member 21 has a plurality of protrusions 21b protruding from a bottom surface 21a, and the laser light L is irradiated between the plurality of protrusions 21b. By irradiating the bottom surface 21a between the plurality of protrusions 21b with the laser light L in this way, heat is more easily conducted to the solder 120 than when the laser light L is irradiated only on the protrusions 21b, and the joining between the first member 21 and the heat generating element 100 is more stable. The second member 22 and the heating element 100 may be joined by welding through irradiation with laser light L.

[0075] The cooling device 3 described above is a cooling device having a concave first member (e.g., first member 21, first member 31) and a second member (e.g., second member 22, second member 32) that covers the opening of the first member, and in which second cooler 20 and third cooler 30, which are examples of two coolers capable of circulating a refrigerant therethrough, are arranged symmetrically with respect to heat generating element 100. The first member 21 of second cooler 20 and heat generating element 100 are joined by irradiation with laser light L, and the first member 31 of third cooler 30 and heat generating element 100 are joined by irradiation with laser light L.

[0076] In the cooling device 3 configured in this manner, it is possible to eliminate the need for grease between the second cooler 20, the third cooler 30, and the heat generating element 100. When grease deteriorates, gaps form between the cooler and the heat generating element, resulting in a decrease in performance. Therefore, the cooling device 3 improves performance and reliability compared to a configuration in which grease is provided between the cooler and the heat generating element. Furthermore, in the cooling device 3, the second cooler 20, the third cooler 30, and the heat generating element 100 are joined together, so there is no need for a member such as the pressing member 70 according to the first embodiment that would be required to improve contact between the second cooler 20, the third cooler 30, and the heat generating element 100. As a result, the configuration can be simplified and the size can be reduced.

[0077] Furthermore, by irradiating the solder 120 with laser light L to melt it, it is possible to suppress the temperature rise of the sealing resin of the heating element 100 and prevent cracking, compared to soldering by overall heating in a reflow furnace, for example. In other words, when heating the entire heating element 100 in a reflow furnace, if the heating element 100 is heated with resin parts such as sealing resin attached, the temperature of the resin also rises and there is a risk of damage during heating, but by irradiating the laser light L, it is possible to heat the heating element 100 instantaneously and locally, so damage to the heating element 100 can be suppressed.

[0078] Furthermore, plating 25 is applied to the surfaces of first members 21 and 31 that face heating element 100 and are joined to heating element 100. This prevents solder 120 from flowing out excessively, making it possible to stabilize soldering. [Explanation of symbols]

[0079] 1, 2, 3...cooling device, 10...first cooler, 11...first member, 12...second member, 13...case, 20...second cooler, 21...first member, 22...second member, 23...case, 30...third cooler, 31...first member, 32...second member, 33...case, 40, 50, 80, 250...connecting member, 60...support member, 70...pressing member, 90...bolt, 100...heating element, 150...laser device, 151...laser head

Claims

1. A cooler that has a concave first member and a second member that covers an opening of the first member, and that cools an object to be cooled by circulating a refrigerant therein, The first member or the second member and the object to be cooled are joined by irradiating them with laser light. cooler.

2. The first member has a plurality of protrusions protruding from a bottom surface, and the laser light is irradiated between the plurality of protrusions. The cooler of claim 1 .

3. A cooling device having a first member having a concave shape and a second member covering an opening of the first member, wherein two coolers capable of circulating a refrigerant therethrough are arranged symmetrically with respect to an object to be cooled, The first member of one of the two coolers and the object to be cooled are joined by irradiating a laser beam, and the first member of the other of the two coolers and the object to be cooled are joined by irradiating a laser beam. Cooling device.

4. The first member has a plurality of protrusions protruding from a bottom surface, and the laser light is irradiated between the plurality of protrusions. The cooling device according to claim 3 .

5. A method for manufacturing a cooling device having a first member having a concave shape and a second member covering an opening of the first member, wherein two coolers capable of circulating a refrigerant therethrough are arranged symmetrically with respect to an object to be cooled, the method comprising: After joining the first member of one of the two coolers to the object to be cooled by irradiating a laser beam, the first member of the other of the two coolers to the object to be cooled is joined by irradiating a laser beam. A method for manufacturing a cooling device.

6. Furthermore, the first member of the one cooler and the second member of the one cooler are joined by irradiating them with a laser beam, and the first member of the other cooler and the second member of the other cooler are joined by irradiating them with a laser beam. A method for manufacturing the cooling device according to claim 5.

7. The joining is performed by welding or soldering by irradiating the laser light. A method for manufacturing the cooling device according to claim 5.

8. When the joining is by soldering, the surface of the first member that faces the object to be cooled and that is joined to the object to be cooled is plated at the portion to be soldered. A method for manufacturing the cooling device according to claim 7.

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