Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
  • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/21—Bonding by welding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/21—Bonding by welding
  • B23K26/24—Seam welding
  • B23K26/28—Seam welding of curved planar seams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/32—Bonding taking account of the properties of the material involved
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/32—Bonding taking account of the properties of the material involved
  • B23K26/322—Bonding taking account of the properties of the material involved involving coated metal parts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/32—Bonding taking account of the properties of the material involved
  • B23K26/323—Bonding taking account of the properties of the material involved involving parts made of dissimilar metallic material

Definitions

• This disclosure relates to a joint in which two metal members are joined together, and a method for manufacturing the joint.
• Patent Document 1 discloses a welding method for joining two metal plates together by laser beam welding.
• a portion of one metal plate and a portion of the other metal plate are stacked together, and the two metal plates are joined by irradiating the stacked portions with a laser beam.
• the present disclosure aims to reduce the size of a joint in which two metal members are joined together by welding.
• each element may be given a reference symbol in parentheses.
• the reference symbol merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present disclosure is not limited in any way by the description of the reference symbol.
• FIG. 1 is a cross-sectional view showing a schematic configuration of a joint body in a first embodiment, which is made up of a first member and a second member that are welded together, and also showing a state in which the first member and the second member are welded together.
• FIG. 2 is a view taken in the direction of the arrow II in FIG. 1 .
• 2 is a flowchart showing a manufacturing process of the bonded body of FIG. 1 in the first embodiment.
• FIG. 2 is a cross-sectional view showing a schematic representation of a portion corresponding to portion IV in FIG. 1 in a comparative example to be compared with the first embodiment.
• 4 is a cross-sectional view showing a part corresponding to part IV in FIG.
• FIG. 8 is a view taken in the direction of an arrow IX in FIG. 7 .
• 10 is a perspective view showing the first member and the second member in the fifth embodiment in the same orientation as in FIG. 8, and corresponds to FIG. 8.
• FIG. 10 is a perspective view showing a second member in the fifth embodiment in the same orientation as in FIG. 9 and corresponds to FIG. 9 .
• FIG. 10 is a perspective view showing a second member in the fifth embodiment in the same orientation as in FIG. 9 and corresponds to FIG. 9 .
• first direction D1, second direction D2, and third direction D3 shown in Figures 1 and 2 may be used to represent the orientation of the joint 8.
• the first direction D1, second direction D2, and third direction D3 intersect with each other, or more precisely, are perpendicular to each other.
• the first direction D1 coincides with the vertical direction when an electrical device having the joint 8 is used, so one side of the first direction D1 is above the vertical direction, and the other side opposite to the one side of the first direction D1 is below the vertical direction.
• the first member 10 is a plate material formed in a flat plate shape with the thickness direction being the first direction D1, and extends in the second direction D2 and the third direction D3.
• This first member 10 is made of a highly conductive material, such as a copper alloy or an aluminum alloy, for electrical conductivity.
• the first member 10 has a welding surface 10a, which is a surface facing one side of the first direction D1.
• This welding surface 10a is formed in a planar shape with the first direction D1 as the normal direction, and therefore extends along the second direction D2 and the third direction D3.
• the first member 10 of this embodiment constitutes a part of an insulating substrate 12 having a laminated structure.
• this insulating substrate 12 has an insulating layer 121 and a back surface conductor layer 122 laminated on the first member 10.
• the insulating layer 121 of the insulating substrate 12 is made of an insulator such as resin or ceramics.
• the insulating layer 121 is laminated on the other side of the first member 10 in the first direction D1 and is joined to the first member 10.
• the back conductor layer 122 is made of the same metal material as the first member 10, and has high electrical conductivity like the first member 10.
• the back conductor layer 122 is laminated on the other side of the insulating layer 121 in the first direction D1 and is joined to the insulating layer 121.
• the insulating substrate 12 is formed in a flat plate shape with the first direction D1 as the thickness direction, and extends in the second direction D2 and the third direction D3.
• the insulating substrate 12 is housed in a case 30 of the electrical device.
• the case 30 of the electrical device is made of resin, for example, and has a case bottom 301 and a case side wall 302.
• the case bottom 301 is provided on the other side of the case 30 in the first direction D1 and extends in the second direction D2 and the third direction D3, forming the bottom of the internal space 30a of the case 30.
• the case side wall 302 extends from the peripheral portion of the case bottom 301 to one side in the first direction D1 and is formed to surround the internal space 30a of the case 30.
• the insulating substrate 12 described above is disposed in the internal space 30a of the case 30 on one side of the case bottom 301 in the first direction D1, and is installed on the case bottom 301.
• the second member 20 is a plate material arranged on one side of the first member 10 in the first direction D1, and is formed so as to be bent at multiple locations.
• the thickness of the plate material constituting the second member 20 is, for example, about 1 mm.
• the second member 20 is joined to the first member 10 by welding.
• the second member 20 is also made of a highly conductive material, such as a copper alloy or an aluminum alloy.
• the second member 20 has an inclined portion 22 and a connecting portion 24.
• the inclined portion 22 has an inclined tip portion 221, which is a tip portion provided on one side of the second direction D2, and an inclined base end portion 222, which is a base end portion provided on the other side of the second direction D2.
• the second member 20 is joined by welding to the welding surface 10a of the first member 10 at the inclined tip portion 221. More specifically, the welding is a fillet weld.
• the inclined tip portion 221 of the second member 20 is joined to the welding surface 10a of the first member 10 by fillet welding.
• FIG. 1 the portions of the inclined tip 221 and the welded surface 10a that are included in the welded area WD where the first member 10 and the second member 20 are joined by welding are shown in dashed lines, but the shape shown by the dashed lines is the shape before welding. This is because the dashed parts included in the welded area WD actually resolidify after being melted by welding, and no longer retain their shape before welding.
• the inclined portion 22 extends along the third direction D3, but is inclined with respect to the second direction D2. Specifically, the inclined portion 22 is inclined with respect to the welding surface 10a so that the further away from the inclined tip portion 221 is to the other side in the second direction D2, the further away from the welding surface 10a is to one side in the first direction D1.
• the inclined portion 22 is inclined so greatly with respect to the welding surface 10a that it cannot be said to be aligned with the welding surface 10a.
• the inclined portion 22 is inclined with respect to the welding surface 10a more than if it were aligned with the welding surface 10a. Therefore, the inclined tip portion 221 is joined to the welding surface 10a as described above, but the inclined base end portion 222 is separated from the welding surface 10a to one side in the first direction D1.
• the inclination angle ⁇ of the inclined portion 22 with respect to the welding surface 10a is about 3 to 45°.
• the connecting portion 24 of the second member 20 is connected to the inclined base end portion 222 of the inclined portion 22.
• the connecting portion 24 is connected to the inclined portion 22 on the side opposite to the inclined tip end portion 221 of the inclined portion 22.
• the connecting portion 24 has a vertical extension portion 241 and a parallel portion 242.
• the vertical extension portion 241 extends from the inclined base end portion 222 to one side in the first direction D1.
• the parallel portion 242 is connected to an end portion of the vertical extension portion 241 that is provided on the opposite side to the inclined base end portion 222, and extends from the end portion of the vertical extension portion 241 to the other side in the second direction D2. Therefore, the parallel portion 242 is connected to the inclined base end portion 222 via the vertical extension portion 241.
• the parallel portion 242 is formed so as to extend along the second direction D2, in other words, in a direction along the welding surface 10a of the first member 10.
• the inclined portion 22 and the vertical extension portion 241 of the second member 20 are housed in the internal space 30a of the case 30.
• the juxtaposed portion 242 of the second member 20 penetrates the other side wall portion 302a of the case side wall portion 302 that is provided on the other side of the second direction D2 relative to the inclined portion 22, and protrudes from the internal space 30a of the case 30 to the outside of the case 30.
• the juxtaposed portion 242 is disposed so as to straddle the internal space 30a of the case 30 and the outside of the case 30.
• the juxtaposed portion 242 has a supported portion 242a located in a through hole formed in the other side wall portion 302a.
• the supported portion 242a is restrained by the other side wall portion 302a so that it cannot be displaced in the first direction D1 relative to the case 30.
• step S02 the pre-welding assembly including the insulating substrate 12, the second member 20, and the case 30 is mounted on a welding table (not shown).
• a welding table not shown
• the pre-welding assembly is fixed on the welding table so that the first direction D1 is vertical and one side of the first direction D1 is above the vertical direction.
• step S03 the light shielding plate 61 included in the welding jig 60 is placed on one side of the inclined tip 221 of the second member 20 in the second direction D2 with a certain distance in that direction.
• This light shielding plate 61 serves to prevent light emitted during welding from scattering to the outside.
• the light shielding plate 61 is placed so that the lower end 611 of the light shielding plate 61 on the other side in the first direction D1 abuts against the welding surface 10a of the first member 10 and spreads in the first direction D1 and the third direction D3.
• step S03 the pressing body 62 included in the welding jig 60 is brought into contact with a portion of the juxtaposed portion 242 of the second member 20 that is closer to one side in the second direction D2 from one side in the first direction D1. Then, the second member 20 is pressed by the pressing body 62 toward the other side in the first direction D1, as indicated by the arrow Ap.
• step S03 in FIG. 3 proceed to step S04.
• step S04 while the inclined portion 22 is maintained in the inclined position in step S03, the inclined tip portion 221 of the second member 20 is joined to the welding surface 10a of the first member 10 by welding with an energy beam BM.
• the energy beam BM used in this step S04 is a visible light laser beam.
• the visible light laser beam is a laser beam with a wavelength of about 350 nm to 700 nm.
• the inclined tip 221 of the second member 20 extends in the third direction D3, and therefore in step S04, the laser welding proceeds while the irradiation position of the inclined tip 221 and the welding surface 10a where the energy beam BM is irradiated is moved in the third direction D3.
• the laser welding in step S04 includes a fillet weld that spans the inclined tip 221 and the welding surface 10a.
• the energy beam BM is wobbled and scanned so that the energy beam BM is irradiated across both the welding surface 10a and the inclined tip 221.
• FIG. 2 shows a schematic diagram of the trajectory Tk of the irradiation position of the energy beam BM during the wobbling scan.
• step S04 When the laser welding in step S04 is completed, the light shielding plate 61 and the pressing body 62 of the welding jig 60 are separated from the first and second members 10 and 20, and the completed welded product is removed from the welding table. In this manner, the joint 8 of this embodiment is manufactured.
• the light shielding plate 61 and the pressing body 62 shown in FIG. 1 are tools used in the manufacturing process to weld the first member 10 and the second member 20 together, and are not included in the electrical device as a product having the joining body 8.
• the second member 20 does not have the inclined portion 22 of this embodiment, but instead has a flat portion 92 that follows the welding surface 10a.
• the first member 10 and the second member 20 are welded with the flat portion 92, which is part of the second member 20, pressed against the welding surface 10a of the first member 10.
• the pressing force with which the second member 20 is pressed against the welding surface 10a by the welding jig 60 during welding can be made smaller than in the comparative example, making it easier to hold the workpiece during welding, i.e., to hold the first and second members 10 and 20.
• the pressing body 62 of the welding jig 60 can be made smaller than the jig corresponding to the pressing body 62 in the comparative example. This allows more room for the layout of the shielding mechanism, including the light shielding plate 61 and the like, which is placed adjacent to the pressing body 62 during welding, and it is possible to increase the design freedom of the shielding mechanism.
• the occupation area As that the inclined portion 22 of this embodiment occupies on the welding surface 10a can be easily reduced in the second direction D2 compared to the occupation area Ac that the flat portion 92 of the comparative example occupies on the welding surface 10a.
• the welding surface 10a in this embodiment is formed in a flat shape, but even if the welding surface 10a is curved when viewed in the direction along the third direction D3, according to this embodiment, it is possible to hold a workpiece during welding and to weld the second member 20 to the welding surface 10a. This is because, unlike the comparative example, in this embodiment, there is no need to press a part of the second member 20 against the welding surface 10a of the first member 10 with a surface.
• the first member 10 and the second member 20 are each made of a copper alloy or an aluminum alloy. Therefore, since the copper alloy and the aluminum alloy have high electrical conductivity, the first member 10 and the second member 20 can be used as part of an electrical circuit.
• the inclined portion 22 in the second member 20 has an inclined base end portion 222 on the side opposite the inclined tip end portion 221.
• the second member 20 has a parallel portion 242 formed along the second direction D2 and connected to the inclined base end portion 222.
• the first member 10 constitutes a part of the insulating substrate 12, and the insulating substrate 12 has, in addition to the first member 10, an insulating layer 121 that is laminated and joined to the other side of the first member 10 in the first direction D1.
• the amount of heat imparted by the energy beam BM to the first and second members 10 and 20 during welding can be made smaller than in the comparative example.
• the insulating layer 121 is made of resin, it is possible to prevent the insulating layer 121 from melting due to heat during welding.
• the second member 20 is provided with an inclined portion 22, and the inclined tip portion 221 of the inclined portion 22 is welded to the welding surface 10a. Therefore, it is easier to ensure a sufficient joint area by welding compared to, for example, a T-joint in which the second member 20 does not have an inclined portion 22 and the vertical extension portion 241 is welded in a position where it is thrust into the welding surface 10a.
• the inclined portion 22 is welded to the welding surface 10a of the first member 10 in an inclined position relative to the welding surface 10a.
• the flat portion 92 is welded in a position along the welding surface 10a, so the angle that the flat portion 92 forms with the welding surface 10a, which corresponds to the inclination angle ⁇ in FIG. 1, is approximately 0°. Therefore, in this embodiment, compared to the comparative example of FIG. 4, stress concentration that occurs at the welded portion WD when an external force is applied to the second member 20, for example, is suppressed. In other words, compared to the comparative example of FIG. 4, the stress intensity factor of the joint 8 can be reduced in this embodiment.
• the energy beam BM is wobbled and scanned so that the energy beam BM is irradiated across both the welding surface 10a and the inclined tip 221.
• a welded area WD that is evenly melted and solidified is formed across both the welding surface 10a and the inclined tip 221, making it possible to perform stable welding.
• the first member 10 and the second member 20 are each made of a copper alloy or an aluminum alloy.
• the energy beam BM used in step S04 in FIG. 3 is a visible light laser beam.
• the absorption rate of the first and second members 10, 20 at the irradiated points of the energy beam BM is higher than when using, for example, a near-infrared laser beam, and the welding surface 10a and the inclined tip portion 221 can be stably melted.
• This is particularly effective in this embodiment because, as shown in FIG. 1, there is a step due to the plate thickness of the inclined portion 22 between the surface on one side of the inclined portion 22 in the first direction D1 and the welding surface 10a.
• the energy beam BM used in step S04 in FIG. 3 is composed of multiple beams BMa, BMb with different focal diameters Da, Db, as shown in FIG. 5.
• the multiple beams BMa, BMb are coaxial laser beams, specifically a first beam BMa and a second beam BMb.
• the first beam BMa's focal diameter, or first beam focal diameter Da is smaller than the second beam BMb's focal diameter, or second beam focal diameter Db.
• this embodiment is similar to the first embodiment. Furthermore, in this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment described above.
• the second member 20 is an insert part and the case 30 is insert molded. In this way, the second member 20 is fixed to the case 30. Since the case 30 is made of resin, it is a low-melting point member that has a lower melting point than the first member 10 and the second member 20.
• the inclined portion 22, the parallel portion 242, and the vertical extension portion 241 of the second member 20 are housed in the internal space 30a of the case 30.
• the external lead-out portion 243 of the second member 20 penetrates the other side wall portion 302a of the case 30 and protrudes from the internal space 30a of the case 30 to the outside of the case 30.
• the external lead-out portion 243 is disposed so as to straddle the internal space 30a of the case 30 and the outside of the case 30.
• the end of the external lead-out portion 243 that is located outside the case 30 is screwed to a conductive member 31 such as a bus bar and electrically connected.
• an insulating substrate 12 is not provided, and instead, the first member 10 is stacked on one side in the first direction D1 with respect to a flat substrate 13 that extends in the second direction D2 and the third direction D3.
• This substrate 13 and the first member 10 are housed in the internal space 30a of the case 30.
• the substrate 13 is disposed on one side in the first direction D1 with respect to the case bottom 301, and is installed on the case bottom 301.
• the second member 20 is in contact with the case 30, which is a low-melting-point member, around the welded portion WD. Therefore, in this embodiment, it is possible to effectively utilize the advantage that the amount of heat imparted by the energy beam BM to the first and second members 10 and 20 during welding can be made smaller than in the comparative example of FIG. 4.
• this embodiment is similar to the first embodiment. Furthermore, in this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment described above.
• this embodiment is a modified version of the first embodiment, but it is also possible to combine this embodiment with the second embodiment described above.
• the connecting portion 24 of the second member 20 has a flexible portion 244 in which a plurality of holes 244a are formed.
• Figure 7 is a cross-sectional view that shows a schematic cross section taken along line VII-VII in Figure 8.
• the hole 244a of the flexible portion 244 penetrates the second member 20 in the thickness direction.
• the flexible portion 244 may have only one hole 244a, in this embodiment, three holes 244a are provided and aligned in the third direction D3.
• the flexible portion 244 is disposed in a portion of the second member 20 where the bent vertical extension portion 241 and the juxtaposed portion 242 are connected. By forming multiple holes 244a in the flexible portion 244 in this manner, the flexible portion 244 is made easier to bend locally within the second member 20.
• this embodiment is similar to the first embodiment. Furthermore, in this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment described above.
• this embodiment is a modification based on the first embodiment, but it is also possible to combine this embodiment with the second or third embodiment described above.
• no hole 244a (see Figure 8) is formed in the flexible portion 244 of the second member 20, and instead, a notch 244b is formed.
• a pair of notches 244b are provided, one at each end of the flexible portion 244 in the third direction D3.
• the notches 244b are formed so as to cut into the third direction D3.
• the flexible portion 244 bends, thereby making it possible to mitigate the effect of the external force on the welded portion WD.
• one or both of the first member 10 and the second member 20 may be plated.
• the plating include nickel plating and chrome plating.
• first and second members 10, 20 are plated in this way, electrical connection processes such as soldering and wire bonding can be easily performed on the plated members of the first and second members 10, 20.
• the first member 10 and the second member 20 are each made of a copper alloy or an aluminum alloy, but this is just one example.
• the first member 10 and the second member 20 may each be made of a metal such as copper or aluminum, or an alloy other than a copper alloy or an aluminum alloy.
• the energy beam BM used in step S04 in FIG. 3 is a visible laser beam, but this is just one example.
• the energy beam BM may be a beam other than a visible laser beam, such as an electron beam.
• the second member 20 is in contact with the case 30 around the welded area WD, but this is just one example.
• the first member 10 is in contact with the case 30 around the welded area WD, or that the first member 10 and the second member 20 are each in contact with the case 30 around the welded area WD.
• the first member constitutes a part of an insulating substrate (12);
• the bonded body according to any one of the first to sixth aspects, wherein the insulating substrate has, in addition to the first member, an insulating layer (121) laminated and bonded to the other side of the first member opposite the one side in the first direction.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Laser Beam Processing (AREA)

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Citations (4)

• 2024
  • 2024-11-25 JP JP2025570556A patent/JPWO2025154394A1/ja active Pending
  • 2024-11-25 WO PCT/JP2024/041627 patent/WO2025154394A1/ja active Pending

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