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JP-7857379-B2 - Welding methods, metal laminates, electrical components, and electrical products

JP7857379B2JP 7857379 B2JP7857379 B2JP 7857379B2JP-7857379-B2

Inventors

  • 松本 暢康
  • 松永 啓伍
  • 村山 太郎
  • 金子 昌充
  • 茅原 崇
  • 繁松 孝
  • 酒井 俊明
  • 安岡 知道

Assignees

  • 古河電気工業株式会社

Dates

Publication Date
20260512
Application Date
20241128

Claims (20)

  1. A welding method for welding a metal member and a plurality of metal foils, wherein the metal foil on the opposite side of a plurality of metal foils that are overlapped in a first direction on a metal member is irradiated with laser light including a first laser beam and a second laser beam with a lower energy density than the first laser beam, A step of irradiating the plurality of metal foils and the metal member with the laser light to form a molten pool, The process of solidifying the molten pool to form a welded joint, It has, In the process of forming the molten pool, The spot of the laser beam is swept over the surface of the metal foil, The absorption energy absorbed by the plurality of metal foils and the metal members from the laser light is such that the absorption energy per unit length in the sweeping direction is 0.14 [J/mm] or less. A welding method wherein the metal member and the plurality of metal foils are made of an aluminum-based metal material .
  2. The welding method according to claim 1, wherein the absorbed energy is greater than or equal to the amount that can melt the metal foil in contact with the metal member among the plurality of metal foils.
  3. The welding method according to claim 2, wherein the absorbed energy is 0.05 [J/mm] or more when the thickness of the multiple metal foils stacked in the first direction is 400 [μm] or more.
  4. The welding method according to any one of claims 1 to 3, wherein the sweep speed of the spot is 300 mm/s or more and 10,000 mm/s or less.
  5. The welding method according to any one of claims 1 to 4, wherein the wavelength of the first laser beam is 800 nm or more and 1200 nm or less, and the wavelength of the second laser beam is 550 nm or less.
  6. The welding method according to claim 5, wherein the wavelength of the second laser beam is 400 nm or more and 500 nm or less.
  7. The welding method according to any one of claims 1 to 6, wherein the laser beam is formed by a beam shaper.
  8. The welding method according to claim 7, wherein the beam shaper is a DOE (Domain-of-Effect).
  9. The welding method according to any one of claims 1 to 8, wherein in the step of forming the molten pool, the sweeping trajectory of the spot on the metal foil is set such that at least a portion of the sweeping trajectory overlaps with a portion of the spot that has already been melted by the irradiation of the laser light.
  10. The welding method according to claim 9, wherein the sweeping trajectory includes an endless portion.
  11. The welding method according to claim 10, wherein the sweeping trajectory has an overall endless shape.
  12. The welding method according to claim 10 or 11, wherein, in the step of forming the molten pool, after the endless portion is formed in the sweeping trajectory, the spot of the laser beam is swept in the region inside the endless portion on the surface.
  13. The welding method according to any one of claims 9 to 12, wherein the sweeping trajectory includes a plurality of adjacent sections.
  14. The welding method according to any one of claims 9 to 13, wherein the sweeping trajectory includes a linear segment connecting two points on the sweeping trajectory.
  15. The welding method according to any one of claims 9 to 14, wherein the sweeping trajectory includes a spiral section.
  16. The welding method according to any one of claims 9 to 15, wherein the sweeping trajectory includes a wobbling section in which the spot orbits around a reference point while the reference point moves in a second direction.
  17. The welding method according to claim 16, wherein the sweeping trajectory includes a section extending linearly in the second direction and a wobbling section that is swept after the linearly extended section and partially overlaps with the linearly extended section.
  18. The welding method according to any one of claims 9 to 17, wherein the sweeping trajectory includes the portion where the sweeping trajectories intersect.
  19. The welding method according to any one of claims 1 to 18, wherein the width of the formed welded portion is 30 [μm] or more and 300 [μm] or less.
  20. A welding method for welding a metal member and a plurality of metal foils, wherein the metal foil on the opposite side of a plurality of metal foils that are overlapped in a first direction on a metal member is irradiated with laser light including a first laser beam and a second laser beam with a lower energy density than the first laser beam, A step of irradiating the plurality of metal foils and the metal member with the laser light to form a molten pool, The process of solidifying the molten pool to form a welded joint, It has, In the process of forming the molten pool, The outer diameter of the weld formed when a point-shaped spot of the laser beam is irradiated onto the metal foil on the side of the plurality of metal foils opposite to the metal member, or the width of the weld formed when the spot of the laser beam is swept over the metal foil on the side of the plurality of metal foils opposite to the metal member, is 30 [μm] or more and 300 [μm] or less. A welding method wherein the metal member and the plurality of metal foils are made of an aluminum-based metal material .

Description

This invention relates to welding methods, metal laminates, electrical components, and electrical products. Conventionally, batteries in which multiple tabs and terminals are joined by laser welding are known (for example, Patent Document 1). Japanese Patent Publication No. 2020-4643 Figure 1 is an illustrative schematic diagram of a laser welding apparatus according to the first embodiment.Figure 2 is an exemplary and schematic cross-sectional view of a metal laminate used as a processing target for the laser welding apparatus of the embodiment.Figure 3 is an exemplary and schematic cross-sectional view of a battery including a metal laminate as the workpiece of the laser welding apparatus of the embodiment.Figure 4 is an illustrative schematic diagram showing a laser beam (spot) formed on the surface of a workpiece by the laser welding apparatus of the first embodiment.Figure 5 is a graph showing the light absorption rate of a metal as a function of the wavelength of the irradiated laser light.Figure 6 is an illustrative flowchart showing the procedure of the welding method according to the embodiment.Figure 7 is an illustrative and schematic cross-sectional view illustrating the mechanism by which a fracture occurs at the boundary between the welded area and the metal foil in a metal laminate.Figure 8 is an illustrative cross-sectional view showing a case where cutting occurs in the welded area due to the welding method described in the reference example.Figure 9 is an illustrative cross-sectional view showing a good joint condition obtained by the welding method of the embodiment.Figure 10 is an illustrative cross-sectional view showing a case where a portion of the metal foil is fractured due to the welding method described in the reference example.Figure 11 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 12 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 13 is a cross-sectional view taken along line XIII-XIII in Figure 12.Figure 14 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 15 is a cross-sectional view taken along the line XV-XV in Figure 14.Figure 16 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 17 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 18 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 19 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 20 is a schematic diagram showing an example of the trajectory of a laser beam spot on the surface of a metal foil by the welding method of the embodiment.Figure 21 is an illustrative schematic diagram of a laser welding apparatus according to a second embodiment.Figure 22 is an explanatory diagram illustrating the concept of the principle of the diffractive optical element included in the laser welding apparatus of the second embodiment.Figure 23 is a schematic diagram showing an example of a laser beam (spot) formed on the surface of a workpiece by the laser welding apparatus of the second embodiment.Figure 24 is an illustrative schematic diagram of a laser welding apparatus according to the third embodiment. The following describes exemplary embodiments of the present invention. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by them, are examples only. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derived effects) that can be obtained by the configuration. The embodiments shown below have similar configurations. Therefore, the configurations of each embodiment yield similar functions and effects based on those similar configurations. Furthermore, similar components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, in each figure, the X direction is represented by arrow X, the Y direction by arrow Y, and the Z direction by arrow Z. The X, Y, and Z directions intersect and are also orthogonal to each other. The Z direction is the normal direction to the surface Wa (machined surface, welded surface) of the workpiece W, the thickness direction of the metal foil 12, and the lamination directi