Abstract: A busbar module includes: a plurality of busbars that are fixed to a plurality of battery cells of a battery module including the plurality of battery cells; and a plate-like flexible circuit body that includes a plurality of connection conductors corresponding to the plurality of busbars, in which the circuit body includes a trunk portion extending in a first direction in which the plurality of battery cells are arranged, and a plurality of branch portions branching from the trunk portion and connected to the busbars, the circuit body includes a first circuit layer and a second circuit layer, and the branch portion has a thin portion composed of any one of the first circuit layer and the second circuit layer, and connects the trunk portion and the busbar in a state where the thin portion is flexurally deformed.

Abstract: There is provided a laser welding method of joining a bus bar and an intermediate member by irradiating a laser beam on a surface of the intermediate member with the bus bar and the intermediate member being overlapped with each other. The laser welding method includes: a first welding step of forming a first welding line by moving the laser beam in a C shape from a welding start point to a welding intermediate point when viewed from a direction orthogonal to a surface of the intermediate member; and a second welding step of forming a second welding line continuous with the first welding line by moving the laser beam from the welding intermediate point to a welding end point located in a welding region formed inside the first welding line from the welding start point and the welding intermediate point.

Abstract: A busbar module includes: busbars that are fixed to battery cells of a battery module; a plate-like flexible circuit body that includes conductors corresponding to the busbars; and a case that accommodates the circuit body and the busbars, in which the circuit body includes a trunk portion and a branch portion connected to the busbar, the branch portion includes a base layer, a metal foil that is the connection conductor, and a coating layer that covers the base layer and the metal foil, the branch portion has a facing portion faces a first surface of the busbar, the metal foil is connected to a connection target at a portion that is more adjacent to a distal end than the facing portion is, and the first surface has a groove-shaped recess provided at a portion facing the metal foil.

Abstract: A busbar module includes: busbars fixed to battery cells of a battery module; a plate-like flexible circuit body; and a case that accommodates the circuit body and the busbars, in which the circuit body includes a trunk portion extending in a first direction in which the battery cells are arranged, and branch portions branching from the trunk portion and connected to the busbars, the branch portion includes a base portion, a fixed portion fixed to the busbar, and an intermediate portion extending from the base portion to the fixed portion is the first direction, a first end portion of the trunk portion has a first through-hole, and the case includes a first protrusion and locks the first end portion with the first protrusion to hold the circuit body in a state where the intermediate portion is flexurally deformed.

Abstract: A terminal fixing method, for fixing one or more terminals to a plurality of lands provided on a substrate by laser welding, includes: constructing the plurality of lands by one or more terminal installation lands on which the terminals are installed and one or more dummy lands each larger than each of the terminal installation lands; irradiating each of divided laser beams emitted from a laser oscillator toward a corresponding land of two or more lands in the plurality of lands by the laser welding; and constructing the two or more lands by two or more terminal installation lands in the terminal installation lands, or one or more terminal installation lands in the terminal installation lands and the one or more dummy lands.

Abstract: Provided is a welded structure in which a voltage detection terminal (21) plated with tin and a busbar (25) plated with nickel are welded, the busbar (25) having a thickness greater than that of the voltage detection terminal (21) and being formed with a protrusion (25c) which protrudes toward the voltage detection terminal (21) on a part of a surface facing the voltage detection terminal (21) at the time of being welded with the voltage detection terminal (21).

Abstract: Provided is a welded structure in which a voltage detection terminal (21) plated with tin and a busbar (25) plated with nickel are welded, the busbar (25) having a thickness greater than that of the voltage detection terminal (21) and being formed with a protrusion (25c) which protrudes toward the voltage detection terminal (21) on a part of a surface facing the voltage detection terminal (21) at the time of being welded with the voltage detection terminal (21).