Abstract: A laser welding method includes: preparing a first member and a second member, the first member and the second member having a first end portion and a second end portion in a first direction, respectively; arranging the second member adjacent to the first member in a second direction intersecting with the first direction such that a distance between the first end portion and the second end portion is 0 or more along the first direction; forming a first molten pool protruding from the first end portion toward at least the second end portion, by emitting laser light to the first end portion; forming a bridging molten pool by emitting laser light to at least the first end portion after the forming of the first molten pool, the bridging molten pool bridging over the first end portion and the second portion; and solidifying the bridging molten pool.

Abstract: A welding method includes performing welding by emitting laser light moving in a sweeping direction relatively to a processing object onto a surface of the processing object to melt a portion of the processing object onto which the laser light is emitted, wherein the laser light includes: first laser light having a wavelength equal to or larger than 800 nm and equal to or smaller than 1200 nm; and second laser light having a wavelength equal to or smaller than 550 nm.

Abstract: A welding method includes: irradiating a plurality of metal foils stacked on a first surface of a metal member in a first direction with laser light to weld the metal member and the plurality of metal foils to each other, the laser light including first laser light having a wavelength of 800 [nm] or more and 1200 [nm] or less and second laser light having a wavelength of 550 [nm] or less, a second surface of a metal foil farthest from the metal member in the first direction among the plurality of metal foils, on a side opposite to the metal member, being irradiated with the laser light.

Abstract: A busbar includes: a plurality of members that are platy; and a welding area in which two of the members are welded, the welding area being linear and extending in a first direction, the welding area being provided approximately between both ends of at least one of the two members in the first direction.

Abstract: A metal foil welding method includes: a first step of stacking a plurality of metal foils; and a second step of welding the plurality of stacked metal foils by irradiating the plurality of metal foils with laser light having a wavelength of 400 nm or more and 500 nm or less.