A jig for laser welding is usable when performing laser welding by applying laser light to a welding-target portion, and includes: an accommodation portion that is able to receive the welding-target portion along a first direction; and an inclined surface extending in a peripheral direction so as to surround the welding-target portion around an axis in the first direction, wherein the inclined surface is able to reflect, in a second direction intersecting the first direction, the laser light emitted toward the jig for laser welding, so as to orient the laser light toward the welding-target portion.

A sheet processing method including irradiating a transparent conductive layer covered with a transparent sheet with a pulsed laser beam such that the pulsed laser beam is applied to a portion of the transparent conductive layer through the transparent sheet, and that the portion irradiated has an insulating property. The pulsed laser beam has a top-hat intensity distribution and has a transmittance through the transparent sheet being higher than a transmittance through the transparent conductive layer.

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.

Disclosed herein are a battery casing, a battery pack, and a method of manufacturing battery packs. The battery casing is configured to house a plurality of battery cells, and includes a first casing, and a second casing coupled to the first casing at a bonding area by laser bonding. The first casing has a convex semicircular cross-sectional shape in the bonding area.