Abstract: Embodiments relate to laser welding methods, monitoring methods, and monitoring systems for a secondary battery. A laser welding method for a secondary battery includes performing laser welding on a positive electrode base having a thin-film shape in which a plurality of positive electrode base tabs are formed at a side, a negative electrode base having a thin-film shape in which a plurality of negative electrode base tabs are formed at a side, and a thin-film multi-tab to be joined to each of the positive electrode base and the negative electrode base, a welded portion in which the multi-tab is welded with the positive electrode base and the negative electrode base being melting-joined by using a laser such that a plurality of welding spots is formed on the welded portion.

Abstract: A gravure printing plate includes a convex portion and two or more polygonal cells partitioned by the convex portion, and including at least one protruding portion disposed at an edge of each of the at least two polygonal cells and extending toward a central portion of the corresponding cell therefrom.

Abstract: A shock absorber for a bump stopper includes a plurality of corrugated projection 12 and corrugated groove 13 which is formed in equal interval around outside of an elastic synthetic resin body 11 having a thickness of 1.5 mm˜5 mm; a locking member 14 formed to mount the shock absorber on the top of the body 11; a through hole 15 formed inside the locking member 14; a leading hole 17 formed to lead cylinder lot L in the central part of a shock absorbing plate 16 forming the lower side of the body 11; a wedge hanging projection 14a formed in the locking member 14 of the body; and an O-ring shock absorbing member T to ease the impact applied to a bent part R in contraction of a body 11, in a “<” or “>”-type bent part R.