Patent ID: 11897054
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Machine tools (Mechanical engineering)
Classification: CPC B  H  Y | IPC B  H

Claim 0:
1. A laser welding method for a secondary battery, the method comprising:
performing laser welding on a positive electrode base having a thin-film shape, a negative electrode base having a thin-film shape, and a thin-film multi-tab, so that each of the positive electrode base and the negative electrode base is joined to the multi-tab,
wherein respective welded portions in which the multi-tab is welded with the positive electrode base and the negative electrode base are melting-joined by using a laser such that a plurality of welding spots is formed on each of the welded portions, and
determining whether a defect of the welded portions exists,
wherein the determining whether a defect of the welded portions exists comprises
irradiating the welded portions with light in a direction from a first surface toward a second surface opposite the first surface of the welded portions, collecting light transmitted through the welded portions to form a first inspection image, and determining whether a perforated defect of the welded portions exists by analyzing the first inspection image, and
irradiating the welded portions with light in a direction from the second surface toward the first surface, collecting light reflected by the welded portions to form a second inspection image, and determining whether a back bead defect of the welded portions exists by analyzing the second inspection image.