Case, portable device, and method for laser welding resin parts

摘要

A technique for preventing the extrusion of fused material from between resin parts when the resin parts are laser welded. A case (12) has a resin first case part (13) transmissive to laser light (La) and including a peripheral portion, and a resin second case part (14) that absorbs laser light (La) joined with the first case part. A light reflector (S) reflective to laser light (Lb) is formed in the peripheral portion of the first case part. A laser welding portion (P1, P2, M) is formed inward from the light reflector between the first case part and the second case part and located at a region reachable by laser light transmitted through the first case part without being reflected by the light reflector. The laser welding portion is for welding the second case part to the first case part with laser light.