Laser welding method

Abstract

To weld a filter made of a laser beam-transmittable fiber material to a case 2 made of a laser beam-nontransmittable resin material by a laser beam LB, the filter 4 is first placed on the case 2; subsequently, the filter 4 is pressurized by a jig 19 to increase the fiber density of a welding portion B2; and then the welding portion B2 is irradiated by the laser beam LB. In the step of increasing the fiber density, a periphery of the welding portion B2 is pressurized by the jig 19 to increase the fiber density of the filter 4 in a larger area than the welding portion B2. Accordingly, the laser beam LB transmitting through the filter 4 melts a part of the case 2, and the melted resin material permeates through gaps between the fibers constituting the filter 4, thereby welding the welding portion to the case 2.

Dependencies are inferred from the claim text.