Spark plug and method for manufacturing the same

摘要

The method involves laser-welding the flange portion (1a) of a chip (1) to the joint face (32,42) of the electrode base metal of either the center electrode (30) or ground electrode (40) to form a weld portion between the electrode base metal and chip, and to reach points on the second face of the flange portion. The points are located inward of corresponding intersections of the second face of the flange portion and imaginary extension lines of generatrices of a side surface of the protrusion (1b) of the chip. The protrusion projects from the first face of the flange portion. An independent claim is also included for the spark plug.