Electronic part comprising a casing with a narrow groove formed in the casing

摘要

The invention provides an electronic part which includes a casing having a recessed portion which is free of accumulation of moisture and gases and in which a piezoelectric element and terminals are received, and a lid sealably covering the recessed portion. The casing and the lid are respectively provided with narrow grooves communicating with the recessed portion. The casing and the lid are welded together by a ultrasonic welding method at their peripheral edges with the exception of the narrow grooves and portions outside thereof, thereby forming a very narrow gap between the casing and the lid.