Crystal unit having stacked structure

摘要

A stacked crystal unit includes: a first crystal plate in which a vibration member links to an outer circumferential frame portion, and a pair of extending electrode extends to the frame portion from excitation electrodes; and a second and third crystal plates which have a concave portion in an area opposite to the vibration member and whose open end surfaces are joined by direct bonding to both principal surfaces of the frame portion in the first crystal plate. The extending electrodes are electrically extended to an outer surface of at least one of the second and third crystal plates via electrode through-holes provided in the frame portion. The electrode through-hole includes: a first electrode through-hole penetrating through the frame portion from the principal surface of the frame portion where the extending electrode extends; and a second electrode through-hole provided in the second or third crystal plate.