Patent ID: 7602107

Claim:
A surface mount type crystal oscillator comprising a substantially rectangular crystal blank, an IC chip having at least an oscillation circuit using said crystal blank, integrated thereon, and a hermetic package for accommodating said crystal blank and said IC chip therein, wherein: said hermetic package comprises a ceramic substrate having a substantially rectangular shape and formed with a metal film which makes a round on one main surface thereof, and a concave metal cover having an open end face bonded to said metal film, said crystal blank comprises excitation electrodes respectively formed on a pair of main surfaces thereof, and a pair of lead-out electrodes extended from said excitation electrodes to both ends on one side of said crystal blank, said ceramic substrate has at least the one main surface formed as a flat surface, said ceramic substrate comprises mounting electrodes at corners on the other main surface thereof for use in mounting said crystal oscillator on a wiring board, said IC chip has its circuit forming surface secured to the one main surface of said ceramic substrate through ultrasonic thermo-compression bonding using bumps, said crystal blank is held in said hermetic package by securing both ends on the one side thereof to a back surface of said IC chip, and said crystal blank is electrically connected to a relay terminal formed on the one main surface of said ceramic substrate using wire bonding.