Surface mount crystal unit and surface mount crystal oscillator

摘要

A surface mount crystal unit comprising a crystal blank, a planar mounting substrate made of silicon and a cover having a shape with a recess and made of glass containing ions having high mobility. The mounting substrate and the cover are bonded by means of anode bonding and the crystal blank is hermetically sealed in a case made up of the mounting substrate and the cover. The mounting substrate has connection electrodes used for a connection with the crystal blank and external terminals to be used to surface-mount the crystal unit. The connection electrodes and external terminals are electrically connected.