JPS645112A - Manufacture of surface acoustic wave device - Google Patents

Abstract

PURPOSE:To prevent the melting of the electrode due to self-charging or self- discharge by forming a discharge preventing pattern made of a thin conductive material with different etching characteristic from comb-line electrodes and wiring electrodes prior to the comb-line electrodes, wiring electrodes and bonding pads. CONSTITUTION:Prior to an image comb-line electrode, earth electrodes 3A-3C, wiring electrodes 1B-3B and bonding pads 1C-3C in their formation, a fine pattern in continuity to a degree not giving adverse effect onto the characteristic of the element onto the piezoelectric substrate by an element forming electrode material and a conductive material having selectivity of etching as the background of the electrodes to form a discharge preventing pattern 7. Thus, the input/output electrodes 1A-1C, earth electrodes 2A-2D, earth electrodes 3A-3C of the image comb-line electrode and the image comb-line electrode 4 are connected mutually between other chips in the same substrate and the substrate is made to the same potential. Thus, the melting of the electrodes due to self- charging and self-discharge is prevented.