Piezoelectric fingerprint sensor has pressure area on upper electrode that causes charge variation in piezoelectric membrane under pressure effect of contact with fingerprint

摘要

The device has a substrate (31), a lower electrode (34) on the substrate, a piezoelectric membrane (35) on the lower electrode, an upper electrode (36) on the membrane, a pressure area (38) on the upper electrode that causes a charge variation in the piezoelectric membrane under the pressure effect of contact with a fingerprint and a non-conducting layer (37) for carrying the pressure area above the lower electrode in an exposed manner.