Fingerprint sensor using a piezoelectric membrane

摘要

A fingerprint sensor for sensing a fingerprint by converting pressure applied to a piezoelectric membrane into an electrical signal is provided, wherein the fingerprint sensor having an aggregate of piezoelectric devices includes: a substrate; a lower electrode formed on the substrate; a piezoelectric membrane formed on the lower electrode; an upper electrode formed on the piezoelectric membrane; a pressuring portion formed on the upper electrode for changing a quantity of charge on the piezoelectric membrane due to pressure exerted by contact of a fingerprint; and a non-conductive layer formed on the lower electrode for supporting and exposing the pressuring portion. Thus, a fingerprint sensor having a simple structure is provided, which is able to precisely sense fingerprint information utilizing a piezoelectric phenomenon. The fingerprint sensor may be applied to systems for identifying persons' identities in public institutions and private enterprises, and in individuals' portable systems.