Fingerprint sensor having enhanced esd protection and associated methods

Abstract

A fingerprint sensor may include a plurality of electrostatic discharge (ESD) electrodes carried by a dielectric layer of a fingerprint sensing portion. The fingerprint sensing portion is for sensing a fingerprint of a user. The fingerprint sensing portion may include the dielectric layer, and, in some embodiments, may also include an array of sensing electrodes also carried by the dielectric layer. Accordingly, each ESD electrode may be interposed between adjacent sensing electrodes. The ESD electrodes attract ESD events and dissipate the energy therein to avoid damaging adjacent sensing electrodes and/or portions of the dielectric layer. The fingerprint sensor may also include an electrically conductive layer connected to the ESD electrodes, which may provide a convenient ground plane, for example, for removing ESD energy from the fingerprint sensor. The electrically conductive layer may extend beneath the sensing electrodes.