A capacitive hybrid flip-chip ASIC and sensor for fingerprint, navigation and pointer detection

A fingerprint detection technology that supports navigation, pointer and fingerprint acquisition is described. The hybrid system consists of a silicon sensor substrate flip-chipped onto a mixed signal ASIC. The sensor is linear and the finger is swept over to scan the fingerprint. To achieve 500 dpi accuracy, separate process optimization for both the ASIC and the sensor substrate gives a alternative solution compared to all silicon sensor approaches. The ASIC is 18 mm/sup 2/ in 0.25 /spl mu/m CMOS and the sensor is 105 mm/sup 2/.