Flip-Chip Ir and Force Sensors For Both Touch and Touchless Elevator Buttons Applications

This study presents the monolithic integration of inductive force sensor and thermoelectric infrared (IR) sensor respectively for the applications of touch/touchless sensing (Fig. 1). Based on the standard CMOS technology, post-CMOS processes, and flip-chip bonding, the proposed sensing chip is designed and implemented. Merits of the design are: (1) SoC: to integrate inductive force sensor (for touch-sensing) and IR sensor (for touchless-sensing) on single chip, (2) Flip-chip bonding: to exploit Si-substrate as the housing of polymer-bump contact interface for inductive force sensor [1] and the cover for IR sensor during loading and polymer-filling, Measurements show IR touchless-sensing (with 37mm sensing distance) and force touch-sensing are simultaneously achieved to demonstrate the concept and feasibility of the presented device.