FORCE SENSING RESISTOR WITH CALIBRATION ELEMENT

摘要

A force sensing resistor includes two substrates. Conductive traces (18) including first (40, 42), common (38), and calibration (44) fingers are on the first substrate (12) and define a contact area. A spacer (16) surrounds the contact area and attaches the substrates together such that a cavity separates the substrates in the contact area. A first resistive layer is on the second substrate and arranged within the cavity. In response to a force moving one substrate (12), the first resistive layer electrically connects the first (40, 42) and common (38) fingers with a resistance dependent upon resistivity of the first resistive layer and the applied force to produce an electrical signal indicative of the applied force. A second resistive layer (46) is arranged within the cavity and electrically connects the calibration (44) and common (38) fingers with a resistance dependent upon resistivity of the second resistive layer (46) to produce an electrical signal indicative of the resistivity of the second resistive layer (46).