How Projected Capacitive Touch Technology Works
Capacitive sensing in touch screens has been around since the 1970’s, but with the recent explosion in popularity of smartphones and tablets, projected capacitive sensors have come to the forefront of touch screen technology.
Most commonly, projected capacitive sensors are made up of three major components; the sensor glass, the cover glass, and a flexible printed circuit (FPC) with controller. The sensor glass is made up of a series of electrodes that are configured into rows and columns. These electrodes are made of a transparent conductive coating called indium tin oxide (ITO). Each electrode is routed back with a metal trace to a connection point where the FPC can be be bonded. The FPC generally contains the controller for the touch sensor.