Another avenue for reducing device costs is through FPC design. The FPC connects individual sense input/output (I/Os) from the touchscreen panel to the touchscreen controller and from the touchscreen controller to the host processor.
FPCs can be active or passive. In active FPCs, the touchscreen controller and any other required external components such as resistors and capacitors are mounted onto the FPC itself. In passive FPCs, the FPC only includes routing traces and the touchscreen controller, and external components are mounted onto a printed-circuit board (PCB).
Whether active or passive, FPCs can be routed in several ways. The more efficient and versatile the routing, the easier it is for other hardware components to be integrated. Keep in mind, however, that costs do increase with the number of layers required for routing. Thoughtful routing on a single layer will help minimize FPC costs. Single-layer routing also has considerable advantages for both signal integrity and compact FPC design.
