Flexible electronics or Flex circuit is the technology for the assembly of circuits on a flexible plastic substrate such as Polyimide. The Flex circuits can be easily flex or bend during its use. The Flex circuit board is manufactured using Polylithographic technology. The Flex circuits find applications like Camera, Cellphone, Satellites etc. Flex circuits are used as connectors where flexibility is needed and they reduces the space considerably. A common application of Flex circuit is the computer key board. LCD display can also be made using Glass or thin transparent foil as substrate so that the entire system can be flexible. Organic LED (OLED) is used in such displays instead of the back light. The thin film of OLED along with the substrate form a flexible LCD display.
Most of the Flexible circuits are wiring connections used to interconnect other active components such as transistors and ICs. In printer, flex circuit is used to move the printer head and in computer, it is used in the moving parts of the Disk drivers. Medical instruments, Mobile phone etc also use flexible circuits to reduce the space for the interconnecting wires. Flexible solar panels are also used in Satellites and Space crafts.
Single and Double sided Flexible circuits can be made using the technology. Single sided flex circuit has a single conductive layer formed of a metal polymer on a flexible dielectric film. Components are present only on one side. Holes are present in the film to pass the leads of the components for interconnections and soldering. Double flexible circuit also has two conductive layers with or without holes. When constructed without hole, the circuit can be accessed only from one side. If hole are present, components can be placed on both the sides. Multi layer flex circuits have more than one conductive layers which are interconnected through the holes.