Circuit boards are the building blocks of nearly all electronic devices. From computers and TVs to touchscreens, thermostats and digital watches, they are found in most electronic devices. As their name suggests, circuit boards are “boards” that feature one or more conductive paths known as a “circuit.” Some electronic devices use rigid circuits, though, others use flexible printed circuits (FPCs).

The Definition of an FPC

An FPC is a type of circuit board that can bend without cracking, breaking or otherwise sustaining damage. They are distinguished from rigid circuit boards by their physical characteristics. Rigid circuit boards are stiff and rigid. FPCs, on the other hand, are flexible. Even if you bend an FPC, its conductive pathways will remain intact, so it will continue to function as intended.

How FPCs Are Made

You might be wondering how FPCs are made. There are many different types of FPCs, so there isn’t a single universal manufacturing process for them. Nonetheless, all FPCs feature conductive traces printed on a substrate. The conductive traces typically consist of copper or a similar conductive ink. For the medium, polyimide may be used.

The Institute of Printed Circuits (IPC) has defined four variations of FPCs. Type 1 FPCs are made of a single layer that features insulating material on either one or both sides. Type 2 FPCs are made of two layers that are separated by an insulating material. They also have plated interconnect holes and provide access to the conductive traces on one or both sides.

Type 3 FPCs are made of three or more layers and feature an insulating material between their respective layers. They also feature plated interconnect holes and provide access to the conductive traces on one or both sides. Finally, Type 4 FPCs are made of two or more layers, which feature an insulating material between them. Unlike the other types of FPCs, they support a rigid printed circuit board.

Why FPCs Are Popular

The main reason FPCs are so popular is because they are flexible. Only FPCs can bend and flex. This makes them ideal for applications involving small electronic devices, such as smartphones and wearable electronics.

FPCs also take up less space than rigid circuit boards. They are almost always smaller than their rigid counterparts. With their small size, FPCs can fit into small electronics.

FPCs are also reliable. They can last for many years — even when regularly bent. The flexible medium on which they are printed will allow FPCs to bend and flex without breaking.