Flexible electronics

Flexible electronics, also known as flex circuits, is a technology for assembling electronic circuits by mounting electronic devices on flexible plastic substrates, such as polyimide, PEEK or transparent conductive polyester film. Additionally, flex circuits can be screen printed silver circuits on polyester. Flexible electronic assemblies may be manufactured using identical components used for rigid printed circuit boards, allowing the board to conform to a desired shape, or to flex during its use. Flexible printed circuits (FPC) are made with a photolithographic technology. An alternative way of making flexible foil circuits or flexible flat cables (FFCs) is laminating very thin (0.07 mm) copper strips in between two layers of PET. These PET layers, typically 0.05 mm thick, are coated with an adhesive which is thermosetting, and will be activated during the lamination process. FPCs and FFCs have several advantages in many applications: Tightly assembled electronic packages, where electrical connections are required in 3 axes, such as cameras (static application). Electrical connections where the assembly is required to flex during its normal use, such as folding cell phones (dynamic application). Electrical connections between sub-assemblies to replace wire harnesses, which are heavier and bulkier, such as in cars, rockets and satellites. Electrical connections where board thickness or space constraints are driving factors. Potential to replace multiple rigid boards or connectors Single-sided circuits are ideal for dynamic or high-flex applications Stacked FPCs in various configurations Cost increase over rigid PCBs Increased risk of damage during handling or use More difficult assembly process Repair and rework is difficult or impossible Generally worse panel utilization resulting in increased cost Flex circuits are often used as connectors in various applications where flexibility, space savings, or production constraints limit the serviceability of rigid circuit boards or hand wiring.