A flexible printed circuit board is a type of PCB designed to meet the needs of flexible electronic circuits. Flexible printed circuits were originally designed to replace traditional wire harnesses. From its first application during World War II to the present, flexible circuit boards have improved exponentially.
Flexible printed circuits are produced using flexible laminates. The flexible laminate holds the conductive foil as well as the dielectric substrate. Flexible circuit boards can be three-dimensionally routed and can be appropriately shaped to fit the available space.
Types of Flexible Printed Circuit Boards
The following four types of flexible PCBs are designed to suit various electronic applications:
l One-sided elasticity
l Double-sided elasticity
l Multi-layer flexibility
l Rigid and soft
Electronic devices may use combinations of two or more of the above flexible circuit board types depending on their design requirements.
Benefits of Flexible Printed Circuit Boards
The main advantages of flexible circuit boards compared to traditional wiring and rigid PCBs include:
l Reduce assembly errors: Flexible circuit boards require less labor in the assembly process, which helps reduce production errors.
l Design freedom: Flexible circuits are not limited to two-dimensional boards, such as rigid boards. In complex applications, they can be designed to interconnect in three dimensions.
l Flexible installation: These circuits are as flexible as wire or ribbon cable, allowing interconnection between two or more planes during installation. Furthermore, they can be bent or twisted during installation and execution without any failure.
l Reliability and durability: In applications with moving parts, flex circuits can bend and move indefinitely without electronic failure. Earlier, most failures used to occur at circuit interconnection points. Therefore, flexible circuit boards can be designed with limited interconnections, which ultimately increases the reliability of the circuit.
l Reduced package size and weight: Flexible circuits are produced using thinner dielectric substrates. As a result, they solve various problems related to space and weight traditionally encountered with rigid boards.
