SEMIPCB

What is Flex PCB?

Flex PCB(also variously referred to around the globe as flex circuits, flexible printed circuit boards, flex print, flexi-circuits) are members of electronic and interconnection family. They consist of a thin insulating polymer film having conductive circuit patterns affixed thereto and typically supplied with a thin polymer coating to protect the conductor circuits. The technology has been used for interconnecting electronic devices since the 1950s in one form or another. It is now one of the most important interconnection technologies in use for the manufacture of many of today's most advanced electronic products. 

In practice there are many different kinds of flexible circuits, including one metal layer, double sided, multilayer and rigid flex circuits.

What is the advantages in using Flex PCB?

Generally speaking, there are 5 advantages in using Flex PCB than traditional rigid PCB, see below:

1. Size

Today's market for electronic interconnect, demands an increased number of I/Os with a high degree of performance and reliability in increasingly miniaturized packages. Constant consideration to further reduce package size is required to support tomorrow’s sophisticated product requirements. Being inherently thin, lightweight, and flexible, flex interconnect facilitates miniaturization, making it a prime candidate for portable devices and applications where space is at a minimum. Flexible PCBs have innate mechanical and electrical properties that make them an ideal selection for emerging applications.

2. Reliability

Flex circuits are a reliable alternative to conventional wiring. The thin flat conductors and insulation that make up flex circuits provide more surface area than traditional wiring resulting in better heat dissipation and current carrying capacity. Flex circuits offer repeatable reliability and facilitate the replacement of heavy bulky wiring harnesses.

3. Malleable 

Flex circuit technology allows for three-dimensional configurations. Flex circuits have the ability to be formed around obstructions through thin openings and into confined areas. Utilizing Flex circuits for three-dimensional applications increases the reliability and integrity of the electrical connection when connecting to peripheral devices. This is achieved by removing unnecessary plated through-holes or surface-mount pads, which are created to house mechanical connectors.

4. Performance

Uniform dielectric and conductor thicknesses, favorable dielectric constant and increasingly finer line and spacing geometry provide improved impedance control required for dense, high-speed signal routing.

5. Cost

If the above factors don't give you reason enough to move to flex circuits, you should also consider the costs involved.  Generally speaking, you really do get more for your money with flexible circuit technology.  It is not uncommon to replace several electronics components with a single flexible circuit that provides equal to or better performance for your system.