The Rigid-Flex PCB’s combine the best of both rigid boards and flexible boards when integrated into one circuit. This two-in-one circuit is interconnected through plated thru holes. Rigid flex circuits enable higher component density while fitting into limited and odd shaped spaces. Rigid-Flex doesn't just maximize efficiency in space and weight, but also greatly improves reliability, eliminating many needs for solder joints and delicate, fragile wiring that are prone to connection issues.
In most rigid flex circuit boards, the circuitry consists of multiple flexible circuit inner layers selectively attached together using an epoxy pre-preg bonding film, similar to a multilayer flexible circuit. However, a multilayer rigid-flex circuit incorporates a board externally, internally or both as needed to accomplish the design.
The Rigid-Flex manufacturing phase is more complex and time consuming than rigid board fabrication. The flexible parts of the assembly have completely different handling, etching and soldering processes from the standard rigid FR4 boards.