RigidFlex

Rigid-flex, or rigid-flex PCB, is a printed circuit board that combines rigid board sections with flexible circuitry in a single assembly. This arrangement enables complex three-dimensional layouts and reduces the need for separate connectors.

Construction typically laminates flexible copper circuits to rigid substrates such as FR-4 or polyimide, with stiffeners to define rigid areas. Flexible layers use polyimide film with copper, and the board is manufactured with modified routing, drilling, and lamination processes; protective coverlays may be applied.

Design considerations include bend radii, trace geometry in flex sections, impedance control, and thermal management. Stiffeners are attached with adhesive or mechanical methods, and tolerances must accommodate bending during assembly and life. The assembly is tested with ICT, flying probe, and environmental tests.

Applications include consumer electronics, mobile devices, wearables, automotive sensors, medical devices, and aerospace equipment where compact form factors are beneficial. The main advantages are space and weight savings, fewer connectors, and improved reliability in certain environments.

Challenges include higher cost and lead times, greater design complexity, and potential reliability issues in hinge areas. Rigid-flex fabrication generally follows IPC guidelines and other industry standards for design, fabrication, and testing.