Rigid-flex circuits are a hybrid construction flex circuit consisting of rigid and flexible substrates which are laminated together into a single structure. Rigid-flex circuits should not be confused with rigidized flex constructions are simply flex circuits to which a stiffener is attached to support the weight of the electronic components locally. A rigidized or stiffened flex circuit can have one or more conductor layers. Thus while the two terms may sound similar, they represent products that are quite different.
The layers of a rigid flex are also normally electrically interconnected by means of plated through holes. Over the years, rigid-flex circuits have enjoyed tremendous popularity among military product designer, however the technology has found increased use in commercial products. While often considered a specialty product for low volume applications because of the challenges, an impressive effort to use the technology was made by Compaq computer in the production of boards for a laptop computer in the 1990s.
Rigid-flex boards are normally multilayer structures, however, two metal layer constructions are sometimes used.
Rigid-flexible PCB's are combinations of flexible and rigid substrates laminated into a single package. Although manufacturing can be as versatile as any engineered design, once completed, it is a 3D interconnect that can be bent and folded into a higher performing PCB. Rigid-flex allows designers to replace multiple PCBs interconnected with connectors, wires and ribbon cables with a single package offering improved performance and reliability in all industries; Audio, Aerospace, Auto, Medical and for miscellaneous electronics manufacturing.
Some more specific applications:
Rigid-flexible circuit boards can be found in applications ranging from consumer electronics to high-end aircraft mounted weapon guidance systems. Overall, military aerospace and medical devices are the most common applications for rigid-flex as they are often the best way to reduce weight, and sometimes the only way to make a device feasible for the end application (e.g., pacemakers, smart jackets, etc.). Encapsulating the features of the rigid board with the FPCB culminate in a product that is as durable as it is malleable. For instance, floating rigid caps used in wearable technology (intelligent clothing) applications not only meet SMT reliability standards but also provide the necessary flexibility that is amenable to the natural contour of the clothing.