Flexible or flex circuit is the technology of assembling circuits by mounting several electronic devices like polyimide and translucent conductive flexible plastic substrates. On the other hand, rigid-flex PCBs allow the boards to conform to a certain shape or to flex during the time it is on use. There are several types of rigid-flex circuits depending on their construction; single-sided flex circuits, back bared flex circuits or double access, sculptured flex circuits, multilayer flex circuits and rigid-flex circuits. Have you ever wondered how rigid-flex PCBs emerged and what they really are? Join us https://www.rushpcb.co.uk/blog/ as we discuss the evolution of rigid-flex PCBs.

The first question that comes into your mind is what rigid-flex PCBs are and how they are made. A rigid-flex PCB is a hybrid construction flexible board consisting of flexible and rigid substrates laminated together in a single structure. Rigid-flex Printed Circuit Boards can be shaped to suit the specifications of design as asserted by the customer. This allows for freedom in the packaging geometry and a reduction in the interconnections and at the same time retaining the density, precision and the repeatability of the PCB is retained. These PCBs are usually multilayer structures although two metal layer constructions are used sometimes. Rigid-flex PCBs find numerous applications in the electronics industry especially in medical, military and aerospace electronic equipment.

So what is the history of rigid-flex PCBs? Over the years, Rigid-Flex PCBs and PCBs at large have enjoyed tremendous developments introduced by changes in technology. These changes can be attributed to the development of Printed Circuit Boards. In the early 1900’s, the concept of PCBs was introduced by the construction of electrical paths on isolated surfaces of boards. This was used in developing and upgrading gramophones and radios. Consequently, the notion of the ‘’through-hole-technique’’ was introduced and a rigid-flex PCB was invented. The fabrication of PCBs was introduced later by a PCB manufacturer in the U.S where they used the automated soldering techniques. PCBs were later adopted by the U.S army and several strides to upgrade them were made. This marked major developments in the electronics world.

From the high speed analog and digital designs to high layer count boards and high pin count BGA with several methods of fabrication like electro-mechanical assembly, box build assembly, cable harness assembly and backplane assembling process, the demand for customized PCBs in various industries increased significantly. With steep competition in the market, PCB manufacturers have always been challenged to differentiate themselves from the chunk by introducing new inventions. As a result, advanced methods used by PCB manufacturers like Surface Mount Technology (SMT), Integrated Circuits (ICs) and Hybrid Circuits have led to state-of-the art-techniques. Sequentially, there is a range of Printed Circuit Board designs which can be fabricated to suit the demands of the customer. These are the rigid-flex PCB. As if that is not enough, older design methods of Rigid-Flex PCBs were characterized by constructions by many layers of adhesives in the rigid areas constructions. However, due to the high thermal coefficient of thermal expansion of adhesives (about 10 to 20 times that of FR-4), the technique of placing vias under a substantial amount of stress during thermal cycles which occur during multiple assembly cycles, RoHS assembly and component temperatures was introduced. Using adhesives in the rigid areas might cause the formation of cracks in the copper plating within via holes. Are you in need of a Rigid-Flex PCB? Please visit us today at https://www.rushpcb.co.uk/ and have the opportunity with the experts. We value all customers from all over the globe

Different from that, there is flexibility in the methods of fabricating rigid-flex PCBs with respect to the micro-drilled holes, material thickness, PCB profiling, surface finishing and solder-mask capabilities. There were some improvements in the functional layouts and design with high-end customizations in the PCBs mechanized in several multilayered boards. With the advancement in technology, the PCB assembly has been expanded to incorporate rigid-flex PCBs with regards to the consigned Printed Circuit Board assembly and complete turnkey solution. This has facilitated tendering to the exact needs of the customers with cost effective approaches being used in the fabrication approaches.

In the current market, most of the PCB manufacturers and fabricators like RUSHPCB provide Rigid-Flex PCBs which have the capability of integrating multiple PCB assemblies and other electronic elements like input, display or storage devices without using cables/connectors and wires and replacing them with light and thin composites which integrate wiring in flexible ribbons and wiring in ultra-thin. Such PCBs have fine spacing or lines, blind and buried vias, high aspect ratio vias, high layer counts which are over 20+, RoHS assembly compliance and high operating temperatures. However, some developments have created plated hole reliability and potential via issues.

So what are the advantages of using Rigid-Flex Printed Circuit Boards? To begin with, these circuit boards combine the merits of rigid and flexible PCBs. Consequently, there is a variety of advantages especially in signal transmission, overall size, stability and PCB assembly. We at RushPCB produce various varieties of Rigid-flex PCBs which can be adjusted to suit your specifications. Moreover, such PCBs have rigid areas and flexible areas thus reducing the number of layers needed for a single board. This translates to using less copper thus the cost of a single board reduces appreciably. As if that is not enough, our Rigid-Flex PCBs combine FR4, polyimide, and thin laminate thus the final product is of high quality. In the same token, the PCBs are rigid and they can connect rigid boards without using connectors or cables thus there is a better signal transmission. Please visit us today https://www.rushpcb.co.uk/ . We have been on the market for long and our products are exceptionally unique.

Table showing a truncated history of electronic rigid-flex PCBs

Year Application 1960’s Rigid-flex PCBs were used in applications for NASA 1970’s Rigid-flex Printed Circuit Boards were used on Missiles and Fighter Aircraft for reduced weight Early 1980’s Rigid-flex PCBs were used in high reliability military electronics 1988 Military version of the VAX computer with the help of electronic Rigid-flex PCBs 1989 24 layer back panel of Military Avionics using REGAL Flex 1990 Invention of Notebook Computer 1991 Commercial Avionics Flight Box using rigid-flex PCBs 1993 Automotive Engine Control Navigation System was invented using rigid-flex PCBs 1994 Boeing 777 instrumentation 2000’s Implantable Medical Chips using rigid-flex PCBs

With the discussion above, you must have some questions about Rigid-Flex PCBs or any other PCB of your choice. What is the cost of a Rigid-Flex PCB? How is it fabricated? How can I get a Rigid-flex circuit that suits my needs? Please smile and visit us at RUSHPCB.CO.UK we have a team of dedicated experts who are ready to help you each second of the clock. The interests of our customers come first so we assure you of happiness while interacting with us.