The Importance of Rigid-Flex PCB Design Guidelines
July 21, 2022 | Cody Stetzel, Cadence Design SystemsEstimated reading time: 2 minutes

I have the tendency to try to replicate the delicacies I’ve ordered at restaurants in my own kitchen. One of my latest attempts at creating restaurant-worthy dishes was a Korean pancake that’s crispy on the outside but soft on the inside. With my amateur cooking skills, it proved to be an impossible task—I could either make only a hard pancake or one that was total fluff.
While I’m still struggling to figure out the trick to bringing together the different textures of a Korean pancake, I’ve had more success in bringing together the hardboard elements and flexible PCB elements of a rigid-flex PCB. Compared to making Korean pancakes, striking the right balance of flexibility and rigidity on a rigid-flex PCB is easy if you abide by rigid-flex PCB design guidelines.
What Is a Rigid-Flex PCB?
For those who have spent their careers designing conventional PCBs on the FR-4 substrate, a rigid-flex PCB may be unfamiliar territory. As the name implies, a rigid-flex PCB is a PCB that combines both elements of a hardboard and a flexible PCB in a single piece.
A rigid-flex design is typically made up of two or more rigid areas that are interconnected by a flexible strip. The synergistic property of the rigid and flex elements allow the PCB to be bent or folded in applications.
Rigid-flex PCBs are getting more attention in recent years, due to the demand for more compact, shock-resistant, and robust electronics. A rigid-flex design eliminates the need for connectors and interconnecting cables. Rigid-flex PCBS are also easier to install, as the entire design is manufactured on a single PCB.
Material Considerations for Rigid-Flex PCB Design
You’ll want to consult your PCB manufacturer before starting a design. Depending on whether the PCB is meant for dynamic bend or stable bend, the choice of copper type, the number of layers, bend radius, and coverlays may differ.
A dynamic bend rigid-flex PCB is installed in an environment where it will constantly be subjected to bending. Therefore, it is recommended to use no more than two layers and ensure that the bending radius is at least 100 times the material thickness.
Meanwhile, it’s possible to have up to 10 to 20 layers for a rigid-flex PCB that’s meant for stable-bend installations. It is not subjected to repeated bending force and that means a smaller bending radius of about 10 times its material thickness is also possible.
To read this article, which appeared in the July 2022 issue of Design007 Magazine, click here.
Testimonial
"Our marketing partnership with I-Connect007 is already delivering. Just a day after our press release went live, we received a direct inquiry about our updated products!"
Rachael Temple - AlltematedSuggested Items
50% Copper Tariffs, 100% Chip Uncertainty, and a Truce
08/19/2025 | Andy Shaughnessy, I-Connect007If you’re like me, tariffs were not on your radar screen until a few months ago, but now political rhetoric has turned to presidential action. Tariffs are front-page news with major developments coming directly from the Oval Office. These are not typical times. President Donald Trump campaigned on tariff reform, and he’s now busy revamping America’s tariff policy.
Global PCB Connections: Understanding the General Fabrication Process—A Designer’s Hidden Advantage
08/14/2025 | Markus Voeltz -- Column: Global PCB ConnectionsDesigners don’t need to become fabricators, but understanding the basics of PCB fabrication can save you time, money, and frustration. The more you understand what’s happening on the shop floor, the better you’ll be able to prevent downstream issues. As you move into more advanced designs like HDI, flex circuits, stacked vias, and embedded components, this foundational knowledge becomes even more critical. Remember: the fabricator is your partner.
MKS’ Atotech to Participate in IPCA Electronics Expo 2025
08/11/2025 | AtotechMKS Inc., a global provider of enabling technologies that transform our world, announced that its strategic brands ESI® (laser systems) and Atotech® (process chemicals, equipment, software, and services) will showcase their latest range of leading manufacturing solutions for printed circuit board (PCB) and package substrate manufacturing at the upcoming 17th IPCA Show to be held at Pragati Maidan, New Delhi from August 21-23, 2025.
MKS Showcases Next-generation PCB Manufacturing Solutions at the Thailand Electronics Circuit Asia 2025
08/06/2025 | MKS Instruments, Inc.MKS Inc, a global provider of enabling technologies that transform our world, today announced its participation in Thailand Electronics Circuit Asia 2025 (THECA 2025), taking place August 20–22 at BITEC in Bangkok.
Point2 Technology, Foxconn Interconnect Technology Partner to Revolutionize AI Cluster Scalability with Terabit-Speed Interconnect
08/06/2025 | BUSINESS WIREPoint2 Technology, a leading provider of ultra-low-power, low-latency mixed-signal SoC solutions for multi-terabit interconnect, and Foxconn Interconnect Technology (FIT), a global leader in precision interconnect solutions, have signed a Memorandum of Understanding (MOU) to accelerate the commercialization of next-generation Active RF Cable (ARC) and Near Pluggable e-Tube (NPE) solutions.