Rigid Flex PCB Basic Layout Guidelines

Green Circuits produces durable rigid-flex PCBs that meet today’s challenge of flawless performance in applications for all types of industries.

A hybrid of the best attributes of rigid and flex circuits, rigid-flex circuits and printed circuit boards perform at a higher level than conventional rigid circuits while taking up less space. Businesses in the aerospace, medical, automotive, military, and consumer electronics sectors increasingly use the versatile rigid-flex PCB.

Responding to demand, Green Circuits adopted new development and fabrication processes for rigid-flex PCBs to ensure consistent, superior performance in our clients’ applications while meeting their tight production deadlines.

• Insulate with bond-ply. We take steps to insulate the rolled copper cladding used for the flex layers of a rigid-flex PCB. An application of adhesive bond-ply prevents the copper from becoming brittle.
• Adjust via spacing. Pliable flex materials remain stable when our designers place vias about 50 millimeters from the edge of the rigid area adjacent to the flex ribbon. That distance is greater than in rigid-only stack-ups, but necessary to retain stack-up stability.
• Alternate flex traces from layer to layer. For wiring to function properly, ribbons must remain flexible. For that reason, we do not position traces on top of each other, layer to layer. Instead, we stagger them vertically for maximum ribbon flexibility. We also carefully crosshatch planes to keep ribbons flexible.
• Adapt adhesive application in multi-layer circuits. Our technicians do not apply adhesive to bendable parts of circuits of more than four flex layers. 

Sometimes it’s difficult to know which type of circuit works best in a product under development. Flex circuits provide the ideal solution for lightweight, compact applications, such as smartphones, or apps that have to withstand extreme temperature fluctuations.

In other cases, rigid circuits are a better choice because they are less expensive to fabricate. Rigid-flex circuits, which offer the functionality of flex circuits and the affordability of rigid circuits, perform ideally in applications such as laptop computers.

If you are unsure which type of circuit or PCB you need, a Green Circuits engineer can answer your questions. Our engineers are knowledgeable Silicon Valley veterans who work for clients such as UC-Berkeley, Toshiba, Rogers Corporation, and Actel. We’ve provided thousands of printed circuit board solutions for them. We can do the same for your company.

Discuss these rigid-flex PCB basic layout guidelines with one of our engineers. Call 408-526-1700 today. Contact us or request a quote online, too.