Multi-board Etching: Managing Rigid-Flex Designs and Conductivity
April 1, 2020 | Hemant Shah, Cadence Design SystemsEstimated reading time: 1 minute

When I was a very young boy, my dad would delight and tease me by flexing his muscles. He did this with a very special flourish. Rather than simply flexing, he would put his thumb in his mouth, blow, and flex, which gave the appearance that huffing and puffing on his thumb made his bicep pop out. This was a great show for a little boy.
In PCB design, we work with a different type of flex. Advances in consumer and industrial electronic devices have allowed manufacturers to produce smaller devices that have more functionality.
Those devices use rigid-flex designs that provide the form factors needed for portability and—many times—include multiple interconnected boards. With all the interconnections between the boards, PCB designers pay equal attention to signal paths and to the electrical connectivity between boards. On the mechanical design side of things, each board must fit within an enclosure that meets the product specifications. As a result, every multi-board design combines electronic design automation (EDA) with mechanical engineering design (MCAD).
The Sum Is Greater Than the Whole
Good troubleshooting techniques involve considering a system as individual parts rather than as a whole. The same techniques apply to your work with multi-board PCB designs. Each board consists of a single unit that has its own lifecycle.
Some product designs may use a single PCB design for multiple functions or for multiple devices. Others may interconnect multiple PCB designs to produce a complete, fully functional system. Depending on the product design, a single PCB design may have multiple uses. No matter the method, the multi-design represents an overall approach to system design.
To read this entire article, which appeared in the February 2020 issue of Design007 Magazine, click here.
Suggested Items
Meet the Author Podcast: Martyn Gaudion Unpacks the Secrets of High-Speed PCB Design
07/10/2025 | I-Connect007In this special Meet the Author episode of the On the Line with… podcast, Nolan Johnson sits down with Martyn Gaudion, signal integrity expert, managing director of Polar Instruments, and three-time author in I-Connect007’s popular The Printed Circuit Designer’s Guide to... series.
Showing Some Constraint: Design007 Magazine July 2025
07/10/2025 | I-Connect007 Editorial TeamA robust design constraint strategy balances dozens of electrical and manufacturing trade-offs. This month, we focus on design constraints—the requirements, challenges, and best practices for setting up the right constraint strategy.
Elementary, Mr. Watson: Rein in Your Design Constraints
07/10/2025 | John Watson -- Column: Elementary, Mr. WatsonI remember the long hours spent at the light table, carefully laying down black tape to shape each trace, cutting and aligning pads with surgical precision on sheets of Mylar. I often went home with nicks on my fingers from the X-Acto knives and bits of tape all over me. It was as much an art form as it was an engineering task—tactile and methodical, requiring the patience of a sculptor. A lot has changed in PCB design over the years.
TTCI Joins Printed Circuit Engineering Association to Strengthen Design-to-Test Collaboration and Workforce Development
07/09/2025 | The Test Connection Inc.The Test Connection Inc. (TTCI), a leading provider of electronic test and manufacturing solutions, is proud to announce its membership in the Printed Circuit Engineering Association (PCEA), further expanding the company’s efforts to support cross-functional collaboration, industry standards, and technical education in the printed circuit design and manufacturing community.
Bell to Build X-Plane for Phase 2 of DARPA Speed and Runway Independent Technologies (SPRINT) X-Plane Program
07/09/2025 | Bell Textron Inc.Bell Textron Inc., a Textron Inc. company, has been down-selected for Phase 2 of Defense Advanced Research Projects Agency (DARPA) Speed and Runway Independent Technologies (SPRINT) X-Plane program with the objective to complete design, construction, ground testing and certification of an X-plane demonstrator.