In a recent interview with Design007 Magazine managing editor Andy Shaughnessy, he asked me about rigid-flex and its new popularity. This seems like a perfect opportunity to dig into the topic and discuss the differentiation between rigid-flex, rigidized flex, and what I am calling a hybrid flex.
The Original: Rigid-flex
Rigid-flex technology was developed years ago for military and aerospace applications. But rigid-flex has become more popular in recent years. Open a cellular phone, for example, and more than likely the internal electronics are mounted on a rigid-flex.
In case you’re not familiar with the technology, a rigid-flex is a blend of a rigid printed circuit board and a flex circuit. To manufacture a rigid-flex, a flex circuit is compressed between layers of a rigid PCB design, which leaves the flex area exposed to, well, flex. The rigid areas are, in most cases, used for placing components. The vias/through-holes in both the rigid and flex areas are aligned and plated just like a normal multilayer circuit solution, creating a hybrid, one-piece integrated solution.
Designers of products are learning the advantages of rigid-flex:
- Denser PCB packaging: The elimination of interconnect giving the PCB designer more maneuverability and room. PCB real estate has become expensive because there are more components on the boards.
- Denser system packaging: This forces designers into 3D solutions. Rigid-flex is the perfect solution because there’s more stuff in the package.
- Simplified assembly: This means improved reliability, and one-piece installation vs. connectors, cables, and/or additional flex jumpers. This all equals an overall lower cost of manufacturing.
- Leveraging materials: The ability to leverage materials from both a PCB and a flex circuit in one integrated package allows for high speed and signal integrity solutions, as well as shielding characteristics.
To read this entire article, which appeared in the June 2023 issue of Design007 Magazine, click here.