Thanks for your interest in our webinar on designing for flex and rigid-flex.
Click the link below to get the slides and recording.
| Question | Answer |
|---|---|
| Were you saying a via is a good idea to be placed near a bend area or a bad idea? | A via placed too close to a bend is generally not recommended, as it can introduce impedance discontinuities and negatively affect signal integrity. |
| What are the options for minimizing trace inductance for a flex cable with a fixed length? | To reduce trace inductance for a fixed length, you have two options: make the trace wider or bring the reference plane closer. Both methods will effectively decrease the trace inductance. |
| Any tips for a multiple flex layers stack-up? I mean, when you have multiple layers, too many to be flexible, Do you have a document describing how to create a design with multiple flex layers stacked up? How do you specify varying lengths for each leaf in such a design? |
At Sierra Circuits, we support up to 8-layer pure flex stack-ups, where all layers are fully bonded together. We don’t build loose-leaf constructions within a single stack. We recommend engaging with your fabricator early to define the stack-up, materials, and mechanical constraints before finalizing the layout. |
| How about high-vibration environments? Anything in particular needs to change? Or is it just an accelerated bending area? | In high-vibration environments, don’t just focus on bend areas; the entire flex is affected. Use RA copper, curved traces, and teardrops to improve fatigue resistance. Add stiffeners and strain relief near connectors and component areas, and avoid placing heavy parts on unsupported flex. Also, choose materials with good damping and ensure connectors are securely retained to prevent failure over time. |