Are you finally starting with Flex circuits?

If you are new with designing flexible circuits?  Here are few “basics” to keep in mind.  Designing flexible circuits is not difficult, but does require adjustments to make sure you achieve the flexibility and reliability that you are are wanting.

Top benefits of flexible circuits:

• Resulting in a solution to a packaging problem
• It helps reduce assembly costs – elimination of connectors and solder joints
• Accurate replacement for wires – simplify system design, reduces number of interconnections and eliminates labor errors.
• Reduce overall weight and allow for tighter space
• Dynamic flexing
• Great for Thermal Management/ High Temp Applications
• Overall cosmetics

Keep in mind some design considerations: Pad Design and Filleting:

• Pads should have tie-downs (rabbit ears). Tie-downs are captured by the coverlay to anchor the copper which results to prevent separation of copper and base materials.
• Filleting: All pads are recommended to be filleted to reduce stress points during flexing operations.

Keep in mind these bending and folding considerations:

• Radius Traces – this helps to alleviate breaking during folding and bending
• I-Beam Effect- when conductors are routed directly on top of one another, stiffness is increased in fold areas. An alternative is to stagger conductors, alternate location to retain maximum flex.
• Fold Lines – tick marks in copper or silkscreen help identify designated location for bending or folding.
• Circuit Trace Width – this should not change in bend areas and the transition should be at least .030” from fold line.
• Bend radius – very general guideline of 10 times material thickness will work with most applications.
• Button Plating – increased flexibility by plating thru holes but not traces.

 Shielding with Copper:

• Solid Copper – this is considered most common for shielding. This can be done on single or double sides of the circuit or to cover selective conductors.
• Crosshatched Copper – crosshatching will help the circuit to retain its flexibility and utulized on entire or selected area,

 Added Stiffeners:

• FR4 – normally used for added rigidity under a connector area. These can manufactured with pressure sensitive adhesive or thermals. This is also used as a carrier panel for assembly.
• Price Circuits LLC manufactures all types of flex technologies.
• Please contact Shelley Lara 630-429-4126 Shelley@PriceCircuitsLLC.com