Conductor annular ring design and filleting

All pads, on both through-hole and surface mounted pads should be filleted to reduce stress points. This helps eliminate breaking during flexing.

Conductor annular ring design and filleting

Tie-downs and radiused traces

Tie-downs are captured by the coverlay to anchor the copper to prevent separation between the copper and the base material. Radiused traces help to reduce breaking during folding and bending.

Tie-downs and radiused traces

I-beam design and stiffeners

I-Beam constructions occur when the inductors on both layers lie directly on top of each other, increasing the stiffness of the circuit through fold areas. A better alternative is stagger conductors, alternating their location to retain the maximum flexibility of the circuit.

Stiffeners design reference

Stiffener and coverlay termination line should overlap a minimum of 12mil to avoid stress points. Eliminating the stress points reduce the chance of traces breaking.

I-beam design and stiffeners

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