4 Layer Flexible PCB Production Record #FPC-20251120-0001

This 4-layer flexible PCB order consisted of 20 single boards measuring 26.6 × 235 mm with an overall thickness of 0.23 mm. Rolled copper at 1/3 oz weight was selected to preserve pliability, paired with 0.3 mm minimum holes, standard 6/6 mil trace spacing, black solder mask, white silkscreen, and immersion gold ENIG finish. No stiffeners were required, allowing the full length to remain dynamically flexible.

Polyimide material handling began the sequence to avoid surface marks or creases on the thin substrate. Inner layer imaging and etching were followed by precise stack alignment and high-pressure lamination. Coverlay lamination was then applied to protect the conductors while maintaining the required bend radius across the narrow, elongated format.

Electroless nickel and immersion gold deposition provided stable pad surfaces, after which dynamic flex testing and electrical testing confirmed consistent performance. The complete run was executed in 10 days, delivering boards that met all dimensional and electrical criteria without deviation.