4 Layer Flexible PCB Production Record #FPC-20260420-0032

For this order of five 4-layer flexible PCBs, panels were produced to dimensions of 475 x 78.5 mm at 0.35 mm thickness from rolled copper polyimide. The specification included 5/5 mil track and spacing, yellow soldermask with white silkscreen, and ENIG immersion gold surface finish. Without stiffeners, maintaining the material's flexibility remained a key consideration during handling, lamination, and testing of the long, narrow format.

Polyimide material handling preceded inner layer imaging, circuit etching, and precise layer stack alignment before high pressure lamination. FPC Coverlay lamination followed, with electroless nickel deposition and immersion gold deposition optimized for uniform coverage on the thin substrate. Dynamic flex testing verified mechanical endurance while electrical testing confirmed netlist integrity across all layers.

Completed over 29 days, the sequence delivered panels meeting every tolerance, with consistent registration and surface quality that supports reliable performance in dynamic applications.