4 Layer FR4 PCB Production Record #FR4-20260103-020

This production record details the manufacturing of five standard 4-layer FR4 PCBs, each with dimensions of 240 x 120 mm and 1.6 mm thickness. The build incorporated 2oz copper weight, 6/6 mil minimum track and spacing, and 0.3 mm minimum hole size. Given the heavier copper, controlled etching was essential following thick copper electroplating to maintain trace accuracy and avoid over-etching on the inner and outer layers.

Layer stack alignment and high pressure lamination ensured solid interlayer bonding. Green soldermask and white silkscreen were applied before electroless nickel and immersion gold deposition for the ENIG surface finish. This choice supports excellent conductivity and oxidation resistance on the standard 4-layer FR4 PCB without impedance control requirements.

The five boards completed electrical testing successfully after 3.4 days of production. This small-quantity run reflects consistent multilayer fabrication with specific attention to the plating and etching demands of 2oz copper.