4 Layer HDI PCB Production Record #HDI-20260718-0002

This order comprised 20 panels of 4-layer HDI PCBs built on 0.8 mm thin FR4 material with overall dimensions of 37 x 26.6 mm. The HDI configuration featured blind vias implemented through laser drilling and sequential lamination techniques, creating a reliable 1-step structure. Given the thin profile, strict controls were maintained during high-pressure lamination and stack alignment to achieve flatness and layer registration within tolerance. The standard 6/6 mil track and spacing with 1 oz copper layers presented no particular geometry challenges, allowing production focus to remain on the via processes including filling and plating.

Green soldermask and white silkscreen were applied prior to electroless nickel and immersion gold deposition that delivered a uniform ENIG surface finish suitable for assembly. Full electrical testing confirmed circuit integrity across the batch. The complete manufacturing sequence from engineering review through final test extended over 23 days, providing adequate time for thorough inspection and process verification at each critical stage. The resulting boards exhibited strong consistency in via reliability and overall surface quality for this thin-profile HDI PCB run.