4 Layer HDI PCB Production Record #HDI-20251022-0007

This High-Density PCB order consisted of five panels of a 4-layer board with blind vias in 1+N+1 configuration. Measuring 58 × 116 mm at 1.0 mm thickness with 1 oz copper, the design used 4/4 mil trace spacing and 0.2 mm minimum holes. Sequential lamination and laser microvia drilling formed the interconnects while blue soldermask, white silkscreen, and immersion gold ENIG provided surface protection and solderability on the standard FR4 base material.

Execution followed a defined sequence of engineering review, inner layer imaging, high-pressure lamination, via filling with plating, electroless nickel deposition, and immersion gold deposition. Layer stack alignment received close attention to maintain registration through the laser drilling and plating steps. Full electrical testing after solder mask application confirmed net continuity and isolation on every panel.

The complete run finished in 12.9 days, producing boards that met all specified tolerances for this tighter-geometry HDI design without impedance control. Process stability across the small quantity ensured consistent via reliability and surface quality for the customer’s application.