8 Layer FR4 PCB Production Record #FR4-20251224-025

This 8-layer FR-4 board measured 130 × 202 mm at 1.6 mm thickness with 1 oz copper throughout and TG150 material. The 210-piece order featured controlled impedance, ENIG surface finish, green solder mask, and via tenting. Panelization was single-board with V-scoring plus routing for separation. Impedance requirements and the provided stackup made this order distinct from standard multilayer runs.

CAM review identified multiple DFM concerns. Process edges contained sharp corners inaccessible to the router, risking residual protrusions on the finished board; adjustments were made to ensure clean contours. Stamp holes at 0.3 mm diameter posed ink intrusion and blocking risks during mask application, which were mitigated through process parameter confirmation. Silkscreen characters positioned too close to pads were shifted where possible or selectively removed with customer approval to maintain minimum 4 mil white oil bridge clearance and prevent mask encroachment. Impedance line identification issues in the working gerber and a calculated 2/3 ohm deviation on inner layers were resolved by cross-verifying the customer table against compensated traces before lamination.

Production confirmation followed these clarifications, with full electrical testing and impedance reporting completed within 14 days. The boards delivered with consistent electrical performance and mechanical quality. For further details on the impedance line verification and stackup compensation, see the related engineering case study.