4 Layer FR4 PCB Production Record #FR4-20260411-036

This 4-layer board measured 101.6 × 101.6 mm with a thick 2.4 mm thickness, TG150 material, and asymmetric copper of 1 oz / 2 oz. Produced as 5 single pieces, the order used lead-free HASL surface finish, green solder mask, and white silkscreen. Minimum holes were 0.3 mm with a tight 4 mil line/space geometry. Process edges of 4 mm on the left and right sides supported V-cut separation. The 12-day schedule included 100% flying probe testing.

DFM review addressed stackup, via treatment, and silkscreen constraints. The customer-supplied stackup required minor adjustment to match available material while preserving overall thickness targets. Via tenting was specified, yet the data showed mixed treatment—one side tented and the opposite side open; the governing approach was confirmed. Certain pads indicated by arrows required network verification. Silkscreen characters fell below reliable printability (line width under 5 mil and height under 30 mil); processing the original artwork would leave the text incomplete or blurred, and this limitation was accepted.

Confirmed stackup revision, via-mask consistency, and silkscreen acceptance were implemented prior to production. The thick boards achieved consistent lead-free HASL coverage and dimensional control within the planned timeline. Full electrical test reports and quality certificates accompanied the shipment, confirming the panels met the specified mechanical and electrical requirements.