8 Layer FR4 PCB Production Record #FR4-20260422-008
| Parameter | Value | Parameter | Value |
|---|---|---|---|
| PCB Type | FR4 PCB | Quantity | 5 pcs |
| Layers | 8 Layers | Board Type | Panel PCB |
| Dimensions | 195 x 114 mm | Copper Weight | 1oz |
| Thickness | 1.6 mm | Min Track / Spacing | 4/4mil |
| Surface Finish | ENIG (Immersion Gold) | Min Hole Size | 0.3mm↑ |
| Solder Mask | Matte Black | Silkscreen | White |
| Stack-up | Custom | Impedance Control | Yes |
This 8-layer FR-4 board was manufactured with standard 1 oz copper layers, green solder mask, white legend, and ENIG surface finish. The order involved impedance control, V-scoring, mechanical forming, and 100% flying probe testing. Key process considerations centered on achieving the required electrical performance while managing tight mechanical features such as slots and larger holes.
DFM review identified multiple specification conflicts. Several slots and large holes exceeded standard drilling capabilities, leading us to recommend and confirm relaxed tolerances of ±0.1 mm with routing for final shaping. Impedance requirements presented a significant challenge: the specified line widths could not simultaneously satisfy both 100 ohm differential and 50 ohm single-ended targets. We proposed and received approval to prioritize 100 ohm differential impedance with corresponding stackup and trace adjustments. Additional issues resolved included inconsistent inner/outer copper thickness specifications (controlled to finished 1 oz outer), solder mask thickness relaxed to standard 8-30 µm range, IPC netlist discrepancies with open/short findings (ultimately waived), unclear processing notes, and panel layout confirmation.
UL marking and production cycle details were added per customer input. All engineering questions were resolved before production release. The order was completed and shipped with full electrical testing and quality documentation confirming adherence to the approved parameters.
These boards integrate multiple microvia layers to support complex routing and high signal density in advanced electronics.
In-depth guide to the most frequent Engineering Queries (EQ) and DFM issues in Multilayer FR4 PCB (4/6/8+ layers) production. Real factory insights on stack-up confirmation, impedance control, copper balance, inner layer design, via treatment, registration, and practical prevention strategies.
| Order ID | PCB Type | Layers | Dimensions | Solder Mask | Surface Finish | Quantity | Action |
|---|---|---|---|---|---|---|---|
| FR4-20260519-001 | FR4 PCB | 10 | 67.6 x 42 | Green | Gold Plating | 20 | View detail |
| FR4-20260515-068 | FR4 PCB | 14 | 244 x 267 | Green | ENIG (Immersion Gold) | 10 | View detail |
| FR4-20260505-010 | FR4 PCB | 8 | 88.4 x 90.2 | Green | ENIG (Immersion Gold) | 100 | View detail |
