Printed circuit boards are connected directly to a motherboard (mainboard) using PC / PCI slot connectors. There exist the PC-AT Standard (also called “ISA”) with a pitch of 2.54mm (0.1 inch) and the PCI Standard with a grid spacing of 1.27mm (0.05 inch) for the gold fingers. Additional there are PCI Express cards (PCIe) with 1.0mm and Mini PCI Express cards (mPCIe) with 0.8mm pitch.
Design-Rules:
- The entire plug area including the gold fingers must not be covered by solder-stop (see diagram)
- Plated-through holes within the contact area are not allowed
- The circuit board surface may be freely selected
- The gold fingers are manufactured using “hard gold” (electroplated gold), Au thickness 0.8 - 2µm
Design Parameters
| PC card | PCI card | PCIe card | mPCIe card | |
|---|---|---|---|---|
| Pitch | 2.54mm | 1.27mm | 1.0mm | 0.8mm |
| Thickness | 1.6mm | 1.6mm | 1.6mm | 1.0mm |
| Chamfer angle | 45° | 20° | 20° | 20°/45° |
| Spacing gold fingers / PCB contour | 0.7mm | 2.0mm | 1.4mm | 0.5mm/0.25mm |
PC card
Bevelling of the gold fingers must be avoided; therefore they must have a spacing of min. 0.7mm from the circuit board contour.
PC card cross-section
Cross-section at the level of the connector; example: FR4 1.6mm
PCI card
To avoid bevelling the gold fingers, a spacing of 2.0mm from the circuit board contour is recommended for PCI cards.
PCI-card Example
PCI-card cross section
Cross-section at the level of the connector; example: FR4 1.6mm
PCIe card (PCI Express)
To avoid bevelling the gold fingers, a spacing of 1.4mm from the circuit board contour is recommended for PCIe cards.
PCIe card cross-section
Cross-section at the level of the connector; example: FR4 1.6mm
Additional Information:
- Via-in-Pad (s. Via Filling)
- Design Paramter
- Basic Design Rules as PDF