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 electroplated gold ("hard gold"), Au thickness 0.8 - 2µm
- Chamfering of the gold fingers must be avoided (see design parameters)
Design Parameters
| PC card | PCI card | PCIe card | mPCIe card | Custom 30° | |
|---|---|---|---|---|---|
| Pitch | 2.54mm | 1.27mm | 1.0mm | 0.8mm | - |
| Material thickness | 1.55mm | 1.55mm | 1.55mm | 1.0mm | 1.55mm |
| Chamfer angle | 45° | 20° | 20° | 20° / 45° | 30° |
| Spacing gold fingers / PCB contour | 0.7mm | 2.0mm | 1.4mm | 0.5mm / 0.25mm | please define |
| Spacing Cu inner layers / PCB contour | 0.7mm | 2.0mm | 1.4mm | 0.5mm/0.25mm | identical to above |
PC card
Chamfering 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 chamfering of 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 chamfering of 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