Printed circuit boards are connected directly to a motherboard (mainboard) using PC / PCI slot connectors. There is a difference between the PC-AT Standard (also called “ISA”) with a grid spacing of 2.54mm (0.1 inch) and the PCI Standard with a grid spacing of 1.27mm (0.05 inch) for the gold fingers (the gold-plated contact pins).
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)
Design parameters
PC-card
To avoid bevelling the gold fingers, a spacing of 2.0mm from the circuit board contour is recommended for PCI cards. Here as well it is recommended to connect the gold fingers with 200µm conductor traces to the circuit board edge.
PCI-card cross-section
PCI-card Example
