A layer of electrolytic gold is mainly used for connections with abrasive wear of the metalized surface, e.g. edge connectors. By means of a selective plating process it is possible to plate Ni/Au onto edge connectors
Gold is plated over Nickel (diffusion barrier) to avoid gold-migration.
- Ni-thickness : 3 – 6 micron
- Au-thickness : 1.0 – 1.5 micron.
It is a requirement that in the pattern design the distance (D) between the top of the connector and the edge of the nearest HMT-pad or SMT-pad is min. 2 mm (80 mil).
The total surface of gold, on both outer layers of the board, needed to cover the gold fingers is expressed in mm² and is used as parameter to calculate the cost for the gold finger contacts. This is a part of the order details and need to be filled out there.