Abstract: The invention is a process for rapidly electroplating certain metals such as gold, nickel, tin-nickel and tin-lead alloys on contact fingers for electronic printed wiring boards. Particularly important is uniform distribution of current amongst the fingers so as to produce uniform metal platings with equal thickness. Also of importance is the provision to alter thickness among the individual fingers so as to plate metal where most needed for particular applications. Uniform and rapid plating are achieved by certain circuit designs together with high parallel flow rates of electroplating solution in the electroplating cell. Both electroplating uniformity and provision for selecting thickness for individual fingers permits savings in amounts of metal used without sacrifices in performance. This is particularly important in the case of gold electroplating because of the high cost and increasing use of gold.

Abstract: A process is described for selectively electroplating gold on metallic surfaces containing copper using a chromate film as a plating mask. This procedure permits reduced use of gold without adversely affecting device performance. In addition, chromate films may be patterned with relatively high dimensional resolution and control so as to achieve gold plating patterns useful in electronic and integrated circuits.

Abstract: A process is described for making modified gold platings of low porosity. This process involves first putting down a gold layer and then passivating this layer using an electrochemical chromating procedure. This process permits use of much thinner gold layers than ordinarily used without the danger of corrosion of underlying base metal.

Abstract: A technique is described for stabilizing gold plated electrical contacts wherein the contacts are treated with an oxidizing agent at elevated temperatures, so resulting in a contact structure which does not evidence resistance drift during subsequent thermal aging. Additionally, the technique may be used to reduce the contact resistance of thermally aged contacts which were not subjected to the foregoing preparative process.

Abstract: A method of electroplating precious metal in localized areas. The deposits obtained are usually nonuniform and limited to only those areas where coating is actually required thus offering considerable economic savings. The method uses shaped anodes approaching the cathodes very closely, high parallel flow rates of electrolyte and high current densities of at least 100 milliamperes per cm..sup.2 in order to electroplate the precious metal quickly. The preferred precious metal is gold. The method is applied to the coating of electronic circuits and components such as connectors and switches.