Abstract: A process is described for cathodically depositing chromate films on metal surfaces. Metal surfaces of interest are copper, and copper alloy surfaces, nickel, and nickel alloy surfaces, and iron and iron alloy surfaces. Particular electrolytic conditions and solution compositions yield chromate films which are advantageous in many applications including protection of surfaces against corrosion and improved adhesive characteristics of metal surfaces toward various films including organic (paint, etc.) films. In addition, chromate films produced in accordance with the described procedure are advantageous as plating masks for electrolytic deposition 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 putting down patterned chromate films on metal substrates. The procedure involves first forming a chromate film on the metal surface and then forming the patterned chromate film. The pattern is formed by sputtering the substrate through a suitable shadow mask. This procedure yields patterned chromate films with high dimensional tolerance limits. Such patterns are particularly useful in the fabrication of electronic artifacts, as for example, a mask in gold plating processes.

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.