Gold plating (electroplating) - Gold per Mil-G-45204C
For your Gold plating and gold electroplating requirements, Professional Plating, Inc. has facilities for gold electroplating both small and large parts in various sized barrels, racks and wiring.
Gold is unique with its yellow color. Also, gold is a precious metal, which means that it will not oxidize in air, so its electrical conductivity stays uniform over long periods of time. It is ideally suited for gold electroplating applications. Gold plating offers good corrosion resistance, good solderability, and when alloyed with cobalt, it has very good wear resistance. Gold is commonly used in electrical switch contacts, connector pins and barrels, and other applications where intermittent electrical contact occurs.
Gold Plating & Gold Electroplating Specification
Specification: MIL-G-45204 Gold Plating, Electrodeposited
- Type I 99.7 % gold minimum; hardness grade A, B, or C. Gold plating used for general-purpose, high-reliability electrical contacts, solderability, and wire wrap connections.
- Type II 99.0 % gold minimum; hardness grade B, C, or D. A general-purpose, wear-resistant gold. It will not withstand high-temperature applications because the hardening agents in the gold plating will oxidize.
- Type III 99.9 % gold minimum; hardness grade A only. Gold plating for semiconductor components, nuclear engineering, thermocompression bonding, and high-temperature application.
Gold Plating & Gold Electroplating - purity and coating thickness
Co-deposited impurities can make soldering more difficult, and for this reason high purity gold plating is preferred. Soldering requirements are best achieved when gold electroplating coatings range between 0.00005 and 0.0001 inch (50 and 100 micro inches) thickness.
Gold Plating & Gold Electroplating - Hardness Grades
- 90 knoop, maximum
- 91-129 knoop, inclusive
- 130-200 knoop, inclusive
- 201 knoop, minimum
Gold over silver is not recommended for electronics hardware.
Gold Plating - Underplate Recommendations
Gold Electroplating - When gold is applied to a copper rich surface such as brass, bronze, or beryllium copper, metal ions from these base metals will diffuse into the gold layer and degrade its hardness and non-oxidizing properties. An antidiffusion underplate such as nickel (electroless or sulfamate) should be applied to prevent this. We recommend electroless nickel under gold where part flexure of deformation is not expected and a bight finish is desirable. Where part flexure or deformation is expected, we recommend sulfamate nickel as the underplate because of its higher ducility.