Electronics

Did you know the humble touchtone telephone typically contains 33 gold-plated contacts? Gold’s main role in electronics is in contacts, switches, relays and connectors. Contacts are electroplated with a very thin film of gold.

This touch of gold on a contact ensures rapid dispersion of heat, and also works to stop oxidation or tarnishing at extreme low or high temperature, providing an atomically clean metal surface with an electrical contact resistance close to zero.

Gold's other main role in electronics is in semiconductor devices, where fine gold wire or strip is used to connect parts such as transistors and integrated circuits, and in printed circuit boards to link components. Again, the need for reliable connections makes gold indispensable.

This bonding wire is one of the most specialised uses of gold; it’s highly refined to more than 99.9% purity, and the wire has a typical diameter of one hundredth of a millimetre.

From Gold.org