As well as gold based finishes on contacts and connectors and gold bonding wires in semiconductor devices, gold is used in

1. Thick and thin film gold paste applications
2. Sputtered gold metallisations
3. Gold based solder alloys
4. Solderable gold based coatings for printed circuit boards

Solder gold alloys are used for connecting metallic surfaces by using a melt, which reacts with both surfaces to be joined and forms a bond following solidification. Alloys are often based on gold with either silicon, copper, nickel, gallium or germanium. Further uses of gold are thick and thin film pastes, whereby a circuit is printed on a ceramic base using an ink-like paste containing gold and sputtering targets used in the production of thin metallisation coatings.

Gold is used in both the case and on the internal substrate components
as a thick film paste on this high frequency receiver.
Picture courtesy of Teledyne Microelectronics.

 

Gold sputtering targets used in the production of thin metallisation coatings.
Picture courtesy of Tanaka KKK, Japan