Electronics

The use of gold in electronics is based on the combination of its electrical conductivity, its ductility and its total freedom from corrosion or tarnishing at either high or low temperatures. Its near perfect corrosion resistance means gold provides an atomically clean metal surface which has an electrical contact resistance close to zero, while its high thermal conductivity ensures rapid dissipation of heat when gold is used for contacts.


It is the gold plating of contacts for switches, relays and connectors that accounts for most of the gold required annually by the electronics industry - an estimated 203 tonnes (6.5 million oz) in 2001, according to GFMS. After jewellery and, in some years, coin, electronics is the biggest fabricator of gold.

The production of gold potassium cyanide (GPC), otherwise known as plating salts, accounts for about seventy per cent of all electronic use. Contacts are normally electro-plated with a very thin film of GPC.

Prior to the gold price rise from $35 per ounce, when gold was cheap, plating thicknesses were often 20 microns but they have since been reduced sharply to 2.5 microns or less, while the contacts themselves have become dramatically smaller. However, the scale of the modern electronics industry means overall gold use has not been reduced.


Gold plated contacts and connectors are an essential part of
modern electronics in everything from computers to television
(Credit: World Gold Council)

Gold-plated contacts are used in everything from washing to computers to telecommunications. The ordinary touch-tone telephone contains thirty-three gold contact points. Gold-plated connectors are an integral part of plugs and sockets for cable terminations, integrated circuit sockets, computer backplates and printed circuit boards. The more sophisticated the equipment and the greater the degree of reliability required, the more gold plating is used in connectors.

This means that in telecommunications, especially satellites, computers and, above all, in defence systems, gold is indispensable. The American space program has made particular use of gold connectors in spacecraft to conduct the subtlest of low voltages.

Gold’s other main electronic use is in fine wire or strip to bond or connect parts of semi-conductors such as transistors and integrated circuits to ensure reliable connections between components. This ‘bonding’ wire is specially refined up to ‘five nines’ (999.99) and has a typical diameter of one hundredth of a millimetre.

A special merit is the ease with which it can be bonded into position in tiny circuits. A third use is 'thick’ and ‘thin’ film used in microcircuitry, in which the circuit is printed on a ceramic base using an ink-like paste containing gold. Originally, ‘thick’ film left a deposit of about 18 microns; ‘thin’ film reduces this by more than one-third.

The high price of gold in the early 1980s caused the electronics industry both to use gold more selectively and sparingly and to look for alternatives. Most manufacturers, however, found there was no practical substitute; nothing quite combined the properties of gold. So fabrication demand has stabilised and fluctuates largely in tandem with a boom or recession in electronics. The fabrication of electronics products is concentrated essentially in Japan , which accounts for almost thirty five per cent and the United States with about twenty per cent. South Korea is now third with ten per cent, followed by Singapore and Taiwan (based on GFMS fabrication figures for 2001).