Electronic Uses of Palladium
Palladium-containing components are used in virtually every type of electronic device, from basic consumer products to complex military hardware. Although each component contains only a fraction of a gram of metal, the sheer volume of units produced results in significant consumption of palladium.
The largest area of palladium use in the electronics sector is in multi-layer ceramic (chip) capacitors (MLCC). Smaller amounts of palladium are used in conductive tracks in hybrid integrated circuits (HIC) and for plating connectors and lead frames.
Capacitors are components that help to control the flow of an electric current through the various parts of a circuit by storing a charge of electricity until it is required. They consist of layers of conductive electrode material (usually palladium or palladium-silver) sandwiched between insulating ceramic wafers.
In the early 1990s MLCC manufacturers responded to the drive towards miniaturisation of consumer goods by producing ever smaller capacitors using less palladium per unit. Soon afterwards came the development of technology to substitute palladium with nickel. This was not significant until 1997, when the increasing palladium price encouraged manufacturing of nickel-based capacitors on a much larger scale.
A hybrid integrated circuit consists of a ceramic substrate on which are mounted a number of different electronic components, including integrated circuits and capacitors. They are linked by conductive silver-palladium tracks. The function of the palladium is to hold the silver in place, without which it would migrate. The automotive industry is the largest market for HIC.
Components inside computers are linked by connectors plated with a conductive layer of precious metal. Palladium is used as an alternative plating material to gold for connectors as it has a lower density and so less weight of metal is required for a coating of similar thickness.
Lead frames are used to connect integrated circuits to other electronic devices. Some manufacturers use palladium to plate the frames as an environmentally preferable alternative to tin-lead solder.
Source: Johnson Matthey