Gold is not a better conductor than copper. Copper is actually a better conductor of electricity than gold. Gold’s electrical conductivity, at 70% of copper, falls short of copper’s superior performance. Notably less reactive, gold resists oxidation and fretting corrosion, in contrast to copper. With a resistivity of 2.214E-8 ohm meters compared to copper’s 1.72E-8 ohm meters, gold exhibits approximately 29% greater resistance in wires. Although commonly misperceived as a better conductor due to its use in contacts, gold’s advantage lies in its non-oxidizing nature, making it ideal for preventing oxide formation. However, gold is still commonly used in certain electrical components and connectors. Here’s why:
- Inertness and Corrosion Resistance: Gold is more inert than copper, meaning it does not corrode as easily. This makes it ideal for applications where corrosion resistance is important, such as in connectors and contacts that need to maintain a reliable electrical connection over time.
- Malleability and Ductility: Gold is highly malleable and ductile, meaning it can be easily shaped and formed into thin layers. This makes it suitable for plating onto connectors and contacts, providing a thin layer of gold that enhances the electrical conductivity and improves the durability of the connection.
- Stability in Unstable Environments: Gold bonding is more reliable in unstable environments, such as outdoor settings, where copper may fail sooner due to its higher oxidation level.
- Aesthetics and Prestige: Gold has a distinct appearance and is often associated with luxury and prestige. In some cases, gold plating may be used for aesthetic purposes or to convey a sense of quality.
The specific properties and requirements of certain electrical components and applications make gold a preferred choice in some cases. While copper excels in conductivity, gold’s malleability and resistance to tarnish recommend it for contact applications. Copper remains optimal for general wiring, aluminum suits larger conductors, and Ni-chrome prevails in heating elements, while diverse metals find specialized roles such as in light bulb bases.
What are the advantages of using gold in electronics.
Gold finds its primary application as a thin plating on connectors due to its unique attributes. Unlike most metals, gold’s resistance to oxidation results in a reliable, smooth surface for consistent connections, crucial for preventing poor mating surfaces caused by uneven oxide layers. This becomes especially vital for thin wires where even slight oxidation can drastically reduce capacity. The absence of potential barriers due to oxide films on gold’s surface prevents diode formation, ensuring unhindered electron flow. In audio equipment lacking gold-plated contacts, distortion can arise from rectification effects caused by these barriers.
Gold’s excellence in bonding wires, owed to its malleability and corrosion resistance, and its benefits in connectors due to corrosion resistance and softness that optimizes contact surface area, make it irreplaceable in electronics. Gold’s nobility, non-corroding nature, high conductivity akin to copper and silver, and ductility for fine wires in ICs further underline its electronic prowess, despite cost considerations leading to thin layers of gold plating over nickel for wear resistance, or selective gold plating. Its combination of properties remains unparalleled, rendering it indispensable in a wide range of electronic applications.
While copper is a better conductor of electricity than gold, the unique properties of gold make it advantageous for specific applications in electronics. These advantages outweigh the higher resistivity of gold compared to copper.