Gold plating is a commonly used surface finishing method, where a thin layer of gold is deposited onto another metal by chemical or electrochemical plating. You may find yourself wondering: How thick is gold plating? How long does gold plating last? We’ve put together a gold plating guide for your projects that may require this type of surface finishing.
How Thick is Gold Plating?
Gold plating is the deposit of a thin layer of gold metal on a substrate, typically in the 0.25 – 5 micron range (0.00001”-0.0002”). Gold is a lustrous, malleable transition metal. It has been used for millennia for making jewelry and coinage. Currently, besides the considerable amount still used in jewelry making, gold is often used for corrosion protection, wear protection, and for its high capacity to pass an electric current. Gold is one of the most conductive metals, slightly below that of silver and copper. Unlike silver and copper, however, gold does not tarnish in air or moisture, and therefore retains its conductivity in more challenging environments. Gold also tends not to be subject to fretting corrosion making for ideal contact surfaces that frequently break contact.
Gold Plating Process
Gold plating baths have become very diverse in their composition and final appearance. Some gold plating baths have been designed for their beautiful appearance and others for their deposit properties. In the electronics industry, the purity of the deposit is of the utmost concern. The higher the purity of the gold deposit, the greater the conductivity of the material.
In the process of gold plating, a part is submerged in a solution containing gold salts. A DC current is applied where the part receives the negative current becoming the cathode, and anodes will receive the positive current creating an electrolytic cell. During this process, gold salts will be oxidized at the anode and travel through the solution along the electrical path, where they are reduced at the cathode and form the gold coating.
Benefits of Gold Plating – Why is Gold Used in Electronics?
Besides the jewelry industry, most gold plating is performed for the electronics industry. Gold is one of the most conductive metals available, and its ability to retain that conductivity in diverse environments makes it an ideal conductor. Gold contacts can be seen in most electronics from cell phones to semiconductors.
Gold is a very durable metal that tends to spread out rather than wear off. For products such as charging stations, this makes an ideal coating for where contacts are made and broken on a regular basis. Many other materials will wear off over time, or fret to the point of lowered contact requiring replacement parts. Gold’s tendency to resist these types of wear makes it an ideal coating for durability.
Gold has a high melting point of 1947°F, giving it the ability to withstand high temperatures without degrading its properties. This high heat-resistance can also protect substrates that could otherwise degrade at elevated temperatures.
Gold does not tend to react with air or water and preserves its properties over a longer period of time than silver or copper. Gold is extremely resistant to environmental corrosion and oxidation. Parts coated in gold tend to be replaced less frequency, making for a long-term advantage in the lifespan of parts.
To learn more about gold plating services, please contact our experienced team at Silvex today.