Gold plating and immersion gold surface treatment processes are used in many high-frequency PCB production. This adds a protective layer to the surface of copper to prevent oxidation of copper and improve welding performance.

There are many surface treatment processes for high-frequency board PCBs I know: such as gold plating, immersion gold, nickel-palladium gold, silver plating, tin spraying, OPS, etc. Different surface treatment processes have different characteristics and applications. Here we mainly introduce the two most common methods: gold plating and immersion gold.

High frequency board production surface treatment process: gold plating

Gold plating is a method of plating a layer of gold on the surface of copper through an electrochemical reaction. Gold is a very stable metal that does not oxidize and has high conductivity and weldability, so gold plating can effectively protect copper lines and improve the performance and life of PCBs.

The advantages of gold plating are:

1. Gold-plated high-frequency boards can be stored for a long time without discoloration or deterioration, making them suitable for long-term use or storage.

2. The gold-plated high-frequency board can withstand high temperatures and will not fall off or deform. It is suitable for high-temperature welding or high-temperature working environments.

3. Gold-plated high-frequency boards can improve signal transmission quality, reduce signal loss and interference, and are suitable for high-frequency, high-speed, and high-precision circuits.

High frequency board production surface treatment process: immersion gold

Immersion gold is a method of depositing a layer of gold on the surface of copper through a chemical reaction. The difference between immersion gold and gold plating is that immersion gold only deposits gold on the pads, while gold plating plating gold on the entire circuit.

The advantages of immersion gold are:

1. The lines of the immersed gold high-frequency board are smooth and have no protrusions or depressions, making it suitable for surface mounting technology and the installation of micro components.

2. The welding performance of immersion gold high-frequency boards is good, because the crystal structure of immersion gold is finer than that of gold plating, and it is easier to combine with solder. Moreover, the hardness of immersion gold is lower than that of gold plating, which makes the solder joints less brittle.

3. The signal transmission quality of the immersion gold high-frequency board is good, because the immersion gold is only immersed on the pad, which will not affect the impedance of the line, and the immersion gold line will not produce gold wires, reducing the risk of failure.