There are some differences in process between PCB immersion gold and chemical gold plating, mainly in the following aspects:
1. Deposition method: The immersion gold process uses chemical deposition to make metal ions form a layer of metal coating on the surface of the circuit board. Electroless gold plating reduces gold ions into metallic gold through a chemical oxidation-reduction reaction and deposits it on the surface of the circuit board.
2. Coating thickness: The metal coating formed by the immersion gold process is thicker, generally about 2-5 microns, and can meet the needs of a variety of applications. The metal coating formed by chemical gold plating is thin, generally about 0.5-1.5 microns, and the thickness of the coating is greatly affected by factors such as reaction time and concentration.
3. Crystal structure: The coating formed by the immersion gold process has a dense crystal structure, is not easily oxidized, and has good corrosion resistance and stability. The crystal structure of the coating formed by chemical gold plating is relatively loose and easily oxidized, so corresponding protective measures need to be taken to improve its stability and corrosion resistance.
4. Appearance quality: The coating formed by the immersion gold process has a smooth and bright appearance, with good aesthetics and decorative effect. The appearance of the coating formed by chemical gold plating may have some defects, such as particles, bubbles, etc., and corresponding treatment measures need to be taken to improve its appearance quality.
5. Production cost: The cost of equipment and raw materials required for the immersion gold process is high, and it requires a high technical level and strict production management. The cost of equipment and raw materials required for chemical gold plating is relatively low, and the operation is simple and easy to control.
To sum up, there are process differences between PCB immersion gold and chemical gold plating, which are mainly reflected in deposition methods, coating thickness, crystal structure, appearance quality and production cost. In practical applications, appropriate processes should be selected according to specific needs to meet actual needs.