The deposit is made by chemical deposition, and a layer of coating is generated by chemical REDOX reaction. Generally, the deposit is thicker, which is one of the chemical nickel gold deposition methods, and can reach a thicker gold layer.
Gold plating USES the principle of electrolysis, also known as electroplating.Other metal surface treatment is also mostly electroplating.
In practical product application, 90% of the gold plate is the heavy gold plate, because the poor welding quality of the gold plate is his fatal shortcoming, which is also the direct reason that many companies abandon the gold plating process!
The gold precipitation process deposits the nickel gold coating with stable color, good brightness, flat coating and good weldability on the surface of the printed circuit.Basically, it can be divided into four stages: pre-treatment (oil removal, micro-erosion, activation and post-immersion), nickel precipitation, gold precipitation, post-treatment (waste water washing, DI washing, drying).The thickness of gold deposit is between 0.025-0.1um.
Gold is applied to the surface treatment of circuit board, because of its strong conductivity, good oxidation resistance, long life, general applications such as pressing the button board, gold finger board, etc., and the most fundamental difference between gold plate and gold plate is that gold plate is hard gold (wear-resisting), gold plate is soft gold (not wear-resisting).
1. The crystal structure formed by gold deposit and gold plating is different. Gold deposit is much thicker than gold plating.
2. The crystal structure formed by gold precipitation is different from that of gold plating. It is easier for gold plating to weld and will not cause welding defects.The stress of gold plate is easier to control, which is more beneficial to the processing of the product.At the same time, because the gold is softer than gold, so gold plate gold fingers do not wear (gold plate shortcomings).
3. The gold plate only has nickel gold on the welding plate, and the signal transmission in skin effect will not affect the signal in the copper layer.
4. The crystal structure is more compact and less prone to oxidation than that of gold plating.
5. As the precision requirements of the PCB are higher and higher, the line width and spacing have reached below 0.1mm.Gold is easy to short circuit.The gold plate only has nickel gold on the pad, so it is not easy to produce short circuit wire.
6. The gold plate only has nickel gold on the welding plate, so the resistance welding on the line is more firmly combined with the copper layer.The project will not affect the spacing when making compensation.
7. For the boards with higher requirements, the flatness is required to be better. Heavy gold is generally adopted.The flatness and service life of gold plate are better than gold plate.