In the circuit board production process, the immersion gold and gold plating process are very common processes. Because these two processes solve the problem of the soldering process, the pads are difficult to flatten. As the society is strict with the function and size of electronic products As the mother board of electronic components, the circuit board becomes more and more precise. Electronic products, especially IC and BGA, have extremely high requirements on the flatness of the circuit board pads, so the immersion gold and gold plating process is in a sense Can replace the tin spray process. The lead-tin alloy welding cycle is much shorter than that of immersion gold or gold-plated plates.
Immersion gold boards and gold-plated boards are a process often used for circuit boards. Many engineers cannot distinguish the difference between the two correctly. Some engineers even think that there is no difference between the two. This is a very wrong view and must be corrected in time. Next, I will talk about the difference between gold-plated and gold-plated pcb circuit boards.
Everyone chooses gold plating. What is gold plating? What we call gold plating on the entire board generally refers to "electroplated gold", "electroplated nickel gold plate", "electrolytic gold", "electric gold", and "electric nickel gold plate". There are soft gold The difference between hard gold and hard gold (generally hard gold is used for gold fingers), the principle is to dissolve nickel and gold (commonly known as gold salt) in chemical water, immerse the circuit board in the electroplating tank and connect the current to the circuit board A nickel-gold plating layer is formed on the surface of the copper foil. The electro-nickel gold is widely used in electronic products due to its high hardness, abrasion resistance, and resistance to oxidation.
So what is immersion gold? Immersion gold is a method of chemical oxidation-reduction reaction to generate a layer of plating, generally thicker, is a chemical nickel-gold layer deposition method, can reach a thicker gold layer.
The difference between circuit board immersion gold process and gold plating process:
1. Generally, the thickness of immersion gold is much thicker than that of gold plating. Immersion gold will be golden yellow and yellower than gilding. Customers are more satisfied with immersion gold depending on the surface. The crystal structure formed by the two is different.
2. Because the crystal structure formed by immersion gold and gold plating is different, immersion gold is easier to weld than gold plating, and will not cause poor welding and cause customer complaints. At the same time, it is precisely because the immersion gold is softer than the gold plating, so the gold finger plate generally chooses gold plating, hard gold is wear-resistant.
3. The immersion gold board only has nickel and gold on the pads. In the skin effect, the signal transmission is on the copper layer and will not affect the signal.
4. Immersion gold has a denser crystal structure than gold plating and is not easy to produce oxidation.
5. As the wiring becomes denser, the line width and spacing have reached 3-4MIL. Gold plating is prone to short circuit of gold wire. The immersion gold board only has nickel gold on the pad, so it will not produce gold wire short circuit.
6. The immersion gold board only has nickel and gold on the pads, so the solder mask on the circuit and the copper layer are more firmly bonded. The project will not affect the spacing during compensation.
7. Generally used for boards with relatively high requirements. The flatness is better. Immersion gold is generally used. Immersion gold generally does not appear as a black pad after assembly. The flatness and stand-by life of the immersion gold plate are as good as the gold plate.