What is circuit board sulfur-free paper (PCB sulfur-free paper)?
Why do circuit boards need to use sulfur-free paper? This has to start from the circuit board manufacturing process of some of the process. The main body of the printed circuit board is copper, which only reacts with oxygen in the air to generate dark brown cuprous oxide. In order to avoid oxidation, PCB in the manufacturing process there is a silver deposition process, so the PCB is also commonly known as silver-plated board. There is a silver deposition process in the manufacturing process, which has become one of the primary final appearance of printed circuit boards. However, there is a great affinity between silver and sulfur, silver in the air when encountering hydrogen sulfide gas or other sulfides, it is easy to generate very insoluble silver salts, resulting in yellowing and blackening of the product, that is, corrosion. Sulfur-free paper itself does not contain sulfur, will not react with the PCB surface of the immersed silver layer, the use of sulfur-free paper wrapped PCB b
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