Gold is the true gold. Even if only a very thin layer is plated, it already accounts for nearly 10% of the cost of the circuit board. There are many merchants in Shenzhen who specialize in purchasing waste circuit boards and use certain means to wash out gold, which is a good income.

　　The use of gold as a coating is for the convenience of welding and for corrosion prevention. Even the gold fingers of memory modules that have been in use for several years still flicker like before. If copper, aluminum, and iron were used in the past, they would now rust into a pile of waste.

　　The gold plating layer is widely used in the solder pads, gold fingers, connector shrapnel and other positions of circuit boards. If you find that the circuit board is actually silver, it goes without saying. If you directly call the consumer rights hotline, it must be that the manufacturer cut corners, did not use the materials properly, and used other metals to deceive customers. The motherboards of the most widely used mobile phone circuit boards are mostly gold-plated or gold-plated, while computer motherboards, audio and small digital circuit boards are generally not gold-plated.

　　The advantages and disadvantages of the gold sinking process are not difficult to come by:

　　Advantages: It is not easy to oxidize, can be stored for a long time, has a flat surface, and is suitable for welding fine gap pins and components with small solder joints. The preferred PCB board with buttons (such as a mobile phone board). Repeated reflow soldering is not likely to reduce its solderability. It can be used as a substrate for COB (Chip On Board) wiring.

　　Disadvantages: High cost and poor welding strength, as the use of electroless nickel plating process can easily lead to black disc problems. The nickel layer will oxidize over time, and long-term reliability is a problem.

　　Now we know that gold is gold, and silver is silver? Of course not, it's tin.