With PVD technology is widely used in the semiconductor industry. "Waterproof Cooling Fan" technology is finally refer to waterproof fan industry. The technology uses a PVD vapor deposition techniques. Waterproof material in high temperature gasification, then slowly deposited on the surface of the motor at low temperatures. "Waterproof Cooling Fan" technology takes a long time and is expensive. The motor will eventually surface to form a very strong protective layer. The protective layer does not decompose water. Hardness, basically afraid of the external force. However, due to the motor and the outside world is powered by wires. The protective layer due to the strong hardness, the assembly process often need to bend the motor and the wire bonding portion. Likely to cause cracks, and is unrecoverable. 50% failure rate. So the fan running water waterproof test. Water first enters the internal PCB board from lead solder, and then caused a short circuit burned between the electronic component pin. "Waterproof Cooling Fan" technology is widely used in high humidity, no fluid water segments. Protection level can reach IP55.