Charging interfaces and plugs are plated with wear-resistant chemical nickel. High hardness PVD in the middle frame, dark black nickel or black tin nickel electroplating in the tablet internal shield, smart watch case electroplating +PVD, high-end wireless headset charging column electroplating rhodium ruthenium or platinum ruthenium or pure platinum. Silver plating on ceramic filter, improve the traditional silver leaching process precious metal loss big problem, electroplated silver film thickness evenly distributed on the product, effectively save metal silver material cost, no high temperature baking, the process is more energy saving and environmental protection.