Introduction to the comparison of chemical coating and metal coating

In previous articles, we have been mentioning the characteristics of Dacromet coating technology and related development and application, so what is the relationship between this coating and metal coating? What is metal coating? Below we have Ask the technical staff of the metal coating manufacturer to introduce to you:
First, what is coating
According to the introduction of Baidu Encyclopedia: Coating is a technical method of covering a layer of material on the surface of a substrate, such as dipping, spraying or spin coating, etc. to cover a layer of photoresist on the surface of the substrate to enhance corrosion resistance. Ability, anti-scratch ability and ink printing adhesion. The coating method can be two kinds of electroplating or electroless plating.

2, chemical coating and metal coating
Metal coating is one of the external surface treatments of printed boards, that is, in order to protect the internal metal material, increase solderability, corrosion resistance, and oxidation resistance, a layer of metal is coated on the surface of the material, and its material is often gold, silver And lead-tin alloy. There are generally two methods of metal coating: chemical coating and electroplating coating.
(1) The electroplating method can make the coating dense, firm, uniform and controllable in thickness, but the equipment is complicated and the cost is high. This method is used for printed boards and coatings with high requirements, such as gold plating on the plug part, etc.
(2) Although electroless plating has simple equipment, convenient operation, and low cost, the thickness of the plating layer is limited and its firmness is poor. Therefore, this method is only suitable for surface coatings that improve solderability, such as copper foil pattern silver plating on the board surface.