PCB lines are now the most common. Most PCBs require painting. Why is this?
The front and back of the pcb circuit are basically copper layers. In the production of pcb circuits, no matter whether the copper layer is produced by variable cost or double-digit addition and subtraction, it will eventually obtain a smooth and maintenance-free surface. Although the physical properties of copper are not as good as aluminum, iron, magnesium, etc., under the premise of ice, pure copper is very easy to be oxidized when it comes into contact with oxygen; considering the presence of co2 and water vapor in the air, the surface of all copper Oxidation-reduction reactions occur immediately after contact with gas. Considering that the thickness of the copper layer in the pcb circuit is too thin, the oxidized copper will become an electrical quasi-stable state, which will greatly affect the electrical characteristics of the entire pcb circuit.
In order to better prevent copper oxidation, and to better separate the electric welding part of the pcb circuit from the non-electric welding part during electric welding, and to better protect the surface of the pcb circuit, technical engineers have created a unique Architectural Coatings. Such a coating can be easily brushed on the surface of the PCB circuit to form a protective layer with a necessary thickness and block the contact of copper and gas. This layer of coating is called attached copper, and the raw material used is solder resist paint.
