A printed circuit board (PCB) design has many different layers, and silkscreen is the topmost layer of a printed circuit board (PCB) and often occurs as the last step in the printed circuit board manufacturing process. As the pcb screen printing must be printed on the PCB surface, each PCB has two silkscreen layers layers at most,on the top side and the bottom side. In order to provide reference marks for components on PCB.
It is a non-conductive epoxy ink, which is a specially formulated ink. Its common color is white color, besides there are other pcb silkscreen colors of yellow, blue,black,red and so on.
Silk screen printing is a layer of oil traces which used to spot component parts, testing points, PCB elements, warning sign, signs and tabs.Useful information for specifying PCB boards to help manufacturers and engineers locate and identify all components during assembly. It is used to pick out elements values, PN numbers,test points, etc.