Detection circuit in PCB board reverse design system

On the unknown printed circuit boards?,when an electronic engineer performs the inverse design or maintenance of electronic equipment, he first needs to understand the connection relationship between the components.
Discussion on Antioxidation of Copper Surface in PCB board Production

At present, in the operation cycle of copper sinking, whole PCB board? electroplating and pattern transfer in the production process of double-sided and multi-layer PCB boards.