SU7 MECHANIC Green UV Instant Curing Solder Mask Ink. It is a specialized ink used to protect printed circuit boards (PCBs) during soldering and prevent short circuits. Here are some key features and uses: Protection: It shields PCB traces from corrosion, moisture, and physical damage. Insulation: It provides insulation between conductive circuits, preventing arcing and short circuits. UV Curing: The ink cures quickly when exposed to ultraviolet (UV) light. Application: It is applied to PCBs after soldering rework to protect traces.