... UL ROHS REACH 3.Environment friendly PCB 4.Timely delivery Blank PCB Boards1,base material:FR-4 epoxy resin2,cooper thickness ... Gold), Immersion Silver , Gold Plating (Flash Gold), OSP, etc.14SoldermaskGreen, White, Red, Yellow, Black, Blue, transparent photosensitive soldermask, Strippable soldermask.15Minimun ... and High Thickness copper21Thickness of Copper0.5-14oz (18-490um) Blank PCB Boards