... -55um Thicknes:1.6mm Surface Treatment:immersion Ag Sterling silver PCB Layer:8Min.Hole copper:25umSurface copper:35- ... thickness: 0.21mm to 7.0mm· Copper thickness: 0.5 OZ to 7.0 OZ· Copper thickness in hole: ... HASL lead free, HAL, Chemical tin, Chemical Gold, Immersion Silver/Gold, OSP, Gold plating · Solder Mask Color: Green/Yellow ... assembly as well as electronic encased products. Sterling silver PCB