... : White(default) or others5) Surface technique: Tin soldering, plating gold, immersion gold,OSPDiscription:1) Layer: 1-402) Board finished thickness: 0.21mm ... : HASL / HASL lead free,HAL, Chemical tin,Chemical Gold, Immersion Silver/Gold,OSP,Gold plating 8) Copper thickness: 0.5-7.0 OZ9 ... assemblies as well as electronic encased products 8-layer chemichal gold PCB