1.4-layer black immersion gold PCB 2.Quality and delivery assurance 3.18 years ... /treatment : HASL / HASL lead free,HAL, Chemical tin,Chemical Gold, Immersion Silver/Gold,OSP,Gold plating 8) Copper thickness: 0.5 ... as electronic encased products Detailed Product Description:4-layer black immersion gold PCBTested by:Testing jigSolder Mask:BlackSilk Screen:Single-sided ...