1.single layerpcb board with rohs 2.lead free HASL 3.two ... Product rangeWe offer a wide range of PCBs such as single-sided, double-sided, multi-layer, high frequency, MCPCB, metal-backed ... (2.5mil) Soldermask Clearance (b)0.1mm (4 mil)Min SMT Pad spacing (c)0.1mm (4 mil)Solder Mask Thickness0 ... find that we are the right PCB supplier you want! single layer pcb