black solder mask PCB 1.high quality, low cost&fast delivery ... sample before production 4.One-stop-service black solder mask PCBWe can provide you all lines of PCB, PCB ... 0.075mm/3mil7. Copper Thickness: 0.5oz-5oz(17µm-175µm)8. Surface Finishing: HASL, Lead free HASL, ENIG, ... Immersion Tin, Immersion Silver, Immersion gold, OSP, Carbon ink.9. Sold mask ...