... :FR-4,Tg135 Specifications(1)2 Layer ENIG PCB (2)UL ROHS Approved PCB (3)High-density ,high-precison PCBPCB production process ... Hole Size3milMax Finished Thickness8mmAspect Ratio≤12:1Max Layers36 LayersSurface FinishImmersion Gold, Immersion Silver, Immersion Tin, HASL, LF-HASL, OSP ... , Gold Finger, etcBase Material TypesFR-4, Metal Base(Aluminum base,Copper ...