1)4-layer computer mother board pcb 2)Base material: ... THINCKNESS0.2mm-6.0mmCAMBERD≤0.75% (DOUBLE SIDE)D≤0.7%(MULTILAYER)IMPENDENCE ... TOLERANCE±0.1mmPROFILEMILLING MOULDING V-CUT CHANFERCOATINGHAL, LEAD FREE HAL, ENIG/IMMERSION GOLD, OSPSOLDER MASK COLORGREEN ... , WHITE,REDTECHNNOLOGYBLOCK,BGA,PEELABLE,CARBON INKASSEMBLYLEAD FREE,NOT LEAD FREELEGEND COLORWHITE, BLACK, YELLOW,GREENCERTIFICATEUL,ROHS ...