... Controlled, Vias Plugged with Solder Mask, RoHS Compliance. 12-Layer PCB,Taconic Material,2.0mm Thickness,Immersion Tin,Impedance Controlled ... Copper Weight10 ozImpedance Control+/- 5% Insulation Resistance1E+12Ω(Normal) Thermal Shock 3x10Sec@288 Centigrade DegreeWarp and Twist<= 0.7%Electric ... Carbon PrintingMaterialFR4, ROGERS, Taconic, ARLON, BT, Ceramic, Aluminum 12-Layer PCB with Taconic Material