... 12-Layer PCB with Taconic Material, Immersion Tin, Impedance Controlled, Vias Plugged with Solder Mask, RoHS Compliance. 12-Layer PCB,Taconic Material,2.0mm Thickness,Immersion Tin,Impedance Controlled,Vias Plugged with ... (conductor peel strength) Impedance Test Ionic Contamination Test-------------------------------------------------------------------------------- 12-Layer PCB with Taconic Material