Multi-Layer PCB High frequency PCB (Rogers, F4BK, Taconic ) Metal PCB (Al-based, Cu-based) HDI PCB assembly 2 layer,1.6mm,immersion gold 2 layer,1.6mm,immersion Tin 4layer,1.6mm,immersion gold,plated slot, 4layer,1.6mm,immersion gold,half holegold finger 4layer,2.0mm,immersion sliver 6layer,2.0mm,immersion gold,BGA,half hole 12layer, 2.4mm, BGA, different impedance 8layer, 0.8mm, immersion gold, ...