... immersion gold,half holegold finger 4layer,2.0mm,immersion sliver 6layer,2.0mm,immersion gold,BGA,half hole 12layer, 2 ... 1.6mm, matt green, BGA,impedance control With regard to our PCB prdocts,pleas find the following specification,table1 and 2 ... resistanceDifferential 90Ω±7%Technology with step slot&step holeHDI3+N+3Application standedIPC-6012 class 2Multilayer PCB Table 2: PCB business:Prototype : ...