4 layer pcb board with blind hole impedance control pcb boardIn the circuit having resistance, inductance and capacitance, the AC ... contrary, and this series circuit.4 layer Blind Via pcb board, one side of the hole in the board surface, and then through to ... ,Western Union Certification:CE,ROHS,FCC,ISO9008,SGS,UL4 layer High Tg pcb board represents: a high heat resistance. Usually high Tg of ...