... resistance value of the difference in size only. Very low resistance material called a good conductor, such ... types of holes are located in the inner layer circuit board, laminated before use through-hole ... and High Frequency PCB: FR4 PCB(2layer,4 layer,multilayer) Rogers(RO4003,RO4350,RO5880,RO3003,RO3010, ... Union Certification:CE,ROHS,FCC,ISO9008,SGS,UL4 layer High Tg pcb board represents: a high heat ...