... Blind hole is connected to the inner surface layer and not through imposition vias.It means a ... is not visible. These two types of holes are located in the inner layer circuit board, laminated before ... and High Frequency PCB: FR4 PCB(2layer,4 layer,multilayer) Rogers(RO4003,RO4350,RO5880,RO3003,RO3010,RO3206 ... Union Certification:CE,ROHS,FCC,ISO9008,SGS,UL4 layer High Tg pcb board represents: a high heat ...