Back drilling board Custom PCB, OEM PCB, HDI PCB, High Frequency Board, High Frequency PCB, Single-Side, Double-Side PCB, PCB Process, Back Drilling Board Supplier Product Type: Back Drilling Board Application Field: Communication Layer/Board Thickness: 12L/2.1mm Surface Finish: ENIG Trace/Space: 5/5mil Smallest Hole Diameter:0.5mm As a PCB board supplier, PCBMAIN specialized in producing HDI PCB, high frequency board, high frequency PCB, single-side PCB, double-side PCB, PCB process, back drilling board, custom PCB, OEM PCB.