Through hole circuit board & half hole PCB, no copper burr residue or warpage in half hole, reduce connectors and save space, apply to Bluetooth module and Signal receiver products. HUIHE CIRCUITS PCB board with holes apply to Bluetooth module and Signal receiver products. Our PCB products have passed ISO9001/ISO13485/IATF16949/UL/RoHS/REACH certification. Half Hole & Through Hole PCB List 2 layer OSP impedance control half hole PCB 2 layer ENIG half hole PCB 4 layer ENIG impedance control half hole PCB electric circuit board 2 layer ENIG impedance control half hole PCB 8 layer ENIG half hole custom PCB 4 layer ENIG impedance control half hole fr4 PCB 4 layer ENIG impedance control half hole PCB 4 layer LF-HASL half hole PCB