Mechanical drilling of printed circuit boards: the state-of-the-art

Purpose - To provide a clear picture of the current status of mechanical drilling of printed circuit boards (PCBs). Design/methodology/approach - A review paper detailing the developments of micro-drill bit and PCB mechanical drilling techniques. Findings - Mechanical drilling will still dominate the PCB hole processing methods. A design method on the basis of theoretical analysis, numerical simulation and experimental verifications is proved as an applicable way to improve the drill bit design efficiency. Newly developed tungsten carbide, novel coating techniques and high-performance steel-shank micro-drill bits are expected. Solutions of micro-drill bits for high-density interconnection, IC substrate flexible PCBs, halogen and lead-free assembly compatible PCBs, as well as 2 mm shank diameter drill bit are worthy of being concerned. Originality/value - The paper highlights the state-of-the-art techniques of micro-drill bit manufacturing and novel developed micro-drill bit. The development direction of micro-drill bit in the future is concluded.