INNOVATIVE MINI 3-AXIS COMPUTER NUMERICAL CONTROL (CNC) MACHINE FOR THE FABRICATION OF PRINTED CIRCUIT BOARDS (PCBS)

In the manufacturing industry of Printed Circuit Boards (PCBs), the quality and reliability of circuits are highly dependent on the accuracy of the manufacturing processes. In this work, all the effects of inaccuracies in etching during the manufacturing process and the causes of malfunction in PCB circuits are investigated and resolved via a Computer Numerical Control (CNC) device. The mechanics behind a PCB milling machine design and construction have been investigated to identify the roots and fundamental techniques in CNC milling technology. To advance innovation in this project, the machine control and command processes as well as the positioning information were forwarded from the controlling software via a serial port connection directly to the milling machine's on-board controller, which in turn controlled the motion and continuous monitoring of the various components that moved the milling head and controlled the spindle speed at speeds ranging from 30,000 to 100,000 RMP. Typically, this drive system comprises nonmonitored stepper motors for X-Y, an on-off nonmonitored solenoid, a pneumatic piston or lead screw for the Z-axis, and a DC motor control circuit for spindle speed, none of which provide positional feedback. This study incorporated both milling and laser etching capabilities into a single CNC machine for PCB milling.