The Effect of Drilling Temperature on Multilayer Board Hole Quality

The Quality of holes drilled in multilayer printed circuit boards and the usable life of a drill are a function of the drilling speed and feed rate per revolution. Investigations have shown that, as the RPM is reduced and the feed rate per revolution (bite) increased, both hole quality and drill life are improved. The temperatures generated during the drilling process have been measured as a function of RPM and feed rate, and shown to be the cause of the variation in drill life and hole quality. Experimental data substantiating these results is presented. Acknowledgement is made to the Institute of Printed Circuits for their permission to reproduce this paper.