Development of a micro-drilling burr-control chart for PCB drilling

• We have developed a chart based on DOEs. It can be used to control the burr size for various process parameters.
• Micro drills were used for drilling PCB. The study aims to optimize the drilling process by minimizing burr formation.
• The chart has been divided into uniform burr, transient burr, preferred burr, drill breakage and critical burr region.
• Taguchi method and multiple regression tests were performed for determining the variance in the burr height.
• It was shown that drill diameter made a statistically significant contribution to the variance in burr height.

A drilling burr-control chart (DBCC), based on experimental results, is a tool for the prediction and control of drilling burrs for a large range of drilling parameters. A micro-drilling burr-control chart (M-DBCC) was developed for a standard double-sided copper-clad laminated (CCL) printed circuit board (PCB) with laminated fiber-reinforced plastic (FRP) substrate. This chart will assist in the selection of favorable drilling parameters for predicting and achieving preferred types of burrs. Burr classification was carried out according to the burr geometric characteristics, burr formation mechanisms, burr height, and drill bit breakage while drilling. The design of experiment (DOE) technique based on the Taguchi method was used to find the most significant drilling parameter affecting burr height. The results show that the drill diameter makes a statistically significant contribution to burr-height variation.