The purpose of through-hole drilling printed circuit boards is twofold:
(1) to produce an opening through the board that will permit a subsequent process to form an electrical connection
between top, bottom, and internal conductor pathways, and
(2) to permit through-the-boardcomponent mounting with structural integrity and precision of location.

The quality of a hole drilled through a printed circuit board is measured by its ability to interface with the following processes: plating, soldering, and forming a highly reliable, non-degrading electrical and mechanical connection.

The goals of this chapter are as follows:

●Understanding the drilling process thoroughly
●Recognizing what might go wrong
●Locating where problems could occur
●Detecting whether problems do occur
●Finding root causes of problems
●Correcting undesirable conditions
●Striving for zero discrepancies