BEST HOLES: NEVER TOO BIG OR TOO SMALL.

Tolerances for hole sizes in printed circuit boards (PCB) and the industry guideline is considered. However, the guideline does not take into account all the relevant tolerances, nor does it recognize any distribution of tolerances. Statistical techniques are used to determine the last hole size based on an analysis which takes into account two relevant subsystems separately and then the information is combined. The first subsystem consists of the component lead, the insertion guides and the insertion guide positioning system. The second subsystem consists of the table, its positioning system, the tooling place and the PCB with its appropriate holes.