Issue link: https://iconnect007.uberflip.com/i/565949
46 The PCB Magazine • September 2015 was validated by showing me a nearly empty reject bin. I said, "That's great—now show me a box of recently re-pointed and passed drill bits," and out came the box. I sat down at the re-point inspection microscope and started inspecting the bits myself. By the third one I had it—huge gouges on the cutting edge! I showed it to management and immediately their glare turned towards the poor operator I just helped bust. I stepped in right there. I explained that the scope was too low of a magnification to properly inspect each bit—especially when the diameters they were running are down to 8 mils. I asked them how exactly does one ac - curately re-point a 10- or 12-mil drill bit when it is barely visible, and then inspect it, all at a relatively high rate of speed (time is mon- ey)? There are multiple facets on the typical drill bit that should be looked at. The lesson here is to look for an automated re-pointing and inspection operation, or out-sourcing to one. Do not settle for less if your designs have smaller vias (< 12 mils). Otherwise you are playing a not-so-fun game of roulette. Next, inspect the drilling area for optimal settings for the material being processed. How are they assigning feed and speed tables to the machines? I have yet to see file servers oft-ware being used in China, such as that from FASTechnologies. This means that the operator is responsible for entering in feeds and speeds based on the type of material—super scary. On more than one occasion I've picked up a trav-eler and asked them to show me the machine settings, only to find out they don't match the F&S tables for the given material. Other times, the machine settings require something to be calculated or converted from their standard F&S tables, but there's no calculator to be found in the department. They really expect operators to do this sort of math in their head—or are they just assigning round num- bers that are close? All of these are opportunities for failure, but I've yet to be presented with a bad cross section…very sneaky. Table I shows some of the failures caused by poor drilling and the effects. figure 3: video of an automatic re-pointing machine. BECOMING AN AuTOMOTIVE SuPPLIER—PROCEED WITH CAuTION continues FEAturE