I agree Glenn. Over the years I have seen drilling process data that suggests the laminate drills differently with the seasons. However, the cure never seems to be off. I wonder how humidity might affect the behavior of the laminated panel. More recently I have heard that laminate suppliers will be changing to a sovlentless process. How might this affect the material behavior? Does anyone have any information on this? Drilbert [log in to unmask] wrote: > > Richard, > Could it be the change of seasons? I believe humidity and > temperature have an affect on several processes from the weaving operation, to > impregnation at the laminator, to stack-up, and press. But, I don't have any > hard data to prove it. Maybe the gremlin is Mother Nature in disguise. > > Glenn Pelkey > Quality/Reliability Engineer > > Richard MacCutcheon <[log in to unmask]> Wrote: > | > | We seem to have developed a gremlin in our registration > | dept. > | A very large portion of scrap is attributed to NO Annular > | Ring (<.002"). > | > | Over 90% of our product is 8-layer GIL with 2 and 7 as > | ground planes. > | Cores are .005 constructed of 1-106 and 1-2313. Prepreg > | is 2313. > | > | Layer to layer misregistration is around .005" on average. > | Artwork pad > | sizes are .022" over the max acceptable hole size. > | Tooling seems to be as > | tight as ever but in the last few weeks we have had an > | inordinate amount of > | scrap due to NO Annular Ring. > | > | What is the best systematic approach to take in > | identifying the problem(s)? > | > | Thanks for your time. > | > | Richard MacCutcheon > |