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