<<We have experienced a random problem with three or four parts relative to rim voids. <<In some cases it was part of the lot and in others it was the whole lot. <<They have been partial, full, top and or bottom. (no consistency) <<They are typically one to two mils down from the surface copper and one to three mils in height. <<They are not specific to any hole size. <<We use Dupont APG715 Dry Film, and develop on a Atotech/Chemcut horizontal system using Potassium Carbonate. Yes, there have been many assumptions made here, regarding whether you use pattern plate or panel plate, etc. Also, people have assumed that the copper was plated, but maybe not enough or not covered with tin or tin/lead properly. It could be that it was never there. When you say that the voids are "down from the surface," do you mean that they include the surface, or do they start inside the knee of the hole? Also, I would like to know the range of hole sizes affected. Are they all "small" (<0.018" dia) or component, or tooling, or all inclusive? We need data. Are the boards particularly thick? Is every hole in each scrap circuit voided, or only 1 (or a handful)? You mention the type of dry film, which indicates to me that you are on the right trail. (How good is your drying after scrubbing, & how long before they are developed?) You also mention that there are "three or four parts" involved. Do they have more holes than others? (Are they at the high end for #of small holes?) As I said before, WE NEED DATA! MB