<<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