I have two minor questions for those of you with more experience.
   
   1) I have been carrying my layers around standing on edge in racks, which 
   is causing some handling damage as I go to larger panels.  I am 
   considering laying them flat between processes, but I think I need 
   something to interleave the layers.  It should be cleanroom compatible and 
   durable and shouldn't contaminate the material.  I looked at regular 
   cleanroom paper, but the stuff we use has an oil base.  Tyvek looks 
   promising, but pricy.  Does anyone out there interleave like this?  What 
   do you use?
   
   2) We've just set up a 100K cleanroom to perform all of our 
   photoprocessing in.  We did it because that's what 'everybody' said is the 
   best way to reduce contamination and improve yield.  My question is; what 
   impact does exceeding the 100K particle count have on parts?  Is it just a 
   yield reduction that will show up on my AOI?  If I find that I've 
   processed out of tolerance, should I track down the affected parts and 
   pitch them or should I just monitor for increased scrap?
   
   I know there is no such thing as a stupid question, but I'm working on it.
   
   Bob Hunt
   Boeing Electonics
   Manufacturing Engineering
   (206) 773-8670