We have been using the "Shadow" process in the manufacturing of 
     multilayer and double-sided, polyimide, epoxy and teflon boards since 
     the beginning of 1995.  The process is working very well for us.  
     There was definitely some process tuning that took place prior to 
     implementation and then optimization occurred throughout the year.  
     
     Care needs to be taken with processes leading up to "SHADOW".  Drills, 
     repoints, # of hits, how rough the hole is;  desmear (we plasma and 
     vapor hone), degree of etchback, again how rough the hole is;  are the 
     types of things which need to be considered.  Aspect ratios, and hole 
     sizes of the product being run are also necessary to consider.  
     
     Just like any new process the three ingredients, the process engineer, 
     the chemistry and the equipment supplier, have to mesh well for a 
     successful process implementation.  It did at our facility, we took 
     out our electroless line in April of 95.
     
     Customer education was important.  Once they realized the quality of a 
     direct metalized interconnect they moved from skeptic to advocate.  
     
     It's definitely a proven, viable process.
     
     I'll discuss it in more detail if you like. 
     
     Neal Preimesberger
     Hughes Missile System Co., Tucson AZ
     602-794-1030 or direct:  [log in to unmask]
     
     We have learned much about this new process, too much to put down in 
     print on an E-mail.  Please feel free to give me a call if you care to 
     discuss this process.