To everyone,
     
     We have, in the past, had problems with bare board warp and 
     delamination in our assembly process (reflow).  We have solved this 
     problem by instituting a baking process at our vendor or in house 
     prior to assembly.  My questions are as follows:
     
     1. Is baking a standard PCB fab process (before shipping)?
     
     2. If so, what is the standard profile?
     
     3. If not, why do some vendors' boards need to be baked to prevent     
        warp and delamination while others don't?
     
     4. Does baking cure both delamination and warp or does it just cure    
        warp?
     
     5. My understanding is that moisture is getting trapped in the board   
        during laminate press (or contamination of some sort) which is      
        leading to the problem during assembly.  Can the moisture           
        entrapment be avoided?  Should we claim to our vendor that he       
        better control contamination in the process?
     
     5. It seems to me that if boards need to be baked before delivering to 
        a customer that there is some poor process control going on.
     
     Someone, please educate me.  Maybe, my perspective is in error.
     
     Thanks,
     
     Roger Held
     Hitachi Computer Products (America), Inc.
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