I have a true class 10,000 room with environmental control.  We
     manufacture flexible circuits with lines and spaces below 2 mils.
     Most of our work is at about 2.5 mils.  The room has been this way
     from before we had requirements below 4 mils.  We keep the temperature
     at 70 plus or minus 3 and the RH at 50% plus or minus 5.

     The only ionizing equipment we use is on the laminator and the
     exposure units themselves.   We do not ionize the entire room.

     We have the room certified by an outside service once a year.  We
     check the condition of the room quarterly.

     Chuck Brummer
     Acuson



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Subject: [TECHNET] FAB: Clean Room environments
Author:  "TechNet Mail Forum." <[log in to unmask]>,          Ed Cosper
<[log in to unmask]> at ccUnix