I need some help for a colleague on thermal dissapation.
A design with one mother board and three daughter boards, ALL 
with 10 lbs in a 5 lb container. The daughter boards are all 
within a half inch of motherboard. Needless to say when 
running inside the box after awhile things tend to get
somewhat hot approx 125 degrees C. If outside in open air the
temp drop is only about 15 degrees C. They do not want to use
fans and conventional heatsinks seem out. A thermal plane on both
outside layers is being considered realizing that although you 
may be able to solder the board once rework is out. Is there
any suggestions out there in the board material. I suggested 
liquid cooling ha ha. I don,t now of any other means of 
bringing the temp down that much without fans. Any help 
would be greatly appreciated. The mechanical designer asking
me this is supposed to do something with the enclosure, but no 
fans are being considered. He has no other ideas either. 
Thanks up front. I could not believe anyone would try and cram
that much electronics in such a small area with no thought for 
heat untill after the design was done. The desity is double sided
surface mount with thru hole jammed on all four boards.
P.S. I could really use this help ASAP so E-Mail or Phone would be great.

Robert M. Wolfe
203-882-6405