Ran two simulations. One was without a heat spreader. One was with a heat spreader. The temperatures can go up to 85 degrees Celsius before the integrated circuits are permanently damaged.

(Before I start on the next part I want to say I should do hand calculations. I would do hand calculations but I am a rising sophomore in college and still have not had thermodynamics. I was told by my summer boss that these numbers are higher than they should be. So before I go and tell him he is wrong I want to make sure that there is nothing wrong with my simulation.  Also, there are many small features that I am sure are not in the model but I was told to do my best with what I was given.)

Attached are two pictures- one from the first simulation without a spreader and one with a spreader. What I am trying to do is take the heat from the ICs (the hottest parts) and spread them through the copper to the top half of the enclosure. It is not supposed to be a heat sink (where it has fins, I believe) as I tried to model one and my boss said not to.  The strange thing is two simulations before, I had numbers ranging from upper 20 degrees Celsius to 92 degrees.  I am not aware of anything that changed, but I reset the simulation because for some odd reason the “run” button would not respond. 

I know I have posted something similar, but I feel like I did not elaborate enough or provide the file for anyone to actually give specific advice.  

I will attach file with the assembly/simulation as well.

By the way, the difference between the two simulations is I did not have the parts heatsink1, heatsinku1, heatsinku2and3(1), heatsinku2and3(2), and heatsinku6 in the simulation. 

TL;DR-  Added a heat spreader but the result is similar and both simulations are way too high according to the overlords

*attach two pictures of temperatures and the file itself