I am sure @tbraxton can elaborate on the files, but they don't look right to me with my limited knowledge.
A significant Creo limitation for thermal is that you have to know the convection coefficient(s). CFD methods have an advantage here. (I don't know anything about Creo CFD, so maybe someone else can elaborate for that tool)
We use Altium for schematic capture and board design and it is easy to generate 3D step files.
For simulation generally you will want to substitute simple blocks/cubes for any more detailed 3D chip models.
For a very simple board I have manually created circuit traces or traced over a .dxf file or image of the board as reference.
The trick with actually modelling the traces is that the element size for the thickness is tiny. I have scaled the thickness up and then reduced the material thermal properties proportionately. As far as the convection coefficient problem, we use full cfd analysis and preferably Ansys Icepak, because Icepack can estimate PCB board thermal conductivity variables based on an imported ECAD and the actual traces, without having to model all those tiny details. Of course if the previous standard is some hand calculations, then any additional level of analysis, like what Creo can do would be a step in the right direction. Anyway, I may be able to give tips for your thermal studies as you go along on this broad subject.
