I have a general heat transfer problem that I would like some more experienced users to review for me if possible (using Flow Simulation without the electronics cooling module). I have a small aluminum electronics enclosure that interfaces with various electrical heat sources through thin TIM material (2mm, with 0.5mm of compression). I am utilizing contact resistance to simulate conductive heat dissipation through the TIM to the housing, and natural convection of the housing to "stagnant" ambient air at 50C. The idea is to assume worst case conditions, very low convective heat transfer coefficient (5 W/(m²K)) through the enclosure walls, and maximum heat generation of the electronics components to determine the maximum operating temperatures of said electronics components under these conditions. I have gotten the model to work well, but what I do not understand is why the PCB seems to absorb the majority of the heat. Is this because of my convective heat transfer assumption? Or am I applying the contact resistance incorrectly? The files are attached, and any help or recommendations are greatly appreciated!