After a number of mishaps in the design of power ICs and modules with respect to devices blowing up it was decided that we would go back to first principles and understand thermal effects and furthermore use thermal modeling to design better, safer and robust ( with respect to thermal operation) devices and modules. In our attempt to do this we came across many different types of information in the literature concerning thermal design. From the very simplistic thermal resistance and power relationships to fairly complicated thermal models. We also came across thermal modeling software information. This was in the year 2008. We took this information and wrote a brief thermal modeling technical note in the hope that we would have less incidents of thermally caused destructive events. Another interesting result of this was that we were able to set up thermal models of MCMs and devices that were not yet in existence and study the effects of thermals on these to – be devices. These models were built up in MATLAB/SIMULINK and were still fairly simple. We used commercially available thermal modeling software for more complex models. All this effort did help and in the end we were able to meet our thermal design goals in a large number of projects. The initial note was released for publication and now resides in: www/signalro.biz >> engineer’s corner for those interested in thermal modeling or thermal effects. We acknowledge the contribution made to thermal modeling by a number of authors both on and off the web.