The Sauna software package from Thermal Software (www.thermalsoftware.com) can be used to simulate a wide variety of electronic components and systems, such as heat sinks (heatsinks), circuit boards (PCB`s), semiconductor stackups (BGA, QFP), high-power LED`s, complete boxes and complex duty cycle transient problems.

 
The Sauna program is quite easy to use. Complex 3D models are created by combining the "building blocks" of circuit boards, plates, and plates with fins. Heat transfer coefficients for both convection and radiation are calculated automatically. All these powerful features are provided at a very moderate price. Sauna can be run on virtually any contemporary Windows PC.

Free Sauna Evaluation Package is available at http://www.thermalsoftware.com/eval_req.htm