Thermal Resistance Networks for Electronics Cooling Solutions: Initial Set Up

During a feasibility analysis for electronics cooling solutions, the objective is to estimate the heat flow using engineering approaches and judgment. By applying a thermal resistance network to the heat flow pathways within the system quantitative estimates for heat flow can be developed as an initial screen for feasibility of component design.

As an example consider a single-chip BGA package on a PCB board in a device. As a first step, the approximate heat transfer paths from the power dissipating components need to be identified to develop the thermal resistance network. For this package the primary heat transfer paths are given in Figure 1.

Figure 1.

Figure 1

Two main heat dissipation paths from the die exist: to the case of the package and secondly, through the BGA and into the PCB.  Heat from the case and board is then passed to the skin of the device for convection to the ambient environment.

In the thermal resistance network the two dissipation paths are represented by two branches: one through the case and a second through the board. The thermal resistance network is given in Figure 2.

Figure 2.

 Figure 2

Flow through the case has resistances: Junction to Case (Θjc), Case to Skin Interior (Ra), Through the Skin (Rs) and Exterior Skin to Ambient (R1); and flow through the board has resistances: Junction to Board (Θjb), Through Board (Rb), Board to Interior of Skin (Ra), Through the Skin (Rs) and Exterior Skin to Ambient (R1).

For a feasibility analysis it is recommended that values providing a conservative assessment are used, aggressive estimates for heat transfer coefficient would severely overestimate the heat transfer rate and may lead to complacency that is not justified. Once an appropriate thermal resistance network has been developed the expected temperature rise for a given operating condition can be obtained. Further details of calculation of the temperature rise for the example described here will be discussed in the next blog. To be sure you don’t miss it,  register on our Electronics Cooling page:


Third Frontier Commission Boosts Ohio Businesses

Third Frontier Commission Invests in Ohio Businesses

Imagine attaching a “booster” to your business, and then imagine the possibilities for growth and expansion. Well, that’s just what the Ohio Third Frontier Commission recently did for Ohio businesses. We believe the following statement pulled from the linked article really says it all:


“Many large manufacturers have embraced simulation-driven design to achieve a degree of market advantage. Simulation-driven design replaces physical product prototyping with less expensive computer simulations, reducing the time to take products to market, while improving quality and cutting costs,” said Pankaj Shah, Executive Director of OSC and OARnet. “Smaller manufacturers largely are missing out on this advantage, because they cannot afford to leverage such solutions. IntelSim offers a sustainable competitive advantage with a significantly lower cost than traditional technologies, demonstrated digital tool kits and built-up capabilities.”


See the full article here:


We are very excited and humbled to play a role in this with all the others – The Ohio Supercomputer Center, Procter & Gamble, Intel, Nimbis Services, TotalSim USA, and Kinetic Vision. Both Luke Gritter,  Research Engineer,  and Sergei Yushanov, Ph.D., Senior Engineer, will be leading the efforts for AltaSim. All of us believe this is just another example of really talented people bringing really great solutions to the people who can really benefit.


More links to explore on this topic