FloTHERM thermal simulation with automated model calibration

November 13, 2015 // By Graham Prophet
The latest version of Mentor Graphics' FloTHERM computational fluid dynamics (CFD) software package delivers an automated method to calibrate simulation models to match transient thermal measurements recorded with the Mentor Graphics T3Ster hardware.

This version of FloTHERM product can help maximise simulation data accuracy and provide additional insight into product reliability in automotive, aerospace and electronics products industries.

Mentor Graphics' T3Ster product is an advanced thermal tester for thermal characterisation of IC packages, LEDs and systems which produces extensive thermal characteristics rapidly. The T3Ster test system delivers highly accurate, real-time measurements of heating and cooling transients based on its advanced implementation of the JEDEC static test method (JESD51-1) and Mentor believes it to be 10x better than alternative solutions.

FloTHERM can now convert a simulated transient thermal response into a structure function curve using the same mathematical process utilised by the T3Ster product. These structure function curves are known to correlate with the physical structure of the device, and are thus the ideal platform to compare simulation with test data. Differences between the structure functions indicate that some aspect of the simulation model is incorrect; typically dimensions or physical properties that are difficult to measure directly such as thermal interface material (TIM) thicknesses or interfacial thermal contact resistances. This FloTHERM version uses optimisation methods to change the model inputs and drive the simulation structure function towards the experimental structure function until a match is achieved. This match indicates that the FloTHERM model is fully calibrated and will respond correctly and accurately in any transient application. Package manufacturers can now certify supply chain models, by providing evidence about the thermal performance of the component in customer applications along with the model itself.

“Working with a fully-calibrated model of a package is often critically important in steady state and transient analyses when accurate prediction of the junction temperature is the objective,” said Ir. Clemens Lasance, principal scientist at Philips Research (retired) and consultant at SomelikeitCool. “The calibration is usually performed by creating a structure function to be compared with the one measured with a T3ster in the lab. The latest version of FloTHERM embeds an