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Thermal modeling and analysis

JTL Engineering can analyse and optimise your IC package or application for thermal behavior using 3D thermal simulations. First a 3D model is created next the material parameters and the boundary condions need to be found. In thermal simulations important material parameters are specific heat and thermal conductivity. Both are dependend on temperature so care is taken to define them correctly.

Boundary conditions define the temperature and energy transfer at the boundaries of the model. Boundaries can act as a heatsink or an insulator. In the case there is air around the model there could be an air flow, which greatly influences the temperature distribution.

Thermal simulations give you insight in the conditions that influence the stationairy temperature and the temperature build up in time.


Stationairy thermal simulation example

Below you see a model of a PCB with some components and an IC. Inside this IC a 1 Watt contineous heatsource is active. The silicon die is contained in a plastic mold. In the first example the model is floating in the air without any air flow. The stationairy temperature distrubution is plotted in the right picture. Inside the package the IC heats up to 381 K.

IC inside a LLP package on a PCB without air flow
pcb with IC package for thermal solver stationairy temperature result after thermal simulation


The next two pictures show the case with a 1 m/s air flow all around the PCB. As can be seen this greatly influences the resulting temperature distribution.

IC inside a LLP package on a PCB with air flow
pcb with IC package for thermal solver stationairy temperature result after thermal simulation

Transient thermal simulation example

Besides calculating the final or stationairy temperature the build up in time of this distribution shows further insight. The example below shows a simulation in time for the packaged device but now the temperature distribution is given for the first 100 ms. The left picture shows the temperature at the surfaces (inside the molding), the right picture shows the temperature distribution in a cross section. It is seen that the heat spreads out from the heat source and is after 100 ms still a local phenomena. The bondwires does affect and the (isolating) molding does not yet significantly affect the solution.

Move the mouse over the image to animate and click to enlarge.

Temperature inside a LLP IC package within the first 100 msec.
Temperature in IC package after 100 ms Temperature in IC package after 100 ms in a cross section


Thermal simulations can greatly enhance your insight into the stationairy and transient temperature distribution of your devices. If you want help send us an email.