Simple Simulation with Temperature Stepping

thermalex05.in : Simple Simulation with Temperature Stepping

Requires: DevEdit 3D/Thermal 3D
Minimum Versions: Atlas 5.22.1.R

This example runs thermal simulation of a 2 transistors. The main sequential tasks are:

  • Specification of two neighboring transistor regions in DevEdit 3D
  • Specification of heat sinks in in DevEdit 3D
  • Interface to Atlas
  • Selection of thermal models and material parameters
  • Specification of temperature stepping parameters
  • Solution of temperature distribution

The structure in this example is defined using DevEdit 3D. Initially the structure was defined using the graphical mode of DevEdit 3D. After the mesh was created, a command file was saved from DevEdit 3D enabling the structure to be re-created in DeckBuild.

The structure used here consists of two neighboring transistors embedded in a substrate material. For thermal modeling the transistors are considered only as heat sources. No internal details of the transistors are considered. An Aluminum region is defined as an electrode on the bottom of the substrate material. This will act in Atlas as a thermal rather than an electrical boundary condition.

The go atlas statement automatically interfaces DevEdit 3D to Atlas. On reading the three dimensional mesh file, Atlas will automatically enter 3D mode.

The material statement is used to define the thermal conductivities of each region using the tc.const parameter. This parameter sets a constant value for thermal conductivity. Later examples show regions with temperature dependent thermal conductivities. The power parameter sets the thermal output of the region. This naturally defines these regions at heat sources.

The command models thermal is all that is required to enable the 3D thermal calculations. The final stage sets solve t1=300 . This defines the temperature of the heat sink (or electrode) number 1. In this example the temperature on electrode 1 is stepped by adding the TEMPSTEP NSTEPS and electrode parameters. TEMPSTEP determines the size of the temperature step and the NSTEPS gives the number of temperature steps to be performed. The electrode parameter identifies which electrode to step as more than one electrode temperature can be defined on the solve statement. The 3D thermal distributions are saved to the file specified by the outfile parameter. The output file name rightmost characters will be incremented alphanumerically so a different file will be saved for each step. These can be viewed in TonyPlot 3D.

To load and run this example, select the Load example button in DeckBuild. This will copy the input file and any support files to your current working directory. Select the run button to execute the example.