Error MessageA Compact Thermal Model (CTM) is Improperly Positioned

Nov 1, 2014


A Compact Thermal Model (CTM) is defined, but the following error is issued:

A Compact Thermal Model (CTM) is improperly positioned




  1. One way to fix this is to modify the model configuration in the originating CAD system. Move the CTM so that it touches only a single PCB part. Another approach is to modify the material definition of one of the PCB parts within CFdesign. Either change the definition of one of the parts to a solid or assign a different solid material that does not include "PCB" in its name.
  2. Check the Material branch (of the Design Study bar) to ensure that the PCB part is not suppressed. Suppressed parts are displayed with a line through their name. To unsuppress the part, right click on it, and click Resume. Note that the mesh will have to be defined again.
  3. Modify the material definition of the material contacting the CTM device.
  4. Modify the material definition of either the TEC or the CTM to eliminate the conflict.

Additional Information

There are several rules governing the positioning of CTM materials:

  1. A CTM must only contact one PCB material (or a solid with "PCB" in its name). One common situation is to sandwich the CTM between two PCB materials. Another is for the CTM to straddle two adjacent PCB materials. Neither of these configurations is supported. The CTM must contact one and only one PCB.
  2. A CTM cannot contact a PCB material that is suppressed. A suppressed part cannot contact the board or case surfaces of the CTM.
  3. CTM materials must contact a part that is assigned a fluid material. CTM modules cannot be completely embedded within a solid.
  4. A CTM must not touch a TEC device.


Simulation CFD