False Error: Multiple material assignments were detected

Project Support
1

Hi Simscale community,

I am quite new to FEM. I am working on a thermal simulation of a PCB. I have two FETs modeled on a copper plate, with pieces of FR4 underneath varied with various orthotropic conductivities to capture the behavior of the vias. The materials are defined and assigned to the bodies. BCs defined and assigned. It meshes fine. When I go to run the simulation, I get this error:

“Please ensure that each CAD entity is only assigned a single material. Multiple material assignments were detected for the following entities: Open CASCADE STEP translator 7.5 1.1, Open CASCADE STEP translator 7.5 1.1, Open CASCADE STEP translator 7.5 1.1”

It is always the case that the two FETs get automatically assigned to the material of this thermal via region underneath the left FET, seen below:

image
image1049×544 49.8 KB

I made a dummy material for this FR4 region, and the two FETs were again automatically assigned that material when I went to run the study. Note: there is normally a thin plate of copper between them, so I don’t think the bodies could be secretly joined, but I’m not sure. I tried to remove the bonds under the FETs, but this didn’t help.

Any ideas? I’m really dumb-struck by this one.

2

Hi @rrillzz, thanks for posting on the forum and sorry for the late reply here!

I currently don’t have access to your project. Could you kindly share it with us so that we can take a closer look at what’s happening?

Best,
Igor

3

Hi Igor,

Thanks for your reply. This issue is actually resolved. I took the following steps:

  1. closed all SimScale tabs on Chrome and reopened; not resolved.
  2. closed Chrome and reopened; not resolved.
  3. restarted computer; RESOLVED

I was surprised this worked for a cloud-based system, but maybe shouldn’t be surprised: the good, old reset is just so classic. Anyways thanks for the follow-up :slight_smile:

4

That’s great @rrillzz! If you have further issues, make sure to post them on a new forum topic :slight_smile:

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