Menu

Discussion Forum

New Discussion
查找

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Heat transfer in a PCB

Posted 2011年9月27日 GMT-4 07:36 Heat Transfer & Phase Change, Geometry, Mesh Version 4.2 4 Replies

Pauli Auramaa
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi,
I'm preparing my thesis with Comsol-software. Target is to make thermal simulation of a LED luminare. I have never before used Comsol, so first I have to learn how it works. I have done some tutoriasl and read material available at the Comsol-site. Now I am at that point that the first model is prepared. It is a simple FR4-PCB (circuit board) and 36 LED chips on it. I have made the model with Comsol geometry tools (see attached file). Now I'd like to generate mesh for simulation, but it does not succeed. Or actually Comsol-software continues the calculation for ever and uses gigabytes memory. What's wrong? I use physics controlled and normal size settings. Is there any simple instructions available how to make the meshing in Comsol Multiphysics?

Attachments:

4 Replies Last Post 2011年10月21日 GMT-4 09:20
Tero Hietanen
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年9月27日 GMT-4 15:52
Hi

Model contain very thin layer below PCB. Mesher is trying to do tetrahedral mesh to this very thin layer and that is making problems. Try to define layer other means (highly conductive layer or thin resistive layer) or make mesh to layer manually. Without layer meshing is working fine (check simplified model).

Best regards

Tero
Hi Model contain very thin layer below PCB. Mesher is trying to do tetrahedral mesh to this very thin layer and that is making problems. Try to define layer other means (highly conductive layer or thin resistive layer) or make mesh to layer manually. Without layer meshing is working fine (check simplified model). Best regards Tero

Attachments:

Pauli Auramaa
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年9月29日 GMT-4 05:00
Tero, thanks for solution of the thin layer problem. Another question is, how thermal vias through PCB should be modeled? Manufacturer of led chips recommend a solder pad layout with vias, which achieves a thermal resistance of 7K/W.
Tero, thanks for solution of the thin layer problem. Another question is, how thermal vias through PCB should be modeled? Manufacturer of led chips recommend a solder pad layout with vias, which achieves a thermal resistance of 7K/W.
Tero Hietanen
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年10月2日 GMT-4 10:19
In Comsol there is no possibility to define thermal resistance. You have to transfer thermal resistance to thermal conductivity, k=s/(R*A) (s=thickness of solder, R=thermal resistance, A=area of solder).

Best regards

Tero
In Comsol there is no possibility to define thermal resistance. You have to transfer thermal resistance to thermal conductivity, k=s/(R*A) (s=thickness of solder, R=thermal resistance, A=area of solder). Best regards Tero
Pauli Auramaa
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年10月21日 GMT-4 09:20
Late thanks for good advice,Tero.
Late thanks for good advice,Tero.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content