Modelling Electric Fields in a Stack of Different Materials

Please login with a confirmed email address before reporting spam

In my simulation, I am working with a stack of different materials in the following arrangement: Aluminum (top), Copper, SiO2, and Aluminum (bottom). When I apply voltages to the planes or boundaries of the Aluminum top and bottom blocks, I observe that the electric field is concentrated in the Copper layer rather than in the SiO2 layer. Given that SiO2 is an insulator, I expected the electric field to concentrate in the SiO2 layer. Typically when modeling capacitive problems, the electric field is concentrated in the dielectric layer and the conductors have constant electric potential which leads to negligible electric field in it.

Interestingly, if I assume that copper is a perfect conductor and the same voltage is applied to both the Aluminum top block's planes and the Copper planes, the electric field is concentrated within the SiO2 layer. This leads us to conclude that the electric field distribution seems to depend more on the planes of voltage application rather than on the material properties.

Could you please provide guidance on how to address this issue? Specifically, is there any way to ensure that the electric field concentrates in the SiO2 layer as expected while still applying the voltage to just the Aluminum blocks? Any suggestions or adjustments to the simulation parameters that could help achieve the desired results would be greatly appreciated.



1 Reply Last Post Jul 31, 2024, 11:25 a.m. EDT
Edgar J. Kaiser Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 3 months ago Jul 31, 2024, 11:25 a.m. EDT

Anika,

you must take into account that in es-physics the only material property taken into account is relative permittivity. So even in case you assign Copper to a domain only the permittivity = 1 is taken into account and it behaves like air. In es-physics you typically exclude the conductors from the computational domains and only assign boundary conditions at metal-dielectric boundaries.

In case you want the model to account for conductivity, you need to use ec-physics.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Anika, you must take into account that in es-physics the only material property taken into account is relative permittivity. So even in case you assign Copper to a domain only the permittivity = 1 is taken into account and it behaves like air. In es-physics you typically exclude the conductors from the computational domains and only assign boundary conditions at metal-dielectric boundaries. In case you want the model to account for conductivity, you need to use ec-physics. Cheers Edgar

Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

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.