Learning Forum

[NewAnsysUser]

I am designing a magnetic component mounted on PCB. There is a ground plane on PCB, which will impact the magnetic field. To get precise inductance, I want to know how to simulate the PCB ground in the ANSYS simulation. Can I treat it as the region boundary (with default tangential H field) in the simulation?

[wrbulat]

If it is reasonable to assume that the ground plane completely (or almost completely) prevents any magnetic flux penetration (e.g., the ground plane is extremely conductive and/or the operating frequency is very high) then you can try making the ground plane flux parallel. This will mimic the effect of induced eddy currents in the ground plane that tend to reduce flux penetration. In Mechanical, only Magnetostatic field calculations are natively exposed, so results will be pure real and neglect time-varying effects. The inductance calculation performed in these magnetostatic analyses are based on the calculated stored magnetic energy in the modeled domain.
The solver that Mechanical uses to calculate results may also do steady state AC and full time transient calculations (these are not natively exposed in Mechanical). If you were to set one of these up, you would specify electrical boundary conditions as well as magnetic ones, and the calculated inductor voltage and current would be out of phase. Also, physically, we would expect eddy currents in the ground plane to induce an emf in the inductor. Whether or not this effect, which is accounted for in time-varying analyses, will be significant is problem dependent.

[NewAnsysUser]

Actually, I am using ANSYS maxwell, but I think the principle should be the same. The operating frequency is 500kHz~1MHz, and the ground plane is about 35 um in thickness. Is that frequency high enough for the ground plane to block the magnetic field? Besides, there is only voltage requirement on the ground plane, but no specific magnetic boundary condition. In this case, shall I only set a metal plane with zero electric potential in the maxwell simulation?