vias assumption in PCB definition

[jmdanet]

Dear all,

I am trying to simulate a PCB using CFD. I have firtsly tried the CFD tool where the metal pourcentage, metal thickness, layer number and thickness of dielectric are used to define an effective material. This method give results in relativemey good agrement with experimentations.

However, such a tool doesn't take the vias concentration into account so I have tried a second way to modelised the PCB. I have defined all my metal path as conductive surfaces (inlcuding the vias) and my dielectric layers as a full matérial (meshed in 3D).  Such a method is clearly not representative of our expériment.

Two questions : 

Has somebody an idea why the two methods disagree?

Could somebody give me an idea of the via concentration considered in the PCB model of CFD?

Thanks in advance.

Jean-Marie

[srhusain]

Can you share your model support file?