Bondwire modeling in HFSS

[wlcsp]

Dear all,

I have questions regarding bondiwire simulation in HFSS:
1. Is it possible to have multiple terminal in lumped port using "drive terminal" solution type?
2. When I use a lumped port for each bondwire, will the coupling between bondwires be taken into account?
3. Imagine I have two dies stacked, the bottom die is larger than the top one. There is an array of bondwires on the left side going from bottom die surface to top die surface. There is also an array of bondwires on the right side going from the bottom die surface to top die surface.
Do all these bondwires have to have the same ground reference? Can I have two references, one on the bottom die surface and another one on the top die surface. Or can I even have four ground references, one on bottom die at the left side, one on bottom die at the right side, and the other two on the top die.
4. When I want to generate a spice equivalent circuit (FWS), and use it for transient simulation, do I need to simulate my HFSS from DC?

many thanks,
wlcsp

 

[godsound]

Dear all,

I have questions regarding bondiwire simulation in HFSS:
1. Is it possible to have multiple terminal in lumped port using "drive terminal" solution type?
2. When I use a lumped port for each bondwire, will the coupling between bondwires be taken into account?
3. Imagine I have two dies stacked, the bottom die is larger than the top one. There is an array of bondwires on the left side going from bottom die surface to top die surface. There is also an array of bondwires on the right side going from the bottom die surface to top die surface.
Do all these bondwires have to have the same ground reference? Can I have two references, one on the bottom die surface and another one on the top die surface. Or can I even have four ground references, one on bottom die at the left side, one on bottom die at the right side, and the other two on the top die.
4. When I want to generate a spice equivalent circuit (FWS), and use it for transient simulation, do I need to simulate my HFSS from DC?

many thanks,
wlcsp

Hi wlcsp,

Lumped ports excite a simplified single-mode field excitation assuming a user-supplied Z0 for S-para Referencing. There is and only is one terminal line per port. You cannot define two or more.

2. Since only single-mode is excited in lumped port, it is not appropiate for excitations where modal superposition is expected, like the coupling between bondwires.

Only waveports handle multiple modes, multiple terminals.

for question 3 and 4, hoping someone else can give answers. sorry.