How to model a package correctly

We've designed a chip. When we measured it in the lab, we got different
results form simulation results. I think that our model of the package
is not accruate. Could anyone tell me how to model a package correctly,
or if there is a paper I can read about it? Thanks a lot.

Best,
Allen

 

Correctly is a big word.
I think you want to know what level of accuracy is sufficient to model the
effects you are seeing.

The package is one of many inaccuracies in the flow you describe.

I think you need to understand what type of inaccuracy you are seeing.

( examples ... bondwire impedance, (i.e will 50 mH of inductance be fatal in
some path ... )

I have asked for an got a many-thousand-device cross coupled model of a
package that was very accurate but useless to me.
It contained mutual inductances between each bonding site etc. ( but did not
model the bond wires ... )

I thing you need to understand typical insertion impedances and do some
"back of the envelope" modeling of what you think your
critical signals can withstand and then insert some "typical" or "minimum"
numbers from your packing source and then re-simulate.

You should be able to model some of the effects you see, or you are looking
in the wrong place ....

good luck

-- Gerry