Re: Modeling for packages (Electrical and thermal).

Greg Edlund (grege@chensys.com)
Fri, 12 Apr 1996 01:38:10 -0500

>Hi All,
>
> I am facing a problem of getting accurate models for packages. I
> am looking for both electrical and thermal characteristics of the
> packages. The vendors doe not have all the data and single package
> measurements are ~1000$$$. Is there a ready data base i can access
> and/or purchase. Is there a common source for this data..?
>
>
> Any help is welcomed with thanks (ALOT!!!).
>
>
>
> regards, yehuda

Yehuda,

I spent several months modeling a BGA package. You
are correct in observing that it's a costly process.
If you're going to simulate the package yourself,
you need to buy a field solver. If you're going to
measure the package yourself, you need a pretty
sophisticated test station (LCR meter, impedance
analyzer, or network analyzer).

I don't think you'll find a ready-made database with
accurate package models because packages vary so much
from vendor to vendor. For example, two identical
lead frames with different die sizes will have different
wire bond inductances.

You also have to address the question of how the models
will be used? Are you simply quoting mutual and self
inductances and capacitances to put in a databook? Will
these values be used in transmission line simulations
to determine signal quality? Will they be used to
model SSO noise? If so, you'll need to extract a SPICE
model with self and mutual inductance terms. Inductance
is only defined for a LOOP, not a single isolated chunk
of metal. There are a lot of subtleties...

I ran across a company that will do package character-
ization for you. I heard one of their guys give a talk
at an HP design seminar, and he seemed to know what he
was talking about.

GigaTest Labs
20480 Pacifica Dr.
Cupertino, CA 95014
(408) 996-7500
(408) 996-7539 FAX
gtl@ix.netcom.com

There is another company that will generate IBIS
behavioral models for a chip. This includes package
parasitics (just the basics).

Zeelan Technology
10550 SW Allen Blvd. Suite 108
Beaverton, OR 97005
(503) 520-1000
(503) 520-1001 FAX
zeelan@netcom.com

--
Greg Edlund                o---/\/\/\---+-----+---o
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