Re: [SI-LIST] : backside metal

Erik Daniel (Daniel.Erik@mayo.edu)
Mon, 13 Sep 1999 08:02:16 -0500

Matt-

I would say that it depends on whether you actually expect current flow through
the back side of the die, or if you are just wanting to supply a ground plane
for shielding/capacitance reasons. If you expect current to flow, you really
need to have a good ohmic contact to the back side, and hence will require
back-side metallization. If not, I would guess that the presence of a good
conductive adhesive and a metallized layer in the underlying package would
suffice. I do not know what your application is or what semiconductor you are
using (although I would guess silicon from the name of your company), but I
would say that more often than not, the latter of the above cases would apply
(i.e., no current flow), as the substrate will likely be insulating or
semi-insulating anyway. If this is the case, however, you want to make sure to
provide a low resistance, low inductance path from your on-chip ground to the
package ground (i.e., the ground metal under the die).

- Erik

On Sep 10, 11:27am, Matt Kaufmann wrote:
> Subject: [SI-LIST] : backside metal
> Hello,
>
> Can anyone comment on the necessity of metallizing the backside of the die
> if we want to ground the backside? In other words, if we want to have an
> electrical connection between the package substrate and the backside of the
> die, is backside metallization required or is the presence of electrically
> conductive adhesive sufficient (assuming the die sits on a grounded die
> pad)?
>
> Thanks,
>
> Matt
>
> Matt Kaufmann
> Senior Packaging Engineer
> Silicon Spice Inc.
> matt@silicon-spice.com
>
>
>
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>-- End of excerpt from Matt Kaufmann

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