RE: [SI-LIST] : RE: Another decoupling question

Dr. Edward P. Sayre ([email protected])
Fri, 17 Sep 1999 15:33:11 -0400

Rich:

Try some of the research done at RPI by Professor Jack MacDonald on the
subject

ed sayre
===========
At 08:26 AM 9/16/99 -0700, Mellitz, Richard wrote:
>How about a barium titinate layer (Dk~100) between power and ground in a
>multilayer ceramic package? It should get you about 20 nF or so?
>Is anyone doing this?
>
>... Rich Mellitz
>Intel
>
> -----Original Message-----
> From: Greim, Michael [mailto:[email protected]]
> Sent: Thursday, September 16, 1999 8:50 AM
> To: '[email protected], "Volk, Andrew M"';
>'[email protected]'
> Subject: [SI-LIST] : RE: Another decoupling question
>
> I can appreciate the value of that, however, I would think
>that
> most manufacturing folks would run kicking and screaming
> from a multi-stage assembly approach. What happens when
> the caps fail as a short. You end up having to pull
>up/reball
> and perhaps scrap a potentially expensive BGA to save the
> .01 cent capacitor.
>
> From a manufacturability perspective, I would advocate
>getting
> as close as possible to the outer edge of the chip and
>decoupling
> on the opposite side of the board. Chips on top of chips is
>a
> bad idea. IMHO.
>
> Michael C. Greim
>Consulting Engineer
> Mercury Computer Systems, Inc email: [email protected]
> 199 Riverneck Road V:
> 978-256-0052/x1607
> Chelmsford, MA 01824-2820 F:
>978-256-4778
>
> > -----Original Message-----
> > From: Volk, Andrew M [SMTP:[email protected]]
> > Sent: Wednesday, September 15, 1999 5:04 PM
> > To: '[email protected]'
> > Subject: RE: Another decoupling question
> >
> > SI Listeners -
> >
> > Another question on decoupling. I have recently heard
>about capacitors
> > that are supposedly thin enough to fit under a standard
>MBGA package
> > (Novacap for one). This would give excellent decoupling
>as it is close to
> > the package power balls, but still mounts on the top of
>the board avoiding
> > backside components.
> >
> > Has anyone had any experience with this type of device and
>this kind of
> > manufacturing step (cap under BGA package)?
> >
> > Andrew Volk
> > Intel Corp.
>
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>

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