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

Volk, Andrew M ([email protected])
Fri, 17 Sep 1999 17:43:45 -0700

Chris -

I agree the best capacitance is on-die. It is expensive in die area, but
becoming more and more essential as edge rates and speeds increase.
However, there exist devices already without such provisions and I was still
wondering whether capacitors can be placed under BGA packages to help
existing power decoupling problems. Is it cost effective and
manufacturable?

Andrew Volk
Intel Corp.

-----Original Message-----
From: Chris Cheng [mailto:[email protected]]
Sent: Friday, September 17, 1999 1:52 PM
To: [email protected]
Subject: RE: [SI-LIST] : RE: Another decoupling question

for ~10nf, you are better of putting it insider the die. (yes, on
die decouping)
chris

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Dr. Edward P. Sayre
> Sent: Friday, September 17, 1999 12:33 PM
> To: [email protected], "Mellitz, Richard";
> '[email protected], "Greim, Michael"'; Volk, Andrew M;
> '[email protected]'
> Subject: RE: [SI-LIST] : RE: Another decoupling question
>
>
> 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.
> >
> > **** To unsubscribe from si-list: send e-mail to
> >[email protected]. In the BODY of message put: UNSUBSCRIBE
> >si-list, for more help, put HELP. si-list archives are accessible at
> >http://www.qsl.net/wb6tpu/si-list ****
> >
> >**** To unsubscribe from si-list: send e-mail to
> [email protected]. In the BODY of message put: UNSUBSCRIBE
> si-list, for more help, put HELP. si-list archives are accessible at
> http://www.qsl.net/wb6tpu/si-list ****
> >
> >
>
>
>
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
> | NORTH EAST SYSTEMS ASSOCIATES, INC. |
> | ------------------------------------- |
> | "High Performance Engineering & Design" |
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
> | Dr. Ed Sayre e-mail: [email protected] |
> | NESA, Inc. http://www.nesa.com/ |
> | 636 Great Road Tel +1.978.897-8787 |
> | Stow, MA 01775 USA Fax +1.978.897-5359 |
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+
>
>
> **** To unsubscribe from si-list: send e-mail to
> [email protected]. In the BODY of message put:
> UNSUBSCRIBE si-list, for more help, put HELP. si-list archives
> are accessible at http://www.qsl.net/wb6tpu/si-list ****
>
>

**** To unsubscribe from si-list: send e-mail to
[email protected]. In the BODY of message put: UNSUBSCRIBE
si-list, for more help, put HELP. si-list archives are accessible at
http://www.qsl.net/wb6tpu/si-list ****

**** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****