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

Knighten, Jim L ([email protected])
Mon, 20 Sep 1999 12:59:03 -0700

The HADCO material is not barium titinate, but a ceramic with a relative
permittivity closer to 40.

Research is being done on this at University of Missouri-Rolla (and other
places). Contact [email protected] <mailto:[email protected]> for available
details.

Jim
________________________________________________________
Dr. Jim Knighten e-mail: [email protected]
<mailto:[email protected]>
Senior Consulting Engineer
NCR
17095 Via del Campo
San Diego, CA 92127 http://www.ncr.com <http://www.ncr.com>
Tel: 858-485-2537
Fax: 858-485-3788

***** Notice the Area Code change from 619 *****

-----Original Message-----
From: Dave Hoover [mailto:[email protected]]
Sent: Friday, September 17, 1999 11:29 AM
To: '[email protected], "Mellitz, Richard"';
'[email protected], "Greim, Michael"'; Volk, Andrew M;
'[email protected]'
Subject: RE: [SI-LIST] : RE: Another decoupling
question

HADCO has a patent on this as a multilayer PCB manufacturer.

Dave
-----Original Message-----
From: Mellitz, Richard [mailto:[email protected]]
Sent: Thursday, September 16, 1999 8:27 AM
To: '[email protected], "Greim, Michael"'; Volk,
Andrew M;
'[email protected]'
Subject: RE: [SI-LIST] : RE: Another decoupling question

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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