Hi Dee,

Yes, we used those X2Y caps on a couple of projects thinking that they
would cut down on the # of caps we'd use and save some routing space.
They didn't really do either.  

Due to the break-out pattern, the "via spread" ends up interrupting your
routing paths and you're not really saving any "space".  We found that
one buried GND via in the middle w/2 microvias would work, but two
buried or through vias off the GND pin worked better (as recommended by
the mfg).  I found them most useful as filtering caps across planes and
when using blind/buried vias and where I didn't have a concentration of
many layers of signals (ie: Not under a fine pitch BGA).  

I can see where they might work between multiple power/ground pins, but
only if you're signal pattern can match the 0603 pattern (pw/gnd/pw
pins).  I didn't try that one.

Cherie Litson, CID+
PCB Design Tech Lead
SonoSite, Inc.
 
IPC Certified Instructor
Office: 425-951-1306
Cell:    206-619-8844

-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of Dee
Stover
Sent: Tuesday, November 20, 2007 7:55 AM
To: [log in to unmask]
Subject: [DC] caps and materials

Hello and Happy Turkey week!

Have any of you used the X2Y caps made by Yageo?  Any words of wisdom to
share?

http://www.x2y.com/


Additionally, have any of you used the 3M embedded capacitor 
material?  Is it any better than specifying a very small distance 
between your planes?  It says it compatible with all pcb processing 
but I don't see it on any of my fabricators materials lists.

http://solutions.3m.com/wps/portal/3M/en_US/electronics/home/productsand
services/products/MicrointerconnectSolutions/EmbeddedCapacitorMaterial/




:-) Dee Stover  [log in to unmask]    x8489
Tech Associate II
National Optical Astronomy Observatories
www.noao.edu 

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