Hi Rick,

Good to hear from you again -I bet you long to get back into our industry ;-)

I seem to remember an article by you (in Circuitree?) where you elaborated on the importance of high Er dielectrics for embedded capacitance planes and the need for a circuit to obtain charge from the plane in a short time.
-You came to the conclusion that the higher the Er, the slower the charge propagation and thus a smaller area of the plane around a circuit was useful.
In fact, you found that the two canceled out and there was no benefit from increasing Er.
http://tinyurl.com/7qqog63 (word doc)

...It sure fascinated me and I wonder if anyone over the years has found reasons why this conclusion would not be correct and if not.... is there really a need for extremely high k materials? (for decoupling)

/Per Viklund



-----Original Message-----
From: EmbeddedNet [mailto:[log in to unmask]] On Behalf Of Rick Ulrich
Sent: den 4 februari 2012 19:17
To: [log in to unmask]
Subject: Re: [EM] Fw: MILAERO007: What Became of the Embedded Passive Boom?

Hey Dennis -

As a guy who was at the forefront of embedded passives for some years I've thought about this a lot and I think the answer is pretty simple.  It was the lack of embeddable capacitance that did it in.  No one ever figured out how to embed a significant amount of capacitance.

Unfilled polymers gave a maximum of about half a nF/cm2 and polymers filled with ferro powders gave up to only 2 nF/cm2.  There's just not a lot you can do with that.  Anodized thin films could go to 100 nF/cm2 but were expensive, very fragile and could not be cheaply manufactured in a PCB.  No easy trimming technology has been demonstrated.

Many of us have spent a lot of time and money working on this with little additional progress.  A major company that many of us worked for at one time put out an RFP for 10 micro-F/cm2 a couple of years ago.  I told them "no way" and I don't think they found anyone that could.

Embedded passives will always have a place in electronics, but there seems no prospect of widespread replacement of surface mount.  I think the issues with capacitance is what prevents this and I frankly see no solution on the horizon.

As for me, I'm now working in analyzing greenhouse gas emissions from agricultural operations.  I had to follow the money and, as long as we have this crazy weather and a democrat in the White House, there will be funding for environmental research.

Best to all of my old friends in the business. I try to keep up with embedded passive development and I appreciate seeing Per's article.

- Rick


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Dr. Richard Ulrich
Professor
Department of Chemical Engineering
BELL 3202
University of Arkansas
Fayetteville AR   72701-1201

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479-575-5645
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-----Original Message-----
From: EmbeddedNet [mailto:[log in to unmask]] On Behalf Of Dennis Fritz
Sent: Friday, February 03, 2012 3:36 PM
To: [log in to unmask]
Subject: [EM] Fw: MILAERO007: What Became of the Embedded Passive Boom?

I know it's been a while since anyone posted to this forum. Here is an article from Per Viklund that may stir discussion.  Also, we are coming up to IPC Expo the end of February, and there will be several committee
meetings on Embedded Components.   Maybe the leaders of those committees
want to promote their sessions on this forum.

Denny Fritz
----- Forwarded by Dennis Fritz/MacDermid/MACDERMID/US on 02/03/2012 04:33 PM -----







  Subject:    MILAERO007: What Became of the Embedded Passive Boom?






What Became of the Embedded Passive Boom?

While the anticipated embedded passive boom never happened, several industry segments have adopted the technology--even depending on it to be successful. While new and exotic to many, EP technology is mainstream to others, especially in the medical, automotive, and military/aerospace industries.

To read this article, go to
http://www.milaero007.com/pages/zone.cgi?a=81481





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