I found it...
The article was published in "Surface Mount Technology" September 1993
by Jeffrey G. Holmes, Motorola, Phoenix, AZ

It was only three pages, I scanned 'em into this address:

http://www.geocities.com/Heartland/Hills/5131/thermal.htm
<http://www.geocities.com/Heartland/Hills/5131/thermal.htm>


                -----Original Message-----
                From:   Bob Landman [mailto:[log in to unmask]]
                Sent:   Wednesday, November 24, 1999 10:39 AM
                To:     DesignerCouncil E-Mail Forum.; Jack Olson
                Subject:        Re:      Re: [DC] Horrible Terrible Mistake
...

                Jack,

                I would be interested in seeing or hearing about it - please
do have a
                look for it.

                Thanks,

                Bob

                ----- Original Message -----
                From: Jack Olson <[log in to unmask]>
                To: <[log in to unmask]>
                Sent: November 24, 1999 10:49 AM
                Subject: Re: [DC] Horrible Terrible Mistake ...


                : I know the article you are talking about, I have saved it
for many
                years. I
                : think it was a TO220 part they used in several different
                configurations with
                : the thermal analysis pictures (colored maps that look like
contour
                maps?)
                : and the results were surprising.
                : All my articles are in a huge box at home (we just moved)
but if you
                want me
                : to find it I will.
                :
                : Jack
                :
                :                 -----Original Message-----
                :                 From:   Abd ul-Rahman Lomax
[mailto:[log in to unmask]]
                :                 Sent:   Tuesday, November 23, 1999 11:05
AM
                :                 Subject:        Re: Horrible Terrible
Mistake ...
                :
                :
                :                 I've asked SMT magazine if they were the
ones who
                printed
                : the article about
                :                 this technique of improving heat
dissipation; I
                could not
                : find it on their
                :                 web site index, which was not readily
searchable. In
                any
                : case, the
                :                 information in the article, as I recall,
had been
                somewhat
                : mangled by
                :                 either poor writing or poor editing and
some of the
                : technical information
                :                 necessary to assess the reported results
was
                missing.
                :
                :                 Next opportunity, I plan to design a test
board and
                verify
                : the prediction.
                :
                :                 [log in to unmask]
                :                 Abdulrahman Lomax
                :                 P.O. Box 690
                :                 El Verano, CA 95433
                :