I found that the solid solder deposit is terrific for fine pitch parts.  We
used a commercial process called Precision Pads Technology (PPT) to solder
mini-bgas we developed in-house.  The parts had 10-mil balls on 20-mil
pitch.  They were a breeze to solder with the PPT solder deposits on the
boards.  I also found that the PPT allowed us to solder PLCCs in Vapor-phase
Reflow systems (not very popular these days due to the CFC ban) without all
of the solder wicking up the leads.  I'd use it for all of our boards it
were up to me ... I'm not sure why it hasn't caught on in the industry.

Gary D. Peterson
Sandia National Labs

-----Original Message-----
From: Lustig, Steven K.. [mailto:[log in to unmask]]
Sent: Thursday, April 08, 1999 4:48 PM
To: [log in to unmask]
Subject: [TN] bare boards with solder paste


TechNetters,

Does anyone have experience using boards that come in with a form of
solder paste already on the pad so that all you need to do is apply some
flux (much less precisely than solder paste application needs to be) and
then go ahead and place your parts, followed by reflow?  My boss has a
brochure from one of the companies which offers this service and I was
wondering how well they work.

Thanks.

-Steve

Steven K. Lustig
Process Engineer
EMS Technologies, Inc.
Norcross, GA
(770) 263-9200 x4714
[log in to unmask]

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