Matthew,

     From my experience with "Flash Gold" boards, I would have less solder
related defects than a HASL'ed board, especially concerning fine pitch, and I
would attribute that to the resulting flatness of the pads.

     Printing is much more consistent (better gasketing of the stencil), and
the solder volume on each pad is not subject to the variances that HASL can
give you. The PCB's are not subjected to the kind of heat that HASL processes
require, so another benefit is less PCB warping too...(that sure has been a
topic lately!)

     I've seen it used on many different types of boards, from motherboards to
memory module boards, PCMCIA boards, Graphic Accelerator boards, you name
it...and I'm sure if there were any issues with reliability they would have
evidenced themselves long ago.

      From what I understand, the amount of gold that is used is so small that
it doesn't affect the solder joint to any real degree...that's why it's so
inexpensive. One thing that I did notice though when I first starting building
gold plated boards, was that the surface mount joints tended not to be quite
as "sparkly" as joints on a HASL'ed board. It's not real noticable mind you,
one might only see the difference if you held both boards next to each other.
One way that you can get the joints to look a little better is to use 2%
silver in your paste...most solder paste vendors won't charge you extra for
that either....if you buy enough paste from them that is.

                                                               -Steve Gregory-

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################