I'm one of those people that sit back and read all the Technet e-mail and
seldom respond.  I find that there is a tremendous amount of information
exchanged between members without fear of "giving the house away". I really
want to commend you all because it truly is a free forum for all to learn.
I would like to offer in response to this question,a joint paper written
with Allen-Bradley engineers regarding this exact subject. This was
published in either 93 or 94 P.C. Fab magazine. It covered many aspects of
finishing a board with matte SM and in particular, its effect on solder
balling.
Again, I thank you all for letting me "listen" in.


>From: Guy Ramsey <[log in to unmask]>
>Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>,        Guy Ramsey
><[log in to unmask]>
>To: [log in to unmask]
>Subject: [TN] matte vrs gloss LPI
>Date: Thu, 14 Oct 1999 09:38:17 -0400
>
>One of our suppliers of PWBs has requested and accross the board process
>deviation. They want (need?) to use gloss LPI instead of the matte finish
>that we specify on all our drawings. They are having problems with the
>matte mask peeling. I have no other details.
>
>We specify matte because it reduces inspector fatigue and improves vapor
>cleaning results (cosmetic).
>
>I have also heard that matte finish solder mask reduces solder balls in the
>SMT reflow process. I have no proof. Does any one know why this would be
>the case?

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

##############################################################
TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################