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 ##############################################################