Sorry - I don't mean to advertise - but you can get this paper (or the entire proceedings) from us. Reprints of SMTA papers are free for our members. -David At 12:06 PM 6/16/98 -0500, you wrote: >Hi Steve - take a look at the following paper: > >"Ball Grid Array, MicroBGA, Chip Scale Packaging, and 0.4mm Ultra Fine >Pitch Implementation At US Robotics", author Ron Evans, et al, pages >141-163, SMTA National Symposium "Emerging Technologies" Proceedings, >October 1997" > >The paper contains some good information on ball grid array pad design and >manufacturing interaction issues that may be relevant to your issues. Good >Luck. > >Dave Hillman >Rockwell Collins >[log in to unmask] > > > > > >"Joy, Stephen C" <[log in to unmask]> on 06/16/98 11:33:00 AM > >Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond > to "Joy, Stephen C" <[log in to unmask]> > >To: [log in to unmask] >cc: (bcc: David D Hillman/CedarRapids/Collins/Rockwell) >Subject: [TN] Solder mask profile information > > > > > We have been having some problems with a BGA device where we see > ball fatigue (solder ball cracks) after temp cycling. We think it > may be related to severe undercut of the solder mask. > > Does anyone have information on different solder mask foot > profiles? How difficult is it to get a straight sidewall on > solder masks? > > Are there any that are much better than others for this > attribute? What would be the trade offs? > > You can contact me off line if you prefer. > > Steve Joy > 503-696-2239 > [log in to unmask] > >################################################################ >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 technical support contact Hugo Scaramuzza at [log in to unmask] or >847-509-9700 ext.312 >################################################################ > >################################################################ >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 technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >################################################################ > > David Gonnerman Director of Publications Plan now to attend: Surface Mount International (San Jose, CA; 8/23-8/27) Electronics Assembly Expo (Providence, RI; 10/24-10/29) SURFACE MOUNT TECHNOLOGY ASSOCIATION Enabling members to achieve success in surface mount and companion technologies through education, training and access to knowledge. 5200 Willson Road, Suite 215, Edina, MN 55424-1343 612-920-7682 F 612-926-1819 [log in to unmask] www.smta.org ################################################################ 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 technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################