Dave Hillman Please explain more about ... > ... you would be much better off using wetting angle and wetting geometries metrics. For instance ... * What are 'wetting angle and wetting geometries metrics'? * How are they measured? * How does measuring of these metrics fit into a higher volume production plant? Thank you Dave Fish ----- Original Message ----- From: "Dave Hillman" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, May 10, 2002 12:33 PM Subject: Re: [TN] Solder after reflow on Gold Immersion finish > Hi Bill! Yes, you may see a change in the solder joint appearance with the > use of the new alternative solderable finishes (e.g. immersion silver, > immersion gold, immersion tin, immersion palladium) depending on the type > of reflow profile you are using (inert or not inert, temperatures) and the > amount of solder paste you deposit (stencil thickness). Provided you have > acceptable wetting angles and acceptable solder geometries you should not > have a reliability issue unless you have a solder joint metallurgy issue > (such as intermetallic embrittlement). Sorry but the days of having a > "bright and shiny" solder joint are quick fading - they will totally > disappear when you begin utilizing a NoPb solder process. Having a "bright > and shiny" solder joint is not good reliability figure of merit - you would > be much better off using wetting angle and wetting geometries metrics. > > Dave Hillman > Rockwell Collins > [log in to unmask] > > > > > > "Brooks,Bill" <[log in to unmask]>@ipc.org> on 05/09/2002 02:09:54 PM > > Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond > to "Brooks,Bill" <[log in to unmask]> > > Sent by: TechNet <[log in to unmask]> > > > To: [log in to unmask] > cc: > > Subject: [TN] Solder after reflow on Gold Immersion finish > > > I'm curious, has anyone seen the solder brightness become dull after reflow > when switching from HASL on the board finish to gold immersion? Any idea > how > to correct for it? > -Bill > > > -----Original Message----- > From: Furrow, Robert Gordon (Bob) [mailto:[log in to unmask]] > Sent: Thursday, May 09, 2002 10:59 AM > To: [log in to unmask] > Subject: Re: [TN] 63/37 solder paste with silver plated boards > > > Ron, > > We routinely use eutectic tin lead solder paste with immersion silver > finished boards with no negative effects. The silver dissolves into the > molten solder pretty uniformly and the concentration is so low as to not be > relevant. The tin/copper intermetallic formation is essentially the same as > with HASL or OSP boards. > > Thanks, > Robert Furrow > Printed Wiring Board Engineer > Supply Chain Networks > Lucent Technologies > 978-960-3224 [log in to unmask] > > > -----Original Message----- > From: Vandendolder, Ron [mailto:[log in to unmask]] > Sent: Thursday, May 09, 2002 1:27 PM > To: [log in to unmask] > Subject: [TN] 63/37 solder paste with silver plated boards > > > Dear Technetters, > > We would like to change from sn 62/pb/36/ag2 solder paste to standard tin > lead eutectic for silver plated boards. Does anyone know if there are any > issues with silver leaching that would force us to remain with the Ag > paste. > We started using the Ag paste years ago and now no one remembers why. The > silver plating on the boards is very thin (immersion 3-8 micro inches). > > Regards, > > Ron VandenDolder > Telaxis Communications > > -------------------------------------------------------------------------- -- > > ----- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send e-mail to [log in to unmask]: > SET > Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- -- > > ----- > > -------------------------------------------------------------------------- -- > > ----- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send e-mail to [log in to unmask]: > SET > Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- -- > > ----- > > -------------------------------------------------------------------------- ------- > > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send e-mail to [log in to unmask]: > SET Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- ------- > > -------------------------------------------------------------------------- ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > -------------------------------------------------------------------------- ------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------