Today I got from one of our new customers a bag wuth brass tags electroplated with BRIGHT tin , NO UNDERPLATING, age 6 months, with very poor solderability. Observatin under microscope- not only pitting, but little mounds of tin and-of course-I am always the lucky one- WHISKERS which could be photographed easily under a zoom microscope. Ain't I lucky??? Gaby ----- Original Message ----- From: "Ingemar Hernefjord (KC/EMW)" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, January 27, 2005 6:21 PM Subject: Re: [TN] Solder tags and tin thickness > Dave, > you were very close to the truth! We have experienced exactly what you mention. Had to skip whole lot of parts, because they were only partly solderable. I'll send a pic offline to you. The zincificaion brotherhood.. > > The manufacturers of these tiny things do not seem to take nickel so serious as you and I, because many of them just specify tin over brass. > > I like both english breakfast and american. I must admit, that I was little bit in doubt about the US early meal appropriateness first time I sat down beside a guy in a typical tramlike bar in Syracuse. Time was about half past six in the morning, I was still halfsleeping, and that guy was digging in a huge stack of pancakes. He drowned the pancakes in syrup and down they went. Then he ordered another stack and ended up with donuts and Coke. Now I make them myself, but use strong english coffee instead of Coke. Dual influence, so as to say. > > Ingemar > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] > Sent: den 27 januari 2005 14:37 > To: [log in to unmask] > Subject: Re: [TN] Solder tags and tin thickness > > > Hi Ingemar! Don't forget that if you don't use a barrier metal between the > solder joint and the brass pin you have a chance of the solder joint > integrity being questionable due to "zincification". Zinc from the brass > can potentially diffusion into the solder joint causing problems. Either a > nickel or a copper barrier plating of the brass pin will eliminate the > phenomena. > > Oh, an alternative American breakfast would be Diet Coke and a Snickers or > Doug's Mt. Dew and a bagel. Remember I said alternative, not healthy! > > Dave Hillman > Rockwell Collins > [log in to unmask] > > > > > "Ingemar > Hernefjord > (KC/EMW)" To > <ingemar.hernefjo [log in to unmask] > [log in to unmask]> cc > Sent by: TechNet > <[log in to unmask]> Subject > [TN] Solder tags and tin thickness > > 01/27/2005 05:45 > AM > > > Please respond to > TechNet E-Mail > Forum > <[log in to unmask]> > ; Please respond > to > "Ingemar > Hernefjord > (KC/EMW)" > <ingemar.hernefjo > [log in to unmask]> > > > > > > > Morning all, what about a simple q while melting first meal of the day? > (US:donuts and coffee ; UK:scrambled eggs, black pudding, sausage, > marmelade, plums,juice, milk, scones, bacon, coffee, cheese, tomatoes, etc) > > Solder tags, pin, eyelets for printed boards, pressfit. We have found large > variations in tin thickness from various manufacturers. Checked about 20 > known makers, and none specified exactly what plating they had. Just > 'tinned brass' or 'special high quality tin process' or 'solderable > plating' etc. Too thin tin will make the pins less solderable after some > months, while exaggerated thickness will cost some extra and cause > tolerance problems. So, gentlemen, what do you prefer for a Veroboard pin > or a backplane ditto? I've proposed minimum 10 microns over nickel if the > pins are brass. Or minimum 25 microns of tin without nickel barrier. Does > this sound reasonable? > > Ingemar Hernefjord > Ericsson Microwave Systems > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > 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/contentpage.asp?Pageid=4.3.16 > for additional information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) > 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) > 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 > ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------