Quite a good way of stopping silver migration is to dilute it with about 98 times its weight in tin and lead. Mike Fenner BSP, OX15 4JQ, England T: +44 1295 722 992 M: +44 789 999 7715 F: +44 1295 720 937 -----Original Message----- From: Burtt, Nigel <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: 10 August 1999 09:41 Subject: [TN] Lead Free Solders >Smarties and Techies, > >Is this fellow (below) correct that any solder containing silver is not >Bellcore compliant? What about the silver loaded Pb/Sn solder paste that >many, many of us use. > >Are we asking for trouble if our products are expected to be in service for >many years? > > >Nigel Burtt >Production Engineering Manager >Dolby - European HQ >Email: [log in to unmask] >Tel: +44 (0)1793 842132 >Fax:+44 (0)1793 842101 > >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >~~~~~~~~~~~~~~~~~ > >-----Original Message----- >From: Mel Pedersen [mailto:[log in to unmask]] >Sent: Monday, August 09, 1999 6:11 PM >To: [log in to unmask] >Subject: Lead Free Solders > > > >This is a spin-off of the "legal issues" string. > >Regarding the legal environmental issues and lead free solder - being a good >hearted bambi loving company we did some investigation into this. The only >suitable lead free solders we found contained silver, which, under the right >conditions, migrates. Migration of silver on a circuit board would, of >course, cause short circuits. Also, Solder containing silver is not >compliant with Bellcore criteria (TR-NWT-000078, 3.2.4). I even spoke with >Bellcore on this issue, and they are very reluctant to approve the use of >solder containing silver unless it can be shown that migration is not an >issue. This would need to be demonstrated on a case by case basis. I got >the impression that this would not be easy to do. > >One of the manufacturers we investigated even claimed thier silver >containing solder was Bellcore compliant. They were not apparantly aware of >silver migration or the Bellcore criteria with regard to this. > >Apparantly, there are a number of cases of this occurring in the past. > >If the lifetime of the equipment is intended to be short (Silver migration >takes time), then this is not an issue...but Telecommunications equipment >(at the CO), is intended to have a long lifetime. > >Any comments? It seems to me that this is one issue where the Greenpeace >types and industry will have a hard time seeing eye to eye. Maybe we should >just all live in caves again....instead of surfing the net we could paint on >rocks.... > >What are your experiences? > >Mel Pedersen Midcom, Inc. >Homologations Engineer Phone: (605) 882-8535 >mailto:[log in to unmask] Fax: (605) 882-8633 > > > > > >-----Original Message----- >From: Lacey,Scott [mailto:[log in to unmask]] >Sent: Thursday, August 05, 1999 10:12 AM >To: [log in to unmask] >Subject: RE: new legal issues > > > >Prop 65 sounds like another case of the "technically illiterate" creating >convoluted laws which burden the productive sector and create more work for >the bureaucrats. The entire electronics industry is tooled up for lead-tin >solders. I doubt that the California market is large enough to justify the >use of lead-free substitutes, and many manufacturers may simply decide not >to expose themselves to potential future liability - the example of the >State-financed tobacco megasuits looms large in corporate offices today. >Massachusetts recently enacted a new victim disarmament law which goes so >far as to regulate the technical aspects of firearm construction, including >melting points of alloys and stringent drop test requirements. Many >manufacturers have simply refused to ship certain firearms into the state, >including current models of the M1911, which the U.S. military found safe >and reliable enough to issue in World Wars I and II, Korea, and Vietnam. If >individual states continue in this vein, either Congress will have to step >in and deal with liability issues, or many of us will find ourselves living >in landlocked islands where some technology is simply unobtainable. I >shudder to think what the legal eagles (or is it vultures?) could find >objectionable in the typical laser printer. "LASERS! High Voltage! These >things are too dangerous to be sold to consumers!" > >As to the Lemelson patents, and barcodes, I can't help but wonder if he was >a Patent Attorney by trade? The group is claiming that he invented barcodes, >cordless phones, cassette players, camcorders, etc. Some years back one of >the automotive magazines published an interesting story about a Patent >Attorney named Selden who patented the automobile. He had every auto >manufacturer in the country paying him royalties, until one by the name of >Henry Ford decided to fight. In the final stages of the court battle >plaintiff Selden, who had never built any autos, was challenged to actually >build a working vehicle according to his patents. The finished vehicle was >brought to a track where it was to race a production Ford in front of the >judge. The Selden "auto" never got to race, due to numerous design defects. >The patents were invalidated, and the auto industry thrived. Will history >repeat itself? > >Scott Lacey > > > >--------- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to [log in to unmask] >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to [log in to unmask], >[log in to unmask], [log in to unmask], or >[log in to unmask] (the list administrators). > > >--------- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to [log in to unmask] >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to [log in to unmask], >[log in to unmask], [log in to unmask], or >[log in to unmask] (the list administrators). > >############################################################## >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 >############################################################## > ############################################################## 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 ##############################################################