Ofer, Following up on what Ioan said, there is a plethora of lead free component finishes that are being marketed right now. Basically, component manufacturers are selecting finishes which are being defined by the market. I've seen Ni, Pd, NiPd, SnAg, SnAgCu, Sn being marketed. In my experience, we have not found any material compatibility issues with using them with SnPb solder or lead free solders (SnAgCu, SnAg, SnCu, SnAgCuSb are the ones we tested). There has been a few papers concerning lead contamination with lead free solders, but we have not seen any negative effects. Ioan is correct about the soldering temperatures. For example, SnPb reflow soldering is performed at around 220C. Depending upon the alloy used, lead free soldering can range from 240C to 260C. The resulting solder joint will have a dull grainy appearance. Lead free solders do not wet as well as SnPb so you may have to use a more aggressive (active) solder flux and / or nitrogen in you soldering process to improve wetting. However, using a more aggressive (active) solder flux may require you using a more aggressive cleaning process to remove the residues left from the soldering process which are baked on due to the higher soldering temperatures. Suggest that you consider monitoring the IPC's Lead Free forum for additional details. Give me a call off line if you want to discuss lead free soldering in more detail. Hope this helps. Good Luck Lee Whiteman Senior Manufacturing Engineer ACI E-Mail: [log in to unmask] <mailto:[log in to unmask]> Ph: (610) 362-1200 x208 Fax: (610) 362-1290 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ofer Cohen Sent: Thursday, May 29, 2003 11:06 AM To: [log in to unmask] Subject: [TN] Combination Leadless and SnPb Hi all, Lately I receive messages from components manufacturers, stating they are moving from Tin-Lead finish to lead-less finish (not specified which one - my regular question that regularly is not being answered). Most of the components are still with the SnPb finish, the PCBs Tg are 145 deg C, unless I had a specific need (extra depth, for instance to move to what is currently called high Tg (and in the future will probably be the standard boards) and the pastes are, of course, SnPb, hence would not survive the higher soldering temperature needed to tickle the lead-less finish. Should I modify the work processes? Should I wait? Are there any workmanship/ reliability effects to these changes? Helppppppppppp... Regards Ofer Cohen Quality Assurance Manager Seabridge Ltd. --------------------------------------------------- Technet Mail List provided as a free 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------