Hi Pankaj, You are not providing complete information, which leads me to believe that you do ot have complete understanding of the issues involved. You say: "...we find the tin plated PCB has much more oval shaped joint then gold plated...[on] the oval shape pad[s]...[with the] same reflow profile." You thus indicate you get different reflow wetting. What you do not indicated is what is underneath either the tin or the gold plating. I would suspect that you have copper under the Sn plating and nickel under the Au plating. It takes significantly more heat to get good dissolution of Ni in Sn than Cu; thus, you need a higher reflow temperature [~15°C] for reflow soldering to Ni. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 904-437-8747, Fax: 904-437-8737 E-mail: [log in to unmask], Website: www.engelmaier.com --------------------------------------------------- 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 -----------------------------------------------------