Steve, "Purple plague" happens in Au-Al wire bonds, not solder joints. I'm not a huge fan of guessing based on optical images. I always say "have it analyzed" Vladimir SENTEC Testing Laboratory Inc. 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca -----Original Message----- From: Steve Gregory <[log in to unmask]> Sender: TechNet <[log in to unmask]> Date: Thu, 17 Nov 2011 13:58:41 To: <[log in to unmask]> Reply-To: TechNet E-Mail Forum <[log in to unmask]>, Steve Gregory <[log in to unmask]> Subject: [TN] Strange Gold? Hi All, Below is a photo of a SON8 footprint that was printed with SAC305 on a gold plated PCB and reflowed. I have never seen this before. Is this "purple plague"? If it is, exactly what causes it? http://stevezeva.homestead.com/Strange_Gold.jpg Steve ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------