Robert, There are a number of papers on the subject I can share with you. I'll send them to you directly. As Vladimir says, it's a really bad idea. Bob Landman President H&L Instruments, LLC LDF Coatings, LLC PO Box 580 34 Post Road North Hampton, NH 03862 tel (603) 964-1818 fax (603) 964-8881 www.hlinstruments.com www.ldfcoatings.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev Sent: Tuesday, September 25, 2012 8:36 PM To: [log in to unmask] Subject: Re: [TN] Leaded Paste and Lead Free BGAs - Do they mix? The balls HAVE TO have enough heat delivered to distribute Pb evenly throughout the joints. As a results they will collapse. Regards, 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: Robert Kondner <[log in to unmask]> Sender: TechNet <[log in to unmask]> Date: Tue, 25 Sep 2012 20:26:28 To: <[log in to unmask]> Reply-To: <[log in to unmask]> Subject: [TN] Leaded Paste and Lead Free BGAs - Do they mix? Hi, I have a customer using leaded paste with lead free BGAs. I think they want to have the balls NOT collapse for better optical inspection. Sounds like a really bad idea to me but I have no explanation where I can say as why. Can anyone make suggestions either way? Thanks, Bob K. ______________________________________________________________________ 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] ______________________________________________________________________ ______________________________________________________________________ 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] ______________________________________________________________________ ______________________________________________________________________ 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] ______________________________________________________________________