Generally speaking the failure is at the pad interface and no the ball to pad when doing high speed shear. It was interesting to read that a resent paper from a solder supplier used FR4 rather than a high TG material may have wanted to avoid all the pads falling off. Bob Willis 2 Fourth Ave, Chelmsford, Essex, CM1 4HA England Tel: (44) 1245 351502 Fax: (44) 1245 496123 Mobile: 07860 775858 www.ASKbobwillis.com Book your place on Bob's "Step by Step Failure Analysis Workshop" 14th May www.ASKbobwillis.com/faworkshops.pdf New "Printed Board Inspection & Quality Control" 3 July www.ASKbobwillis.com/PCBworkshop.pdf -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David Tremmel Sent: 28 April 2008 16:34 To: [log in to unmask] Subject: [TN] SAC shear strength Hello TechNet, I have some questions regarding SAC solder (SAC305 / SAC405 in this case): Does lower SJ shear strength equal less IMC brittle failures? How does the cooling rate of SAC affect shear strength? Does it increase it or lower it? Thank you in advance for your answers and have a nice day !! David Tremmel Value Recovery --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------