Agreed the limiting factor is likely to be pad adhesion: did some work in this area a while ago which indicated you could rework the pads or at least copper foil same thickness as the pads >8 times, but that in real world unsupported pads (i.e. no though connection etc) would consistently unstick after around 4-5 goes. This was very much a pragmatic exercise just to determine an order of size, too many real world variables with arbitrary numbers to give a scientific answer. These numbers would be lower now as pad sizes have decreased Best regards Mike Fenner Applications Engineer, European Operations Indium Corporation T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Leadfree: http://Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Graham Collins Sent: Tuesday, October 09, 2001 4:17 PM To: [log in to unmask] Subject: Re: [TN] # of rework cycle for SMT gullwing component Moonman - when I worked for Celestica (Toronto) we only allowed 2 for any surface finish. I worked both HASL and OSP. I believe there was more concern with pads lifting than intermetallic layer. Besides - if you have to replace a part 3 times you have some serious issues to work. regards Graham Collins Process Engineer, Northrop Grumman Atlantic Facility of Litton Systems Canada (902) 873-2000 ext 6215 >>> [log in to unmask] 10/08/01 03:53PM >>> For fine pitch and BGA, HP and Celestica used to allow two cycles for HASL (ring a ding) and three for OSP and ENIG. Why is that? MoonMan ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------