Kevin, In IPC-A-610 Rev. D, it states clearly, for Class 3, "Minimum heel fillet height is equal to solder thickness plus lead thickness." If you have parts where the pad layout spread is larger than your component, then the larger the difference will get you further away from the acceptable spec. Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)594-0602 cell [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Kevin Glidden Sent: Monday, March 06, 2006 10:29 AM To: [log in to unmask] Subject: [TN] Heel Overhang Hello again. Question on IPC-610 (class 3) criteria. For SMT solder joints, there appear to be criteria set for TOE overhang, but not HEEL overhang. Is this an oversite or a purposeful omission? Is there a limit on how much the heel of an "L" shaped SMT lead can be off the pad lengthwise? The obvious and defined limit is "does not violate minimum electrical clearance", but does anyone else have info on this criteria? Thanks again, Kevin Glidden --------------------------------------------------- Technet Mail List provided as a 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/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 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------