Hi Jon: Solder wicks up between the walls of the Throughole and the leads. It has been said in this forum that lead free solder has a harder time to wick up the same as 63/37, but only 75 vertical fill is expected to be within spec. Also the machine's requirements need to be accommodated. Build a small batch of boards, inspect and make adjustments, if they are called for, perhaps adjust the hole down 3 mils. You are in unknown territory. Best of Luck, Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D. Sent: Monday, January 30, 2006 3:49 PM To: [log in to unmask] Subject: Re: [TN] Optimum dia of thru-holes Jon, I noticed that you are not getting any replies. It may be that no one has addressed this particular issue with that much of a hole aspect ratio difference yet with Pb-free solder. A hole diameter .020" larger than the lead is on the high end of the ratio for a standard .062" board thickness. There are standards for this listed in IPC 6012 and elsewhere. But they deal with 63/37, and this may have to be re-visited with Pb-free solder. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jon McDowell Sent: Monday, January 30, 2006 1:08 PM To: [log in to unmask] Subject: [TN] Optimum dia of thru-holes Group I recently sent the message below, and would like to ask another question. For SAC305 what is the optimum over sizing of though holes, as compared to the lead diameter. Hello group My name is Jon McDowell, and I work as a Quality Technician at ECCO in Boise ID. We manufacture back-up warning alarms for the auto/truck industries. I have a question for you. We are using the Pansert AVKII through hole insertion machine, which call out that the diameter for through holes be .020 larger than the upper tolerance of the wire diameter being inserted in that hole. However I have been informed that a hole which is .020 over the lead diameter may cause problems with soldering, particularly with the SAC95 solder. Can anyone advise on this. Thank You Jon McDowell Electronic Controls Co (ECCO) 833 W Diamond St Boise Id 83705 P 208 395-8025 --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------