I am presently reviewing an IPC Video script titled "Through-Hole Rework". In it they state that rework should be done only if and when absolutely necessary, that is when the joint is unacceptable. If it is acceptable, even minimally acceptable, leave it alone. The reasoning is that reworking can do more harm than good. This video is scheduled to begin production in late October, so should be available by the end of the year (I would guess). The technical advisor is from PACE and a large number of people contributed input, so I am inclined to think it is worth paying attention to. If you haven't seen any of the IPC training videos, especially the newer ones, you will be impressed with the graphics and clarity of explanations. I am and I have seen a LOT of them! As you can guess, they are available through IPC. Patty ---------- From: TechNet-request To: TechNet Subject: Re: Through Hole wave Vs. rework Date: Tuesday, October 15, 1996 8:36AM Several years ago there was an article that said anytime you "solder sculpt" a connection, you degrade the integrity of the pwb by 80%. I believe it had something to do with trapped moisture and the cosmetics of the joint without preheating could cause outgassing. Going back farther than IPC-A-610, Mil Std 454 Req 5 also dealt with the acceptability of a partially filled connection. ______________________________ Reply Separator _________________________________ Subject: Through Hole wave Vs. rework Author: [log in to unmask] at SMTPpost1 Date: 10/10/96 4:46 PM We are building a board that has 8 layers with multiple ground planes, this combined with Entek plus coating and a no clean process is making it difficult to optimize the wave solder profile to get 100% fill with a fillet on all pins on the top side of the board. The IPC A-610 rev B specification calls out 75% fill as being acceptable (table 4-1, pg. 52) on through hole solder joints. We are pushing our subcontractors to get 100% fill with a fillet on each pin. Since we are setting our expectations to 100% fill on these solder joints the subcontractor is having to touch up some of the solder joints to meet this requirement (they are touching up the pin from the solder side letting the solder flow through the board to the top) Thus my question... Is a solder joint that is 75% filled over the wave stronger (more reliable) than a solder joint that has been touched up to get to 100% with a fillet? What is the effect to long term reliability of touching up a through hole solder joint? I would really like some reference material on this subject if anyone has a source. Thanks, Mark Weiler [log in to unmask] 512-728-8323 *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************