Not solder paste. Paste flux, aka tacky flux. Not a problem on a warm or hot board. This is a leaded part. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Blomberg, Rainer (FL51) Sent: Thursday, October 06, 2005 11:47 AM To: [log in to unmask] Subject: Re: [TN] Solder Protrusions Phil, How does one apply solder paste to a board before it has cooled down? Rainer Blomberg -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phillip Bavaro Sent: Tuesday, October 04, 2005 11:22 PM To: [log in to unmask] Subject: Re: [TN] Solder Protrusions Hi Mary Jane, My question is if you are using hot air to remove the flat pack, why aren't you using the same hot air to resolder the replacement part? If it were me, I would have the replacement part put back on the board immediately, before it has cooled down, and thereby reduce the number of temperature cycles the board has to go through. The hot air will not give you any peaks to worry about as long as you use a paste flux to facilitate the wetting of the solder. You may not have the luxury of doing both operations at the same time, but I would still opt to use the hot air on a flatpack. Just make sure you bump the flatpack pads before putting down the part. Hope this helps.... Phil Mary Jane Chism <[log in to unmask]> wrote: We are experiencing icicles (solder protrusions) as the results of rework being performed on a flatpak. The process is hot air removal of the flat pak and hand soldering for replacement. In the process of hand soldering, the operators are touching some of the surface mount capacitors around the flat pak causing solder protrusions off of the solder fillet of the capacitors. In IPC-A-610, it states as long as the solder protrusions do not violate height requirement and electrical clearance, they would be acceptable. However, I feel the objective of performing rework is that you only perform the operation of soldering without putting any thermal stress on the rest of the components. I realize this is hard for anyone to actually answer this, but my question is, if you can answer this, would you: 1. Re-address your rework process and also get rid of the icicles? 2. Re-address your rework process but let the icicles go? 3. Don't do the rework? 4. Get different rework operators to perform the rework? Your comments will be very much appreciated. Thanks. Mary Jane Chism --------------------------------------------------- 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 -----------------------------------------------------