Hi Joe! Going through a aqueous cleaner won't cause problems with 2nd side reflow. The moisture that you have to worry about is the moisture that is absorbed over time. Sticking to the floor life time guidelines that go along with the limits of each part, i.e.; Level 1, 2, 3, etc., is what you need to be concerned about. You don't need to re-bake the assemblies if you're within the floor life of the part. -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Macko, Joe @ IEC Sent: Wednesday, September 06, 2006 11:31 AM To: [log in to unmask] Subject: [TN] Populated board bake out after 1st side reflow/DI wash Fellow techs, Hello. A general question came up about the need to re-bake a double sided board after 1st side reflow/DI wash before starting 2nd side assembly. The concern is that the board (or mounted MSDs) may absorb enough moisture going through the high-pressure DI water in-line cleaner to potentially cause a problem during 2nd side reflow. There are some MSDs mounted on the 1st side but both sides are assembled before exceeding any of the component's floor life. It has been suggested that some level of bake out should be performed after 1st side cleaning to prevent potential problems during 2nd side reflow but the push back is that this adds cost, handling, etc... that may introduce its own associated problems and is not really necessary. Thanks again. It is great to have a knowledgeable forum such as TechNet. Joe --------------------------------------------------- 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 -----------------------------------------------------