Hello Al, Yes, I strongly suspect you can use an inline with DI water to clean underneath a < 1 mil stand-off. Most current technologies, which were sometimes successful a stand-of height of 2-3 mils or greater, are not successful at lower standoff heights. Many of these systems were developed when 10 mil standoffs were the norm. Realizing the limitations of current technologies, we undertook theoretical and empirical analysis to determine how to direct DI water, and, air in a manner that caused penetration and flow underneath a 1 mil standoff component.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Theoretical analysis was undertaken with Finite Elemental Analysis model of such parts-in-process. The FEA computation model included the process area; from the water and air delivery systems to the area underneath the 1mil standoff flip chip. The results demonstrated how-to (and how-not-to) effectively penetrate, and, cause a continual flushing/drying action underneath this tight clearance area. While the surface tension is high with water, properly applied mechanical energy is required to overcome the many forces that are encountered at this low standoff, densely populated geometry. Application testing with test coupons and real-world assemblies has confirmed to us that the implied theory of the computational modeling does hold true in the real world. Thru this applied technology, new levels of capability have been achieved in cleaning low standoff devices. These findings have been published and are available. Continued analysis of surface cleaning and related surface energy's is underway. The first part of this continued analysis was recently presented at SMTAI, held in Chicago, USA. Shean Dalton Austin American Technology (512) 335-6400 www.aat-corp.com <http://www.aat-corp.com> Hello Technetters: > > Processing a 16"x20", .125" thick double-side mixed-tech (smt both sides, > and pth component side) with at least two .8mm BGAs with .45mm balls: > > one is a 84 pin package is a 9 x 15 - 135 - ball matrix with 51 > depopulated balls in the center of the package > the other is a 8 x 12 - 96 ball - matrix with 8 depopulated balls - 4 at > either end of the matrix > > > Two quick questions: > > Can I clean (in-line) using di water only if I use OA flux? Or, do I need > to switch to no-clean for BGAs less than 1mm? > For rework, flux only? Or can I micro-stencil or dispense? > > > As always, thanks in advance for your replies, > > > Al Kreplick > Sr. Mfg. Eng. > Teradyne, Inc. > 500 Riverpark Drive > Mail Stop NR500 1-1 > North Reading, MA 01864 > Tel: 978-370-1726 > Pager: 888-561-6485 > > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > PS: Go Red Sox! > --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------