Having conducted a number of trials on the surface tension forces on the BGA joints they are far higher than any you will see on leaded surface mount parts. Double sided reflow of BGA should not be a problem if all other factors in the design are correct. If you can do double side leaded then you can do it with BGA. Video filming during rework trials it was possible to show the effect trying to misaligned parts they just keep coming back into position. SMT Plus in the USA has copies of my video tapes on BGA. Bob Willis Process Engineering Consultant Electronic Presentation Services 2 Fourth Avenue, Chelmsford, Essex CM1 4HA. England. Tel: (44) 01245 351502 Fax: (44) 01245 496123 Home Page: http://ourworld.compuserve.com/homepages/Bwillis Email: [log in to unmask] *************************************************************************** * 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. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************