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]


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