Waste Not, Want Not

Ferry, Jeff
April 2003
Circuits Assembly;Apr2003, Vol. 14 Issue 4, p48
Trade Publication
The article presents a procedure that will simplify ball grid array (BGA) rework. Leftover solder is commonly removed from the site after rework, but prepping the pads, depositing fresh solder paste, placing the new BGA and heating the board takes time. The irregular solder pattern may result in opens or shorts with the replacement BGA and could cause irregular balls. Even performing the same operation on the same site on the same circuit assembly type in succession may expose the assembly to unexpected thermal variation, since the rework machine can build up residual heat and experience voltage of airflow variation.


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