Hi Richard,

I had a small run SMT assembly operation in Texas. And I specifically had my pick and place machine equipped with the necessary vision and lighting to properly align BGA packages. If there is really a contract manufacturer out there turning out 1% yields on BGA assembly, and who is still staying in business, I might have to think about getting back into the business again.

Check their equipment. If they're using automated pick and place equipment, make certain that the vision system uses oblique lighting to inspect and align the BGA package. Direct lighting will not easilly produce good results (you generally end up with what is called a "dark field" of vision when trying to image the balls).

They may be placing the BGAs with a manual pick and place machine. If so they may be relying on the operator's eye to align the part. Even manual systems with "vision" only show the operator the top down view of the part. Unless they have a "split vision" system to do the alignment with, they are never going to reliably place more than a few parts per hour.

Whatever kind of operation they are using, they are oviously demanding far greater through put than can be achieved. In short, there is no way that this is even close to reasonable. Find another contractor.