Rework-Induced Solder Balls

摘要

Figure 1 is a good example of solder balling under a BGA that is certainly outside of IPC criteria. The ball will have undoubtedly reduced the insulation separation distance below the minimum for the product design. The solder ball is most likely the result of using paste to rework the part, with excessive paste resulting in a solder ball. In such cases, it's worth looking at the new range of dip pastes for rework, as they can eliminate rework stencils.