| 摘要 |
A method and art apparatus are proposed for inspecting solder balls on a BGA (Ball Grid Array) package, which are capable of rejecting defectively-bonded solder balls while allowing properly-bonded ones to pass therethrough. The proposed method and apparatus are characterized by the use of a rotatable disk having a plurality of flaps arranged at equal angular intervals along the perimeter thereof, and which is capable of being rotated in steps if a force greater than a preset threshold torque is being applied tangentially to any one of the flaps. The threshold torque is set to be equal to or less than the shear-resistant strength of a properly-bonded solder ball but greater than the shear-resistant strength of a defectively-bonded one. During an inspection procedure, the BGA package is moved toward the rotatable disk to allow each solder ball to push against one of the flaps on the rotatable disk. If a solder ball is a properly-bonded one, it would be capable of pushing open the flap and therefore passing through the inspection procedure; otherwise, for a defectively-bonded solder ball, it would be rejected and broken apart from the BGA package by the flap. Therefore, as the entire BGA package has undergone the inspection procedure trough the rotatable disk, all properly-bonded solder balls would remain in position over the BGA package, while all defectively-bonded ones would be removed. |
