Abstract: 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.

Abstract: A method and apparatus is proposed for inspecting solder balls on a BGA (Ball Grid Array) package, which is capable of rejecting defectively-bonded solder balls while allowing properly-bonded ones to pass therethrough. The proposed method and apparatus is 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 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.