Method and apparatus for filling a ball grid array

摘要

A work cell for populating a ball grid array employs gravity for transferring solder balls from a tooling plate to the ball grid array. The tooling plate is positioned on a gantry along with a reservoir for solder balls. The gantry, along with the tooling plate and reservoir, is rotated through about one hundred and eighty degrees to spread the solder balls over the tooling plate and to recapture loose solder balls as the gantry rotates. A riser cylinder moves a ball grid array into juxtaposition with the populated tooling plate prior to the point (i.e. angle of rotation) at which gravity operates to drop the solder balls out of the tooling plate. Further rotation results in gravity transfer of the solder balls to a (fluxed) ball grid array. Apparatus employing more than one work cell is also described.