Patent ID: 7514351

Claim:
A method for mounting solder balls on electrodes formed on an upper surface of a substrate comprising the steps of: forming an insulating material on the upper surface of the substrate over the electrodes; forming first opening portions in the insulating material to expose the electrodes; forming second opening portions in the insulating material and thereby exposing the substrate; arranging a first mask in the second opening portions on the upper surface of the substrate such that the first mask has a thickness substantially the same as a thickness of the insulating material; filling a flux in the first opening portions and onto the electrodes whereby the first mask prevents the flux from filling in the second opening portions; removing the first mask from the substrate so as to expose the second opening portions; providing a second mask having a supporting portion and a masking portion; arranging the second mask over the substrate such that the supporting portion is received in the second opening portions on the upper surface of the substrate and the masking portion is set above the insulating material such that the masking portion does not contact the insulating material; forming ball feeding openings in the masking portion of the second mask such that the ball feeding openings are arranged over the first opening portions; depositing mounting the solder balls on the flux formed on the electrodes; removing the second mask from the substrate; and joining the solder balls to the electrodes.