Patent ID: 7105432

Claim:
A method for placing an array of conductive spheres on prefluxed bond pads of a substrate, the method comprising: providing a substrate having a surface with a first pattern of bond pads; providing a stencil plate having upper and lower surfaces with a second pattern of through-holes therethrough, the second pattern of through-holes corresponding to the first pattern of bond pads; providing a hopper with an open top and configured to receive, hold and dispense conductive spheres as the hopper is closely moved across the upper surface of the stencil plate; determining if each through-hole contains a conductive sphere; placing the stencil plate over the substrate to align the first and second patterns; moving the hopper across the upper surface of the stencil plate to a position beyond the second pattern of through-holes to drop the conductive spheres through the through-holes onto the bond pads; and removing the substrate from adjacent the stencil plate.