Patent ID: 7635079
Filing Date: 2009-12-22
Classification: H01L,H05K,Y10T

Abstract:
1. An assembly system for placing a plurality of conductive spheres on a substrate having an upper surface having conductive sites comprising one of recessed sites and level sites with respect to the upper surface, the assembly comprising: a stencil plate with upper and lower surfaces, and a pattern of a plurality of through-holes, the diameter of each through-hole of the plurality of through-holes of the pattern is greater than the diameter of each conductive sphere of the plurality of conductive spheres by up to 1 mm, the stencil plate configured to place the plurality of conductive spheres in the pattern of the plurality of through-holes on a surface of the substrate; a hopper having side walls formed at a continuous uninterrupted angle extending from an upper opening at the top of the hopper having a first dimension for feeding the plurality of conductive spheres into a smaller bottom opening having a second dimension smaller than the first dimension of the upper opening extending across a first pattern for dispensing the plurality of conductive spheres into the plurality of through-holes extending across the stencil plate, the smaller bottom opening having a width in a range of at least two diameters of a conductive sphere to about ten diameters of a conductive sphere, the hopper having a bottom lower surface spaced from an upper surface of the stencil plate a distance in the range of about less than one-third the diameter of a conductive sphere; and a positioning apparatus for moving said hopper over said pattern of the plurality of through-holes relative the stencil plate to place the plurality of conductive spheres into the plurality of through-holes onto one of the recessed sites and level sites of the upper surface of the substrate.