Semiconductor wafer and method of ball drop on thin wafer with edge support ring

Abstract

A semiconductor wafer has an edge support ring around a perimeter of the semiconductor wafer and conductive layer formed over a surface of the semiconductor wafer within the edge support ring. A first stencil is disposed over the edge support ring with first openings aligned with the conductive layer. The first stencil includes a horizontal portion over the edge support ring, and a step-down portion extending the first openings to the conductive layer formed over the surface of the semiconductor wafer. The horizontal portion may have a notch with the edge support ring disposed within the notch. A plurality of bumps is dispersed over the first stencil to occupy the first openings over the conductive layer. A second stencil is disposed over the edge support ring with second openings aligned with the conductive layer to deposit a flux material in the second openings over the conductive layer.

Dependencies are inferred from the claim text.