COMPLIANT INTERCONNECT PILLARS WITH ORIENTATION OR GEOMETRY DEPENDENT ON THE POSITION ON A DIE OR FORMED WITH A PATTERNED STRUCTURE BETWEEN THE PILLAR AND A DIE PAD FOR REDUCTION OF THERMAL STRESS

摘要

Pillars (300 306 502) having a directed compliance geometry are arranged to couple a semiconductor die (400 500) to a substrate. The direction of maximum compliance of each pillar (300 306 502) may be aligned with the direction of maximum stress caused by unequal thermal expansion and contraction of the semiconductor die (400 500) and the substrate. Pillars (300 306 502) may be designed and constructed with various shapes having particular compliance characteristics and particular directions (302 304 308 310 504) of maximum compliance. The shape and orientation of the pillars (300 306 502) may be selected as a function of their location on a die (400 500) to accommodate the direction and magnitude of stress at their location. Pillars (610) may also be fabricated with particular shapes by patterning a material (604) such as a passivation material on a pad on a die (600) to increase the surface area upon which the pillar (610) is plated or deposited.