Patent ID: 6864167

Claim:
A method of forming solder bump electrical connections to a plurality of electrical contact pads of a plurality of wafer-mounted semiconductor dies, the method comprising: providing a semiconductor wafer having a plurality of semiconductor dies and associated electrical contact pads formed thereon, the wafer having a passivation layer having openings therein, the openings being in registration with the contact pads, the layer including a layer of photodefinable material formed over the passivation layer; photolithographically processing the photodefinable material in a manner such that, in the region around the periphery of wafer, the layer of photodefinable material is exposed to an illumination source thereby forming a photo mask ring of exposed photodefinable material in a region around the periphery of wafer such that the photo mask ring has an inner boundary and an outer boundary with the inner boundary extending a distance inward from the edge of the wafer and such that another region of the layer of photodefinable material-inside the inner boundary of the photo mask ring remains unpatterned and undeveloped; and further photolithographically processing said another region to form a pattern of openings in the layer of photodefinable material inside the the inner born photo mask ring, the pattern of openings being formed in registration with openings formed in the passivation layer and in registration with the electrical contact pads to form a solder mask, the openings not extending onto the photo mask ring; forming solder bumps to establish electrical connections to the plurality of electrical contact pads; and singulating the wafer to form individual semiconductor dies.