Wire bonded flip-chip assembly of semiconductor devices

Abstract

A semiconductor assembly comprising a semiconductor chip having an active and a passive surface, said active surface including an integrated circuit and a plurality of bonding pads; said bonding pads having a metallization suitable for wire bonding; an array of interconnects of uniform height, each of said interconnects comprising a wire loop substantially perpendicular to said active surface, each of said loops having both wire ends attached to a bonding pad, respectively, and a major and a minor diameter, said loops being oriented parallel with regard to the plane of the opening and having constant offsets in both direction and magnitude of their apex relative to their bonding pad centers; said wire loops having sufficient elasticity to act as stress-absorbing springs; an electrically insulating substrate having first and second surfaces, a plurality of electrically conductive routing strips integral with said substrate, and a plurality of contact pads disposed on said first surface, with attachment material disposed on each of said contact pads; each contact pad being attached to one of said wire loops, respectively, such that electrical contact between said chip and said substrate is established, while forming a gap therebetween having a width of approximately said major loop diameter; encapsulation material within said gap; a plurality of contact pads disposed on said second surface of said substrate; and solder balls attached to each of said contact pads disposed on said second surface of said substrate.