US Patent 9147635 Contact-based encapsulation

An electrical connection between two chips includes an IC pad on a first chip, an IC pad on a second chip, a first barrier metal over the IC pad of the first chip, a second barrier metal over the IC pad of the second chip, a malleable electrically conductive metal, different from the barrier metals, trapped between the first barrier metal and the second barrier metal, the first barrier metal, the malleable conductive metal and the second barrier metal forming a complete electrically conductive path between the IC pad of the first chip and the IC pad of the second chip.