US Patent 9865569 Planarity-tolerant reworkable interconnect with integrated testing

A structure includes an electrical interconnection between a first substrate including a plurality of protrusions and a second substrate including a plurality of solder bumps, the plurality of protrusions includes sharp tips that penetrate the plurality of solder bumps, and a permanent electrical interconnection is established by physical contact between the plurality of protrusions and the plurality of solder bumps including a metallurgical joint.