A novel MCM package enabling proximity communication I-O

A novel packaging approach is described that is based on micro-machined features integrated into CMOS chips. Our solution combines two key self-alignment mechanisms for the first time: solder reflow self-alignment and a novel micro-ball and pyramidal pit for passive self-alignment. We report on the demonstration of a MCM package with large footprint semiconductor CMOS chips interconnected by Proximity Communication (PxC), characterization of their high accuracy assembly process, and metrology of the resulting chip misalignment. Our goal is to develop a scalable, lead-free packaging approach by which large NxN PxC-enabled chip arrays are assembled with high precision on organic substrates in a cost effective manner while using industry standard parts and tooling.