Chiplet Interconnect Repair for Clustered Defects with Minimal Propagation Delay

Abstract

Chips with multiple interconnected dies offer significant advantages over those consisting of only a single monolithic die, driving the rapid adoption of multi-die packages in the market. Die-to-die interconnects are typically realized as large, dense arrays of fine-pitch micro-bumps or hybrid bonds, prone to manufacturing defects like shorts and opens. To address this, typically spare interconnects are included to “repair” defective ones. Repairing is implemented by avoiding the defective interconnects and detouring the functional signals over spare interconnects. This paper proposes a repair scheme for chiplet interconnects with minimal propagation delay for those chiplets that communicate at high speed and do not tolerate too much delay on their interface. Compared to the default UCIe repair scheme, our proposed solution also demonstrates an improved repair rate in case of clustered defects.