High Density and Low-Temperature Interconnection Enabled by Mechanical Self-Alignment and Electroless Plating

摘要

In this work, we propose and demonstrate the use of metal electroless plating along with mechanical self-alignment as a method to create high density scalable interconnects between chiplets using a low temperature process flow. Void free and selective bonding of a copper pillar array at 50 ^m pitch using electroless nickel deposition is demonstrated at a temperature of 95°C and atmospheric pressure. Mechanical self-alignment using precision ruby balls is demonstrated to attain alignment accuracies within 2 μm.