Exploring Pressureless Nano-Copper Sintering for Power Chip Interconnection

This study explores the potential of pressureless nano-copper sintering for power chip interconnections. As electronics evolve towards miniaturization and higher power density, traditional interconnection materials such as nano-silver, despite their excellent thermal and electrical properties, face challenges like high cost and susceptibility to electromigration. Nano-copper, with comparable electrical conductivity and superior thermal performance at a lower cost, emerges as a promising alternative. The study examines the impact of sintering atmosphere and temperature on shear strength. Results show that nitrogen-protected environments significantly enhance bonding by preventing oxidation, while samples sintered in air exhibit minimal strength due to surface oxidation. Additionally, sintering at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$230^{\circ}\mathrm{C}$</tex> provides stronger bonds compared to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$200^{\circ}\mathrm{C}$</tex>, indicating improved diffusion and bonding at higher temperatures. SEM analysis of samples sintered at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$300^{\circ}\mathrm{C}$</tex> demonstrates optimal bonding, with minimal voids, making <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$300^{\circ}\mathrm{C}$</tex> an ideal sintering temperature for reliable power chip packaging using nano-copper.