Synthesis of Cu Sintering Paste Using Growth of Nanofiber on Cu Microparticles Mixed with Formic Acid

A sintering paste for bonding copper plates was synthesized using Cu formate nanofibers on Cu microparticles, mixed with formic acid. Copper oxide nanofibers of 10 mu m grown at 400 degrees C on Cu microparticles on the surface were transformed into copper formate nanofibers through the mixing of formic acid. Compared to Cu bulk particles or nanoparticles, Cu formate on Cu microparticles decomposed into metallic Cu at a lower temperature of 210 degrees C, facilitating the sintering of copper paste. The growth of nanofiber on Cu microparticles allowed for an increase in the reaction rate of formation to copper formate, aggregating surface area, and decomposition rate of copper formate, resulting in fast sintering.