老化气氛对低温烧结铜纳米颗粒接头热稳定性的影响

Third-generation semiconductors are essential for high-temperature and high-power applications in power electronics. Sintered Cu nanoparticles present promising thermal and mechanical properties as interconnect materials in extreme environments. However, the effects of thermal aging under different atmospheric conditions on their performance require further investigation. This work investigates the shear strength, microstructural evolution, and thermal conductivity of sintered Cu joints aged at 250 °C and 500 °C in air, vacuum, and argon atmospheres. The results demonstrate that thermal aging improves shear strength by reducing porosity, with higher pressure sintering (20 MPa) leading to better densification and oxidation resistance. Oxidation is mainly confined to the interface due to the dense Cu structure, limiting oxygen diffusion and preventing internal degradation. However, prolonged aging time results in crack formation and propagation, particularly at 500 °C, where the growth of a Cu oxide layer at the joint-substrate interface degrades thermal conductivity. These findings emphasize the critical role of porosity control, aging temperature, and atmospheric conditions in enhancing the thermal stability and mechanical reliability of sintered Cu joints for high-temperature power electronics applications.