Optimization and simulation of nano-silver paste sintered copper interconnection process.

In this paper, the nano-silver paste-based femtosecond laser-assisted copper interconnection process was optimized by pickling modification of the copper surface and preheating treatment of the silver paste, which significantly improved the copper interconnection strength. Meanwhile, the effect of the height and consistency of the copper surface array microstructure prepared by femtosecond laser on the copper interconnection strength was investigated. The results demonstrated that the copper interconnection strength is mainly influenced by the high consistency of the surface array microstructure. In addition, for the pickling modification treatment process of the copper surface, the strength of copper interconnection under the modification of a weak acid (8% acetic acid) and a strong acid (3% hydrochloric acid) was studied. The shear strength of sintered joint could reach 41.64 MPa under weak acid corrosion conditions, about 2 times higher than the strong acid corrosion conditions. Finally, the temperature and stress distribution of copper interconnection in service were analyzed by finite element simulation, and the lifetimes were predicted under temperature cycling conditions (− 50 °C to 250 °C). The results proved that the reliability of sintered structure could meet the operational requirements.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.The authors and their respective affiliations are correct [ABSTRACT FROM AUTHOR]