Simulation of Electrojet Printing of Nano Metal Paste as Interconnect Bonding Intermediate

Nano metal paste has broad prospects as interconnect bonding intermediate with high density bumps, but the existing nano metal transfer technologies limit the accurate coverage of bumps by nano metal paste. In this study, a direct transfer technology based on electrojet printing is proposed to achieve accurate coating of micron bumps. The process of electrojet printing was simulated, and the effect of driving voltage and nano metal paste on the electrojet printing behavior were explored. The simulation results show that the cone jet of 3.6 µm is generated Efficiently at 3800 V. In addition, the decrease in the efficiency of electrojet printing due to the increase of surface tension and viscosity coefficient of solution can be attenuated by increasing the driving voltage.