Effect of insulating layer on damage of flexible Ag nanoparticle line under high-density electric current

The demand for printed electronics is increasing with the development of flexible devices. Flexible electric line printed with metal nanoparticle ink is widely used. Electromigration (EM), is a phenomenon in which metal atoms are transported by electron wind under high current density, and it is important to reduce EM damage to improve device reliability. It is already known that EM damage occurs in Ag nanoparticle line not covered with an insulating layer, but EM damage in Ag nanoparticle line covered with an insulating layer has not been investigated. In this study, high-density current loading tests were conducted on Ag nanoparticle line with and without insulating layer to investigate EM damage. Test specimens were fabricated using an inkjet printer, and high-density current loading tests were conducted using a current testing machine to measure the potential drop for a constant current in the line using the four-terminal method. After the test, the surface of the test section was observed using a microscope. Damage occurred on the anode side of the line section of the Ag nanoparticle line with an insulating layer, and decrease in the potential drop was observed in the early stages of the high-current loading test. From the results, it was confirmed that EM damage occurred in the Ag nanoparticle line with an insulating layer as well as in the Ag nanoparticle line without an insulating layer.