A Study on Copper/Silver Core-Shell Microparticles with Silver Nanoparticles Hybrid Paste and its Intense Pulsed Light Sintering Characteristics for High Oxidation Resistance

Abstract

In this study, a silver (Ag) coated copper (Cu) core-shell microparticles paste were fabricated and screen-printed on Polyimide (PI) substrates. It was sintered via intense pulsed light (IPL) sintering technique. IPL irradiation condition (i.e. pulse duration, irradiation energy) was optimized to obtain high conductivity and good oxidation resistance characteristics. To increase the packing density of the pastes and its oxidation resistance, Ag nanoparticles (Ag NPs) were added to Cu/Ag core-shell microparticles (core-shell MPs) paste with optimal mass ratio. To analyze the sintering and oxidation characteristics of hybrid pastes (Ag NPs + core-shell MPs), a scanning electron microscope (SEM) and a focused ion beam (FIB) was used. To demonstrate the mechanism of the sintering process on hybrid pastes, heat generation at the junctions between particles were simulated using Multiphysics COMSOL program. The packing density of the hybrid pastes was investigated using CATIA digital mock-up (DMU) program. In addition, to confirm the heat generation with respect to the packing density of the hybrid pastes, in-situ temperature monitoring process was conducted. As a result, hybrid paste pattern sintered with IPL showed excellent oxidation resistance (resistance increase rate in 300 degrees C for 5 h: 4.92%), and high electrical conductivity (6.54 mu Omega cm).