Self-sintering conductive inks

Abstract

Self-sintering conductive inks can be printed and self-sintered with a simple and low-cost process mechanized by exothermic alkali metal and water reaction, with enhanced electrical and thermal performance by liquid metal fusion. Such self-sintering conductive inks may include a gallium-alkali metal component and a water absorbing gel component. After patterning, the self-sintering inks, on reaching a designed trigger temperature (including room temperature), may metallize through a two-step process. Initially the gallium-alkali metal component activates and reacts with water released from the water absorbing gel component. Then the exothermic reaction between the water and the alkali element creates an intense and highly localized heating effect, which liquefies all metallic components in the ink and, on cooling, creates a solid metal trace or interconnect. Post cooling, the metal trace or interconnect cannot be reflowed without a significant temperature increase or other energetic input.