Direct patterning by NanoPaste~® and its application

摘要

Direct patterning of NanoPaste~® is a smart process for environment compared with conventional method like photography. Total process is simplified and the waste stemming from etching and cleansing steps is eliminated. The fine conductive pattern was demonstrated on various substrates. The thermal behavior of silver nanoparticles was investigated. Nanoparticle of 5nm in diameter can be sintered at temperature much lower than silver melting point to form a bulk metallic structure. Patterns with 70μm US were obtained by piezo type ink-jet printer. The sintering process has newly developed for copper NanoPaste~® and copper circuit patterning was achieved by ink-jet printing. The fabrication of SiP is described. Super ink-jet technology provides the ultra-fine patterning with several micrometer rules and produces micro-bumps that are three dimensional structures. NanoPaste~® is demonstrated to be a promising candidate for alternative material to the conventional plated silver. Sintered layer of silver NanoPaste~® shows high bonding strength equivalent to the value for the silver plated surface in the ultrasonic bonding.