Effect of Temperature/Humidity Treatment Conditions on Interfacial Adhesion Energy between Inkjet-Printed Ag and Polyimide

Abstract

The effect of temperature/humidity treatment conditions on the interfacial adhesion energy of inkjet-printed Ag/polyimide systems was investigated for metallization of inkjet printing techniques in flexible printed circuit board applications. The interfacial adhesion energy was determined from 180° peel tests by calculating the plastic deformation energy of peeled metal and polyimide films from the energy balance relationship during the steady-state peeling process. After 76 h of temperature/humidity treatment, there is an increase in interfacial adhesion energy. This is a chemical bonding effect because there exists good quantitative correlations between the interfacial bonding energy and the Ag* peak area fraction from X-ray photoemission spectroscopy (XPS) data of peeled metal surfaces. After 196 and 388 h of temperature/humidity treatment, there is a decrease in interfacial adhesion energy, which seems to degrade polyimide by hydrolysis reaction with water molecules.