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

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 degrees 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 76h 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. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/JJAP.48.08HL02