EVALUATION OF HALOGEN-FREE LAMINATES USED IN HANDHELD ELECTRONICS
Authors: David Lau, Laura J. Turbini, Julie Liu, and Y. Norman Zhou Company: University of Waterloo and Research in Motion Date Published: 10/4/2009
Abstract: The purpose of this study is to examine the thermal properties of various halogen-free laminates used in handheld electronic products and to correlate these properties with the manufacturing requirements. Thermal properties investigated are the z-axis CTE, time to delamination at 260°C and 288°C and temperature to decomposition. SEM and EDS mapping analyses have been done on the laminates to determine the chemical composition and volume fraction of the fillers used in the epoxy. Three different fillers were identified: Al(OH)3, Mg(OH)2 and SiO2. Results show that the SiO2 fillers reduce the z-axis CTE and increase the time to delamination. The decomposition of the Al(OH)3 fillers above 200oC contributes to increases in z-axis CTE and promotes delamination.
Key words: halogen-free; inorganic fillers; coefficient of thermal expansion; time to delamination; temperature to decomposition