Title :
Nanoindentation investigation of copper bonding wire and ball
Author :
Fan, Xiangquan ; Qian, Kaiyou ; Wang, Techun ; Cong, Yuqi ; Zhao, Mike ; Zhang, Binhai ; Wang, Jiaji
Author_Institution :
Dept. of Mater. Sci., Fudan Univ., Shanghai, China
Abstract :
Copper is the most cost-effective alternative to gold which is used in wire bonding. Hardness of bonding wire and FAB (free air ball) is double-edged swords, wire with higher hardness and strength can build more reliable loop, but damage the bounding pad on the chip more easily. Precisely measuring hardness is meaningful for improving the performance and reliability of the bonding process. Nanoindenter is a powerful experimental technique for detecting mechanical properties of materials. In this work, the mechanism of nanoindentation and the selection of hardness test parameters were studied. Hysitron´s nanoindenter with Berkovich tip was used to measure hardness of 0.8 mil (20 mum) 4N(99.99%wt of copper) copper ball bonding wire, FAB and bonded ball. It is confirmed that copper wires get harder mainly in ball formation and ball bond form process.
Keywords :
bonding processes; copper; gold; nanoindentation; Au; Berkovich; Cu; Hysitron´s nanoindenter; ball bond; ball formation; bonding ball; bonding wire; free air ball; nanoindentation investigation; Bonding processes; Copper; Gold; Materials testing; Mechanical factors; Nondestructive testing; Plastics; Semiconductor device measurement; Thermal conductivity; Wire;
Conference_Titel :
Electronic Packaging Technology & High Density Packaging, 2009. ICEPT-HDP '09. International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-4658-2
Electronic_ISBN :
978-1-4244-4659-9
DOI :
10.1109/ICEPT.2009.5270642
