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

fYear

2009

fDate

10-13 Aug. 2009

Firstpage

790

Lastpage

794

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/ICEPT.2009.5270642

Filename

5270642