caa a22 4500 463231988 CHVBK 20180405153245.0 cr unu---uuuuu 170326e20070101xx s 000 0 eng 10.1007/s10853-006-1148-7 doi (NATIONALLICENCE)springer-10.1007/s10853-006-1148-7 Fundamentals of thermo-sonic copper wire bonding in microelectronics packaging [Elektronische Daten] [S. Murali, N. Srikanth, Y. Wong, Charles Vath III] Fine copper wire bonding is capable of making reliable electrical interconnections in microelectronic packages. Copper wires of 0.8-6mil diameter have been successfully bonded to different bond pad metallized and plated substrate materials such as Al, Cu, Ag, Au and Pd. The three metallurgical related factors; solid-solubility and diffusion of dissimilar contact metals, oxide film breakage and plastic deformation of asperities play a critical role in the bonding. Plastic deformation of an asperity is the most significant factor one has to consider to attain good bonding. Soft aluminum metal (30-40 VHN), with a lower % asperity threshold deformation is easier to wire bond than harder metallic surfaces (Ni, W, Mo, Cr, Co, Ta) of 150-500 VHN. Good adhesion of wire bonding is achieved for the surface roughness (Ra) of 0.01-0.15μm and 0.02-0.6μm of bare and plated surfaces respectively. It is rationalized that the application of ultrasonic energy principally breaks the oxide film and deform the asperities, while a compressive force increases the proximity of asperities. Hence wire welds to bond pad surface by molecular attraction and inter diffusion. Storage of copper ball bonds at 175°C for 100-1,000h forms copper aluminide at the interface. EDAX and Auger analysis reveal 22at% Al+78 at% Cu composition of the aluminides and Cu3Al2 empirical formula is calculated, which, does not match with any of the reported copper aluminides. Hardness of the copper ball bonds and stitch bonds are higher than wire exhibiting work hardening of the bonds on processing. Springer Science+Business Media, LLC, 2006 Murali S. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut Srikanth N. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut Wong Y. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut Vath III Charles ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/2(2007-01-01), 615-623 0022-2461 42:2<615 2007 42 10853 https://doi.org/10.1007/s10853-006-1148-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-1148-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Murali S. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut NATIONALLICENCE 700 1- Srikanth N. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut NATIONALLICENCE 700 1- Wong Y. ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut NATIONALLICENCE 700 1- Vath III Charles ASM Technology Singapore, 2, Yishun Avenue 7, 768924, Singapore, Singapore aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/2(2007-01-01), 615-623 0022-2461 42:2<615 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer