TY - GEN
T1 - Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment
AU - Unami, N.
AU - Noma, H.
AU - Sakuma, K.
AU - Shigetou, A.
AU - Shoji, S.
AU - Mizuno, J.
PY - 2011
Y1 - 2011
N2 - We studied the effects of surface treatment using vacuum ultraviolet (VUV) and formic acid vapor for SnCu-Au flip-chip bonding. Sn-rich solder bumps are widely used for flip-chip interconnections because of low melting temperature and high mechanical strength. For fine pitch interconnections, surface modification is needed before the bonding process. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) were used to investigate Sn surfaces. The results showed how the VUV/O 3 surface treatment removes the carbon-based organic contaminants from the Sn surfaces and the formic acid treatment reduces the metal oxides of Sn. Combination of VUV/O 3 and formic acid treatments improved shear strength of a bonded sample. The average shear strength of each bump with VUV/O 3 and/or formic acid treatment is about twice that of a bump with no treatment.
AB - We studied the effects of surface treatment using vacuum ultraviolet (VUV) and formic acid vapor for SnCu-Au flip-chip bonding. Sn-rich solder bumps are widely used for flip-chip interconnections because of low melting temperature and high mechanical strength. For fine pitch interconnections, surface modification is needed before the bonding process. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) were used to investigate Sn surfaces. The results showed how the VUV/O 3 surface treatment removes the carbon-based organic contaminants from the Sn surfaces and the formic acid treatment reduces the metal oxides of Sn. Combination of VUV/O 3 and formic acid treatments improved shear strength of a bonded sample. The average shear strength of each bump with VUV/O 3 and/or formic acid treatment is about twice that of a bump with no treatment.
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U2 - 10.1109/ISAPM.2011.6105704
DO - 10.1109/ISAPM.2011.6105704
M3 - Conference contribution
AN - SCOPUS:84856413231
SN - 9781467301473
T3 - Proceedings - International Symposium on Advanced Packaging Materials
SP - 220
EP - 225
BT - APM 2011 Proceedings - 2011 International Symposium on Advanced Packaging Materials
T2 - 2011 International Symposium on Advanced Packaging Materials, APM 2011
Y2 - 25 October 2011 through 28 October 2011
ER -