Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment

N. Unami, H. Noma, K. Sakuma, A. Shigetou, Shuichi Shoji, Jun Mizuno

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

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.

Original languageEnglish
Title of host publicationProceedings - International Symposium on Advanced Packaging Materials
Pages220-225
Number of pages6
DOIs
Publication statusPublished - 2011
Event2011 International Symposium on Advanced Packaging Materials, APM 2011 - Xiamen
Duration: 2011 Oct 252011 Oct 28

Other

Other2011 International Symposium on Advanced Packaging Materials, APM 2011
CityXiamen
Period11/10/2511/10/28

Fingerprint

formic acid
Formic acid
Surface treatment
Vapors
Vacuum
Shear strength
Auger electron spectroscopy
Soldering alloys
Oxides
Strength of materials
Melting point
Carbon
X ray photoelectron spectroscopy
Metals
Impurities

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Materials Science(all)

Cite this

Unami, N., Noma, H., Sakuma, K., Shigetou, A., Shoji, S., & Mizuno, J. (2011). Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment. In Proceedings - International Symposium on Advanced Packaging Materials (pp. 220-225). [6105704] https://doi.org/10.1109/ISAPM.2011.6105704

Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment. / Unami, N.; Noma, H.; Sakuma, K.; Shigetou, A.; Shoji, Shuichi; Mizuno, Jun.

Proceedings - International Symposium on Advanced Packaging Materials. 2011. p. 220-225 6105704.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Unami, N, Noma, H, Sakuma, K, Shigetou, A, Shoji, S & Mizuno, J 2011, Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment. in Proceedings - International Symposium on Advanced Packaging Materials., 6105704, pp. 220-225, 2011 International Symposium on Advanced Packaging Materials, APM 2011, Xiamen, 11/10/25. https://doi.org/10.1109/ISAPM.2011.6105704
Unami N, Noma H, Sakuma K, Shigetou A, Shoji S, Mizuno J. Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment. In Proceedings - International Symposium on Advanced Packaging Materials. 2011. p. 220-225. 6105704 https://doi.org/10.1109/ISAPM.2011.6105704
Unami, N. ; Noma, H. ; Sakuma, K. ; Shigetou, A. ; Shoji, Shuichi ; Mizuno, Jun. / Investigations of fluxless flip-chip bonding using vacuum ultraviolet and formic acid vapor surface treatment. Proceedings - International Symposium on Advanced Packaging Materials. 2011. pp. 220-225
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