Title :
Metal surface cleanliness and its improvement on bonding
Author :
Wang, Ying-Hui ; Suga, Tadatomo
Author_Institution :
Sch. of Eng., Univ. of Tokyo, Tokyo, Japan
Abstract :
The cleanliness of Au, Cu and Sn surfaces by Ar fast atom beam (FAB) and Ar-plasma treatment was investigated using X-ray photoelectron spectroscopy (XPS). Oxides and organic residues can be removed and clean metal surfaces can be achieved using Ar-FAB activation. The vacuum background of Ar-plasma pretreatment influenced the cleanliness to metal surfaces. The influence of surface cleanliness was investigated by bonding micro-bumps of Au/Sn and Sn-Ag-Cu micro-bumps at 25-100°C. Au/Sn micro-bumps were successfully bonded t to Au and Cu thin films and Au/Sn micro-bumps at room temperature. Regardless of the vacuum background, Ar RF plasma pretreatment improves the bondability of Au/Sn and Sn-Ag-Cu micro-bumps at low temperatures in ambient air.
Keywords :
X-ray photoelectron spectra; bonding processes; copper; plasma materials processing; silver; tin; Au; Au-Sn; Cu; Sn; Sn-Ag-Cu; temperature 25 C to 100 C; Bonding; Copper; Gold; Plasma temperature; Surface contamination; Tin;
Conference_Titel :
Electronic Packaging Technology & High Density Packaging (ICEPT-HDP), 2010 11th International Conference on
Conference_Location :
Xi´an
Print_ISBN :
978-1-4244-8140-8
DOI :
10.1109/ICEPT.2010.5582798
