Solderability of tinned FeNi under bump material

Author

Chen, Cai ; Zhang, Lei ; Shang, J.K.

Author_Institution

Shenyang Nat. Lab. for Mater. Sci., Chinese Acad. of Sci., Shenyang, China

fYear

2009

fDate

10-13 Aug. 2009

Firstpage

670

Lastpage

673

Abstract

Finding new under bump materials (UBM) is of significant importance with the shrinkage of pitch size in advanced high density packaging. FeNi alloy has been found to be a good UBM candidate for its slower interfacial reaction during reflow and aging. However, solderability of FeNi has to be improved. 58Fe42Ni and 92Fe8Ni alloy platings with electrodeposited tin finish were investigated by wetting balance method in a SnAgCu liquid bath. Results showed that tin finish can reduce the initial wetting time t_b of 58Fe42Ni and change the non solderable 92Fe8Ni to be the same wetting performance as 58Fe42Ni. The maximum wetting force of tin finished both FeNi alloys were larger than the bare alloy. However, after the maximum was reached, a slight decline of the wetting force was observed. The decline depended on the thickness of tin finish, with the thicker tin finish resulting in a higher steady plateau on the wetting force curve.

Keywords

electrodeposition; iron alloys; metallisation; nickel alloys; solders; wetting; FeNi; advanced high density packaging; electrodeposited tin finish; interfacial reaction; pitch size; under bump materials; wetting force; Copper; Force measurement; Inorganic materials; Iron alloys; Materials science and technology; Metallization; Nickel; Packaging; Testing; Tin alloys;

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.2009.5270666

Filename

5270666