Intermetallic growth between Sn-Ag-(Cu) solder and Ni

Author

Yang, Seung Taek ; Chung, Yoon ; Kim, Young-Ho ; Hong, B.H. ; Park, K.R. ; Song, H.G. ; Moris, J.W., Jr.

Author_Institution

Dept. of Mater. Eng., Hanyang Univ., Seoul, South Korea

fYear

2001

fDate

2001

Firstpage

219

Lastpage

224

Abstract

The intermetallic formation between Sn-Ag-(Cu) solders and metal pads was characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). The intermetallic phase formed in the interface between Sn-Ag-Cu and Au/Ni/Cu pad in a tape BGA package is likely to be a ternary compound of Cu-Ni-Sn from EDS analysis. Cu was also segregated in the solder/Ni interface. XRD analysis confirmed that η-Cu₆Sn₅ type intermetallic phase formed in the interface between Cu containing solders and Ni substrates and Ni₃Sn₄ intermetallic formed in the Sn-Ag solder/Ni interface. The Cu atoms in the solder seem to diffuse in the solder/Ni interface and to form η-Cu₆Sn₅ type intermetallic in the Sn-Ag-Cu specimens. The increase in the Cu concentration of the solder increased the intermetallic thickness after reflow

Keywords

X-ray chemical analysis; X-ray diffraction; assembling; ball grid arrays; copper alloys; diffusion; environmental factors; integrated circuit packaging; interface structure; nickel; reflow soldering; scanning electron microscopy; segregation; silver alloys; tin alloys; Au/Ni/Cu pad; Cu containing solders; Cu diffusion; Cu segregation; Cu₆Sn₅; CuNiSn; EDS; Ni pad; Ni substrates; Ni₃Sn₄; Ni₃Sn₄ intermetallic; SEM; Sn-Ag solder/Ni interface; Sn-Ag-Cu solder; SnAgCu-Au-Ni-Cu; SnAgCu-Ni; X-ray diffractometry; XRD; XRD analysis; energy dispersive spectroscopy; eta-Cu₆Sn₅ type intermetallic phase; intermetallic formation; intermetallic growth; intermetallic phase; intermetallic thickness; metal pads; scanning electron microscopy; solder Cu concentration; solder reflow; solder/Ni interface; tape BGA package; ternary Cu-Ni-Sn compound; Assembly; Costs; Dispersion; Environmentally friendly manufacturing techniques; Intermetallic; Lead compounds; Scanning electron microscopy; Soldering; Thermal resistance; X-ray scattering;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Materials and Packaging, 2001. EMAP 2001. Advances in

Conference_Location

Jeju Island

Print_ISBN

0-7803-7157-7

Type

conf

DOI

10.1109/EMAP.2001.983988

Filename

983988