Effects of Bi and Ni addition on shear strength of low-Ag lead-free solder joints

Author

Sun Fenglian ; Zou Pengfei ; Liu Yang

Author_Institution

Sch. of Mater. Sci. & Eng., Harbin Univ. of Sci. & Technol., Harbin, China

Volume

1

fYear

2011

fDate

22-24 Aug. 2011

Firstpage

177

Lastpage

180

Abstract

The objective of this paper is to investigate the shear fracture mechanism of solder ball. The shear strength of solder joints were measured by Joint Strength Tester. The results indicate that addition of the Ag element has a significant effect on the shear strength of Sn-Ag-Cu solder joints. The shear strength of Sn0.7Ag0.5Cu-BiNi solder joints is higher than that of Sn-0.3Ag-0.7Cu and Sn-3.0Ag-0.5Cu solder joints as -reflowed or after aging. The 3-D morphology of shear fracture shows that lots of typical dimples were distributed in the solder joints after reflow. But fracture dimples in Sn-0.7Ag-0.5Cu-BiNi solder joints were less than the other two solders and they were all composed of tiny compounds. The fractured position was much more close to the IMC. It indicated that the Sn0.7Ag0.5Cu-BiNi solder shows the best toughness. After aged for 196 hours, the scale of IMC in the surface of shear fracture increases, dimples appear and the shear strength of solder joints decrease.

Keywords

bismuth; fracture toughness; nickel; shear strength; silver; solders; test equipment; 3-D morphology; Ag; Bi; IMC; Ni; aging; fracture toughness; joint strength tester; low-silver lead-free solder joints; shear fracture; shear fracture mechanism; solder ball; Intermetallic; Joints; Lead; Nickel; Reliability; Sun; Shear fracture; dimple; shear strength;

fLanguage

English

Publisher

ieee

Conference_Titel

Strategic Technology (IFOST), 2011 6th International Forum on

Conference_Location

Harbin, Heilongjiang

Print_ISBN

978-1-4577-0398-0

Type

conf

DOI

10.1109/IFOST.2011.6020997

Filename

6020997