The Correlation between the Liquid Structure and the Viscosity of Sn-Cu Lead-Free Solders

Abstract:

Article Preview

The liquid structure of two lead-free solder Molten alloys, Sn-0.5Cu and Sn-1.8Cu (wt.%), has been examined using X-ray diffraction method. The main peak for liquid structure of Sn-0.5Cu is similar to that of pure Sn. A pre-peak has been found in the low Q part on the structure factor S(Q) of Sn-1.8Cu tested under 320°C, but it disappeared finally when the testing temperature reached 350°C. The both viscosity was measured using a torsional oscillation viscometer. It was found that the anomalous variations of viscosity had a direct relation with the transition of the liquid structure, which is consonant with the results of high temperature X-ray diffraction. The microstructure of the solder matrixes as well as interfacial reaction between liquid solders and Cu substrates was also studied. The results show that particle-like Cu6Sn5 intermetallic compounds (IMCs) emerge in Sn-1.8Cu solder matrix. The IMC layer at Sn-1.8Cu/Cu joint is thicker than that at Sn-0.5Cu/Cu interface. The correlative effect of liquid structure on phase evolution in the solder joints is analyzed.

Info:

Periodical:

Advanced Materials Research (Volumes 97-101)

Edited by:

Zhengyi Jiang and Chunliang Zhang

Pages:

679-682

DOI:

10.4028/www.scientific.net/AMR.97-101.679

Citation:

X. M. Pan et al., "The Correlation between the Liquid Structure and the Viscosity of Sn-Cu Lead-Free Solders", Advanced Materials Research, Vols. 97-101, pp. 679-682, 2010

Online since:

March 2010

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.