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Indexed by:会议论文

Date of Publication:2013-08-11

Included Journals:EI、CPCI-S、SCIE、Scopus

Page Number:377-381

Key Words:synchrotron radiation imaging; Ag3Sn; Cu6Sn5; morphology transformation; cooling rate

Abstract:By virtue of the synchrotron radiation imaging combing the analysis of the actual soldering morphology data in lab, we have a more specific understanding of the characteristic of nucleation and growth of Ag3Sn. In furnace cooling conditions, inside the pure Sn3.0Ag solder, there is no sheet Ag3Sn formed. The IMC at the soldering interface is a priority site for the nucleation of the Ag3Sn in the soldering interface reaction for the surface of Cu6Sn5 formed in soldering reaction providing the surface energy of nucleation and decreasing the energy needed for nucleation and growth. Ag3Sn grew around Cu6Sn5 inside the Sn3.5Ag solder in furnace cooling process. Ag3Sn embedded itself in Cu6Sn5, suppressing the growth of Cu6Sn5, and finally affecting the morphology of Cu6Sn5. With the decrease of cooling rate, the size of Ag3Sn increases and the morphology transforms from nano particles to linear distribution with continuous structure, then to sheet morphology. The fast cooling rate provides large degree of supercooling for the nucleation of Ag3Sn; however the slow cooling rate offers abundant time for the diffusion of elements.