SOMMADOSSI silvana Andrea
Structural investigation in Cu-In-Sn alloys around 60 at.% Cu for Pb-free transient liquid phase bonding
S. SOMMADOSSI; G. AURELIO; G.J. CUELLO
Journal of Physics: Conference Series (JPCS)
Lugar: Bristol; Año: 2010
The study of the Cu-Sn-In ternary system has acquired in recent years a great importance, due to new environmental regulations forcing to eliminate the use of Pb in bonding technologies for electronic devices, such as Transient Liquid Phase Bonding . There is a lack of basic information on this system regarding some intermetallic phases which grow in the bonding zone, particularly the so-called eta-phase (Cu2In or Cu6Sn5) that exists in both the binary and the ternary phase diagrams and whose description has been confusing and ambiguous. In this work, preliminary data are presented obtained for a series of six alloys with about 60 at.% Cu and with In and Sn contents ranging from 0 to 20 at.%, quenched from 300ºC. The alloys were characterized using differential scanning calorimetry , electron probe microanalysis and neutron diffraction . Thermodiffraction experiments were performed on the instrument D1B in ILL-Grenoble. Temperature scans indicate a relation between the phase transitions observed in the calorimetry curves with structural modifications of the intermetallic phases. The D1B data also suggest the formation of superstructures in the Cu6Sn5 phase and even for the Cu3Sn, pointing to the need of further investigation to clarify the present findings.