1. Lead-free Solder Alloys: Enthalpies of formation of (Ag,Cu,Ni)-Sn binary alloys U. Saeed, H. Flandorfer, H. Ipser Institute of Inorganic Chemistry / Materials Chemistry University of Vienna

2.  Introduction  Experimental technique  Enthalpy of solution  Enthalpy of formation  Summary Contents

3.  Estimation of phase stability  Optimization of Thermodynamic datasets for CALPHAD  Theoretical calculations of physical properties Introduction Enthalpy of formation  Binary IMCs in Ag-Sn, Cu-Sn, Ni-Sn systems  Extended ternary solubilities in Cu-Ni-Sn system  No ternary or quaternary IMCs formation  Six binaries & four ternaries in Ag-Cu-Ni-Sn system

4. Cu-Sn Cu 41 Sn 11 Cu 6 Sn 5 Cu 3 Sn Ni-Sn Ni 3 Sn 4 Ni 3 Sn 2 Ni 3 Sn Ag-Sn Ag 4 Sn Ag 3 Sn Intermetallics in binary systems

5. Cu-Ni-Sn 600 °C Cu 3 Sn (  ) Ni 3 Sn 4 Ni 3 Sn 2 -HT Ni 3 Sn LT Cu 3 Sn- HT

6. Schematic of Calvet type HT1000 Calorimeter Automatic drop device

7. xA(solid) + yB (solid) A X B y (Solid) DT  f H 298 (A x B y ) = x∙  sol H  (A) + y∙  sol H  (B) -  sol H  (A x B y ) Solution calorimetry = = liquid solvent MT Heating Melting Mixing

8. Enthalpy of solution

10.  f H of Ag-Sn & Cu-Sn IMCs Reference state: Solid

11.  f H of NiSn IMCs Reference state: Solid

12.  f H of ternary solubilities (Cu,Ni) 3 Sn 2 - HT (Cu,Ni) 3 Sn 4 Reference state: Solid

13.  f H of ternary solubilities (Cu,Ni) 3 Sn Reference state: Solid

14. Summary  Solution calorimetery technique was used  Reinvesitigation of enthalpy of formation of binary intermetallic compounds  Agreement with the previously presented of data  Enthalpy of formation of extended ternary solubilities in Cu-Ni-Sn system

15. Thanks for paying attention