Over the past decade, ceramic packaging materials have continued to increase in both chemical and structural complexity. At processing temperatures of 800 C to 900 C, the possibilities for interactions at interfaces between dissimilar materials are numerous. It is therefore important to establish a method for interpretation and prediction of interfacial reactions. We have investigated the system Ag-Bi2O3-Nb2O5-O as the first step in developing such a method. We have completed an isothermal phase equilibrium diagram at 850 C, which provides the basis for a thermodynamic model. By assuming local equilibrium and thermodynamic mobility of Ag and Bi2O3 at interfaces, the conventional phase diagram has been recast as an isothermal chemical potential diagram. Comparison of interfacial reaction zones predicted by the chemical potential model with those observed in Ag/BiNbO4 and Ag/BiNb5O14 reaction couples affirms the mobility of Ag at the interface. Thermogravimetric monitoring of O2 uptake has allowed us to obtain kinetic information as well. The possibility of a combined thermodynamic/kinetic model of interfacial interaction is discussed.
Proceedings Title: Ceramic Interconnect Technology, Conference | | 2003 IMAPS Conference and Exhibition on Ceramic Interconnect Technology the Next Generation
Conference Dates: April 1, 2003
Conference Title: Proceedings of SPIE--the International Society for Optical Engineering
Pub Type: Conferences
Ag-Bi<sub>2</sub>O<sub>3</sub>-Nb<sub>2</sub>O<sub>5</sub>-O, interfacial reaction, kinetics, LTCC, phase diagram, thermocynamics