Analysis of isothermal solidification kinetics during TLP bonding involving two-dimensional solid–liquid interface migration

A new approach is used to model transient liquid phase (TLP) bonding without the simplification assumption of one-dimensional solid–liquid interface migration. In contrast to the general assumption that the single parameter, Φ, that is often used to represent the isothermal solidification kinetics during TLP bonding is constant, this work reports for the first time by coupled numerical simulation and experimental verification that a condition exists where Φ becomes a variable parameter that increases with time. This unique isothermal solidification kinetics behaviour is attributable to a combination of two-dimensional migration of the solid–liquid interface and solute diffusion in a direction along the increase in radius of curvature.