Preferential growth of intermetallics under temperature gradient at Cu–Sn interface during transient liquid phase bonding: insights from phase field simulation

The data of (i) heats of transport values and (ii) coefficients for expressions of free energy density of phases used to generate the results in the paper   titled "Preferential growth of intermetallics under temperature gradient at Cu–Sn interface during transient liquid phase bonding: insights from phase field simulation" are provided in this dataset.

(i ) The heats of transport (Q*) values of Cu and Sn species in LIQUID (Sn-rich), IMC (CU6SN5) and FCC (Cu-rich) phases at  T=523.15 K (constant cold side temperature) are available in heat_of_transport.csv file. The numerical quantities in the Q* column of the file are expressed in the unit of kJ/mol. In this work, these Q* values have been independently validated to work for applied thermal gradients (\(\nabla T\)a) of 1.5E+5 K/m and 1.5E+6 K/m Thus, the following meanings hold true for the column names of this data file:

phase - it is the name of a phase studies (e.g. Cu-rich FCC phase,  Sn-rich LIQUID phase and Cu6Sn5 IMC phase. the data type is   string, and has no unit. 

species - the element Cu and Sn of the binary Cu-Sn system. the data type is a string, and has no unit. 

T (K) - it is the constant temperature (T = Tcold = 523.15 K)  at the bottom cold edge  of a rectangular  computational domain of width = 498 nm and height = 747 nm. the data is a float value, and has a unit of K.   The information about cold edge temperature Tcold being the constant reference temperature, and the hot edge temperature being Thot=  Tcold +  \(\nabla T\)a , is a novelty of this work. While most of the other works are based upon hot edge being maintained at constant temperature by a thermal  heater, this work presents the data with the temperature of cold edge maintained constant by a thermal cooler. 

Q* (kJ/mol) - The data of heat of transport values expressed in terms of unit of kJ/mol can be either negative or positive. In this work, the values presented in the table have been validated for applied vertical thermal gradients of   (\(\nabla T\)a) of 1.5E+5  and 1.5E+6 K/m .

(ii) The chemical free energy density of a phase i (i = LIQUID, IMC or FCC ) at 523.15 K has been expressed with  the function fi = 0.5 * Ai * (ci - ceq,i)2 + Bi * (ci - ceq,i) + Ci; where ci is the mole-fraction (composition) of Sn in a phase.  The data consisting of the numerical values of coefficients Ai, Bi and Ci on the units of J/m3 are provided in the file free_energy_density.csv. Besides these coefficients, the file also consists the quantified values of the equilibrium composition ceq,i at each phase. It is to be noted that ceq,i has no units.