First principles calculation of elastic and lattice constants of orthorhombic Cu3Sn crystal

The structure and elastic properties of a common intermetallic compound, Cu3Sn, at the interface of a solder and Cu metallization were investigated by the plane-wave pseudo-potential (PW-PP) method using the generalized gradient approximation (GGA). Through energy minimization, the lattice constants of the Cu3Sn orthorhombic crystal were calculated to within a very small range of the experimental values. Based on the structural information, the elastic constants of Cu3Sn crystal were determined from the first principles calculations. Using the single crystal results, the elastic constants of the polycrystalline Cu3Sn compound were predicted from the continuum theories. The predictions provided reasonable agreements with experimental data available.