A process utilizing thermoplastic adhesives for surface mounting or laminating two or more substrate surfaces consisting of a combination of thermoplastic-polyimide (TPI) adhesive layers, one of which is B-staged or partially cured, and the other of which is C-Staged or fully cured, employed both as direct coatings and/or stand alone bondfilms, as well as their advantageous use in joining materials of mismatched Coefficients of Thermal Expansion (CTE).