Materials Informatics Technique for Designing Strong-Adhesion Interfaces in Electronics Devices

A materials-informatics technique for designing strong flat interfaces has been developed by use of advanced simulation that can calculate the delamination energy as the adhesion strength. In this study, this technique is applied to the design of metal (or alloy) with strong adhesion to polyimide, which is an example resin used for printed circuit boards. At the first stage, the interatomic spacings were selected as the important, dominant metal parameters from four metal parameters (the short-distance and long-distance interatomic spacings, electronegativity, and surface energy density) by using sensitivity analysis based on the design-of-experiments method with the delamination-energy data calculated from the advanced simulation. At the second stage, the adhesion strength (delamination energy) is expressed as a function of the important alloy parameters (i.e., the short-distance and long-distance interatomic spacings) by using Kriging-method-based artificial intelligence. At the third stage, by solving the maximum-value problem of the function, it was found that the metal that has the same short-distance and long-distance interatomic spacings as those of the resin has the strongest adhesion to the resin. Finally, it was confirmed that the metal (Ni-12%Mn) that satisfies this lattice-matching condition has the strongest adhesion by conducting a scratch test. Thus, lattice matching was found to be the most important factor in the adhesion.