As higher levels of reliability are sought, it will become increasingly important to understand the relationship between the adhesive formulation and its bonded substrate. Johnson Matthey has been addressing this need by using molecular modeling to simulate the physical effects of adhesive components on properties such as adhesion, surface spread or bleed, and underfill flow. By using a molecular modeling method as opposed to a continuum calculation, the individual components of an adhesive may be theoretically manipulated without pre-determination of properties or property effects. The potential utility of the technique lies in the prediction or confirmation of property trends when different components or processes are used. Additionally, the molecular scale helps to gain insight of the interfacial contribution to performance.