Workable Shrinkage Test for the Fiber Optic and Microelectronic Industries
In particular, the overriding concern of these industries with precision alignment manufacturing processes and the adverse effect of adhesive shrinkage upon cure on this requirement have led us to develop a novel shrinkage test suited to the small adhesive volumes typically applied to each component in photonics manufacturing. Application of this reliable and repeatable shrinkage test has led our research team to investigate the impact of programmed cure cycles on bulk properties, including shrinkage, for a selection of commercially available photo-initiated and thermally cured polymers. This methodology can be expanded to study the effects of external conditions such as thermal cycling and creep, measuring material-volume changes at each step of the process to allow quantifiable determination of the bulk-material changes.
In the preliminary study, shrinkage measurements were made for a number of representative materials, including photo-polymerizable acrylics and epoxies as well as a thermoset epoxy. Our research team’s investigations have shown that through the application of programmed cure cycles – a technique we call StepCure™, a degree of control over the bulk shrinkage expressed by a given material can be obtained. These results clearly demonstrate the utility of StepCure in UV-curing applications.