Patent ID: 11940266

Abstract:
Processes for rapidly and accurately measuring the coefficient of moisture expansion for materials, such as adhesives, are disclosed. A replication technique may be used to manufacture highly flat and smooth adhesive samples. Moisture is introduced in a controlled humidity atmosphere, distortion is monitored with an accurate laser interferometer (e.g., ˜1 nanometer (nm) accuracy), and measurements are correlated with moisture content change. Such processes decrease sample size by three orders of magnitude as compared with conventional techniques and have a smaller adhesive mass requirement, which enables measurement of expensive microelectronic adhesives that were previously cost-prohibitive to measure. Also, thinner films allow CME measurements of ultraviolet (UV) cured adhesives that would otherwise have depth of penetration issues. Furthermore, saturation occurs quickly, allowing pre-stabilization at room temperature, which enabled parametric studies as a function of processing or cure state. Additionally, testing occurs within hours versus months, enabling short lead times for root-cause investigations.