Process for rapidly measuring coefficient of moisture expansion (CME) values for materials

Issue
 Date
Patent No.
US 11,940,266 B2
Category
Method or Process (e.g. a way to accomplish a given result)

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.

Keywords: adhesive, Moisture
International Class: G01B11/24, G01N21/84, G06T7/00, G06T7/64