<title>Development and application of micro-moire interferometer</title>

Abstract

Consumers' demand for small, portable, increased functionality, more powerful and lower cost products has been the driving force in the technological advances of electronics packaging. This pushes the trend toward the development of smaller and higher power electronic packages. Due to the coexistence of variety materials with different coefficient of Thermal Expansion in the electronic packages, reliability becomes a concern, especially with smaller package sizes. The thermal mismatches often result in the delamination of interfaces between two materials, which eventually leads to ultimate mechanical and/or electrical failure. With its unique combinations of high sensitivity, optical contrast, range and good spatial resolution, Moire interferometry technique has increasingly been employed in the analysis of thermal deformation in electronic packages. However, with the commercial available moire interferometer, spatial resolution of the system leaves much to be desired. The inability of commercial moire interferometer to monitor local deformation such as at the die attachment level or the die corner thus limits deformation studies at those critical areas.