MCM structures with poled dielectrics to improve testability

To improve multichip module (MCM) testability, we have used a new, recently-demonstrated technique to detect on-substrate electric field strength. This technique employs a noninvasive, laser-based instrument to probe MCM structures fabricated with poled polyimide interlayer dielectrics and thin film metallizations on silicon carriers. Circuit elements characteristic of MCMs were probed to detect electric field strength. The electrical, mechanical, and optical properties of these electro-optic dielectric layers were determined to investigate the effect of the poling and processing operations on the efficacy of the polyimide as both a dielectric layer and an electro-optic material suitable for laser probing.