Probing the Interfacial Adhesion Strength in Compositional Libraries of Epoxy Films

Abstract

We are developing a measurement platform, based on the edge delamination test geometry, geared towards combinatorial and high-throughput (C&HT) assessment of interfacial adhesion and reliability of epoxy films bonded to a rigid substrate. A critical parameter space to be explored is composition of the epoxy formulation. We have constructed an automated mixing and deposition system for creating discrete and continuous gradients in composition of viscous epoxy formulations. By dicing the combinatorial library into a contiguous discrete sample array, the interfacial adhesion strength can be deduced from the critical stress required to debond each film cell from the substrate. These results can be used to predict the adhesion reliability of epoxy formulations as a function of composition and applied stress.

Symmetrical “Sandwich” Polybutadiene Film with High-Frequency Low Dielectric Constants, Ultralow Dielectric Loss, and High Adhesive Strength

“…The excellent dielectric materials not only had exceptional adhesion but also had a very low dielectric constant and dielectric loss. , However, strong adhesion and excellent dielectric properties of polymer materials were often contradictory. On one hand, strong adhesion requires that polymer chains contained polar functional groups such as aminos, cycloxyls, and isocyanates, which can enhance the interfacial forces between polymer chains and microstrip conductors by electrostatic interaction, thereby improving the durability and reliability of integrated circuit boards. On the other hand, the orientation polarization of the intrinsic dipole moments combined with the dipole polarization of polar functional groups decisively caused a large increase in the dielectric loss; so, optimizing the dielectric properties (especially low dielectric loss) required that polymer chains contained nonpolar functional groups.…”

Gradient and Microfluidic Library Approaches to Polymer Interfaces

“…In that particular study, an epoxy stress-generating layer was coated directly on the PMMA films; an orthogonal thickness gradient of epoxy was applied to generate a gradient in the stress profile. We have also employed compositional gradients in epoxy films [92], as well as gradients in temperature (both curing temperature and quench temperature).…”