Property Prediction of Ag-Filled Isotropic Conductive Adhesive through the Analysis of Its Curing and Decomposition Kinetics

Han Jiang,Xinping Zhang,Minbo Zhou

doi:10.3390/catal12020185

Abstract

In this study, various thermal analyses were carried out on a self-developed and commerce-oriented Ag-filled isotropic conductive adhesive (ICA) and its unfilled matrix resin through which glass transition temperature (Tg) and thermal endurance could be quantitatively predicted. An autocatalyzed kinetic model was used to describe the curing reaction, which was proven to be in good consistency with the experimental data. The activation energies for the curing reaction of the ICA and the matrix resin were determined to be 68.1 kJ/mol and 72.9 kJ/mol, respectively, which means that the reaction of the ICA was easier to occur than its unfilled matrix resin. As a result, the time–temperature profile could be calculated for any Tg requested based on the kinetic model of curing and the DiBenedetto equation. Further, the thermal decomposition stability of the ICA and its unfilled matrix resin were also studied. The activation energies for the thermal decomposition of the ICA and the matrix resin were calculated to be 134.1 kJ/mol and 152.7 kJ/mol, respectively, using the Ozawa–Flynn–Wall method, which means that the decomposition of ICA was easier to occur. The service life of the resin system at a specific temperature could therefore be calculated with their activation energy. The addition of micro-scale Ag flakes did not change the curing and decomposition mechanisms by much.

Highlights

Resin-based conductive adhesives have become widely used in many electronic packaging applications as interconnect materials, such as chip-on-glass and chip-on-flex, among which isotropic conductive adhesive (ICA) plays an increasingly important role [1]
It is known that the formation of each individual chemical link between molecules produces a certain amount of heat
Kinetic determination is useful because it shows the course of the conversion, i.e., how many of the reactive groups that can realistically react have already reacted [15]

Summary

Introduction

Resin-based conductive adhesives have become widely used in many electronic packaging applications as interconnect materials, such as chip-on-glass and chip-on-flex, among which isotropic conductive adhesive (ICA) plays an increasingly important role [1]. A deep understanding of the curing mechanisms and their effects on the properties of ICA is of great importance to the prediction and optimization of the curing processes (e.g., curing time and temperature) for the desired performance. ICA is often used in high-temperature applications such as ceramic substrates and chip components. As the decomposition of the matrix resin at high temperatures may cause the ultimate destruction of ICA interconnection, it is meaningful to know how long ICA bonding can withstand a particular temperature before a certain amount of degradation occurs [3]

Methods

Results

Conclusion