The curing reaction of a conductive adhesive was studied with a differential scanning calorimeter (DSC) under isothermal conditions in the range of 10O-16O0C. An autocatalyzed kinetic model was used to describe the curing reaction. The rate constant and the reaction orders were determined and used in the model to predict the progress of the curing reactions. A good agreement is found between the proposed kinetic model and the experimental reaction rate data. The reaction rate constants were correlated with the isothermal temperature by the Arrhenius equation. The activation energy for the curing reaction is determined to be 94.9 kJ/mol. The reaction order which represents the effects of the unreacted materials is found to be a parabolic h c t i o n of temperature. But the effects of the reacted materials on the reaction rate change sharply at around 120 "C. Unlike some previous results on epoxy curing kinetics, the sum of the two reaction orders is not a constant for this conductive adhesive. Thermogravimetric Analyzer (TGA) was used to study the weight loss during thermal processes. The degradation temperature of the conductive adhesive was found to be 250 "C. The properties of the corresponding unfilled Epoxy were also studied with the DSC and TGA. Results were compared with those obtained from the conductive adhesive. Tests were conducted to investigate the mechanical and electrical property changes during cure.Conductive adhesives have become an attractive altemative to solder joints as the interconnect medium since they provide many advantages such as low processing temperatures and less environment contamination [ 1-31. In recent years, extensive studies have been conducted fix conductive adhesives in various areas such as joint reliability testing [4], electrical properties and microstructure development [ 5 ] , and joint residual stress analysis [6]. The physical, electrical and mechanical properties of conductive adhesives depend to a large extent on the degree of cure of the epoxy composition in the conductive adhesives. Thus, a hlly understanding of the cure mechanisms of conductive adhesives and their effects on the properties of adhesives can provide tools to optimize cure schedule so that residual stresses in the conductive adhesive joint are minimal. In this study, the curing reaction of an isotropically conductive was studied with a differential scanning calorimeter (DSC) under isothermal and dynamic conditions. An autocatalyzed kinetic model was used to describe the curing reaction. Thermogravimetric Analyzer (TGA) was used to study the O -7 8 O~-~5 7 -~9 7 $4.00 01 997 IEEE 550 weight loss during thermal processes. The properties of the corresponding unfilled Epoxy were also studied with the DSC and TGA and results were compared with those obtained from the conductive adhesive. A dynamic mechanical analyzer (DMA) was used to study the mechanical property change during dynamic cure process. It was found that the adhesive starts to become rigid when the degree of cure reaches about 0.75 and the ri...
This paper discusses material behaviors of holographic materials in terms of mechanical, thermomechanical properties and their effects on optical efficiency. Experiments were carried out to characterize coefficient of thermal expansion, stress strain curves, and dynamic mechanical behaviors of photopolymers. It has been found that in-plane deformation of photopolymer has a minimum effect on the diffraction efficiency while out-of-plane deformation can significantly contribute to the diffraction efficiency of holographic optical elements.
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