Effects of curing agent and curing conditions on material properties of epoxy/ $BaTiO_3$ composite embedded capacitor films (ECFs)

Abstract

There have been many researches related to the material properties and reliability of epoxy resin. Furthermore, the material properties and reliability of epoxy resin is closely related with curing agent and curing conditions. Curing behavior of epoxy resin can be changed by curing conditions that affect to the degree-of-cure and material properties of epoxy resin after cured. By understanding the relation between curing behavior depending on curing conditions and material properties of epoxy resin after cured, curing conditions of epoxy resin for ECF can be optimized. In this study, $epoxy/BaTiO_3$ composite embedded capacitor films (ECFs) were fabricated using dicyandiamide (DICY) as a curing agent and 3-(4-chlorophenyl)-1,1-dimethylurea as a curing accelerator to investigate the curing behaviors and material properties of epoxy resins and ECFs with different curing agent, temperature and time. First, amount of curing accelerator was optimized in terms of glass transition temperature ($T_g$), coefficients of thermal expansion (CTE), and chemical structure. From these results, the content of curing accelerator was optimized as 1wt%. In addition, effect of the curing accelerator addition on activation energy of epoxy resin was analyzed using the peak temperatures of differential scanning calorimeter (DSC) dynamic scans. The activation energy was reduced as 1wt% of curing accelerator was added because it enhanced the reactivity of DICY. The curing behaviors of epoxy resins with DICY 2wt%, DICY 6wt%, and the mixture of DICY 2wt% and curing accelerator 1wt% were also examined using DSC. According to results, peak of DSC dynamic scan was narrow and deep as DICY contents increased and curing accelerator lowered the curing on-set temperature and peak temperature of epoxy resin. Effect of curing temperature on material properties of epoxy resins and ECFs were investigated in terms of $T_g$, peel adhesion strength, CTE, and chemical structure changes. Epoxy resins and ...