Dielectric polymer materials with high energy density and low dielectric loss are highly desired for applications in advanced electronic devices and electric power systems. Here, we report on flexible dielectric composites using semiconductor nanoparticles as fillers and polyvinylidene fluoride (PVDF) as a matrix. The introduction of a small amount of ZnO filler results in significantly enhanced voltage breakdown strength and energy density in comparison with pure PVDF. Based on the multi-core model, combining the electric double layer theory and the interface contact theory, we investigate mechanisms and come out with that transportation of carriers under applied voltage is regulated by the charged interface, which delays the formation of the conduction path. Besides, the electric field imposed on the composites is alleviated by the internal micro-electric field.

Flexible polymer composites with high dielectric constant and breakdown strength thus high energy storage density are highly desired in electrical and electronic technologies. In this study, hybrids of nano Ag particles discretely grown on the surface of BaTiO3 nanofibers (BTnfs) were synthesized and used to fabricate PVDF based nanocomposites. The results demonstrated that the dielectric constant and energy storage density of the composites were largely enhanced. An energy density of 10.25 J/cm3 was obtained for the composite containing only 2.5 vol% hybrids, increased by more than 2 times in comparison with pure PVDF.

In general, although abundant literature studies are available on epoxy resin systems, a complete description of the curing kinetics in epoxy-cyanate ester composites relevant to the microelectronics industry is still lacking. Herein, curing behaviors of Ajinomoto build-up films, which are epoxy/silica composites, were studied by the non-isothermal differential scanning calorimetry method, and then, three non-isothermal curing kinetics models and model-free curing methods were used to analyze curing behaviors. In addition, a copper layer was also deposited onto the surface of the build-up film, and its interfacial adhesion property was also analyzed at different pre-curing conditions. The results showed that the curing reaction of the build-up film contains two curing reaction processes, and the first curing process is suited for the autocatalytic curing model, while the other curing process is suited for the Kamal curing kinetics model. Three model-free curing methods were used to calculate the activating energy at different degrees of curing, which indicated that the activating energy is variable during the whole curing process. The interfacial adhesion strength between the build-up film and copper layer decreased with the increase in the degree of curing, which is attributed to the contribution of mechanical anchoring. This work will offer guidance in curing behaviors for improving interfacial bonding force and controlling warpage behavior for chip substrates in the future.