Dielectric Polymers

Abstract

Polymer-based dielectric materials have attractive features making them potentially promising alternatives to usually used inorganic and ceramic-based dielectric materials due to a number of reasons including (a) higher flexibility; (b) easy, cost-effective processing feasibility; and (c) attractive chemical stability along with readily changeable characters. However, one of the main disadvantages of this type of polymer dielectric is their lower thermal stability which limits their wider application potentials. In addition, usually polymer dielectric materials show low dielectric constants compared to inorganic dielectric materials. In addition, dielectric characters can be designed by introducing polarizable groups into polymer chains by increasing free volume by inducing porosity as well as copolymerization. Besides this, the value of dielectric constant can be effectively increased by synthesizing nanocomposites by introducing inorganic fillers into composite structure to acquire high dielectric constants. Dielectric polymers have many applications in electronics. For example, the performance of advanced polymer dielectrics is useful to realize high-power electronic circuits in a miniature form. However, these polymeric materials are required to fulfill different criteria (such as thermal, environmental, and electrical stability, low moisture uptake, high breakdown voltage or low leakage current, low dielectric constant, low loss tangent, high glass transition temperature, and low surface roughness) for their effective applications in different devices including in microelectronics. Many investigations have been reported on the use of polymer dielectrics and evaluated the feasibility of utilizing these materials for various applications. Briefly three types of polymer dielectrics (such as dielectric polymers, organic-inorganic material-based hybrid composites, and coated polymer dielectrics) along with other necessary elements are selectively discussed in this chapter. In addition, behaviors of dielectric elastomers are also briefly covered.