Preventing Electrical Shorts in Parallel-Plate Capacitors with Single-Printed Dielectric Layer

Abstract

Double-printing of dielectric layers is commonly used to prevent electrical shorts in parallel-plate capacitors, but this increases the thickness of the dielectric layer and diminishes the corresponding capacitance. Double-printing also complicates the production process and increases production costs. In this paper, it is demonstrated that capacitors with single-printed dielectric layers are without shorts if the layer is completely polymerized. Therefore, electrical shorts could also be related to the state of polymerization in a defect-free dielectric layer. To demonstrate this, the electrical functionality of capacitors with single-printed dielectric layers was studied in terms of intrinsic properties of the ultraviolet (UV) curable dielectric layer, which were varied according to the curing energy. The chemical structure of the cured layer was analyzed with infrared spectroscopy to obtain the appearance of polymerizable groups and crosslinks within the polymer structure. Differential scanning calorimetry was used to measure the glass transition temperature of the dielectric material. It increases rapidly with UV curing until the polymerization is completed, whereas a small increase with further curing confirms crosslinking of the polymer. The influence of structuring effects within a dielectric layer in the presence of electrical shorts between electrodes is discussed. This research confirms that a completely polymerized layer forms a barrier to leakage and helps to prevent the formation of conductive paths between electrodes. Therefore, a connection between the structure of polymerized layer and its electrical properties is highly reasonable.