Evaluation of polyvinylpyrrolidone as a dispersant of barium titanate for multilayer ceramic capacitor (MLCC) application

Uniform dispersion of nanoparticles (NPs) in polymeric binders is crucial in determining the mechanical properties of dielectric sheets, which can reduce factors contributing to the electrical failure of multilayer ceramic capacitors (MLCCs). Selecting the appropriate dispersants is essential for optimizing the interfacial interaction between the surface of NPs and binders. General strategies for designing dispersants involve making the chemical structures of dispersants similar to those of binders to increase material compatibility. However, to diversify the range of material choices, it is necessary to consider dispersants with chemical structures different from those of the binders. In this study, polyvinylpyrrolidone (PVP) was selected as a dispersant for barium titanate (BaTiO₃; BT) NPs and PVP-coated NPs were incorporated into a polyvinylbutyral (PVB) binder. PVP enhanced the dispersibility of the BT slurries and improved the mechanical properties of the dielectric sheets, which ultimately enhanced the electrical characteristics of MLCC. Therefore, the findings of this study demonstrate that PVP is a promising dispersant for BT NPs, contributing to the manufacturing of MLCCs with superior electrical performance.

Graphical abstract

The BT NP was well-coated with PVP dispersants and was stably dispersed in mixed solvent (EtOH/Tol). The PVP provides hydrogen bond acceptor sites on the surface of BT, which enhanced the interfacial interaction between the surface of BT and the PVB binder. This result leads to the increase of the mechanical properties of the dielectric sheet and the improvement of the electrical properties (BDV and short rate) of MLCC