Plasma Sprayed Ceramic Tray Members for Firing Ceramic Capacitors

Multilayer ceramic chip capacitors (MLCCs) are produced in large numbers for use in automobiles, cell phones, flat panel displays, and other products. Like many circuit components, they are being required in more compact sizes, larger capacities, and reduced costs year by year. MLCCs are kiln-fired on stacked carriers made from Al₂O₃-SiO₂ covered with a Y₂O₃-stabilized ZrO₂ topcoat and an Al₂O₃ basecoat. This paper presents the rationale behind the selection of the coating materials and evaluates processes by which they can be applied. It compares the microstructure and properties of sintered, atmospheric plasma sprayed (APS), and water stabilized plasma sprayed (WSP) yttria-stabilized zirconia and discusses the advantages and disadvantages of each process.