Cold‐Sintered Multilayer Ceramic NTC Thermistors: Fabrication and Evaluation

ABSTRACT The cold‐sintering process (CSP) enables the densification of ceramics at significantly reduced temperatures by applying heat and pressure in the presence of a transient liquid phase (TLP). Although CSP has been successfully demonstrated for a wide range of ceramic materials, its application to complex structures such as multilayer ceramic capacitors remains challenging. This difficulty arises from the stringent requirements imposed on the TLP, which must be compatible with multilayer fabrication processes. Specifically, the TLP must (i) exhibit limited reactivity with the organic components necessary for tape casting, (ii) remain stable in air, and (iii) maintain thermal stability. In this study, we identify the eutectic composition of LiCl–KCl and present it as a promising TLP that satisfies these requirements for the spinel‐based NiMn 2 O 4 ceramic and 70 Ag–30 Pd electrodes. Moreover, using LiCl–KCl, multilayer negative‐temperature coefficient thermistors were fabricated via CSP. This achievement represents an important step toward integrating CSP with multilayer ceramic components, thereby broadening the applicability of both.