Printable Epoxy Paste for Varistor Applications

Varistors are passive, two-terminal solid state semiconductor devices that are used to provide over-voltage or over-current protection to electrical and electronic circuits. Metal-oxide varistors (MOVs) are typically made up of a durable ceramic material, which protects them against sudden surges of high current or energy. However, there are some drawbacks of MOVs, such as having a short life span and a large dynamic resistance. NAMICS has developed a solvent-less epoxy paste that has shown non-linear properties and sustained reliability, very similar to that of an MOV. With NAMICS’s proprietary blend of epoxy and other additives, we were able to achieve low-voltage varistor values (< 16 V) with minimal leakage current, comparable to commercially available MOVs being sold today. Printed varistor epoxies have a chance to revolutionize the semiconductor industry by offering miniaturization of components and a solder-less, one-step curing process, all while maintaining the same properties that are offered by MOVs.