Ceramic cantilever hotplates for devices and testing platforms

Ceramic hotplates using classical thick-film technology or low-temperature cofired ceramic (LTCC) find a wide range of potential applications: infrared sources, fuel cell components and packaging, microreactors and sensors. This versatility is made possible by the relative ease of structuration and moderate cost achievable with these technologies. However, mass production of simple, low-cost sensors and disposable samples for materials characterisation requires very simple devices. In this work, we therefore investigate the manufacture and performance of simple cantilever hotplates, out of alumina, glass or LTCC, determining their thermal performance and stability, and the dependence of these characteristics on heater technology and substrate material. We also examine the influence on uniformity and losses of adding a guard heater and, in the case of LTCC, of simple cutouts for additional thermal decoupling. In a further step, additional experiments are carried out to determine the respective contributions of conduction, convection and radiation on the thermal losses, with finite-element modelling being applied to support/confirm the experimental data. Finally, a few demonstrators are presented and characterised.