Development, design and fabrication of a measurement chip for thermal material characterization based on the 3-omega method

The knowledge of thermal properties of materials is important for many fields of technology such as thermal management for microelectronics, for the selection of interface or filler materials as well as for thermal simulations. We developed, designed and fabricated a characterization chip for the measurement of the thermal conductivity and diffusivity of, e.g., pastes, gels, fluids, polymers and bulk samples. The measurement principle is based on an extension of the 3-omega method. For the traditional 3-omega method a thin metal heater line must be deposited on top of the sample, which is often impractical and even impossible for non-solid samples or samples with rough surfaces. We are using an extension of the 3-omega method, which also allows to measure the thermal properties of such materials for which the traditional 3-omega method is not applicable. In our measurement system, the sample can be simply put onto a chip in which the 3-omega heater is already integrated. Due to the use of through-glass vias, the complete top side of the chip is available for the sample deposition. In this work, the design and fabrication of the chips and measurements of the thermal properties of reference samples are presented.