A Fully Integrated Measurement Setup for the In-Situ Characterization of Vertical Thermolegs with the Help of the Transfer Length Method

The electrical and thermal characterization of micro thermoelectric generators (µTEGs) is critical for optimal performance in system design and manufacturing. For this purpose, a fully integrated in-situ measurement setup for measuring contact resistance and determining the thermoelectric properties of powder-based thermoelectric materials and fabricated thermolegs of a µTEG has been developed. The effect of pressure and temperature during the hot-pressing of the powder-based thermolegs during the µTEG manufacturing processes was evaluated using a novel measurement concept which allows in-situ measurement of the contact resistance between the TE material and the conductors provided on the PCB substrate. The traditional transfer length measurement (TLM) is utilized in an atypical vertical implementation for contact measurement here. Based on the promising results from this system, a full measuring platform (ZT-Card) is designed to assess all important thermoelectric material parameters of a microminiaturized thermoleg as well as the contact resistance to the metal lines connecting thermolegs in a µTEG.