This work shows a possibility of assembly and connection technology for use under high temperatures up to 1000 °C. A packaging concept was developed, and all the necessary material and joining technologies have been verified to be suitable for use at 1000 °C. A working sensor was built and measured in comparison to the resonator alone. All packaging materials and structures were measured electrically and dielectrically. Equivalent circuits for the packages up to 2 MHz and 1000 °C are available.

In this work, a ceramic housing was designed using the versatile low-temperature cofired ceramics (LTCC) to test this technology at temperatures above 400°C. Inside the housing, a prototype sensor chip was mounted to monitor the signal quality during an applied heat treatment up to 600 °C. All devices failed at around 450–500 °C due to material migration from the glass seal of the housing to the sensing structures of the mounted chip. Elemental analysis identified bismuth as a contaminant.

A new packaging method to mount a membrane-based thermal flow sensor, flush with the surface, is presented. Therefore, a specific design for the housing is shown that is also adaptable to other conditions. It has been experimentally shown that it is important to mount the sensor flush with the surface. If not, vortices can occur (depending on velocity and the fluid properties) or the reduction of the channel cross section plus a decrease in sensitivity have to be taken into account.