Development of a Thermal Flow Sensor Based on the Ensinger Microsystems Technology

Abstract:
Ensinger GmbH and Hahn-Schickard have jointly developed a PEEK-based thermal flow sensor with direction detection, consisting of a heating element and two temperature sensors. In general, compared to ceramic-based or silicon flow sensors, PEEK impresses with its lower thermal conductivity. The latter should lead to an improvement in sensor sensitivity, making the thermal flow sensor suitable for a demonstrator setup. The PEEK-based thermal flow sensor was manufac-tured using the Ensinger Microsystems Technology. This technology is based on centro-symmetrical discs of TECACOMP(r) PEEK LDS fabricated by injection compression molding. Such disks feature multiple elements of trench structures, into which the sensor and heating elements as well as the leads can be inserted, using a combination of laser direct structuring and electroless plating for the leads and a combination of physical vapor deposition and polishing for the sensor and heating elements. Subsequent dicing of the individual elements and connecting them to a separately developed readout and control printed circuit board, allowed investigating the performance of the first thermal flow sensors in a facile flow channel.