Thick-film technology-based gas sensors have been known for many years. On a ceramic substrate, a thick-film heater, electrodes, and a gas sensitive layer are deposited. Due to the ease of layer deposition, such structures are usually manufactured as planar ones. However, recently-suggested cylindrical pipe-type substrates made in LTCC technology offer unique inherent advantages for gas sensor technology, like a uniform temperature profile along the gas sensitive layer or a reduction of the distortion of the gas flow in the pipe.
As shown in our previous study, cylindrical LTCC substrates with inner electrodes and integrated heaters may be very promising in the field of high-temperature gas sensors. In this paper, we continue our work on cylindrically shaped LTCC sensor substrates, with special focus on the construction of a platform with multiple heater/electrodes couples for multi-array gas sensors. For such multi-sensor structures, decoupling of the heat sources is the most important platform feature. Therefore, a cylindrical substrate with integrated heaters was FEM-modeled and optimized in the first stage. Subsequently, tubes with three integrated heaters were prepared. In this paper, it is discussed how reduced thermal masses can be obtained by thinner tube walls or by the integration of laser-patterned cavities and how different integrated heat sources can be decoupled.