Design and processing of low-range piezoresistive LTCC force sensors

Low-temperature cofired ceramic (LTCC) combines many advantageous features for low-range (force & pressure) piezoresistive sensors: ease of 3D structuration, availability of very thin sheets, low elastic modulus and yet reasonable mechanical strength. This work covers the design and fabrication low-range LTCC force sensors down to ideally 10 mN, together with mechanical characterisation of LTCC substrates. We show that LTCC is a viable substrate for piezoresistive sensing, and that 3D structuration can be used to both increase the output signal and simplify production. Moreover, very sensitive LTCC sensors may be manufactured, provided specific thick-film conductors with a sintering behaviour closely matched to that of the LTCC are applied.