Thick Film Accelerometers in LTCC Technology—Design Optimization, Fabrication, and Characterization

Diaphragms and beams for force and pressure sensors, e.g., are state of the art in mechanical elements of MEMS in LTCC technology. These elements sustain small strains and small deformations under load. A number of sensor and actuator applications, however, require movable elements that allow higher deformations while the local strains are still low. Springs, accelerometers, actuators, positioners, and valves are examples of such applications. For an accelerometer we developed an approach fabricate leaf springs, integrated into the LTCC technology. The working principle of the accelerometer is based on a seismic mass disposed on two parallel leaf springs that carry piezoresistors connected such that they form a measuring bridge. In the first design optimization step, we used an FEA model for finding an optimized design meeting our sensitivity requirements, inclusiding resonance frequency. In the second step, we made a tolerance analysis that calculates the probability distributions of functional variables...