Low cost capacitive inclination sensors based on selectively metallized polymer

We report on an innovative low cost concept for micromechanical capacitive inclination sensors based on MID-technology (Moulded Interconnect Device) where three dimensional polymer devices are fabricated by injection moulding and covered by a structured metal layer using electroless plating and laser ablation. The sensor concept based upon an extended electrode design which combines two differential capacitors arrangements for a measurement range of ± 180°. First MID-demonstrators were fabricated and characterized. The demonstrators show very promising properties. The sensors have a nice linear characteristic within ± 45° and 45°-135° with a resolution of about 0,01° and a nonlinearity better than 0.5% FSO. At different angular rates a dynamical hysteresis occurs. The dynamical hysteresis is proportional to the rotational speed of the sensor. The temperature dependence is very low and almost linear. No failure occurred within first reliability tests of 100 sensors with thermal shock test and constant damp heat storage.