Development of a mass flow sensor based on Low Temperature Cofired Ceramics for analysis of exhaust gas up to 500 °C

The regulation of exhaust gas in the Exhaust Gas Recirculation (EGR) in modern diesel engines lacks of precise mass flow measurements because of very high gas temperatures. We present the fabrication of a thermal Low Temperature Cofired Ceramic (LTCC) mass flow sensor which can withstand the harsh environment of the EGR. Due to the innovative fabrication method it is possible to create very thin freestanding LTCC membranes with active parts like heaters and temperature sensors. The LTCC sensor is packaged with Low Temperature Transfer Tape (LTTT) technology on an Al ₂ O ₃ element to implement high temperature stable electrical and mechanical connection.