Mems mass flow sensor assembly and method of making the same

A MEMS silicon thermal mass flow sensor assembly comprising:

• A MEMS silicon thermal mass flow sensor chip having four thermistors as sensing elements which include a micro-heater thermistor, an ambient temperature sensing thermistor, a upstream thermistor and a downstream thermistor;
• wherein said MEMS silicon mass flow sensor chip having through-holes on silicon substrate that are filled with conductive materials and electrically connected to the thermistors on the front surface;
• and
• A MEMS silicon mass flow sensor carrier haying the printed circuitry board that provides direct soldering to the said silicon mass flow sensor;
• and wherein the printed circuitry board can be equipped with or without control electronics;
• wherein said MEMS silicon mass flow sensor chip having a thermal isolating cavity beneath the micro-heater thermistor, the upstream thermistor and the downstream thermistor;
• wherein said MEMS silicon mass flow sensor chip having surface passivation with the highly thermal conductive materials;
• wherein said MEMS silicon mass flow sensor chip having the backside contacts connecting to the conductive through substrate materials and is ready to connect through direct soldering to the sensor carrier;
• and
• wherein in a case if the silicon substrate is conductive, the through substrate holes shall be in the form of through substrate rings that are filled with isolation materials.