Patent ID: 9683968
Date: 2017-06-20
CPC Classifications: G01N

Claim:
1. A combination sensor, comprising: a pressure sensor having an actuator which has a first resonant frequency; a cavity, coupled to the pressure sensor and able to receive a substance; wherein the cavity, in an absence of the substance, has a second resonant frequency in response to excitation by the actuator; wherein the cavity, in a presence of the substance, has a third resonant frequency in response to excitation by the actuator; wherein the first resonant frequency differs from the second and third resonant frequencies; a sensor circuit including a driver module configured to excite the actuator, an actuator power level monitor and a detection module, wherein the detection module is configured to output a substance detected signal in response to the third resonant frequency in the cavity; wherein the sensor circuit is embedded within a semiconductor chip covered by an overmolding layer, wherein the cavity is an opening within the overmolding layer, wherein the opening has a width, a height, and a length, and wherein the first, second and third cavity resonant frequencies are based on the width, height and length of the overmolding layer opening.