Provided is an inertial sensor module having excellent detection accuracy. The inertial sensor module includes: a first sensor having a first axis, a second axis, and a third axis as detection axes; and a second sensor having accuracy higher than that of the first sensor and having the third axis as a detection axis. The first sensor and the second sensor are disposed on an inner bottom surface which is one plane in a package. The first sensor and the second sensor are sealed by the package in an airtight manner.

The present disclosure is directed to a MEMS-based rotation sensor for use in seismic data acquisition and sensor units having same. The MEMS-based rotation sensor includes a substrate, an anchor disposed on the substrate and a proof mass coupled to the anchor via a plurality of flexural springs. The proof mass has a first electrode coupled to and extending therefrom. A second electrode is fixed to the substrate, and one of the first and second electrodes is configured to receive an actuation signal, and another of the first and second electrodes is configured to generate an electrical signal having an amplitude corresponding with a degree of angular movement of the first electrode relative to the second electrode. The MEMS-based rotation sensor further includes closed loop circuitry configured to receive the electrical signal and provide the actuation signal. Related methods for using the MEMS-based rotation sensor in seismic data acquisition are also described.

The present disclosure is directed to a MEMS-based rotation sensor for use in seismic data acquisition and sensor units having same. The MEMS-based rotation sensor includes a substrate, an anchor disposed on the substrate and a proof mass coupled to the anchor via a plurality of flexural springs. The proof mass has a first electrode coupled to and extending therefrom. A second electrode is fixed to the substrate, and one of the first and second electrodes is configured to receive an actuation signal, and another of the first and second electrodes is configured to generate an electrical signal having an amplitude corresponding with a degree of angular movement of the first electrode relative to the second electrode. The MEMS-based rotation sensor further includes closed loop circuitry configured to receive the electrical signal and provide the actuation signal. Related methods for using the MEMS-based rotation sensor in seismic data acquisition are also described.

The present invention discloses a three-axis accelerometer. The three-axis accelerometer comprises: a substrate; at least one anchor block fixedly disposed on the substrate; a first X-axis electrode, a second X-axis electrode, a first Y-axis electrode, a second Y-axis electrode, a first Z-axis electrode and a second Z-axis electrode all fixedly disposed on the substrate; a framework suspended above the substrate and comprising a first beam column, a second beam column disposed opposite to the first beam column and at least one connecting beam connecting the first beam column and the second beam column; a proof mass suspended above the substrate; and at least one elastic connection component configured to elastically connect to the at least anchor block, the connecting beam, and the proof mass. The three-axis accelerometer can realize high-precision acceleration detection on three axes with only one proof mass, and in particular, can provide a fully differential detection signal for the Z axis, thereby greatly improving detection precision.

The present invention discloses a three-axis accelerometer. The three-axis accelerometer comprises: a substrate; at least one anchor block fixedly disposed on the substrate; a first X-axis electrode, a second X-axis electrode, a first Y-axis electrode, a second Y-axis electrode, a first Z-axis electrode and a second Z-axis electrode all fixedly disposed on the substrate; a framework suspended above the substrate and comprising a first beam column, a second beam column disposed opposite to the first beam column and at least one connecting beam connecting the first beam column and the second beam column; a proof mass suspended above the substrate; and at least one elastic connection component configured to elastically connect to the at least anchor block, the connecting beam, and the proof mass. The three-axis accelerometer can realize high-precision acceleration detection on three axes with only one proof mass, and in particular, can provide a fully differential detection signal for the Z axis, thereby greatly improving detection precision.

This disclosure describes techniques of configuring capacitive comb fingers of an accelerometer resonator into discreet electrodes with drive electrodes and at least two sense electrodes. The routing of electrical signals is configured to produce parasitic feedthrough capacitances that are approximately equal. The sense electrodes may be placed on opposite sides of the moving resonator beams such that the changes in capacitance with respect to displacement (e.g. dC/dx) are approximately equal in magnitude and opposite in sign. The arrangement may result in sense currents that are also opposite in sign and result in feedthrough currents of the same sign. The sense outputs from the resonators may be connected to a differential amplifier, such that the difference in output currents may mitigate the effect of the feedthrough currents and cancel parasitic feedthrough capacitance. Parasitic feedthrough capacitance may cause increased accelerometer noise and reduced bias stability.

This disclosure describes techniques of configuring capacitive comb fingers of an accelerometer resonator into discreet electrodes with drive electrodes and at least two sense electrodes. The routing of electrical signals is configured to produce parasitic feedthrough capacitances that are approximately equal. The sense electrodes may be placed on opposite sides of the moving resonator beams such that the changes in capacitance with respect to displacement (e.g. dC/dx) are approximately equal in magnitude and opposite in sign. The arrangement may result in sense currents that are also opposite in sign and result in feedthrough currents of the same sign. The sense outputs from the resonators may be connected to a differential amplifier, such that the difference in output currents may mitigate the effect of the feedthrough currents and cancel parasitic feedthrough capacitance. Parasitic feedthrough capacitance may cause increased accelerometer noise and reduced bias stability.

A physical quantity sensor includes a physical quantity sensor element including a lid joined to a substrate to define a housing space in the inside and a physical quantity sensor element piece housed in the housing space and a circuit element bonded to the outer surface of the lid via an adhesive material. In the lid, an electrode is provided to extend from an inner wall of a through-hole, which pierces through the lid from the housing space to a surface on the opposite side of the side of the physical quantity sensor element piece and is sealed by a sealing member, to a peripheral edge of the through-hole at the surface on the opposite side. In a sectional view, thickness of a region at the peripheral edge of the electrode is smaller at the opposite side of the side of an opening of the through-hole than the opening side.

A physical quantity sensor includes a physical quantity sensor element including a lid joined to a substrate to define a housing space in the inside and a physical quantity sensor element piece housed in the housing space and a circuit element bonded to the outer surface of the lid via an adhesive material. In the lid, an electrode is provided to extend from an inner wall of a through-hole, which pierces through the lid from the housing space to a surface on the opposite side of the side of the physical quantity sensor element piece and is sealed by a sealing member, to a peripheral edge of the through-hole at the surface on the opposite side. In a sectional view, thickness of a region at the peripheral edge of the electrode is smaller at the opposite side of the side of an opening of the through-hole than the opening side.

A self-calibration method for an accelerometer having a proof mass separated by a gap from a drive electrode and a sense electrode includes initializing the accelerometer to resonate, applying a first bias voltage to the sense electrode and a second bias voltage to the drive electrode to obtain a first scale factor, measuring a first acceleration over a first time interval, swapping the first bias voltage on the sense electrode with the second bias voltage previously on the drive electrode and the second bias voltage on the drive electrode with the first bias voltage previously on the sense electrode so that a bias voltage on the sense electrode is set to the second bias voltage and a bias voltage on the drive electrode is set to the second bias voltage to obtain a second scale factor, measuring a second acceleration over a second time interval, and calculating a true acceleration.