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CN-224216098-U - MEMS inertial sensor

CN224216098UCN 224216098 UCN224216098 UCN 224216098UCN-224216098-U

Abstract

The utility model provides an MEMS inertial sensor which comprises a shell, a top cover and connecting pieces, wherein the top cover is fixedly connected above the shell, the connecting pieces are inserted into four corners of the top surface of the top cover and are in threaded connection with the four corners of the shell, a plate body is fixedly connected to the bottom of the inner side of the shell, a capacitor is arranged on the plate body, an elastic beam is connected to the top surface of the capacitor, a mass block is fixedly connected between the elastic beams, and the mass block is movably connected to the surface of the plate body. The sensor has the advantages that the sensor is assembled with the panel through the mounting lug, the screw and the panel, the mounting lug is improved, the top opening of the reserved hole of the mounting lug is changed into a conical shape, the mounting lug is improved into a magnetic attraction-insertion composite lug, and a guide magnetic ring is embedded into the top opening of the reserved hole, so that the sensor can be magnetically attracted and guided during the installation of the small screw, the installation of the sensor is more convenient, the installation time consumption is greatly reduced, and the installation tolerance is reduced.

Inventors

  • Ran Xumao

Assignees

  • 无锡芸莅半导体科技有限公司

Dates

Publication Date
20260508
Application Date
20250627

Claims (6)

  1. 1. The MEMS inertial sensor is characterized by comprising a shell (1), a top cover (2) and connecting pieces (3), wherein the top cover (2) is fixedly connected above the shell (1), the connecting pieces (3) are inserted into four corners of the top surface of the top cover (2), and the connecting pieces (3) are in threaded connection with the four corners of the shell (1); The bottom of the inner side of the shell (1) is fixedly connected with a plate body (4), a capacitor (9) is arranged on the plate body (4), the top surface of the capacitor (9) is connected with an elastic beam (5), a mass block (6) is fixedly connected between the elastic beams (5), and the mass block (6) is movably connected on the surface of the plate body (4); A plurality of movable electrodes (7) are fixedly connected to two sides of the mass block (6), and a fixed electrode (8) is fixedly connected to the top surface of the plate body (4); The output end of the capacitor (9) is unidirectionally connected with the MEMS chip (10), the output end of the MEMS chip (10) is unidirectionally connected with the output line (11), and the output line (11) penetrates through the shell (1); The side surface and the bottom surface of the shell (1) are covered with shielding layers (12), and the surface of the top cover (2) is covered with the shielding layers (12); The novel plastic shell is characterized in that mounting lugs (13) are fixedly connected to two sides of the shell (1), preformed holes (14) are formed in the mounting lugs (13), the inner diameter of top openings of the preformed holes (14) gradually decreases from top to bottom, and guide magnetic rings (15) are fixedly connected to the top openings of the preformed holes (14).
  2. 2. The MEMS inertial sensor of claim 1, wherein the housing (1) and the top cover (2) are made of aluminum alloy, and the connecting piece (3) is specifically a cross screw.
  3. 3. A MEMS inertial sensor according to claim 2, wherein the plate (4) is bonded to the inside of the housing (1), and the mass (6) moves linearly on a shaft fixed to the top surface of the plate (4).
  4. 4. A MEMS inertial sensor according to claim 3, wherein the distance between the movable electrode (7) and the fixed electrode (8) is variable, and the MEMS chip (10) and the plate (4) are fixed by pin welding.
  5. 5. A MEMS inertial sensor according to claim 4, wherein the shielding layer (12) is made of metal, and the mounting lug (13) is welded to the housing (1).
  6. 6. The MEMS inertial sensor of claim 5, wherein the guide magnetic ring (15) is a neodymium-iron-boron magnet, and the guide magnetic ring (15) is embedded in a top opening of the preformed hole (14).

Description

MEMS inertial sensor Technical Field The utility model relates to the technical field of inertial sensors, in particular to an MEMS inertial sensor. Background Microelectromechanical Systems (MEMS) inertial sensors, particularly accelerometers, have been widely used in many fields such as consumer electronics, automotive electronics, industrial control, navigation positioning, and the like, due to their small size, low cost, low power consumption, high reliability, and the like. The core working principle is generally based on detecting the displacement change of an inertia sensitive mass block under the action of external acceleration, and converting the displacement change into a measurable electric signal through the effects of capacitance, piezoresistance and the like. Existing MEMS inertial sensors typically include a sealed housing structure (e.g., a metal or ceramic housing plus a top cover) to protect the internal delicate MEMS sensitive structures and processing chips (ASICs) from environmental (e.g., humidity, particulate matter) and external disturbances. The internal structure mainly comprises capacitors (typically consisting of movable and fixed electrodes) fixed on a substrate, inertial mass connected between the capacitors, and elastic beams (e.g. folded beams) supporting the mass. When acceleration is applied to the sensor, the mass is slightly displaced by inertia against the restoring force of the elastic beam, resulting in a change in the spacing between the movable electrode and the fixed electrode, thereby causing a change in capacitance. The capacitance change is detected by the integrated MEMS chip and converted into a voltage signal, which is then output to an external system via a lead. However, although the MEMS sensor itself is compact, some challenges remain in its practical installation and application process, especially in the context of miniaturization and high density integration: The high accuracy of mounting alignment is difficult-conventional mounting methods typically use micro bolts or screws to secure the sensor to the mounting panel by providing through holes in the mounting ears (or bosses) of the sensor housing. For the miniature MEMS sensor, the size of the mounting lug is very small, and the reserved mounting aperture is only in the sub-millimeter level. This makes it extremely difficult to precisely align and insert the tip of the tiny screw into the narrow mounting hole during the assembly process. The operator needs extremely high tolerance and fine handling, often with the aid of a magnifying glass or a precision jig, resulting in inefficient installation and long time-consuming. Disclosure of utility model The object of the present utility model is to solve at least one of the technical drawbacks. Therefore, an object of the present utility model is to provide a MEMS inertial sensor, which solves the problems mentioned in the background art and overcomes the shortcomings of the prior art. In order to achieve the above purpose, an embodiment of an aspect of the present utility model provides an MEMS inertial sensor, which includes a housing, a top cover, and a connecting piece, wherein the top cover is fixedly connected above the housing, the four corners of the top surface of the top cover are plugged with the connecting piece, and the connecting piece is in threaded connection with the four corners of the housing; the bottom of the inner side of the shell is fixedly connected with a plate body, a capacitor is arranged on the plate body, the top surface of the capacitor is connected with elastic beams, a mass block is fixedly connected between the elastic beams, and the mass block is movably connected on the surface of the plate body; A plurality of movable electrodes are fixedly connected to two sides of the mass block, and a fixed electrode is fixedly connected to the top surface of the plate body; The output end of the capacitor is unidirectionally connected with an MEMS chip, the output end of the MEMS chip is unidirectionally connected with an output line, and the output line passes through the shell; the side surface and the bottom surface of the shell are covered with shielding layers, and the surface of the top cover is covered with the shielding layers; The two sides of the shell are fixedly connected with mounting lugs, preformed holes are formed in the mounting lugs, the inner diameter of the top opening of each preformed hole is gradually reduced from top to bottom, and a guide magnetic ring is fixedly connected to the top opening of each preformed hole. In any of the above embodiments, it is preferable that the material of the housing and the top cover is aluminum alloy, and the connecting member is specifically a cross screw. By adopting the technical scheme, the mass block is usually made of silicon material and is used as an inertia sensitive element to generate displacement under the action of acceleration. Elastic beams are arranged at two e