MEMS micro high sensitivity magnetic field sensor and manufacturing method

Abstract

A MEMS micro type of magnetic field transducer with high sensitivity consists of MEMS twisted micro lens with two fixed ends, magnetism sensitive film and collimator with double optical fiber. It is featured as forming twist space of component between metal feedback electrode and magnetism sensitive film, packaging said collimator by utilizing optical package resin through regulation frame. Its preparing method is also disclosed.

Description

technical field [0001] The invention relates to a structure and a manufacturing method of a miniature high-sensitivity magnetic field sensor, in particular, utilizes semiconductor microfabrication technology combined with semiconductor materials to realize the structural manufacture of the miniature high-sensitivity magnetic field sensor. Through different packages, the device can detect magnetic fields in various environments such as vacuum, air, and underwater. The invention belongs to the field of magnetic field sensors. Background technique [0002] The magnetic field sensor is a sensor sensitive to magnetic signals or parameters that can be converted into magnetic signals. It is the earliest and most widely used type of sensor. The compass, one of my country's four great inventions, is a sensor that utilizes this phenomenon. Magnetic field sensors have been industrialized in many fields, with an annual usage of more than one billion pieces, widely used in motors, elect...

AI Technical Summary

Problems solved by technology

[0004] (1) Superconducting quantum interferometers (SQUIDs) magnetometers are the most sensitive magnetic field sensors so far, but it is difficult to make superconducting Josephson junctions, and requires low-temperature refrigeration equipment and high operating costs

[0005] (2) Based on the optical coherent layout trapping (CPT) principle, the optical magnetic resonance magnetometer selects the energy level most sensitive to the change of the magnetic field in the atomic energy level for monitoring. The smallest sensitive magnetic field change is on the order of pT, but its structure is too complex, and it needs to be compared with the time-frequency reference with high frequency stability when detecting the signal

[0006] (3) The fluxgate sensor is a widely used high-sensitivity magnetic field sensor, which can be sensitive to the change of the magnetic field at the nT level, but its disadvantage is that the device Both volume and power consumption are relatively large

Optical fiber magnetic field sensors are mainly divided into two categories: the first type is magnetostrictive optical fiber magnetic sensor, which requires a very long (tens of cm) optical fiber interferometer covered with magnetostrictive material, which is large in size and The excessive length of the fiber optic interferometer brings practical problems; at the same time, due to the hysteresis effect of the magnetostrictive material, the device needs to increase the bias and feedback excitation coil to achieve feedback, which will bring a large power consumption

The second type is a magnetic sensor based on the Faraday rotation optical effect. This kind of sensor is not only large in size and consumes a lot of power. At the same time, the Faraday rotation angle of the magneto-optic crystal is not only related to the strength of the magnetic field, but also related to the wavelength of light. Therefore, it also requires temperature control circuits and Automatic power control circuit to ensure the stability of the output light wavelength

[0008] The above high-sensitivity magnetic field sensors all have problems such as large volume, high power consumption, and high cost, which greatly limit their application range. Therefore, it is necessary to further develop miniaturized, low-power, and low-cost high-sensitivity magnetic field sensors[ (1) Wang Yuanqing. Principles and applications of new sensors. Mechanical Industry Press, 2002. (2) Clarke. Principles and applications of SQUID S .Proc.of the IEEE, 1989,17(8):1208-1223.(3) Chen Xuegang, He Xingdao, Zou Wendong. Magnetic field probe design of optical fiber magnetic field sensor. Instrument Technology and Sensors, 2004 No.2: 5-6.]

Judging from the various high-sensitivity magnetic field sensors currently under development, problems in volume, power consumption, cost, and large-scale mass production have not yet been resolved.

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