High-sensitivity MEMS photoelectric galvanometer, making and detecting method thereof

A micro-electronic machinery and galvanometer technology, applied in the measurement of current/voltage, measurement device, measurement of electrical variables, etc., can solve the problems of temperature drift, it is difficult to reach below the milliamp level, and the feedback current is small, so as to reduce the overall Size, good light transmission characteristics, effect of volume reduction

Active Publication Date: 2010-05-12
SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

Early micro-current amplifiers made of carefully selected vacuum tubes can achieve high sensitivity, but vacuum tubes have fatal shortcomings of large volume and serious temperature drift
Nowadays, micro-current amplifiers are generally made of integrated operational amplifier chips, but there are difficulties in meeting the requirements of low noise interference, low drift, and fast response.
Operational amplifiers also have problems such as offset voltage, offset current, bias current, and temperature drift. After the continuous accumulation of integral capacitance, the phenomenon of so-called "integral drift" appears, which causes great errors in measurement.
[0004] Another method for detecting weak currents does not require an amplifier [Xiang Xiaomin, Zeng Weilu, Gao Xuejun. A new magnetic modulation DC current measurement method [J]. Journal of Huazhong University of Science and Technology, 1998, 26(12): 64-67. ], its principle is mostly to measure the change of the magnetic field generated by the current, such as the Hall sensor, etc., but its detection sensitivity is relatively low, and it is difficult to reach below the milliampere level. At present, it is difficult to measure the non-contact DC micro current below 1mA Realized, if the Hall element is used, even if the magnetic focus method is used, the minimum current is about 20mA or more to respond. The traditional comparator has high accuracy in measuring current, but it uses the principle of closed-loop measurement, and the circuit structure is complex, which is often used for large current measurement. It is difficult to measure the microcurrent of milliamp and microamp level by this method. The main reason is that the feedback current is too small and the stability is poor. The low-temperature superconducting comparator with superconducting quantum interference device can achieve high measurement accuracy ( 10 -12 A), but this instrument needs to work at low temperature, and reading data at room temperature requires sophisticated temperature control and compensation devices, and the entire set of instruments is expensive

Method used

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  • High-sensitivity MEMS photoelectric galvanometer, making and detecting method thereof
  • High-sensitivity MEMS photoelectric galvanometer, making and detecting method thereof
  • High-sensitivity MEMS photoelectric galvanometer, making and detecting method thereof

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Embodiment Construction

[0035] The lead wire inside the coil is made on the lower layer of the metal drive coil ( Figure 6 ), with a damping coil on the back ( Figure 4 ) device as an example to illustrate the implementation, wherein silicon dioxide is the insulating layer, silicon is the substrate, aluminum is used as the material of the MEMS drive coil and lead wires, the torsion plane, the metal coil, and the torsion beam are all rectangular, and the specific steps are as follows (for non-resistive Similar steps can be used for the structure of the nylon coil and the lead wire on the upper layer of the metal drive coil):

[0036] 1. Selection of device parameters

[0037] A. According to the initial value of the parameters of the rotation plane (length, width, height), the parameters of the lead wires and the parameters of the front metal drive coil and the back damping coil (number of turns, length, width, height, single-turn coil width, coil spacing) to calculate the entire Calculate the mom...

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Abstract

The invention relates to an optical electric galvanometer, based on Micro-Electronic Mechanic System (MEMS). It is characterized in that: it use micro mechanical technique to prepare the screw coil MEMS torsion micro lens; it can avoid amplify circuit, that directly inputting the tested current or low-frequency weak current into driving coil, to be arranged in the strong magnetic field generated by external permanent magnet; the driving coil drives the micro lens to deflect from original position by the torque generated by Lorentz force; it uses dual optical fiber collimator to test the characters that sensitive to the angle; according to the relationship between the optical signal loss and the torsion angle, via optical electric conversion and signal processing, attaining the current value. The invention can avoid amplify circuit at the input end, to attain amp level and pF level, to overcome the defects of noise disturb and excursion when amplifying the micro weak current signal. Andit can realize the optical electric separation at input and output ends synchronously, with small volume, simple structure, lower cost and better anti-vibration ability.

Description

technical field [0001] The invention relates to a high-sensitivity MEMS photoelectric galvanometer and its production and detection method, which is a detection ampere to picoampere level used in the technical fields of measurement and testing, electric power, biology, semiconductors, and chemical analysis. current photogalvanometer. Background technique [0002] The monitoring and detection technology of weak current is more and more applied in many fields such as weak signal precision measurement, biological current detection, semiconductor, electric power, chemical analysis, industrial production and so on. The detection and control of weak currents plays an important role in the field of metrology, and the sensitivity and accuracy of weak current detection equipment have also received more attention; bioelectrodes are important tools for studying life phenomena at the molecular level, most of which are current Output type, the current signal is usually interfered by a v...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R19/00
Inventor 吴亚明赵本刚高翔刘玉菲徐静
Owner SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI
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