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It has been noted that the spin-valve sensor exhibits lower sensitivity with higher temperature because of the variation of GMR ratio, which could lead to the measurement error in applications where working temperature changes largely over seasons or times. This paper aims to investigate and compensate the temperature effect of the spin-valve sensor.

A spin-valve sensor is fabricated based on microelectronic process, and its temperature relevant properties are investigated, in which the transfer curves are acquired within a temperature range of −50°C to 125°C with a Helmholtz coil and temperature chamber.

It is found that the sensitivity of spin-valve sensor decreases with temperature linearly, where the temperature coefficient is calculated at −0.25 %/°C. The relationship between sensitivity of spin-valve sensor and temperature is well-modeled.

The temperature drift model of the spin-valve sensor’s sensitivity is highly correlated with tested results, which could be used to compensate the temperature influence on the sensor output. A self-compensation sensor system is proposed and built based on the expression modeled for the temperature dependence of the sensor, which exhibits a great improvement on temperature stability.

The Giant MagnetoResistance (GMR) effect, discovered in France in 1988, has already been applied in magnetic sensors and has promise in other applications. The rapid acceptance of this technology is due to GMR’s unique characteristics such as high sensitivity, good temperature stability, and excellent linearity over a wide sensing range. In this article GMR materials are described as are their application in magnetic field sensors. New GMR structures utilizing spin valves and spin dependent tunneling (SDT) will offer even more potential for expanding the horizon of solid state magnetic sensing. Comparisons are made to sensors using conventional technology. Integrated GMR sensors that have signal conditioning and output electronics monolithically integrated with the sensor offer further uses of this new technology. Beyond the sensor itself, other control system functions have the potential for using the same GMR materials to make magnetic isolators and nonvolatile memories.

The noise measurement on magnetoresistive (MR) sensors is generally conducted by techniques including single-channel data sampling and fast Fourier transform (FFT) analysis as well as two-channel cross-correlation. The single-channel method is easy to implement and is widely used in the noise measurement on MR sensors, whereas the two-channel method can only eliminate part of the system noise. This study aims to address two key issues affecting measurement accuracy: calibration of the measurement system and the elimination of system noise.

The system is calibrated by using a low-noise metal film resistor in that the system noise is eliminated through power spectrum subtraction. Noise measurement and analysis are conducted for both thermal noise and detectivity of magnetic tunnel junction (MTJ) sensor.

The thermal noise measurement error is less than 2%. The detectivity of the MTJ sensor reaches 27 pT/Hz^1/2 at 2 kHz.

This study provides a more practical solution for noise measurement and system calibration on MR sensors with a bias voltage and magnetic field.

The purpose of this paper is to achieve a very accurate localization of hidden metallic objects in human medicine applications.

The proposed methodology takes advantage of the eddy current effect within a metallic object. Its magnetic reaction field will be measured, e.g. with giant magnetic resistor (GMR) sensors.

A comparison of measurements and numerical results obtained by finite element computations demonstrate the reliability and positively gives a clue about the feasibility of the suggested method.

While measuring noisy signals, the use of a lock‐in amplifier is rather expensive; especially, in applications with a high number of GMR sensors the use of channel multiplexer must be considered, which again may generate noise.

The paper shows how appropriate shielding of external fields in the measurement setup ensures results of satisfying quality.

Wafer bonding is a key process for 3 D advanced packaging of integrated circuits. It requires very high accuracy for the wafer alignment. To solve the problems of large movement stroke, position calibration error and low production efficiency in optical alignment, this paper aims to propose a new wafer magnetic alignment technology (MAT) which is based on tunnel magneto resistance effect. MAT can realize micro distance alignment and reduces the design and manufacturing difficulty of wafer bonding equipment.

The current methods and existing problems of wafer optical alignment are introduced, and the mechanism and realization process of wafer magnetic alignment are proposed. Micro magnetic column (MMC) marks are designed on the wafer by the semiconductor manufacturing process. The mathematical model of the space magnetic field of the MMC is established, and the magnetic field distribution of the MMC alignment is numerically simulated and visualized. The relationship between the alignment accuracy and the MMC diameter, MMC remanence, MMC thickness and sensor measurement height was studied.

The simulation analysis shows that the overlapping double MMCs can align the wafer with accuracy within 1 µm and can control the bonding distance within the micrometer range to improve the alignment efficiency.

Magnetic alignment technology provides a new idea for wafer bonding alignment, which is expected to improve the accuracy and efficiency of wafer bonding.

This paper aims to solve the typical thermal airflow sensor's high power consumption and integration difficulties, based on the FS5 thermal element and constant temperature measurement method, a flow sensor is developed with high measurement accuracy, low power consumption, small size, low cost and easy system integration.

A small wind tunnel was used to test and assess the sensor's measurement range, reaction time, stability, repeatability, measurement accuracy and multi-temperature calibration was performed in the temperature range of −10°C to 30°C. The effect of ambient temperature on the sensor's measurement data is investigated, and the coefficient correction method of power function was investigated to implement the sensor's software temperature compensation function.

The results show that the sensor is stable and repeatable, the output voltage has a power function relationship with the airflow rate, the flow rate measurement range is 0–18 m/s, the response time is less than 3 s, the measurement accuracy at high flow rates is within 0.4 m/s and the temperature-corrected airflow rate measurement error is less than 5%. Setting the temperature calibration interval to 2°C and 5°C has the same temperature compensation effect, reducing the sensor's calibration effort significantly.

This paper demonstrates that a thermostatic method is used to construct a thermal wind speed sensor that delivers accurate measurements in the wind speed measuring range of 0–18 m/s under test conditions. In addition, the sensor's performance is evaluated, and calibration tests for a wide range of temperatures are done. Finally, based on the power function correction method, a temperature compensation algorithm is proposed.

The purpose of this paper is to analyze the manufacturing of diffusion-junction heterorectifier with account relaxation of mismatch-induced stress. On the basis of the analysis, the authors formulate recommendations to increase sharpness of the p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility.

The authors formulate recommendations to increase sharpness of p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility. To formulate the recommendations, the authors analyzed the manufacturing of the junction. The authors introduce an analytical approach to analyze the manufacturing.

The authors find a possibility to increase sharpness of p-n-heterojunction, homogeneity of concentration of dopant in the junction and charge carrier mobility.

The results are original.

Precision active vibration isolation system (AVIS) is crucial for the mechanical processing equipment in the field of precision manufacturing. Working reliability and efficiency of the system directly influence operating condition of the equipment and the quality of work pieces.

A complete structure of the AVIS includes two parts: the excitation part and the passive vibration isolation system (PVIS). The excitation part consists of voice coil motors (VCMs). In this paper, the working process of AVIS is studied particularly via linear simplification on the decoupling model and the mechanical dynamic equations to solve the vibration problem, and they are validated by the experiments.

According to dynamic analysis and experiment on an AVIS on different reference points, the VCMs are used as actuators in the AVIS to excite the PVIS, and the performance characteristics of the whole AVIS is well reflected by the amplitude–frequency curves, the bode diagrams and the power spectral density curves.

This study has provided a way for obtaining the inner structure and working condition of the AVIS, which are essential to better control of the AVIS and to further study it in precision manufacturing application.