Magneto-Sensitive Wire Surface Etching for Noise Reduction
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Solution Overview
Problem
Magnetic impedance sensors using amorphous wires manufactured by the in-rotating liquid spinning method face issues with abnormal noise and poor hysteresis characteristics, particularly when measuring small magnetic fields, which affects accuracy and sensitivity, especially in applications like augmented reality and detecting foreign metallic particles.
Innovation Solution
The method involves removing the process-affected residual layer generated during the wire drawing process by etching, using acidic liquids like nitric acid or electrolytic etching, to reduce surface irregularities and residual stress, thereby minimizing abnormal noise and enhancing hysteresis characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the amorphous wire is manufactured using the in-rotating liquid spinning method and subjected to wire drawing and heat treatment, then the wire can be worked into targeted wire diameter for stabilization of output, but abnormal noise is generated during measurement which deteriorates accuracy
Solution Approach 1:
The patent applies preliminary action by performing etching treatment on the amorphous wire before final heat treatment to remove the process-affected residual layer. This preliminary removal of the noisy surface layer prevents abnormal noise generation in subsequent measurements, allowing the wire to achieve both precise dimensions and high measurement accuracy without the noise interference that would otherwise occur
Solution Approach 2:
The patent extracts the harmful process-affected residual layer from the amorphous wire surface through etching treatment. By removing this specific layer that contains irregularities and residual stress causing abnormal noise, the patent eliminates the source of measurement interference while preserving the bulk material properties needed for stable output and precise wire diameter
2Measurement precision
If the magneto-sensitive wire is used with high sensitivity for measuring very small magnetic fields, then detection resolution should be high, but abnormal noise generation makes it difficult to measure very small magnetic fields
Solution Approach 1:
The patent converts the harmful effect of the process-affected residual layer into a benefit by using controlled etching treatment. The etching process, which initially seems to remove material and potentially worsen surface conditions, actually eliminates the source of abnormal noise by removing the irregularities and residual stress in the residual layer, thereby enabling high-detection-resolution measurements of very small magnetic fields
3Productivity
If conventional manufacturing methods are used without etching, then the manufacturing process is simpler and more productive, but excellent hysteresis characteristics cannot be obtained
Solution Approach 1:
The patent applies parameter changes by modifying the surface condition parameter through etching treatment. By changing the surface morphology and removing the process-affected residual layer, the patent improves hysteresis characteristics while maintaining manufacturing efficiency. The etching parameters (time, concentration, temperature) are optimized to achieve the desired surface condition without excessive material removal or process complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively suppresses abnormal noise and improves hysteresis characteristics, enabling high-accuracy magnetic field measurements, including those of very small fields, thereby enhancing the performance of magnetic impedance sensors.
Implementation Method 1
removing the process-affected residual layer generated during the wire drawing process by etching, using acidic liquids like nitric acid
Implementation Method 2
removing the process-affected residual layer generated during the wire drawing process by etching, using acidic liquids like nitric acid or electrolytic etching
Implementation Method 3
magneto-sensitive wire for magnetic impedance sensor that can measure an external magnetic field with a considerably high degree of accuracy
Implementation Method 4
Magnetic impedance sensors of a detection coil output type are widely known in the art and used in various fields as magnetic sensors that can measure the magnetic strength with a high degree of accuracy and high responsivity
Data Source
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AI summary
A magneto-sensitive wire for a magnetic impedance sensor and a method of manufacturing the same are provided which can prevent generation of abnormal noise in an output voltage and deterioration in hysteresis characteristics and enable higher-accuracy measurement than conventional magneto-sensitive wires. The magneto-sensitive wire (1) comprises an amorphous wire for detecting magnetism. The magnetic impedance sensor (6) has the magneto-sensitive wire (1) and a detection coil (3) around the magneto-sensitive wire (1). The magnetic impedance sensor (6) is configured to apply a pulse current to the magneto-sensitive wire (1) and detect a voltage generated in the detection coil (3) thereby capable of measuring strength of a magnetic field. The voltage has magnitude in response to strength of an external magnetic field. The magneto-sensitive wire (1) is a Co-based amorphous wire manufactured using an in-rotating liquid spinning method and finished by wire drawing. The magneto-sensitive wire (1) is subjected to removal treatment for a process-affected residual layer generated at a surface and near the surface due to finishing by the wire drawing.