Eddy current probe based on optical transparent conducting medium material and film thickness measuring system and method

Abstract

The invention discloses an eddy current probe based on an optical transparent conductive medium material and a thin film thickness measuring system and method, a coil structure in the eddy current probe is designed in a flat winding mode, and longitudinal space is saved so as to adapt to a narrow measuring environment. The eddy current probe is light and handy in structural design and very convenient to use and process, and the thin film thickness measuring system disclosed by the invention combines the spectrum confocal sensor and the eddy current probe into a whole and enables signal transmitting surfaces to be kept parallel by utilizing a fixing clamp, a spiral regulator and a line concentration clamp, so that a light path and an electromagnetic wave can be parallel or coaxial; the spiral adjuster is used for adjusting the distance between the eddy current sensor and the signal transmitting surface of the spectrum confocal sensor, thereby adapting to the working distances of different types of sensors, and ensuring that the measured values are within the required ranges of effective measuring range, sensitivity and the like. According to the measurement method, the precision and the resolution are improved through combined measurement of the spectrum confocal sensor and the eddy current sensor.

Description

technical field [0001] The invention belongs to the field of thin film (coating) thickness measurement, and relates to an eddy current probe based on an optically transparent conductive medium material and a non-contact non-destructive measurement system and method for thin film thickness composed of the same. Background technique [0002] In order to meet the surface quality of some parts in the fields of aircraft and automobile manufacturing, as well as the corresponding requirements for anti-corrosion, insulation, heat insulation, vibration isolation, anti-radar wave reflection, etc., coupled with the modern design concept for the pursuit of beautiful industrial products and personalized patterns , Functional films are often coated on the surface of these parts, such as anti-rust paint film, heat insulation layer, insulating coating, anti-reflection layer, etc. Among them, the thickness detection of the coating is an important index to measure the coating isolation abilit...

AI Technical Summary

Problems solved by technology

At present, most non-contact measurement solutions are mainly measured by optical and electromagnetic principles, such as laser interferometry, ellipsometry, capacitance / inductance method, computational imaging, etc.; laser interferometry and ellipsometry are based on optical wavelength and phase. , it has high requirements on experimental instruments and measurement environment, such as anti-vibration, constant temperature, etc., which is not conducive to real-time detection; electromagnetic fields are easily disturbed, so the measurement method purely based on electromagnetics also has high requirements on measurement devices and measurement environment. In the case of a planar structure, the accuracy and sensitivity decrease. When the working distance is long, the resolution is not enough, and it can only rely on the conductive properties of the measured object, and cannot complete the measurement of the surface coating of insulating objects or the thickness of insulating parts; calculation Although the imaging method can accurately calculate parameters such as displacement through reflection imaging and transmission imaging, it is expensive and complicated to solve, and is not suitable for large-scale applications.

[0004] In summary, the existing relatively mature technology is difficult to meet the demand for non-contact measurement of film thickness in many precision manufacturing fields, and the complexity of the measurement method , cost, and requirements for the measurement environment are limited, and are not suitable for large-scale real-time detection; the existing eddy current probes are basically made of non-transparent materials, and it is difficult to cooperate with optical sensors for coaxial measurement; at the same time, the overall structure of the coil The flat design is not carried out, and the coil outlet method is not designed as side wiring, which not only makes the installation method single, but also makes it difficult to compress the probe volume, which is not suitable for precision measurement in some environments with limited space

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