During the online production process of modern thin film coating and plating processes, real-time online thickness measurement of film thickness and coating thickness is required. Due to the shortcomings of traditional radiographic film thickness detectors such as low detection accuracy, easy offset, and difficulty in calibration, The actual quality control of process products has a great impact. The SIMV coating (film thickness) online thickness gauge uses nano-optical interference to measure 20 layers of unused coatings and films at the same time, with an accuracy as high as 1nm. , which perfectly solves the shortcomings of traditional radioactive online thickness gauges such as radiation, long offset period, low detection accuracy, and inability to detect coating thickness. Thermo Fisher's coating thickness online thickness gauge has high detection accuracy and can be automatically calibrated online in real time, effectively ensuring the detection accuracy of the online thickness gauge.

【Detection Principle】

　　When light of a specific wavelength passes through different materials (different thicknesses, densities, compositions), the spectral fringes formed after multiple reflections on the surface and inside are completely different. The system analyzes the spectrum of the reflected light received. The interference fringe characteristics are matched and compared with the spectral curves in the system library, and the characteristic curves are simulated and fitted, and then the coatings with different composition thicknesses are measured online.

　　1. The incident light is reflected multiple times on the upper and lower surfaces of the film.

　　2. The intensity of reflected light is related to the refractive index of the film, the refractive index of the substrate, the film thickness, and the wavelength.

　　3. With the refractive index known, calculate the film thickness as a function of the measured reflected light intensity and wavelength.

　　From the comparison of the two pictures above, we can find that the spectral interference fringes produced after light of a specific wavelength is internally reflected by a different material (different thickness, density, type) are completely different. As shown in the black line in the picture above, according to each The interference fringes are compared and simulated with the fringes in the system library to detect the actual material thickness.

【System functions】

Serial Number	Functional Overview
1	Measure the coating or coating thickness, the thickness range is 10 nanometers - 100 micrometers, the accuracy reaches 2 nanometers or the thickness is 0.4%, the accuracy reaches 0.1 nanometers, and the measurement stability is 0.3 nanometers.
2	Accurately measure the sample's color and reflectance curve in the visible light range of 380-780 nm.
3	The measurement software supports physical models within 20 layers and measures multiple parameters simultaneously.
4	It has a refractive index model editing and fitting function. For films ranging from 100 nanometers to several microns, the film thickness and refractive index parameters can be measured simultaneously with the software when the refractive index is unknown.
5	The software has the function of modeling the roughness of the sample, back reflection, and multi-angle incidence.
6	The software can also perform simulations using different incident angles and polarizations for models of known samples to calculate reflectance curves under different circumstances.
7	The software also has a material database of nearly a thousand materials, and also supports functional (Cauchy, Cauchy-Urbach, Sellmeier), physical optics (Drude-Lorentz, Tauc-Lorentz), hybrid (Maxwell Garnett, Bruggeman) EMA and other refractive indexes. Model.
8	Customers can also manage materials and menus and retrospectively check measurement results through the software’s own database.
9	We also provide customized detection systems for our customers' online systems.

【Software Introduction】

　　The basic diagram of the main interface of the software is as shown below:

【Field Application】

　　The on-site application of the coating/adhesive layer online thickness measurement system in protective films and tapes is shown in the figure below.