THz Time-Domain Ellipsometer for Material Characterization and Paint Quality Control with More Than 5 THz Bandwidth

Applied Sciences

卷:12

Björn Globisch¹  Lars Liebermeister¹  Robert Kohlhaas¹  Rüdiger Mästle²  Helge Ketelsen² 

[1] Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin, Germany;

[2] Helmut Fischer GmbH, Industriestraße 21, 71069 Sindelfingen, Germany;

关键词: ellipsometry;    THz time-domain spectroscopy;    material characterization;    thin film measurement;    automotive paints;    quality control;   

DOI  :  10.3390/app12083744

来源: DOAJ

【 摘 要 】

Quality control of car body paint in the automotive industry is a promising industrial application of terahertz technology. Terahertz time-domain spectroscopy in reflection geometry enables accurate, fast, and nondestructive measurement of individual layer thicknesses of multi-layer coatings. For high precision thickness measurements, the frequency dependent complex refractive index of all layers must be calibrated very accurately. THz time-domain ellipsometry is self-referencing and provides reliable, frequency resolved material properties with high signal-to-noise ratio. The method is characterized by a high sensitivity to optical material properties and layer thicknesses. We present characterization results in the frequency range 0.1–6 THz for typical automotive paints and different substrates such as polypropylene (PP), which features a high material anisotropy. We demonstrate that the broadband material properties derived from ellipsometry allow for inline thickness measurements of multi-layer car body paints with high accuracy.

【 授权许可】

Unknown