The Process Engineering research group at TU Wien developed an inline ellipsometry system using robust polarization cameras from SVS-Vistek for precise determination of coating thickness and quality. By measuring linear and circular polarization and computing characteristic parameters R45 and Rz, the system enables efficient monitoring of coatings in electronics, pharmaceutical, plastic, and glass manufacturing. It achieves early defect detection and supports applications in OLED displays, battery electrodes, and photovoltaic modules.
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Polarization Imaging Enables Precise Stress Detection And Surface Inspection
Polarization-based machine vision solutions have become integral across industrial sectors, enabling precise assessment of stress distributions in transparent components, monitoring complex surfaces, and detecting low-contrast, black-on-black printed characters. These imaging systems are vital in tire manufacturing, evaluating material integrity, and in pharmaceutical production, inspecting blister packs to identify defective tablet encasements. Combining polarization analysis and high-resolution imagery, they ensure reliable, non-destructive quality control in demanding environments and enable rapid decision-making.
TU Vienna uses ellipsometry over transmission for coating characterization
Instead of transmission measurements, the TU Vienna process engineering team led by Ferdinand Bammer employs ellipsometry to characterize thin films through reflected light polarization. By capturing intensity data at polarizer orientations of 0°, 45°, 90°, and 135°, the setup records four polarization states. These readings enter a mathematical model that calculates the ellipsometric angles Ï and Î. Interpreting these parameters enables non-contact assessment of coating layer thickness and material properties.
By integrating a quarter-wave plate into the optical path, the system acquires comprehensive polarization data across linear and circular components. This additional optical element transforms phase-shifted polarization states into measurable intensity variations, enabling accurate calculation of ellipticity parameters. Such full polarization characterization facilitates robust determination of film thickness with high precision. When combined with appropriate calibration routines, the enhanced data improves sensitivity to subtle variations in multilayer coatings, ensuring reliability.
Because the polarization ellipse orientation cannot be unambiguously determined from four linear measurements alone, the Vienna research team incorporates a quarter wave plate into the optical setup. This addition captures circularly polarized components in addition to linear polarization data. Using these measurements, they derive R45 and Rz ratios. As a result, the combined data provide a complete and precise description of the polarization state, enabling detailed and robust optical characterization.
Rising Demand for Inline Ellipsometry Across High-Tech Manufacturing Sectors
Processes across multiple industries are relying on inline ellipsometry systems to provide real-time measurement of thin film thickness and properties. High-precision layer monitoring is critical in electronics fabrication and OLED display production where uniformity affects performance. Similarly, fuel cell membrane manufacturing, battery electrode assembly and photovoltaic module fabrication demand inline metrology. Pharmaceutical, food and beverage packaging also benefit from continuous automated inspection, ensuring consistent quality and compliance across production lines.
SVS-Vistek exo250ZGE captures reliable 24.5fps at five megapixel precision
Bammer uses the exo250ZGE GigE Vision model with a 5-megapixel sensor to capture up to 24.5 frames per second. For applications demanding higher data rates up to 75 fps, the USB3-based exo250ZU3 delivers the necessary speed. When maximum spatial detail is required, the exo253ZU3 offers 12.3 megapixels. SVS-Vistek cameras are recommended for their industry-leading low-noise performance among currently available models, optimizing inline quality inspection across various industrial applications. This configuration enhances measurement accuracy significantly.
SVS-Vistek expertise, support accelerate ellipsometry integration at TU Wien
During the initial stages of collaboration, SVS-Vistek distinguished itself through deep technical expertise and rapid response times. Their engineers offered prompt troubleshooting and guidance, ensuring any integration questions were addressed without delay. By maintaining continuous dialogue between SVS-Visteks specialists and the TU Wien process engineering team, the project achieved seamless deployment of exo-series polarization cameras into the inline ellipsometry setup. This close cooperation accelerated development schedules and reduced time-to-validation milestones.
Translating Polarization Measurement Insights into Robust Industrial Inline Solutions
According to Ferdinand Bammer, an obstacle lies in distilling the intricate scientific principles governing polarization-based layer measurement into an industry-scale, streamlined workflow suitable for continuous inline integration. He emphasizes the necessity of presenting this complex optical metrology in clear, jargon-free terms tailored to industrial management. By aligning polarimetric analytics with operational protocols and comprehensible performance metrics, laboratory-demonstrated accuracy can be reliably scaled up for field-proven, robust, real-time quality control deployment.
Vienna Ellipsometry Deployed Inline for PET Bottles Quality Assessment
Early adopters have deployed the Vienna ellipsometry approach in both laboratory setups and industrial inspection stations for PET bottle analysis. Although inline versions cannot reach the extreme resolution associated with laboratory ellipsometers, measurement precision of approximately ten percent of coating thickness satisfies requirements within the packaging sector. This compromise between resolution and inline compatibility enables real-time process monitoring and quality assurance without disrupting high-volume production workflows and industrial processing demands.
Growing demand boosts polarization ellipsometry for advanced coatings control
Growing demands for reliable, surface-wide quality inspections of coatings in emerging technologies such as displays, photovoltaics, batteries, and catalysts drive the increasing relevance of polarization and ellipsometry techniques. According to Bammers projections, advanced polarization camera systems can deliver comprehensive layer analysis across substrates, detecting thickness variations and inconsistencies. It extends quality control applications into diverse sectors, improving production yields, reducing defect rates, and supporting next-generation manufacturing through real-time inline monitoring.
Polarisation Enables Precise Contactless Layer Thickness Material Quality Assessment
Polarization refers to the orientation of electromagnetic light waves along specific planes. By filtering light to permit specific vibration directions, systems isolate linear and circular polarization states. Upon reflecting from a surface, the waves polarization undergoes alterations in phase and amplitude, encoding information about the interface. Image processing systems capture these modified polarization signatures to perform non-contact measurements of thin-film thicknesses and assess material properties like refractive index and composition.
TU Wien and SVS-Vistek enable inline coating thickness control
The integrated inline ellipsometry setup developed by TU Wien, paired with high-resolution SVS-Vistek polarization cameras, delivers continuous monitoring of film thickness and material consistency directly on production lines. It captures both linear and circular polarization changes upon reflection, enabling immediate detection of deviations in multilayer coatings. By offering rapid, area-based measurements, this solution enhances quality assurance across electronics, pharmaceutical, and packaging sectors, reducing waste and downtime while supporting future expansion into advanced manufacturing technologies.
