The latest dimensional metrology, inspection and quality news
Did you look at the monitor today? You will most likely answer this question with "yes"-after all, touch screens and displays are everywhere, whether in smartphones, coffee machines, ATMs, in our cars, or in our workplaces. Thinner displays and vivid display quality, bizarre shapes, and newly applied technologies have opened up additional market potential for the consumer electronics and industrial markets. However, at the same time, they have put forward higher and higher requirements for functionality and optical quality.
In order to meet these stringent standards, ISRA VISION develops and produces mature inspection methods to ensure end-to-end process and quality control-from raw glass production, film and foil, to complete displays and finished products. These methods have improved the efficiency and profitability of display production, and ultimately improved customer satisfaction.
The touch display screen allows convenient and intuitive operation of equipment and machines; in addition, they are sturdy and easy to clean. Therefore, they are becoming more and more common in production plants, medical technology and other industrial applications. The automotive industry is currently leading the development trend in this field, introducing column-to-pillar displays that span the entire width of the vehicle in the new generation of cars. These provide important cockpit functions and allow the operation of all communication and infotainment systems of the car. In addition, they are very suitable, usually with curved shapes and integrated sensors. This trend is expected to continue in other applications. This will require new glass processing and finishing procedures, as well as corresponding inspection procedures in the manufacturing process. This type of quality inspection is essential to meet stringent requirements in terms of mechanical load robustness, trouble-free functionality and operability, fit and optical quality.
Quality assurance starts with raw materials
Whether using TFT or OLED technology, modern displays are composed of many layers made of different materials, which are usually very thin. The optical film, thin film, thin glass and cover glass in the actual TFT or OLED display are glued together during the production process to achieve a perfect combination of form and function. However, even the smallest defects in one of the layers can damage the characteristics and functions of the display. ISRA VISION is the industry leader in optical inspection and defect inspection for every layer; its solutions identify and remove defective materials before installation, minimize the number of imperfect final products produced and increase the profitability of production. ISRA VISION’s SMASH is a system for inspecting the surface of optical films. It can detect defects, including small scratches, traces and production residues on film materials, as well as coatings on coils. The linear camera ensures a high detection speed of up to 1,000 m/s while also achieving the highest image resolution. At the same time, customized lighting supports reliable detection and intelligent classification of defects that are invisible to the naked eye. In turn, this can lead to conclusions about the cause or defective process parameters, which can be continuously monitored and optimized.
Automatic detection of display glass
The thin display glass is also fully automated like an optical film. ISRA VISION FPM-Inspect (FLAT PANEL MASTER) combines proven optical quality control technology with precise material handling technology for clean rooms. This allows the system to identify even the smallest surface, glass or edge defects. In addition, FPM-Inspect can monitor particle contamination on the substrate, allowing it to draw conclusions about clean room air quality. Here, the inspection system also uses mature software algorithms to improve the production process and detect and eliminate the causes of defects. Even when 100% monitoring of uniformity, waviness and reflective optics are performed on large glass surfaces, ISRA VISION PowerPlate can provide accurate data within a few seconds. In addition to the internal and surface defects of the material, this also allows immediate detection of 3D shape defects, preventing further processing of related materials.
Perfect Union: Quality control before and after joining
Perfect optical films, films and display glass form the basis of high-quality displays. However, they only become fixed units with optical properties and functions after they are connected together in the production process. In this production step, quality control is as important as inspecting raw materials: dents and other defects on the cover glass may appear when the adhesive layer is bonded. These defects cannot be recognized with the naked eye, but will affect the optical performance and function of the product. SpecGAGE3D specializes Developed to reliably detect local irregularities, supporting structures or read-through before and after connecting the display layers using the deflection method. For this, the fringe pattern is projected onto the display, and the reflections are captured by multiple cameras and then evaluated. Then immediately classify any detected defects.
Special challenge-curved glasses and displays
The deflection measurement method is very suitable for inspecting curved glass and displays, such as the cover glass of a smartphone. Since displays of the same size require a smaller installation width, curved edges and concave shapes are becoming more and more popular here and in the automotive industry. And the shape allows the information to be seen more easily at the edges. At the same time, they put forward more stringent requirements in terms of quality inspection, because in addition to perfect surface and optical quality, they must also fit and shape completely correctly.
ISRA VISION's SpecGAGE3D inspection system generates measurement data (superimposed with digital twin target data in CAD comparison) to achieve efficient and reliable shape inspection of curved and flat displays and plastic optical devices (such as light guides). Therefore, it creates a difference map of the inspected material, accurate to the nearest micrometer. The system uses point comparison, profile cross-section, or full-surface evaluation to reliably and effectively check for deviations from target geometry, and then visualize them.
Bending molds can be a source of bending and flat panel display defects. With NetGAGE3D, ISRA VISION can reliably identify defects in graphite molds and also provide precision measurement technology for this purpose. Doing so can ensure perfect quality, thereby reducing the possibility of defects that may reproduce in thousands of displays during the production process.
Reliable and precise: 100% quality control of the final product
The original glass and foil are impeccable, the parts are glued together without any flaws, and the finished display is installed in the final product. It is time for a final inspection to ensure that the finished product has a perfect appearance and is free of errors. This is still often performed as a manual visual inspection-with all the shortcomings such as subjective judgment, the dependence of the inspection results on the person performing the test, and the general limitation of humans' ability to recognize minimal quality deviations. This final inspection has a great impact on the profitability of production: if the screening of small defects is too strict, profits will be reduced, and excessively relaxed quality inspections will lead to customer complaints and dissatisfaction. Fast, fully automatic and 100% optical inspection solutions solve this problem. It is easy to integrate, can detect typical appearance defects such as scratches, bubbles, indentation and polishing marks, and provide objective and reliable results. ISRA VISION's SpecGAGE3D inspection system is also used for final control and is very suitable for the measurement and inspection of all transparent and reflective surfaces. The inspection system can inspect flat or curved displays, as well as 2D / 3D cover glass, the glass back of smartphones and other smooth housing parts. The system immediately decides how to classify the goods according to the defined tolerance range and automatic defect classification.
Clear quality of end-to-end process monitoring
Increasingly larger and thinner glass, flexible materials, and complex shapes place more and more stringent requirements on the manufacture of displays. In order to meet these strict standards and ensure the best possible quality while achieving high productivity and process reliability, companies need end-to-end process and quality control. It starts with the inspection of raw materials and accompanies the entire production process to the final product. When defects are detected in the process, the connected inspection solution ideally allows them to be precisely linked to the cause in the upstream production step. This can also track and monitor the impact of process parameter changes on all further processes. ISRA VISION provides a broad portfolio of optical inspection solutions for every step of display manufacturing. Thanks to the collected inspection data, factory operators can continuously optimize their processes to achieve the best product quality, production stability, and ultimately profitability. Therefore, they provide flawless materials and products-and guarantee high customer satisfaction. In addition, the deployment of fully automated inspection systems in production plants can ensure compliance with current and future quality standards, such as the requirements of the automotive industry.
Through 100% optical inspection, you can also guarantee to meet future requirements for the shape, appearance and function of displays in production. To this end, ISRA VISION works closely with leading manufacturers and customer development departments in all key industries, and can convene a close network of experts and engineers from Asia and the world. Whenever new materials, technologies and applications require further development of inspection solutions, ISRA VISION has already embarked on implementing them in existing and new quality assurance systems and developing them at the same time.
For more information, please visit: www.isravision.com