Optical in - line inspection technology for micro defect detection
Faultless glass substrates up to the 11th generation
Glass substrates are used for the production of FPD displays, touchscreens or TFT monitors , all of which have one thing in common: They represent the interface between man and machine. Customers expect a flawless feel and appearance regardless of the device – be it a MP3 player or a smartphone . For glass manufacturers, this means continuously assuring highest quality standards in order to satisfy customers and to compete on a global level. With the Flat Panel Master product line, ISRA VISION offers a solution: Fully automated and flexible optical ins pection technology for 100% monitored substrate manufacturing processes and in consequence, highest product quality and production efficiency.
Production of substrates is divided into several complex steps, each of which only provides about 5% of the value add. Nevert heless, every single stage in the production counts: Whenever defective substrate is passed on to the next process, any further added refinement will be worthless – as will be the final product. For that reason, a consistent and complete inspection is needed from the very beginning until the end of the production chain – not only fo r qualitative but also for economic reasons.
So far, minimal material thickness and microscopic defect sizes have been a challenge even for optical inspection systems. With its product line Flat Panel Master, ISRA offers a complete solution for a highly reliable contact - free in - line inspection of glass substrates. Core of the technology are line scan cameras with a resolution of up to several μm, an innovative illumination concept as well as software with comprehensive analysis options. In addition, the pro duct line offers four combinable modules , which allow 100% defect detection along the entire production process and are compatible up to the 11 th generation of thin glass .
Even smallest particle concentrations on the surfaces of glass substrate will have negative impact on the following panel production process. Flat Panel Master - Particle, a special module suitable for usage in the clean room, reliably detects particles of μm size. It assures that only faultless thin glass is passed on to the following c oating process. The gained inspection data gives insight about the degree of particle density in the clean room and can be used to optimize the preliminary cleaning procedure.
The Flat Panel Master - Inspect module specializes on the detection and classif ication of glass defects such as bubbles , scratches, stains and inclusions. To do so , it uses an innovative setup which combines multiple optical channels in a single sensor. The patented Online - Moiré t echnology measures the optical refraction of the glass and helps to identify defects with a high degree of reliability and precision. With fast and separately switchable LEDs different illumination effects can be realized without complex multi - angle lighting arrangements. The effort pays out: Early defect det ection avoids scrap at the end of the production process and reduces costs.
Flawless edges are essential for the dimensional accuracy of thin glass and minimize the risk of breakage . The Flat Panel Master - Edge inspection module checks the substrate edge s using mult i – view technology (nearly 360°) to detect defects like cracks, shells, shiners and break outs with unmatched precision . The compact sensor can be integrated in a fixed position or on a movable axis, giving the system the flexibility to be easil y adapted to any kind of glass transportation device. Aside from the quality documentation, the inspection protocol delivers information for the optimization of the grinding process . The recorded data supports the operator to define the optimal date of sub stitution of the grinding wheel as well as the edge cutter to maximize the uptime .
The Flat Panel Master - Review module is designed for the microscopic analysis of selected defects at the end of the production line as well as off - line. Relevant defects ca n be selected and enlarged using several zooming factors. The software helps to find the root - cause of the defect and offers the opportunity to reclassify the imperfection in order to re - grade substrates if needed. Glass manufacturers have the certainty of a doubly secured quality decision.
The contact - free inspection of the highly precise Flat Panel Master provides a high potential for the improvement of the glass substrate quality and consequently of the finished displays. Apart from that, statistically p repared inspection data and extensive analysis functions ensure transparency and help to build knowledge about the production processes as a basis for further optimization . Using this knowledge, manufacturing parameters can be adjusted which improves produ ction efficiency and reduces costs.