The term flat panel displays (FPDs) covers a growing number of technologies, which manufacture video display screens used in very many items, for example mobile phones and television screens or laptop computers.
The current FPD types include:
- LCD (Liquid Chrystal Display)
- AM LCD (Active Matrix Liquid Chrystal Display)
- OLED (Organic Light Emission Diode)
- LED (Light Emitting Diode)
- PDP (Plasma Display Panel)
Driven by end-user demands for better product quality and lower costs, FPD manufacturers are constantly searching for improved process equipment. Larger and thinner glass substrates as well as tighter requirements lead to new challenges for equipment manufacturers. The display substrates are categorized by size and named by generations (GEN). For instance Gen 8 substrates have a size of 2160 x 2460 mm and can produce the panels needed for 18 32-inch liquid crystal display (LCD) televisions. Photomasks must follow the size of LCD generation, because they are used as original plates to transfer patterns to TFT and color filter substrates.
Touch panels have become very popular since the area of smartphones and tablets. Many other devices like eBooks, navigation devices and car displays have followed this trend. Here, the two main technologies used are analog resistive and projected capacitive.
The VPG series of Maskless Lithography Systems can be used for all display related applications either for photomask manufacturing or direct writing of individual layers.
For all display related applications the quality requirements on photomasks are exceptional. One key specification is the so-called Mura condition, a Japanese term for "unevenness" as a result of any disturbance in a regular periodic pattern. If the Mura condition is not meeting the specific demand, dark spots or patches may occasionally appear on the final display. The VPG series of Maskless Lithography Systems offer special Mura optimization functions for good Mura condition and excellent CD uniformity and resolution.