53.3: Manufacturing of 4th Generation OLED Masks with the Laser MicroJet® Technology

Display manufacturers are investing heavily into production lines for OLED (Organic Light-Emitting Diode) displays. Volume production of active-matrix OLED has already started. The production will increase through the TV mobile phones demand for high-resolution mobile displays as the AM OLED can switch pixels 1,000 times faster than TFT-LCD technology. A typical mask is only 40 micron thick and has millions of tiny but lengthy apertures. The requirement for accuracy is very high, since several masks are used for the same display. A new micro-machining technology, - a hybrid of laser and water jet technology, the water jet-guided laser, also called as Laser MicroJet® technology - has been developed for OLED mask cutting. By combining a hair-thin low-pressure water jet and a powerful short-pulsed Ytterbium fiber laser, the problem of heat damage has been completely solved. The Laser MicroJet® technology can produce small delicate openings with totally clean edges (no dross or slag). The cut apertures are free of contamination and thermal stress. Precision (few microns) and speed (25,000 – 30,000 apertures per hour) is so high so that the manufacturing costs for OLED masks can be drastically reduced. The process is applicable for any mask dimension. Synova cutting systems, which have a cutting area of 1300 × 900 mm for producing 4th generation OLED masks are being used now at major mask manufacturers.