You can’t see it, so you probably take it for granted. But think for a moment about all the glass that you use in everyday life. From windows to windshields, light bulbs to flat panel screens, these variations of melted sand are a fundamental part of many technologies. One of the key applications is for LCD panels, which require glass that is especially smooth and uniform in thickness. Corning is the market leader in LCD glass, with Asahi Glass Company (AGC) providing a significant portion as well. Glass also works well at blocking air and water vapor, which is necessary for encapsulating OLED displays.
At present, LCD and OLED panels are made in “batch mode” production. This means that the glass substrates are cut into rectangles for processing, then then cut into individual panels. In general, larger substrates translate into more efficient production, especially for large displays (though there are indications that we may be nearing some of the limits for those efficiencies). The dream is to be able to produce displays on long ribbons of glass that move continuously through the different production steps, much like a newspaper is printed on a giant printing press using rolls of paper. Roll-to-roll processing could be much more efficient than batch processing. Among the many problems, one stands out; have you ever tried to roll up a sheet of glass?
Corning and AGC have both managed this trick, as shown in this photo. At SID 2011, both companies demonstrated glass that is just 0.1 mm thick and can be rolled up. How thick is 0.1 mm? It’s about the same thickness as a sheet of paper. Managing this material is tricky, as you might imagine. The Corning demo showed a loop of glass traveling over a series of three rollers, and plastic film was attached to the edges on both sides of the glass to protect the edges from damage as it rolled around.
Still, the advantages of this thin glass are plenty. Even if you don’t use roll-to-roll production, the glass is thinner and much lighter than standard LCD glass (which is typically 0.7 mm thick, or about the thickness of a credit card). While you can’t wrap it around a pen, it does make it possible to create more flexible displays which could lead to novel applications. The big bet, however, is that this could help lower production costs even further, and help meet the consumer’s continued expections of larger displays for less money.