SCHOTT solutions no. 2/2012 > Thin Glass

Extremely thin, transparent and rollable pure glass! SCHOTT is the only manufacturer capable of producing it in thicknesses of only 25 micrometers thanks to its unique down-draw technology. Photo: SCHOTT/A. Sell

Ultra-thin and Talented

Rolled up glass that contains microelectronics – perhaps this will no longer remain a vision for the future. After all, SCHOTT has managed to manufacture the world’s thinnest glass using a continuous drawing technique and roll it up.

Thilo Horvatitsch

That quiet crackling sound that can be heard between Uwe Wilkens’s fingers is not transparent thin foil, but rather the excitement that accompanies this topic. The Strategic Marketing Manager who works for SCHOTT will be introducing something new to the market that is prophesied to have a bright future ahead of it: special glass only micrometers in thickness that can be manufactured as a continuous ribbon and then be rolled up. ”Only a couple of years ago, not even the experts would have dreamed this is possible,” Wilkens says. Although thin glass is already available on the market, SCHOTT is currently the only manufacturer capable of producing it in a thickness of only 25 microns.

In the meantime, several 100 meters of this ultra-thin material have been carefully wound onto a roll and unrolled again at the SCHOTT plant in Grünenplan, Germany. The fact that this ultra-thin glass is so flexible and unbreakable can be attributed not only to the stability of the material itself, but also to the sophisticated manufacturing technique that employs down-draw technology (see details below). ”We currently offer material thicknesses of between 100 and 25 micrometers. However, the limitations haven’t been tested yet. We have already manufactured glass that is even thinner,” Wilkens adds.
Special glass from off the roll (top) and its qualities open the door to a world of applications that people have been dreaming of for some time, for instance using OLED lighting elements (see picture below) that can be printed onto this ultra-thin material. Photo above: SCHOTT/C. Costard. Photo below: The OLLA project/Fraunhofer IPMS
Ultra-thin glass in cut sheet form has already been introduced to the market. This, but especially the new version that comes on a roll, will open up a world of applications that we have been dreaming of for some time. After all, this extremely thin and flexible glass can replace materials that offer flexibility and are durable, yet cannot offer the outstanding physical and chemical properties of glass. Plastics, for instance, have one key disadvantage: they are not gas-tight and therefore do not offer enough protection for electronic components from environmental influences. Special glass, on the other hand, stands up to high temperatures and offers long-term stability, is durable, highly resistant to chemicals, and resists diffusion. Furthermore, it also protects against UV radiation. This also applies for the environmentally friendly thin glass that SCHOTT offers, like D 263® T eco and AF 32® eco, for instance. Both will also be available on a roll.

Nevertheless, it is not just the special properties of glass that enable it to unlock new areas of application, but also the fact that it can be packed onto a roll. Maybe it will be possible, for instance, to produce electronic switches with the help of a continuous printing process using the “roll to roll” manufacturing process. In this case, the switches would no longer be vapor deposited onto individual glass substrates, printed, etched or exposed. Instead, the glass would be guided through the various processing stations directly off of the roll and then come out uncut as a roll again at the end on a continuous process production line. This type of industrial processing also opens up new possibilities with respect to performance, quality and costs because this process will now allow for OLED illumination elements to be printed onto the microsheets. OLEDs (Organic Light Emitting Diodes) are composed of organic semiconductive materials on the basis of carbon molecules and form thin- film illumination surfaces. In the past, plastic has been used to produce light sources, but offers only insufficient long-term protection for the relatively sensitive material of the future, OLED. Renowned companies in Asia and Europe have now discovered the advantages ultra-thin glass has to offer and are already testing this innovative material.

Market opportunities will arise in other fields as well. For instance, an Asian customer is using ultra-thin glass as a substrate for battery cells for mobile devices, and mass production is even expected to begin soon. Plenty of other applications are possible, for example electronic components and printed circuit boards, or gas-tight sheathing of solid materials like pipelines for use in joining systems.
Nevertheless, this razor thin glass can also be used as an attractive design element in the area of interior design or in motor vehicles. After all, it can even be manufactured in 3-D glass geometries with the help of forming technology. A laminate that consists of ultra-thin glass and plastic that combines the benefits of both materials could be just one of the interesting application possibilities.

One thing is clear, however, packaging and further processing of this glass, in particular, requires cooperation with the users. ”SCHOTT has always worked very closely with the industry and this will be no exception,” Wilkens promises. ”Our customers are showing great interest and this confirms us on our way.” The current plan calls for setting up permanently installed rolling machines and online inspection systems for use in quality control, but also laser cutting systems, in other words, setting up production capacities by the end of the year. Ultra-thin glass from off the roll is scheduled to be officially introduced to the market in 2013. <|

Down-Draw: Technology with Tensile Strength