Transforming the Idea of Ultra-Thin Glass into a Reality
tesa is part of a publically sponsored research consortium that’s leading the development of transparent, flexible, low-energy display and lighting products.
5 Oct 2017
tesa is developing new bonding technologies for KONFEKT, an innovative industry research consortium for flexible electronics.
Imagine a smartphone that folds up like a wallet to fit in your pocket, but opens up to reveal a tablet-sized screen. Sound like something you might see in a science fiction movie? Glassmakers are already manufacturing bendable ultra-thin glass and they say foldable glass is just around the corner. With a minimal thickness of 25 micrometers ultra-thin glass is thinner than a single human hair, and in ultra-thin thicknesses of less than 150 micrometers, this glass has proven to be bendable yet stable. Due to its measure of flexibility, the glass can be wrapped onto rolls.
Compared to other substrate materials such as plastics, metals, or silicon, ultra-thin glass offers some serious advantages, including superior optical quality, mechanical resistance, chemical consistency, and temperature stability.
In order to develop new technologies for the use of glass on roll in organic electronics, tesa joined together with other development partners the consortial project KONFEKT, with initial emphasis on the production of future generations of OLED applications.
The collaborative development project KONFEKT (thin glass for glass-polymer laminates) is supported by the German Federal Ministry of Education and Research by a total investment of €5.6 million and will run through 2018. The main goal is to deliver a glass on roll, which meets the highest possible quality standards, in order to achieve a robust and very resistant glass on roll that maintains its functional surface area through coating and laminating processes. Therefore, the participating partners tesa SE, SCHOTT, VON ARDENNE and Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP are focusing on the optimisation of avoiding any breakage of the ultra-thin glass while rolling or processing.
Within the research consortium, the four partners are focusing on two features of thin glass: The first feature is the development of a laminate made of ultra-thin glass with a barrier adhesive tape which will serve as a hermetic encapsulation of electronic components. The second feature will center on ways that ultra-thin glass can serve as a functional substrate for demanding applications, such as components for organic electronics.
First results of the project were already introduced by the partners at Vision Flexible Glass, an international technology and networking event in April 2017 at Fraunhofer FEP in Dresden, Germany.
tesa and SCHOTT are developing in the first subproject a flexible glass that enables an encapsulation of sensitive material and strengthens the improvement of roll-to-roll (R2R) processes. At the same time, VON ARDENNE is developing a vacuum coating system specifically for the roll-to-roll coating of flexible glass. The process development regarding deposition of functional layers with this innovative system is driven by Fraunhofer FEP.
Although the KONFEKT project will continue to run for another year, it has already made significant progress. In cooperation, tesa and SCHOTT have developed a way to protect sensitive electronic components such as OLEDs from humidity and oxygen by using ultra-thin glass. Flexible glass is well suited as a top ultra-barrier (z barrier) because it forms a chemically impermeable layer that is impenetrable to water vapor and oxygen, even at a thickness of 25 micrometers. Plus, it does not feature pinholes.
tesa’s expertise as a developer of specialty adhesive tapes comes into play in lateral sealing and optically clear adhesives that do not interact with sensitive OLED materials. The ultra-thin glass will be delivered to the user laminated with a special adhesive layer. This adhesive layer ensures that the components are not only sealed hermetically by the glass on their surface, but also experience no lateral diffusion of liquids and gases (x/y barrier). The combination of these two materials provides complete protection, thanks to the functional x/y/z barrier.
When finalised, this roll application will provide processing companies with a high-quality, cost-effective sealing process while offering consumers a more reliable encapsulation capable of protecting their sensitive electronics from aging and damage.
The KONFEKT project continues to push toward its ultimate goal of developing a robust, very resistant glass on roll that maintains a functional surface area throughout the coating and laminating processes. Developing sufficiently durable and flexible OLEDs will require additional research and development, which is why each partner selected to participate in the KONFEKT project brings its unique expertise to the consortium.
SCHOTT provides a deep knowledge in the processing and chemical optimisation of glass. tesa SE, with a long history of providing adhesive tapes on rolls, gives the glass its finish by laminating it with special adhesive and functional layers. Fraunhofer FEP utilises it’s decades of vapor deposition process experience. Finally, VON ARDENNE specialises in the development and manufacture of roll-to-roll coating machinery for films and metal strips, and contributes an expertise in magnetron sputtering for large-scale glass coating.
The Konfekt research project is supported by the German Federal Ministry of Education and Research (BMBF) - funding project 13Nl2974.