December 9, 2019

Project KODOS - On the move into application: Optoelectronic systems on thin glass

The recently launched KODOS project  (“Konfektionierter Dünnglas-Verbund für optoelektronische Systeme”, Thin  Glass Composites for Optoelectronic Systems), funded by the German  Federal Ministry of Education and Research, is designed to transform  thin glass into finished products along the entire value chain. The  companies EMDE development of light, Volkswagen and Deutsche Werkstätten  Hellerau, which focus on application development, have joined forces  with the technology suppliers tesa, VON ARDENNE, Flabeg, 4JET microtech,  SURAGUS, and the Fraunhofer Institute for Organic Electronics, Electron  Beam and Plasma Technology FEP. The aim of the consortium is to be able  to offer a complete modular system of functional materials,  semi-finished products, tools, and technologies for the roll-to-roll  production of optoelectronic systems on thin glass.

Sophisticated ultra-thin glasses have been on the market for some  time now. They are thinner than display glass in mobile phones or  laptops and can do a lot more. Due to their excellent properties, such  as flexibility, very smooth surface or scratch resistance, they are also  very suitable as functional surfaces in furniture or cars and as a  substrate for optical systems.
In order to serve new applications cost-efficiently and in a  market-oriented manner, a consortium of nine industrial and research  partners has now formed, which is laying the basis for this in the  public-funded project KODOS.

The automobile manufacturer Volkswagen will evaluate and qualify the  use of thin glasses as functional decorative surfaces in cars. For this  purpose, the laminated optical basic devices produced in the project are  to be tested for their resilience and crash safety. They illustrate the  properties of functional surfaces such as lighting, decorative symbols  and touch functions.

The Deutsche Werkstätten Hellerau will seal wooden surfaces with the  ultra-thin glass as high-tech material and integrate additional  functions such as organic light emitting diodes (OLEDs) or sensor  surfaces into furniture.

Thomas Emde of EMDE development of light and consortium leader  summarizes: "The aim of the project is to explore and develop  economically relevant applications for thin glass. For example, OLED  technology can be used as a display and control element in combination  with touch functionality based on thin glass in architecture, furniture,  household appliances and retail applications. The desired innovation is  the combination of coating, structuring, contacting and lamination, as  well as the development of a production-ready transition from the  processed roll to the ready-to-install semi-finished product". The EMDE  development of light will create in the project the requirements  definitions for a process optimization in the areas of roll-to-roll and  OLED production.

All the above mentioned steps pose a major challenge, especially  because of the special mechanical properties of thin glass. As a result  of the project, the consortium will be able to offer a complete modular  system of functional materials, semi-finished products, tools and  technologies.

For lamination of basic elements, tesa provides encapsulation  adhesive tapes for thin glass-based organic electronic devices. These  must guarantee an improved service life in order to meet the high  temperature requirements of the automotive industry. In addition,  technologies are being researched for full-surface and partial direct  coatings of thin glass foils with functional layers, such as  hole-injection layers for OLEDs, electrical contacts, or decorative  prints.

Flabeg develops important process steps that are necessary to be able  to use 3D-formed thin glass laminates with touch function, decoration  and including splinter protection properties as built-in parts in the  vehicle interior. The project partner is researching in particular the  hot molding process and the lamination of uniaxially and biaxially bent  thin glass.

Functional elements utilizing thin glass to be developed in the  project consortium are an important basis for later integration into  applications during the course of the project. An essential process at  the beginning of the value chain is the functionalization of the glass  surfaces by means of PVD coating.

In order to be able to produce economically, the processing of thin  glass in roll-to-roll PVD coating systems is most reasonable. The aim of  the plant manufacturer VON ARDENNE in the project is therefore to  ensure stable, continuous process control with a high material yield and  to develop quality parameters for evaluating the usability of the  supplied thin glass rolls. In addition, the coating processes and  components providing functionalities for subsequent processes  (lamination, thermal deformation, laser cutting) are to be optimized.

In close cooperation with the scientists of the Fraunhofer Institute  for Organic Electronics, Electron Beam and Plasma Technology FEP,  conceptual solutions for the technologically and economically meaningful  interlocking of individual steps in the production chain (illustration  of the process chain vacuum coating - encapsulation lamination - OLED  contacting and separation) are formulated. The Fraunhofer FEP  specialists are developing efficient coating technologies for electrodes  and OLEDs. They will introduce new structuring tiers into roll-to-roll  production. At this point, the work will dovetail with the know-how of  the project partner SURAGUS in the field of process-integrated  characterization of essential electrical and optical properties. SURAGUS  develops the measurement technology for the characterization of the  entire laminated OLED.

After successful production of the optical, thin glass-based devices,  the next process step is the separation of the finished OLEDs from the  roll. Currently, no reliable technologies exist at this point in the  process chain. In order to use the enormous competitive advantage of  roll-to-roll production, it is necessary to develop a separation  technology that enables yielding OLEDs with high edge strength and  service life.

An advantageous solution technology for this is laser separation,  which is being researched by 4JET microtech. In principle, laser-cut  glass edges can have strengths that meet the requirements of OLEDs. In  particular, it is possible to produce practically any cutting contours  and thus any OLED shapes. The specific challenges of glass-polymer  laminates will be investigated within the framework of the joint project  and competitive manufacturing technologies will be developed.

Within the next three years, the project consortium will work on the  development of technologies, that are practical and suitable for  industrial use. In addition, the project includes the implementation of  initial persuasive basic devices with the innovative material ultra-thin  glass and preparation of technology demonstrators.

The project partners thank the German Federal Ministry of Education  and Research for the funding of the project "KODOS – Konfektionierter  Dünnglas-Verbund für optoelektronische Systeme” (Thin Glass Composites  for Optoelectronic Systems) within the framework of the funding  initiative “Photonik nach Maß”.

(Source:  Fraunhofer FEP - Mediathek -  Press release 19/2019)