Materials of the highest quality are crucial for an optimal television experience. Precisely grown sapphire crystals form the basis for modern µLED screen technologies, which impress with sharper images and more intense colors.
In specially developed furnaces, the raw materials are first melted in crucibles before crystal growth is started through targeted cooling. The temperatures exceed those in most other technical production furnaces and, despite the inhospitable conditions, the work here is surgically clean and extremely precise. Even the smallest defects in the crystal structure affect the quality of the finished end product.
However, not only high quality, but also security of supply and energy saving are among the priorities of the Austrian company FameTec. They are the only large-scale producers of sapphire for µLED applications in Europe. With their patented McSap process, they are able to grow several sapphire crystals in the furnace at the same time. This leads to an emission reduction of over 90% compared to the main production process of the Asian competitors.
Impact and effects
In order to monitor and control the quality of crystal growth, researchers at Materials Center Leoben Forschung GmbH developed virtual models.
For the first time, all complex processes in the production process were described and coupled in a model. The model starts with the temperature distribution in the furnace and continues with the heat transport and the movement of the liquid sapphire melt through to the solidification and cooling processes. The prevailing temporal and local temperature differences in the sapphire crystal served as the basis for a comprehensive crystal plasticity model, which is able to calculate the formation and distribution of defects in the crystal.
The models that have been developed are now being used for process and design optimization in order to determine the influence of structural adaptations or changes in process operation. The aim is to achieve energy savings and further improve product quality. In addition, the virtual models are also able to calculate the process in real time, which opens up the possibility of linking the models with current process data. This means that the quality of the initial product can already be determined during the manufacturing process and any necessary adjustments can be made.
Project coordination (Story)
Dr. Georg Reiss
Key Scientist Digital Manufacturing Processes
Materials Center Leoben Forschung GmbH
Georg.reiss@mcl.at
IC-MPPE / COMET-Zentrum
Materials Center Leoben Forschung GmbH
Vordernberger Straße 12
8700 Leoben
T +43 (0) 3842 45922-0
mclburo@mcl.at
www.mcl.at
Project partners
• Materials Center Leoben Forschung GmbH, Austria
• FameTec GmbH, Austria
• QubeDot GmbH, Germany
• Montanuniversität Leoben, Austria