Results have been announced for the research project ‘Integrated High-Volume Production along the LED Value-Added Chain for Large Wafers and Panels’ (InteGreat), which ran between December 2014 and February 2018 supported by the German Ministry for Education and Research (BMBF) as part of the ‘Photonic Process Chains’ initiative.
The project consortium comprised seven partners from science and industry: Osram Opto Semiconductors GmbH of Regensburg, Germany (project coordinator), Osram, the Fraunhofer Institute for Integrated Systems and Device Technology (IISB), the Fraunhofer Institute for Reliability and Microintegration (IZM), Würth Elektronik, LayTec AG and Mühlbauer GmbH & Co KG.
The partners investigated time-honored manufacturing approaches and know-how along the entire LED production process with the aim of identifying potential areas for optimization. New approaches that were investigated included manufacturing very small surface-emitting LED chips and packaging technologies, among other things. The insights allow for LED products to be given additional properties that would have been difficult or even impossible to achieve with the technologies previously used to produce LEDs.
At the heart of the project was wafer-level packaging as well as investigations into planar contacts. One of the pioneering approaches to emerge from the project is planar interconnect technology in which the bond wire is replaced by a thin flat metal connection. This moves the surface emitter to the surface of the package. The light can therefore be used more directly, unlike with conventional components. This leads to smaller losses in efficiency and luminance and consequently to greater brilliance and cost savings in operation. Other new technologies along the entire value-added chain for functional full-color video wall modules with a 1mm pixel pitch were successfully demonstrated.
The results of the project can be applied not only to large-format video walls but also to new applications such as in ambient lighting and sensor systems. Due to the modular structure of the project comprising four work packages, many results can now be quickly transferred to product development and production. The integration of LEDs in industrial applications and also in areas such as the mobility of the future can therefore be accelerated, it is reckoned. The results also open up potential in infotainment.
“Our powerful consortium of partners from science and industry has delivered extraordinary achievements in three years,” believes Frank Singer, predevelopment group leader at Osram Opto Semiconductors.
