The aim of this research work is to encapsulate printed organic electronics using digital printing processes. The printing process should be able to apply the encapsulation material at low temperatures to any materials with any geometry without damaging the component to be encapsulated. For example, processes such as inkjet printing, nanojet printing, and possibly also spray coating or dispensers should be used.
The manufacturing process developed in this way will be able to encapsulate components produced by means of digital printing on 2D and 3D surfaces also by means of digital printing. At the end of the project, a demonstrator will be created, which consists of a 3D component with an organic optoelectronic functionality produced entirely by digital printing, whose service life reaches the values required for the application due to the encapsulation developed in this project.
Figure: Inkjet; Source: iMEET & FAPS, FAU
Due to digitization and the current industrial development (Industry 4.0), digital printing has gained outstanding importance in the field of printed electronics. The technology has the ability to manufacture components and parts much more cost-effectively than with conventional methods.
The current development of printing technology has shown that various electronic components made of organic materials, also called organic electronics (OE), can already be produced by digital printing, such as organic photovoltaics (OPV), organic photodiodes (OPD), organic field effect transistors (OFETs) and organic light emitting diodes (OLEDs). This technology offers a good compromise between cost and performance of electronic components compared to the conventional production of electronic components.
Despite the advances in the printing of organic electronics, high-quality encapsulation must continue to be carried out using a vacuum process, as printing processes are not yet available for this. Although the vacuum process can produce very high quality barrier layers, it is particularly suitable for planar components with regard to the encapsulation geometry, since shading effects can result in an inhomogeneous coating for more complex 3D objects. In addition, the complex process is characterized by high temperatures, expensive equipment, low throughput and waste of material.
However, the encapsulation of organic electronics is decisive for their service life and thus also for their overall cost efficiency. It serves to protect the component from oxygen and water molecules, which attack the component through chemical reactions with the active layer or the electrodes. Up to now, however, high-quality encapsulations could not be produced using digital printing. For this reason, digital printing must be adapted so that encapsulation layers of sufficient quality can be printed. This avoids the above-mentioned disadvantages of the current vacuum encapsulation. In this way, it is possible to print inks on 3D objects of any shape and in any pattern at low cost.
This research project will help to raise the printing production of organic electronics to an industrially relevant level. At the same time, this enables the cost-effective functionalization of numerous 2D and 3D objects with optoelectronic components. Numerous market sectors and industries will benefit from these results, such as the automotive industry, healthcare, printing technology, “Internet of Things” (IoT), smart buildings and various consumer electronics such as mobile phones.
Figure: 5-axis robot system; Source: Neotech AMT
Benefits and economic importance for SMEs
- The quality of the barrier layers, the simplicity of the process and the low process temperatures enable new functionalities for MID technologies that were previously not possible, such as light and energy sources or sensors.
- The technology developed provides manufacturers with economic advantages, as the investment costs are lower than those for conventional vacuum coating systems
- High flexibility in production through flexible changes to the product layout as well as economical small series production
- Suppliers and companies in the field of mechanical engineering and automatic system technologies benefit directly from the MID market growth