Executing Organisation: German Federation of Industrial Research Associations (AiF) | Federal Ministry of Economic Affairs and Energy (BMWi)
Up to now, Mechatronic Integrated Devices (MID) have opened up completely new possibilities for electromechanical connecting elements by integrating functions with dimensions ranging from millimeters to a few centimeters. For applications with larger dimensions of a few decimeters, currently there is no efficient and cost-effective process. Within the scope of the project, electrically conductive structures on large-area components are to be generated and characterized by means of direct-printing processes in combination with subsequent laser irradiation. The main advantages are the substitution of the time-consuming furnace sintering process by a flexible laser process and the resulting selective heat input into the component.
The silver particle inks and pastes are applied to the component surface using piezo inkjet and dispensing systems. Selective adjustment of the laser beam profile using a Spatial Light Modulator (SLM) is intended to achieve a defined energy input during laser irradiation. The aim is to attain a high densification of the structure and at the same time to avoid thermal damage to the irradiated materials.
Selective laser irradiation was used to conduct parameter studies on different silver particle pastes on plastic and glass substrates. By selecting suitable irradiation parameters, conductivities above 10 MS/m could be achieved for both micro- and nanoparticle pastes. The image at the right illustrates the competitiveness of the process regarding conductivity compared to conventional sintering processes. In the production of printed conductors, high adhesion strengths between substrate and paste could be detected through cross cuts (left image) in order to ensure the functionality of the component even under mechanical stress.