The well-known green printed circuit boards shape the image of electronics. But they are only suitable for circuits that operate at frequencies well below 100 GHz. In addition, boards for high-frequency systems and radar technology are mostly based on lithographic processes, which are, however, optimized for mass production. Creating an appropriate exposure mask is too cost-intensive for medium quantities of up to 10,000 units, as typically produced by small and medium-sized enterprises (SMEs). The latest additive processes and precision printing technology could close the gap between individual and mass production.
The Karlsruhe Institute of Technology (KIT) has now set a laboratory dedicated to research and develop such production techniques. Its heart is a configurable, micrometer-precise printing platform with which packaging can be realized in the future in a highly flexible and cost-effective way, explains Professor Thomas Zwick, head of the Institute for RF Technology and Electronics at KIT. The packaging depends very much on the application - for example with regard to the size and orientation of antennas. For this reason, mass-produced off-the-shelf solutions are usually not suitable. Radar technology at very high frequencies up to the terahertz range is suitable for many other applications, as the high frequency makes higher measurement accuracy, higher data transmission rates and further miniaturization possible.
The research laboratory at KIT combines equipment for additive and maskless deposition and structuring processes into a flexible printing platform. In addition, special measuring systems enable the determination of the frequency response of components and systems at more than 500 GHz. In order to print electrical circuits, various methods are already available in which materials with the most varied electrical properties are used as ink - two-dimensional ones such as ink jet and aerosol jet or three-dimensional ones such as laser lithography. For circuits beyond the frequency of 100 GHz, the aim is to increase the resolution and combine the complementary properties. The big challenge is the exact positioning of the components: Printing processes are to be coordinated with micrometer precision so that components from the various printers work together optimally and circuits become as small as possible.