Digital printing technologies play an important role in microelectronics, microsystems engineering, and sensor systems. Recently, scientists at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen, Germany, have discovered that they can use various printing methods to produce electronic components and sensors. The tiny resistors, transistors, circuit paths, and capacitors are first designed on screen and then printed directly onto 2Dand 3D substrates. Instead of paper inks, they are using “functional inks,” electronic materials in liquid or paste form.
To automate the process of applying printed electronics to components with flat and 3D surfaces, the researchers set up a robot-assisted production line to allow different printing methods to be combined in a single run. Modules for silk-screen, inkjet, dispenser, and aerosol-jet printing are integrated in the production unit.
This makes it possible to print structures of different surface areas, widths, and thicknesses on the substrate, they said. Aerosol-jet printing, for instance, enables the deposit of extremely fine structures with a width of only 10 micrometers onto the component. In this non-contact process, the conductive ink is transformed into an aerosol using compressed air, and then fed to the print head through a fine tube. The print head focuses the aerosol jet on the surface of the substrate, which doesn't necessarily have to be flat or smooth. It is also possible to vary the thickness of the printed features and create multilayer structures, they said.