Aerosol Printing of High Resolution Films for LTCC-Multilayer Components

Abstract

For the electronic packaging of sensor stable and cost-efficient fine line printing technologies on LTCC and high frequency laminates are needed. Especially common technologies like screen printing and thin film techniques are unsuitable for fine structures or too expensive. In addition, there is no direct write technology for 3D LTCC designs as well as for high reliability cofiring structures. Closing this gap, aerosol printing technology is used to print high resolution conductors on planar and nonplanar substrates. Aerosol printing is a direct write noncontact printing technology of functional layers. After pneumatic atomization, the ink is transformed into 1–5 μm droplets. The resulting continuous aerosol stream is focused by a sheath gas in the printing head. Thus, the long standoff distance between the substrate and the deposition tip of max. 5 mm allows 3D printing on nonplanar substrates. With optimized inks and printing parameters, line widths of 10 μm are achievable. This paper will present applications for aerosol printed functional layers on LTCC. These are, for example, aerosol printed films embedded in cofired LTCC, fine line structures for high frequency applications, and the evaluation of printed 3D structures like LTCC stairways. Furthermore, the 90° contact of unconventional sensor designs will be presented.