Inkjetprinting of Vertically Integrated RC-Circuits

Abstract

Both capacitors and resistors are widely used passive components. Considering micro hybrid circuits printing of both devices is required. Striving for space-saving layouts, multi-layer capacitors are requested. Additionally, vertical integration of devices is desirable. However, today's screen printing technology cannot be applied to uneven surfaces, limiting the aspect ratio and the ability of vertical integration. Thus, usually SMD capacitors are preferred. In order to increase the degree of vertical integration, resistors are printed on top of printed capacitors, creating RC-circuits. The mask-less inkjet printing allows for realization of such structures. To keep the process simple, no in-between-sintering is applied; the entire component is co-fired in one final step.To model the electric behavior of the RC-circuits, both the capacitors' and resistors' behavior is compared to non-integrated devices of the same size and shape. Based on these results, it is shown how existing single-device models can be applied to integrated devices.To improve the sintering process, furthermore the impact of heat on the behavior of the used organic additives is examined. The solid additives have to burn thoroughly. It is analyzed whether there is a liquid phase during sintering and how this may affect the resulting structure.