Generation of Printed Electronics on Thermal Sensitive Substrates by Laser Assisted Sintering of Nanoparticle Inks

Abstract

Direct printing technologies enable the generation of arbitrary electrical conductive structures on 3D surfaces and thus the fabrication of new and innovative mechatronic integrated devices (MID). In order to fabricate electrical circuits, a new approach using a laser beam for sintering a silverbased nanoparticle ink is investigated, reducing the thermal load on the device by a selective energy input compared to a standardized furnace process. Thus, processing of temperature sensitive and low-cost substrate materials for applications such as covering or trim parts is enabled. However, laser assisted generation of highly conductive printed structures is often accompanied by defects such as line deformations and requires a deeper understanding regarding the influence of the laser process on the production of defect-free circuits. This paper explores the benefits and limits of laser assisted sintering of printed electronics promising a fast and flexible production of complex conductive circuits on a small time scale in contrast to furnace sintering processes. For an evaluation of characteristic properties, four point measurements and adhesion tests are carried out on the conductive structures. In order to guarantee safe and reliable operation of the printed structures, the long-term characteristics are determined by means of a temperature change test.