Doctoral dissertation

High-precision digital printing processes for better printed electronics

The performance of electronic devices and their physical size go hand in hand. So far, the limited resolution of printing technologies has prevented the fabrication of miniaturized high-performance printed electronics devices, and the wider adoption of such devices into our every-day lives. This doctoral study investigates ways to drive the miniaturization further despite these challenges.

Continuous improvements in lithographic fabrication processes toward higher resolution have led to the development of highly miniaturized silicon based electronic devices. This has resulted in increased operating speeds, lower energy consumption and smaller package sizes, which together have enabled the ubiquitous adoption of electronics into our every-day lives. At the moment, the printed electronics fabrication processes suffer from limited resolution. However, as demonstrated in this thesis, there are multiple application fields where pushing the envelope of digital printing technologies towards higher resolution and higher levels of miniaturization results in increased and, in some cases, completely new functionalities.

In electronics packaging, high-resolution digital printing processes are used to achieve a highly customizable process flow with reduced environmental impact while maintaining the high I/O-density of the package. In the field of application specific integrated printed circuits, the high-resolution printing technologies are compared with each other and against the lithographic fabrication method. In this case, the printing increased functionality provided by the high-resolution printing technologies is the field-configurability of the devices. It is also shown, that the monolithic integration of printed active and passive components on ultra-thin, biocompatible substrates with digital printing technologies enables the fabrication of highly skin-conformable devices for biosignal amplification. This type of functionality through the miniaturization of the device thickness is enabled by printing technologies alone and cannot be achieved with conventional active/passive components due to their physical size and rigidity.

As conclusion, the digital printing processes show great potential for increasing performance of printed electronics.

The doctoral dissertation of M. Sc. Mika-Matti Laurila in the field of electrical engineering titled High-precision digital printing processes for electronics fabrication will be publicly examined in the Faculty of Information Technology and Communication Sciences at Tampere University at 12:00 on Friday 13.9.2019 in auditorium FA033 of the Festia building (Korkeakoulunkatu 8, Tampere).  The Opponent will be Professor Mark D. Poliks, Center for Advanced Microelectronics Manufacturing, Binghamton University. The Custos will be Professor Matti Mäntysalo, Faculty of Information Technology and Communication Sciences, Tampere University.

The thesis is available online at the http://urn.fi/URN:ISBN:978-952-03-1219-0