Inkjet printed flexible user interface module

Environmental aspects and the trend towards sustainable development in the electronics industry are very strong business drivers in selecting technologies for the electronics industry. All this together with demands for fast formulation of product concepts from R&D to manufacture are added incentives for businesses to benefit from printed electronics. Consequently, printed electronics may turn out to be an enabling technology providing critical success factors for future business. Over the last few years, printed electronics, especially inkjet technology, has been an emerging candidate for manufacturing flexible printed circuit boards (FPC). However, for any broader industrialization of printed electronics, it is necessary to take a holistic approach to product design. That is, the manufacturing processes and their possible limitations must be taken into account early in R&D and concept design for any benefits in reduced design time and project costs. This paper focuses on the applicability of inkjet technology through a demonstrator case. We introduce aspects of design and fabrication related to producing inkjet-printed flexible circuit boards. As a result, a set of two-sided inkjet-printed FPCs used as an interface module in a mobile phone was manufactured. The functionality of the fabricated prototype modules was tested by installing them in mobile phones and testing their electrical performance. Our conclusion is that inkjet printing is a viable option for future flexible circuit manufacturing. Materials and processes must, of course, be further developed, but demonstrators can even now be fabricated that in certain applications reach the electrical performance of a traditional flexible circuit board.