Inkjet-printed interconnects for unpackaged dies in printed electronics

This work details manufacturing processes developed to integrate an unpackaged silicon die onto a paper substrate, as part of constructing a hybrid inkjet-printed paper-based circuit. This integration between rigid components and flexible substrates is beneficial in low-cost applications and capitalises on the advantages of both the well-established integrated circuit technology and the emerging paper-based electronics platforms. A superglue incline at the chip edge formed a ramp for printing the silver interconnects between the paper-based circuit and the chip pads. Two printing protocols are compared, the first a single layer using 5 μm drop spacing, and the second using a 35 μm drop spacing for three layers. An unpackaged RFID tag die is successfully integrated and is presented as proof of concept.The Council for Scientific and Industrial Research (CSIR) in Pretoria, including funding this work under the Young Researcher Establishment Fund (YREF) and parliamentary grant funding.https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=2220hj2020Electrical, Electronic and Computer Engineerin