University of Oulu

E. Hannila, K. Remes, T. Kurkela, T. Happonen, K. Keränen and T. Fabritius, "The Effect of Torsional Bending on Reliability and Lifetime of Printed Silver Conductors," in IEEE Transactions on Electron Devices, vol. 67, no. 6, pp. 2522-2528, June 2020, doi: 10.1109/TED.2020.2990125

The effect of torsional bending on reliability and lifetime of printed silver conductors

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Author: Hannila, Esa1; Remes, Kari1; Kurkela, Timo2;
Organizations: 1Optoelectronics and Measurement Techniques Research Unit, University of Oulu, Oulu, Finland
2VTT Technical Research Centre of Finland Ltd., Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.7 MB)
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Language: English
Published: Institute of Electrical and Electronics Engineers, 2020
Publish Date: 2020-06-26


Capability of high-speed and low-cost manufacturing makes the printing techniques a very promising approach for large-area flexible electronics mass manufacturing. Due to fast and intensive technology development, the lack of knowledge about the reliability and lifetime of printed electronics is obvious, requiring further investigation. Especially, the effect of torsional bending on lifetime is a mostly unexplored field of reliability testing. In this article, a torsional bending test of parallel printed silver conductors (0.3-, 0.5-mm pitch) on polymer substrate (polyethylene terephthalate, 125-μm thickness) was conducted and analyzed. According to the experimental results, torsional bending causes wear-out type failures in conductors and the length-to-width (LTW) ratio of the sample’s substrate was observed to have a significant impact on reliability. If the LTW ratio is smaller than 3, the lifetime of printed conductor seems to collapse and samples lasted for approximately only 17 bending cycles on average. Lifetime was improved by increasing the LTW ratio and samples withstood over hundreds of cycles with LTW ratio of higher than 15. However, the distance of a conductor from the edge of the substrate was not observed to have any significant influence on the reliability under torsional bending.

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Series: IEEE transactions on electron devices
ISSN: 0018-9383
ISSN-E: 1557-9646
ISSN-L: 0018-9383
Volume: 67
Issue: 6
Pages: 2522 - 2528
DOI: 10.1109/TED.2020.2990125
Type of Publication: A1 Journal article – refereed
Field of Science: 213 Electronic, automation and communications engineering, electronics
Funding: This work is financially supported by Business Finland funded project (Dnro 3944/31/2014), Academy of Finland’s FIRI funding (grant no. 320017) and European Regional Development Fund’s Novel Digitally Fabricated Materials for Electronics, Optics and Medical Applications (grant no. A74080).
Academy of Finland Grant Number: 320017
Detailed Information: 320017 (Academy of Finland Funding decision)
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