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Thesis defence

Last March 17, 2022, our colleague Chaimaa El Hadjjaji has presented her research work entitled: “Optimization of the performances of microwave components, 2D or 3D printed on polymer substrates”.

This thesis focused on the optimization of the electrical conductivity of microwave components, printed by direct writing technologies (AJP, IJP, microdispensing) on polymeric substrates (2D and 3D) sensitive to high temperatures and long processing times of thermal sintering.

Chaimaa has studied different ways of annealing printed metal lines, using different technologies available at CTTC. The characterization methods implemented allowed first to evaluate the dielectric properties of the selected substrates by resonant cavities, then the electrical conductivity of the metallic lines for different substrate-metal-process combinations, using ring resonators. The surface states of the rough polymer substrates were also taken into account, by a thorough topographic characterization, then the improvement of these surfaces was studied through different approaches, including the use of lasers.

SEM pictures of various silver coatings realised by microdispensing – ©CTTC

Electrical conductivities for various methods studied in this work, and comparison with literature ©CTTC

1] W. Gu et al., ‘Fast near infrared sintering of silver nanoparticle ink and applications for flexible hybrid circuits’, RSC Adv., vol. 8, no. 53, pp. 30215–30222, 2018, doi: 10.1039/C8RA04468F.

[2] K.-H. Sung, J. Park, and H. Kang, ‘Multi-Layer Inkjet Printing of Ag Nanoparticle Inks and Its Sintering with a Near-Infrared System’, Int. J. Precis. Eng. Manuf., vol. 19, no. 2, pp. 303–307, Feb. 2018, doi: 10.1007/s12541-018-0037-8.

[3] E. Sowade, H. Kang, K. Y. Mitra, O. J. Weiß, J. Weber, and R. R. Baumann, ‘Roll-to-roll infrared (IR) drying and sintering of an inkjet-printed silver nanoparticle ink within 1 second’, J. Mater. Chem. C, vol. 3, no. 45, pp. 11815–11826, Nov. 2015, doi: 10.1039/C5TC02291F.

This research work was realised at the XLIM Institute (XLIM Lab, CNRS #7252), under the responsibility of Dr. Nicolas Delhote, Associate Professor and Pr Serge Verdeyme.

CTTC thanks Region Nouvelle-Aquitaine for the financial support all along the research work, as well as CANOE and ALPhANOV technological centres for their support.