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The partners at the General Assembly meeting held in Portugal in March 2015.

Prominent - Processes for MEMS by Inkjet Enhanced Technologies

During the second reporting period, all potential ink-jet material pre-evaluations were done and most of the testing completed and based on these results final demonstrators were selected. Surface activation for inkjet process was successfully demonstrated and Innophysics introduced a new configuration of the μPlasmaPrint system to commercial markets. Partner poLight announced during the period collaboration with STMicroelectronics to ”use STMicroelectronics TFP MEMS technology to manufacture its TLens autofocus lens, a product that brings new camera autofocus performance to smartphones”

For more information, please have a look on the website.

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Prominent Results in Conferences, Publications and Theses

Since the last newsletter in December 2014, Prominent has been present at the 7th International Exhibition and Conference for Printed Electronics LOPEC, München, Germany on March 3-5, 2015, Please see the Poster.

Prominent results were published in the following highly ranked journals and theses. The summaries of the publications are given below.

Information about all the conferences and other publicity is available on the Prominent website.

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”Comparison of laser and intense pulsed light sintering (IPL) for inkjet-printed copper nanoparticle layers”, in Scientific Reports 5, 8832 (2015), by Juha Niittynen, Enrico Sowade, Hyunkyoo Kang, Reinhard R. Baumann & Matti Mäntysalo.

 ”Comparison of Sintering Methods and Conductive Adhesives for Interconnections in Inkjet-Printed Flexible Electronics”, Doctor of Science thesis, Tampere University of Technology by Juha Niittynen. Defended on April 24, 2015.

The publication ”Comparison of laser and intense pulsed light sintering (IPL) for inkjet-printed copper nanoparticle layers” analyses the sintering of inkjet-printed copper nanoparticle structures with laser and intense pulsed lighting (IPL) sintering techniques. Both sintering techniques were found to be suitable for sintering the tested copper nanoparticle ink on polymer film substrate. Differences were observed as well, laser sintering requires significantly more energy per area to achieve the similar conductivity as with IPL. The sintering techniques were both identified as viable alternatives to be used with inkjet-printing but having distinguished advantages and disadvantages. The laser sintering is found to be highly customizable and accurately controlled while IPL is superior for larger areas. The doctoral thesis ”Comparison of Sintering Methods and Conductive Adhesives for Interconnections in Inkjet-Printed Flexible Electronics” evaluates the different sintering techniques for inkjet-printed nanoparticle inks as well as interconnections based on conductive adhesives. Several sintering techniques were identified to be adequate alternatives for the traditional thermal sintering with different advantages and challenges. Both isotropic and anisotropic electrically conductive adhesive materials were deemed usable for external interconnections for inkjet-printed structures.

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 ”High-Aspect-Ratio Through Silicon Vias for High-Frequency Application Fabricated by Magnetic Assembly of Gold-Coated Nickel Wires in IEEE Transactions on Components, Packaging and Manufacturing Technology 5, 21 (2015) by S.J. Bleiker, A.C. Fischer, U. Shah, N. Somjit, T. Haraldsson, N. Roxhed, J. Oberhammer. G. Stemme, and F. Niklaus.

In this paper, we demonstrate a novel manufacturing technology for high-aspect-ratio vertical interconnects for high-frequency applications for frequencies of up to 75 GHz. The manufacturing approach is based on magnetic assembly of gold-coated nickel wires that are subsequently insulated with a low-k thermosetting polymer. As compared with conventional TSV designs, this novel concept offers a more compact design and a simpler, potentially more cost-effective manufacturing process. Moreover, this fabrication concept is very versatile and adaptable to many different applications, such as interposer, micro electromechanical systems, or millimeter wave applications. For evaluation purposes, coplanar waveguides with incorporated TSV interconnections were fabricated and characterized.

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Development of Through Glass Vias (TGVs) for Interposer Applications” Master of Science thesis, KTH by Vlad Viorel Cornean. Defended on December 11, 2014. 

In this thesis work the manufacturing of through glass vias (TGVs) based on KTH’s magnetic assembly process is presented for the first time. TGVs were fabricated by introducing nickel wires in via-holes on pre-fabricated glass substrates and applying a spin-on polymer to isolate the nickel wires from the sidewalls of the via-holes. Another focus of this work was optimizing the magnetic assembly process in terms of yield and reliability.

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Summer Greetings,

 

Wishing you a Sunny and Relaxing Summer 2015,
Prominent partners

 

The image on the left is from Vila do Conde, Portugal, where the General Assembly meeting was held.

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