Title: Low thermal budget photonic processing of highly conductive Cu interconnects based on CuO nanoinks. Potential for flexible printed electronics

Abstract

The developing field of printed electronics nanoparticle based inks such as CuO show great promise as a low-cost alternative to other metal-based counterparts (e.g., silver). In particular, CuO inks significantly eliminate the issue of particle oxidation, before and during the sintering process, that is prevalent in Cu-based formulations. We report here the scalable and low-thermal budget photonic fabrication of Cu interconnects employing a roll-to-roll compatible pulse-thermal-processing (PTP) technique that enables phase reduction and subsequent sintering of inkjet-printed CuO patterns onto flexible polymer templates. Detailed investigations of curing and sintering conditions were performed to understand the impact of PTP system conditions on the electrical performance of the Cu patterns. Specifically, the impact of energy and power of photonic pulses on print conductivity was systematically studied by varying the following key processing parameters: pulse intensity, duration and sequence. Through optimization of such parameters, highly conductive prints in < 1 s with resistivity values as low as 100 n m has been achieved. We also observed that the introduction of an initial ink-drying step in ambient atmosphere, after the printing and before sintering, leads to significant improvements in mechanical integrity and electrical performance of the printed Cu patterns. Moreover, the viability of CuOmore » reactive inks, coupled with the PTP technology and pre ink-drying protocols, has also been demonstrated for the additive integration of a low-cost Cu temperature sensor onto a flexible polymer substrate.« less

Authors:

Rager, Matthew S. ^[1]; Aytug, Tolga ^[2]; Veith, Gabriel M. ^[1]; Joshi, Pooran C. ^[1]

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

Publication Date:

Thu Dec 31 00:00:00 EST 2015

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1237154

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Materials and Interfaces

Additional Journal Information:

Journal Volume: 8; Journal Issue: 3; Journal ID: ISSN 1944-8244

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

77 NANOSCIENCE AND NANOTECHNOLOGY; ink-jet printing; CuO nanoparticle; pulsed thermal processing; photonic sintering; printed electronics; conductive ink; flexible substrates; sensor