Laser sintering of copper nanoparticles on top of silicon substrates

Abstract

This study examines the sintering of inkjet printed nanoparticle copper ink in a room environment using a laser as a high speed sintering method. Printed patterns were sintered with increasing laser scanning speed up to 400 mm s(-1). The resistivities of the sintered structures were measured and plotted against the scanning speeds. Increased resistivity seems to correlate with increased scanning speed. A selections of analytical methods was used to study the differences in microstructure and composition of the sintered structures. Based on the results, no discernable difference in the microstructure was noticed between the structures sintered using 20 mm s(-1) to 400 mm s(-1) scanning speeds; only the structure scanned using 5 mm s(-1) speed showed a vastly different microstructure and no resistivity was measurable on this structure. Compositional studies revealed that, apart from the structure scanned with 5 mm s(-1) speed which contained the highest oxygen, the rest of the structures showed a steady oxygen increase with increased scanning speed.

Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration

“…Cu is relatively cheap and readily available and so the exploitation of CuO NMs has increased over recent years. For example, the antimicrobial properties of CuO NMs could promote its use as an alternative to silver and gold NMs in products, to reduce their manufacturing cost [ 16 ]. CuO NMs are also useful in heat transfer fluids and/or semiconductors [ 13 , 17 ] and as inks [ 16 , 18 , 19 ].…”

Metallic Nanoparticle Inks for 3D Printing of Electronics

“…Despite the successful fabrication of conductive copper patterns, this complex and time-consuming method required a vacuum chamber [67] and involved sintering at high temperatures that might not be feasible for use with temperature-sensitive substrates. Literature also has shown that IPL sintering [72][73][74][75] and laser sintering [72,76] techniques are able to sinter copper nanoparticle inks at high speed in ambient conditions with low complexity, while maintaining high electrical conductance within the printed patterns. There is difficulty in translating this time-consuming thermal sintering method into the electronic industry, which requires high-speed fabrications for mass production in the ambient environment.…”

“…[157] • Ag loading), Applied Nanotech, Inc. [31] • Metalon® JS-A221AE (50 wt% Ag loading), Nova-Centrix [163] Copper nanoparticle inks • Electrical Conductivity: 58.8 × 10 6 S m −1 [25] • Thermal conductivity: [25] • Melting point: 1357.77 K [26] • Excellent electrical and thermal conductivity [64] • Reduced • Electrodes [75] • RFID tags [80] • Thermal sintering [78] • Intense pulse light (IPL) sintering [72][73][74][75]78,164] • Laser sintering [72,76] • Thermal sintered at above 350 °C in a reducing atmosphere [157] • Ag loading), Applied Nanotech, Inc. [31] • Metalon® JS-A221AE (50 wt% Ag loading), Nova-Centrix [163] Copper nanoparticle inks • Electrical Conductivity: 58.8 × 10 6 S m −1 [25] • Thermal conductivity: [25] • Melting point: 1357.77 K [26] • Excellent electrical and thermal conductivity [64] • Reduced • Electrodes [75] • RFID tags [80] • Thermal sintering [78] • Intense pulse light (IPL) sintering [72][73][74][75]78,164] • Laser sintering [72,76] • Thermal sintered at above 350 °C in a reducing atmosphere…”

Inkjet printing technology for increasing the I/O density of 3D TSV interposers

“…However, at the time, no suitable inkjettable Ni ink was available for this experiment. Copper ink could be another alternative option; however, in our experience, Cu annealing processes are relatively complex, typically requiring photonic or thermal annealing in inert atmosphere with forming gas 22,23 .…”