Copper Ink for Printed Electronics

Promethean Particles to showcase new copper pre-inks at IDTechEx Printed Electronics 2015, Berlin.

Nanoparticle-based copper can be manufactured sustainably at industrial scale and shows high conductivity even with no formulation

Nottingham, UK; April 23, 2015: At Printed Electronics 2015 in Berlin, 28-29 April, Promethean Particles is showcasing a new material which could provide a viable alternative to the use of silver for conductive inks in printed electronics. The IDTechEx event is Europe’s premier expo for new developments in high tech flexible electronics applications.

For many years silver has been the metal of choice for conductive inks due to its high conductivity and stability to oxidation. However, copper has always been of high commercial interest due to the potential cost savings it could realise. The difficult challenge of manufacturing suitable copper inks has meant that silver continues to dominate as copper is more likely to oxidise leading to poor conductivity.

Promethean is pleased to announce it has developed a dispersed copper concentrate for ink manufacturers to use as a raw material for producing conductive inks that can be printed using a variety of techniques. The “pre-ink”, which can be thought of as a conductive “pigment” for ink formulators, remains stable as non-oxidised copper metal for a period of several months and contains only copper and an antioxidant. These copper particles offer a lower sintering temperature at which conductivity is obtained, thus allowing conductive tracks to be deposited onto less thermally-stable substrates (often flexible polymer-based materials). In addition conductivity has even been achieved when sintering the deposited material in air.

The patented continuous process used to produce the dispersion uses simple copper precursors and off-the-shelf reactor components, making it a sustainable, economic manufacturing route. Promethean has demonstrated scale up of the process using pilot facilities in Nottingham and is currently capable of producing up to 500 g Cu per hour and is offering copper loadings of up to 50 wt% in a variety of solvents including water.

“This material has the potential to be a very significant development for the future of conductive inks,” said Promethean CEO Dr Sandy Reid. “The copper dispersion allows ink-formulators a high-performance option for printing conductive tracks which is both cost-effective and available at commercial scale”.

“We are unaware of another process that offers such an economical route for the production of conductive inks and we hope this is just the first step to continued development of a range of ink materials for printed electronics applications” she added.

Promethean were founded in 2007 and have developed a route for the continuous synthesis of a wide range of inorganic nanomaterials which can be used in a variety of applications. This year they are starting the build of a full-scale manufacturing facility located in the UK.

Promethean will be exhibiting samples at stand G11 throughout the tradeshow.