Functional printing by focused flow co-extrusion
Conferences & Talks

• Dave Fork, Invited Talk
• Karl Littau
• Scott Solberg
• Ranjeet Rao
• Marco Prondzinski
• Andre Kalio
• David Duff
• Craig Eldershaw
• Al Lewis

IBM Almaden Research Center

5 March 2010
San Jose, California, USA

description

This presentation introduces a novel, non-contact, high-throughput, mask-less technology for direct-printing high aspect ratio functional materials onto substrates of technological interest. The first application of this technique has been for silver gridlines on the front surface of solar cells.[1]   Narrower and taller front gridlines can increase the solar cell’s current and decrease the series resistance compared to screen printed gridlines. The contact nature of screen printing also reduces the yield due to breakage and is an impediment to lowering cost by introducing thinner wafers. The initial commercial application of this work is to provide a production-worthy drop-in alternative to screen printing to simultaneously increase solar cell yield and performance without requiring additional processing steps. We call this technique focused flow co-extrusion, and view it as a general purpose thick film printing method. Other applications of the printing method appear to be likely. One application of interest is to create densely interdigitated structures for electrochemical devices. A battery structure of particular interest is air cathodes for metal air batteries. Such cathodes require a large area of three phase boundary for efficient oxygen uptake. Directed assembly of densely interdigitated structures of hydrophobic and hydrophilic materials is one promising route toward advanced electrode fabrication at manufacturable costs and throughput. We’ll discuss how focused flow co-extrusion may be able to fabricate such structures.

[1] D. K. Fork and T. Hantschel, US 2007/0110836 A1, Extrusion/Dispensing Systems and Methods.