NovaCentrix, a leader in printed electronics manufacturing technologies were recently granted an U.S. Patent 7,820,097 entitled “Electrical, Plating and Catalytic Uses of Metal Nanomaterial Compositions”. This covers in part the use of flash lamps to sinter metal-based inks and materials on low-temperature substrates such as paper and plastic and includes high-speed and roll-to-roll processing. This process is critical to the advancement of innovative new products in photovoltaics, displays, RFID, sensors, batteries, capacitors, and smart packaging.
“One of the most exciting aspects of this technology is its scalability and economy. Inexpensive flexible substrates can now be used. Furthermore, processing can be performed at hundreds of feet per minute in a roll-to-roll environment,” said Dr. Kurt Schroder, Chief Scientist and lead patent author. “In addition to processing silver, gold, and nickel used in conductive inks, the high speed process can sinter easily-oxidized particles such as copper in an ambient air environment, thus eliminating the need for a reduction furnace or inert atmosphere. This room-temperature process enables truly inexpensive conductive traces for printed electronics.”
The claims are shown below and I have included the full set as they illustrate how the main broad claim 1 has been defined and the dependant claims used to expand on the materials, the substrate and the manner in which the printing process can be accomplished.
1. A method for sintering materials comprising: depositing a material on a substrate, wherein said substrate has a decomposition temperature below 450 degrees Celsius, wherein said material has at least one dimension less than 1 micrometer, wherein said material includes at least one metal; and irradiating said material on said substrate in ambient air by a flash lamp for sintering said material on said substrate, for a duration between one microsecond and one hundred milliseconds such that the conductivity of said material on said substrate increases by at least two-fold.
2. The method of claim 1, wherein said at least one metal is copper.
3. The method of claim 1, wherein said material is included within an ink formulation.
4. The method of claim 1, wherein said substrate comprises a substance selected from the group consisting of PET, polyester, polymers, resins, paper products, organic compounds, laminates, and combinations thereof.
5. The method of claim 1, wherein said depositing includes producing a film or pattern on said substrate from said material included within an ink formulation.
6. The method of claim 1, wherein said depositing further includes printing.
7. The method of claim 6, wherein said printing is selected from the group consisting of screen printing, inkjet printing, gravure, laser printing, xerographic printing, pad printing, painting, dip pen, syringe, airbrush, lithography, flexography and combinations thereof.
8. The method of claim 1, wherein said method further includes moving said substrate when said material is being irradiated by said flash lamp.
9. The method of claim 8, wherein said substrate is being moved continuously.
10. The method of claim 8, wherein said substrate is dispensed from a roll.