Method of forming conductors at low temperatures using metallic nanocrystals and product
AssigneeThe Regents of the University of California
InventorsVivek Subramanian, Daniel Huang, Steven Volkman, Frank Liao
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Abstract
Metallic nanoparticles are provided which can be used in forming metallic film conductors at reduced temperatures compatible with plastic carriers for the film conductors. This is realized by using a lower molecular weight organic encapsulant of the nanoparticle and thereby reducing the temperature at which the organic encapsulant evaporates. Further, the sintering or melting temperature of the metallic nanoparticle is reduced by using a lower sized nanoparticle, thereby increasing the particle surface area relative to the particle volume and thus reducing the required heat and melting temperature of the particle.
Claims32
A method of forming an electrical conductor pattern from metallic nanoparticles at temperatures below the melting point of plastic comprising the steps of:
- a) depositing a composition comprising organic molecule encapsulated metallic nanoparticles and a solvent in a predetermined pattern onto a substrate;
- b) evaporating said solvent;
- c) annealing said encapsulated metallic nanoparticles to evaporate said organic molecules, and
- d) sintering or melting said metallic nanoparticles to form said electrical conductor pattern;
- wherein said organic molecule has a molecular weight that permits step (c) to be conducted at a temperature below the melting point of plastic at atmospheric pressure.
A method of forming an electrical conductor pattern from metallic nanoparticles at temperatures below the melting point of plastic comprising the steps of:
- a) depositing a composition comprising organic molecule encapsulated metallic nanoparticles and a solvent in a predetermined pattern onto a substrate;
- b) evaporating said solvent;
- c) annealing said encapsulated metallic nanoparticles to evaporate said organic molecules, and
- d) sintering or melting said metallic nanoparticles to form said electrical conductor pattern;
- wherein said metallic nanoparticles have a particle average maximum dimension that permits step (d) to be conducted at a temperature below the melting point of plastic at atmospheric pressure.
A metallic nanoparticle composition compatible for use in printing low resistance conductors on a plastic base comprising organic molecule encapsulated metallic nanoparticles wherein said organic molecule has a molecular weight that permits evaporated of said organic molecules after deposition of said composition onto a substrate at a temperature below the melting point of plastic at atmospheric pressure.
A metallic nanoparticle composition compatible for use in printing low resistance conductors on a plastic base comprising organic molecule encapsulated metallic nanoparticles wherein said metallic nanoparticles have a particle average maximum dimension that permit sintering of said metallic nanoparticles after deposition of said composition onto a substrate at a temperature below the melting point of plastic at atmospheric pressure.
A method for forming copper nanoparticles comprising the speps of (a) dissolving copper chloride dihydrate in tetrahydrofuran to form a solution;
- (b) adding alkylamine to the solution from step (a);
- (c) adding sodium borohydride to the product of step (b);
- (d) separating the ethanol-insoluble solids from the product of step (c), said solids comprising copper nanoparticles.
Dependencies are inferred from the claim text.