# US 10,308,828 B2 · Reactively assisted ink for printed electronic circuits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,828 B2 - Document ID: US10308828B2 - Status: Granted - Kind: B2 - Application number: 15/835,012 - Filed: 2017-12-07 - Published: 2018-06-14 - Granted: 2019-06-04 - Earliest claimed: 2016-12-14 - Assignees: The Charles Stark Draper Laboratory, Inc. - Applicants: The Charles Stark Draper Laboratory, Inc. - Inventors: Gregory M. Fritz; Sara Barron - Web page: https://patentgrep.com/patent/US10308828B2 ## CPC - C09D 11/52: Electrically conductive inks - C09D 11/30: Inkjet printing inks - C09D 11/322: Pigment inks - C09D 11/54: Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink - H05K 1/09: Use of materials for the {conductive, e.g. } metallic pattern - H05K 1/092: {Dispersed materials, e.g. conductive pastes or inks} - H05K 3/10: in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern - H05K 3/12: using {thick film techniques, e.g.} printing techniques to apply the conductive material {or similar techniques for applying conductive paste or ink patterns} - H05K 3/125: {by ink-jet printing} - H05K 3/1283: {After-treatment of the printed patterns, e.g. sintering or curing methods} - H10W 20/48: Insulating materials thereof - H10W 70/098: {Applying pastes or inks, e.g. screen printing (H10W70/095 takes precedence)} - H10W 70/666: {Organic materials or pastes} - H05K 2203/1163: Chemical reaction, e.g. heating solder by exothermic reaction - H10W 20/4473: {Conductive organic materials, e.g. conductive adhesives or conductive inks} - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract An ink contains particles containing metal that reacts during sintering to produce an electrically conductive line or area having a diffusivity that is less than the diffusivity of the metal before the reaction. Resulting electronic circuits therefore exhibit longer useful lives, compared to conventionally inkjet printed circuits. ## Claims ### Claim 1 An ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity. ### Claim 2 (depends on 1) An ink according to claim 1, wherein the at least some of the particles that comprise the first metal also comprise the substance. ### Claim 3 (depends on 1) An ink according to claim 1, wherein the at least some of the particles that comprise the first metal are distinct from the at least some of the particles that comprise the sub stance. ### Claim 4 (depends on 1) An ink according to claim 1, wherein the first mass diffusivity comprises a first propensity to electromigrate. ### Claim 5 An ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first diffusivity, and wherein the second diffusivity is less than about 1E-25 cm2/s at 25 °C. ### Claim 6 An ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is at least about 100 times less than the first mass diffusivity. ### Claim 7 (depends on 1) An ink according to claim 1, wherein resistivity of the product is less than about 500 μΩ-cm. ### Claim 8 (depends on 1) An ink according to claim 1, wherein the product remains entirely solid up to at least about 300° C. ### Claim 9 (depends on 1) An ink according to claim 1, wherein: the first metal has a thermal stability; the product has a thermal stability greater than the thermal stability of the first metal; the first metal has an electrical stability; and the product has an electrical stability greater than the electrical stability of the first metal. ### Claim 10 An ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity, and wherein the chemical reaction is exothermic. ### Claim 11 (depends on 1) An ink according to claim 1, wherein the first metal comprises: Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C; and/or an oxide of Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C; and/or a nitride of Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C; and/or a phosphide of Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C. ### Claim 12 (depends on 1) An ink according to claim 1, wherein the product comprises: an intermetallic of Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C; and/or a solid solution of Cu, Al, Ag, Au, Pd, Pt, Si, Ti, Zr, Rh, Ir, Os, Ta, Mg, Ru, Fe, Ni, Co and/or C. ### Claim 13 (depends on 1) An ink according to claim 1, wherein the substance comprises a second metal, different from the first metal. ### Claim 14 (depends on 1) An ink according to claim 1, wherein the substance comprises a non-metal. ### Claim 15 An ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity, wherein the first metal comprises Al; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the substance comprises a second metal, different from the first metal, the second metal comprises Cu, the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity and the product comprises CuAl2. ### Claim 16 A method for making an ink, the method comprising: dispersing a plurality of particles in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a mass diffusivity that is less than the first mass diffusivity. ### Claim 17 An ink kit comprising: a first ink comprising a plurality of first particles dispersed in a first carrier fluid, wherein each first particle of the plurality of first particles comprises a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; and a second ink, separate from the first ink, the second ink comprising a plurality of second particles dispersed in a second carrier fluid, each second particle of the plurality of second particles comprising a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity. ### Claim 18 A method for making an ink kit, the method comprising: providing a first ink by dispersing a plurality of first particles in a first carrier fluid, wherein each first particle of the plurality of first particles comprises a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; and providing a second ink, separate from the first ink, by dispersing a plurality of second particles in a second carrier fluid, each second particle of the plurality of second particles comprising a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity. ### Claim 19 A method for fabricating an electric conductor, the method comprising: applying an ink to a substrate, the ink comprising a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity, wherein the first diffusivity is greater than about 1E-30 cm2/s at 25° C.; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity; and reacting the first metal with the substance, according to the chemical reaction, to produce the product on the substrate. ### Claim 20 A method for fabricating an electric conductor, the method comprising: applying a first ink to a substrate, the first ink comprising a plurality of first particles dispersed in a first carrier fluid, wherein each first particle of the plurality of first particles comprises a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; applying a second ink to the substrate, distinct from the first ink, the second ink comprising a plurality of second particles dispersed in a second carrier fluid, each second particle of the plurality of second particles comprising a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity; and reacting the first metal with the substance, according to the chemical reaction, to produce the product on the substrate. ### Claim 21 A printer for printing an electrically conductive circuit on a substrate, the printer comprising: a reservoir containing ink, the ink comprising: a plurality of particles dispersed in a carrier fluid, wherein: at least some of the particles comprise a first metal having a first mass diffusivity, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C.; and at least some of the particles comprise a substance with which the first metal is chemically reactive to produce a product during a chemical reaction, wherein the product is electrically conductive and has a second mass diffusivity that is less than the first mass diffusivity; an ink jet or nozzle in fluid communication with the reservoir and configured to spray droplets or extrude a line of the ink onto the substrate in a pattern according to an electronic signal, thereby producing deposited ink on the substrate; and an energy source configured to heat the deposited ink sufficiently to initiate the chemical reaction to react the first metal with the substance in the deposited ink, according to the chemical reaction, to produce the product on the substrate. ### Claim 22 (depends on 1) An ink according to claim 1, wherein the first mass diffusivity is greater than about 1E-30 cm2/s at 25° C. ### Claim 23 (depends on 1) An ink according to claim 1, wherein the second mass diffusivity is at least about 100 times less than the first mass diffusivity. ### Claim 24 (depends on 1) An ink according to claim 1, wherein the chemical reaction is exothermic. ### Claim 25 (depends on 13) An ink according to claim 13, wherein the first metal comprises Al, the second metal comprises Cu and the product comprises CuAl2.