# US 9,751,797 B2 · Corona ignition device with improved seal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,797 B2 - Document ID: US9751797B2 - Status: Granted - Kind: B2 - Application number: 14/822,073 - Filed: 2015-08-10 - Published: 2016-02-11 - Granted: 2017-09-05 - Earliest claimed: 2014-08-10 - Assignees: Federal-Mogul Ignition Company - Applicants: Federal-Mogul Ignition Company - Inventors: Keith Firstenberg; William J. Walker, Jr.; Patrick J. Durham; James D. Lykowski - Web page: https://patentgrep.com/patent/US9751797B2 ## CPC - C03C 8/18: containing free metals - C03C 27/00: Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing (C03C17/00 takes precedence; layered structures comprising at least one glass sheet B32B17/00; wired glass C03B; joining glass to ceramics C04) - H01B 1/16: the conductive material comprising metals or alloys - H01T 13/34: characterised by the mounting of electrodes in insulation, e.g. by embedding - H01T 19/00: Devices providing for corona discharge (for charging electrographic elements G03G15/02) - H01T 21/00: Apparatus or processes specially adapted for the manufacture or maintenance of spark gaps or sparking plugs - H01T 21/02: of sparking plugs - C03C 2204/00: Glasses, glazes or enamels with special properties - C03C 2205/00: Compositions applicable for the manufacture of vitreous enamels or glazes - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - H01T: SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES (overvoltage protection circuits H02H) ## Abstract An electrically conductive glass seal for providing a hermetic bond between an electrically conductive component and an insulator of a corona igniter is provided. The glass seal is formed by mixing glass frits, binder, expansion agent, and electrically conductive metal particles. The glass frits can include silica (SiO2), boron oxide (B2O3), aluminum oxide (Al2O3), bismuth oxide (Bi2O3), and zinc oxide (ZnO); the binder can include sodium bentonite or magnesium aluminum silicate, polyethylene glycol (PEG), and dextrin; the expansion agent can include lithium carbonate; and the electrically conductive particles can include copper. The finished glass seal includes the glass in a total amount of 50.0 to 85.0 weight (wt. %), and electrically conductive metal particles in an amount of 15.0 to 50.0 wt. %, based on the total weight of the glass seal. ## Claims ### Claim 1 A corona igniter, comprising: an electrically conductive component; an insulator surrounding said electrically conductive component; an electrically conductive glass seal providing a hermetic bond between said electrically conductive component and said insulator; said electrically conductive glass seal including at least one glass in a total amount of 50.0 to 85.0 wt. %, and electrically conductive metal particles in an amount of 15.0 to 50.0 wt. %, based on the total weight of said glass seal; wherein the glass seal includes gas-filled pores in an amount of 25.0 to 75.0 vol. %, based on the total volume of the glass seal; and said glass seal is electrical conductive. ### Claim 2 (depends on 1) The corona igniter of claim 1, wherein said gas-filled pores are present in an amount of 35.0 to 45.0 vol. %, based on the total volume of said glass seal and said gas-filled pores are spaced from one another by said glass and said electrically conductive metal particles. ### Claim 3 (depends on 1) The corona igniter of claim 1, wherein said glass seal has an electrically conductivity ranging from 9×106 S/m to 65×106 S/m. ### Claim 4 (depends on 1) The corona igniter of claim 1, wherein said electrically conductive component includes a central electrode surrounded by said insulator, and a firing tip at an end of said central electrode, said firing tip including a plurality of branches each extending radially outwardly from a center axis. ### Claim 5 (depends on 1) The corona igniter of claim 1, wherein said at least one glass includes silica (SiO2), boron oxide (B2O3), aluminum oxide (Al2O3), bismuth oxide (Bi2O3), and zinc oxide (ZnO); and said electrically conductive particles include copper. ### Claim 6 (depends on 1) The corona igniter of claim 1, wherein said at least one glass includes silica (SiO2) in an amount of 35.0 to 40.0 wt. %, boron oxide (B2O3) in an amount of 20.0 to 28.0 wt. %, aluminum oxide (Al2O3) in an amount of 10.0 to 15.0 wt. %, bismuth oxide (Bi2O3) in an amount of 10.0 to 15.0 wt. %, and zinc oxide (ZnO) in an amount of 3.0 to 5.0 wt. %, based on the total weight of said at least one glass. ### Claim 7 (depends on 6) The corona igniter of claim 6, wherein said at least one glass further include alkali metal oxides in a total amount of 2.0 to 6.0 wt. % and alkaline earth metal oxides in a total amount of 3.0 to 7.0 wt. %, based on the total weight of said at least one glass. ### Claim 8 (depends on 1) The corona igniter of claim 1, wherein said gas-filled pores are present in an amount of 35.0 to 45.0 vol. %, based on the total volume of said glass seal. ### Claim 9 (depends on 1) The corona igniter of claim 1, wherein said gas-filled pores are spaced from one another by said glass and said electrically conductive metal particles. ### Claim 10 (depends on 1) The corona igniter of claim 1, wherein said electrically conductive metal particles include copper. ### Claim 11 (depends on 10) The corona igniter of claim 10, wherein said electrically conductive metal particles include flakes of the copper and have a particle size of less than 45 microns. ### Claim 12 (depends on 1) The corona igniter of claim 1, wherein said glass seal has an electrical conductivity above 30×106 S/m.