Method of manufacturing grid electrodes for electron tubes
AssigneeU.S. Philips Corporation
InventorsBernhard Lersmacher, Horst Seifert, Johannes Wilhelmus Antonius Krol
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Abstract
Method of manufacturing grid electrodes wherein a grid sleeve is produced by depositing pyrolytic graphite on a polished mandril of glassy carbon and provided with apertures by means of the laser beam, then the finished grid is provided, by means of hot gas pyrolysis, with a second layer of highly oriented pyrolytic graphite, and thermally and/or mechanically after-treated at 3000.degree. to 3800.degree. K and 10-500 bar.
Claims8
A method of manufacturing grid electrodes for electron tubes, in which pyrolytic graphite is deposited by thermal decomposition of carbon-containing gases on a mandril having a smooth surface and the resulting molded body is separated from the mandril and provided with grid-like apertures, characterized in that the molded body after the formation of the grid is covered again with a thin layer of pyrolytic graphite and that the steps of deposition on the mandril and the covering again of the molded body having grid-like apertures are carried out at a temperature of the carbon-containing gas that is higher than the temperature of the mandril and of the molded body, respectively.
Dependencies are inferred from the claim text.