The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 1993
Filed:
Jan. 22, 1991
Kazuhiro Okaniwa, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A process for fabricating an electron emitting vacuum type device having a tipped electron emitter supported on a substrate and disposed in a vacuum for emitting electrons. The process utilizes a substrate having opposed substantially planar front and rear surfaces. The front surface, carrying a series of conical depressions, is plated with a metallic layer of electron emitting material which lines the apertures to form metallic structures having tips buried in the substrate. A first material removal process, comprising grinding, is performed on the rear of the substrate to remove the bulk of the substrate but leaving the tips protected within the substrate. A second operation comprising a finishing operation is then applied to the rear surface to advance the plane of the rear surface from an as-ground to an as-finished position. The finishing operation employs a wet etching solution, and may employ mechanical friction (free of abrasive particles) to assist the speed of etching and uniformity of the finished surface. The as-finished plane of the surface serves to expose the metallic tips so that they can serve as emitters in a vacuum tube device.