Outgassing of CRT shadow mask coatings caused by electron bombardment

Author

Koitabashi, Masayasu ; Kimura, Hiroshi ; Shimoji, Sadao ; Yamamoto, Morio

Author_Institution

Mitsubishi Electr. Corp., Hyogo, Japan

Volume

37

Issue

12

fYear

1990

fDate

12/1/1990 12:00:00 AM

Firstpage

2644

Lastpage

2651

Abstract

A UHV system with a quadrupole mass spectrometer in a nude condition was used to investigate the outgassing characteristics of the coatings of CRT shadow mask during electron bombardment. The coatings of Bi₂O₃, WO₃ and Fe₃O₄ were electron bombarded with energies from 15 to 30 keV and currents up to 100 μA. The Bi₂O₃ coating released a larger amount of gas than WO₃ and Fe₃O ₄, but its amount decreased to the same extent as that of the others with heat treatment at temperatures higher than 450°C. The main components of released gas were CO, CO₂, CH₄, and H₂, and the release of O₂ was also observed for the Bi₂O₃ coating without heat treatment. This O₂ release was found to be caused by the decomposition of unstable carbonate, which was formed by the reaction of Bi₂O ₃ with CO₂ in the presence of moisture during the preparation of the coating. These outgassing behaviors are discussed quantitatively from the viewpoint of preventing oxidizing gas release

Keywords

cathode-ray tubes; desorption; electron beam effects; mass spectroscopic chemical analysis; protective coatings; 100 muA; 15 to 30 keV; Bi₂O₃; CO; CO₂; CRT shadow mask coatings; Fe₃O₄; H₂; O₂; UHV system; WO₃; carbonate decomposition; electron bombardment; heat treatment; methane; outgassing characteristics; oxidizing gas release; quadrupole mass spectrometer; Cathode ray tubes; Coatings; Electrons; Gases; Glass; Heat treatment; Mass spectroscopy; Rough surfaces; Steel; Surface roughness;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.64547

Filename

64547