Title :
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
fDate :
12/1/1990 12:00:00 AM
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;
Journal_Title :
Electron Devices, IEEE Transactions on
