GB1411565A - Dielectirc body and discharge panel - Google Patents

Abstract

1411565 Coated dielectric surfaces OWENSILLINOIS INC 17 July 1972 [15 July 1971] 33310/72 Heading B2E [Also in Division H1] A dielectric charge storage surface comprises a substrate, e.g. of soda line silicate glass, coated with a first layer of at least one compound of a group IA element a group IIA element, Al, Si, Ti, Zr or Hf or mixtures thereof, a second layer of at least one compound of a Group IA element, a Group IIA element, Al, Si, Ti, Zr or Hf or mixtures thereof, which is chemically different from the first layer and a third layer of an electron emissive material, the combination of the first and second layer being sufficient to prevent ion migration from the dielectric layer and sufficient to provide a thermally and structurally stable base for the third layer and the second layer being chemically inert relative to the third layer. The thickness of each layer may be at least 100Š, preferably 200- 10000Š. Preferred compounds for the first and second layers are oxides, nitrides, fluorides, borides and carbides. Preferably the third layer is electrically non-conductive and may be lead oxide or magnesium oxide. The first layer may be silica, alumina and zirconium oxide. At least one layer may be CsF or CsI. At least one layer may be in the form of isolated islands of conductive or semiconductive material. In preferred embodiments the first layer is of silica, the second layer is of aluminium oxide and the third layer is lead oxide or the first layer is of silica, the second layer is of zirconium oxide and the third layer is of lead oxide or the first layer is of magnesium oxide, the second layer is of zirconium oxide and the third layer is of lead oxide or the first layer is of silicon nitride, the second layer is of silica and the third layer is of lead oxide or the first layer is of magnesium oxide, the second layer is of aluminium oxide and the third layer is of lead oxide or the first layer is of silica, the second layer is of aluminium oxide and the third layer is of magnesium oxide or the first layer is of silica, the second layer is of zirconium oxide and the third layer is of magnesium oxide or the first layer is of magnesium oxide, the second layer is of zirconium oxide and the third layer is of magnesium oxide or the first layer is of silicon nitride, the second layer is of silica and the third layer is of magnesium oxide. Each of the 3 layers may be applied to the dielectric surface by vapour deposition, chemical vapour deposition, wet spraying on to the surface followed by drying, dry spraying, electron beam evaporation, plasma flame and/or arc spraying and/or deposition and sputtering target techniques.