Browse Prior Art Database

Method of Sealing Gas Panels

IP.com Disclosure Number: IPCOM000081855D
Original Publication Date: 1974-Aug-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Foster, BJ: AUTHOR [+2]

Abstract

In the fabrication of a gas-discharge display panel, it is necessary to seal together two glass substrates containing electrodes and dielectric overlays. In order to prevent degradation of the overlay dielectric, it is desirable to seal the assembly at low temperatures. This maximum temperature, in turn, imposes limitations on the properties of the seal glasses. For example, even if the glass is to be sealed below 480 degrees C, the best available glass tends to have too high a thermal expansion, which results in tensile-stress-associated fatigue problems in the field.

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Method of Sealing Gas Panels

In the fabrication of a gas-discharge display panel, it is necessary to seal together two glass substrates containing electrodes and dielectric overlays. In order to prevent degradation of the overlay dielectric, it is desirable to seal the assembly at low temperatures. This maximum temperature, in turn, imposes limitations on the properties of the seal glasses. For example, even if the glass is to be sealed below 480 degrees C, the best available glass tends to have too high a thermal expansion, which results in tensile-stress-associated fatigue problems in the field.

The mismatch and associated fatigue problems can be overcome by selecting two glasses for the seal, one of lower thermal expansion than the other. Referring to the figure, the primary seal 10 (inner) is made of high expansion, low viscosity glass while the secondary seal (outer) 11 is composed of compatible seal glass, which by itself cannot be used for the entire seal because of its high viscosity. The outer seal 11, being almost stress-free, will not crack, and since the static fatigue is one of stress-dependence, the primary seal 10 is protected.

Glasses suitable for inner and outer seals are shown below in two columns. Inner or Primary Outer or Secondary Seal 10 Seal 11 Glass Ex #1 Ex #2 Ex #1 Ex #2 PbO 71.0 70.0 66.0 60.6 B(2)O(3)11.5 14.2 14.0 16.0 ZnO 10.5 11.0 10.5
13.0 SiO(2) 3.0 3.0 2.0 2.4 Al(2)O(3)-- 0.8 3.5 2.0 BaO 1.5 1.0 -- -- CuO 2.5 -- 2.5
3.0 Bi(2)O(3)...