Browse Prior Art Database

Double Resist Layer Shadow Masking

IP.com Disclosure Number: IPCOM000085848D
Original Publication Date: 1976-Jun-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 33K

Publishing Venue

IBM

Related People

Gardner, T: AUTHOR [+2]

Abstract

In conventional fabrication of gaseous discharge display devices, conductor arrays are formed on glass plates, overcoated with a layer of glass dielectric and the plates sealed with specified parameters of gas mixture and pressure. Actuation of selected line pairs by appropriate drive signals then provides a display at the coordinate line intersections.

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Double Resist Layer Shadow Masking

In conventional fabrication of gaseous discharge display devices, conductor arrays are formed on glass plates, overcoated with a layer of glass dielectric and the plates sealed with specified parameters of gas mixture and pressure. Actuation of selected line pairs by appropriate drive signals then provides a display at the coordinate line intersections.

One of the problems in this fabrication process relates to forming the conductor arrays on the glass plates, particularly on panels of high resolution. A thin-film technique utilizes an additive process in which a single resist layer is etched and the conductor metal, chrome-copper-chrome for example, evaporated onto the etched plate. This method limits the thickness of the conductor layer and tends to produce jagged edges due to fracturing at the resist edge. A method to deposit thicker films without edge fracture by eliminating the etch operation described above is as follows.

Referring to the drawings, Fig. 1 illustrates a glass substrate 11 to which a continuous layer of positive photoresist 13 thicker than the metal to be deposited is applied to the substrate 11. The resist 13 is dried and exposed to ultraviolet light. A second continuous layer 15 of positive photoresist is then applied, oven dried and exposed through a mask to ultraviolet light.

Upon developing the masked image, a pattern duplicating the mask is produced in the top layer 15 as shown in Fig. 2. Further developing opens up a cavity 17 in the previously exposed bottom layer 13, which allows the top layer 15 to slightly overhang the bottom layer of resist in the masked areas. This assembly is then placed in a vacuum system for evaporation.

As the chrome-copper-chrome layers are produced in sequence, the evaporated metal passes through the...