Browse Prior Art Database

Passivated Chrome Etch

IP.com Disclosure Number: IPCOM000077578D
Original Publication Date: 1972-Aug-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Gardiner, TR: AUTHOR

Abstract

In a plasma display panel fabrication, conductors are deposited on glass substrates and then insulated from direct contact with the gas by a deposited glass dielectric. While it is desirable to use copper conductors, copper does not adhere to glass so that an under layer of chrome is utilized. An upper layer of chrome is utilized over the copper to prevent the copper from being attacked by the glass frit during the panel fabrication, while the upper chrome layer is oxidized to increase the resistance of the chrome film against chemical attack. A method of eliminating the over layer of chromium on the output edges of the panel during further processing, to expose the copper conductors during further processing requires a chrome etchant.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 81% of the total text.

Page 1 of 2

Passivated Chrome Etch

In a plasma display panel fabrication, conductors are deposited on glass substrates and then insulated from direct contact with the gas by a deposited glass dielectric. While it is desirable to use copper conductors, copper does not adhere to glass so that an under layer of chrome is utilized. An upper layer of chrome is utilized over the copper to prevent the copper from being attacked by the glass frit during the panel fabrication, while the upper chrome layer is oxidized to increase the resistance of the chrome film against chemical attack. A method of eliminating the over layer of chromium on the output edges of the panel during further processing, to expose the copper conductors during further processing requires a chrome etchant. Because of its chemical inertness, conventional certain chrome etchants will not etch the chrome oxide film, while others etch the film at a substantially reduced rate. A method of etching the chrome layer film utilizing a reverse form of electroplating operates as follows.

A voltage source 1 is connected through a voltmeter 3 and ammeter 5 to a stainless steel cathode 7, which is immersed in a solution of 6-molar sodium hydroxide 11 in a container 13. The part to be etched is utilized as a cathode 9 and thus also immersed in the solution and connected to the opposite terminal of power supply 1, to complete the normal electroplating system. Utilizing the stainless steel cathode 7, a two volt potential is suff...