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Crucible for Electrobeam Gun Evaporation

IP.com Disclosure Number: IPCOM000073408D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Renken, HH: AUTHOR

Abstract

This crucible, consisting of an insulating cup 10, has a conductive path through the insulating cup 10 in order to remove electron-beam current supplied to the crucible by electron beam 12 during evaporation. An aperture 14 is machined or cast in the bottom of the insulating cup 10, which is typically boron nitride or a high temperature ceramic. A conductive plug 16 of carbon or a high temperature metal, such as tungsten or tantalum, is inserted in the aperture 14. This conductive plug 16 is sufficient to carry the electron-beam current, which is usually less than about 1 amp, without a significant voltage drop across the plug to copper cooling block 18. Under these conditions, no significant chemical reaction occurs between an aluminum melt 20 and the conductive plug 16, resulting in increased purity of evaporant stream 22.

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Crucible for Electrobeam Gun Evaporation

This crucible, consisting of an insulating cup 10, has a conductive path through the insulating cup 10 in order to remove electron-beam current supplied to the crucible by electron beam 12 during evaporation. An aperture 14 is machined or cast in the bottom of the insulating cup 10, which is typically boron nitride or a high temperature ceramic. A conductive plug 16 of carbon or a high temperature metal, such as tungsten or tantalum, is inserted in the aperture 14. This conductive plug 16 is sufficient to carry the electron-beam current, which is usually less than about 1 amp, without a significant voltage drop across the plug to copper cooling block 18. Under these conditions, no significant chemical reaction occurs between an aluminum melt 20 and the conductive plug 16, resulting in increased purity of evaporant stream 22.

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