Browse Prior Art Database

Level Control for Continuous Electron Beam Sources

IP.com Disclosure Number: IPCOM000090033D
Original Publication Date: 1969-Jan-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Menz, W: AUTHOR

Abstract

In continuous electron beam vapor deposition sources in which the top of a source rod is vaporized, it is important to keep the molten top of the source rod a constant distance from substrate 10 on which deposition of film 11 is being made. Thermocouples can be used to control the level of this molten liquid based on differences in the amount of heat radiated to them. Source rod 12 has molten liquid surface 14 produced by electron beam 16 from electron gun 17. Heat from surface 14 passes through shield 18 to first and second thermocouples 20 and 22. The latter are positioned so that the heat radiated to them is equal when surface 14 is at the desired distance from substrate 11. When surface 14 is lower than its desired position, thermocouple 20 receives more radiated heat than thermocouple 22.

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 99% of the total text.

Page 1 of 2

Level Control for Continuous Electron Beam Sources

In continuous electron beam vapor deposition sources in which the top of a source rod is vaporized, it is important to keep the molten top of the source rod a constant distance from substrate 10 on which deposition of film 11 is being made. Thermocouples can be used to control the level of this molten liquid based on differences in the amount of heat radiated to them. Source rod 12 has molten liquid surface 14 produced by electron beam 16 from electron gun 17. Heat from surface 14 passes through shield 18 to first and second thermocouples 20 and 22. The latter are positioned so that the heat radiated to them is equal when surface 14 is at the desired distance from substrate 11. When surface 14 is lower than its desired position, thermocouple 20 receives more radiated heat than thermocouple 22. This produces an electrical output of a given polarity to amplifier 24. This provides an output current to drive servomotor 26 connected to gears 28 to raise rod 12. When such rod is raised so that surface 14 is at its desired position, no output current is supplied to servomotor 26. Conversely, if surface 14 is above its desired location, thermocouple 22 receives more radiated heat than thermocouple 20. This gives a current of opposite polarity which is amplified to drive servomotor 26 in the opposite direction lowering rod 12 until surface 14 is in the desired position.

1

Page 2 of 2

2

[This page contains 1 picture or oth...