Browse Prior Art Database

Work Member Positioning

IP.com Disclosure Number: IPCOM000092074D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Piepenbring, FJ: AUTHOR

Abstract

In electron beam apparatus for welding, drilling, etc., the detection of secondary electrons, emitted by a metal mark hit by an electron beam, is used for positioning the work member. Such method, in addition to necessitating a suction field, has the disadvantage that accurate positioning is rendered difficult by the broad spectrum of secondary electrons.

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Work Member Positioning

In electron beam apparatus for welding, drilling, etc., the detection of secondary electrons, emitted by a metal mark hit by an electron beam, is used for positioning the work member. Such method, in addition to necessitating a suction field, has the disadvantage that accurate positioning is rendered difficult by the broad spectrum of secondary electrons.

For position detection, this method utilizes a mark in materials such as aluminum and silver which, when hit by the electron beam, emit a solid-body plasma radiation. At electron energies of 80-150 kev and using, for example, a silver mark emitting a 3300 angstroms wavelength, photomultiplier.

Alternatively, a metal mark can be used which, when hit by the electron beam, emits a characteristic X-ray radiation detectable by a scintillator. Both types of marks have the advantage that the emitted radiation has a narrow, accurately detectable spectrum.

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