Browse Prior Art Database

Magnetic Storage Device

IP.com Disclosure Number: IPCOM000094866D
Original Publication Date: 1965-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Ravi, CG: AUTHOR

Abstract

In this magnetic thin-film storage device, a biasing field that increases the range of usable bit drive currents is supplied from a continuous magnetic keeper film superimposed over the magnetic storage medium.

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Magnetic Storage Device

In this magnetic thin-film storage device, a biasing field that increases the range of usable bit drive currents is supplied from a continuous magnetic keeper film superimposed over the magnetic storage medium.

The upper drawing shows the device and its associated drive lines in section. The device includes metallic substrate 2 which serves both as the mechanical support for the device and as the return path for the drive lines. Magnetic film 4 is deposited on substrate 2. The easy axis of magnetization is transverse to the plane of the drawing. Bit sense lines 8 on polymeric backing 6 are positioned about the surface of film 4 with the direction of current flow being transverse to the easy axis of magnetization. Glass film 10 encapsulates lines 8. Word lines 12 are disposed about the surface of encapsulating glass 10 with the direction of current flow being parallel to the direction of easy axis of magnetization. A second glass film 11 is disposed about lines 12. Keeper 14 is then vacuum- deposited to complete the device.

During the vacuum deposition of keeper 14, which is preferably Mo- Permalloy or a similar material, a magnetic field is applied. This induces a preferred magnetic direction in the keeper. The field is oriented to skew the storage film a few degrees from the intended easy axis of magnetization. Owing to the high remanence in the keeper material, the reference axis from which the magnetic dipoles rotate now becomes the ske...