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Browse Prior Art Database

MBM Bias Field Structure without Faceplates

IP.com Disclosure Number: IPCOM000052869D
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Bowers, GH: AUTHOR [+3]

Abstract

This article discloses a novel magnetic bubble package which is smaller vertically and less costly than those previously available.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
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MBM Bias Field Structure without Faceplates

This article discloses a novel magnetic bubble package which is smaller vertically and less costly than those previously available.

Fig. 1 shows a magnetic bubble chip 10 mounted on a substrate 11 using the usual bonding techniques. Immediately above the chip 10 a permanent magnet 12 is placed in position. Any material, such as barium ferrite, with an energy level of at least 1.4H would be usable as this magnet. By tilting the magnet at an angle of about 2.15 Degrees a holding field of appropriate strength will be realized in the bubble chip. The orthogonal coils 13 and 14 are now wound around the chip 10 and the magnet 12.

By enclosing the holding magnet 12 and the chip 10 inside the orthogonal coils 12 and 13 the two faceplates and one of the permanent magnets usually found in such packages can be eliminated, resulting in reduced package size and lower cost.

This package also improves temperature tracking between chip and magnet because they are located near one another and are both inside the major heat- producing elements (coils 13 and 14) within the module.

Additionally, in Fig. 2 the permanent magnet geometry in such magnetic bubble packages can be redesigned so that a DC magnetic bias field of sufficient strength and uniformity can be provided in such a package without faceplates. For an air gap of 0.250 inch between two PLASTIF0RM* 1.4H permanent magnets 15 and 16 (of dimension 22 mm by 22 mm by 0.026'') located...