Read Rite Corporation

Qsecure, Inc.

Edgar M Williams

Peter G Bischoff

Daniel A Nepela

Weidong Li

David Pariseau

Kerry Dennis Brown

Chak M Leung

Erich P Valstyn

Shih-Cheng Cheng

Joyce Thompson

Carroll S Gooden

Shin-ichi Akoh

A magnetic device that includes a magnetic stripe for recording a combination of dynamic and static magnetic data. The magnetic stripe includes at least two regions of material with substantially different coercivities. One region contains static information and the other can be re-written with dynamic information.

Stripline magnetic writing of dynamic magnetic data bits in surrounding regions of static magnetic data bits

A Q-Chip MEMS magnetic device comprises a thin-film electronic circuit for implantation in the Track-2 area of a magnetic stripe on the back of a credit card. The Q-Chip MEMS magnetic device periodically self-generates new sub-sets of magnetic data that are to be read in combination with other magnetic data that is permanently recorded in the surrounding surface of the magnetic stripe. A collocated battery and microcontroller provide operating power and new data for magnetic bit updates. A swipe sensor triggers such updates by sensing electrical contact with a legacy card reader. Several thin-film coils of wire are wound end-to-end around a common, flat, ferrous core. These are driven by the microcontroller. In one instance, such core comprises 'hard' magnetic material with a coercivity of 200-300 Oersteds. Magnetic data written from the corresponding adjacent coils will persist for later readings by a legacy card reader. In another instance, the core comprises 'soft' magnetic material with a coercivity of about one Oersted. A media stripe of &#x201c;hard&#x201d; magnetic film material overlays respective coils to receive magnetic data transfers. Magnetic data written from the corresponding adjacent coils will persist in the overlaying hard media for later readings by a legacy card reader. In a data input mode, the thin-film coils can be used as readers to provide updates and new programming to the microcontroller.

Magnetic data recording device

A thin film magnetic head is fabricated having soft metal layers of 0.25 to 1 micron thickness disposed on each side of the first and second magnetic layers of Permalloy forming the magnetic yoke. The soft layers are formed between the ceramic substrate and the first Permalloy layer, between the first Permalloy layer and the insulation surrounding the electrical coil of the head, between the insulation and the second Permalloy layer, and between the second Permalloy layer and the insulating overcoat of the head. The soft metal has a coefficient of thermal expansion between that of the Permalloy and that of the ceramic substrate and insulation materials. In this way, stress buffers are provided to minimize the mismatch and thermal stress transfer between the Permalloy and the other materials of the adjacent layers, resulting in improved domain stability and a significant reduction in popcorn noise.

Thin film magnetic head with stress relief layering

A tripad air bearing slider useful in a disk drive is designed with two outer pads that extend from two or more tapered sections at the leading edge of the slider towards the trailing edge. The pads are configured and angled so that a desired lift force is obtained that acts in opposition to a force provided by a spring loaded flexure or load beam. The angles that define the shape of the three pads are formed by simple mechanical cutting, using a diamond cutting wheel, for example, or alternatively by ion milling or reactive ion etching.

Tripad air bearing magnetic head slider

A thin film magnetic head is fabricated with a multiplicity of magnetic yokes that interact effectively with an electrical coil. The magnetic P1 and P2 pole sections of the yoke are very narrow and form closely spaced envelopes about the coil. The multiple yokes are inductively linked to the coil so as to provide an increased number of flux interactions for a given length of coil turn. With this magnetic head design, signal output is increased, thermal noise is reduced, and the signal-to-noise ratio is effectively improved.

Thin film magnetic heads with multiple yokes

A thin film magnetic head is fabricated with a yoke structure, including P1 and P2 magnetic layers, having a width in the range of about 5 to 58 microns, preferably about 30 microns. The very narrow width minimizes popcorn noise, improves high frequency response and affords increased head circuit efficiency.

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Palo Alto, CA, United States of America

Edgar M Williams