Method for manufacturing a thin-film EAS and marker
First Claim
1. A method for manufacturing a thin-film magnetic device, including:
- providing a substrate having a surface characterized by first and second axes that are perpendicular to each other;
applying to the surface of the substrate a magnetic field oriented parallel to the first axis;
growing a relatively thin thin-film layer of magnetic material on the substrate in the presence of the magnetic field to a thickness sufficiently thick that the layer exhibits magnetic properties that are substantially independent of surface effects, but sufficiently thin that the easy axis of magnetization of the material is oriented parallel to the second axis.
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Accused Products
Abstract
A method for manufacturing a nonlinear, dual-axis thin-film magnetic device which can be used as an electronic article surveillance system marker. The method includes providing a substrate having a surface characterized by first and second generally perpendicular axes. A magnetic field oriented parallel to the first axis is applied on the surface of the substrate. A first stack of relatively thin thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the substrate. The relatively thin thin-tim layers are grown in the presence of the magnetic field to a thickness sufficiently thick that the layers exhibit magnetic properties that are substantially independent of surface effects, but sufficiently thin that the easy axis of magnetization is oriented parallel to the second axis. A second stack of relatively thick thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the first stack. The relatively thick thin-film layers are grown in the presence of the magnetic field to a thickness sufficiently thick that the easy axis of magnetization is oriented parallel to the first axis.
25 Citations
22 Claims
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1. A method for manufacturing a thin-film magnetic device, including:
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providing a substrate having a surface characterized by first and second axes that are perpendicular to each other; applying to the surface of the substrate a magnetic field oriented parallel to the first axis; growing a relatively thin thin-film layer of magnetic material on the substrate in the presence of the magnetic field to a thickness sufficiently thick that the layer exhibits magnetic properties that are substantially independent of surface effects, but sufficiently thin that the easy axis of magnetization of the material is oriented parallel to the second axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for manufacturing a magnetic marker of the type used in an electronic article surveillance system, including:
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providing a web of flexible substrate having a surface and characterized by first and second axes that are perpendicular to each other; providing a deposition station including sources of magnetic and nonmagnetic materials; driving the web in alternating forward and reverse passes through the deposition station; providing a magnetic field source and applying to the surface of the substrate at the depostition station a magnetic field oriented parallel to the first axis; depositing a second axis aligned thin-film layer of magnetic material on the substrate in the presence of the magnetic field during each of a plurality of second axis aligned stack-forming forward and reverse passes through the deposition station, each second axis aligned layer being deposited to a thickness sufficiently thick that the layer exhibits magnetic properties that are substantially independent of surface effects, yet sufficiently thin that the easy axis of magnetization of the material is oriented parallel to the second axis; depositing a thin-film layer of nonmagnetic material between each second axis aligned layer during each of the plurality of second axis aligned stack-forming forward and reverse passes through the deposition station, to form a second axis aligned stack of relatively thin thin-film layers of magnetic material separated by layers of nonmagnetic material and having an easy axis of magnetization oriented parallel to the second axis; depositing a first axis aligned thin-film layer of magnetic material on the substrate in the presence of the magnetic field during each of a purality of first axis aligned stack-forming forward and reverse passes through the deposition chamber, each first axis aligned layer being deposited to a thickness sufficiently thick that the easy axis of magnetization of the material is oriented parallel to the first axis; depositing a thin-film layer of nonmagnetic material between each first axis aligned layer during each of the plurality of first axis aligned stack-forming forward and reverse passes through the deposition station, to form a first axis aligned stack of relatively thick thin-film layers of magnetic material separated by layers of nonmagnetic material and having an easy axis of magnetization oriented parallel to the first axis; and separating, from the web, a magnetic marker section including the first axis aligned and second axis aligned stacks of magnetic thin-film layers. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A method for manufacturing a thin-film magnetic device, including:
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providing a substrate having a surface characterized by first and second axes that are perpendicular to each other; applying to the surface of the substrate a magnetic field oriented parallel to the first axis; growing a plurality of relatively thin thin-film layers of magnetic material to form a stack of the relatively thin layers; growing each relatively thin layer to a thickness sufficiently thick that the stack exhibits magnetic properties that are substantially independent of surface effects, yet sufficiently thin that the easy axis of magnetization is oriented parallel to the second axis; and growing a thin-film layer of nonmagnetic material between each of the relatively thin thin-film layers of magnetic material of the stack.
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Specification