Patents by Inventor Douglas Johnson Werner
Douglas Johnson Werner has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6570743Abstract: The present invention extends the high resistance lead layers of a read head straight back into the head from each of the first and second edges of the read sensor. This lessens the length of each of the high resistance lead layers so that they do not have to be made thicker to satisfy resistance requirements. Accordingly, a lateral width of each high resistance lead portion along the ABS and a thickness thereof are chosen so as to minimize the thickness while yet satisfying the resistance requirements. Further, a method of making the first and second lead layers is provided that minimizes the thickness of the high resistance lead layers. Instead of constructing the high resistance lead layers first, the present method constructs the high resistance lead layers after defining a stripe height of the read sensor so that the lateral expanse of the high resistance lead layers is not altered by ion milling, which ion milling increases the resistance of the high resistance lead layers.Type: GrantFiled: July 14, 2000Date of Patent: May 27, 2003Assignee: International Business Machines CorporationInventors: Glen Adam Garfunkel, Wen-Chien (David) Hsiao, Edward Hinpong Lee, Douglas Johnson Werner
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Patent number: 6504689Abstract: A tunnel junction read head is provided with free and pinned layers which are recessed from the ABS with the free layer being connected to a flux guide which extends the free layer to the ABS for conducting signal fields to the free layer from a rotating magnetic disk. With this arrangement the typical narrow spacing between the free and pinned layers at the ABS is obviated so that upon lapping of the read head during its construction, conductive material will not be smeared between these layers so as to cause shorting therebetween.Type: GrantFiled: July 12, 2000Date of Patent: January 7, 2003Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Douglas Johnson Werner
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Patent number: 6430011Abstract: The present invention extends the high resistance lead layers of a read head straight back into the head from each of the first and second edges of the read sensor. This lessens the length of each of the high resistance lead layers so that they do not have to be made thicker to satisfy resistance requirements. Accordingly, a lateral width of each high resistance lead portion along the ABS and a thickness thereof are chosen so as to minimize the thickness while yet satisfying the resistance requirements. Further, a method of making the first and second lead layers is provided that minimizes the thickness of the high resistance lead layers. Instead of constructing the high resistance lead layers first, the present method constructs the high resistance lead layers last so that the high resistance lead layers are not altered by subsequent processing steps.Type: GrantFiled: April 21, 2000Date of Patent: August 6, 2002Assignee: International Business Machines CorporationInventors: Glen Adam Garfunkel, Wen Chien David Hsiao, Edward Hinpong Lee, Douglas Johnson Werner
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Publication number: 20020101690Abstract: The hard disk drive of the present invention includes a magnetic head wherein the read head portions have gap insulation layers between the magnetic shields. The gap insulation layers are made up of multilayered laminations of an oxide or nitride of a metal such as aluminum, silicon, chromium, and tantalum. A preferred embodiment of the present invention includes laminated G1 and G2 gap insulation layers having 5-10 laminations, and having a total thickness of approximately 50 Å to 500 Å.Type: ApplicationFiled: January 29, 2001Publication date: August 1, 2002Inventors: Hardayal Singh Gill, Douglas Johnson Werner
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Patent number: 6219212Abstract: A magnetic tunnel junction (MTJ) device for use as a magnetic field sensor in a magnetic disk drive or as a memory cell in a magnetic random access (MRAM) array has an antiferromagnetic (AFM) layer formed of electrically insulating antiferromagnetic material. The magnetic tunnel junction in the sensor is formed on a first shield, which also serves as an electrical lead, and is made up of a stack of layers forming an MTJ sensor stripe. The layers in the stack are an AFM layer, a pinned ferromagnetic layer exchange biased with the AFM layer so that its magnetic moment cannot rotate in the presence of an applied magnetic field, a free ferromagnetic layer whose magnetic moment is free to rotate in the presence of an applied magnetic field, and an insulating tunnel barrier layer disposed between the pinned layer and the free layer. The MTJ sensor stripe is generally rectangularly shaped with parallel side edges and a back edge and a front edge at the air bearing surface (ABS).Type: GrantFiled: September 8, 1998Date of Patent: April 17, 2001Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Douglas Johnson Werner
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Patent number: 6176005Abstract: The present invention extends the high resistance lead layers of a read head straight back into the head from each of the first and second edges of the read sensor. This lessens the length of each of the high resistance lead layers so that they do not have to be made thicker to satisfy resistance requirements. Accordingly, a lateral width of each high resistance lead portion along the ABS and a thickness thereof are chosen so as to minimize the thickness while yet satisfying the resistance requirements. Further, a method of making the first and second lead layers is provided that minimizes the thickness of the high resistance lead layers. Instead of constructing the high resistance lead layers first, the present method constructs the high resistance lead layers after defining a stripe height of the read sensor so that the lateral expanse of the high resistance lead layers is not altered by ion milling, which ion milling increases the resistance of the high resistance lead layers.Type: GrantFiled: December 15, 1998Date of Patent: January 23, 2001Assignee: International Business Machines CorporationInventors: Glen Adam Garfunkel, Wen-Chien David Hsiao, Edward Hinpong Lee, Douglas Johnson Werner
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Patent number: 6085406Abstract: The high resistance lead layers of a read head extend straight back into the head from each of the first and second edges of the read sensor. This lessens the length of each of the high resistance lead layers so that they do not have to be made thicker to satisfy resistance requirements. Accordingly, a lateral width of each high resistance lead portion along the ABS and a thickness thereof are chosen so as to minimize the thickness while yet satisfying the resistance requirements. Further, a method of making the first and second lead layers is provided that minimizes the thickness of the high resistance lead layers. Instead of constructing the high resistance lead layers first, the present method constructs the high resistance lead layers last so that the high resistance lead layers are not altered by subsequent processing steps.Type: GrantFiled: October 21, 1998Date of Patent: July 11, 2000Assignee: International Business Machines CorporationInventors: Glen Adam Garfunkel, Wen Chien (David) Hsiao, Edward Hinpong Lee, Douglas Johnson Werner
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Patent number: 6029339Abstract: An inductive write head has a pole tip region between an air bearing surface (ABS) and a flare point, and a yoke region located between the flare point and a back gap. The write head includes first and second pole piece layers, wherein the second pole piece layer has first and second components. The first component extends from an ABS end, which is located at the ABS, to a recessed end which is located in the yoke region. The second component extends from a recessed end, which is spaced from the ABS, to the back gap. The second component interfaces with the first component in a stitched region so that the first component defines a pole tip in the pole tip region and the second component defines a yoke in the yoke region. A first insulation layer extends from a recessed end, which is spaced from the ABS, into the yoke region. The recessed end of the first insulation layer defines a zero throat height. The first component is sandwiched between the first insulation layer and the second component.Type: GrantFiled: March 4, 1998Date of Patent: February 29, 2000Assignee: International Business Machines CorporationInventors: Thomas Young Chang, Mohamad Towfik Krounbi, Edward Hinpong Lee, Douglas Johnson Werner
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Patent number: 5894385Abstract: An orthogonal magnetoresistive (MR) read sensor is provided having an MR sensing element which is perpendicular to an air bearing surface (ABS) and has an easy axis which is parallel to the ABS. The MR sensor further has top and bottom flux guides in series with the bottom and the top portion of the MR sensing element, respectively The bottom flux guide extends perpendicular from the ABS. Bottom and top leads are connected to the bottom and top flux guides, respectively, in a spaced-apart relationship for conducting a sense current through the MR sensing element. The MR sensing element and the bottom lead are electrically insulated from each other by an insulating layer which is placed between the sensing element and the bottom lead. Electrically insulating the sensing element from the bottom lead makes the sensing efficiency of the sensing element independent of the size of the bottom lead thus improving the performance and manufacturability of the orthogonal MR sensor.Type: GrantFiled: June 24, 1997Date of Patent: April 13, 1999Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Douglas Johnson Werner
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Patent number: 5828530Abstract: An orthogonal spin valve read head is provided wherein a spin valve sensor is asymmetrically located between first and second shield layers so that image currents in the first and second shield layers produce a resultant image field which partially or completely counterbalances a stiffening field from antiferromagnetic, pinned and spacer layers in the MR sensor when sense current is conducted therethrough. Accordingly, the spin valve sensor may be located a greater distance from the second shield layer by providing a mid-gap layer between the spin valve sensor and a second gap layer. In one example, the total thickness of the mid-gap and second gap layer is four times as thick as the first gap layer which results in the image fields from the first and second shield layers completely counterbalancing the field from the antiferromagnetic, pinned and spacer layers due to the sense current.Type: GrantFiled: May 16, 1997Date of Patent: October 27, 1998Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Bruce A. Gurney, Joseph Francis Smyth, Virgil Simon Speriosu, Douglas Johnson Werner
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Patent number: 5805391Abstract: An inductive write head has a pole tip region between an air bearing surface (ABS) and a flare point, and a yoke region located between the flare point and a back gap. The write head includes first and second pole piece layers, wherein the second pole piece layer has first and second components. The first component extends from an ABS end, which is located at the ABS, to a recessed end which is located in the yoke region. The second component extends from a recessed end, which is spaced from the ABS, to the back gap. The second component interfaces with the first component in a stitched region so that the first component defines a pole tip in the pole tip region and the second component defines a yoke in the yoke region. A first insulation layer extends from a recessed end, which is spaced from the ABS, into the yoke region. The recessed end of the first insulation layer defines a zero throat height. The first component is sandwiched between the first insulation layer and the second component.Type: GrantFiled: October 28, 1996Date of Patent: September 8, 1998Assignee: International Business Machines CorporationInventors: Thomas Young Chang, Mohamad Towfik Krounbi, Edward Hinpong Lee, Douglas Johnson Werner
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Patent number: 5761013Abstract: Disclosed is a planarizing layer for use in an MR read/inductive write head combination, and a method for constructing the same. In the preferred embodiment, a planarizing layer comprising a plurality of planar sections of conductive material is formed in the plane of the lower pole piece of an inductive head. The planar sections, in cooperation with the lower pole piece, provide a substantially planar surface on which to form the inductive coil. Two of the planar sections are electrically coupled to respective MR leads, and include protrusions extending from the perimeter of the inductive coil to enable electrical access by a pair of read terminal pads. A third planar section is electrically coupled to the inner coil tap of the inductive coil, and includes a protrusion extending from the perimeter of the inductive coil to enable electrical access by a write terminal pad.Type: GrantFiled: June 7, 1995Date of Patent: June 2, 1998Assignee: International Business Machines CorporationInventors: Hin Pong Edward Lee, Douglas Johnson Werner
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Patent number: 5696656Abstract: An orthogonal spin valve read head is provided wherein a spin valve sensor is asymmetrically located between first and second shield layers so that image currents in the first and second shield layers produce a resultant image field which partially or completely counterbalances a stiffening field from antiferromagnetic, pinned and spacer layers in the MR sensor when sense current is conducted therethrough. Accordingly, the spin valve sensor may be located a greater distance from the second shield layer by providing a mid-gap layer between the spin valve sensor and a second gap layer. In one example, the total thickness of the mid-gap and second gap layer is four times as thick as the first gap layer which results in the image fields from the first and second shield layers completely counterbalancing the field from the antiferromagnetic, pinned and spacer layers due to the sense current.Type: GrantFiled: September 6, 1996Date of Patent: December 9, 1997Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Bruce A. Gurney, Joseph Francis Smyth, Virgil Simon Speriosu, Douglas Johnson Werner
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Patent number: 5653013Abstract: A method of making a thin film orthogonal MR head is provided which includes a single MR stripe, a first lead layer which has first and second ends and a second lead layer which has first and second ends, the first end of the first lead layer being connected to the bottom portion of the MR stripe and the first end of the second lead layer being connected to a top portion of the MR stripe. First and second terminals are provided, the second end of the first layer being connected to the first terminal and the second end of the second lead layer being connected to the second terminal. The second lead layer extends across the MR stripe between the top and bottom portions of the MR stripe so as to induce a magnetic bias field into the MR stripe when a sense current is conducted through the MR stripe via the first and second terminals. Only the first and second terminals are employed for providing sense current for the MR stripe and transverse biasing of the MR stripe.Type: GrantFiled: June 7, 1995Date of Patent: August 5, 1997Assignee: International Business Machines CorporationInventors: Hardayal Singh Gill, Douglas Johnson Werner