# US 8,570,683 B2 · Low permeability material for a side shield in a perpendicular magnetic head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,683 B2 - Document ID: US8570683B2 - Status: Granted - Kind: B2 - Application number: 13/168,083 - Filed: 2011-06-24 - Published: 2012-12-27 - Granted: 2013-10-29 - Earliest claimed: 2011-06-24 - Assignees: HGST Netherlands B.V. - Applicants: Yusuke Takahashi; Hiromi Shiina; Kazue Kudo; Yohji Maruyama; Kaori Suzuki - Inventors: Yusuke Takahashi; Hiromi Shiina; Kazue Kudo; Yohji Maruyama; Kaori Suzuki - Web page: https://patentgrep.com/patent/US8570683B2 ## CPC - G11B 5/3116: {Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence)} - G11B 5/1278: {specially adapted for magnetisations perpendicular to the surface of the record carrier} - Y10T 428/1164: with protective film - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract In one embodiment, a perpendicular magnetic head includes a main magnetic pole, a side shield disposed on both sides of the main magnetic pole in a track width direction, the side shield including a material having a saturation magnetic flux density of no greater than about 1.0 T, and a trailing shield disposed on a trailing side of the main magnetic pole, wherein the trailing shield and the side shield are physically separated from one another. In another embodiment, the side shield includes a first magnetic film, and the trailing shield includes a second magnetic film, wherein a magnetic permeability of the first magnetic film is lower than a magnetic permeability of the second magnetic film. ## Claims ### Claim 1 A perpendicular magnetic head, comprising: a main magnetic pole; a side shield disposed on both sides of the main magnetic pole in a track width direction, the side shield comprising a material having a saturation magnetic flux density of less than 1.0 T, wherein the material of the side shield comprises nickel (Ni) and iron (Fe); and a trailing shield disposed on a trailing side of the main magnetic pole, wherein the trailing shield and the side shield are physically separated from one another, and wherein the side shield does not generate perpendicular anisotropy. ### Claim 2 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein at least a portion of the side shield comprises a single layer or multilayer alloy film of nickel (Ni) in a range from Ni100 wt % to Ni84Fe16 wt %. ### Claim 3 (depends on 2) The perpendicular magnetic head as recited in claim 2, wherein the alloy film of nickel comprises an element other than nickel (Ni) and iron (Fe). ### Claim 4 (depends on 3) The perpendicular magnetic head as recited in claim 3, wherein the element other than nickel (Ni) and iron (Fe) comprises at least one of: chromium (Cr), molybdenum (Mo), and sulfur (S). ### Claim 5 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield comprises a side shield material, wherein each 1 μm thick section of a magnetic film of the side shield material has a magnetic permeability of no greater than about 1000. ### Claim 6 (depends on 1) A magnetic data storage system, comprising: at least one magnetic head as recited in claim 1; a magnetic disk medium; a drive mechanism for passing the magnetic disk medium over the at least one magnetic head; and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head. ### Claim 7 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the material of the side shield having the saturation magnetic flux density of less than 1.0 T is a first magnetic film, wherein the trailing shield comprises a second magnetic film, and wherein a magnetic permeability of the first magnetic film is lower than a magnetic permeability of the second magnetic film. ### Claim 8 (depends on 7) The perpendicular magnetic head as recited in claim 7, wherein the trailing shield and the side shield are physically separated from one another. ### Claim 9 (depends on 7) The perpendicular magnetic head as recited in claim 7, wherein at least a portion of the first magnetic film comprises a single layer or multilayer alloy film of nickel (Ni) in a range from Ni100 wt % to Ni84Fe16 wt %. ### Claim 10 (depends on 7) A magnetic data storage system, comprising: at least one magnetic head as recited in claim 7; a magnetic disk medium; a drive mechanism for passing the magnetic disk medium over the at least one magnetic head; and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head. ### Claim 11 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield is in direct physical contact with the trailing shield except in a region above the main pole. ### Claim 12 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the saturation magnetic flux density of the side shields is less than 0.9 T. ### Claim 13 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the saturation magnetic flux density of the side shields is less than 0.8 T. ### Claim 14 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the saturation magnetic flux density of the side shields is less than 0.7 T. ### Claim 15 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield comprises a single layer or multilayer alloy film, the side shield having a nickel (Ni) content in a range from Ni100 wt % to Ni90 wt %. ### Claim 16 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield is a multilayer film comprising Ni and Fe, where the Ni concentration in the entire side shield is greater than 87 wt % Ni. ### Claim 17 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield is a multilayer film comprising layers of Ni and layers of NiFe. ### Claim 18 (depends on 17) The perpendicular magnetic head as recited in claim 17, wherein the Ni concentration in the side shield is at least 90 wt % Ni. ### Claim 19 (depends on 17) The perpendicular magnetic head as recited in claim 17, wherein at least a portion of the side shield comprises a multilayer alloy film of nickel (Ni), iron (Fe), and at least one additional element, the at least one additional element being selected from a group consisting of: chromium (Cr), molybdenum (Mo), and sulfur (S), wherein a Ni concentration in the entire side shield is at least 84 wt % Ni, and wherein at least two layers of the multilayer alloy film have different concentrations of Ni. ### Claim 20 (depends on 1) The perpendicular magnetic head as recited in claim 1, wherein the side shield has a region of multiple layers and a region of a single layer, wherein the single layer is thicker than two adjacent ones of the multiple layers.