Patents by Inventor Fenglin Liu

Fenglin Liu 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).

  • Patent number: 7382577
    Abstract: A trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The necessary taper is produced by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: June 3, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Po Kang Wang, Fenglin Liu
  • Patent number: 7359150
    Abstract: A trimmed upper pole piece for a magnetic write head is presented, said pole piece having a uniform width above and below a write gap layer and said pole piece being formed on a pedestal of uniform width projecting from a planar surface of a magnetic shield layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the typical alumina write-gap filling material. The present pole piece uses NiCr, NiFeCr or Ru as write gap filling materials because they have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and allow a uniform trimming to occur.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: April 15, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Fenglin Liu
  • Publication number: 20070177301
    Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed by a RIE process using specific gases applied to a shield layer through a masking layer formed of material that has a slower etch rate than the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. The differential in etch rates maintains the opening dimension within the mask and allows the formation of a wedge-shaped trench within the shield layer that separates the layer into two shields. The pole tip is then plated within the trench and, being aligned by the trench, acquires the wedge-shaped cross-section of the trench. An upper shield is then formed above the side shields and pole.
    Type: Application
    Filed: February 2, 2006
    Publication date: August 2, 2007
    Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Jiun-Ting Lee
  • Publication number: 20060012915
    Abstract: A trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The necessary taper is produced by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.
    Type: Application
    Filed: September 16, 2005
    Publication date: January 19, 2006
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Po Wang, Fenglin Liu
  • Patent number: 6960281
    Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The present method produces the necessary taper by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: November 1, 2005
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Po Kang Wang, Fenglin Liu
  • Publication number: 20050168871
    Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a uniform width above and below a write gap layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the alumina write-gap filling material. The present method uses NiCr, NiFeCr or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant.
    Type: Application
    Filed: March 28, 2005
    Publication date: August 4, 2005
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Fenglin Liu
  • Patent number: 6887355
    Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a uniform width above and below a write gap layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the alumina write-gap filling material. The present method uses NiCr, NiFeCr or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: May 3, 2005
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Fenglin Liu
  • Publication number: 20040184190
    Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The present method produces the necessary taper by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.
    Type: Application
    Filed: March 21, 2003
    Publication date: September 23, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Po Kang Wang, Fenglin Liu
  • Publication number: 20040085674
    Abstract: A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a uniform width above and below a write gap layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the alumina write-gap filling material. The present method uses NiCr, NiFeCr or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant.
    Type: Application
    Filed: October 31, 2002
    Publication date: May 6, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Fenglin Liu