Patents by Inventor Charles Changqing Chen

Charles Changqing Chen 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).

  • Publication number: 20090211898
    Abstract: CoCrPtB is a conventional material used in some of the layers of a thin film magnetic media structure used for recording data in data storage devices such as hard drives. Typically the CoCrPtB layers used for magnetic media have high Cr and low B in bottom magnetic layers and low Cr and high B in top magnetic layers. In accordance with one embodiment of this invention and to improve media electrical performance, fifth elements, such as Ta, Nb and Hf, etc. were added to the CoCrPtB materials, resulting in CoCrPtB-X, to enhance the grain segregation. The five element CoCrPtB-X layers were deposited using a pulsed direct current sputter technique instead of conventional direct current sputtering techniques. The resulting magnetic media structure having CoCrPtB-X alloy layers exhibits an increase in coercivity Hc and improvement in recording performance.
    Type: Application
    Filed: February 24, 2009
    Publication date: August 27, 2009
    Applicant: Seagate Technology LLC
    Inventors: Charles Changqing Chen, Thanh Thien Ha, Abebe Hailu, Taesun Ernest Kim, Mariana Rodica Munteanu, Steve Kuo-Hsing Hwang
  • Patent number: 7504166
    Abstract: CoCrPtB is a conventional material used in some of the layers of a thin film magnetic media structure used for recording data in data storage devices such as hard drives. Typically the CoCrPtB layers used for magnetic media have high Cr and low B in bottom magnetic layers and low Cr and high B in top magnetic layers. In accordance with one embodiment of this invention and to improve media electrical performance, fifth elements, such as Ta, Nb and Hf, etc. were added to the CoCrPtB materials, resulting in CoCrPtB—X, to enhance the grain segregation. The five element CoCrPtB—X layers were deposited using a pulsed direct current sputter technique instead of conventional direct current sputtering techniques. The resulting magnetic media structure having CoCrPtB—X alloy layers exhibits an increase in coercivity Hc and improvement in recording performance.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: March 17, 2009
    Assignee: Seagate Technology LLC
    Inventors: Charles Changqing Chen, Thanh Thien Ha, Abebe Hailu, Taesun Ernest Kim, Mariana Rodica Munteanu, Steve Kuo-Hsing Hwang
  • Patent number: 7393601
    Abstract: A magnetic recording medium having a substrate, underlayer, a low moment stabilizing layer, an antiferromagnetic coupling layer, a low magnetic layer having a magnetic saturation of equal to or less than 250 emu/cm2, and a high moment magnetic layer having a magnetic saturation of more than 250 emu/cm2, in this order, is disclosed. The magnetic recording medium has a weak coupling strength of Jex ?0.05.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: July 1, 2008
    Assignee: Seagate Technology LLC
    Inventors: Charles Changqing Chen, Shoutao Wang, Alan Huang
  • Patent number: 6878460
    Abstract: A thin film magnetic according medium with enhanced coercivity is provided. The magnetic recording medium comprises a non-magnetic substrate having a surface and a layer stack atop the substrate surface. The layer stack comprises a magnetic recording layer and a dual intermediate layer structure below the magnetic recording layer comprising a base layer and a non-magnetic layer between the base layer and the magnetic recording layer. The non-magnetic layer has a thickness less than that necessary for RKKY coupling between the base layer and the magnetic recording layer, and provides the medium with increased coercivity.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: April 12, 2005
    Assignee: Seagate Technology LLC
    Inventors: Abebe Hailu, Charles Changqing Chen, Taesun Ernest Kim
  • Publication number: 20040253486
    Abstract: CoCrPtB is a conventional material used in some of the layers of a thin film magnetic media structure used for recording data in data storage devices such as hard drives. Typically the CoCrPtB layers used for magnetic media have high Cr and low B in bottom magnetic layers and low Cr and high B in top magnetic layers. In accordance with one embodiment of this invention and to improve media electrical performance, fifth elements, such as Ta, Nb and Hf, etc. were added to the CoCrPtB materials, resulting in CoCrPtB—X, to enhance the grain segregation. The five element CoCrPtB—X layers were deposited using a pulsed direct current sputter technique instead of conventional direct current sputtering techniques. The resulting magnetic media structure having CoCrPtB—X alloy layers exhibits an increase in coercivity Hc and improvement in recording performance.
    Type: Application
    Filed: May 27, 2004
    Publication date: December 16, 2004
    Inventors: Charles Changqing Chen, Thanh Thien Ha, Abebe Hailu, Taesun Ernest Kim, Mariana Rodica Munteanu, Steve Kuo-Hsing Hwang
  • Patent number: 6500567
    Abstract: In this invention, an ultra thin layer of CoCr alloy nucleation layer is sputtered at an extremely low deposition rate above a predominantly (200) oriented Cr film followed by a CoCrPt based alloy sputtered film at higher rates and moderate temperatures. This structure creates a media which has very high Hc, and excellent PW50, low noise and excellent low TNLD values. By using this technique, the CoCrPt magnetic film achieves excellent in-plane crystallographic orientation, and high Hc is achieved with minimal amount of Pt addition to the magnetic film. The method allows very fine grain structure of cobalt to be formed which contributes to good signal to noise ratio. A fine grain structure combined with chromium segregation between the grains improve the signal to noise ratio even more. A high degree of in-plane c-axis orientation is achieved in the cobalt layer which provides very high hysteresis loop squareness which helps to improve the OW and TNLD.
    Type: Grant
    Filed: October 3, 2000
    Date of Patent: December 31, 2002
    Assignee: Komag, Inc.
    Inventors: Gerardo Bertero, Charles Changqing Chen, Tu Chen, Tsutomu Yamashita, Makoto Imakawa, Michinobu Suekane
  • Patent number: 6150015
    Abstract: In this invention, an ultra thin layer of CoCr alloy nucleation layer is sputtered at an extremely low deposition rate above a predominantly (200) oriented Cr film followed by a CoCrPt based alloy sputtered film at higher rates and moderate temperatures. This structure creates a media which has very high Hc, and excellent PW50, low noise and excellent low TNLD values. By using this technique, the CoCrPt magnetic film achieves excellent in-plane crystallographic orientation, and high Hc is achieved with minimal amount of Pt addition to the magnetic film. The method allows very fine grain structure of cobalt to be formed which contributes to good signal to noise ratio. A fine grain structure combined with chromium segregation between the grains improve the signal to noise ratio even more. A high degree of in-plane c-axis orientation is achieved in the cobalt layer which provides very high hysteresis loop squareness which helps to improve the OW and TNLD.
    Type: Grant
    Filed: December 4, 1997
    Date of Patent: November 21, 2000
    Assignee: Komag, Incorporated
    Inventors: Gerardo Bertero, Charles Changqing Chen, Tu Chen, Tsutomu Yamashita, Makoto Imakawa, Michinobu Suekane