Patents by Inventor Ellis T. Cha

Ellis T. Cha 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: 8274751
    Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: September 25, 2012
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Zhu Feng, Xiaofeng Zhang, Ellis T. Cha
  • Patent number: 8139306
    Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: March 20, 2012
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Zhu Feng, Xiaofeng Zhang, Ellis T. Cha
  • Publication number: 20110299191
    Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.
    Type: Application
    Filed: April 1, 2011
    Publication date: December 8, 2011
    Inventors: Zhu Feng, Xiaofeng Zhang, Ellis T. Cha
  • Patent number: 8045295
    Abstract: Method and apparatus are presented for electrically coupling a slider to ground. In one embodiment, a bonding pad is provided on a side of the slider body separate from the bonding pad(s) used for read/write signals. This separate bonding pad is electrically coupled within the slider body to components that are to be coupled to ground. A separate conductor provided on the suspension (e.g., a trace, a flex circuit, etc.) may be electrically coupled to the separate bonding pad via gold ball bonding. The conductor is also coupled to ground in the hard-disk drive device (e.g., via the preamplifier). The use of the separated bonding pad and trace may negate the need to use a conductive adhesive to electrically ground the slider via its attachment to the tongue of a slider.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: October 25, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Yen Fu, Ellis T. Cha, Po-Kang Wang, Hong Tian, Manuel Hernandez, Yaw-Shing Tang, Ben Hu
  • Patent number: 8027127
    Abstract: In a balanced head gimbal assembly for improved seeking performance, a slider having a magnetic head with a set of read elements to read data and a set of write elements to write data, an air-bearing surface, and a non-air-bearing surface is coupled to a suspension. The suspension includes a loadbeam, a flexure, and a balancing weight. The loadbeam is coupled to an actuator arm. The flexure, coupled to the loadbeam, has a window through which a dimple, coupled to the loadbeam, contacts a dimple contact point. The balancing weight, coupled to the flexure, has a configuration which permits alignment of a center of mass of the head gimbal assembly with the dimple contact point.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: September 27, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Qinghua Zeng, Yen Fu, Li-Yan Zhu, Chao-Hui Yang, Ellis T. Cha
  • Patent number: 8018682
    Abstract: A magnetic disk is protected by a bilayer. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: September 13, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 8014104
    Abstract: A protective bilayer on a magnetic read/write head or magnetic disk is formed as an adhesion enhancing and corrosion resistant underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is a transition metal oxynitride, having the general formula MeOxNy, where Me represents a single element or an alloy of the following transition metal elements: Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, here x can be within the range between 0 and 3 and y is in the range between approximately 0 and 2. Adjusting the values of x and y contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Methods of forming the adhesion layer, include reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Grant
    Filed: March 21, 2007
    Date of Patent: September 6, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 8009387
    Abstract: A method for forming a protective bilayer on a magnetic read/write head or magnetic disk. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: August 30, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 7978436
    Abstract: A method and apparatus for improving flying height stability in a small form factor hard disk drive that typically moves at lower speeds is achieved by a slider having an ABS with an air channel and pocket. The air channel and pocket are configured to increase the amount of aerodynamic lift provided by normally smaller amounts of intake air at the inner diameter of the rotating disk and, thereby, to achieve a desired flying height profile.
    Type: Grant
    Filed: June 5, 2007
    Date of Patent: July 12, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Ellis T. Cha, Zhu Feng, Xinjiang Shen, Sindy Yeung
  • Publication number: 20110146047
    Abstract: In a balanced head gimbal assembly for improved seeking performance, a slider having a magnetic head with a set of read elements to read data and a set of write elements to write data, an air-bearing surface, and a non-air-bearing surface is coupled to a suspension. The suspension includes a loadbeam, a flexure, and a balancing weight. The loadbeam is coupled to an actuator arm. The flexure, coupled to the loadbeam, has a window through which a dimple, coupled to the loadbeam, contacts a dimple contact point. The balancing weight, coupled to the flexure, has a configuration which permits alignment of a center of mass of the head gimbal assembly with the dimple contact point.
    Type: Application
    Filed: February 28, 2011
    Publication date: June 23, 2011
    Inventors: Qinghua Zeng, Yen Fu, Li-Yan Zhu, Chao-Hui Yang, Ellis T. Cha
  • Patent number: 7957104
    Abstract: A flexure with improved temperature sensitivity is disclosed. An embodiment of the present invention includes a bi-layered flexure that raises or lowers a read/write element a distance that is approximately equal to the distance of protrusion and retraction at varying temperatures.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: June 7, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Yen Fu, Ellis T. Cha, Chao-Hui Yang
  • Patent number: 7907368
    Abstract: In a balanced head gimbal assembly for improved seeking performance, a slider having a magnetic head with a set of read elements to read data and a set of write elements to write data, an air-bearing surface, and a non-air-bearing surface is coupled to a suspension. The suspension includes a loadbeam, a flexure, and a balancing weight. The loadbeam is coupled to an actuator arm. The flexure, coupled to the loadbeam, has a window through which a dimple, coupled to the loadbeam, contacts a dimple contact point. The balancing weight, coupled to the flexure, has a configuration which permits alignment of a center of mass of the head gimbal assembly with the dimple contact point.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: March 15, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Qinghua Zeng, Yen Fu, Li-Yan Zhu, Chao-Hui Yang, Ellis T. Cha
  • Patent number: 7885040
    Abstract: An apparatus with a head gimbal assembly designed to reduce movement and rotation of components of the head gimbal assembly structure is disclosed. One embodiment head gimbal assembly may comprise a flexure including a ramp limiter, a suspension assembly further comprising a suspension tongue, a slider further comprising a magnetic head; and a load beam further comprising a lift tab; and a ramp further comprising a step to engage and support the ramp limiter and support and constrain the movement of the slider. In certain embodiments, the flexure may further comprise a flexure rail located at its end to reduce movement and rotation of the suspension tongue.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: February 8, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Chao-Hui Yang, Qinghua Zeng, Yen Fu, Ellis T. Cha
  • Publication number: 20100307911
    Abstract: A method for forming a protective bilayer on a magnetic read/write head or magnetic disk. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Application
    Filed: August 2, 2010
    Publication date: December 9, 2010
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Publication number: 20100310904
    Abstract: A magnetic disk is protected by a bilayer. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Application
    Filed: August 2, 2010
    Publication date: December 9, 2010
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 7837885
    Abstract: An embodiment of the present invention is an ABS design with a pitch ladder feature. This embodiment has an air flow squeezing channel which consists of one airflow blocker and three etching steps. The airflow blocker can be used to limit the incoming air flow from the leading edge of the ABS. Additionally, the embodiment contains an air channel that reduces altitude sensitivity by channeling air at the inner diameter into a sub-ambient pressure cavity.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: November 23, 2010
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Ellis T. Cha, Zhu Feng, Xinjiang Shen, Sindy Yeung
  • Patent number: 7782569
    Abstract: A method for forming a protective bilayer on a magnetic read/write head or magnetic disk. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: August 24, 2010
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 7760468
    Abstract: An apparatus allowing for a slider for use in a disk drive is disclosed. An embodiment of the present invention may include a leading side, a trailing side, at least two main rails, a slider surface with an air bearing surface, and at least one trench substantially parallel to the width of the slider. The trench in the air bearing surface results in a lower compression length of the slider and allows for particles to be channeled off of the disk surface.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: July 20, 2010
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Ellis T. Cha, Guoqiang Zheng, Sindy Yeung
  • Patent number: 7679857
    Abstract: In a system and method for a non-contact measurement of the fly height of a slider above a magnetic data storage medium using electrostatic force, a slider with a read/write head flies over a magnetic data storage medium. A series of distinct voltages are applied between the slider and the magnetic data storage medium, and corresponding read-back signals are recorded. Using the recorded read-back signals, coefficients for an empirical curve-fit equation are calculated. The coefficients are normalized and converted into a fly height measurement.
    Type: Grant
    Filed: August 27, 2008
    Date of Patent: March 16, 2010
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Li-Yan Zhu, Chao-Hui Yang, Yen Fu, Ellis T. Cha
  • Patent number: 7617737
    Abstract: In a system and method for adjusting a static torque on a slider in a head-gimbal assembly, a substantially rigid mass is placed on an air-bearing surface (ABS) of a slider. A static attitude of the slider is measured, and an adjustment location and intensity for a flexure to yield a zero slider static attitude are calculated. The flexure is adjusted based on the measurement and calculations.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: November 17, 2009
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Li-Yan Zhu, Chao-Hui Yang, Yen Fu, Ellis T. Cha