Patents by Inventor Cheukman LUI

Cheukman LUI 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: 10486283
    Abstract: A manufacturing method of a slider includes steps of: (a) providing a row bar with a plurality of slider elements connecting together; (b) lapping surfaces of the row bar so as to obtain a predetermined requirement; (c) lowering the temperature of the surfaces lapped in the step (b) before and/or during lapping; and (d) cutting the row bar into a plurality of sliders. The present invention can prevent a local high temperature generated on the magnetic head during lapping so that the performance of the magnetic head is improved.
    Type: Grant
    Filed: July 6, 2017
    Date of Patent: November 26, 2019
    Assignee: SAE MAGNETICS (H.K.) LTD.
    Inventors: Chiuming Lueng, Mankit Lee, Lorest Garcia Pingul, Yasutoshi Fujita, Cheukman Lui, Chiyuen Mok, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Patent number: 9899046
    Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a plurality of second magnetic fields with different intensities in a second direction to the magnetic head, and measuring a second output parameter curve, and judging whether a variation that is beyond an allowable value is presented on the second output parameter curve, therein the second direction passes through the ABS and at an angle whose absolute value is an acute angle to the ABS. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: February 20, 2018
    Assignee: SAE Magnetics (H.K.) Ltd.
    Inventors: Cheukman Lui, Chiuming Lueng, Hokei Lam, Mankit Lee, Kwokkam Leung, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Publication number: 20170304987
    Abstract: A manufacturing method of a slider includes steps of: (a) providing a row bar with a plurality of slider elements connecting together; (b) lapping surfaces of the row bar so as to obtain a predetermined requirement; (c) lowering the temperature of the surfaces lapped in the step (b) before and/or during lapping; and (d) cutting the row bar into a plurality of sliders. The present invention can prevent a local high temperature generated on the magnetic head during lapping so that the performance of the magnetic head is improved.
    Type: Application
    Filed: July 6, 2017
    Publication date: October 26, 2017
    Inventors: Chiuming LUENG, MANKIT LEE, LOREST GARCIA PINGUL, YASUTOSHI FUJITA, CHEUKMAN LUI, CHIYUEN MOK, CHEUKWING LEUNG, JUREN DING, RONGKWANG NI
  • Patent number: 9355660
    Abstract: A testing method of a magnetic head includes: applying a first magnetic field with a constant intensity in a first direction that is the same with that of the longitudinal bias field to the magnetic head, simultaneously applying a second magnetic field with variant intensities in a second direction traversing the air bearing surface, and measuring a first noise; applying a third magnetic field with a constant intensity in a third direction that is opposite to the first direction to the magnetic head, simultaneously applying the second magnetic field with variant intensities in the second direction, and measuring a second noise; and analyzing noise change between the first noise and the second noise. The invention can screen out defective magnetic heads that possess poor noise characteristic and unstable performance.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: May 31, 2016
    Assignee: SAE MAGNETICS (H.K.) LTD.
    Inventors: Hokei Lam, Mankit Lee, Cheukman Lui, Wahchun Chan, Juren Ding, Rongkwang Ni, Cheukwing Leung, Wanyin Kwan
  • Patent number: 9121888
    Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a second magnetic field with different intensities in a second direction and the changing first magnetic fields in a first direction, and measuring a plurality of second output parameter curves; and judging whether a variation that is beyond an allowable value is presented on the second output parameter curves, thereby screening out a defective magnetic head, therein the first direction is perpendicular to the air bearing surface of the magnetic head, and the second direction is perpendicular to the shielding layers of the magnetic head. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head and with high precision.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: September 1, 2015
    Assignee: SAE MAGNETICS (H.K.) LTD.
    Inventors: Chiuming Lueng, Cheukman Lui, Mankit Lee, Hokei Lam, Kwokkam Leung, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Patent number: 8984738
    Abstract: A manufacturing method of a slider includes steps of (a) providing a row bar with a plurality of slider elements connecting together, the row bar having an air bearing surface, a back surface opposite the air bearing surface, a bonding surface and a bottom surface opposite the bonding surface; (b) grinding the bottom surface of the row bar; (c) lapping the air bearing surface of the row bar so as to obtain a predetermined requirement, and applying a first magnetic field with a first direction during lapping the air bearing surface, and the first direction being parallel to the air bearing surface and the bonding surface; and (d) cutting the row bar into a plurality of individual sliders. The present invention can maintain a good performance of a magnetic head during the manufacturing process.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: March 24, 2015
    Assignee: SAE Magnetics (H.K.) Ltd
    Inventors: Chiuming Lueng, Mankit Lee, Lorest Garcia Pingul, Yasutoshi Fujita, Cheukman Lui, ChiYuen Mok, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Patent number: 8935132
    Abstract: A spectral simulation method during a noise testing for a magnetic head, includes steps of (a1) detecting several first noise profiles for several magnetic head samples under a first frequency bandwidth range by a dynamic testing machine; (b1) separating each first noise profile into at least two noise curves including a first noise curve and a second noise curve at a predetermined frequency bandwidth, wherein the first noise curve has a frequency bandwidth range lower than that of the second noise curve; (c1) fitting several mathematical equations according to the second noise curves; and (d1) establishing a correlative equation among the mathematical equations, so as to simulate the second noise curve for each magnetic head. The present invention can simulate a second noise curve of the noise profile in a higher frequency bandwidth and establishing the correlative equation according to the second noise curve.
    Type: Grant
    Filed: February 8, 2012
    Date of Patent: January 13, 2015
    Assignee: SAE Magnetics (H.K.) Ltd.
    Inventors: Hokei Lam, Cheukman Lui, Chiuming Lueng, Kaichiu Cheung, Wahchun Chan, Juren Ding, Rongkwang Ni
  • Publication number: 20140334279
    Abstract: A testing method of a magnetic head includes: applying a first magnetic field with a constant intensity in a first direction that is the same with that of the longitudinal bias field to the magnetic head, simultaneously applying a second magnetic field with variant intensities in a second direction traversing the air bearing surface, and measuring a first noise; applying a third magnetic field with a constant intensity in a third direction that is opposite to the first direction to the magnetic head, simultaneously applying the second magnetic field with variant intensities in the second direction, and measuring a second noise; and analyzing noise change between the first noise and the second noise. The invention can screen out defective magnetic heads that possess poor noise characteristic and unstable performance.
    Type: Application
    Filed: June 21, 2013
    Publication date: November 13, 2014
    Inventors: Hokei LAM, Mankit LEE, Cheukman LUI, Wahchun CHAN, Juren DING, Rongkwang NI, Cheukwing LEUNG, Wanyin KWAN
  • Patent number: 8664950
    Abstract: A method for measuring longitudinal bias magnetic field in a tunnel magnetoresistive sensor of a magnetic head, the method includes the steps of: applying an external longitudinal time-changing magnetic field onto the tunnel magnetoresistive sensor; determining a shield saturation value of the tunnel magnetoresistive sensor under the application of the external longitudinal time-changing magnetic field; applying an external transverse time-changing magnetic field and an external longitudinal DC magnetic field onto the tunnel magnetoresistive sensor; determining a plurality of different output amplitudes under the application of the external transverse time-changing magnetic field and the application of different field strength values of the external longitudinal DC magnetic field; plotting a graph according to the different output amplitudes and the different field strength values; and determining the strength of the longitudinal bias magnetic field according to the graph and the shield saturation value.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: March 4, 2014
    Assignee: SAE Magnetics (H.K.) Ltd.
    Inventors: Siuman Mok, Hokei Lam, Cheukwing Leung, Juren Ding, Rongkwang Ni, Wanyin Kwan, Cheukman Lui, Chiuming Lueng
  • Publication number: 20130219699
    Abstract: A manufacturing method of a slider includes steps of: (a) providing a row bar with a plurality of slider elements connecting together; (b) lapping surfaces of the row bar so as to obtain a predetermined requirement; (c) lowering the temperature of the surfaces lapped in the step (b) before and/or during lapping; and (d) cutting the row bar into a plurality of sliders. The present invention can prevent a local high temperature generated on the magnetic head during lapping so that the performance of the magnetic head is improved.
    Type: Application
    Filed: February 29, 2012
    Publication date: August 29, 2013
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Chiuming Lueng, Mankit Lee, Lorest Garcia Pingul, Yasutoshi Fujita, Cheukman Lui, ChiYuen Mok, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Publication number: 20130212871
    Abstract: A manufacturing method of a slider includes steps of (a) providing a row bar with a plurality of slider elements connecting together, the row bar having an air bearing surface, a back surface opposite the air bearing surface, a bonding surface and a bottom surface opposite the bonding surface; (b) grinding the bottom surface of the row bar; (c) lapping the air bearing surface of the row bar so as to obtain a predetermined requirement, and applying a first magnetic field with a first direction during lapping the air bearing surface, and the first direction being parallel to the air bearing surface and the bonding surface; and (d) cutting the row bar into a plurality of individual sliders. The present invention can maintain a good performance of a magnetic head during the manufacturing process.
    Type: Application
    Filed: February 22, 2012
    Publication date: August 22, 2013
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Chiuming Lueng, Mankit Lee, Lorest Garcia Pingul, Yasutoshi Fujita, Cheukman Lui, ChiYuen Mok, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Publication number: 20130204590
    Abstract: A spectral simulation method during a noise testing for a magnetic head, includes steps of (a1) detecting several first noise profiles for several magnetic head samples under a first frequency bandwidth range by a dynamic testing machine; (b1) separating each first noise profile into at least two noise curves including a first noise curve and a second noise curve at a predetermined frequency bandwidth, wherein the first noise curve has a frequency bandwidth range lower than that of the second noise curve; (c1) fitting several mathematical equations according to the second noise curves; and (d1) establishing a correlative equation among the mathematical equations, so as to simulate the second noise curve for each magnetic head. The present invention can simulate a second noise curve of the noise profile in a higher frequency bandwidth and establishing the correlative equation according to the second noise curve.
    Type: Application
    Filed: February 8, 2012
    Publication date: August 8, 2013
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Hokei LAM, Cheukman LUI, Chiuming LUENG, Kaichiu CHEUNG, Wahchun CHAN, Juren DING, Rongkwang NI
  • Publication number: 20120275047
    Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a plurality of second magnetic fields with different intensities in a second direction to the magnetic head, and measuring a second output parameter curve, and judging whether a variation that is beyond an allowable value is presented on the second output parameter curve, therein the second direction passes through the ABS and at an angle whose absolute value is an acute angle to the ABS. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head.
    Type: Application
    Filed: April 29, 2011
    Publication date: November 1, 2012
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Cheukman Lui, Chiuming Lueng, Hokei Lam, Mankit Lee, Kwokkam Leung, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Publication number: 20120274317
    Abstract: A method of testing anti-high temperature performance of a magnetic head comprises applying a second magnetic field with different intensities in a second direction and the changing first magnetic fields in a first direction, and measuring a plurality of second output parameter curves; and judging whether a variation that is beyond an allowable value is presented on the second output parameter curves, thereby screening out a defective magnetic head, therein the first direction is perpendicular to the air bearing surface of the magnetic head, and the second direction is perpendicular to the shielding layers of the magnetic head. The present invention can screen out defective magnetic heads that possess poor anti-high temperature performance without heating the magnetic head and with high precision.
    Type: Application
    Filed: April 29, 2011
    Publication date: November 1, 2012
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Chiuming Lueng, Cheukman Lui, Mankit Lee, Hokei Lam, Kwokkam Leung, Cheukwing Leung, Juren Ding, Rongkwang Ni
  • Publication number: 20120249130
    Abstract: A method for measuring longitudinal bias magnetic field in a tunnel magnetoresistive sensor of a magnetic head, the method includes the steps of: applying an external longitudinal time-changing magnetic field onto the tunnel magnetoresistive sensor; determining a shield saturation value of the tunnel magnetoresistive sensor under the application of the external longitudinal time-changing magnetic field; applying an external transverse time-changing magnetic field and an external longitudinal DC magnetic field onto the tunnel magnetoresistive sensor; determining a plurality of different output amplitudes under the application of the external transverse time-changing magnetic field and the application of different field strength values of the external longitudinal DC magnetic field; plotting a graph according to the different output amplitudes and the different field strength values; and determining the strength of the longitudinal bias magnetic field according to the graph and the shield saturation value.
    Type: Application
    Filed: July 1, 2011
    Publication date: October 4, 2012
    Applicant: SAE Magnetics (H.K.) Ltd.
    Inventors: Siuman MOK, Hokei LAM, Cheukwing LEUNG, Juren DING, Rongkwang NI, Wanyin KWAN, Cheukman LUI, Chiuming LUENG