公开(公告)号：US08935132B2

公开(公告)日：2015-01-13

申请号：US13368762

申请日：2012-02-08

申请人： Hokei Lam ,  Cheukman Lui ,  Chiuming Lueng ,  Kaichiu Cheung ,  Wahchun Chan ,  Juren Ding ,  Rongkwang Ni

发明人： Hokei Lam ,  Cheukman Lui ,  Chiuming Lueng ,  Kaichiu Cheung ,  Wahchun Chan ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G06F17/10 ,  G11B5/455 ,  G11B19/04

CPC分类号： G11B5/455 ,  G11B19/048

摘要： 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.

摘要翻译： 在磁头的噪声测试期间的光谱模拟方法包括以下步骤：（a1）通过动态测试机检测在第一频率带宽范围内的几个磁头样本的几个第一噪声分布; （b1）将每个第一噪声分布分解成包括预定频率带宽的第一噪声曲线和第二噪声曲线的至少两个噪声曲线，其中所述第一噪声曲线具有低于所述第二噪声曲线的频带宽度范围; （c1）根据第二噪声曲线拟合几个数学方程; 和（d1）在数学方程之间建立相关方程，以便模拟每个磁头的第二噪声曲线。 本发明可以模拟较高频带宽噪声分布的第二噪声曲线，并根据第二噪声曲线建立相关方程。

公开(公告)号：US20120275047A1

公开(公告)日：2012-11-01

申请号：US13064993

申请日：2011-04-29

申请人： Cheukman Lui ,  Chiuming Lueng ,  Hokei Lam ,  Mankit Lee ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

发明人： Cheukman Lui ,  Chiuming Lueng ,  Hokei Lam ,  Mankit Lee ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G11B27/36

CPC分类号： G11B5/455 ,  G01R33/1207 ,  G11B5/4555 ,  G11B20/1816 ,  G11B27/36

摘要： 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.

摘要翻译： 一种测试磁头的抗高温性能的方法包括：向第二方向施加具有不同强度的多个第二磁场到磁头，以及测量第二输出参数曲线，并且判断是否超出 允许值呈现在第二输出参数曲线上，其中第二方向穿过ABS并以与ABS绝对值成锐角的角度相交。 本发明可以在不加热磁头的情况下屏蔽具有差的抗高温性能的有缺陷的磁头。

公开(公告)号：US20130204590A1

公开(公告)日：2013-08-08

申请号：US13368762

申请日：2012-02-08

申请人： Hokei LAM ,  Cheukman LUI ,  Chiuming LUENG ,  Kaichiu CHEUNG ,  Wahchun CHAN ,  Juren DING ,  Rongkwang NI

发明人： Hokei LAM ,  Cheukman LUI ,  Chiuming LUENG ,  Kaichiu CHEUNG ,  Wahchun CHAN ,  Juren DING ,  Rongkwang NI

IPC分类号： G06F17/10

CPC分类号： G11B5/455 ,  G11B19/048

摘要： 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.

摘要翻译： 在磁头的噪声测试期间的光谱模拟方法包括以下步骤：（a1）通过动态测试机检测在第一频率带宽范围内的几个磁头样本的几个第一噪声分布; （b1）将每个第一噪声分布分解成包括预定频率带宽的第一噪声曲线和第二噪声曲线的至少两个噪声曲线，其中所述第一噪声曲线具有低于所述第二噪声曲线的频带宽度范围; （c1）根据第二噪声曲线拟合几个数学方程; 和（d1）在数学方程之间建立相关方程，以便模拟每个磁头的第二噪声曲线。 本发明可以模拟较高频带宽噪声分布的第二噪声曲线，并根据第二噪声曲线建立相关方程。

公开(公告)号：US20120274317A1

公开(公告)日：2012-11-01

申请号：US13064994

申请日：2011-04-29

申请人： Chiuming Lueng ,  Cheukman Lui ,  Mankit Lee ,  Hokei Lam ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

发明人： Chiuming Lueng ,  Cheukman Lui ,  Mankit Lee ,  Hokei Lam ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G01R33/12

CPC分类号： G01R33/1207 ,  B82Y25/00 ,  G01R33/12 ,  G11B5/455 ,  G11B5/4555 ,  G11B27/36

摘要： 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.

摘要翻译： 一种测试磁头的抗高温性能的方法包括：在第二方向施加不同强度的第二磁场，并在第一方向上改变第一磁场，并测量多个第二输出参数曲线; 并且判断在所述第二输出参数曲线上是否存在超出允许值的变化，从而筛选出所述第一方向上的有缺陷的磁头垂直于所述磁头的所述空气支承表面，并且所述第二方向垂直 到磁头的屏蔽层。 本发明可以在不加热磁头的情况下高精度地筛选出具有差的抗高温性能的有缺陷的磁头。

公开(公告)号：US20110235214A1

公开(公告)日：2011-09-29

申请号：US12801518

申请日：2010-06-11

申请人： Chiuming Leung ,  Kosuke Tanaka ,  Kazuki Sato ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Mankit Lee

发明人： Chiuming Leung ,  Kosuke Tanaka ,  Kazuki Sato ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Mankit Lee

IPC分类号： G11B5/48 ,  G11B5/33

CPC分类号： G11B5/398 ,  B82Y25/00 ,  G01R33/093 ,  G01R33/098 ,  G11B5/3932

摘要： A MR sensor includes a first shielding layer, a second shielding layer, a MR element formed therebetween, and a pair of hard magnet layers respectively placed on two sides of the MR element. The MR element comprises an AFM layer formed on the first shielding layer, a pinned layer formed on the AFM layer and a free layer formed between the pinned layer and the second shielding layer. The free layer is funnel-shaped, which having a first edge facing the air bearing surface and a second edge opposite the first edge, and the first edge has a narrower width than that of the second edge. The structure of the MR sensor can improve MR height control performance, and improve the ESD performance and decrease the PCN and RTN and, in turn, get a more stable performance. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

摘要翻译： MR传感器包括第一屏蔽层，第二屏蔽层，在其间形成的MR元件和分别放置在MR元件的两侧上的一对硬磁体层。 MR元件包括形成在第一屏蔽层上的AFM层，形成在AFM层上的钉扎层和形成在钉扎层和第二屏蔽层之间的自由层。 自由层是漏斗形的，其具有面向空气支承表面的第一边缘和与第一边缘相对的第二边缘，并且第一边缘具有比第二边缘窄的宽度。 MR传感器的结构可以提高MR高度控制性能，提高ESD性能，减少PCN和RTN，进而获得更稳定的性能。 本发明还公开了一种磁头，HGA和盘驱动单元。

公开(公告)号：US09899046B2

公开(公告)日：2018-02-20

申请号：US13064993

申请日：2011-04-29

申请人： Cheukman Lui ,  Chiuming Lueng ,  Hokei Lam ,  Mankit Lee ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

发明人： Cheukman Lui ,  Chiuming Lueng ,  Hokei Lam ,  Mankit Lee ,  Kwokkam Leung ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G11B5/455 ,  G11B20/18 ,  G11B27/36 ,  G01R33/12

CPC分类号： G11B5/455 ,  G01R33/1207 ,  G11B5/4555 ,  G11B20/1816 ,  G11B27/36

摘要： 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.

公开(公告)号：US08582248B2

公开(公告)日：2013-11-12

申请号：US12929198

申请日：2011-01-06

申请人： Chiuming Lueng ,  Kazuki Sato ,  Yohei Koyanagi ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Siuman Mok

发明人： Chiuming Lueng ,  Kazuki Sato ,  Yohei Koyanagi ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Siuman Mok

IPC分类号： G11B5/39

CPC分类号： G11B5/3912 ,  B82Y10/00 ,  B82Y25/00 ,  G11B5/3909 ,  G11B2005/3996

摘要： A MR sensor comprises a first shielding layer, a second shielding layer, a MR element and a pair of hard magnet layers sandwiched therebetween, and a non-magnetic insulating layer formed at a side of the MR element far from an air bearing surface of a slider. The MR sensor further comprises a first non-magnetic conducting layer formed between the first shielding layer and the MR element, and the first non-magnetic conducting layer is embedded in the first shielding layer and kept separate from the ABS. The MR sensor of the invention can obtain a narrower read gap to increase the resolution power and improve the reading performance, and obtain a strong longitudinal bias field to stabilize the MR sensor so as to increase the total sensor area and, in turn, get an improved reliability and performance. The present invention also discloses a magnetic head, a HGA and a disk drive unit.

摘要翻译： MR传感器包括第一屏蔽层，第二屏蔽层，MR元件和夹在其间的一对硬磁体层，以及形成在MR元件的远离空气轴承表面的一侧的非磁性绝缘层 滑块 MR传感器还包括形成在第一屏蔽层和MR元件之间的第一非磁性导电层，并且第一非导电层嵌入第一屏蔽层中并与ABS分离。 本发明的MR传感器可以获得更窄的读取间隙，以提高分辨率和提高读取性能，并获得强的纵向偏置场以稳定MR传感器，从而增加总传感器面积，从而获得 提高可靠性和性能。 本发明还公开了一种磁头，HGA和盘驱动单元。

公开(公告)号：US20120287529A1

公开(公告)日：2012-11-15

申请号：US13067163

申请日：2011-05-12

申请人： Chiuming Lueng ,  Mankit Lee ,  Wanyin Kwan ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

发明人： Chiuming Lueng ,  Mankit Lee ,  Wanyin Kwan ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G11B21/12

CPC分类号： G11B5/607 ,  G11B19/048

摘要： A close loop method for measuring head SNR, for a storage device comprising a storage media and a head, comprising steps of: (a) loading the head on the media with a dynamic fly height; (b) measuring an initial environmental temperature value Ti and measuring the head signal signalload; (c) unloading the head; (d) adjusting a power which controls the dynamic fly height until a real-time environmental temperature value T2 is equal to the initial environmental temperature T1; (e) measuring the head noise value noiseunload, (f) calculating the head SNR with the follow equation: Head_SNR = 20 × log  ( signal load noise unload ) . The method of the present invention can obtain a fair condition between the signal and noise measurement, thereby a reliable and accurate head SNR can be obtain. The present invention also provides a close loop method for measuring media SNR.

摘要翻译： 一种用于测量头部SNR的闭环方法，用于包括存储介质和头部的存储装置，包括以下步骤：（a）将所述头部以动态飞行高度装载在所述介质上; （b）测量初始环境温度值Ti并测量头信号信号负载; （c）卸下头部; （d）调整控制动态飞行高度的功率，直到实时环境温度值T2等于初始环境温度T1; （e）测量头噪声值噪声负载，（f）使用以下等式计算头信噪比：Head_SNR = 20×log（信号负载噪声卸载）。 本发明的方法可以在信号和噪声测量之间获得公平的条件，从而可以获得可靠和准确的头信号。 本发明还提供了一种用于测量介质SNR的闭环方法。

公开(公告)号：US08664950B2

公开(公告)日：2014-03-04

申请号：US13067887

申请日：2011-07-01

申请人： Siuman Mok ,  Hokei Lam ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Cheukman Lui ,  Chiuming Lueng

发明人： Siuman Mok ,  Hokei Lam ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni ,  Wanyin Kwan ,  Cheukman Lui ,  Chiuming Lueng

IPC分类号： G01R33/12

CPC分类号： G01R33/098

摘要： 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.

摘要翻译： 一种用于测量磁头的隧道磁阻传感器中的纵向偏置磁场的方法，所述方法包括以下步骤：将外部纵向时变磁场施加到隧道磁阻传感器上; 在外部纵向时变磁场的应用下，确定隧道磁阻传感器的屏蔽饱和度值; 将外部横向时变磁场和外部纵向直流磁场施加到隧道磁阻传感器上; 在外部横向时变磁场的应用和外部纵向直流磁场的不同场强值的应用中确定多个不同的输出幅度; 根据不同的输出幅度和不同的场强值绘制图形; 并根据曲线图和屏蔽饱和度值确定纵向偏置磁场的强度。

公开(公告)号：US08634157B2

公开(公告)日：2014-01-21

申请号：US13067163

申请日：2011-05-12

申请人： Chiuming Lueng ,  Mankit Lee ,  Wanyin Kwan ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

发明人： Chiuming Lueng ,  Mankit Lee ,  Wanyin Kwan ,  Cheukwing Leung ,  Juren Ding ,  Rongkwang Ni

IPC分类号： G11B21/12 ,  G11B20/10

CPC分类号： G11B5/607 ,  G11B19/048

摘要： A close loop method for measuring head SNR, for a storage device comprising a storage media and a head, comprising steps of: (a) loading the head on the media with a dynamic fly height; (b) measuring an initial environmental temperature value T1 and measuring the head signal signalload; (c) unloading the head; (d) adjusting a power which controls the dynamic fly height until a real-time environmental temperature value T2 is equal to the initial environmental temperature T1; (e) measuring the head noise value noiseunload, (f) calculating the head SNR with the follow equation: Head_SNR = 20 × log ⁡ ( signal load noise unload ) . The method of the present invention can obtain a fair condition between the signal and noise measurement, thereby a reliable and accurate head SNR can be obtain. The present invention also provides a close loop method for measuring media SNR.

摘要翻译： 一种用于测量头部SNR的闭环方法，用于包括存储介质和头部的存储装置，包括以下步骤：（a）将所述头部以动态飞行高度装载在所述介质上; （b）测量初始环境温度值T1并测量头信号信号负载; （c）卸下头部; （d）调整控制动态飞行高度的功率，直到实时环境温度值T2等于初始环境温度T1; （e）测量头噪声值噪声负载，（f）通过以下等式计算头信噪比：Head_SNR = 20×log⁡（信号负载噪声卸载）。 本发明的方法可以在信号和噪声测量之间获得公平的条件，从而可以获得可靠和准确的头信号。 本发明还提供了一种用于测量介质SNR的闭环方法。