Sae Magnetics (h.k.) Limited

Cheukman Lui

Juren Ding

Rongkwang Ni

Cheukwing Leung

Chiuming Lueng

Mankit Lee

Hokei Lam

Yasutoshi Fujita

Wanyin Kwan

Wahchun Chan

Chiyuen Mok

Kwokkam Leung

Lorest Garcia Pingul

Kaichiu Cheung

Siuman Mok

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.

Manufacturing method of a slider

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.

Method of testing anti-high temperature performance of a magnetic head and apparatus thereof

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.

Testing method of a magnetic head, and testing apparatus thereof

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.

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.

Manufacturing method of a slider and manufacturing apparatus thereof

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.

Spectral simulation method during noise testing for a magnetic head, and noise-testing method for a magnetic head by using the same

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.

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Hong Kong, China

Cheukman Lui