Tdk Corporation

Sae Magnetics (h.k.) Limited

Man Tse

Yosuke Antoku

Kosuke Tanaka

Eric Cheuk Wing Leung

Kazuki Sato

Masashi Sano

Noboru Yamanaka

Takayasu Kanaya

Cheukwing Leung

Takayuki Nishizawa

Masaru Iida

Kazumi Nakatogawa

Luke Hung Leung Chung

WaSze Tsang

Eric Leung

Luke Chung

A magnetic head disposed in a slider, that is arranged at an interval from a magnetic disk includes a sensor disposed in a position that is opposed to the magnetic disk, a heat conductive film that is positioned on an air bearing surface opposed to the magnetic disk, and that is formed so as to overlap the sensor, of which a height in a direction perpendicular to the air bearing surface is more than a height of the sensor, and that transfers a temperature change of the air bearing surface to the sensor, and a pair of lead films electrically connected to the sensor and not electrically connected to the heat conductive film.

Magnetic head including sensor

For obtaining a flying height of a magnetic head from a magnetic disk, the magnetic head being placed in a slider arranged at an interval with the magnetic disk, an initial setting process and a flying height detecting process are performed. In the initial setting process, driving power to a heater is increased gradually, from a state where the heater arranged at a position in proximity to the magnetic head in the slider is not driven, until the magnetic head makes contact with the magnetic disk. Then, in each stage, an electrical resistance value of the sensor arranged at a position in proximity to the magnetic head in the slider, which is increased due to the heat from heater, and either an approach distance of the magnetic head toward the magnetic disk or the flying height of the magnetic head from the magnetic disk are acquired. Then, basic data is prepared by obtaining the relationship between a variation of the electrical resistance value of the sensor and the flying height of the magnetic head from the magnetic disk, which is obtained in each stage or which calculated from the approach distance in each stage. In the flying height detecting process, an electrical resistance value of the sensor is determined, and a variation of the electrical resistance value is calculated from the determined values. Then, the flying height of the magnetic head from the magnetic disk in the state where the electrical resistance value was determined is obtained based on the basic data obtained in the initial setting process, using the calculated variation of the electrical resistance value.

Method of determining flying height of magnetic head

A method for testing performance of a magnetic head slider includes the steps of: (1) rotating the disk and positioning the slider over the rotating disk at an initial fly-height; (2) exciting the fly-height actuator to make the slider touch the disk and recording a touch down spacing of the read head of the slider; (3) backing off the slider at a predetermined backoff amount from the disk; (4) testing dynamic performance of the slider to obtain a reference value which is related to the spacing between the disk and the slider; (5) varying the initial fly-height of the slider; (6) repeating the steps (2) to (4) with the backoff amount fixed; and (7) calculating a dynamic fly-height gamma ratio based at least in part on the recorded touch down spacing and the obtained reference values.

Method for testing performance of a magnetic head slider

A method of measuring temperature of a TMR element includes a step of obtaining in advance a temperature coefficient of element resistance of a discrete TMR element that is not mounted on an apparatus, by measuring temperature versus element resistance value characteristic of the discrete TMR element in a state that a breakdown voltage is intentionally applied to the discrete TMR element and a tunnel barrier layer of the discrete TMR element is brought into a stable conductive state, a step of bringing a tunnel barrier layer of a TMR element actually mounted on the apparatus into a stable conductive state by intentionally applying the breakdown voltage to the mounted TMR element having the same structure as that of the discrete TMR element whose temperature coefficient has been measured, a step of measuring an element resistance value of the mounted TMR element with the tunnel barrier layer that has been brought into a stable conductive state, and a step of obtaining a temperature corresponding to the measured element resistance value from the previously measured temperature coefficient of element resistance.

Method of measuring temperature of tunnel magnetoresistive effect element

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Hong Kong, China

Man Tse