Tdk Corporation

Sae Magnetics (h.k.) Limited

Kenji Inage

Nozomu Hachisuka

Hiroshi Kiyono

Shunji Saruki

Toshiaki Maeda

Takehiro Isoda

Masanori Sakai

Norikazu Ota

Koichi Terunuma

Norio Takahashi

Hiromichi Umehara

Keisuke Takasugi

Koji Shimazawa

Masashi Shiraishi

Yoshihiro Tsuchiya

Masato Takahashi

Takeshi Wada

Kazumasa Fukuda

Takeo Kagami

Haruyuki Morita

Tatsushi Shimizu

Katsumichi Tagami

Tetsuya Kuwashima

Taro Oike

Yoshihiro Kudo

Yuzuru Iwai

Ken-ichi Takano

Pak Kin Wong

Masahide Kohno

Jun Shouji

Daichi Takano

A magnetic sensor includes an insulating layer including a flat portion and a protruding portion, a first MR element, and a second MR element. The protruding portion includes a first inclined surface and a second inclined surface. The first MR element is disposed on the first inclined surface. The second MR element is disposed on the second inclined surface. The protruding portion extends in a first direction parallel to a top surface of a substrate, and includes a plurality of recess portions each recessed in a direction parallel to the top surface of the substrate at an end of the protruding portion in the first direction.

Sensor

A magnetic sensor includes a plurality of resistor sections each including a plurality of MR elements, and a plurality of protruding surfaces each structured to cause the plurality of MR elements to detect a specific component of a target magnetic field. The plurality of MR elements are disposed dividedly in first to fourth areas corresponding respectively to the plurality of resistor sections. The plurality of protruding surfaces include a structural body extending across at least two of the first to fourth areas.

Magnetic sensor

Sensor having at least part of sensor element disposed on inclined surface of protruding portion of support member

A TMR effect element with sufficiently reduced element resistance and restricted popping noise is provided, which comprises a tunnel barrier layer formed primarily of a metal oxide including many electric charge sites. The electric charge sites density n and the mobility &#x3bc; of electrons trapped due to the electric charge sites satisfy a relationship expressed by: 0&#x3c;(n&#x2212;n)&#xb7;(&#x3bc;&#x2212;&#x3bc;)&#xb7;(n&#x3bc;)&#x3c;0.2, where nand nare densities of tunnel electrons when an element resistance is a minimum and maximum respectively during reading signals and &#x3bc;is the mobility of electrons when not trapped.

Tunnel magnetoresistive effect element with limited electric popping output voltage

A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.

Method and apparatus for testing tunnel magnetoresistive effect element, manufacturing method of tunnel magnetoresistive effect element and tunnel magnetoresistive effect element

A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.

Provided is a magnetoresistive device capable of stably maintaining sufficient output characteristics even under a higher temperature environment while responding to a demand for a higher recording density. The magnetoresistive device comprises an MR film including a fixing layer made of IrMn, an outer pinned layer of which the magnetization direction is fixed in a +Y direction by the fixing layer, and an inner pinned layer of which the magnetization direction is fixed in a &#x2212;Y direction by the fixing layer, a pair of conductive lead layers and a constant current circuit which flows a sense current in a +X direction so as to generate a current magnetic field toward a &#x2212;Y direction in the inner pinned layer, and in the magnetoresistive device, a conditional expression (1) is satisfied. Thereby, the magnetization directions of the outer pinned layer and the inner pinned layer can be stabilized, so even under a high temperature environment, the magnetoresistive device can obtain stable output characteristics, and can respond to a demand for a higher recording density.

Magnetoresistive device supplying sense current thereto dependent upon a relationship existent between the thickness of the fixed layer and its magnetization

A thin-film magnetic head includes at least one inductive write head element and at least one read magnetic head element, capable of controlling a spacing between a magnetic recording medium and the at least one magnetic read head element by heating. A gain SG (nm/&#xb0; C.) of the spacing is greater than a spacing gain threshold SG(nm/&#xb0; C.) defined by the following expression:

Thin-film magnetic head, head gimbal assembly with thin-film magnetic head, magnetic disk drive apparatus with head gimbal assembly, method for designing thin-film magnetic head and manufacturing method of thin-film magnetic head

Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.

Method and apparatus for testing tunnel magnetoresistive effect element

Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.

A thin-film magnetic head includes a TMR element and a resistor element connected in parallel with the TMR element. A resistance value Rof the TMR element itself is R&#x2267;240 &#x3a9;, a product RA of the resistance value of the TMR element itself and a cross-sectional area of the TMR element is RA&#x2267;3 &#x3a9;&#xb7;&#x3bc;m, and a resistance value Rof the resistor element is R&#x2266;480&#x3a9;.

Thin-film magnetic head with tunnel magnetoresistive effect element electrically connected in parallel with a resistor element

A magnetoresisive device comprises an MR element, bias field applying layers located adjacent to the side portions of the MR element, and two electrode layers that feed a sense current to the MR element. The electrode layers overlap one of the surfaces of the MR element. The total overlap amount of the two electrode layers is smaller than 0.3 &#x3bc;m. The MR element is a spin-valve GMR element. The MR element incorporates a base layer, a free layer, a spacer layer, a pinned layer, an antiferromagnetic layer, and a cap layer that are stacked in this order. The pinned layer includes a nonmagnetic spacer layer, and two ferromagnetic layers that sandwich this spacer layer.

Magnetoresistive device in a thin-film magnetic head and method of manufacturing same having particular electrode overlay configuration

A head suspension assembly includes a magnetic head slider with at least one thin-film magnetic head element, a support member for supporting the magnetic head slider at a top end portion thereof, a drive circuit electrically connected to the at least one thin-film magnetic head element, and at least two diode elements connected toward one direction in parallel with terminals which are connected across the at least one thin-film magnetic head element. Each of the diode elements has a turn-on voltage higher than the maximum output voltage of the at least one thin-film magnetic head element.

Head suspension assembly

A method for testing a composite type magnetic head having a MR element and an inductive element includes a current application step of applying a current to the inductive element, with applying no external magnetic field to the magnetic head, and a measurement step of measuring output characteristics of the MR element after the current application step is finished.

Method and apparatus for testing composite type magnetic head having a magnetoresistive element and an inductive element

A current which will change an initial magnetization state of a shield layer for a MR element is applied to an inductive element, and output characteristics of the MR element is measured.

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Tokyo, Japan

Kenji Inage