Abstract: To facilitate a change in the number and layout of magnetic field detection devices to be arranged in an array. A magnetic field detection device includes a cancel coil wound around a bobbin, a cover member fixed to the bobbin and covering the cancel coil in a direction perpendicular to the axial direction of the cancel coil, and magnetic sensors fixed to the bobbin or cover member. The cover member has side surfaces and extending in the z-direction and positioned on mutually opposite sides. The side surfaces have first and second engagement portions, respectively, and the first engagement portion has a shape engageable with the shape of the second engagement portion. This makes it possible to arrange a desired number of the magnetic field detection devices.

Abstract: To reduce the number of components and simplify the circuit configuration in a magnetic field detection device capable of detecting a weak magnetic field without using a shield room. A magnetic field detection device includes a cancel coil wound around a winding core part of a bobbin, magnetic sensors fixed to mutually different positions of the bobbin, and a feedback circuit that makes a cancel current flow in the cancel coil according to an output signal from the magnetic sensor to cancel the environmental magnetic field in a cancel space. Since the cancel coil is used in common for the magnetic sensors, it is possible to reduce the number of components to be used and to simplify the circuit configuration.

Abstract: To increase, in a magnetic sensor having a magnetoresistive strip and a ferromagnetic film, a magnetic bias to be applied to a magnetoresistive element by magnetically coupling the magnetoresistive strip and ferromagnetic film. A magnetic sensor 1 includes a magnetoresistive strip S, an insulating film 13 that covers the magnetoresistive strip S, and ferromagnetic films M1 and M2 formed on the insulating film 13 and arranged in the x-direction through a magnetic gap G extending in the y-direction. The ferromagnetic films M1 and M2 overlap a plurality of hard magnetic members H through the insulating film 13. This allows two adjacent hard magnetic members H to be magnetically coupled through the ferromagnetic films M1 and M2. This makes it possible to increase the magnetic bias to be applied to a magnetoresistive element R without involving an increase in the size of the hard magnetic member H.

Abstract: A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the substrate and a surface thereof faces the element formation surface. The arithmetic mean waviness Wa of the surface of the magnetism collecting member is 0.1 ?m or less. When the arithmetic mean waviness Wa of the surface of the magnetism collecting member that faces the element formation surface is set to 0.1 ?m or less, it is possible to significantly suppress a deterioration in detection sensitivity due to the presence of a gap between the element formation surface and the magnetism collecting member and to significantly reduce variations in detection sensitivity among products.

Abstract: A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the surface of the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the element formation surface. The magnetism collecting member has a surface positioned on the side opposite to the surface, and both the surfaces are flattened. This reduces a gap between the element formation surface and the magnetism collecting member and reduces variations among products. In addition, since the surface is also flattened, the magnetism collecting member has no directionality with respect to the sensor chip when it is mounted on the substrate, so that working efficiency during assembly can be improved.

Abstract: To reduce the number of components and simplify the circuit configuration in a magnetic field detection device capable of detecting a weak magnetic field without using a shield room. A magnetic field detection device includes a cancel coil wound around a winding core part of a bobbin, magnetic sensors fixed to mutually different positions of the bobbin, and a feedback circuit that makes a cancel current flow in the cancel coil according to an output signal from the magnetic sensor to cancel the environmental magnetic field in a cancel space. Since the cancel coil is used in common for the magnetic sensors, it is possible to reduce the number of components to be used and to simplify the circuit configuration.

Abstract: To facilitate a change in the number and layout of magnetic field detection devices to be arranged in an array. A magnetic field detection device includes a cancel coil wound around a bobbin, a cover member fixed to the bobbin and covering the cancel coil in a direction perpendicular to the axial direction of the cancel coil, and magnetic sensors fixed to the bobbin or cover member. The cover member has side surfaces and extending in the z-direction and positioned on mutually opposite sides. The side surfaces have first and second engagement portions, respectively, and the first engagement portion has a shape engageable with the shape of the second engagement portion. This makes it possible to arrange a desired number of the magnetic field detection devices.

Abstract: To increase, in a magnetic sensor having a magnetoresistive strip and a ferromagnetic film, a magnetic bias to be applied to a magnetoresistive element by magnetically coupling the magnetoresistive strip and ferromagnetic film. A magnetic sensor 1 includes a magnetoresistive strip S, an insulating film 13 that covers the magnetoresistive strip S, and ferromagnetic films M1 and M2 formed on the insulating film 13 and arranged in the x-direction through a magnetic gap G extending in the y-direction. The ferromagnetic films M1 and M2 overlap a plurality of hard magnetic members H through the insulating film 13. This allows two adjacent hard magnetic members H to be magnetically coupled through the ferromagnetic films M1 and M2. This makes it possible to increase the magnetic bias to be applied to a magnetoresistive element R without involving an increase in the size of the hard magnetic member H.

Abstract: Disclosed herein is a magnetic sensor that includes a sensor chip having a first magnetic layer, a second magnetic layer, and a magnetosensitive element; a first magnetism collecting member covering the first magnetic layer; and a second magnetism collecting member having a body part covering a back surface of the sensor chip, a first protruding part connected to the body part and covering a side surface of the sensor chip, and a second protruding part connected to the first protruding part and covering the second magnetic layer. The second protruding part has a first surface facing the second magnetic layer. The first surface is higher in flatness than at least one of the other surfaces of the second magnetism collecting member.

Abstract: A coupling structure of optical components has a first optical component, a second optical component and a coupling solder layer. The first optical component has a lensed fiber, a first holder holding the lensed fiber and a first metal layer formed on a first connecting end face of the first holder. The second optical component has a waveguide, a second holder holding the waveguide and a second metal layer formed on a second connecting end face of the second holder. The coupling solder layer is in direct contact with both of the first metal layer and the second metal layer, and formed with solder.

Abstract: A coupling structure of optical components has a first optical component, a second optical component and a coupling solder layer. The first optical component has a lensed fiber, a first holder holding the lensed fiber and a first metal layer formed on a first connecting end face of the first holder. The second optical component has a waveguide, a second holder holding the waveguide and a second metal layer formed on a second connecting end face of the second holder. The coupling solder layer is in direct contact with both of the first metal layer and the second metal layer, and formed with solder.

Abstract: A thermally assisted magnetic head (TAMH) slider having an air bearing surface and a back surface opposite the air bearing surface, which includes a slider substrate, a magnetic head portion configured on the slider substrate and having a waveguide formed therein, a semiconductor surface emitting laser configured on the back surface with an emitting surface facing the back surface; and a lens configured between the semiconductor surface emitting laser and the waveguide for focusing lights emitted from the semiconductor surface emitting laser on an incident end of the waveguide. The TAMH slider has stable performance, and can rapidly write data to a magnetic recording medium with high recording density.

Abstract: A method of testing a TAMH includes providing a slider body having a waveguide embedded therein with an incidence end extending toward a back surface of the slider body; providing a light source unit including a light source and a unit substrate; coating a bonding material layer on the back surface, under the bottom, or both on the back surface and under the bottom of the unit substrate; coating a localization material layer on the back surface; aligning the light source unit to the slider body; causing a light emitted from the light source and allowed to be incident on the incidence end to anneal the localization material layer to generate an annealing mark; removing the light source unit or the light source from the slider body; and measuring a position offset between the annealing mark and the incidence end. The method can evaluate alignment accuracy of a slider body and a light source unit in two dimensional directions.

Abstract: A method of manufacturing a thermally-assisted magnetic head includes providing a light source unit including a laser diode; providing a reflection board, and a photo detector; driving the laser diode to emit a light beam towards the reflection board; performing an alignment between the light source unit and the thermally-assisted magnetic recording head section, based on a reflected light of the light beam reflected by the reflection board, then passed through the optical waveguide and finally detected by the photo detector obtaining the maximum power in a LED emission state of the laser diode; and bonding the light source unit to the slider after the alignment is completed. It improves alignment accuracy between a light source unit and a slider during a bonding process therebetween, prevents a laser diode of the light source unit instability, and improves performance of the thermally-assisted magnetic head finally.

Abstract: A method of manufacturing a thermally-assisted magnetic head includes providing a light source unit including a laser diode; providing a reflection board, and a photo detector; driving the laser diode to emit a light beam towards the reflection board; performing an alignment between the light source unit and the thermally-assisted magnetic recording head section, based on a reflected light of the light beam reflected by the reflection board, then passed through the optical waveguide and finally detected by the photo detector obtaining the maximum power in a LED emission state of the laser diode; and bonding the light source unit to the slider after the alignment is completed. It improves alignment accuracy between a light source unit and a slider during a bonding process therebetween, prevents a laser diode of the light source unit instability, and improves performance of the thermally-assisted magnetic head finally.

Abstract: A head stack assembly includes a mounting base, a plurality of drive arms connected with the mounting base, and multiple pairs of head gimbal assemblies connected with the drive arms. Each head gimbal assembly includes a thermal assisted magnetic head, the thermal assisted magnetic head has an air bearing surface, a bottom surface opposite to the air bearing surface, and a laser diode module mounted on the bottom surface and adapted to emit a downward laser light to a write element of the thermal assisted magnetic head and an upward laser light, wherein a light shielding structure is provided to prevent the upward laser light emitting to other laser diode modules to generate light coupling, thereby improving thermal stability of the thermal assisted magnetic head.

Abstract: A method of manufacturing a thermally-assisted magnetic head includes aligning the light source unit to the thermally-assisted magnetic head section on the slider body; and performing a bonding between the unit substrate and the slider body with a bonding layer in between. And process of the bonding includes irradiating the bonding layer with a first laser shot, pausing for a time interval after the first laser shot, and then irradiating a second laser shot, wherein a first irradiating power of the first laser shot is weaker than a second irradiating power of the second laser shot, and a first irradiating time of the first laser shot is shorter than a second irradiating time of the second laser shot. The method can keep an accurate alignment of the unit substrate with respect to the slider after a bonding process and, in turns improve performance of the thermally-assisted magnetic head.

Abstract: A thin film made of a conductive material is formed on one surface of a long-sheet-shaped flexible base. The flexible base formed with the thin film made of the conductive material is wound in a roll shape to fabricate an original roll of coils. The flexible base formed with the thin film made of the conductive material is unwound from the original roll of coils, and rewound around an outer periphery of a core to fabricate a wound body. The wound body is cut in a direction orthogonal to the longitudinal direction of the core to make a coil intermediary body. A cut surface of the coil intermediate body which is cut from the wound body is lapped. Lead wires are attached to both ends of a winding section comprised of the conductive material within the coil intermediary body. The foregoing steps are performed in sequence to manufacture a coil.

Abstract: To provide a method of, and a device for, detecting smear of a magnetic head, in which detection of smear development before magnetic head assembly is made possible by measuring electrical resistance values between pads and shields of a slider that is integrated with a head main body portion, and in addition, throughput increases. The method of detecting smear of a magnetic head includes measuring electrical resistance values between pads of a slider having an integrated head main body portion, or between the pads and a conductor portion that is connected to a shield of the head main body portion to thereby detect smear development.

Abstract: To provide a method of, and a device for, detecting smear of a magnetic head, in which detection of smear development before magnetic head assembly is made possible by measuring electrical resistance values between pads and shields of a slider that is integrated with a head main body portion, and in addition, throughput increases. The method of detecting smear of a magnetic head includes measuring electrical resistance values between pads of a slider having an integrated head main body portion, or between the pads and a conductor portion that is connected to a shield of the head main body portion to thereby detect smear development.