A thin film magnetic head includes an upper shield section, a lower shield section and a magnetoresistance device section between the upper shield section and the lower shield section. The magnetoresistance device section is connected to the upper shield section and the lower shield section through conductive layers. Current flows through the magnetoresistance device section via the upper shield and the lower shield.

Thin film magnetic head

An object of the invention is to provide a thin film magnetic head which can exhibit a high-performance head characteristic without complicating the manufacturing procedure, and a method of manufacturing the same. A coil connection is integrated into one body and constituted part of the thin film coil. A connection middle pattern is provided on the coil connection at the time of forming a pole tip so that the position of the upper surface of the connection middle pattern becomes higher than that of the top pole tip. After the whole portion is covered by an insulating film, the connection middle pattern also can be exposed by polishing the surface of the insulating film until the top pole tip is exposed. Therefore, unlike the case where no connection middle pattern is provided, it is not necessary to have a step of forming an opening by partially removing part of the insulating film. As a result, the number of manufacturing steps can be reduced.

Thin film magnetic head and method of manufacturing the same

Submucosal glands contribute to airway surface liquid (ASL), a film that protects all airway surfaces. Glandular mucus comprises electrolytes, water, the gel-forming mucin MUC5B, and hundreds of different proteins with diverse protective functions. Gland volume per unit area of mucosal surface correlates positively with impaction rate of inhaled particles. In human main bronchi, the volume of the glands is ∼ 50 times that of surface goblet cells, but the glands diminish in size and frequency distally. ASL and its trapped particles are removed from the airways by mucociliary transport. Airway glands have a tubuloacinar structure, with a single terminal duct, a nonciliated collecting duct, then branching secretory tubules lined with mucous cells and ending in serous acini. They allow for a massive increase in numbers of mucus-producing cells without replacing surface ciliated cells. Active secretion of Cl(-) and HCO3 (-) by serous cells produces most of the fluid of gland secretions. Glands are densely innervated by tonically active, mutually excitatory airway intrinsic neurons. Most gland mucus is secreted constitutively in vivo, with large, transient increases produced by emergency reflex drive from the vagus. Elevations of [cAMP]i and [Ca(2+)]i coordinate electrolyte and macromolecular secretion and probably occur together for baseline activity in vivo, with cholinergic elevation of [Ca(2+)]i being mainly responsive for transient increases in secretion. Altered submucosal gland function contributes to the pathology of all obstructive diseases, but is an early stage of pathogenesis only in cystic fibrosis.

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Airway Gland Structure and Function.

An inductive transducer having first and second magnetic pedestals disposed between first and second magnetic pole layers and adjacent to a media-facing surface, the pedestals separated by a submicron, nonmagnetic gap. The first pedestal extends less than the second pedestal from the media-facing surface, defining a short throat height. The second pedestal extends further to provide sufficient area for stitching to the second pole layer. The stitching and the thickness provided by the pedestals allow plural coil layers to be disposed between the pole layers, and the second pedestal, as well as other features, can be defined by high-resolution photolithography. The two coil layers have lower resistance, lower inductance and allow the pole layers to be shorter, improving performance. All or part of either or both of the pedestals may be formed of high magnetic saturation material, further enhancing performance.

Inductive transducer with stitched pole tip and pedestal defining zero throat height

A method of forming a head comprises forming a write transducer on a wafer, cutting the wafer to produce a slider bar with a cut surface, and planarizing the cut surface of the slider bar. Forming the write transducer can include forming a first pole layer and forming a first pole pedestal layer over the first pole layer, where the first pole pedestal layer includes a tapered portion defined by a first end having a nose width less than a desired final nose width, and a second end having a zero throat width greater than the desired final nose width. Planarizing the cut surface of the slider bar exposes the first pole pedestal layer until a width thereof approximately equals the desired final nose width.

Method of forming a magnetoresistive device

A thin film magnetic head has a first magnetic core member carried by a substrate, a gap layer formed on the first magnetic core member, and a second magnetic core member formed in a spaced relation with the first magnetic core member. The second magnetic core member is coupled to the first magnetic core member to form a magnetic path and to have an end portion of the gap layer sandwiched by gap defining portions of the first and second magnetic core members. A coil conductor is wound about the magnetic path. In one embodiment, the first magnetic core member includes a first magnetic layer made of a magnetic material having stable magnetic properties during heat treatment and the second magnetic core member includes a second magnetic layer made of a material having a saturation flux density higher than that of the material of the first magnetic core member.

Thin film magnetic head having at least one magnetic core member made at least partly of a material having a high saturation magnetic flux density

Disclosed is a magnetic disk apparatus including a magnetic reproducing head portion, and a magnetic recording head including an upper magnetic core having a end portion and a rear portion. As a resist for a frame which is used for forming the rear portion, a negative resist or an electron beam resist is used, whereby the frame is formed without any adverse effect of halation from a coil insulating film. That is, it is possible to manufacture a magnetic recording head in which the rear portion of an upper magnetic core is not emerged at the face opposed to a medium, and hence to obtain a magnetic disk apparatus exhibiting an areal recording density of 5 Gbit/in 2 or more by mounting a magnetic recording/reproducing head including such a magnetic recording head.

Thin film magnetic head and magnetic disk apparatus including the same

Stroboscopic electron-beam tomography has been achieved for time-resolved measurement of the magnetic recording thin-film head. The transition characteristics of magnetic field distributions were compared; the driving current was found to have a temporal resolution of 1 ns. Both the driving current waveforms and the magnetic field distributions are measured by a pulsed electron beam with the same timing pulse gate. This measurement was successfully applied to Ni-Fe and CoTaZr amorphous thin-film disk heads. It was found that the magnetic field distribution change with time is not uniform and that the peak field is a few nanoseconds behind the driving current for Ni-Fe heads. The frequency characteristics of these heads correspond for the magnetic field delay to the driving current. The frequency characteristics of the head whose magnetic field delay is longer are inferior to those of the head whose magnetic field delay is shorter. >

Time resolved measurement of dynamic micro-magnetic field by stroboscopic electron beam tomography

In order to study the magnetic behaviors of pinned layers under different conditions, we applied compressive mechanical stress to a device and measured the transfer curve changes using a high-field (10 kOe) quasi-static tester. This permitted us to determine the behaviors of the pinned layers and the free layer. The results of the transfer curve measurements led to a classification of these curves. The governing conditions for each category were also determined. A normal transfer curve occurs when "E/sub j/>E/sub u//spl Gt/E/sub k/(AP1) and E/sub k/(AP2)," where: AP1 is the pinned layer adjacent to the antiferromagnetic (AFM) layer; AP2 is the pinned layer adjacent to the spacer; E/sub u/ is the coupling energy constant between the antiferromagnetic layer and the AP1; E/sub j/ is the anti-parallel coupling energy constant between AP1 and AP2 through the Ru; and E/sub k/(AP1) and E/sub k/(AP2) are the induced uniaxial anisotropic energy constants in AP1 and AP2 due to magnetostriction resulting from stress applied giant magnetoresistive (GMR) sensor.

The behavior of pinned layers using a high-field transfer curve

The dynamic behavior of a 180° wall was observed in a Co‐based amorphous alloy film using a Kerr microscope. As a function of an anisotropy direction the amplitude of the 180° wall movement was measured with the drive field applied transverse to the 180° wall of the closure domain structure. The anisotropy direction was varied by magnetic heat treatment. It was found that the 180° wall moved independently of the anisotropy direction, that is, the 180° wall movement is related only to the applied high‐frequency field. To clarify the cause of the 180° wall movement, the magnetic energy of the domain structure and the eddy current loss caused by the high‐frequency field were calculated. However, the movement could not be understood completely in terms of energy balance since the magnetostatic energy increases faster than the decrease of the eddy current loss, when the 180° wall moves.

Sasaki Shinobu

Papers

Thin film magnetic head having at least one magnetic core member made at least partly of a material having a high saturation magnetic flux density

Thin film magnetic head and magnetic disk apparatus including the same

Time resolved measurement of dynamic micro-magnetic field by stroboscopic electron beam tomography

The behavior of pinned layers using a high-field transfer curve

180° wall movement in a magnetic thin‐film closure domain structure in a high‐frequency field