摘要:
In formation of an upper shield of a magnetic thin film head by electroplating, a current density of electroplating is regulated stepwise with time. Thus, in the upper shield formation, a film composition and magnetic characteristic with respect to the direction of film thickness can be controlled precisely, making it possible to provide a magnetic thin film head featuring significantly reduced noise-after-write and output fluctuation.
摘要:
In formation of an upper shield of a magnetic thin film head by electroplating, a current density of electroplating is regulated stepwise with time. Thus, in the upper shield formation, a film composition and magnetic characteristic with respect to the direction of film thickness can be controlled precisely, making it possible to provide a magnetic thin film head featuring significantly reduced noise-after-write and output fluctuation.
摘要:
Embodiments of the present invention help to provide a perpendicular magnetic recording head capable of writing a signal in a track having a small width. According to one embodiment, a perpendicular magnetic recording head includes an auxiliary pole, a main pole, a yoke, a coil, a first soft magnetic film and a second soft magnetic film. The yoke is in contact with the main pole. The coil is wound around a magnetic circuit composed of the auxiliary and main poles and the yoke. The first soft magnetic film is provided on both sides of the main pole with a non-magnetic film provided between the first soft magnetic film and the main pole. The second soft magnetic film is provided on the trailing side of the main pole with the non-magnetic film provided between the second soft magnetic film and the main pole. The first and second soft magnetic films are two types of plated magnetic films. One type of the plated magnetic films have respective thicknesses of 0.5 nm to 20 nm and respective body centered cubic lattice crystal structures. The other types of the plated magnetic films have respective thicknesses of 0.5 nm to 20 nm and respective face centered cubic lattice crystal structures. The two types of the plated magnetic films are alternately laminated with four or more layers. This can achieve the magnetic disk drive capable of reducing a possibility to erroneously delete a signal after the signal being written and preventing degradation of characteristics of a high frequency signal.
摘要:
Embodiments of the present invention help to provide a perpendicular magnetic recording head capable of writing a signal in a track having a small width. According to one embodiment, a perpendicular magnetic recording head includes an auxiliary pole, a main pole, a yoke, a coil, a first soft magnetic film and a second soft magnetic film. The yoke is in contact with the main pole. The coil is wound around a magnetic circuit composed of the auxiliary and main poles and the yoke. The first soft magnetic film is provided on both sides of the main pole with a non-magnetic film provided between the first soft magnetic film and the main pole. The second soft magnetic film is provided on the trailing side of the main pole with the non-magnetic film provided between the second soft magnetic film and the main pole. The first and second soft magnetic films are two types of plated magnetic films. One type of the plated magnetic films have respective thicknesses of 0.5 nm to 20 nm and respective body centered cubic lattice crystal structures. The other types of the plated magnetic films have respective thicknesses of 0.5 nm to 20 nm and respective face centered cubic lattice crystal structures. The two types of the plated magnetic films are alternately laminated with four or more layers. This can achieve the magnetic disk drive capable of reducing a possibility to erroneously delete a signal after the signal being written and preventing degradation of characteristics of a high frequency signal.
摘要:
Embodiments of the present invention provide a magnetic disk drive capable of allowing higher data transfer rates and higher recording densities. According to one embodiment, an upper magnetic core and lower magnetic core comprise a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is about 30±1° C., pH is about 2.0−1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Since each layer's crystal structure is different from that of its adjacent lower layer, epitaxial growth is broken within each layer. Thus, since crystal grains are reduced in size, it is possible to lessen the decrease of the permeability μ at higher frequencies.
摘要:
Embodiments of the invention provide a lustrous and uniform plating film having high-performance magnetic characteristics and a thin film magnetic head usable in a high frequency recording band by using the plating film of the invention at a magnetic pole portion. Plating is performed in a plating bath at a low pH of about 1.5 to 2.3. The accuracy of pH control is improved. A magnetic film with the addition of a high resistive metal such as Cr or Mo is formed under the plating condition. Further, the magnetic characteristic is improved by applying a heat treatment to the plating film in a magnetic field, according to specific embodiments of the present invention. A plating film with brightness and uniformity having high saturation magnetic flux density can be formed by reducing the hysteresis loss and the eddy current loss as the magnetic characteristics by the above techniques.
摘要:
Embodiments of the present invention provide a magnetic shield composed of size-controlled small crystal grains and provide a more after-write read noise free thin film magnetic head. According to one embodiment of the present invention, an upper magnetic shield uses a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is 30±1° C., pH is about 2.0−1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Each layer's crystal structure is different from that of its upper and lower layers, which results in size-controlled small crystal grains since the epitaxial growth is broken. Since crystal grains are reduced in size, it is possible to suppress the after-write read noise and therefore attain a read head which allows recording at higher frequencies.
摘要:
Embodiments of the invention provide a lustrous and uniform plating film having high-performance magnetic characteristics and a thin film magnetic head usable in a high frequency recording band by using the plating film of the invention at a magnetic pole portion. Plating is performed in a plating bath at a low pH of about 1.5 to 2.3. The accuracy of pH control is improved. A magnetic film with the addition of a high resistive metal such as Cr or Mo is formed under the plating condition. Further, the magnetic characteristic is improved by applying a heat treatment to the plating film in a magnetic field, according to specific embodiments of the present invention. A plating film with brightness and uniformity having high saturation magnetic flux density can be formed by reducing the hysteresis loss and the eddy current loss as the magnetic characteristics by the above techniques.
摘要:
Embodiments of the present invention provide a magnetic disk drive capable of allowing higher data transfer rates and higher recording densities. According to one embodiment, an upper magnetic core and lower magnetic core comprise a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is about 30±1° C., pH is about 2.0−1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Since each layer's crystal structure is different from that of its adjacent lower layer, epitaxial growth is broken within each layer. Thus, since crystal grains are reduced in size, it is possible to lessen the decrease of the permeability μ at higher frequencies.
摘要:
Embodiments of the present invention provide a magnetic shield composed of size-controlled small crystal grains and provide a more after-write read noise free thin film magnetic head. According to one embodiment of the present invention, an upper magnetic shield uses a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is 30±1° C., pH is about 2.0-1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Each layer's crystal structure is different from that of its upper and lower layers, which results in size-controlled small crystal grains since the epitaxial growth is broken. Since crystal grains are reduced in size, it is possible to suppress the after-write read noise and therefore attain a read head which allows recording at higher frequencies.