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1. 发明专利

JPH09161226A PRODUCTION OF RECORDING AND REPRODUCING SEPARATION HEAD 失效
公开(公告)号：JPH09161226A
公开(公告)日：1997-06-20
申请号：JP31802095
申请日：1995-12-06
申请人： HITACHI LTD
发明人： KOBAYASHI TETSUO , KAGAWA MASAYOSHI
IPC分类号： G11B5/31 , G11B5/39
摘要： PROBLEM TO BE SOLVED: To provide a process for producing a recording and reproducing separation head which is small in the magnetization transition width in a track width direction at the time of recording with respect to the recording and reproducing separation head. SOLUTION: An upper shielding film 18 and a magnetic gap film 20 are etched down to the middle of the upper shielding film until the track width size approximately equal to the track width size of an upper magnetic core 31 is attained, by which a projecting part is formed. The spread of the leaking magnetic flux at the track end at the time of recording is suppressed and the magnetization transition width at the track end is diminished. Either of a photoresist and the upper magnetic core used at the time of etching the nonmagneic metallic films and upper magnetic core formed by electroplating is used as a mask for the mask at the time of etching.

2. 发明专利

JPH0573839A MAGNETIC DISK DEVICE 失效
公开(公告)号：JPH0573839A
公开(公告)日：1993-03-26
申请号：JP23296591
申请日：1991-09-12
申请人： HITACHI LTD
发明人： SANO MASAAKI , ARAI REIKO , KOMURO MATAHIRO , MITSUOKA KATSUYA , IWAKURA TADAYUKI , KAGAWA MASAYOSHI , TANABE MASANORI , KAWAKAMI HIROJI
IPC分类号： G11B5/31
摘要： PURPOSE:To provide a magnetic disk device having high recording density and mounted with a thin film magnetic head in which recording and reproduction are sufficiently performed on a high coersive force medium, the drop of the reproducing output at the time of increasing recording current is sufficiently small and also the unstable element of the magnetic core itself is controlled. CONSTITUTION:In the magnetic disk device mounted with a thin film magnetic head in which a magnetic circuit is constituted of a lower magnetic core 3 and a upper magnetic core 7 made by a plating method, as a substrate film to plate the lower magnetic core 3 and the upper magnetic core 7, a material having a higher saturation magnetic flux density than that of the magnetic cores 3, 7, is used.

3. 发明专利

JP2001101617A THIN FILM MAGNETIC HEAD, ITS MANUFACTURING METHOD AND MAGNETIC DISK DEVICE 失效
公开(公告)号：JP2001101617A
公开(公告)日：2001-04-13
申请号：JP27279899
申请日：1999-09-27
申请人： HITACHI LTD , HITACHI KYOWA ENG CO LTD
发明人： OIKAWA GEN , MORIJIRI MAKOTO , KAGAWA MASAYOSHI , SHIINA HIROMI
IPC分类号： G11B5/31
摘要： PROBLEM TO BE SOLVED: To provide a thin film magnetic head capable of ensuring precise dimensions of an upper writing pole by properly selecting the material of a conductive substrate film of plating and a contact film. SOLUTION: This manufacturing method of a thin film magnetic head comprises a stage (1) of forming the contact film 2 having tight adhesiveness to the conductive substrate film of plating and a photoresist on the conductive substrate film 1 of plating, a stage (2) of forming a photoresist frame 3 on the contact film, a stage (3) of removing the contact film corresponding to a part on which a plating film is formed, a stage (4) of forming the plating film 6 on the part after removing the contact film, a stage (5) of removing the resist frame and a stage (6) of, thereafter, removing the unnecessary contact film, the unnecessary conductive substrate film of plating and the unnecessary plated film.

4. 发明专利

JP2001034916A COMPOSITE THIN FILM MAGNETIC HEAD AND STORAGE COMPRISING THE SAME 失效
公开(公告)号：JP2001034916A
公开(公告)日：2001-02-09
申请号：JP20666299
申请日：1999-07-21
申请人： HITACHI LTD
发明人： KAGAWA MASAYOSHI , SAITO HARUNOBU , KOJIMA SHUICHI , OKAZAKI KOJI , ISHIKAKE KENJI
IPC分类号： G11B5/39
摘要： PROBLEM TO BE SOLVED: To reduce the so-called popcorn noise which is a spike-like random noise component appearing in a reproduction output immediately after a recording operation by forming an upper magnetic shielding layer comprising a first magnetic shielding layer, with a thickness in a specific range, close to a magneto-resistance effect sensor for reproduction and a second magnetic shielding layer deposited onto the first magnetic shielding layer. SOLUTION: An upper magnetic shielding layer 16 is composed of a portion (underlying film) 16a (first magnetic shielding layer) close to an MR sensor section 14 and the other portion (upper magnetic shielding layer portion) 16b (second magnetic shielding layer) than the underlying film 16a of the upper magnetic shielding layer 16, and the thickness of the underlying film 16a is in the range from 0.1 μm to 1.0 μm. Permalloy containing nickel(Ni) and iron as its main components is used as the underlying film 16a, and the underlying film 16a is deposited by sputtering to achieve a desired thickness and magnetostriction constant. It is desirable that the composition of Ni in the underlying film 16a is in the range from 81.5% to 85% and the magnetostriction constant of the underlying film 16a is in the range from 0 to -5×10-6.

5. 发明专利

JPH1166519A MAGNETORESISTANCE EFFECT THIN FILM MAGNETIC HEAD 失效
公开(公告)号：JPH1166519A
公开(公告)日：1999-03-09
申请号：JP22411997
申请日：1997-08-20
申请人： HITACHI LTD
发明人： KAGAWA MASAYOSHI , YOSHIDA AKIRA , KAWAKAMI HIROJI , KOBAYASHI TETSUO , SAITO HARUNOBU
IPC分类号： G11B5/31 , G11B5/39
摘要： PROBLEM TO BE SOLVED: To control spike type random noise element by forming a lower magnetic shield layer with a material having a coercive force larger than magnetic field to be applied to the lower magnetic shield layer during the write operation. SOLUTION: A lower magnetic shield layer 12 is formed of a material having a coercive force Hc of the film larger than the magnetic field applied during the recording operation or of a material having a large unisotropic magnetic field Hk. It is also possible to use a material having a large coercive force Hc and a large unisotropic magnetic field Hk. In the case of an MR head where a film having the single axis magnetic unisotropy is arranged on the lower magnetic shield layer with the magnetization easy axis directed to the track width direction, when a coercive force Hc of film is set to 5(Oe) or more, magnetization change of the lower magnetic shield is kept within a minor loop even if it is operated with an excitation coil and the magnetization condition after the recording operation does not become unstable due to the magnetic hysteresis. Popcorn noise appearing in the reproduced output of MR sensor after the recording operation can be controlled.

6. 发明专利

JP2002170211A SPIN VALVE TYPE VERY LARGE MAGNETORESISTIVE HEAD, AND ITS MANUFACTURING METHOD 失效
公开(公告)号：JP2002170211A
公开(公告)日：2002-06-14
申请号：JP2000365771
申请日：2000-11-28
申请人： HITACHI LTD
发明人： ARASAWA MASATOSHI , TANAKA ATSUKO , MORIJIRI MAKOTO , NISHIOKA KOICHI , KOJIMA SHUICHI , KAGAWA MASAYOSHI
IPC分类号： G01R33/09 , G03F7/20 , G11B5/31 , G11B5/39 , H01L43/08 , H01L43/12
摘要： PROBLEM TO BE SOLVED: To suppress fluctuation in a reproducing output waveform by applying a magnetic domain control field to a spin valve type very large magnetoresistive layer to set a free magnetic layer as a signal magnetic domain while a constant dielectric breakdown withstand pressure is secured to maintain electric reliability in a spin valve type very large magnetoresistive head. SOLUTION: A spin valve type very large magnetoresistive laminate layer D1 having a trapezoidal sectional shape is formed by laminating an antiferromagnetic layer 1, a fixed magnetic layer 3, a free magnetic layer 4, and a nonmagnetic protective layer 5 on a lower insulating gasp layer 7. In this case, the etching amount of the lower insulating gap layer 7 is set equal to/lower than 10 nm, which is generated when a spin valve type giant magneto-resistance effect layer is formed on the laminate layer D1, and an angle θbetween the tangential line of the side face of the laminate layer D1 in the center of the free magnetic layer 4 in a film thickness direction and the center line of the free magnetic layer 4 is set equal to/higher than 45 deg.. Thus, the spin valve type very large magnetoresistive head capable of securing a constant dielectric breakdown withstand pressure, suppressing fluctuation in a reproducing output waveform and improving electric reliability and magnetic reliability is obtained.

7. 发明专利

JP2002092828A MAGNETORESISTIVE EFFECT TYPE THIN FILM MAGNETIC HEAD 失效
公开(公告)号：JP2002092828A
公开(公告)日：2002-03-29
申请号：JP2000282177
申请日：2000-09-18
申请人： HITACHI LTD
发明人： KAGAWA MASAYOSHI , TADOKORO SHIGERU , KOYAMA NAOKI , MIYAMOTO NORIFUMI , ISHIKAKE KENJI
IPC分类号： G01R33/09 , G11B5/39 , H01F10/16 , H01L43/08
摘要： PROBLEM TO BE SOLVED: To reduce instability of output fluctuation, asymmetrical fluctuation, Barkhausen noise and the like without incurring the reduction of reproducing output by stabilizing a magnetic domain structure in a free layer of a MR sensor part. SOLUTION: In a magnetoresistive effect type thin film magnetic head provided with a lower magnetic shield, a magnetoresistive effect sensor 61 for reproduction, hard magnetic layers 64 and 65 disposed at both end parts of the sensor opposite to each other and stabilizing the magnetic domain structure of the sensor, an upper magnetic shield, an upper magnetic core for recording and a magnetizing coil for recording operation, the magnetoresistive effect sensor for reproduction has a gradient leaned to the negative side for a magnetic distortion constant from the center part to the both end parts of the sensor. Then the magnetoresistive effect type thin film magnetic head has a magnetic distortion controlling layer 62 for controlling the magnetic distortion constant of the sensor and an underground layer 63 for controlling the magnetic characteristics of the hard magnetic layers between the sensor and the hard magnetic layers.

8. 发明专利

JPH11120520A MAGNETORESISTIVE EFFECT HEAD AND MAGNETIC MEMORY SYSTEM USING THE SAME 失效
公开(公告)号：JPH11120520A
公开(公告)日：1999-04-30
申请号：JP28491697
申请日：1997-10-17
申请人： HITACHI LTD
发明人： SATO KATSUMI , KOBAYASHI TETSUO , KAGAWA MASAYOSHI , MITSUOKA KATSUYA , KAWABE TAKASHI
IPC分类号： G11B5/39
摘要： PROBLEM TO BE SOLVED: To lower a reading error rate of a magnetic memory system occurring in the output fluctuation of a head and the asymmetricalness of waveforms by mounting a magnetic head which is small in the output fluctuation and the asymmetricalness of the waveforms. SOLUTION: A magnetic domain control layer 34 formed on an underlying metal layer 35 comes into contact with an MR layer 31 formed on a magnetosensitive part 38, a soft magnetic layer 32 and a nonmagnetic layer 33 in a joint part 37. The magnetic domain control layer 34 has a nearly perpendicular angle in the taper angle 40 of the three layer active regions and is, therefore, not formed on the MR layer 31 having soft magnetic characteristics and the soft magnetic layer 32. Since the film thickness of the underlying metal layer 35 is adequately thick, the magnetic domain control layer 34 and the MR layer 31 do not have exchange bond and the magnetic domain control layer 34 is laminated in the position where the MR layer 31 and the magnetostatic interaction are max. The magnetic domain control layer 34 having large coercive force is formed in the end region 39 and the longitudinal bias magnetic field, based on the magnetostatic interaction between the magnetic domain control layer 34 and the MR layer 31 is formed.

9. 发明专利

JPH0896329A MAGNETORESISTIVE EFFECT HEAD 失效
公开(公告)号：JPH0896329A
公开(公告)日：1996-04-12
申请号：JP23278394
申请日：1994-09-28
申请人： HITACHI LTD
发明人： YUHITO ISAMU , KAGAWA MASAYOSHI , NISHIOKA KOICHI
IPC分类号： G11B5/39
摘要： PURPOSE: To provide a magnetoresistive effect head with which Barkhausen noise is suppressed without degrading reproduced output by determining the saturation magnetic flux density of hard magnetic film and positional relation between film thicknesses and electrode. CONSTITUTION: The distance (d) between the end of noise suppressing film 8 and the end of the electrode 9 of the magnetoresistive effect head formed by using a hard magnetic film for suppressing the Barkhausen noise is set at >=1/20 of the saturation magnetic flux density Bs × film thickness (t) of the hard magnetic film. As a result, the Barkhausen noise in suppressed without degrading the bias effect by the reproduced output. The noise suppression by the hard magnetic film is effective for both of magnetoresistance effect film and bias film.

10. 发明专利

JP2002185060A DUAL-SPIN-VALVE TYPE THIN-FILM ELEMENT AND ITS MANUFACTURING METHOD, AND THIN-FILM MAGNETIC HEAD 失效
公开(公告)号：JP2002185060A
公开(公告)日：2002-06-28
申请号：JP2000381693
申请日：2000-12-11
申请人： HITACHI LTD
发明人： OKAZAKI KOJI , NISHIOKA KOICHI , TAJIMA YASUNARI , SHIGEMATSU KEISHI , KAGAWA MASAYOSHI
IPC分类号： G01R33/09 , G11B5/39 , H01F10/16 , H01F10/26 , H01F10/32 , H01L43/08 , H01L43/12
摘要： PROBLEM TO BE SOLVED: To provide a dial-spin-valve type thin-film element that shows excellent soft magnetic characteristics or proper Hint and λ with a high MR ratio. SOLUTION: In this dual-spin-valve type thin-film element having a lamination Fery type fixing layer, a free magnetic layer is formed by at least one kind of a lamination layer selected from among NiFe alloy, Co, and CoFe alloy. In this case, in upper and lower sets of the lamination Fery type fixing layers, the film thickness of fixing magnetic layer at the side of the free magnetic layer is set thicker than that of the fixing magnetic layer at the side of an antiferromagnetic layer in both the upper and lower sections.

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