US20010034185A1 - Thin-film magnetic head manufacturing method and apparatus - Google Patents
Thin-film magnetic head manufacturing method and apparatus Download PDFInfo
- Publication number
- US20010034185A1 US20010034185A1 US09/863,731 US86373101A US2001034185A1 US 20010034185 A1 US20010034185 A1 US 20010034185A1 US 86373101 A US86373101 A US 86373101A US 2001034185 A1 US2001034185 A1 US 2001034185A1
- Authority
- US
- United States
- Prior art keywords
- lapping
- thin
- film magnetic
- finish
- magnetic head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 170
- 239000010409 thin film Substances 0.000 title claims abstract description 158
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 53
- 239000000758 substrate Substances 0.000 claims description 39
- 239000000314 lubricant Substances 0.000 claims description 17
- 238000012544 monitoring process Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 description 28
- 230000008569 process Effects 0.000 description 23
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 230000008859 change Effects 0.000 description 7
- 229910052593 corundum Inorganic materials 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- 229910001845 yogo sapphire Inorganic materials 0.000 description 6
- 239000012530 fluid Substances 0.000 description 5
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 4
- 230000001939 inductive effect Effects 0.000 description 4
- 101000760620 Homo sapiens Cell adhesion molecule 1 Proteins 0.000 description 3
- 101001139126 Homo sapiens Krueppel-like factor 6 Proteins 0.000 description 3
- 102100040160 Rabankyrin-5 Human genes 0.000 description 3
- 101710086049 Rabankyrin-5 Proteins 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000002950 deficient Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 3
- 101000710013 Homo sapiens Reversion-inducing cysteine-rich protein with Kazal motifs Proteins 0.000 description 2
- 101000661816 Homo sapiens Suppression of tumorigenicity 18 protein Proteins 0.000 description 2
- 101000661807 Homo sapiens Suppressor of tumorigenicity 14 protein Proteins 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910000889 permalloy Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 101000911772 Homo sapiens Hsc70-interacting protein Proteins 0.000 description 1
- 230000005290 antiferromagnetic effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 108090000237 interleukin-24 Proteins 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000000992 sputter etching Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3163—Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
- G11B5/3166—Testing or indicating in relation thereto, e.g. before the fabrication is completed
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3163—Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
- G11B5/3169—Working or finishing the interfacing surface of heads, e.g. lapping of heads
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3163—Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
- G11B5/3173—Batch fabrication, i.e. producing a plurality of head structures in one batch
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B33/00—Constructional parts, details or accessories not provided for in the other groups of this subclass
- G11B33/10—Indicating arrangements; Warning arrangements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/187—Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features
- G11B5/1871—Shaping or contouring of the transducing or guiding surface
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49034—Treating to affect magnetic properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49036—Fabricating head structure or component thereof including measuring or testing
- Y10T29/49041—Fabricating head structure or component thereof including measuring or testing with significant slider/housing shaping or treating
Definitions
- the present invention relates to a thin-film magnetic head manufacturing method and apparatus for precisely lapping thin-film magnetic heads for use in magnetic disk devices and the like.
- thin layers constituting thin-film magnetic elements are stacked in order on a substrate made of Al 2 O 3 -TiC (alumina titanium carbide) by sputtering, and the thin layers are worked by photolithography or ion milling as required.
- a substrate made of Al 2 O 3 -TiC alumina titanium carbide
- a thin-film magnetic element 1 is a so-called “MR (magnetoresistive)/inductive combined magnetic head” in which an MR magnetic head having a magnetoresistive sensor for reading recorded information and an inductive magnetic head for writing are combined.
- the thin-film magnetic elements 1 are electrically connected by electrodes 4 connected thereto.
- the substrate 2 is cut along the dotted lines to yield a slider bar as shown in FIG. 6.
- the height of the magnetoresistive sensor of the MR magnetic head in the thin-film magnetic element 1 must be adjusted to a predetermined value.
- the MR height is adjusted by lapping an ABS (air-bearing surface) 3 a shown in FIG. 6 while using some of a plurality of magnetoresistive sensors as monitor elements, and measuring DC resistance values (DCR values) between the electrode layers connected to both ends of the magnetoresistive sensors.
- the height of the magnetoresistive sensors can be set at an appropriate value.
- the slider bar 3 is cut along the dotted lines shown in FIG. 6 into individual thin-film magnetic heads. Individual substrates cut from the slider bar 3 serve as sliders.
- the ABS 3 a of the slider faces a recording medium and receives a levitating force when the recording medium moves.
- Lapping for adjusting the MR height is performed by using, for example, a lapping plate 21 shown in FIG. 8.
- the slider bar 3 shown in FIG. 6 is placed so that the ABS 3 a thereof is in contact with the surface of the lapping plate 21 .
- the lapping plate 21 is rotationally driven to lap the ABS 3 a of the slider bar 3 .
- FIGS. 9A and 9B are flowcharts showing the process of lapping for adjusting the MR height.
- Lapping is performed in two stages, rough lapping (FIG. 9A) with a lapping fluid applied on the upper surface of the lapping plate 21 , and finish lapping (FIG. 9B) with a lubricant applied on the lapping plate 21 as necessary.
- finish lapping shown in FIG. 9B, lapping is similarly performed while the DCR values of the monitor elements are being monitored, and it is completed when the DCR values fall into the finish tolerance range, which means that the MR heights also falls into the finish tolerance range.
- FIGS. 11A and 11B are side views of the slider bar 3 and the thin-film magnetic element 1 , respectively, before lapping is started, and during or after lapping.
- a cover layer 5 is formed to cover the thin-film magnetic element 1 .
- This cover layer 5 is made of Al 2 O 3 or SiO 2.
- the lapping fluid contains fine particles, and the ABS 3 a is lapped therewith.
- the thin-film magnetic element 1 primarily made of Al 2 O 3 , NiFe (permalloy), or the like is lapped at a higher rate than the slider bar 3 made of Al 2 O 3 -TiC (alumina titanium carbide) or the like. Therefore, as shown in FIG. 11B, a level difference is likely to be formed between the ABS 3 a of the slider bar 3 and a surface 1 a of the thin-film magnetic element 1 opposing the recording medium in rough lapping.
- the opposing surface 1 a of the thin-film magnetic element 1 is likely to be lapped at a high rate by the fine particles in the lapping fluid, which increases the amount of level difference (recession).
- the amount of level difference (recession) is represented by the letter “R”.
- the recession R is zero when the opposing surface 1 a of the thin-film magnetic element 1 is flush with the ABS 3 a of the slider bar 3 , and the direction in which the recession R increases is designated the “positive (+) direction”.
- the opposing surface 1 a of the thin-film magnetic element 1 is lapped at a higher rate than the ABS 3 a of the slider bar 3 . Therefore, in a case in which a substantial recession R is produced during rough lapping, that is, when a great difference remains in the levels between the ABS 3 a of the slider bar 3 and the opposing surface 1 a of the thin-film magnetic element 1 , if finish lapping is performed while monitoring only the DCR values, as shown in FIG. 9B, a substantial recession R remains when the DCR values of the thin-film magnetic element 1 falls into the finish height tolerances.
- the lapping plate 21 is rotated at approximately 100 rpm for the purpose of lapping.
- the lapping plate 21 is controlled by trapezoidal driving so that the power applied to a motor for driving the lapping plate 21 is switched from the driving state to a stop state at the completion of finish lapping.
- the lapping plate 21 rotating at a high speed is rapidly stopped at the completion of finish lapping, flaws are produced on the ABS 3 a of the slider bar 3 and the opposing surface 1 a of the thin-film magnetic element 1 .
- an object of the present invention is to provide a thin-film magnetic head manufacturing method and apparatus in which lapping is performed so as to minimize the recession between an ABS of a slider bar and a surface of a thin-film magnetic element opposing a recording medium.
- Another object of the present invention is to provide a thin-film magnetic head manufacturing method and apparatus in which flaws are prevented from being produced on an ABS of a slider bar at the completion of finish lapping.
- a thin-film magnetic head manufacturing method for forming a thin-film magnetic element including a magnetoresistive sensor by stacking thin-film layers, such as an insulating layer, a magnetic layer, and a conductive layer, on a substrate, and for adjusting the MR height by lapping the substrate and the thin-film magnetic element in the height direction while measuring the resistance value of the magnetoresistive sensor, wherein lapping is continued until the lapping time exceeds a predetermined time and the resistance value or the MR height converted from the resistance value falls into the finish tolerances.
- thin-film magnetic element including a magnetoresistive sensor by stacking thin-film layers, such as an insulating layer, a magnetic layer, and a conductive layer, on a substrate, and for adjusting the MR height by lapping the substrate and the thin-film magnetic element in the height direction while measuring the resistance value of the magnetoresistive sensor, wherein lapping is continued until the lapping time exceeds a predetermined time and the resistance value or the MR height converted from the resistance value falls
- lapping is not performed with reference only to the resistance value or the height value converted from the resistance value, which is different from that in the conventional art, and lapping is monitored until the lapping time exceeds a predetermined time.
- lapping time exceeds the predetermined time and the resistance value or the height converted from the resistance value falls into the finish tolerances, lapping is completed.
- a thin-film magnetic head manufacturing method for forming a thin-film magnetic element including a magnetoresistive sensor by stacking thin-film layers, such as an insulating layer, a magnetic layer, and a conductive layer, on a substrate, and for adjusting the MR height by lapping the substrate and the thin-film magnetic element in the height direction while measuring the resistance value of the magnetoresistive sensor, wherein the rotation rate of a lapping plate in a lapping machine used for lapping is switched to a lower rate at least once to complete lapping when the resistance value or the MR height converted from the resistance value falls below a reference value.
- the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once, and the rotation of the lapping plate is stopped to complete lapping.
- lapping includes the two stages of rough lapping and finish lapping, and the predetermined lapping time corresponds to the time that has elapsed from the beginning of finish lapping.
- Lapping may include the two stages of rough lapping and finish lapping, and the rotation rate may be switched during finish lapping.
- Rough lapping which places more importance on lapping speed than on lapping accuracy, is performed at a high speed until the MR height approaches a target value, and it is switched to finish lapping, which places importance on lapping accuracy, when the MR height comes close to the target value. This can increase the lapping accuracy and shortens the overall lapping time.
- the aspect of the invention in which the finish lapping time has been monitored to determine if its has exceeded the predetermined time may be carried out by monitoring the time elapsed from the beginning of lapping in a method having a single lapping stage instead of the two stages of rough lapping and finish lapping.
- the rotation rate may be switched in the method having a single lapping stage.
- the predetermined lapping time is set to be, for example, more than two minutes, more preferably, more than three minutes.
- the rotation rate of the lapping plate is, for example, 70 to 100 rpm before switching, and is 5 to 20 rpm after switching.
- the recession from the thin-film magnetic element to the surface of the substrate opposing the recording medium may be measured after the completion of finish lapping, and the lapping conditions of the next lapping may be changed so that the recession, or the MR height or resistance of the magnetoresistive sensor, is appropriate.
- the time from the beginning of finish lapping to the completion of finish lapping may be measured, and the lapping conditions of the next lapping may be changed so that the measured lapping time is within a predetermined range.
- the lapping conditions may include, for example, the amount of adjustment of the MR height during rough lapping and the timing for feeding a lubricant during finish lapping.
- a plurality of different lapping conditions such as the MR height in rough lapping and the timing for feeding a lubricant in finish lapping, are ranked, listed in a table, stored, and selected from the table by selecting the rank.
- the operator can set the lapping conditions (MR height, the lubricant feeding time) for the next lapping simply by selecting the rank in the lapping conditions in the table based on data from the results of the previous lapping (recession, MR height or resistance, finish lapping time). Therefore, it is possible to shorten the time taken for setting, to reduce setting errors, and to improve the quality and yield of thin-film magnetic heads.
- lapping may be performed with reference to the resistance, or the MR height may be converted from the resistance so that it is determined base on the converted value whether the lapping amount of the finishing value is appropriate.
- lapping may be performed while monitoring the resistance as it falls into a predetermined range or the finish tolerances, whereas the lapping state may be monitored using the MR height converted from the resistance.
- a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, determining whether the lapping time exceeds a predetermined time, and controlling the lapping machine until the lapping time exceeds the predetermined time and the resistance or the MR height falls into finish tolerances.
- a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; a speed changing means for changing the rotation rate of a lapping plate in the lapping machine; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, and controlling the speed changing means so that the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once when the resistance or the MR height converted from the resistance falls below a reference value.
- a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; a speed changing means for changing the rotation rate of a lapping plate in the lapping machine; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, determining whether the lapping time exceeds a predetermined time, controlling the lapping machine until the lapping time exceeds the predetermined time and the resistance or the MR height falls into finish tolerances, and controlling the speed changing means so that the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once when the resistance or the
- the lapping machine performs lapping in two stages of rough lapping and finish lapping and the control means measures the lapping time from the beginning of finish lapping, or the lapping machine performs lapping in two stages of rough lapping and finish lapping and is controlled by the control means so that the rotation rate of the lapping plate is switched during finish lapping.
- the apparatus further includes a memory device for storing a table containing a plurality of ranked lapping conditions, and the control means sets, as a lapping condition for the next lapping, the lapping condition read from the table according to the finishing result of finish lapping.
- FIGS. 1A and 1B are flowcharts showing a thin-film magnetic head manufacturing method according to an embodiment of the present invention.
- FIGS. 2A and 2B are flowcharts showing the steps subsequent to ⁇ circle over (3) ⁇ or ⁇ circle over (5) ⁇ in FIG. 1B.
- FIG. 3 is a graph showing the relationship between finish lapping time and a recession.
- FIG. 4 is a graph showing the relationship between the rotation rate of a lapping plate immediately before a lapping machine is stopped and the depth of flaws produced on an ABS of a slider bar and a thin-film magnetic element when the lapping machine is stopped.
- FIG. 5 is a perspective view showing a state in which thin-film magnetic elements are formed on a substrate.
- FIG. 6 is a perspective view of a slider bar cut from the substrate shown in FIG. 5.
- FIG. 7 is a cross-sectional view of the thin-film magnetic elements on the slider bar shown in FIG. 5, as viewed from the direction of the ABS.
- FIG. 8 is a perspective view of a lapping plate for use in lapping the ABS of the slider bar shown in FIG. 5.
- FIGS. 9A and 9B are flowcharts showing a lapping process in a conventional thin-film magnetic head manufacturing method.
- FIG. 10 is a block diagram of a thin-film magnetic head manufacturing apparatus according to an embodiment of the present invention.
- FIGS. 11A and 11B are partial side views of the slider bar shown in FIG. 6 to be lapped by the lapping plate shown in FIG. 8, respectively, showing the states at the beginning of lapping, and during or after lapping.
- plural thin-film magnetic elements 1 are formed on a substrate 2 made of Al 2 O 3 -TiC (alumina titanium carbide) or the like by a thin-film process, as shown in FIG. 5.
- the substrate 2 shown in FIG. 5 is shaped like a disk, and plural thin-film magnetic elements 1 are formed in plural rows at regular intervals.
- FIG. 7 is a partial enlarged sectional view of the thin-film magnetic elements 1 on a slider bar 3 cut along an ABS 3 a .
- a thin-film magnetic head 1 is a combination of an inductive magnetic head and an MR magnetic head using a magnetoresistive sensor.
- FIG. 7 shows only the MR magnetic heads in the thin-film magnetic heads 1 , and does not show the inductive magnetic heads and a cover layer for covering the thin-film magnetic elements 1 (see FIG. 11).
- an underlying insulating layer 1 b of Al 2 O 3 or the like is formed on the slider bar 3 .
- a lower shielding layer 1 c is made of a magnetic material, such as a NiFe alloy.
- a lower gap layer 1 d is made of an insulating material, such as Al 2 O 3 , on the lower shielding layer 1 c .
- a plurality of magnetoresistive sensors 1 e are arranged in a row in the direction of the ABS (in the X-direction in FIG. 7).
- a multilayer film if is formed of a spin-valve film (a kind of GMR (giant magnetoresistive) element) composed of, for example, an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer, and a free magnetic layer.
- GMR giant magnetoresistive
- electrode layers 1 g are made of a nonmagnetic metal material such as Cr (chromium).
- an upper shielding layer 1 i of a NiFe alloy (permalloy) or the like is formed on the upper gap layer 1 h.
- the multilayer film 1 f is an element using a giant magnetoresistive effect, in which the electric resistance changes according to changes of the leakage field from a recording medium, whereby recording signals are detected.
- a slider bar. 3 is formed, as shown in FIG. 6. Some of the thin-film magnetic elements 1 formed on the slider bar 3 are used as monitor elements.
- the ABS 3 a is lapped while measuring DC resistance values (DCR value) between the electrode layers 1 g , thereby determining the height (the length in the Y-direction) of the multilayer films 1 f constituting the magnetoresistive sensors 1 e.
- the slider bar 3 is lapped by rotating a lapping plate 21 shown in FIG. 8 and putting the ABS 3 a of the slider bar 3 into contact with the surface of the lapping plate 21 .
- FIGS. 1 and 2 are flowcharts showing the lapping process.
- lapping for adjusting the height of the thin-film magnetic elements 1 placed on the slider bar 3 is performed in two stages, rough lapping and finish lapping.
- Rough lapping is performed by applying on the lapping plate 21 a lapping fluid containing diamond polycrystalline fine particles having an average particle diameter of 0.1 ⁇ m to 50.5 ⁇ m.
- Step 1 rank setting for rough lapping is made in Step 1 (ST 1 ).
- the lank setting will be described later with reference to Tables 1, 2, and 3.
- Rough lapping using the lapping plate 21 is started in Step ST 2 , and the above-described DCR is read during lapping in Step ST 3 .
- Step ST 4 rough lapping is completed in Step ST 4 .
- the slider bar 3 is lapped so that the DCR comes close to a finishing value in a short time. While it is watched in Step ST 4 whether the DCR is within the predetermined range, it is possible to convert the DCR to the height of the magnetoresistive sensor (multilayer film if) and to complete rough lapping when the converted value falls into a predetermined value.
- finish lapping is performed, as shown in FIG. 1B.
- a lubricant is supplied on the lapping plate 21 .
- the timing for feeding the lubricant is based on the lapping rank shown in Table 1 , as will be described later.
- the time is monitored from the beginning of finish lapping (ST 6 ) in Step ST 7 .
- the time is obtained from the measurement result shown in FIG. 3, as will be described below, and is, for example, more than two minutes, more preferably, more than three minutes.
- the time is thus preset, and a recess flag is set when the elapsed time exceeds the preset time.
- Step ST 9 the DCR is read in Step ST 9 , and is converted to an MR height in Step ST 10 .
- Step ST 11 it is determined whether the MR height falls into the finish tolerances. When the MR height is out of the finish tolerances, finish lapping is continued, and the determination is repeated. In this case, it may be determined in Step ST 11 only by monitoring the DCR, without converting the DCR to the MR height, whether finish lapping has been properly performed.
- Step ST 12 it is determined in Step ST 12 whether the recess flag is set to be on or off.
- the recess flag is set to be on, the elapsed time exceeds the preset time. Since both the conditions are satisfied, that is, the preset time has elapsed and the MR height is within the finish tolerances, finish lapping is completed (Step ST 13 ).
- Step ST 12 When the recess flag is not on in Step ST 12 , the MR height is within the finish tolerance, whereas-the ABS 3 a of the slider bar 3 has not been sufficiently lapped and there is a high probability that the a substantial recession remains. In this case, lapping is continued, the elapsed time is checked again in Step ST 7 , and it is determined in Step ST 11 whether the MR height is within the finish tolerance range. In a case in which the MR height is out of the finish tolerance range even when the above operations are repeated, the slider bar 3 is judged defective.
- the ABS 3 a of the slider bar 3 which is lapped at a low rate, can be sufficiently lapped, and the recession R between the ABS 3 a and an opposing surface 1 a of the thin-film magnetic element 1 (see FIG. 11B) can be minimized.
- the finish lapping time does not exceed the preset time and the MR height is out of the finish tolerance range, and therefore, the slider bar 3 is judged defective.
- FIG. 3 shows an example of result of measurement taken to determine the preset time in Step ST 7 .
- the horizontal axis represents the elapsed finish lapping time
- the vertical axis represents the recession between the ABS 3 a of the slider bar 3 and the opposing surface 1 a of the thin-film magnetic element 1 .
- the recession is zero when the opposing surface 1 a of the thin-film magnetic element 1 is flush with the ABS 3 a of the slider bar 3 , and the direction in which the recession increases is designated the “positive direction”.
- the slider bar 3 is made of Al 2 O 3 -TiC, and the thin-film magnetic element 1 is multilayer element made of Al 2 O 3 , NiFe, Cu, and so on.
- the recession decreases to 10 nm two minutes after the beginning of finish lapping, and decreases approximately zero three minutes after and remains stably. Therefore, a preferable finish lapping time is more than two minutes, more preferably, more than three minutes.
- the recession can fall within a range of 0 nm to 10 nm. Since the recession conventionally ranges from 0 nm to 30 nm, it is possible to substantially reduce the increase and variations in recessions by performing finish lapping while measuring the elapsed time. This improves the quality of the thin-film magnetic elements, in particular, to reduce the spacing loss and to thereby improve writing/reading characteristics.
- Steps ST 17 and ST 18 shown in FIG. 2B may be added before the MR height (or the DCR) falls into the finish tolerance in Step ST 11 .
- the rotation rate of the lapping plate 21 is set at approximately 100 rpm before the switching to a lower rate in Step ST 18 . While the DCR is converted to the MR height and it is determined in Step ST 17 whether the MR height falls below the reference value, for example, the rotation rate of the lapping plate 21 is switched to approximately 20 rpm when the MR height falls below the sum of the finishing value +0.5 ⁇ m to 1 ⁇ m.
- FIG. 4 is a graph showing the relationship between the rotation rate of the lapping plate 21 immediately before the lapping machine is stopped and the depth of flaws produced on the slider bar 3 and the thin-film magnetic element 1 after the lapping machine is stopped.
- the lapping plate 21 of the lapping machine which is rotating at, for example, approximately 100 rpm
- the depth of flaws produced on the slider bar 3 and the thin-film magnetic element 1 ranges from 5 nm to 20 nm.
- the lapping plate rotating at, for example, approximately 20 rpm is stopped by trapezoidal driving control
- the depth of flaws falls into the range of 1 nm to 2 nm.
- the flowchart shown in FIG. 1B need not always include the step of switching the rotation rate of the lapping plate shown in FIG. 2B. Furthermore, only the step of switching the rotation rate of the plate in FIG. 2B may be performed without performing the step of checking the elapsed time in FIG. 1B.
- the step of checking the elapsed time in FIG. 1B and/or the step of switching the rotation rate of the plate in FIG. 2B may be performed in a single lapping stage, instead of two stages of rough lapping and finish lapping.
- a table may be formed to include ranked lapping conditions necessary for lapping settings, and the lapping conditions may be changed stepwise based on actual lapping circumstances for individual lapping machines.
- the elapsed time sometimes does not exceed the predetermined time in Step ST 7 .
- the thin-film magnetic element 1 is subjected to a greater degree of lapping than the ABS 3 A of the slider bar 3 in rough lapping shown in FIG. 1A, and a substantially large recession R has been formed when rough lapping is shifted to finish lapping.
- the finish lapping process shown in FIG. 1B is also influenced by the timing for feeding a lubricant onto the lapping plate 21 .
- the recession between the ABS 3 a of the slider bar 3 and the thin-film magnetic element 1 must be reduced by lapping the ABS 3 a for more than the predetermined time.
- the recession is influenced by the timing for feeding the lubricant.
- Step ST 14 it is determined in Step ST 15 whether the rank-changing flag is set to be on at the completion of finish lapping.
- a rank for the next rough lapping process is changed in Step ST 16 (ST 1 ).
- the timing for feeding the lubricant in finish lapping is changed.
- the MR height in rough lapping and the timing for feeding a lubricant for finish lapping are set in combination as lapping conditions (lapping ranks).
- the lubricant feeding timing is represented as the DCR of the magnetoresistive sensor.
- ranks are set according to the MR height after rough lapping.
- a case in which the MR height after rough lapping is 0.9 ⁇ m, a case in which the MR height is 0.8 ⁇ m, a case in which the MR height in 0.7 ⁇ m, etc., are respectively set as ranks 1, 2, 3, etc.
- the DCR when feeding the lubricant for finish lapping is represented by a, b, c, d, and e in Table 1, it is actually set at an optimal value for each lapping machine 32 .
- the change in lapping ranks makes it possible to decrease the probability that slider bars will be defective in Step ST 12 in the finish lapping process shown in FIG. 1B, and to reduce the overall lapping time. Furthermore, it is possible to reduce the influence of differences in characteristics of lapping machines, and to achieve uniform quality.
- Table 2 shows comparisons of recessions, DCRs, and finish lapping times among sample slider bars having thin-film magnetic elements subjected to rough lapping and finish lapping performed by three lapping machines. TABLE 2 Machine 1 Machine 2 Machine 3 Rank 3 3 3 3 Lapping time 3:10 2:00 2:00 (mm:sec) Recession ⁇ 1.5 ⁇ 1.3 ⁇ 0.7 (nm) Excess DCR Within +2 +5 ( ⁇ ) Tolerances
- Table 2 shows the lapping results of the three lapping machines 1 , 2 , and 3 when all the lapping ranks of the lapping machines are set at Rank 3 shown in Table 1, and when the reference time in Step ST 7 in the finish lapping process shown in FIG. 1B is set at 2 minutes.
- Step ST 14 the rank-changing flag is turned on.
- the lapping ranks of Machines 2 and 3 are changed.
- the lapping ranks are changed based on the following rank-changing table 3 set according to the excess DCR values in finish lapping.
- rank is selected based on the DCR value in Table 3 , it may be based on the MR height calculated from the DCR value. TABLE 3 Rank Excess DCR Within tolerances Rank 3 ( ⁇ ) 1 Rank 3 2 Rank 2 3 Rank 2 4 Rank 1 5 Rank 1
- Table 5 shows a rank-changing table for use in setting a rank for the next lapping process based on the finish lapping time and the DCR values of the samples in the previous lapping process performed in Rank 3 .
- the DCR value is within the tolerances and the finish lapping time is equal to more than 2 minutes and less than 3 minutes in the previous lapping process in Rank 3 , the rank need not be changed, and therefore, the next lapping process is performed in Rank 3 .
- finish lapping time can be shortened by changing the rank to Rank 5 .
- FIG. 10 is a block diagram of a thin-film magnetic head manufacturing apparatus according to an embodiment of the present invention.
- the resistance values of the magnetoresistive sensors of the thin-film magnetic elements 1 formed on the slider bar 3 shown in FIG. 6 are measured by a resistance measuring device 31 serving as a resistance measuring means of the present invention, and the ABS 3 a of the slider bar 3 and the thin-film magnetic elements 1 in the thin-film magnetic head are lapped by the lapping machine 32 in the direction of the height, thereby adjusting the MR height.
- a computer 35 constructs a control means of the present invention.
- the computer 35 controls the resistance measuring device 31 and the lapping machine 32 , receives data therefrom, converts the resistances of the magnetoresistive sensors to MR heights, refers to the lapping condition tables in a memory device 34 , displays data, such as measured resistance values, and gives instructions to the operator.
- the time in which the thin-film magnetic elements 1 are lapped by the lapping machine 32 is measured by a timer 33 connected to the lapping machine 32 . Furthermore, the computer 35 controls the lapping machine 32 so that the lapping machine 32 continues lapping until the lapping time exceeds a predetermined time and the resistance value or the MR height converted from the resistance value falls into the finish tolerances.
- the lapping machine 32 has also a speed change gear 32 b serving as a speed changing means for changing the rotation rate of the lapping plate 32 a in a stepwise manner.
- the computer 35 controls the speed change gear 32 b so that the rotation rate of the lapping plate 32 a is switched to a lower rate at least once to complete lapping when the resistance of the thin-film magnetic element 1 or the MR height converted from the resistance value falls below the reference value.
- the speed change gear 32 b may be omitted, or the timer 33 may be omitted.
- the lapping machine performs lapping in two stages, rough lapping and finish lapping, whereas the lapping machine may perform a single-stage lapping.
- the tables, as in Tables 3 and 5, showing a plurality of different rough and finish lapping condition ranks may be stored as a database in the memory device 34 , and be read when the rank change is required.
- the memory device 34 may be connected to the computer 35 connected to the lapping machine directly or via a network.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Abstract
Description
- 1. Field of the Invention
- The present invention relates to a thin-film magnetic head manufacturing method and apparatus for precisely lapping thin-film magnetic heads for use in magnetic disk devices and the like.
- 2. Description of the Related Art
- In manufacturing thin-film magnetic heads, in general, thin layers constituting thin-film magnetic elements, such as insulating layers, magnetic layers, and conductive layers, are stacked in order on a substrate made of Al2O3-TiC (alumina titanium carbide) by sputtering, and the thin layers are worked by photolithography or ion milling as required.
- In order to manufacture thin-film magnetic heads, plural thin-film
magnetic elements 1 are formed in plural rows on asubstrate 2, as shown in FIG. 5 (FIG. 5 shows only some of the thin-film magnetic elements 1). A thin-filmmagnetic element 1 is a so-called “MR (magnetoresistive)/inductive combined magnetic head” in which an MR magnetic head having a magnetoresistive sensor for reading recorded information and an inductive magnetic head for writing are combined. The thin-filmmagnetic elements 1 are electrically connected byelectrodes 4 connected thereto. Thesubstrate 2 is cut along the dotted lines to yield a slider bar as shown in FIG. 6. - In manufacturing a thin-film magnetic head, the height of the magnetoresistive sensor of the MR magnetic head in the thin-film
magnetic element 1 must be adjusted to a predetermined value. The MR height is adjusted by lapping an ABS (air-bearing surface) 3 a shown in FIG. 6 while using some of a plurality of magnetoresistive sensors as monitor elements, and measuring DC resistance values (DCR values) between the electrode layers connected to both ends of the magnetoresistive sensors. - By lapping the
ABS 3 a until the DCR value fall into the finish tolerances, the height of the magnetoresistive sensors (MR height) can be set at an appropriate value. After the MR height is adjusted, theslider bar 3 is cut along the dotted lines shown in FIG. 6 into individual thin-film magnetic heads. Individual substrates cut from theslider bar 3 serve as sliders. TheABS 3 a of the slider faces a recording medium and receives a levitating force when the recording medium moves. - Lapping for adjusting the MR height is performed by using, for example, a
lapping plate 21 shown in FIG. 8. Theslider bar 3 shown in FIG. 6 is placed so that theABS 3 a thereof is in contact with the surface of thelapping plate 21. Thelapping plate 21 is rotationally driven to lap theABS 3 a of theslider bar 3. - FIGS. 9A and 9B are flowcharts showing the process of lapping for adjusting the MR height.
- Lapping is performed in two stages, rough lapping (FIG. 9A) with a lapping fluid applied on the upper surface of the
lapping plate 21, and finish lapping (FIG. 9B) with a lubricant applied on thelapping plate 21 as necessary. - In rough lapping, as shown in FIG. 9A, lapping is continued while the DCR values of the monitor elements are being monitored, and is completed when the DCR values fall into a predetermined DCR range.
- In finish lapping shown in FIG. 9B, lapping is similarly performed while the DCR values of the monitor elements are being monitored, and it is completed when the DCR values fall into the finish tolerance range, which means that the MR heights also falls into the finish tolerance range.
- In a conventional lapping method, as shown in FIGS. 9A and 9B, however, a level difference is likely to remain between the
ABS 3 a of theslider bar 3 and the thin-filmmagnetic element 1 in a completed thin-film magnetic head. - FIGS. 11A and 11B are side views of the
slider bar 3 and the thin-filmmagnetic element 1, respectively, before lapping is started, and during or after lapping. When the thin-filmmagnetic element 1 is formed (the process shown in FIG. 5), acover layer 5 is formed to cover the thin-filmmagnetic element 1. Thiscover layer 5 is made of Al2O3 or SiO2. - In rough lapping, as described with reference to FIG. 9A, the lapping fluid contains fine particles, and the
ABS 3 a is lapped therewith. - The thin-film
magnetic element 1 primarily made of Al2O3, NiFe (permalloy), or the like is lapped at a higher rate than theslider bar 3 made of Al2O3-TiC (alumina titanium carbide) or the like. Therefore, as shown in FIG. 11B, a level difference is likely to be formed between theABS 3 a of theslider bar 3 and asurface 1 a of the thin-filmmagnetic element 1 opposing the recording medium in rough lapping. - In particular, in rough lapping with the lapping fluid applied on the surface of the
lapping plate 21, theopposing surface 1 a of the thin-filmmagnetic element 1 is likely to be lapped at a high rate by the fine particles in the lapping fluid, which increases the amount of level difference (recession). Hereinafter, the amount of level difference (recession) is represented by the letter “R”. The recession R is zero when theopposing surface 1 a of the thin-filmmagnetic element 1 is flush with theABS 3 a of theslider bar 3, and the direction in which the recession R increases is designated the “positive (+) direction”. - Since rough lapping, as shown in FIG. 9A, is performed while monitoring only the DCR values of the magnetoresistive sensors, when the DCR values fall into a predetermined range, that is, when the heights of the magnetoresistive sensors (MR height) fall into a predetermined range, it is impossible to determine the extent to which the
ABS 3 a of theslider bar 3 has been lapped. For this reason, even when theopposing surface 1 a of the thin-filmmagnetic element 1 has been sufficiently lapped and the MR height values are within the predetermined range, theABS 3 a of theslider bar 3 has not been sufficiently lapped and a substantial recession R is produced in the positive direction. - In the subsequent finish lapping process, the
opposing surface 1 a of the thin-filmmagnetic element 1 is lapped at a higher rate than theABS 3 a of theslider bar 3. Therefore, in a case in which a substantial recession R is produced during rough lapping, that is, when a great difference remains in the levels between theABS 3 a of theslider bar 3 and theopposing surface 1 a of the thin-filmmagnetic element 1, if finish lapping is performed while monitoring only the DCR values, as shown in FIG. 9B, a substantial recession R remains when the DCR values of the thin-filmmagnetic element 1 falls into the finish height tolerances. - That is, although too large a recession R remains at the completion of rough lapping, and the
ABS 3 a of theslider bar 3 is not lapped to sufficiently reduce the recession R due to a short finish lapping time, finish lapping is completed. - Because of the need to cope with recent increases in density of recording media, thin-film magnetic heads have been required to minimize the distance between the opposing surface of the thin-film magnetic element and a recording medium in a driving state to reduce spacing loss as much as possible. If a substantial recession is produced in such a thin-film magnetic head as described above, the spacing loss increases, and this impairs writing/reading characteristics.
- In general, the
lapping plate 21 is rotated at approximately 100 rpm for the purpose of lapping. Conventionally, thelapping plate 21 is controlled by trapezoidal driving so that the power applied to a motor for driving thelapping plate 21 is switched from the driving state to a stop state at the completion of finish lapping. When thelapping plate 21 rotating at a high speed is rapidly stopped at the completion of finish lapping, flaws are produced on theABS 3 a of theslider bar 3 and theopposing surface 1 a of the thin-filmmagnetic element 1. - The flaws on the
ABS 3 a of theslider bar 3 remain unchanged on an ABS of the slider, floating characteristics on the recording medium becomes unstable, or flaws may be produced on the surface of the recording medium. - In order to solve the above problems in the conventional art, an object of the present invention is to provide a thin-film magnetic head manufacturing method and apparatus in which lapping is performed so as to minimize the recession between an ABS of a slider bar and a surface of a thin-film magnetic element opposing a recording medium.
- Another object of the present invention is to provide a thin-film magnetic head manufacturing method and apparatus in which flaws are prevented from being produced on an ABS of a slider bar at the completion of finish lapping.
- According to one aspect of the present invention, there is provided a thin-film magnetic head manufacturing method for forming a thin-film magnetic element including a magnetoresistive sensor by stacking thin-film layers, such as an insulating layer, a magnetic layer, and a conductive layer, on a substrate, and for adjusting the MR height by lapping the substrate and the thin-film magnetic element in the height direction while measuring the resistance value of the magnetoresistive sensor, wherein lapping is continued until the lapping time exceeds a predetermined time and the resistance value or the MR height converted from the resistance value falls into the finish tolerances.
- According to the present invention, lapping is not performed with reference only to the resistance value or the height value converted from the resistance value, which is different from that in the conventional art, and lapping is monitored until the lapping time exceeds a predetermined time. When the lapping time exceeds the predetermined time and the resistance value or the height converted from the resistance value falls into the finish tolerances, lapping is completed. By continuing the lapping for longer than the predetermined time while monitoring the resistance, as described above, it is possible to sufficiently lap the ABS of the substrate (slider bar) having a low lapping rate, to minimize the recession between the ABS and the surface of the thin-film magnetic element, and to make the recession zero.
- According to another embodiment of the present invention, there is provided a thin-film magnetic head manufacturing method for forming a thin-film magnetic element including a magnetoresistive sensor by stacking thin-film layers, such as an insulating layer, a magnetic layer, and a conductive layer, on a substrate, and for adjusting the MR height by lapping the substrate and the thin-film magnetic element in the height direction while measuring the resistance value of the magnetoresistive sensor, wherein the rotation rate of a lapping plate in a lapping machine used for lapping is switched to a lower rate at least once to complete lapping when the resistance value or the MR height converted from the resistance value falls below a reference value.
- When the lapping comes close to an end, that is, when the resistance value or the MR height converted from the resistance value falls below a reference value, the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once, and the rotation of the lapping plate is stopped to complete lapping. This makes it possible to reduce flaws in the ABS of the slider and the surface of the thin-film magnetic element, to improve the floating characteristics of the thin-film magnetic head, and to prevent a magnetic head from producing flaws on a recording medium.
- It is possible to adopt both the aspect of the invention of switching the rotation rate of the lapping plate in the lapping machine used for lapping at least once when the resistance value or the MR height converted from the resistance value falls below a reference value, and the aspect of the invention of continuing lapping until the lapping time exceeds a predetermined time and the resistance or the MR height converted from the resistance value falls into the finish tolerances.
- Preferably, lapping includes the two stages of rough lapping and finish lapping, and the predetermined lapping time corresponds to the time that has elapsed from the beginning of finish lapping.
- Lapping may include the two stages of rough lapping and finish lapping, and the rotation rate may be switched during finish lapping.
- Rough lapping, which places more importance on lapping speed than on lapping accuracy, is performed at a high speed until the MR height approaches a target value, and it is switched to finish lapping, which places importance on lapping accuracy, when the MR height comes close to the target value. This can increase the lapping accuracy and shortens the overall lapping time.
- In these two stages, rough lapping and finish lapping, by monitoring whether the finish lapping time is longer than a predetermined time, it is possible to prevent, for example, insufficient lapping of the substrate, which will result in a large recession, when the recession in rough lapping is too large, that is, when the thin-film magnetic element has been subjected to a greater degree of lapping than the substrate, and lapping is completed in a short time of subsequent finish lapping.
- The aspect of the invention in which the finish lapping time has been monitored to determine if its has exceeded the predetermined time may be carried out by monitoring the time elapsed from the beginning of lapping in a method having a single lapping stage instead of the two stages of rough lapping and finish lapping.
- Similarly, the rotation rate may be switched in the method having a single lapping stage.
- Preferably, the predetermined lapping time is set to be, for example, more than two minutes, more preferably, more than three minutes.
- Preferably, the rotation rate of the lapping plate is, for example, 70 to 100 rpm before switching, and is 5 to 20 rpm after switching.
- In the present invention, the recession from the thin-film magnetic element to the surface of the substrate opposing the recording medium may be measured after the completion of finish lapping, and the lapping conditions of the next lapping may be changed so that the recession, or the MR height or resistance of the magnetoresistive sensor, is appropriate.
- The time from the beginning of finish lapping to the completion of finish lapping may be measured, and the lapping conditions of the next lapping may be changed so that the measured lapping time is within a predetermined range.
- The lapping conditions may include, for example, the amount of adjustment of the MR height during rough lapping and the timing for feeding a lubricant during finish lapping.
- Preferably, a plurality of different lapping conditions, such as the MR height in rough lapping and the timing for feeding a lubricant in finish lapping, are ranked, listed in a table, stored, and selected from the table by selecting the rank.
- When the lapping conditions necessary for lapping are collected, ranked according to the MR heights, listed in a table, and stored according to the lapping machine, the operator can set the lapping conditions (MR height, the lubricant feeding time) for the next lapping simply by selecting the rank in the lapping conditions in the table based on data from the results of the previous lapping (recession, MR height or resistance, finish lapping time). Therefore, it is possible to shorten the time taken for setting, to reduce setting errors, and to improve the quality and yield of thin-film magnetic heads.
- In the present invention, lapping may be performed with reference to the resistance, or the MR height may be converted from the resistance so that it is determined base on the converted value whether the lapping amount of the finishing value is appropriate.
- That is, when the resistance of the magnetoresistive sensors is measured in the above methods, lapping may be performed while monitoring the resistance as it falls into a predetermined range or the finish tolerances, whereas the lapping state may be monitored using the MR height converted from the resistance.
- According to another aspect of the present invention, there is provided a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, determining whether the lapping time exceeds a predetermined time, and controlling the lapping machine until the lapping time exceeds the predetermined time and the resistance or the MR height falls into finish tolerances.
- According to another aspect of the present invention, there is provided a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; a speed changing means for changing the rotation rate of a lapping plate in the lapping machine; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, and controlling the speed changing means so that the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once when the resistance or the MR height converted from the resistance falls below a reference value.
- According to a further aspect of the present invention, there is provided a manufacturing apparatus for carrying out the above-described thin-film magnetic element manufacturing method, including a holding means for holding a thin-film magnetic head in which a thin-film magnetic element including a magnetoresistive sensor is formed on a substrate; a lapping machine for lapping the substrate and the thin-film magnetic element in the thin-film magnetic head held by the holding means; a resistance measuring means for measuring the resistance of the magnetoresistive sensor during lapping; a speed changing means for changing the rotation rate of a lapping plate in the lapping machine; and a control means for monitoring the resistance measured by the resistance measuring means or the MR height converted from the resistance, determining whether the lapping time exceeds a predetermined time, controlling the lapping machine until the lapping time exceeds the predetermined time and the resistance or the MR height falls into finish tolerances, and controlling the speed changing means so that the rotation rate of the lapping plate in the lapping machine is switched to a lower rate at least once when the resistance or the MR height converted from the resistance falls below a reference value.
- Preferably, the lapping machine performs lapping in two stages of rough lapping and finish lapping and the control means measures the lapping time from the beginning of finish lapping, or the lapping machine performs lapping in two stages of rough lapping and finish lapping and is controlled by the control means so that the rotation rate of the lapping plate is switched during finish lapping.
- Preferably, the apparatus further includes a memory device for storing a table containing a plurality of ranked lapping conditions, and the control means sets, as a lapping condition for the next lapping, the lapping condition read from the table according to the finishing result of finish lapping.
- Further objects, features, and advantages of the present invention will be apparent from the following description of the preferred embodiments with reference to the attached drawings.
- FIGS. 1A and 1B are flowcharts showing a thin-film magnetic head manufacturing method according to an embodiment of the present invention.
- FIGS. 2A and 2B are flowcharts showing the steps subsequent to {circle over (3)} or {circle over (5)} in FIG. 1B.
- FIG. 3 is a graph showing the relationship between finish lapping time and a recession.
- FIG. 4 is a graph showing the relationship between the rotation rate of a lapping plate immediately before a lapping machine is stopped and the depth of flaws produced on an ABS of a slider bar and a thin-film magnetic element when the lapping machine is stopped.
- FIG. 5 is a perspective view showing a state in which thin-film magnetic elements are formed on a substrate.
- FIG. 6 is a perspective view of a slider bar cut from the substrate shown in FIG. 5.
- FIG. 7 is a cross-sectional view of the thin-film magnetic elements on the slider bar shown in FIG. 5, as viewed from the direction of the ABS.
- FIG. 8 is a perspective view of a lapping plate for use in lapping the ABS of the slider bar shown in FIG. 5.
- FIGS. 9A and 9B are flowcharts showing a lapping process in a conventional thin-film magnetic head manufacturing method.
- FIG. 10 is a block diagram of a thin-film magnetic head manufacturing apparatus according to an embodiment of the present invention.
- FIGS. 11A and 11B are partial side views of the slider bar shown in FIG. 6 to be lapped by the lapping plate shown in FIG. 8, respectively, showing the states at the beginning of lapping, and during or after lapping.
- In the procedure for manufacturing a thin-film magnetic head, plural thin-film
magnetic elements 1 are formed on asubstrate 2 made of Al2O3-TiC (alumina titanium carbide) or the like by a thin-film process, as shown in FIG. 5. Thesubstrate 2 shown in FIG. 5 is shaped like a disk, and plural thin-filmmagnetic elements 1 are formed in plural rows at regular intervals. - FIG. 7 is a partial enlarged sectional view of the thin-film
magnetic elements 1 on aslider bar 3 cut along anABS 3 a. A thin-filmmagnetic head 1 is a combination of an inductive magnetic head and an MR magnetic head using a magnetoresistive sensor. FIG. 7 shows only the MR magnetic heads in the thin-filmmagnetic heads 1, and does not show the inductive magnetic heads and a cover layer for covering the thin-film magnetic elements 1 (see FIG. 11). - As shown in FIG. 7, an underlying insulating layer1 b of Al2O3 or the like is formed on the
slider bar 3. On the underlying insulating layer 1 b, alower shielding layer 1 cis made of a magnetic material, such as a NiFe alloy. Furthermore, alower gap layer 1 d is made of an insulating material, such as Al2O3, on thelower shielding layer 1 c. On thelower gap layer 1 d, a plurality ofmagnetoresistive sensors 1 e are arranged in a row in the direction of the ABS (in the X-direction in FIG. 7). - In the center of the
magnetoresistive sensor 1 e, a multilayer film if is formed of a spin-valve film (a kind of GMR (giant magnetoresistive) element) composed of, for example, an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer, and a free magnetic layer. On both sides of themultilayer film 1 f,electrode layers 1 g are made of a nonmagnetic metal material such as Cr (chromium). - An upper gap layer1 h of an insulating material, such as Al2O3, is formed on the
magnetoresistive sensor 1 e, and anupper shielding layer 1 i of a NiFe alloy (permalloy) or the like is formed on the upper gap layer 1 h. - The
multilayer film 1 f is an element using a giant magnetoresistive effect, in which the electric resistance changes according to changes of the leakage field from a recording medium, whereby recording signals are detected. - By cutting the
substrate 2 shown in FIG. 5 along the dotted lines, a slider bar. 3 is formed, as shown in FIG. 6. Some of the thin-filmmagnetic elements 1 formed on theslider bar 3 are used as monitor elements. TheABS 3 a is lapped while measuring DC resistance values (DCR value) between theelectrode layers 1 g, thereby determining the height (the length in the Y-direction) of themultilayer films 1 f constituting themagnetoresistive sensors 1 e. - While the DC resistance (DCR) of the thin-film magnetic element is measured in this embodiment, it is possible to apply alternating current to the thin-film magnetic element and to measure the AC resistance (impedance).
- The
slider bar 3 is lapped by rotating a lappingplate 21 shown in FIG. 8 and putting theABS 3 a of theslider bar 3 into contact with the surface of the lappingplate 21. - FIGS. 1 and 2 are flowcharts showing the lapping process.
- In this embodiment, lapping for adjusting the height of the thin-film
magnetic elements 1 placed on theslider bar 3 is performed in two stages, rough lapping and finish lapping. - Rough lapping is performed by applying on the lapping plate21 a lapping fluid containing diamond polycrystalline fine particles having an average particle diameter of 0.1 μm to 50.5 μm.
- In the rough lapping process, as shown in FIG. 1A, rank setting for rough lapping is made in Step1 (ST1). The lank setting will be described later with reference to Tables 1, 2, and 3. Rough lapping using the lapping
plate 21 is started in Step ST2, and the above-described DCR is read during lapping in Step ST3. When the DCR falls into a predetermined range, rough lapping is completed in Step ST4. In this rough lapping process, theslider bar 3 is lapped so that the DCR comes close to a finishing value in a short time. While it is watched in Step ST4 whether the DCR is within the predetermined range, it is possible to convert the DCR to the height of the magnetoresistive sensor (multilayer film if) and to complete rough lapping when the converted value falls into a predetermined value. - Next, finish lapping is performed, as shown in FIG. 1B. In finish lapping, a lubricant is supplied on the lapping
plate 21. The timing for feeding the lubricant is based on the lapping rank shown in Table 1, as will be described later. - In the finish lapping process shown in FIG. 1B, the time is monitored from the beginning of finish lapping (ST6) in Step ST7. The time is obtained from the measurement result shown in FIG. 3, as will be described below, and is, for example, more than two minutes, more preferably, more than three minutes. The time is thus preset, and a recess flag is set when the elapsed time exceeds the preset time.
- Next, the DCR is read in Step ST9, and is converted to an MR height in Step ST10. In Step ST11, it is determined whether the MR height falls into the finish tolerances. When the MR height is out of the finish tolerances, finish lapping is continued, and the determination is repeated. In this case, it may be determined in Step ST11 only by monitoring the DCR, without converting the DCR to the MR height, whether finish lapping has been properly performed.
- When the MR height falls into the finish tolerances, it is determined in Step ST12 whether the recess flag is set to be on or off. When the recess flag is set to be on, the elapsed time exceeds the preset time. Since both the conditions are satisfied, that is, the preset time has elapsed and the MR height is within the finish tolerances, finish lapping is completed (Step ST13).
- When the recess flag is not on in Step ST12, the MR height is within the finish tolerance, whereas-the
ABS 3 a of theslider bar 3 has not been sufficiently lapped and there is a high probability that the a substantial recession remains. In this case, lapping is continued, the elapsed time is checked again in Step ST7, and it is determined in Step ST11 whether the MR height is within the finish tolerance range. In a case in which the MR height is out of the finish tolerance range even when the above operations are repeated, theslider bar 3 is judged defective. - By always continuing finish lapping for more than the preset time, the
ABS 3 a of theslider bar 3, which is lapped at a low rate, can be sufficiently lapped, and the recession R between theABS 3 a and an opposingsurface 1 a of the thin-film magnetic element 1 (see FIG. 11B) can be minimized. In a case in which too large a recession R remains at the completion of rough lapping, both the conditions are not satisfied, that is, the finish lapping time does not exceed the preset time and the MR height is out of the finish tolerance range, and therefore, theslider bar 3 is judged defective. - FIG. 3 shows an example of result of measurement taken to determine the preset time in Step ST7. In this graph, the horizontal axis represents the elapsed finish lapping time, and the vertical axis represents the recession between the
ABS 3 a of theslider bar 3 and the opposingsurface 1 a of the thin-filmmagnetic element 1. The recession is zero when the opposingsurface 1 a of the thin-filmmagnetic element 1 is flush with theABS 3 a of theslider bar 3, and the direction in which the recession increases is designated the “positive direction”. - The
slider bar 3 is made of Al2O3-TiC, and the thin-filmmagnetic element 1 is multilayer element made of Al2O3, NiFe, Cu, and so on. - According to the measurement result shown in FIG. 3, the recession decreases to 10 nm two minutes after the beginning of finish lapping, and decreases approximately zero three minutes after and remains stably. Therefore, a preferable finish lapping time is more than two minutes, more preferably, more than three minutes.
- When the elapsed time is preset at more than two or three minutes as described above, the recession can fall within a range of 0 nm to 10 nm. Since the recession conventionally ranges from 0 nm to 30 nm, it is possible to substantially reduce the increase and variations in recessions by performing finish lapping while measuring the elapsed time. This improves the quality of the thin-film magnetic elements, in particular, to reduce the spacing loss and to thereby improve writing/reading characteristics.
- In the finish lapping process shown in FIG. 1B, Steps ST17 and ST18 shown in FIG. 2B may be added before the MR height (or the DCR) falls into the finish tolerance in Step ST11.
- When finish lapping comes close to the end and the MR height falls below a reference value in Step ST17 of FIG. 2B, the rotation rate of the lapping
plate 21 is switched to a lower rate at least once (ST 18). When the MR height falls into the finish tolerance range in Step ST11 after switching, the lappingplate 21 is stopped to complete finish lapping. - In this embodiment, the rotation rate of the lapping
plate 21 is set at approximately 100 rpm before the switching to a lower rate in Step ST18. While the DCR is converted to the MR height and it is determined in Step ST17 whether the MR height falls below the reference value, for example, the rotation rate of the lappingplate 21 is switched to approximately 20 rpm when the MR height falls below the sum of the finishing value +0.5 μm to 1 μm. - FIG. 4 is a graph showing the relationship between the rotation rate of the lapping
plate 21 immediately before the lapping machine is stopped and the depth of flaws produced on theslider bar 3 and the thin-filmmagnetic element 1 after the lapping machine is stopped. When the lappingplate 21 of the lapping machine, which is rotating at, for example, approximately 100 rpm, is stopped by trapezoidal driving control, the depth of flaws produced on theslider bar 3 and the thin-filmmagnetic element 1 ranges from 5 nm to 20 nm. In contrast, when the lapping plate rotating at, for example, approximately 20 rpm is stopped by trapezoidal driving control, the depth of flaws falls into the range of 1 nm to 2 nm. - While the rotation rate of the lapping plate is switched only once in this embodiment, it may be switched any number of times.
- The flowchart shown in FIG. 1B need not always include the step of switching the rotation rate of the lapping plate shown in FIG. 2B. Furthermore, only the step of switching the rotation rate of the plate in FIG. 2B may be performed without performing the step of checking the elapsed time in FIG. 1B.
- The step of checking the elapsed time in FIG. 1B and/or the step of switching the rotation rate of the plate in FIG. 2B may be performed in a single lapping stage, instead of two stages of rough lapping and finish lapping.
- In the lapping process, a table may be formed to include ranked lapping conditions necessary for lapping settings, and the lapping conditions may be changed stepwise based on actual lapping circumstances for individual lapping machines.
- For example, in the process shown in FIG. 1B, even when the MR height or the DCR of the magnetoresistive sensor is within the finish tolerances, the elapsed time sometimes does not exceed the predetermined time in Step ST7. This is because the thin-film
magnetic element 1 is subjected to a greater degree of lapping than the ABS 3A of theslider bar 3 in rough lapping shown in FIG. 1A, and a substantially large recession R has been formed when rough lapping is shifted to finish lapping. - Furthermore, if the DCR set in Step ST4 in the rough lapping process shown in FIG. 1A is too great, that is, if the height of the thin-film
magnetic element 1 is reduced excessively (lapping is performed excessively) in rough lapping, too large a recession R is similarly produced, and the DCR sometimes falls into the finish tolerance range before the predetermined time elapses in finish lapping shown in FIG. 1B. - The finish lapping process shown in FIG. 1B is also influenced by the timing for feeding a lubricant onto the lapping
plate 21. In finish lapping, the recession between theABS 3 a of theslider bar 3 and the thin-filmmagnetic element 1 must be reduced by lapping theABS 3 a for more than the predetermined time. The recession is influenced by the timing for feeding the lubricant. - Therefore, if the recess flag is not set to be on even when the MR height is within the finish tolerance range in Step ST11 shown in FIG. 1B, a rank-changing flag is set in Step ST14. Then, as shown in FIG. 2A, it is determined in Step ST15 whether the rank-changing flag is set to be on at the completion of finish lapping. When the rank-changing flag is set to be on, a rank for the next rough lapping process is changed in Step ST16 (ST1). Moreover, the timing for feeding the lubricant in finish lapping is changed.
- The following Table 1 shows examples of the above-described lapping conditions (lapping ranks).
TABLE 1 MR Height in Rough DCR in Feeding Rank Lapping (μM) Lubricant (Ω) 1 0.9 a 2 0.8 b 3 0.7 c 4 0.6 d 5 0.5 e - In Table 1, the MR height in rough lapping and the timing for feeding a lubricant for finish lapping are set in combination as lapping conditions (lapping ranks). The lubricant feeding timing is represented as the DCR of the magnetoresistive sensor. Furthermore, ranks are set according to the MR height after rough lapping. A case in which the MR height after rough lapping is 0.9 μm, a case in which the MR height is 0.8 μm, a case in which the MR height in 0.7 μm, etc., are respectively set as
ranks machine 32. - For example, in a case in which
Rank 1 is set in Step ST1 in FIG. 1A, when the rank-changing flag is set to be on in Step ST15 in FIG. 2A, the rank is changed in the next lapping process (thenext slider bar 3 or the next lot). In this case, it is preferable to create a table of ranks, for example, based on the excess amount of DCR (the amount of deviation from the finishing height) in finish lapping, as shown in Table 3. - The change in lapping ranks makes it possible to decrease the probability that slider bars will be defective in Step ST12 in the finish lapping process shown in FIG. 1B, and to reduce the overall lapping time. Furthermore, it is possible to reduce the influence of differences in characteristics of lapping machines, and to achieve uniform quality. Table 2 shows comparisons of recessions, DCRs, and finish lapping times among sample slider bars having thin-film magnetic elements subjected to rough lapping and finish lapping performed by three lapping machines.
TABLE 2 Machine 1Machine 2Machine 3Rank 3 3 3 Lapping time 3:10 2:00 2:00 (mm:sec) Recession −1.5 −1.3 −0.7 (nm) Excess DCR Within +2 +5 (Ω) Tolerances - The above Table 2 shows the lapping results of the three
lapping machines Rank 3 shown in Table 1, and when the reference time in Step ST7 in the finish lapping process shown in FIG. 1B is set at 2 minutes. - Referring to
Machine 1, the DCR is within the tolerances, and the finish lapping time is 3 minutes and 10 seconds. In contrast, inMachines - Accordingly, the lapping ranks of
Machines - While the rank is selected based on the DCR value in Table3, it may be based on the MR height calculated from the DCR value.
TABLE 3 Rank Excess DCR Within tolerances Rank 3 (Ω) 1 Rank 32 Rank 23 Rank 24 Rank 15 Rank 1 - DCR values of samples lapped by
Machines machines rank 3. That is, the amount of the height of the thin-film magnetic element to be reduced in rough lapping is reduced. Table 4 shows the results of rough lapping and finish lapping after this change.TABLE 4 Machine 2Machine 3Rank 2 13 Lapping time 2:15 3:52 (mm:sec) Recession −2.4 −3.1 (nm) Excess DCR within tolerances within tolerances (Ω) - The finish lapping results in Table 4 show that the DCR values of
Machines - When the finish lapping time is long, it can be shortened by changing rough lapping conditions.
- For example, it is possible to shorten the finish lapping time according to a lapping rank changing table shown in Table 5.
TABLE 5 Finish lapping time (mm) 2 to 3 3 to 4 4 to 5 Excess DCR Within rank 3rank 4rank 5 (Ω) tolerances 1 rank 3rank 4rank 52 rank 2rank 3rank 43 rank 2rank 3rank 44 rank 1rank 2rank 35 rank 1rank 2rank 3 - Table 5 shows a rank-changing table for use in setting a rank for the next lapping process based on the finish lapping time and the DCR values of the samples in the previous lapping process performed in
Rank 3. When the DCR value is within the tolerances and the finish lapping time is equal to more than 2 minutes and less than 3 minutes in the previous lapping process inRank 3, the rank need not be changed, and therefore, the next lapping process is performed inRank 3. If the DCR value is within the tolerances and the finish lapping time is equal to or more than 4 minutes and less than 5 minutes in the lapping process inRank 3, the MR height is insufficiently reduced in rough lapping inRank 3, as shown in Table 1, and too much time is taken for the MR height to fall into the finish tolerance range in finish lapping. Accordingly, in this case, finish lapping time can be shortened by changing the rank toRank 5. - FIG. 10 is a block diagram of a thin-film magnetic head manufacturing apparatus according to an embodiment of the present invention.
- In the thin-film magnetic head manufacturing apparatus shown in FIG. 10, the resistance values of the magnetoresistive sensors of the thin-film
magnetic elements 1 formed on theslider bar 3 shown in FIG. 6 are measured by aresistance measuring device 31 serving as a resistance measuring means of the present invention, and theABS 3 a of theslider bar 3 and the thin-filmmagnetic elements 1 in the thin-film magnetic head are lapped by the lappingmachine 32 in the direction of the height, thereby adjusting the MR height. - A
computer 35 constructs a control means of the present invention. Thecomputer 35 controls theresistance measuring device 31 and the lappingmachine 32, receives data therefrom, converts the resistances of the magnetoresistive sensors to MR heights, refers to the lapping condition tables in amemory device 34, displays data, such as measured resistance values, and gives instructions to the operator. - The time in which the thin-film
magnetic elements 1 are lapped by the lappingmachine 32 is measured by atimer 33 connected to the lappingmachine 32. Furthermore, thecomputer 35 controls the lappingmachine 32 so that the lappingmachine 32 continues lapping until the lapping time exceeds a predetermined time and the resistance value or the MR height converted from the resistance value falls into the finish tolerances. - The lapping
machine 32 has also aspeed change gear 32 b serving as a speed changing means for changing the rotation rate of the lappingplate 32 a in a stepwise manner. Thecomputer 35 controls thespeed change gear 32 b so that the rotation rate of the lappingplate 32 a is switched to a lower rate at least once to complete lapping when the resistance of the thin-filmmagnetic element 1 or the MR height converted from the resistance value falls below the reference value. - In the block diagram of FIG. 10, the
speed change gear 32 b may be omitted, or thetimer 33 may be omitted. - In the thin-film magnetic head manufacturing apparatus of this embodiment, the lapping machine performs lapping in two stages, rough lapping and finish lapping, whereas the lapping machine may perform a single-stage lapping.
- The tables, as in Tables 3 and 5, showing a plurality of different rough and finish lapping condition ranks may be stored as a database in the
memory device 34, and be read when the rank change is required. Thememory device 34 may be connected to thecomputer 35 connected to the lapping machine directly or via a network. - While the present invention has been described with reference to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Claims (30)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/863,731 US6419552B2 (en) | 1999-01-28 | 2001-05-23 | Thin-film magnetic head manufacturing method and apparatus |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11-020456 | 1999-01-28 | ||
JP11020456A JP2000222711A (en) | 1999-01-28 | 1999-01-28 | Production of thin-film magnetic head and apparatus for production therefor |
US09/488,694 US6299507B1 (en) | 1999-01-28 | 2000-01-20 | Thin-film magnetic head manufacturing method and apparatus |
US09/863,731 US6419552B2 (en) | 1999-01-28 | 2001-05-23 | Thin-film magnetic head manufacturing method and apparatus |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/488,694 Division US6299507B1 (en) | 1999-01-28 | 2000-01-20 | Thin-film magnetic head manufacturing method and apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010034185A1 true US20010034185A1 (en) | 2001-10-25 |
US6419552B2 US6419552B2 (en) | 2002-07-16 |
Family
ID=12027586
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/488,694 Expired - Lifetime US6299507B1 (en) | 1999-01-28 | 2000-01-20 | Thin-film magnetic head manufacturing method and apparatus |
US09/863,731 Expired - Lifetime US6419552B2 (en) | 1999-01-28 | 2001-05-23 | Thin-film magnetic head manufacturing method and apparatus |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/488,694 Expired - Lifetime US6299507B1 (en) | 1999-01-28 | 2000-01-20 | Thin-film magnetic head manufacturing method and apparatus |
Country Status (3)
Country | Link |
---|---|
US (2) | US6299507B1 (en) |
JP (1) | JP2000222711A (en) |
CN (2) | CN1188837C (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080012556A1 (en) * | 2006-06-12 | 2008-01-17 | Sae Magnetics (H.K.) Ltd. | Element for detecting the amount of lapping having a resistive film electrically connected to the substrate |
US7869309B2 (en) | 2005-08-11 | 2011-01-11 | Seagate Technology Llc | Dual wire integrated WAMR/HAMR writing head |
US10699741B1 (en) | 2019-01-08 | 2020-06-30 | International Business Machines Corporation | Multi-channel magnetic recording head having compliantly encapsulated transducers |
CN111872828A (en) * | 2020-07-15 | 2020-11-03 | 湘潭大学 | Magnetic suspension polishing device and operation method thereof |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001205556A (en) * | 2000-01-28 | 2001-07-31 | Tdk Corp | Polishing method for magnetic head slider |
JP2001344716A (en) * | 2000-06-02 | 2001-12-14 | Sony Corp | Method for manufacturing magnetoresistive head |
JP2002299729A (en) * | 2001-03-30 | 2002-10-11 | Fujitsu Ltd | Method for manufacturing magnetoresistance effect read element |
US6786803B2 (en) * | 2002-11-19 | 2004-09-07 | International Business Machines Corporation | Onboard multiphase electronic lapping guide design for MR heads |
US7212381B2 (en) * | 2003-08-14 | 2007-05-01 | Seagate Technology Llc | Slider having adjusted transducer recession and method of adjusting recession |
JP4274554B2 (en) * | 2004-07-16 | 2009-06-10 | キヤノン株式会社 | Element substrate and method for forming liquid ejection element |
US7245459B2 (en) * | 2004-09-30 | 2007-07-17 | Hitachi Global Storage Technologies Netherlands Bv | Critically exposed lapping of magnetic sensors for target signal output |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01153242A (en) | 1987-12-04 | 1989-06-15 | Tdk Corp | Method for controlling workpiece shape |
US5095613A (en) | 1990-06-29 | 1992-03-17 | Digital Equipment Corporation | Thin film head slider fabrication process |
SG47479A1 (en) * | 1992-08-25 | 1998-04-17 | Seagate Technology | A magnetoresistive sensor and method of making the same |
US5321882A (en) | 1992-09-22 | 1994-06-21 | Dastek Corporation | Slider fabrication |
TW243530B (en) * | 1992-12-30 | 1995-03-21 | Ibm | Magnetoresistive sensor with improved microtrack profile for improved servo-positioning precision |
US5406694A (en) | 1993-11-24 | 1995-04-18 | Rocky Mountain Magnetics, Inc. | Scalable method of fabricating thin-film sliders |
US5722156A (en) | 1995-05-22 | 1998-03-03 | Balfrey; Brian D. | Method for processing ceramic wafers comprising plural magnetic head forming units |
US5632669A (en) * | 1995-05-26 | 1997-05-27 | Censtor Corporation | Interactive method for lapping transducers |
US5930084A (en) * | 1996-06-17 | 1999-07-27 | International Business Machines Corporation | Stabilized MR sensor and flux guide joined by contiguous junction |
-
1999
- 1999-01-28 JP JP11020456A patent/JP2000222711A/en not_active Withdrawn
-
2000
- 2000-01-20 US US09/488,694 patent/US6299507B1/en not_active Expired - Lifetime
- 2000-01-28 CN CNB001004905A patent/CN1188837C/en not_active Expired - Lifetime
- 2000-01-28 CN CNB2004100623795A patent/CN1275228C/en not_active Expired - Lifetime
-
2001
- 2001-05-23 US US09/863,731 patent/US6419552B2/en not_active Expired - Lifetime
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7869309B2 (en) | 2005-08-11 | 2011-01-11 | Seagate Technology Llc | Dual wire integrated WAMR/HAMR writing head |
US20080012556A1 (en) * | 2006-06-12 | 2008-01-17 | Sae Magnetics (H.K.) Ltd. | Element for detecting the amount of lapping having a resistive film electrically connected to the substrate |
US7422511B2 (en) * | 2006-06-12 | 2008-09-09 | Sae Magnetics (H.K.) Ltd. | Element for detecting the amount of lapping having a resistive film electrically connected to the substrate |
US10699741B1 (en) | 2019-01-08 | 2020-06-30 | International Business Machines Corporation | Multi-channel magnetic recording head having compliantly encapsulated transducers |
CN111872828A (en) * | 2020-07-15 | 2020-11-03 | 湘潭大学 | Magnetic suspension polishing device and operation method thereof |
Also Published As
Publication number | Publication date |
---|---|
CN1275228C (en) | 2006-09-13 |
CN1188837C (en) | 2005-02-09 |
JP2000222711A (en) | 2000-08-11 |
CN1567435A (en) | 2005-01-19 |
US6299507B1 (en) | 2001-10-09 |
US6419552B2 (en) | 2002-07-16 |
CN1262503A (en) | 2000-08-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7359152B2 (en) | Thin film magnetic head structure, method of manufacturing the same, and method of manufacturing thin film magnetic head | |
US7206172B2 (en) | Electrical lapping guide embedded in a shield of a magnetic head | |
US8351162B2 (en) | Magnetic head with electro lapping guide | |
US5597340A (en) | Ultimate inductive head integrated lapping system | |
US7287316B2 (en) | Lapping monitor device, system and method | |
JP3439129B2 (en) | Manufacturing method of magnetic head | |
US8065788B2 (en) | Method for manufacturing a slider for a perpendicular magnetic recording head | |
US8146237B2 (en) | Method of manufacturing a magnetic head | |
US20080013219A1 (en) | Methods of manufacturing magnetic heads with reference and monitoring devices | |
JP3471520B2 (en) | Method of manufacturing magnetoresistive head and method of manufacturing magnetoresistive head | |
US6757144B2 (en) | Flux guide read head with in stack biased current perpendicular to the planes (CPP) sensor | |
US6299507B1 (en) | Thin-film magnetic head manufacturing method and apparatus | |
US20080251099A1 (en) | Method for removing smear and magnetic recording/reproducing apparatus with function of removing smear | |
US6568992B1 (en) | Method for controlling MRE stripe height | |
US7810226B2 (en) | Method of manufacturing a thin-film magnetic head having an element having a lower layer with a narrower width | |
JP2007058968A (en) | Thin film magnetic head structure and manufacturing method thereof, and manufacturing method of thin film magnetic head | |
US6859678B1 (en) | Method and apparatus for manufacturing magnetoresistive element, software and system for controlling manufacturing of magnetoresistive element, software for estimating resistance value of magnetoresistive element, and computer system | |
US6328859B1 (en) | Method of making second pole tip of a write head with a narrow track width | |
US7933099B2 (en) | Thin-film magnetic head having electric lapping guide and method of making the same | |
US20020066177A1 (en) | Method for manufacturing magneto-resistive effect type magnetic heads | |
US8082657B2 (en) | Method for manufacturing an electrical lapping guide for magnetic write head core width optimization | |
US20220059131A1 (en) | Built-In Resistance Sensor for Measuring Slider Level Pole Width at Point "A" (PWA) for PMR/MAMR Writers | |
US8117736B2 (en) | Method of lapping a magnetic head slider | |
US10672423B2 (en) | Electronic test structures for one or more magnetoresistive elements, and related methods | |
JPH11250417A (en) | Manufacture of magnetic head |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
CC | Certificate of correction | ||
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
AS | Assignment |
Owner name: TDK CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALPS ELECTRIC CO., LTD.;REEL/FRAME:020362/0204 Effective date: 20071220 Owner name: TDK CORPORATION,JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALPS ELECTRIC CO., LTD.;REEL/FRAME:020362/0204 Effective date: 20071220 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |