US20020001671A1 - Method of manufacturing lapping control sensor for magnetoresistive effect head - Google Patents
Method of manufacturing lapping control sensor for magnetoresistive effect head Download PDFInfo
- Publication number
- US20020001671A1 US20020001671A1 US09/497,756 US49775600A US2002001671A1 US 20020001671 A1 US20020001671 A1 US 20020001671A1 US 49775600 A US49775600 A US 49775600A US 2002001671 A1 US2002001671 A1 US 2002001671A1
- Authority
- US
- United States
- Prior art keywords
- layer
- sensor
- insulation layer
- magnetoresistive effect
- 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
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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
- B24B49/10—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation involving electrical means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
- G01B7/06—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness
- G01B7/10—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness for measuring thickness using magnetic means, e.g. by measuring change of reluctance
-
- 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
-
- 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
- G11B5/3109—Details
- G11B5/3116—Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks
-
- 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
-
- 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.]
-
- 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
-
- 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
- Y10T29/49043—Depositing magnetic layer or coating
-
- 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
- Y10T29/49043—Depositing magnetic layer or coating
- Y10T29/49044—Plural magnetic deposition layers
Definitions
- the present invention relates to a lapping control sensor used in controlling a height of a magnetoresistive effect (MR) head (MR height) when the MR head is fabricated, to a lapping control method using the sensor and to a manufacturing method of the sensor.
- MR magnetoresistive effect
- the MR height of a plurality of MR heads is collectively controlled by lapping one surface (ABS, Air Bearing Surface) of each bar obtained by cutting each row from a wafer so that the plurality of MR heads are aliened in one row.
- ABS Air Bearing Surface
- ELG electric lapping guide
- RLG resistance lapping guide
- Each of the ELGs or RLGs is mainly composed of a resister which is adjacent to the ABS surface to be lapped and extends in parallel.
- the ELG or RLG teaches an amount of lapping by changing its terminal voltage or its resistance due to the reduction of the height of the resister polished with polishing of the MR height.
- Such ELG with respect to the throat height of a magnetic pole gap in an inductive head, not to the MR height, is known by, for example, U.S. Pat. No. 4,689,877 and Japanese Unexamined Patent Publication No. 63(1988)-191570.
- FIG. 1 shows a multi-layered structure of a conventional ELG or RLG.
- the conventional ELG or RLG has a multi-layered structure consisting of a metallic layer (shield layer) 10 , an insulation layer (shield gap layer) 11 , a resister layer (MR layer) 12 and lead conductors 13 and 14 , which are made of the same material and layer thickness as those of the MR head.
- a short circuit may be formed temporarily between the lead conductors 13 and 14 via the metallic layer 10 and smears 15 (burrs) which may be protruded from the metallic layer 10 during the lapping control of the MR height.
- the smear metals 15 produced on the lapped surface of the metallic layer 10 are extended across the insulation layer 11 to contact the lead conductors 13 and 14 when the lapping direction is a direction of an arrow shown in FIG. 1, resulting in forming the electric short circuit between the metallic layer 11 and the lead conductors 13 and 14 .
- a lapping direction is set in the opposite direction to the direction of the arrow in FIG. 1.
- a recession between a substrate (slider) and an under film formed thereon becomes remarkably large causing the characteristics of the MR head itself to greatly deteriorate.
- a lapping control sensor for a MR head including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the MR head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a MR layer and a lead conductor layer is provided.
- the insulation layer of the lapping control sensor has a thickness larger than that of the shield gap insulation layer of the MR head.
- the thickness of the insulation layer of the sensor is 0.1 ⁇ m or more.
- a lapping control sensor for a MR head including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the MR head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a MR layer and a lead conductor layer.
- the metallic layer, the insulation layer, the resister layer and the lead conductor layer of the sensor are made of the same material as that of the lower shield layer, the shield gap insulation layer, the MR layer and the lead conductor layer of the MR head, respectively.
- the insulation layer of the lapping control sensor has a thickness larger than that of the shield gap insulation layer.
- the thickness of the insulation layer of the sensor is 0.1 ⁇ m or more.
- an insulation layer of the lapping control sensor is formed so as to have a thickness of 0.1 ⁇ m or more which is thicker than the thickness of a shield gap insulation layer of the MR head, noise generation due to the metallic smears can be prevented. Accordingly, the MR height can be securely and stably controlled to a correct value.
- a lapping control method using the above-mentioned sensor is provided.
- the lapping control of a height of the MR layer of the MR head is executed in response to a signal from the lapping control sensor.
- a method for manufacturing a lapping control sensor includes the steps of sequentially depositing a metallic layer and an insulation layer at a position in parallel with a MR head during depositing steps of a lower shield layer and a shield gap insulation layer of the MR head, in which the insulation layer of the sensor has a thickness larger than that of the shield gap insulation layer and the thickness of the insulation layer of the sensor is 0.1 ⁇ m or more, and sequentially depositing a resistor layer and a lead conductor layer on the insulation layer during depositing steps of a MR layer and a lead conductor layer of the MR head.
- each of a plurality of lapping control sensors is located near the respective MR heads.
- the metallic layer, the insulation layer, the resister layer and the lead conductor layer of the sensor are made of the same material as that of the lower shield layer, the shield gap insulation layer, the MR layer and the lead conductor layer of the MR head, respectively.
- FIG. 1 is a cross-sectional view schematically showing a multilayered structure of a conventional lapping control sensor
- FIG. 2 is a view schematically showing a plane structure of a lapping control sensor of a preferred embodiment of the present invention
- FIG. 3 is a cross-sectional view schematically showing the multi-layered structure of a lapping control sensor of FIG. 2;
- FIGS. 4 a to 4 d are cross-sectional views explaining the manufacturing method of the lapping control sensor
- FIG. 5 is a characteristic diagram illustrating the relationship between a thickness of an insulation layer of the lapping control sensor and an error ratio of resistance measurement
- FIGS. 6 a to 6 c are characteristic diagrams of the change in measured values of resistance with respect to lapping time when the thickness of the insulation layer is small.
- FIGS. 7 a to 7 c are characteristic diagrams of the change in measured values of resistance with respect to lapping time when the thickness of the insulation layer is large.
- FIG. 2 illustrates a plan view of MR heads and a lapping control sensor in a part of a bar obtained by cutting each of rows of a wafer in which numerous MR heads were arranged in a matrix.
- FIG. 2 is, however, a transparent view because an inductive head and the like have actually been mounted on the bar and thus these MR heads and the lapping control sensor cannot be directly seen from outside.
- reference numerals 20 and 20 a denote the bar and the ABS surface to be lapped of the bar 20 .
- reference numerals 21 and 22 denote two of a plurality of MR heads formed in one row along the bar 20
- 23 denotes one of lapping control sensors formed in a space between the MR heads in parallel therewith. In this case, it is desirable that another lapping control sensors are provided at both end portions of the bar 20 .
- reference numerals 21 a and 22 a denote MR layers of the respective MR heads 21 and 22 formed on a shield gap insulation layer
- 21 b and 21 c, and 22 b and 22 c denote lead conductors connected across the respective MR layers 21 a and 22 a
- reference numeral 23 a denotes a resister layer of the lapping control sensor 23
- 23 b and 23 c denote lead conductors connected across the resistor layer 23 a
- the MR layers 21 a and 22 a and the resister layer 23 a are disposed in parallel with the ABS surface 20 a so that one sides of the layers are adjacent to the ABS surface 20 a.
- FIG. 3 illustrates the multi-layered structure of the lapping control sensor 23 shown in FIG. 2.
- reference numeral 30 denotes a metallic layer made of the same material and provided with the same layer thickness as those of the lower shield layer of the MR head
- 31 denotes an insulation layer made of the same material as that of the shield gap insulation layer of the MR head but provided with a layer thickness of for example 0.1 ⁇ m which is larger than that of the lower shield layer of the MR head.
- reference numeral 32 denotes a resister layer made of the same material and provided with the same layer thickness as those of the MR layer of the MR head
- 33 and 34 denote lead conductors made of the same material and provided with the same layer thickness as those of the lead conductor of the MR head.
- FIGS. 4 a to 4 d are cross-sectional views explaining a manufacturing method of the lapping control sensor of the embodiment shown in FIG. 2.
- the metallic layer 30 is first formed on an under layer (not shown). This metallic layer 30 is formed by the same processes as the formation of the lower shield layer of the MR head. Therefore, the layer 30 is formed made of the same material and provided with the same thickness as those of the lower shield layer.
- an insulation layer 31 ′ is formed on the layer 30 and on the under layer.
- This insulation layer 31 ′ is formed by the same processes as the formation of the shield gap insulation layer of the MR head. Therefore, the layer 31 ′ is made of the same material and provided with the same thickness as those of the shield gap insulation layer.
- an insulation material is further deposited by using a lift off process or the like so as to form an insulation layer 31 having a thickness of for example 0.1 ⁇ m or more, which is greater than that of the insulation layer in other areas.
- the insulation layer 31 having such a greater thickness may be formed on only the lapping control sensor as mentioned above, or on any area other than the MR head area.
- the resister layer 32 ( 23 a ) is formed on the insulation layer 31 .
- This resister layer 32 ( 23 a ) is also formed by the same processes as the formation of the MR layer of the MR head. Therefore, the resister layer 32 ( 23 a ) is made of the same material and provided with the same thickness as those of the MR layer.
- the lead conductors 33 ( 23 b ) and 34 ( 23 c ) connected across the resister layer 32 ( 23 a ) are formed.
- These lead conductors 33 ( 23 b ) and 34 ( 23 c ) are also formed by the same processes as the formation of lead conductors of the MR head. Therefore, the lead conductors 33 ( 23 b ) and 34 ( 23 c ) are made of the same material and provided with the same thickness as those of the lead conductors of the MR head.
- the insulation layer of the lapping control sensor is formed to have a thickness of 0.1 ⁇ m or more which is greater than the thickness of the shield gap insulation layer of the MR head. Therefore, when the bar 20 is lapped from the ABS surface 20 a side to control the MR height using this sensor, the formation of short circuits between the lead conductors 33 ( 23 b ) and 34 ( 23 c ) due to smears produced can be prevented. Therefore, the generation of noises in detecting outputs can be also securely prevented.
- FIG. 5 illustrates relationships between a thickness of the insulation layer of the lapping control sensor and an error ratio of the resistance measurement.
- Marks ⁇ and ⁇ represent characteristics of lapping control sensors with the metallic layers 30 made of different materials, respectively.
- the error ratio of the resistance measurement is given from the number of continuous abnormal measurements divided by the total number of measurements.
- the measurement period of resistance is 0.1 sec.
- the number of continuous abnormal measurements means the number of measurements in which measured values of resistance did not continuously indicate normal resistance values during lapping process of the same bar.
- the normal resistance value means that the measured value of resistance is larger than the last measured value (the value measured at 0.1 sec. before) and that the measured value of resistance is larger than the maximum measured value of resistance measured during the lapping process of the same bar.
- the thickness of the insulation layer of a lapping control sensor is 0.1 ⁇ m or more.
- FIGS. 6 a to 6 c indicate change in measured values of resistance with respect to lapping time for various samples of the lapping control sensor with a thin insulation layer having a thickness of 0.08 ⁇ m.
- FIGS. 7 a to 7 c indicate change in measured values of resistance with respect to lapping time for various samples of the lapping control sensor with a thick insulation layer having a thickness of 0.1 ⁇ m or more.
- the MR head Since the MR head has a thin shield gap insulation layer, smears may be produced during controlling the MR height, resulting that the smears may produce short circuits between lead conductors of the MR head.
- the method of manufacturing the MR head includes the steps of controlling the MR height without using lead conductors and removing such smears, no problems occur.
Abstract
A lapping control sensor for a MR head includes a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the MR head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a MR layer and a lead conductor layer is provided. The insulation layer of the lapping control sensor has a thickness larger than that of the shield gap insulation layer of the MR head. The thickness of the insulation layer of the sensor is 0.1 μm or more.
Description
- The present invention relates to a lapping control sensor used in controlling a height of a magnetoresistive effect (MR) head (MR height) when the MR head is fabricated, to a lapping control method using the sensor and to a manufacturing method of the sensor.
- The MR height of a plurality of MR heads is collectively controlled by lapping one surface (ABS, Air Bearing Surface) of each bar obtained by cutting each row from a wafer so that the plurality of MR heads are aliened in one row. To control the mutual MR height of the plurality of MR heads of a bar and the mutual MR height of the MR heads of a plurality of bars to a corrective value, there are usually provided a plurality of lapping control sensors called as an electric lapping guide (ELG) or a resistance lapping guide (RLG) which detects the height of a lapped ABS surface, in each bar. The lapping of the ABS surface can be controlled in response to electric signals from the ELGs or RLGs.
- Each of the ELGs or RLGs is mainly composed of a resister which is adjacent to the ABS surface to be lapped and extends in parallel. The ELG or RLG teaches an amount of lapping by changing its terminal voltage or its resistance due to the reduction of the height of the resister polished with polishing of the MR height. Such ELG with respect to the throat height of a magnetic pole gap in an inductive head, not to the MR height, is known by, for example, U.S. Pat. No. 4,689,877 and Japanese Unexamined Patent Publication No. 63(1988)-191570.
- In manufacturing the MR head, the ELG or RLG is generally formed in the same process of manufacturing the MR head so as to have the same layered structure as that of the MR head. FIG. 1 shows a multi-layered structure of a conventional ELG or RLG. As shown in the figure, the conventional ELG or RLG has a multi-layered structure consisting of a metallic layer (shield layer)10, an insulation layer (shield gap layer) 11, a resister layer (MR layer) 12 and
lead conductors - Recently, in order to increase the bit density in a magnetic disk unit, narrower gap of the MR shield has been demanded. In order to make the shield gap narrower, it is necessary to decrease the thickness of the MR layer and/or the thickness of the shield gap insulation layer. However, there is a limit in decreasing the layer thickness of the MR layer because the characteristics of the head will be deteriorate. Thus, the thickness of the shield gap insulation layer sandwiching this MR layer has to be decreased. When the thickness of the shield gap insulation layer in the MR head is decreased, thickness of the
insulation layer 11 in the ELG or RLG is also decreased as well. - When the thickness of the
insulation layer 11 of the ELG or RLG is decreased as mentioned above, a short circuit may be formed temporarily between thelead conductors metallic layer 10 and smears 15 (burrs) which may be protruded from themetallic layer 10 during the lapping control of the MR height. Thesmear metals 15 produced on the lapped surface of themetallic layer 10 are extended across theinsulation layer 11 to contact thelead conductors metallic layer 11 and thelead conductors lead conductors - In order to prevent the production of metallic smears when lapping the metallic layer, it may be considered to provide no metallic layer as an under layer of the ELG or RLG. However, if the resistor layer of the ELG or RLG has no under layer, it cannot have the same resistive change characteristics as the MR layer of the MR head due to differences between surface characteristics such as unevenness of the under layer. In order to enhance the controllability of the MR height, it is desirable that the resistor layer of the ELG or RLG and the MR layer of the MR element have the same resistive change characteristics.
- In order to prevent the production of metallic smears when lapping the metallic layer, it is also considered that a lapping direction is set in the opposite direction to the direction of the arrow in FIG. 1. However, when the lapping direction is reversed, a recession between a substrate (slider) and an under film formed thereon becomes remarkably large causing the characteristics of the MR head itself to greatly deteriorate.
- It is therefore an object of the present invention to provide a lapping control sensor which can securely and stably control a MR height of a MR head to a correct value.
- It is another object of the present invention to provide a lapping control method using the sensor and a manufacturing method of the sensor.
- According to the present invention, a lapping control sensor for a MR head, including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the MR head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a MR layer and a lead conductor layer is provided. The insulation layer of the lapping control sensor has a thickness larger than that of the shield gap insulation layer of the MR head. The thickness of the insulation layer of the sensor is 0.1 μm or more.
- Also, according to the present invention, a lapping control sensor for a MR head, including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the MR head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a MR layer and a lead conductor layer. The metallic layer, the insulation layer, the resister layer and the lead conductor layer of the sensor are made of the same material as that of the lower shield layer, the shield gap insulation layer, the MR layer and the lead conductor layer of the MR head, respectively. The insulation layer of the lapping control sensor has a thickness larger than that of the shield gap insulation layer. The thickness of the insulation layer of the sensor is 0.1 μm or more.
- Since an insulation layer of the lapping control sensor is formed so as to have a thickness of 0.1 μm or more which is thicker than the thickness of a shield gap insulation layer of the MR head, noise generation due to the metallic smears can be prevented. Accordingly, the MR height can be securely and stably controlled to a correct value.
- According to the present invention, furthermore, a lapping control method using the above-mentioned sensor is provided. In this method, the lapping control of a height of the MR layer of the MR head is executed in response to a signal from the lapping control sensor.
- According to the present invention, also, a method for manufacturing a lapping control sensor is provided. This method includes the steps of sequentially depositing a metallic layer and an insulation layer at a position in parallel with a MR head during depositing steps of a lower shield layer and a shield gap insulation layer of the MR head, in which the insulation layer of the sensor has a thickness larger than that of the shield gap insulation layer and the thickness of the insulation layer of the sensor is 0.1 μm or more, and sequentially depositing a resistor layer and a lead conductor layer on the insulation layer during depositing steps of a MR layer and a lead conductor layer of the MR head.
- It is preferred that each of a plurality of lapping control sensors is located near the respective MR heads.
- It is also preferred that the metallic layer, the insulation layer, the resister layer and the lead conductor layer of the sensor are made of the same material as that of the lower shield layer, the shield gap insulation layer, the MR layer and the lead conductor layer of the MR head, respectively.
- Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
- FIG. 1 is a cross-sectional view schematically showing a multilayered structure of a conventional lapping control sensor;
- FIG. 2 is a view schematically showing a plane structure of a lapping control sensor of a preferred embodiment of the present invention;
- FIG. 3 is a cross-sectional view schematically showing the multi-layered structure of a lapping control sensor of FIG. 2;
- FIGS. 4a to 4 d are cross-sectional views explaining the manufacturing method of the lapping control sensor;
- FIG. 5 is a characteristic diagram illustrating the relationship between a thickness of an insulation layer of the lapping control sensor and an error ratio of resistance measurement;
- FIGS. 6a to 6 c are characteristic diagrams of the change in measured values of resistance with respect to lapping time when the thickness of the insulation layer is small; and
- FIGS. 7a to 7 c are characteristic diagrams of the change in measured values of resistance with respect to lapping time when the thickness of the insulation layer is large.
- FIG. 2 illustrates a plan view of MR heads and a lapping control sensor in a part of a bar obtained by cutting each of rows of a wafer in which numerous MR heads were arranged in a matrix. FIG. 2 is, however, a transparent view because an inductive head and the like have actually been mounted on the bar and thus these MR heads and the lapping control sensor cannot be directly seen from outside.
- In the figure,
reference numerals bar 20. Also,reference numerals bar bar 20. - In FIG. 2, furthermore,
reference numerals respective MR heads respective MR layers reference numeral 23 a denotes a resister layer of thelapping control sensor resistor layer 23 a As shown in the figure, theMR layers resister layer 23 a are disposed in parallel with theABS surface 20 a so that one sides of the layers are adjacent to theABS surface 20 a. - FIG. 3 illustrates the multi-layered structure of the
lapping control sensor 23 shown in FIG. 2. In FIG. 3,reference numeral 30 denotes a metallic layer made of the same material and provided with the same layer thickness as those of the lower shield layer of the MR head, and 31 denotes an insulation layer made of the same material as that of the shield gap insulation layer of the MR head but provided with a layer thickness of for example 0.1 μm which is larger than that of the lower shield layer of the MR head. Also reference numeral 32 (23 a) denotes a resister layer made of the same material and provided with the same layer thickness as those of the MR layer of the MR head, and 33 and 34 (23 b and 23 c) denote lead conductors made of the same material and provided with the same layer thickness as those of the lead conductor of the MR head. - FIGS. 4a to 4 d are cross-sectional views explaining a manufacturing method of the lapping control sensor of the embodiment shown in FIG. 2. The
metallic layer 30 is first formed on an under layer (not shown). Thismetallic layer 30 is formed by the same processes as the formation of the lower shield layer of the MR head. Therefore, thelayer 30 is formed made of the same material and provided with the same thickness as those of the lower shield layer. - Then, as shown in FIG. 4b, an
insulation layer 31′ is formed on thelayer 30 and on the under layer. Thisinsulation layer 31′ is formed by the same processes as the formation of the shield gap insulation layer of the MR head. Therefore, thelayer 31′ is made of the same material and provided with the same thickness as those of the shield gap insulation layer. Then, as shown in FIG. 4c, on theinsulation layer 31′ of only the lapping control sensor, an insulation material is further deposited by using a lift off process or the like so as to form aninsulation layer 31 having a thickness of for example 0.1 μm or more, which is greater than that of the insulation layer in other areas. Theinsulation layer 31 having such a greater thickness may be formed on only the lapping control sensor as mentioned above, or on any area other than the MR head area. - Then, as shown in FIG. 4d, the resister layer 32 (23 a) is formed on the
insulation layer 31. This resister layer 32 (23 a) is also formed by the same processes as the formation of the MR layer of the MR head. Therefore, the resister layer 32 (23 a) is made of the same material and provided with the same thickness as those of the MR layer. Then, as shown in FIG. 3, the lead conductors 33 (23 b) and 34 (23 c) connected across the resister layer 32 (23 a) are formed. These lead conductors 33 (23 b) and 34 (23 c) are also formed by the same processes as the formation of lead conductors of the MR head. Therefore, the lead conductors 33 (23 b) and 34 (23 c) are made of the same material and provided with the same thickness as those of the lead conductors of the MR head. - In this embodiment of the present invention, the insulation layer of the lapping control sensor is formed to have a thickness of 0.1 μm or more which is greater than the thickness of the shield gap insulation layer of the MR head. Therefore, when the
bar 20 is lapped from theABS surface 20 a side to control the MR height using this sensor, the formation of short circuits between the lead conductors 33 (23 b) and 34 (23 c) due to smears produced can be prevented. Therefore, the generation of noises in detecting outputs can be also securely prevented. - FIG. 5 illustrates relationships between a thickness of the insulation layer of the lapping control sensor and an error ratio of the resistance measurement. Marks ␣ and × represent characteristics of lapping control sensors with the
metallic layers 30 made of different materials, respectively. the error ratio of the resistance measurement is given from the number of continuous abnormal measurements divided by the total number of measurements. The measurement period of resistance is 0.1 sec. The number of continuous abnormal measurements means the number of measurements in which measured values of resistance did not continuously indicate normal resistance values during lapping process of the same bar. The normal resistance value means that the measured value of resistance is larger than the last measured value (the value measured at 0.1 sec. before) and that the measured value of resistance is larger than the maximum measured value of resistance measured during the lapping process of the same bar. - It has been found from experience that when the error ratio of resistance measurement is larger than 1.5%, a lapping control using a lapping control sensor becomes impossible. Thus, it is necessary from FIG. 5 that the thickness of the insulation layer of a lapping control sensor is 0.1 μm or more.
- FIGS. 6a to 6 c indicate change in measured values of resistance with respect to lapping time for various samples of the lapping control sensor with a thin insulation layer having a thickness of 0.08 μm. Whereas FIGS. 7a to 7 c indicate change in measured values of resistance with respect to lapping time for various samples of the lapping control sensor with a thick insulation layer having a thickness of 0.1 μm or more.
- As apparent from FIGS. 6a to 6 c and FIGS. 7a to 7 c, when the insulation layer is thin as 0.08 μm, a large amount of noise is found in measured values of resistance. However, when the insulation layer is thick as 0.1 μm, no noise is found and measured values of resistance are increased in accordance with passage of time. Therefore, by executing the lapping control using the latter lapping control sensor, it can be securely and stably control an MR height of the MR head to a corrective value.
- Since the MR head has a thin shield gap insulation layer, smears may be produced during controlling the MR height, resulting that the smears may produce short circuits between lead conductors of the MR head. However, since the method of manufacturing the MR head includes the steps of controlling the MR height without using lead conductors and removing such smears, no problems occur.
- Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
Claims (9)
1. A lapping control sensor for a magnetoresistive effect head, said sensor including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the magnetoresistive effect head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a magnetoresistive effect layer and a lead conductor layer, said insulation layer of said lapping control sensor having a thickness larger than that of said shield gap insulation layer of said magnetoresistive effect head, the thickness of said insulation layer of said sensor being 0.1 μm or more.
2. The sensor as claimed in claim 1 , wherein said sensor is located near said magnetoresistive effect head.
3. A lapping control sensor for a magnetoresistive effect head, said sensor including a multi-layered structure of a metallic layer, an insulation layer, a resister layer and a lead conductor layer, and being provided in parallel with the magnetoresistive effect head which has a multi-layered structure of at least a lower shield layer, a shield gap insulation layer, a magnetoresistive effect layer and a lead conductor layer, said metallic layer, said insulation layer, said resister layer and said lead conductor layer of said sensor being made of the same material as that of said lower shield layer, said shield gap insulation layer, said magnetoresistive effect layer and said lead conductor layer of said magnetoresistive effect head, respectively, said insulation layer of said lapping control sensor having a thickness larger than that of said shield gap insulation layer, the thickness of said insulation layer of said sensor being 0.1 μm or more.
4. The sensor as claimed in claim 3 , wherein said sensor is located near said magnetoresistive effect head.
5. A lapping control method using the sensor as claimed in claim 1 , wherein the lapping control of a height of said magnetoresistive effect layer of said magnetoresistive effect head is executed in response to a signal from said lapping control sensor.
6. A lapping control method using the sensor as claimed in claim 3 , wherein the lapping control of a height of said magnetoresistive effect layer of said magnetoresistive effect head is executed in response to a signal from said lapping control sensor.
7. A method for manufacturing a lapping control sensor comprising the steps of:
sequentially depositing a metallic layer and an insulation layer at a position in parallel with a magnetoresistive effect head during depositing steps of a lower shield layer and a shield gap insulation layer of said magnetoresistive effect head, said insulation layer of said sensor having a thickness larger than that of said shield gap insulation layer, the thickness of said insulation layer of said sensor being 0.1 μm or more; and
sequentially depositing a resistor layer and a lead conductor layer on said insulation layer during depositing steps of a magnetoresistive effect layer and a lead conductor layer of said magnetoresistive effect head.
8. The method as claimed in claim 7 , wherein said metallic layer, said insulation layer, said resister layer and said lead conductor layer of said sensor are made of the same material as that of said lower shield layer, said shield gap insulation layer, said magnetoresistive effect layer and said lead conductor layer of said magnetoresistive effect head, respectively.
9. The method as claimed in claim 7 , wherein said sensor is formed to locate near said magnetoresistive effect head.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/497,756 US6399148B2 (en) | 1997-08-07 | 2000-02-04 | Method of manufacturing lapping control sensor for magnetoresistive effect head |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP224436-1997 | 1997-08-07 | ||
JP22443697A JP3395590B2 (en) | 1997-08-07 | 1997-08-07 | Polishing control sensor for magnetoresistive head and polishing control method using the sensor |
JP9-224436 | 1997-08-07 | ||
US09/130,446 US6083081A (en) | 1997-08-07 | 1998-08-06 | Lapping control sensor for magnetoresistive effect head, lapping control method using the sensor and manufacturing method of the sensor |
US09/497,756 US6399148B2 (en) | 1997-08-07 | 2000-02-04 | Method of manufacturing lapping control sensor for magnetoresistive effect head |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/130,446 Division US6083081A (en) | 1997-08-07 | 1998-08-06 | Lapping control sensor for magnetoresistive effect head, lapping control method using the sensor and manufacturing method of the sensor |
US09/497,756 Division US6399148B2 (en) | 1997-08-07 | 2000-02-04 | Method of manufacturing lapping control sensor for magnetoresistive effect head |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/497,756 Division US6399148B2 (en) | 1997-08-07 | 2000-02-04 | Method of manufacturing lapping control sensor for magnetoresistive effect head |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020001671A1 true US20020001671A1 (en) | 2002-01-03 |
US6399148B2 US6399148B2 (en) | 2002-06-04 |
Family
ID=16813752
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/130,446 Expired - Lifetime US6083081A (en) | 1997-08-07 | 1998-08-06 | Lapping control sensor for magnetoresistive effect head, lapping control method using the sensor and manufacturing method of the sensor |
US09/497,756 Expired - Fee Related US6399148B2 (en) | 1997-08-07 | 2000-02-04 | Method of manufacturing lapping control sensor for magnetoresistive effect head |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/130,446 Expired - Lifetime US6083081A (en) | 1997-08-07 | 1998-08-06 | Lapping control sensor for magnetoresistive effect head, lapping control method using the sensor and manufacturing method of the sensor |
Country Status (3)
Country | Link |
---|---|
US (2) | US6083081A (en) |
JP (1) | JP3395590B2 (en) |
SG (1) | SG86331A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6982042B2 (en) | 2003-02-28 | 2006-01-03 | Hitachi Global Storage Technologies Netherlands, B.V. | Ion bombardment of electrical lapping guides to decrease noise during lapping process |
US7551406B1 (en) | 2005-07-01 | 2009-06-23 | Western Digital (Fremont), Llc | Dual electrical lapping guides with common bonding pad |
US7554767B1 (en) * | 2005-07-01 | 2009-06-30 | Western Digital (Fremont), Llc | Electrical lapping guide disposed laterally relative to a shield pedestal |
US11219511B2 (en) | 2005-10-24 | 2022-01-11 | Biomet 3I, Llc | Methods for placing an implant analog in a physical model of the patient's mouth |
US11389275B2 (en) | 2011-05-16 | 2022-07-19 | Biomet 3I, Llc | Temporary abutment with combination of scanning features and provisionalization features |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6347983B1 (en) | 1999-06-09 | 2002-02-19 | Seagate Technology Llc | ELG for both MRE sensor height and resistance monitoring |
DE10196239T1 (en) | 2000-05-25 | 2003-08-07 | Seagate Technology Llc | Improved lapping sensor for recording heads |
US6930864B2 (en) * | 2002-03-22 | 2005-08-16 | International Business Machines Corporation | Methods and apparatus for defining the track width of a magnetic head having a flat sensor profile |
US6793557B2 (en) * | 2002-05-24 | 2004-09-21 | International Business Machines Corporation | Removable lapping guide for magnetic recording head and method of use |
US7014530B2 (en) * | 2003-09-29 | 2006-03-21 | Hitachi Global Storage Technologies Netherlands B.V. | Slider fabrication system for sliders with integrated electrical lapping guides |
US7206172B2 (en) * | 2004-02-20 | 2007-04-17 | Hitachi Global Storage Technologies Netherlands B.V. | Electrical lapping guide embedded in a shield of a magnetic head |
US7108578B2 (en) * | 2004-11-12 | 2006-09-19 | Hitachi Global Storage Technologies Netherlands B.V. | System and method for manufacturing magnetic heads |
US7574791B2 (en) * | 2005-05-10 | 2009-08-18 | Hitachi Global Storage Technologies Netherlands B.V. | Method to fabricate side shields for a magnetic sensor |
US8151441B1 (en) | 2008-03-27 | 2012-04-10 | Western Digital (Fremont), Llc | Method for providing and utilizing an electronic lapping guide in a magnetic recording transducer |
US8066893B2 (en) * | 2008-12-23 | 2011-11-29 | Hitachi Global Storage Technologies Netherlands B.V. | Method for creating a magnetic write pole having a stepped perpendicular pole via CMP-assisted liftoff |
US8165709B1 (en) | 2009-02-26 | 2012-04-24 | Western Digital (Fremont), Llc | Four pad self-calibrating electronic lapping guide |
US8291743B1 (en) | 2009-05-27 | 2012-10-23 | Western Digital (Fremont), Llc | Method and system for calibrating an electronic lapping guide for a beveled pole in a magnetic recording transducer |
US8443510B1 (en) | 2009-05-28 | 2013-05-21 | Western Digital (Fremont), Llc | Method for utilizing an electronic lapping guide for a beveled pole in a magnetic recording transducer |
US8307539B1 (en) | 2009-09-30 | 2012-11-13 | Western Digital (Fremont), Llc | Method for modeling devices in a wafer |
US10672423B2 (en) * | 2018-04-10 | 2020-06-02 | Seagate Technology Llc | Electronic test structures for one or more magnetoresistive elements, and related methods |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4841625A (en) * | 1982-05-07 | 1989-06-27 | Computer And Communications Technology Corporation | Automatic throat height control for film head |
US4689877A (en) * | 1985-08-29 | 1987-09-01 | International Business Machines Corp. | Method and apparatus for controlling the throat height of batch fabricated thin film magnetic transducers |
JPH0710495B2 (en) * | 1987-01-29 | 1995-02-08 | インタ−ナショナル ビジネス マシ−ンズ コ−ポレ−ション | Polishing guide resistor |
US5023991A (en) * | 1988-08-31 | 1991-06-18 | Digital Equipment Corporation | Electrical guide for tight tolerance machining |
US5479308A (en) * | 1993-11-15 | 1995-12-26 | Voegeli; Otto | Magnetoresistive transducer including interdiffusion layer |
US5463805A (en) * | 1994-02-07 | 1995-11-07 | Seagate Technology, Inc. | Method of lapping MR. sensors |
KR100201681B1 (en) * | 1996-01-03 | 1999-06-15 | 포만 제프리 엘 | Highly sensitive magnetoresistive sensor with a series flux guide |
-
1997
- 1997-08-07 JP JP22443697A patent/JP3395590B2/en not_active Expired - Fee Related
-
1998
- 1998-07-31 SG SG9802823A patent/SG86331A1/en unknown
- 1998-08-06 US US09/130,446 patent/US6083081A/en not_active Expired - Lifetime
-
2000
- 2000-02-04 US US09/497,756 patent/US6399148B2/en not_active Expired - Fee Related
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6982042B2 (en) | 2003-02-28 | 2006-01-03 | Hitachi Global Storage Technologies Netherlands, B.V. | Ion bombardment of electrical lapping guides to decrease noise during lapping process |
US20060027528A1 (en) * | 2003-02-28 | 2006-02-09 | Hitachi Global Storage Technologies | Ion bombardment of electrical lapping guides to decrease noise during lapping process |
US7332099B2 (en) * | 2003-02-28 | 2008-02-19 | Hitachi Global Storage Technologies Netherlands B.V. | Ion bombardment of electrical lapping guides to decrease noise during lapping process |
US7551406B1 (en) | 2005-07-01 | 2009-06-23 | Western Digital (Fremont), Llc | Dual electrical lapping guides with common bonding pad |
US7554767B1 (en) * | 2005-07-01 | 2009-06-30 | Western Digital (Fremont), Llc | Electrical lapping guide disposed laterally relative to a shield pedestal |
US11219511B2 (en) | 2005-10-24 | 2022-01-11 | Biomet 3I, Llc | Methods for placing an implant analog in a physical model of the patient's mouth |
US11389275B2 (en) | 2011-05-16 | 2022-07-19 | Biomet 3I, Llc | Temporary abutment with combination of scanning features and provisionalization features |
Also Published As
Publication number | Publication date |
---|---|
JPH1166520A (en) | 1999-03-09 |
JP3395590B2 (en) | 2003-04-14 |
US6083081A (en) | 2000-07-04 |
US6399148B2 (en) | 2002-06-04 |
SG86331A1 (en) | 2002-02-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6399148B2 (en) | Method of manufacturing lapping control sensor for magnetoresistive effect head | |
US5597340A (en) | Ultimate inductive head integrated lapping system | |
US6683749B2 (en) | Magnetic transducer having inverted write element with zero delta in pole tip width | |
EP0383738B1 (en) | Lapping control system for magnetic transducers | |
US6532646B2 (en) | Method of manufacturing magnetic head | |
US6609948B1 (en) | Method of making an electronic lapping guide (ELG) for lapping a read sensor | |
US6027397A (en) | Dual element lapping guide system | |
US6344951B1 (en) | Substrate having magnetoresistive elements and monitor element capable of preventing a short circuit | |
US5588199A (en) | Lapping process for a single element magnetoresistive head | |
US20050168884A1 (en) | Magnetic tunnel effect type magnetic head, and method of producing same | |
US7422511B2 (en) | Element for detecting the amount of lapping having a resistive film electrically connected to the substrate | |
US6034849A (en) | Thin film magnetic head and method of manufacturing the same | |
US4489484A (en) | Method of making thin film magnetic recording heads | |
EP0357236B1 (en) | A batch fabrication process for magnetic heads | |
US6510030B1 (en) | Transducing head and method for forming a recessed shield for a transducing head | |
US6195871B1 (en) | Method of manufacturing magnetic head elements | |
US5911455A (en) | Method of manufacturing a thin-film magnetic head | |
US6557241B1 (en) | Method of manufacturing combination type thin film magnetic head and wafer for use therefor | |
US7168155B2 (en) | Method of manufacturing an integrated thin film head | |
US5467881A (en) | Method of manufacturing an MR read head which eliminates lead-to-shield shorts at the ABS of the MR read head | |
JP3384366B2 (en) | Method for manufacturing thin-film magnetic head | |
US5811018A (en) | Magnetic barrier for gap control in interleaved tape head design | |
US6671133B1 (en) | Thin-film magnetic head and method of manufacturing same | |
US5956215A (en) | High density thin film coupled element read head with support element to prevent damage to magnetoresistive element | |
US6433971B1 (en) | Thin film magnetic head adaptable to gap narrowing and substrate for forming the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
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 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20140604 |