JP2008226298A - Bar for manufacturing magnetic head slider and manufacturing method of magnetic head slider - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bar for manufacturing a magnetic head slider, with which a medium-opposing plane of the magnetic head slider is accurately processed. <P>SOLUTION: In a bar 52 where a plurality of slider forming parts 1 are arranged side by side through margins for cutting 53, a polishing pressure adjusting means (dummy pattern 55 of a convex shape) is provided at a medium-opposing plane ABS of each of the margins for cutting 53. Convex parts (read/write part 4 and rail parts 5a, 5b) of the slider forming part 1 is formed being deviated mainly to the leading side considering performance of the slider 1 of a completed state, and the dummy pattern 55 is formed being deviated mainly to a trailing side. As a whole bar 52, dispersion of distribution of convex parts of the medium-opposing planes ABS is corrected by the dummy pattern 55. Thereby, the sum of area of parts of a convex shape positioned at the leading side equals substantially with the sum of area of parts of a convex shape positioned at the trailing side of the medium-opposing plane ABS. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic head slider manufacturing bar and a magnetic head slider manufacturing method.

  As a high-speed, large-capacity, high-reliability, low-cost recording medium, a hard disk drive is widely used for recording digital information. A hard disk drive is provided with a head arm assembly having an arm and a head gimbal assembly provided at the tip of the arm corresponding to a magnetic disk as a recording medium. The head gimbal assembly has a thin film magnetic head slider (hereinafter referred to as “slider”) that supports a thin film magnetic head that records and reproduces information on a recording medium. The surface on which the slider faces the recording medium is called a medium facing surface (ABS: Air Bearing Surface).

  When recording or reproducing information to or from the recording medium, the slider slightly floats on the recording medium rotating at high speed by air pressure. Thus, the distance between the medium facing surface and the surface of the recording medium when flying by air pressure is called the flying height. Since the bit length of the recording medium is shortened when the flying height is reduced, reducing the flying height is effective for increasing the density of the recording medium. For this reason, with the recent demand for higher recording density of hard disk drives, it is required to further suppress the flying height.

  In order to generate an appropriate wind pressure between the slider and the recording medium, a concavo-convex shape for adjusting the air flow is formed on the medium facing surface of the slider that floats in this manner. Of the concavo-convex shape, the convex portion (in this specification, the convex portion refers to a portion close to the recording medium, and the concave portion refers to a portion far from the recording medium) and the circumference of the recording medium mainly. This part includes a rail part extending in the direction and substantially constitutes the medium facing surface.

  Due to many years of technological development, the recording density of hard disk drives is exceeding 100 gigabits per square inch, and miniaturization and improved characteristics of thin-film magnetic heads are required as the density increases. As a thin film magnetic head, a composite thin film magnetic head having a structure in which a reproducing head having a magnetoresistive element (MR element) for reading and a recording head having an inductive electromagnetic transducer for writing is laminated is widely used. Yes.

  With the miniaturization and improvement of characteristics of such a thin-film magnetic head, the length (MR height) of the MR element for reading is shortened, and the controllability of the medium facing surface polishing process for determining the MR height is reduced. There is a need for further improvements. In addition, in the perpendicular magnetic recording write head, it is also required to improve the accuracy of the length (NH) of the inductive electromagnetic transducer for writing. That is, it is required to accurately control the lengths (MR height and NH) of two elements located at positions away from each other in the thin film magnetic head. Therefore, it is particularly important to strictly control the polishing amount and the polishing angle of the medium facing surface.

  In manufacturing the slider, first, a wafer in which a plurality of elements are formed in a two-dimensional matrix is manufactured, and then the wafer is cut into strips to form a bar in which a large number of slider portions are connected. In the bar, slider forming portions and cut margins that are portions to be sliders are alternately formed. A plurality of sliders are manufactured from one bar by cutting the cutting allowance.

  Specifically, for example, by sticking a bar in a state where a plurality of elements made using semiconductor technology are arranged in a wafer to a processing jig through a resin or the like, and pressing the bar against a polishing surface plate, The flat surface of the bar on which the surface to be the medium facing surface of the slider is located (hereinafter, for simplicity, this plane is also simply referred to as “medium facing surface”) is polished. Then, the back surface of the bar (surface opposite to the medium facing surface) is polished. A temporary protective film that is a mixed film of Si and diamond-like carbon (DLC) is formed on the medium facing surface, and in this state, a part of the medium facing surface is partially removed by dry etching or the like. To form an uneven shape. The convex portions are the read / write portion and rail portion of the thin film magnetic head. Thereafter, after removing the temporary protective film, the back surface of the bar is held by a soft and adsorbent material (for example, nitrile rubber (NBR)), and the medium facing surface is repolished (final polishing). The final polishing of the medium facing surface improves the smoothness of the read / write portion and the rail portion. Then, a pattern made of DLC is formed on the medium facing surface to form a protective film. Finally, the cutting margin is cut and cut into individual sliders.

  By accurately performing the final polishing of the medium facing surface, the shape of the slider (crown, cross crown, twist, etc.) is well controlled, and pole tip recession (PTR) is also stabilized. In addition, the magnetic space can be reduced and stabilized. Patent Documents 1 to 4 each disclose a method for manufacturing a slider similar to or similar to this.

  In order to polish the medium facing surface with high accuracy, the MR height of each MR element during polishing of the medium facing surface is monitored, and the polishing conditions are changed accordingly. This MR height monitor measures the resistance value of an actual MR element during polishing, and the electrical characteristics of a sensor disposed in the vicinity of the MR element, such as an ELG (Electro Lapping Guide) sensor, or an RLG (Resistance Lapping Guide). ) It is implemented by measuring the electrical resistance value of the sensor.

In addition, in order to remove burrs when a pattern made of DLC is formed on the medium facing surface, PTR abnormality due to heating before polishing the medium facing surface, etc., after forming a pattern made of DLC on the medium facing surface, A method has been proposed in which finish polishing is performed again and DLC is applied again. This allows DLC to adhere to the entire surface of the medium facing surface, so that the generation of particles due to this slider can be reduced.
JP 11-238214 A JP 2003-208709 A JP 2000-163727 A JP 2006-59501 A

  As described above, when polishing the medium facing surface, which may be performed twice, the back surface (the surface opposite to the medium facing surface) is held and the medium facing surface is stably applied to the polishing platen at a desired angle. You may not be able to touch. As shown in FIG. 11A, the recent shape of the medium facing surface ABS of the slider 61 is the leading side (the side positioned forward in the direction of travel relative to the recording medium when the slider 61 is used). This is because the uneven shape is poorly balanced on the trailing side (the side located behind the direction of travel relative to the recording medium when the slider is used). That is, the balance of the areas of the protrusions on the medium facing surface ABS is poor. For example, as shown in FIG. 11A, there are many protrusions such as the rail part 61a on the leading side and few protrusions on the trailing side. .

  As described above, the slider 61 is manufactured by cutting the cutting margin 63 of the bar 62 to which the plurality of slider forming portions 61 are connected. As shown in detail in FIG. 11A, the slider 61 has a large variation in the planar distribution of the convex portions on the leading side and the trailing side, so that the center of the bar 62 shown in FIG. The difference between the total area of the convex portion located on the leading side from the line CL and the total area of the convex portion located on the trailing side from the center line CL is large, and the balance is poor.

  In the drawings other than FIG. 11A, the shape of the rail portion is shown very simplified (partially omitted). Most cutting allowances 63a consist only of thin cutting lines, but some cutting allowances 63b can have a large area to provide the polishing sensor 64. However, the polishing sensor 64 is arranged almost regardless of the balance of the convex portion of the entire bar 62.

  As described above, since the balance of the area of the convex portion of the bar 62 is poor, it is difficult to stably hold the medium facing surface ABS of the bar 62 when polishing. This is because, on the trailing side with a small number of convex portions, the pressing force (polishing pressure) per unit area against the polishing surface plate is large, and the polishing rate increases, whereas there are many convex portions. This is because, on the leading side, the pressing force (polishing pressure) per unit area against the polishing surface plate is small, and the polishing rate becomes slow. In particular, if the back surface of the bar 62 is held by a processing jig via a soft member such as resin or NBR, even if the bar 62 can be accurately fixed to the processing jig at a desired angle before polishing. It is conceivable that the angle of the bar 62 is changed during polishing due to a difference in polishing rate. Thus, when the polishing accuracy of the medium facing surface ABS is poor, the slider 61 having desired performance cannot be manufactured.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic head slider manufacturing bar capable of manufacturing a magnetic head slider with high accuracy, particularly capable of processing a medium facing surface with high accuracy in order to realize further higher recording density of a hard disk drive, and a desired bar. It is an object of the present invention to provide a manufacturing method for manufacturing a magnetic head slider capable of obtaining the above performance.

  The present invention is a bar for manufacturing a thin film magnetic head slider, in which a plurality of slider forming portions serving as thin film magnetic head sliders are arranged in the longitudinal direction, and a cutting margin is provided between each slider forming portion. Further, a polishing pressure adjusting means is provided on the surface side of the bar where the pattern of the medium facing surface of the thin film magnetic head slider is formed.

  According to this configuration, the polishing pressure is adjusted by the polishing pressure adjusting means when polishing the surface to be the medium facing surface, which is particularly important with respect to the performance of the magnetic head slider, thereby making it difficult to cause a difference in polishing rate. it can. As a result, the bar can be stably held, and there is little risk of a deviation in the angle of contact with the polishing plate, and high-precision polishing is possible. And a magnetic head slider having desired characteristics can be easily manufactured.

  The polishing pressure adjusting means is a convex dummy pattern provided at the cutting margin. Further, in the cutting margin provided with the polishing sensor, the convex dummy pattern is preferably provided in a region including the polishing sensor. The dummy pattern is preferably provided near the portion of the cutting margin that becomes the trailing edge of the thin film magnetic head slider.

  Further, it is preferable that the polishing pressure adjusting means is arranged so as to correct the variation in the distribution of the convex portions in the surface where the pattern of the medium facing surface of the thin film magnetic head slider is formed. As a result, the surface to be the medium facing surface can be brought into contact with the polishing surface relatively evenly, and the polishing accuracy can be easily improved.

  The method of manufacturing a thin film magnetic head slider according to the present invention includes a step of forming a bar in which a plurality of slider forming portions serving as a thin film magnetic head slider are arranged in the longitudinal direction, and a medium of the thin film magnetic head slider on one surface of the bar. The step of forming the pattern of the opposing surface, the step of forming the polishing pressure adjusting means closer to the trailing edge of the thin film magnetic head slider at the cutting margin, and the bar are positioned between the slider forming portions. Cutting the cutting allowance to form a thin film magnetic head slider. The polishing pressure adjusting means is a convex dummy pattern provided at the cutting margin. Then, the medium facing surface pattern of the thin film magnetic head slider and the convex dummy pattern may be formed simultaneously.

  According to the present invention, the polishing pressure is adjusted by the polishing pressure adjusting means when polishing the surface to be the medium facing surface, so that the entire bar can be polished at a uniform polishing rate. Therefore, a magnetic head slider having a desired performance can be easily manufactured.

  Embodiments of the present invention will be described below.

  First, the configuration of a magnetic head slider (hereinafter referred to as “slider”) manufactured according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of the slider 1 as viewed from the medium facing surface side, and FIG. 2 is a sectional view taken along the line AA in FIG.

  The slider 1 has a substrate 7 and a thin film magnetic head portion 3 that is a laminate. The slider 1 has a substantially hexahedron shape, and is a medium facing surface ABS in which one of the six faces faces the recording medium P. A concave / convex pattern (also referred to as “medium facing surface pattern” or “ABS pattern”) is formed on the medium facing surface ABS of the slider 1, and the convex portion is a read / write provided with read / write elements of the thin film magnetic head portion 3 It consists of a portion 4 and rail portions 5 a and 5 b having steps, and the other portions are recessed portions 6.

  When the recording medium P rotates, an air flow passing between the recording medium P and the slider 1 causes a downward lift in the y direction in FIG. The slider 1 floats from the surface of the recording medium P by this lift. 1 is the track crossing direction of the recording medium P, and the z direction is the circumferential direction of the recording medium P. The rail portions 5a and 5b are formed along the z direction as a whole, and the thin film magnetic head portion 3 is formed at the end portion (left side in FIG. 2) of the slider 1 on the air outflow side.

  Accordingly, air enters the medium facing surface ABS through a slight gap between the rail portion 5b and the recording medium P, strikes the read / write portion 4 while being rectified by the rail portions 5a on both sides, and the read / write portion 4 and the recording medium. It flows so as to escape from the gap with P. As a result, the slider 1 floats from the surface of the recording medium P. Thus, the slider 1 can float from the recording medium P by the concave and convex portions of the medium facing surface ABS when the thin film magnetic head 3 performs reading or writing on the recording medium P. It is adjusted by the uneven shape.

  FIG. 2 shows a cross-sectional view of the slider 1 shown in FIG. 1 along the line AA. In FIG. 2, the recording medium P extends in parallel with the medium facing surface ABS above the medium facing surface ABS. The thin-film magnetic head unit 3 includes a magnetoresistive effect element that reads magnetic recording from the recording medium P and an inductive magnetic transducer element that writes magnetic recording on the recording medium P, but only one of them. You can do it. The inductive magnetic transducer may be either a longitudinal magnetic recording system that performs recording in the in-plane direction of the recording medium P or a perpendicular magnetic recording system that performs recording in the out-of-plane direction of the recording medium P.

The thin film magnetic head unit 3 has a configuration in which the layers located on the left side of FIG. 2 are sequentially laminated on a substrate 7 made of a ceramic material such as AlTiC (Al ₂ O ₃ .TiC) on the right side of FIG. In the following description, the left side of FIG. 2 is represented as the upper side, and the right side of FIG. 2 is represented as the lower side. On the substrate 7, a shield layer 8 made of, for example, permalloy (NiFe) is formed via an insulating layer. On the shield layer 8, an MR element 9 as a reading element is provided facing the medium facing surface ABS. The MR element 9 is an element using a magnetosensitive film exhibiting a magnetoresistance effect, such as an AMR (anisotropic magnetoresistance effect) element, a GMR (giant magnetoresistance effect) element, or a TMR (tunnel magnetoresistance effect) element. Can be used. The MR element 9 is connected to a pair of lead layers (not shown) that send the read signals.

  On the shield layer 8 and the MR element 9, a lower magnetic pole layer 10 made of a magnetic material such as permalloy or CoNiFe that can be formed by a plating method is formed. The lower magnetic pole layer 10 has a function as a lower magnetic pole layer of the recording head and a function as an upper shield layer of the reproducing head (MR element 9).

  An upper magnetic pole layer 12 is provided on the lower magnetic pole layer 10 via a recording gap 11 for insulation. As the material of the recording gap 11, for example, a nonmagnetic metal material that can be formed by a plating method such as NiP is used. As the material of the upper magnetic pole layer 12, for example, a magnetic material that can be formed by a plating method such as permalloy or CoNiFe is used, and a high saturation magnetic flux density material is particularly preferable. The lower magnetic pole layer 10 and the upper magnetic pole layer 12 are connected by a connecting portion 13 to form one U-shaped conductor as a whole.

  Between the upper magnetic pole layer 12 and the lower magnetic pole layer 10, between the medium facing surface ABS and the connection portion 13, two-stage coils 14 a and 14 b made of a conductive material such as copper are provided. The coils 14 a and 14 b are provided by being wound around the connection portion 13 and supply magnetic flux to the upper magnetic pole layer 12 and the lower magnetic pole layer 10. The coil 14a is surrounded by the insulating layer 15 and the coil 14b is surrounded by the insulating layers 16 and 17 and insulated from the surroundings. A lead layer (not shown) for receiving a current signal from the outside is connected to the coil 14b. Finally, an overcoat layer 18 is formed so as to cover the top pole layer 12 and the lead layer. As a material for the overcoat layer 18, for example, an insulating material such as alumina is used. In addition, in the example shown in FIG. 2, although it is the structure which has the coils 14a and 14b of 2 steps | paragraphs of stacking, this is only an illustration and even if the coil of 1 step | paragraph stacking or three or more layers stacking is provided Good.

  In the medium facing surface ABS, the rail portion 5a protrudes most with respect to the recording medium P, and the read / write portion 4 is drawn into the recording medium P by about 1 to 3 nm from the rail portion 5a. The steps of the rail portions 5a and 5b are not necessarily required. The level difference between the read / write portion 4 and the recess 6 is 1 to 5 μm. A protective film 19 having a thickness of about 1 to 4 nm made of a mixed film of Si and DLC is formed on the medium facing surface ABS. The back surface 20 of the medium facing surface ABS of the slider 1 serves as a contact surface with the flexure 21 (see FIG. 10) that supports the slider 1.

  The MR element 9 described above functions as a reproducing head for reading, and the magnetic pole layers 10 and 12 and the coils 14a and 14b sandwiching the recording gap 11 function as a recording head for writing. In FIG. 2, for convenience, the MR element 9 is shown larger, but actually, the length of the reproducing head (MR height) and the length of the recording head (NH) are greatly different.

  Next, with reference to the flowchart shown in FIG. 3 and the step diagrams of FIGS. 4 to 9, the slider 1 manufacturing method of the present invention will be described in particular with reference to the surface of the slider 1 serving as the medium facing surface ABS. In the following, for the sake of convenience, description will be made focusing on the processing of the “medium facing surface ABS”.

(Step 31)
First, a rectangular parallelepiped bar 52 is formed. The bar 52 is positioned at a pair of main surfaces extending in the longitudinal direction, a pair of end surfaces 52a and 52b extending in the width direction orthogonal to the length direction, and both ends in the width direction. And a pair of side surfaces 52c and 52d extending in the longitudinal direction. In FIG. 4B, only the medium facing surface ABS of the pair of main surfaces is shown, and the main surface on the back side is not shown.

  Specifically, a large number of thin film magnetic head portions 3 having the above-described configuration are stacked on a circular substrate 7 serving as a base of a wafer 51 (see FIG. 4A) by a thin film process. The slider forming portion 1 is formed. Further, until this step 31, the measuring element (polishing sensor) 54 is formed in a part of the cutting allowance 53 positioned between the slider forming portions 1. The measuring element 54 is, for example, a resistance film that configures an RLG (Resistance Lapping Guide) sensor for managing the polishing amount of the medium facing surface ABS in Step 39, and may have the same configuration as the MR element 9. The measuring element 54 is composed of a conductive metal film such as NiFe, Cu, NiCr, Au, or NiCu. The measuring element 54 is polished so as to exhibit a predetermined initial resistance value for polishing amount management. The measuring element 54 is formed so as to be positioned in a convex dummy pattern 55 formed in step 36 described later. Details of the dummy pattern 55 which is a polishing pressure adjusting means which is a main feature of the present invention will be described later.

  Then, the wafer 51 is cut to produce a plurality of strip-shaped bars 52 shown in FIG.

(Step 32)
The back surface 20 (see FIG. 2) of the bar 52 opposite to the medium facing surface ABS is polished. In this polishing operation, for example, the polishing table is rotated while supplying a water-soluble or oil-based lapping solution containing diamond abrasive grains on a polishing table (not shown). And it carries out by fixing the bar | burr 52 and pressing the back surface 20 against the rotating grinding | polishing stand. As a result, the back surface 20 becomes smooth and can be securely fixed to the flexure 21 (see FIG. 10) when the slider 1 is completed.

(Step 33)
Next, the bar 52 is once cleaned.

(Step 34)
The medium facing surface ABS of the cleaned bar 52 is polished. As shown in FIG. 5, this polishing operation is performed so that the MR height of the MR element 9 (height from the medium facing surface ABS to the end of the opposite MR element 9) is larger than a predetermined size (margin). And a desired MR height can be obtained by polishing the medium facing surface ABS in a later step. In the polishing operation, for example, although not shown, the back surface 20 is held by a processing jig via a resin or the like on the surface of a polishing plate formed by embedding diamond abrasive grains in the surface of a disk made of Sn (tin). This is performed by pressing the medium facing surface ABS of the bar 52. As a result, the position of the medium facing surface ABS moves to the inside (the side on which the coil 14a and the like are present) as a whole compared to before step 34.

(Step 35)
Next, as shown in FIG. 6, a temporary protective film 45 having a thickness of about 1 to 4 nm made of a mixed film of Si and DLC is formed on the medium facing surface ABS, for example, by sputtering.

(Step 36)
Then, as shown in FIG. 7, an uneven pattern (medium facing surface pattern) is formed on the medium facing surface ABS. Specifically, a part of the medium facing surface ABS is removed by dry etching such as ion milling or RIE (reactive ion etching) to form the recess 6 and the rail portion 5b. The parts that are not removed are the read / write part 4 and the rail part 5a. Note that the processing accuracy in the depth direction at this time is about 30 nm.

In the processing process of the medium facing surface ABS, that is, the concavo-convex portion forming process, conventionally, the medium facing surface ABS is exposed to a chemically active liquid such as an acid, an alkali, or an organic solvent. The Fe-based alloy material, which is a magnetic flux material, was corroded, and the magnetic pole portions (the lower magnetic pole layer 10 and the upper magnetic pole layer 12) of the medium facing surface ABS tended to be slightly recessed. However, in this embodiment, since the temporary protective film 45 is formed in step 35 before the concavo-convex portion forming step, corrosion of the magnetic pole portion using the Fe-based alloy material having poor corrosion resistance can be prevented. The reason why DLC is used as the temporary protective film 45 of this embodiment is that, in addition to sufficient corrosion resistance, a dense thin temporary protective film 45 with a film thickness of about 1 to 4 nm can be formed, as will be described later. This is because it can be easily removed and can be formed into an accurate shape without hindering the formation of the concavo-convex shape of the rail portions 5a, 5b and the like. However, as the temporary protective film 45, it is also possible to use an inorganic material such as SiO ₂ which has corrosion resistance and can be easily removed and has the same properties as DLC.

  In this concavo-convex portion forming step, a convex dummy pattern 55 is formed at each cutting margin 53 located between the slider forming portions 1. In the cutting allowance 53 where the measurement element 54 exists, a convex dummy pattern 55 is provided in a region including the measurement element 54, that is, so as to surround the outer periphery of the measurement element 54. This convex dummy pattern 55 functions as the polishing pressure adjusting means of the present invention.

(Step 37)
Next, as shown in FIG. 8, the temporary protective film 45 formed in step 35 and remaining on the surfaces of the read / write unit 4 and the rail unit 5a is removed in step 36 by dry etching such as milling or RIE. Here, the temporary protective film 45 is temporarily removed because the rail portion 5a under the temporary protective film 45 is flatly polished in step 34, and the temporary protection is also performed in the uneven portion forming process in step 36. Since it is protected by the film 45, high flatness is maintained, and variations in flatness are suppressed, such a portion having good flatness is exposed and used as a reference for the subsequent process. This is because the flatness of the medium facing surface ABS at the time of completion is improved, and variations in flatness are suppressed. Second, since the temporary protective film 45 is damaged during the uneven portion forming process, the temporary protective film 45 is temporarily removed, and a healthy protective film 44 (see FIG. 2) is formed later. This increases the reliability of the slider 1. The reason why the temporary protective film 45 is removed at this stage (step 37) rather than at the time of re-polishing in step 39 described later is very difficult to remove in the next polishing process because DLC is high in hardness. This is because, at this stage, it is more effective to perform batch removal by dry etching.

  The reason why dry etching is used to remove the temporary protective film 45 is that only the thin temporary protective film 45 of 1 to 4 nm is made uniform while minimizing damage to other parts of the slider 1 and the lower layer of the temporary protective film 45. This is because it can be removed. However, the temporary protective film 45 may be removed by a polishing process.

(Step 38)
Next, the bar 52 is preheated at 100 to 200 ° C. for 1 to 2 hours. This is to correct a difference in thermal deformation generated between the substrate 7 and the thin film magnetic head unit 3 due to a temperature difference between polishing and use as a product. When the hard disk drive equipped with the slider 1 is driven, the temperature around the thin film magnetic head unit 3 (all the film formation layers) is close to 100 ° C., and a temperature difference occurs between the thin film magnetic head unit 3 and the substrate 7. Since the coefficients of thermal expansion of the substrate 7 and the thin film magnetic head unit 3 are different, the overcoat layer 18 and the like partially protrude and a step is generated. Then, due to the residual stress generated in the substrate 7 and the thin film magnetic head part 3, when returning to room temperature, these do not return to the state before heating, and the overcoat layer 18 or the like partially protrudes (step). Remains. In contrast, when preheating is performed and the polishing is performed after returning to room temperature, the residual stress is released. Therefore, even if reheating and cooling are repeated, no protrusion (step) remains when the temperature returns to room temperature. The preheating may be performed before the first polishing process (step 34) or may be performed before each polishing process (steps 34 and 39).

(Step 39)
Next, the medium facing surface ABS is re-polished (final polishing) at room temperature. Specifically, although not shown, the back surface 20 of the bar 52 is held by a soft and adsorptive material such as NBR, and the medium facing surface ABS of the bar 52 is pressed against a rotating polishing plate for polishing. The polishing amount is managed using the measuring element 54. As a result, as shown in FIG. 9, the smoothness of the rails 5a and 5b and the read / write portion 4 is improved, and the edges R1, R2, R3, and R4 of the rail portions are rounded. The adhesion of foreign matter to the periphery of the part can be suppressed. The operational effects of the dummy pattern 55, which is the main feature of the present invention, will be described in detail later.

(Step 40)
A protective film 44 (see FIG. 2) is formed on the re-polished medium facing surface ABS. The protective film 44 is a DLC film having a thickness of about 1 to 4 nm, which is the final protective film, like the temporary protective film 45 formed in Step 35. Since the temporary protective film 45 may be damaged in the processing process of the medium facing surface ABS in step 36, it is temporarily removed in step 37, and in this step 40, a sound protective film is formed on the medium facing surface ABS. 44 is reformed. Thereby, the reliability of the surface of the medium facing surface ABS and the slider 1 is enhanced. As the protective film 44, an inorganic material such as SiO ₂ can also be used.

(Step 41)
The bar 52 on which the final protective film 44 is formed is washed.

(Step 42)
Next, the bar 52 is cut at the cutting margin 43, and a large number of sliders 1 having the configuration shown in FIGS.

  In the present embodiment, the dummy pattern 55 is provided in the cutting allowance 43, so that the slider 1, particularly the MR height and NH can be formed with high accuracy. This will be described in detail.

  The polishing process of the medium facing surface ABS in Step 39 needs to be performed with high precision in order to obtain an accurate MR height and NH, and therefore a measuring element (resistive film) 54 is used. Specifically, although not shown, the measuring element 54 is polished before step 39 at the latest to obtain an initial electrical resistance value, and a controller is connected to the measuring element 54 via a pad and a wire. Keep it. When the medium facing surface ABS is polished, the measuring element 54 located at the cutting margin 53 is also polished at the same time. As the area of the measuring element 54 decreases as the measuring element 54 is polished, the electrical resistance value increases. That is, the change in the electrical resistance value from the initial state of the measuring element 54 can be obtained, and based on the change, the area reduction amount due to the polishing of the measuring element 54 can be obtained. The polishing amount of the medium facing surface ABS can be obtained. In this way, by polishing the medium facing surface ABS while monitoring the electric resistance value of the measuring element 54, the polishing can be stopped when it is confirmed that the desired polishing amount has been reached. As a result, the MR height and NH can be formed with high accuracy.

  The control of the polishing amount using the measuring element 54 as described above is based on the premise that the bar 52 is firmly held and is stably pressed against the polishing plate at a desired angle. However, conventionally, the bar 52 holding the back surface 20 with a soft and adsorptive material such as NBR is not stable, and there is a possibility that the angle of contact with the polishing plate may be wrong. As described above, this is because, as described above, the distribution of the convex portion is varied in the medium facing surface ABS, that is, the total area of the convex portion located on the leading side from the center line CL in the width direction of the bar 52. And the total area of the convex portion located on the trailing side from the center line CL in the width direction is large (see FIG. 11), and therefore, a difference occurs in the polishing pressure and the polishing speed.

  On the other hand, in this embodiment, as shown in FIG. 4B, a convex dummy pattern 55 is provided at the cutting margin 53 of the bar 52. This dummy pattern 55 is on the opposite side to the deviation in the width direction of the bar 52 of the planar distribution of the convex portions (read / write portion 4 and rail portions 5a, 5b) formed in the slider forming portion 1. They are biased. That is, the convex portions (read / write portion 4 and rail portions 5a, 5b) of the slider forming surface 1 are arranged in the slider forming surface 1 so as to be biased toward the leading side from the center line CL. The dummy pattern 55 is arranged in the cutting margin 53 so as to be biased from the center line CL toward the trailing side (closer to the portion that becomes the trailing edge). As a result, in the medium facing surface ABS, the total area of the convex portions located on the leading side (on the one side surface 52c side) from the center line CL and the trailing side (on the other side surface 52d side) from the center line CL. ) Is substantially equal to the total area of the convex portions located in ().

  In this way, the uneven distribution of the convex portions of the medium facing surface ABS is corrected in the entire bar 52 by the convex dummy pattern 55, so that the leading side and the trailing side during polishing of the medium facing surface ABS are corrected. Thus, the polishing pressure becomes equal, and the polishing speed becomes equal. As a result, the bar 52 can be stably held and pressed accurately at a desired angle against the rotating polishing plate, thereby improving the polishing accuracy. In addition, as described above, by polishing the medium facing surface ABS while monitoring the electric resistance value of the measuring element 54, high-accuracy polishing is possible, and desired MR height and NH can be obtained with high accuracy. Can do.

  Since the dummy pattern 55 has no function other than equalizing the area of the convex portion, it may be formed in an appropriate shape and size considering only the balance of area and weight. In the cutting allowance 53 provided with the measurement element 54, a dummy pattern 55 is formed in a region including the measurement element 54, that is, surrounding the outer periphery of the measurement element 54. At least at the time of polishing in step 39, the surface of the measuring element 54 is exposed to exhibit a predetermined initial resistance value, thereby enabling monitoring of the polishing amount. Since the measuring element 54 is usually a very small element, it is difficult to maintain the balance of the area of the convex portion of the bar 52 in the medium facing surface ABS with only the measuring element 54. However, in the present embodiment, as described above, the protrusion of the bar 52 on the medium facing surface ABS is provided by the convex dummy pattern 55 provided in the region including the measurement element 54, that is, surrounding the outer periphery of the measurement element 54. The balance of the area of the shape portion can be maintained.

  In the present embodiment, in the slider forming portion 1, the layout of the read / write portion 4 and the rail portions 5a and 5b necessary for obtaining desired characteristics in the completed state of the slider 1 is not changed, and the slider 1 in the completed state is changed. In the cutting margin 53 that does not remain (does not affect the characteristics of the slider 1), as described above, the dummy pattern 55 having a position, shape, and size determined in order to improve the polishing accuracy is formed. can do.

  In the example shown in FIG. 4, the measuring element 54 is provided at every third cutting allowance 53 out of all the cutting allowances 53 provided between the slider forming portion 1 and the slider forming portion 1 in the bar 52. A dummy pattern 55 is provided in a region including the same. And it is formed in the substantially same external shape as the dummy pattern 55 provided in the cutting margin 53 in which the measuring element 54 is not provided. It should be noted that which cut margin 53 is formed with the measuring element 54 may be appropriately determined according to the necessity for use as a polishing amount sensor. It is also possible to provide the measurement elements 54 in all the cutting allowances 53. In this case, the dummy patterns 55 may be provided in the regions including the respective measuring elements 54 in all the cutting allowances. In the example shown in FIG. 4B, the outer shape of the dummy pattern 55 is a square, but it may be a more complicated planar shape.

  Further, in the example shown in FIG. 4B, all the cutting allowances 53 have a certain area, and a dummy pattern 55 is provided for each. However, some of the cutting allowances are thin. It is also possible to employ a configuration in which only the cutting line is provided and the dummy pattern 55 is not provided. That is, a configuration in which the dummy pattern 55 is provided at a ratio of one to two or more slider forming portions 1 may be employed.

  As described above, the position, shape, and size of the convex dummy pattern 55 are not limited to the example illustrated in FIG. 4B, and the read / write unit 4 and the rail unit that are the convex portions of the slider forming unit 1. Any change is possible as long as the total area of the convex portions in the width direction is balanced in the medium facing surface ABS, which is set according to the positions, shapes, and sizes of 5a and 5b.

  The convex dummy pattern 55 may be formed at the same time as the ABS pattern is formed in step 36 as described above, but may be formed before or after that. However, from the viewpoint of process shortening, it is preferable to form the dummy pattern 55 and the ABS pattern at the same time.

  The head arm assembly 22 including the slider 1 of the present invention described above will be described with reference to FIG.

  A plurality of head arm assemblies 22 are provided in a hard disk device (not shown) according to the number of disks. The head arm assembly 22 has an arm 23 and a head gimbal assembly 24 provided at the tip of the arm 23, and the other end of the arm 23 is supported by a rotating shaft 25. The head gimbal assembly 22 includes a slider 1 having a thin film magnetic head portion 3 (see FIG. 2), a flexure 21 that supports the slider 1, and a load beam 26 that connects the flexure 21 to an arm 23. The head arm assembly 22 rotates around the shaft 25 to position the slider 1 at a predetermined position with respect to the recording medium P. In FIG. 10, the slider 1 is provided on the lower side of the recording medium P, but a similar head arm assembly 22 is also installed on the upper side of the recording medium P.

It is a perspective view of the magnetic head slider manufactured by this invention. FIG. 2 is a sectional view taken along line AA showing the magnetic head slider of FIG. 1. 3 is a flowchart showing a method for manufacturing a magnetic head slider of the present invention. (A) is a perspective view which shows an example of the wafer of this invention, (b) is a typical top view which shows an example of the bar | burr of this invention. It is sectional drawing of the slider formation part which shows the manufacturing method of the magnetic head slider of this invention in order. It is sectional drawing of the slider formation part which shows the manufacturing method of the magnetic head slider of this invention in order. It is sectional drawing of the slider formation part which shows the manufacturing method of the magnetic head slider of this invention in order. It is sectional drawing of the slider formation part which shows the manufacturing method of the magnetic head slider of this invention in order. It is sectional drawing of the slider formation part which shows the manufacturing method of the magnetic head slider of this invention in order. FIG. 2 is a perspective view of a head arm assembly including the magnetic head slider shown in FIG. 1. (A) is a top view which shows the detailed structure of the conventional magnetic head slider, (b) is a typical top view which shows an example of the conventional bar.

Explanation of symbols

1 Magnetic head slider (slider forming part)
3 Thin-film magnetic head 4 Read / write (convex)
5a, 5b Rail part (convex part)
6 Recess 7 Substrate 9 MR element 10 Lower magnetic pole layer 11 Recording gap 12 Upper magnetic pole layers 14a and 14b Coil 51 Wafer 52 Bar 53 Cutting margin 54 Measuring element (Polishing sensor)
55 Polishing pressure adjusting means (dummy pattern)
P Recording medium ABS Medium facing surface

Claims (8)

In a bar for manufacturing a thin film magnetic head slider, in which a plurality of slider forming portions serving as thin film magnetic head sliders are arranged in the longitudinal direction,
A cutting margin for cutting is provided between each slider forming portion,
A bar for manufacturing a thin film magnetic head slider, characterized in that a polishing pressure adjusting means is provided on the side of the bar on which the pattern of the medium facing surface of the thin film magnetic head slider is formed.   The bar for manufacturing a thin film magnetic head slider according to claim 1, wherein the polishing pressure adjusting means is a convex dummy pattern provided at the cutting margin.   The bar for manufacturing a thin film magnetic head slider according to claim 2, wherein the convex dummy pattern is provided in a region including the polishing sensor at the cutting margin provided with a polishing sensor.   4. The bar for manufacturing a thin film magnetic head slider according to claim 2, wherein the convex dummy pattern is provided near a portion of the cutting margin that becomes a trailing edge of the thin film magnetic head slider. 5.   5. The polishing pressure adjusting means is arranged so as to correct variation in the distribution of convex portions in a plane on which a pattern of the medium facing surface of the thin film magnetic head slider is formed. 6. A bar for manufacturing the thin film magnetic head slider according to the item. Forming a bar in which a plurality of slider forming portions to be thin film magnetic head sliders are arranged in the longitudinal direction;
Forming a pattern of the medium facing surface of the thin film magnetic head slider on one surface of the bar;
Forming a polishing pressure adjusting means near a portion of the cutting margin that becomes a trailing edge of the thin film magnetic head slider;
Forming a thin film magnetic head slider by cutting a cutting margin located between the slider forming portions of the bar to form the thin film magnetic head slider.   7. The method of manufacturing a thin film magnetic head slider according to claim 6, wherein the polishing pressure adjusting means is a convex dummy pattern provided at the cutting margin.   8. The method of manufacturing a thin film magnetic head slider according to claim 7, wherein the medium facing surface pattern of the thin film magnetic head slider and the convex dummy pattern are formed simultaneously.

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