JP2001155305A - Method for machining magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a magnetic head in which a high precision track width regulating groove is efficiently cut and in which high reliability and improved input/output characteristics are realized. SOLUTION: This method is applied to a magnetic head 1 where metallic magnetic films 5, 6 are formed on the gap-constituting faces of core halves 2, 3 and track width regulating grooves 9, 10 constituting a projected magnetic tape working face 11 corresponding to a recording track width are prepared by cutting/machining on a magnetic tape sliding face 8 by means of a grinding stone 50. In the cutting/machining of the track width regulating grooves 9, 10, the grinding stone 50 is used on which a shaping process is performed on the outer circumferential face 51 after another shaping process is performed on the side face 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head processing method, and more particularly, to a metal head used for recording and reproducing information signals and the like on a high coercive magnetic recording medium.
The present invention relates to a magnetic head processing method suitable for an in-gap type magnetic head and the like.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus, high-density recording and short-wavelength recording of information signals and the like have been achieved. A high-precision magnetic head is used to record and reproduce information signals and the like on a magnetic tape with a narrow track specification. Such a magnetic recording / reproducing apparatus includes, for example, a so-called metal tape in which a ferromagnetic powder is used as a magnetic powder in a magnetic layer formed on a nonmagnetic support, or a ferromagnetic metal material formed on a nonmagnetic support by a vapor deposition method or the like. A so-called evaporation tape or the like directly formed on the substrate is used. Further, the magnetic recording / reproducing apparatus has a so-called metal-in-metal structure in which a main core is formed of, for example, a magnetic oxide material, and a metal magnetic thin film made of a soft magnetic metal magnetic material is formed on a constituent surface of a magnetic gap.
A gap type magnetic head (hereinafter, abbreviated as MIG head) 100 is used.

[0003] In other words, the MIG head 100 is configured as shown in FIG.
As shown in (1), a pair of core halves 101 and 102 are integrally joined by a glass 103, and a magnetic gap 104 is formed by a magnetic gap forming surface butted against each other. The MIG head 100 has a configuration in which the magnetic gap 104 is substantially equal to the recording track width t of the recording medium by performing a grinding step of the track width regulating grooves 105 and 106 on the sliding surface of the magnetic tape. Also, MI
The G head 100 includes the pair of magnetic core halves 10.
The metal magnetic thin film 10
7 and 108 are each formed as a film.

[0004]

Incidentally, in the MIG head 100, the track width regulating grooves 105, 106 are provided.
There is a limit to the processing accuracy of the above, and as shown in FIG. 21, both side surfaces 105a and 106a form inclined surfaces opposed to each other with the magnetic gap 104 therebetween. Therefore, in the MIG head 100, these side surfaces 10
Leakage magnetic fluxes are generated in the magnetic recording media 5a and 106a, and recording and reproduction of information signals and the like are performed on a magnetic recording medium beyond a specified recording track width, thereby deteriorating accuracy.

Therefore, in the MIG head 100, in order to make the magnetic gap 104 a predetermined width corresponding to the width of the recording track, the core halves 101, 10
In a state in which the magnetic tape 2 is integrated, a grinding process is performed on the sliding surface of the magnetic tape by using a blade grindstone to cut the track width regulating grooves 105 and 106 so that the contact surface of the magnetic tape becomes convex. In the grinding of such track width regulating grooves, it is required to form the track width regulating grooves constituting the contact surface of the magnetic tape of a minute width with high precision, and many tracks are maintained while maintaining the machining precision. A width regulating groove must be formed. In the conventional grinding method, the track width regulating grooves 105 and 106 are ground using a processing grindstone whose side surface is finished by, for example, an electrodeposited dresser of SD3000 and an outer peripheral surface is finished by an electrodeposited dresser of SD400. .

However, in the conventional grinding method, it is difficult to finish the outer peripheral surface of the processing whetstone as a ground surface having a sufficient surface accuracy by finishing with the electrodeposited dresser, so that the surface in contact with the magnetic tape is formed. There is a problem that the shape change of the track width regulating grooves 105 and 106 becomes large. For this reason, in the conventional magnetic head processing method, the track width regulating groove cannot be formed with high accuracy due to the conditions of the grinding process, and thus the width of the contact surface of the magnetic tape and the width t of the recording track vary, resulting in MIG.
There is a problem that the yield of the head 100 is poor.

[0007] Further, in the case of a processing whetstone, when finishing treatment is performed by an electrodeposition dresser, dripping is generally likely to occur at an outer peripheral edge portion. The amount of sag increases as the grain size of the abrasive grains on the finishing side increases. The processing grindstone has a problem that the outer peripheral edge portion is chamfered by performing the side surface finishing process after the conventional outer peripheral surface finishing process is performed, thereby deteriorating the accuracy of the track width regulating groove. there were.

Therefore, the present invention solves the above-mentioned conventional problems and efficiently manufactures a highly accurate track width regulating groove to manufacture a magnetic head having high reliability and improved input / output characteristics. It has been proposed for the purpose of providing a magnetic head processing method that has become possible.

[0009]

According to the present invention, there is provided a magnetic head processing method according to the present invention, in which a metal magnetic film is formed on at least one of the core halves at a gap forming surface and a magnetic tape slide is formed. The present invention is applied to a magnetic head in which a track width regulating groove which forms a convex magnetic tape contact surface corresponding to the width of a recording track is formed on a moving surface. In the magnetic head processing method, a track width regulating groove is formed by performing a shaping process on a side surface and then performing a grinding process using a processing grindstone having a shaping process on an outer peripheral surface.

[0010] In the method of processing the magnetic head, a processing whetstone is used in which a board dresser made by mixing abrasive grains is brought into contact with the outer peripheral surface to perform a shaping process on the outer peripheral surface. The control groove is ground.
Further, in the method of processing the magnetic head, an abutment plate that is moved toward and away from the outer peripheral surface while being rotated is abutted, and powder abrasive grains are melted between the outer peripheral surface and the abutment plate. The abrasive solution is supplied, and the outer peripheral surface is shaped and the grinding wheel is used to grind the track width regulating groove.

According to the magnetic head processing method of the present invention configured as described above, the grinding surface of the grinding wheel for grinding the track width regulating groove forming the surface of the magnetic tape can be finished with high precision. A high precision track width regulating groove with little variation is continuously formed. Therefore, according to the magnetic head processing method, the magnetic gap corresponding to the width dimension of the recording track is formed through the convex magnetic tape contact surface, so that a recording medium having a narrow recording pitch and a narrow track specification can be obtained. On the other hand, a magnetic head having high reliability for recording and reproducing information signals and the like with high accuracy and improved input / output characteristics is efficiently manufactured.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. The magnetic head processing method according to the embodiment is provided in a magnetic recording / reproducing apparatus using a metal tape with a narrow recording pitch and a narrow track specification, and records and reproduces information signals and the like shown in FIG.
The method is applied to the processing method of the head 1. Of course, the present invention is not limited to the MIG head 1 and is suitably applied to other high-density recording-compatible magnetic heads, particularly to a relatively large magnetic head such as a bulk type magnetic head.

The MIG head 1 has a basic configuration similar to that of a conventional MIG head, and a pair of core halves 2 and 3 manufactured through a predetermined process using a single crystal ferrite or a polycrystal ferrite as a material are joined together. The intermediate member 20 integrated by the non-magnetic material 4 such as molten glass is subjected to an appropriate processing including a grinding step which will be described in detail later. The processing steps of the MIG head 1 are basically the same as the conventional processing steps, and do not require significant changes in the steps and equipment.

In the MIG head 1, the core halves 2 and 3 are made of a soft magnetic oxide, for example, Mn-Zn ferrite or Ni-Zn.
It is formed in a predetermined shape by a single crystal ferrite such as a system ferrite or a polycrystal ferrite. In the MIG head 1, soft magnetic metal film layers 5 and 6 are formed on butted end faces of the core halves 2 and 3. MIG head 1
As described above, by joining the core halves 2 and 3 integrally with the nonmagnetic material 4 as described above, the magnetic gap 7 is formed at the butted ends by the soft magnetic metal film layers 5 and 6 via the nonmagnetic material 4. Is composed.

The soft magnetic metal film layers 5 and 6 are made of, for example, Fe--Al--Si or Fe--Ni--Al--S
Au, Co, Ti, Cr, Nb, Mo, Ta, i, Fe-Ga-Si, Fe-Al-Ge
A crystalline material to which one or more kinds of Ru, Pd, N, C, O and the like are added is used. Further, the soft magnetic metal film layers 5 and 6 include:
Its material is mainly Zr, Ta, Ti, H
f, Mo, Nb, and other amorphous materials, or Co, Fe, mainly Zr, Ta, Ti, Hf,
Mo, Nb, Si, Al, B, etc., at least one type and N, C,
A microcrystalline material to which one or more kinds of O and the like are added is used.
The soft magnetic metal film layers 5 and 6 are formed on the opposite end faces of the core halves 2 and 3 by using these materials as a thin film forming method such as a vapor deposition method or a sputtering method. In addition,
Of course, the soft magnetic metal film layers 5 and 6 may be formed on one of the magnetic gap forming surfaces of the core halves 2 and 3.

The MIG head 1 has a pair of track width regulating grooves 9 and 10 which are parallel to each other over the entire region in the longitudinal direction along both side edges of the magnetic tape sliding surface 8 where the magnetic gap 7 is formed. Formed by the following grinding process. MIG
In the head 1, a convex magnetic tape contact surface 11 is formed in the central region of the magnetic tape sliding surface 8 left uncut by the track width regulating grooves 9, 10 over the entire region in the length direction. The MIG head 1 has track width regulating grooves 9, 10.
Are formed to be substantially equal to the width of the recording track t, so that the width of the surface 11 of the magnetic tape contacting surface is reduced to the recording track t.
Is equivalent to In order to reinforce the magnetic tape contact surface 11, the MIG head 1 has track width regulating grooves 9, 1 and 2.
0 is filled with reinforcing glass 12a, 12b.

The MIG head 1 has concave portions 13a, 13b formed on opposing butting surfaces of the core halves 2, 3, respectively.
By the joint, the magnetic gap 7
Is defined. The MIG head 1 has winding guide grooves 14 on the side surfaces of the core halves 2 and 3 facing the depth regulating grooves 13 respectively.
a and 14b are formed. In the MIG head 1, coils (not shown) are wound around the core halves 2 and 3, respectively, using the recess 13a and the winding guide groove 14a and the recess 13b and the winding guide groove 14b as guides.

In the MIG head 1, the core halves 2, 3 and the soft magnetic metal film layers 5, 6 cooperate to form a closed magnetic circuit.
In the MIG head 1, the core halves 2 and 3 constitute an auxiliary core portion, and the soft magnetic metal film layers 5 and 6 constitute a main core portion. The MIG head 1 uses a magnetic tape sliding surface 8 by a magnetic flux leaking from a magnetic gap 7 based on an information signal or the like.
The information signal and the like are recorded on the metal tape which rubs and travels, and the information signal and the like are reproduced by a magnetic flux change based on the information signal and the like recorded on the metal tape.

In the MIG head 1, as shown in FIG.
0 is the bottom surface 9a, 10a and the side surface 9b, 10
Since b is formed with high dimensional accuracy, its width is formed substantially equal to the width t of the fine recording track of the metal tape. For this reason, the MIG head 1 has a processing grindstone 50 whose grinding surface has been finished with high precision with respect to the intermediate body 20 in which the base materials 21 constituting the core halves 2 and 3 are integrated as described in detail later. Are used to form the track width regulating grooves 9 and 10 by grinding.

That is, the MIG head 1 is formed by sequentially performing predetermined processes using the base material 21 for forming the core halves 2 and 3 shown in FIG. The base material 21 is made of an oxide soft magnetic material such as a Mn-Zn ferrite material or a Ni-Zn ferrite material as described above, and has a length of about 34.5 mm, a width of about 2.5 mm, It has an outer dimension of about 1 mm in thickness. As shown in FIG. 4, the base material 21 extends over the entire area of the main surface 21 a in the length direction.
The gap from one end face 21b is made substantially equal to the depth g of the magnetic gap 7, and a substantially trapezoidal concave groove 22 constituting the depth regulating groove 13 is processed.

Further, a plurality of glass filling grooves 23 are formed in the substrate 21 at right angles to the concave grooves 22. Glass filling groove 2
Numerals 3 are respectively formed corresponding to regions where the MIG heads 1 are cut out from the base material 21, and are melted to form a bonding material when the pair of base materials 21 are bonded to form the intermediate body 20 as described later. A non-magnetic glass rod is filled. The glass filling groove 23 may not be particularly formed. On the other main surface of the base material 21, a concave groove 24 corresponding to the concave groove 22 and constituting the winding guide groove 14 is formed.

The substrate 21 is polished so as to have a center line surface roughness of 0.2 μm to 1.0 μm with respect to the main surface 21 a. As shown in FIG. 5, a soft magnetic metal film layer 25 of the above-described soft magnetic metal material is formed on the entire surface of the main surface 21a of the base 21 where the concave groove 22 is formed. The base 21 may be formed on the soft magnetic metal film layer 25 with, for example, Au forming the gap film 26 as shown in FIG. When the gap film 26 is bonded to the base material 21 as described later, the bonding is performed by the heat diffusion effect of Au by applying a pressure treatment and a heat treatment.
Note that the soft magnetic metal film layer 25 has the principal surface 2 described above.
The film may be formed on the main surface 21a in a step before the step of forming the grooves 22 and 23 for 1a.

As shown in FIG. 7, the base member 21 is formed by melting the glass rod filled in the glass filling groove 23 after the above-described steps, so that the main surface 21a is joined to the pair (21A, 21B). Are joined to form an intermediate body 20. The intermediate body 20 has a magnetic gap 7 as shown in FIG.
Is formed on one end face 21a on which the track width regulating grooves 9 and 10 are formed using a processing grindstone 50. Each track width regulating groove 9, 10 is described in detail in FIG.
As shown in FIG. 5, the magnetic gap 7 is formed in parallel with each other at predetermined intervals, and is formed as an inclined groove having a predetermined angle with respect to the width direction in which the magnetic gap 7 is provided with an azimuth angle. The intermediate body 20 has a plurality of protruding portions 28 that are left uncut by the adjacent track width regulating grooves 9 and 10. These convex portions 28 constitute the surface 11 for contacting the magnetic tape. Each track width regulating groove 9,
Needless to say, 10 may be a linear groove having an azimuth angle of 0 °. Also, each track width regulating groove 9,
Although the bottom 10 is ground with its bottom surfaces 9a and 10a in a planar shape, it may be V-shaped, for example.

The track width regulating grooves 9 and 10 are
The width dimension of the magnetic gap 7 formed on the surface 11 of the magnetic tape, specifically, the width dimension of the magnetic recording tape 7 is formed with high dimensional accuracy so as to substantially coincide with the width dimension t of the fine recording track as described above. You. Therefore, for the grinding of the track width regulating grooves 9, 10, a processing grindstone 50 having a ground surface subjected to a high-precision finishing process as described in detail later is used, and the bottom surfaces 9a, 10a and the side surfaces 9b, 10b are formed. The track width regulating grooves 9 and 10 finished with high surface accuracy are formed to form the magnetic tape contact surface 11. Intermediate 20 includes
Molten glass 2 between track width regulating grooves 9 and 10
9 are filled. The molten glass 29 is a part constituting the above-mentioned reinforcing glass part 12, and the surface 11
Of the outer peripheral edge of the magnetic tape is prevented, and the contact width of the magnetic tape is maintained.

As shown in FIG. 9, the intermediate body 20 is subjected to cylindrical grinding in which one end surface 20a on which the magnetic tape sliding surface 8 is formed is formed into an arc shape. The intermediate body 20 is subjected to slicing from the center of each of the track width regulating grooves 9 and 10 sandwiching the surface 11 of the magnetic tape, so that a large number of head chips 30 are formed as shown in FIG.
To form a MIG head chip.

As shown in FIG. 12, the working grindstone 50 has a plurality of track width regulating grooves 9 and 10 sequentially formed on one end surface of the intermediate body 20 with the outer peripheral surface 51 and the side surface 52 as ground surfaces. The processing grindstone 50 has a thickness of 20 μm to 500 μm.
m, the grain size of the abrasive grains is # 2000 (the average grain size of the abrasive grains is 3
A grindstone having an average particle diameter of 0.2 to 0.6 μm is used. The processing whetstone 50 has a product name S manufactured by Reed Co., Ltd.
D2 / 4BZ057 (Φ99-TO.2-X2) was used. The processing whetstone 50 has a side surface 5 as described in detail later.
After the shaping process of No. 2 is performed, the shaping process of the outer peripheral surface 51 is performed. As shown in the drawing, the processing grindstone 50 is a connecting portion between the outer peripheral surface 51 and the side surface 52 which have been subjected to the shaping process, and the outer peripheral edge 53 constituting the cutting teeth has no vibration over the entire circumference and has a high height. The track width regulating grooves 9 and 10 are formed with high accuracy and a small amount of variation by being formed while maintaining the squareness of accuracy.

As shown in FIG. 13, the processing grindstone 50 is rotated and driven, and the side surface 52 of the abutment plate 60 is rotated.
At the same time, the abrasive solution 62 is supplied from the supply pipe 61 and the side surface 52 is shaped. The processing grindstone 50 is rotationally driven at 100 to 300 revolutions per minute by a drive mechanism (not shown), and is slid at a speed of 100 mm per minute in a direction indicated by an arrow x in the drawing.

The abutment plate 60 has a width of, for example, 10 mm,
A brass plate having a thickness of 1 mm is used, and a direction parallel to the side surface 52 of the processing grindstone 50 (FIG.
The direction of contact and separation with the side surface 52 (the direction of arrow x) (FIG. 1)
(3 arrow y direction). The abutment plate 60 may be a material plate having chemical resistance to the abrasive solution 55, for example, a glass plate or the like, but is formed of a hard material having a Vickers hardness of about 300 to 1000 with high surface accuracy. Is used. Butt plate 60
Holds the abrasive grains of the processing whetstone 50 and performs a finishing process on the side surface 52 thereof.

As the abrasive solution 62, a solution in which powder abrasives such as green carbon (GC), white alumina (WA) or diamond are dissolved in a solvent is used.
The particle size of the abrasive powder is equal to or three times the particle size of the grinding wheel 50, that is, # 600 (the average particle size of the abrasive particles is 20 μm).
m to 30 μm) to # 8000 (the average particle size of the abrasive particles is 0.2 μm to 0.6 μm).
The abrasive solution 62 specifically includes Asahi Diamond GC
# 3000 is used. This abrasive powder is mixed with a solvent mainly composed of pure water at a weight ratio of 0.5 to 5 times, and a lubricant containing a surfactant is mixed with the solvent at a ratio of 1/10 to 1
/ 30. Tap water may be used as the solvent, but since the influence of impurities such as chlorine may affect the dispersion rate of the abrasive powder, it is preferable to use the pure water described above.

The abutment plate 60 is pressed against the side surface 52 under the above-described rotating operation conditions, and the abrasive solution 62 is constantly supplied between the abutment plate 60 and the shaping process. . The working grindstone 50 is moved by 0.2 μm for each reciprocation in the y direction and cumulatively 30 μm to 40 μm in the y direction while the abutment plate 60 is slid in the x direction under the above operating conditions. By performing such a shaping process, the side surface 52 of the processing whetstone 50 is finished with a center line surface roughness of 0.5 μm to 2 μm with a surface accuracy of 0.5 μm to 2 μm.

By the way, when the above-mentioned shaping process of the side surface 52 is performed, the grinding amount of the processing grindstone 50 gradually increases at the outer peripheral side edge portion 53 due to the processing characteristics of the surface grinding method, and as shown in FIG. As shown, a sagging portion 54 that cuts to the outer peripheral surface 51 side occurs. The processing grindstone 50 is in a state where it is not formed with high accuracy due to the unevenness of the outer peripheral side edge portion 53 constituting the incised tooth portion due to the sagging portion 54 having an inconsistent cutting amount. Therefore, the processing whetstone 5
0, after performing shaping processing of the side surface 52, the outer peripheral surface 51
Is performed.

As shown in FIG. 14 (a), the outer peripheral surface shaping process is performed while the machining grindstone 50 is driven to rotate.
1 is abutted against the main surface 65a of the board dresser 65. In the processing grindstone 50, the sagging portion 54 is ground by the outer peripheral surface shaping process as shown by a chain line in FIG. The board dresser 65 has a width of 10 mm and a grain size equal to or three times that of the grinding wheel 50, that is, from # 600 (the average grain size of the abrasive grains is 20 μm to 30 μm) to # 8000 (the average grain size of the abrasive grains). Particle size 0.2
(μm to 0.6 μm) is used.
The board dresser 65 has a specific particle size of GC # 20.
00 board dressers are used.

In the outer peripheral surface shaping process, the processing grindstone 50 is
4 (a), move in the direction of arrow y1 (toward the side surface 52) so as to pass through the entire surface of the board dresser 65, and
The outer peripheral surface 51 is shaped by moving the outer peripheral surface 51 by 0.5 μm in the direction of arrow z1 (shaping direction of the outer peripheral surface 51) in each reciprocating operation. Processing whetstone 50 is 1000
It is rotated at a speed of rotation to 3000 rotations and y
It is moved in one direction at a speed of 120 mm per minute. Further, the grinding water is continuously supplied to the board dresser 65 to such an extent that the main surface 65a is moistened.

As shown by Δx in FIG. 14 (b), the outer peripheral surface 51
Is ground in the range of 30 μm to 40 μm, so that the sagged portion 54 whose surface accuracy is not sufficiently maintained is removed. Therefore, in the machining grindstone 50, the outer peripheral side edge 53 constituting the cutting teeth portion is formed with high accuracy by the outer peripheral surface 51 and the side surface 52 that are precisely shaped.

The processing grindstone 50 has the surfaces 51 and 52 described above.
After performing the finishing process, the break-in grinding is performed, and the intermediate body 20 is used for the grinding of the track width regulating grooves 9 and 10. After grinding the polycrystalline ferrite substrate by 300 mm, the processing grindstone 50 is subjected to break-in grinding in which the single crystal ferrite block is ground by 100 mm. The processing whetstone 50 has 8000 rotations per minute, and the moving speed of the processing table is 30 mm per minute.
0 is ground.

The above-mentioned shaping process is performed on the processing whetstone 50, which is rotated at 8000 revolutions per minute, and the processing table is set at 3 times per minute.
Under the processing conditions of the moving speed of 0 mm, the processing of grinding the track width regulating grooves 9 and 10 on the end faces 20 a of the ten intermediate bodies 20 having a width of 2 mm was performed. Similarly, using a conventional processing grindstone, processing for grinding the track width regulating grooves 9 and 10 was performed under the same processing conditions. By grinding the track width regulating grooves 9 and 10, the width dimension of the protruding portion 28 which is left uncut and forms the surface 11 for contacting the magnetic tape was measured.

The width dimension of the convex portions 28 is measured in order from the starting side of the grinding process of the track width regulating grooves 9 and 10 shown by the arrow in FIG. It was measured. The measurement results are as shown in FIG. FIG. 3A shows a case where the grinding process is performed using the processing grindstone 50 on which the above-described shaping process is performed, and FIG. 3B shows a case where the grinding process is performed using the conventional processing grindstone. Is shown. In the figure, the vertical axis represents the width dimension of each convex portion 28, and the horizontal axis represents each convex portion 28.

Each of the convex portions 28 is formed by grinding the track width regulating grooves 9 and 10 by using the processing grindstone 50 which has been subjected to the above-mentioned shaping processing, so as to be processed as is apparent from FIG. When the variation between the start and the end is within 0.5 μm,
A highly accurate track width regulating groove 9 with very little variation,
10 are formed. On the other hand, when the track width regulating grooves 9 and 10 are ground by using a conventional processing grindstone, the track width regulating grooves 9 whose variation amounts to 1.5 μm or more as shown in FIG. , 10 are formed.

Therefore, the processing grindstone 50 can efficiently form the track width regulating grooves 9 and 10 with less variation and high accuracy by performing the shaping processing on the outer peripheral surface 51 after performing the shaping processing on the side surface 52 described above. Formed. As a result, the MIG head 1 can be manufactured with a high yield, and the surface 11 for contacting the magnetic tape is formed with extremely small accuracy corresponding to the width t of the fine recording track. Therefore, the MIG head 1 records and reproduces information signals and the like with high accuracy on a metal tape having a narrow recording pitch and a narrow track specification.

By the way, in the processing whetstone 50, FIG.
As shown in FIG. 6, by performing the above-described shaping process on the outer peripheral surface 51 using a board dresser 65 having a large grain size, in other words, a small average grain size of the abrasive grains, the track width regulating grooves 9 and 10 can be made higher. It is formed with high precision to reduce the fluctuation amount of the recording track width. In this case, the grinding efficiency of the processing grindstone 50 by the board dresser 65 is deteriorated, so that the time required for the shaping process of the outer peripheral surface 51 increases.

On the other hand, as shown in the figure, the processing grindstone 50 is formed by subjecting the outer peripheral surface 51 to the above-mentioned shaping process using a board dresser 65 having a small grain size, in other words, a large average grain size of the abrasive grains. When the accuracy of the outer peripheral surface 51 is slightly lowered, the dimensional accuracy of the track width regulating grooves 9 and 10 is deteriorated, and the fluctuation amount of the recording track width is also increased. Processing whetstone 5
In the case of 0, since the grinding efficiency by the board dresser 65 is large in this case, the time required for the shaping process of the outer peripheral surface 51 can be reduced.

That is, as shown in FIG. 17, for the processing grindstone 50a which has been subjected to the above-mentioned shaping processing of the outer peripheral surface 51 using the board dresser 65 having a grain size of 400, the fluctuation amount of the recording track width is 1.8 μm, The processing time was 5 minutes. In addition, for the processing grindstone 50b that has been subjected to the above-described shaping processing of the outer peripheral surface 51 using the board dresser 65 having a grain size of 2000, the fluctuation amount of the recording track width is 0.8 μm.
m, and the processing time was 20 minutes. With respect to the processing grindstone 50c which has been subjected to the above-described shaping processing of the outer peripheral surface 51 using the board dresser 65 having a grain size of No. 3000, the fluctuation amount of the recording track width was 0.7 μm, and the processing time was 30 minutes. With respect to the processing grindstone 50d in which the above-described shaping processing of the outer peripheral surface 51 was performed using the board dresser 65 having a grain size of 4000, the fluctuation amount of the recording track width was 0.5 μm, and the processing time was 40 minutes.

FIG. 18 is a table showing the correspondence between the grain size of the abrasive grains or the grindstone and the grain size with respect to the count. For example, in the case of grain size 400, the average grain size of the abrasive grains is 40 μm to 60 μm. In the case of grain No. 1300, the average grain diameter of abrasive grains is 5 μm to 12 μm.
The average particle size of abrasive grains is 3 μm
To 8 μm. Further, the average particle diameter of the abrasive grains is 2 μm to 6 μm in the particle diameter of No. 3000, and the average particle diameter of the abrasive grains is 2 μm to 4 μm in the No. 4000 particle diameter. Furthermore, the average particle size of the abrasive grains is 0.2 μm
To 0.6 μm.

Therefore, in the MIG head 1, the track width regulating grooves 9, 10 are formed after the shaping process of the side surface 52, and thereafter the grain size No. 2000 to 8000 of which the shaping process of the outer peripheral surface 52 is performed as described above. 0.2 to 8 μm in particle size
Grinding is performed using a processing grindstone 50 having a specification of μm. In addition, the processing grindstone 50 has the same or three times the grain size,
That is, particle size 600-8000, 0.2μ in particle size
outer surface 5 using a board dresser 65
1 is performed.

In the first embodiment described above, the processing grindstone 50 is mounted on the outer peripheral surface 5 using the board dresser 65.
Although the first shaping process is performed, the present invention is not limited to such a shaping method. As with the side surface 52, the processing whetstone 50 may perform a shaping process using a butting plate and an abrasive solution. As shown in FIG. 19, the processing grindstone 50 is rotated and driven, and its outer peripheral surface 51 is abutted against the main surface 70 a of the abutment plate 70, and an abrasive solution 72 is continuously supplied from a supply pipe 71. Outer surface 5
1 is performed.

That is, the working grindstone 50 is moved by a driving mechanism (not shown) in the direction of the arrow y2 in FIG.
Side) so as to pass through the entire surface of the abutment plate 70, and at the same time, it is moved by 0.2 μm with respect to the direction of arrow z2 in FIG. The processing grindstone 50 is driven to rotate at 100 to 300 revolutions per minute, and is slid at a speed of 80 mm per minute in the direction of arrow y2 in FIG. The butting plate 70 has its main surface 7
0a and the outer peripheral surface 51 of the grinding wheel 50
Is always supplied. The abutment plate 70 has a material plate having a chemical resistance to the abrasive solution 52, for example, a width of 10 mm.
Is used, but a brass plate may be used. The abutment plate 70 is formed of a hard material having a Vickers hardness of about 300 to 1000 with high surface accuracy, holds the abrasive grains of the processing grindstone 50, and finishes the outer peripheral surface 51 thereof.

As the abrasive solution 72, a solution in which powder abrasives such as green carbon (GC), white alumina (WA) or diamond are dissolved in a solvent is used.
The particle size of the abrasive powder is equal to or three times the particle size of the grinding wheel 50, that is, # 600 (the average particle size of the abrasive particles is 20 μm).
m to 30 μm) to # 8000 (the average particle size of the abrasive particles is 0.2 μm to 0.6 μm).
The abrasive solution 72 specifically includes GC made by Asahi Diamond.
# 3000 is used, and this abrasive powder is mixed with a solvent mainly composed of water in a weight ratio of 0.5 to 5 times, and a lubricant containing a surfactant is added to the mixture in a ratio of 1/10 to 1
/ 30. The lubricant is
The dispersibility of the abrasive powder is improved by the mixed surfactant, and specifically, JC-7030 manufactured by Johnson Co. is used. Tap water is used as the solvent, but pure water may be used because the influence of impurities such as chlorine may affect the dispersion ratio of the abrasive powder.

As shown by Δx in FIG. 19 (b), the outer peripheral surface 51
Is ground in the range of 30 μm to 40 μm, so that the sagged portion 54 whose surface accuracy is not sufficiently maintained is removed. Therefore, in the machining grindstone 50, the outer peripheral side edge 53 constituting the cutting teeth portion is formed with high accuracy by the outer peripheral surface 51 and the side surface 52 that are precisely shaped.

The processing grindstone 50 also has the surfaces 51 and 52 described above.
After performing the finishing process, the break-in grinding is performed, and the intermediate body 20 is used for the grinding of the track width regulating grooves 9 and 10. After grinding the polycrystalline ferrite substrate by 300 mm, the processing grindstone 50 is subjected to break-in grinding in which the single crystal ferrite block is ground by 100 mm. The processing whetstone 50 has 8000 rotations per minute, and the moving speed of the processing table is 30 mm per minute.
0 is ground.

Using the processing whetstone 50 that has been subjected to the above-mentioned shaping processing, the same as in the first embodiment described above, this is
Under the processing conditions of 000 rotations and a moving speed of the processing table of 30 mm per minute, the processing of grinding the track width regulating grooves 9 and 10 on the end face 20a of ten intermediate bodies 20 having a width of 2 mm was performed. By grinding the track width regulating grooves 9 and 10, the width dimension of the protruding portion 28 remaining and constituting the magnetic tape contact surface 11 was measured, and the result is shown in FIG. In the figure, the vertical axis represents the width dimension of each convex portion 28, and the horizontal axis represents each convex portion 28.

Each of the convex portions 28 is formed by grinding the track width regulating grooves 9 and 10 using the processing grindstone 50 subjected to the above-mentioned shaping process, so that the amount of fluctuation between the start and end of the processing is reduced. When the thickness is within 0.5 μm, the track width regulating grooves 9 and 10 with high accuracy and extremely small variation are formed.

[0052]

As described above in detail, according to the magnetic head processing method of the present invention, a metal magnetic film is formed on at least one of the core halves at the gap-constituting surface, and the processing whetstone is used. The track width regulating groove is applied to a magnetic head in which the track width regulating groove is ground, and the grinding of the track width regulating groove is performed by using a processing whetstone in which the outer peripheral surface is shaped after performing the side surface shaping processing. Grinding. Therefore, according to the magnetic head processing method of the present invention, the track width regulating grooves that are ground by the processing grindstone whose grinding surface has been finished with high precision are continuously formed with extremely high precision, thereby achieving narrow recording. It is possible to efficiently manufacture a magnetic head having high reliability for recording and reproducing information signals and the like with high precision on a recording medium having a specification of a narrow pitch and a narrow track and improved input / output characteristics.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view illustrating a MIG head and a processing grindstone for grinding a track width regulating groove.

FIG. 2 is a plan view of a main part of the MIG head.

FIG. 3 is an explanatory view of a manufacturing process of the MIG head, and is a perspective view of a base material.

FIG. 4 is an explanatory view of the manufacturing process, showing a state in which a concave groove that forms a depth regulating groove is formed.

FIG. 5 is an explanatory view of the manufacturing process, showing a state where a soft magnetic metal film layer is formed.

FIG. 6 is an explanatory diagram of the manufacturing process, showing a state in which an Au film constituting a gap film is formed.

FIG. 7 is an explanatory view of the manufacturing process, and is a view showing a state in which a base material is joined to form an intermediate.

FIG. 8 is an explanatory view of the manufacturing process, showing a state where a track width regulating groove is formed on one end surface of the intermediate body.

FIG. 9 is an explanatory view of the manufacturing process, showing a state where one end face of the intermediate body is formed in an arc shape.

FIG. 10 is an explanatory diagram of the manufacturing process, showing a cut head chip.

FIG. 11 is a perspective view illustrating a grinding step of a track width regulating groove using a processing grindstone.

FIG. 12 is a side view of the main part.

FIG. 13 is a diagram illustrating a shaping process of a side surface of a processing whetstone.

FIG. 14 is a diagram illustrating a shaping process of an outer peripheral surface of a processing grindstone.

15A and 15B are dimensional characteristic diagrams obtained by measuring a track width of a track width regulating groove, wherein FIG. 15A is a dimensional characteristic diagram when a shaping-processed grinding wheel is used, and FIG. It is a dimensional characteristic diagram at the time of using a processing whetstone.

FIG. 16 is a diagram for explaining the characteristics of the grain size of the abrasive grains of the board dresser used in performing the shaping process of the grinding surface of the processing whetstone, the shaping time, and the variation amount of the formed recording track width.

FIG. 17 is a view showing a list summarizing characteristics of a grain size of a board dresser used when shaping a ground surface of a processing whetstone, a finishing time, and a fluctuation amount of a formed recording track width.

FIG. 18 is a diagram showing a correspondence table between the grain size (count) of the grindstone and the grain size.

FIG. 19 is a diagram illustrating another shaping process of the outer peripheral surface of the processing grindstone.

FIG. 20 is a dimensional characteristic diagram obtained by measuring a track width of a track width regulating groove formed using the processing grindstone.

FIG. 21 is a plan view of a main part of a conventional MIG head.

[Explanation of symbols]

1 MIG head (magnetic head), 2-3 core halves,
4 Non-magnetic material, 5,6 soft magnetic metal film layer, 7 Magnetic gap, 8 Magnetic tape sliding surface, 9,10 Track width regulating groove, 11 Magnetic tape contact surface, 12 Reinforced glass part, 1
3 depth regulating groove, 14 winding guide groove, 20 intermediate, 21 base material, 28 convex portion, 50 processing whetstone, 5
1 outer peripheral surface, 52 side surface, 53 outer peripheral edge, 54 sagging part, 60 abutment plate, 61 supply pipe, 62 abrasive solution, 65 board dresser, 70 abutment plate, 71 supply pipe, 72 abrasive solution

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D093 AA01 AB03 AC01 DA02 FA18 JA01 5D111 AA23 DD04 DD22 FF02 GG16 JJ24 KK01

Claims (10)

[Claims] A track forming a metal magnetic film on at least one of the core halves of a gap forming surface and a convex magnetic tape contact surface corresponding to the width of a recording track on a magnetic tape sliding surface. In the method for processing a magnetic head in which a width regulating groove is formed, the track width regulating groove is subjected to a shaping process on a side surface, and then subjected to a grinding process using a processing grindstone subjected to a shaping process on an outer peripheral surface. A magnetic head processing method characterized by being formed by: 2. The magnetic processing apparatus according to claim 1, wherein the processing grindstone is subjected to a shaping process by abutting a board dresser made by mixing abrasive grains against an outer peripheral surface. Head processing method. 3. A processing grindstone having a thickness of 20 μm to 500 μm and an average particle size of abrasive grains of 0.5 μm to 5 μm is used for the processing whetstone, and the board dresser has an average particle size of 0 μm to 5 μm. 0.5 μm to 2
The method according to claim 2, wherein a board dresser prepared by mixing 5 µm abrasive grains is used. 4. The processing whetstone is abutted against an abutment plate that is moved toward and away from a side surface while being rotationally driven, and melts powder abrasive grains between the side surface and the abutment plate. 3. The magnetic head processing method according to claim 2, wherein an abrasive solution is supplied and the side surface is shaped. 5. The grinding wheel has its outer peripheral surface abutted against an abutment plate while being rotationally driven, and an abrasive solution in which powder abrasive is dissolved is supplied between the outer peripheral surface and the abutment plate. 2. The method according to claim 1, wherein the shaping process is performed. 6. The magnetic head processing method according to claim 5, wherein the finishing abrasive solution is prepared by mixing a powder abrasive such as green carbon, white alumina or diamond with a solvent. . 7. A processing whetstone having a thickness of 20 μm to 500 μm and an average particle diameter of abrasive grains of 0.5 μm to 5 μm is used for the processing whetstone. Is 0.5 μm to 2
6. The magnetic head processing method according to claim 5, wherein the finishing abrasive solution in which 5 μm powder abrasive is mixed with a solvent is supplied to perform a shaping process on an outer peripheral surface. 8. The above-mentioned finishing abrasive solution contains a surfactant in a mixed solution obtained by mixing powder abrasives with a solvent mainly composed of water at a weight ratio of 0.5 to 5 times. 6. The magnetic head processing method according to claim 5, wherein a finishing abrasive solution prepared by adding 1/10 to 1/30 times of a lubricant is used. 9. The magnetic plate according to claim 5, wherein the butting plate is made of a glass material or a brass material having a Vickers hardness of 300 to 1000 on its ground surface. Head processing method. 10. The processing whetstone is rotated and driven, and abutment plates that are moved toward and away from the side surface are abutted, and powder abrasive grains are melted between these side surfaces and the abutment plate. 6. The magnetic head processing method according to claim 5, wherein the prepared abrasive solution is supplied to perform a shaping process on a side surface thereof.