JPH09180124A - Method for forming slide surface of magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely form a curvature (round surface) of a tape slide surface of a magnetic head. SOLUTION: A tip core 7 is arranged while projecting the tape slide surface 1 of the tip core 7 from the circumference of a rotary member 3 having a prescribed diameter, and a lapping means 2 arranged so as to abut on the tape slide surface 1 of the tip core 7 is provided. Then, by protruding the tape slide surface 1 more than a reference value decided by the diameter of the rotary member 3, the size of the tip core 7 and a prescribed curvature, and lapping it, the tape slide surface of the prescribed curvature is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a tape sliding surface of a magnetic head, and more particularly to a method of forming a curvature of the tape sliding surface.

[0002]

2. Description of the Related Art Conventionally, various types of magnetic heads have been proposed as magnetic heads used in magnetic recording / reproducing devices such as VTRs, and ferrite heads and MIG heads (metal in.
Gap heads) or laminated heads are known. Digital VTRs have recently been added to the increasing density of magnetic tapes.
The relative speed of the tape to the head is 10.2 m / s, which is about three times as fast as the 8 mm VTR.
The thickness of the magnetic tape has become thinner with the miniaturization of TR. Therefore, the contact surface of the magnetic head with the magnetic tape requires a highly accurate sliding surface curvature to ensure a good contact. Has been done.

In a conventional magnetic head used in, for example, an 8 mm VTR, a tape sliding surface is obtained in a state in which one of the above-mentioned various magnetic heads is completed, for example, in the state shown in FIG. 1 is lapped with a lapping tape (polishing tape) 2 to form a curved surface (hereinafter referred to as R surface) having a predetermined shape.

That is, a motor 4 is disposed below the cylindrical spindle 3, the spindle 3 is rotated in the direction of the arrow, and the magnetic head 5 disposed on the spindle 3 is rotated to move the tape. The R surface of the moving surface 1 is polished. When mounting the magnetic head 5 on the spindle 3, first, the magnetic head 5 is fixed on the head base 6 used for mounting the magnetic head 5 on the drum of the VTR and the like, and after predetermined positioning, the head is further moved. The base 6 is fixed to the spindle 3 so that the base 3 is positioned to a predetermined size.

[0005]

As described above, the number of man-hours for polishing the R surface of the tape sliding surface of the magnetic head is such that the mounting of the head base 6 on the spindle 3 and the magnetic head 5 are adjusted.
It was troublesome to adjust and attach the head to the head base 6, and the number of steps was large.

[0006] In general, in the manufacturing process of the R surface shape of the sliding surface of this tape, lapping is performed using a wrapping tape as described above. However, polishing using this wrapping tape differs from mechanical grinding in that the shape of the finished R surface largely depends on the stiffness (Stiffness) of the wrapping tape, and is ultimately determined by the contact state between the wrapping tape and the tip of the head chip. It has a uniform shape.

Further, in lapping the tape sliding surface 1 of the magnetic head 5 with a lapping tape, the magnetic head 5 having the R surface formed with a curvature slightly larger than the curvature of the tape sliding surface determined by a predetermined design value is used. When fixed on the base 6 and the distance from the outer periphery of the spindle 3 to the tip of the tape sliding surface 1 of the magnetic head 5 (hereinafter referred to as the protrusion amount) is AT, as compared with the reference protrusion amount as shown in FIG. 6B. A state in which the wrapping tape 2 is pushed in as shown in FIG. 6A (+ AT
(Direction), the R shape of both ends 9L and 9R is smaller than the R shape of the gap 8 part, and the sliding area of the magnetic tape is reduced, so that there is a problem that the life of the head is shortened and good hitting is difficult. .

Further, as shown in FIG. 6C, when the protrusion amount AT is pulled in from the wrapping tape 2 in the −AT direction as compared with the reference protrusion amount AT shown in FIG. 6B, both ends 9L of the magnetic head 5 shown by a broken line in FIG. 6C. There was a problem that the tape sliding surface 1 could not be formed into the standard R surface shape because of the occurrence of contact residue at the 9R portion.

The present invention is intended to provide a method for forming a sliding surface of a magnetic head which solves the above problems. The object of the invention is to obtain a highly accurate R surface shape of a tape sliding surface. In order to obtain a forming method.

[0010]

As shown in FIG. 1, a method of forming a sliding surface of a magnetic head according to the present invention forms a predetermined curvature on a tape sliding surface 1 in a completed state of a chip core 7. In the method of forming the sliding surface of the magnetic head configured as described above,
Lapping means 2 in which the chip core 7 is arranged so as to project the tape sliding surface 1 of the chip core 7 from the circumference of the rotating member 3 having a predetermined diameter, and is arranged so as to be in contact with the tape sliding surface 1 of the chip core 7. The diameter of the rotating member 3, the size of the chip core 7 and the protrusion reference value AT of the chip core 7 which is determined by the desired curvature are set to cause the protrusion to exceed the reference value AT for lapping.

According to the magnetic head sliding surface forming method of the present invention, the tape sliding surface 1 of the chip core can be polished with extremely high accuracy, so that a high quality magnetic head can be easily obtained.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A method of polishing a tape sliding surface of a magnetic head of the present invention to a predetermined curvature will be described in detail below with reference to the drawings.

The magnetic head applied to the present invention is applicable to an R surface forming method for forming a predetermined curvature on a tape sliding surface such as a ferrite head, a laminated head, or a MIG head. Digital VTR for consumer use
A suitable MIG head applied to the above will be described. Prior to explaining the configuration of the present invention, MI is described with reference to FIGS.
The manufacturing process of the G head chip core 1 will be described in detail.

First, in order to obtain the chip core of the MIG head, as shown in FIG. 4A, the oxide magnetic material (hereinafter referred to as ferrite) substrate 11 is flattened by using a surface grinder or the like. Although Mn-Zn ferrite is used as the substrate 11 in this example, other ferrite materials such as Ni-Zn ferrite may be used. Further, although the single crystal substrate having the plane orientation as shown in FIG. 4A is used, a single crystal substrate or a polycrystal substrate having another plane orientation or a bonded substrate of the single crystal ferrite and the polycrystal ferrite may be used.

Next, as shown in FIG. 4B, the magnetic ferrite substrate 11
The winding groove 17 and the glass groove 19 are formed using a slicing machine or the like along the longitudinal direction.

Further, as shown in FIG. 4C, a slicing machine or the like is used to form a track width regulating groove 12 in a direction substantially orthogonal to the winding groove 17 and the glass groove 19 to perform track width setting. An enlarged view of part A of the track width regulation groove 12 is shown in FIG. 4C '. The track 13 between the track width regulating grooves 12 of FIG. 4C 'becomes the track 13 constituting the magnetic gap 8. The surface of the track 13 is mirror-finished by polishing or the like.

Next, as shown in FIG. 4D, the magnetic ferrite substrate 11 is cut in the longitudinal direction with the same width w ₁ . In this step, the substrate 11a on which the glass groove 19 and the winding groove 17 are formed and the substrate 11b without the winding groove 17 and the like form a pair, and the substrates 11a and 11b finally form the outer core 7 of the chip core 1 described later.
b and the inner core 7a.

Next, as shown in FIG. 4E, the magnetic metal 14 is formed on the pair of substrates 11a and 11b by sputtering or the like.
4E 'of the enlarged view of the B part of FIG. 4E and FIG. 4 of the enlarged view of the C part.
E ″, and a magnetic gap 8 is formed on it.
A gap film 15 is formed (see FIG. 4E ').

In this example, FeRuG is used as the magnetic metal 14.
Although an aSi (SMX) film was used, sendust,
Sendust + O, Sendust + N, SMX + O, SMX
+ N or other crystalline magnetic film, Fe-based microcrystalline film, Co-based fine film
A crystal film may be used. In this example, the magnetic gap 8
On the gap film 15_TwoA membrane was used, but Ta_TwoO
_FiveOther oxide film such as Si, Si_ThreeN_FourNitride film, etc.
Is a metal film of Cr, Al, Si, Pt, etc. and their combination.
Even if a gold film or a laminated film combining them is used
good. In addition, Si is used to improve the adhesion between the substrate and the metal film.
O_Two, Ta_TwoO _FiveOxide film of Si, Si_ThreeN_FourNitride, etc.
Film or metal film such as Cr, Al, Si, Pt and the like
These alloy films or laminated films combining them
You may use as a base film of a metal film. In this example,
5 nm thick SiO as a base film for improving adhesion_TwoUse membrane
Was. In this process, the substrate 11a and the substrate 11b are separated
Then, the magnetic metal film 14 is formed on the substrate 11b.
The metal film thickness was changed.

Next, as shown in FIG. 4F, the low melting glass rod 16 is inserted into the glass groove 9 while pressing the surfaces of the substrates 11a and 11b on which the gap film 15 has been formed but against each other.
It is heated to 0 to 700 ° C. and glass bonded.

Next, the substrate 11a side of the blocks joined as shown in FIG. 4G is given a predetermined thickness (w) using a surface grinder or the like.
After that, the head sliding surface 1 side is subjected to cylindrical grinding.

Next, after the winding guide groove is processed and the contact groove is processed, the target chip thickness t and chip width w are obtained.
4H, the glass block 19 is cut so as to be orthogonal to the longitudinal direction of the joining block, and the glass groove 19 is also cut off from the substantially half position. This cutting of the chip thickness t is performed in a predetermined state with the substrates 11a and 11a of the two joining blocks having different azimuth angles being inward with respect to the two temporary parallel lines and being tilted by the azimuth angle and being fixed in a V shape. It is cut to have a chip thickness t and a chip width w, and is cut off in parallel with the azimuth angle of the target chip core during the processing of the contact width.

The chip core 7 thus manufactured from the substrate 11 is constructed as shown in FIG. 3A, and the joint blocks 11a and 11b are cut at the chip thickness t to form the inner core 7a and the outer core 7b, and determine the track width. The magnetic gap 8 is composed of an oxide film such as SiO ₂ sputtered on the magnetic metal film 14, and the winding groove 17 and the winding guide groove 1 are formed.
8 and the glass groove 19 are formed in the outer core 1b, the inner core 7a is formed in a plate shape, and the inner core 7a and the outer core 7b are formed.
Are joined and integrated by a low melting point glass 20 or the like.

The pair of head chips 7A,
When a double azimuth head for recording / reproducing using 7B is manufactured, the head core 6 is arranged with the inner cores 7a of the pair of chip cores 7A and 7B facing each other as shown in FIG. They are mounted so as to face each other by 180 degrees so that recording and reproduction of four oblique tracks can be simultaneously performed on the magnetic tape by one rotation of the rotating drum.

In this example, the tape sliding surface 1 is polished at the stage of manufacturing the chip core 7 obtained in FIG. 4H. That is, the tape sliding surface 1 of the chip core 7 is cylindrically ground to have a predetermined curvature, but the R surface in this case has a value larger than a predetermined design value.

As shown in FIG. 1, such a chip core 7 is rotated by a motor 4 as rotating means, for example, an upper surface circular portion 21 of a cylindrical spindle 3 via an adhesive as shown in the plan view of FIG. To fix. Of course, it may be fixed via a screw or the like. In this manner, the chip core 7 arranged on the upper circular portion 21 of the spindle is pressed by the lid 10 having the notch 16 and is fixed so as not to move.

In the above-mentioned structure, one chip core 7 is fixed on the upper circular portion 21 of the spindle, but a plurality of chip cores 7 may be arranged at angular positions where the circumference is evenly arranged.

The reference value of the protrusion amount AT of the chip core 7 to be polished from the outer circumference of the upper circular portion 21 of the spindle 3 having the above-described structure is the desired curvature of the chip core 7, the width w of the chip core 7 and the chip core thickness t and the spindle 2. Calculated from the diameter.

Now, considering only the curvature of the chip core 7 in the width direction w (X-X axis direction) in the perspective view of FIG. 3, the following protrusion amount AT of the chip core 7 is obtained.

If the desired curvature of the chip core = 7 mm, the chip core width w = 1.5 mm, and the diameter of the spindle 3 = 40 mm, the reference protrusion amount AT is 75 μm.

Such a design (standard) protrusion amount 75 μm
If a lapping tape 2 coated with an abrasive for lapping is arranged so as to surround a spindle 3 and the spindle 3 is rotated at a predetermined speed via a motor 4, a predetermined curvature should be obtained. However, in reality, due to variations in the curvature of the tape sliding surface 1 at the time of production, variations in the chip core width w, etc., residuals occur at both ends 9L and 9R of the magnetic head 5 (chip core 7) as shown in FIG. 6C. It was confirmed.

Therefore, in the present invention, the reference protrusion amount AT
As a result of protruding further to the wrapping tape 2 side,
A highly accurate chip core having no polishing residue on the curvature of the tape sliding surface 1 was obtained.

Example The design protrusion amount AT75 μm when the chip curvature is 7 mm, the chip core width is 1.5 mm, and the spindle diameter is 40 mm is as follows.
This example will be described with reference to Table 1 below in which the chip cores of the above are sequentially projected in the + AT direction (wrapping tape direction).

[0034]

[Table 1]

As shown in Table 1, when the protrusion amount AT is increased in the + AT direction as compared with the reference protrusion amount AT to change from 75 μm to 80 μm, 85 μm, 90 μm, both ends 9L and 9R of the tape sliding surface 1 The remaining contact does not occur at 80 μm or more, but both ends 9L and 9R of the tape sliding surface 1
Partial wear occurs at 90 μm or more, and the R shape is 5.
When it was 5 mm or less, the R shape was 7 mm> 5.5 mm, and there was a problem of excessive polishing at both ends 9L and 9R.

Therefore, by selecting a range of 5 μm to 15 μm with respect to the design (reference) protrusion amount AT, the curvature shape of the tape contact surface 1 is good as shown in the judgment example of Table 1 (x defective, o acceptable). The chip core 7 was obtained.

As shown in FIG. 3A, the curvature of the tape sliding surface 1 of the chip core 7 depends on the thickness direction t (Y-Y) of the chip core 7.
It is made so that it can also be attached to (direction). In this case, the wrapping tape 2 is polished while being curled also in the width direction of the tape. Therefore, in the direction of the thickness t of the chip core 7, the protrusion amount A with respect to the reference design curvature is also similarly described above.
It is apparent that if T is stretched in the + AT direction (the lapping tape 2 direction), the problem of the head chip 7 remaining in the front-rear direction (thickness direction) and overpolishing can be solved in FIG. 3A. Actually, the dimension in the thickness direction t (for example, 80 μm) is extremely small with respect to the dimension in the width direction w (for example, 1100 μm) of the chip core 7, so that a hit residue in the Y-Y axis direction and excessive polishing in the front-back direction are problems. It can not be said that.

As described above, according to the method of forming the sliding surface of the magnetic head of the present invention, the curvature of the tape sliding surface can be formed with extremely high precision and a high quality magnetic head can be obtained.
A magnetic head suitable for R etc. can be provided. Although the MIG head has been described in the above embodiments, it is obvious that the present invention can be applied to heads having other configurations such as other ferrite heads.

[0039]

According to the method of forming the tape sliding surface of the magnetic head of the present invention, a highly accurate chip core capable of polishing the curvature (R-shaped surface) of the tape sliding surface to a value extremely close to the reference design value is obtained. You can

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a method of forming a sliding surface of a magnetic head according to the present invention.

FIG. 2 is a plan view of a polishing method explanatory diagram of the present invention.

FIG. 3 is an explanatory diagram of a chip core of the present invention.

FIG. 4 is an explanatory view of a method of manufacturing the chip core of the present invention.

FIG. 5 is an explanatory view of a conventional method of polishing a magnetic head.

FIG. 6 is an explanatory diagram of a conventional magnetic head protrusion amount.

[Explanation of symbols]

 1 Tape sliding surface 2 Lapping tape 3 Spindle 7 Chip core AT protrusion amount

Claims (2)

[Claims] 1. A method of forming a sliding surface of a magnetic head, wherein a predetermined curvature is formed on a tape sliding surface in a completed state of the chip core, wherein the chip core is formed from a circumference of a rotary member having a predetermined diameter. A tape sliding surface of the chip core is provided so as to project, and a lapping means is arranged so as to be in contact with the tape sliding surface of the chip core, the diameter of the rotating member, the size of the chip core, and a desired curvature. A method for forming a sliding surface of a magnetic head, wherein lapping is performed by projecting the chip core more than a predetermined protrusion standard value. 2. The protrusion amount of the chip core is 5 to 15
The method for forming a sliding surface of a magnetic head according to claim 1, wherein the sliding surface is μm.