JPH11213321A - Production of magnetic head and magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method for magnetic head which easily realizes track control of high precision by processing the track control at a time in the stage of a core bar and not generating errors which have been a problem in a conventional method and are accumulated in every process. SOLUTION: A prescribed groove is formed on a prescribed surface of one of two core half bodies, and the surface of the core half body where the groove 23 is formed and a corresponding surface of the other core half body are polished into a prescribed surface roughness, and a prescribed nonmagnetic thin film is stuck to polished surfaces, and surfaces to which the nonmagnetic thin film is stuck of the pair of core half bodies are brought into contact with each other, and in this contact state, they are subjected to heat treatment at a prescribed temperature and are press-fixed to form a core bar 21. A line 26 on the surface of the core bar 21 is used to form plural holes 27 at such intervals practically on the line 26 from the surface of the core bar 21 toward the opposite surface by electro-discharge machining that a prescribed track width is left. Further, plural holes 27 of the core bar 21 are packed with molten glass, and the core bar 21 is cut by a prescribed size including the prescribed track width, thus producing the magnetic heads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic head suitable for a high-density magnetic recording / reproducing apparatus such as a VHS-VTR and a DVC, and a magnetic head.

[0002]

2. Description of the Related Art A magnetic head, which is a key device in magnetic recording technology, is a bulk type head using a magnetic hard brittle material as a base material or a MIG (Metal Metal) using a soft magnetic alloy thin film as a main magnetic path.
There are various types of heads, such as an In Gap type head and a laminated type head, and various companies use them in accordance with desired characteristics of a system to be mounted.

In particular, a bulk type head mainly made of an iron oxide ferrite material has a wide range of applications, mainly a VTR, and even today, metal heads are becoming mainstream. It is recently produced by various companies and installed in many magnetic recording systems.

[0004] However, the bulk type head is in conflict with the demand for higher precision, and on the other hand, there is also a strong demand for cost reduction, and it is indispensable to introduce a head structure and a construction method with higher productivity.

Hereinafter, a conventional magnetic head and a method for manufacturing the same will be described with reference to the drawings.

FIG. 5 is an overall view of a magnetic head mainly including a magnetic hard brittle material.

The conventional magnetic head 42 shown in FIG. 5 serves as a main substrate and is standardized by a magnetic recording system mounted on core halves 36 and 37 which are generally made of magnetic hard brittle material of single crystal ferrite. Glass 3 having a magnetic gap 38 formed in dimensions and a track having a track width TW, sealing the core halves 36 and 37, and reinforcing the track.
9 and a winding window 40 formed in the core half 36.

The magnetic gap 38 is formed at a desired angle θ with respect to a head chip end face 41 which is a reference according to a system to be mounted.

FIGS. 6, 7 and 8 are process diagrams of the conventional magnetic head, and show a method of manufacturing the magnetic head 42 shown in FIG. 5 up to the head chip.

FIG. 6 (a) shows a pair of core halves 43 and 44 made of a magnetic hard brittle material. Magnetic gap surface 45 of core half 43 facing core half 44
In a later step, a groove is formed to form a winding window 47 for winding a copper wire in a later step, and the magnetic gap surfaces 45, 46 to which the core halves 43, 44 face each other and are crimped in the later step have predetermined surface roughness. Mirror-polished to form a highly accurate core facing surface.

FIG. 6B is a view showing track grooves formed in the core halves 43 and 44.
The track regulating grooves 4 are provided on the magnetic gap surfaces 45 and 46 of 44.
A plurality of tracks 8 and 49 are formed at predetermined intervals and depths to form a track TW whose dimensions are standardized by the system.

Next, FIG. 7C is a view showing the formation of a gap between the pair of core halves, and FIG. 7D is a detailed view of a circle A in FIG. 7C. Core half 4 with track groove
3 and 44 are opposed to each other on the magnetic gap surface, and
0 is fixed to a predetermined accuracy and held by a jig, and the track grooves are melted and filled at a predetermined temperature to fill the glass halves 43 and 44, thereby sealing the core halves 43 and 44. 52 is obtained.

However, although not shown in the drawing, both core halves 4
On the surfaces facing the magnetic gaps 3 and 44, a nonmagnetic film serving as a magnetic gap is generally formed in advance by means such as evaporation or sputtering.

FIG. 8 (e) is a view showing a process of dividing the gap bar 52 into magnetic heads of a predetermined size. Cut to head size 5
3, 54, 55, 56, 57, 58, 59, 60 to obtain the magnetic head chip 61 shown in FIG.

[0015]

However, in the conventional method of manufacturing a magnetic head, when considering a magnetic head in which a track width of a recording pattern tends to be narrow due to a demand for a higher density of a magnetic recording technology, a core is required. The track matching accuracy of the half body is also severely limited, and the accuracy of sub-micron or less is required in some systems. Therefore, the conventional magnetic head method that depends on the track matching accuracy is a limit in accuracy.

Further, as one of the trends toward higher precision, lowering the cost of the magnetic head is an essential issue, and there is a demand for a device for reducing the cost by introducing a method of higher production efficiency.

An object of the present invention is to provide a magnetic head manufacturing method and a magnetic head which are effective for solving the above-mentioned problems.

[0018]

According to a first aspect of the present invention, there are provided two columnar core halves made of a predetermined magnetic hard and brittle material, and one of the two core halves is provided. Substantially parallel to a straight line at one predetermined end of the surface,
A groove having a predetermined shape and a predetermined depth is formed, and the predetermined surface of the core half in which the groove is formed and the surface of the other core half corresponding to the predetermined surface are formed by a predetermined method. A state in which a predetermined non-magnetic thin film is applied to at least one of the polished surfaces of the pair of core halves, the pair of core halves is brought into contact, and the contact is maintained. Then, heat-treat at a predetermined temperature and press-bond to form a core bar,
Utilizing a linear portion of the contacting portion on the surface of the core bar, from the surface of the core bar to a surface opposite to the surface, substantially on the linear portion, at an interval leaving a predetermined track width. By electric discharge machining, a plurality of holes are formed, a plurality of holes of the core bar are filled with molten glass of a predetermined temperature, the core bar is cut into a predetermined size including the predetermined track width, and the magnetic head is cut. A method for manufacturing a magnetic head, comprising:

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) A method of manufacturing a magnetic head according to the present invention will be described with reference to the drawings.

FIGS. 1, 2 and 3 are process diagrams of the magnetic head of the present invention, showing a method of manufacturing a magnetic head chip.

FIG. 1A shows core halves 11 and 12 which are main substrates and are made of a magnetic hard brittle material of single crystal ferrite in the magnetic head of the present invention. A groove is formed in the core half 11 on the side of the magnetic gap surface 13 to be pressed against the core half 12 later, and the magnetic gap surfaces 13 and 14 are mirror-polished to a predetermined surface roughness. To finish. Note that the magnetic gap surface 14 is a surface of the core half 12 that faces the core half 11 later and is pressed.

Next, FIG. 1B is a process chart for forming a magnetic gap spacer on the core halves 11 and 12, and FIG.
Magnetic gap members 16 and 17 serving as magnetic gap spacers are applied to the magnetic gap surfaces 13 and 14 shown in (a) by a method such as sputtering or vapor deposition.

Next, FIG. 1C is a view showing a temporarily sealed state of the core halves 11 and 12, and the magnetic gap surfaces 13 and 14 are shown.
After holding the core halves 11 and 12 with the jigs 19 and 20 so that the core bars 11 and 12 are brought into contact with each other, the core halves 21 are obtained by heat treatment at a predetermined temperature and pressure bonding. In FIG. 1C,
The contact surface between the magnetic gap surfaces 13 and 14 is the magnetic gap surface 1
It is represented as 8.

In the present embodiment, the core halves 11,
As a sealing material for the temporary sealing of 12, a material that melts at a predetermined sealing temperature in the magnetic gap members 16 and 17 was used, and the core halves 11 and 12 were pressed using the sealing material. A similar effect can be obtained also by a method in which molten glass is stored in grooves separately provided on the magnetic gap surfaces 13 and / or 14 and pressed. Therefore, the method of temporarily sealing the core halves 11, 12 is not limited to the method described above.

FIG. 2D shows a process for forming a regulated predetermined track width on the core bar 21. Discharge machining is performed from the medium sliding surface 22 side to the apex 24 of the winding window 23 with a discharge electrode core 25 of a predetermined size, for example, φ0.1, and a plurality of discharges with the machining axis centered on the magnetic gap line 26. The holes 27 are formed at predetermined intervals to regulate the recording / reproducing track width TW. At this time, the discharge holes 27 are processed so that the processing depth does not penetrate through the winding window 23. The shape of the discharge hole 27 has a shape that substantially transfers the shape of the discharge electrode core 25.

FIG. 2E shows a state in which the discharge hole 27 of the core bar 21 is filled with a glass 28 melted at a predetermined temperature. The filling of the molten glass 28 reinforces the track. Then, the core halves 11 and 12 constituting the core bar 21 are fully bonded.

Next, FIG. 3F is a view showing a method of cutting the core bar 21 to obtain a magnetic head chip from the core bar 21.
That is, in the direction of the angle AZ with respect to the perpendicular of the magnetic gap line 29, the cutting widths 30, 31, 32, 33, 3
4, the core bar 21 is cut to obtain a magnetic head chip 35 shown in FIG.

Thereafter, although not shown, a magnetic head chip is adhered to a metal base, and the magnetic head is completed through processes such as tape polishing and winding of the medium sliding surface 22.

Next, the magnetic head obtained as described above will be described.

FIG. 4A is an overall view showing a magnetic head of the present invention, and FIG. 4B shows details of a circle A near the magnetic gap of the magnetic head.

As shown in FIG. 4, the magnetic head of the present invention serves as a main substrate and has a standard according to a magnetic recording system mounted on core halves 1 and 2 made of magnetic hard brittle material of single crystal iron oxide ferrite. Core gap 1 having a magnetic gap 3 and a track width TW formed with reduced dimensions.
And a glass 4 for sealing the track and reinforcing the track, and a winding window 5 in one core half 1.

The magnetic head 3 has a structure shown in FIG. 4B in the vicinity of the magnetic gap 3 where the structural features are remarkable. Track control grooves 8 and 9 formed by electric discharge machining for controlling a track having a predetermined width TW, and glass 4 filled in the track control grooves 8 and 9. Further, a magnetic gap member (omitted in the drawing) is attached at a predetermined thickness at the bonding interface of the magnetic gap 3. Further, as shown in FIG. 4B, the track is located on the surface of the magnetic gap.
A substantially vertical perpendicular line at one end in the direction from the core halves 1 to 2;
Tilt angle AZ standardized by the mounted system
It is configured to form.

In the above-described embodiment, the description has been made using single crystal ferrite as the magnetic hard brittle material. However, the magnetic hard brittle material is not limited to single crystal ferrite.
Polycrystalline ferrite may be used.

[0035]

As is apparent from the above description, according to the present invention, since the truck regulation is processed at the core bar stage at one time, an error which accumulates in each process which has been a problem in the conventional method is not generated. It is possible to provide a method of manufacturing a magnetic head that easily realizes high-precision track control.

Further, according to the present invention, recording fringing, which is a problem in mounting on an actual machine, can be greatly reduced, so that the effective track width can be regulated with high precision.

Further, the present invention can reduce complicated steps in accuracy, thereby contributing to high accuracy.
It is possible to provide a method of manufacturing a magnetic head that achieves a significant cost reduction.

[Brief description of the drawings]

FIG. 1 is a diagram of a first half of a method of manufacturing a magnetic head according to a first embodiment of the present invention;

FIG. 2 is a diagram of a middle part of a method for manufacturing a magnetic head according to the first embodiment of the present invention;

FIG. 3 is a diagram of the latter half of the method of manufacturing the magnetic head according to the first embodiment of the present invention;

FIG. 4 is a diagram showing a magnetic head according to the first embodiment of the present invention;

FIG. 5 is a diagram showing a conventional magnetic head.

FIG. 6 is a diagram showing a first half of a conventional method of manufacturing a magnetic head.

FIG. 7 is a view of a middle part of a conventional magnetic head manufacturing method.

FIG. 8 is a diagram of a latter half of a conventional method for manufacturing a magnetic head.

[Explanation of symbols]

 1, 2 core half 3 magnetic gap 4 glass 5 winding window 8, 9 track regulating groove 11, 12 core half 13, 14 magnetic gap surface 15 winding window 16, 17 magnetic gap member 18 magnetic gap surface 19, 20 Jig holding 21 Core bar 22 Medium sliding surface 23 Winding window 24 Apex 25 Discharge electrode core 26 Magnetic gap line 27 Discharge hole 28 Glass 29 Magnetic gap line 30-34 Cutting width 35 Magnetic head chip 36, 37 Core half body 38 Magnetic Gap 39 Glass 40 Winding window 41 Head chip end surface 42 Magnetic head 43, 44 Core half 45, 46 Magnetic gap surface 47 Winding window 48, 49 Track regulating groove 50 Track gap 51 Glass 52 Gapped bar 53-60 Cutting 61 Magnetic Head chip TW Track width θ Desired angle AZ Tilt Angle

Claims (3)

[Claims] 1. Two columnar core halves made of a predetermined magnetic hard and brittle material are prepared, and a predetermined surface of one of the two core halves is attached to a predetermined one end of the surface. Forming a groove having a predetermined shape and a predetermined depth substantially in parallel with the straight line of, the predetermined surface of the core half having the groove formed therein, and the predetermined surface of the other core half having the groove formed therein A surface corresponding to the above is polished to a predetermined surface roughness, a predetermined non-magnetic thin film is applied to at least one of the polished surfaces of the pair of core halves, and the pair of core halves is brought into contact. In a state where the contact is maintained, heat treatment is performed at a predetermined temperature and pressure bonding is performed to form a core bar, and a straight portion of the contacting portion on the surface of the core bar is used, from the surface of the core bar to the surface thereof. Substantially in the direction of the opposite surface, substantially on the straight portion, A plurality of holes are formed by electric discharge machining at intervals to leave a track width of the core bar, and a plurality of holes of the core bar are filled with molten glass of a predetermined temperature, and the core bar has a predetermined size including the predetermined track width. And producing a magnetic head. 2. The magnetic hard and brittle material is a polycrystalline or single crystal iron oxide ferrite.
The manufacturing method of the magnetic head described. 3. A magnetic head manufactured by using the method of manufacturing a magnetic head according to claim 1.