JPH0618050B2 - Method of manufacturing magnetic head and flange used for its implementation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a magnetic head and a flange used for carrying out the method. More specifically, the present invention relates to a method of manufacturing a magnetic head using a substrate made of a hard and brittle material such as a ceramic magnetic material or a ceramic non-magnetic material, and an improvement of a flange for mounting a grinding wheel on a grinding wheel shaft in the manufacturing method. .

(Prior Art) Conventionally, in a composite magnetic head using a hard and brittle material such as ferrite and a magnetic material such as Sendust alloy, which has wear resistance and is easy to process, in the gearup portion, the magnetic material is filled. A substrate provided with a large number of track grooves is abutted so that the magnetic materials in the track grooves face each other, bonded, and sliced. In this manufacturing method, it is necessary to form a large number of track grooves of several tens μm on a substrate having a size of 10 to 40 mm at a constant pitch.
Although the precision of grinding machines in recent years has improved in the groove processing direction to the extent that it does not hinder the manufacture of magnetic heads, the error in the feed in the direction orthogonal to the track groove, that is, the index feed error in the groove processing position, is still insufficient. It has not been improved so much, and it is difficult to make the track groove spacing, that is, the track pitch, constant in one substrate. Therefore, in the conventional method of forming a gap by stacking a pair of substrates that have been processed separately, the position of the magnetic material in the track groove is displaced when the substrates are bonded, and a track pitch error is likely to occur, resulting in poor yield. Was becoming.

In order to prevent this, a manufacturing method has been proposed in which a track pitch error is processed by processing a track groove on one substrate and then cutting into two substrates (JP-A-57-162116).
issue). For example, as shown in FIG. 6, a large number of track grooves 202 are pierced on a substrate 201 to apply a magnetic material 203, and the magnetic material 203 on the gear-op facing surface 204 is removed to remove the track grooves 202.
After leaving the magnetic material 203 inside,
A pair of substrates 201A and 201B are manufactured by bisecting in a direction orthogonal to 202, winding grooves 205 are formed on one substrate 201A, and then these are bonded to each other with a non-magnetic material 206 such as laminated glass. There is.

On the other hand, a grinder is generally used for groove processing for manufacturing a magnetic head. Not only the machine accuracy of this grinder but also the accuracy of mounting the grinding wheel on the grinder influences the above-described groove machining accuracy. In this grinding, the grindstone is not generally assembled on the processing machine, and it is usual to replace the whole flange with the grindstone attached to the flange. The conventional flange is composed of a flange body, a holding flange, and a nut for fixing the holding flange to the flange body, and usually has a structure for holding one grindstone. Further, as shown in FIG. 7, in order to improve productivity, two grindstones 104 and 105 are mounted with a spacer 103 interposed between the flange main body 101 and the pressing flange 102, and this is attached to the pressing flange 102 and the nut. There is also a multi-flange that is fixed at 105.

(Problems to be Solved by the Invention) However, according to a conventional manufacturing method in which a groove such as a track groove is formed on one substrate and then cut into two substrates, the track groove forming a gearup and the track groove are attached. When the shape of the magnetic material is linearly symmetric with respect to the gap as shown in FIG. 6, the pair of substrates are simply superposed so as to be folded, so that the same groove can be superposed to form the gap and a track pitch error occurs. However, in the case of the point-symmetrical shape, that is, in the shape in which one of the substrates is rotated by 180 ° and overlapped with each other, the track grooves are shifted and the magnetic materials are abutted, so that the groove intervals are not uniform, that is, the track pitch error is likely to occur.

On the other hand, when grinding hard and brittle materials such as ferrite substrates, a fine-grained grindstone is used to prevent chipping and high precision,
High speed grinding must be done. Therefore, it is necessary to use a static pressure spindle in order to perform high-speed grinding, and to eliminate runout in the radial and thrust directions of the grindstone in order to improve accuracy.

However, the conventional method of attaching the grindstone to the grindstone shaft while still attached to the flange cannot secure the thrust runout accuracy, and therefore cannot be machined with the above accuracy. For this reason, in order to ensure accuracy, the grindstone mounting surface must be self-cut to the accuracy of the hydrostatic spindle after the flange is mounted on the grindstone shaft.

However, in the case of the multi-flange, the grindstone mounting surface of the main body can be self-cut when the first grindstone is mounted, but cannot be self-cut when the second grindstone is mounted because the spacer is not fixed. Even if self-cutting is possible, it is necessary to cut the end face of the spacer.
There is a drawback that the interval between the grindstones becomes shorter after each self-cut. Further, in the case of a flange for a single blade, although it is possible to self-cut, it is not possible to process a plurality of track grooves at the same time and the processing capability is low, and the above-mentioned conventional method has to be adopted as the groove processing method. There is a disadvantage.

INDUSTRIAL APPLICABILITY The present invention enables a manufacturing method and its implementation in which a track pitch error does not occur regardless of whether the head shape is line-symmetrical with respect to the gearup, point-symmetrical, or the groove shapes are different between a pair of substrates. It is intended to provide a flange.

(Means for Solving Problems) In order to achieve the above object, the magnetic head manufacturing method of the present invention arranges a pair of grinding means at a predetermined interval and arranges the grinding means and a pair of substrates in parallel. While simultaneously providing track grooves on one substrate to the other substrate by the other grinding means, the grinding means is sequentially moved simultaneously in a direction perpendicular to the groove direction to provide a plurality of track grooves on each substrate. A step, a step of providing a magnetic material for forming a gap in the track groove, a step of superposing and joining the pair of substrates so that the magnetic materials face each other in the same track groove forming order, and thereafter, a large number of And a step of cutting out a head chip.

Also, the flange used in the manufacture of the magnetic head is
A flange main body having at least two reference surfaces for attaching a grindstone, a first pressing flange that is fitted into the flange main body and holds the grindstone between the first reference surface of the main body, and the flange main body and screw together. A first tightening nut for fixing the first pressing flange, a receiving flange fixed to a second reference surface of the flange body, and a second pressing flange for holding another grindstone between the receiving flange and The second tightening nut is screwed to the flange body to fix the second pressing flange.

(Operation) Therefore, even if the groove intervals in one substrate are not constant, the track grooves are processed such that the groove intervals between the pair of substrates have the same pitch. Therefore, even if the shape of the grindstone is line-symmetrical, point-symmetrical, or different with respect to the gear, track grooves are formed at the same position between the pair of substrates, and a track pitch error does not occur.

Further, since the flange self-cuts the reference surface of the flange body and the grindstone mounting surface of the receiving flange to mount the grindstones, the grindstones can be independently and accurately mounted on the flange.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

First, a specific apparatus example for carrying out the method of the present invention will be described in detail with reference to the drawings.

FIG. 3 and FIG. 4 show an example of a grinder with a plan view and a front view. This grinder comprises at least a grindstone shaft 26, a grindstone head 22, a grinding feed table 23, a work indexing column 24 and a bed 25, and a set of grindstones mounted on the grindstone shaft 26 via a flange 10. 12 and 16 and a pair of substrates 1A and 1B installed on the grinding feed table 23 are provided with relative feed and a work indexing column 24.
By changing the groove processing position, a large number of track grooves 2 are processed.

Flange 1 for attaching the grindstones 12, 16 to the grindstone shaft 26
As shown in FIG. 2, 0 is a flange main body 11 mounted on the grindstone shaft, a first pressing flange 13 that is fitted into the flange main body 11 and holds the first grindstone 12 between the main body 11 and the flange. A tightening nut 14 that is screwed with the flange body 11 to fix the first pressing flange 13 to the flange body, a receiving flange 15 that is fixed to the second reference surface 20 of the flange body, and a second portion between the receiving flange 15 It consists of a second pressing flange 17 that holds the grindstone 16 and a second tightening nut 18 that is screwed into the flange body 11 and clamps and fixes the second flange 17, and a plurality of grindstones 12 and 16 are individually attached to the flange body 11. It has a structure that can be attached. The first reference surface 19 uses the first grindstone 12 for the first pressing flange 13
The second reference surface 20 is sandwiched directly between the second reference surface 20 and the second pressing flange 17 via the receiving flange 15 and the second grindstone 1
Hold 6 The tightening nuts 14 and 18 are left-handed screws so that they are not loosened by rotation during grinding. The flange body 11 and the receiving flange 15
Is made of an aluminum alloy and has a self-cutting surface, that is, the outer surface of the receiving flange 15 except the first reference surface 19 for mounting the grindstone and the grindstone mounting surface 21 of the receiving flange 15, which is lightweight and hard to be damaged. The load on the grindstone shaft 26 is reduced. Second mounted between the receiving flange 15 and the second pressing flange 17
Unlike the first grindstone 12, the grindstone 16 has a structure with a small inner diameter. However, when the same grindstone as the first grindstone 12 is used, it is adjusted by using a spacer (not shown). As the grindstones 12 and 16, a diamond grindstone is usually adopted, and a pair of those having a line-symmetrical shape, a point-symmetrical shape or mutually different shapes with respect to the gearup g is used.

Next, a method of manufacturing the magnetic head according to the present invention, which is carried out by using the above-mentioned flange, will be described. In this embodiment, a composite magnetic head in which a thin film of a ferromagnetic metal is formed on a substrate and a magnetic gap is formed by the thin metal film is taken as an example.

First, the assembling of the grindstones 12 and 16 prior to processing will be described. The flange body 11 is screwed to the grindstone shaft 26. At the tip of the grindstone shaft 26, a screw, which is in a direction opposite to the grindstone shaft rotating direction, is usually left-handed. What is self-cutting?
The flange body 11 is rotated by another blade while rotating 6
Alternatively, it is to cut or grind another flanged member. Next, the first grindstone 12 is attached to the flange body 1
After it is fitted in 1, it is fixed using the first pressing flange 13 and the nut 14. Next, the second reference surface 2 of the flange body 11
Fix the receiving flange 15 to 0 with a screw or the like. Then, the whetstone mounting surface 21 of the receiving flange 15 is self-cut to move the second whetstone 16 to the second pressing flange 17,
Secure with nuts 18.

After mounting the flange, the pair of substrates 1A and 1B are separated by a predetermined distance L.
Are installed in parallel on the cutting feed table 23 of the grinder. Here, the predetermined interval L is preferably the interval between the two grindstones 12 and 16 attached to the flange 10 or a value close thereto. Then, by the two grindstones 12 and 16 mounted on the grindstone shaft 26 of the grinder through the flange 10 shown in FIG. 2, the tape sliding contact surface 5 is formed on the gear-up facing surface 3 of the substrates 1A and 1B. A large number of rectangular track grooves 2 extending in a direction orthogonal to each other are formed at a predetermined pitch [FIG. 1 (a)]. The side wall surface 6 of the track groove 2 is used as a thin film forming surface for forming the thin film 4 of ferromagnetic metal, and is orthogonal to the gap facing surface 3. In the case of this track shape, the grindstones 12 on the left side and the grindstone 16 on the right side in the drawing are different from each other in shape and are symmetrical, and when a pair of substrates 1A, 1B are butt-joined in point symmetry, a ferromagnetic thin film is used. 4 is effective because it is unlikely to cause a deviation. Further, when the rectangular track groove 2 is continuously formed, the surface adjacent to the side wall surface / thin film forming surface 6 is inclined, so that the thin film 4 having a low density is formed in this portion, and the film deposition is performed. It is suitable for cracks and the like due to the stress at the time and is easy to process. Face-up face 3 of this inclined surface
The inclination θ with respect to 5 to 85 °, preferably 15 to 70
It is desirable that the angle is in the range of 30 °, most preferably 30 to 60 °. Of course, the shape of the track groove 2 is not limited to that shown in the drawing, and various shapes such as a square shape, a V shape or a trapezoidal shape can be adopted. Further, as shown in FIG. 5, a pair of substrates 1A,
1B may be composed of track grooves 2 having different shapes, for example, a combination of V-shape and R-shape.

These are then washed, sputtered, vacuum deposited,
A thin film 4 of ferromagnetic metal is deposited on the thin film forming surface 6 of the track groove 2 by using a vacuum thin film forming technique such as ion plating or an electrolytic thin film forming technique or by sticking a thin film. The film is attached to the gear-op facing surface 3, preferably from a direction of 40 to 45 ° with respect to the gear-op facing surface, from a ferromagnetic metal such as Sendust alloy or permalloy alloy, or other magnetic circuit-configurable material such as Co-Zr-. Amorphous alloys such as Nb amorphous alloy and other metals having a high saturation magnetic flux density are sputtered to form a uniform thickness in the groove direction [First
Figure (b)]. Sputtering, for example, when targeting a standard Sendust alloy, in an argon gas atmosphere,
It is carried out at a substrate temperature of 200 ° C at a rate of about 400 Å / min. By alternately sputtering ferromagnetic metal and non-magnetic material, a multilayer film structure with a thickness of 5 to 6 μm per layer is usually formed, and vortices in the high frequency band are generated. Current loss can be reduced. The crystal grain size of the ferromagnetic metal in each layer is 200 to 330 Å for 220 plane growth and 520 to 422 plane growth for reducing eddy current loss in the high frequency band.
It is adjusted to 570Å.

Next, the track groove 2 is filled with a high melting point glass 7 to protect the thin film 4 [glass bonding]. After that, the gear-up facing surface 3 and the tape sliding contact surface 5 are ground to remove excess magnetic material and glass from each surface to make a flat surface having a predetermined surface roughness. Grinding is usually done by lapping to give a mirror finish.

Thereafter, although not shown, a winding groove is formed on the gear-op facing surface 3 of the one substrate 1A [boat-shaped processing]. Then, spacers (not shown) made of a non-magnetic material such as SiO ₂ are formed on the gap facing surfaces 3 of both substrates 1A and 1B by sputtering.

Next, the pair of substrates 1A and 1B are faced to each other and the metal thin film 4
They are joined so as to abut each other [gear bonding FIG. 1 (d)].

After the above-mentioned gear-up bonding, although not shown,
The tape sliding contact surface 5 is cylindrically polished, the tape sliding contact surface 5 is finished into a curved surface, and the tape sliding width is widened if necessary, and the gearup g takes a predetermined azimuth angle with respect to the tape sliding direction. Slice diagonally, or cut out many head chips without taking the azimuth angle. At this time,
Since the head chip is cut out by a predetermined width around the gear-up portion, that is, the thin film forming surface 6 portion and the inclined surface 7 in the vicinity thereof.
Since only the part remains in the product as a finished product, and the outside of the part is cut off, there is no problem even if cracks occur in the flat gear-up facing surface 3 part.

Then, after inspection, it is attached to the support head base, and the sliding surface finish processing that improves familiarity in the track direction is applied and winding is performed. The method of forming the groove at the same time can also be used when forming the groove for inserting the non-magnetic material.

(Effects of the Invention) As is apparent from the above description, the present invention provides a set of grindstones and a pair of substrates arranged in parallel at a predetermined interval,
While simultaneously providing track grooves on one substrate with one grindstone on the other substrate with the other grindstone, the grinding means is moved simultaneously in the direction perpendicular to the groove direction at the same time to simultaneously form a plurality of track grooves on a pair of substrates. Since the processing is performed, it is possible to process the grooves having the same pitch between the substrates.
Therefore, even if the groove pitch in one substrate is not constant, the track grooves can be processed so that the groove pitch between the pair of substrates has the same pitch. Even with a symmetrical shape or a different shape without symmetry, the track groove is formed at the same position between the pair of substrates, and the gap can be accurately formed without causing a track pitch error. Moreover,
Since highly precise groove processing can be simultaneously performed on a pair of substrates, manufacturing efficiency is improved.

Further, in the flange of the present invention, the grindstones can be independently fixed to the two reference surfaces of the flange main body, so that the grindstone mounting surfaces can be self-cut and accurately mounted. Further, since no spacer is interposed between the grindstones, the relative distance between the grindstones does not change.

[Brief description of drawings]

1 (a) to (d) are processing flow charts showing the manufacturing method of the method of the present invention, FIG. 2 is a vertical cross-sectional view of a central half section showing an embodiment of the flange of the present invention, and FIG. 3 is a grinder. FIG. 4 is a front view of the grinder, FIG. 5 is a front view showing another embodiment of the track groove, and FIG. 6 is a processing flow chart showing a conventional magnetic head manufacturing method. FIG. 7 is a schematic structural view showing a conventional flange. 1A, 1B ... Substrate, 2 ... Track groove, 4 ... Ferromagnetic thin film, 6 ... Thin film forming surface, 10 ... Flange, 11 ... Flange body, 13 ... First pressing flange, 14 ... 1 nut, 15 ... receiving flange, 17 ... second pressing flange, 18 ... second nut 12, 16 ... first whetstone, second whetstone as grinding means

Claims (2)

[Claims] 1. A pair of grinding means are arranged at a predetermined interval, and the grinding means and a pair of substrates are arranged in parallel, and one grinding means forms a track groove on one substrate and the other grinding means forms a track groove on the other substrate. A step of simultaneously moving the grinding means in the direction perpendicular to the groove direction at the same time to provide a plurality of track grooves on each substrate; a step of providing a magnetic material for forming a gap in the track grooves; A method of manufacturing a magnetic head, comprising a step of superposing and joining the pair of substrates so that they are opposed to each other so as to be arranged in the same track groove formation order, and then cutting out a large number of head chips. 2. A flange main body having at least two reference surfaces for attaching a grindstone, and a first pressing flange for fitting the grindstone between the flange main body and the first reference surface of the main body, A first tightening nut that is screwed to a flange main body to fix the first pressing flange, a receiving flange fixed to a second reference surface of the flange main body, and a first holding pin for holding another grindstone between the receiving flange. 2 presser flange,
A second tightening nut that is screwed into the flange body and fixes the second pressing flange, and self-cuts the first reference surface of the flange body and the grindstone mounting surface of the receiving flange to form a plurality of grindstones into the flange body. Flange characterized by being attached to each separately.