JPH01109502A - Manufacture of composite type magnetic head - Google Patents

Abstract

PURPOSE:To eliminate a grinding process to determine a track width by making the thickness of a metallic magnetic film adhered and formed on an oxide magnetic material larger than the depth of a V groove for a track width. CONSTITUTION:A V groove 4 for a track width is processed to an oxide magnetic material 2 and further, a V groove 8 is processed with a width of the head chip cutting thickness or above. At this time, the depth of the groove of grooves 4 and 8 is determined by the thickness of the metallic magnetic film of a completed composite type magnetic head or by the angle formed by the grinding quantity of the metallic magnetic film and a magnetic gap together with the metallic magnetic adhered surface. Next, a metallic magnetic material 3 is adhered on the surface. The film thickness is larger than the depth of a V groove 4. Next, the metallic magnetic surface is ground and the metallic magnetic surface is smoothed on the V groove 4. Next, at the same angle as the groove 4, a track width regulating groove 9 is processed and SiO2 is vapor deposited onto the magnetic gap surface and made into a magnetic pole piece. In the same way, a twisting line groove 5 is processed, other magnetic pole piece is manufactured and made into a pair. To the magnetic pole piece of a pair, a glass deposition 7 is executed, the magnetic gap is formed, a magnetic medium facing surface is in a circular arc shape processed and sliced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a composite type, which is suitable for a narrow track width VTR video head, and is made by depositing a metal magnetic film on an oxide magnetic material using vacuum thin film formation technology. The present invention relates to a method of manufacturing a magnetic head.

[Summary of the invention]

After forming V-shaped grooves in the oxide magnetic material so that the magnetic gear and the surface to which the metal magnetic film is adhered are non-parallel, a metal magnetic film is deposited on the oxide magnetic material by sputtering or the like. In the composite magnetic head.

Conventionally, a method has been used in which the protrusion of the V-groove is polished to a specified track width. However.

As tracks become narrower, a track width accuracy of ±1 to 2 .mu.m is required.2The above-mentioned composite magnetic head uses an oxide magnetic material with a width of 15 to 20 mm in the longitudinal direction.

The yield rate in track width machining is low and is a factor in increasing costs. In the present invention, in order to solve this problem, grooves such as V-shaped grooves are provided at the magnetic gap forming position and the position adjacent thereto on the block made of oxide magnetic material, and the grooves formed at the magnetic gap forming position are After a metal magnetic film is deposited and formed to be thicker than the depth, the metal magnetic surface is polished to provide a predetermined track width at the adjacent position in the track perpendicular direction.

Therefore, according to the present invention, (1) polishing of the protrusion of the groove to obtain a predetermined track width is eliminated, and the desired track width accuracy is obtained by using the known trunk width regulating groove machining method for a single-structure magnetic head. Be able to do it.

[Conventional technology]

In order to improve image quality in VTRs which record and reproduce data with a narrow track width in order to increase density or downsize, high coercive force tapes of 8000e or higher, such as metal tapes, are beginning to be used as magnetic media. However, the saturation magnetic flux density of oxide magnetic materials commonly used in image heads is about 4000 to 4500 Gauss.
When this head is used to record on a high coercive force tape such as the one described above, the edge portion of the gap becomes saturated and the recording magnetic field expands, reducing the recording efficiency. On the other hand, the saturation magnetic flux density is 10,0
Sendust, which is close to 00 Gauss, has a small resistivity and a high frequency (and the effective permeability decreases due to the skin effect. Therefore, a crystalline alloy magnetic film such as Sendust, which has a saturated, high magnetic flux density, or We have placed an amorphous alloy film that eliminates the causes of deterioration of the basic characteristics of the magnetic head, such as a decrease in magnetic permeability, an increase in coercive force, and hysteresis loss, without sacrificing crystal magnetic anisotropy. A composite magnetic head using a magneto-magnetic material has been proposed in the past.The surface on which the magnetic alloy film and the oxide magnetic material are adhered on the surface facing the magnetic medium of this composite magnetic head is a non-magnetic portion, and the magnetic This magnetic gap acts as a pseudo magnetic gap in contrast to the magnetic gap that detects the original magnetic flux, and in high-density VTRs that are used up to high frequency bands, it causes a deterioration of the characteristics of the magnetic head as a gap loss. This air gap loss is determined by the equation (1), but if the recording wavelength is equal to the pseudo gap length or is equal to an integer fraction thereof, the loss becomes infinite and the reproduction output becomes zero, or the pseudo gap length This shows that the longer the wavelength and the shorter the recording wavelength, the greater the loss.

In formula (1), Lg: void loss 9g: void length.

λ: recording signal wavelength Therefore, in a composite magnetic head,
As shown in No. 9214, the magnetic alloy film and the oxide magnetic material are deposited on a surface perpendicular to the track.

A manufacturing method has been provided in which the above-mentioned characteristic deterioration is prevented by tilting at an arbitrary angle and utilizing azimuth loss.

A block assembly diagram for this manufacturing method is shown in FIG.

(1, 2: oxide magnetic material, 3: metal magnetic film.

5: Winding groove, 6: Magnetic gap, 7: Bath-deposited glass) In this manufacturing method, first, a V-groove is provided in the oxide magnetic material, a metal magnetic film is deposited, and the oxide magnetic material protrusion is formed. After polishing the metal magnetic film adhered to the metal magnetic film to obtain the desired trunk width and adhering a magnetic gap thin film (Sin), a magnetic gear lubricant is formed by glass welding. Form and create a composite magnetic sodobronk. After this, the composite magnetic head chip is completed by slicing to a desired thickness. FIG. 8 is an enlarged view of the track surface of the completed chip.

[Problem that the invention seeks to solve]

In the conventional method described above, no matter what shape the groove is formed in the oxide magnetic material, after forming the metal magnetic film, the protruding portion of the groove must be polished in order to obtain the desired track width. The processing accuracy of this track width is ±1 to 2 μm.
Therefore, it is necessary to frequently check the amount of polishing in the track width determination polishing process, and the track width accuracy is required for all track sections provided in the longitudinal direction of the grooved oxide magnetic material. be. For this reason, the yield in this process is low, leading to an increase in the production cost of the single-combined magnetic head.

The present invention aims to solve these drawbacks and provide a manufacturing method that does not require a polishing step to determine the track width.

[Means for solving problems]

In order to achieve the above object, the present invention is characterized in that the thickness of the metal magnetic film deposited on the oxide magnetic material is made thicker than the depth of the V-groove for track width.

That is, in the present invention, a V groove and a V groove for track width are formed at a predetermined depth in each block made of an oxide magnetic material, and a metal magnetic film is deposited thereon to be thicker than the depth of the groove for track width. After the surface of the magnetic film, which has been formed in an uneven shape along the groove shape, is ground into a flat surface, a track width regulating groove is provided, and the remaining flat portion is used as a magnetic gap surface. Since the metal magnetic film is thicker than the depth of the V-groove for track width, it can be left on a flat surface. A magnetic gap formed by pairing with a block made of an oxide magnetic material to which another metal magnetic film is adhered, manufactured in the same way, has a desired angle with the surface of the metal magnetic film to which the oxide magnetic material is adhered.

[Effect]

As a result, according to the manufacturing method of the present invention, the accuracy of the track width is determined only by the dimension in the width direction of the track width groove provided in the oxide magnetic material and the dimension of the track width regulating groove. These grooves can be machined with an accuracy of ±1 μm by a known method using slicing, so that production yield can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6. First, as shown in FIG. 3, a V-groove 4 for track width is machined in the oxide magnetic material 2 so as to have a desired track width.
Furthermore, the width is greater than the cutting thickness of the head chip, making it V1f8! Process. At this time, the depth of the six grooves 4 and 8 depends on the thickness of the metal magnetic film of the completed composite magnetic head or the amount of polishing of the metal magnetic film and the angle that the magnetic gap makes with the surface on which the metal magnetic film is adhered. It is determined. The angle to the magnetic gap of the 6 grooves is 45°, and the thickness of the magnetic head chip is '&150 μm.
When the cutting allowance is 100 .mu.m, the grooves 8 may be machined at a pitch of 250 .mu.m from a position 125 .mu.m away from the center of the track width V groove 4. Next, as shown in FIG. 4, a metal magnetic material 3 is deposited on the grooved oxide magnetic material using a vacuum technique. The thickness of the film to be deposited is set to be smaller than the depth of the V-groove 4 for track width. At this time, if a film thickness of 10 .mu.m is to be ensured at the minimum portion, the distance between the tops of the grooves 4 is 10 .mu.m, and if the trunk width is 3.mu.m, the thickness will be 15 .mu.m or more. However, in consideration of workability during post-process gap surface polishing, it is preferable to form the layer with a thickness of about 20 μm. After this, the metal magnetic surface is polished to smooth the metal magnetic surface on the trunk width groove.

Next, as shown in FIG. 5, a track width regulating groove 9 is machined at the same angle as the groove so as to have a predetermined track width, and an S LO is formed with a predetermined thickness on the magnetic gap surface using vacuum technology to form a magnetic pole. Take it as a piece. In addition, the other magnetic pole piece with the winding groove 5 is manufactured in the same manner as described above to form a pair. As shown in Fig. 6, these paired magnetic pole pieces are glass welded (7: glass) to form a magnetic gap, and the surface facing the magnetic medium is processed into an arc shape.
-A, A'-A', . . . , a composite magnetic head shown in a perspective view in FIG. 1 is completed. In addition,
FIG. 2 is an enlarged plan view of a main part showing the magnetic medium facing surface of the magnetic head of FIG. 1, and 6 indicates a magnetic gap.

In this embodiment, the grooves provided on the oxide magnetic material are V-shaped, but it is obvious that the same effect can be obtained even if the grooves are formed in various shapes such as a U-shape.

〔Effect of the invention〕,.

According to the present invention, without performing track width determining polishing,
A method of manufacturing a magnetic head that can obtain a predetermined track width with high precision and that satisfies the above-mentioned requirements can be realized, thereby making it possible to improve the production yield and reduce the number of man-hours required for reverse fabrication.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of a magnetic head to which the present invention is applied, FIG. 2 is an enlarged plan view of essential parts showing the magnetic medium facing surface of the magnetic head of the present invention, and FIGS. 3 to 6 are A schematic perspective view showing the manufacturing process of the magnetic head shown in FIG. 1 in order, FIG. 3 showing each V-groove processing step, and FIG. 4 showing a metal magnetic film deposition step. Figure 5 shows the track width regulating groove machining process, Figure 6 shows the pole piece joining and slicing process, Figure 7 is a perspective view showing the pole piece joining and slicing process by the conventional method, and Figure 8 shows the process. FIG. 3 is an enlarged plan view of a main part of a surface facing a magnetic medium. 1.2... Oxide magnetic material (magnetic pole piece), 3...
- Metal magnetic film, 4... Track width groove, 5... Winding groove. 6...Magnetic gap, 7...Glass, 8...V groove. 9...Track width regulation groove.

Claims (1)

[Claims] 1. A composite magnetic head in which V-shaped grooves are formed on a block made of oxide magnetic material, a metal magnetic film is deposited using vacuum thin film formation technology, and then processed to have a predetermined track width. In the manufacturing method, a V-shaped groove or the like is provided at the magnetic gap forming position and a position adjacent thereto on the block, and a metal magnetic film is deposited to be thicker than the depth of the groove provided at the magnetic gap forming position. After that, the metal magnetic surface is polished, and track width regulating grooves are provided at the adjacent positions so that a predetermined track width is obtained.