JPH08279109A - Magnetic head and its production - Google Patents

Abstract

PURPOSE: To improve the magnetic characteristics of a magnetic layer as a smooth plane is obtainable with the magnetic layer without receiving the influence of the roughening of the surface of a substrate by arranging a coating type SiO2 thin film between the substrate and magnetic layer of a magnetic head. CONSTITUTION: The coating type SiO2 thin film is so formed as to cover the substrate 1 formed with a magnetic core groove 1a. The surface of the substrate 1 is coated with the coating type SiO2 thin film and the surface including the inside of the magnetic core groove 1a is smoothed by forming the coating type SiO2 thin film 2a on the substrate 1 in such a manner. The coating type SiO2 thin film is formed by applying a coating liquid for film formation on the substrate and baking the coating. The film thickness depends on the concn. of the SiO2 of the coating liquid for forming the coating type SiO2 thin film and the number of revolutions of an automatic spinner for applying the coating liquid while rotating in order to enhance the uniformity of the film thickness. The film of a suitable thickness is obtainable by controlling the concn., etc., described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head suitable for video tape recorders, video cassette recorders, magnetic disk devices and the like and a method for manufacturing the same, and more particularly to a magnetic head in which a magnetic layer serving as a magnetic core is formed by a thin film process. And a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, high density recording of information signals has been advanced in the field of magnetic recording such as video tape recorders, video cassette recorders, magnetic disk devices, etc. Therefore, for a magnetic head that is responsible for recording and reproduction, high efficiency is achieved by downsizing the magnetic core,
Low inductance is required by thinning the coil,
Along with this, processing of the magnetic head has become complicated and precise.

When manufacturing such a magnetic head, for example, first, a groove (hereinafter referred to as a magnetic core groove) along the shape of a magnetic core is ground on a substrate made of a non-magnetic material with a grindstone or the like. To form a magnetic core forming surface. Next, a magnetic layer to be a magnetic core is formed by sputtering or the like on the substrate having the magnetic core groove formed therein. Here, the magnetic layer is
Not only a single magnetic film is formed, but a laminated structure in which a plurality of metal magnetic films are laminated via an insulating film may be used in order to reduce eddy current loss. Next, a groove (hereinafter, referred to as a groove for forming a thin film coil) is formed on the substrate on which the magnetic layer is formed.
It is called winding groove. ) And a groove for separating the magnetic layer for each magnetic core (hereinafter referred to as a separation groove) are formed by a grindstone or the like. Next, the magnetic core groove, the winding groove, and the separation groove are melt-filled with glass having a low melting point, and the surface is smoothed,
A thin film coil is formed so as to pass through the winding groove in the glass portion. As described above, the magnetic head half body in which the magnetic core and the thin film coil are formed on the substrate is manufactured. And
After joining the pair of magnetic head halves thus manufactured through the magnetic gap so that the magnetic cores face each other, by cutting each magnetic core and processing it into a predetermined shape,
A magnetic head is manufactured.

[0004]

In the above magnetic head, the magnetic characteristics of the magnetic layer are greatly affected by the surface property of the substrate on which the magnetic layer is formed. And
If the surface of the substrate is not smooth, the magnetic properties of the magnetic layer will deteriorate.

However, in the above-described magnetic head, it is difficult to sufficiently smooth the surface of the substrate, especially the inside of the magnetic core groove which is the surface for forming the magnetic core. That is, although the magnetic core groove is formed by a grindstone or the like, it is difficult to make the machined surface sufficiently smooth by machining with the grindstone or the like, and the machined surface becomes rough. Therefore, at present, grinding is performed by changing the type of grindstone depending on the material of the substrate so that the roughness of the processed surface is reduced, and further, the grinding speed is slowed or the grinding is performed several times. I'm splitting up.

However, even with such a method, it is difficult to sufficiently smooth the surface of the substrate, and deterioration of the magnetic characteristics of the magnetic layer cannot be avoided. Moreover, if you slow down the grinding process or divide the grinding process into several times,
There is a problem that the time required to process the magnetic core groove becomes long and the manufacturing efficiency of the magnetic head is reduced.

Therefore, the present invention has been proposed in view of such a conventional situation, and smoothes the surface of the substrate,
An object of the present invention is to provide a magnetic head capable of improving the magnetic characteristics of the magnetic layer and shortening the time required for processing the magnetic core groove, and a method for manufacturing the same.

[0008]

The magnetic head of the present invention completed in order to achieve the above-mentioned object has a pair of magnetic head halves in which a magnetic core half is formed on a substrate made of a non-magnetic material. , A magnetic head formed by joining via a magnetic gap, wherein coating type SiO _{2 is provided} between the substrate and the magnetic core half.
The feature is that a system thin film is arranged.

The magnetic head may have a magnetic core half body filled with glass and a thin film coil formed on the glass portion.

In the magnetic head, it is preferable that at least a portion of the end portion of the magnetic core half body which is in contact with the glass is flattened.

On the other hand, the method of manufacturing the magnetic head of the present invention is
A method of manufacturing a magnetic head comprising a pair of magnetic head halves joined together via a magnetic gap, wherein when a magnetic head half is produced, a magnetic core forming surface is first formed on a substrate made of a non-magnetic material. The magnetic core groove for forming the magnetic core groove is cut, and then SiO ₂ is formed on the substrate on which the magnetic core groove is formed.
A coating liquid for forming a coating film is applied to form a coating type SiO ₂ -based thin film, then a magnetic layer is formed on a substrate on which the coating type SiO ₂ -based thin film is formed, and then a magnetic layer is formed. A winding groove for arranging the thin-film coil and a separation groove for separating the magnetic layer for each magnetic core are formed on the formed substrate, and then a glass core is formed in the magnetic core groove, the winding groove and the separation groove. And then forming a thin film coil in the glass portion so as to pass through the winding groove.

[0012]

In the magnetic head of the present invention, since the coating type SiO ₂ thin film is disposed between the substrate and the magnetic layer, the magnetic layer is
It is formed on a smooth coating type SiO ₂ -based thin film without being affected by the surface roughness of the substrate. Since the magnetic layer is formed on a smooth flat surface, the magnetic characteristics of the magnetic layer are improved.

Moreover, in this magnetic head, when the magnetic core groove is processed, the roughness of the substrate surface is reduced,
There is no need to slow down the grinding process or to perform the grinding process in several steps.

In the method of manufacturing the magnetic head of the present invention, the coating type SiO ₂ thin film is formed on the substrate after the magnetic core groove is formed on the substrate by machining, so that the surface is smoothed. . Therefore, the magnetic layer has a smooth coating type Si without being affected by the surface roughness of the substrate.
Since it is formed on the O ₂ -based thin film, magnetic characteristics are improved.

Moreover, in this method of manufacturing a magnetic head,
When processing the magnetic core groove, it is not necessary to reduce the speed of the grinding process or perform the grinding process in several steps so that the roughness of the substrate surface is reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

The magnetic head of this embodiment is a magnetic head used in a video tape recorder, a video cassette recorder, etc., and as shown in FIGS. 1 and 2, a pair of magnetic head halves 10a, 10b has a magnetic gap. They are joined and integrated so as to abut each other via g.

Here, the magnetic head halves 10a, 10b
Is a substrate 1, a coating type SiO ₂ -based thin film (not shown) formed on the substrate 1, a magnetic layer 2 formed on the coating type SiO ₂ -based thin film and functioning as a magnetic core, and a magnetic layer. 2 has a glass 3 filled therein and a thin film coil 4 formed on the glass 3 portion by a thin film forming process. The pair of magnetic head halves 10a and 10b are joined via a non-magnetic material so that the respective magnetic layers 2 abut each other and a front gap fg and a back gap bg are formed between the respective magnetic layers 2. It

The above magnetic head will be described in detail below through its manufacturing method.

First, as shown in FIG. 3, MnO--NiO.
A substrate 1 made of a non-magnetic material such as a system is prepared. Here, the size of the substrate 1 is, for example, about 30 mm in length and about 30 m in width.
m and the thickness is about 2 mm.

Next, as shown in FIG. 4, in order to form an inclined surface on which a magnetic core is formed, that is, a magnetic core forming surface, a plurality of magnetic core grooves 1a are formed on the substrate 1. It is formed in parallel and at equal intervals so that one of the inner surfaces becomes an inclined surface. The magnetic core groove 1a has a depth of about 130, for example, using a grinding wheel having one surface molded at about 45 degrees.
Dozens of them are formed so that the width is about 150 μm, the inclination of the inclined surface is about 45 degrees. Here, the inclination of the inclined surface is
The angle need not be 45 degrees, but is preferably about 45 degrees in consideration of the pseudo gap and the track width accuracy.

The magnetic core groove 1a thus formed is
Since it is formed by a grinding wheel or the like, its processed surface is in a rough state, for example, as shown in FIG. 5 in which the side surface of the magnetic core groove 1a is enlarged. If such roughness is present, the magnetic characteristics of the magnetic layer formed in the subsequent step are deteriorated. Therefore, it is preferable to smooth the processed surface of the magnetic core groove 1a. However, the magnetic core groove 1
Since the substrate 1 on which a has been formed has a complicated shape, it is very difficult to smooth the processed surface of the magnetic core groove 1a by ordinary mirror surface treatment.

Therefore, in this embodiment, a coating type SiO ₂ thin film is formed so as to cover the substrate 1 on which the magnetic core groove 1a is formed. Thus, by forming a coating type SiO ₂ based thin film on the substrate 1, for example, as shown in FIG. 6 an enlarged side surface of the magnetic core groove 1a part, the surface of the substrate 1 is coated type SiO ₂ based thin film Magnetic core groove 1 covered by 2a
It is smoothed including the inside of a.

Here, the coating type SiO ₂ -based thin film is formed, for example, by coating the substrate with a coating liquid for forming a SiO ₂ -based film and baking it. Specific examples of such a coating liquid for forming a SiO ₂ film include a product name “OCD” manufactured by Tok. The coating liquid for forming a SiO ₂ film is for forming a film containing SiO ₂ as a main component by a coating / firing method in the process of manufacturing various electronic components, and its composition is, for example, a silicon compound. (RnSi (O
H) _4-n ) and additives (diffusion impurities, glass forming agent, organic binder) as organic solvent (alcohol main component,
Ester, ketone). As such a coating liquid for forming a SiO ₂ -based film, various ones are known depending on the purpose of use and the use thereof.
In the case of CD, mainly type-1, type-2, type-7
It is classified into three types of products, and the concentration of these can be easily changed according to the purpose of use.

The thickness of the coating-type SiO ₂ -based thin film when such a coating liquid for forming a SiO ₂ -based coating is used is SiO ₂
It depends on the SiO ₂ concentration of the coating liquid for forming a coating film and the number of revolutions of an automatic spinner that applies the coating liquid for forming a coating film of SiO ₂ while rotating to increase the uniformity of the film thickness.
Specifically, for example, using a type-1 or type-2 of the above OCD, 15 seconds rotation time of automatic spinner during application, coating type SiO ₂ based thin film firing conditions as 30 minutes at 500 degrees When the film is formed, the relationship between the film thickness of the coating type SiO ₂ -based thin film, the SiO ₂ concentration of the OCD, and the rotation speed of the automatic spinner is as shown in FIG. 7.

As described above, the film thickness of the coating type SiO ₂ -based thin film can be controlled by the SiO ₂ concentration and the rotation speed of the automatic spinner. Therefore, when forming the coating type SiO ₂ based thin film by using such SiO ₂ film-forming coating liquid, so that the surface of the substrate is sufficiently smooth, the thickness of the coating type SiO ₂ based thin film Can be controlled to a suitable thickness to form a film.

In the present embodiment, among such coating liquids for forming a SiO ₂ film, OCD type-2 having a SiO ₂ concentration of 5.9%, which is suitable for step coverage and a protective film, was used. This type-2 is P, Al, As, T
It is a coating liquid for forming a SiO ₂ film, to which a glass forming agent of a compound such as i is added. However, O other than type-2
It goes without saying that a CD, for example, a type-7 of a SiO ₂ film alone may be used. Then, using this OCD, spin coating is performed using an automatic spinner dedicated to OCD to improve the film thickness uniformity of the coating type SiO ₂ -based thin film, and the OCD is applied to the surface of the substrate. The substrate surface is annealed for about 1 hour to coat the surface of the substrate with Si.
An O ₂ type thin film was formed. Thus, in this embodiment, the film thickness is about 0. 0 on the substrate having the surface roughness Ra = 80 to 90 nm.
A coating type SiO ₂ thin film was formed on the surface of the substrate so as to have a thickness of 1 μm. As a result, the surface of the substrate was improved sufficiently smoothly.

As described above, in this embodiment, after the magnetic core groove is formed, the coating type SiO ₂ thin film is formed and the surface of the substrate is smoothed. Therefore, when forming the magnetic core groove, In order to reduce the roughness of the core groove, it is not necessary to slow down the grinding process or divide the grinding process into several steps, and the time required to process the magnetic core groove can be shortened.

Next, as shown in FIG. 8, a magnetic layer 2 is formed on the substrate 1 on which the coating type SiO ₂ thin film 2a is formed. Here, the magnetic layer 2 may be composed of a single magnetic film, but in order to have high sensitivity in a high frequency region, a plurality of metal magnetic films are laminated by interposing an insulating film. You had better. However, in the case where the magnetic layer 2 has a laminated structure as described above, the thickness of the insulating film needs to be such that a sufficient insulating effect can be obtained, and is made as thin as possible so that the insulating film does not act as a pseudo gap. There is a need.

Therefore, in this embodiment, the magnetic layer 2 is made of sendust (Fe-Al-Si alloy) and has a thickness of about 5 μm.
Made of alumina and a metal magnetic film of about 0.15 μm thick
And the insulating film of No. 1 were alternately laminated so that the metal magnetic film had three layers. As described above, by forming the magnetic layer 2 into a laminated structure, eddy current loss is reduced, and higher sensitivity can be obtained especially in a high frequency region.

Here, although sputtering is suitable as a film forming method for the magnetic layer 2, a physical film forming method (PVD) other than sputtering such as vapor deposition or molecular beam epitaxy (MBE), or a chemical method. Film forming method (CVD) or the like may be used.

The material of the metal magnetic film is preferably sendust, but other metal magnetic materials such as an alloy similar to sendust, a nitriding type soft magnetic alloy, and a carbonizing type soft magnetic alloy can also be used. . Also, the insulating film is not limited to alumina, and SiO ₂ , SiO, or a mixture thereof can be used.

Next, as shown in FIG. 9, the magnetic core groove 1a is formed.
Winding groove 1 for arranging thin film coil 4 at right angles to
b and a separation groove 1c for separating the magnetic layer 3 for each magnetic core are formed.

Here, the winding groove 1b has a shape in which the magnetic layer 2 on the front gap side is narrowed obliquely toward the front gap fg, as shown in FIG.
For example, the front gap side of the winding groove 1b is formed by a grindstone having a slope of about 45 degrees. As described above, when the magnetic layer 2 on the front gap side is narrowed toward the front gap fg, the magnetic flux is concentrated and high recording sensitivity is obtained. However, if the shape of the winding groove 1b is such that the magnetic layer 2 on the front gap side is narrowed toward the front gap fg, the angle of the slope on the front gap side of the winding groove 1b is not 45 degrees. Further, the shape of the winding groove 1b on the front gap side may be an arc shape or a polygonal shape. Further, the depth of the winding groove 1b may be a depth that does not divide the magnetic layer 2,
If it is too deep, the magnetic path length increases and the magnetic flux transmission efficiency decreases. Therefore, in this embodiment, the winding groove 1b is formed to a depth of about 20 μm from the apex of the slope of the magnetic core groove 1a. The width of the winding groove 1b is determined by the width of the thin-film coil 4 and the number of windings to be formed in a later step, and in this embodiment, it is set to about 140 μm.

On the other hand, the separation groove 1c may have any shape as long as the magnetic layer 2 is divided, and in this embodiment, it has a rectangular shape which is easy to process. The depth of the separation groove 1c needs to be such that the magnetic layer 2 is completely divided. In this embodiment, the separation groove 1c is formed to a depth of about 150 μm from the bottom of the magnetic core groove 1a. . The width of the separation groove 1c is determined by the desired balance between the length of the front gap fg and the length of the back gap bg of the magnetic head. However, since the length of the magnetic layer 2 on the front gap side wraps the medium sliding surface when the magnetic head is finally processed into a predetermined shape, the finally desired front gap f
The separation groove 1c is formed with a length longer than g. Therefore, in this example, the separation groove 1c is formed so that the length of the magnetic layer 2 on the front gap side is about 300 μm and the length of the magnetic layer 2 on the back gap side is about 85 μm.

Since the winding groove 1b and the separation groove 1c thus formed are formed by a grinding wheel or the like like the magnetic core groove 1a, the processed surface is in a rough state. When such roughness exists, the cross-sectional portion 1d of the magnetic layer 2 which is a part of the processed surface also becomes rough,
If the magnetic layer 2 has the laminated structure as described above, the metal magnetic film may cross the adjacent insulating film and be electrically connected to another metal magnetic film in the cross-sectional portion 1d of the magnetic layer 2. . Further, if such roughness is present, there is also a problem that bubbles tend to be generated in the glass 3 when the glass 3 is filled in a later step. Therefore, it is preferable to smooth the processed surface of the winding groove 1b and the separation groove 1c. However, the substrate 1 on which the winding groove 1b and the separation groove 1c are formed
Has a complicated shape, so with normal mirror surface treatment,
It is very difficult to smooth the processed surface of the winding groove 1b and the separation groove 1c.

Therefore, in this embodiment, the processed surfaces of the winding groove 1b and the separation groove 1c are smoothed by etching.

Specifically, for example, after the substrate 1 is tilted by about 30 degrees from the ion irradiation direction, ion etching is performed on the entire surfaces of the substrate 1 and the magnetic layer 2 for about 1 hour in an Ar gas atmosphere. Etching is performed for about 1 μm. However,
It goes without saying that the angle between the ion irradiation direction and the substrate 1, the time for ion etching, and the type of gas may be appropriately changed depending on the types and shapes of the substrate 1 and the magnetic layer 2, and the surface roughness.

Alternatively, for example, after the substrate 1 is tilted by about 30 degrees from the powder irradiation direction in the atmosphere for about 1 hour, the powder is injected at high speed toward the surfaces of the substrate 1 and the magnetic layer 2. Then, powder beam etching is performed on the entire surface of the substrate 1 and the magnetic layer 2 to perform etching of about 1 μm. Here, the size of the powder is preferably about 100 to 500 μm. However, it goes without saying that the angle between the powder irradiation direction and the substrate 1, the time for powder beam etching, and the type of powder may be appropriately changed depending on the types and shapes of the substrate 1 and the magnetic layer 2, and the surface roughness. .

It should be noted that such etching is not limited to ion etching or powder beam etching, but may be performed by wet etching or the like. Furthermore, the smoothing of the processed surface of the winding groove 1b and the separation groove 1c is not due to such etching, but is the same as when the magnetic core forming groove is smoothed.
It may be smoothed by forming an iO ₂ -based thin film.

By smoothing the winding groove 1b and the separation groove 1c in this manner, bubbles are less likely to be generated in the glass 3 when the glass 3 is filled in the subsequent step, and a thin film coil is formed in the subsequent step. In doing so, defects such as disconnection due to such bubbles are less likely to occur. Moreover, when the processed surface of the winding groove 1b and the separation groove 1c is smoothed by etching, the cross-sectional portion 1d of the magnetic layer 2 which is a part of the processed surface of the winding groove 1b and the separation groove 1c is also smoothed. Since the cross section of the laminated structure of the magnetic layer 2 becomes clear, the cross section 1d of the magnetic layer 2
Insulation failure in (3) is eliminated, and insulation between the metal magnetic films is sufficiently achieved.

Next, as shown in FIG. 10, the magnetic core groove 1
a, the winding groove 1b, and the separation groove 1c are melt-filled with the glass 3 having a low melting point.

Next, the surface of the glass 3 is mirror-finished to be smoothed, and as shown in FIG. 11, a thin film is formed on the glass 3 by a thin film forming process so as to pass through the winding groove 1b. The coil 4 is formed.

Next, as shown in FIG. 12, the magnetic head half blocks 11a and 11 are cut by cutting one row for each magnetic core.
b is produced, and the pair of magnetic head half blocks 11a and 11b produced in this way are joined by gold joining or the like so that the magnetic layers 2 are butted. However, the magnetic head half blocks 11a and 11b may be joined by a chemical joining method using an adhesive or the like.

Finally, the magnetic cores are cut one by one and ground into a predetermined shape to join the pair of magnetic head halves 10a and 10b as shown in FIG. A magnetic head is manufactured.

Although the thin film coil is formed on both of the pair of magnetic head halves in the above-described embodiment, the thin film coil may be formed on only one of the magnetic head halves.

Further, in the above-mentioned embodiment, the magnetic head half block is prepared by cutting the substrate on which the magnetic layer, the thin film coil, etc. are formed one by one for each magnetic core. After joining, the magnetic cores were cut one by one, but the magnetic layer, the thin-film coil, and other substrates were previously cut one by one for each magnetic core to create a magnetic head half. The magnetic head halves may be bonded to each other, or the substrates on which the magnetic layers and the thin-film coils are formed may be bonded as they are, and the magnetic cores may be cut one by one afterwards.

Next, the effect of the coating type SiO ₂ thin film will be described.

FIG. 13 shows the magnetic permeability of the magnetic layer when a coating type SiO ₂ thin film is formed on the surface of the substrate on which the magnetic core forming groove is formed as described above, and the coating type SiO ₂ thin film is formed. And the magnetic permeability of the magnetic layer when the magnetic layer is formed without it. As is clear from FIG. 13, the magnetic permeability of the magnetic layer is higher when the magnetic layer is formed on the coating type SiO ₂ thin film. Specifically, for example, when the frequency is 10 MHz, whereas the magnetic permeability when the formation of the magnetic layer without forming the coating type SiO ₂ based thin film is a mu = 738, coating type SiO ₂ system The magnetic permeability when the magnetic layer is formed on the thin film is μ = 1619.

By the way, as shown in FIG. 14, the magnetic core j1 has a width t1 of about 20 μm and a length t2 of about 240 μm.
The height t3 is about 240 μm, and the coil k1 is the magnetic core j1.
In the case of a magnetic head wound in the height direction, the relation between the output of the magnetic head and the magnetic permeability is as shown in FIG.

As described above, the frequency is 10M
At Hz, the magnetic permeability when the magnetic layer was formed without forming the coating-type SiO ₂ -based thin film was μ = 738, while the magnetic layer was formed on the coating-type SiO ₂ -based thin film. since the magnetic permeability when the formation has a mu = 1619, and a magnetic head forming a magnetic layer on which it was formed a coating type SiO ₂ based thin film, without forming a coating type SiO ₂ based thin film Compared to a magnetic head having a magnetic layer, as shown in FIG.
It can be seen that the output is improved by about 2 dB.

Next, the abrasive grains used for forming the magnetic core groove and the like, the film thickness of the coating type SiO ₂ -based thin film, and the magnetic characteristics of the magnetic layer will be described in more detail.

When the magnetic core groove or the like is ground, abrasive grains having an appropriate grain size are used. Specifically, the grain size is 50-
Abrasive grains that exceed 60 μm make it difficult to perform fine processing.
Since the Ra of the processed surface becomes too large, it is not suitable for forming a magnetic core groove or the like. On the other hand, abrasive grains having a grain size of less than 10 to 15 μm are apt to be clogged during the grinding process and take too much time for the grinding process, and therefore are not suitable for forming the magnetic core groove and the like. Therefore, in forming the magnetic core groove, etc., the grain size is about 10 to 60 μm.
Abrasive grains in the range of are used.

Table 1 shows the Ra of the machined surface when the magnetic core groove and the like are formed by using the abrasive grains made of synthetic diamond having a grain size of about 10 to 60 μm.

[0055]

[Table 1]

As described above, when grinding is performed using the abrasive grains, the Ra of the processed surface is large. Therefore, a coating type SiO ₂ thin film is formed in order to smooth the processed surface. Then, a coating type SiO ₂ thin film is formed and smoothed, and then a magnetic layer to be a magnetic core is formed.

By the way, when the coating type SiO ₂ -based thin film and the magnetic layer are formed after the grinding process using the abrasive grains as described above, the grain size of the abrasive grains, the film thickness of the coating type SiO ₂ -based thin film, and the magnetic The relationship with the coercive force Hc of the layer is as shown in FIG. 16, for example.

In FIG. 16, when the magnetic layer is formed on a sufficiently smooth surface, its coercive force Hc is about 35.
[A / m]. When the magnetic core groove is formed with abrasive grains having a grain size of 50 to 60 μm, the coercive force Hc of the magnetic layer is about 70 [A / m] when there is no coating type SiO ₂ -based thin film.
Therefore, in order to improve the coercive force Hc to about 35 [A / m], it is necessary to form a coating type SiO ₂ thin film having a film thickness of about 100 nm. Further, when the magnetic core groove is formed with abrasive grains having a grain size of 20 to 30 μm, the coercive force Hc of the magnetic layer is obtained when there is no coating type SiO ₂ thin film.
Is about 56 [A / m], and this holding force Hc is about 35
To improve to [A / m], the film thickness is about 61 nm
It can be seen that it is necessary to form the coating type SiO ₂ thin film. When the magnetic core groove is formed with abrasive grains having a grain size of 10 to 15 μm, the coercive force Hc of the magnetic layer is about 45 [A / m] when there is no coating type SiO ₂ thin film. It can be seen that in order to improve Hc to about 35 [A / m], it is necessary to form a coating type SiO ₂ -based thin film having a film thickness of about 29 nm.

From the viewpoint of the magnetic characteristics of the magnetic layer, even if the magnetic core groove is formed by using abrasive grains having a grain size of more than 60 μm, the film thickness is 100 nm.
It seems that it is sufficient to form a coating type SiO ₂ thin film that exceeds 100 nm, but coating type Si with a film thickness exceeding 100 nm
When a magnetic head is manufactured by depositing an O ₂ -based thin film, the coating type SiO ₂ -based thin film is exposed on the sliding surface of the medium in large numbers, which is not preferable from the viewpoint of the sliding characteristics of the medium.

Therefore, a suitable range of the film thickness of the coating type SiO ₂ thin film is about 29 to 100 nm. The thickness of such a coating type SiO ₂ -based thin film is, for example, Si
It can be controlled by changing the SiO ₂ concentration of the O ₂ -based film forming coating solution. Specifically, for example, the above-mentioned OC
By adjusting the SiO ₂ concentration of D type-2 in the range of 1.5 to 6.0% and adjusting the rotation speed of the automatic spinner to an appropriate value, coating of a desired film thickness in the range of 29 to 100 nm is performed. A type SiO ₂ thin film can be obtained.

[0061]

As is clear from the above description, in the magnetic head of the present invention, since the magnetic layer, that is, the magnetic core is formed on the smooth coating type SiO ₂ thin film, the magnetic characteristics of the magnetic core are improved. To do. Therefore, a high output can be obtained with the magnetic head of the present invention.

Moreover, in this magnetic head, the roughness of the substrate surface is reduced when the magnetic core groove is processed.
There is no need to slow down the grinding process or to perform the grinding process in several steps. Therefore, in this magnetic head, the processing time of the magnetic core groove is short and the manufacturing efficiency is excellent.

In the method of manufacturing a magnetic head of the present invention, the magnetic layer serving as the magnetic core is formed on the smooth coating type SiO ₂ thin film, so that the magnetic characteristics of the magnetic core are improved. Therefore, according to the method of manufacturing a magnetic head of the present invention, a high output magnetic head can be manufactured.

Moreover, in this magnetic head manufacturing method,
When processing the magnetic core groove, it is not necessary to slow down the grinding process or perform the grinding process several times so that the roughness of the substrate surface is reduced. The time can be shortened and the manufacturing efficiency of the magnetic head can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of a magnetic head to which the present invention is applied.

FIG. 2 is an enlarged perspective view of an essential part showing an enlarged vicinity of a magnetic gap of the magnetic head shown in FIG.

FIG. 3 is a perspective view showing an example of a substrate.

FIG. 4 is a perspective view showing an example of a state in which a magnetic core groove is formed on a substrate.

FIG. 5 is a side view schematically showing a state of a processed surface of a magnetic core groove formed by a grinding wheel.

FIG. 6 is a side view schematically showing a state of a processed surface of a magnetic core groove after forming a coating type SiO ₂ thin film.

FIG. 7: Thickness of the coating type SiO ₂ thin film and S of OCD
and iO ₂ concentration, is a characteristic diagram showing an example of the relationship between the rotation speed of the automatic spinner.

FIG. 8 is a perspective view showing an example of a state in which a magnetic layer is formed on a substrate.

FIG. 9 is a perspective view showing an example of a state where winding grooves and separation grooves are formed on a substrate and a magnetic layer.

FIG. 10 is a perspective view showing an example of a state where glass is filled in the magnetic core groove, the winding groove, and the separation groove.

FIG. 11 is a perspective view showing an example of a state in which a thin film coil is formed.

FIG. 12 is a perspective view showing an example of a state in which a pair of magnetic head half blocks are joined.

FIG. 13 is a characteristic diagram showing an example of the influence of the coating type SiO ₂ thin film on the frequency characteristic of the magnetic permeability of the magnetic layer.

FIG. 14 is a perspective view showing an example of a magnetic head.

FIG. 15 is a characteristic diagram showing a relationship between magnetic permeability and output of a magnetic head.

FIG. 16 is a characteristic diagram showing an example of the relationship between the grain size of the abrasive grains, the film thickness of the coating type SiO ₂ thin film, and the coercive force Hc of the magnetic layer.

[Explanation of symbols]

1 Substrate 1a Magnetic Core Groove 1b Winding Groove 1c Separation Groove 2 Magnetic Layer 2a Coating Type SiO ₂ System Thin Film 3 Glass 4 Thin Film Coil 10a, 10b Magnetic Head Half 11a, 11b Magnetic Head Half Block g Magnetic Gap fg Front Gap bg Back gap

Claims (4)

[Claims] 1. A magnetic head in which a pair of magnetic head halves each having a magnetic core half formed on a substrate made of a non-magnetic material are joined via a magnetic gap, wherein the substrate and the magnetic core half are joined. A magnetic head characterized in that a coating type SiO ₂ -based thin film is arranged between them. 2. The magnetic head according to claim 1, wherein glass is filled on the magnetic core half body and a thin film coil is formed on the glass portion. 3. The magnetic head according to claim 2, wherein at least a portion of the end portion of the magnetic core half body that is in contact with the glass is flattened. 4. A method of manufacturing a magnetic head comprising a pair of magnetic head halves joined together via a magnetic gap, wherein a magnetic core groove for forming a magnetic core forming surface is formed on a substrate made of a non-magnetic material. cutting and, on the substrate where the magnetic core grooves are formed, by applying a SiO ₂ film-forming coating liquid to form a coating-type SiO ₂ based thin film, the coating-type SiO ₂ based thin film is formed substrate A magnetic layer is formed on the magnetic layer, and a winding groove for arranging the thin-film coil and a separation groove for separating the magnetic layer for each magnetic core are formed on the substrate on which the magnetic layer is formed. Glass is filled in the core groove, the winding groove, and the separation groove, and a thin film coil is formed in the glass portion so as to pass through the winding groove to produce a magnetic head half body. Production method.