JPH06195629A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To relatively easily produce a magnetic head having satisfactory magnetic characteristics in a high frequency band, well inhibiting the reaction of melt bonding glass with metallic magnetic thin films and the generation of stress and exerting no harmful influence on magnetic recording characteristics. CONSTITUTION:Thin films based on Fe-Al-Si and contg. N2 and Ru are used as metallic magnetic thin films 14a, 14b having high saturation magnetic flux density formed near a magnetic gap. A two-layered structure consisting of a Cr2O3, film 18a (18b) and an SiO2 film 19a (19b) is imparted to nonmagnetic thin films constituting the magnetic gap and the nonmagnetic thin films are allowed to also act as films preventing the reaction of melt bonding glass 6 with the metallic magnetic thin films 14a, 14b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for performing magnetic recording or reproduction by sliding a magnetic core on a magnetic recording medium, and in particular, the magnetic core is mainly made of ferrite,
The present invention relates to a magnetic head in which a metal magnetic thin film having a high saturation magnetic flux density is arranged in the vicinity of a magnetic gap, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, in devices such as VTRs (video tape recorders) and DATs (digital audio tape recorders), magnetic recording media having high coercive force have been used in order to increase the density of magnetic recording. As a result, as a magnetic head, a magnetic thin film of high saturation magnetic flux density such as sender or amorphous was formed and deposited by a vacuum thin film forming method on the abutting surface facing the magnetic gap of a magnetic core formed mainly of ferrite. Magnetic head, so-called MIG
(Metal in gap) heads have come to be used.

FIG. 9 is a diagram showing an example of the structure of this type of MIG head. 1b is a magnetic core half made of ferrite, 3 is a winding window, 4a and 4b are sendust thin films, 5 is a winding groove, 6 is welding glass, 7 is a magnetic recording medium sliding surface, and g is a magnetic gap. is there.

FIG. 10 is an enlarged view of the main part of the MIG head of FIG. 9, and FIG. 10B shows the vicinity of the magnetic gap of the magnetic recording medium sliding surface 7 of the head of FIG.
FIG. 10A is an enlarged view of a portion A in FIG.

In the figure, 8a and 8b are sendust thin films 4a and 4
b, a protective film for preventing the reaction between the fused glass 6 and 9a, 9
Reference numeral b is a non-magnetic thin film (gap thin film) that serves as a magnetic gap. As shown in the figure, the protective films 8a and 8b are present only at the boundaries between the sendust thin films 4a and 4b and the fused glass 6, and are not present at the magnetic gap portion g.

The reason for this is that the thickness of the protective films 8a and 8b can be determined independently of the width of the magnetic gap (gap length).

[0007]

However, the magnetic head having the above-mentioned structure has the following problems.

First, with the above-mentioned structure, the accuracy of the track width cannot be maintained. This is because when removing the protective films 8a and 8b from the magnetic gap portion g, the lapping process is performed on the magnetic gap forming surface, but the precision of the lapping process is generally poor. The reason for this is that in the case of lapping, generally, a ferrite flat plate is used and processing is performed on a plurality of heads at the same time. This is because the precision is deteriorated and the protective films 8a and 8b are not generally arranged perpendicular to the magnetic gap, so that the variation in the processing amount directly leads to the variation in the track width.

Further, the manufacturing process thereof becomes quite complicated. That is, after the protective films 8a and 8b are formed and deposited, the gap forming surface wrapping process described above is required until the gap thin films 9a and 9b are formed and deposited. This means not only that one lapping step is added, but an additional step such as cleaning of the adherend surface and pretreatment is required because a mechanical step is inserted between two thin film forming steps such as sputtering. Therefore, the number of processes will increase considerably.

On the other hand, in recent years, as the magnetic head is being tracked and the wavelength of magnetic recording is being shortened, in the MIG head as well, in order to improve the magnetic characteristics especially in the high frequency region, the magnetic thin film containing nitrogen is used as the magnetic thin film. It has been proposed to use thin films. For example, by adding N ₂ to the Fe-Al-Si film, it sticks uniaxial induced magnetic anisotropy in the film, but can improve the high frequency characteristics. As a method of including nitrogen in the magnetic thin film, it is common to use a sputtering gas at the time of forming the magnetic thin film as a gas containing argon (Ar) and nitrogen (N), and to form by a reactive sputtering method.

However, when the nitrogen-containing thin film is used, the following problems occur.

First, the stress of a film formed by sputtering or the like is high, and the ferrite substrate is warped. This is generally known because a small amount of N ₂ is put in Ar gas and reactive sputtering is performed. As an example, 100 SCCM (Standard Cubic at 7 mm Torr
Centimeters per Minute) 5 N ₂ gas in Ar gas
%, And when the substrate temperature is 200 ° C., −10 ×
A large compressive stress of 10 ⁹ (dyn / cm ² ) is generated, and the ferrite substrate is warped.

For this reason, the gap dimension is distorted or the magnetic characteristics are deteriorated immediately after the gap formation surfaces are butted, which is a serious problem.

Secondly, the nitrogen-containing magnetic thin film has a strong reaction with the fused glass. Especially, in the case of the Fe-Al-Si-based sendust thin film, the addition of N ₂ causes the reactivity to rapidly increase. , Will cause bubbles.

The bubbles are also generated in a portion which is in sliding contact with the magnetic recording medium, which damages the magnetic recording medium and causes a large amount of magnetic components of the magnetic head to adhere due to the separation of the magnetic components, which causes dropout and the like. It was Due to these causes, the defect rate is generally high in the MIG head using the nitrogen-containing metal magnetic thin film.

In order to prevent this, it is conceivable to form a thick protective film as described above, but Cr ₂ O ₃ and Cr films, which are optimal as protective films, have very good wear resistance to the magnetic recording medium, and are not welded. Since it does not wear as compared with the glass or the SiO ₂ film of the gap material, it becomes a convex portion on the sliding surface of the magnetic recording medium. Therefore, the protrusion may damage the magnetic recording medium.

Under the above background, the present invention has a relatively simple manufacturing process, has good magnetic properties in a high frequency range, and sufficiently suppresses the reaction between the fused glass and the metal magnetic thin film and the generation of stress. An object of the present invention is to provide a magnetic head that does not have any adverse effect on magnetic recording characteristics and a method for manufacturing the magnetic head.

[0018]

[Means for Solving the Problems] Under such a purpose,
In the magnetic head of the present invention, at least one of the pair of magnetic core halves made of ferrite is coated with a metal magnetic thin film, and the pair of magnetic core halves are bonded together by a fused glass via the metal magnetic thin film and the magnetic gap. In the magnetic head thus formed, the non-magnetic thin film forming the magnetic gap extends between the fused glass and the metal magnetic thin film, and also acts as a protective film for protecting the metal magnetic thin film from the fused glass. The main component is Si, and N ₂ and Ru are added.

In the method of manufacturing a magnetic head according to the present invention, a track groove for defining a track width by defining a magnetic gap forming surface is formed on at least one of a pair of magnetic core halves made of ferrite. A metal magnetic thin film containing the inside of the track groove and containing Fe—Al—Si as a main component and added with N ₂ and Ru is adhered to the end surface of the magnetic core half having the groove formed. The non-magnetic thin film, which serves as a protective material for the magnetic gap material and the metal magnetic thin film, is applied to the end surface on which the metal magnetic thin film is applied, over the range including the magnetic gap forming surface and the inside of the track groove. After the deposition of the thin film, a pair of magnetic core halves are bonded by means of fused glass via the metallic magnetic thin film and the non-magnetic thin film.

[0020]

According to the structure of the magnetic head as described above, by appropriately adding Ru and N _2, it is possible to suppress the occurrence of problems due to the addition of Ru and N ₂ and to fully enjoy their respective advantages. Therefore, the manufacturing process is relatively simple and the magnetic characteristics in the high frequency range can be improved, while the reaction between the fused glass and the metal magnetic thin film and the generation of stress can be sufficiently suppressed.

[0021]

1 (B) is a view of a main portion of a magnetic head according to an embodiment of the present invention as seen from a sliding surface of a magnetic recording medium.
(A) is an enlarged view of a main part thereof.

In the figure, 1a and 1b are magnetic core halves made of ferrite, and sendust thin films 14a and 14b containing N ₂ and Ru are deposited on the end faces of these magnetic core halves. Then, Cr as a protective film is formed on the sendust thin films 14a and 14b containing N ₂ and Ru.
₂ O ₃ films 18a and 18b are deposited.

Here, the Cr ₂ O ₃ films 18a and 18b are formed.
Is the sendust thin films 14a and 14b for the welded glass 6.
It acts as a protective film for preventing the reaction of 1) and is also deposited on the gap forming surface of the gap part g as a magnetic gap material. Further, 19a and 19b are SiO ₂ films as magnetic gap materials, and Cr ₂ O ₃ films 18a and 18b
It is deposited on b.

2A to 2F show an embodiment of a method of manufacturing a magnetic head according to the present invention. This example is shown in FIGS.
It is a method of manufacturing the magnetic head shown in FIG.

First, as shown in FIG. 2A, Mn-Zn
As shown in the drawing, the winding groove 44 and the track groove 43 are formed on the ferrite plate 45 by a precision surface grinder.

Next, the composition after the film formation is Fe--Al--Si--Ru--using a facing target type sputtering apparatus.
Reactive sputtering was performed in Ar + N ₂ so as to obtain N, and a sendust thin film 46 containing N ₂ and Ru was deposited as shown in FIG. 2B.

Further, as shown in FIG. 2C, 200 Å of Cr ₂ O ₃ thin film 47 acting as a magnetic gap material and a protective film is deposited on this sendust thin film 46, and then, as shown in FIG.
As shown in (D), a SiO ₂ film serving as a magnetic gap material was deposited on the Cr ₂ O ₃ thin film 47 by 2800Å.

After heat treatment at 450 ° for 2 hours to relax the stress as described later, after forming a film kerf 49 on the sliding surface side of the magnetic recording medium as shown in FIG. 2D. ,
Cut the entire block in two.

In this state, the respective core halves are used as shown in FIG.
Butt as shown in (F), low melting point glass (PbO7
0 wt%, SiO ₂ 20 wt%, B ₂ O ₃ 5 wt%, ZnO 5
wt%) 50 and fused at around 550 ° to be integrated.

After that, the head core chip is obtained by cutting along the broken lines indicated by A and B in FIG. 2 (F). Here, the appearance of one head core chip itself is similar to that shown in FIG. 9 in appearance.

The details of the magnetic head of this embodiment will be described below.

First, in the magnetic head of this embodiment, the sendust thin films 14a and 14b contain N ₂ . As described above, when the nitrogen-containing magnetic thin film is used, the effect of improving the magnetic characteristics in the high frequency range can be obtained, which will be specifically described below.

Table 1 shows the directions of easy magnetization when a plurality of types of magnetic films were formed with a film thickness of 5 μm on a non-magnetic substrate having the same linear expansion coefficient (110 × 10 ⁻⁷ ) as a 0.5 inch diameter ferrite. μ of 6MH _Z for this and 90 ° different hard magnetization directions
e (permeability) is shown. As is clear from Table 1, the improvement of the magnetic permeability in the easy magnetization direction and the hard magnetization direction is achieved by adding N ₂ .

[0034]

[Table 1]

The reason for this is not clear, but N ₂
Inferring from the fact that the Fe-Al-Si film added with is greatly improved in magnetic permeability in the subsequent heat treatment step,
It is considered that the magnetic film with many defects in the N ₂ -containing film immediately after sputtering is recrystallized in a certain direction to increase the orientation and generate uniaxial anisotropy.

FIG. 3 shows the X-ray diffraction results immediately after sputtering the first magnetic thin film, and FIG. 4 shows the X-ray diffraction results after the heat treatment at 550 ° C. for 2 hours. As can be seen from these drawings, the orientation of the (110) plane is extremely strong after the heat treatment.

On the other hand, in the case of the MIG head using the magnetic film of only Fe--Al--Si, when mounted on the VTR and still reproduction is performed on the vapor deposition (ME) tape, the action of the lubricant of the vapor deposition tape is obtained. May cause corrosion and wear, resulting in a reduction in output. Especially when there is a F Motokei acetal bond in the lubricant (-OCF ₂ O-), this problem is remarkable, there is a corrosion reaction as this reason.

However, 2 atm with respect to Fe-Al-Si
% Or more N ₂ is added, no corrosive wear occurs and output reduction does not occur. It is considered that this is because the corrosion resistance is improved by adding N ₂ to Fe-Al-Si. It is also considered that the addition of N ₂ makes the grain boundaries finer.

Incidentally, such an effect is obtained by Fe--Al--Si.
The same can be obtained by adding Ru to Ru, and the corrosion resistance is also improved by adding Ru, and the output does not decrease even when still reproduction is performed on the vapor deposition tape. In the case of Ru, it was confirmed that the output did not decrease when 1 at% or more was added.

The reason for adding Ru is that when a corrosion-resistant metal such as Cv, Ti, or platinum group metal is added to the Fe-based magnetic material, Ru has the highest corrosion resistance effect without decreasing the magnetic flux density. This is because it is a high element. Further, since the existence of F ions used as a lubricant for the ME tape described above is a major factor of the above-mentioned corrosion, Ru that is strong against F ions is used.

On the other hand, as shown in Table 1, the magnetic characteristics of the Fe-Al-Si film containing Ru are almost the same as those of Fe-Al.
It is the same as the -Si film or deteriorates slightly, and uniaxial anisotropy cannot be applied. However, in the case of the Fe-Al-Si-Ru film, there is no difference in the head manufacturing process from the case of using the Fe-Al-Si film in which Ru is not added, and there is no change in the stress of the magnetic film or glass. The reactivity does not become high.

By the way, as described above, Fe-Al-S
Addition of N ₂ to the i film increases the reactivity with the fused glass. The reason for this is that Fe- containing N ₂ is added.
In the case of an Al-Si film, since it reacts with Al having the highest nitrogen affinity in this film, a dense non-conductive film that has reacted with oxygen with a high Al component is not formed on the film surface, It is presumed that a large factor is that the reaction with glass is intense due to an insufficient non _- conductive film such as Fe _1-x O _x having a high reactivity.

FIG. 5 is a diagram showing Auger analysis from the surface of the Fe--Al--Si film toward the depth direction, and FIG. 6 shows Fe.
8 is a diagram showing an Auger analysis from the surface of a -Al-Si-N (8 at%) film in the depth direction. These results are
In each case, a film processed under the same atmosphere and heating conditions as glass welding was used.

In the case of the magnetic head of this embodiment, since the film acting as the magnetic gap is also used as the reaction preventive film between the fused glass and the sendust film, the reaction preventive film cannot be made so thick. It becomes a problem.

Therefore, in the magnetic head of the present embodiment, as described above as one solution to this problem, Fe is used.
-Al-Si film with respect to nitrogen (N) and ruthenium (R
By adding u) in an appropriate amount so as not to cause a defect due to the addition of each of them, the reaction with the fused glass which occurs with the addition of nitrogen is suppressed.

Regarding the reactivity with this fused glass, N
The reactivity can be suppressed by setting the addition amount of N to be 6 at% or less, and the smaller the addition amount of N is, the better. In particular, R
When u is added in an amount of 0.05 at% or more, the reactivity becomes lower. It is considered that this is because the effect is further improved by adding Ru, which does not easily react with glass. It goes without saying that the greater the amount of Ru added, the lower the reactivity.

In the magnetic head of this embodiment, the structure of the reaction preventing film and the film acting as the magnetic gap material is C
It has a double structure of an r ₂ O ₃ film and a SiO ₂ film. The Cr ₂ O ₃ film is very effective from the viewpoint of preventing the reaction with the fused glass, but if it has a thickness of 1000 Å or more, the magnetic gap rises after running on the magnetic recording medium, spacing loss, binder adhesion, etc. Will be caused.

The thickness of this Cr ₂ O ₃ film is 100Å
If the amount is less than the above, the film quality is poor and the above-mentioned reaction preventing film cannot be fulfilled. Therefore, in the magnetic head of this embodiment, the Cr ₂ O ₃ film is 100 to 1000 Å.
And the remaining portion is a SiO ₂ film. The SiO ₂ film has the same wear characteristics as fused glass and ferrite.

In this example, the amount of nitrogen added was in the range of 1 to 8 at% in consideration of the reactivity with glass. Even in this range, uniaxial anisotropy can be generated without any problem, and high frequency characteristics can be improved. Particularly, the optimum value of the added amount is 4 at%. Figure 7 is a 2at% the amount of Ru in the Fe-Al-Si-Ru- N film, shows the permeability of 6MH _Z in direction of easy magnetization and hard magnetization direction in the case of changing the addition amount xat% of N ing. This has been confirmed by the examination of X-ray diffraction, and when the amount of N added is 4 at%, the degree of (110) orientation is the highest, and the peak value is also high. As is clear from FIG. 7, the amount of N added is 3
It can be seen that the high frequency characteristics are significantly improved when the content is up to 6 at%.

Next, this time by fixing the amount of N to 4at%, Figure 8 shows the permeability of 6MH _Z in direction of easy magnetization and hard magnetization direction in the case of changing the addition amount yat% of Ru . As is clear from the figure, when the amount of Ru added is increased, 4 at
The magnetic characteristics hardly change up to about%. 2at for details
%, The magnetic property is the best, and if it exceeds 5 at%, the magnetic property deteriorates, and it is understood that this 5 at% is the boundary value.

On the other hand, in the Fe-Al-Si-Ru-N film, when the amount of Ru added is 2 at% and the amount of N added is 4 at%, the stress during film formation is -4 × 10 ^-9 (dyn). / m ² ), which is much smaller than that of the Fe-Al-Si film, and the stress can be made almost zero by performing post-annealing at 450 ° for 2 hours. This is Ru at 2 at
%, The coefficient of linear expansion decreased by 20 × 10 ⁻⁷ / deg compared to the case of not adding Ru, and it was possible to bring the coefficient of linear expansion close to that of the underlying ferrite. This effect is further enhanced by further adding Ru.

For reference, Fe-Al-Si-N is used.
The linear expansion coefficient of the (4 at%) film is 170 × 10 ⁻⁷ / deg, and Fe—Al—Si—Ru (2 at%)-N (4 at%).
The linear expansion coefficient of the film is 120 × 10 ⁻⁷ / deg.

Further, even when a still image is reproduced from the above vapor deposition tape, Fe--Al--Si--Ru (yat
%)-N (xat%) film, x is 1
If (at%) or more and Y is 0.05 (at%) or more,
Corrosion and wear due to the reaction of the vapor deposition tape with the lubricant do not occur. Preferably x is 1 (at%) or more and Y is also 1 (at%)
The above is desirable. X for this corrosive wear
The higher both y and y, the less likely it is to occur.

In the magnetic head of the invention of the present application, in view of various factors as described above, the component of the magnetic film is Fe--
The Al-Si as the main component, was assumed to N _2, Ru is added. Furthermore, at least N is 1 at% to 8 at
%, And Ru at 0.05 at% to 5 at%, a very large effect can be obtained. Ideally, N is 3 at% to 6 a.
t% and Ru are 1 at% to 4 at%.

[0055]

As described above, according to the magnetic head of the present invention, in the magnetic head in which the magnetic core is mainly made of ferrite and the metal magnetic thin film having a high saturation magnetic flux density is arranged in the vicinity of the magnetic gap, The non-magnetic thin film forming the structure extends between the fused glass and the metal magnetic thin film, and also acts as a protective film for protecting the metal magnetic thin film from the fused glass, thereby simplifying the manufacturing process and reducing the track width. of while high accuracy is can be achieved, the thin magnetic metal film mainly composed of Fe-Al-Si, by shall N _2, Ru is added, the high-frequency characteristic improvement or welding glass and the metallic magnetic film The reaction and the generation of stress can be suppressed,
It is possible to obtain an ideal magnetic head in which uneven wear and corrosion are less likely to occur.

According to the method of manufacturing the magnetic head of the present invention, the magnetic head as described above can be manufactured by a relatively simple process.

[Brief description of drawings]

FIG. 1 is a diagram of a magnetic head according to an embodiment of the present invention seen from a sliding surface of a magnetic recording medium, and an enlarged view of a main part thereof.

FIG. 2 is a diagram showing a manufacturing process of the magnetic head shown in FIG.

FIG. 3 is a diagram showing an X-ray diffraction result immediately after sputtering an Fe—Al—Si—N film.

FIG. 4 is a diagram showing an X-ray diffraction result after heat treatment of a Fe—Al—Si—N film at 550 ° C. for 2 hours.

FIG. 5 is a diagram showing Auger analysis from the surface of the Fe—Al—Si film in the depth direction.

FIG. 6 is a diagram showing an Auger analysis from the surface of the Fe—Al—Si—N (8 at%) film toward the depth direction.

FIG. 7 N of Fe-Al-Si-Ru (2at%)-N film
FIG. 6 is a diagram showing changes in magnetic characteristics when the addition amount of is changed.

FIG. 8: R of Fe-Al-Si-Ru-N (4 at%) film
It is a figure which shows the change of a magnetic characteristic when changing the addition amount of u.

FIG. 9 is a perspective view showing a configuration of a conventional magnetic head.

FIG. 10 is a view of the magnetic head of FIG. 9 viewed from a sliding surface of a magnetic recording medium, and an enlarged view of a main part thereof.

[Explanation of symbols]

1a, 1b Magnetic core half body composed of ferrite core 6 Welded glass 14a, 14b Sendust thin film containing nitrogen and ruthenium 18a, 18b Cr ₂ O ₃ film 19a, 19b SiO ₂ film 12a, 12b Welded glass 45 Ferrite plate 46 Nitrogen and Sendust thin film containing ruthenium 47 Cr ₂ O ₃ film 48 SiO ₂ film 50 Low melting point glass

Claims (6)

[Claims] 1. A metal magnetic thin film is deposited on at least one of a pair of magnetic core halves made of ferrite, and the pair of magnetic core halves are bonded by means of fused glass via the metal magnetic thin film and a magnetic gap. In the magnetic head, the non-magnetic thin film forming the magnetic gap extends between the fused glass and the metal magnetic thin film, and also acts as a protective film for protecting the metal magnetic thin film from the fused glass. The thin film contains Fe-Al-Si as a main component, and N
_2. A magnetic head characterized by being added with Ru. 2. The non-magnetic thin film comprises a Cr ₂ O ₃ film and Si.
The magnetic head according to claim 1, comprising two layers of an O ₂ film. 3. The magnetic head according to claim 2, wherein the Cr ₂ O ₃ film is arranged on the metal magnetic thin film side and has a film thickness of 100Å to 1000Å. 4. The metal magnetic thin film contains Fe—Al—Si as a main component, N is 1 at% to 8 at%, and Ru is 0.05.
The magnetic head according to claim 1, wherein the magnetic head is added at at% to 5 at%. 5. The metal magnetic thin film contains Fe—Al—Si as a main component, N is 3 at% to 6 at%, and Ru is 1 at%.
5. The magnetic head according to claim 4, wherein the magnetic head is added at 4 at%. 6. A step of forming a track groove for defining a track width by defining a magnetic gap forming surface on at least one of a pair of magnetic core halves made of ferrite, and the magnetic core having the track groove formed therein. Depositing a metal magnetic thin film containing Fe—Al—Si as a main component and containing N ₂ and Ru added to the end face of the half body, and the metal of the magnetic core half body A step of applying a non-magnetic thin film, which serves as a protective material for the magnetic gap material and the metal magnetic thin film, to the end surface on which the magnetic thin film is applied, over a range including the magnetic gap forming surface and the track groove; A method of manufacturing a magnetic head, characterized in that, after the nonmagnetic thin film is deposited, the pair of magnetic core halves are bonded by means of fused glass via the metal magnetic thin film and the nonmagnetic thin film.