JPH04370509A - Magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To provide the magnetic head which is used for VTRs, DATs, FDDs, etc., solves the problem of the embrittling of glass by the reaction of glass and soft magnetic alloy thin films at the time of forming a gap and the generation of peeling on the gap surfaces and has excellent reliability without having the reaction of the glass and the soft magnetic alloy thin films and the process for production of this head. CONSTITUTION:Metal oxide films 3, nonmagnetic metallic films 4 and glass films 5 are successively formed in the gap part of the magnetic head and the boundary part between the soft magnetic alloy thin films 2 and the glass 7 regulating the track width.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to VTR, DAT, FD
The present invention relates to a magnetic head used in D, etc., and a manufacturing method thereof.

0002

2. Description of the Related Art In recent years, as trends in magnetic recording technology require characteristics in a high frequency range for video heads and the like, there is a demand for magnetic heads and recording media that can adequately handle submicron recording wavelengths. Under these current circumstances, magnetic heads use recording media with high coercive force Hc (for example, metal, B
a-Fe tape), a soft magnetic alloy thin film (e.g. sendust, amorphous material, etc.) with a higher saturation magnetic flux density Bs than non-metallic magnetic materials such as ferrite is placed near the ferrite gap. Magnetic heads with a similar structure were developed, some of which were put into practical use, and 8mm and DAT
It is installed for.

A conventional method of manufacturing a magnetic head will be described below with reference to the drawings. FIG. 4 is a process diagram showing a conventional method for manufacturing a magnetic head in which a soft magnetic alloy thin film of several micrometers is disposed near the magnetic gap. FIG. A winding groove 14 is machined on at least one side, and the gap joint surface is polished to a mirror surface.

FIG. 2B shows a pair of core halves 13 in which track width regulating grooves 15 are formed on the gap joining surfaces.

Figure (c) shows a soft magnetic alloy thin film 16 on the gap junction surface, and a SiO2 film and a glass film (
A pair of core halves 13 formed thereon (omitted in the figure) are shown.

FIG. 1D shows a magnetic core 18 assembled by molding a glass 17 into the track width regulating groove 15 with the gap joint surfaces butted against each other. Cut it along the line (e) in the same figure (e
) is obtained.

[0007]Although not shown in the figure, the cut head chip is then bonded to a metal base, etc., and the front side of the head chip, which slides against a medium such as a magnetic tape, is polished to a curvature appropriate to the system to be mounted. Winding is performed to complete the magnetic head.

[0008]

However, in the conventional magnetic head using the soft magnetic alloy thin film 16 on the gap surface, the glass 17 and the soft magnetic alloy thin film 1 are separated when forming the gap.
As a result of the reaction in step 6, the glass 17 becomes brittle, and peeling occurs on the gap surface due to processing loads such as chip cutting and tape sliding surface polishing, and the gap depth (GapDep) in the reaction layer increases.
There was a problem that th) could not be measured accurately. The present invention solves these conventional problems and aims to provide a highly reliable magnetic head and a method for manufacturing the same.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention forms a soft magnetic alloy thin film, and then sequentially forms a metal oxide film, a non-magnetic metal film, and a glass film. This prevents the reaction with

The manufacturing method includes a step of processing a winding groove and polishing the gap abutting surface to a mirror finish, a step of forming a track width regulating groove, a step of forming a soft magnetic alloy thin film, and a step of forming a thin film of a soft magnetic alloy, and using metal as the gap material. It consists of a step of sequentially forming an oxide film, a nonmagnetic metal film, and a glass film, and a step of molding and bonding glass into the track width regulating groove with the gap surfaces of the pair of core halves abutting each other.

[0011]

[Operation] Therefore, according to the present invention, by using a material that is stable at high temperatures as the gap member, the reaction between the glass and the soft magnetic alloy thin film can be suppressed, and a magnetic head with excellent reliability can be obtained. As for the manufacturing method, it can be manufactured by simply increasing the number of steps for forming the film in the gap portion, and is excellent in mass production.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1(a) shows the configuration of a magnetic head in an embodiment of the present invention.
FIG. 2B is an enlarged view of the vicinity of the gap of the magnetic head.

As shown in the figure, if the core material is made of ferrite or the like, Fe-Al-Si such as Sendust is applied to the gap surface of the core material 1.
Soft magnetic alloy thin film 2 such as CoaMb or FeaMb having a structure in which the composition of nitrogen is modulated in the thickness direction
is formed, and on top of the soft magnetic alloy thin film (hereinafter referred to as Sendust film) 2 made of Sendust etc., a metal oxide film 3 made of SiO2 film etc. is deposited as a gap material with a thickness of 1000 Å , Cr, W, Pt, Ir, Nb,
A nonmagnetic metal film (Cr is used in this embodiment) 4 made of Ta, Ti, Zr, or Hf is formed to a thickness of 250 Å, and a glass film 5 is formed to a thickness of 150 Å.

The core material 1 is provided with a winding window 6, and the pair of core materials 1 are joined together by a glass 7 for joining. If the total thickness of the SiO2 film 3, Cr film 4, and glass film 5 exceeds 3000 Å, the recording and reproducing characteristics in the high frequency region will deteriorate due to gap length loss.

As described above, by disposing the Cr film 4 and the glass film 5 on the SiO2 film 3 as gap materials, a highly reliable magnetic head without reaction between the sendust film 2 and the glass 7 can be obtained.

In the soft magnetic alloy thin film 2 represented by CoaMb, M is Nb, Ta, Zr, Hf, Ti.
, No, and W, and a and b expressed in atomic ratio are each 0.80≦a≦
0.95, 0.05≦b≦0.20 and a+b=1.0, or a soft magnetic alloy thin film 2 represented by FeaMb
In the case of , M is Nb, Ta, Zr, Hf, Ti, Mo,
Consists of one or more elements selected from Cr, W, Mn, Re, Ru, and a and b are each 0.70≦a≦0
．． 95, 0.05≦b≦0.30 and a+b=1.0 can be used, and similar effects can be obtained.

Next, a method of manufacturing a magnetic head according to an embodiment of the present invention will be explained with reference to the drawings. FIG. 2 is a process diagram showing a method for manufacturing a magnetic head according to an embodiment of the present invention. FIG. After that, the gap abutting surface 9 is processed into a mirror surface.

FIG. 2B shows a state in which track width regulating grooves 10 have been formed. FIG. 3(c) is a view of the track section from the running surface side of a medium such as a magnetic tape. After forming a sendust film 2 of about 4 μm on the gap abutting surface 9, an SiO2 film 3 as a gap material, A Cr film 4 and a glass film 5 are formed.

FIG. 2(d) shows the core block 1 gap-bonded at a temperature at which good characteristics of the sendust film 2 can be obtained.
1, and glass 7 is used to bond the core block 11.

FIG. 3E shows a head chip 12 obtained by cutting the core block 11 shown in FIG.

FIG. 3 shows a sample in which a 4 μm thick Fe-Al-Si alloy film such as a sendust film 2 and a 0.1 μm thick SiO2 film 3 were formed on a ferrite substrate, and then a predetermined amount of Cr film 4 was formed on the ferrite substrate. The reaction layer between the glass 7 and the sendust film 2 that is formed when the glass 7 is melted is measured, and the effect of suppressing the reaction is seen when the amount of Cr film 4 deposited is about 50 Å, and when it reaches 250 Å, the reaction stops. I could barely observe it.

Similar effects were obtained with other metal oxide films 3 or other non-magnetic metal films 4, although differences were observed in how the reaction was reduced. The SiO2 film 3 is necessary to indicate the boundary between the soft magnetic alloy thin film 2 and the Cr film 4 in order to measure the gap length with an optical microscope, and its film thickness and measurement conditions are shown in (Table 1).

[0023]

[Table 1]

As shown in Table 1, when the thickness of the SiO2 film 3 was less than about 300 Å, it became difficult to measure the gap length.

Further, in a magnetic head in which the glass film 5 for adhesion is not provided on the Cr film 4 or the film thickness is less than 100 Å, there is a problem in reliability due to the accumulation of magnetic powder on the gap abutting surface 9 during tape running. Ta. Therefore, considering the above data, the SiO2 film 3 has a thickness of at least 300 Å.
As described above, it is necessary to form the Cr film 4 for reaction prevention at least 50 Å, and the glass film 5 for bonding the gap portion at least 100 Å.

As described above, according to the above embodiment, the sendust film 2 provided near the gap abutting surface 9
Since the SiO2 film 3, the Cr film 4, and the glass film 5 are sequentially formed on the upper surface, the glass 7 does not peel off from the gap surface, and high reliability can be obtained.

[0027]

Effects of the Invention As is clear from the above embodiments, the present invention forms a metal oxide film, a non-magnetic metal film that is stable at high temperatures, and a glass film in the gap portion, so that a soft magnetic alloy thin film and a glass film are formed in the gap portion. This has the effect that the reaction of the glass is suppressed and a highly reliable magnetic head can be manufactured with fewer steps.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view of a magnetic head according to an embodiment of the present invention; FIG. 1(b) is an enlarged plan view of the main part of the magnetic head near the gap;

[Fig. 2] (a) is an external shape diagram of a core material used in a method for manufacturing a magnetic head according to an embodiment of the present invention; (b) is an external shape diagram of a core material used in the method for manufacturing a magnetic head according to an embodiment of the present invention after performing a step of forming track width regulating grooves on the core material in the same embodiment; (c) is an external view of the core material of the same example. (d) is an external view of the track portion of the magnetic head after the thin film forming process in the same example. (e) is an external view of the core block after the core bonding process in the same example. External view of a magnetic head obtained from a core block by the chip cutting process in Example

FIG. 3 is a characteristic diagram showing the relationship between the thickness of the Cr film and the reaction layer of glass and sendust film in one embodiment of the present invention.

FIG. 4(a) is an external appearance diagram of a core material used in a conventional magnetic head manufacturing method; FIG. Figure (c) is an external view of the core after the thin film forming process in the conventional example. (d) is an external view of the core block after the core bonding process in the conventional example. (e) is the core block after the chip cutting process in the conventional example. External view of the magnetic head obtained from

[Explanation of symbols]

1 Core material 2 Sendust film (soft magnetic alloy thin film) 3 SiO2
Film (metal oxide film) 4 Cr film (non-magnetic metal film) 5 Glass film 7 Glass

Claims (7)

[Claims] 1. A magnetic head having a core material mainly made of ferromagnetic oxide and having a soft magnetic alloy thin film disposed in the gap, at the gap portion and at the boundary between the soft magnetic alloy thin film and glass regulating the track width. A magnetic head characterized by sequentially forming a metal oxide film, a nonmagnetic metal film, and a glass film. 2. The metal oxide film, the nonmagnetic metal film, and the glass film have a thickness of 300 Å or more, 50 Å or more, and 100 Å or more, respectively, and a total thickness of 3000 Å or less. magnetic head. 3. Cr, W, Pt, Ir as a non-magnetic metal film
, Nb, Ta, Ti, Zr, or Hf. 4. Fe such as Sendust as a soft magnetic alloy thin film
-Claim 1 characterized in that an Al-Si alloy is used.
The magnetic head described. 5. The magnetic head according to claim 1, wherein the soft magnetic alloy thin film is represented by CoaMb and has a structure in which the nitrogen composition is modulated in the thickness direction. Here, M consists of one or more elements selected from Nb, Ta, Zr, Hf, Ti, Mo, and W, and a and b represent the atomic ratio,
The following formula shall be satisfied. 0.80≦a≦0.95 0.05≦b≦0.20 a+b=1.0 6. The magnetic head according to claim 1, wherein the soft magnetic alloy thin film is represented by FeaMb and has a structure in which the nitrogen composition is modulated in the thickness direction. Here, M is Nb, Ta, Zr, Hf, Ti, Mo, Cr, W, M
It is made of one or more elements selected from n, Re, and Ru, where a and b represent an atomic ratio, and satisfy the following formula. 0.70≦a≦0.95 0.05≦b≦0.30 a+b=1.0 7. In a magnetic head whose main core material is a ferromagnetic oxide, a step of mirror-polishing the gap-forming surfaces of the core halves that form a pair of magnetic heads, and regulating the winding groove and track width. A step of forming a groove, a step of forming a soft magnetic alloy thin film, and a step of sequentially forming a metal oxide film, a nonmagnetic metal film, and a glass film as gap materials so that the total film thickness becomes a predetermined gap length. A method of manufacturing a magnetic head, comprising the steps of: molding and bonding glass into a track width regulating groove with the gap surfaces of a pair of core halves abutted against each other;