JPS6362805B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method of manufacturing a magnetic head used in a magnetic recording and reproducing device. (Structure of a conventional example and its problems) Conventionally, when manufacturing a narrow track magnetic head for a VTR or the like, a method as shown in FIG. 1 has been used. In FIG. 1A, numeral 1 denotes a head core made of sendust or an amorphous alloy, which is sandwiched with a substrate 2 made of glass or ceramic. Reference numeral 3 represents a gap surface, on which a non-magnetic material such as SiO ₂ is deposited to provide a desired gap length using a sputtering method or the like. 4 is a rod-shaped low melting point glass, which is heated while applying pressure from both sides of the head core to soften it and form the joint 4'.
A magnetic gap portion is formed to obtain a magnetic head as shown in FIG. The problem with this manufacturing method is that both cores are mechanically pressed and bonded together to form a magnetic gap.
If the flatness of the gap surface 3 is even slightly poor, not only will the desired gap length not be obtained, but the adhesive strength will also decrease, causing cracks to occur in the glass joint 4'. In addition, the actual VTR
Since the magnetic head gap portion has an azimuth angle, the gap surface 3 has an inclination angle of approximately 10°.
When pressed mechanically from the side, core misalignment occurs, which has the disadvantage that left and right track misalignment tends to occur. (Objective of the Invention) It is an object of the present invention to provide a method for manufacturing a magnetic head that eliminates the drawbacks of the conventional method and allows the magnetic gap portion and the head core portion to be formed simultaneously without using much of an adhesion process. It is. (Structure of the Invention) The magnetic head manufacturing method of the present invention involves simultaneously irradiating a laser beam when creating an amorphous alloy that will become the core material of the magnetic head by a sputtering method or a vapor deposition method. An alloy film having a nonmagnetic oxide layer inside an amorphous alloy is created by selectively oxidizing and depositing the amorphous alloy, and this oxide layer is used as a magnetic gap to manufacture a magnetic head. (Embodiment of the Invention) An embodiment of the present invention will be described with reference to FIGS. 2 to 4. FIG. 2 shows a method of manufacturing a magnetic head core using a laser as a sputtering device. Figure a
, 11 is a cathode, 12 is a target for forming an amorphous alloy, 13 is a water-cooled substrate holder, 14 is a substrate, 15 is a bell jar, 16 is a laser light source, 17 is a condenser and a laser light intake window, and 18 is a Showing laser light. As shown in FIG. 2B, the substrate 14 is provided with a winding window 14' in advance and is fixed on the holder 13 so that the laser beam 18 hits a desired position. The inside of the bell gear 15 is evacuated, Ar gas is introduced, and the target 12 is sputtered to form an amorphous alloy film on the substrate 14. In the present invention, at this time, the laser 1
8 was simultaneously irradiated to form a film on the substrate while selectively oxidizing a part of the amorphous alloy film, so that the cross section of the obtained film had a structure as shown in Figure 3a. do. In the figure, 21 is a substrate, 22 is an amorphous alloy film, 23 is an oxide layer produced by laser beam irradiation, and 24 is a laser beam. In Figures 2 and 3, the laser beam is tilted at an angle θ with respect to the substrate surface direction, but this is called the azimuth angle in the case of a VTR head, and it is necessary to tilt the magnetic gap by approximately 10°. This is because there is. FIG. 3b shows a typical AC B/H curve at 60 Hz in the portions indicated by 22 and 23 in FIG. 3a. If the amorphous alloy film 22 in the figure a has the following composition, it will exhibit excellent soft magnetic properties as shown by 32 in the figure b, and when oxidized, it will become non-magnetic, and its BH curve exhibits the characteristics shown at 33 in Figure b, and plays the role of the gap portion of the magnetic head. Note that an amorphous alloy film suitable for such a purpose has the following composition. Co _a M _a ′T _b X _c R _d ...(1) However, M, T, X, and R are each one or more elements selected from the following element groups, and M: Fe, Ni , Mn, Cr, Mo, W T: Ti, Zr, Hf, Nb, Ta X: Si, B, CR R: Y and rare earth elements, a, a', b, c, d are atoms of each element 70≦a≦95 0≦a′≦10 0≦b≦20 0≦c≦30 0≦d≦5 …(2) and a+a′+b+c+d=100 5≦b+c≦30 ...(3). The reason why Co is included as a main component in formulas (1) and (2) is that in addition to obtaining a zero-magnetostrictive amorphous alloy, unlike Fe, the residual content in the bell jar can be removed by laser light irradiation.
This is because it easily becomes nonmagnetic after reacting with O ₂ gas and oxidizing. Additionally, Ni has low saturation magnetization and is not suitable as a head core material. Even if Co is the main component, if its atomic percent is 95% or more, it becomes difficult to make it amorphous, and if it is less than 70%, the saturation magnetization of the alloy film is too small for magnetic head cores, so 70≦a≦95 is desirable. . In formula (1), M is a typical additive used to adjust magnetostriction, but if it is included in too large a quantity, the magnetostriction will shift significantly positive in the case of Fe and Mn, and in the case of Ni, Cr, Mo. , W deteriorates the saturation magnetization, so the amount added is 10 atomic%.
It is desirable not to exceed. In formula (1), R represents Y and a rare earth element, which is effective in increasing the crystallization temperature, but if the amount added exceeds 5 at%, the soft magnetic properties will deteriorate, so it is desirable that d≦5. . However, since M and R are not essential elements for forming an amorphous state, they do not necessarily need to be included as constituent elements. In the formula (1), T and X are elements capable of forming an amorphous state, and it is necessary to contain at least 5 atomic % of either or both of them. In addition, in the case of T, if it exceeds 20% in atomic percent, and in the case of X, it exceeds 30%.
%, the saturation magnetization will decrease significantly and the material will become unsuitable as a magnetic head core material, so b≦20, c
It is desirable that it be ≦30. A magnetic head obtained in the form shown in FIG. 3a can be easily manufactured by adding the steps shown in FIG. 4. 41 in the figure
4 is an upper plate, 42 is an amorphous alloy film, 43 is a substrate, 4
1' and 43' are winding holes, 44 is an oxide layer serving as a magnetic gap, and 45 is a winding wire. The upper plate 41 and the alloy film surface 42 are bonded using resin or low melting point glass. The case where a sputtering device is used has been described above, but the same applies to the case where a vapor deposition device is used. Examples to which specific materials, dimensions, etc. are applied are shown below. (1) Example 1 Ar gas pressure of 4 ×
30 μm thick amorphous alloy film at 10 ^-2 Torr
Co ₈₀ Sm ₂ Mn ₆ Si ₁₀ B ₁₂ is formed by a sputtering method. At this time, the wavelength is 0.8 μm and the output is 5 m.
Using a W semiconductor laser, an amorphous alloy film is formed while continuously irradiating the magnetic gap position on the substrate as shown in FIG. The beam diameter of the laser beam is focused to 0.8 μm, and the amorphous alloy film is formed by reciprocating the laser device about 100 μm in the depth direction of the magnetic gap. Only the areas exposed to light oxidize black, and the width of this layer is 1.0 μm. The thus obtained product is joined and wound as shown in FIG. 4 to complete the magnetic head. This effective magnetic gap was measured to be 1.0 μm. (2) Example 2 A 30 μm thick amorphous alloy film was deposited on a non-magnetic ferrite substrate with winding holes attached to a water-cooled substrate holder under an Ar gas pressure of 4×10 ^-2 Torr.
Co ₈₀ Mo ₅ Ti ₁₅ is formed by sputtering method,
At this time, a semiconductor laser with a wavelength of 0.8 μm and an output of 10 mW was used to create a beam with a beam width of 0.8 μm and a length of 10 μm.
While irradiating the laser beam, an amorphous alloy film is formed in the same manner as in Example 1 so that the beam width is aligned with the gap length direction and the beam length direction is aligned with the gap depth direction. In this case, if the laser beam is continuously irradiated, the width of the oxide layer will become blurred and widened, so the irradiation pulse width is 1/100 seconds, the number of pulses is
Irradiation is performed at 10/sec. The width of the resulting oxide layer, that is, the magnetic gap length, is optically 0.6 μm.
It is. Using the obtained amorphous alloy film, a magnetic head was completed in the same manner as in Example 1, and the effective magnetic gap was measured to be 0.7 μm. (3) Example 3 In the same manner as in Example 2, an amorphous alloy film of Co ₈₆ Mn ₂ Nb ₉ Zr ₃ was formed by sputtering on a glass substrate having a winding hole, and at the same time a wavelength of 0.4μ was applied.
Example 2 above using a helium cadmium laser with an output of 100 mW, a beam diameter of 0.4 μm, an irradiation pulse width of 1/200 seconds, and a pulse number of 10/second.
An amorphous alloy film with a thickness of 30 μm is formed by the same operation as above. The width of the oxide layer of the obtained film is optically
It is 0.3 μm. Using this film, a magnetic head is completed in the same manner as in Example 1 above. The effective magnetic gap length was measured to be 0.3 μm. The table shows the results of a comparative test between 50 magnetic heads obtained in Example 3 and 50 magnetic heads manufactured by the conventional manufacturing method shown in FIG.

【table】

[Table] The glass plate and amorphous alloy used in the conventional example are as follows:
The same material as in Example 3 was used, and the gap material was
Two layers of SiO ₂ and low melting point glass were used. (Effects of the Invention) The magnetic head manufacturing method of the present invention is not only an effective method for manufacturing a magnetic head having an extremely high-precision magnetic gap, but also a method for manufacturing the magnetic gap at the same time as making the core part. In addition to simplifying the manufacturing process and lowering the cost, there are various other effects such as the ability to easily create a magnetic gap with an azimuth angle.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional method for manufacturing a magnetic head, FIG. 2 is an explanatory diagram of a method for manufacturing a core portion of a magnetic head according to an embodiment of the present invention, and FIG. 3 is a sectional view of the same and a B/H characteristic diagram. , and FIG. 4 are explanatory diagrams of the manufacturing process of the same magnetic head. DESCRIPTION OF SYMBOLS 1... Head core part, 2... Substrate, 3... Gap surface, 4... Low melting point glass, 11... Cathode, 12...
Target, 13...Substrate holder, 14...Substrate,
14'...Window window, 15...Belgear, 16...Laser light source, 17...Intake window, 18...Laser light,
21...Substrate, 22...Amorphous alloy film, 23...Oxide layer, 24...Laser light, 32, 33...BH curve, 41...Top plate, 42...Amorphous alloy film, 43...Substrate, 41 ', 43'... Winding hole, 44... Oxide layer,
45...Wound wire.

Claims (1)

[Claims] 1. When forming a soft magnetic amorphous alloy film on a substrate to form the core of a magnetic head by sputtering or vapor deposition, a laser beam is simultaneously applied to a predetermined position where a magnetic gap is formed. 1. A method for manufacturing a magnetic head, which comprises irradiating the soft magnetic amorphous alloy film to oxidize the soft magnetic amorphous alloy film at that location, thereby simultaneously forming a core portion and a gap portion of the magnetic head. 2. The method of manufacturing a magnetic head according to claim 1, wherein the amorphous alloy film has a composition represented by the following formula. Co _a M _a ′T _b X _{c R} dHowever, M, T, , Mo, W T: Ti, Zr, Hf, Nb, Ta ≦a≦95 0≦a′≦10 0≦b≦20 0≦c≦30 0≦d≦5, and a+a′+b+c+d=100 5≦b+c≦30.