JPS6120212A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To inexpensively and efficiently manufacture magnetic heads which performs writing and reproducing with a high storage density, by forming the main body of the thin film magnetic head by laminating two or more thin film magnetic materials and cutting off a part of the gap forming end section of the thin film magnetic material of the outer layer, and then, filling the cut off section with a nonmagnetic material. CONSTITUTION:A lower magnetic material 2, insulating body 4, and upper magnetic material 6 are successively laminated on a base board 1 and each of the upper and lower magnetic layers is separated into two layers 2a and 2b and 6a and 6b with insulating bodies 10 and 11 respectively being put between them 2a and 2b and 6a and 6b. Then a closed magnetic path is formed by magnetically connecting the rear ends of the thin film magnetic head and a laminated cross section 7 is formed by machining the front end section of head. Then partial end parts of the outer layers 2b and 6b at the front end section of the magnetic head main body are cut off after performing etching process on the laminated cross section 7 of the main body and a recessed section is formed. After filling the recessed section with a nonmagnetic material, the excessive nonmagnetic material is removed and, at the same time, the head front end section is machined so that a prescribed gap depth can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of manufacturing a thin film magnetic head, and more particularly to a method of manufacturing a thin film magnetic head for both writing and reading functions for a high recording density system.

[Background of the invention]

Thin-film magnetic heads use a thin magnetic thin film to sharply concentrate the magnetic field at the tip of the head, and are therefore characterized in that they can achieve high magnetic recording density.

FIG. 1 is an enlarged sectional view showing an example of a conventional thin film magnetic head, in which a lower magnetic body 2 is placed on a substrate l, and a gap 3 is provided at one end.
An insulator 4, a conductor winding 5, and an upper magnetic body 6 are sequentially deposited to form an insulator 4, a conductor winding 5, and an upper magnetic body 6, and the tip 7 facing the magnetic medium is cut off parallel to the running direction of the magnetic medium. Note that the rear ends of the lower magnetic body 2 and the upper magnetic body 6 are magnetically connected to form a closed magnetic path except for the notched portion of the gap 3.

In the thin film magnetic head constructed as described above, the thickness of the tips of the upper and lower magnetic bodies is called the ball length (P), and the distance between the tips of the upper and lower magnetic bodies is called the gap length (G, ).

In order to obtain a high recording density thin film magnetic head with a small write current, small pattern shift, and good read voltage recording density characteristics, the relationship between the above pole length P and gap length G and the minimum recording wavelength λ is as follows. , JP-A-52-92709 discloses that it is necessary to satisfy the formula 2P+G, <λ. For example, if the magnetization density of the magnetic medium is 400@/w, the recording wavelength is 5/jm
Then, PX'd, which satisfies 2P0G, <λ (=5 μm),
The value of is, for example, P=2 (μm) and G=1 (μm) or less, which is an extremely small value.

During reproduction of high-density recording, etc., the shift in the peak of the reproduction wavelength that occurs when the interval between successive magnetic flux reversals becomes small is called peak shift, and known techniques for reducing this peak shift include , Numerical
Analysis of WriBng andRJe
adding witn multiturn film
Heads.

IEEE, 'I'transaction on M
agnetics, VoL.

MAG-16, A5, September
198Q, it is disclosed that it is important to make the pole length P equal to or less than 1/4 of the recording wavelength λ.

By the way, as a means for obtaining this small pole length P, the thickness t of the lower magnetic body 2 and the upper magnetic body 6 is determined. It is easy to think of making it thinner. However, if t is made thinner, the upper and lower magnetic bodies 2 and 6 easily become magnetically saturated, and therefore it is not possible to obtain a magnetic field Ha strong enough to magnetize the recording medium in the gap 3. In particular, in order to sandwich the conductor winding 5 between the upper magnetic body 6 and the lower magnetic body 2, the distance between the lower magnetic body 2 and the upper magnetic body 6 must be greater than the thickness of the conductor winding 5. be. On the other hand, a distance equal to the gap length G must be provided between the lower magnetic body and the upper magnetic body at the tip of the magnetic head. For this purpose, one of the upper and lower magnetic bodies, for example, the upper magnetic body 6, has a structure having a slope portion that slopes toward the rear of the gap 3, as shown in the figure. When forming the upper magnetic body 6 having such an fpr surface portion by a vapor deposition method or the like, the thickness t of the slope portion of the upper magnetic body 6 is necessarily “m = t,” where the slope of the slope is θ. COBθ, which is thinner than the other horizontal portions.For this reason, the sloped portion of the upper magnetic body 6 is more likely to be magnetically saturated than other portions of the closed magnetic path during recording, and a stronger recording magnetic field Ha is applied in the gap 3. On the other hand, when writing information onto a recording medium, in order to avoid magnetic saturation of the upper and lower magnetic bodies 2 and 6 and obtain a strong recording magnetic field in the gap 3, the tips of the upper and lower magnetic bodies must be A method can be considered to reduce the length of the parallel part, that is, the magnetic gap depth Ga. However, in this method, when the film thickness t of the magnetic material is reduced to about 2 μm, the magnetic gap depth Ga is extremely reduced to about 3 μm. It needs to be made smaller.

This point will be explained in detail below.

In a disk head that writes new information and erases old information, the magnetic fields H and Fi that should be generated in the gap 3
It is necessary to expect about 5 to 10 times the coercive force of the recording medium. Here, if the tip width of the head, that is, the width in the direction perpendicular to the paper surface of FIG.
is expressed by the following equation.

Φo = 11oXHa XWXGt ・”(
1) On the other hand, the maximum amount of magnetic flux ΦC flowing within the upper magnetic body 6 is expressed by the following formula.

Φc = Bm XWX t. −(2
) ΦC≦ΦG, the maximum allowable value of the gap depth Gd is given by the following formula.

In equation (3), Bs = 10,000 Gauss = 2 AmS
If i(G = 5,000 oersteds, the maximum allowable value of Gd is 4 μm. Also, when depositing the upper magnetic material 6 by a method such as vapor deposition or sputtering, the thickness of the sloped portion t/, becomes thinner, and the maximum allowable value of Gd becomes smaller.For example, when the inclination angle θ of the slope part is 45 degrees, t'
. When calculated by substituting ==t, -cos45° into equation (3), the allowable maximum value Ga#-1:, Ga528 μm, which is extremely small, is obtained. That is, in the magnetic head, it is necessary to make the pole length P at the tip of the magnetic body particularly small while keeping the magnetic resistance of the magnetic core as small as possible without reducing the thicknesses t, t' of the magnetic body. As shown in Fig. 2, a method for minimizing the pole length P at the tip of the head without reducing the film thickness of the magnetic body is to align the planes provided at the tip of the magnetic body of the magnetic head with each other, as shown in Figure 2. It is known to make the ends 8a, 8b located away from each other a non-magnetic region. According to this, as shown in FIG. 2, after cutting the surface of the magnetic material facing the recording medium, a hot resist is applied to the ends of the F section magnetic material 2.6 that are far away from each other on the thin film. A non-magnetic or weakly magnetic region is formed by implanting oxygen ions into the top surface of the mask to oxidize the magnetic material. However, in this conventional method of manufacturing a magnetic head, it is necessary to perform mask alignment on the pole portions 9a and 9b. For example, in order to manufacture with an accuracy of within ±20% when the pole length P is 2 μm, it is necessary to perform mask alignment. When doing so, the 1F deviation is 0.4 μm1, that is, less than the wavelength of light. Therefore, in the conventional magnetic head manufacturing method, when minimizing the ball length P, mask alignment is impossible9, and a magnetic thin film magnetic head with high recording density cannot be obtained.

[Purpose of the invention]

An object of the present invention is to efficiently produce a magnetic head for a magnetic recording system that writes and reproduces data at high storage density at low cost without reducing the thickness of the magnetic core or reducing the magnetic gap depth Ga. The present invention relates to a method of manufacturing a thin-film magnetic head that can be manufactured using a thin-film magnetic head.

[Summary of the invention]

In the present invention, a thin film magnetic head body is formed by laminating two or more thin film magnetic materials, a part of the gap forming end of the outer thin film magnetic material is cut off, and this cut portion is filled with a nonmagnetic material to increase the This is a method of manufacturing a thin film magnetic head for both writing and reading for a recording density system.

The thin film magnetic head that is the target of the above manufacturing method is manufactured by forming a lower magnetic body 2 in two layers on a substrate 1 by sputtering, plating, etc. with a thin insulating layer 10 interposed therebetween, as shown in FIG. 3, for example. 2a and 2b, and the upper magnetic body is formed into two layers 6a and 6b with a thin insulating layer 11 interposed therebetween, and a conductor winding 5 is disposed between the upper and lower magnetic bodies. . Further, the rear end portions of the upper and lower magnetic bodies are magnetically connected, and the tip portions are separated from each other with a gap 3 in between to form magnetic poles. Furthermore, the ball length P at the magnetic pole
One end portion of the outer thin film magnetic material layers 2b and 6b forming a part of is cut off, and the cut portion is filled with a non-magnetic material.

In a thin-film magnetic head configured such that the tip of the magnetic pole is filled with a non-magnetic material, the ball length P at the tip can be made small, and the thin-film magnetic material can achieve high recording density without becoming magnetically saturated during a write operation. can be achieved.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a process explanatory diagram showing an example of the method for manufacturing the thin film magnetic head of the present invention, which includes a lamination process, a cutting process, and a filling process. The next trap will be explained separately for each process.

Lamination process In this lamination process, first, a lower magnetic body 2, an insulator 4, and an upper magnetic body 6 are sequentially laminated on a substrate 1 by a sputtering method or a plating method, and the lower magnetic body 2 is stacked with an insulator 10 interposed. 2 layers 2a.

2b, and the upper magnetic body 6 is similarly formed into two layers 6a and 6b with an insulator 11 interposed therebetween to form a thin film magnetic head body. The upper and lower magnetic bodies 2 consisting of these two layers
, 6, each outer layer is etched using a magnetic material having a high etching speed, such as Fe-N1 (composition ratio:
8.5%: Ni81.5%) KCr or Au, pt
Each inner layer 2a is made of a magnetic material to which a small amount of precious metal such as .

6a is a magnetic material with a low etching rate, such as F.
e-Ni alloy (composition ratio: Fe18°5%:Ni81.5
%) to provide a difference in etching speed by chemical etching between the inner and outer layers of each magnetic material. Subsequently, the rear end of a thin film magnetic head (not shown) is magnetically connected to form a closed magnetic path, while the tip of the head is cut to form a laminated cross section 7. This laminated cross section 7 consists of the substrate 1, the lower magnetic bodies 2b, 'la, the gap 3, and the upper magnetic bodies 6a, 6b. Next, the laminated cross section 7 of the thin film magnetic head body is etched by a chemical etching method. Apply processing. Upper and lower magnetic bodies 2.
The outer layers 2b and 6b, which are etched at a higher etching speed than the inner layers 2a and 6a, are selectively etched, and a portion of the outer layer 2b and 6b at the tip of the magnetic head body is cut off to form a recess. be done. Note that even when the magnetic materials of the inner and outer layers of the upper and lower magnetic bodies are the same, by making the outer layer thicker than the inner layer, the etching speed can be differentiated by utilizing the difference in the circulation of the etching solution. be able to. Furthermore, as another cutting method, when the upper and lower magnetic bodies 2 and 6 are stacked, a local battery is formed between the inner and outer layers using a chemical etching method without interposing the insulating layer 10.11 between the layers, and the polar parts are Outer layer 2 using battery reaction
b, 6b can be selectively etched.

Filling process: Next, after filling the recesses excised in the cutting process with a non-magnetic material by sputtering, the excess filled non-magnetic material is removed by cutting and polishing, and at the same time, the gap is made to a predetermined depth (dd) Cut and polish the tip of the head so that it looks like this. As a filling method, instead of the sputtering method, a plating method using the outer layers of the upper and lower magnetic bodies as electrodes may be used as appropriate1, and other existing filling methods may be used. According to the thin-film magnetic head obtained through the above-described lamination, cutting, and filling steps, the magnetic pole tips have non-magnetic (including weakly magnetic) portions in regions located far away from each other, and the gap length P can be made small, and the gap depth G- can be formed arbitrarily.

Furthermore, in the manufacturing method according to the present invention, a part of the tip of the magnetic head is removed using the selective etchability of two or more layers of thin film magnetic material, so there is no need to provide a mask formed of hot resist or the like. , it is possible to set the gap length P with high accuracy.

In the thin-film magnetic head thus obtained, the regions of the tips of the magnetic poles at positions K1 that are far from each other are non-magnetic or weakly magnetic, so that the pole length P of the opposing tips of the magnetic poles can be made small. Therefore, the magnetic flux distribution density is lowered near the tip of the magnetic pole, a strong magnetic field can be obtained in the gap during writing, and the effect of reducing peak shift can be obtained during reading.

FIG. 5 is an explanatory cross-sectional view showing an example of a single magnetic pole head used for perpendicular magnetic recording. In a single-pole head used for perpendicular magnetic recording, it is necessary to form a head with a short pole length in order to realize high-density recording. In the figure, 101
102 and 103 are magnetic materials disposed on both sides of the magnetic material 101 with insulators 104 and 105 interposed therebetween, and the magnetic materials 102 and 103 are made of materials with a higher etching speed than the magnetic material 101. It is formed.

Above and below the magnetic bodies 102 and 103 are conductor windings 108°10
Nine circumferences are provided, and insulators 106 and 107 are deposited by sputtering or the like to form a single magnetic pole head.

The tip of the single magnetic pole head formed in this manner is cut off parallel to the running direction of the recording medium to form an end surface 110. Next, a portion of the tips of the magnetic bodies 102 and 103 is removed by chemical etching or a method, and this removed portion 11 is removed.
1, 112 is formed, the cut portion is filled with a nonmagnetic material, and then the tip of the magnetic pole head is cut and polished to make it smooth, thereby obtaining a single magnetic pole head for use in perpendicular magnetic recording. In this way, in the manufacturing method according to the present invention, by laminating two or more magnetic materials and mutually changing the chemical properties of each layer, high recording can be easily achieved without mask alignment using methods such as photoresist. High density thin film magnetic heads can be manufactured.

〔Effect of the invention〕

From the above explanation, according to the present invention, even if the ball length of the magnetic head and the recording wavelength of the recording medium are close to each other, a thin film magnetic head with a small amount of peak softness in the readout waveform and a high recording density can be easily manufactured at a low cost. It has the remarkable effect that it can be obtained with.

[Brief Description of the Drawings] Fig. 1 is an enlarged sectional view showing an example of a conventional thin film magnetic head, Fig. 2 is a sectional view of a conventional thin film magnetic head with an improved magnetic pole tip, and Fig. 3 is a manufacturing method of the present invention. FIG. 4 is a cross-sectional view showing an example of a thin film magnetic head manufactured by the method, FIG. 4 is a process explanatory diagram of the manufacturing method of the present invention, and FIG. 5 is an example of a single magnetic pole head used for perpendicular magnetic recording by the manufacturing method of the present invention. FIG. 1... Substrate, 2a, 2b... Lower magnetic body, 3...
Gap, 4... Insulator, 5... Conductor winding, 6a,
5b... Upper magnetic body, 7... Tip surface of magnetic head,
8...Resection part.

Claims (1)

[Claims] A thin film magnetic head body is formed by laminating one or more thin film magnetic materials, a part of the gap forming end of the outer thin film magnetic material is cut off, and a non-magnetic material is applied to this cut portion. A method for manufacturing a thin film magnetic head, characterized in that it is formed by filling. 2. Claim 1 is characterized in that the method for cutting off a part of the gap forming end of the outer thin film magnetic material is a chemical etching method that utilizes selective etchability of each thin film magnetic material. A method for manufacturing a thin film magnetic head.