JP2796998B2 - Method for manufacturing thin-film magnetic head - Google Patents

Description

The present invention relates to a method for manufacturing a thin film magnetic head.

(Prior Art) With the development of the information-oriented society, BPI (linear density) and TPI (track density) of an external storage device of a computer have been improved in order to improve areal recording density. For the magnetic heads, the former is a technical improvement item in that the former improves the recording / reproducing ability and the operating frequency of a short wavelength, and the latter is a technical improvement item in which the track width is narrowed.

A conventional method of manufacturing a thin-film magnetic head will be described with reference to FIGS.

FIGS. 3, 4, and 5 are a perspective view of a thin-film magnetic head for a fixed disk, which is generally called a slider, as viewed from a disk-facing surface, an enlarged plan view and a side sectional view as viewed from the front of the slider, and It is the principal part enlarged plan sectional view seen from the opposing surface.

In FIG. 3, after forming a thin-film magnetic head 2 on the surface of a substrate 1 by using a thin-film forming technique, the slider is cut out so as to cross the magnetic pole surface, and the slider is shaped and formed into a substrate holder 2a. A gimbal or the like (not shown) is adhered and used by floating above a fixed disk.

Next, a method of manufacturing the thin-film magnetic head 2 will be described with reference to FIG. First, the lower magnetic layer 3 is formed on the surface of the substrate 1.
Then, after the magnetic gap layer 4 is formed in an overlapping manner, it is formed into a crumb shape by applying a photoresist, a photolithography technique and an etching technique. At this time, the magnetic gap layer 4 has a shorter head than the lower magnetic layer 3 and a lower magnetic layer 3.
Is exposed to form a connection portion 3a. Next, a coil layer 5 extending over the magnetic gap layer 4 and the surface of the substrate 1;
A wiring pattern 6 having terminal portions 6a connected to the coil layer 5 is formed. Next, an upper magnetic layer 7 similar to and slightly smaller than the lower magnetic layer 3 is formed, and is connected to the lower magnetic layer 3 at the connection portion 3a to form a magnetic circuit. Finally,
A plurality of thin film magnetic heads 2 arranged side by side on the substrate 1 are separated and shaped to obtain a slider shown in FIG.

FIG. 5 is a sectional view of a cut surface indicated by a chain line in FIG. 4 and corresponds to a plan view of a disk facing surface of the slider shown in FIG. In the figure, the width of the upper magnetic layer 7 indicated by the dimension line L is equal to the track width of the fixed disk.

The thin-film magnetic head 2 having such a configuration is provided with the lower magnetic layer 3.
Since it is necessary to place the upper magnetic layer 7 thereon, the width of the lower magnetic layer 3 is set to a size obtained by adding ΔL ₁ and ΔL ₂ to the left and right of the track width L, respectively, as a margin when forming the upper magnetic layer 7. There is a need. When the track width is 10 μm or more, this Δ
L ₁ + ΔL ₂ is usually 2 μm to 3 μm.

Here, the fixed disk device will be described. When recording information from a magnetic head to a fixed disk, a guard is provided between tracks in order to provide a margin for positioning the magnetic head and a margin for magnetic flux leakage to the side of the track width during recording (recording bleeding). An unrecorded area called a band is provided. To increase the track density, it is natural that the track width is narrowed, but similarly, narrowing the guard band is also an effective means. Therefore, when reducing the track width, it is important to reduce ΔL ₁ + ΔL ₂ at the same time.

However, in the above-described conventional manufacturing method, even if ΔL ₁ + ΔL ₂ is specified to be small on the design drawing, the thin film forming technique is not involved, so that a lamination failure in which the upper magnetic layer 7 protrudes from the lower magnetic layer 3 occurs. However, there is a problem that it is difficult to suppress ΔL ₁ + ΔL ₂ to 2 μm or less.

A method of partially etching the upper magnetic layer 7 and the lower magnetic layer 3 to solve the above problem will be described with reference to FIG.

First, the lower magnetic layer 3 having a thickness of t _2, the width of the portion of the scoop-like pattern is larger than the track width L, the dimension line in the drawing L "
It is formed so as to have a width indicated by. Next, a magnetic gap layer 4 covering leaving the connecting portion 3a of the lower magnetic layer 3 of the above, after forming the coil layer 5, to form the upper magnetic layer 7 having a thickness of t ₁ on the entire surface (FIG. 6 ( a)).

Next, an etching mask 8 having a width L 'wider than the track width L is formed of a metal material having a selectivity by chemical etching with respect to the photoresist or the upper magnetic layer 7 or a layered structure of them. (FIG. 6 (b)).

The thickness t ₃ of the above etching mask 8, the upper magnetic layer 7 to overetching, the magnetic gap layer 4 and the lower magnetic layer 3 is dimensioned so that the track width L.

Next, using the etching mask 8 as a mask, etching is performed using an ion beam of argon or the like (FIG. 6C), since unnecessary portions of the upper magnetic layer 7, the magnetic gap layer 4, and the lower magnetic layer 3 are removed. Finally, when the etching mask 8 is removed, the lower magnetic layer 3 and the upper magnetic layer 7 having substantially the same width as shown in FIG. 6D are obtained. At this time, the width of the upper magnetic layer 7 is the track width L, and the width of the lower magnetic layer 3 is also substantially the same as the track width L.

(Problems to be Solved by the Invention) However, in the above-described manufacturing method, the layers to be removed by etching are the three layers of the lower magnetic layer 3, the magnetic gap layer 4, and the upper magnetic layer 7, so that the etching time becomes longer. However, there is a problem that the number of steps for forming the etching mask 8 increases. Further, since the layer to be etched is thick, the etching mask 8 also needs to be thickened accordingly. Particularly when a photoresist is used as the etching mask, there is a possibility that deformation due to heat may occur. Even if the resist was able to be cured stably by using it, there was a problem that it was difficult to form a thick resist pattern with high accuracy.
Since the upper magnetic layer 7 having a track width L to be formed by etching is smaller than the width L 'of the formed etching mask 8, there is also a problem that the upper magnetic layer 7 tends to fluctuate depending on the shape of the pattern and the etching state and is difficult to control. Even if a metal material such as titanium having a small etching rate with respect to an energy beam such as argon ions is used for the etching mask 8, the pattern of the etching mask 8 is formed using the etching mask in order to form the track width L. In addition, there is a problem in that a large number of dimensional fluctuation factors are required for increasing the precision of the track width and control is difficult.

SUMMARY OF THE INVENTION The present invention solves the above-described problems, and provides a method of manufacturing a thin-film magnetic head at a low manufacturing cost, in which a highly accurate track width can be obtained with high accuracy.

(Means for Solving the Problems) In order to solve the above problems, a method of manufacturing a thin film magnetic head according to the present invention provides a method of manufacturing a thin film magnetic head, comprising: a track width of upper and lower magnetic layers facing each other via a magnetic gap layer; In a method of manufacturing a thin-film magnetic head including at least a final etching step of forming an etching mask, an etching mask is provided to cover the ends of the upper and lower magnetic layers on the medium facing surface side and to provide an opening near a magnetic gap where the upper and lower magnetic layers face each other Forming a lower magnetic layer having a required track width and a thickness larger than the required thickness as a mask in the opening, and etching the lower magnetic layer formed with a width wider than the upper magnetic layer. Is what you do.

(Operation) According to the above manufacturing method, the lower magnetic layer is etched using the upper magnetic layer having the required track width as a mask, so that not only can the upper and lower magnetic layers be formed substantially equal to the track width, but also the upper and lower magnetic layers can be formed. Since the layer is etched using an etching mask having an opening in the vicinity of the magnetic gap where the layers oppose, the end of the upper magnetic layer facing the medium is formed with a uniform thickness, the leakage magnetic flux is small, and the recording characteristics are good. A thin film magnetic head.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

1A to 1D are an enlarged plan view of a main part of a thin-film magnetic head according to the present invention and an enlarged cross-sectional view of a main part showing an etching process in the order of steps.

In FIG. 1A, the final etching step of the thin-film magnetic head according to the present invention is the same as that of the conventional example shown in FIG. 4, but the upper magnetic layer shown by the dimension line t ₁ ′ in FIG. thickness of 7, the point is a value obtained by adding the thickness t ₂ of the lower magnetic layer 3 to a thickness t ₁ of the upper magnetic layer 7 shown in FIG. 5 is differences. Therefore, the description of the manufacturing method up to this point is omitted.

In the final etching step, the magnetic gap layer 4 and the lower magnetic layer 3 that are not covered with the upper magnetic layer 7 are etched by an energy beam such as argon ions using the upper magnetic layer 7 as a mask (FIG. 1C). At this time, the upper magnetic layer 7 serving as a mask is also etched. The magnetic layer 7, and terminates the etching upon reaching a thickness t ₁ (FIG. 1 (d)) and the formation of the track portion of the thin-film magnetic head 2 is terminated.

The lower magnetic between the thickness t ₁ of the upper magnetic layer 7 'from t ₁ is the final dimensions, if the form of at least the thickness t ₂ of the lower magnetic layer 3 thicker, that t _1' is t ₁ Upper magnetic layer 7 of layer 3
Unnecessary portions indicated by ΔL ₁ and ΔL ₂ on both sides of are removed. The upper magnetic layer 7 and the lower magnetic layer 3 form a positive taper after the end of the etching.
The initially formed track width L hardly changes.

Here, in order to prevent the coil layer 5 and the wiring pattern 6 other than the lower magnetic layer 3 from being damaged by the above-described etching, an etching mask is provided in a region that does not need to be etched. This etching mask
As shown in FIG. 2, an opening 9a is provided in a region near a magnetic gap where the upper magnetic layer 7 and the lower magnetic layer 3 face _each other with photoresist or SiO ₂ or the like. Note that the material of the etching mask 9 may be other than photoresist or SiO ₂ . However, when an etching mask other than SiO ₂ is used, the etching mask 9 is finally removed.

In this manner, when etching is performed using an etching mask that covers the ends of the upper and lower magnetic layers on both sides facing the medium and that has an opening near the magnetic gap where the upper and lower magnetic layers face each other, the end of the medium facing surface is an etching mask. Does not cause excessive etching as the upper magnetic layer approaches the edge of the medium facing surface, and therefore,
The magnetic layer has a uniform thickness, does not vary depending on the grinding position, has a small leakage magnetic flux, and can provide a thin film magnetic head having good recording characteristics.

(Effects of the Invention) As described above, according to the present invention, a high-precision thin film magnetic head for a narrow track having upper and lower magnetic layers having substantially the same width can be obtained. In addition, since the final etching step for obtaining the same width is easy, a manufacturing method with high operation reliability can be obtained. Furthermore, in etching, since the etching mask having an opening in the vicinity of the magnetic gap where the upper and lower magnetic layers face each other is used, the end of the upper magnetic layer facing the medium is formed with a uniform film thickness, and leakage magnetic flux is small, A thin-film magnetic head with good recording characteristics can be manufactured.

[Brief description of the drawings]

1 (a) to 1 (d) are main part plan views of a thin film magnetic head according to an embodiment of the present invention and enlarged cross-sectional views of main parts showing the final etching step in the order of steps, and FIG. FIG. 3 (a) is a plan view and a side sectional view of an etching mask formed in a final etching step of the embodiment.
FIG. 4B is an enlarged perspective view of a head in which the completed thin film magnetic head is integrated into a block, and FIGS. 4A and 4B are plan views of the thin film magnetic head formed on a substrate before cutting. FIG. 5 is a plan sectional view corresponding to a disk-facing surface, and FIG. 6 is an enlarged sectional view of a main portion showing a final etching step of a conventional thin-film magnetic head provided with a final etching step in the order of steps. DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... thin film magnetic head, 3 ... lower magnetic layer, 3a ... connection part, 4 ... magnetic gap layer, 5 ... coil layer, 6 ... wiring pattern, 6a ... terminal part, 7 upper magnetic layer, 9 etching mask, 9a opening.

Claims (1)

(57) [Claims] 1. A method of manufacturing a thin-film magnetic head including at least a final etching step of forming a track width of an upper and lower magnetic layer opposed to a magnetic recording medium via a magnetic gap layer, the method comprising: An etching mask is formed which covers an end on the surface side and has an opening in the vicinity of the magnetic gap where the upper and lower magnetic layers face each other, and has an upper magnetic layer having a required track width and a thickness greater than a required thickness. A method of manufacturing a thin-film magnetic head, comprising etching a lower magnetic layer having a width wider than that of the upper magnetic layer as a mask in the opening.