JPH0478013A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To realize the precise detection of depth length by forming a polygonal detection marker shaped into a triangle whose one apex, at lest, is cut off into a circular arc shape or a stright line shape. CONSTITUTION:At the time of the pattern etching of a first coil conductor layer 3, the detection marker 4 for detecting the depth length is formed simultaneously at the vicinity of a magnetic gap, and the shape of the marker 4 is formed into a right-angled equilateral triangle ABC from which the right-angled equilateral triangles BDE and CGF including the apexes B and C are removed, and consequently, the shape of the marker is formed into a pentagon ADEFG with three right angles. Thus, since an acute-angled shape part is not formed, even if a photo-resist is heat-treated in order to form the marker, the change of the size of a photo-resist pattern is not caused. Thus, an error due to the pattern etching is not caused at all, and the depth length can be highly precisely detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is based on PCM (Pulse Code M
The present invention relates to an improvement of a depth marker for detecting the depth length of a magnetic gap of a thin film magnetic head used in a recording/reproducing device or the like.

[Summary of the invention]

When detecting the depth of the magnetic gap of a thin-film magnetic head, the present invention forms a detection marker of a specific shape to accurately detect the depth of the magnetic gap of the thin-film magnetic head and to control the depth. It is designed to be easy to do.

[Conventional technology]

In general, a thin film magnetic head consists of a lower magnetic layer, a coil conductor layer, and an upper magnetic layer that constitute the head, and an insulator layer that insulates the lower magnetic layer, coil conductor layer, and two magnetic layers. Since it is formed using vacuum thin film forming technology such as sputtering, it is excellent in mass production and can obtain a head with uniform characteristics.In addition, since patterning is performed using photolithography technology, it can be formed with minute dimensions such as narrow tracks and narrow gaps. It is easy to convert. Therefore, in the thin-film magnetic head, the magnetic field involved in recording becomes steep, making it possible to perform high-density recording, high resolution, and further miniaturization.

However, due to the structure of the thin film magnetic head mentioned above, it is difficult to increase the number of turns of the coil conductor layer, and therefore, in order to increase the recording efficiency of the head, the depth length must be set to an extremely small value of about 10 μm. It's gone.

Therefore, in this type of thin film magnetic head, it is important to accurately control the depth length to a predetermined value.

Therefore, conventionally, as shown in FIG. 4, a marker 4' for detecting the depth length of a right-angled isosceles triangle is formed on a thin-film magnetic head, and the width of this marker ( A method has been adopted in which the depth length is controlled by measuring and converting the depth length.

The marker is formed using a coil conductor layer in the vicinity of the magnetic gap using photolithography technology.

[Problem to be solved by the invention]

However, in a shape like the right-angled isosceles triangle shown in FIG. 4, the patterning accuracy of the resist and the etching accuracy of the marker described above can significantly deform the shape from the ideal state shown by the broken line as shown in FIG. result,
There is a problem in that an error occurs in the width of the marker appearing on the surface facing the magnetic recording medium (ΔL + ΔL'), making it difficult to accurately detect the depth length.

Therefore, the present invention was proposed to solve the above-mentioned problems. It eliminates errors caused by resist patterning accuracy and pattern etching accuracy, detects depth length with high accuracy, and controls depth length. The purpose is to provide a simple thin film magnetic head.

[Means to solve the problem]

According to the present invention, the above object can be achieved by the following thin film magnetic head.

The upper magnetic layer forms a magnetic circuit through the cooperation of the coil conductor layer formed on the lower magnetic layer and the lower magnetic layer, and the lower magnetic layer is insulated from the coil conductor layer and the upper magnetic layer. In a thin M&TI magnetic head made of an insulating layer, a magnetic gap having a polygonal shape in which at least one vertex of a triangle is cut into an arc or a straight line is formed on the lower magnetic layer by the same layer as the coil conductor layer. A thin film magnetic head characterized in that a detection marker for detecting depth length is formed.

C action] In this way, by forming a polygonal detection marker on the lower magnetic layer in the same layer as the coil conductor layer, in which at least one vertex of the triangle is cut out into an arc or a straight line, the resist is removed. The influence of errors due to patterning accuracy, pattern etching accuracy, etc. is eliminated, and the depth length can be detected with high accuracy.

[Preferred embodiment]

Examples of aspects of the thin film magnetic head of the present invention include the following.

The recording medium has a lower magnetic layer, an insulating layer, a coil conductor layer, and an upper magnetic layer in this order, and a magnetic gap layer that reaches a recording medium contact surface of the head between the lower magnetic layer and the upper magnetic layer. A depth marker is formed on the head surface that reaches the contact surface, and the two edges of the depth marker on the side remote from the contact surface are sufficiently larger than the apex angle of a normal triangle (for example, 60 degrees for an equilateral triangle). (preferably interior angle 9
A thin-film magnetic head having a polygonal shape with four or more sides (of 0" or more), the base of which is exposed to the opposing surface, and the two sides on both sides of the base being non-parallel to each other.

Further, the thin film magnetic head of the present invention can be obtained through a primary intermediate. That is, it has a lower magnetic layer, an insulating layer, a coil conductor layer, and an upper magnetic layer in this order, a magnetic gap layer between the lower magnetic layer and the upper magnetic layer, and a depth marker for detecting the gap depth. The depth marker is formed on the surface of the head intermediate body, and the two edges of the depth marker on the side remote from the outer edge of the head intermediate body corresponding to the recording medium contacting surface of the head are sufficiently larger (preferably) than the apex angle of a normal triangle. is a polygon with four or more angles (having an internal angle of 90° or more), and has a depth marker machining part in the head machining part that extends continuously from the contact surface, and the depth marker machining part has an inner angle of 90° or more. A thin film magnetic head intermediate body forming an extension of two mutually non-parallel sides of the depth marker that intersect with each other.

The thin film magnetic head of the present invention can be manufactured, for example, as follows.

A lower magnetic layer, an insulating layer, a coil conductor layer, and an upper magnetic layer are sequentially provided, a magnetic gap layer is provided between the lower magnetic layer and the upper magnetic layer, and a depth marker for detecting the gap depth is provided between the heads. The depth marker is formed on the body surface, and the depth marker positions the outer edge of the thin-film magnetic head intermediate body, which has a polygonal shape with at least one corner of the rectangle cut off, at a reference position that defines the gap depth O of the rear end edge of the gap layer. A method of manufacturing a thin film magnetic head in which a recording medium facing surface is formed by polishing the surface by a predetermined amount.

Preferably, the cut apex is located on a side remote from the flash edge of the head intermediate body corresponding to the recording medium contacting surface of the head, and the cut edge is usually a straight line (or may be a gentle arc). ).

Preferably, the width of the depth marker in the direction parallel to the recording medium contact surface increases or decreases continuously up to at least an arbitrary plane between the contact surface and the reference position.

More preferably, the predetermined amount of polishing is determined by measuring the width of one end of the polishing surface exposed to the polished surface.

Note that the edge angle of the depth marker refers to the angle at which two adjacent sides and their extensions intersect with each other. Therefore, it may be in the shape of an edge or an arc.

The depth marker having the specific shape and its removal portion can be formed at a desired position with high precision without being affected by errors caused by resist patterning precision, pattern etching precision, and the like. Therefore, the depth length of the magnetic gear can be calculated by simply measuring the length of the base of the Debsmer's groove exposed on the contact surface of the thin film magnetic head.

The width of the depth marker in the direction parallel to the recording medium contacting surface is continuously increased or decreased to at least an arbitrary plane between the contacting surface and the reference position, according to the manufacturing method of the thin film magnetic head. In the case where the width of the depth marker is manufactured, the width of the depth marker has a unique correspondence with the gap depth at least in the range between the contact surface and the arbitrary surface. Therefore, the gap depth can be calculated by measuring the width of the depth marker at least in the above range.

The reference position is preferably a straight line or a plane. Further, by controlling the width of the depth marker, a magnetic head can be manufactured by controlling the gap depth.

In the manufacturing method, by measuring the width of one end of the marker exposed on the polished surface to determine a predetermined amount of polishing, it is possible to precisely polish the recording medium contacting surface and to easily automate the process. I can do it.

[Example] An example of the present invention will be described below with reference to the drawings.

In the thin film magnetic head according to the embodiment of the present invention, as shown in FIGS. 1 and 2, a 5i02, etc. A first insulating layer 2 is formed.

The lower magnetic layer 1 is made of Mn-Znn-based material)
□, Fe-Ni alloy (
Permalloy) and Fe-Aj7Si alloy (Sendust)
A composite substrate in which ferromagnetic metal materials such as amorphous alloys are laminated is used.

Further, on the first insulating layer 2, a first fill conductor layer 3 made of a metal conductor layer such as Cu or Aj> is pattern-etched in a spiral shape (three turns in this example) at predetermined intervals. .

In these two embodiments, a detection marker 4 for detecting the depth length is also formed in the vicinity of the magnetic gap at the same time as the pattern etching of the first coil conductor layer 3.

Furthermore, a second insulator layer 5 is formed to cover the first coil conductor layer 3, and has the same winding direction as the first coil conductor layer 3, and is formed on the second insulator layer 5. A spiral-shaped (two turns in this embodiment) second coil conductor layer 8 is formed to be electrically connected to the first coil conductor layer 3 through the coil contact window 7 .

The coil conductor layers 3 and 8 are not limited to a spiral multilayer type, but may have any type of winding structure such as a helical type.

Further, a third insulating layer 9 is formed on the second coil conductor layer 8, and furthermore, a gap spacer 10 made of 3i02 or the like and the third insulating layer 9 are formed in the front gap portion.
The upper magnetic layer 1 is made of a ferromagnetic metal material such as permalloy, sendust, or amorphous alloy.
1 has a predetermined track width.

This is how it was formed. By supplying a driving current to the coil conductor layer 3.8, the lower magnetic layer 1 and the upper magnetic layer 11 cooperate to form a magnetic circuit, so that recording and reproduction can be performed. ing.

Furthermore, although not shown in the figure, a protective layer made of 5i02 or the like is formed to cover the upper magnetic layer 11, etc., and after being flattened, it is coated with a non-magnetic material such as ceramic through an adhesive such as glass. A protective plate is fusion-bonded.

In the thin film magnetic head constructed in this way, for example, by providing a pentagonal marker, the processing accuracy of the depth length of the magnetic gap by polishing can be greatly improved.

The detection marker 4 formed on the thin film magnetic head of this embodiment will be described in detail below.

FIG. 3 shows an enlarged plan view of the detection marker of this embodiment.

Marker 4 in Figure 3 is right-angled isosceles triangles BDE and CGF that include vertices B and C of right-angled isosceles triangle ABC.
As a result, the marker shape is a pentagon ADHFG with three right angles.

Of the markers 4, the line segment GF is located closer to the coil conductor layers 3 and 8 than the rear edge (la) (depth length, -0) of the magnetic gear amplifier, that is, the depth length DP-
The O line is AG or FE of the markers 4 above.
formed at any position across the

In order to detect the depth length (D, ) in the above marker shape, processing is performed sequentially in the Y direction from the magnetic recording medium contacting surface 6 using a wrapping means such as tape wrap, so that the depth length (D, ) appearing on the magnetic recording medium contacting surface 6' is If the detection marker width is L, the depth length DP at this time is D, -L-Lo-χ. (
Lo: Depth length, distance from -0 to line segment GF,
(χ: length of line segment CG) In other words, by not creating an acute-angled portion like the shape of marker 4 above, there is no dimensional change in the photoresist pattern even if the photoresist is heat-treated to form the marker. Therefore, errors caused by subsequent pattern etching are completely eliminated, and the depth length can be detected with high accuracy.

Here, in the length region of the line segment DE in the marker 4, even if polishing is performed in the Y direction, the length of the line segment in the X direction does not change and the depth length cannot be determined.
There is no problem in calculating the actual depth length by keeping the length of the line segment DE long to a certain extent and by keeping the length of the line segment DE as short as possible to the extent that the pattern of the marker 4 is not deformed.

Our experiments have shown that if the length of the line segment DE is 3 μm or more, deformation of the detection marker pattern can be suppressed. Of course, this also applies to the line segment GF.

Note that the present invention is not limited to the above embodiments.9
For example, as shown in Figure 6, right isosceles triangles ADE and BF that include vertices A, B, and C are
The shape excluding G and CHI, as shown in Figure 7, isosceles right triangle ADE, BFG, CHI and rectangle JK.
It is preferable that the shape is such that LM is removed, and the depth length of the magnetic gap can be calculated by DP-LL, -χ.

Further, in the embodiment, a shape having a shape of a right isosceles triangle having its corners cut off has been described, but it goes without saying that any shape having a shape of a triangle having its corners cut off may be used. In addition, as shown in Fig. 8, the depth is long, -172L-Lo -y (y:
Of course, a shape that can be calculated by the distance between point A and line segment DE may also be used.

By the way, in this embodiment, the detection marker 4 may be formed at the same time as the first coil conductor layer 3 or the second coil conductor layer 8, of course.

Further, although two detection markers 4 are formed in this embodiment, it goes without saying that the same effect can be achieved with just one of them.

Further, although all the above explanations have been made regarding the case of a coil conductor layer or two layers, it goes without saying that the same applies to a single layer coil conductor layer.

〔Effect of the invention〕

As is clear from the above explanation, in the thin film magnetic head of the present invention, when detecting the depth length of the magnetic gap, by using a specific detection marker whose shape does not change due to pattern etching of the detection marker, the detection accuracy of the depth can be improved. will improve.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an example of a thin film magnetic head according to the present invention. FIG. 2 is a sectional view taken along line a-a in FIG. 1, and FIGS. The detection marker of the embodiment is shown too enlarged. FIG. 1. Lower magnetic layer 1a... Rear edge of magnetic gap (depth length, = O) 2. First insulator layer 3. First coil conductor layer 4.
・Detection marker 5・Second insulator layer 6.6'...Magnetic recording medium facing surface 7...Coil contact window section 8...Second coil conductor layer 9...Third insulator layer 10 ... Gap spacer 11 ... Upper magnetic layer X ... Magnetic recording medium facing direction Y ... Polishing direction Fig. 1

Claims (1)

[Claims] The upper magnetic layer forms a magnetic circuit through the cooperation of the coil conductor layer formed on the lower magnetic layer and the lower magnetic layer, and the lower magnetic layer is insulated from the coil conductor layer and the upper magnetic layer. In a thin film magnetic head comprising an insulating layer, the same layer as the coil conductor layer is placed on the lower magnetic layer to form a polygonal magnetic gap having at least one vertex of a triangle cut into an arc or a straight line. A thin film magnetic head characterized in that a detection marker for detecting the length is formed.