JPH06309627A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a thin film magnetic head capable of reducing the dispersion in a gap depth GD between respective elements and obtaining a required characteristic. CONSTITUTION:A first monitor pattern 15 consisting of an isosceles triangle (a length of the base (a)= height (h)) arranging the base 15a in parallel with the arrangement direction of a magnetic head element and where the vertex 15b arrives at one side boundary line L1 of an allowable range of the GD is formed adjacent to respective magnetic head elements 11 on a substrate 10. Further, a rectangular second monitor pattern 16 having a thickness (t) coinciding with the width of the allowable size of the GD is arranged so that the upper side 16a and the lower side 16b coincide with both boundary lines (L2, L1) of the allowable range of the GD close to that. Then, an additional grinding amount is obtained from the width of the exposure part of the pattern 15 onto a grinding surface, and the judgement whether a nondefective or not is performed by the presence of the exposure of the pattern 16. That is, the GD is controlled simply only by viewing the grinding surface (without measuring a size, etc.).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin film magnetic head used in a magnetic recording device such as an HDD or a computer, and more specifically to an improvement for keeping GD constant.

[0002]

2. Description of the Related Art As a conventional method for manufacturing a thin film magnetic head, a lower magnetic pole layer and a gap layer are formed at a predetermined position on the surface of a disk on which a member constituting a slider is attached on the back side by using a semiconductor process. , A predetermined number of insulating layers, coil layers, and upper magnetic pole layers are sequentially laminated, and a transparent protective layer is further formed on the upper surface of the magnetic layers, thereby forming a large number of magnetic head elements in a grid pattern. Then, a thin film magnetic head with a slider is manufactured by polishing and cutting a predetermined portion of the substrate to form a predetermined shape.

By the way, the characteristics of the thin-film magnetic head, in particular, the electromagnetic conversion characteristics are measured from the contact surface of the magnetic recording medium to the APE.
It is affected by the length of GD (gap depth), which is the distance to X (the rising point of the insulating layer formed immediately above the gap layer). Therefore, it is necessary to manufacture the GD so that it has a predetermined length.

Therefore, conventionally, when a large number of magnetic head elements 2 are formed on the substrate 1 in a grid pattern, the monitor patterns 3 for GD management are formed at the same time at both ends of the magnetic head elements 2 arranged horizontally. (See FIG. 4). The monitor pattern 3 is in the form of a strip and is formed so as to be substantially parallel to the laterally arranging direction of the magnetic head elements 2 and to include a portion (polishing end position) which is the tip of the gap in the final product. It The upper part of the monitor pattern 3 is covered with a transparent member such as a protective layer so that it can be visually recognized from above the outside.

When the GD is controlled (manufactured to have a predetermined length) by using the monitor pattern 3 as described above, first, the substrate 1 is cut in the lateral direction and, as shown in FIG.
The processing block bodies 4 for columns are taken out. Then, the end surface 4a on the gap side (floating side) of the cut-out processing block body 4 is polished. At this time, the distance from the reference side 3a on the back side (upper side in the drawing) of the monitor pattern 3 to the polishing surface is monitored, and polishing is performed while balancing so that the distances on both sides are equal (d1 = d2). . Then, when the distances d1 and d2 reach the set reference distance, the polishing process is ended. Then, the polishing amount from the end face 4a is the same in each part, and the APEX position 2 of each element 2 is
Since a is also arranged on a straight line, the GD of each element is kept the same.

[0006]

However, the conventional manufacturing method described above has the following problems. That is,
In order to measure the distances d1 and d2 from the reference side 3a of the monitor pattern 3 to the polishing surface, it is necessary to inspect from the upper surface side of the processing block body 4 using a microscope. In order to see the position, the focus position of the microscope is adjusted to the upper surface (front surface) of the processing block body 4, while to see the position of the reference side 3a of the monitor pattern 3, the focus position of the microscope is set to a predetermined distance from the upper surface. It is necessary to adjust to a deep position (usually, since the monitor pattern is formed by plating the upper surface of the substrate, the monitor pattern is located below the surface of the processing block body 4 by the thickness of the protective layer). Since there is a difference in the depth of focus between the two as described above, it is necessary to move the vertical axis of the microscope when measuring the above distance, which deteriorates the measurement accuracy. Then, the distance d
Since 1 and d2 must be measured with submicron accuracy, sufficient GD management cannot be performed due to an error due to the difference in depth.

Further, during the above polishing process, when a warp or the like occurs around a certain magnetic head element, the polishing amount varies, and even the monitor patterns 3 on both ends are formed.
Although the GD dimension management using the method is within a predetermined range, the actual GD dimension of the element may be out of the allowable range. That is, the GD may vary, and even if it varies, the phenomenon cannot be detected at that stage. (By measuring the characteristics after the product is commercialized, it is detected that the product is defective. ). Therefore, if the GD cannot be accurately controlled and the GD varies, the desired characteristics (especially electromagnetic conversion characteristics) as described above.
There is a problem that is not obtained.

The present invention has been made in view of the above background, and an object of the present invention is to enable easy and accurate checking of GD, to reduce variations in GD among elements, and Another object of the present invention is to provide a method of manufacturing a thin film magnetic head capable of obtaining the above characteristics.

[0009]

To achieve the above object, in the present invention, a lower magnetic pole layer is provided on a substrate, and a nonmagnetic material layer for a gap and an APEX position are determined on the lower magnetic pole layer. An insulating layer, a predetermined number of coil layers, and an insulating layer that covers the coil layers are laminated in a predetermined positional relationship, and further, an upper magnetic pole layer and a protective layer are formed on the upper surface to form a large number of magnetic head elements, Next, a predetermined portion of the substrate is cut so that the magnetic head elements are arranged in a horizontal row, a predetermined surface of the cut member is polished, and a distance from the polished surface to the APEX is set to a predetermined length. In addition, on the premise of a method of manufacturing a thin film magnetic head, which is formed by cutting a predetermined portion of the cut member, the cut member gradually increases from the polishing surface side to the back side. When forming the magnetic head element, a pair of monitor patterns consisting of a first monitor pattern having a narrower width and a second monitor pattern which is close to the first monitor pattern and defines the maximum allowable polishing position for the polishing are formed. In addition, a plurality of sets are formed at predetermined positions of the magnetic head element array arranged in the horizontal row. Then, the inspection of the distance from the polishing surface to the APEX during the polishing process is performed by confirming from the appearance state of the monitor pattern pair exposed on the polishing surface side.

Further, preferably, the second monitor pattern is formed at substantially the same position as the allowable range of the distance from the polishing surface to the APEX, and more preferably, the first monitor pattern of the first monitor pattern is formed. The shape is a substantially isosceles triangular shape having the same height as the base. Further, the upper side of the monitor pattern pair may be covered with a transparent or semi-transparent member, and it is more preferable that at least one pair of such monitor pattern pairs be formed close to each magnetic head element.

[0011]

By forming a magnetic head element and a monitor pattern pair at a predetermined position on the substrate and then cutting the substrate at the predetermined position, the magnetic head elements are arranged in a horizontal row and a plurality of monitor pattern pairs exist. . And
The first monitor patterns and the second monitor patterns are set to have the same relative position with respect to the magnetic head element. When polishing is performed in this state, only the first monitor pattern is exposed on the polishing surface at the beginning of polishing,
Moreover, the width of the exposed portion becomes shorter as the polishing progresses. Therefore, the remaining amount to be polished (additional polishing amount) is calculated from the width of the exposed portion, and by continuing the polishing with this as a guide, overpolishing does not occur and reliable and reliable polishing processing is performed. Further, by polishing so that the widths of the exposed portions of the plurality of first monitor patterns are constant, it is possible to perform polishing in a well-balanced manner parallel to the arrangement direction of the magnetic head elements.

If the polishing is performed for a predetermined distance, the second
The monitor pattern of is exposed on the polishing surface. Since the second monitor pattern defines the maximum allowable polishing position, the polishing process is finished at an appropriate position before it disappears. This allows the APEX of the magnetic head element to be polished from the polishing surface.
It can be estimated that the distance (GD) to the position is within the allowable range. That is, the GD can be checked by looking at the state of the monitor pattern pair exposed on the polished surface.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a method of manufacturing a thin film magnetic head according to the present invention will be described in detail below with reference to the accompanying drawings. That is, in this example, as shown in FIGS. 1 and 2, a large number of magnetic head elements 11 are formed at predetermined positions (on each grid-like intersection) on the substrate 10 according to a normal semiconductor process.
As a result, the magnetic head elements 11 are arranged at predetermined intervals in a horizontal row, and the processing block body 12 as shown is formed by cutting the substrate 10 in parallel at predetermined positions above and below the magnetic head element 11. To be done. The specific manufacturing method of the magnetic head element 11 (the magnetic pole layer, the gap layer, the insulating layer, the coil layer, the protective layer, and the like are sequentially laminated in a predetermined positional relationship) is the same as the conventional method. The description is omitted.

Here, in the present invention, the above processing block body 1
In order to manage the distance GD from the end surface 12a of the second floating side 2 to the APEX position 11a of the magnetic head element 11 to be a predetermined distance, the substrate 10
The first and second monitor patterns 15 and 16 are provided at predetermined positions above.
Is provided, and whether or not the GD is within a predetermined range is determined by observing the polishing status of both monitor patterns 15 and 16.

First of all, the above monitor patterns 15 and 1
6, each magnetic head element 11 will be described.
Is formed adjacent to. At the same time when the lower insulating layer that defines the APEX position is formed, a metal pattern is formed at a predetermined position on the upper surface of the substrate 10 by plating or the like.
By simultaneously forming the lower insulating layer in this manner, it is possible to accurately determine the relative positional relationship with the position of the insulating layer (APEX) of the paired magnetic head element.

Then, the first monitor pattern 15 is
The base 15a is composed of an isosceles triangle arranged in parallel with the arrangement direction of the magnetic head element 11, and the apex 15b of the isosceles triangle has one boundary line of the GD permissible range (on the side close to the floating side, a non-defective product). Location where GD is the longest within the range) L
I am trying to reach the top one. Further, in the present example, as shown in FIG.
The height h is made equal (a = h).

On the other hand, the second monitor pattern 16 has a rectangular shape, and its thickness t matches the width of the allowable dimension of GD, and the upper side 1 of the second monitor pattern 16 is
6a and the lower side 16b are made to coincide with both boundary lines (L2, L1) of the GD allowable range. As a result, as is clear from the figure, the second monitor pattern 1
The first monitor pattern 1 on the extension line of the lower side 16b of
The apex 15b of 5 is located. And further,
The upper side of both monitor patterns 15 and 16 is covered with a transparent protective layer (the same as the protective layer covering the upper side of the magnetic head element) 17, and both monitor patterns 1 from the front side.
5 and 16 can be confirmed.

Next, the polishing step of the processing block body 12 performed while performing GD control using both monitor patterns 15 and 16 formed as described above will be described. First, as shown in FIG. 2A, the bottom surface 15 a of the first monitor pattern 15 is initially exposed on the end surface 12 a of the processing block body 12. When polishing in this state,
The exposed portion of the first monitor pattern 15 becomes linearly smaller according to the amount of polishing (FIG. 6B). Further, in this example, since the height is the same as the bottom surface of the first monitor pattern 15, the length a ′ of the exposed surface is the distance to the current vertex 15b (height of triangle), that is, after this. This is the distance to be polished. In this way, by monitoring the length of the exposed surface, a guideline for how much polishing should be performed later can be known, and the occurrence of defective products due to excessive polishing can be suppressed in advance. Further, by polishing so that the exposed surfaces of the first monitor patterns 15 have the same length a ', it is possible to perform polishing in a well-balanced manner.

Then, when the polishing progresses and the end face 12a falls within the allowable range of GD, the first monitor pattern disappears and the second pattern 16 is exposed instead, as shown in FIG. And the second monitor pattern 1
Since No. 6 is formed within the allowable range, it is guaranteed that GD is within the allowable range while the second monitor pattern 16 is exposed. If the second monitor pattern 16 disappears due to overpolishing as shown in FIG. 6D, the GD is too short and the product is defective.

When the product is in a non-defective state as shown in FIG. 6C, the polishing process is finished, and thereafter, the end surface 12a on the air bearing surface side of the processing block body 12 is grooved and the rail for levitation is used. After forming the portion, the thin film magnetic head with a slider is manufactured by cutting at a predetermined position to separate each magnetic head element and finishing. Since the shape of the slider is shown by the chain double-dashed line in FIG. 1 (A), a part of the second monitor pattern 16 remains at the end of the polishing process, but the remaining second monitor pattern 16 remains. The second monitor pattern 16 is also removed during the manufacture of the rail portion, so that it is not exposed on the end face of the final thin film magnetic head. It should be noted that specific processing steps of the processing process can be the same as those of the conventional one, except for checking the GD dimension using a pair of monitor patterns, and therefore specific illustration and detailed description are omitted. .

Further, in this example, both dummy patterns 15 and 1
Since the transparent protective layer 17 is located on the upper surface of 6, it can be seen from the upper side and the end surface 12a side, and FIG.
It is possible to more easily confirm in which state (D) the state is (determination as to whether or not the product is a non-defective product).

Further, in this example, since the monitor pattern is provided next to each magnetic head element, there is almost no positional deviation of the distance between each pair of layers from the air bearing surface side, and the monitor pattern is It can be estimated that the processing state is the same as the inside or outside of the allowable range of the GD dimension for each pair of magnetic head elements, and more accurate GD management is possible.

In this example, as a result of checking the GD dimension, when some of the magnetic head elements arranged in one horizontal row have a GD dimension longer than the allowable dimension, It is possible to deal with this by individually performing correction processing for each element.

Further, in the above-mentioned embodiment, the pair of monitor patterns is formed next to each magnetic head element, but the present invention is not limited to this, and the monitor pattern can be installed at any location. The number may be n or may be random. Further, as in the conventional case, it may be provided only at both ends of one horizontal line and not provided next to each magnetic head element in principle. That is, if at least two pairs of the first and second monitor patterns are provided, the width of the exposed surface of the plurality of first monitor patterns can be monitored to perform polishing in a well-balanced manner. This is because if the second monitor pattern is exposed, it can be estimated that the GDs of all the magnetic head elements are within the allowable range.

In the above embodiment, the shape of the first monitor pattern is an isosceles triangle having a predetermined size and shape (base = height), but an isosceles triangle having a height different from the base may be used. Further, it is possible to use a scalene triangle and various other shapes, and the point is that the width thereof gradually decreases toward the back side (tip). Then, by obtaining the width of the portion currently exposed on the end face and the remaining distance to the tip thereof by conversion, it is possible to prevent the generation of defective products due to excessive polishing and the standard of polishing.

Further, the positional relationship between the first and second monitor patterns to be formed is not limited to that of the above-mentioned embodiment, and for example, as shown in FIG. The thickness t'of the second monitor pattern 16 'is made longer than the allowable range (L1 to L2) of GD, and the lower side 16'b of the second monitor pattern 16' is the first monitor pattern 15 '.
They are arranged so as to partially overlap with each other, or as shown in FIG. 6B, the apex 15 "b of the first monitor pattern 15" and the lower side 16 "of the second monitor pattern 16" as in the above embodiment. Even if the height positions of b are made to coincide with each other, it is possible to make various modifications such as setting the position to a predetermined position (for example, a central part) within the GD permissible range (L1 to L2). The patterns may not overlap with each other, and a predetermined gap may be formed between the apex of the first monitor pattern and the lower side of the second monitor pattern in the polishing direction. That is, in any state, if the arrangement relationship of each pattern is known in advance, a good product or a defective product can be known in any state (relationship of the exposed portion of the pattern). This is because it can be determined whether or not it is.

That is, the point is that the width of the first monitor pattern can be used to determine the standard of the remaining amount to be polished, and the second monitor pattern (if necessary, the first monitor pattern G is also used
It suffices if the polishing limit within the allowable range of D can be determined.

Furthermore, the upper surfaces of both monitor patterns are made of an opaque material (however, the material used to form the patterns is different).
It may be covered with. That is, even in such a case, by looking at the monitor pattern exposed on the end surface,
It is possible to determine the remaining amount of polishing and whether or not it is a non-defective product.

[0029]

As described above, in the method of manufacturing a thin film magnetic head according to the present invention, the GD can be easily and accurately confirmed by confirming the polishing state of the first and second monitor patterns from the outside (polishing surface side). Can be checked. That is, as a general rule, the GD is checked by looking at the exposed portion of each monitor pattern exposed on the polishing surface, so that there is no difference in the depth of focus as in the past, and the measuring instrument (microscope)
No need to move the axis of the
Moreover, it is not necessary to measure specific dimensions to check whether or not the product is good, but it is sufficient to simply look at the exposed state of each monitor pattern on the polished surface, and monitoring in the submicron order can be performed easily and accurately. Like In addition, since the width of the first monitor pattern gradually narrows as the polishing progresses, the remaining amount of polishing can be predicted by looking at the width of the exposed portion, and defective products due to excessive polishing are generated. It can be suppressed as much as possible. Therefore, it is possible to accurately manage the GD dimension and suppress variations in electromagnetic conversion characteristics as much as possible.

When the second monitor pattern is formed at substantially the same position as the allowable range of the distance from the polishing surface to the APEX, the second monitor pattern is exposed on the polishing surface. Since it is a non-defective product when it is a non-defective product and is not exposed, it can be extremely easily determined whether or not it is a non-defective product. When the shape of the first monitor pattern is a substantially isosceles triangle having the same height as the base, the distance to the position of the apex of the triangle is equal to the width of the exposed portion, so that the apex If the position (relative position with respect to the allowable range) is known in advance, the additional polishing amount can be known without converting the remaining additional polishing amount (or by simply performing simple addition / subtraction).

Further, when the upper part of the monitor pattern pair is covered with a transparent or semi-transparent member, the polishing status of the monitor pattern pair can be confirmed from the upper side, so that the GD management becomes easier. Furthermore,
When at least one monitor pattern pair is formed close to each magnetic head element, the GD of the magnetic head element can be managed more accurately.

[Brief description of drawings]

FIG. 1 is a diagram showing a preferred embodiment of a method of manufacturing a thin film magnetic head according to the present invention.

FIG. 2 is a diagram for explaining changes in the exposed state of the polishing surface according to the progress of polishing.

FIG. 3 is a diagram showing a modification of first and second monitor patterns.

FIG. 4 is a diagram showing a conventional method of manufacturing a thin film magnetic head.

[Explanation of symbols]

 Reference Signs List 10 substrate 11 magnetic head element 11a APEX position 12 processing block body 12a end face (polishing surface) 15 first monitor pattern 16 second monitor pattern 17 protective layer (transparent layer)

Claims (5)

[Claims] 1. A lower magnetic pole layer is provided on a substrate, and a nonmagnetic material layer for a gap, an insulating layer for determining an APEX position, a predetermined number of coil layers, and insulation covering the coil layer are provided on the lower magnetic pole layer. A plurality of magnetic head elements are formed by laminating layers in a predetermined positional relationship and further forming an upper magnetic pole layer and a protective layer on the upper surface thereof, and then the substrate is arranged so that the magnetic head elements are arranged in a horizontal row. Of the APE is cut, and a predetermined surface of the cut member is ground, and the APE is cut from the ground surface.
In a method of manufacturing a thin film magnetic head, wherein a distance to X is formed to have a predetermined length, and further, a predetermined portion of the cut member is cut, in the cut member, from the polishing surface side to the back side. A pair of monitor patterns consisting of a first monitor pattern having a width gradually narrowing as it goes, and a second monitor pattern which is close to the first monitor pattern and defines a maximum allowable polishing position for the polishing is provided as the magnetic field. When forming the head elements, a plurality of sets are formed at predetermined positions of the magnetic head element rows arranged in the horizontal row, and the distance between the polishing surface and the APEX at the time of the polishing process is inspected. A method of manufacturing a thin film magnetic head, characterized in that it is performed by confirming from the appearance state of the pair of monitor patterns exposed to the side. 2. The method of manufacturing a thin-film magnetic head according to claim 1, wherein the second monitor pattern is formed at substantially the same position as an allowable range of the distance from the polishing surface to the APEX. . 3. The shape of the first monitor pattern,
3. The method of manufacturing a thin film magnetic head according to claim 1, wherein the thin film magnetic head has a substantially isosceles triangular shape having a height equal to that of the base. 4. The above-mentioned monitor pattern pair is covered with a transparent or semi-transparent member.
4. The method for manufacturing a thin film magnetic head according to any one of 3 above. 5. The method for manufacturing a thin film magnetic head according to claim 1, wherein at least one pair of the monitor pattern is formed close to each magnetic head element. .