JPH0762592A - Production of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To excellently form a magnetic film by electroplating on all the product parts on a ceramic substrate and to uniformize the film thickness distribution of each product part in the production of a thin-film magnetic head. CONSTITUTION:A conductive film is formed on a ceramic substrate, a photoresist pattern is formed thereon to form a magnetic film by electroplating, and the unnecessary magnetic film is removed by wet etching to form many magnetic pole patterns to constitute the product part. In this case, a part to be cut out as the product part 12 is formed at the part except the vicinity of the periphery of the substrate 10, and a dummy part 14 equivalent in shape to the product part is formed over the entire periphery to produce a thin-film magnetic head. Consequently, the variation of the product is suppressed, and the product yield is improved.

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. More specifically, when manufacturing a thin film magnetic head, a dummy part having the same shape as the dummy part is formed on the outer periphery of a product part on a ceramic substrate. The present invention relates to a method for improving the film thickness distribution of a magnetic film formed by electroplating by forming the film.

[0002]

2. Description of the Related Art In a thin film magnetic head for a hard disk, two upper and lower magnetic films (magnetic pole patterns) provided on a ceramic substrate (wafer: a slider after cutting and separating) are separated by a gap film, and a magnetic field is generated and induced between them. A coil film for current pickup is provided. The ceramic substrate has high hardness, and Al ₂ O ₃ (aluminum oxide) and Ti which have high electric conductivity as ceramics.
A mixed ceramic with C (titanium carbide) is used, on the surface of which a protective layer of Al ₂ O ₃ is provided. A thin film of permalloy (FeNi alloy) is used for the magnetic film. As a thin film forming method, there are a sputtering method and an electroplating method, and the electroplating method has an advantage that a film can be formed at a temperature near room temperature.

In the electroplating method, a magnetic pole pattern is formed by the following wafer processing. Al ₂ O ₃ -TiC
A conductive film is formed by a vapor deposition method on a ceramic substrate having an Al ₂ O ₃ protective layer provided on the surface of the substrate, and a photoresist pattern is provided so as to form a main magnetic film portion. Then, a magnetic film (permalloy or the like) is formed by electroplating. The formed magnetic film of each product portion has a main magnetic film that serves as a magnetic pole pattern of the thin film magnetic head in the center, and has unnecessary magnetic films that function as a yoke in the electroplating process on both sides thereof. Remove the photoresist pattern,
The conductive film in the portion without the magnetic film is removed by the ion milling method (ion beam etching method). Then, the main magnetic film is covered with a photoresist pattern to be protected, and the unnecessary magnetic film is removed by a wet etching method. afterwards,
The photoresist pattern is removed.

As shown in FIG. 2, a large number (for example, about 1,000) of product parts 12 having such a magnetic pole pattern are regularly arranged and formed on one substantially circular ceramic substrate 10. Finally, it is cut line by line with a dicing machine, and the cut bars are shaped as sliders, and then separated into individual pieces. Therefore, in order to facilitate the cutting work and the shape working work as a slider, as shown in the figure, the product is formed by a large rectangular block having the same shape, and the same number of product parts are present in one cut bar. Place groups.

In the prior art, the product portion having the magnetic pole pattern was formed only on the portion which is finally cut out as the product portion on the ceramic substrate. As described above, in order to improve the efficiency of the cutting work, the product groups are arranged so as to be grouped by a large rectangular block of the same shape. There was no blank area.

[0006]

The thickness of the magnetic film formed on the ceramic substrate must be uniform for each magnetic pole pattern (each product part). This is because the variation in film thickness directly affects the quality (characteristics) of the product part. If a large number of magnetic pole patterns are formed on a very large ceramic substrate by electroplating, the electroplating conditions will inevitably differ between the peripheral part and the central part, and even if the conditions are carefully set,
It is difficult to reduce the variation in the film thickness distribution of the magnetic film.

An object of the present invention is to enable good magnetic film formation by electroplating for all product parts on a ceramic substrate in the manufacture of a thin film magnetic head.
Further, it is to provide a method capable of making the film thickness distribution of each product part more uniform.

[0008]

According to the present invention, a conductive film is formed on a ceramic substrate, a photoresist pattern is provided on the conductive film to form a magnetic film by electroplating, and then the unnecessary magnetic film is wetted. In a method of arraying and forming a large number of magnetic pole patterns to be a product portion by removing by etching, a portion to be cut out as a product portion is formed in a portion except the vicinity of the outer periphery of the ceramic substrate, and the entire outer periphery thereof is
This is a method of manufacturing a thin film magnetic head in which a dummy part having a shape similar to that of a product part is formed.

[0009]

When the film thickness distribution when the magnetic film is formed by the electroplating method according to the prior art is examined, it has been found that the film thickness variation is large in the product portion on the outer peripheral side. This compares the product part on the outer peripheral side that has a part where the magnetic film pattern is disturbed in the adjacent part with the product part (the part near the center) where the magnetic film pattern is regularly arranged in all the adjacent parts. And the current density when performing electroplating is different. Therefore, as in the present invention, when a magnetic pole pattern having a shape similar to that of the product portion is formed as a dummy portion also on the outer peripheral portion of the product portion of the thin film magnetic head, the dummy portion has a buffer function for the product portion. As a result, the film thickness distribution of the product part is made uniform.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing an embodiment of the arrangement of product parts (magnetic pole patterns) according to the present invention. The manufacturing of the thin film magnetic head may be basically performed by the same process as the conventional process. A conductive film is formed by vapor deposition on a ceramic substrate having a protective layer of Al ₂ O _{3 on} the surface of an Al ₂ O ₃ —TiC substrate, and a photoresist pattern is provided to form a main magnetic film portion. Then, a magnetic film (permalloy or the like) is formed by electroplating. The formed magnetic film of each product portion has a shape in which the center is a main magnetic film that serves as a magnetic pole pattern of the thin film magnetic head, and both sides thereof are unnecessary magnetic films that function as a yoke in the electroplating process. The photoresist pattern is removed, and the conductive film in the portion without the magnetic film is removed by the ion milling method (ion beam etching method). Then, the main magnetic film is covered with a photoresist pattern for protection, and the unnecessary magnetic film is removed by a wet etching method. Then, the photoresist pattern is removed.

In the present invention, as shown in FIG. 1, a large number (for example, about 1,000) of product parts 12 having such a magnetic pole pattern are regularly arranged on one substantially circular ceramic substrate 10. To be done. Finally, it is cut line by line with a dicing machine, and the cut bars are shaped as sliders, and then separated into individual pieces. Therefore, in order to facilitate cutting work and shape working work as a slider, product group groups are arranged so that a single rectangular bar has the same number of product parts that are grouped together in a large rectangular block of the same shape. To do. Here, the feature of the present invention resides in that the dummy portion 14 having the same shape as the product portion is arranged and formed further outside the product portion 12 over the entire outer circumference thereof. Here, the dummy parts 14 are arranged one by one on the entire outer circumference of the product part 12.

The dummy portion 14 does not necessarily have to be a complete magnetic pole pattern, and may be a part of the magnetic pole pattern when the area of the outer periphery of the product portion 12 is small on a ceramic substrate. If the area is large, a plurality of dummy parts 14 may be arranged. In any case, as described above, the product portion 12 is arranged so that it can be easily and easily cut, and the shape of the cut bar can be easily processed. It is desirable to arrange so as to surround.

The film thickness of each product portion of one ceramic substrate was measured, and the average value, standard deviation, maximum value, minimum value, and R value (maximum value-minimum value) were obtained. Show. Use the same shape and same size ceramic substrate,
The conventional method and the method of the present invention were compared under the same conditions so that the same number of product parts were formed. According to the method of the present invention, a dummy part is provided on the entire outer circumference of the product part. The measurement points are for all product parts, totaling 10
There are 65 locations.

[0014]

[Table 1]

From this result, R / X = 2 in the conventional method.
7.8%, whereas in the method of the invention R / X = 17.
It was 4%, and it was confirmed that the film thickness distribution was improved by about 10%.

[0016]

As described above, the present invention is a method of forming a portion to be cut out as a product portion in a portion excluding the vicinity of the outer periphery of the ceramic substrate and forming a dummy portion having the same shape as the product portion over the entire outer periphery. Therefore, when the magnetic film is formed by electroplating, the dummy portion of the outer peripheral portion acts as a buffer against the product portion, and at least each product portion has the same magnetic pole pattern in the adjacent peripheral portion, so that the electric The variation in current density of plating is reduced, the film thickness distribution is made uniform, and the film thickness of the magnetic film formed over the entire product portion of the ceramic substrate is made more uniform. Therefore, variations in product characteristics are suppressed, and the manufacturing yield is improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of an arrangement state of product parts according to the method of the present invention.

FIG. 2 is an explanatory diagram of an arrangement state of product parts according to a conventional method.

[Explanation of symbols]

 10 Ceramic substrate 12 Product part 14 Dummy part

Claims (1)

[Claims] 1. A product part obtained by forming a conductive film on a ceramic substrate, providing a photoresist pattern on the conductive film, forming a magnetic film by an electroplating method, and then removing an unnecessary magnetic film part by a wet etching method. In a method of forming a large number of magnetic pole patterns in an array, a portion to be cut out as a product portion is formed in a portion except the vicinity of the outer periphery of the ceramic substrate, and a dummy portion having the same shape as the product portion is formed over the entire outer periphery. A method of manufacturing a thin film magnetic head characterized by the above.