JPS61240419A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To improve the grinding precision of the titled magnetic head by partially etching a protective film to expose a mark setting pattern which is formed simultaneously with the production of a magnetic head element and using the mask setting pattern as the position standard to form a stock removal measuring pattern on the protective film. CONSTITUTION:An upper protective film on the region including a mask setting mark is etched and removed. A pattern of a nonmagnetic film for regulating the zero-depth of the gap of a magnetic head element is used for the mask setting mark and used as a standard for positioning the end part on the leading end side of the head. A grinding mark is formed on the upper protective film by using the exposed mask setting mark as the standard. Although the material of the grinding mark is not limited, metals are generally used in consideration of the excellent visibility and Au, Cu, Al, Ti, etc., can be satisfactorily used. The substrate is cut, ground and polished to obtain the final head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for ensuring final polishing accuracy of a magnetic head in which magnetic poles, coils, etc. are manufactured from thin films.

[Summary of the invention]

The present invention provides a magnetic head in which a protective film is formed on magnetic head elements such as magnetic poles, coils, and gaps that are manufactured using thin film technology, and a pattern for measuring the polishing amount is formed on the protective film with high precision. It also improves the polishing accuracy of magnetic heads.

[Prior art]

The thin film magnetic field for Winchester disk drives is A40° or Bi for protection on the magnetic field element.
The OH oxide protective film ht2a~40μ is usually formed by important people. Although these protective films are transparent, due to their refractive index, the amount of polishing can be measured using a combination of ordinary white light and an optical microscope, which does not meet the Fi measurement accuracy required.

First of all, mIK4 as a corresponding technology? Improving measurement accuracy by using a special wavelength, and forming an electric resistance element on IF5 at the same time to confirm the amount of polishing when manufacturing the magnetic head element.
A common method is to measure the amount of polishing by detecting the absolute value of the resistance or the disconnection of the resistor.

[Problems and Objectives to be Solved by the Invention] However, the first corresponding technique requires special equipment and has limitations on the material of the protective film. In the second corresponding technique, the resistance measurement terminal must be brought into contact with the head, and furthermore, it is difficult to manufacture a resistance element that measures a wide range.

The present invention is intended to solve these problems, and its purpose is to provide a polishing amount measuring method that uses a non-contact measurement and a normal optical system, and is not limited to the protective film material bS. shall be.

[Means to solve the problem]

The magnetic head manufacturing method of the present invention involves partially etching the protective film to expose nine mask alignment patterns that are simultaneously formed at the time of manufacturing the magnetic head element, and using the mask alignment patterns as positional references to etch the mask on the protective film. A pattern for measuring the amount of polishing is formed, and this pattern is detected optically and transferred to a magnetic field.
It is characterized by performing hard polishing.

[Operation] According to the above configuration of the present invention, the positional accuracy of the polishing amount measurement pattern that is created simultaneously with the magnetic head element and is formed based on the mask alignment pattern is verified. 41 more
i! Since a pattern for measuring the amount of polishing is formed on the protective pattern,
The amount of polishing can be precisely measured using an ordinary optical microscope at any step such as after cutting the substrate, before polishing, during polishing, after polishing, etc. Moreover, since the protection III is not formed on the pattern for measuring the amount of polishing, the measurement accuracy is not affected in any way even if the material of the protection film is changed. Therefore, according to the present invention, it is possible to manage the amount of polishing with high precision.

〔Example〕

As an embodiment of the present invention, the manufacturing process of a magnetic head will be described in terms of the steps after the stage where a magnetic head element is formed by a thin film process.

1) Formation of upper protective film. A thin film of alumina, silicon oxide, silicon nitride, etc. is formed by a thin film forming method such as sputtering to protect the magnetic hedad element. Film thickness is 20
It is larger than the total thickness of the magnetic head element by ~50 μm.

++) Upper protective film 9 pin, poly, and sing.

Upper part 41@Ratabbing is performed to eliminate unevenness on the film and obtain a flat surface. The abrasive grains are diamond or silicon carbide, and the polishing disc is a tin disc or a plastic disc.

Next; (Mechanochemical polysing or sputter etching in vacuum is performed to remove the process-affected layer. At this stage, the lead wire is bonded to the lead electrode #
'i Be exposed.

If not exposed, it will be exposed in step 111).

Ill) Upper protective film etching. As shown in FIG. 1, the upper protective film in the area containing the mask alignment mark, that is, the area surrounded by the dotted line in FIG. 1, is removed by etching.

The mask alignment mark uses a pattern of a nonmagnetic film that defines the position of the zero gap depth of the magnetic head element, and the position of the end on the head tip side is used as the basis for alignment. By doing this, the position of zero gear depth can be determined even if the nonmagnetic film is formed using a 7-photoresist and heat-treated to cause it to sag and thereby disrupt the pattern accuracy.

lv) Polishing mark formation. Manifested in step 111)
Top based on the mask alignment mark! Forming polishing marks on the protective film. The shape of the polishing mark is not particularly limited, but may be one as shown in Figure TA2, for example. There are no restrictions on the material of the polishing mark, but metal is generally used from the viewpoint of good car visibility, and AU, Oπ, At, Ti, etc. may be used.

■] Extraction electrode processing. After the electrical connection of the electrode portion for bonding the lead wire is made good, the altered layer on the surface of the electrode portion is removed by sputter etching to form a fresh film on the electrode portion. If the polishing mark in step IV) is AM, it can be formed at the same time as step IV) and step 11 V) can be omitted.

After step V), the substrate is cut, ground, and polished to complete the final head.

As is clear from this example, the polishing mark accurately indicates the zero depth position of the gear tab. Moreover, this polishing mark is formed on the upper protective film and can be easily observed at all times.

Although the polishing marks are exposed, there is no problem if a film formation method that provides high adhesion, such as sputtering, is used. Third
There will be no problem if it is placed in a position that will not be affected by grinding and polishing as shown in the figure.

rEffects of the Invention] As stated above, according to the present invention, by providing a pattern for measuring the amount of polishing on the upper protective film, the amount of polishing can always be measured.
Since it can be easily and accurately performed, and the position of the mask pattern can be accurately confirmed, the polishing amount measurement pattern can be formed with high precision. Therefore, according to the present invention, it is possible to accurately measure the amount of grinding and polishing, and an effect that greatly contributes to improving the yield of magnetic heads can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view of a magnetic head substrate on which magnetic head elements are formed. FIGS. 2 and 3 are schematic diagrams showing examples of polishing marks. 1...Substrate 2...Magnetic head element 3...Mask alignment mark 4...Top protected film etching region 5...
・Magnetic pole 6... Polishing mark 7... Reference line for zero gap depth Genjin Kamide Suwa Seikosha Co., Ltd.

Claims (1)

[Claims] (1) a) A magnetic head in which magnetic poles, electrical conductors, electrical insulators, gap spacers, etc. are formed and laminated as thin films on a substrate, and a protective film layer is formed thereon, b) After the protective film is formed, A method for manufacturing a magnetic head, comprising: etching the protective film on the mask alignment pattern; c) providing on the protective film a polishing amount measurement pattern positioned by the mask alignment pattern.