JPH06124418A - Manufacture of substrate for thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the accuracy of a gap depth after a sliding face is ground and to prevent the processing distortion on the surface of a substrate by forming the substrate of a thin film magnetic head through electrolytic etching with the use of a photomask after preliminary mechanical processing. CONSTITUTION:A plurality of glass grooves 12 are formed on the surface of a ferrite substrate 11. A photoresist mask 14 is formed on the upper surface of the grooves 12. Electrolytic etching is performed to the parts of the grooves 12 with the use of an electrolyte such as phosphoric acid, sulfuric acid or the like. After etching, the mask 14 is removed and a non-magnetic material 13, e.g. glass or the like is molded to make a substrate surface 15 flat. As a result, the substrate for a thin film magnetic head is obtained. The mechanical processing is conducted with high accuracy, the variability of the recording/ reproducing outputs is reduced and the magnetic characteristic 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 magnetic head substrate, which is suitable for obtaining a thin film magnetic head having good magnetic recording / reproducing characteristics used in, for example, a DCC tape recorder. A method of manufacturing a substrate for use is provided.

[0002]

2. Description of the Related Art A conventional method for manufacturing a substrate for a thin film magnetic head has been performed according to the procedure shown in FIG. First, as shown in FIG. 2A, a plurality of glass grooves 2 are formed on the surface of a thin film magnetic head substrate 1 made of ferrite or the like by a machining method such as dicing, and then as shown in FIG. A non-magnetic material 3 such as glass is molded, and the substrate surface 5 is flattened and polished as shown in FIG. 2C to obtain a substrate for a thin film magnetic head. Next, as shown in FIG. 2D, the thin film magnetic head element is formed by stacking thin films on the substrate by aligning the mask with the glass groove end face as a reference, stacking and flattening the passivation film 7, Mirror surface polishing of the medium sliding surface 9 by adhesion of the protective plate 8, line segmentation, cylindrical grinding and tape polishing,
A head chip was obtained by sequentially performing chip cutting.

[0003]

In the conventional thin film magnetic head substrate described above, when a plurality of rows of head chip elements are formed on a magnetic substrate made of ferrite or the like, a glass groove (groove portion) is machined (dicing). Etc.) and there was a problem in processing accuracy. This variation in processing accuracy (straightness or pitch) leads to variation in the gap depth (Gd) after polishing the sliding surface, and eventually to variation in recording / reproducing output. Also, in machining such as dicing, processing strain occurs near the surface of the ferrite substrate after processing the groove,
There is a problem that the magnetic characteristics are deteriorated.

In view of the above problems, the present invention is for a thin film magnetic head capable of accurately producing a gap depth (Gd) after polishing a sliding surface and preventing processing distortion from occurring on a substrate surface after processing a groove. It is to provide a method for manufacturing a substrate.

[0005]

According to the present invention, a step of forming a groove portion narrower than a required width by machining on a magnetic substrate, a step of forming a photomask for etching the groove portion, electrolytic etching, etc. And a step of enlarging the width of the groove portion according to the above step to manufacture a thin film magnetic head substrate.

[0006]

According to the present invention, after the groove is formed by machining in advance, etching or the like is performed as the correction processing of the groove. At the time of this post-treatment (etching), it suffices to carry out abrasive etching after forming the groove portion by machining in advance, so that the treatment time may be short. Further, the etching is performed in a state where a photomask is formed in the groove portion, and this photomask is formed at an accurate position by alignment regardless of the position of the groove portion formed by machining. Therefore, even if the position of the groove formed by machining is displaced, the position of the groove is corrected during the etching process and the groove is formed at an accurate position. Further, the machined surface is removed by etching to remove the magnetostriction due to the machining.

[0007]

1 (A) to 1 (E) are sectional views showing an embodiment of a method of manufacturing a substrate for a thin film magnetic head according to the present invention.

First, as shown in FIG. 1A, a plurality of glass grooves 12 are formed on the surface of a ferrite substrate 11 by a machining method such as dicing. Next, as shown in FIG. 2B, a photoresist mask 14 is formed on the upper surface of the glass groove 12, and, for example, phosphoric acid (H ₃ PO ₄ ) or sulfuric acid (H ₂ S) is used.
The glass groove 12 is electrolytically etched using an electrolytic solution such as O ₄ ). The photoresist mask 14 is formed so as to form the glass groove 12 'at a position determined by the design, regardless of the glass groove 12 formed by the machining method, and the etching process is performed in that state. After the etching process, the photoresist mask 14 is removed, a non-magnetic material 13 such as glass is molded as shown in FIG. 1C, and then a substrate surface 15 is formed as shown in FIG.
Is planarized and polished to obtain a thin film magnetic head substrate.

As shown in FIG. 1D, the glass groove end surface 16
After forming a thin film magnetic head element by stacking a thin film on a substrate by aligning a mask based on the above, a passivation film 17 is stacked and flattened, and a protective plate 18 is adhered, line cutting, cylindrical grinding and tape are performed. Polishing is performed and the medium sliding surface 19
Is mirror-polished and divided into chips to obtain a head chip as shown in FIG.

[0010]

According to the present invention, the following effects can be obtained by obtaining the substrate of the thin-film magnetic head by electrolytically etching that portion after preliminary machining by using a photomask.

The machining accuracy can be improved to ± 0.25 μm, which is one digit or more, as compared with the machining accuracy of ± 3 μm, and the variation of the gap depth (Gd) and thus the recording / reproducing output can be improved.

By removing the processing strain on the groove surface, the magnetic characteristics can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing procedure of a substrate for a thin film magnetic head according to the present invention.

FIG. 2 is a diagram showing a procedure for manufacturing a conventional thin film magnetic head substrate.

Claims (1)

[Claims] 1. A step of forming a groove portion narrower than a required width by machining on a magnetic substrate, a step of forming a photomask for etching the groove portion, and a width of the groove portion being enlarged by electrolytic etching or the like. And a method of manufacturing a substrate for a thin film magnetic head, the method including: