JPS60171615A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the adhesive property between the bottom yoke and top yoke of a thin film magnetic head and to reduce the level difference at the rear end part of the top yoke so as to prevent a wire from being broken, by putting a thin film of a magnetic metal between rear ends of the bottom and top yokes. CONSTITUTION:A thin film of a magnetic metal is put between rear ends of the bottom yoke 2 and top yoke 6 of a thin film magnetic head having a magnetic gap composed of a lower insulating layer 3 between front ends of the bottom and top yokes 2 and 6. By putting the thin film, the adhesive property between the top and bottom yokes 6 and 2 is improved and the level difference at the rear end part of the top yoke 6 is reduced. Therefore, the thickness of the rear section of the top yoke 6 is increased and, as a result, prevention of wire breakage and reduction in magnetic reluctance can be contrived and, at the same time, possibility of over-etching to the bottom yoke is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thin film magnetic head in which a magnetic metal thin film layer is interposed between the rear ends of upper and lower yokes.

[Technical Background of the Invention] FIGS. 1 to 3 show the general configuration of a thin-film magnetic head, and FIG. 1 is a plan view partially shown in cross section;
FIGS. 2 and 3 are sectional views taken along mm and mm in FIG. 1, respectively.

In these figures, 1 is a slide glass.

The substrate is made of alumina or the like, and a lower yoke 2 is formed in a predetermined pattern on the upper surface of the substrate 1 using a magnetic material. Further, a lower insulating layer 3 made of silicon oxide or the like is formed on the upper surface of the substrate so as to cover the lower yoke. A spiral conductive pattern 4 made of copper, aluminum, gold, etc. is formed on the upper surface of the lower insulating layer 3 so as to pass between the lower yoke 2 and the upper yoke 6 one after another. has been done. An upper insulating layer 5 is formed on the upper surface of the lower insulating layer 3 so as to cover the entire area except for the inner end of the spiral conductive pattern 4, and a lower yoke covers the rear end of the spiral conductive pattern 4. An upper yoke 6 made of a magnetic material is formed in a predetermined pattern in close contact with the rear end of the yoke 2. Further, a magnetic gap 7 is formed between the front end of the lower yoke 2 and the front end of the upper yoke 6 by the lower insulating layer 3. In the figure, reference numeral 8.9 denotes a pair of lead wire connection terminals, one of which terminals 8 is connected to the inner end of the conductive pattern 4 and led out beyond the pattern 4. The other terminal 9 is connected to the outer end of the conductive pattern.

A thin film magnetic head having such a configuration is manufactured as follows.

(a) First, a magnetic material such as permalloy is deposited on the substrate 1 by vapor deposition or sputtering, a predetermined pattern is formed using photoresist, and etching is performed. After the etching is completed, the photoresist is peeled off to form the lower yoke 2. do.

(b) Next, on this lower yoke 2, a lower insulating layer 3 is formed in the same manner, (l) Further, a spiral conductive pattern 4 is formed thereon in the same manner.

(d) Thereafter, polyimide or the like is applied to a thickness of about 10 μm, thermally cured, and then etched to form the upper insulating layer 5.

(e) Next, permalloy or the like is deposited by vapor deposition or sputtering, and the upper yoke 6 is formed by etching.

Note that 10 in the figure is a medium such as a magnetic tape that is used in contact with the front ends of the yokes 2 and 6.

[Problems with the Prior Art] In the thin-film magnetic head configured as described above, in order to form a magnetic circuit between the lower yoke 2 and the upper yoke, both yokes 2.6 must be in close contact between their rear ends. However, in conventional thin-film magnetic heads, the adhesion in this area is not necessarily sufficient, and there is a risk that magnetic resistance may increase. Also, when etching through holes in the upper insulating layer 5 at the connection portion between the lower yoke 2 and the upper yoke 6,
Since the degree of etching is not known, there is a risk that the lower insulating layer 3 will be over-etched, which poses a major problem in manufacturing. Furthermore, since almost the entire area of the conductive pattern 4 is covered with the upper insulating layer 5, there is a problem in that the heat dissipation effect is poor and the conductive pattern 4 becomes overheated. Therefore, if the thickness of the pattern 4 is increased in order to reduce the resistance value and prevent overheating, the upper yoke 6 shown in FIG.
Since the step H at the rear end increases accordingly, the thickness at the step at the rear of the upper yoke 6 becomes thinner, creating a risk of wire breakage. The magnetic resistance of the magnetic circuit increases, and as a result, there is a risk that the level of the electrical signal sent through the connection terminals 8 and 9 will decrease.

Purpose of the Invention] The present invention was made based on the above circumstances, and its purpose is to improve the adhesion between the lower yoke and the upper yoke, and to reduce the step at the rear end of the upper yoke. It is an object of the present invention to provide a thin film magnetic head which is easy to manufacture and which prevents wire breakage and reduces magnetic resistance by increasing the thickness of the rear part of the upper yoke, and which is free from the risk of over-etching the lower yoke.

[Summary of the Invention] In order to achieve the above object, the present invention sequentially stacks a lower yoke made of a magnetic material, a lower insulating layer, a conductive pattern, an upper insulating layer, and an upper yoke made of a magnetic material on a substrate, and In a thin film magnetic head in which a magnetic gap is formed by the lower insulating layer between the front end of the lower yoke and the front end of the upper yoke, a magnetic metal thin film layer is interposed between the rear end of the lower yoke and the rear end of the upper yoke. It is characterized by:

[Embodiment of the Invention] FIG. 4 shows an embodiment of the present invention, and is a sectional view of a portion of a thin film magnetic head corresponding to FIG. 2.

As shown in the figure, a lower yoke 2 made of a magnetic material, a lower insulating layer 3, a conductive pattern 4, an upper insulating layer 5, and an upper yoke 6 made of a magnetic material are sequentially laminated on a substrate 1. A magnetic gap 7 is formed by the lower insulating layer between the front end of the upper yoke 6 and a magnetic metal such as chromium, titanium, etc. between the rear end of the lower yoke 2 and the rear end of the upper yoke 6. Thin 1111111 is inserted. Further, lead wire connection terminals 8 and 9 are connected to the inner and outer ends of the conductive pattern 4, respectively (not shown in FIG. 4). In addition, in Figure 4, the first
Components that are the same as those in the figures through FIG. 3 are designated by the same reference numerals.

Therefore, this thin film magnetic head can be manufactured as follows.

(a) First, a substrate 1 made of slide glass, alumina, etc.
A magnetic material such as permalloy is deposited thereon by vapor deposition or sputtering, a predetermined pattern is formed using photoresist, and etching is performed. After the etching is completed, the photoresist is peeled off to form the lower yoke 2.

(b) Next, on this lower yoke 2, a magnetic metal thin film layer 11 made of chromium, titanium, etc. and having a thickness of 0.5 μm or less is formed in the same manner, (C) Next, a lower part made of silicon oxide etc. An insulating layer 3 is formed in a similar manner, and (d) a spiral conductive pattern 4 consisting of one layer or multiple layers is further formed thereon in a similar manner.

(e) Thereafter, an insulating material such as polyimide is applied to a thickness of about 10 μm using a spinner, cured by heat, etched, and the photoresist is peeled off to form the upper insulating layer 5.
form.

(f) Next, permalloy or the like is deposited by vapor deposition or sputtering, and the upper yoke 6 is formed by etching.

By interposing the magnetic metal thin film layer 9 between the rear end of the lower yoke 2 and the rear end of the upper yoke 6 as described above, the adhesion between the rear ends of the lower yoke 2 and the upper yoke 6 is improved. Moreover, since the step H' at the rear end of the upper yoke 6 is reduced by the thickness of the magnetic metal thin film layer 11, the magnetic resistance can be reduced. By reducing the step H-, the thickness at the step at the rear of the upper yoke 6 can be increased, and wire breakage can be prevented. Furthermore, when performing through-hole etching in the upper insulating layer 5 at the connecting portion between the lower yoke 2 and the upper yoke 6, the lower insulating layer 3 can be protected by the magnetic metal thin film layer 11, and the lower insulating layer 3 can be protected by the magnetic metal thin film layer 11.
There is no risk of over-etching, and therefore manufacturing is facilitated. Furthermore, in order to prevent the conductive pattern 4 from overheating, the thickness of the pattern 4 can be slightly increased if necessary.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to improve the adhesion between the lower yoke and the upper yoke, and to increase the thickness of the stepped portion at the rear of the upper yoke. It is also possible to prevent wire breakage and reduce magnetic resistance, and there is no fear of over-etching of the lower insulating layer, making it possible to provide a thin-film magnetic head that is easy to manufacture.

[Brief explanation of drawings]

1 to 3 show the general structure of a thin-film magnetic head, and FIG. 1 is a plan view partially shown in cross section;
FIGS. 2 and 3 are sectional views along nm and mm in FIG. 1, respectively, and FIG. 4 is a sectional view corresponding to FIG. 2 showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Lower yoke, 3... Lower insulating layer, 4... Conductive pattern, 5... Upper insulating layer, 6
... Upper yoke, 11... Magnetic metal thin film layer. Applicant's representative Patent attorney Takehiko Suzue Figure 4 Commissioner of the Patent Office Kazuo Wakasugi 1. Indication of the case Patent application 1982-27447 g 2. Name of the invention Thin film magnetic head 3, moss FF 113 Relationship to the beach incident Patent applicant (35G) Tokyo Electric Co., Ltd. 4, Agent 6, Amended edge drawing 7, Contents of amendment: Engraving of the drawing (no change in content)

Claims (2)

[Claims] (1) A lower yoke made of a magnetic material, a lower insulating layer, a conductive pattern, an upper insulating layer, and an upper yoke made of a magnetic material are sequentially laminated on a substrate, and the lower yoke is placed between the front end of the lower yoke and the front end of the upper yoke. A thin film magnetic head characterized in that a magnetic gap is formed by an insulating layer and a magnetic metal thin film layer is interposed between the rear end of the lower yoke and the rear end of the upper yoke. (2) v as set forth in claim (1), wherein the magnetic metal thin film layer is made of chromium or titanium.
sM magnetic head.