JPS6246416A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent a coil conductor from being subjected to disconnection and deterioration in characteristics by half-etching an insulating layer in contact with an upper magnetic film at the formation part of the upper magnetic film and keeping the insulating layer other than the formation part of the upper magnetic film at its original thickness. CONSTITUTION:Since the 3rd insulating layer 16 is thinned with thickness Tb by half etching at the formation part of the upper magnetic film 18, a difference in the level of the upper magnetic film 8 can be reduced and its inclination can be reduced. Consequently, the characteristics can be prevented from deterioration. Since the 3rd insulating layer 16 other than the formation part of the upper magnetic film 18 is kept at thickness Ta, the 2nd coil conductor 15 is protected and the 2nd coil conductor 15 can be prevented from disconnection due to overetching at the formation of the upper magnetic film 18.

Description

[Detailed description of the invention] Industrial field of application The present invention is directed to PCM (Pulse Code Mocl).
(1) The present invention relates to a thin film magnetic head used in recording/reproducing devices and the like.

The present invention provides a thin film magnetic head in which a coil conductor and an upper magnetic film are provided on a substrate with an insulating layer interposed therebetween, in which the insulating layer in the area where the upper magnetic film is formed is formed thinner than in other parts. The steps of the upper magnetic film are reduced to prevent deterioration of characteristics, and the coil conductor is also prevented from being over-etched in areas other than the area where the upper magnetic film is formed.

C4 Conventional technology Thin film magnetic heads used in PCM recording and reproducing devices, etc.
Generally, it has a structure in which a coil conductor, an upper magnetic film, etc. are laminated on a substrate (lower magnetic material). Further, an insulating layer is usually provided between the coil conductor and the upper magnetic film. This insulating layer has the function of maintaining insulation between the coil conductor and the upper magnetic film (insulating function), as well as the function of preventing disconnection of the coil conductor due to over etching during the formation of the upper magnetic film (
wire breakage prevention effect).

D0 Problems to be Solved by the Invention By the way, the above-mentioned two effects of the insulating layer are dependent on the thickness of the insulating layer. That is, for both of the above-mentioned effects of the insulating layer, it is preferable that the insulating layer be thicker, and more excellent effects can be obtained. Note that the effect of thickness on the insulation effect is small and can be almost ignored.

However, when the above insulation layer is made thicker, the step of the upper magnetic film formed on the coil conductor through the insulating layer increases, resulting in a decrease in the magnetic path cross-sectional area and the occurrence of cracks at this step, resulting in deterioration of the characteristics. This will cause deterioration. Also,
Opposite 1: If the insulating layer is made thinner, the step difference in the upper magnetic film becomes smaller, but there is a risk that the above-mentioned disconnection prevention effect will be impaired and the coil conductor will be disconnected.

Therefore, the present invention has been proposed in view of the above-mentioned conventional problems, and provides a thin film magnetic head that can prevent disconnection of the coil conductor and reduce the step difference in the upper magnetic film to prevent deterioration of characteristics. The purpose is to provide

In order to achieve the above-mentioned object, a thin film magnetic head according to the present invention includes a thin film magnetic head in which a genus number of coil conductors and an upper magnetic film are laminated on a substrate with an insulating layer interposed therebetween. It is characterized by the fact that the insulating layer in contact with the film is half-etched in the area where the upper magnetic film is formed.

21 Effects According to the present invention, since the insulating layer is half-etched in the portion where the upper magnetic film is formed, an upper magnetic film with small steps can be obtained.

Furthermore, since the insulating layer has a sufficient thickness in areas other than the area where the upper magnetic film is formed, the coil conductor is not over-etched when the upper magnetic film is etched.

G. Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1(A), the thin film magnetic head of this embodiment is of a two-channel type, and valley heads 1 and 2 are formed symmetrically. Hereinafter, I-It! in FIG. 1 (A) and FIG. 1 above). i! This will be explained with reference to FIG. 1 (Bl), which is a cross-sectional view. A first coil conductor 13 is formed in a loop shape on a substrate (lower magnetic material) 11 with a first insulating layer 12 in between.

The substrate 11 may be made of Mn-Zn ferrite or Mi.
- Fe-Ni alloy (Permalloy) or Fe-AJ -8i alloy (Sendust) on a ferromagnetic oxide substrate made of Zn-based ferrite, etc., or a non-magnetic substrate such as ceramic
A composite substrate formed by laminating ferromagnetic metal materials such as ferromagnetic metal materials, or a composite substrate formed by laminating ferromagnetic metal materials such as permalloy or sendust on the ferromagnetic oxide substrate is used.

Further, a second insulating layer 14 is formed on the first coil conductor 13, and a second coil conductor 14e1C-hZ++ connected to the first coil conductor 13 is formed on the second insulating layer 14.
,--f@shihlr3shi/,lbora'-QJ-1?1-
The iZLir conductor 13 and the second coil conductor 15 are both made of Cu, AJ, or the like.

Further, an eighth insulating layer 16 is formed on the second insulating layer 14 and the second coil conductor 15, and a gap film 17 serving as a magnetic gap g is formed on the substrate 11 on the front gap side.
is formed of 5in2 or AjlzOa or the like.

The first to third insulating layers 12, 14, and 16 are also made of SiO2, Anion, or the like. In addition, the gap film 17
And on the third insulating layer 16, a loop-shaped coil conductor 1
An upper magnetic film 18 made of Sendust or the like is formed to straddle 3.15 and bond to the substrate 11 on the back gap side.

Here, the third insulating layer 16 in contact with the upper magnetic film 18 is formed to have a thickness Tb in the portion where the upper magnetic film 18 is formed, and to have a thickness Ta in other portions. Here, Ta is the thickness necessary to protect the second coil conductor 15 from over-etching during the formation of the upper magnetic film 18, Tb is the thickness required to reduce the step height of the upper magnetic film 18, and lf 7th grade If five monkeys 107. Bunaa Next, in order to make the present invention more clear, a method for manufacturing the above-mentioned thin film magnetic head will be schematically explained with reference to FIGS. 2 to 6.

tf. As shown in FIG. Second coil conductor 13
．． 15 are sequentially formed by, for example, sputtering, photolithography, or the like.

In this step, the third insulating layer 16 is formed to have a thickness of Ta.

Next, as shown in FIG. 3, the resist is patterned in a pattern that is an inversion of the pattern of the upper magnetic film 18 that will be formed in a later step.

Next, half etching is performed using RIE (reactive ion etching) or the like, and as shown in FIG. Let Tb be the thickness at the part). The amount of etching at this time is Ta-Tb. Further, at the same time, the edge portion can be sloped so that the one step difference caused by the third insulating layer 16 becomes gentle.

A magnetic film 18a, which will become the upper magnetic film 18, is deposited over the entire surface.

Then, pattern etching is performed to form an upper magnetic film 18 as shown in FIG. 6, thereby completing a thin film magnetic head.

According to the thin film magnetic head of this embodiment, the third insulating layer 16 is formed thinly (thickness T) by half etching in the portion where the upper magnetic film 18 is formed, so that the step of the upper magnetic film 18 can be reduced. It can be made smaller and the slope can be made gentler. Therefore, deterioration of characteristics can be prevented. Furthermore, since the thickness of the third insulating layer 16 other than the portion where the upper magnetic film 18 is formed is maintained at Ta, the second coil conductor 15 is protected and the second coil conductor 15 is protected from over-etching when the upper magnetic film 18 is formed. It is possible to prevent wire breakage.

Additionally, in general, in multi-channel thin film magnetic heads where the pitch between each head is narrow, when forming the upper magnetic film, the magnetic film that becomes the upper magnetic film between the valley heads tends to be difficult to etch. According to the example thin film magnetic head,
As shown in FIG. 7, the step difference in the magnetic film 18a that becomes the upper magnetic film 18 between each head 1 and 2 becomes smaller, and even if the resist 21 is somewhat thick, the etching speed is reduced due to the shadow effect. The magnetic film 18a between the heads 1 and 2 can be etched relatively easily. Note that the coil portions 22.22 below the third insulating layer 16 each consist of a coil conductor 13.15 and an insulating layer 12.14, but detailed illustration is omitted.

Effects of the Invention As is clear from the description of the embodiments described above (0), according to the thin film magnetic head according to the present invention, the insulating layer in contact with the upper magnetic film is half-etched at the portion where the upper magnetic film is formed. , it is possible to obtain an upper magnetic film with a small step difference, and it is possible to prevent deterioration of characteristics.
Since the upper magnetic film is placed on the upper magnetic film, the coil conductor is protected, and disconnection of the coil conductor due to over-etching during formation of the upper magnetic film can be prevented. Therefore, a thin film magnetic head having excellent recording/reproducing characteristics can be obtained, and the reliability of the thin film magnetic head can be improved.

[Brief explanation of the drawing]

FIG. 1 (Al is a plan view showing the main part configuration of an embodiment of a thin film magnetic head according to the present invention, FIG. 1 (Bl is a plan view of FIG. 1 (A)
It is a 1-1 sectional view in . 2 to 6 are schematic cross-sectional views showing the manufacturing method of the thin film magnetic head of the above embodiment in the order of steps. FIG. 2 is a coil conductor and insulating layer forming step, FIG. 3 is a resist coating step, and FIG. The figure shows a half-etching process by RIE, FIG. 5 shows an upper magnetic film forming process,
FIG. 6 shows the upper magnetic film etching process. FIG. 7 is a schematic cross-sectional view between the valley heads. 11・・・・・・・・・Substrate

Claims (1)

[Claims] In a thin film magnetic head in which a plurality of layers of coil conductors and an upper magnetic film are laminated on a substrate with an insulating layer interposed therebetween, the insulating layer in contact with the upper magnetic film is a forming part of the upper magnetic film. A thin film magnetic head characterized by being half-etched.