JPH10233008A - Manufacture of thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately form a pole part of an upper magnetic pole. SOLUTION: The manufacture of the thin magnetic head is performed to establish its structure by layering a lower magnetic pole 14 on a substrate 12, a gap layer 16, a gap depth position regulating insulation layer 18, a coil layer 22 held by an insulation layer 20 and an upper magnetic pole 24 in order in this method. After forming the lower magnetic pole 14, the gap layer 16 and the gap depth position regulating insulation layer 18, the pole part 24a of the upper magnetic pole 24 and its adjacent part 24c are formed. Afterward, the coil layer 22 in a required number of stages held by the insulation layer 20 is formed, and a yoke part 24b of the upper magnetic pole 24 is provided on this coil layer 22 so as to be overlapped with and continued to the adjacent part 24c of the upper magnetic pole 24. It is preferable that the pole part 24a of the upper magnetic pole 24 and its adjacent part 24c are formed to cover an apex part at the tip of the gap depth position regulating insulation layer 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a thin-film magnetic head, and more particularly to a method of forming an upper magnetic pole thereof. More specifically, according to the present invention, the step of forming the upper magnetic pole is divided into a step of forming a pole part and its vicinity, and a step of forming a yoke part. Performed after the step of determining the position of the coil and before the step of forming the coil layer,
The present invention relates to a method for manufacturing a thin film magnetic head in which an upper magnetic pole is formed by forming a yoke after a step of forming a coil layer. This technique is useful for a method of manufacturing various thin film magnetic heads for a hard disk drive.

[0002]

2. Description of the Related Art There are various types of thin-film magnetic heads for hard disk drives, and typical examples thereof include an induction type and an MR composite type. The induction type has a configuration in which two upper and lower magnetic poles provided on a substrate are separated by a gap layer, and a coil layer for generating a magnetic field and for induction current pickup is interposed between the two magnetic poles. The MR compound type uses an MR effect (magnetoresistive effect) for reading (reproducing) information, and uses upper and lower magnetic poles and a magnetic field generating coil layer similar to the induction type for writing information. In these, the upper and lower magnetic poles are usually made of a plating layer of a magnetic material such as a NiFe alloy, and are formed with a necessary thickness in a portion defined by the resist.

FIG. 2 is a plan view of an example of an inductive type thin film magnetic head, and FIG. 3 shows a vertical cross section (y-y cross section) of the head element portion 10. Ceramic substrate 1 serving as slider
2, a lower magnetic pole 14, a gap layer 16, a gap depth position defining insulating layer 18, a coil layer 22 sandwiched between insulating layers 20, and an upper magnetic pole 24 are laminated in this order. The gap layer 16 includes a lower magnetic pole 14 and an upper magnetic pole 24.
To form a predetermined magnetic gap in the storage medium facing surface. The upper magnetic pole 24 is composed of a narrow pole portion 24a and a wide yoke portion 24b having a spreading structure continuing from the pole portion 24a. The lower magnetic pole 12 is substantially the same. The coil layer 22 is formed in one or a plurality of layers (two in FIG. 3), and recently, a three- to four-layer structure is developed as the number of coil turns increases. Thus, the head element section 10
Is configured. From the coil layer 22, the coil end is pulled out to the terminal formation position by the coil lead wire pattern 26, and a terminal 28 for attaching an external lead wire is provided at that position. Note that the entire element portion is covered and protected by the protective layer 29.

[0004] Here, the width of the pole portion 24a of the upper magnetic pole 24 is what is called a "core width", which corresponds to the track width. To increase the recording density, it is important to reduce the track width. At present, a core having a width of about 3 μm is commercialized, but attempts are being made to further narrow the track.

[0005] Such a head element section 10 is manufactured through the following steps (see FIG. 4). In FIG. 4, for simplification of the drawing, the number of coil layers is only one, but actually, the coil layers are stacked in two to four layers. (A) First, a lower magnetic pole 14 having a predetermined shape is formed on a ceramic substrate 12 using a photoresist, and a gap layer 16 of alumina is formed on the ceramic substrate 12 including the lower magnetic pole 14.
To form (B) Next, on the gap layer 16, an insulating layer 18 for defining a gap depth position (Apex position) is provided. (C) The coil layer 22 and the insulating layer 20 are provided on the gap depth position defining insulating layer 18 by a required number of steps (about 2 to 4 steps).
Laminate sequentially. (D) Patterning is performed thereon by using a photoresist 30 to form the upper magnetic pole 24 having a predetermined shape. (E) An upper magnetic pole 24 is formed on the patterned portion by electroplating. (F) Then, the attached resist 30 is removed.

[0006]

The height A ₁ of the element portion immediately after the formation of the uppermost insulating layer 20 is about 15 μm even when the coil layer has two steps. In this state, the upper magnetic pole 2
4 (thickness: about 4 μm), in order to prevent plating from overflowing, the resist 30 has a resist film thickness B ₁ of 5 at the portion on the insulating layer 20 where the film thickness is minimum.
A thickness of about 1 μm is required, and in this state, the resist film thickness C ₁ reaches about 20 μm at the point where the thickness of the resist at the pole portion is maximum. When the number of coil turns increases and the coil layer increases in three or four steps, the resist film thickness becomes increasingly thicker. For example, in the case of four steps, the resist film thickness at the pole portion becomes the maximum. in the resist film thickness C ₁ 40
About 45 μm.

As described above, the width (core width) of the magnetic pole for writing / reading information, particularly the pole portion of the upper magnetic pole, determines the track width. In the above example, it is about 3 μm. In the future, it is considered that the width of the magnetic pole will be further narrowed for higher density (narrower track), and it is required to form a magnetic pole pole portion with high precision and narrow width.
When forming the upper magnetic pole, especially in the pole portion, the resist film becomes thicker and thicker as the number of coil layers increases on the one hand, and the track width becomes narrower and deeper as the density becomes higher. Since a pattern must be formed, it is extremely difficult to form a pattern with high precision.

An object of the present invention is to provide a method of manufacturing a thin-film magnetic head capable of forming a pole portion of an upper magnetic pole with high accuracy.

[0009]

According to the present invention, a lower magnetic pole, a gap layer, an insulating layer defining a gap depth position, a coil layer sandwiched by insulating layers, and an upper magnetic pole are laminated on a substrate in this order. This is a method of manufacturing a thin film magnetic head having a structure.
Here, the feature of the present invention is that after forming a lower magnetic pole, a gap layer, and a gap depth position defining insulating layer, a pole portion of an upper magnetic pole and its vicinity are formed, and then the required number of steps sandwiched by the insulating layers is reduced. The point is that a coil layer is formed, and a yoke portion of the upper magnetic pole is provided on the coil layer so as to overlap and be continuous with the vicinity of the pole of the upper magnetic pole. Preferably, the pole portion of the upper magnetic pole and the vicinity thereof are formed so as to cover the tip apex portion of the gap depth position defining insulating layer.

After forming the insulating layer for defining the position of the gap depth and before forming the coil layer, application and exposure of a resist for forming the pole portion of the upper magnetic pole and the vicinity thereof are performed. Since the height of the element portion is low, the thickness of the resist can be reduced. More specifically, the resist film thickness at the pole portion where the resist film thickness is maximum is within about 7 μm. Therefore, a narrow pole portion of the upper magnetic pole can be formed accurately. In particular, even if the coil layer becomes thicker, such as three to four steps, the required resist film thickness is always substantially constant irrespective of the thickness of the coil layer, and even if the pole portion becomes narrower (the track becomes narrower). ) I will be able to respond enough.

In the manufacturing process, after forming the gap depth position defining insulating layer, the insulating layer may be subjected to ion milling. In such a case, immediately after the formation of the insulating layer, the top end apex portion is covered. If the pole portion of the upper magnetic pole and its vicinity are provided, the position does not move because the tip apex portion is not shaved,
In manufacturing, the dimensional accuracy of the gap depth is improved.

[0012]

FIG. 1 is a process explanatory view showing one embodiment of a method of manufacturing a thin film magnetic head according to the present invention. The finally manufactured thin film magnetic head is basically the same as that shown in FIG. For simplicity of the drawing, the coil layer is illustrated as having the simplest single-stage configuration, but the thickness of the coil-forming portion is increased, such as a plurality of coil layers, especially three to four stages. The method of the present invention is more effective.

First, as shown in FIG. 1A, a lower magnetic pole 14 and a gap layer 16 are formed on a ceramic substrate 12. For example, the lower magnetic pole 14 is an electroplated film of a magnetic material such as a NiFe alloy, and the gap layer 16 is an alumina film. On this gap layer 16, a gap depth position regulating insulating layer 18 is provided. This is, for example, a hard bake film of a resist. The leading edge of the gap depth position regulating insulating layer 18 is a portion called Apex, and the gap depth from the pole tip after slider processing to the Apex position is the gap depth.

In the present invention, after the gap depth position defining insulating layer 18 is formed, the pole portion 24a of the upper magnetic pole and its neighboring portion 24c are formed. For this purpose, first, a resist 40 is applied, and is exposed and patterned so as to remove the pole portion and its vicinity. After that, an electroplating film such as a NiFe alloy is formed. The pole portion 24a of the upper magnetic pole and its neighboring portion 24c are formed so as to cover the tip apex portion of the gap depth position regulating insulating layer 18.

Next, as shown in FIG. 1B, the adhering resist is removed, and a coil layer 22 surrounded by an insulating layer 20 is formed. Specifically, it is formed by forming the coil layer 22 having a predetermined pattern and providing the insulating layer 20 thereon. As described above, here, the coil layer 22 has a configuration of only one step, but generally, the coil layer is formed in a plurality of steps, more recently, three to four steps as the number of coil turns increases. Therefore, the coil layer and the insulating layer are repeatedly laminated and formed a plurality of times.

Thereafter, as shown in FIG. 1C, the yoke portion 24b of the upper magnetic pole 24 is provided so as to partially overlap the pole near portion 24c of the upper magnetic pole so as to be continuous. Therefore, a resist 42 is applied, exposed, patterned into a predetermined shape, and electroplated with a NiFe alloy or the like.

As shown in (A) of FIG. 1, element height A ₂ immediately after formation of a gap depth position-defining insulating layer 18 is about 7～8Myuemu, attempts to form the upper magnetic pole in this state Then, the resist film thickness B ₂ is 5 μm on the gap depth position defining insulating layer 18 where the film thickness of the resist 40 is minimum.
m is required. In this state, the pole portion 24a
The resist film thickness C at the point where the resist film thickness is maximum
₂ fits in about 7 μm. Therefore, even if a core width of 3 μm or less is required, a resist pattern can be formed with high accuracy. This is shown in FIG. Thickness C ₁ of the resist 30 in the prior art about when the coil layer is a two-stage 20
[mu] m, becomes a becomes in four stages about 40～45Myuemu, the present invention the thickness C ₂ of the resist 42 by a method, independently of always about 7μm to the number of stages of the coil layer, in particular the number of stages of the coil layer number and a core width ( It can be seen that this is effective when the (pole width) W becomes narrow (narrow track).

Incidentally, as a result of the experiment, the relationship between the resist film thickness and the pattern accuracy is as shown in Table 1. The collected data is
The width variation of the pole pole portion in the wafer obtained when the resist film thickness was set to 20 μm and 10 μm and the pattern width was set to 3.4 μm was measured. 20
μm corresponds to the case of two coil layers in the conventional method, and is 10 μm.
m may be considered to correspond to the case of the method of the invention. From the results shown in Table 1, it can be seen that the smaller the resist film thickness, the higher the pattern accuracy and the smaller the dimensional variation. Assuming that the number of coil layers is three or four, the difference in the dimensional variation is expected to be further increased, and the effectiveness of the present invention is proved.

[0019]

[Table 1]

Although the above embodiment is directed to a case where the thin-film magnetic head is of the inductive type, the present invention can be applied to, for example, an MR composite type. An MR composite thin-film magnetic head utilizes an MR effect (magnetoresistive effect) in which electric resistance is changed by a magnetic field or magnetization for reading (reproducing) information, and is provided with an MR sensing portion having an MR element on a substrate. And a write element unit having a magnetic field generating coil thereon. Also in the case of such an MR composite type, the method of the present invention can be applied since the information writing section has the same structure as the induction type.

[0021]

According to the present invention, as described above, the formation of the upper magnetic pole is divided into the formation of the pole and its vicinity and the formation of the yoke, and the formation of the pole and its vicinity is performed at the gap depth position. By performing the process after the formation of the specified insulating layer and before the coil layer formation, the resist film thickness at the pole portion formation location can be reduced to less than half the conventional thickness, so that the pattern formation can be performed accurately even on the narrow upper pole pole portion. become able to.

The recording density of a hard disk drive can be improved by reducing the track width. For that purpose, it is necessary to narrow the track of the thin-film magnetic head for writing and reading. In order to form a pattern in which a narrow pole pole portion can be defined with high precision by using a resist, it is advantageous that the resist is thinner. In the present invention, since the resist film thickness that defines the width of the pole portion (core width) can be reduced, a highly accurate pattern can be formed, the yield is improved, and the track can be narrowed.

Further, in the present invention, the apex portion of the tip of the insulating layer defining the gap depth is covered with the portion near the pole of the upper magnetic pole immediately after the formation of the insulating layer. Therefore, even when ion milling is performed in a subsequent step, the tip apex portion defined by the insulating layer is not shaved, so that the apex position does not fluctuate. , And this also improves the yield.

[Brief description of the drawings]

FIG. 1 is a process explanatory view showing one embodiment of a method of manufacturing a thin film magnetic head according to the present invention.

FIG. 2 is a plan view showing an example of a thin-film magnetic head.

FIG. 3 is a cross-sectional view of the head element.

FIG. 4 is an explanatory view showing an example of a method for manufacturing a conventional thin-film magnetic head.

FIG. 5 is a comparative explanatory diagram of a conventional method and a method of the present invention.

[Explanation of symbols]

 12 Substrate 14 Lower magnetic pole 16 Gap layer 18 Gap depth position defining insulating layer 20 Insulating layer 22 Coil layer 24 Upper magnetic pole 24a Pole part 24b Yoke part 24c Pole vicinity part

Claims (2)

[Claims] 1. A lower magnetic pole, a gap layer, a gap depth defining insulating layer, a coil layer sandwiched between insulating layers,
In a method of manufacturing a thin-film magnetic head having a structure in which an upper magnetic pole is laminated and formed in this order, after forming a lower magnetic pole, a gap layer, and a gap depth position defining insulating layer, a pole portion of the upper magnetic pole and a portion in the vicinity thereof are formed. Thereafter, a required number of coil layers sandwiched by insulating layers are formed, and a yoke portion of the upper magnetic pole is provided thereon so as to be continuous with the vicinity of the pole of the upper magnetic pole. Head manufacturing method. 2. The method of manufacturing a thin-film magnetic head according to claim 1, wherein the pole portion of the upper magnetic pole and the vicinity thereof are formed so as to cover the apex portion at the tip of the gap depth position defining insulating layer.