JPH03156712A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To prevent the insulation defect between conductor coil layers and a lower magnetic layer and the electrical disconnection of the conductor coil layers by forming the rear end 8 of a lower magnetic core to a multistage structure having an intermediate flat surface and depositing and forming insulating layers and the conductor coil layers on the rear end part. CONSTITUTION:The rear end part 8 has the two-stage structure having the intermediate flat surface 9 and a 1st gentle slope 10 is formed between the front surface 2a of the lower magnetic core 2 and the intermediate flat surface 9. A 2nd gentle slop 11 is formed between the intermediate flat surface 9 and the front surface 1a of a substrate 1. The insulating layers 6 are deposited and formed on the upper surface 2a of the lower magnetic core 2, the 1st slope 10, the intermediate flat surface 9, and the upper surface 1a of the substrate 1. The conductor coil layers 3 are deposited and formed on the insulating layers 6. The insulating layers 6 and the conductor coil layers 3 do not become thin. The insulation defect between the lower magnetic core 2 and the conductor coil layers 3 and the electrical disconnection of the conductor coil layers 3 are prevented in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a thin film magnetic head suitable for high-density recording or reproduction.

(b) Conventional technology Conventionally, this type of thin film magnetic head has been used, for example, in
As shown in Publication No. 46415 (GIIB 5/31), etc., magnetic circuits, conductor coils, electrodes, etc. are formed on a substrate using an insulating layer using a thin film deposition method and photolithography technology. Compared to conventional bulk magnetic heads consisting of a magnetic core and windings, it is easier to downsize and create multiple channels.

FIG. 18 is a top view of a conventional thin film magnetic head, and FIG. 19 is a sectional view taken along line AA' in FIG.

In the figure, (1) is a substrate made of a magnetic material such as Ni-Zn ferrite or a non-magnetic material such as crystallized glass, and on the substrate (1) is a lower magnetic core (made of a ferromagnetic metal material such as Sendust). 2) is coated. Conductive coil layers (3) (3) and upper magnetic cores (4) (4) are formed on the lower magnetic core (2) via an insulating layer (not shown). Further, the lower magnetic core (2) of the substrate (1)
), the part where the lower magnetic core is not formed is located on the rear side.
Electrode portions (5), (5), etc. connected to the conductor coil layers (3, (3), etc.) are formed by adhesion. As shown in FIG. 19, the conductive coil layer (3) is formed on the lower magnetic core (2) and the substrate (1) via an insulating layer (6) such as Sin. Furthermore, a gap spacer is formed between the lower magnetic core (2) and the upper magnetic core (4) (4).

However, in the above-mentioned thin film magnetic head, as shown in FIG. Microcracks (28) (28) occur at the thinner and steeper edges, as shown in FIGS. 20(a) and (b).
Furthermore, due to stress concentration in these parts, the insulating layer (6)
Alternatively, the conductor coil layer (3) may peel off, resulting in poor insulation between the conductor coil layer (3) and the lower magnetic core (2), or electrical disconnection of the conductor coil layer (3).

Note that the lower magnetic core (2) is formed over the entire upper surface of the substrate (1), and a conductive coil layer (3) is formed on the lower magnetic core (2) with an insulating layer (6) interposed therebetween.
The above-mentioned drawbacks can be prevented by attaching the electrode portion (5). However, in this case, since the lower magnetic core (2) is located below the electrode part (3) via the insulating layer (6), the lower magnetic core (2) is separated from the electrode part (5). Difficult to completely insulate. Further, when the lower magnetic core (2) is formed over the entire upper surface of the substrate (1), the substrate (1) may warp due to the difference in thermal expansion coefficient between the substrate (1) and the lower magnetic core (2). There is a risk that cracks may occur or the lower magnetic core (2) may peel off. In particular, when forming a large number of thin film magnetic heads on one large substrate, in order to prevent the above-mentioned substrate (1) from warping or cracking, and the lower magnetic core (2) from peeling off, as shown in FIG. 17! Each thin-film magnetic head is divided into lower magnetic cores (2), (2), and so on.

(c) Problems to be Solved by the Invention The present invention has been made in view of the drawbacks of the above-mentioned conventional examples.
It is an object of the present invention to provide a thin film magnetic head in which poor insulation between the conductor coil layer and the lower magnetic layer at the rear end of the lower magnetic core and electrical disconnection of the conductor coil layer are prevented.

(d) Means for Solving the Problems The present invention comprises forming a lower magnetic core, a conductive coil layer, and an upper magnetic core in sequence on a substrate with an insulating thin film interposed therebetween, and forming the lower magnetic core on the rear side of the lower magnetic core of the substrate. A thin film head in which an electrode portion connected to the conductor coil layer is formed in a portion where the lower magnetic core is not formed through an insulating layer, the rear end portion of the lower magnetic core having a multi-stage structure having an intermediate flat surface, It is characterized in that the insulating layer and the conductor coil layer are formed on the rear end.

Furthermore, in the present invention, at least one of between the upper surface of the lower magnetic core and the intermediate flat surface and between the intermediate flat surface and the upper surface of the substrate is formed into a gentle slope at the rear end of the lower magnetic core. It is characterized by being formed by.

The present invention also provides a structure in which a lower magnetic core, a conductor coil layer, and an upper magnetic core are sequentially laminated on a substrate with an insulating thin film interposed therebetween, and a lower magnetic core located on the rear side of the lower magnetic core of the substrate is not formed. In a thin film magnetic head in which an electrode portion connected to the conductor coil layer is formed in a portion via an insulating layer, a shape correction is performed such that a surface shape of a rear end corner of the lower magnetic core is gentler than that of the corner. The present invention is characterized in that an insulating layer and a conductive coil layer are formed on the front lower magnetic core and on the shape correction portion.

Furthermore, the present invention is characterized in that the corner of the rear end of the lower magnetic core is formed with a gentle slope.

(E) Effect According to the above structure, the insulating layer and the conductive coil layer are easily deposited even on the rear end of the lower magnetic core, and the insulating layer and the conductive coil layer are not thinned and stress concentration is also prevented. Does not occur.

(F) Example Hereinafter, a first example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a top view of the thin film magnetic head of the first embodiment, FIG. 2 is a sectional view taken along line BB' in FIG. 1, and FIGS.
Components that are the same as those in the figures are given the same reference numerals, and their explanations will be omitted.

The rear end of the thin film magnetic head of this example has an intermediate flat surface (
9), and a gentle first slope (10) is formed between the upper surface (2a) of the lower magnetic core (2) and the intermediate flat surface (9). Flat surface (
A gentle second slope (11) is formed between the upper surface (1a) of the substrate (1) and the upper surface (1a) of the substrate (1). on the upper surface (2a) of the lower magnetic core (2), the first slope (10), the intermediate flat surface (9), the second slope (11), and the upper surface (1a) of the substrate (1). An insulating layer (6) is formed on the insulating layer (6), and a conductive coil layer (3) is formed on the insulating layer (6).
is formed by adhesion.

Next, we will discuss the manufacturing method of the thin film magnetic head of the first embodiment, especially the vicinity of the rear end of the lower magnetic core @B-B in Figure 1.
'This will be explained with reference to FIGS. 3 to 7, which correspond to cross-sectional views.

First, as shown in FIG. 3, a lower magnetic layer (12) having a thickness of 5 μm, which will become the lower magnetic core (2), is formed on the substrate (1) by vacuum deposition, sputtering, or the like.

Next, a first resist (1) is applied on the lower magnetic layer (12).
After applying 3) and patterning the first resist (13) into the desired shape of the lower magnetic core by exposure and development,
By performing dry etching such as ion beam etching, the unnecessary portion of the lower magnetic layer (12) is removed by 2.5 μm as shown in FIG.
Intermediate flat surface (9) with a height of 2.5 μm from 1a)
form. The first resist (13) may be patterned so that the lower magnetic core will be arranged as shown in FIG. 8 in the future.

Next, after removing the first resist (13) by peeling and cleaning, the lower magnetic layer (12) is removed as shown in FIG.
) A second resist l-(14) having a low viscosity of 100 CI) or less is applied over the entire upper surface of the substrate. said second regis)
(14) has a low viscosity, so the upper magnetic layer (12)
A second resist (
The upper surface of 14) becomes a gentle slope (16).

Next, after removing the rear portion (14a) of the second resist (14) applied on the intermediate flat surface (9) by exposure and development, post-baking is performed at a baking temperature of 80 to 150°C. As shown in FIG. 6, the rear end of the second resist (14) is shaped like a gentle slope (17).
), and the thickness of the resist (14) @2 near the corner (18) of the stepped portion (15) is made thinner.

Next, after forming the second resist I-(14), unnecessary portions of the lower magnetic layer (12) are removed by dry etching such as ion beam etching, as shown in FIG. A lower magnetic core (2) having a predetermined shape is formed. The lower magnetic core (
The shape of 2) is such that the thickness of the second resist (14) near the corner (18) is thin, resulting in a gentle first slope (lO) due to overetching. At the rear end, the second resist (14
) is removed by etching along the slope (17) at the rear end, resulting in a gentle second slope (11).

Thereafter, after removing the second resist l-(14) by peeling and cleaning, an insulating layer (
6) and a conductor coil layer (3) on the insulating layer (6).
By forming , the vicinity of the rear end of the lower magnetic core of the thin film magnetic head of this embodiment shown in FIG. 2 is formed.

In the thin film magnetic head of the first embodiment as described above, the rear end Q opening of the lower magnetic core (2) has a two-stage structure with an intermediate flat surface (9), and the upper surface of the lower magnetic core (2) (
A gentle first slope (10) is formed between the intermediate flat surface (9) and the intermediate flat surface (9).
9) and the upper surface (1a) of the substrate (1).
Since the insulating layer (6) and the conductive coil layer (3) formed on the rear end Ω of the lower magnetic core (2) do not become thinner, the lower magnetic core Poor insulation between the core (2) and the conductor coil layer (3) and electrical disconnection of the conductor coil layer (3) are prevented.

In the first embodiment, the upper surface of the lower magnetic core (2) (
2a) and the intermediate flat surface (9) and between said intermediate flat surface (9)
) and the top surface (1a) of the substrate (1).
Although it is formed by the second slope (10) (11),
Even if the structure does not have a gentle slope as described above, a multi-stage structure can reduce the above-mentioned insulation defects and electrical disconnections.

Next, a second embodiment of the present invention will be described in detail.

FIG. 8 is a cross-sectional view of the main parts of the thin film magnetic head of the second embodiment, and corresponds to FIG. 2 of the first embodiment, and the same parts as in FIG. do.

In the thin film magnetic head of the second embodiment, the lower magnetic core (2)
on the first corner (19) formed between the intermediate flat surface (9) and the first slope (10), and on the top surface (1) of the substrate (1).
a) and the second slope (11) of the lower magnetic core (2).
Second shape correction sections (21) and (22) are formed.

The first and second shape correction sections (21) and (22) are made of Ti,
Cr, Cu, AI! ,,Al-3i,Afi-Cu,A
Metals such as u, W, AJl, 0. ,Tie,.

It is made of a metal compound such as TiN, or an organic resin such as polyimide resin or novolac resin, and the upper surface (2
1a) (22a) has a gently curved surface or slope. An insulating layer (6) is formed between the lower magnetic core (2) and the first.
The second shape correction portions (21) and (22) are coated and formed.

Next, a method of manufacturing the thin film magnetic head of the second embodiment will be described, particularly the vicinity of the rear end of the lower magnetic core as in the first embodiment, with reference to FIGS. 9 to 15.

First, as shown in FIG. 9, a lower magnetic layer (12) with a thickness of 5 μm, which will become the lower magnetic core (2), is deposited on a substrate (1).

Next, a first resist (1) is applied on the lower magnetic layer (12).
3) and dry etching such as ion beam etching to form the rear end Ω of the lower magnetic layer (12) into the first corner (18) as shown in FIG.
), the first inclined part (23), the first corner part (19), the intermediate flat surface (9), the second corner part (24), the second inclined part (2
5) and a two-stage shape having a second corner (20) to form a lower magnetic core (2).

Next, after removing the first resist (13), the first resist (13) is removed.
As shown in Figure 1, a second resist (I4) with a low viscosity of 100 Cp or less is applied to the entire upper surface of the lower magnetic core (2).
Apply. Since the second resist (14) has a low viscosity, its surface shape is gentle, and the second resist (14) is located near the first and second corners (18) (24). ) is formed thinner than other parts. Note that after coating and forming the second resist (14),
By post-baking at a baking temperature of 100 to 150° C., the surface shape of the second resist (14) can be made even more gentle.

Next, after forming the second resist (14), the entire surface of the second resist (14) is etched by dry etching such as ion beam etching. At this time, the second resist (14) and the lower magnetic core (2) are etched at the same speed, and the first and second corners (18) (2) are etched at the same speed.
4) By performing overetching in the vicinity, the first
As shown in Figure 2, the first and second corners (18) (24
) The shape of the vicinity is processed and formed into gentle first and second slopes (10) and (11) that are equal to the surface shape of the second resist.

Next, after removing the second resist (14), as shown in FIG.
Cr, Cu, AX, AJ! -3i, Al-(:u, Au
, W, etc., or At, 0. A shape correction layer (26) is formed by depositing a metal compound such as , Ti01, TiN, etc. by vapor deposition, sputtering, etc., or by spin coating an organic resin such as polyimide resin or novolac four fingers, and further the shape correction layer ( 26) Above said second register) (
A third resist (27) having the same viscosity as 14) is applied and formed. Since the third resist (27) has a low viscosity, its surface shape is gentle. Further, the first and second corners (1) of the lower magnetic core (2)
9) Since the third resist (27) accumulates in the vicinity of (20), the thickness of the third resist (27) at that part becomes larger than the thickness at other parts. As a result, the surface shape of the third resist (27) near the first and second corners (19) and (20) becomes even more gentle.

Next, after forming the third resist (27), the third resist (27) is formed.
Under uniform etching conditions in which the etching speed of the resist (27) and the shape correction layer (26) are equal, the lower magnetic core (2) is flattened as shown in FIG. 15 through the state shown in FIG. Dry etching such as ion beam etching is performed until the shape correction layer (26) formed on the flat upper surface (2a) and the intermediate flat surface (9) is removed. In the vicinity of the first and second corners (19) and (20), the third
Since the thickness of the resist (27) is large, the shape correction layer (26) remains in this part, and the first and second shape correction parts (21) and (22) are formed. The surface shape of the first and second shape correction portions (21) and (22) is a gently curved surface or slope similar to the surface shape of the third register (27) in that portion.

Thereafter, on the lower magnetic core (2) and the first and second
The second embodiment shown in FIG. The vicinity of the rear end of the lower magnetic core of the thin film magnetic head is formed.

In the thin film magnetic head of the second embodiment described above, the rear end Q opening of the lower magnetic core (2) has the first and second slopes (10) (1
1) and the first and second shape correction portions (21) and (22), the insulating layer (6 ) and the conductor coil layer (3) are not thinned, and microcracks do not occur in those areas, resulting in poor insulation between the lower magnetic core (2) and the conductor coil layer (3), and the conductor coil. Electrical disconnection of layer (3) is prevented.

In the second embodiment described above, a two-stage structure is formed on the rear end of the lower magnetic core (2), but as shown in FIG. 16, the same effect as described above can also be obtained with a single-stage structure. I can do it.

(G) Effects of the Invention According to the present invention, a thin-film magnetic head is provided which prevents thinning of the insulating layer and conductive coil layer at the rear end of the lower magnetic core, and also prevents insulation defects and disconnection defects due to stress concentration. can be provided.

[Brief explanation of the drawing]

1 to 7 relate to a first embodiment of the present invention, in which FIG. 1 is a top view of a thin film magnetic head, and FIG. 2 is taken along line BB' in FIG. 1.
3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are cross-sectional views of essential parts showing a method of manufacturing a thin film magnetic head, respectively. 8 to 16 relate to a second embodiment of the present invention, in which FIG. 8 is a cross-sectional view of the main part of a thin film magnetic head, FIG. 9, FIG. 10, FIG. 11, FIG. 12, and FIG. 13. , Figures 14 and 15
The figures are a cross-sectional view of main parts showing the manufacturing method of a thin-film magnetic head, and
FIG. 16 is a sectional view of the main part of the thin film magnetic head. 17th
The figure is a diagram showing an arrangement pattern of the lower magnetic core. 1st
8 to 20 relate to a conventional example, FIG. 18 is a top view of a thin film magnetic head, FIG. 19 is a sectional view taken along line AA' in FIG. 18, and FIG. 20 is a diagram showing microcracks. (1)...Substrate, (1a)...Top surface, (2)...
Lower magnetic core, (2a)...upper surface, (3)...conductor coil layer, (4)...upper magnetic core, (5)...electrode portion, (6)...insulating layer, Iyu... Rear end, (9
)...Intermediate flat surface, (10)...First slope, (1
1)...Second slope, (19)...First corner, (
20)...Second corner, (21)...First shape correction section, (22)...Second shape correction section.

Claims (4)

[Claims] (1) A lower magnetic core, a conductor coil layer, and an upper magnetic core are sequentially laminated on a substrate with an insulating thin film interposed therebetween, and the lower magnetic core is not formed on a portion of the substrate located on the rear side of the lower magnetic core. In a thin film magnetic head in which an electrode portion connected to a conductive coil layer is formed via an insulating layer, the rear end of the lower magnetic core has a multi-stage structure having a flat intermediate surface, and the insulating layer and the insulating layer are disposed on the rear end. A thin film magnetic head characterized by having a conductive coil layer deposited thereon. (2) At the rear end of the lower magnetic core, at least one of between the upper surface of the lower magnetic core and the intermediate flat surface and between the intermediate flat surface and the upper surface of the substrate is formed with a gentle slope. A thin film magnetic head according to claim 1, characterized in that: (3) A lower magnetic core, a conductive coil layer, and an upper magnetic core are sequentially laminated on a substrate with an insulating thin film interposed therebetween, and the lower magnetic core is not formed on a portion of the substrate located on the rear side of the lower magnetic core. In a thin film magnetic head in which an electrode portion connected to a conductor coil layer is formed via an insulating layer, a shape correction portion whose surface shape is gentler than that of the corner portion is formed at a rear end corner of the lower magnetic core. A thin film magnetic head characterized in that an insulating layer and a conductive coil layer are formed on the lower magnetic core and the shape correction section. (4) The thin film magnetic head according to claim (3), wherein a corner of the rear end of the lower magnetic core is formed with a gentle slope.