JPH02137109A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To work a relief plane with the small number of processes and high accuracy by defining first and second marker films as the index of working depth. CONSTITUTION:A band-shaped first detecting marker film 3 is formed with arranging one side to a relief plane 9 in an area to express the tolerance range of the working depth for the plane 9 on a lower magnetic core 1 of a thin film magnetic head. Further, with being overlapped to the first detecting marker film 3, a second detecting marker film 4 is formed and for this second detecting marker film 4, width in a track width direction is gradually increased or decreased with the prescribed rate of change in a gap depth direction. Accordingly, by executing re-working based on necessary working quantity, the end face of the first detecting marker film 3 is exposed and it can be confirmed that the working depth of the plane 9 is in the tolerance range. Thus, the relief plane 9 can be easily worked with the satisfactory accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic head installed in a magnetic recording/reproducing device, and particularly relates to a thin film magnetic head suitable for recording/reproducing high-band signals. .

(Prior art) As shown in FIG. 3, a thin film magnetic head has a substrate (5) with
Lower magnetic core (1), SiO□ layer (6), coil conductor (
2><21), insulating layer (62) and upper magnetic core (7)
are sequentially laminated, and a protective plate (51) is further provided on the upper surface of the laminate with a contact layer (8) interposed therebetween.
0), the magnetic gap portion (60) is exposed.

In a thin film magnetic head, the recording medium and the opposing surface (50)
In order to properly maintain the sliding contact state, as shown in Fig. 6, the sides of the contact surface (50) in the track width direction are machined such as polishing to form a flank (9) that does not come into contact with the recording medium. Recessed,
This limits the width of the contact surface (50) in the track width direction (contact width W) to approximately 300 μm. Further, the gap depth length D (the depth distance in the direction perpendicular to the facing surfaces of the magnetic gap portion) is extremely small at 7 μ-, and the coil conductors (2) (21) are spread near the gap depth ends.

Therefore, when machining the flank surface (9), if the machining depth in the gap depth direction becomes deeper than a predetermined value, the coil conductor (2
)(21) will be cut. On the contrary, flank (9)
If the machining depth is shallower than a predetermined value, there is a risk that the recording medium will come into sliding contact with the flank surface (9) due to surface vibration during operation as a magnetic head, and be damaged. For this reason, the escape surface (
Processing 9) requires high accuracy of, for example, ±5μ theory.

Therefore, as shown in FIG. 6, a band-shaped marker film (40) is provided on the upper surface of the lower magnetic core (1) in the region from the upper limit to the lower limit of the allowable machining depth range of the flank (9).

A thin film magnetic head with a
26818 [G11BS/311).

In this magnetic head, when machining the flank (9), a marker is placed on the machined surface! By cutting the tool (90) to the depth position where the end face of the marker film (40) appears,
The flank surface (9) can be formed with a tolerance according to the width in the gap depth direction of 0).

(Problem to be Solved) However, the conventional marker film (40) has a narrow width (10
Since the marker film (40) is formed in the shape of a μ ring, it is necessary to frequently check the presence or absence of the marker film (40) during processing of the flank surface (9), which poses a problem of complicating the process. Also, the flank (9
), it is found that the depth of cut of the tool is within the allowable range, but the deviation of the depth of cut from the target value (median value of the allowable range) is unknown, so the depth of cut for the next magnetic head is changed. There was a problem that it could not be corrected.

An object of the present invention is to provide a thin-film magnetic head having a structure in which the flank surface (9) can be precisely and easily processed.

(Means for Solving the Problems) On the lower magnetic core <1) of the thin film magnetic head according to the present invention, a strip-shaped first detection marker film is formed in an area representing the permissible range of processing depth of the flank (9). <3) is 1 on the flank (9)
The first detection marker film (
3), a second detection marker rtA (4) whose width in the track width direction gradually increases or disappears at a predetermined rate of change in the gap depth direction is formed.

(Function) In the processing process of the flank (9), the second detection marker 1IA
(4) When processing to a depth where the end face is exposed, the second
Since the width of the detection marker film 4) in the track width direction changes depending on the machining depth, the amount of machining required to reach the target machining depth can be known from the measured value of the width.

By performing reprocessing based on the required processing amount, the first
The end face of the detection marker film (3) is exposed, thereby confirming that the machining depth of the flank (9) is within the permissible range.

(Effects of the Invention) According to the thin film magnetic head of the present invention, the first
By using the second marker film as an indicator of the machining depth, the flank surface can be machined with high precision and with fewer man-hours than in the past.

In addition, by measuring the width of the end face of the second detection marker film after machining the flank surface, it is possible to know the error from the target machining depth, so this error can be fed back to the next Herad tip machining process. , it is possible to correct the depth of cut of the tool.

(Examples) Examples are provided to explain the present invention, and should not be interpreted to limit or reduce the scope of the invention described in the claims.

An example of the configuration of a thin film magnetic head according to the present invention will be explained based on FIGS. 1 to 5. In addition, Fig. 1 and Fig. 4 are
A protective plate (51), a contact layer (8) of the magnetic head shown in the figure,
FIG. 6 is a plan view in which illustration of the first insulating layer (61) and the 5i02 layer (6) is omitted. Further, the hatching in FIGS. 1 and 4 does not indicate a cross section, but is added to clarify the shapes of the second detection marker film (4) and the first coil conductor (2).

As shown in Fig. 3, on a substrate (5) made of non-magnetic ceramic such as barium titanate, a lower magnetic core (1) made of Sendust, an 810□ layer (6) which will become a gap spacer, and a C
First coil conductor (2) made of u, first insulating layer (61), C
A second coil conductor (21) made of u, a second insulating layer (62),
and an upper magnetic core (7) made of Sendust are sequentially laminated, and a protective plate (5) made of non-magnetic ceramic is placed on the upper surface of the laminated body via a bonding layer (8) made of glass or synthetic resin.
1) is in place.

5i02 of the lower magnetic core (1) as shown in Figures 1 and 2
A pair of strip-shaped first detection marker films (3) are formed on the upper surface of the layer (6) with their long sides aligned with the flanks (9). Moreover, the first detection marker film (3) and SiO□
A pair of second detection marker films (4) each having a triangular shape are arranged between the layer (6) and the bottom side thereof aligned with the flank surface (9) and the apex thereof aligned with the coil conductor side of the first detection marker M(3). It is formed to align with the long side of.

In this embodiment, as described later, the first and second detection marker films (3) and (4) are connected to the first and second coil conductors (
2) Since they are formed at the same time as (21), both marker films (3) and (4) are Cu films with a thickness of about 2μ, respectively, and there is a layer between the two films with a thickness of about 1μ as shown in FIG. The first insulating layer of the ring (6
1) is interposed.

Hereinafter, the machining process of the flank (9) will be explained based on FIGS. 4 and 5.

In addition, the thin film forming process and the protective plate (
The bonding process of 51) is similar to that of a conventional magnetic head, but the second detection marker film (4) is attached to the first coil conductor (2) at the same time, and the first detection marker is attached to the second coil conductor (21) at the same time. Each film (3) is formed into a predetermined shape described later by mask sputtering. At this time, the first insulating layer (61) is interposed between the two films (3) and (4). The second detection marker Jll (4) is connected to the first detection marker film (3
) can also be formed on the surface.

As shown in Figure 4, the second detection marker J before flank surface machining
ll(4) is Y= between the width Y of the base and the height (H+T)
2 There is a relationship (H+T), and the base is the opposing surface (50
), one end of the base coincides with the side surface (9a) on the contact surface (50) side of the flank (9), and the position of the apex is aligned with the first Detection marker membrane (
3) coincides with the long side of the coil conductor (2).

On the other hand, the first detection marker film (3) has a rectangular shape that is long in the track width direction, and the length of the short side X is centered around the position of the flank (9), and the tolerance for machining accuracy of the flank (9) T(
5 μm), and one short side is aligned with the side surface (9 m).

Figures 5 (a), (b), and (c) show how the end face shapes of the first and second detection marker films (3) and (4) exposed on the machined surface change depending on the machined depth of the flank surface. represents.

As shown in Fig. 5(a), a second detection marker film (4
) is exposed with width Y, it is detected that processing has progressed to side A in FIG. Therefore, if the tool is then further cut by H (=Y/2-T) shown in FIG. 4, the flank (9) of a predetermined depth can be formed.

If only the second detection marker IK (4) is exposed with a width of Y + (Y + < Y) as shown in Figure 5 (b), it is clear that the tool only needs to cut further by Y +/2 T. .

Furthermore, when the second detection marker film (4) is exposed with a width Yi (Y*<Y+) and the first detection marker film (3) is exposed as shown in FIG. 5(c), within the allowable error ( ±T>, the flank (9) is formed.The first detection marker film (3) and the second detection marker Jl[(4) are made of Cu, and there is a 5i02 layer between them. Because they are interposed, it is easy to distinguish between the two membranes.

In this case, since the machining error can be calculated as Ys/2T, it is possible to improve the yield by correcting the depth of cut of the tool by the error when machining the next magnetic head.

According to the above manufacturing process of the thin film magnetic head, the coil conductor (
2) Since the marker films (3) and (4) are formed at the same time as (21), the manufacturing process is not complicated compared to conventional magnetic heads that do not include marker films.

Further, when machining the flank (9), the inclination of the blade surface of the tool with respect to the head tip can be detected by the difference in width between the left and right markers 11 (4) (4) exposed on the machining surface.

Ratio Y of the length of the bottom of the second detection marker film (4) and the height
By increasing /(H+T), it is possible to increase the accuracy of measuring the machining depth accordingly.

The drawings and the description of the above embodiments are for illustrating the present invention, and do not limit the invention described in the claims.
Nor should it be construed as limiting the scope.

Further, the configuration of each part of the present invention is not limited to the above embodiments, and various modifications can be made within the technical scope of the claims. For example, the first and second
Detection marker 1N! (3) (4) is the coil conductor (2
)(21) It goes without saying that the effects of the present invention can also be obtained by using only one of the methods close to (21).

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the characteristic parts of the thin film magnetic head according to the present invention, the second factor is an oblique view of the first and second detection marker films, and the third section is the thin film magnetic head shown in FIG. 4 is a plan view showing the flank surface machining process, FIG. 5 is a front view showing changes in the machined surface during the machining process, and FIG. 6 is the first section of a conventional thin film magnetic head. A plan view corresponding to (1)... lower magnetic core (2) (21)...
・Coil conductor 3)...First detection marker film (4)...Second detection marker film (50)...Contact surface (9)...Flank surface procedure amendment form (voluntary) Heisei 1 February 23, 2016 1° Case Patent Application No. 63-291823 2° Title of the Invention Relationship to the Thin Film Magnetic Head 3° Correction Case Patent Applicant (188) Sanyo Electric Co., Ltd. Details of the 6° Amendment "Mask sputtering" in the 4th and 5th lines of page 8 of the book was corrected to "sputtering and etching."that's all

Claims (1)

[Claims] 1 A lower magnetic core, a coil conductor, and an upper magnetic core are laminated on a substrate via an insulating layer, and the surface facing the recording medium (5
In a thin film magnetic head, a flank (9) for defining the width W of the contact surface (50) is provided on the side in the track width direction of 0) by machining. core(
1) A strip-shaped first detection marker film (3) is formed on the region representing the permissible machining depth range of the flank surface (9) with one side aligned with the flank surface (9). A thin film magnetic head characterized in that a second detection marker film (4) whose width in the track width direction changes in the gap depth direction is formed overlapping the first detection marker film (3).