JPH0237513A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To reduce the influence of the leakage of magnetic flux and to lower electrical resistance in a winding coil by increasing distance between first and second cores at a rear part, separating the winding coil to two parts, and connecting them in series, respectively. CONSTITUTION:The first and second cores 2 and 3 are provided on a nonmagnetic substrate 1 in such a way that they are superposed at a tape sliding plane side and are separated from each other at the rear part. The cores 2 and 3 are formed in Y shape. A magnetic head 6 is constituted at a front part by superposing the cores 2 and 3, and another end parts of the cores 2 and 3 are coupled with a rear core 7. The cores 2 and 3 consist of magnetic thin films 2a, 2b and 3a, 3b, respectively, and the thin films 2a and 3a are formed on the substrate 1. The thin films 2a and 3a are separated magnetically with a nonmagnetic insulator 4. The thin film 2b is superposed on the thin film 3a at the front part, and is laminated on the thin film 2a at the rear part. The thin film 3b is laminated on the thin film 3a at the rear part, and a nonmagnetic insulator 5 is provided between the thin films 2b and 3b. The winding coils 10 and 11 are provided at joining parts 8 and 9, respectively, and are connected in series.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to thin film magnetic heads used in VTRs and the like, and particularly to thin film magnetic heads suitable for high-density recording.

[Conventional technology]

BACKGROUND OF THE INVENTION With the trend towards higher density magnetic recording, thin film magnetic heads have been developed that use high saturation magnetic flux density metal magnetic films such as sendust, amorphous, and permalloy as core materials. In this type of magnetic head, in order to narrow the track width of the head and obtain stable magnetic characteristics, the core and wound coil are formed by patterning using thin film forming technology. In a conventional thin film magnetic head in which a core, a wire-wound coil, etc. are formed in this way, for example, as described in Japanese Unexamined Patent Publication No. 55-84020, the upper core and lower core are connected at a point other than the magnetic gap. There is only one joint, and the winding coil is single-wound.

That is, FIGS. 10(a) and 10(b) are a cross-sectional view and a top view of such a conventional thin-film magnetic head.
A lower core 21 is formed on a non-magnetic substrate 20, a non-magnetic insulator 22 and a winding coil 23 are laminated on this lower core 21, and an upper core 24 is formed thereon. On the sliding surface side of the tape, non-magnetic P! of a predetermined thickness is applied. The lower core 21 and the upper core 24 face each other via the edge, and a magnetic gap 25 is formed. Also, in the rear part,
One joint between the lower core 21 and the upper core 24 is formed. Thereby, a closed magnetic path is formed between the lower core 21 and the upper core 24.

In such a configuration, the winding coil 25 is connected to the lower part 121.
, non-magnetic IP between the upper core 24! It is single-wound spirally approximately parallel to the surface of the non-magnetic substrate 20 so as to cut off the magnetic flux that passes through the edge body 22 and through the closed magnetic path formed by these cores.

As another example of a conventional thin film magnetic head, for example, as described in Japanese Patent Laid-Open No. 164915/1982, the magnetic gap is not parallel to the nonmagnetic substrate as in the above conventional thin film magnetic head, but the magnetic gap is parallel to the nonmagnetic substrate. A device in which the surface of the nonmagnetic substrate is substantially perpendicular is known. In such a thin film magnetic head, first and second cores are arranged on the surface of a nonmagnetic substrate so that a magnetic gap is formed at the tape sliding surface, and the rear core connects these first and second cores in the rear part. A closed magnetic path is formed between the first core, the rear core, and the second core. The winding coil is provided as a one-turn coil by winding the joint between the first or second core and the rear core.

Furthermore, as other examples of conventional thin film magnetic heads, as described in Japanese Patent Application Laid-Open No. 60-83207, similar to the thin film magnetic head described in the above-mentioned Japanese Patent Application Laid-Open No. 60-164915, there are other examples of conventional thin film magnetic heads. The first and second electrodes provided on the surface of the magnetic substrate
A thin film magnetic head is known in which a coil is wound around each of the first and second cores.

[M problems that the invention attempts to solve]

By the way, in the thin film magnetic head (FIG. 10) described in the above-mentioned Japanese Patent Application Laid-open No. 55-84020, the winding coil A/2
Since 3 is wound in a spiral, the conductor length per turn becomes longer as it goes outside the spiral, and therefore,
In order to obtain a large playback output, the number of turns is increased (this increases the overall length of the winding coil 23, increasing coil resistance and deteriorating performance.In addition, the upper core 2
4 and the lower core 121 are separated by the non-magnetic insulator 22, but are relatively close to each other, so that the upper core 24. A leakage of magnetic flux occurs between the lower cores 21. Consideration was given to this point (・.

In the thin film magnetic head described in the upper part of Japanese Patent Application Laid-open No. 60-164913, the first and second cores are separated by a non-magnetic insulator.
, a second core is coupled via a rear core. Therefore, leakage of magnetic flux in the nonmagnetic insulator can be suppressed.

However, the winding coil in this thin-film magnetic head has one turn, and if an attempt was made to increase the number of turns, it would still wind up in a spiral shape.
Problems similar to those of the thin film magnetic head described in the above publication occur, and if the number of turns is increased without increasing the size, the area of the joint between the first or second core and the rear core will be reduced. There is a problem that the magnetic resistance of the closed magnetic circuit increases.

In the thin film magnetic head described in JP-A-60-83207, the winding coil is wound around the first and second coils, so the conductor length per turn is all equal, and the total length of the winding coil is However, in forming this winding coil, first half of each turn is formed on a non-magnetic substrate, and then the first and second cores are formed. , forming the other half.For this,
There are joints between the wire-wound coil conductors, and there are two joints per turn. This junction has a large electrical resistance (therefore, there is a problem in that the greater the number of turns, the greater the electrical resistance of the loosely wound coil.

It is an object of the present invention to provide a thin film magnetic film in which the busy magnetic gap is parallel to the non-magnetic substrate surface so as to solve such problems, reduce the influence of magnetic flux leakage, and reduce the magnetic resistance of the winding coil. It is possible to provide the head.

[A shortcut to solving problems]

In order to achieve the above object, the present invention overlaps the first and second cores on the front side to form a magnetic gap, separates them from each other on the 9A side, and connects them to each other from the rear core.
A first winding coil is wound around the joint between the core and the rear core, and a second winding coil is wound around the joint between the second core and the rear core in the same direction with respect to the magnetic flux direction. The first and second winding coils are connected in series.

[Effect]

A closed magnetic path is formed by the first core, rear core, and second core. In the front part, the first. By stacking the second cores, a magnetic gap is formed parallel to the surface of the substrate, and in the rear part, the first and second cores are separated, so that
Leakage of magnetic flux between these can be reduced. Since the first and second winding coils are provided and connected in series, each winding coil has a spiral shape, and the number of turns of each can be reduced (to reduce the diameter of the spiral). However, these first
Since the entire second winding coil constitutes the full winding coil of the thin film magnetic head, the number of turns in this full winding coil is large, and the total length of the coil is short (which means that the electrical resistance is small).

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a four-dimensional oblique view showing an embodiment of the thin film magnetic head according to the present invention, where 1 indicates a non-? a-based substrate, 2 is the first core,
2&, 2b is a magnetic thin film, 5 is a second core, sa, 3b is a magnetic thin film, 4.5 is a non-magnetic insulator, 6 is a magnetic gap,
7 is a rear core, 8.9 is a joint, and 10-1 is a winding coil.

In the figure, the first and second cores 2.5 are placed on the non-extrusion substrate 1 so that they overlap at the front part on the tape sliding surface side (the front side of the drawing) and are separated from each other at the shear part. 5, and when viewed from above, the first and second cores 2.3 form a Y-shape. In the front part, these first and second cores 2
, 3 are overlapped to form a magnetic head 6 parallel to the surface of the non-magnetic substrate 10, and in the rear portion, the ends of the first and second cores 2.3 are coupled by a rear core 7.

As a result, the first core 2, rear core 7, second core 5
A closed magnetic path is formed.

To explain the first and second cores 2.3 in more detail, the first core 2 consists of magnetic thin films 2a and 2b, and the second
The core 3 also consists of magnetic thin films 54, 3b. The magnetic thin film J[2a- is formed on the non-magnetic substrate 1, and the magnetic thin film 54 is also formed on the non-magnetic substrate 1. magnetic thin film 3
A extends from the tape sliding surface to the rear part, but the magnetic thin film 2a extends from the middle of the magnetic thin film 54 to the 91st part. Therefore, a Y-shaped pattern is formed by the magnetic thin films 2g and 3g, but the magnetic thin films 2a and 3a are magnetically separated by the nonmagnetic insulator 4. Further, the magnetic thin film 2b overlaps the magnetic thin film 1 [3] in the front part, and is laminated on the magnetic thin film 2G in the 9a part. Magnetic thin film 5
b is a magnetic thin layer [3aK laminated in the rear part, magnetic thin g
2b.

A non-magnetic insulator 5 is provided between 3b and these are magnetically separated. Therefore, a magnetic gap 6 is formed by the overlapping of the magnetic thin films 2b and 3M at the front portion.

Joint 8 between the first core 2 and the rear core 7 at the rear part
is provided with a winding coil 10 wound around this, and a winding coil 11 wound around this is also provided at the joint 9 between the second core 15 and the rear core 7. It is provided. These winding coils 10.11 are wound in the same direction with respect to the direction of the magnetic flux cutting through them, and are connected in series. Therefore, the magnetic fluxes generated in these winding coils 10.11 are added together and flow through the closed magnetic path, and the signal voltages generated in each of the winding coils 10.11 due to changes in the magnetic flux flowing through the closed magnetic path are added together and output.

Figure 2 + a) is the division of Figure 1 @ A - A K G 5
It is a cross-sectional view, and FIG. 2(b) is also taken along the dividing line B-BK.
FIG. As shown in the figure, the nonmagnetic substrate 1, the first and second cores 2 and 5, and the winding coils 10 and 11 are covered with a nonmagnetic insulator 12.

Next, a specific example of the manufacturing method of this embodiment will be explained with reference to FIG.

First, a Co-based amorphous magnetic material is formed to a desired thickness on a non-magnetic substrate 1 using a sputtering device, and etched into a Y-shaped pattern using an ion milling method to form magnetic thin films 2m and 5b. At this time, 2 m of magnetic thin film
, 5a are formed by the notch 13a reaching the non-magnetic substrate IK,
They are separated from each other (Fig. 3 (α)). Next, a layer of non-magnetic insulator such as 5iCh is formed until the notch 134 is completely buried, and the magnetic thin film 24. This non-magnetic insulator layer is removed while flattening until the button is exposed, forming a notch 13a K non-magnetic insulator 4 (FIG. 5(b)). Note that a nonmagnetic insulator also remains on the nonmagnetic substrate 1, but this is not shown. After forming a film of non-magnetic insulating material to form the magnetic gap 6 by sputtering, the above magnetic material is formed to a predetermined thickness, and magnetic g2b and 5b are formed on the magnetic mzas 34 by the ion mink method. . At this time, the magnetic film 2b,
A cut 13b separating the magnetic thin film 54 is provided until it reaches the non-magnetic insulating material on the magnetic thin film 54 (FIG. 3(C)). Then, a layer of non-magnetic insulator is formed until the notch 15b is completely buried, and the non-magnetic insulator is removed while flattening until the magnetic film a2bt3b is exposed, forming the non-magnetic insulator 5 (fifth Figure (14).

Next, the non-magnetic insulating layer at the rear end of the magnetic thin films 2b and 5b is completely removed, and a protruding joint 8. is formed with a magnetic material to form a film thicker than the wound coil. ? A non-magnetic insulating layer is formed on the entire surface and then heated to cover the magnetic thin films 2b and 5b. After that, 3 of Cr-Cu-Cr
A layer of conductive film is formed by vapor deposition to a desired coil film thickness, and by ion milling, the conductor film is formed around the joint part 8.9,
Winding coils 10 and 11 connected to each other in 1tC'rfK rows are formed (FIG. 3(e)). At this time, the winding coil 10
．． No. 11 has opposite winding directions. Then, a non-magnetic insulating layer is formed to embed the winding coil 10.11, a through hole is provided except for the non-magnetic insulating layer at the terminal portion of the winding coil 10.11, and again the Or-Cu-Cr 3 A layer of conductive film is deposited, and the coil lead wire 1 is formed by ion milling.
4.15, these coil lead wires 14.15 are embedded with a non-magnetic insulating material. Additionally, the joint 8.9
The nonmagnetic insulating layer is removed while planarizing until the magnetic thin films 2a, 2b, ! are exposed, and finally, the magnetic thin films 2a, 2b, ! The rear portion 17 is formed in the same manner as Sa, 5b (FIG. 3(f)).

As mentioned above, in this example, the 1st degree WJ2 in the 91st part
Cores 2 and 3 can be sufficiently separated, so the magnetic flux between them can be significantly reduced, and two winding coils are provided, which are balanced so that the induced signal voltage is added. Even if these winding coils are spiral-shaped, the number of turns in each coil can be reduced and the total length of the coil can be shortened (thus, a large signal voltage can be obtained, and these winding coils can be formed integrally without joints). For this purpose,
The electrical resistance of all the winding coils can be made small (possible.Here, the winding coils 10 and 11 are each 5 turns, and the whole winding coil is 10 turns, and the overall electrical resistance at this time is 2Ω.
The noise level due to electromagnetic induction due to balanced winding was also suppressed to the same level as in the case of conventional manual balanced winding.

In addition, since there are no inclined parts in the first and second cores 2, 3, rear core 7, and the joints between them, there is no deterioration in the magnetic properties of the magnetic thin films that constitute them. During the department, the first and second cores 2.
Since the magnetic gap 6 is formed with the film thickness of 5% of that at the rear portion, a core squeezing effect occurs at the magnetic gap 6 portion. In areas other than the front magnetic gap 6, the core is a two-layer magnetic thin film with an insulating layer interposed therebetween, so the characteristics in the high frequency band are improved compared to single-layer cores and a.

FIG. 4 is a perspective view showing another embodiment of the thin film magnetic head according to the present invention, in which reference numerals 16 and 17 indicate bonding surfaces, and parts corresponding to those in FIG. 1 are given the same reference numerals. Also, the fifth
The figure is a sectional view taken along the first and second cores 2.5 in FIG. 4.

In this embodiment, the rear core 7 is directly joined to the first and second cores 2.3 at the joint surface 16-7 at a portion 91 in FIGS. 4 and 5. For this purpose, 1 winding coil 1
0.11 are formed so as to straddle the cores 2 and 3, respectively, and go under the rear portion 77. Of course, the winding coil [,
11, cores 2 and 3, and rear core 7, non-magnetic I!
! A rim is provided. The structure other than this is the same as the embodiment shown in FIG. 1, and the operation and effect are also the same.

The manufacturing method of this example includes the first step up to the step shown in FIG.
This is similar to the embodiment shown in the figure. After the step shown in FIG. 3(j), a nonmagnetic insulating layer is formed to cover the first and second cores 2 and 5, and the gap between the first and second cores 2.5 (i.e., a small
Winding coil 10.
A recessed portion deeper than the film thickness of No. 11 is provided. And Cr
A three-layer conductor film of -Cu-Cr is formed by vapor IFK to the desired coil film thickness, and a fifth layer is formed using an ion milling method.
A winding coil 10.11 is formed as described in FIG. These winding coils 10.11 pass through the recess between the first and second cores 2.5. After that,
A non-magnetic insulating layer is provided at 5 to completely fill this recess and cover the winding coil #10.11, and a through hole is provided except for the non-magnetic insulating layer at the terminal portion of the winding coil #10.11. A three-layer conductor layer of Cr-Cu-Cr is deposited,
Coil lead wires are formed by ion milling. Then, a non-magnetic insulating layer is formed and the coil lead wire is embedded.
Through-holes are provided so that the surfaces to which the rear cores 7 of the first and second cores 2.5 are bonded are exposed, and the bonding surfaces 1 of the first and second cores 2.3 are connected between these through-holes.
6.17 (FIG. 4) and flatten it so that it is on the same plane as that, and form the rear core 7 there.

FIG. 6 is a perspective view showing still another embodiment of the thin film magnetic head according to the present invention, in which parts corresponding to those in FIG. 4 are designated by the same reference numerals.

In addition, FIG. 7 shows the first and second cores 2.3 in FIG.
FIG.

In this embodiment, as shown in FIG. 6, flcZ diagram, the first
, the second core 2.5 is made of a single-layer magnetic thin film, and the fal core 2 is superimposed on the g2 core 3 at the front part to form a magnetic gear pufferfish 6. First and second cores 2.3
They are magnetically separated by a non-magnetic insulator forming a magnetic gap 6. Further, as in the embodiment described in FIG. 4, in the rear portion, the shear core 7 is directly joined to the first and second cores 2°3 at the joint surfaces 16 and 17;
It is lifted between the first and second cores 2.5, so that the winding coils 10.11 are formed on the same plane and go under the rear core 7.

This embodiment also provides the same functions and effects as the embodiment shown in FIG. However, the first core 2 in the front part has one inclined part, and the rear core 7 has two inclined parts, but when forming these films, by using a method such as sputtering with an increased angle, Deterioration of magnetic properties at these inclined portions can be reduced.

Next, a specific example of the manufacturing method of this example will be explained with reference to FIG. 8.

In the same figure, first, a magnetic thin film such as sendust is formed on a non-magnetic substrate 1 to a desired thickness using a sputtering device, and a first core 2 is formed using an ion milling method (
Figure 8 (4)). Then, a nonmagnetic insulating layer such as 5i02 is formed on the entire surface with a desired thickness by sputtering,
Furthermore, a magnetic thin film such as Sendust is formed to a desired thickness, and a second core 5 is formed by ion milling.

At this time, in the overlapping part of the first and second cores 2.5,
The above non-magnetic Il! A magnetic gap 6 is formed by the edge layer (FIG. 8(b)). Next, the first and second co-12.3
bury it with a nonmagnetic insulating layer and planarize its surface. Then, a three-layer conductor 1K of Cr-Cu-Cr is deposited to a desired coil thickness, and by ion milling, a winding wire centered on the joint surface 16-7 of the first and second cores 2.3 is formed. A coil 10.11 is formed (FIG. 8(C)).

Next, a through hole is formed by removing the non-magnetic insulating layer at the terminal portion of the winding coil 10.11, and the coil is drawn out @ 14.15 t-formation in the same manner as the step shown in FIG. 3(e). do. Then, pull out the coil again with the non-magnetic insulating layer @
After embedding 14.15, a through hole is provided to expose the bonding surface 16.17 of the first and second cores 2°3, a magnetic thin film such as sendust is formed by sputtering, and the rear core is removed by ion milling. form 7 (
Figure 8 (c4).

Although the present invention has been described in detail above, the present invention is not limited to only certain embodiments. for example,
In the above embodiments, CO-based amorphous or sendust is used as the core material, but other magnetic materials such as amorphous with other compositions or permalloy may also be used. In addition, the manufacturing method is to stack each layer one after another, but the embedded first and second cores 2 and 3, the rear core 7, the protruding joint 8°9, and the winding coil 10. Other methods such as a method of forming the first and second cores 2 and 5, a joint portion 8.9, and a winding coil 10.11 in this order and gluing the rear core 7 thereon. You can also use By attaching the rear core 7 to the first and second cores 2 and 3, the manufacturing time can be shortened compared to the case where each layer is sequentially formed.

Further, in each of the embodiments, the method of manufacturing the winding coil 10° 11 with a single-layer binding is shown, but it is also possible to divide the coil into two layers and laminate them. Figure 9 shows the winding coil 10.1
The case where 1 is made into two layers is shown.

Further, FIGS. 1, 4, and 6 show examples of joining the first and second cores 2.5 and the rear core 7, and the winding coil 10. I
Although examples of the arrangement of t have been shown, any of these examples can be used in any embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, since the distance between the cores can be increased, the influence of leakage magnetic flux can be significantly reduced, and since the winding coil is divided into two and each is connected in series, The conductor length per turn of the winding coil can be shortened, the electrical resistance of the entire winding coil can be significantly reduced, and a reproduced output with low impedance noise and good C/N can be obtained.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an embodiment of a four-film magnetic head according to the present invention, Figure 2 is a sectional view of this embodiment, and Figure 6 is a process diagram showing a specific example of the manufacturing method of this embodiment. FIG. 4 is a perspective view showing another embodiment of the thin film magnetic head according to the present invention, FIG. 5 is a sectional view of this embodiment, and FIG. 6 is a perspective view showing still another embodiment of the thin film magnetic head according to the present invention. 7 is a sectional view of this embodiment, FIG. 8 is a process diagram showing a specific example of the manufacturing method of this embodiment, and FIG. 9 is a diagram showing still another embodiment of the thin film magnetic head according to the present invention. Cross-sectional view, Figure 10 (4
) is a cross-sectional view showing an example of a conventional thin-film magnetic head;
b) is also a plan view. DESCRIPTION OF SYMBOLS 1... Nonmagnetic substrate, 2... First core, 3... Second core, 6... Magnetic gap, 7... ++y core,
8, 9...Joint part, 10.11...Wound coil, 1
6.17...Joint surface.躬 I ロ 躬 2I￥1 躬图(α) (d-) (b) (e) 躬wa口躬圀(cL) 躬波CC）Osu

Claims (1)

[Claims] 1. In a thin film magnetic head formed by sequentially forming magnetic thin films on a substrate to form a magnetic core, a first and a second magnetic thin film made of the magnetic thin films are used.
The cores are overlapped at the front part on the tape sliding surface side to form a magnetic gap parallel to the surface of the substrate, and at the rear part, the first and second cores are separated by a predetermined distance and are connected via the rear core. By combining the first and second cores, the magnetic core is formed, and a first winding coil is formed around the joint between the first core and the rear core, and a first winding coil is formed between the second core and the rear core. 1. A thin film magnetic head characterized in that a second winding coil is provided so as to be wound in the same direction with respect to the direction of magnetic flux, and the first and second coils are connected in series.