JPH1074307A - Production of composite magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an inductive head and a mangetoresistive(MR) head in the relation of position according to the design by forming the MR head on a third magnetic core of a thin film inductive head as a lower layer shield. SOLUTION: Since the production processes are carried out for each substrate unit, the polishing amt. varies a little depending on the position in the substrate. By forming a second magnetic core 5, the track width and the pole height end are decided by the point A where the rear end face of the second core 5 is in contact with a gap material. The point A is not moved in a polishing process to eliminate difference in levels produced by a magnetic coil 7, etc., and thereby, the pole height end is independent from fluctuation in the polishing process. Then a film of a third magnetic core 9 is formed into a specified pattern as shown in the process (f), and then subjected to heat treatment to improve characteristics of the magnetic core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite magnetic head for performing magnetic recording and reproduction.

[0002]

2. Description of the Related Art Recent advances in magnetic recording technology have resulted in several Gb / s
The high recording density of the ink 2 has been realized. This dramatic increase in recording density is due to the realization of a composite magnetic head combining a thin-film inductive head for performing recording and an MR head for performing reproduction.
This composite magnetic head is manufactured by simultaneously forming hundreds to thousands of elements formed on one substrate by a thin film process. Materials that promote high output, such as anisotropic MR materials, spin valve materials, and artificial lattice GMR materials, have been developed as element materials for the MR head, and have been advanced.

On the other hand, a thin-film inductive head uses a NiFe film having a saturation magnetic flux density of about 10 KG as a magnetic core. FIG. 5 is an example of a sectional view of a conventional general composite type magnetic head.
A head 100 is formed, on which an inductive head 200 is formed. Each configuration is a substrate 1
5, a magnetic thin film shield film 95, an insulating layer 105, M
The R element 115, the lead 125, the insulating layer 135, the first magnetic core 145 of the shield and inductive head, the magnetic gap and insulating layer 45, the coil 75, the insulating layer 85, and the second magnetic core 35 are laminated. . The saturation magnetic flux density of the magnetic core of the thin-film inductive head influences the writing ability, and the writing ability increases if a material having a high saturation magnetic flux density is used. Currently known high saturation magnetic flux density materials include alloys such as FeTaN, FeTaC, and FeHfC. These materials require heat treatment at 300 ° C. or higher to obtain soft magnetic properties.

In order to use a thin-film inductive head employing a high saturation magnetic flux density material for the composite magnetic head, a thin-film inductive head is placed on the MR head in the same manner as the structure of the conventional composite magnetic head as shown in FIG. Is manufactured, the function of the MR element is fatally deteriorated due to the heat treatment of the high saturation magnetic flux density material. Also, in order to avoid deterioration due to the heat treatment of the MR element, a thin film inductive head is first manufactured and heat treated,
After that, when manufacturing an MR head, it was difficult to manufacture an MR element due to steps such as coils of a thin-film inductive head.

Japanese Patent Application Laid-Open No. Sho 60-177420 discloses a method of manufacturing a composite magnetic head by forming a thin-film inductive head on a substrate and arranging an MR head thereon. FIG. 6 is a sectional view of the magnetic head. Each configuration has a first magnetic core 3 on a substrate 15.
5, insulating layer 85, coil 75, magnetic gap 45, second magnetic core 95 and shield, insulating layer 105, MR element 1
15 and leads 125, insulating layer 135, shield 14
5 are laminated. In the manufacturing method, as shown in FIG. 7A, a first magnetic core 35 having a concave portion for accommodating a coil is attached on the substrate 15, and a coil 75 is formed in the concave portion. Next, as shown in step (b), an insulating film 85 is applied, and the coil 75 and the first magnetic core 35 are buried. Next, as shown in step (c), polishing is performed until the first magnetic core 35 is exposed, and the gap forming surface is flattened. Next, as shown in step (d), an insulating film 45 serving as a magnetic gap is applied, a second magnetic core 95 is applied thereon, and an insulating film 105 is further formed. Next, as shown in step (e), the MR element 115, the lead 125, and the insulating film 13 are formed.
5. The shield 145 is attached to complete the composite magnetic head.

[0006]

However, when a composite magnetic head is to be manufactured by the method disclosed above, the end of the pole height of the front gap portion formed by the first magnetic core and the second magnetic core. The point is that, depending on the processing amount at the time of flattening polishing, for example, as shown in FIG. 8, at the polishing amount of h1, the one at the end point of a1 moves to a2 at h2. Due to the formation, there is a problem that the end point of the pole height varies depending on the location due to the difference in the amount of polishing in the substrate.

[0007] Variations in the end point of the pole height of the thin-film inductive head are caused by the MR to be formed thereon.
The correlation distance between the device and the depth end of the device will be different for each device, and in the method of simultaneously polishing the pole height and the MR depth as a composite magnetic head after the wafer process, the designed pole height and MR depth cannot be obtained, and the performance and The production yield is reduced.

[0008]

In order to solve the above-mentioned problems, there is provided a method of manufacturing a plurality of composite magnetic heads comprising a thin-film inductive head and an MR head collectively on a substrate. Forming a first magnetic core on a substrate, disposing a second magnetic core on the first magnetic core via a magnetic gap material, and forming a magnetic gap having a predetermined depth; Arranging a magnetic coil; and attaching the magnetic coil to first and second magnetic coils.
A step of burying and covering the magnetic gap of the predetermined depth with a magnetic core and protecting the magnetic gap of the predetermined depth from a polishing operation in a subsequent polishing step, and polishing the unevenness on the surface of the insulating material to flatten it. A step of exposing a top surface of a second magnetic core, and forming a third magnetic core for magnetically connecting the exposed second magnetic core and the first magnetic core to the flattened insulating material Forming a third magnetic core on the third magnetic core of the thin-film inductive head as a lower shield. To provide a method of manufacturing a magnetic head.

Further, the top surface of the second magnetic core disposed on the first magnetic core via a magnetic gap material is formed higher than the top surface of a magnetic coil disposed later, and the surface of the insulating material is formed. A method of manufacturing a composite magnetic head in which the top surface of the magnetic coil is not exposed in the step of polishing the irregularities of the above and exposing the upper surface of the second magnetic core.

The second magnetic core is disposed on the first magnetic core formed on the projection formed on the substrate with a magnetic gap material interposed therebetween, so that the top surface thereof is formed later. Provided is a method for manufacturing a composite magnetic head that is formed higher than a top surface of a magnetic coil to be arranged. A composite magnetic head in which the second magnetic core is formed to be thicker than the height of a magnetic coil disposed later, so that the top surface of the second magnetic core is formed higher than the top surface of the magnetic coil disposed later. And a method for producing the same.

[0011]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of a composite magnetic head manufactured according to the present invention. A first magnetic core material 3 is adhered on a surface of the ceramic substrate 1 on which a concave portion is formed by processing the convex portion 2 of alumina, and a magnetic gap material 4 is formed on a front gap portion on the medium sliding surface side. The second magnetic core 5 is directly adhered on the first magnetic core 3 via the first magnetic core 3 and in the rear gap portion, and forms a closed magnetic path of the thin-film inductive head together with the third magnetic core 9. A magnetic coil 7 is formed in a recess formed by the first magnetic core material 3 with a first insulating layer 6 interposed therebetween, and is filled with an insulating material 8 to intersect the closed magnetic path. On the third magnetic core 9, an MR element 11 and a lead 12 are further interposed via a third insulating layer 10.
However, a shield film 14 is further laminated via a fourth insulating layer 13 to form a composite magnetic head.

Referring to FIG. 2, a manufacturing method according to the first embodiment of the present invention will be described. However, for the sake of simplicity, the manufacturing process of a plurality of magnetic heads is represented by one magnetic head manufacturing process.
First, as shown in step (a), an Al2O3 film of about 20 μm is formed on a ceramic substrate such as Al2O3-TiC by sputtering or CVD, and a magnetic coil having a predetermined thickness is sufficiently arranged. The Al2O3 film at the portion where the magnetic coil is disposed is removed by ion milling or wet etching so as to be able to do so. After that, an FeTaN alloy film as a first magnetic core material is formed. The magnetic core material is desirably a material having a high saturation magnetic flux density, and may be an FeTaC alloy film, an FeN alloy film, or the like in addition to the FeTaN alloy film. The first magnetic core is formed by forming a resist into a predetermined shape,
A wrist-off method in which the first magnetic core is formed and the resist is removed is possible. Alternatively, the first magnetic core material may be entirely formed and a predetermined shape may be formed by milling.

Next, as shown in step (b), a magnetic gap material 4 serving as a recording gap is formed, and a second magnetic core material 5 is formed. The second magnetic core material other than the front gap portion and the back gap portion is removed by milling.
In particular, the end A of the second magnetic core opposite to the medium sliding surface of the front gap portion serves as a pole height end of the recording head. In this case, by making the shape of the second magnetic core a substantially rectangular parallelepiped, the magnetic path does not open even when the pole height is extremely small. This can be applied to all cases of the present invention. Next, as shown in step (c), a first insulating layer 6 is formed, and then a magnetic coil 7 is formed. Here, the magnetic coil is formed by a frame plating method or the like. As shown in the step (d) after the formation of the magnetic coil 7,
The insulating material 8 is formed to a thickness equal to or greater than the thickness of the magnetic coil. At this time, a magnetic gap having a predetermined depth is formed in advance, and is buried and protected by the insulating material 8 at the same time. Therefore, the magnetic gap having the predetermined depth does not fluctuate in the next polishing step. . Thereafter, as shown in step (e), the insulating material 8 is polished by mechanical polishing or chemical mechanical polishing (CMP) to eliminate a surface step caused by the magnetic coil 7 or the like. The polishing is completed when the second magnetic core 5 buried in the insulating material 8 is exposed on the polished surface.

Since the work at this time is performed on a substrate basis, there is a slight difference in the polishing amount depending on the position in the substrate. However, the track width and the pole height end are reduced by the formation of the second magnetic core 5. 2 is established by the point A in contact with the gap material on the rear end surface of the core 5 of the second core 5.
This point A does not move, and the pole height end is irrelevant to variations in polishing and the like. Next, step (f)
As shown in (3), the third magnetic core 9 is formed into a film and formed into a predetermined shape. Thereafter, heat treatment is performed to improve the characteristics of the magnetic core. After the heat treatment, as shown in step (g), an insulating layer 10, an MR film 11, and an electrode film 12 are formed to form an MR element. Further, an insulating layer 13 and a shield film 14 are formed. Thereafter, terminals and a protective film (not shown) are formed to complete the composite magnetic head.

FIG. 3 shows a manufacturing method according to a second embodiment of the present invention. As shown in step (a), a first magnetic core material 3 is applied on a ceramic substrate 1, and a second magnetic core 5 is placed thereon via a magnetic gap material 4 as shown in step (b). And process the front gap portion and the back gap portion. A magnetic coil 7 is formed in a concave portion between the front gap portion and the back gap portion as shown in step (c), and an insulating material 8 is formed to a film thickness equal to or greater than the coil thickness as shown in step (d). I do. Thereafter, as shown in step (e), the insulating material 8 is polished by mechanical polishing or chemical mechanical polishing (CMP) to eliminate a surface step caused by the magnetic coil 7 and the like. The polishing is completed when the second magnetic core 5 buried in the insulating material 8 is exposed on the polished surface. Next, a third magnetic core 9 is attached as shown in step (f). Thereafter, heat treatment is performed to improve the characteristics of the magnetic core. After the heat treatment, as shown in step (g), an insulating layer 10, an MR film 11, and an electrode film 12 are formed to form an MR element. Further insulating layer 1
3. The shield film 14 is formed. Thereafter, terminals and a protective film (not shown) are formed to complete the composite magnetic head.

FIG. 4 shows a manufacturing method according to a third embodiment of the present invention. As shown in a step (a), a first magnetic core material 3 is applied on a ceramic substrate 1, a recess for accommodating a magnetic coil is processed, and a magnetic gap material is formed thereon as shown in a step (b). The second magnetic core 5 is attached via the first magnetic core 4. Next, a magnetic coil 7 is formed in the recess as shown in step (c), and an insulating material 8 is formed to a thickness equal to or greater than the coil thickness as shown in step (d). Thereafter, as shown in step (e), the insulating material 8 is polished by mechanical polishing or chemical mechanical polishing (CMP) to eliminate a surface step caused by the magnetic coil 7 or the like. The polishing is completed when the second magnetic core 5 buried in the insulating material 8 is exposed on the polished surface. The composite magnetic head is completed through the steps shown in FIG.

[0017]

Since the pole height end is determined, the positional relationship between the inductive head and the MR head is as designed, and a composite magnetic head having excellent characteristics and a good production yield can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a composite magnetic head of the present invention.

FIG. 2 is a manufacturing process diagram of the first embodiment of the present invention.

FIG. 3 is a manufacturing process diagram of a second embodiment of the present invention.

FIG. 4 is a manufacturing process diagram of a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional composite magnetic head.

FIG. 6 is a sectional view of a conventional composite magnetic head.

FIG. 7 is a manufacturing process diagram of a conventional composite magnetic head.

FIG. 8 shows the relationship between the amount of polishing and the movement of the depth end during conventional flattening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Convex part 3 1st magnetic core 4 Magnetic gap material 5 2nd magnetic core 7 Magnetic coil 8 Insulating material 9 3rd magnetic core 11 MR element

Claims (4)

[Claims] 1. A method for manufacturing a plurality of composite magnetic heads comprising a thin film inductive head and an MR head on a substrate collectively, wherein the method for manufacturing a thin film inductive head includes forming a first magnetic core on the substrate. Arranging a second magnetic core on the first magnetic core via a magnetic gap material to form a magnetic gap having a predetermined depth, arranging a magnetic coil, A step of burying and covering the first and second magnetic cores with an insulating material and protecting the magnetic gap having the predetermined depth from a polishing operation in a subsequent polishing step, and polishing the irregularities on the surface of the insulating material. Exposing the top surface of the second magnetic core, and connecting the exposed second magnetic core and the first magnetic core magnetically.
Forming a magnetic core over the planarized insulating material over a magnetic coil. The method of manufacturing an MR head comprises the steps of: forming a third magnetic core on a third magnetic core of the thin-film inductive head; A method for manufacturing a composite magnetic head, comprising a step of forming a core as a lower shield. 2. A top surface of a second magnetic core disposed on the first magnetic core via a magnetic gap material is formed higher than a top surface of a magnetic coil disposed later, and a surface of the insulating material is provided. 2. The method according to claim 1, wherein the top surface of the magnetic coil is not exposed in the step of polishing the unevenness to expose the upper surface of the second magnetic core. 3. The second magnetic core is disposed on a first magnetic core formed on a projection formed on a substrate with a magnetic gap material interposed therebetween so that a top surface thereof is formed later. 3. The method of manufacturing a composite magnetic head according to claim 2, wherein said magnetic coil is formed higher than a top surface of said magnetic coil. 4. The second magnetic core is formed to be thicker than the height of a magnetic coil to be disposed later, so that the top surface of the second magnetic core is higher than the top surface of a magnetic coil disposed later. 3. The method for manufacturing a composite magnetic head according to claim 2, wherein: