JPH01285009A - Magnetic head, thin film coil used for it and manufacture thereof - Google Patents

Abstract

PURPOSE:To reduce a magnetic path length and to improve a recording and reproducing efficiency by inserting a thin film coil without a substrate into the winding window of a magnetic head. CONSTITUTION:The substrate of a thin film coil 17 used in being combined with magnetic head cores 10 and 10' is removed after the thin film 17 is formed, the thin film coil 17 without the substrate and the magnetic head core half bodies 10 and 10' are combined, thereafter, the magnetic head core half bodies 10 and 10' are mutually joined and unified, and they are made into the magnetic head. In such a way, by removing the substrate of the thin film coil 17, a winding window 12 to insert the thin film coil 17 can be made small. Thus, the magnetic head can be obtained in which the magnetic path length is small, which is excellent in the recording and reproducing efficiency, simultaneously, in which the time passage change of a gap length is not generated, in which the destruction strength of the head is high, and further, which is excellent in a mass producibility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, a thin film coil used therein, and a method for manufacturing the same.

[Conventional technology]

Conventionally, as a magnetic head used in a magnetic recording device such as a VTR device, a magnetic head disclosed in Japanese Patent Application Laid-Open No. 57-53819 and the like has been used. These magnetic heads are shown in FIG.

The magnetic core halves 10 and 10' made of ferromagnetic material are integrally bonded via a gap material 11.A coil 13 is wound around a winding window 12, and recording and recording is performed by passing a signal current through this. It is configured to perform playback. The track width regulating groove is filled with a filler 14 such as glass.

Although such a magnetic head has excellent recording and reproducing characteristics, the following problems have been encountered in order to further improve the recording and reproducing efficiency. That is, in order to increase the efficiency, it is necessary to shorten the length of the magnetic path that goes around the first winding window 12 and reduce the magnetic resistance. The problem is that the first winding window 12 cannot be made smaller than a certain limit in order to later wind the coil 13 around the winding window 12, and therefore the magnetic path length cannot be shortened. The size of the winding window of the above-mentioned magnetic head varies depending on the number of turns, but for example, if the winding diameter is 30 μm and the number of turns is 20 times, the length of the magnetic path that goes around the winding window must be 2 or more times. When the winding window is made smaller, there is a problem in that it becomes difficult to wind the coil.

As a magnetic head that solves the above problem and reduces the magnetic path length by forming the coil in a small space, as shown in FIG. A magnetic head formed and shaped by a method is known. In this head, the windings are formed by a thin film fabrication method and a thin film processing method, so fine patterns can be formed, and a large number of windings can be formed in a short distance, so the length of the magnetic path can be shortened. However, since the thin film manufacturing method and thin film processing method are also used for forming and processing the magnetic poles, there is a problem in that the number of steps for manufacturing the magnetic head increases and productivity decreases.

[Problem to be solved by the invention]

In order to solve this problem, we prepared a magnetic core half with a minute winding window formed in advance and a minute thin film coil fabricated by thin film manufacturing and thin film processing methods, and after combining these, we created a magnetic core half. A magnetic head having a structure in which the bodies are joined and integrated is described in Japanese Patent Laid-Open No. 137125/1983. That is, as shown in FIG. 4, in order to simplify the winding work, this specification describes a method in which a printed circuit board 19 on which a plurality of spiral conductor patterns 18 are printed and wired is bent so that the conductor patterns overlap each other. It is described that this is passed through the core half body 10.10' to form a coil of a magnetic head.

Further, in the specification of Japanese Utility Model Application No. 58-101315, as shown in FIG. 5, in (a), the winding window of the magnetic head is
It is described that a conductor pattern 18 formed on a flexible insulating film 20 is inserted, and in (b) the conductors are connected to each other along the broken lines to form a coil. but,
In all of these examples, a winding wire is formed on an insulating film as a base, and in order to insert the winding wire together with the insulating film into a winding window, the winding wire including the insulating film as a base is formed. There is a problem that the size of the magnetic path increases and the magnetic path length does not become sufficiently small.

Further, when a thin film coil having an insulating film as a base is used as described above, the following problems occur.

That is, when manufacturing a VTR head as shown in FIG. 2, glass bonding is generally performed in the step of bonding the magnetic core halves together. When an organic adhesive such as a resin is used in the above bonding and integration process, the bonding strength of the magnetic core halves is low, so the head is prone to breakage, and moisture in the air is absorbed by the organic adhesive, causing swelling. , giving rise to a first order problem in which the gap length varies. As described above, it is necessary to perform glass bonding in the process of joining and integrating the magnetic core halves, but at this time it is necessary to heat the magnetic core halves to a high temperature of at least 400° C. or higher. on the other hand.

What is the insulating film that serves as the base of the above thin film coil?

It is made of organic materials such as polyester, and it has 400
When heated above .degree. C., high-temperature heating is performed as in the glass bonding process in order to cause deformation and decomposition.

I can't stand the process.

The present invention solves the above-mentioned problems of the conventional technology in a head that combines a magnetic core half with a minute winding window and a minute thin film coil, and then joins the magnetic core halves together. It was done for the purpose of

[Means to solve the problem]

In order to solve the above problems, in the present invention, the base of the thin film coil used in combination with the magnetic helad core is removed after the M film coil is formed, and after the thin film coil without the base is combined with the magnetic head core half, The magnetic head core halves are joined together to form a magnetic head. By removing the base of the thin film coil as described above, the winding window into which the thin film coil is inserted can be made smaller, the magnetic path length can be reduced, and the recording and reproducing efficiency can be improved.

[Effect]

As the substrate of the thin film coil of the present invention, an organic film such as polyester or polyimide can be used. Further, it is possible to provide an organic layer such as a resist or the like which is dissolved by an organic solvent on a substrate such as Si or ceramics, and further form a thin film coil thereon. The organic film or organic layer serving as the base of these thin film coils can be dissolved with an organic solvent or removed by oxidation in oxygen plasma, and only the thin film coil without the base can be taken out.

The step of removing the base described above may be performed before the step of combining the magnetic head core half and the thin film coil, but it is better to perform the step of removing the base after the above step. In the assembly process, the thin film coil has the advantage of being easy to handle and having excellent productivity.

In the present invention, a method for manufacturing a thin film coil includes forming a conductor film, forming a resist pattern on the conductor film, and patterning the conductor by wet etching, ion milling, plasma etching, etc.; There is a method of forming a pattern and forming a conductor in the recessed portions of the resist pattern by vapor deposition or plating. To manufacture the thin film coil used in the present invention,
Any of the above methods can be used.

As the conductor of the thin film coil used in the present invention, Cu, AΩ
etc. are used. A trace amount of impurity may be added to these materials in order to improve heat resistance and strength. Further, in order to improve adhesion or prevent reaction with glass, a Cr film may be formed on the surface of the conductor. An insulating layer of an inorganic material is formed on the surface of the thin film coil. As this insulating layer, 5i
Oxides such as Oz+Si○ and AQxOs can be used. The oxide layer can be formed by a sputtering method, a CVD method (vapor phase growth method), or the like.

In addition, the thin film coil is immersed in a solution (so-called coating type SiO2 solution) in which Si hydroxide is melted in an organic solvent or the like,
By drying, an oxide insulating layer of 5 iOz or the like can be formed on the surface of the thin film coil. Further, as a method for manufacturing the thin film coil of the present invention, there is also a method of forming the coil by a thin film processing method in which a resist pattern is formed on a conductive metal sheet such as Cu and unnecessary parts are etched.

Note that the thin film coil manufactured by the method of the present invention can be used not only for magnetic heads but also for transformers. In this case, a thin film coil with its base removed is inserted into one half of the magnetic core of the transformer, and the other half of the magnetic core is joined together to form a transformer. The transformer using the thin film coil of the present invention has the characteristics that the magnetic length can be shortened similarly to the magnetic head, so that the loss is small and the transformer can be made compact. The above transformer is suitable as a step-up transformer for increasing the output signal generated from the magnetic head.

〔Example〕

Next, the present invention will be explained in detail with reference to examples.

Embodiment 1 FIG. 1 shows an embodiment of the magnetic head of the present invention. As shown in FIG. 1(a), in the magnetic head of the present invention, a thin film coil 17 from which the base body has been removed is combined with a minute winding window 12 formed in a magnetic core half 10 made of a ferromagnetic material. Magnetic core half 10.10 as shown in figure (b)
' are joined and integrated through a gap material 11 using a joining material 21 such as glass. 5i on the surface of the thin film coil 17
The oxide layer is removed from the terminal portion 22 of the thin film coil, which is insulated with an oxide layer such as FT. By combining the removed thin-film coils, it is possible to bond them at high temperatures using glass, and it is also possible to obtain a highly efficient magnetic head with a shortened magnetic path length.

FIG. 6 shows a method for manufacturing the magnetic head of the present invention and the thin film coil used therein.

In FIG. 6(a), a coil lead wire 24 is formed on an organic film 23 made of polyester, polyimide, or the like. The lead wire 24 is formed by forming a conductor film such as Cu, then protecting the portion to be left as the lead wire with a resist film, etc., and etching the other portion by ion milling, reactive ion beam etching, or plasma etching. Law.

There are methods to remove it, such as wet etching.

Further, it is possible to apply a resist on the film, remove the resist in a portion that should become a lead wire, and form a conductor film such as Cu on the removed portion by a lift-off method, a plating method, etc. to form a lead wire. Next, place SiO2 on the lead wire 24.
, Al2203, etc., and through holes for connecting the lead wires and the coils are formed by the above-mentioned ion milling method, reactive ion beam etching method, plasma etching method, wet etching method, etc.

Next, in FIG. 6(b), a thin film coil 25 is formed by the above-mentioned ion milling method, reactive ion beam etching method, plasma etching method, wet etching method, shift-off method, plating method, or the like.

Next, in FIG. 6(c), the above organic film is removed with a solvent such as hydrazine, and only the thin film coil and its lead wire portion are taken out. In this thin film coil, a frame 2 is used to prevent the individual thin film coils from falling apart.
Adding the number 6 is preferable because it facilitates handling and improves productivity.

Next, in FIG. 6(d), the terminal portion 27 is removed.

An insulating layer is applied to the surface of the thin film coil. In this example,
The thin film coil, excluding the terminal portion 27, is immersed in a coated SiO2 solution and dried to form an inorganic insulating layer 36 of 5 iOz or the like on the surface of the thin film coil.

Next, in FIG. 6(E), the rear contact portion 29 of the previously formed magnetic core half block 28 is installed so as to penetrate through the central hole 30 of the thin film coil. Next, the 6th
In the figure (f), the other magnetic core half block 2
8' are aligned so that the track widths match, and heated, melted, and fixed using a bonding material 31 such as glass to form a bonded block 32. Next, a magnetic head 33 similar to that shown in FIG. 1 is obtained by cutting along the broken line in FIG.

As in this embodiment, by using a thin film coil from which the organic film serving as the base is removed, the coil can be attached to the minute winding window 34, and a magnetic head with short magnetic path length and excellent recording and reproducing efficiency can be created. You can get it. In addition, in order to remove the organic film, it is possible to use a bonding material such as glass that is heated at high temperatures, so that the gap length does not change over time and a magnetic head with high breaking strength can be obtained. By combining a magnetic head core half block 28 containing a large number of magnetic helad core halves and a thin film coil assembly 35 in which a large number of thin film coils are connected to one frame, a large number of magnetic heads can be obtained simultaneously. It has excellent mass productivity.

Example) Another example of the manufacturing method of the magnetic head of the present invention and the thin film coil used therein is shown in FIG. 7. In this example, a method of forming an insulating layer on the surface of the thin film coil is shown.

Instead of using the coating type 5iOz shown in FIG. 6(d),
An insulating layer produced by a thin film formation method such as sputtering is used.

That is, in FIG. 7(a), an inorganic insulating layer 36 of 5iOz, AflzOa, etc. is formed on the organic film 23.
Next, in FIG. 7(b), lead wires 2 are formed on top of this in the same way as in the method of FIG. 6(a).
4, and further a thin film coil is formed in the same manner as 25 in FIG. 6(b).

Next, in FIG. 7(c), an inorganic insulating layer 36 such as SiOzrAQzos is formed on the coil surface other than the terminal portion 27. Next, similarly to Fig. 6 (c),
The organic film 23 is removed and the thin film coil assembly 35 is taken out, and then combined with a magnetic head core half block to form a magnetic head as shown in FIGS. 6(e) and 6(f).

Example 3 Another example of the manufacturing method of the magnetic head of the present invention and the thin film coil used therein is shown in FIG. 8. In this example, Si
, on a substrate 37 such as glass, ceramics, metal plate, etc.
An organic film 23 is formed, and Example 1 is further formed on the organic film 23.
A thin film coil and a magnetic head are manufactured by the same method as described in 2. The organic film used in this example can be obtained by coating a polyimide resin or the like on a substrate and curing it by heating. Alternatively, a cyclized rubber-based resist resin or the like can be applied and cured before use. After forming a thin film coil, these organic films are coated with hydrazine,
Alternatively, only the thin film coil can be taken out by dissolving it using a solvent such as a phenolic resist removal solution. By using a hard substrate under the organic film as in this example, it is possible to improve the deflection and bending of the film that tends to occur when forming coils and insulating layers when only a flexible and bright organic film is used. , it has the advantage of being easy to produce thin film coils.

Example 4 Another example of the manufacturing method of the magnetic head of the present invention and the thin film coil used therein is shown in FIG. ), an organic film 23 is formed on a substrate 37, and a thin film coil assembly 35 with an insulating layer 36 attached is formed.Next, as shown in the cross-sectional view of FIG. The rear contact portion 29 of the magnetic head core half block 28 is passed through the inner part 30 of the thin film coil. Thereafter, the organic film 23 is dissolved with an organic solvent, and the substrate 37 and the thin film coil are separated. Thereafter, as in FIG. 6(f), it is combined and integrated with the other magnetic head core half block 28' to obtain a magnetic head.

In this embodiment, since the thin film coil is combined with the magnetic core half block before being separated from the substrate, one alignment is certain, and even if the thin film coil warps or bends when separated from the substrate, the coil and Magnetic cores can be easily combined. Incidentally, in this embodiment, the frame 26 shown in FIGS. 6 and 7 is not necessary and is therefore removed.

In this example, instead of the thin film coil formed on the substrate shown in FIG. 9(A), a thin film coil formed on the organic film is used as shown in FIG. 7(C). Before melting the film, turn the organic film and thin film coil over, and combine the thin film coil and magnetic core half block as shown in Fig. 9 (c) in the same manner as described in Fig. 9 (b), and then It is also possible to dissolve organic films using organic solvents. According to this method, by using a transparent organic film, alignment with the magnetic core half block is facilitated, and workability is improved.

Further, in the case of this method, since the organic film to be removed is exposed on the surface, there is an advantage that it is easy to remove with a solvent. In addition to removal using a solvent, it is also possible to arrange an organic film in oxygen plasma and remove it. In this case, there is an advantage that dust and foreign matter are less likely to adhere to the magnetic core compared to the case where an organic solvent is used.

Embodiment 5 Another example of the method of manufacturing the magnetic head of the present invention and the thin film coil used therein is shown in FIG.

In this embodiment, a second organic film 38 is provided between the substrate 37 and the organic film 23 as shown in FIG. 10(A). Thereafter, the substrate 37 and the organic film 23 on which the thin film coil is formed are separated using a solvent that dissolves only the second organic film 38. Thereafter, the organic film 23 is removed by a method similar to that described in FIG. 9(c) to produce a magnetic head. In this embodiment, for example, a polyimide resin is used as the organic film 23, a cyclic rubber resist resin is used as the second organic film 38, a phenolic resist removal liquid is used as the solvent for the second organic film, and hydrazine is used as the solvent for the organic film 23. A basic solution such as can be used. Since these organic films are insoluble in acetone, there is no problem even if an organic solvent such as acetone is used to remove the resist used for coil formation or the like. According to this embodiment, since a thin film coil is formed on an organic film supported by a hard substrate, workability in the thin film coil forming process is excellent, and also in the process of combining the magnetic head half core and the thin film coil. has the advantage that alignment is easy.

Embodiment 6 Another example of the method of manufacturing the magnetic head of the present invention and the thin film coil used therein is shown in FIG.

In this embodiment, the process is similar to that shown in FIG. 9(a).

An organic film 23 is formed on a substrate 37, and a thin film coil assembly 35 is formed on this. Next, as shown in FIG. 11, the portion of the substrate on which the thin film coil is formed is removed by plasma etching, wet etching, reactive ion beam milling, or the like. For example, when Si is used as the substrate, the substrate can be dissolved without dissolving the organic film 23 by using hydrofluoric acid. Combining a magnetic core half block and a thin film coil,
Next, the organic film 23 is removed using a solvent or oxygen plasma as described above to produce a magnetic head.

Embodiment 7 Another example of the manufacturing method of the magnetic head of the present invention and the thin film coil used therein is shown in FIG.

The thin film coil in this embodiment is processed into a coil shape by a thin film processing method in which a metal sheet such as Cu is used as a conductor, and a resist pattern is formed on the sheet and then etched. Therefore, no substrate is used to form the thin film coil.

In FIG. 12(A), S i
An inorganic insulating layer 36 such as Ox, A (lx's) is formed, and then unnecessary portions of the inorganic insulating layer 36 are removed into a predetermined shape including a through hole 47 for connecting the lead wire and the coil.Next 12(b), lead wires 24 are formed in the same manner as in Example 2. Next, the first
In FIG. 2(c), a resist is formed on the back surface of the metal sheet 46 and patterned, and the portions not covered with the resist are further subjected to wet etching, ion milling, and reactive ion beam etching.

It is removed by plasma etching or the like, and the thin film coil 25 indicated by the broken line is taken out. After that, Figure 6 (c) ~ (g)
An inorganic insulating layer is formed on the surface of the thin film coil by the same method as described above, and a magnetic head is assembled. In this embodiment, since a metal sheet is used as the conductor, it is easy to increase the thickness of the conductor, and there is an advantage that it is easy to obtain a low-resistance coil.

``The magnetic head shown in FIG. 1 has been cited as an example of the magnetic head of the present invention, but in addition to the case where the magnetic core is made of a single magnetic material such as ferromagnetic ferrite, there is also one magnetic head of the present invention. For the magnetic core used in the head, a high saturation magnetic flux density of Fe-AQ-Si alloy, amorphous alloy, Fe-8i alloy, Fe-C alloy, etc. is used near the gap of 1 ferromagnetic ferrite. A magnetic core with a metal magnetic film formed thereon, or a magnetic core with the metal magnetic film formed on a nonmagnetic substrate can also be used.

FIG. 13 shows an example of a magnetic head in which a magnetic core using a metal magnetic film is combined with the thin film coil of the present invention. FIG. 13(a) shows a magnetic core half body 41.41' having a metal magnetic film 40 formed on a substrate 39 protruding into a chevron shape, and a thin film coil 43 assembled to the winding window of the magnetic core half body. , the magnetic core halves are joined together via a gap 42 using a bonding material 44 to form a magnetic head. The grooves near the sliding surface are filled with a filler 45.

Note that when glass is used as the binding material 44, the filler material 45
As the material, glass having the same or higher softening temperature, or non-magnetic materials such as highly heat-resistant ceramics and oxides can be used.

FIG. 13(b) shows an example of a magnetic head formed by forming a metal magnetic film on a surface oblique to the gap surface, and FIG. 13(c) shows an example of a magnetic head.
This is an example in which a magnetic head is formed by forming a metal magnetic film so as to fill a concave groove formed on a substrate.

By combining a magnetic core using a metal magnetic film with such a high saturation magnetic flux density and the thin film coil of the present invention, a magnetic head with even better recording characteristics and excellent reproduction efficiency due to its short magnetic path length can be created. can be manufactured with high productivity.

〔Effect of the invention〕

As described above, in the magnetic head of the present invention, the magnetic path length is small by combining the thin film coil from which the organic film serving as the base has been removed and the magnetic core.
It is possible to obtain a magnetic head with excellent reproduction efficiency, no change in gap length over time, high breaking strength of the head, and excellent mass productivity.

[Brief explanation of the drawing]

1 and 13 are perspective views showing one embodiment of the magnetic head of the present invention, FIG. 2 is a plan view and a front view of a conventional magnetic head, and FIG. 3 is a sectional view of a coil portion of a conventional magnetic head. 4 to 5 are perspective views showing an example of a conventional magnetic head, and FIGS. 6 to 12 are perspective views and sectional views showing a method for manufacturing the magnetic head and thin film coil of the present invention. be. 10, :LO', 41.41'...magnetic core half,
11.42... Gap material, 12.34... Winding window. 13... Coil, 14.45... Filler, 15,3
7゜39...Substrate, 16...Magnetic pole, 17, 25, 4
3... Thin film coil, 18... Conductor pattern, 19.
...Printed board, 20...Insulating film, 21, 31
, 44... Bonding material, 22.27... Terminal portion, 23.
...Organic film, 24...Lead wire, 26...
Frame, 28° 28'...Magnetic head core half block, 29...Rear contact portion, 30...Coil center hole, 32...Coupling block, 33...Magnetic head, 35...Thin film Coil assembly, 36... Inorganic insulating layer, 38... Second organic film, 40...
Metal magnetic film, 46...Metal sheet 1st ward certain 2 figure %3 figure) (b) swear t mouth 13 Lecture failure ha 0 ku > 19 1st sheet ZO hand color @ 74) t, mγ 9 Figure ■ 10 Figure 11 Figure 38 Sai Z') Drop Ne 5 (q Mutsu Film W 12 Figure 46 Metal Sea Y 47 Nun L-Hole Fu 13 Mouth Cow 5 Mitsutachi Mo Mishin)

Claims (16)

[Claims] 1. 1. A magnetic head in which half magnetic head cores are integrally connected to each other via a gap material, characterized in that a thin film coil without a base is inserted into a winding window of the magnetic head. 2. A thin film coil from which a base body has been removed is inserted into a winding window formed in a magnetic head core half, and then the other magnetic head core half and the magnetic head core half are assembled and joined together to form an integral body. A method of manufacturing a magnetic head. 3. A thin film coil formed on a base body is inserted into a winding window formed on a magnetic head core half body, and then the base body is removed, and the other magnetic head core half body and the magnetic head core half body are combined. A method of manufacturing a magnetic head characterized by joining and integrating the magnetic heads. 4. A thin film coil made by processing a metal sheet using a thin film processing method is inserted into the winding window formed in the magnetic head core half, and then the other magnetic head core half and the magnetic head core half are combined and joined together. A method of manufacturing a magnetic head, characterized in that: 5. A magnetic head according to claim 1, characterized in that the magnetic head core halves are integrally joined by glass. 6. A method of manufacturing a magnetic head according to any one of claims 2 to 4, characterized in that glass is used to join and integrate the magnetic head core halves. 7. 1. A thin film coil for a magnetic head, characterized in that a thin film coil is formed on a base by a thin film manufacturing method and a thin film processing method, and the base is removed. 8. A thin film coil for a magnetic head, characterized by processing a conductive metal sheet using a thin film processing method. 9. A method of manufacturing a magnetic head according to any one of claims 2, 3 and 6, characterized in that an organic film is used as the substrate. 10. In the method for manufacturing a magnetic head according to any one of claims 2, 3, and 6, the substrate is formed by forming an organic film on a substrate such as Si, glass, ceramics, or a metal plate. A method of manufacturing a magnetic head characterized by the following. 11. 11. The method of manufacturing a magnetic head according to claim 10, further comprising using a substrate in which a second organic film is formed between the substrate and the organic film. 12. 11. A method of manufacturing a magnetic head according to claim 10, characterized in that a substrate is used from which the substrate on the back surface of the thin film coil portion is removed. 13. In the method of manufacturing a magnetic head according to any one of claims 9, 10, 11, and 12, the organic film is removed using a solvent that dissolves the organic film. A method of manufacturing a magnetic head. 14. In the method of manufacturing a magnetic head according to claims 9, 10, 11, and 12, the organic film is removed by oxidizing in oxygen plasma. Head manufacturing method. 15. A thin film coil according to claim 7 or 8, characterized in that the coil has an inorganic insulating layer formed of coated SiO_2 on the surface of the coil. 16. In the method for manufacturing a magnetic head according to any one of claims 2, 4, 6, 9, 10, 13, and 14, after removing the base, a thin film is formed. A method for manufacturing a magnetic head, which comprises immersing a coil in a coated SiO_2 solution and drying it to form an inorganic insulating layer on the surface of the thin film coil.