JPH08263810A - Magnetic head and its production - Google Patents

Abstract

PURPOSE: To use a magnetism detecting element utilizing a magnetic impedance effect and to obtain a magnetic head capable of making reproduction with high sensitivity by this detecting element and dealing with the trend toward the higher density of recording. CONSTITUTION: A closed magnetic path is composed of a first core 10 formed by joining core half bodies 10A, 10B consisting of magnetic materials via a magnetic gap G and a second core 16 formed as the magnetism detecting element described above. The core half bodies 10A, 10B and glass 14 of a nonmagnetic material packed therebetween are exposed on the base of the first core 10 on the side opposite to its magnetic recording medium-sliding surface. The second core 16 is constituted as a high permeability magnetic film formed via an insulating film 15 on the base of the first core 10 and is so formed as to cover the respective core half bodies 10A, 10B across the glass 14 part of the base. Conductive films 18 are formed as terminals on both ends of the core 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for magnetically recording or reproducing information on a magnetic recording medium and a method for manufacturing the same, and more particularly to a magnetic head using a magnetic detecting element utilizing a magnetic impedance effect and a method for manufacturing the same. It is about.

[0002]

2. Description of the Related Art Recently, digital magnetic recording equipment has been miniaturized. For example, in a hard disk of an external storage device of a computer or a digital compact cassette (DCC) of a digital audio, a conventional inductive magnetic head has a track width. In addition, a magnetoresistive (hereinafter abbreviated as MR) element is used for the reproducing head because a decrease in S / N occurs due to a decrease in relative speed. The MR element does not depend on the speed of the medium and is suitable for taking out the output at a low speed, but since the resistance change rate is only a few percent, it is necessary to develop an element with higher sensitivity for future high density. Is desired.

Therefore, a magnetic impedance (hereinafter abbreviated as MI) element disclosed in Japanese Patent Application Laid-Open No. 6-281712 has recently attracted attention, and a high frequency current in the MHz band is passed through a magnetic material, and both ends thereof are passed. Is a phenomenon in which the amplitude of the voltage changes by several tens of percent with a minute magnetic field of several Gauss, that is, the magneto-impedance effect is used.

The advantage of the MI element is that it is not excited in the lengthwise direction of the magnetic material, so that there is no influence of the demagnetizing field, the element length can be shortened to about 1 mm or less, and it is suitable for downsizing, and the resolution of magnetic flux detection. However, the MR element has a low sensitivity of 0.1 Oe and a high sensitivity of about 10 ⁻⁵ Oe. Further, the amount of change in impedance can be obtained in the order of several tens of percent for the MI element, while that for the MR element is about 3%.

[0005]

However, when the MI element is used as a magnetic head having an open magnetic path, a problem arises with respect to the minute magnetization of the magnetic recording medium, as described below.

Normally, the MR element is made to function with a thickness of several hundred angstroms, whereas the MI element requires a thickness of the order of micron in order to use the effect of the eddy current, and the impedance has a certain level of impedance in terms of performance. To get
The MI element requires the length of the element. As for the actual length, the MR element can function even if it is 100 μm or less, but it is difficult to make the MI element function at 100 μm or less.

However, when the recording wavelength of the magnetic recording medium is shortened, the magnetic flux generated by the recording magnetization of the medium becomes difficult to occur,
With the rectangular MI element, as shown in FIG. 10, it becomes difficult to guide the magnetic flux from the magnetic recording medium 100 deep into the MI element 101. This means that the MI element, which has a high sensitivity, cannot take advantage of its ability when the magnetic path is open.

Therefore, as a method for making the best use of the ability of the MI element, a closed magnetic circuit structure is adopted so that the magnetic flux from the medium is sufficiently applied to the MI element. Need to be satisfied.

1) As mentioned above, it is necessary to secure a region for securing the effective length of the MI element.

2) Since a drive current is passed through the MI element, it is necessary to electrically insulate the MI element from the surrounding magnetic path so that there is no electrical short circuit or current flow to the sliding surface.

3) It is easy to pull out the terminals of the MI element.

4) Excellent productivity.

Therefore, an object of the present invention is a magnetic head adopting a structure of a closed magnetic circuit that makes the best use of the capability of a magnetic detecting element utilizing the magnetic impedance effect, which satisfies the above-mentioned points and can be reproduced with high sensitivity and recording. It is an object of the present invention to provide a magnetic head and a method of manufacturing the same that can cope with higher density.

[0014]

In order to solve the above-mentioned problems, according to the present invention, a first core formed by joining a pair of core halves made of a magnetic material via a magnetic gap, and a magnetic impedance. In a magnetic head that forms a closed magnetic path with a second core formed as a magnetic detection element utilizing the effect and obtains reproduction output from both ends of the magnetic detection element, a sliding surface of the magnetic recording medium of the first core. The pair of core halves and a non-magnetic material provided between the core halves are exposed on the bottom surface on the side opposite to the magnetic detection element serving as the second core. Is formed as a high-permeability magnetic film formed on the bottom surface of the core via an insulating film, and is formed so as to extend over the nonmagnetic material portion of the bottom surface and hang on each of the pair of core halves. Adopted.

In the method of manufacturing the magnetic head, a core block corresponding to a plurality of the first cores continuous in the track width direction is provided on the side opposite to the surface processed on the sliding surface of the magnetic recording medium. On the bottom surface, an insulating film, a high-permeability magnetic film that serves as a magnetic detection element, and a conductive film that serves as a terminal for extracting a reproduction output from the magnetic detection element are sequentially formed, and then,
A method of obtaining a plurality of the magnetic heads by cutting the core block at a predetermined interval in the track width direction is adopted.

[0016]

According to the structure of the magnetic head of the present invention, first, the region for obtaining the effective length of the magnetic detecting element can be sufficiently secured on the bottom surface of the first core. The magnetic path of the entire magnetic head is slightly stretched in the medium sliding direction and becomes large, but it can be made smaller by shortening the gap depth direction.
Further, the drive current flowing through the magnetic detection element can be applied without any problem because the insulating film is interposed between the first core and the magnetic detection element.

Further, by forming conductive films as terminals on both ends of the magnetic detection element, the size of the terminals is sufficient and the area where the terminals can be soldered can be secured.

Therefore, it is possible to realize a closed magnetic circuit structure in which the magnetic flux from the magnetic recording medium is sufficiently applied to the magnetic detecting element, and to provide a magnetic head capable of reproducing with high sensitivity and corresponding to high density recording. it can.

According to the above-mentioned manufacturing method of the present invention,
A large number of magnetic heads can be obtained at one time from one core block, which is excellent in productivity.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings.

[First Embodiment] FIG. 1 shows the structure of a first embodiment of a magnetic head according to the present invention. (A) shows a sliding surface of a magnetic recording medium which is in sliding contact with a magnetic recording medium (not shown). (Hereinafter, abbreviated as a sliding surface), (b) shows a side surface, and (c) shows a bottom surface opposite to the sliding surface.

In FIG. 1, 10 is a first core,
A pair of core halves 10A, 10B made of ferrite, which is a ferromagnetic oxide magnetic material, are butted against each other on the sliding surface side via a magnetic gap G, and are joined by glass 14, which is a non-magnetic material. Glass 14 is the core half 10A, 1
It is filled between 0B, and is also filled in the regulation groove 12 formed on the sliding surface to regulate the track width of the magnetic gap G. The core half 1 is provided on both ends of the bottom surface of the first core 10 in the sliding direction of the magnetic recording medium (hereinafter referred to as the medium sliding direction).
The bottom surfaces of 0A and 10B are exposed as magnetic path connection surfaces 11A and 11B that connect a magnetic path to an MI element as a magnetic detection element using a magnetic impedance effect described later, and the glass 14 is exposed in the middle part. There is. The width W of the glass 14 in the medium sliding direction on the bottom surface determines the effective length of the MI element.

The second core 16 as an MI element is formed on the bottom surface of the first core 10. However, since it is necessary to electrically insulate the cores 10 and 16 from each other, a SiO film is formed by a vacuum film forming technique.
_An insulating film 15 made of an oxide such as ₂ , Cr ₂ O ₃ and TiO _{2 is} formed on the bottom surface of the core 10 and then a second core 16 made of a high-permeability magnetic film is provided.

If the insulating film 15 is too thick, the core 1
Since the magnetic resistance of the junction between 0 and 16 increases and the efficiency decreases, the upper limit is set to 1 μm, and the lower limit is set to 0.1 μm from the minimum thickness for obtaining electrical insulation.

The second core 16 as the MI element is made of Fe.
It is assumed that a high-permeability magnetic film such as a -Co-B system amorphous film, a Fe-C system, or a Fe-N system microcrystalline film is formed by a vacuum film forming technique, and the entire width of the glass 14 portion of the core 10 is crossed. Further, it is assumed that the film is formed on the entire bottom surface of the core 10 so as to cover both the magnetic path connection surfaces 11A and 11B. As a result, a closed magnetic circuit is formed by the first core 10 and the second core 16, and the magnetic flux due to the recording magnetization of the magnetic recording medium is sufficiently transmitted to the second core 16 as the MI element via the first core 10. Is applied.

In order to fully bring out the function of this magnetic film as an MI element, the axis of easy magnetization of the magnetic film should be as shown in FIG.
In the direction of the arrow in (c) (track width direction),
It is set by cooling in a magnetic field or controlling the bias and incident angle during film formation. If the thickness of the magnetic film is too thin, the magnetic resistance of the entire magnetic head increases, and if it is too thick, the impedance of the MI element decreases and the MI effect decreases, so the thickness is set between 1 μm and 20 μm. Also, MI
If the effective length W of the element is 0.1 mm or less, almost no MI effect can be obtained.

Further, as terminals of the MI element, conductive films 18 made of Cu, Au, etc. are formed on both ends of the core 16 in the medium sliding direction so as not to reach the area of the element effective length W. Reproduced outputs are extracted from both ends of the MI element via the conductive film 18.

Next, a method of manufacturing the magnetic head of this embodiment will be described with reference to FIGS. 2 (a) to 2 (e) and FIGS. 3 (a) to 3 (d).

The first core 10 conforms to the method of manufacturing the core of the induction type magnetic head as found in the conventional VTR head, but since only the sliding portion needs to be taken out, it has the same size as the conventional one. The number of pieces taken from the ferrite material increases.

First, as shown in FIG. 2A, the surface of a ferrite material 20 formed in the shape of a rectangular thick plate from ferrite, which is a ferromagnetic oxide magnetic material, as a core material is surface-polished. Then, as shown in FIG. 2B, the gap depth of the magnetic gap G of the magnetic head and the element effective length W described above.
A plurality of trapezoidal restriction grooves 22 for restricting are formed in the ferrite material 20 in parallel.

Further, as shown in FIG. 2 (c), on the surface of the ferrite material 20, a regulating groove 24 corresponding to the regulating groove 12 in FIG. 1 for regulating the rack width in the direction perpendicular to the regulating groove 22 is formed. Are formed in parallel at equal intervals.

Then, on the surface of the ferrite material 20, SiO ₂ and Cr ₂ O ₃ (not shown) for forming a magnetic gap are formed.
After forming a thin film of a gap material such as, for example, as shown in FIG. 2 (d), a ferrite material 20 'processed in exactly the same manner as the ferrite material 20 is butted, and the glass rod 26 is inserted into the regulation groove 22. , Glass-fused ferrite materials 20, 2
Join 0 '. The glass of the glass rod 26 becomes the glass 14 in FIG. The amount of glass used at this time is the regulation groove 2.
Supply enough to fill the entire 2,24 area.

Thereafter, as shown in FIG. 2 (e), the block in which the ferrite materials 20 and 20 'are joined is cut along the cutting line shown by the broken line, and the first block as shown by A, B and C is cut. A core block 28 corresponding to a plurality of cores 10 continuous in the track width direction is taken out. For finishing, the cut surface of the taken out core block 28 on the side of the regulation groove 22 is subjected to surface grinding.

Next, a magnetic film corresponding to the second core 16 as the MI element is formed on the bottom surface of the core block 28. Before that, as shown in FIG. to obtain, SiO ₂ on the entire bottom surface of the core block 28,
An insulating film 30 made of an oxide such as Cr ₂ O ₃ and corresponding to the insulating film 15 in FIG. 1 is formed in a thickness range of 0.1 μm to 1 μm.

Then, as shown in FIG. 3B, on the insulating film 30, Fe-Co- which becomes the second core 16 of the MI element is formed.
A high-permeability magnetic film 32 such as a B-based amorphous film, a Fe-C-based or a Fe-N-based microcrystalline film is formed by a vacuum film forming technique. The thickness of the magnetic film 32 is usually set in the range of 1 μm to 20 μm in order to determine the impedance and the magnetic resistance of the element so that a predetermined circuit constant and core efficiency are obtained.

Further, as shown in FIG. 3C, the conductive film 34 made of Cu, Au or the like, which is the conductive film 18 of the terminal of the MI element, is magnetic so that it does not overlap the region of the element effective length W. A film is formed along both longitudinal edges of the film 32 by a vacuum film forming technique. When the adhesion strength of the conductive film is required, a Cr film may be formed as a base.

Finally, as shown in FIG. 3D, the core block 28 is cut along the broken line at predetermined intervals in the track width direction from the sliding surface side to obtain a large number of magnetic heads of this embodiment at a time. To be

Although the details of the mounting process of this magnetic head are omitted, as shown in FIG. 4, the magnetic head is attached to the base 40 and the sliding surface is lapped to obtain a predetermined gap depth. The wire 42 connected to the terminal 41 on the 40 side is soldered to the conductive film 18 of the terminal.

Next, the characteristics of the magnetic head of this embodiment will be described. A comparison was made between the magnetic head composed of a rectangular MI element with an open magnetic path and the magnetic head of this embodiment. Both of the MI elements were made of Fe-Ta-C-based microcrystalline film, and had the same size with a thickness of 5 μm, a width of 0.2 mm and an effective length of 0.5 mm. The head has a magnetic gap width of 5 μm and a rack width of 0.2 mm.
The conditions were the same as for the open type tip section. The characteristics were compared by scanning a magnetic tape recorded at a wavelength of 10 μm and comparing the amount of change in impedance. as a result,
While the open type changed only about 1.5%, the head of this example showed a change of 5.3%.
As described above, it was possible to provide a magnetic head which can perform reproduction with high sensitivity and can cope with high density recording.

[Other Embodiments] Next, other embodiments will be described with reference to FIGS.
This will be described with reference to FIG. In these figures, parts common to or corresponding to those in FIGS. 1 and 4 of the first embodiment are designated by common reference numerals, and description of common parts is omitted.

[Second Embodiment] The output of the magnetic head shown in the first embodiment incorporates the impedance of the MI element, mainly the inductance component, as an inductor of an oscillator such as a Colpitts oscillator, and changes in impedance are reflected in the amplitude of the oscillation circuit. It is converted to modulation and the output is taken out by the detection circuit. In order to operate this circuit in a stable manner, it is necessary to secure an impedance (inductance) of a certain size, and even in the head of the first embodiment, depending on usage conditions,
It is necessary to devise another means to further increase the impedance.

FIG. 5 shows the head of the second embodiment of the present invention which has been devised. Although the bottom surface side of the first core of the head is shown in FIG. 5, the insulating film 15 on the bottom surface of the first core 10 is not shown for convenience of description.

In the embodiment shown in FIG. 5A, two MI elements (second cores) 16 having a narrow width in the track width direction are provided.
A and 16B are formed in parallel on the bottom surface of the first core across the glass 14 so that both ends of the first core bottom face the magnetic path connection surfaces 11A and 11B, and both elements 16A and 16B are formed into a thin conductive film 5.
0 is connected in series.

According to this structure, the magnetic circuit is of a parallel type, and the impedance can be electrically obtained in series while suppressing an increase in the magnetic resistance, which is very effective.

As a modification of this embodiment, FIG.
If the MI elements 16A and 16B are connected in series by the thin connecting portion 51 made of a magnetic film continuous to the magnetic films of the MI elements 16A and 16B without using the above-described conductive film 50 as shown in FIG. By omitting the film 50, the manufacturing process can be simplified and the cost can be reduced.

The number of MI elements is not limited to two, and three or more MI elements may be provided side by side and connected in series.

[Third Embodiment] In the first embodiment, the first core 10 is a core half body 10A made entirely of ferrite.
Although it is configured as a ferrite core formed by joining 10B, as shown in FIGS. 6A to 6C as a third embodiment, the core halves 10A and 10B made of ferrite are abutted to each other via the magnetic gap G. It may be configured as an MIG (metal in gap) core in which a metal magnetic film 61 is formed on the abutting surface.

[Fourth Embodiment] FIGS. 7A to 7C.
As shown as the fourth embodiment, the first core 10 may be configured as a laminated core in which a plurality of laminated high-permeability metal magnetic films 71 are sandwiched with a non-magnetic material 72. According to the fourth and third embodiments, an improvement in S / N can be expected, and when a recording function is provided as in the next fifth embodiment, an improvement in recording function can be expected.

[Fifth Embodiment] In the first to fourth embodiments,
Although the head has only the reproducing function, the structure shown in FIG. 8 as the fifth embodiment can also have the recording function.

In the configuration of FIG. 8, a through hole 80 is provided in the glass 14 portion between the core halves 10A and 10B constituting the first core 10, and the coil winding 82 is passed through the through hole 80 to allow the core 10 to pass through. By winding it around, it is possible to have a recording function as an induction type head, and to be used for both recording and reproduction. Here, the second core 16 as the MI element becomes a part of the magnetic path of the induction type head, but since the cross-sectional area of the core 16 can be made larger than the magnetic path cross-sectional area in the vicinity of the magnetic gap G, the magnetic saturation No worries, you can demonstrate the recording function. In addition, the MI element has a large saturation magnetic flux density of more than 1 T, such as Fe-N system or Fe
By using a -C-based microcrystalline type magnetic film, the degree of freedom in recording is further increased.

Further, the coil winding 82 can be used to flow a direct current at the time of reproduction to apply a DC bias to the MI element, whereby the reproduction waveform and gain can be adjusted. As shown in FIG. 11, by shifting the MI characteristic to the left as shown by the arrow, a substantially linear response to a magnetic field near the external magnetic field 0 can be obtained, and a large gain can be obtained.

[Sixth Embodiment] FIG. 9 shows a sixth embodiment in which the terminal is led out. In this embodiment, the bottom surface of the first core 10 on which the second core 16 as an MI element and the conductive film 18 as a terminal are formed is an inclined surface inclined with respect to the sliding surface. According to such an embodiment, at the time of mounting, the connection of the wire 42 shown in FIGS. 4 and 8 to the conductive film 18 by soldering can be easily performed, and the terminal can be easily pulled out.

The above-mentioned second embodiment, fifth embodiment,
In the sixth embodiment, the first core may be a ferrite core as in the first embodiment, but the MIG core of the third embodiment,
Alternatively, it goes without saying that the laminated core of the fourth embodiment may be used.

Although the MR element can have the same structure as that of each of the above-described embodiments, if the thickness of the MR element is about several hundreds of angstroms, the efficiency decrease is large due to the increase in the magnetic resistance of the second core, and the magnetic field is closed. It has no effect as a road. Further, the recording function cannot be realized because magnetic saturation occurs due to the small cross-sectional area of the MR element. An open magnetic path is suitable because the MR element has a short effective length.

[0055]

As is apparent from the above description, according to the present invention, the magnetic impedance effect is utilized with the first core formed by joining a pair of magnetic core half bodies through a magnetic gap. Formed as a magnetic detection element
In a magnetic head that forms a closed magnetic path with the core of (1) and obtains a reproduction output from both ends of the magnetic detection element, the pair of core halves are provided on the bottom surface of the first core opposite to the sliding surface of the magnetic recording medium. And the non-magnetic material provided between the core halves is exposed, and the magnetic detection element serving as the second core is a high magnetic layer formed on the bottom surface of the first core via an insulating film. Since a magnetic permeability magnetic film is formed so as to extend over the non-magnetic material portion of the bottom surface and hang on each of the pair of core half portions, an effective length of the magnetic detection element is ensured. At the same time, the insulating property can be secured, and the terminal can be easily pulled out. Therefore, it is possible to realize the structure of the closed magnetic path in which the magnetic flux from the magnetic recording medium is sufficiently applied to the magnetic detection element, and the reproduction is performed with high sensitivity. Can handle high density recording It is possible to provide the care head.

Also, since the magnetic path cross-sectional area of the magnetic detection element of the second core can be made large, there is a margin for magnetic saturation, so a coil winding is wound around the first core to provide a recording function. Alternatively, it is possible to apply a DC bias to the magnetic detection element.

Further, according to the present invention, in the method of manufacturing a magnetic head, the first core is processed into a magnetic recording medium sliding surface of a core block corresponding to a plurality of continuous first cores in the track width direction. On the bottom surface on the side opposite to the surface where the magnetic block is formed, an insulating film, a high-permeability magnetic film to be a magnetic detection element, and a conductive film to be a terminal for taking out a reproduction output from the magnetic detection element are sequentially formed, and then the core block is formed. Since a method of obtaining a plurality of the magnetic heads by cutting at a predetermined interval in the track width direction is adopted, it is possible to obtain a large number of magnetic heads from one core block at a time.
The excellent effect of excellent productivity can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view, a side view, and a bottom view of a sliding surface showing a structure of a magnetic head according to a first embodiment of the invention.

FIG. 2 is a perspective view showing a manufacturing process of the magnetic head.

FIG. 3 is a perspective view showing the same manufacturing process.

FIG. 4 is a perspective view showing a mounted state of the magnetic head.

FIG. 5 is a bottom view showing the structure of the magnetic heads of the second embodiment and its modification.

FIG. 6 is a plan view, a side view, and a bottom view of a sliding surface showing a structure of a magnetic head of a third embodiment.

FIG. 7 is a plan view, a side view, and a bottom view of a sliding surface showing a structure of a magnetic head according to a fourth embodiment.

FIG. 8 is a perspective view showing a structure of a magnetic head of a fifth embodiment in a mounted state.

FIG. 9 is a side view showing the structure of the magnetic head of the sixth embodiment,
It is a bottom view and the side view of a different direction.

FIG. 10 is an explanatory diagram showing how magnetic flux is applied from the medium to the MI element when the magnetic path is open.

FIG. 11 is a graph showing how MI characteristics shift when a DC bias is applied.

[Explanation of symbols]

 10 1st core 10A, 10B Core half body 11A, 11B Magnetic path connection surface 12 Regulation groove 14 Glass 15,30 Insulating film 16,16A, 16B 2nd core (MI element) 18,34 Conductive film (terminal) 20 , 20 'Ferrite material 22, 24 Restriction groove 26 Glass rod 28 Core block 32 Magnetic film 40 Base 42 Wire 50 Conductive film 51 Connecting portion 61, 71 Metal magnetic film 72 Non-magnetic material 80 Through hole 82 Coil winding

Claims (12)

[Claims] 1. A first magnetic core formed by joining a pair of magnetic core halves with a magnetic gap interposed therebetween, and a second magnetic core formed as a magnetic detection element utilizing the magneto-impedance effect. A pair of core halves on the bottom surface of the first core opposite to the sliding surface of the magnetic recording medium, and the core halves. The non-magnetic material provided between the bodies is exposed, and the magnetic detection element serving as the second core is a high-permeability magnetic film formed on the bottom surface of the first core via an insulating film. A magnetic head, which is formed so as to extend over the nonmagnetic material portion of the bottom surface and hang on each of the pair of core half portions. 2. The magnetic head according to claim 1, wherein the non-magnetic material is filled between the pair of core halves as a glass for welding for joining the pair of core halves. 3. The insulating film has a thickness of 0.1 μm to 1 μm.
The magnetic head according to claim 1 or 2, wherein 4. The magnetic head according to claim 1, wherein the high-permeability magnetic film as the magnetic detection element has a thickness of 1 μm to 20 μm. 5. A plurality of magnetic detection elements as the second core are arranged in parallel on the insulating film on the bottom surface of the first core, and the plurality of magnetic detection elements are electrically connected in series. The magnetic head according to any one of claims 1 to 4. 6. A coil winding is wound around the first core,
6. The magnetic head according to claim 1, wherein the coil winding is used for magnetic recording or for applying a DC bias to the magnetic detection element. 7. The bottom surface of the first core is inclined with respect to the sliding surface of the magnetic recording medium of the first core, according to any one of claims 1 to 6. Magnetic head. 8. The magnetic detection element is an Fe—N type or F type.
8. The magnetic head according to claim 1, wherein the magnetic head is made of an eC magnetic film. 9. The ferrite core according to claim 1, wherein the first core is configured as a ferrite core formed by joining a pair of core halves made of ferrite as a whole. The magnetic head described. 10. The first core is a metal-in-gap core formed by joining a pair of core halves, each of which is made of ferrite and has a metal magnetic film formed on an abutting surface abutted via a magnetic gap. The magnetic head according to claim 1, wherein the magnetic head is formed. 11. The magnetic head according to claim 1, wherein the first core is formed as a laminated core formed by laminating high magnetic permeability magnetic films. . 12. A closed magnetic circuit is formed by a first core formed by joining a pair of core halves made of a magnetic material via a magnetic gap, and a second core formed by a magnetic detection element utilizing a magnetic impedance effect. In the method of manufacturing a magnetic head configured to obtain a reproduction output from both ends of the magnetic detection element, a magnetic recording medium sliding surface of a core block corresponding to a plurality of the first cores continuous in the track width direction. An insulating film, a high-permeability magnetic film serving as a magnetic detection element, and a conductive film serving as a terminal for extracting a reproduction output from the magnetic detection element are sequentially formed on the bottom surface opposite to the processed surface, and then the core is formed. A method of manufacturing a magnetic head, wherein a plurality of the magnetic heads are obtained by cutting blocks at predetermined intervals in a track width direction.