JP2007141368A - Magnetic head and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic head which ensures good tape contact on the entire surface of the gap part of a sliding surface, and a manufacturing method for obtaining the magnetic head by a simple method. <P>SOLUTION: The magnetic head 10 for writing a servo signal in a traveling recording medium includes: a magnetic core formed by bonding a magnetic core half 3 having a metal magnetic film 2 which becomes a sliding surface with the recording medium on its surface to a magnetic core half 4 having a wiring groove 4a; and an exciting coil formed by winding a conductor on the wiring groove 4a of the magnetic core. The magnetic core half 3 includes a groove which is opened on the side opposed to the forming surface of the metal magnetic film 2, and having two slopes, wherein opening length in the traveling direction of the recording medium is set so that the opposite side is longer than the forming surface of the metal magnetic film 2. The groove is filled with hard nonmagnetic material and fused to form a shape support part 7b, wherein the thermal expansion factor of the hard nonmagnetic material is smaller than that of a material of the magnetic core half 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic head for writing a servo signal on a traveling recording medium and a method for manufacturing the same.

  For example, as the capacity and transfer rate of data to be recorded on a recording medium (magnetic tape) such as a computer backup device increases, the recording / reproducing head must trace a predetermined track at high speed and accurately. Further, the recording / reproducing head needs to move between tracks at a high speed and instantly move to a specific position of a specific track.

  As a method of stabilizing this operation, a servo signal is written on the magnetic tape in advance, the position on the magnetic tape is detected based on the signal of the servo-only reproducing head that has read the servo signal, and the recording / reproducing head runs stably. There is a way. In addition, such a method in which servo signals are written in advance on a tape is advantageous for compatibility between different recording / reproducing apparatuses, and can cope with further higher density in the future.

  A magnetic head for writing a servo signal is generally configured by winding a coil around a magnetic core formed of a magnetic material having a high magnetic permeability (see, for example, Patent Document 1). Such a magnetic head is called an electromagnetic induction type (inductive type) magnetic head because it performs recording on a magnetic recording medium using electromagnetic induction between a magnetic core and a coil.

  In the magnetic head, the magnetic core functions as a path for transmitting magnetic flux, such as from the coil to the magnetic recording medium during recording and from the magnetic recording medium to the coil during reproduction. Further, in the magnetic core, a minute gap, that is, a magnetic gap is formed at a portion facing the magnetic recording medium. The magnetic head records a magnetic signal on the magnetic recording medium by applying a leakage magnetic field generated in the magnetic gap to the magnetic recording medium.

  Incidentally, in recent years, in the field of magnetic recording, in order to reduce the size and increase the capacity of magnetic recording media, the recording density of magnetic signals has been further increased, and fine magnetic signals are accurately recorded and reproduced. It is requested. Therefore, for example, a metal tape in which a ferromagnetic metal powder as a magnetic powder used for a magnetic layer for recording magnetic signals is coated and applied on a base film, or a vapor deposition tape in which a ferromagnetic metal material is directly deposited on the base film. Magnetic recording media exhibiting a high coercive force such as the above have been widely used.

  In order to enable recording on a magnetic recording medium exhibiting these high coercive forces, for example, high magnetic permeability such as Fe-based alloys, Fe-Ni-based alloys, Fe-Co-based alloys and the like is shown. A magnetic head in which a metal magnetic material exhibiting a high saturation magnetic flux density is combined with, for example, a ferrite material has been proposed.

  In addition, a plurality of gaps (hereinafter referred to as “Gap”) having different inclinations are arranged at predetermined intervals on the magnetic head for writing servo signals. The gap material is made of a nonmagnetic material. It is also a well-known fact that the strength of the gap part increases when a metal film is deposited by various methods so as to cover the nonmagnetic material. The process of manufacturing the gap can be achieved by using a general photographic printing method that has been used for a long time. Since the Gap portion is brought into contact with the tape without any gap, a signal to be recorded can be written efficiently and strongly, so the surface of the magnetic head that slides with the magnetic tape (hereinafter referred to as the sliding surface) is a lens polishing device. Etc. to give a flat mirror finish.

JP 2002-170204 A

  However, a magnetic head having an ideal sliding surface processed into a flat and mirror-like state needs to be adjusted with high accuracy when attached to the apparatus. Although it is necessary to make uniform contact with the magnetic tape at all gaps, the ideal tape contact is always set to all gaps due to misalignment and inclination when the magnetic head is attached to the apparatus, and variations in the tape width direction. It is not done in the department.

  If a gap is generated between the tape and the servo head, the magnetic flux leaked from the gap part cannot magnetize the tape medium efficiently, and the magnetization intensity of the recorded servo pattern becomes weak, resulting in a decrease in the recorded output. Get up. In this case, the protrusion of the head is increased in order to increase the surface pressure between the servo head and the tape for the purpose of avoiding the loss of recording due to the gap, and the wear of the head is promoted. Further, uneven wear occurs due to non-uniform adhesion between the tape and the head sliding surface, which hinders the extension of the head life.

  The present invention has been made in view of the above problems in the prior art, and can provide a magnetic head capable of obtaining a good tape contact over the entire gap portion of the sliding surface and a simple method for obtaining the magnetic head. It aims at providing the manufacturing method which can be performed.

  The present invention provided to solve the above problems is for writing a servo signal on a traveling recording medium, and has a magnetic core half A having a metal magnetic film on the surface as a sliding surface with the recording medium. And a magnetic core formed by joining a magnetic core half B having a winding groove and an excitation coil in which a conducting wire is wound around the winding groove of the magnetic core. A is composed of two inclined surfaces that open on the side opposite to the surface on which the metal magnetic film is formed and have an opening length in the running direction of the recording medium that is longer on the side opposite to the surface on which the metal magnetic film is formed. The groove has a hard nonmagnetic material filled and fused, and the hard nonmagnetic material has a thermal expansion coefficient smaller than that of the material constituting the magnetic core half A. A magnetic head characterized by the above-mentioned (claim) ).

  Further, the metal magnetic film has a gap portion that is a source of leakage magnetic flux, and the two inclined surfaces of the groove are arranged so as to be axisymmetric with respect to the center line of the gap portion. Is preferred.

  Furthermore, the shape of the sliding surface with the recording medium may be convex in the running direction of the magnetic recording medium. At this time, the height of the convex shape is preferably 5 to 80 nm.

  The present invention provided to solve the above problems is for writing a servo signal on a traveling recording medium, and has a magnetic core half A having a metal magnetic film on the surface as a sliding surface with the recording medium. And a magnetic core formed by joining a magnetic core half B having a winding groove and an exciting coil in which a conducting wire is wound around the winding groove of the magnetic core. Forming a first groove on one main surface of a magnetic core substrate A which is an original plate of the magnetic core half A, filling the first groove with a hard nonmagnetic material A, and fusing it to form a base glass; A step of forming a metal magnetic film on the base glass forming surface of the magnetic core substrate A, and an opening length in the recording medium running direction on the main surface opposite to the base glass forming surface of the magnetic core substrate A. The opposite side is longer than the glass forming side Forming a second groove having two inclined surfaces, and filling the second groove with a hard non-magnetic material B having a smaller coefficient of thermal expansion than the material constituting the magnetic core substrate A. A step of forming a shape support portion, the magnetic core substrate A, and a magnetic core substrate B having a plurality of magnetic core halves B having a winding groove formed on one main surface thereof. For each magnetic core block, the step of joining so that the shape support portion forming surface of the magnetic core substrate B and the winding groove forming surface of the magnetic core substrate B are in contact with each other, and the magnetic core substrate A and the magnetic core substrate B bonded And a step of obtaining a magnetic core by cutting. A method of manufacturing a magnetic head (claim 5).

  Here, it is preferable that the hard nonmagnetic material A and the constituent material of the magnetic core substrate A have substantially the same thermal expansion coefficient.

  Further, the metal magnetic film has a gap portion that is a source of leakage magnetic flux, and the two inclined surfaces of the second groove are formed so as to be symmetric with respect to the center line of the gap portion. It is preferable that

  The magnetic core substrate A and the magnetic core substrate B are bonded to each other on the metal layer provided on the shape support portion forming surface of the magnetic core substrate A and the winding groove forming surface of the magnetic core substrate B. It is preferable that the metal layer is diffusion bonded at a temperature below the glass transition point of the hard nonmagnetic material.

According to the magnetic head of the present invention, since the sliding surface has no surface undulation and has an appropriate convex shape, a good tape contact can be obtained over the entire gap portion of the sliding surface. Thereby, the life of the magnetic head can be extended.
According to the method for manufacturing a magnetic head of the present invention, the sliding surface of the magnetic head can be formed into an appropriate convex shape without surface undulation by a simple method, and the entire gap portion of the sliding surface is satisfactory. It becomes possible to obtain a tape contact.

The configuration of the magnetic head according to the present invention will be described below.
FIG. 1 is a schematic diagram showing the configuration of a magnetic head according to the present invention.
A magnetic head 10 according to the present invention is a configuration example of a bulk thin film head used for simultaneously writing servo signals to a recording medium that has a plurality of gap portions with different inclinations, and serves as a sliding surface with the recording medium, and serves as a magnetic path. The magnetic core half 3 having the metal magnetic film 2 constituting the surface and the magnetic core half 4 having the winding groove 4a are joined to each other, and a conductor is wound around the winding groove of the magnetic core. And an exciting coil (not shown).

  Here, the material constituting the magnetic core halves 3 and 4 is a conventionally known magnetic material, and may be either single crystal ferrite or polycrystalline ferrite. For example, Mn—Zn ferrite and the like can be mentioned.

FIG. 2 shows an enlarged portion of the magnetic core 3 of the magnetic head 10.
The magnetic core half 3 has a first groove 3a extending in the magnetic recording medium width direction W immediately below the gap portion 2g of the metal magnetic film 2, and the first groove 3a is filled with a hard nonmagnetic material A. The base glass 7a is formed by fusing.

  The metal magnetic film 2 is a film made of an Fe-based microcrystalline film or other soft magnetic alloy having a high saturation magnetic flux density such as NiFe having a thickness of several μm. The gap portion 2g is a writing pattern (gap) made of a non-magnetic material formed on the base glass 7a and having a height that reaches the sliding surface of the recording medium so as to divide the metal magnetic film 2. When recording on the recording medium, the gap pattern 2g can be recorded on the traveling recording medium by blocking the magnetic flux generated by the current flowing through the exciting coil by the gap 2g.

The hard nonmagnetic material A may be any nonmagnetic material that can be fused to the magnetic core half 3 to ensure a certain level of strength. For example, silica glass is used. The hard nonmagnetic material A may be the same as the hard nonmagnetic material B. However, as will be described later, the thermal expansion coefficient in the temperature range of 100 to 500 ° C. is substantially the same as the thermal expansion coefficient of the magnetic core half 3. It is preferable that In addition, that the thermal expansion coefficient is substantially the same means that the difference between the two is within ± 1 × 10 ⁻⁷ .

  Further, the magnetic core half 3 is opened on the side opposite to the surface on which the metal magnetic film 2 is formed, and the opening length in the recording medium running direction L is longer on the side opposite to the surface on which the metal magnetic film is formed. It has the 2nd groove | channel 3b which consists of one inclined surface, and also has the shape support part 7b formed by filling and fuse | melting the hard nonmagnetic material B to this 2nd groove | channel 3b.

Here, the hard non-magnetic material B is a non-magnetic material having such rigidity that it can be fused to the magnetic core half 3 to maintain the shape of the magnetic core, and its thermal expansion coefficient α _G is The thermal expansion coefficient α _{C of} the material constituting the magnetic core half 3 is smaller. Specifically, the relationship between the thermal expansion coefficients of the hard nonmagnetic material B and the constituent material of the magnetic core half 3 is preferably the following relational expression in the temperature range of 100 to 500 ° C.
0 <α _C −α _G ≦ 10 × 10 ⁻⁷

  Moreover, it is preferable that the two inclined surfaces of the second groove 3b are arranged so as to be line-symmetric with respect to the center line CL of the gap portion 2g. The center line CL of the gap 2g is a normal to the surface of the metal magnetic film 2 at the average center position of all the plurality of gaps 2g.

  Moreover, although the junction part 6 of the magnetic core half 3 and the magnetic core half 4 may be bonded by using an instantaneous adhesive or an epoxy resin adhesive, it is preferably formed by a low-temperature metal diffusion bonding method described later. . Thereby, the flatness and dimensional stability as a magnetic core improve, and it contributes to the effect of this invention.

In FIG. 3, the detail of the junction part 6 of the magnetic core half 3 and the magnetic core half 4 is shown.
The junction 6 between the magnetic core half 3 and the magnetic core half 4 is formed between the junction surface of the magnetic core half 3 and the junction surface of the magnetic core half 4 with a metal film 6a / diffusion metal film 6b / metal film 6a. Are laminated with good adhesion. Further, the magnetic core half 3 and the metal film 6a, the magnetic core half 4 and the metal film 6a are also in close contact with each other, and the magnetic core half 3 and the magnetic core half 4 are firmly bonded.

The metal film 6a is a thin film made of, for example, Cr or Ti having a thickness of about 50 nm.
The diffusion metal film 6b is originally made into one layer by the mutual diffusion at the time of bonding of the vapor deposition films such as Au formed on the metal film 6a of the magnetic core half 3 and the metal film 6a of the magnetic core half 4 respectively. The thickness is uniform in the range of 20 to 400 nm.

  With the configuration described above, the magnetic head 10 of the present invention has a moderate convex shape in the running direction L of the magnetic recording medium, with no surface waviness (good flatness) as the shape of the sliding surface with the recording medium. Thus, a good tape contact can be obtained over the entire gap portion of the sliding surface (FIG. 4). Thereby, the life of the magnetic head can be extended. The height of the convex shape is preferably 5 to 80 nm.

Next, a method for manufacturing the magnetic head of the present invention will be described.
The present invention is a method for manufacturing the magnetic head 10 described above. Hereinafter, the method of manufacturing the magnetic head according to the present invention will be described step by step with reference to FIGS.

(S11) A first groove 3a corresponding to the magnetic core half body 3 is formed on one main surface of the magnetic core substrate 13 which is an original plate of the plurality of magnetic core half bodies 3 (FIG. 5A).

(S12) Next, the hard nonmagnetic material A (7L) is filled and fused in the first groove 3a (FIG. 5 (b)), and the hard nonmagnetic material A protruding at this time is polished to remove the base glass 7a. At the same time, the surface on which the base glass 7a is formed is made flat. At this time, if a material having substantially the same thermal expansion coefficient as the constituent material of the magnetic core substrate 13 is used as the hard nonmagnetic material A, the balance of the volume shrinkage of the respective materials at the time of fusion is achieved, and the magnetic core substrate 13 and thus The magnetic core half 3 is preferable because it is easy to ensure flatness by polishing. In the present invention, the flatness (undulation of unevenness) after polishing of the surface can be 100 nm or less from one end to the other end in the recording medium width direction.

(S13) The metal magnetic film 2 is formed on the base glass forming surface of the magnetic core substrate 13 (FIG. 6).
Specifically, first, a nonmagnetic hard film such as silicon dioxide is formed by sputtering on almost the entire surface of the base glass forming surface of the magnetic core substrate 13. Next, a resist material is uniformly coated on the nonmagnetic hard film with a uniform thickness, and exposure is performed by applying light using a semiconductor mask having a gap pattern. Then, the magnetic core substrate 13 is immersed in a developing solution for a predetermined time, and unnecessary resists according to the mask are dissolved and removed, leaving only the necessary shapes. Next, reactive ion etching or ion etching is used to remove unnecessary non-magnetic hard film exposed from the remaining resist, and then the remaining gap / resist pillars are washed away with a solvent to remove the gap. Part 2g is obtained. Thereafter, a metal magnetic film having a high saturation magnetic flux density is formed on the base glass forming surface by any of sputtering, vapor deposition, and plasma CVD, and the metal magnetic film deposited on the gap portion 2g is buffed or lens is formed. The metal magnetic film 2 is completed by removing the surface by polishing and, if necessary, finishing it to a flat surface by mirror finishing such as lens polishing.

(S14) Then, two inclined surfaces are formed so that the opposite surface side is longer than the base glass forming surface side as the opening length in the recording medium running direction on the main surface opposite to the base glass forming surface by inverting the magnetic core substrate 13 A second groove 3b is formed (FIG. 5C). At this time, the two inclined surfaces of the second groove 3b are preferably arranged so as to be symmetrical with respect to the center line CL of the gap 2g (see FIG. 2).

(S15) The second groove 3b is filled with a hard nonmagnetic material B (7M) having a smaller thermal expansion coefficient than that of the material constituting the magnetic core substrate 13, and is fused (FIG. 7D). At this time, due to the difference in thermal expansion coefficient between them, the stress that pulls the magnetic core half 3 toward the shape support portion 7 b along the second groove 3 b for each block (magnetic core half 3) of the magnetic core substrate 13. Arise. Thereby, when it is set as the magnetic core half body 3, it can be set as the moderate convex shape which made the gap part 2g the vertex in the running direction L of a magnetic recording medium as a shape of a sliding surface with a recording medium.

The relationship between the thermal expansion coefficients of the hard nonmagnetic material B and the constituent material of the magnetic core substrate 13 (magnetic core half 3) is a convex shape by using the following relational expression in the temperature range of 100 to 500 ° C. The height is 5 to 80 nm, which is preferable for obtaining good tape contact over the entire gap portion of the sliding surface.
0 <α _C −α _G ≦ 10 × 10 ⁻⁷

  Next, the polishing removal portion P is removed by polishing the hard nonmagnetic material B that protrudes (FIG. 8) to form the shape support portion 7b and flatten the surface on which the shape support portion 7b is formed (FIG. 7). (E)). Since the bonding metal film 6a / diffusion metal film 6b is formed in a later step, the surface roughness Ra of the bonding surface 3c on the shape support portion forming surface side is desirably 10 nm or less. Further, the flatness (undulation of the unevenness) of the surface is preferably 100 nm or less from one end to the other end in the recording medium width direction.

(S16) In the magnetic core substrate 13, a guide groove 13a is formed as a countermeasure against chipping accompanying processing when the magnetic core half body 3 having a head size is cut out from the substrate 13. Next, in the case of a magnetic head, a shoulder drop groove 13b having an inclination is formed for the purpose of allowing the recording medium (tape) to smoothly enter the sliding surface (FIG. 7 (f)).

(S17) A vapor deposition film having a two-layer structure of metal film 6a / diffusion metal film 6b is formed on the bonding surface 3c of the magnetic core substrate 13. Here, the metal film 6a is for ensuring adhesion between the magnetic core substrate 13 and the diffusion metal film 6b, and is, for example, a thin film made of Cr or Ti having a thickness of about 50 nm. The diffusion metal film 6b is a metal thin film that can be diffusion bonded at a temperature below the glass transition point of the hard nonmagnetic materials A and B. For example, the diffusion metal film 6b has a uniform thickness of 10 to 200 nm, preferably 10 to 100 nm. It is a deposited film such as Au.

(S18) For the main surface opposite to the bonding surface 4b of the magnetic core substrate 14 which is the original plate of the plurality of magnetic core halves 4, the flatness of the surface varies from one end to the other end in the recording medium width direction. Polishing is performed to 100 nm or less until then, and then a winding groove 4a corresponding to the magnetic core half 4 is formed on the bonding surface 4b (FIG. 9). Thereafter, the bonding surface 4b is finished flat by lens polishing or the like. Since the bonding metal film 6a / diffusion metal film 6b is formed in a later step, the surface roughness Ra of the bonding surface 4b is preferably 10 nm or less. Further, the flatness of the surface is preferably 100 nm or less from one end to the other end in the recording medium width direction.

(S19) Next, on the bonding surface 4b of the magnetic core substrate 14, a vapor deposition film having a two-layer structure of the metal film 6a / diffusion metal film 6b similar to that in step S17 is formed.

(S1a) Using the magnetic core substrate 13 after step S17 and the magnetic core substrate 14 after step S19, the bonding surface 3c (shape support portion 7b forming surface) of the magnetic core substrate 13 and the bonding surface 4b of the magnetic core substrate 14 are used. The metal film 6a / diffusion metal film 6b are brought into contact with each other (facing surface of the winding groove 4a) to perform low-temperature metal diffusion bonding (FIG. 10).

  Here, the low temperature metal diffusion bonding means that the diffusion metal film 6b provided on the bonding surface 3c of the magnetic core substrate 13 and the diffusion metal film 6b provided on the bonding surface 4b of the magnetic core substrate 14 are made of a hard nonmagnetic material A. , B is diffusion bonded at a temperature below the glass transition point. Specifically, in the case of a diffusion metal film 6b made of Au, bonding is performed by heat treatment at a heating temperature of 150 to 300 ° C. and a processing time of several minutes to several hours in a state where both diffusion metal films 6b are abutted with each other at a pressure of about 10 to 20 MPa. Is possible.

(S1b) Finally, the combined substrate 16 in which the magnetic core substrate 13 and the magnetic core substrate 14 are joined is cut at the cutting location aa ′ to obtain the magnetic core blocks 17 for each row constituting the magnetic core. (FIG. 11).
Thereafter, a conducting wire is wound around the winding groove 5a of the obtained magnetic core to form an exciting coil, and the magnetic head 10 is completed.

  With the manufacturing method of the present invention described above, the shape of the sliding surface with the recording medium has no surface undulation (good flatness) and has an appropriate convex shape in the running direction L of the magnetic recording medium, and the sliding surface The magnetic head 10 having good tape contact over the entire gap portion can be obtained by a simple method.

Hereinafter, an example in which the magnetic head of the present invention was actually manufactured will be described.
Example 1
In accordance with the magnetic head manufacturing method described above, a magnetic head 10 for a magnetic tape having a width of 1/2 inch was manufactured under the following conditions.
(1) Magnetic cores 3 and 4; ferrite substrate (dimension 30 × 30 mm), thermal expansion coefficient (100 to 500 ° C.): 105 × 10 ⁻⁷
(2) Hard nonmagnetic material A; coefficient of thermal expansion (100 to 500 ° C.): 105 × 10 ⁻⁷
(3) Hard non-magnetic material B; coefficient of thermal expansion (100 to 500 ° C.): 95 × 10 ⁻⁷
(4) Metal film 6a / Diffusion metal film 6b; Cr (thickness 50 nm) / Au (thickness 100 nm)
(5) Low-temperature metal diffusion bonding conditions in step S1a; pressurization: 20 MPa, heating temperature: 290 ° C., treatment time: 1.5 hours

  As a result, the shape of the sliding surface of the obtained magnetic head with respect to the recording medium had good flatness and a convex shape in the running direction L of the magnetic recording medium. FIG. 12 shows the result of measuring the shape of the sliding surface of the magnetic head with the recording medium (travel direction L of the magnetic recording medium). The height of the convex shape was 8 to 80 nm. When this magnetic head is used in a servo signal writing device, it can have a high writing capability in all the gap portions, and the magnetic tape feeding speed can be doubled compared with the conventional one without changing the protruding amount of the magnetic head with respect to the magnetic tape. It was confirmed that there was no decrease in the recording output even when the value was raised.

(Comparative Example 1)
In Example 1, the magnetic head was manufactured in the same manner as in Example 1 except that the thermal expansion coefficient (100 to 500 ° C.) of the hard nonmagnetic material B was smaller than 95 × 10 ⁻⁷ . In this case, the shrinkage of the shape support portion 7b becomes excessive, the base glass 7a is cracked, and the product yield is significantly reduced.

(Comparative Example 2)
A magnetic head was manufactured in the same manner as in Example 1 except that the thermal expansion coefficient (100 to 500 ° C.) of the hard nonmagnetic material B was 105 × 10 ⁻⁷ in Example 1. In this case, the sliding surface of the magnetic head had a maximum height of 40 nm and the flatness deteriorated.

(Comparative Example 3)
In Example 1, the magnetic head was manufactured in the same manner as in Example 1 except that the thermal expansion coefficient (100 to 500 ° C.) of the hard nonmagnetic material B was larger than 105 × 10 ⁻⁷ . In this case, the shape of the sliding surface of the magnetic head was concave in the running direction L of the magnetic recording medium, which was disadvantageous for the tape contact.

It is the schematic which shows the structure of the magnetic head based on this invention. It is an expanded sectional view of the magnetic core by the side of a sliding surface used for the magnetic head of this invention. It is an expanded sectional view of the junction part of the magnetic cores in the magnetic head of this invention. It is a figure which shows the sliding state with the recording medium of the magnetic head of this invention. FIG. 6 is a manufacturing process diagram (1) of a magnetic head according to the present invention. It is sectional drawing of the magnetic core at the time of metal magnetic film formation of this invention. FIG. 6 is a manufacturing process diagram (1) of a magnetic head according to the present invention. It is sectional drawing of the magnetic core of the shape support part formation stage of this invention. It is the schematic of the magnetic core board | substrate which has the winding groove | channel used for the magnetic head of this invention. It is a figure which shows the joining state of the magnetic cores of this invention. It is a figure which shows the cutting state of the unification board of the present invention. FIG. 3 is profile data of a sliding surface of the magnetic head of Example 1 with a recording medium (travel direction L of the magnetic recording medium). FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Metal magnetic film, 2g ... Gap part, 3, 4 ... Magnetic core half body, 3a ... 1st groove | channel, 3b ... 2nd groove | channel, 3c, 4b ... Joining surface, 4a ... Winding groove | channel, 6 ... Joining 6a ... metal film, 6b ... diffusion metal film, 7a ... base glass, 7b ... shape support, 7L, 7M ... hard nonmagnetic material, 10 ... magnetic head, 13, 14 ... magnetic core substrate, 16 ... combined substrate , 17 ... Magnetic core block

Claims (8)

A magnetic core half A having a metal magnetic film on its surface as a sliding surface with respect to the recording medium, and a magnetic core half B having a winding groove for writing a servo signal on a traveling recording medium In a magnetic head comprising a magnetic core formed by bonding and an exciting coil in which a conducting wire is wound around a winding groove of the magnetic core,
The magnetic core half A is opened on the side opposite to the surface on which the metal magnetic film is formed, and the opening length in the recording medium running direction is 2 longer than the side on which the metal magnetic film is formed. A groove having two inclined surfaces, and the groove is filled and fused with a hard non-magnetic material,
A magnetic head characterized in that the hard nonmagnetic material has a thermal expansion coefficient smaller than that of the material constituting the magnetic core half A. The metal magnetic film has a gap part that is a source of leakage magnetic flux,
2. The magnetic head according to claim 1, wherein the two inclined surfaces of the groove are arranged so as to be line-symmetric with respect to a center line of the gap portion.   The magnetic head according to claim 1, wherein a shape of a sliding surface with the recording medium is a convex shape in a running direction of the magnetic recording medium.   The magnetic head according to claim 3, wherein the height of the convex shape is 5 to 80 nm. A magnetic core half A having a metal magnetic film on its surface as a sliding surface with respect to the recording medium, and a magnetic core half B having a winding groove for writing a servo signal on a traveling recording medium In a method of manufacturing a magnetic head comprising: a magnetic core formed by bonding; and an exciting coil in which a conducting wire is wound around a winding groove of the magnetic core.
A first groove is formed on one main surface of a magnetic core substrate A, which is an original plate of a plurality of magnetic core halves A, and a hard nonmagnetic material A is filled in the first groove and fused to form a base glass. Process,
Forming a metal magnetic film on the base glass forming surface of the magnetic core substrate A;
A second surface comprising two inclined surfaces in which the opposite surface side of the magnetic core substrate A opposite to the base glass forming surface is longer than the base glass forming surface side as the opening length in the recording medium running direction. Forming a groove of
Filling the second groove with a hard non-magnetic material B having a smaller coefficient of thermal expansion than the material constituting the magnetic core substrate A and fusing it into a shape support portion;
The magnetic core substrate A and the magnetic core substrate B in which a winding groove is formed on one main surface of a plurality of magnetic core halves B, the shape support portion forming surface of the magnetic core substrate A, and the magnetic A step of bonding so that the winding groove forming surface of the core substrate B is in contact;
A method of manufacturing a magnetic head, comprising: a step of cutting a magnetic core substrate A and a magnetic core substrate B bonded to each magnetic core block to obtain a magnetic core.   6. The method of manufacturing a magnetic head according to claim 5, wherein the hard nonmagnetic material A and the constituent material of the magnetic core substrate A have substantially the same thermal expansion coefficient. The metal magnetic film has a gap portion that is a source of leakage magnetic flux,
6. The method of manufacturing a magnetic head according to claim 5, wherein the two inclined surfaces of the second groove are formed so as to be axisymmetric with respect to a center line of the gap portion.   The magnetic core substrate A and the magnetic core substrate B are joined by a metal layer provided on the shape support portion forming surface of the magnetic core substrate A and a metal layer provided on the winding groove forming surface of the magnetic core substrate B. 6. The method of manufacturing a magnetic head according to claim 5, wherein diffusion bonding is performed at a temperature below the glass transition point of the hard nonmagnetic material.

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