JPS6323208A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To obtain a good reproduced output characteristic without causing a ruggedness in the frequency characteristic of the reproduced output by exposing a metallic core and a ferrite magnetic material near a magnetic gap onto a tape slide face so that the boundary line of junction is inclined to the magnetic gap. CONSTITUTION:On a tape slide face 49, the boundary line of junction between a metallic core 45 and a projecting end part 52a is inclined at theta=3-30 deg. to a magnetic gap 50 and that between a metallic core 46 and an inclined wall 51b of a winding groove 51a is inclined at theta=3-30 deg. to the magnetic gap 50. Since the boundary line of junction formed by the projecting end part 52a and the metallic core 45 and that formed by the inclined wall 51b and the metallic core 46 are inclined to the magnetic gap 50, the contour effect is reduced by the azimuth loss in case of the use not to generate a ruggedness in the frequency characteristic of the reproduced output.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite magnetic head for recording and reproducing suitable for magnetic recording media having high coercive force.

(Conventional example and its problems) Recently, in order to achieve higher performance and ultra-miniaturization in magnetic recording and reproducing devices, for example, magnetic recording media such as magnetic tape have a high coercive force that enables higher density. ,for example,
Magnetic metals are used, and on the other hand, research and development is progressing on magnetic heads that can sufficiently record magnetic tapes with such high coercive force. A metallic magnetic material with high saturation magnetic flux density is placed near the magnetic gap, and a ferrite magnetic material with excellent high frequency characteristics is placed in the other main magnetic circuits, and both are joined together to form the magnetic core body. So-called composite magnetic heads have been put into practical use.

FIGS. 18 to 20 are perspective views of a conventional composite magnetic head, which will be described below with reference to each figure. In each figure, the same components are designated by the same reference numerals.

In FIG. 18, reference numeral 1o denotes a magnetic core body, in which magnetic core halves 11 and 12 are joined together via a magnetic gap 13. The magnetic core halves 11, 12 are basically composed of blocks of ferrite magnetic material 14°15, but in the vicinity of the magnetic gap 13 there are blocks having a higher saturation magnetic flux density than the ferrite magnetic material 14°15, for example,
A metal core '16.17 made of a metal-based magnetic material such as Sendust (Fe, Ai Si alloy) is bonded.

The bonding boundaries 18, 19 between the ferrite magnetic material 14, 15 and the metal core 16, 17 are parallel to the magnetic gap 13, respectively. 20 is a winding window for winding a coil (not shown). 21 is a non-magnetic material made of, for example, glass, and is filled by welding into the track width regulating groove 22 formed near the magnetic gap 13 to join the magnetic core halves 11 and 12 together. 23 is a tape sliding surface. In use, when the magnetic tape is moved relative to the tape sliding surface 23 of the magnetic core body 10, the bonding boundary lines 18 and 19 are parallel to the magnetic gap, so they act as a pseudo gap; As a result of the contour effect, there are drawbacks such as unevenness in the frequency characteristics of the reproduced output due to the magnetic gap 13.

In order to eliminate the above drawbacks, as another conventional example, the 19th
The magnetic core body 24 of the composite magnetic head as shown in the figure can be seen, and in this magnetic core body 24, the joining boundary line 29° 30 of the metal core 27, 28 joined to the magnetic core half body 25, 26 Since it is formed in a substantially ■-shape with respect to the magnetic gap 13, it does not act as a pseudo gap, but the ferrite magnetic material 14, 15, which is a brittle material in manufacturing, is formed into a ■-shape without chipping or other damage. In addition, it is extremely difficult to manufacture the track width of the metal cores 27 and 28 formed on the tape reservoir surface 23 with high precision, and it is costly in terms of man-hours and yield. There were some problems, such as being disadvantageous.

FIG. 20 shows another conventional example, in which numeral 31 indicates a magnetic core body. This magnetic core body 31 is a magnetic core half body 32.3
The magnetic core halves 32 and 33 are formed by depositing a metallic magnetic material on a non-magnetic substrate 34 and 35 by thin film forming means. By doing so, a metal core 3,6,3,7 is formed, and non-magnetic plates 38,39 are respectively bonded thereon.

The thickness of the metal cores 36, 37 needs to be the same as the required track width, so forming the metal cores 36, 37 using thin film forming techniques such as sputtering takes a long time, and also reduces the magnetic gap. Since the formation of the above needs to be carried out individually, there are drawbacks such as hindering productivity and being disadvantageous in terms of cost.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and includes a pair of magnetic core halves made of a pair of magnetic ferrite materials in each abutting surface of the magnetic ferrite materials. A metal magnetic film with high saturation magnetic flux density is formed, a pair of magnetic core halves are joined together via a non-magnetic thin film, and a magnetic gap is formed on the tape sliding surface between the metal magnetic films. In the composite magnetic head, a winding groove consisting of an inclined wall having an inclination angle of θ1 with respect to the abutting surface is formed in the abutting surface of at least one of the magnetic core halves, and
A track width regulating groove having an inclination angle of θ2 with respect to a perpendicular to the extending direction of the inclined wall is formed, and the metal magnetic film is deposited on at least the inclined wall to form a magnetic gap forming surface. cutting the magnetic gap forming surface along a plane that is substantially perpendicular to the magnetic gap forming surface and substantially perpendicular to the track width regulating groove;
To provide a composite magnetic head comprising a magnetic core body in which a bonding boundary line formed by the metal magnetic film and the magnetic ferrite material is exposed on the tape sliding surface so as to have an inclination angle of θa with respect to the magnetic gap. The purpose is to

(Example) FIG.
A front view showing the magnetic core main body 40 in the example, the same figure (
b) is I-I of the magnetic core body 40 shown in FIG. 1(a).
1(C) is a side view of the magnetic core body 40 shown in FIG. 1(a).

Hereinafter, the magnetic core body 40 will be explained using FIGS. 1(a) to (C).
The configuration of is explained. 41.42 is the magnetic core half,
A ferrite core 43.44 made of a 1yln-Zn ferrite magnetic material having high magnetic permeability, for example, and a metal core 45 made of a metal magnetic film such as Sendust, which has a higher saturation magnetic flux density than the ferrite core 43.44. 4
6. 47 and 48 are non-magnetic materials made of, for example, glass, and are cup-shaped formed by track width regulating grooves 43a provided in the ferrite core 43 and track width regulating grooves 44a provided in the ferrite core 44. It is filled into the groove and forms a part of the tape sliding surface 49. 50 is a magnetic gap made of a non-magnetic material, and metal cores 45 and 46 are exposed on the tape sliding surface 49 so as to have a required track width.

51 is a winding window for winding a coil (not shown).

Reference numeral 53 is a non-magnetic material made of, for example, glass, which is filled in a part of the winding window 51 and serves as a reinforcing material for joining the magnetic core halves 41 and 42 together.

The metal core 45 has a track width regulating groove 43a provided in the ferrite core 43 and a protruding end 52 of the abutment surface 52.
a by a thin film forming means such as sputtering, and on the tape sliding surface 49, the bonding boundary line between the tip portion 52a and the metal core 45 is located at the magnetic gap 5.
It has an inclination angle of θ-3 to 30° with respect to 0.

The metal core 46 has a track width regulating groove 44a provided in the ferrite core 44 and a winding 1115 forming a winding window 51.
1a by the same thin film forming means as described above, and on the tape sliding surface, the bonding boundary line between the inclined wall 51b of the winding groove 51a and the metal core 46 also coincides with the magnetic gap 50.
The structure is configured to have an inclination angle of θ-3 to 30” with respect to the main body.

In the magnetic core body 40 of the present invention, as described above, the bonding boundary line formed by the tip portion 52a and the metal core 45 and the bonding boundary surface formed by the inclined wall 51b and the metal core 46 are respectively relative to the magnetic gap 50. Since it is slanted, the contour effect is reduced by azimuth loss during use, and unevenness does not occur in the frequency characteristics of the reproduced output.

Next, an embodiment of a method for manufacturing the magnetic core body 40 in a composite magnetic head according to the present invention will be described.

2 to 14 are schematic illustrations of main steps for explaining an embodiment of the method for manufacturing the magnetic core body 40 shown in FIGS. 1(a) to 1(c).

Hereinafter, each figure will be sequentially explained.

The first step is as shown below, and as shown in FIG. A first winding groove 61 having an inclined wall 61a having an angle of θ1=25° to 706 with respect to 60a is formed to obtain a first magnetic core half block 62. This inclined wall 61a is a surface on which a gold R magnetic film will be formed as described later.

The second step is as shown below, and as shown in FIG.
A second magnetic core half block 65 is obtained by forming a plurality of sets of two first grooves 64 having an angle of θ2 with respect to the second magnetic core half block 65.

At this time, the protruding end portion 60b formed by the first grooves 64, 64, which are a set of two grooves, is configured to be slightly narrower than the desired track width.

The third step is as shown below, and as shown in FIG. The first groove 64 and the first winding groove 61 are covered with gold, which has a higher saturation magnetic flux density than a ferrite magnetic material such as sendust. Magnetism 1 [! 66 is formed by a thin film forming means such as sputtering to obtain a third magnetic core half block 67.

The fourth step is as shown below, and as shown in FIGS. 5 and 6, the first groove 64 in which the metal magnetic film 66 of the third magnetic core half block 65 is formed and the first After filling the winding groove 61 with a non-magnetic material 68 made of, for example, glass, crystallized glass, or ceramic,
The unnecessary non-magnetic material 68 and a part of the metal magnetic film 66 are removed by polishing with a grindstone, a lapping machine, etc., and a part 68a of the non-magnetic material 68 is left in the first winding groove 61, and a new part of the non-magnetic material 68 is removed. After forming the second winding groove 61b, further on the polished surface,
A fourth magnetic core half block 69 is obtained by forming a thin layer 11 (not shown) of a non-magnetic material made of, for example, SiO2.

The fifth step is as shown below, and as shown in FIGS. 7 and 8, the fourth magnetic core half is placed on one plane 60a of a second magnetic substrate 60 equivalent to the magnetic substrate 6o. By providing a plurality of sets of second grooves 70 so as to accurately face the first grooves 64 provided in the magnetic core half block 65 when abutted against the body block 69, these two grooves A second protruding end portion 71 is formed between the grooves 70° and 70, and
A fifth magnetic core half block 72 is obtained by processing the upper surface of the second tip 71 so that the inclination angle is θ3 with respect to the plane 60a. At this time, as shown in FIG. 8, the surface 71a of the second protruding end 71 is made lower by [1] than the plane 60a.

The sixth step is as shown below, and in Figures 9 and 10.
As shown in the figure, a flat surface 6 in which the second groove 70 is formed
After forming a metal magnetic film 73 on 0a so as to cover the second tip 71, a non-magnetic material 74 such as glass is filled into the second groove 70 in which the metal magnetic film 73 is formed. After that, unnecessary non-magnetic material 74 and a part of the metal magnetic film are removed by polishing using a grindstone or a lapping machine, and further,
A non-magnetic material made of, for example, 5i02 is formed on this polished surface to obtain the sixth magnetic core half block 76.

The seventh step is as shown below, and as shown in FIG. 11, the fourth magnetic core half block 69 obtained in the fourth step and the sixth magnetic core half block obtained in the sixth step are After abutting the magnetic core half blocks 76 so that the first grooves 64 and the second grooves 70 correctly face each other, they are joined and integrated by hot pressing in an electric furnace or the like to obtain a composite block 77. At this time, a portion 6 of the non-magnetic material 68 provided in the second winding groove
8a and a non-magnetic material 68 filled in the first and second grooves.
and 74 act as a bonding material.

The eighth step is as shown below, and as shown in FIG. A plurality of first magnetic core bodies 79 are obtained by cutting along a cutting line 78 that passes approximately through the center line of the grooves 64 and 70.

The ninth step is as shown below.
As shown in FIG. 2, the first and second grooves 6 are cut along the cutting line 80 shown by a dashed line at the tip of the first magnetic core body 79.
After cutting in the direction of the arrow so as to be substantially perpendicular to 4.70, the magnetic core body 40 shown in FIG. 1 is obtained by polishing the tip to a predetermined extent.

Next, by such cutting, the metal core 45.46 and the ferrite core 43.44 are separated as shown in FIG. 1(a).
The protruding end portion 52a of 4. The junction border of H is 528 and 4
4b has an inclination angle with respect to the magnetic gap 50.

FIG. 13 shows the tip 6 of the fourth magnetic core half 69 in FIG.
0b is a perspective view showing an enlarged cross section near the inclined wall 61a, and a cut 180 is a metal magnetic material provided on the inclined wall 61a.
It is clear that 1166 is inclined by θ2 with respect to the processing direction 2 of the winding groove 61, and as a result, the cut surface 80 of the metal magnetic film 66 exposed on the tape sliding surface 43 has an upper base hl and a lower base h2. As a result, the bonding boundary line 80a between the metal magnetic film 66 and the magnetic substrate 60 has an inclination angle of θ0 with respect to the plane 66a, which is the magnetic gap forming surface, and is non-parallel to the magnetic gap. becomes.

In addition, the inclination angle θ0 of the joining boundary line 80, the inclination angle θl of the inclined wall 61a, the inclination angle θ2 of the first groove with respect to 7 in the processing direction of the first winding groove 61, and the inclination angle θ0 of the joining boundary line 80a.
is tan θQ=:tan θ IXtan θ2
It is expressed by the relational expression .=(1).

As shown in FIG. 14, this formula (1) is expressed as follows: In the small triangle 81 where the upper base hi of the trapezoid 80 shown in FIG.
When the maximum cutting length of is Δx1 and the width of the tip portion 60b is W, it can be derived from the following relational expression.

Furthermore, in video tape recorders and the like, azimuth recording is performed, and for this purpose it is necessary to tilt the magnetic gap 50 shown in FIG. 1(a) by a predetermined angle with respect to the bottom surface of the magnetic core body 40. . - In the manufacturing process of the present application, if it is desired that the magnetic gap has a predetermined azimuth angle, the composite block is cut in the eighth step so that it has a predetermined azimuth angle with respect to the normal to the plane 60a. It is clear that the relationship in equation (1) does not change even if such a cut is made.

In addition, in order to control the life dimensions tl and t2 during tip polishing, the film thickness S of the gold g magnetic film 66 is measured in advance, and the lengths of the upper base h1 and lower base h2 generated by polishing are actually measured. It can be determined as follows.

As shown in FIG. 10, the sixth magnetic core half 76 has a surface 71a of the protruding end portion 71 that becomes the bonding surface of the metal magnetic material 11173.
is configured in advance to have an inclination angle of θ3 with respect to the plane 60a that is the magnetic gap forming surface, so even when cutting along the cutting SSO, the bonding boundary line exposed on the tape sliding surface is not relative to the magnetic gap. Therefore, it will be tilted by θ3.

In this example, when the track width W - 50 μm, the recording wavelength λ - 4 μm, and θ low θ3 = 0°, the output due to the pseudo gap was less than -25 dB with respect to the main signal. By setting the angle to .degree., it became possible to reduce the pseudo signal output to -40 dB or less, and good frequency characteristics were obtained. Moreover, as mentioned above, the angle 6 formed by the magnetic gap and the boundary joining line is θ1. θ2 or θ3
Since it is a function of θ1. This can be achieved by appropriately determining θ2 or θ3, allowing a design with a large degree of freedom.

As described above, the manufacturing process of the magnetic core body 10 of the composite magnetic head according to the present invention consists of the ninth process, and according to this manufacturing process, the bonding area between the magnetic substrate 60 and the metal magnetic ff 166 is increased. As a result, the magnetic resistance due to bonding is reduced, making it possible to create a magnetic head with excellent recording and reproducing efficiency. Furthermore, since the surface direction of the metal magnetic film corresponds to the track width direction, the film thickness of the metal magnetic film can be formed to be less than the track width, resulting in good film formation efficiency.

In addition, after forming the metal magnetic film 66.73 etc. on the magnetic substrate 60, polishing using a grindstone, lapping machine, etc. is the main process, so processing distortion remains on the surface where the magnetic gap is formed by the metal magnetic ff66.73. It does not cause problems such as peeling of the film.

Lifespan dimension t1 indicating the magnetic gap depth. The value of t2 is obtained by actually measuring the lengths of the upper base h1 and lower base h2, and using this actual measurement value h1.
．． Since it can be found by substituting h2 into equations (5) and (6), the life dimension t1. The value of t2 can be managed with high precision.

Furthermore, when the magnetic core half blocks 77 and 69 are joined together using an electric furnace or the like, the non-magnetic material 68 acts as a bonding agent by welding, so it is necessary to use a reinforcing non-magnetic material. There is no metal magnetic film 68, and a uniform product can be obtained.
It is also a heat treatment for restoring the magnetic properties of the metal, which is extremely convenient.

FIG. 15 is a plan view showing the tape sliding surface of the magnetic core body 90 in the second embodiment of the composite magnetic head according to the present invention, and the following description will be made using the same figure.

In the figure, the same components as in the first embodiment are denoted by the same reference numerals.
The explanation will be omitted.

The difference from the magnetic core body 10 of the first embodiment is that the metal magnetic cores 93 and 94 provided in the magnetic core halves 91 and 92 are not provided above the track width regulating grooves 43a and 44a. The other configurations are completely the same, and the explanation will be omitted.

Next, a method of manufacturing a magnetic core body 90 according to a second embodiment will be explained using FIGS. 16 and 17. In this embodiment, there are differences compared to the method of manufacturing the first embodiment. is the metal magnetism 116 in the third step and the sixth step
6 and 73 are slightly different, and the other manufacturing steps are completely the same. Therefore, the explanation will be limited to the differences between the third step and the sixth step from the first embodiment, and the same components will be used. are given the same number and the explanation will be omitted.

In the first embodiment, the metal magnetic film 66 provided on the magnetic core half block 67 is also formed in the track width regulating groove 64, as shown in FIG. 4, but in the second embodiment In the magnetic core half block 95, the metal magnetic film 96 is provided only on the slope 161a of the winding groove 61, as shown in FIG.

This is metal magnetism! This can be realized by masking the parts other than the inclined wall 61a when forming the wall 196.

Further, in the first embodiment, the metal magnetic film 73 provided on the magnetic core half block 72 is also formed in the track width regulating groove 70 as shown in FIG. In the core half block, as shown in FIG. 17, only the surface 71a of the tip 71 is coated with gold IvA! 9!97 is set up. Similar to the above, this can be realized by masking the portion other than the surface 71a of the tip portion 71 when forming the metal magnetic film 97.

As described above, in the manufacturing method of the second embodiment, since the track width is determined only by the widths 11 and 12 of the first and second tip portions Sob and 71, a desired track width can be formed with high precision. have

(Effects of the Invention) As described above, the composite magnetic head of the present invention has a winding groove formed of an inclined wall having an inclination angle of θ1 with respect to the abutting surface in the abutting surface of at least one of the magnetic core halves. θ with respect to the vertical plane in the extending direction of this inclined wall.
A track width regulating groove having an inclination angle of 2 is formed, a magnetic gap forming surface is formed by depositing the gold R magnetic film on at least the inclined wall, and the track width regulating groove is substantially perpendicular to the magnetic gap forming surface. Moreover, by configuring the magnetic gap forming surface to be cut along a plane substantially perpendicular to the track regulating groove, the bonding boundary line formed by the metal core and the ferrite magnetic material near the magnetic gap can be cut. Since the bonding boundary line is configured to be exposed on the tape sliding surface so as to have an inclination angle of 0 with respect to the magnetic gap, the bonding boundary line does not act as a pseudo gap, and therefore, unevenness occurs in the frequency characteristics of the reproduced output. Therefore, it is possible to obtain good reproduction output characteristics.

Further, the inclination angle θ0. θ1 and θ2 are tanθ0 blood t
Since there is a mutual relationship of an θ1 ・tan θ2, the angle θa between the junction boundary line and the magnetic gap is θ1. By appropriately determining θ2, it can be set arbitrarily, resulting in the advantage that the contour characteristics of the composite magnetic head can be controlled as desired.

[Brief explanation of the drawing]

FIG. 1(a) shows the first part of the composite magnetic head according to the present invention.
A front view showing the magnetic core body in the example, FIG.
1(a) is a cross-sectional view of the magnetic core body shown in FIG. 1(a), and FIG. 1(C) is a side view of the magnetic core body 40 shown in FIG. are shown in Figure 1 (a) to (C
) is a schematic explanatory diagram of the main steps for explaining one embodiment of the method for manufacturing the magnetic core body shown in FIG. Planar views showing the surface, Figures 16 to 17 are 15
Schematic explanatory diagram of the main steps of the magnetic core body shown in the figure, No. 18
20 are perspective views of a conventional composite magnetic head. 40.79.90... Magnetic core body, 60... Magnetic substrate, 60b, 71... Tip end, 61.61b...
Winding groove, 61a... inclined wall, 62, 65.67.69
゜72.76.95.98...Magnetic core half block, 64.70...Groove, 66.73.96.97...
Metal magnetic film, 68.74...Nonmagnetic material, 77...
composite block. (d) (b) (go) 71 times? 2n 5 days old Puni (11r: $
7 1410 years old I5 le]
pu1° 1θ 61 years old (
6El U← IQ (D age 17
ε 2 20 Fi:I Procedure Nem Specie (Method) % Formula % 2, Name of the invention Composite magnetic head 3, Relationship to the person making the amendment case Patent applicant address 3, Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture Chome 12-4
, Date of amendment order (1) Insert ``Figure'' between ``14'' and ``wa'' written on page 23, line 3 of Mei 11I.

Claims (2)

[Claims] (1) A metal magnetic film having a higher saturation magnetic flux density than the magnetic ferrite material is formed on the abutting surfaces of each of the magnetic core halves made of a pair of magnetic ferrite materials, and a non-magnetic thin film is formed between the pair of magnetic core halves. In a composite magnetic head in which a magnetic gap is formed on the tape sliding surface between the metal magnetic films and the metallic magnetic films are joined together through a winding groove formed of an inclined wall having an inclination angle of θ_1, and a track width regulating groove having an inclination angle of θ_2 with respect to a perpendicular to the extending direction of the inclined wall; A magnetic gap forming surface is formed by depositing the metal magnetic film on the magnetic gap forming surface, and the metal magnetic film is formed along a plane substantially perpendicular to the magnetic gap forming surface and substantially perpendicular to the track width regulating groove. A magnetic core is formed by cutting this magnetic gap forming surface and exposing the bonding boundary line formed by the metal magnetic film and the magnetic ferrite material on the tape sliding surface so as to have an inclination angle of θ_0 with respect to the magnetic gap. A composite magnetic head consisting of a main body. (2) These inclination angles θ_0, θ_1 and θ_2 are tan
θ_0=tanθ_1・tanθ_2・・・・・・・・・
- A composite magnetic head according to claim 1, characterized by having the following mutual relationship (1).