JPH06236509A - Magnetic head - Google Patents

Abstract

PURPOSE:To inhibit the cracking of melt bonding glass and ferrite substrates as well as to prevent the corrosion of metallic magnetic films by the melt bonding glass even in the absence of protective films and to suppress the reduction of regenerative output due to decrease of track width. CONSTITUTION:Ferrite substrates 3, 5 are laminated on ferrite substrates 4, 6 with formed metallic magnetic films 1, 2 with glass films 10, 11 in-between and track width regulating grooves 18, 19 are formed in the substrates 3-6 to obtain a pair of magnetic core halves. The objective magnetic head is produced by bonding the magnetic core halves with melt bonding glass 9 with a gap in-between. The glass transition temp. Tg of glass for laminating the substrates 3-6 is made higher than the yield point Tc of the melt bonding glass 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on, for example, a video tape recorder, and more particularly to a glass used for laminating ferrite substrates and a fused glass used for gap bonding.

[0002]

2. Description of the Related Art In the field of magnetic recording, for example, as a magnetic head for high-density magnetic recording having excellent high frequency characteristics, development of a laminated metal film head in which metal magnetic thin films are laminated in multiple layers with an insulating film interposed therebetween. Is being done.

An example of such a magnetic head is shown in FIG.
As shown in FIG. 5, a pair of magnetic core substrates 103, 104 and 105, 106 are formed by laminating a plurality of laminated metal films 101, 102 in which metal magnetic thin films having a small thickness are laminated with an insulating film interposed therebetween.
Magnetic core halves 107, 1 produced by being sandwiched by
The end surfaces of the laminated metal films 101 and 102 are abutted with each other and joined together by a fused glass 109.

Generally, in the magnetic head, since the film thickness of the laminated metal films 101 and 102 is set to the track width TW of the magnetic gap g, the magnetic core substrate 103,
Substrates made of non-magnetic material such as ceramics or crystallized glass are used for 104, 105 and 106.

However, in such a magnetic head, in order to achieve higher density recording, the track width T
As W is narrowed, as shown in FIG. 30, the head efficiency is deteriorated due to the decrease in the core cross-sectional area of the laminated metal films 101 and 102.

For this reason, in the prior art, it has been proposed to use an oxide magnetic material such as ferrite for the magnetic core substrates 103, 104, 105 and 106 in order to prevent deterioration of head efficiency by ensuring the core cross-sectional area. Has been done.

According to this, even when the track width TW is narrowed, as shown in FIGS. 31 to 33,
In a magnetic head using a ferrite substrate, it is possible to suppress a reduction in head reproduction output due to deterioration in head efficiency, as compared with a magnetic head using a non-magnetic substrate. In particular, when the track width TW is extremely narrow, that is, 5 μm, the effect is remarkable.

By the way, the magnetic core substrates 103, 104,
A magnetic head using ferrite for 105 and 106 is manufactured according to the following procedure. First, FIG.
As shown in FIG.
First, a groove 111 having a substantially U-shaped cross section is formed in advance in the portion near the magnetic gap by machining or the like over the entire substrate.

Next, as shown in FIG. 35, the groove 111 is formed.
The inside is filled with glass 112 as a non-magnetic material. Then
The glass 112 overflowing from the groove 111 is flat-polished until the main surface 110a of the ferrite substrate 110 is exposed, and then the polished surface is mirror-finished.

Next, a laminated metal film 113 is formed by laminating a thin metal magnetic thin film on the mirror-finished main surface 110a through an insulating film. Then, a glass film 114 for joining and integrating a ferrite substrate, which will be described later, is laminated on the laminated metal film 113 by sputtering or the like.

Next, as shown in FIG. 38, the ferrite substrates 115 of the same shape, which are produced in the same manner as the glass film 114, are superposed on each other.
0 and 115 are bonded and integrated by the glass film 114. Then, the joining block 116 is attached to the glass 11
It divides from the center of the groove 111 filled with 2 and divides into two.

Next, as shown in FIG. 39, winding grooves 119 and 120 and glass grooves 121 and 122 for winding a coil are formed in each of the divided magnetic core half blocks 117 and 118. . Next, after the magnetic gap forming surfaces of each of the magnetic core half blocks 117 and 118 are mirror-finished, a gap film is formed on each magnetic gap forming surface.

Then, the magnetic core half block 11 is formed.
As shown in FIG. 40, 7 and 118 are joined and integrated by a fused glass 123. Next, the auxiliary winding grooves 124 and 125 are formed in the joined and integrated block, and the sliding surface for the magnetic recording medium is cylindrically polished.

Finally, by cutting the chip into a predetermined size, the magnetic head shown in FIG. 41 is completed.

[0015]

However, in the above-mentioned manufacturing method, not only the steps of FIGS. 34 to 36 for regulating the track width are complicated, but also the steps of FIG.
A step is generated between the glass 112 filled in the groove 111 formed in the ferrite substrate 110 and the ferrite substrate 110, which adversely affects the film characteristics when sputtering the magnetic metal film.

That is, when the surface 110a on which the laminated metal film 113 of FIG. 36 is formed is mirror-finished, as shown in FIG. 42, a step H occurs due to the difference in hardness. For example, the step H is about 20 nm to 30 nm. When the metal magnetic thin film is laminated on the surface where the step H is generated via the insulating film, the continuity of the magnetic film is lost and the magnetic characteristics of the laminated metal film 113 are deteriorated, as shown in FIG. To do.

In order to solve this problem, in the prior art, a metal magnetic thin film is laminated in multiple layers on a ferrite substrate having no groove, with an insulating film interposed, and a glass film is formed thereon. Then, it is joined and integrated with a ferrite substrate in which a groove is not formed, and is divided into two parts by a surface serving as a magnetic gap, and then a track width regulating groove for regulating a track width is formed in the ferrite substrate by machining.

After forming the winding groove and the glass groove on the ferrite substrate, the ferrite substrates having the winding groove and the like formed thereon are butted against each other via a gap film, and fused in the track width regulating groove. Fill the glass. After that, cylindrical polishing is performed and the magnetic head is completed by cutting into a predetermined chip shape.

However, when the magnetic head is manufactured by the above-mentioned method, the manufacturing process can be simplified and the deterioration of the magnetic characteristics of the laminated metal film can be suppressed, but the fused glass filled in the track width regulating groove can be used. The laminated metal film is eroded, the track width is substantially reduced, and the reproduction output is reduced.

Therefore, as shown in FIG. 44, the ferrite substrate 129 on which the laminated metal films 126 and 127 are formed,
Magnetic core half body 1 in which 131 is laminated with ferrite substrates 128 and 130 via glass films 140 and 141
Track width regulating grooves 134, 1 formed in 32, 133
In the laminated metal films 126 and 127 which come into contact with the fused glass 136 filled in the film 35, metal films such as Cr, Ti, Zr and Ta, or Cr ₂ O ₃ , TiO ₂ , ZrO ₂ and Ta.
It is conceivable to form the protective films 137 and 138 which are not easily corroded by the fused glass 136 such as a metal oxide such as ₂ O ₅ .

However, the materials used for the protective films 137 and 138 are the laminated metal films 126 and 127, the fused glass 136, the ferrite substrates 128, 129 and 130,
Since the abrasion resistance when the tape slides is higher than that of 131, when the head is worn out, as shown in FIG.
7,138 protrudes. When the information signal is reproduced by running the magnetic tape 139 in this state, as shown in FIG. 46, a spacing loss is generated by the protrusion amount S of the protective films 137 and 138, and the reproduction output is lowered. To do.

When the magnetic head is manufactured by the above method, the track width regulating grooves 134 and 135 are formed at the time of fusion.
Cracks were generated in the fused glass 136 poured inside,
Gap length accuracy deteriorates significantly. After forming the laminated metal films 126 and 127, the ferrite substrate 128,
If the heating temperature at the time of stacking 129, 130 and 131 is too high, not only the film characteristics of the stacked metal films 126 and 127 are adversely affected, but also the stacked metal films 126 and 127
Due to the difference in coefficient of thermal expansion between 127 and the ferrite substrates 129 and 131, cracks occur in the ferrite substrates 129 and 131.

Also, paying attention to the glass films 140 and 141, at the contact portion between the ferrite substrate and the glass film, the strength of the ferrite is deteriorated due to the reaction between the ferrite and the glass during heating when laminating the ferrite substrates, and the substrate lamination. In various subsequent processes, the fracture 142 inside the ferrite shown in FIG. 47 occurs. Furthermore, due to the reaction between the ferrite and the glass, a bubble 143 is generated in the glass film, and a magnetic recording medium such as abrasion powder of a tape is deposited in the bubble 143, which causes a head clog.

Therefore, the present invention has been proposed in view of such a conventional technical situation, and prevents the metal magnetic film from being corroded by the fused glass even without the protective film, and the reproduction is performed by reducing the track width. Reliability that suppresses the decrease in output, suppresses the occurrence of cracks in the fused glass and the ferrite substrate, prevents the reaction between the glass film and the ferrite substrate, and suppresses the fracture of ferrite and the generation of bubbles in the glass film. It is an object of the present invention to provide an excellent magnetic head.

It is another object of the present invention to provide a magnetic head capable of achieving high output even when the track is narrowed and capable of favorably recording / reproducing on / from a high density magnetic recording medium.

[0026]

In order to achieve the above object, the present invention provides a ferrite substrate on which a metal magnetic film is formed with a glass substrate on which a ferrite substrate is laminated, and track width regulation is performed on the ferrite substrate. In a magnetic head manufactured by gap-bonding a pair of magnetic core halves each having a groove formed with fused glass, the glass transition point Tg of the glass used for laminating the ferrite substrates is the glass of fused glass. It is characterized in that it is higher than the yield point Tc.

In the magnetic head according to claim 1, the glass transition point T of the glass used for laminating the ferrite substrates.
g is 450 ° C. or higher, and the glass deformation point Tc is 650 ° C. or lower.

In the magnetic head according to claim 1, fusion bonding
The temperature of the glass is within the temperature range of 500 ℃ to 600 ℃.
The viscosity of the glass at the desired temperature is 10³Pa · s or more,
10 ^FourIt has a viscosity corresponding to one of Pa · s or less,
In addition, the viscosity of the fused glass when fused is 10^FourPa · s
The above is characterized.

In the magnetic head according to claim 1 or 3, the fused glass is a PbO-based low melting point glass.

The magnetic head according to claim 1 is characterized in that the track width is 15 μm or less.

In the magnetic head according to the first aspect, a high melting point nonmagnetic metal film or an interface film made of an oxide material is provided between the glass used for laminating the ferrite substrates and the ferrite substrate. Characterize.

[0032]

First, the glass transition point Tg and the glass deformation point Tc will be briefly described. The glass transition point Tg and the glass deformation point Tc are obtained from the thermal expansion curve of glass shown in FIG. The thermal expansion curve is obtained from temperature and elongation. The elongation rate is, for example, as shown in FIG. 3, a ratio of the elongation ΔL of the length T of the sample T generated up to a certain temperature t higher than the standard temperature (generally room temperature) and the length L ₀ at the standard temperature in percentage. It is a representation. That is, elongation rate = (ΔL /
It becomes L ₀ ) × 100 (%). In the above thermal expansion curve, the point at which the elongation rate rises sharply from a certain temperature is the glass transition point Tg, and the point at which the elongation rate shows the maximum value is the glass yield point Tc.
Becomes

When the glass deformation point Tc of the fused glass used for gap bonding is higher than the glass transition point Tg of the glass used for laminating the ferrite substrates, the fused glass is cracked by the mechanism described below. Occurs. After the fused glass begins to harden until the glass used for stacking the substrates hardens, the line A-A ', the line of the one magnetic core half 201 with the magnetic gap g shown in FIG. The movement of the metal magnetic film on BB ′ will be considered from the viewpoint of thermal expansion (contraction).

The magnetic core half body 201 is integrally bonded by a sputtered glass film 205 formed by sputtering glass on a ferrite substrate 203 having a metal magnetic film 202 formed thereon and a ferrite substrate 204 having no metal magnetic film formed thereon. It is manufactured by forming a track width regulation groove 206, a winding groove, and a glass groove in this. Then, the other magnetic core half body manufactured in the same manner and this magnetic core half body are gap-bonded by the fused glass 207.

Here, the glass deformation point of the fused glass 207 is Tcw, and the glass transition point of the sputtered glass film 205 is Tcw.
gs, the thermal expansion coefficient of the ferrite substrates 203 and 204 is α
f, the coefficient of thermal expansion of the metal magnetic film 202 is αm, and the length of the magnetic core half 201 in the tape sliding direction is L, the glass deformation point Tcw of the fused glass 207 is the glass transition point of the sputtered glass film 205. Higher than Tgs (Tcw> Tg
s) Therefore, after the fused glass 207 starts to solidify at the glass deformation point Tcw, until the glass of the sputtered glass film 205 completely solidifies at the glass transition point Tgs, the metal magnetic film viewed from the surface of thermal expansion (contraction). The movement of 202 becomes the movement in the contraction direction, and the contraction amount of the metal magnetic film 202 on the line AA ′ and the line BB ′ is expressed as follows.

The contraction amount Δa of the metal magnetic film 202 on the line AA ′ is Δa≈L × αf × (Tcw-Tgs).
The reason for using the thermal expansion coefficient αf of ferrite here is that the metal magnetic film 202 on the line AA ′ is firmly bonded to the ferrite substrate 203 by sputtering or the like, and the thickness of the ferrite substrate 203 >> Metal magnetic film 2
This is because, due to the film thickness of 02, the movement is determined by the thermal expansion coefficient of ferrite.

On the other hand, the shrinkage amount Δb of the metal magnetic film 202 on the line BB ′ is Δb = L × αm × (Tcw-Tbs). The metal magnetic film 202 on the line BB ′ is not restricted in movement by the ferrite substrate 204 until the glass of the sputtered glass film 205 is completely hardened, and thus contracts according to the thermal expansion coefficient of the metal magnetic film 202. .

Generally, the coefficient of thermal expansion αm of the metal magnetic film 202 is larger than the coefficient of thermal expansion αf of the ferrite substrates 203 and 204 (αm> αf), so that the shrinkage amount on the line BB ′ side becomes large. . Therefore, as shown in FIG. 6, a force F in the direction of opening the magnetic gap g is generated with the magnetic gap g formed on the abutting surfaces of the magnetic core halves 201 and 208 as a boundary. Then, the stress F first causes cracks in the fused glass 207 on the line BB ′ side,
After that, a crack grows up to the fused glass 207 on the line AA ′ side through the magnetic gap g.

To prevent this, the glass of the sputtered glass film 205 is completely solidified before the solidification of the fused glass 207 is started, and the movement of the metal magnetic film 202 on the line BB ′ side is caused by the ferrite substrate 204. It just has to be regulated. That is, the glass transition point T of the glass of the sputtered glass film 205
It is necessary that g is higher than the glass deformation point Tc of the fused glass 207.

From this point of view, in the magnetic head according to the present invention, the glass transition point Tg of the glass used for laminating the ferrite substrates is set to the glass deformation point Tc of the fused glass.
Since it is higher than the above, the fused glass used for gap bonding does not crack.

Further, in the magnetic head according to the present invention, the glass transition point Tg is 450 ° C. or higher and the glass deformation point T is
By using glass having c of 650 ° C. or lower when laminating ferrite substrates, cracking of the ferrite substrate during substrate lamination is suppressed, and highly reliable fused glass is cracked during gap bonding. Can be used without

Further, in the magnetic head according to the present invention, the viscosity of the fused glass at a given temperature within the temperature range of 500 ° C. to 600 ° C. is 10 ³ Pa.
Pb corresponding to any of s or more and 10 ⁴ Pa · s or less
Since it is an O-based low melting glass and the viscosity of the fused glass when fused is 10 ⁴ Pa · s or more, even if there is no protective film between the metallic magnetic film and the fused glass. Erosion of the metal magnetic film by the fused glass is suppressed, and the reproduction output is not reduced due to the reduction of the track width of the magnetic gap.

Further, in the magnetic head according to the present invention, even when the track width is 15 μm or less, there is no reduction in the track width, so that the reproduction output does not deteriorate,
High density recording is achieved.

In the magnetic head according to the present invention, a high melting point nonmagnetic metal film or an interface film made of an oxide material is provided between the glass used for laminating the ferrite substrates and the ferrite substrate. Therefore, during heating when laminating the ferrite substrates, the strength of the ferrite substrate is not deteriorated due to the reaction between the ferrite and the glass, and bubbles are not generated in the glass film.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings. In the magnetic head of this embodiment, as shown in FIG. 1, the metallic magnetic films 1 and 2 are a pair of ferrite substrates 3, 4 and 5, 6 from the thickness direction.
It is composed of a pair of magnetic core halves 7 and 8 sandwiched between the magnetic core halves 7 and 8 so that the end faces of the metal magnetic films 1 and 2 abut each other and the fused glass 9
The gap is joined by.

The magnetic core halves 7 and 8 are composed of a metal magnetic film 1 and a pair of ferrite substrates 3, 4 and 5, 6 as shown in FIG. The glass films 10, 1 for stacking the other ferrite substrates 3, 5 so as to sandwich the metal magnetic films 1, 2 formed on one main surface of the one ferrite substrate 4, 6
1 is joined and integrated.

The metal magnetic films 1 and 2 are thin magnetic metal thin films 1a, 1b and 1 for the purpose of improving high frequency characteristics.
c and 2a, 2b, 2c as insulating films 12a, 12b and 1
It is a laminated metal film formed by laminating multiple layers via 3a and 13b. In addition, the metal magnetic films 1 and 2 improve the adhesion with the ferrite substrates 4 and 6,
It is formed on the adhered surfaces of the ferrite substrates 4 and 6 with underlying films 14 and 15 interposed therebetween.

Magnetic metal thin films 1a, 1b, 1c and 2a,
2b and 2c include, for example, sendust (Fe-Al-S
Any of i) and Fe-Ru-Ga-Si, or a film made of a crystalline magnetic metal material obtained by adding O, N or the like to these or a Fe-based or Co-based microcrystalline magnetic metal material can be used. Among them, fused glass 9 used for gap bonding
Since a fused glass having excellent strength, weather resistance and abrasion resistance is used as the above, a film made of a crystalline magnetic metal material or a microcrystalline magnetic metal material is suitable. Regarding the film thickness, it is desirable to set it to 2 to 5 μm per layer, for example.

The insulating film 2 is made of, for example, SiO.
Oxide films such as ₂ , Ta ₂ O ₅ , Al ₂ O ₃ and Si ₃ N ₄
A nitride film or the like is used. Regarding the film thickness, 0.1
It is preferably about 0.3 μm.

On the other hand, the base films 14 and 15 are formed of SiO.₂，
Ta₂O_FiveOxide film such as Si₃N _FourNitride film such as C
Metal films of r, Al, Si, Pt, Ti, etc. and their combination
A gold film or a laminated film combining them is used.
In this embodiment, the SiO 2 film has a thickness of 50 nm.₂A film consisting of
used.

The glass films 10 and 11 are films made of low-melting glass used for joining the pair of ferrite substrates 3, 4 and 5, 6 to the respective ferrite substrates 3, 4 and 5, 6. Is formed on the surface. As the glass films 10 and 11, for example, a glass sputtered film produced by sputtering, a frit glass film applied by spin coating, or the like is used. In this example, a glass sputtered film having a thickness of 0.1 to 0.5 μm was used.

Further, interface films 16b and 17b are provided between the glass films 10 and 11 and the magnetic metal films 1a and 2a in order to prevent a reaction between them. Also,
Between the glass films 10 and 11 and the ferrite substrates 3 and 5, it is possible to prevent the strength of ferrite from deteriorating due to the reaction between the ferrite and glass and the generation of bubbles in the glass film during heating when laminating the ferrite substrates. Therefore, the high melting point non-magnetic metal film or the interface film 16a made of an oxide material,
17a is provided.

The interface films 16a, 16b and 17a,
As 17b, for example, SiO₂, Ta₂O_Five, Cr₂
O₃, TiO₂, ZrO₂, Al₂O₃Oxide film, etc.
Si ₃N_FourSuch as nitride film, Cr, Ti, Zr, Ta, etc.
Metallic films and their alloy films or products combining them
A layer film or the like is used. In this embodiment, the film thickness is 0.1 μm
A film made of Cr was used.

Generally, in a laminated metal film head, the wettability between the metal film and the glass is extremely higher than the wettability between ceramics, a non-magnetic material such as crystallized glass, and an oxide magnetic material such as ferrite. Since it is inferior, a method of providing an interface film having good wettability with glass at the interface between the metal film and glass is generally used (JP-A-61-8051).
1, JP-A-4-255902, JP-A-4-32410
4).

However, when ferrite is used as the substrate, if a conventional interface film is provided only at the interface between the metal film and the glass, the reaction between the ferrite and the glass during heating when stacking the ferrite substrates. Due to
The strength of the ferrite deteriorates, and fracture occurs from the inside of the ferrite in various processes after the substrate is laminated. Further, due to the reaction between the ferrite and the glass, bubbles are generated in the glass film, and magnetic recording media, for example, abrasion powder of the tape are accumulated in the bubbles, which causes a problem such as head clogs.
Therefore, in this embodiment, the interfacial films 16a and 17a are also provided between the ferrite substrates 3 and 5 and the glass films 10 and 11 to prevent the problem caused by the reaction between the ferrite and the glass.

The magnetic core halves 7 and 8 have track width regulating grooves 18 and 19 for regulating the track width TW of the magnetic gap g which operates as a recording / reproducing gap.
Are formed by notching both end portions in the film thickness direction of the metal magnetic films 1 and 2 present on the respective butting surfaces.

The magnetic core halves 7 and 8 are provided with winding grooves 20 and 21 for winding a coil in the middle of the abutting surfaces as grooves having a substantially U-shaped cross section. ing. Further, on the side surfaces of the magnetic core halves 7 and 8 facing the winding grooves 20 and 21, winding auxiliary grooves 22 and 23 are also substantially cross-sectional in order to make the winding state of the coil good. It is formed as a shallow U-shaped groove. Further, in order to make the bonding strength of the magnetic core halves 7 and 8 stronger, the glass cores 24 are formed in the rear end edge portion on the side opposite to the magnetic gap g. , 25
Are formed.

The magnetic core halves 7 and 8 configured as described above are the metal magnetic films 1 and 1 present on the abutting surfaces.
The end faces of the two are abutted via a gap film (not shown), and are bonded together by a fused glass 9 to be integrated, and a magnetic gap g that operates as a recording / reproducing gap between the abutting faces of the metal magnetic films 1, 2. Is configured.

In the magnetic head composed of these magnetic core halves 7 and 8, since the metal magnetic films 1 and 2 and the ferrite substrates 3, 4 and 5 and 6 form a closed magnetic path,
Even if the track width TW of the magnetic gap g is narrowed (for example, 15 μm or less), the core cross-sectional area is ensured, so that the reduction of the head effectiveness can be prevented and high-density magnetic recording can be performed. Further, in such a magnetic head, the fused glass 9 is filled in the track width regulating grooves 18 and 19 formed in each of the magnetic core halves 7 and 8 and facing each other. The contact with the magnetic recording medium is secured.

In particular, the magnetic head of this embodiment is used for laminating the ferrite substrates 3, 4 and 5, 6 in order to prevent cracks from occurring in the fused glass 9 used for gap bonding. Glass film 10,1
The glass transition point Tg of No. 1 and the glass deformation point Tc of the fused glass 9 are defined as follows.

That is, the glass transition point Tg of the glass films 10 and 11 is set higher than the glass deformation point Tc of the fused glass 9. By defining in this way, the glass of the glass films 10 and 11 is completely solidified before solidification of the fused glass 9 is started by the mechanism described above, and the magnetic metal thin film 1a on the side in contact with the glass films 10 and 11 is formed. Since the movement of 2a is restricted by the ferrite substrates 3 and 5, the fused glass 9 is prevented from cracking.

Further, in this embodiment, it is possible to suppress the occurrence of cracks in the ferrite substrates 4 and 6 during the lamination of the substrates and to use the highly reliable fused glass 9 to prevent the cracks in the fused glass 9. The glass transition point Tg and the glass deformation point Tc of the glass films 10 and 11 used for stacking the substrates are defined as follows in order to perform the gap bonding without the generation.

That is, the glass transition point Tg of the glass films 10 and 11 is 450 ° C. or higher, and the glass deformation point Tc is 650 ° C.
Below. By defining as above, the ferrite substrates 4 and 6 are not cracked, and the highly reliable fused glass 9 can be used without cracking.

Here, the maximum temperature applied during the lamination of the substrates does not cause deterioration of the magnetic characteristics of the metal magnetic films 1 and 7.
The limit is 00 ° C. Therefore, the upper limit of the glass deformation point Tc of the glass for stacking the substrates must be lower than 650 ° C. If it is more than this, cracks occur in the ferrite substrates 4 and 6 when the substrates are laminated. On the other hand, when the glass transition point Tg is 450 ° C. or lower,
When a highly reliable fused glass 9 is used at the time of gap bonding, cracks occur in the fused glass 9.

Further, in this embodiment, in order to suppress the erosion of the metal magnetic films 1 and 2 by the fused glass 9 used for gap bonding and reduce the decrease in the track width TW, the viscosity of the fused glass 9 and The viscosity of glass at the time of fusion is specified as follows.

That is, if the fused glass 9 is 500 ° C. or higher,
Viscosity of glass at an arbitrary temperature within a temperature range of 600 ° C. or lower is a viscosity corresponding to any one of 10 ³ Pa · s or more and 10 ⁴ Pa · s or less, and the fused glass 9 when fused Viscosity of 10 ⁴ Pa · s or more. When a crystalline magnetic metal film or a microcrystalline magnetic metal film is used for the metal magnetic films 1 and 2, the temperature at the time of glass filling is set to the upper limit as described above in order to prevent deterioration of magnetic properties of the metal film due to heat. Is 700 ° C., the fusion glass 9 is Pb
O-based low melting point glass is used.

Usually, a PbO-based low melting point glass used for gap fusion of a magnetic head using a metal magnetic film has a temperature at which the viscosity of the glass becomes 10 ³ Pa · s, that is, a so-called working point Tw is 300. ℃ ~ 600 ℃, 10 ³ Pa · s ~ 10 ⁴ P in fusion work
It is used with a viscosity of a · s. Working point Tw is 500
Glass whose temperature is lower than ℃ is mainly used for a magnetic head which uses an amorphous magnetic alloy having a low heat resistance as a metal film.
Both weather resistance and wear resistance are greatly inferior.

Therefore, the fused glass used for the magnetic head using the crystalline magnetic metal film or the microcrystalline magnetic metal film having higher heat resistance than the amorphous magnetic alloy is
It is desirable that the working point Tw is 500 ° C. or higher. Further, the viscosity of the glass during the glass filling are defined as 10 ⁴ Pa · s or more, 10 ⁴ for Pa · s is not more than the metallic magnetic film 2 is eroded as shown in FIG. 21 Is.

Further, as described above, the upper limit of the yield point Tc of the glass used for substrate lamination is 650 ° C. in order to suppress the occurrence of cracks in the ferrite substrate during substrate lamination. When a glass corresponding to the above is used for the substrate lamination, the viscosity of the gap-fused glass is 10
Glass with a temperature of ⁴ Pa · s at 600 ° C. or lower can be used without cracks in the glass.

Here, the reason why the glass transition point Tg and the like are specified as described above will be explained based on the results of experiments actually conducted under the following conditions. First, an experiment was conducted to make it possible to prevent cracks from occurring in the fused glass 9 by making the glass transition point Tg of the glass used for laminating substrates larger than the glass deformation point Tc of the fused glass 9. It was

Experimental conditions (a) As the glass for laminating the substrates, the following three types of glass were used. Glass A: Tg = 400 ° C., Tc = 440 ° C. Glass B: Tg = 430 ° C., Tc = 480 ° C. Glass C: Tg = 465 ° C., Tc = 495 ° C.

(B) The following materials were used for the fused glass 9. Glass D: Tg = 380 ° C., Tc = 410 ° C., Tw = 5
20 ° C. Glass E: Tg = 410 ° C., Tc = 440 ° C., Tw = 5
50 ° C. Glass F: Tg = 420 ° C., Tc = 450 ° C., Tw = 5
80 ° C

(C) A magnetic head was prepared from the combination of the glasses of (a) and (b) above, and it was observed whether or not cracks were generated in the fused glass 9. The results are shown in Table 1. In Table 1, ◯ means that no crack was generated, and × means that crack was generated.

[0074]

[Table 1]

From these results, when the glass transition point Tg of the glass for stacking the substrates is lower than the glass deformation point Tc of the fused glass 9, the fused glass 9 is cracked as shown in FIG. Occur. On the other hand, when the glass transition point Tg of the glass for stacking the substrates is higher than the glass deformation point Tc of the fused glass 9, cracks are not seen in the fused glass 9.

In addition, in this experiment, the gap length was set to 0.2 μm, whereas in the case where the fused glass 9 had cracks, the gap length was 0.3 to 0.
The gap was 4 μm, which resulted in a defective gap. On the other hand, in the case where no crack was generated, the gap length was almost the target. Therefore, by suppressing the occurrence of cracks, the gap length accuracy can be significantly improved.

Next, the glass transition point Tg of the glass for stacking the substrates is 450 ° C. or higher, and the glass deformation point Tc is 650 ° C.
By doing the following, the ferrite substrate 4,
An experiment was conducted to prevent the occurrence of cracks in No. 6 and the occurrence of cracks when using a fused glass having high reliability during gap bonding.

Experimental Conditions (a) As the glass for laminating the substrates, the following three types of glass were used. Glass A: Tg = 430 ° C., Tc = 480 ° C. Glass B: Tg = 465 ° C., Tc = 495 ° C. Glass C: Tg = 580 ° C., Tc = 650 ° C.

(B) The following glass was used as the fusing glass 9. Glass D: Tg = 410 ° C., Tc = 440 ° C., Tw = 5
50 ° C. Glass E: Tg = 420 ° C., Tc = 450 ° C., Tw = 5
80 ° C

(C) A magnetic head was produced from the combination of the glasses of (a) and (b) above, and the ferrite substrates 4 and 6 were used when laminating the substrates.
It was observed whether or not cracks were generated in the glass, or whether or not cracks were generated in the fused glass 9 during the gap bonding.
The results are shown in Table 2.

[0081]

[Table 2]

As can be seen from these results, in the magnetic head using the glass A in which the glass transition point Tg of the glass for stacking the substrates was 450 ° C. or less, cracks were generated in the fused glass 9. On the other hand, the glass transition point Tg is 450
In the magnetic head using the glass B having the glass deformation point Tc of 650 ° C. or higher and the glass deformation point Tc of 650 ° C. or lower, no crack was observed when any of the fused glass 9 was used.

Further, in the magnetic head using the glass C,
Since the glass deformation point Tc is 650 ° C., heating at the time of stacking the substrates was performed at a temperature of 700 ° C., and due to the difference in thermal expansion coefficient between the ferrite substrates 3, 4, 5, 6 and the metal magnetic films 1, 2. The stress generated becomes too large, and after the substrates are laminated,
As shown in 2, cracks occurred in the ferrite substrates 4 and 6.

Considering that the upper limit of the heat resistance in terms of magnetic properties of the metal magnetic films 1 and 2 is 700 ° C., the upper limit of the glass deformation point Tc of the glass used for laminating the substrates is preferably 650 ° C. Can be said. Therefore, the glass transition point Tg of the glass used for stacking the substrates is 450 ° C. or higher,
By setting the glass deformation point Tc to 650 ° C. or less, it is possible to suppress the occurrence of cracks in the ferrite substrates 4 and 6 when laminating the substrates, and to use the highly reliable fused glass 9 at the time of gap bonding without the occurrence of cracks. can do.

Next, an experiment was conducted in which the erosion of the metallic magnetic films 1 and 2 by the fused glass 9 can be prevented by defining the viscosity of the fused glass 9 at the time of filling the glass.

Experimental Conditions (a) As the fused glass 9, three kinds of PbO-based low melting point glass having different working points Tw shown below were used. Glass A: Tg = 445 ° C., Tc = 470 ° C., Tw = 6
00 ° C glass B: Tg = 420 ° C, Tc = 450 ° C, Tw = 5
80 ° C. Glass C: Tg = 380 ° C., Tc = 410 ° C., Tw = 5
20 ° C

(B) When the magnetic head is filled with glass, the viscosity of the glass is generally 10 ³ Pa · s to 10 ⁴ Pa ·
s, and the holding time at the temperature at which a predetermined viscosity is obtained at the time of filling, that is, the so-called stabilization time is set to 60 minutes.
Therefore, for each of the glass A, the glass B, and the glass C used as the filled glass this time, the following five viscosities a, b, c, from the viscosity characteristic data of the glass shown in FIG.
At a temperature at which d and e were obtained, the stabilization time was set to 60 minutes and glass filling was performed to manufacture a magnetic head. These combinations are shown in Table 3.

[0088]

[Table 3]

(C) With respect to the magnetic heads produced by the combinations shown in Table 3, the reduction amount of the track width TW caused by the erosion of the metal magnetic films 1 and 2 by the fused glass 9 was measured by using a scanning electron microscope. It was measured. The result is shown in FIG.
Note that, as shown in FIG. 24, the reduction amount of the track width TW indicates a value obtained by subtracting the track width TW ′ that has been left after the glass fusion is eroded from the track width TW before the glass fusion.

From this result, the amount of decrease in the track width TW caused by the fusion glass 9 corroding the metal magnetic films 1 and 2 largely depends on the viscosity at the time of glass filling,
When the viscosity at the time of glass filling is 10 ⁴ Pa · s or more, track width TW of 0.1 μm or less in any glass
It was found that the amount decreased. Further, in the case of the glass viscosity of 10 ³ Pa · s to 10 ⁴ Pa · s which has been conventionally adopted, the maximum reduction amount of the track width TW is 1.5 μm.
It turns out that it will be about m.

In FIG. 25, the data when the viscosity when the glass is filled is 10 ^4.5 Pa · s is missing,
This is because the reduction amount of the track width TW when the glass is filled with the viscosity of 10 ^4.5 Pa · s is almost indistinguishable.

Next, FIG. 26 shows the relationship between the reduction amount of the track width TW and the reduction amount of the head reproduction output. As can be seen from FIG. 26, when the reduction amount of the track width TW is 0.1 μm, the reproduction output reduction is 0.1 dB or less in any of the heads having the track width TW of 5 μm, 10 μm, and 15 μm. Therefore, it was found that the reduction in the reproduction output was at a level at which there was no practical problem.

From the above, the track width regulating groove 18,
Filling 19 with fused glass 9 ^FourViscosity over Pa · s
The magnetic properties of the fused glass 9
Even if a protective film is not attached to the end faces of the films 1 and 2, the fused glass 9
Generated by erosion of metal magnetic films 1 and 2
The reduction amount of the width TW can be suppressed to 0.1 μm or less,
The decrease in reproduction output due to the decrease in the track width TW is set to 0.
It can be 1 dB or less.

Finally, by providing the interface films 16a and 17a between the glass films 10 and 11 used for laminating the ferrite substrates and the ferrite substrates 3 and 5, the glass films 10 and 11 and the ferrite substrates 3 and 5 are provided. Experiments were carried out to prevent the reaction with 5.

Experimental Conditions (a) The following two types of glass were used as the glass for laminating the substrates. Glass A: Tg = 430 ° C., Tc = 480 ° C. Glass B: Tg = 465 ° C., Tc = 495 ° C. (b) 0.1 μm thick Cr was used as the interface film. (c) A magnetic head was created without using the combination of (a) and (b) above, and without an interface film, to determine whether breakage occurred in the ferrite and whether bubbles were generated in the glass film. I observed. The results are shown in Table 4.

[0096]

[Table 4]

As can be seen from these results, the glass film 1
An interfacial film 16 is provided between 0 and 11 and the ferrite substrates 3 and 5.
In the magnetic heads provided with a and 17a, neither glass A nor glass B was found to have fractures inside the ferrite or bubbles inside the glass film. Further, in the magnetic heads in which the interface films 16a and 17a were not provided, breakage in the ferrite and generation of bubbles in the glass were observed in both the glass A and the glass B.

Experiments in which the tensile bond strength tester measures the bond strength after heat treatment when a glass film is provided on a ferrite substrate through a Cr film and when the glass film is directly formed on the ferrite substrate Also did.

As a result, when the Cr film (interface film) was not provided, it was 213.5 Kg / cm ² , and when the Cr film (interface film) was provided, it was 749.7 Kg / cm ² and clearly the Cr film was provided. It was found that the adhesive strength was better. Moreover, when the Cr film is provided, the glass film is not broken in the glass film, whereas when the Cr film is not provided, the glass film is broken in the ferrite film. It was confirmed in this experiment that it was due to the reaction of.

From the above, the glass films 10 and 11 and the ferrite substrates 3 and 5 used for laminating the ferrite substrates are formed.
By providing the interface films 16a and 17a between and, it is possible to prevent the deterioration of the ferrite strength due to the reaction between the glass films 10 and 11 and the ferrite substrates 3 and 5, and to break the ferrite from the inside during various processing after the substrate is laminated. Can be prevented. Further, the glass films 10, 11 and the ferrite substrate 3,
By providing the interface films 16a and 17a between the
Bubbles in the glass film due to the reaction between the glass films 10 and 11 and the ferrite substrates 3 and 5 can be prevented, and the magnetic recording medium, for example, the abrasion powder of the tape is accumulated in the bubbles to prevent head clogs. Occurrence can be prevented.

In the above-described magnetic head, the track width restricting grooves 18 and 19 are continuously formed from the sliding surface side of the magnetic recording medium to the back side, but as shown in FIG. Track width regulation groove 1 only on the moving surface side
The present invention can be applied to the magnetic heads having Nos. 8 and 19 and the same operation and effect. In the magnetic head described above, the metal magnetic films 1 and 2 are formed so as to be parallel to the sliding direction of the magnetic recording medium.
The present invention can be applied to a magnetic head formed so as not to be parallel to the sliding direction of the magnetic recording medium as shown in (a) and (b).

Next, a method of manufacturing the above-described magnetic head shown in FIG. 1 will be described in the order of steps with reference to the drawings. First, as a magnetic core substrate, a pair of ferrite substrates 26 and 27 having the same shape as shown in FIGS.
Is prepared, and one main surface 2 of these ferrite substrates 26, 27 is prepared.
6a and 27a are mirror-finished by polishing or the like.

As the ferrite substrates 26 and 27, substrates made of single crystal ferrite or polycrystalline ferrite, a bonding substrate of single crystal ferrite and polycrystalline ferrite, or a bonding substrate of single crystal ferrite having different plane indices is used. May be.

Next, on one main surface 26a of the one ferrite substrate 26, metal magnetic films 28 and 29 are formed by mask sputtering so as to be parallel to each other with a predetermined interval in a required minimum area. . When forming the metal magnetic films 28 and 29, as shown in FIG. 8, a base film 30 made of SiO ₂ is formed to have a film thickness of 50 nm in order to improve the adhesion with the ferrite substrate 26 and the like. did. In order to improve the high frequency characteristics, the metal magnetic films 28 and 29 are magnetic metal thin films 28a and 2 via the insulating films 31a and 31b.
It was formed by stacking 8b and 28c in multiple layers.

The magnetic metal thin films 28a, 28b, 28
c has a film thickness per layer of 2 to 5 μm, and a track width regulation groove described later provides a predetermined track width,
The insulating films 31a and 31b are laminated so that the film thickness is about 1.2 to 3 times the predetermined track width.

In this embodiment, when the track width is set to 5 μm, the magnetic metal thin films 28a, 28b per layer are
The film thickness of 28c was set to 3 μm, and SiO ₂ films of 0.2 μm thickness were stacked as three insulating films 31a and 31b. When the track widths were set to 10 μm and 15 μm, the magnetic metal thin films 28a, 28b and 28c and the insulating films 31a and 31b per layer had the same thickness as the head having a track width of 5 μm, and six layers were stacked.

Next, the ferrite substrate 27 on the metal magnetic films 28 and 29 and on which the metal magnetic films 28 and 29 are not formed.
As shown in FIGS. 10 and 11, low melting point glass films 31 and 32 having a thickness of 0.1 to 0.5 μm are formed on one main surface 27a by sputtering. At that time, the metal magnetic film 28,
The metal magnetic film 2 is formed on the surface 29 and on the ferrite surface 27a.
8 and 29 and interface films 33 and 34 were formed to prevent the reaction between ferrite and glass.

In this example, Cr was formed to have a thickness of 0.1 μm, and then PbO glass was laminated to have a thickness of 0.2 μm. The low melting point glass films 31, 32
May be formed on either one of the ferrite substrates 26 and 27.

Next, as shown in FIG. 12, one ferrite substrate 27 is laminated on the other ferrite substrate 26 so as to sandwich the metal magnetic films 28 and 29, and the magnetic force of the metal magnetic films 28 and 29 is magnetically bonded while being pressure-bonded. Heat at 500 ° C. to 650 ° C. is applied so that deterioration of characteristics does not occur. As a result, as shown in FIG. 13, the low-melting-point glass films 31 and 32 are melted and fused with each other, and are cooled, whereby the ferrite substrate 2 is cooled.
6, 27 are joined and integrated.

Next, the joined substrate 34 joined and integrated is formed.
With the same angle θ as the azimuth angle given to the magnetic head to be manufactured, the line AA ′, the line BB ′, and the line C− in FIG.
Cut at the position indicated by C '. Then, after removing unnecessary portions of the ferrite by using a surface grinder or the like, winding grooves 37 for winding the coil are formed on the magnetic core half blocks 35, 36 as shown in FIGS. 15 and 16. Glass grooves 39 and 40 for glass fusion with 38 are formed on the respective butting surfaces.

The winding grooves 37, 38 and the glass grooves 39, 4
Although 0 is formed as a groove having a substantially U-shaped cross section, one side surface 37a, 38a of each winding groove 37, 38 is an inclined surface. The other side surface 37 of the winding grooves 37, 38
b and 38b may be inclined surfaces or vertical surfaces.

Next, the magnetic core half blocks 35,
Track width restricting grooves 41 and 42 for restricting the track width are formed in 36, respectively. The track width regulating grooves 41, 42 are the winding grooves 37, 38 and the glass groove 3
In the direction substantially orthogonal to 9, 40, the metal magnetic films 28, 29
Part of both ends in the film thickness direction is shaved off to form a groove having a substantially U-shaped cross section over the entire block.

Next, the magnetic core half blocks 35,
Gap forming surfaces 35a, 36a which are abutting surfaces of 36
Is mirror-finished by polishing. Then, after forming a gap film on the gap forming surface 35a of one magnetic core half block 35 or the gap forming surfaces 35a and 36a of both magnetic core half blocks, as shown in FIG. The blocks 35 and 36 are butted while aligning the tracks, and the gap bonding is performed while pouring the fused glass 43.

As a result, these magnetic core half blocks 3
5, 36 are joined and integrated by the fused glass 43,
A magnetic gap g that operates as a recording / reproducing gap is formed between the abutting surfaces of the metal magnetic films 28 and 29. Also,
At the time of glass fusion, glass 31, 32 for stacking substrates
And the glass transition point Tg of the fused glass 43 and the glass deformation point T
Since c and the like are defined as described above, the fused glass 43
Since the ferrite substrates 26 and 27 are not cracked, and the viscosity of the fused glass 43 at the time of glass fusion is defined as described above, the metal magnetic films 28 and 29 are eroded and the track width is reduced. It will not decrease.

Then, after forming a winding auxiliary groove in the ferrite block joined and integrated by the fused glass 43, the sliding surface of the magnetic recording medium is cylindrically polished to give a predetermined width to a predetermined chip shape. Cut so that

Between the glass films 31 and 32 used for stacking the ferrite substrates and the ferrite substrate 27,
Since the interface film 34 is provided as described above, the strength of the ferrite does not deteriorate due to the reaction between the glass films 31 and 32 and the ferrite substrate 27, and the ferrite is used in various processes from the substrate lamination to the completion of the chip shape. It does not break from inside. Further, since no bubbles are generated in the glass film due to the reaction between the glass films 31 and 32 and the ferrite substrate 27, the magnetic recording medium, for example, abrasion powder of tape is not deposited in the bubbles, and the head clogs are not formed. There is no such problem.

As a result, the magnetic head capable of excellent recording and reproduction on the high density recording medium shown in FIG. 1 is completed.

[0118]

As is clear from the above description, in the magnetic head of the present invention, the glass transition point of the glass used for laminating the ferrite substrates is set to be higher than the glass deformation point of the fused glass used for the gap bonding. Because it is high,
It is possible to prevent cracks from occurring in the fused glass, and it is possible to make the gap length accuracy of the magnetic gap highly accurate.

In the magnetic head of the present invention, the glass used for laminating the ferrite substrates has a glass transition point Tg of 450 ° C. or higher and a glass deformation point Tc of 650 ° C. or lower. It is possible to avoid the occurrence of cracks in the substrate, it is possible to use fused glass with high reliability without cracks during gap bonding, and it is possible to greatly improve the reliability of the head.

Further, in the magnetic head of the present invention, PbO-based low melting point glass is used as the fusion glass used for the gap bonding, and the viscosity at the time of filling the glass is 10 ⁴ Pa.
Since it is set to s or more, the metal film can be prevented from being corroded by the fused glass without a protective film for preventing the metal film from being corroded, and the reduction of the track width can be significantly suppressed. Therefore, even in the case of a magnetic head having an extremely narrow track width of 15 μm or less, the decrease in reproduction output due to the decrease in track width is 0.1 dB.
It can be: Therefore, according to the magnetic head of the present invention, recording / reproducing can be performed in a good state even on a high density recording medium.

Further, in the present invention, since the high melting point nonmagnetic metal film or the interface film made of an oxide material is provided between the glass used for laminating the ferrite substrates and the ferrite substrate, the glass and the ferrite are provided. The strength of the ferrite does not deteriorate due to the reaction with, and it does not break from inside the ferrite during various processing after the substrate is deposited.
Further, since bubbles do not occur in the glass film due to the reaction between the glass and the ferrite, the magnetic recording medium, for example, abrasion powder of tape is not deposited in the bubbles. Therefore, problems such as head clogs do not occur and the reliability of the head can be greatly improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head to which the present invention is applied.

FIG. 2 is an enlarged plan view of an essential part showing an enlarged magnetic gap portion of a magnetic head to which the present invention is applied.

FIG. 3 is a diagram for explaining the elongation rate of glass.

FIG. 4 is a characteristic diagram showing a thermal expansion curve of glass.

FIG. 5 is an enlarged plan view of an essential part for explaining a mechanism in which a fused glass is cracked.

FIG. 6 is an enlarged plan view of an essential part showing a state where cracks have occurred in the fused glass.

FIG. 7 is a perspective view sequentially showing a process of manufacturing the magnetic head of the present invention, showing a process of forming a metal magnetic film on one ferrite substrate.

FIG. 8 is an enlarged cross-sectional view of an essential part showing the steps of manufacturing the magnetic head of the present invention in order and showing an enlarged part of the metal magnetic film formed on one ferrite substrate.

FIG. 9 is a perspective view sequentially showing the steps of manufacturing the magnetic head of the present invention, showing the step of mirror-finishing the main surface of the other ferrite substrate.

FIG. 10 is a fragmentary enlarged cross-sectional view showing a step of forming a glass film on a metal magnetic film, sequentially showing steps of manufacturing the magnetic head of the present invention.

FIG. 11 is an enlarged cross-sectional view of an essential part showing a step of manufacturing the magnetic head of the present invention in sequence, showing a step of forming a glass film on a ferrite substrate.

FIG. 12 is a perspective view showing a step of manufacturing a magnetic head of the present invention in sequence, showing a step of joining ferrite substrates.

FIG. 13 is an enlarged cross-sectional view of an essential part showing in sequence the steps of manufacturing the magnetic head of the present invention, showing the metal magnetic film portion of the bonded ferrite substrate in an enlarged manner.

FIG. 14 is a perspective view sequentially showing the steps of manufacturing the magnetic head of the present invention, showing the step of cutting the bonded ferrite substrate.

FIG. 15 is a perspective view sequentially showing a process of manufacturing the magnetic head of the present invention, showing a process of forming a winding groove and a glass groove in one magnetic core half block.

FIG. 16 is a perspective view sequentially showing a step of manufacturing the magnetic head of the present invention, showing a step of forming a winding groove and a glass groove in the other magnetic core half block.

FIG. 17 is a perspective view sequentially showing a step of manufacturing the magnetic head of the present invention, showing a step of forming a track width regulating groove in one magnetic core half block.

FIG. 18 is a perspective view sequentially showing a step of manufacturing the magnetic head of the present invention, showing a step of forming a track width regulating groove in the other magnetic core half block.

FIG. 19 is a perspective view showing a glass fusing step, which sequentially shows steps for manufacturing the magnetic head of the present invention.

FIG. 20 is an enlarged plan view of an essential part of a magnetic gap portion showing a state in which a crack has occurred in the fused glass.

FIG. 21 is an enlarged plan view of an essential part of a magnetic gap portion showing a state in which the metal magnetic film is eroded by the fused glass.

FIG. 22 is an enlarged plan view of an essential part of a magnetic gap portion showing how a crack is generated in a ferrite substrate.

FIG. 23 is a characteristic diagram showing the viscosity characteristic of the glass used in the experiment.

FIG. 24 is an enlarged plan view of an essential part of a magnetic gap portion for explaining a track width reduction amount.

FIG. 25 is a characteristic diagram showing the relationship between the viscosity of the glass used in the experiment and the track width reduction amount.

FIG. 26 is a characteristic diagram showing the relationship between the track width reduction amount and the head output reduction amount of the magnetic head used in the experiment.

FIG. 27 is a perspective view showing another example of the magnetic head of the present embodiment.

FIG. 28 is a plan view showing still another example of the magnetic head of the present embodiment, in which the metal magnetic film is not parallel to the sliding direction of the magnetic recording medium, and FIG. This is an example in which the film is tilted in the direction opposite to the magnetic gap, (b)
Shows an example in which the metal magnetic film is inclined in the same direction as the magnetic gap.

FIG. 29 is a perspective view of a magnetic head using a non-magnetic material as a magnetic core substrate.

FIG. 30 is a characteristic diagram showing a relationship between track width and head efficiency of a magnetic head made of a non-magnetic material as a magnetic core substrate.

FIG. 31 is a characteristic diagram showing the relationship between frequency and relative output when the track width of a magnetic head made of a non-magnetic material or ferrite as a magnetic core substrate is set to 20 μm.

FIG. 32 is a characteristic diagram showing the relationship between frequency and relative output when the track width of a magnetic head made of a non-magnetic material or ferrite as a magnetic core substrate is set to 15 μm.

FIG. 33 is a characteristic diagram showing the relationship between frequency and relative output when the track width of a magnetic head made of a non-magnetic material or ferrite is set to 5 μm as a magnetic core substrate.

FIG. 34 is a perspective view showing a glass filling groove processing step, which sequentially shows steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate and a method of forming no track width regulating groove.

FIG. 35 is a perspective view showing a glass filling step, which sequentially shows steps of manufacturing a magnetic head using a method in which a non-magnetic material is used as a magnetic core substrate and a track width regulating groove is not formed.

FIG. 36 is a perspective view showing a magnetic film forming surface mirror surface processing step, which sequentially shows steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate and without forming track width regulating grooves.

FIG. 37 is a perspective view showing a step of forming a magnetic metal film and a glass film, which sequentially shows steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate without forming track width regulating grooves.

FIG. 38 is a perspective view showing a substrate bonding step, which sequentially shows steps of manufacturing a magnetic head by a method using a non-magnetic material as a magnetic core substrate without forming track width regulating grooves.

FIG. 39 is a perspective view showing a cutting, winding groove, and glass groove forming step sequentially showing steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate and not forming track width regulating grooves. .

FIG. 40 is a perspective view showing a gap bonding step, which sequentially shows steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate and a method of forming no track width regulating groove.

FIG. 41 is a perspective view showing a chip cutting step, which sequentially shows steps of manufacturing a magnetic head by a method in which a non-magnetic material is used as a magnetic core substrate and a track width regulating groove is not formed.

FIG. 42 sequentially shows steps of manufacturing a magnetic head by using a non-magnetic material as a magnetic core substrate without forming track width regulating grooves, and enlarging a glass filling portion when a magnetic film forming surface is mirror-finished. FIG.

FIG. 43 is an enlarged cross-sectional view of an essential part showing a step of manufacturing a magnetic head by a method using a non-magnetic material as a magnetic core substrate and not forming a track width regulating groove, showing a metal magnetic film formation portion in an enlarged manner is there.

FIG. 44 is an enlarged plan view of an essential part of a magnetic head in which a protective film for preventing corrosion by glass is interposed at the interface between the metal magnetic film and the fused glass.

FIG. 45 is an enlarged cross-sectional view of essential parts showing a state in which the sliding surface of the magnetic recording medium of the magnetic head in which the protective film for preventing erosion by glass is interposed at the interface between the metal magnetic film and the fused glass is worn.

FIG. 46 is a diagram showing a contact state with respect to a magnetic recording medium when a sliding surface of the magnetic recording medium of a magnetic head in which a protective film for preventing corrosion by glass is interposed at an interface between the metal magnetic film and the fused glass is worn. FIG.

FIG. 47 is an enlarged view of an essential part showing a state in which breakage in the ferrite and bubbles in the glass film are generated when the glass film and the ferrite substrate are in direct contact with each other.

[Explanation of symbols]

1, 2 ... Metal magnetic film 1a, 1b, 1c, 2a, 2b, 2c ... Magnetic metal thin film 3, 4, 5, 6 ... Ferrite substrate 7, 8 ... Magnetic core half body 9. ..Fused glass 10, 11 ... Glass film 12a, 12b, 13a, 13b ... Insulating film 16a, 16b, 17a, 17b ... Interfacial film 18, 19 ... Track width regulating groove 20, 21・ ・ ・ Winding groove 22, 23 ・ ・ ・ Winding auxiliary groove 24, 25 ・ ・ ・ Glass groove

Claims (6)

[Claims] 1. A ferrite substrate having a metal magnetic film formed thereon, and a ferrite substrate laminated on the ferrite substrate via a film made of glass,
In a magnetic head manufactured by gap-bonding a pair of magnetic core halves each having a track width regulating groove formed therein with a fused glass, the glass transition point Tg of the glass used for laminating the ferrite substrates is: A magnetic head having a glass deformation point Tc higher than that of a fused glass. 2. The glass used for laminating the ferrite substrate has a glass transition point Tg of 450 ° C. or higher and a glass deformation point Tc of 650 ° C. or lower.
The magnetic head described. 3. The viscosity of the fused glass at a given temperature within a temperature range of 500 ° C. or more and 600 ° C. or less is 1 or less.
A viscosity corresponding to any of 0 ³ Pa · s or more and 10 ⁴ Pa · s or less, and the viscosity of the fused glass at the time of fusing is 10 ⁴ Pa · s or more. Item 1. The magnetic head according to Item 1. 4. The magnetic head according to claim 1, wherein the fused glass is a PbO-based low melting point glass. 5. The magnetic head according to claim 1, wherein the track width is 15 μm or less. 6. The magnetic film according to claim 1, wherein a high melting point nonmagnetic metal film or an interface film made of an oxide material is provided between the glass used for laminating the ferrite substrates and the ferrite substrate. head.