JPS61236012A - Production of composite substrate for thin film magnetic head - Google Patents

Abstract

PURPOSE:To produce easily a laminated thin film magnetic head by interposing a specified nonmagnetic oxide ceramic sheet and a glass sheet between soft ferrite sheets whose mirror-finished principal planes are opposed to each other, laminating and forming the material by heating and compressing and then polishing the outer principal plane of ferrite. CONSTITUTION:A nonmagnetic oxide ceramic sheet 3 having a thermal expansion coefficient which differs from the thermal expansion coefficient of a soft ferrite sheet by <=1X10<-6>/deg and whose both surfaces are mirror-finished is interposed between the 2 soft ferrite sheets 1 and 2 whose mirror-finished principal planes are opposed to each other and further laminated and stuck through a glass sheet 4 having 400-850 deg.C softening point and a thermal expansion coefficient which differs from the thermal expansion coefficient of the ferrite sheet by <=1X10<-6>/deg between the soft ferrite sheet and the ceramic sheet. The material is then laminated and formed by heating the material to a temp. at which the viscosity of the glass sheet becomes 10<3>-10<7.6> poise or further the hot formed body is hydrostatically pressed. Then the outer principal plane of each soft ferrite is polished to <=200Angstrom surface roughness and a composite substrate consisting of 3 principal layers can be manufactured. A bulk-type thin film magnetic head can be thus manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a composite substrate for a thin film magnetic head used in a magnetic disk device, etc., and in particular, to magnetic recording.

A method of manufacturing a composite substrate for a thin film magnetic head on which read and erase heads can be stacked is provided.

Background Art In general, thin-film magnetic heads have excellent frequency characteristics and are manufactured using a manufacturing process based on semiconductor technology, making it possible to manufacture high-precision magnetic heads at low cost. It is considered that

Thin film magnetic heads include inductive heads used as recording and reproducing heads and magnetoresistive heads used as reproducing heads.

As shown in FIG. 6, the inductive head includes a lower core (20) made of a substrate such as soft ferrite, and a permalloy core (20) disposed on the lower core (20) through a gap.

Upper core made of sendust, or amorphous (
21), a conductor (23) such as copper disposed within an insulating layer (22) within the upper core (21), and a protective film layer (24) coated on the outside of the upper core.

As shown in FIG. 7, the magnetoresistive element head includes a substrate (25) serving as a magnetic shield material, a magnetoresistive element (26) made of permalloy disposed with a predetermined gap, and a magnetoresistive element (26) on both sides of the element [26]. The protective film layer (28) includes a yoke material [27] disposed in the protective film layer (28).

In order to create a configuration that combines recording and reproducing heads, such as tunnel-type, straddle-type, and bulk-type magnetic heads for floppy disks, it is conceivable to make the thin-film magnetic head have a two-layer structure. If the second layer thin film magnetic head is directly constructed after the first layer thin film magnetic head is created, the shape of the second layer substrate will become complicated due to the core shape of the first layer, and there is a concern that the magnetic properties will deteriorate. Ru.

Also, it is possible to provide a protective film layer between the first layer and the second thin film magnetic head, but after manufacturing the first layer magnetic head, the protective film layer is provided, and then the protective film layer is polished, etc. It is necessary to finish it into the required shape, and there is no hope of improving dimensional accuracy.
Further, there is a problem in that forming a thick protective film layer requires a large number of steps and costs.

Additionally, in order to manufacture a thin film magnetic head with a laminated structure, there is a method in which thin film magnetic heads are manufactured individually and then laminated together. Since this is a unit work, there is a problem in that it requires a large amount of man-hours and costs.

OBJECTS OF THE INVENTION In view of the current situation, an object of the present invention is to provide a method for manufacturing a substrate for a thin film magnetic head, which allows a thin film magnetic head having a laminated structure to be easily manufactured.

Structure and Effects of the Invention The present invention is characterized in that the difference between the coefficient of thermal expansion of the soft ferrite plates is 1xio between two soft ferrite plates whose mirror-finished main surfaces face each other.
A non-magnetic oxide ceramic plate having a thermal expansion coefficient of 6/deg or less and mirror-finished on both sides is interposed, and a softening point of 400 ℃ to 850℃, the difference in thermal expansion coefficient from the above soft ferrite plate is 1x 10-
These are laminated closely together through glass plates having a coefficient of thermal expansion of 8/deg or less, and the glass viscosity of the glass plates is 10/deg.
Heat to a temperature of 3 to 1 hiropoise, 0.1ki4 to 1
Laminate molding is performed by applying a pressure of 00 kcJ4, or the molded body is further subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less, and soft ferrite, A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made up of three main layers of ceramics and soft ferrite, and at least one of two soft ferrite plates with mirror-finished main surfaces facing each other. and/or a non-magnetic oxide material with a mirror-finished surface on both sides, which has a coefficient of thermal expansion of 1X 10-6/deg or less and a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the soft ferrite plate interposed between the two soft ferrite plates. A glass layer having a softening point of 400°C to 850°C and a coefficient of thermal expansion with a difference of 1×10'/deg or less from the coefficient of thermal expansion of the soft ferrite plate is adhered to at least one mirror surface of the ceramic plate, and the glass layer is The glass layers are laminated in close contact with each other on the center side, heated to a temperature such that the glass viscosity of the glass layer is 103 to 107 Il poise, and a pressing force of 0.1 layer Mi + t' to 100 h-J is applied, and the layers are laminated one after another or all at once. The molded body is then subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less to form three main layers of soft ferrite, ceramics, and soft ferrite. This is a method of manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made of a composite substrate comprising:

By the method of this invention, a composite substrate consisting of three main layers of soft ferrite, ceramics, and soft ferrite is obtained, and since this composite substrate has a ceramic layer and a glass layer mainly for lamination bonding between the soft ferrite layers, two The soft ferrite layers are electrically separated, and magnetic circuits can be formed on the soft ferrite layer surfaces on both main surfaces of the substrate.

That is, as shown in FIG. 4, an erasing head (30) is formed on one soft ferrite layer (1) surface of the composite substrate [10] according to the present invention, and a recording head (30) is formed on the other soft ferrite layer (2) surface. A thin-film magnetic head with a bulk type structure for a floppy disk having a reproducing head (31) formed thereon can be manufactured.

Further, as shown in FIG. 5, a composite substrate (1
0) one soft ferrite! A recording head [32] is formed on one side (1), and a soft ferrite layer (2) is formed on the other side.
A magnetoresistive element magnetic head having a configuration in which a reproducing head (33) is formed on the surface can be manufactured.

Based on the Drawings (Disclosure of the Invention) FIGS. 1 to 3 are assembly explanatory views showing a method for manufacturing a composite substrate according to the present invention.

In the manufacturing method shown in FIG. 1, the soft ferrite plates (IX2
) is I x 10-6 / deg
Non-magnetic oxide ceramic plate (3) with the following coefficient of thermal expansion and mirror-finished amphiboid surfaces to a surface roughness of 500A or less
and then each soft ferrite plate (1) (2)
and the ceramic plate (3), the softening point is 400℃~
At 850°C, the difference in thermal expansion coefficient from the soft ferrite plate (IX2) is IX 10-6/deg or less. Glass viscosity of plate (4) is 103~
Heat to a temperature of 1 hiropoise and heat to 54~1oo
The laminated molded product is laminated by applying a pressing force of ha, or the laminated molded body is further subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite plate (1M2) is diamond polished or mechanochemically polished, 200AJ'l.

Polished to the lower surface roughness, soft ferrite (1),
This is a manufacturing method for producing a composite substrate (10) according to the present invention, which is composed of multiple layers of glass (4), ceramics (3), glass (4), and soft ferrite (2).

The manufacturing method shown in Fig. 2 is based on one soft ferrite plate (
1) A glass layer having a softening point of 400°C to 850°C and a coefficient of thermal expansion whose difference from the coefficient of thermal expansion of the soft ferrite plate is 1X10-6/deci or less on the main surface mirror-finished to have a surface roughness of 500A or less. (5) is deposited by a glazing method or a sputtering method, and the main surface side mirror-finished to have a surface roughness of 500 A or less is opposed to the non-magnetic oxide ceramic (3) that will serve as the intermediate layer, and the glass layer (5) Heating to a temperature where the glass viscosity is 103 to 1076 poise,
Laminated and crimped by applying a pressure of 0.1 to 100 degrees,
Next, a similar glass layer (5) was applied to the other surface of this ceramic plate (3) under the above conditions, and the main surface side of the other soft ferrite plate (2) was mirror-finished to a surface roughness of 5008 or less. The glass layer (4) is laminated closely on the center side, and the glass viscosity of the glass layer (5) is 103 to 1Q7.
Heat to a temperature of J poise, 0.1ki4~1001
Laminate molding by applying a pressure of 00k', or further,
The laminated body is subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is diamond polished or mechanochemically polished to a surface roughness of 200 A or less, resulting in soft ferrite (1), Glass (5), Ceramics (3), Glass (5), Soft ferrite (
2) is a manufacturing method for producing a composite substrate (10) according to the present invention consisting of multiple layers.

In the manufacturing method shown in Figure 2, the ceramic plate (3) is first
A glass layer (5) is applied to one of the ferrite plates (1).
), and also apply the glass layer (5) to the other ferrite plate (2) and laminated and press-bond them together, etc., and the main surface and the other material to which the glass layer is applied, and the laminated assembly. The order may be appropriately selected depending on workability, efficiency, material of each layer, etc.

The manufacturing method shown in FIG. 3 is a glazing method on one side of the non-magnetic oxide ceramic plate (3).

With a sputtering method, the softening point is 400°C to 850°C,
A glass layer (5) having a coefficient of thermal expansion whose difference from the coefficient of thermal expansion of the soft ferrite plate (IX2) is 1 x 10-6 /dec+ or less is deposited, and the surface roughness of one soft ferrite plate (1) is The other soft ferrite plate (2) is placed opposite to the main surface side that has been mirror-finished to a thickness of 500 Å or less.
A glass layer (5) having similar properties is applied to the main surface mirror-finished to a surface roughness of 500A or less by a glazing method or a sputtering method, and this is applied to the ceramic plate (3).
The glass layer (5) is laminated closely on the center side of the glass layer (5), and the glass layer (5) has a glass viscosity of 103 to 107.
Heat to a temperature of 5 poise and reduce to 0.1ki4~1009. Laminate molding by applying a pressing force of J, or further hot isostatic press treatment of the laminated molded body, and then diamond polishing or mechanochemical polishing of the outer main surface of each soft ferrite plate (IX2), Composite substrate (10) according to the present invention polished to a surface roughness of 200 A or less and consisting of multiple layers of soft ferrite (1), glass (5), ceramics (3), glass (5), and soft ferrite (2). This is a manufacturing method for manufacturing.

In the manufacturing method shown in Fig. 3, the glass layer (5) is applied to the bidirectional surfaces of the ceramic plate (3) and laminated and crimped. 5)
The mating material to which the glass layer is applied and the main surface may be appropriately selected depending on the workability, the material of each layer, etc.

Preferred embodiments of the invention In this invention, the soft ferrite used is Inn Zn ferrite, 11no 21
mo1%~38mo1%, Zn06m01%~25m
01%, Fe2O3 51 mo1% to 56 mo1% is preferable, and as the NL-ZTI ferrite, NLO215 mo1% to 25 m01%, zTl○2
5 mo1%~351T101%, Fa20349 m
A composition of 01% to 59 mo1% is preferable.

In addition, soft ferrite has a theoretical density of 9939
% or more, and the bore size is 0.
．． 5. It is desirable that it be less than um.

If the oxide ceramic of the intermediate layer is a non-magnetic ceramic whose coefficient of thermal expansion is less than or equal to the coefficient of thermal expansion of the soft ferrite plate,
A&203 series, TLO2BaO series, TLO□ and 20 series,
ZrO2 type, MgO type, crystallized glass, etc. can be selected as appropriate. In addition, the porosity of ceramics is o, oi
% or less is desirable.

Furthermore, if the difference between the coefficient of thermal expansion of the ceramic and the coefficient of thermal expansion of the soft ferrite plate exceeds IX 10-6/deg, cracks will occur in the ferrite or ceramics of the composite substrate, and the magnetic properties of the ferrite will deteriorate. Undesirable.

Glass mainly used for lamination and bonding has a softening point of 400°C to 8.
At 50℃, the difference between the thermal expansion coefficient of the soft ferrite plate is
Various types of glass can be used as long as they have a coefficient of thermal expansion of 1x10-6/de() or less, such as silicic acid glass, limestone glass, and high lead glass. It is desirable to have properties such as abrasion resistance and chemical stability.

Furthermore, if the softening point of the glass is less than 400°C, the required head dimensional accuracy cannot be obtained during the heat treatment of the magnetic film in the post-process, so it cannot be commercialized, and if the softening point exceeds 850°C, the glass When forming a layer of soft ferrite and soft ferrite, heating deteriorates the magnetic properties of the soft ferrite, which is not preferable, and the softening point is set at 400°C to 850°C.

Furthermore, if the difference between the coefficient of thermal expansion of the glass and the coefficient of thermal expansion of the soft ferrite plate exceeds 1xlPe/deg, it is not preferable because it will cause cracks in the ferrite or glass of the composite substrate and will also deteriorate the magnetic properties of the ferrite. .

In this invention, when bonding glass and ferrite, heating to a temperature that makes the glass viscosity 103 to 10711 poise is more than 107I5 poise, that is, at a temperature below the softening point of glass, the adhesive strength with soft ferrite is If the temperature is weak and the glass viscosity is 103 poise, the fluidity of the glass will be too high, the intermediate glass layer will flow, making it impossible to ensure shape accuracy, and the reaction between ferrite and glass will be large, resulting in poor ferrite properties. This is because it is undesirable because it tends to cause deterioration and the formation of bubbles inside the glass.

Also, when crimping glass and ferrite, 0.1ki4~
100, 3. Loading force of Q is 0.1kq
If it is less than 4, the adhesive force is weak, and areas that are not bonded are likely to be formed at the interface between the ferrite and the glass.
If it exceeds g/cm2, the deformation will be large and it will become a ferrite.

This is because cracks are likely to occur in ceramics and glass.

Further, in the present invention, the reason why soft ferrite and glass are laminated and then subjected to hot isostatic pressing is to eliminate any air bubbles in the glass layer interposed between soft ferrite and ceramics.

As for the hot isostatic pressing treatment conditions, the atmospheric pressure is preferably 10 atm to 2000 atm. If it is less than 10 atm, the effect of reducing bubbles in the glass layer is small, and if it exceeds 2000 atm, there is no effect of reducing bubbles. However, this is not desirable because it is not suitable for mass production and increases IC costs, and the temperature conditions are such that the viscosity of the glass used is 109 poise to 10 as poise, that is, the softening point of glass -100 °C to the softening of glass. A temperature range of +100°C is preferable; at a temperature equivalent to a viscosity exceeding 109 poise, the fluidity of the glass is poor, the bubble reduction effect is small, and 1Qas
At a temperature equivalent to the viscosity of the glass without poising and swirling, the fluidity of the glass is large and the basic shape tends to be easily deformed, which is not preferable.

The hot isostatic press treatment atmosphere is 020, 01 when the soft ferrite is Ni Zn ferrite.
% to 10% Ar atmosphere is preferable, and l″In −
In the case of Zn-based ferrite, Ar atmosphere or 020
．． An atmosphere containing 1% or less of Ar is preferred.

In addition, in this invention, the reason why the surface roughness of the soft ferrite layer is limited to 200 Å or less is that a magnetic thin film is formed on this surface, and the surface roughness affects the characteristics of the thin film. A high degree of polishing is required, preferably 50 Å or less, and finishing by diamond polishing is also possible, but mechanochemical polishing is preferable to obtain higher properties.

The diamond polishing method includes: Abrasive grains: diamond, particle size of 1 f or less, lap pressure: 0.01 kCJ4 to 1 kCJ4, rotational speed: 10 m/min to 100 m/min.

Lap surface plate; preferable conditions are Sn, Ca, and cloth;
As a mechanochemical polishing method, abrasive grains: MgO, ZrO2, /V2O3, 5jD2 powder 1
Particle size 111m or less, lap pressure: 0.01 k, 34-1 kCJ4,
Rotation speed: 10m/m! n~100m/m! Sleep wrap surface plate: Preferable conditions are Sn, solder, and cloth.

The thickness of the composite substrate obtained by this invention is desirably 5+ nm or less, taking into consideration the intended use, alignment during pattern formation, ease of processing during mass production, etc.
Preferably, it is 0.1 mm to 2 mm.

In addition, the thickness ratio between the ceramic layer and the soft ferrite layer of the composite substrate is appropriately selected depending on the application and usage method, but ceramic thickness/soft ferrite thickness =
0.01-1 is preferable.

In manufacturing composite substrates, the glass layer thickness is 0.05 mm.
In the above, a glass plate can be used, but since it is difficult to manufacture a glass plate with a thickness of less than 0.05 mm, a glazing method or a sputtering method is applied to the mirror-polished main surface of soft ferrite or ceramics.

A glass layer can be deposited by a method such as the above, and the glass layer and ferrite or ceramics may be welded together, or the glass layers may be welded to each other, and soft ferrite and ceramics can be easily bonded by such a method.

Examples Example 1 Softening point 700°C 1 Coefficient of thermal expansion 100 x 10-7 /
deg, 50, 81 TIIr+X Both sides of a silicate glass plate measuring 50.8 mm x 0.07 mm thick were polished to a surface roughness of 500 Å or less by mirror polishing.

NLO217.8not%, ZnO32.5mo1%,
Fe2O349,7mo1% composition, thermal expansion coefficient 92X
10-7 /de(], NL ZTI series huerite material thickness 0.4+ with dimensions of 550.8mm x 508mm
+nr+, and the cut surface was mirror polished to a surface roughness of 500 Å or less. ,.

Also, 50.8mm x 50.8mm x thickness 0.2mtn
By mirror polishing both sides of the Ti12-BaO plate of the same size,
Finished with a surface roughness of 500 Å or less.

After that, soft ferrite, glass, ceramics, glass, and soft ferrite were layered in this order in an atmospheric atmosphere.
It was heated to 900°C (temperature corresponding to the glass viscosity of 105 poise) and compressed with a pressing force of 0.5ki4.

The soft ferrite surface of the obtained multilayer composite substrate material is
It was finished to a surface roughness of 50 by mechanochemical polishing under the following conditions. The thickness of the obtained composite substrate was 0.7 mm, and the thickness of each soft ferrite was 0.25 mm.

Mechanochemical polishing method Using suspension in pure water Abrasive grains: 5LO2 powder 1 particle size 200 people, Lap pressure crab o, 1x4, Rotation speed; 50m/min, Lap surface plate; Sn.

Example 2 tlno 2B, 7m01%, ZnO20,8mo1%
, Fe2O352,5mo1% composition, thermal expansion coefficient 106
X10-7/deg, 50.8mtnX50.8+r
A lln Zn-based ferrite material with ++n dimensions was cut to a thickness of 0.41 TIIT+, and the surface roughness was finished to 0.5 Am.

Also, 50.8mm x 50.8mm x thickness 0.21TI
Both sides of a Tj 02-BaO plate with an IT1 dimension were polished to a surface roughness of 500A or less by mirror polishing.

After that, softening point is 560℃, thermal expansion coefficient is 98X 10-7
/deg lead is silicate glass mesh size #3
50 paste was screen printed on the mirror surface of the ceramic plate using a #150 screen, held at 400°C in the atmosphere for 1 hour, and further held at 850°C for 15 minutes for glazing. A glass layer of 2011 m thick was formed, and then the glass surface was mirror polished to remove 5 layers to give a surface roughness of 5008 or less.

The mirror polished surface of ceramic glass was stacked on the mirror surface of two ferrite sheets, and heated at 800°C in an N2 atmosphere.
(Temperature corresponding to the above-mentioned glass viscosity of 104 poise) and press-bonded with a pressing force of 0 to 5 ks4.

Then, the laminate was subjected to hot isostatic press treatment in which the laminate was held at 600''C (temperature corresponding to the viscosity of glass 107 poise) for 30 minutes at a pressure of 500 atm in an Ar atmosphere containing 0.002% 02. was applied to eliminate all air bubbles in the glass.

The soft ferrite surface of the obtained multilayer composite substrate material was finished to a surface roughness of 50A by mechanochemical polishing under the following conditions. The thickness of the obtained composite substrate was 0.7 mm, and the thickness of each soft ferrite was 0.25 mm.

Mechanochemical polishing method using abrasive grains suspended in pure water; Mgo powder 1 diameter average 0 μm, lap pressure crab 0.1 kt, rotation speed, 50 m/min.

Lap surface plate; 5TI0

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are assembly explanatory views showing a method for manufacturing a composite substrate according to the present invention. 4 and 5 are explanatory diagrams of a thin film magnetic head using a composite substrate according to the present invention. 6 and 7 are explanatory diagrams of a thin film magnetic head using a conventional substrate. 1.2...Soft ferrite plate, 3...Ceramics, 4...Glass plate, 5...Glass layer, 10...
Composite substrate, 30... Erasing head, 31... Recording and reproducing head, 32... Recording head, 33... Reproducing head. Fig. 4 Fig. 5 @ Fig. 6 Fig. 7 Voluntary Proceeding Paperback October 4, 1985 1. Indication of the Case 1985 Patent Application No. 77130 2. Title of Invention Composite substrate for thin film magnetic head Manufacturing method 3, relationship with the case of the person making the amendment Applicant 4, "Claims" in the attorney's specification, 1゜The scope of claims from page 1, line 5, page 5, line 2 of the specification is as follows: Correct as shown below. Between two soft ferrite plates with their mirror-finished main surfaces facing each other, there is a difference in thermal expansion coefficient of 1x 1 from the above soft ferrite plate.
A non-magnetic oxide-based ceramic plate with a thermal expansion coefficient of 0-6/deg or less and mirror-finished surfaces is interposed, and a softening point of 400°C is interposed between the soft ferrite plate and the non-magnetic oxide-based ceramic plate. ℃ to 850 ℃, the difference between the thermal expansion coefficient of -1,7 ftoferite plate is 1xio-s/d
Glass plates having a coefficient of thermal expansion equal to or less than eq are laminated in close contact, heated to a temperature at which the glass viscosity of the glass plates becomes 10 to 10 mm, and laminated by applying a pressure of 0.1 to 300 kg/cm2. 1. A method for manufacturing a composite substrate for a thin-film magnetic head, which comprises polishing the outer main surface of each soft ferrite to a surface roughness of 200 A to form a composite substrate consisting of ferrite, ceramics, and soft ferrite layers. 2 Between two soft ferrite plates with mirror-finished main surfaces facing each other, the difference in thermal expansion coefficient from the above soft ferrite plate is 1X10.
A non-magnetic oxide ceramic plate with a coefficient of thermal expansion of -6/de (I or less and mirror-finished on both sides) is interposed, and a softening point between the soft ferrite plate and the non-magnetic oxide ceramic plate is At 400°C to 850°C, the difference in thermal expansion coefficient from the soft ferrite plate is 1x10-6.
The glass plates are laminated closely together through glass plates having a coefficient of thermal expansion of less than /deg, so that the glass viscosity of the glass plates is 10
Heat to a temperature of 3 to 1076 voices, 0.1kL4
Laminate molding is performed by applying a pressure of ~100h4, the laminated molded body is subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less to form soft ferrite, ceramics. A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made of three main layers of soft ferrite. 3 The mirror surface of at least one of two soft ferrite plates whose mirror-finished main surfaces face each other and/or The difference in coefficient of thermal expansion of the soft ferrite plate interposed between the two soft ferrite plates is 1X 10"6 /deQ At least one mirror surface of a non-magnetic oxide ceramic plate having the following coefficient of thermal expansion and having mirror-finished surfaces on both sides has a softening point of 400°C to 850°C and a difference of 1x from the coefficient of thermal expansion of the soft ferrite plate. A glass layer having a thermal expansion coefficient of 10-6 /deg or less is deposited, the glass layer is laminated closely to the center side, and heated to a temperature at which the glass viscosity of the glass layer becomes 103 to 1Q7B voids,
Applying pressure of o, nc = i4 to 1ooH, the layers are laminated one after another or all at once, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 A or less to form soft ferrite, A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made of three main layers of ceramics and soft ferrite. 4 The mirror surface of at least one of two soft ferrite plates whose mirror-finished principal surfaces face each other, and/or The difference in thermal expansion coefficient between the two soft ferrite plates interposed between the two soft ferrite plates is lX10'''6/deg. At least one mirror surface of a non-magnetic oxide ceramic plate having the following coefficient of thermal expansion and having mirror-finished surfaces on both sides has a softening point of 400°C to 850°C and a difference in thermal expansion coefficient from the soft ferrite plate of IX 10. A glass layer having a coefficient of thermal expansion of -6/deg or less is applied, the glass layer is laminated closely to the center side, and heated to a temperature such that the glass viscosity of the glass layer becomes 103 to IQ7.6 poise, and the glass layer is heated to a temperature such that the glass viscosity of the glass layer becomes 103 to IQ7.6 poise. Applying a pressure of 94 to 1 kg to 100 mm, the laminated body is laminated one after another or all at once, and the laminated body is subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is A method for manufacturing a composite substrate for a thin-film magnetic head, characterized by polishing the surface to a roughness and forming a composite substrate consisting of three main layers of soft ferrite, ceramics, and soft ferrite.'' 2, Specification, page 5, 17
Gyozuki's F "There is a magnetoresistive element head" is corrected to "There is a magnetoresistive element head, etc.". 3. On page 6, line 9 of the specification cylinder, amend "built in" to "built in." 4. Amend "electrically" to "magnetically" on page 10, line 4 of the specification. 5. “Glass layer (4)” on page 12 of the specification, lines 16 to 17
)" to F glass layer (May. 6. Correct "K2O" on page 15, line 19 of the specification cylinder to "Ca0J." 7. Correct "Glass and ferrite" on page 17, line 7 of the specification. Correct it to "Glass, ceramics and ferrite." 8. Correct J for "soft ferrite" on page 17, line 10, blank line 11 to "J for soft ferrite and ceramics." 9. Specification, page 17 10. Correct “Glass and ferrite J” on page 17, line 17 of the specification to “Glass, ceramics, and ferrite J.” 11. Specification "Ferrite and glass" on page 17, line 19 of the specification is corrected to "ferrite and ceramics and glass." 13. From page 18, line 20 of the specification tube to page 19, line 1, ``basic'' is corrected to ``substrate.''

Claims (1)

[Claims] 1. Between two soft ferrite plates whose mirror-finished main surfaces face each other, the difference in thermal expansion coefficient from the soft ferrite plate is 1×10.
^-^ A non-magnetic oxide ceramic plate with a thermal expansion coefficient of 6/deg or less and mirror-finished on both sides is interposed, and a softening point is set between the soft ferrite plate and the non-magnetic oxide ceramic plate. At 400℃ to 850℃, the difference in thermal expansion coefficient from the above soft ferrite plate is 1×10^-^
These are laminated and adhered via glass plates having a coefficient of thermal expansion of 6/deg or less, so that the glass viscosity of the glass plates is 10
＾3〜10＾7＾. ^Heat to a temperature of 6 poise, 0
．． Laminate molding is performed by applying a pressure of 1 kg/cm^2 to 100 kg/cm^2, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less to form soft ferrite, ceramics, and soft ferrite. A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made up of three main layers. 2 Between two soft ferrite plates with their mirror-finished main surfaces facing each other, the difference in thermal expansion coefficient from the soft ferrite plate above is 1×10.
^-^ A non-magnetic oxide ceramic plate with a thermal expansion coefficient of 6/deg or less and mirror-finished on both sides is interposed, and a softening point is set between the soft ferrite plate and the non-magnetic oxide ceramic plate. At 400℃ to 850℃, the difference in thermal expansion coefficient from the above soft ferrite plate is 1×10^-^
These are laminated and adhered via glass plates having a coefficient of thermal expansion of 6/deg or less, so that the glass viscosity of the glass plates is 10
＾3〜10＾7＾. ^Heat to a temperature of 6 poise, 0
．． Laminate molding is performed by applying a pressure of 1 kg/cm^2 to 100 kg/cm^2, and the laminated molded body is subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is
A method for manufacturing a composite substrate for a thin-film magnetic head, which comprises polishing the composite substrate to a surface roughness of Å or less to form a composite substrate consisting of three main layers of soft ferrite, ceramics, and soft ferrite. 3 The mirror surface of at least one of two soft ferrite plates whose mirror-finished main surfaces face each other and/or the difference in coefficient of thermal expansion of the above-mentioned soft ferrite plate interposed between the two soft ferrite plates is 1×10^-^ A non-magnetic oxide ceramic plate having a thermal expansion coefficient of 6/deg or less and mirror-finished on both sides has a softening point of 400°C to 850°C and a difference in thermal expansion coefficient from that of the soft ferrite plate. is coated with a glass layer having a coefficient of thermal expansion of 1×10^-^6/deg or less, and the glass layer is laminated closely to the center side, so that the glass viscosity of the glass layer is 10^3 to 10^7^. ^Heat to a temperature of 6 poise, 0.1kg/cm^2 to 100kg/cm^
Applying the pressure of step 2, the layers are laminated one after another or all at once, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less to form the three main layers: soft ferrite, ceramics, and soft ferrite. A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made up of layers. 4 The mirror surface of at least one of two soft ferrite plates whose mirror-finished principal surfaces face each other and/or the difference in thermal expansion coefficient of the above-mentioned soft ferrite plate interposed between the two soft ferrite plates is 1×10^-^ A non-magnetic oxide ceramic plate having a thermal expansion coefficient of 6/deg or less and mirror-finished on both sides has a softening point of 400°C to 850°C and a difference in thermal expansion coefficient from that of the soft ferrite plate. is coated with a glass layer having a coefficient of thermal expansion of 1×10^-^6/deg or less, and the glass layer is laminated closely to the center side, so that the glass viscosity of the glass layer is 10^3 to 10^7^. ^Heat to a temperature of 6 poise, 0.1kg/cm^2 to 100kg/cm^
Applying the pressure of step 2, the layers are laminated one after another or all at once, and the laminated body is subjected to hot isostatic pressing, and then the outer main surface of each soft ferrite is polished to a surface roughness of 200 Å or less. A method for manufacturing a composite substrate for a thin film magnetic head, characterized in that the composite substrate is made of three main layers of soft ferrite, ceramics, and soft ferrite.