JPH03150712A - Step up transformer for multitruck magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To improve a space factor with the compact transformer by holding and integrating magnetic cores for plural pieces for step up transformers apart about a distance at which the cores do not magnetical interference with each other on nonmagnetic base bodies. CONSTITUTION:A step up assembly 1 is combined with plural pieces of the unit step up transformers 2. Magnetic material layers 4, 4 of a prescribed thick ness are deposited and formed on the side walls of grooves 3a of an approxi mately semicircular shape bored on both sides at the opposite ends of the nonmagnetic base bodies 3, 3. The end faces of these layers 4, 4 which faces oppose to each other, are magnetically coupled to each other, by which the plural annular magnetic cores 5 are formed and are spaced form each other to the extent of not receiving the magnetical interference with each other. The base bodies 3, 3 are fixed to each other. The assembly 1 is reduced in size as far as possible by forming the cores 5 in such a manner. The respective unit transformers having good high-frequency characteristics are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a step-up transformer for a multi-track magnetic head and a method for manufacturing the same, and particularly to a step-up transformer for a multi-track magnetic head that can improve assembly workability. This invention relates to a transformer and its manufacturing method.

[Prior Art] Recently, the capacity of magnetic memories such as floppy disks and hard disks has been increasing, and metal floppy disks with increased density of magnetic material have been developed as magnetic recording media. The signals used have increased linear recording density and/or track density. Among the methods for increasing the recording density, the latter track density can be achieved relatively easily by narrowing the track width of the magnetic head, and therefore, efforts are currently being made to narrow the track of the magnetic head. As the track density of floppy disks and the like increases, the floppy disk drive requires a high-precision track servo, so servo signals are recorded on the floppy disk in advance and then transferred using a magnetic head. A system has been developed that reads the information and applies track servo.

By the way, from the viewpoint of mass production, it is advantageous to use a multi-track magnetic head capable of simultaneously recording signals on a plurality of tracks as the magnetic head for recording the above-mentioned servo signals. However, in multi-track magnetic heads, the number of coil turns wound around each unit magnetic head chip is limited, making it impossible to obtain the necessary and sufficient recording/playback characteristics. A step-up transformer is often attached to do this.

FIG. 9 is a perspective explanatory view showing such a conventional multi-track magnetic head and a step-up transformer.

In FIG. 9, a multi-track magnetic head is generally indicated by the reference numeral 50, and in the illustrated example, four unit magnetic head chips 51 and a non-magnetic material ( For example, a spacer 52 made of ceramic such as barium titanate is provided. Each unit magnetic helad chip 51 is stacked and combined with a spacer 52 interposed therebetween so that its working gap 51 is aligned in a straight line, and both members 51, 52 are fixed together with appropriate adhesive means. 54 is a head coil wound around each unit magnetic head chip 51.

Incidentally, it is desirable that the interval between the unit magnetic head chips 51 be as small as possible in order to increase the track density, reduce the number of contact surfaces with the magnetic recording medium, and improve the contact condition. Therefore, this space factor requirement is met. Therefore, the number of windings of the head coil 54 is restricted, and necessary and sufficient recording/reproduction characteristics cannot be obtained.
As shown in the figure, for example, a ring-shaped core 61 made of a magnetic material (a ring-shaped core made of ferrite, etc.) includes a head-side transformer coil 62 with a small number of turns, and an amplifier-side transformer coil 63 with a large number of turns. A step amplifier transformer 60 formed by winding the magnetic head 51 is attached to each unit magnetic head chip 51. Then, the head-side transformer coil 62 of the step-up transformer 60 and the head coil 54 are connected, and the amplifier-side transformer coil 63 is connected to an amplifier-side circuit system (not shown), and the windings of the step-up transformer 60 are connected. The head output was amplified as much as necessary according to the line ratio.

[Problems to be Solved by the Invention] However, the step-up transformer 60 according to the prior art described above has a configuration in which an independent step-up transformer 60 is attached to each unit magnetic head chip 51, so that each step-up transformer It is difficult to compactly mount 60 all at once on a head carriage or to integrate it with a multi-track magnetic head, which generally results in poor assembly workability and a lack of mass productivity.

The present invention was made in view of the above points, and its purpose is to be compact and have a good space factor.
An object of the present invention is to provide a step-up transformer for a multi-track magnetic head that has excellent assembly applicability and a method for manufacturing the same.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a step-up transformer to be attached to a multi-track magnetic head capable of simultaneously recording and reproducing information on a plurality of tracks on a magnetic recording medium. A plurality of magnetic cores for a step-up transformer, which are made of magnetic material and form a closed magnetic circuit, are held and integrated on a non-magnetic base at a distance that prevents magnetic interference from each other. .

In addition, in order to achieve the above-mentioned object, the present invention provides a method for manufacturing a step-up transformer to be attached to a multi-track magnetic head capable of simultaneously recording/reproducing information on a plurality of tracks on a magnetic recording medium. a groove forming step of forming a plurality of substantially parallel grooves for regulating the shape of the magnetic core; and a magnetic material having high magnetic permeability and high saturation magnetic flux density by physical vapor deposition on one surface of the non-magnetic substrate on which the grooves are formed. a magnetic material layer forming step to form a layer, a polishing step to flatten the surface on which the magnetic material layer is formed to expose the upper plane of the non-magnetic substrate, and a polishing step to expose the upper plane of the non-magnetic substrate after the polishing step has been completed. The method further includes a joining step of joining and integrating the base bodies so that the end surfaces of the magnetic material layers are in close contact with each other and face each other.

[Function] For example, a plurality of grooves with approximately semicircular cross sections (grooves for regulating the shape of the magnetic core) are formed in a plate-shaped nonmagnetic base material (base material that becomes a nonmagnetic base) made of ceramics, nonmagnetic metal, etc. By sputtering etc. on the non-magnetic base material in which the grooves are formed, CO is
A magnetic material layer (a magnetic material layer that serves as the half core of the step-up transformer) is formed from a magnetic alloy material having high magnetic permeability and high saturation magnetic flux density, such as base amorphous magnetic alloy, sendust, permalloy, etc., and then , the surface on which the magnetic material layer is formed is polished to expose the upper plane of the non-magnetic base material.

Subsequently, as described above, the two non-magnetic base materials, each having a magnetic material layer with a half-core core formed only on the wall surface of the groove, are polished by depositing a magnetic material layer on them as described above. The two non-magnetic base materials are aligned so that their end faces are in close contact with each other and face each other, and the two non-magnetic base materials are joined and integrated by appropriate adhesive means, thereby forming a closed magnetic path with the corresponding magnetic material layers. After a while, the two became one.
A non-magnetic base material is sliced in a direction perpendicular to the grooves described above to separate it into multiple blocks, thereby creating a block in which ring-shaped magnetic cores are magnetically separated and arranged in parallel at predetermined intervals. is obtained, and then a composite/integrated step-up transformer is fabricated by applying primary and secondary windings to each magnetic core.

In the step-up transformer assembly manufactured in this manner, the magnetic cores for a plurality of step-up transformers forming a closed magnetic circuit are held on a non-magnetic substrate at a distance sufficient to prevent magnetic interference from each other. Because it is compactly integrated.

Assembling the multi-track magnetic head and amplifier circuit is simplified, greatly improving productivity. Also,
Since it is compactly integrated, it can be easily integrated into a head carriage, for example.

[Example] The present invention will be described below with reference to illustrated embodiments.

FIG. 1 is a perspective view showing a step-up transformer for a multi-track magnetic head according to a first embodiment of the present invention.

In the figure, a step-up transformer assembly (hereinafter referred to as SUT assembly 1) is generally indicated by the symbol 1, and in this embodiment, it is applied to a 4-track type multi-track magnetic head. Four unit step-up transformers 2 (hereinafter referred to as units 5UT2) are combined to form a SUT assembly l.

In Fig. 1, numerals 3 and 3 are non-magnetic substrates made of, for example, ceramic materials such as barium titanate and photoceram, and non-magnetic metal materials such as copper and aluminum. A magnetic material layer (half core) 4.4 having a predetermined thickness is adhered and formed on the wall surface of the circular groove 3a. The corresponding end faces of the magnetic material layers 4, 4 are magnetically coupled, thereby forming four ring-shaped magnetic cores 5 (ring-shaped closed magnetic circuit) and mutually They are spaced apart enough to avoid magnetic interference. The magnetic material layer 4 is, for example.

It is made of a magnetic alloy material having high magnetic permeability and high saturation magnetic flux density, such as amorphous Co--Nb--Zr magnetic alloy, sendust, permalloy, etc., and is formed to a predetermined thickness by a known physical vapor deposition method such as sputtering. Note that the nonmagnetic substrate 3,
The three members are properly fixed to each other by adhesive means (for example, resin adhesive).

With such a thin film forming technique, the magnetic material layer 4, that is, the magnetic core 5
By forming the SUT assembly 1, it is possible to make it as small as possible. In this case, if a non-magnetic metal with low resistivity is used as the non-magnetic base 3, a magnetic shielding effect can be obtained, and each The spacing between the magnetic cores can be further narrowed, making it possible to further reduce the overall size. Furthermore,
By using the magnetic alloy of the above-mentioned materials, each unit 5UT2 with good high frequency characteristics can be obtained.

Further, 6 is a head-side transformer coil, and 7 is an amplifier-side transformer coil, which are wound interlinked with the magnetic core 5 of each unit 5UT2 using the circular hole formed by the ring-shaped magnetic core 5. Therefore, the number of turns of the amplifier side transformer coil 7 is increased by a predetermined number than the number of turns of the head side transformer coil 6, depending on the desired degree of transformer amplification.

In the SUT assembly l having the above-mentioned configuration, each of the head-side transformer coils 6 is connected to the head coil of the corresponding unit magnetic head of the multi-track magnetic head by appropriate means, and each of the amplifier-side transformer coils is connected to the head coil of the corresponding unit magnetic head of the multi-track magnetic head. 7 are respectively connected to the amplifier circuit system by appropriate means, thereby amplifying the head output with an amplification factor corresponding to the winding ratio of both transformer coils 6.7.

In this way, in the present invention, since the plurality of units 5UT2 are compactly integrated in a state of being magnetically isolated, the S
The installation of the UT assembly l itself is simple and has a good space factor, and the installation and assembly work efficiency is greatly improved compared to the conventional method.

The second UgJ is a perspective view of the essential parts showing one example of the mounting form of the SUT assembly l. In the figure, the SUT assembly l is mounted together with a multi-track magnetic head on a helad carriage of a floppy disk drive. An example is shown.

In the figure, IO is a Herad carriage, to which a multi-track magnetic head 20 is attached via a gimbal spring 11. This multi-track magnetic head 20 has 4
one unit magnetic head chip 21 and an adjacent head chip 2
a spacer 22 made of a non-magnetic material interposed between the two sliders 23.2 and sliders 23.2 made of a non-magnetic material attached to both sides.
The working gaps 25, which are aligned on a straight line, are arranged at equal intervals with a predetermined pitch. Further, a head coil 26 is wound around each unit magnetic helad chip 20, and each head coil 26 is connected to a conductive pattern on a first flexible printed wiring board 12 attached to the head carriage 10. . The SUT assembly 1 is fixed on the head carriage 10 by appropriate adhesive means, and the head-side transformer coil 6 of each unit 5UT2 is connected to the first
It is connected to the conductive pattern of the flexible printed wiring board 12, thereby connecting the corresponding head coil 26 and the head-side transformer coil 6. Further, the amplifier side transformer coils 7 of each unit 5UT2 are respectively connected to the conductive patterns of the second flexible printed wiring board 13.
It is connected to an amplifier circuit outside the head carriage 10 via.

According to the example shown in FIG. 2, the SUT assembly can be compactly mounted on the head carriage lO together with the multi-track magnetic head 20, and the step-up transformer for the multi-track magnetic head applied to this kind of floppy disk can be used. The number of SUT assemblies shown in FIG. It is also possible to attach it outside the head carriage IO.

Next, according to FIG. 3, the SU of the first embodiment shown in FIG.
A method of manufacturing the T assembly 1 will be explained.

First, as shown in FIG. 3(a), a plate-shaped non-magnetic base material (base material that will become the non-magnetic substrate 3) 30 made of barium titanate is prepared.
A plurality of (four in this example) grooves 30a having a substantially semicircular cross section for regulating the shape of the magnetic core are formed by machining in parallel on one surface of the zero-order [1! As shown in I(b),
On the surface of the non-magnetic base material 30 in which the grooves 30a have been formed, the above-described magnetic material layer 4 made of, for example, an amorphous Co-Nb-Zr magnetic alloy is deposited and formed by sputtering. As shown in C), the surface on which the magnetic material layer 4 was formed was polished flat until the upper plane of the non-magnetic base material 30 was exposed, so that the magnetic material layer 4 was provided only on the wall surface of the groove 30a. A non-magnetic base material 30 is produced.

Subsequently, the two non-magnetic base materials 30, 30 obtained as shown in FIG. 3(C) are butted so that the end surfaces of the corresponding magnetic material layers 4 are butted together, as shown in FIG. 3(d). Align them so that they are in close contact and secure them together with resin adhesive. After that,
The thus integrated member is sliced at a predetermined thickness in a direction perpendicular to the groove 30a (at the dotted line position in FIG. 3D) and divided into a plurality of blocks. Each of the divided blocks consists of the non-magnetic base 3 shown in FIG.
, 3 corresponds to a member in which the ring-shaped magnetic core 5 is disposed, and by winding the head-side transformer coil 6 and the amplifier-side transformer coil 7 around the magnetic core 5, the SUT shown in the first figure can be obtained. There will be a number of assemblies to be assembled.

FIG. 4 is an explanatory diagram showing the main steps of a method for manufacturing a step-up transformer (SUT assembly) for a multi-track magnetic head according to a second embodiment of the present invention.

In this example, the method shown in FIG. 3 (
The steps up to step b) are completely the same, and the magnetic material layer 4 is formed on the surface of the non-magnetic base material 30 on which the #8 groove 30a is formed. Next, as shown in FIG. 4(a). As shown in FIG. 2, bonding glass 31 is filled on the surface on which magnetic material layer 4 is formed. This bonding glass 31 is made of low melting point glass, as shown in FIG. As shown in (b).

The surface to which the bonding glass 31 is applied is polished flat until the upper plane of the nonmagnetic base material 30 is exposed.

At this time, since the bonding glass 31 protects the magnetic material layer 4 within the groove 30a, the magnetic material layer 4 is not damaged, which is convenient. Subsequently, as shown in FIG. 4(b), the remaining glass 31 is removed by mechanical cutting, leaving only a small amount of the bonding glass 31 filled in the groove 30a. As shown in FIG. 4(C), the two non-magnetic base materials 30, 30 are aligned so that the end surfaces of the corresponding magnetic material layers 4 butt and come into close contact with each other, and are joined together by the bonding glass 31. stick.

Thereafter, the thus-integrated member is sliced at a predetermined thickness (sliced at the dotted line position in FIG. By winding the head side transformer coil 6 and amplifier side transformer coil 7 around each block, the SU
A T-assembly assembly will be obtained.

In addition, in this embodiment, a magnetic field H is applied in a direction parallel to the groove 30a (in the direction of the arrow shown in the figure) during the filling of the bonding glass 31 shown in FIG. 4(a) and the heat treatment during bonding shown in FIG. 4(C). When this voltage is applied, the axis of easy magnetization of the magnetic material layer 4 is guided in a direction perpendicular to the magnetic path direction, so that the magnetic permeability in the magnetic path direction increases and the frequency characteristics of each unit 5UT2 become good.

FIG. 5 is an explanatory diagram showing a part of the manufacturing process of a step-up transformer (SUT assembly) for a multi-track magnetic head according to a third embodiment of the present invention.
In the non-magnetic matrix 30 in which the magnetic material M4 is formed in the groove 30a,
A bonding reinforcement 11 (glass filling groove) 30b is formed in the middle of the groove 30a, and the bonding glass 31 filled in the bonding reinforcing groove 30b firmly bonds the two non-magnetic base bodies 30 to each other. It is. Bonding by the bonding glass 31 filled in such a bonding reinforcing groove 30b,
By adding to the first embodiment or the second embodiment,
The reliability of joining can be further improved.

FIG. 6 shows a step-up transformer (SUTffi three-dimensional) for a multi-track magnetic head according to a fourth embodiment of the present invention.
In this embodiment, the magnetic material layer 4A formed on the wall surface of the groove 3a of the non-magnetic substrate 3 (the groove 30a of the non-magnetic base material 30) is formed by using the non-magnetic interlayer material 32. It has a multilayer structure in which layers are sequentially laminated through the magnetic core to reduce eddy current inside the magnetic core and reduce electromagnetic conversion loss. In this case, the thickness t of the single layer of the magnetic material layer 4A is determined by the skin depth depending on the material of the magnetic material layer 4A.

Here, in each of the embodiments described above, the groove 3a of the non-magnetic substrate 3 (the groove 30a of the non-magnetic base material 30) is made approximately semicircular, and the magnetic core 5 is annular. For example, as in the fifth embodiment of the present invention shown in FIG.
A magnetic material layer 4 may be formed in the groove 30a-1 (3a-1) having a rectangular cross section to form a rectangular magnetic core 5.
When the rectangular magnetic core 5 (magnetic material layer 4.4) is formed by physical vapor deposition, the film thickness becomes thinner at the hanging wall of the groove 3a-1 (30a-1), so the present invention shown in FIG. As in the sixth embodiment, the substantially trapezoidal groove 3a-2 (30a-2) may be formed, and the magnetic material layer 4 may be uniformly formed on the side wall of the groove.

Although the present invention has been described above with reference to the illustrated embodiments, those skilled in the art can make various modifications without departing from the spirit of the present invention.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a step-up transformer for a multi-track magnetic head that is compact, has a good space factor, and has excellent assembly applicability, and a method for manufacturing the same, and has great industrial value. is huge.

[Brief explanation of the drawing]

1 to 8 relate to each embodiment of the present invention, FIG. 1 is a perspective view showing a step-up transformer for a multi-track magnetic head according to the first embodiment of the present invention, and FIG.
The installation of the step-up transformer assembly of the embodiment is a perspective view of the essential parts showing one example of the form, FIG. 3 is an explanatory diagram showing the manufacturing method of the step-up transformer assembly of the first embodiment, and FIG. FIG. 5 is an explanatory diagram showing the main steps of a method for manufacturing a step-up transformer for a multi-track magnetic head according to a second embodiment of the invention, and FIG. An explanatory diagram showing a part of the manufacturing process, FIG. 6 is an enlarged explanatory diagram of the main part of a step-up transformer for a multi-track magnetic head according to a fourth embodiment of the present invention, and FIG. 7 is an explanatory diagram showing a fifth embodiment of the present invention. FIG. 8 is an enlarged explanatory diagram of essential parts of a step-up transformer for a multi-track magnetic head according to the sixth embodiment of the present invention, and FIG. FIG. 2 is a perspective explanatory view showing a track magnetic head and a step-up transformer. l...Step up transformer assembly (SUT
Assembly), 2...Unit step-up transformer (unit 5UT), 3...Nonmagnetic base, 3a, 3
a-1, 3a-2... Groove for regulating magnetic core shape, 4... Magnetic material layer, 5... Magnetic core %
6...Head side transformer coil, 7...
・Amplifier side transformer coil, lO...Head carriage, 11...Gimbal spring, 12...
...First flexible printed wiring board, 13...
...Second flexible printed wiring board, 20...
・Multi-track magnetic head, 2I・old unit magnetic head chip, 22・・・spacer, 23.24・
...Slider, 25...Operating gap,
26...Head coil, 30...Nonmagnetic base material, 30a, 30a-1, 30a-2...
Groove for regulating the shape of the magnetic core, 30b... Bonding reinforcement groove (groove for glass filling). 31...Glass for bonding, 32...Nonmagnetic interlayer material. IF5 Figure 1: Step-up transformer assembly 2: j1st step-up transformer 3: Non-! Last name 14 lines 4: m material layer 5: a, air core 6: to / shi adjacent trasis coil 7: 7 Hupu monk J transformer coil I2il 1F3 figure 4m figure 5 figure 6s figure 7 figure 8) (

Claims (9)

[Claims] (1) In a step-up transformer to be attached to a multi-track magnetic head capable of simultaneously recording and reproducing information on multiple tracks on a magnetic recording medium, a plurality of step-up transformers made of magnetic material and forming a closed magnetic circuit are used. A step-up transformer for a multi-track magnetic head, characterized in that magnetic cores are held and integrated with a non-magnetic base at a distance that prevents magnetic interference from each other. (2) In claim 1, the magnetic core for the step-up transformer is made of a magnetic material layer having high magnetic permeability and high saturation magnetic flux density formed by physical vapor deposition on the non-magnetic substrate. A step-up transformer for multi-track magnetic heads featuring: (3) A step-up transformer for a multi-track magnetic head according to claim 2, wherein the magnetic material layer has a multilayer structure with a nonmagnetic material layer interposed therebetween. (4) A step-up transformer for a multi-track magnetic head according to claim 1, wherein the step-up transformer for a multi-track magnetic head is mounted on a head carriage together with the multi-track magnetic head. (5) In claim 4, a head coil wound around each unit magnetic head chip of the multi-track magnetic head and a head-side transformer coil wound around each magnetic core of the step-up transformer include: A step-up transformer for a multi-track magnetic head characterized in that compatible parts are connected to each other via a flexible printed wiring board. (6) In a method for manufacturing a step-up transformer to be attached to a multi-track magnetic head capable of simultaneously recording and reproducing information on multiple tracks on a magnetic recording medium, a groove for regulating the shape of the magnetic core is formed on one surface of a non-magnetic substrate. a step of forming a plurality of grooves in parallel, and a step of forming a magnetic material layer of forming a magnetic material layer having high magnetic permeability and high saturation magnetic flux density by physical vapor deposition on one surface of the non-magnetic substrate in which the grooves are formed. , a polishing step of polishing the surface on which the magnetic material layer is formed flat to expose the upper plane of the non-magnetic substrate, and polishing the two non-magnetic substrates after the polishing step by polishing the end surfaces of the magnetic material layers of each other. A method for manufacturing a step-up transformer for a multi-track magnetic head, comprising a step of joining and integrating the transformers so that they are in close contact with each other and face each other. (7) In claim 6, a glass deposition step of depositing and filling bonding glass onto the magnetic material layer after the magnetic material layer forming step, and a glass deposition step of depositing and filling the bonding glass on the magnetic material layer after the polishing step, A step-up for a multi-track magnetic head, further comprising a step of removing a portion of the glass for bonding, leaving only a small amount of the bonding glass remaining, and bonding in the bonding step is performed by the glass. Transformer manufacturing method. (8) A step-up transformer for a multi-track magnetic head according to claim 7, characterized in that an external magnetic field is applied in the direction in which the grooves are formed during heat treatment in the glass adhesion step and the bonding step. Production method. (9) In claim 6, a glass filling groove is formed between the grooves for regulating the shape of the magnetic core, and the bonding in the bonding step is performed by the bonding glass filled in the glass filling groove. A method for manufacturing a step-up transformer for a multi-track magnetic head, characterized in that: