JPH0194514A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To manufacture the title head for high density recording with a simple manday, with a high yield and inexpensively by forming a groove to regulate the track width of at least one magnetic gap linearly and over the whole width of the joint body of core pieces. CONSTITUTION:A groove 29 to regulate the track width of an erasing gap 5 is linear, and it is formed in the block condition of the joint body of core pieces 20-23 over the whole width of the block. Consequently, it can be easily processed with high position accuracy and dimension accuracy, and the positioning of both gaps 2 and 5 due to the position of the groove 29 is easily attained. Further, a core assembly 33 and sliders 7 and 8 are connected by the redeposit of a deposited glass 31, which has been charged and deposited to the groove 29, in the block condition of the joint body of the core pieces. Thus, the small magnetic head for the high density recording can be manufactured with the simple manday, with the high yield and inexpensively.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a visiting type magnetic head for magnetically recording or reproducing information on a magnetic recording medium, and particularly relates to a method for manufacturing a visiting type magnetic head, each of which is composed of a plurality of cores. The present invention relates to a method of manufacturing a magnetic head in which two magnetic circuits are connected in parallel in the sliding direction of a magnetic recording medium, and sliders are joined to both sides of the magnetic circuit to reinforce the core of the magnetic circuit and lift and touch the magnetic recording medium.

[Prior Art] As this type of magnetic head, there is an LIH head used in magnetic disk devices widely used as external storage devices for computer systems and the like. Conventionally, a so-called tunnel erase type magnetic head has been widely used for this magnetic disk device, which records only in the center of a track on a magnetic recording medium disk and erases the edges on both sides.

FIG. 5 explains the structure of a conventional tunnel erase type magnetic head called a bulk type, and shows the magnetic recording medium sliding surface of the head.

In FIG. 5, reference numeral 10 denotes a magnetic core (hereinafter referred to as a recording/reproducing core) constituting a magnetic circuit for recording/reproducing. This recording/reproducing core 10 includes two front cores 10a1iob joined via a magnetic gap (hereinafter referred to as a recording/reproducing gap) 2 for recording and reproducing, and a not-shown front core 10a1iob joined to the rear end portions of both cores 10a and 10b. It consists of a back core of

Grooves 11.11' are formed on both sides of the recording/reproducing gap 2 to regulate the track width and position thereof.
11'' is filled with welded glass for joining the front core 10a110b.

Further, in FIG. 5, reference numeral 12 denotes a magnetic core (hereinafter referred to as an erasing core) constituting a magnetic circuit for erasing. The erasing core 12 includes two front cores 12a and 512b that are joined together with two magnetic gaps (hereinafter referred to as erasing gaps) 5.5' for erasing, and a free spacer that is joined to the rear ends of both cores 12a and 12b. It consists of the illustrated back core.

The erase gap of 5.5° is indicated by arrow A in the sliding direction of the magnetic recording medium.
They are arranged on both sides of the recording/reproducing gap 2 when viewed in the direction. Further, a groove 13 is provided between the erase gaps 5.5'' for regulating the track width and position.
is filled with welded glass that joins the front cores 12a and 12b.

The recording/reproducing core 10 and the erasing core 12 are coupled in parallel in the A direction of the medium sliding direction with the recording/reproducing core 10 on the upstream side.

Further, on both sides of both cores 10.12, there are sliders 7. which are reinforcing members that sandwich and reinforce both cores 10.12, and which also come into contact with the disk to stabilize the sliding movement of both cores 10.12.
8 are joined.

With this structure, during recording, the recording/reproducing core 1° first records on the track of the disk sliding in the direction of arrow A, and then the erasing core 12 records the recording signals on both sides of the recording track, leaving the center part. will be deleted.

In this tunnel erase type, data is written using signals of two different frequencies, high and low, and the written data is erased by overwriting new data on top of it, so-called override.

However, with this tunnel erase type, when the magnetic gap width of the recording/reproducing core is narrowed in order to increase the recording density, the depth of recorded magnetization becomes shallow, especially for high-frequency recording signals, so erasure by override occurs. There is a problem that sometimes the low-frequency recording signal remains unerased, resulting in noise.

For example, in order to achieve a linear recording density of 35 KBPI using a barium-ferrite medium for a disk, the width of the magnetic gap in the recording/reproducing magnetic core must be narrowed to about 0.35 μm, but in this case, override erasing must be done. The magnitude of the noise signal due to the remainder is about -20 dB relative to the recording signal. In practice, this noise level is required to be -26 dB or less, which poses a problem.

In order to solve this problem, a structure called a pre-erase type shown in FIG. 6 has recently been proposed as a magnetic head for a magnetic disk drive. In FIG. 6, members common or equivalent to those in FIG. 5 of the tunnel erase type are given the same reference numerals.

As shown in FIG. 6, the advance erase type differs from the tunnel erase type in that the erase core 12 is arranged on the upstream side in the medium sliding direction (direction A), and the recording/reproducing core 10
is placed downstream.

Further, only one erasing gap 5 is provided, and it is arranged so as to overlap with the recording/reproducing gap 2 when viewed toward the A direction.

Further, the track width of the erasing gap 5 regulated by grooves 17.17° provided on both sides is larger than that of the recording/reproducing gap 2.

With this structure, during recording, the erasing core 12 first erases the track of the disk that slides in the forward direction, and then the recording/reproducing core 10 performs recording. Unlike the tunnel erase type, erasing is performed reliably, noise due to unerased data can be suppressed, and override characteristics are no longer a problem.

[Problems to be Solved by the Invention] By the way, if the structure shown in FIG. 6 is used to cope with higher recording density and larger capacity and to increase the track density, both cores 10.
The dimensions of each part of 12 are extremely small. For example 3.5
A magnetic head for inch floppy disks with a track density of 135 TPI and a capacity compatible with IMB.
Comparing the track width of recording/reproducing gap 2 in Figure 6 with the gap interval between recording/reproducing gap 2 and erasing gap 5 for the 405TPI with triple track density and 12MB capacity, the table below shows that become.

However, when the dimensions of each part of both cores 10 and 12 become extremely small, both cores 10 and 12 are removed in the manufacturing process of the head.
It becomes difficult to process grooves 0 and 12, and in particular, it becomes difficult to process grooves 17 and 17'' that regulate the track width of the erase gap 5.

In addition, since the thickness of both cores 10.12 is reduced, both cores 10.12 are easily damaged during the manufacturing process, particularly when both cores 10, 12 are joined to the slider 7.8.

As a result, there has been a problem in that the yield of the head decreases and the manufacturing cost increases.

Furthermore, the connection between both cores 10, 12 and slider 7.8 is as follows:
Welding using fused glass is preferable to using adhesives in terms of environmental resistance and reliability, but welding using fused glass has the problem of being difficult and requiring a lot of man-hours, such as the method of applying or filling the glass joints. there were.

This problem is not limited to the advance erase type shown in FIG. 6, but is also common to the tunnel erase type shown in FIG.

[Means for Solving the Problems] In order to solve these problems, in the method for manufacturing a magnetic head according to the present invention, a plurality of base materials, which are base materials from which each of a plurality of cores constituting two magnetic circuits is cut out, are used. A step of joining the core pieces through a plurality of magnetic gaps of the two magnetic circuits, and a step of forming a track width of at least one of the magnetic gaps on a surface of the joined body obtained in the step to be processed into a 6B recording medium sliding surface. a step of forming a regulating linear groove across the entire width of the bonded body in a direction intersecting each magnetic gap; a step of filling and welding the grooves of the bonded body with welding glass after this step; A step of cutting the body to a predetermined thickness to obtain a core assembly as a joined body of the plurality of cores, and reinforcing the core assembly and installing a slider that slides on the magnetic recording medium by welding glass in the groove of the core assembly. A configuration was adopted in which the core assembly was joined to the core assembly by re-welding.

[Function] According to such a configuration, the groove regulating the track width of the at least one magnetic gap is linear and formed over the entire width of the joined body of the core piece, so it can be easily machined and has high positional accuracy and dimension. Can be formed with precision. Furthermore, the slider can be bonded to the core assembly very easily by re-welding the welded glass that was previously filled and welded into the groove in the state of the core piece being joined.

[Example] Hereinafter, details of an example of the present invention will be described with reference to FIGS. 1 to 4. Here, the method for manufacturing a magnetic head for a magnetic disk device described above is taken as an example, and parts in FIGS. 1 to 4 that are common or equivalent to those in FIGS. 5 and 6 of the conventional example are described as an example. The same symbols are attached.
The explanation will be omitted or only mentioned briefly.

Figure 1 on the paperback JJL side explains the structure of an erase-first type magnetic head for a magnetic disk drive manufactured by the manufacturing method of the first embodiment of the present invention. It shows a joined body of the core, the front core portion of the erased core, and the slider. The upper surface of the joined body in the figure serves as a medium sliding surface that slides on a disk of a magnetic recording medium (not shown).

The basic structure of the illustrated assembly is the same as the conventional example shown in FIG. A plate-shaped erasing core 12 provided with an erasing gap 5 larger than 2 is arranged adjacent to the erasing core 12 in the direction of arrow A in the medium sliding direction with the erasing core 12 on the upstream side. Also, both cores 10.12
Sliders 7.8 are joined on both sides of the . In addition, both cores 1
For 0.12, each pair of front cores 10a
, 10b to 12a, 12b are shown butted and joined together via the recording/reproducing gap 2 to the erasing gap 5. Only the front core portion is shown, and the back core joined thereto is not shown. The front core portions of both cores 10.12 are joined together as a core assembly 33.

Here, the difference between the head of this embodiment and the conventional one is that on the upper surface of the medium sliding surface of both cores 10.12 in the figure, there are grooves indicated by reference numerals 29 and 29 along both side edges thereof.
It is formed to extend in a straight line over the entire area of the 12 medium sliding surfaces. And as shown, this groove 29.29
The track width of the erase gap 5 of the erase core 12 is regulated by this.

Further, the grooves 29.29 are filled with welded glass 31, and the slide duff 8 is welded to both cores 10.1.
It is joined to both sides of 2.

The slider 7.8 is formed into a block shape with a substantially L-shaped cross section, and relief grooves 7b and 8b are formed for escaping coil windings (not shown) wound around both cores 10.12. ing. And both sliders 8.9 have clearance grooves 7b,
It is joined to both cores 10.12 with the end faces of the portion extending on ab serving as joint surfaces 7a, 8a.

Then, in the assembly of the core assembly 33 of both cores 10 and 12 and the slider 7.8, a bobbin on which a coil winding (not shown) is wound around the core assembly 33 and a back core (not shown) are joined to form a magnetic head main body. is configured.

Next, the manufacturing process of such a magnetic head is shown in FIGS.
This will be explained with reference to (F). In the manufacturing process of the head of this embodiment, first, the front cores 10a and 10f of the recording/reproducing core 10 are
Each of the core pieces 20 and 21 shown in FIG. 2 (Δ) is processed from a high permeability magnetic material as a base material from which each of the ob is cut out.

One core piece 20 is formed with an escape groove 20b for escaping the coil winding, and has a substantially U-shaped cross section.

On the end face of one side extending on the relief groove 20b, there is a groove 1 shown in FIG.
Grooves 20a corresponding to the seedlings 3 are formed at intervals of the track width.

Further, the other core piece 21 is formed into a rectangular flat plate shape,
A groove 21a corresponding to the above-mentioned groove 3 is provided at the upper edge of the inner side.
are formed at intervals of the above track width.

On the other hand, core pieces 22 and 23 shown in FIG. 2(B) are processed from a high permeability magnetic material as a base material for cutting out each of the front cores 12a112b of the erasing core 12. An escape groove 22a is formed in one core piece 22, and the cross section is formed into a substantially U-shape. Further, the other core piece 23 is formed into a rectangular flat plate shape.

Next, as shown in FIG. 2(C), each core piece 20 to 2
3 are butted together and joined by glass welding. That is, first, the core pieces 20 and 21 are butted together via the recording/reproducing gap 2 made of a non-magnetic thin film gap spacer, and the grooves 20a and 21a and the triangular space below them are filled with welding glass 25 and welded. and join. In addition, the core pieces 22 and 23 are butted together through the erasing gap 5, and a welding glass 25 is placed in the triangular space between them.
Fill and weld and join.

Furthermore, the joined body of core pieces 20 and 21 and the core piece 22
．． The bonded body of No. 23 is attached to the bonding surface 2 through a welded glass (not shown).
Butt weld and join in step 6.

Next, as shown in FIG. 2(D), core pieces 20 to 23
As mentioned above, a linear groove 29 regulating the track width of the erasing gap 5 is formed on the upper surface in the figure, which is the medium sliding surface in the block of the assembled body, parallel to the direction of the arrow in the medium sliding direction, and the recording/reproducing gap 2 Then, the entire width of the block of the bonded body is cut in a direction perpendicular to the erasing gap 5, and the gaps are formed at intervals corresponding to the track width of the erasing gap 5.

Next, as shown in FIG. 2(E), each of the grooves 29 is filled with welding glass 31 and welded.

Note that the welding glass 31 is made of a material whose melting point is sufficiently lower than that of the welding glass 25 for joining the core pieces 20 to 23 so that the heat during welding does not affect the dimensions of the recording/reproducing gap 2 and the erasing gap 5. .

Next, the block of the core piece assembly shown in FIG. 2(E) is cut along the cutting line indicated by reference numeral 32 in the same drawing, cut to a predetermined thickness, and the lower part shown in the drawing is removed. A core assembly 33 (F) is obtained.

Next, as shown in FIG. 1, the sliders 8.9 are butted against both sides of the core assembly 33, the whole is heated, and the slider 8.9 is attached to the core assembly 33 by re-welding the welded glass 31.
．． Join 9.

Thereafter, as described above, a bobbin around which a coil winding (not shown) is wound and a back core (not shown) are attached to the core assembly 33 to form a magnetic head main body.

In addition, in the step of joining the core assembly and the slider described above, it is also possible to use adhesive bonding together with re-welding of the welded glass 31.

According to the manufacturing process of this embodiment as described above, the groove 29 that regulates the track width of the erase gap 5 is linear, and in the state of the block of the joined body of the core pieces 20 to 23 in FIG. 2(D). Since it is formed over the entire width of the block, it can be easily machined and can be machined with high positional and dimensional accuracy. Moreover, the position of both gaps 2.5 can be easily aligned based on the position of this groove 29. Furthermore, since the core assembly 33 and the slider 7.8 are joined together by re-welding the welded glass 31 that was previously filled in the groove 29 and welded in the block state of the core piece assembly shown in FIG. It is easy to perform and requires less man-hours. Further, since no excessive force is applied to the core assembly 33 during the joining process, damage to the core assembly 33 can be prevented.

For these reasons, according to this embodiment, a magnetic head for high-density recording, which is composed of the core assembly 33 shown in FIG. It can be manufactured with high yield in the process and can be manufactured at low cost.

Next, FIGS. 3(A) to 3(D) illustrate the manufacturing process of a core assembly of a tunnel erase type magnetic head for a magnetic disk device as a second embodiment of the method of the present invention. .

In the process of this embodiment, first, as shown in FIG. 3(A), core pieces 20 to 23, which are the base materials of the front cores of the recording/reproducing core and the erasing core, are prepared in the same manner as in the first embodiment described above. are butted against each other through the recording/reproducing gap 2 and the erasing gap 5, and are joined by welding a welding glass 25.

However, before this joining, the track width regulating grooves (2 (1a, 21a in the first embodiment)) are not provided for the core pieces 20 and 21, similarly to the core pieces 22 and 23.

Next, as shown in FIG. 3(B), core pieces 20 to 23
On the upper surface in the figure, which is the medium sliding surface of the joining block, a linear groove is formed to intersect at an angle with respect to both gaps 2.5 as a groove to regulate the track width and position of the recording/reproducing gap 2 and the erasing gap 5. They are formed at equal intervals across the entire width of the joint block in the direction of the joint block.

Next, as shown in FIG. 3(C), each of the grooves 36 is filled with a welding glass 37 having a sufficiently lower melting point than the welding glass 25 and welded.

Next, the block shown in FIG. is removed to obtain the core assembly 38 shown in FIG. 3(D).

Next, as in the case of the first embodiment, the core assembly 38 is assembled.
A slider (not shown here) is brought into contact with both sides of the fused glass 37, and the slider is bonded to the welded glass 37 again.

According to this embodiment, the same operation and effect can be obtained for the same reasons as in the first embodiment, and in addition, the groove 36 allows the track III of the recording/reproducing gap 2 to be
/ and T are also regulated, and there is no need to provide grooves corresponding to the grooves 20a and 21a of the first embodiment, which simplifies the manufacturing process and further reduces manufacturing costs.

By the way, according to the second embodiment described above, in the core assembly 38 of FIG. 3(D), there is a space between the grooves 36 at the joint part with the slider due to the welding of the welded glass 37. Since the strength becomes weak, which poses a problem especially when processing the sliding surface, composite bonding may be performed by further applying an adhesive.

Therefore, in order to increase the bonding strength, as a third embodiment of the present invention, in the process of FIG. 29 shall be formed. With such a configuration, the core assembly 40 shown in FIG. 4 is manufactured. According to this core assembly 40, the bonded portion with the slider due to re-welding of the welded glass 37 filled in the groove 29 extends over the entire length of the core assembly in the medium sliding direction, and there is no empty space in the bonded portion, so that the bonded portion with the slider is High bonding strength can be obtained.

[Effects of the Invention] As is clear from the above description, in the method for manufacturing a magnetic head according to the present invention, a plurality of core pieces, which are base materials from which each of a plurality of cores constituting two magnetic circuits is cut out, are A step of joining a magnetic circuit through a plurality of magnetic gaps, and a linear groove regulating the track width of at least one of the magnetic gaps on a surface to be machined into a magnetic recording medium sliding surface of the joined body obtained in the step. a step of forming the bonded body over the entire width of the bonded body in a direction intersecting each magnetic gap, a step of filling the groove of the bonded body with welding glass and welding it, and a step of forming the bonded body to a predetermined thickness after the step. A step of cutting the core assembly into a core assembly as a joined body of the plurality of cores, and reinforcing the core assembly and re-welding the welded glass in the groove of the core assembly to a slider that slides on the magnetic recording medium. Since we have adopted a structure that includes a process of bonding to the assembly, two magnetic circuits each consisting of a plurality of cores are provided as a magnetic head and connected in line in the 6N memory medium sliding direction, and both 1111 Among the heads to which the slider is bonded, an excellent effect can be obtained in that a head for high-density recording, in particular, can be manufactured at low cost with a high yield through a simple process.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of the main part of a magnetic head manufactured by the method of the first embodiment of the present invention, and FIG.
F) is an explanatory diagram of the manufacturing process of the first embodiment, FIGS. 3(A) to (D) are explanatory diagrams of the manufacturing process of the second embodiment of the present invention, and FIG. 4 is an explanatory diagram of the manufacturing process of the second embodiment of the present invention. FIGS. 5 and 6 are perspective views of the core assembly manufactured according to the embodiment, and are top views of the magnetic recording medium sliding surface of different conventional 6N air heads for magnetic disk drives. 2... Recording/playback gap 5... Erase gap 7.8
...Slider 10...Recording/playback core 12...
Erase cores 20 to 23...Core pieces 25.31.37...Fused glass 29.36...Grooves 33.38, 40...Core assembly 12514 4-bi [、He-Nodo! ° ship part / l perspective r te] Fig. 1 4 o 7 / de > burikoara > Buri no Yogyo Uda Fig. 4

Claims (1)

[Claims] A step of joining a plurality of core pieces, which are base materials from which a plurality of cores constituting two magnetic circuits are cut out, through a plurality of magnetic gaps of the two magnetic circuits, and forming a linear groove for regulating the track width of at least one of the magnetic gaps over the entire width of the joined body in a direction intersecting each magnetic gap on a surface of the joined body to be processed into a magnetic recording medium sliding surface; After the step, filling the grooves of the bonded body with welding glass and welding it; and After the step, cutting the bonded body to a predetermined thickness to obtain a core assembly as a bonded body of the plurality of cores. A method of manufacturing a magnetic head, comprising the steps of reinforcing the core assembly and joining a slider that slides on the magnetic recording medium to the core assembly by re-welding the welded glass in the groove of the core assembly.