JPH06290435A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To improve the yield and to reduce the cost. CONSTITUTION:A core chip blank 1 is inserted into a long hole 4 of a slider 2, and then, a bar-shaped glass 3 for sealing is placed between projections 5, and the bar-shaped glass 3 for sealing is melted to join the core chip blank 1 with the slider 2. The projections 5 are arranged discontinuously along the side of the long hole 4. Thus, the dispersion in the step difference between the core chip and the slider is reduced, and the classifying work of the core when the gap depth is machined is unnecessitated, thereby there is no flaws and no residual distortion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head used in a floppy disk drive device, and more particularly to a step of joining a core chip and a slider in a series of manufacturing steps of a magnetic head. is there.

[0002]

2. Description of the Related Art Recently, a floppy disk drive device is a 3.5 inch 135 TPI (Track Per I).
(nch) type is predominant, and the magnetic heads for it are mainly tunnel erase type and bulk type, and this tendency is expected to continue for a while. The storage capacity of 2 MB is the mainstream, and this trend is expected to continue for some time. Under such circumstances, the market demand for magnetic heads has been limited to one cost. Therefore, it is desired to provide an inexpensive magnetic head whose quality is maintained.

The structure of the prior art will be described below with reference to the drawings. FIG. 4 is a perspective view showing a method of manufacturing a magnetic head having a two-body slider, FIG. 5 is a perspective view showing a magnetic head having an integrated slider according to the prior art, and FIG.
FIG. 6 is a perspective view showing a step of combining a core chip blank and a slider-blank in the method of manufacturing the magnetic head of FIG. 5.

In the background as described above, a magnetic head of a type having an integrated slider as shown in FIG. 6 has appeared. Before that, a two-piece slider as shown in FIG.
Was used.

In FIG. 4, reference numeral 81 is a core chip, 82 is a slider-L, and 83 is a slider-S.
Is composed of a large slider-L82 and a small slider-S83.
1 is sandwiched. In manufacturing a magnetic head having a two-body slider of this type, both sliders are machined from a large block of ceramic with a diamond wheel, or are molded once by powder compression molding or injection molding. Since it is made by finishing several places, there was a problem that the processing cost was high.

Further, in manufacturing a magnetic head having a two-body type slider, a slider L82 and a slider L82 are used.
With the core chip 81 sandwiched by S83,
Since the both are bonded by an adhesive or glass, the lower surfaces 82a, 83a, 81a of the core chip 81, the slider-L82, and the slider-S83 are on the same surface by the action of the frictional force on the respective contact surfaces. It had the drawback of not being able to align with each other. The step between the core chip and the slider caused by this phenomenon is referred to as a core chip / slider step (hereinafter abbreviated as CS step). Figure 7
Is a graph showing the variation of the CS step, and the variation is about 20 μm in width.

Reference numeral 81b shown in FIG. 4 denotes a recording / reproducing gap depth (hereinafter abbreviated as GD), which together with an erasing GD (not shown) is important for determining the quality of electromagnetic conversion characteristics of the magnetic head as is well known. Is a factor. The slider
The core chip 81 is formed by the L82 and the slider-S83.
A joined body obtained by sandwiching and joining is called a core 84. The GD
The upper surface of the core 84 on which the sliding contact surface is formed is polished in order to obtain the above. The method of polishing is that hundreds of the cores 84 are aligned on a flat plate for GD processing. Bond and process the plates in one go.

At this time, as a condition for processing so that the GD of the hundreds of cores 84, which is one processing unit, is reduced, the distance from the lower surface of the core chip 81 to the lower end of the gap is the back height. The size 81c is the back height size 81c of all the core chips 81.
And that the CS step variation is small,
It is important that the core 84 is adhered to the GD processing plate so that the thickness of the adhesive is constant.

By the way, the allowable variation of the GD dimension is 2
In the case of MB, it is practically within ± 10 μm. Therefore, if the CS step variation is about 20 μm in width as described above,
That alone would be about the same as the allowable variation in the GD dimension. Therefore, core chip 81 is
It becomes necessary to divide into groups of ˜5 μm and to process with a polishing white suitable for each group, and the layering work for dividing into groups is required.

Therefore, a magnetic head having an integrated slider has appeared in order to reduce the cost.
In FIG. 5, reference numeral 71 is a core chip, and 72 is a slider integrally formed with the slider 72, and a long hole 73 for inserting a core chip is formed in the slider 72 so as to penetrate from the sliding surface side to the lower surface side. The core chip 71 is inserted into the elongated hole 73 and then joined with glass 74. The blank of the slider 72 was integrally molded by injection molding and had a shape as shown in FIG.

That is, 91 is a core chip blank, 92 is a slider, which is a blank of the slider 72, and 93.
Is a long hole for inserting the core chip blank 91, 94 is a projection continuously arranged along the long sides on both sides of the long hole 93, and has a length slightly extended from both ends of the long side. It is a rod-shaped glass for sealing, and the length of the rod-shaped glass 95 is substantially equal to the outer dimension of the slider-92. The protrusion 94 is formed so as to stand up from the sliding surface and position the glass rod 95.

FIG. 8 is a cross-sectional view showing a BB cross section when the respective parts of FIG. 6 are combined, and the dimensions of the respective element parts are represented by symbols. That is, a is the inner spacing of the protrusion 94, and b
Is the distance between the long sides of the long holes 93, c is the diameter of the glass rod 95,
d is the thickness of the core chip blank 91, e is the height of the protrusion 94, and f is the core chip blank 91 and the slider-9.
2 and the lower surface step, that is, the CS step. The space a is wider than the space b.

The core chip blank 91 is shown in FIG.
The height is about 100 μm higher than the height of the core chip 71 shown in FIG. The sealing rod-shaped glass 95 is placed between the protrusions 94 and melted. At this time, the height of the landing surface 96 on which the rod-shaped glass 95 is placed is 100 μm higher than the height of the core chip blank 91. When the core chip blank 91 is inserted into the long hole 93, the core chip blank 9
1 is accurately determined, and the core chip blank 9
A clearance of about 20 μm is provided between the core chip blank 91 and the slider 92 so that 1 can move smoothly without being affected by the frictional force.

In manufacturing the magnetic head having an integrated slider, the slider on an assembly jig (not shown) is used.
The core chip blank 91 is inserted into the long hole 93 of 92 from the sliding surface side to bring the lower surface into close contact with the jig surface,
4, the rod-shaped glass 95 is placed, the rod-shaped glass 95 is melted in an electric furnace, and the glass is permeated and filled in the gap between the core chip blank 91 and the long hole, and the slider-92 is filled with the glass. The core chip blank 91 is joined.

After the joining as described above, the projection 94 is ground and removed together with the molten glass, and the sliding surface is polished to finish the surface smooth and the desired accuracy of the GD is obtained. Although illustration is omitted because the subsequent steps are not important at this time, after inserting the recording / reproducing and erasing coil assemblies into the core legs of the core chip and incorporating the back core into the core leg ends to complete the magnetic circuit, Adhere to the gimbal spring and wire to the coil terminal to complete the magnetic head.

[0016]

As described above, in the method of manufacturing a magnetic head according to the prior art, in the magnetic head of the two-body type slider, the CS step variation becomes large, and therefore the core of the magnetic head for GD processing is increased. Stratification work was required.

In the magnetic head of the integrated slider as shown in FIG. 5, since there is no frictional resistance when the core chip blank is incorporated in the slider, it seems that the CS step f has less variation. On the contrary, it has grown. Therefore, at the time of GD processing, as in the case of the two-body type slider, the core layering work is still necessary.

Therefore, not only the work is increased, but also the core outside the width of the CS step variation is naturally low in appearance rate, so that the products of each grouped layer are processing units. There was a problem that it had to be stored as inventory until the quantity reached a certain amount, and the processing turn became longer.

Further, cores on the outer side of the width of the CS step variation also occur with a smaller appearance rate. In many cases, these eventually have to be defective, which results in a decrease in yield and a break in cost reduction.

During the layering work of the CS step, stress is applied to the lower surface of each of the core chip, the slider-L and the slider-S, so that scratches or chips are likely to occur, and no scratches or chips are generated. However, the quality was deteriorated due to the residual distortion. There is also a problem that the glass is insufficiently filled due to the deviation of the rod-shaped glass.

The object of the present invention is to solve the above-mentioned problems, to reduce variations in CS step, and thus to reduce the number of man-hours for GD processing, keep inventory to a minimum, and shorten processing time. An object of the present invention is to provide a method of manufacturing a magnetic head that can be manufactured at low cost while maintaining quality.

[0022]

A method of manufacturing a magnetic head having a core chip and an integral slider having an elongated hole into which the core chip can be inserted,
On the sliding surface side of the slider, at least one side along the long side of the elongated hole is formed with discontinuously arranged protrusions, the core chip is inserted into the elongated hole, and the protrusion is guided. As a rod, a rod-shaped glass is placed, the rod-shaped glass is melted, the core chip is bonded to the slider, and then the protrusion is removed.

Further, the protrusion is characterized in that the height of the rod-shaped glass from the landing surface is approximately half the thickness of the core chip.

The diameter of the rod-shaped glass is substantially the same as the thickness of the core chip.

Further, the protrusion is also provided at the intermediate position together with both longitudinal ends of the elongated hole of the slider, and the height of the protrusion formed at the intermediate position is lower than the height of the protrusion formed at the both ends. It is characterized by

[0026]

According to the method of manufacturing the magnetic head of the present invention, the glass is filled with an unnecessarily large amount of glass and the gap is sufficiently filled, so that the bonding position of the core chip with respect to the slider can be stably secured. .

[0027]

EXAMPLE To solve the problem, first, using an integrated slider in which projections are continuously formed along the long side of the long hole, the influence of the glass amount for sealing on the variation in CS step is investigated. It was FIG. 9 shows a CS manufactured by this magnetic head manufacturing method.
It is a graph which shows the variation of a level | step difference, and is a result at the time of experimenting, changing the diameter c of the rod-shaped glass 95. Here, the height e of the protrusion 94 was fixed to 200 μm. In FIG. 9, the vertical axis is the CS step f, and the horizontal axis is the frequency N. (A) shows a case where the diameter c of the rod-shaped glass 95 is 300 μm, (b) shows a case of 400 μm, and (c) shows a case of 500 μm.
In each case, the farther from practical use the large variation is, the smaller the diameter c of the rod-shaped glass 95 is, the smaller the variation tends to be. The smaller the diameter c of the rod-shaped glass 95 is, the more cost is reduced, and the amount of glass to be removed is small, which is advantageous.

Next, the influence of the protrusion height e was investigated. Figure 10
[Fig. 4] is a graph showing variations in CS step f as a result of the experiment. In (a), the height e of the protrusion 94 is 200 μm, (b) is 100 μm, (c) is 0 μm, and (d) is −100 μm. -100 μm
Means that the landing surface 96 of the slider 92 together with the projection 94
This means that they have been removed by grinding by 00 μm, and at this time, the landing surface 96 and the core chip blank 91 have almost the same height. It can be seen that the lower the protrusion 94, the smaller the variation in the CS step f. (C) is approximately ± 4 μm, (D)
Is approximately ± 3 μm.

Consider the results of this experiment. FIG. 11 is a cross-sectional view showing a state after the rod-shaped glass 95 of FIG. 6 is melted, but the molten glass 95 a melted by heating the rod-shaped glass 95 is filled so as to bridge between the protrusions 94. ing. The core chip blank 91 is the molten glass 95.
Since it is pulled up by the surface tension of a,
The position of the core chip blank 91 is not stable, resulting in C
The variation of the S step f is increased.

According to the results of the above-mentioned experiment, it is necessary to eliminate the protrusions and to make the height of the landing surface of the rod-shaped glass substantially equal to the height of the core chip blank. However, if the projection is abolished, the slider itself cannot position the rod-shaped glass, so the inventors thought that the projection should be provided with a minimum length required for guiding the rod-shaped glass. Since the height of the protrusion is not unnecessarily increased, it is set to about half the diameter, which is sufficient for guiding the glass rod. Further, the smaller the diameter of the rod-shaped glass is, the more advantageous it is, but if the amount of glass is too small, insufficient filling occurs. Therefore, it was thought that the diameter should be made smaller within the range where insufficient filling occurs.

A description will be given below with reference to the drawings. 1 is a perspective view showing a method of manufacturing a magnetic head according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing cross sections A and A after the assembly of FIG. 1 is completed. Since the cross section of the protrusions parallel to the cross sections A and A is the same as that of FIG. 8, the same symbols are used for the same element dimensions and the cross sectional views are omitted. In FIG. 1, 1 is a core chip blank. Reference numeral 2 is a slider integrally formed by injection molding, which is made of calcium titanate-based ceramics. 3 is a rod-shaped glass for sealing. Reference numeral 4 is an elongated hole formed on the sliding surface side of the slider-2 so that the core chip blank 1 can be inserted from the sliding surface side of the slider-2. Reference numeral 5 is a projection that is present only near both ends of the long side of the elongated hole 4, and is a projection that rises from the sliding surface, and 6 is a landing surface on which the rod-shaped glass 3 is placed.

In the step of joining the core chip blank 1 and the slider-2, the core chip blank 1 is inserted into the elongated hole 4 of the slider-2 in a predetermined direction, and the rod-shaped glass 3 is attached to the attachment surface 6 between the protrusions 5. It is placed and heated and melted to fill the gap between the core chip blank 1 and the slider-2 with glass to form a bonded core. The protrusion 5 and other protrusions adjacent to the slider-2 are ground and removed together with the protruding glass, and then polished to smooth the sliding contact surface.

FIG. 2 shows a core cross section of a portion without the protrusion 5. Landing surface 6 of slider-2 on which rod-shaped glass 3 is placed
Is almost the same as the height of the core chip blank 1 and the length and height of the protrusions 5 are limited, so that the influence of the surface tension of the molten glass 3a on the core chip blank 1 is extremely small. Therefore, the core chip blank 1 is never lifted.

If the height of the protrusion from the landing surface of the slider is approximately half the thickness of the core chip blank, it is sufficient to guide the rod-shaped glass having a diameter substantially equal to the thickness of the core chip blank without play. is there.

Generally, the thickness dimension of the core chip is 300 μm
It is a degree. Now, the thickness dimension d of the core chip blank 1 is set to 3
When it is set to 00 ± 10 μm, the distance b between the long sides of the long holes 4 of the slider-2 is set to 340 ± 10 μm, and the inner distance a of the protrusion 5 is set to 370 ± 10 μm. The interval a
Is slightly wider than the interval b for the convenience of die manufacturing. Slightly means about ab = 30 μm. It is desirable that this value does not exceed 200 μm at the maximum so that the rod-shaped glass 3 does not rattle between the protrusions 5.

The rod-shaped glass 3 has a rod-like shape with a uniform cross-section, and any cross-sectional shape can be applied, but a circular shape is inexpensive in view of cost. As for the diameter c of the rod-shaped glass 3, the smaller the diameter c, the smaller the variation in the CS step, and the risk of insufficient filling when the diameter c is smaller than the thickness of the core chip blank. It is the same as or slightly smaller than the inner spacing a of the protrusions 5 and is substantially equal to the thickness of the core chip blank 1. Such a diameter c is 300 to 350 μ
m corresponds, and the diameter c is set to 320 μm in the embodiment.

Further, disposing the protrusions discontinuously reduces the amount of glass attracted to the inner surface of the protrusion by surface tension.
Even if a thin rod-shaped glass having a diameter substantially equal to the thickness of the core chip blank was used, insufficient filling of the glass did not occur, and variations in the CS step could be reduced. Further, since the thin rod-shaped glass is used, the unit price of the rod-shaped glass is reduced and the amount of glass to be ground after melting is reduced, so that the processing time is shortened and the life of the grindstone is extended.

As described above, when the variation of the CS step f was investigated by the method of manufacturing the magnetic head of the present invention in which the locations of the protrusions for guiding the rod-shaped glass were limited and the dimensions of each part were set, FIG. The same result as (d) was obtained. The variation of the CS step f of ± 3 μm is a sufficiently practical value, and the CS after the core chip blank 1 and the slider-2 are bonded together is
The work of stratifying the steps is no longer necessary.

Since the core layer blanking work is eliminated, no stress is applied to the core chip blank or the lower surface of the slider due to the layer grouping work, so that no scratches or chips occur and no residual strain occurs. .

Further, if the layering work of the core is eliminated, the core can be processed in the next step (GD processing step) without stagnation, so that it is not necessary to store it as an inventory and the processing turn is shortened. Further, since the variation in CS step can be reduced, the GD accuracy of the completed magnetic head is remarkably improved. As a result, the variations in the electromagnetic conversion characteristics of the magnetic head are reduced, and particularly reproduction output, overwriting, and resolution.
The variation of the option is reduced.

FIG. 3 shows another embodiment of the present invention. In FIG. 3, three protrusions are provided on each of the long sides of the long hole 4. The height of the central projection 5a is lower than the projections 5b and 5c at both ends by about 50 to 100 μm. The protrusion is rod-shaped glass 3
It is necessary to provide at least two places on at least one side of the long hole because it is for guiding the guide, but when a protrusion is provided along both long sides, at least one place on one side and two places on the other side. I wish I had it. That is, the protrusions are characterized by being discontinuously arranged on at least one side along the long side of the long hole.

In the assembly shown in FIG. 3, the surface tension of the molten glass causes the glass to be attracted to the central protruding portion, which supplements the glass supply to the central portion where the filling space is large, and the frequency of insufficient filling is further increased. Less. This is particularly effective for a slider in which the longitudinal dimension of the slot is relatively long.

[0043]

According to the present invention, since the projections for guiding the glass on the rod are discontinuously arranged, when the rod-shaped glass is heated and melted, the portion where the molten glass bridges between the projections is formed. As a result, the surface tension of the glass melt prevents the core chip blank from being lifted. Since the core chip blank was not lifted, the position of the core chip blank was stable, and the CS step variation could be reduced.

If the protrusions are provided not only at both ends of the elongated hole of the slider but also in the middle, the glass supply to the central portion is supplemented, and the frequency of insufficient filling is further reduced. The protrusions are limited in length, have a low height, and have a very small influence of surface tension, and therefore, the variation in CS step is not increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method of manufacturing a magnetic head according to an embodiment of the present invention.

2 is a cross-sectional view showing cross sections A and A after the assembly of FIG. 1 is completed.

FIG. 3 is a perspective view showing a method of manufacturing a magnetic head that is another embodiment of the present invention.

FIG. 4 is a perspective view showing a method of manufacturing a magnetic head having a two-body slider, which is a conventional technique.

FIG. 5 is a perspective view of a magnetic head having an integrated slider according to the related art.

6 is a perspective view showing a method of manufacturing the magnetic head of FIG.

FIG. 7 is a graph showing variations in CS step of a magnetic head having a two-body slider.

8 is a sectional view showing a B section of FIG.

FIG. 9 is a graph showing an experimental result of an integrated slider for examining the influence of the glass amount.

FIG. 10 is a graph showing an experimental result of an integrated slider for examining the influence of the height of a protrusion.

FIG. 11 is a cross-sectional view showing a state after melting the rod-shaped glass of FIG.

[Explanation of symbols]

 1 Core chip blank 2 Slider-3 Rod glass 4 Long hole 5, 5a, 5b, 5c Protrusion a Distance between protrusions b Distance between long sides of long hole c Diameter of rod glass d Thickness of core chip blank e Height of protrusion

Claims (4)

[Claims] 1. A method of manufacturing a magnetic head, comprising: a core chip; and an integrated slider having an elongated hole into which the core chip can be inserted.
On the sliding surface side of at least one side along the long side of the long hole, the protrusions that are discontinuously arranged are formed, the core chip is inserted into the long hole, and the protrusion is used as a guide for the rod-shaped glass. Is mounted, the rod-shaped glass is melted to bond the core chip to the slider, and then the protrusion is removed. 2. The method of manufacturing a magnetic head according to claim 1, wherein the protrusion has a height from a surface on which the rod-shaped glass is attached to the protrusion that is approximately half the thickness of the core chip. 3. The method of manufacturing a magnetic head according to claim 1, wherein the diameter of the rod-shaped glass is substantially the same as the thickness of the core chip. 4. A protrusion is also provided at an intermediate position together with both ends in the longitudinal direction of the elongated hole of the slider, and the height of the protrusion formed at the intermediate position is higher than the height of the protrusion formed at the both ends. The method of manufacturing a magnetic head according to claim 1, wherein the magnetic head is made lower.