JPH0664693B2 - Magnetic head manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a magnetic head, and more particularly to a method of manufacturing a floating magnetic head, in which a process for forming an air bearing surface is improved to achieve high-precision flying. The present invention relates to a method of manufacturing a magnetic head capable of forming a surface.

[Conventional technology]

Among the conventional magnetic head manufacturing methods, Japanese Patent Application No. 57-75
Two examples described in No. 647 will be described with reference to FIGS. 5 to 12.

FIG. 5 is a perspective view of a floating type thin film magnetic head (hereinafter, simply referred to as “magnetic head”). In the figure, there is one magnetic head, and this magnetic head 1 has a magnetic conversion portion 1B as an element formed by thin film technology on an element formation surface 1A of a slider which is a floating portion.
Is formed. In this magnetic head 1, a plurality of magnetic conversion parts 1B are usually formed on a continuous thin plate material (hereinafter referred to as "head block"), and a plurality of head blocks are provided for each magnetic conversion part 1B. Is manufactured separately. In the figure, 2A and 2B are air bearing surfaces, 2C and 2D
Is a groove.

6 to 9 show one conventional method of manufacturing a magnetic head, FIG. 6 is an explanatory view showing a processing step, and FIG. 7 is an explanatory view showing a state where a cutting groove is formed on the back surface of the head block, FIG. 8 is an explanatory view of a state where the back surface of the head block is adhered to a processing jig, and FIG. 9 is an explanatory view of a state where an air bearing surface is formed on the front surface of the head block and the head block is cut and divided for each element. Is.

In the figure, the same symbols as in FIG. 5 indicate the same items. In the figure, 3 is a head block, and this head block 3 has a size of 5 to 10 magnetic heads 1 and has a length of 25
It has a size of -40 mm, a width of 4-5 mm, and a thickness of 1-2 mm, and the air bearing surfaces 2A and 2B are formed on the surface. 4 is a processing jig, and 1C is a cutting groove provided on the back surface of the head block.

The steps of the conventional method of manufacturing a magnetic head will be described below with reference to FIG.

First, the head block 3 is adhered to the processing jig 4 with the surface side serving as the air bearing surfaces 2A and 2B facing down. Next, a processing reference surface is formed on the back surface of the head block 3 by grinding, lapping or the like. Then, a groove 1C for cutting is formed on the back surface of the head block 3, and an air bearing surface 2A on the front surface of the head block 3 and
It is provided leaving 0.3 to 0.5 mm from 2B. (See FIG. 7).

Next, the head block 3 is separated from the processing jig 4 and inverted, and the processing reference surface on the back surface of the head block 3 is adhered to the processing jig 4 again (see FIG. 8).

Then, the surface of the head block 3 is ground, and grooves 2C and 2D are formed on the surface of the head block 3 to form air bearing surfaces 2A and 2B. The air bearing surfaces 2A and 2B of the head block 3 are wrapped. Next, the head block 3 is cut at a position corresponding to the cutting groove 1C and divided into a plurality of pieces for each element (magnetic conversion portion 1B) (see FIG. 9).

Then, the magnetic head 1 is manufactured by separating the head block 3 divided for each element from the processing jig 4.

10 to 12 show another conventional magnetic head manufacturing method, FIG. 10 is an explanatory view showing a processing step, and FIG. 11 is an explanatory view showing a state where the back surface of the head block is bonded to a processing jig. , First
FIG. 12 is an explanatory view showing a state in which an air bearing surface is formed on the surface of the head block and the head block is cut and divided for each element.

In the figure, the same reference numerals as those in FIGS. 5 to 9 indicate the same elements.
In the figure, 4A is a grindstone relief groove provided on the upper surface of the processing jig 4, and the grindstone relief groove 4A is provided at a position corresponding to the cutting position of the head block 3.

The steps of the conventional method of manufacturing a magnetic head will be described below with reference to FIG.

First, the head block 3 is adhered to the processing jig 4 with the surface side serving as the air bearing surfaces 2A and 2B facing down. Next, a processing reference surface is formed on the back surface of the head block 3 by grinding, lapping or the like. Subsequently, the head block 3 is attached to the processing jig 4
Then, it is peeled off and inverted, and the processing reference surface of the back surface of the head block 3 is adhered to the processing jig 4 again (see FIG. 11).

Then, the surface of the head block 3 is ground, and grooves 2C and 2D are formed on the surface of the head block 3 to form air bearing surfaces 2A and 2B. The air bearing surfaces 2A and 2B of the head block 3 are wrapped. The head block 3 is cut at a position corresponding to the grindstone escape groove 4A of the processing jig 4 to divide the head block 3 into a plurality of pieces for each element (magnetic conversion portion 1B) (see FIG. 12).

Then, the magnetic head 1 is manufactured by separating the head block 3 divided for each element from the processing jig 4.

The magnetic head 1 is 0.3 to 0.5 from the surface of the magnetic disk.
Since it is necessary to float with a gap of about μm, the flatness of the air bearing surfaces 2A and 2B of the magnetic head 1 is required to have an accuracy of about 0.05 to 0.1 μm.

[Problems to be solved by the invention]

However, the above-mentioned second conventional method of manufacturing a magnetic head is
There is a difference in whether or not the cutting groove 1C is machined on the back surface of the head block 3 in advance.
The air bearing surfaces 2A and 2B are formed by grinding and groove processing on the surface of, and the air bearing surfaces 2A and 2B are lapped, and then the head block 3 is cut for each element. That is, in the conventional method of manufacturing a magnetic head, the machining distortion generated by the grinding groove machining is retained in the head block 3,
Since the flatness is obtained by lapping and then the head block 3 is cut, the machining strain retained in the head block 3 is released by the cutting of the head block 3, and as a result, the flatness produced by the lapping becomes new. There is a problem that distortion occurs and the air bearing surfaces 2A and 2B of the magnetic head 1 do not have highly accurate flatness.

An object of the present invention is to provide a method of manufacturing a magnetic head that can obtain highly accurate flatness on the air bearing surface of the magnetic head.

[Means for solving problems]

According to the present invention, the air bearing surface is formed on the surface of the head block, and thereafter the head block is cut into each element, and the adhesive does not melt at a temperature higher than the temperature at which the processing strain remaining in the head block is released. It is characterized in that the head block is heated below a moderate temperature, and then the air bearing surface of the head block is wrapped.

[Action]

According to the present invention, by forming the air bearing surface on the surface of the head block and then cutting the head block, most of the processing strain generated by the air bearing surface forming processing (grinding groove processing) in the head block is released. . Also, by heating the cut head block for each element at a temperature above the temperature at which the processing strain remaining in the head block is released and below the temperature at which the adhesive does not melt, the adhesive strength of the adhesive is increased. Since it is slightly lowered, the processing strain slightly remaining in the head block can be released almost completely while the head block is adhered to the jig. On the other hand, since the head block does not move much with respect to the jig, there is no influence on the gap depth in air bearing surface lapping.

〔Example〕

The first embodiment of the method of manufacturing a magnetic head according to the present invention will be described below.
This will be described with reference to FIGS.

In the figure, the same reference numerals as those in FIGS. 5 to 12 indicate the same parts.

In the process of the method for manufacturing a magnetic head of the present invention in this embodiment, as shown in FIG. 1, first, the head block 3 is adhered to the processing jig 4 with the surface sides serving as the air bearing surfaces 2A and 2B facing down. Next, a processing reference surface is formed on the back surface of the head block 3 by grinding, lapping or the like. Subsequently, the head block 3 is peeled off from the processing jig 4 and inverted, and the processing reference surface on the back surface of the head block 3 is bonded to the processing jig 4 again with an adhesive (not shown) (FIG. 2). reference).

Then, the surface of the head block 3 is ground, and grooves 2C and 2D are formed on the surface of the head block 3 to form air bearing surfaces 2A and 2B. Then, the head block 3 is cut at a position corresponding to the grindstone clearance groove 4A of the processing jig 4 to divide the head block 3 into a plurality of elements (magnetic conversion portions 1B) (see FIG. 3). At this time, in the head block 3, most of the processing strain caused by the grinding of the air bearing surfaces 2A and 2B and the processing of the grooves 2C and 2D is released.

However, since the cut head block 3 is still adhered to the processing jig 4 with the adhesive, the above-mentioned processing strain still remains on the head block 3 to some extent.
In order to remove this residual processing strain, it is necessary to heat the adhesive to slightly reduce the adhesive strength. However,
If the heating temperature of the adhesive is raised too much, the adhesive melts and the adhesive strength is significantly reduced, and the head block 3 is moved in the XYZ directions (short direction, longitudinal direction of the magnetic head 1,
It largely moves in the thickness direction), and has a great influence on the gap depth accuracy in the air bearing surface lapping process which is the next step.

In this way, in order to eliminate the above-mentioned residual processing strain while solving the problem of gap depth accuracy in air bearing surface lapping processing due to excessively high heating temperature, the head block is considered in consideration of the thermal characteristics of the adhesive. At a temperature above the temperature at which the residual processing strain is released and below the temperature at which the adhesive does not melt, for example, below the softening point of the adhesive, generally about 50 ° C to 65 ° C.
Heating is performed at ℃ for 2 to 10 hours. By this heating, the above-mentioned residual processing strain is almost completely released, as is apparent from the explanatory view of FIG. 4 described later.

Then, the air bearing surfaces 2A and 2B of the head block 3 are wrapped to provide flatness. Subsequently, the magnetic head 1 is manufactured by separating the above-mentioned head block 3 from the processing jig 4. At this time, the air bearing surface 2A after lapping
And 2B have a flatness of 0.02 to 0.03 μm, and the air bearing surfaces 2A and 2B after peeling have a flatness of 0.02 to 0.04 μm. As a result, the flatness of the air bearing surface after lapping and the air bearing surface after peeling are It is clear that the amount of change from the flatness was extremely small and the influence of processing strain could be eliminated.

From the above, in order to guarantee the final flatness of 0.05 μm or less, the flatness at the time of lapping the air bearing surfaces 2A and 2B may be controlled.

FIG. 4 is an explanatory view (graph) showing the optimum aging temperature of the heating process in the magnetic head manufacturing method of the present invention.

In the graph (graph), the vertical axis represents the amount of change in flatness in the X direction (short direction of the magnetic head 1) (μm / 20 × − ×) and the amount of change in flatness in the Y direction (longitudinal direction of the magnetic head 1) (μm / Four
・-・) Is shown, and the horizontal axis shows the heating temperature (° C).

As is clear from this figure (graph), when the heating temperature is 50 ° C. or higher, the Y-direction flatness change amount becomes particularly large. As a result, the processing strain remaining in the head block 3 (magnetic head 1) is almost released. On the other hand, if the heating temperature is raised too high, the adhesive that bonds the head block 3 to the processing jig 4 melts, and the linearity of the cut head blocks 3 (magnetic heads 1) is broken, resulting in flatness. Equally important gap depth defects may occur frequently.

From the above, the optimum heating temperature is 65 ° C or lower, which is 50 ° C or higher and at which the adhesive does not melt.

In addition, the heating time (holding time) in the above-mentioned figure (graph) is 1 hour.

Although the thin film head has been described in the above embodiments, the method of manufacturing a magnetic head of the present invention can be applied to a monolithic head, a composite head, and the like.

〔The invention's effect〕

As is apparent from the above, the magnetic head manufacturing method of the present invention has no effect on the gap depth, and highly accurate flatness can be obtained on the air bearing surface of the magnetic head.

[Brief description of drawings]

1 to 4 show an embodiment of a method of manufacturing a magnetic head according to the present invention, FIG. 1 is an explanatory view showing a processing step, and FIG. 2 is a state in which the back surface of a head block is adhered to a processing jig. FIG. 3 is an explanatory view showing a state in which an air bearing surface is formed on the surface of the head block and the head block is cut and divided for each element, and FIG. 4 is an explanatory view showing an optimum heating temperature. is there. FIG. 5 is a perspective view of the magnetic head. 6 to 9 show one conventional method of manufacturing a magnetic head, FIG. 6 is an explanatory view showing a processing step, and FIG. 7 is an explanatory view showing a state where a cutting groove is formed on the back surface of the head block, FIG. 8 is an explanatory view of a state where the back surface of the head block is adhered to a processing jig, and FIG. 9 is an explanatory view of a state where an air bearing surface is formed on the front surface of the head block and the head block is cut and divided for each element. Is. 10 to 12 show another conventional magnetic head manufacturing method, FIG. 10 is an explanatory view showing a processing step, and FIG. 11 is an explanatory view showing a state where the back surface of the head block is bonded to a processing jig. , First
FIG. 12 is an explanatory view showing a state in which an air bearing surface is formed on the surface of the head block and the head block is cut and divided for each element. 1 ... Magnetic head, 2A and 2B ... Air bearing surface, 2C and 2D
...... Groove, 3 ...... Head block, 4 ...... Processing jig.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshikazu Tsuji 2880, Kozu, Odawara-shi, Kanagawa Stock company Hitachi Ltd. Odawara factory (56) Reference JP-A-55-135320 (JP, A)

Claims (1)

[Claims] 1. A plurality of elements are formed on a head block,
A method of manufacturing a magnetic head by separating the head block for each element, which comprises the following steps (a) to (f). (A) Bond the back surface of the head block to the jig with an adhesive. (B) An air bearing surface is formed on the surface of the head block. (C) The head block is cut into each element. (D) The head block is heated at a temperature not lower than a temperature at which the processing strain remaining in the head block is released and at a temperature at which the adhesive does not melt. (E) Wrap the air bearing surface of the head block. (F) Peel off the head block from the jig.