JPH06304860A - Polishing method for thin film magnetic head - Google Patents

Abstract

PURPOSE:To provide a polishing method wherein a tool life of a surface plate is semipermanently obtained by reducing pole recession, in polishing work for a floating surface of a thin film magnetic head. CONSTITUTION:A fine helical groove 23 of 0.3mm or less groove width and 0.4mm or less groove space pitch and a radial groove 24 of crossing with the helical groove radially in a direction of surface plate radius are provided in a polishing reference surface 22 of a tin-made polishing surface plate 21, to polish a floating surface of a thin film magnetic head while supplying a polishing liquid 11, contained with free abrasive grains, to the polishing reference surface 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of polishing a floating surface of a thin film magnetic head during a manufacturing process of the thin film magnetic head used in a magnetic recording / reproducing apparatus. More specifically, a method of polishing a floating surface of a thin film magnetic head for reducing a step between the floating surface of the thin film magnetic head and a pole (hereinafter referred to as pole recession), which is one of the factors that deteriorates the recording / reproducing characteristics of the thin film magnetic head Regarding

[0002]

2. Description of the Related Art As mentioned above, the pole recession is
As one of the causes for lowering the recording / reproducing characteristics of the thin film magnetic head, it has been regarded as a problem in the past. Specifically, it is a step between the floating surface of the thin-film magnetic head and the pole, and is the recess of the pole when viewed from the floating surface with the floating surface of the thin-film magnetic head as a reference surface. It is generally called "Paul recession" by people involved in. By the way,
Ideally, it is desirable that there be no step between the floating surface of the thin film magnetic head and the pole so that the recording / reproducing characteristics of the thin film magnetic head are not deteriorated, and that pole recession does not occur.

The pole recession will now be described with reference to the drawings. FIG. 4 shows a thin film magnetic head. (A) is a perspective view of a thin film magnetic head.
(B) shows the pole recession, and is a sectional view taken along the line YY of the F portion shown in (a). FIG. 4B
The step between the floating surface 41 and the pole 42 including the step between the floating surface 41 and the protective film 43 shown in FIG.

At the end of the floating surface 41 of the thin film magnetic head 40, there is a pole 42 surrounded by a protective film 43. Further, since the floating surface 41 of the thin-film magnetic head 40 is required to be in a mirror surface state, normally, polishing is performed while supplying a polishing liquid containing loose abrasive grains onto a polishing plate made of soft metal. Finish. The reason why the soft metal is used for the polishing platen is that the surface roughness can be reduced and the mirror surface can be finished. When polishing the floating surface 41, the protective film 43 at the end of the floating surface 41 of the thin-film magnetic head 40 and the pole 42 surrounded by the protective film 43 should also be polished at the same time as the floating surface 41. become.

By the way, in the polishing performed while supplying the polishing liquid containing the loose abrasive grains onto the polishing platen made of soft metal, the action of the loose abrasive grains on the workpiece is that the loose abrasive grains are on the polishing platen. It is a composite processing action of the working action in the embedded state and the working action with loose abrasive grains left on the polishing surface plate, but the loose abrasive grains remain free on the polishing surface plate. With the working action, the floating surface 41 of the thin film magnetic head 40, the pole 42 at the end of the floating surface 41, and the protective film 43.
When the and are simultaneously polished, a step is generated at the boundary portion between the floating surface 41 of the thin film magnetic head 40 and the protective film 43, and further, the pole 42 is dented in the surface of the protective film 43, so that FIG. A step (step between the floating surface 41 and the pole 42), that is, a pole recession occurs.

The occurrence of such a pole recession is
The material of the floating surface 41 of the thin film magnetic head 40 and the protective film 43.
Due to the difference in mechanical properties and the difference in hardness between the material of the pole and the material of the pole. Generally, the material of the floating surface 41 of the thin film magnetic head 40 is alumina titanium carbide based ceramics, the material of the protective film 43 is alumina, and the material of the pole 42 of the thin film magnetic head 40 is soft magnetic metal. Comparing the hardnesses of these three materials, the soft magnetic metal that is the material of the pole 42 of the thin-film magnetic head 40, the alumina that is the material of the protective film 43, and the alumina-titanium carbide-based ceramics that is the main material of the floating surface 41 are low in this order. Due to the hardness, the floating surface 4 of the thin-film magnetic head 40 in a state in which the working action is performed while the loose abrasive grains remain free on the polishing platen.
When No. 1 is polished, a portion having a lower hardness is eroded so that free abrasive grains in a free state are dug up, and a step as shown in FIG. 4B, that is, a pole recession occurs.

Therefore, in the conventional polishing method of the floating surface for reducing the pole recession in the manufacture of the thin film magnetic head, it is necessary to prevent the free abrasive grains from working on the polishing surface plate while the free abrasive grains remain free. As a method, for example, as disclosed in Japanese Patent Laid-Open No. 62-292358, first, free abrasive grains are embedded in a polishing platen, and thereafter, the free abrasive grains are left without being embedded in the polishing platen. Perform a work to remove loose abrasive grains, create a polishing surface plate with the loose abrasive particles fixed in advance, and dilute the polishing surface plate with the free abrasive particles fixed (polishing liquid that does not contain the free abrasive particles). There is a method of polishing the floating surface by supplying only it.

[0008]

However, in the above-mentioned conventional method, the work of embedding free abrasive grains on the polishing platen and the work of removing the free abrasive grains remaining on the polishing platen without being embedded. Therefore, free abrasive grains had to be fixed in advance on the polishing platen.

Further, according to the above-mentioned conventional method, the floating surface is polished by a cutting edge having only free abrasive grains (hereinafter referred to as fixed abrasive grains) fixed on the polishing surface plate in advance. For this reason, when polishing a large number of floating surfaces in the mass production process of thin-film magnetic heads, if the cumulative operating time of the polishing surface plate with loose abrasive grains fixed increases, the cutting edges of the fixed abrasive grains gradually wear out or shatter. Or
Alternatively, the fixed abrasive grains may drop off from the polishing surface plate or deeply dive into the polishing surface plate. Due to these factors, the processing ability of the polishing surface plate to which the loose abrasive grains are fixed will gradually decrease as the cumulative use time of the polishing surface plate increases.
That is, there was a life in the duration of the processing ability of the polishing platen having the loose abrasive grains fixed thereto. Since the tool life per polishing surface plate prepared is short, in order to mass-produce thin-film magnetic heads, it is often necessary to create a polishing surface plate to which loose abrasive grains are fixed, or to fix spare loose abrasive grains. I had to prepare a polishing surface plate at all times.

In order to solve these problems, an object of the present invention is to realize polishing of a floating surface mainly by a fixed abrasive grain cutting edge without preparing a polishing surface plate to which loose abrasive grains are fixed. It is an object of the present invention to provide a method of polishing a floating surface of a thin film magnetic head which enables the polishing. Another object of the present invention is to provide a method for final finishing polishing of the floating surface of a thin film magnetic head, which reduces the pole recession of the thin film magnetic head and makes the tool life semi-permanent.

[0011]

In order to achieve the above object, the present invention provides a method for finishing a floating surface in a thin film magnetic head having a floating surface, in which a groove is formed on a polishing reference surface of a polishing surface plate. Using a polishing platen having a spiral groove having a pitch of 0.4 mm or less and a groove width of 0.3 mm or less, and a radial groove intersecting with the spiral groove, a polishing liquid containing free abrasive grains is used. The floating surface of the thin film magnetic head is polished while being supplied to the polishing reference surface of the polishing platen.

[0012]

The spiral groove provided on the polishing reference surface of the polishing surface plate used in the polishing method of the floating surface of the thin film magnetic head of the present invention is formed finely as described above, so that the area occupied by the groove portion on the polishing reference surface is reduced. It is larger than the area occupied by the effective polishing reference surface (the portion other than the groove, the flat portion at the tip of the convex-concave portion of the groove), and therefore the free abrasive grains that are not embedded in the polishing reference surface and are in a free state. Are efficiently removed into the spiral groove.

Further, since the fine spiral groove is provided on the polishing reference surface of the polishing surface plate, the area where the polishing reference surface and the floating surface of the thin film magnetic head contact each other at the time of polishing becomes small, and the polishing reference surface The pressure exerted on the floating surface is increased to promote the effect of the loose abrasive grains being embedded in the polishing reference surface. Then, the floating surface of the thin film magnetic head is polished while supplying the polishing liquid containing loose abrasive particles to the polishing reference surface of the polishing surface plate, so that the polishing reference surface of the polishing surface plate has new cutting edges one after another. Free loose grains are embedded. Therefore, in the polishing method for final finishing of the floating surface of the thin-film magnetic head according to the present invention, the loose abrasive grains are efficiently removed, and the polishing is mainly performed by the fixed abrasive grains.

As described above, the polishing surface plate used in the polishing method of the thin film magnetic head according to the present invention promotes the action of embedding the free abrasive grains in the polishing reference surface. Further, in the polishing method according to the present invention, the free abrasive grains are removed. The floating surface of the thin film magnetic head is polished while supplying the included polishing liquid to the polishing reference surface of the polishing platen, so that free abrasive grains having new cutting edges are embedded in the polishing reference surface of the polishing platen one after another. . Therefore, when mass-producing thin film magnetic heads, even if the floating surfaces of many thin film magnetic heads are polished with the same polishing platen and the cumulative use time of the polishing platens increases, the processing ability of the polishing platens decreases. There is nothing to do. Therefore, when the polishing method according to the present invention is used, the working capacity of the polishing platen is semipermanently maintained, and the tool life is semipermanent. That is, when the polishing surface plate having loose abrasive grains adhered thereto in the above-mentioned conventional technique is used, the working capacity has a lifespan, and the floating surface of many thin film magnetic heads is polished in mass production of thin film magnetic heads. In order to do so, the tool life per polishing surface plate prepared is short, so a polishing surface plate with loose abrasive particles fixed in advance is frequently created, or a spare polishing surface plate with loose abrasive particles fixed is prepared in advance. However, the polishing method of the present invention eliminates the need.

Further, the radial grooves provided on the polishing reference surface of the polishing surface plate used in the polishing method of the thin film magnetic head of the present invention intersect the fine spiral grooves and become radial in the radial direction of the polishing surface plate. Because
It acts as a passage for guiding the loose abrasive grains removed in the fine spiral groove to the outer peripheral portion of the polishing platen. During polishing, the polishing platen is rotated, so the loose abrasive grains are subjected to the centrifugal force generated by the rotation of the polishing platen together with the polishing liquid, and flow toward the outer peripheral portion of the polishing platen through the radial grooves as passages. Efficiently discharged to the outside of the board.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. 2A and 2B show a polishing surface plate used in the present invention. FIG. 2A is a plan view of a polishing reference surface 22 of the polishing surface plate 21, and FIG. 2B is an X of an E portion shown in FIG. -X is a sectional view of an essential part, showing a fine spiral groove 23.
The groove width and groove pitch are shown. On the polishing reference surface 22 of the polishing platen 21, fine spiral grooves 23 having a fine groove interval pitch, and radial grooves 24 which intersect the fine spiral grooves 23 and are radial in the radial direction of the polishing platen 21. And are provided. The material of the polishing platen 21 is tin, which is a soft metal, in consideration of the ease of embedding loose abrasive grains during polishing and the mirror-like finish surface quality required for the floating surface of the thin film magnetic head. ing. However, as described above, since the material of the polishing platen 21 is tin, which is a soft material, it is generally a simple means as a method of forming a groove on the polishing platen, and therefore, in the cutting process that is usually performed often, Since chips are likely to adhere to the cutting edge portion of the tip of the cutting tool at the time of cutting formation, or the groove shape is likely to be plastically deformed to easily generate burrs, it is difficult to form fine grooves with high shape accuracy.
Therefore, in the present embodiment, the groove pitch is made fine within a range that can be easily formed by cutting without adversely affecting the shape accuracy of the groove, and the fine spiral groove 23 is formed by cutting. There is. Fine spiral groove 23 of this embodiment
The specific dimension of the groove width is 0.3 mm, and the dimension of the groove interval pitch is 0.4 mm.

FIG. 1 is an explanatory view of a method for polishing a floating surface of a thin film magnetic head according to the present invention. A thin film magnetic head according to the present invention is manufactured by using a polishing apparatus 10 generally called a single lapping type lapping machine. The polishing method of No. 2 shows a state in which the floating surface of the thin film magnetic head 40 is polished. The polishing surface plate 21 is the polishing surface plate shown in FIG. 2, and the polishing reference surface 22 of the polishing surface plate 21 has a fine spiral groove 23 and a polishing surface intersecting with the fine spiral groove 23. Radial radial grooves 24 are provided in the radial direction of the board 21. When polishing the floating surface of the thin-film magnetic head 40, the polishing surface plate 21 is rotated counterclockwise (in the direction of arrow A) by a motor (not shown), and the polishing reference surface 22 contains the polishing liquid 11 containing loose abrasive grains. , Pump 12
Is continuously supplied through the tube 18. The polishing liquid 11 containing free abrasive grains is put in a bottle 16 and is constantly stirred by a stirrer 17 so that the free abrasive grains do not precipitate in the polishing liquid. In addition, a column 19a is provided on the polishing apparatus 10, and a roller arm 19b having a V-shape is attached to the tip of the upper end of the column 19a. In addition, a roller arm 19 having the shape of a letter "H"
A pair of rollers 14 each having an outer ring rotatable in the clockwise direction (arrow B direction) are attached to the two tips of b. As for the arrangement of the roller 14, the outer ring of the roller 14 rotatable in the clockwise direction (the direction of arrow B) is in contact with the outer cylindrical surface of the hollow cylindrical work carrier 13a placed on the polishing reference surface 22 of the polishing surface plate 21. , Work carrier 1
The outer cylindrical surface of 3a is arranged at a position where the roller 14 receives it.

The work carrier 13a is placed on the polishing reference surface 22 of the polishing surface plate 21 which is rotating counterclockwise (direction of arrow A), and at the same time, the outer cylindrical surface of the work carrier 13a is watched. The roller 14 with an outer ring rotatable in the direction (arrow B direction) receives the work carrier 13a so that the work carrier 13a stays on the polishing platen 21 and is not rotated together with the polishing platen 21, so that the work carrier 13a moves on the polishing apparatus 10. The arrangement position of the work carrier 13a is fixed. When the polishing surface plate 21 is rotated, the polishing reference surface 22 of the polishing surface plate 21 in which the lower surface of the work carrier 13a is in contact with the polishing surface plate 21 has a difference in the radius of rotation between the inner portion and the outer portion. A peripheral speed difference occurs. Since the radius of gyration of the polishing reference surface 22 is naturally larger in the outer portion than in the inner portion, the peripheral speed of the outer portion is faster than that of the inner portion. The difference in peripheral speed between the inner and outer portions of the polishing reference surface 22, that is, the peripheral speed of the outer portion is faster than the peripheral speed of the inner portion of the polishing reference surface 22, so that the polishing surface plate 21 moves clockwise ( When rotated in the direction of arrow A), the work carrier 1
A counterclockwise (arrow C) rotational force is applied to 3a,
The work carrier 13a makes a rotation motion in the counterclockwise direction (direction of arrow C). At this time, the roller 14 is rotated clockwise (arrow B
The outer ring rotatable in the direction) also functions as a guide for the work carrier 13a to rotate in the counterclockwise direction (arrow C direction).

Inside the hollow cylindrical work carrier 13a, there is disposed a polishing plate jig 15 having a floating surface of the thin-film magnetic head 40 adhered downwardly on the lower surface. The polishing plate jig 15 is a polishing plate jig. Since it is placed on the reference surface 22, the polishing surface plate 2
By the rotational movement of 1 in the counterclockwise direction (direction of arrow A), it moves counterclockwise (direction of arrow A) and collides with the inner cylindrical surface of the work carrier 13a. After the collision, the polishing plate jig 15 is also rotated by the rotary motion of the polishing platen 21.
The outer peripheral portion of is pressed against the inner cylindrical surface of the work carrier 13a. Further, since the work carrier 13a is rotating in the counterclockwise direction (arrow C direction) as described above,
The polishing plate jig 15 is also rotated in the counterclockwise direction (the direction of arrow D) to start the rotational movement.

As described above, the polishing plate jig 15 is arranged on the polishing reference surface 22 of the polishing surface plate 21, and the thin film magnetic head 40 faces the floating surface downward on the lower surface of the polishing plate jig 15. Further, the polishing plate jig 15 is bonded in the counterclockwise direction (direction of arrow C) on the polishing reference surface 22 of the polishing surface plate 21 rotating counterclockwise (direction of arrow A). Rotational motion is given in the counterclockwise direction (arrow D direction) by the work carrier 13a which rotates. Therefore, the floating surface of the thin-film magnetic head 40 and the polishing reference surface 22 of the polishing platen 21 relatively slide, and the polishing reference surface 22 includes the polishing liquid 11 containing loose abrasive grains.
However, since it is continuously supplied by the pump 12 through the tube 18, the floating surface of the thin film magnetic head 40 is polished.

On the lower surface of the work carrier 13a, a plurality of ceramics having the same workability as the material of the floating surface of the thin film magnetic head 40 or a plurality of alumina titanium carbide based ceramics having the same material as the floating surface of the thin film magnetic head 40 are formed. The ceramic chips 13b are bonded at regular intervals. The lower surface of these ceramic chips 13b, that is, the surface in contact with the polishing reference surface 22 of the polishing platen 21, is finished by adhering to the lower surface of the work carrier 13a with good flatness, and the individual surfaces are the same. Aligned in the plane. The ceramic chip 13 b has a function of embedding the loose abrasive grains on the polishing reference surface 22 in the polishing reference surface 22. Further, even if the cumulative use time of the polishing surface plate 21 is increased, partial wear (uneven wear) of the polishing reference surface 22 is prevented from occurring and the flatness of the polishing reference surface 22 is maintained. ing. Ceramic chip 13
b is adhered to the lower surface of the work carrier 13a,
The outer diameter of the work carrier 13a is larger than the width dimension of the polishing surface plate 21 in the radial direction.
Overhangs inside and outside the polishing reference surface 22 of the polishing platen 21. Therefore, during polishing, the ceramic chip 13b slides evenly over the polishing reference surface 22 to prevent partial abrasion (uneven wear) of the polishing reference surface 22 and maintain the flatness of the polishing reference surface 22. Further, the pressure applied to the ceramic chip 13b is controlled by the thin film magnetic head 40.
The flatness of the polishing reference surface 22 is also maintained by setting the pressure larger than the pressure applied to the polishing reference surface 22. In the abrasion of the polishing reference surface 22, the overall and even abrasion caused by the even sliding over the entire surface with the ceramic chip 13b is larger than the partial abrasion caused by the partial sliding with the thin film magnetic head 40. .
Therefore, even if partial abrasion occurs on the polishing reference surface 22 due to partial sliding with the thin film magnetic head 40, even greater abrasion, that is, the ceramic chips 13b slide evenly over the entire surface. The resulting uniform and even wear cancels out the partial wear and maintains the flatness of the polishing reference surface 22.

In the polishing method of the present invention, as described above, the polishing surface plate shown in FIG. 2, that is, the fine spiral groove 23 having a fine groove pitch and the radial spiral intersecting with the fine spiral groove 23 are provided. A polishing surface plate 21 having a groove 24 and a polishing reference surface 22 is used.
Therefore, when polishing the floating surface of the thin film magnetic head 40 while supplying the polishing liquid 11 containing loose abrasive grains, the action of removing the loose abrasive grains from the polishing reference surface 22 and the polishing reference surface 22 of the free abrasive grains are performed.
Since the action of embedding in the inner surface is promoted, the polishing process of the floating surface is mainly performed by the abrasive grains fixed to the polishing reference surface 22, and the pole recession is reduced.

FIG. 3 shows that by forming the spiral groove finely, the action of removing the loose abrasive grains from the polishing reference surface and the action of embedding the free abrasive grains in the polishing reference surface are promoted, and the pole recession is actually performed. 9 is a graph of the experimental results confirming that the reduction is achieved, and shows the relationship between the pitch dimension of the spiral groove and the pole recession. In this experiment, a liquid containing a commercially available polishing oil agent and a commercially available polishing diamond paste (oil paste containing diamond abrasive grains having a particle diameter of ¼ μm) at a concentration of 10% was used as a polishing liquid. . Then, the floating surface of the thin-film magnetic head was polished while supplying the polishing liquid containing the abrasive grains to the polishing reference surface of the polishing surface plate. Further, the force applied to the floating surface of the thin film magnetic head during polishing is about 1100 g per square centimeter.
And The vertical axis of the graph of FIG. 3 is the pole recession measured after polishing the floating surface of the thin-film magnetic head, and the horizontal axis of the graph is the groove interval pitch dimension of the spiral groove set as the experimental condition. In addition, in this experiment, the groove pitch pitch dimension of the spiral groove of the experimental condition was 2.0 mm, 0.8
Although the three conditions of mm and 0.4 mm were used, the groove width dimension was constant at 0.3 mm under any of the groove interval pitch dimension conditions. Therefore, the smaller the groove interval pitch dimension of the spiral groove shown on the horizontal axis of the graph, the finer the spiral groove is formed on the polishing reference surface. The graph of the experimental results in FIG. 3 shows that when polishing the floating surface of the thin film magnetic head, forming finer spiral grooves on the polishing reference surface of the polishing surface plate reduces pole recession. Is shown. Specifically, in the case of a spiral groove having a groove width dimension of 0.3 mm, the pole recession having a groove spacing pitch dimension of 50 mm was 50 nm when the groove spacing pitch dimension was 2.0 mm.
It was reduced to 20 nm by finely dividing to m.

Generally, ideally, there should be no step between the floating surface of the thin film magnetic head and the pole, that is, pole recession, so that the recording / reproducing characteristics of the thin film magnetic head are not deteriorated. There is. However, not all thin film magnetic heads with pole recession are impractical defective products. Practically, it depends on the performance of the total recording / reproducing characteristics required for the magnetic recording / reproducing apparatus incorporating the thin film magnetic head, but even a thin film magnetic head with pole recession can be used depending on the amount of pole recession. It becomes a good thin film magnetic head. Specifically, in the current mass production of thin-film magnetic heads, generally, thin-film magnetic heads having a pole recession of 30 nm or more are defective products, and thin-film magnetic heads having a pole recession of less than 30 nm are generally good products. ing.
Therefore, the above experimental result, that is, a spiral shape having a groove width of 0.3 mm and a groove interval pitch of 0.4 mm is provided on the polishing reference surface of the polishing surface plate.
Polishing the floating surface of the thin-film magnetic head while supplying the polishing liquid containing loose abrasive particles to the polishing reference surface of the polishing surface plate reduces the pole recession to 20 nm. If introduced, in the final finishing polishing step of the floating surface in the manufacture of the thin film magnetic head, the occurrence of defective products in which the pole recession reaches 30 nm or more is eliminated, and the manufacturing yield of the thin film magnetic head is improved.

[0025]

The polishing platen used in the polishing method for the final finishing of the floating surface of the thin film magnetic head according to the present invention has a groove width of 0.3 mm or less and a groove interval pitch of 0.4.
Fine spiral grooves within mm were provided on the polishing reference surface of the polishing surface plate, and further radial radial grooves intersecting with the fine spiral grooves were provided in the radial direction of the polishing surface plate. Therefore, the area occupied by the groove portion in the polishing reference plane becomes larger than the area of the effective polishing reference surface (the portion other than the groove, the flat portion at the tip of the convex portion of the concave-convex shape of the groove), and during polishing, Free abrasive grains which are not embedded in the polishing reference surface but are in a free state efficiently drop into the spiral groove and are removed from the surface of the polishing reference surface. In addition, the loose abrasive grains that have fallen into the spiral groove receive the centrifugal force generated by the rotation of the polishing surface plate during polishing, and flow toward the outer peripheral portion of the polishing surface plate through the radial groove as a passage to polish the surface. Efficiently discharged to the outside of the surface plate. Therefore, according to the thin film magnetic head polishing method of the present invention,
It is not necessary to previously perform a work of embedding the free abrasive grains in the polishing reference surface and a work of removing the free abrasive grains remaining without being embedded to prepare the polishing platen having the free abrasive grains fixed thereto. Also, by polishing the floating surface of the thin film magnetic head while supplying a polishing liquid containing loose abrasive grains, the floating surface of the thin film magnetic head is mainly polished by the cutting edge of the fixed abrasive grains, reducing pole recession of the thin film magnetic head. Therefore, in the final finishing polishing process of the floating surface in the manufacture of the thin film magnetic head, the occurrence of defective products in which the pole recession reaches 30 nm or more is eliminated. Therefore, the yield in manufacturing the thin film magnetic head can be improved.

In the final finishing polishing method for the floating surface of the thin film magnetic head according to the present invention, a spiral groove having a groove width of 0.3 mm or less and a groove interval pitch of 0.4 mm or less is provided on the polishing reference surface of the polishing surface plate. The pressure applied to the polishing reference surface and the floating surface of the thin-film magnetic head can be increased to accelerate the action of embedding loose abrasive grains in the polishing reference surface. Further, in the final finishing polishing method for the floating surface of the thin-film magnetic head according to the present invention, the floating surface is polished while supplying a polishing liquid containing loose abrasive grains. Therefore, free abrasive grains having new cutting edges are successively embedded in the polishing reference surface of the polishing surface plate. Therefore, in the final finishing polishing method for the floating surface of the thin-film magnetic head according to the present invention, the floating surface of a large number of thin-film magnetic heads is polished, and even if the cumulative use time of the polishing surface plate is increased, the processing ability of the polishing surface plate is increased. Does not decrease. That is, the tool life of the polishing platen can be made semi-permanent.

The polishing surface plate having loose abrasive grains adhered thereto in the prior art has a limited processing time, and when the thin film magnetic head is mass-produced, the tool life of the polishing surface plate is short. It is necessary to frequently prepare a polishing surface plate to which loose abrasive particles are fixed beforehand, or to always prepare a polishing surface plate to which preliminary free abrasive particles are fixed. However, according to the present invention, since the floating surface is polished while supplying the polishing liquid containing the loose abrasive grains, the free abrasive grains having new cutting edges are successively supplied to the polishing reference surface of the polishing surface plate. To be done. Further, in the present invention, as described above, it is also possible to promote the action of the free abrasive grains being embedded in the polishing reference surface, so that the free abrasive grains having new cutting edges are successively embedded in the polishing reference surface of the polishing platen. . Therefore, even if the cumulative use time of the polishing platen is increased, the machining capability of the polishing platen is not reduced, and the tool life of the polishing platen is semipermanent. It is not necessary to frequently prepare a polishing surface plate to which particles are fixed, or to always prepare a polishing surface plate to which spare loose abrasive particles are fixed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method of polishing a floating surface of a thin film magnetic head according to an embodiment of the present invention.

FIG. 2 is a view showing a polishing surface plate used in a polishing method according to the present invention. FIG. 6A is a plan view of a polishing reference surface of a polishing surface plate. (B) is
FIG. 7A is a cross-sectional view taken along the line XX of FIG.

FIG. 3 is a graph showing the relationship between the groove pitch of spiral grooves on the polishing platen and the pole recession.

FIG. 4 is a diagram showing an external shape of a thin film magnetic head.
(A) is a perspective view of a thin film magnetic head. (B) is
FIG. 7A is a cross-sectional view of the YY main portion of the F portion illustrated in (a).

[Explanation of symbols]

 11 Polishing Liquid 21 Polishing Surface Plate 22 Polishing Reference Surface 23 Spiral Groove 24 Radial Groove

Claims (7)

[Claims] 1. A method of final finishing polishing of a floating surface in the production of a thin film magnetic head having a floating surface, wherein a polishing surface plate having a groove is provided on a polishing reference surface of the polishing surface plate to contain free abrasive grains. A polishing method for a thin film magnetic head, characterized in that the floating surface of the thin film magnetic head is polished while supplying the polishing liquid to the polishing reference surface of the polishing surface plate. 2. The polishing method for a thin film magnetic head according to claim 1, wherein the pitch between the grooves is 0.4 mm or less and the groove width is 0.3 mm or less. 3. The method of polishing a thin-film magnetic head according to claim 1, wherein the groove is a spiral groove extending from the center of the polishing surface plate to the outer periphery. 4. A method of final finishing polishing of a floating surface in the production of a thin film magnetic head having a floating surface, comprising: using a polishing surface plate having a groove on a polishing reference surface of the polishing surface plate to remove free abrasive grains. In the polishing method of the thin film magnetic head, which polishes the floating surface of the thin film magnetic head while supplying the contained polishing liquid to the polishing reference surface of the polishing surface plate, intersects with the groove and from the center of the polishing surface plate. A polishing method for a thin film magnetic head, characterized in that a polishing surface plate provided with a discharge groove for discharging loose abrasive grains in a direction toward the outer periphery is provided separately from the groove. 5. The method of polishing a thin film magnetic head according to claim 4, wherein the pitch between the grooves is 0.4 mm or less and the groove width is 0.3 mm or less. 6. The method of polishing a thin film magnetic head according to claim 4, wherein the groove is a spiral groove extending from the center of the polishing plate to the outer periphery. 7. The method of polishing a thin film magnetic head according to claim 4, wherein the discharge groove is a radial groove radially formed in a polishing platen.