JPH068233A - High precision grinding and cutting device and grinding and cutting method using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a high-precision grinding apparatus and a grinding cutting method thereof, which have high flatness of the cutting surface and can reduce deformation of processing strain. Constitution: A Y table (rotary table) 3 provided via a tilting table 2 rotates 180 ° in synchronization with the reciprocating movement of an X table 1 in the X direction. The work 4 mounted on the rotary table 3 is connected to the Z table and is also connected to the grindstone shaft 6 that descends in the Z direction in synchronization with the movement of the X table 1. The both sides of the cutting groove are alternately ground by only one arbitrary surface of the grindstone 7 so that only one surface a always contributes to the cutting. At the time of cutting, a predetermined grindstone tilting angle θ (usually within 1 °) is set within the YZ plane. As a result, it is possible to balance the grinding resistance acting on both side surfaces of the cutting groove and make the processing strain uniform. A thin film magnetic head for high density recording / reproducing, which is suitable for cutting a thin and hard material and has high reliability, can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding and cutting apparatus for grinding and cutting a hard material such as ceramics with high accuracy and a grinding and cutting method using the same.

[0002]

2. Description of the Related Art A conventional cutting machine or grinding cutting device generally presses a rotating grindstone against a work and cuts it by using both sides of the grindstone. That is, when the work is ground and cut, a force is applied from the work to both side surfaces of the grindstone, but this force is generally unbalanced on both side surfaces. Therefore, when a hard material such as ceramics is ground and cut with a cut piece thickness of 1 to several mm, the grindstone is bent to cause "warpage" or "waviness" on the cut surface, and the flatness of the cut surface is 10 μm. It is about / 40 mm, which means that the cutting surface flatness cannot be obtained with high precision, and because the action on the work is different on both sides of the grindstone, the internal stresses on the cut surfaces on both sides are different.
For this reason, there is a drawback that the whetstone is warped more than "sled" due to the bending of the whetstone.

[0003] As for what is related to this type of cutting accuracy, for example, "Cutting Technology Guide", page 587 (published by: Industrial Technology Service Center, edited by: Cutting Technology Guide Editorial Committee), which describes a 5-inch wafer. Is mentioned.

[0004]

That is, since the conventional cutting machine and grinding cutting device use both side surfaces of the grindstone, the shape of the grindstone corners on both side surfaces of the grindstone changes, or the grindstone properties such as crushing and clogging occur. And other factors cause the forces applied to both side surfaces of the grindstone to become unbalanced, resulting in “warpage” in the cut surface of the workpiece. In other words, accuracy deterioration occurs, but it is remarkable especially when the material is hard and a thin plate is cut. For example, a processing example of a rotary levitation type thin film magnetic head will be described. In this type of head, after applying a semiconductor process, a large number of thin film elements are formed on a non-magnetic ceramic substrate forming a slider body, It is made by cutting, grinding, lapping, etc. of each thin film element, but the "warpage" due to internal stress on the cut surface, that is, deformation of processing strain, deteriorates the alignment accuracy of thin film elements, and the variation in the gap depth of the magnetic head etc. There was a problem of causing performance degradation due to.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art. The first object of the present invention is suitable for processing hard materials such as ceramics, that is, cutting while reducing processing strain. A grinding and cutting device capable of cutting while keeping the flatness of the surface high, a second purpose is to provide a grinding and cutting method using the same, and a third purpose is to provide a magnetic head manufacturing method using the same. Especially.

As a result, it becomes possible to realize a high-precision grinding and cutting device and a high-precision cutting method using the same, a desired cut surface flatness can be obtained, and deformation of processing strain can be reduced, for example, rotation. In the case of a floating thin-film magnetic head, deformation due to processing strain can be prevented, and the recording density can be improved by making the gap depth of the thin-film magnetic head uniform, and the characteristics of the cut head element can be improved. Since they are available, it is possible to reduce the manufacturing process that has been conventionally required for that purpose.

[0007]

Means for Solving the Problems As a result of various experimental studies on the relationship between the cutting surface and the force applied to the grindstone, the inventors have found that
Instead of simultaneous grinding at the wheel corners on both sides of the conventional grindstone, only one side of the grindstone always contributes to cutting, and both sides of the cutting groove are alternately ground by only one side of the grindstone. I obtained the knowledge that I should do so. The present invention has been made on the basis of such knowledge. A first object of the present invention is to attach a work piece set on an X table to a grindstone shaft rotatably held on a Z table while reciprocating the work piece in the X direction. In the grinding and cutting device, the grinding stone is cut in the Z direction by a predetermined amount in synchronization with the reciprocating motion in correspondence with the grinding amount in the Z direction so that the workpiece is cut by the grinding stone. A Y table, which is rotatably arranged and carries a work, and means for setting and holding a predetermined grindstone tilting angle θ in the YZ plane of the Y table, and a predetermined grindstone tilting in the YZ plane. While maintaining the angle θ, the Y table fixedly mounted on the X table is rotated by 180 ° in synchronization with the reciprocating motion in the X direction, so that the whetstone is always kept constant. This is achieved by a high-precision grinding and cutting device capable of grinding on one side. That is, the high-precision grinding and cutting apparatus of the present invention always focuses on making the processing state uniform, and alternately grinds both sides of the cutting groove only on one side of the grindstone so that only one side corner portion of the grindstone contributes to cutting. It was made to cut.

Incidentally, instead of reciprocating the X table in the X direction, the grindstone shaft may be reciprocating in the X direction. However, in this case, the grindstone shaft has three functions of rotating the grindstone, lowering it by a constant amount in the Z direction according to the grinding amount, and reciprocating in the X direction, which complicates the mechanism. .

A second object is to reciprocate the work set on the X table in the X direction, while synchronizing the grindstone attached to the grindstone shaft rotatably held on the Z table with the reciprocating motion. In the grinding cutting method, the work is cut by grinding the grindstone by lowering the work piece in the Z direction by a predetermined amount in proportion to the grinding amount.
A Y that is rotatably arranged on the table and carries a work
While the table keeps a predetermined grindstone tilting angle θ in the YZ plane, the work piece can always be ground on one surface of the grindstone by rotating 180 degrees in synchronization with the reciprocating movement in the X direction. It is achieved by the high precision grinding and cutting method.

A third object is to prepare a magnetic head block by previously arranging and forming a large number of thin film magnetic head elements on a non-magnetic ceramic substrate at predetermined intervals, and the magnetic head block. As a workpiece, and a step of cutting and separating individual thin film magnetic head elements from this, and a step of forming sliders by grinding and lapping. A method of manufacturing a magnetic head comprising a block as a work, and a step of cutting and separating individual thin film magnetic head elements from the block by a high-precision grinding and cutting method capable of achieving the second object. Is achieved.

[0011]

The X table is for reciprocating the work in the X direction, and the Y table is for rotating the work 180 ° on the X table in synchronization with the reciprocating motion of the X table. The left and right side surfaces of the grinding groove are alternately replaced, and the work has a function of grinding the work with a constant grindstone tilting angle .theta. Further, the grindstone of the grindstone shaft fixed to the Z table descends in the Z direction by a constant amount in synchronization with the reciprocating motion of the X table and corresponding to the previous grinding amount, and comes into contact with a new grinding surface. Since only one side of the grindstone contributes to the cutting in this way, the flatness of the cut surface is improved by balancing the force applied to the grindstone, and the internal stress of the cut surface becomes equal on both sides of the cut piece, so Deformation due to distortion is reduced.
The X-table, Y-table, Z-table drive, and grindstone rotation speed are all controlled automatically by a controller using a computer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. <Embodiment 1> FIG. 1 is a plan view of a high precision grinding and cutting apparatus according to an embodiment of the present invention, and FIG. 2 is a side view thereof. The grinding and cutting method will be described. (1) Constitution of grinding and cutting device: As shown in FIGS. 1 and 2, a rotary table 3 serving as a Y table is arranged on a X table 1 which can reciprocate in the X direction via a tilting table 2. . The rotary table 3 on which the work 4 is mounted is moved in the X direction of the work 4 with the tilting table 2 supporting the work 4 being operated to be slightly displaced in the YZ plane by a predetermined grindstone tilting angle θ. It is configured so that it can be rotated 180 ° in the XY plane in synchronization with the reciprocating motion to reverse the direction. A rotary grindstone 7 is connected to the end of the grindstone shaft 6 connected to the Z table, and can be moved in the Z-axis direction as well as in the Y-direction.

(2) Regarding the cutting operation mechanism of the grinding and cutting device: The cutting operation by the high precision grinding and cutting device thus constructed will be described with reference to the drawings. Here, a comparative example in which the rotary table 3 is not operated and a case in which the rotary table 3 is operated and the direction is periodically changed by 180 ° in synchronization with the operation of the X table 1 will be described.

A) In the case of the comparative example in which the rotary table is not cut and operated: FIGS. 3 to 5 show the cutting when the rotary table 3 is cut without using the both sides a and b of the grindstone 7. FIG. 3 is an enlarged cross-sectional view of a main part as viewed from the direction V of FIG. 1, showing the relationship between the shape of the cutting groove d of the work and the grindstone 7 as the process advances. In the figure, the circles indicate that the work advancing direction is toward the front, and the circles indicate that the work advancing direction is toward the back. The procedure of the cutting method is
First, as shown in FIG. 2, the work 4 is sucked by the vacuum chuck 5. The height of the grindstone shaft 6, the cut amount, the total cut amount, the stroke amount of the X table 1, the cutting pitch, and the number of slices are set. At the time of cutting, the tilting table 2 is slightly displaced to the + θ axis (θ is preferably within 1 °),
The X table 1 moves to the back, and the workpiece 4 is moved by the grindstone 7.
The second grinding is performed. The state at this time is shown in FIG.
When the stroke amount of the X table 1 is completed, the grindstone shaft 6 lowers the cutting amount, and the tilting table 2 is moved by -θ.
The sequence in which the axis is slightly displaced, the X table 1 is moved to the front, and the second grinding (see FIG. 4) is performed is repeated up to the total cutting amount, and one cutting is completed. This is completed by cutting the number of slices at intervals of the cutting pitch.

During the cutting operation performed in this manner, only the corners of the grindstone 7 act and the side surfaces of the grindstone do not act as shown in FIGS. 3 to 5, so that the grinding resistance applied to both side surfaces of the grindstone 7 is not affected. Even if there is a balance, since both corners individually act on both side surfaces of the cutting groove d, the bending is also constant on each side surface of the cutting groove d. Therefore, the cutting surface, which is the envelope surface of the corner of the grindstone 7 at each cutting depth, is processed flat. However, since the processing strains on both sides of the cutting piece applied from both corners of the grindstone 7 are unbalanced, the cutting piece is deformed by 1.5 μm / 40 mm.

B) In the case of the present embodiment in which the rotary table is operated to perform grinding cutting: FIGS. 6 to 8 show the cutting of the work 4 as the cutting progresses when only one side a of the grindstone 7 of the present invention is used. The relationship between the shape of the groove d and the grindstone 7 is shown in FIG.
It is a principal part expanded sectional view seen from the direction. As in FIGS. 3 to 5, those marked with a circle indicate that the direction in which the work is moving is toward you.
Those with a mark indicate that the work advancing direction is at the back. While rotating the rotary table 3 in synchronism with the reciprocating motion of the X table 1 by periodically reversing 180 °, the grindstone 7
When cutting is performed using only one surface a, the cutting surface flatness can be set to about 0.5 μm / 40 mm by balancing the grinding resistance acting on both side surfaces of the cutting piece as shown in FIG. In deformation, 0.1 μm / 40
could be reduced to mm.

According to the embodiment described above, even if the sample to be cut is thin, high-precision cutting flatness can be obtained by reducing the processing strain, so that the grinding and lapping steps can be omitted and the number of steps can be reduced. There is an effect.

<Embodiment 2> An alumina titanium carbide wafer having a plate thickness of 4 mm and a Vickers hardness of 1300 was used as a sample by the high precision grinding and cutting apparatus shown in FIGS. 1 and 2 of Embodiment 1 under the following conditions. Disconnected. <Conditions of this Example> ・ Amount of cutting per cut: 2 μm ・ Cutting pitch: 1 mm ・ Cutting distance: 40 mm ・ Grinding stone peripheral speed: 1500 m / min ・ X table feed speed: 500 mm / min ・ Tilt angle of tilting table 2 θ: Within 1 ° The cutting flatness thus obtained is 0.5 μm / 40
It was mm.

On the other hand, for comparison, the same sample was sliced by conventional creep feed cutting under the following conditions. <Conditions for Comparative Example> -Cut amount: 4.5 mm-Cutting pitch: 1 mm-Grinding stone peripheral speed: 1200 m / min-Sample feed speed: 10 mm / min The cutting flatness thus obtained was 10 μm / 40 mm. As is clear from the comparison between the two examples, the cutting effect of the present invention was extremely remarkable.

<Embodiment 3> This embodiment shows an example in which the cutting method of the present invention is applied to the manufacture of a rotary floating thin film magnetic head. FIG. 9 shows the structure of a rotary levitation type thin film magnetic head. 1A is a perspective view showing the entire thin-film magnetic head 9, and FIG. 1B is an enlarged view of a main part of the magnetic element 10. The structure itself of the thin film magnetic head 9 is well known, in which the magnetic head element thin film 10 is formed on the end surface 9c of the non-magnetic ceramic substrate 9a, the substrate 9a is provided on the slider body, and 9b and 9d are provided on the air bearing surface side, respectively. It is a sliding part and a groove. The gap depth 8 of the magnetic head element 10 is an important factor for the recording / reproducing density and directly affects the product accuracy.

FIG. 10 shows a part of the process after cutting the substrate. Although not shown in the drawing, a large number of thin film magnetic head elements 10 are formed on a non-magnetic ceramic substrate (alumina system is used here) 13 in advance at predetermined intervals by applying semiconductor lithographic technique and thin film forming process. The magnetic head block 13 is prepared in advance by arranging and forming the magnetic head blocks 13. Next, using this magnetic head block 13 as a work, the cutting apparatus of Example 1 is used to separate the thin film magnetic head elements into individual thin film magnetic head elements through a two-step cutting process. FIG. 10 shows a state in which a plurality of magnetic head blocks 13a arranged in one row are cut out by this first-stage cutting.
As shown in FIGS. 3A to 3C, when the flatness of the cut surface is poor at the time of cutting the substrate, the head block 13a is deformed by the shrinkage of the adhesive 12 when it is bonded to the air bearing surface polishing jig 11, An error will occur in the gap depth 8 when polishing the air bearing surface. In the figure, 14 indicates the flatness of the cut surface, and 15 indicates the amount of deformation due to processing strain.

According to the present invention, the cut surface flatness is 10 μm /
Improved from 40 mm to 0.5 μm / 40 mm, deformation of processing strain is from 0.3 μm / 40 mm to 0.1 μm / 40 m
The recording density is 50 Mbit / inch ² to 300 as the product performance of the magnetic disk device equipped with a thin film magnetic head.
It has become possible to manufacture high precision thin film magnetic heads up to Mbit / inch ² . In consideration of the manufacturing process, a highly accurate cutting flatness can be obtained, so that the grinding and lapping steps can be omitted, and the number of steps can be reduced. In the actual manufacturing process of the magnetic head, after processing the air bearing surface (sliding portion 9b and groove 9d) after FIG. 10 (c), it is cut into individual head blocks 13b [see FIG. 10 (c)]. Schematic display], and finally the thin film magnetic head 9 of FIG. 9 is completed.
In the above example, the substrate of the magnetic head was described as an example of the sample to be cut, but the feature of the present invention is that it is possible to improve the flatness of the cut surface while reducing the processing strain of the thin and hard material. It goes without saying that it can be widely applied to other fields in which this kind of demand is made.

[0023]

As described above in detail, according to the present invention, the intended purpose can be achieved. That is, it is possible to realize a high-precision grinding and cutting apparatus and a grinding and cutting method using the same, which can improve the flatness of the cutting surface and reduce the deformation due to processing strain, and particularly to cut and process a thin and hard material such as a thin film magnetic head. It is suitable for the magnetic head, and since the processing strain is reduced, it is possible to realize a magnetic head having excellent magnetic characteristics that can be used for high-density recording and reproduction.

[Brief description of drawings]

FIG. 1 is a plan view of a high precision grinding and cutting apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 shows a comparative example of grinding cutting, and is an enlarged cross-sectional view of a main part showing the relationship between the shape of the cutting groove of the work and the grindstone when the rotary table is not operated and both side surfaces of the grindstone are used.

FIG. 4 is an enlarged sectional view of an essential part showing the relationship between the shape of the cutting groove of the work and the grindstone.

FIG. 5 is an enlarged sectional view of an essential part showing the relationship between the shape of the cutting groove of the work and the grindstone.

FIG. 6 is an enlarged sectional view of an essential part showing the relationship between the shape of the cutting groove of the work and the grindstone in the case of the embodiment of the present invention in which the rotary table is operated and only one side of the grindstone is used.

FIG. 7 is an enlarged sectional view of an essential part showing the relationship between the shape of the cutting groove of the work and the grindstone.

FIG. 8 is an enlarged sectional view of an essential part showing the relationship between the shape of the cutting groove of the work and the grindstone.

FIG. 9 is a perspective view of a thin film magnetic head manufactured by applying the present invention.

FIG. 10 is a perspective view of the magnetic head block similarly showing a part of the process after cutting the substrate.

[Explanation of symbols]

1 ... X table, 2 ... tilting table, 3 ... rotating table, 4 ... work, 5 ... vacuum chuck, 6 ... grinding wheel shaft, 7
… Whetstone, 8… Gap depth, 9
... thin-film magnetic head, 9a ... non-magnetic ceramic substrate, 9b ... sliding part, 9c ... slider end surface, 9d ... groove, 10 ... magnetic head element, 11 ... air bearing surface polishing jig, 12 ... adhesive, 13a ... head Block (thin film magnetic head), 14
... Cut surface flatness, 15 ... Deformation amount due to processing strain.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Takeshita 2880 Kozu, Odawara-shi, Kanagawa Hitachi Ltd. Odawara Plant

Claims (10)

[Claims] 1. While reciprocating a work set on an X table in the X direction, a grindstone mounted on a grindstone shaft rotatably held on a Z table is synchronized with the reciprocating motion to match the grinding amount. In a grinding and cutting apparatus configured to cut the work by grinding with the grindstone by lowering the work in a certain amount in the Z direction, a Y table rotatably arranged on the X table and mounting the work, The Y table is provided with means for setting and holding a predetermined grindstone tilting angle θ in the YZ plane, and installed and fixed on the X table in a state of holding the predetermined grindstone tilting angle θ in the YZ plane. A high-precision grinding and cutting apparatus capable of performing grinding by a constant one side of a grindstone by rotating the Y table by 180 ° synchronously with reciprocating movement in the X direction. 2. Synchronizing with the reciprocating motion of the X table,
2. The high precision grinding and cutting apparatus according to claim 1, wherein a Y table which is rotated by 0 ° is mounted on the X table via a tilting table. 3. The high precision grinding and cutting apparatus according to claim 1, wherein the grindstone shaft is reciprocated in the X direction instead of reciprocating the X table in the X direction. 4. A reciprocating motion of a work set on an X table in the X direction, while a grindstone attached to a grindstone shaft rotatably held on a Z table is synchronized with the reciprocating motion.
A grinding and cutting method in which the work is cut by grinding the grindstone by lowering the work piece in the Z direction by a predetermined amount in accordance with the grinding amount. The work is mounted rotatably on the X table. The Y table keeps a predetermined grindstone tilting angle θ in the YZ plane and is rotated by 180 ° in synchronization with the reciprocating movement in the X direction, so that the workpiece is always ground on one side of the grindstone. High precision grinding and cutting method that can be done. 5. The high precision grinding and cutting method according to claim 4, wherein the grindstone tilting angle θ is within 1 °. 6. The work as a hard substrate as claimed in claim 4.
Alternatively, the high-precision grinding and cutting method described in 5. 7. The high precision grinding and cutting method according to claim 6, wherein the hard substrate is a ceramic substrate. 8. A step of preparing a magnetic head block by preliminarily arranging and forming a large number of thin film magnetic head elements on a non-magnetic ceramic substrate at predetermined intervals; A method of manufacturing a rotary floating thin film magnetic head, comprising the steps of cutting and separating the thin film magnetic head element, and forming a slider by grinding and lapping, wherein the magnetic head block is used as a work. A method of manufacturing a magnetic head, comprising a step of cutting and separating individual thin film magnetic head elements by the step of cutting and separating by the high precision grinding and cutting method according to claim 4. 9. The method of manufacturing a magnetic head according to claim 6, wherein the non-magnetic ceramic substrate is made of alumina ceramics. 10. A thin film magnetic head manufactured by the method for manufacturing a magnetic head according to claim 8 or 9.