JP2001347447A - Tape polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform more uniform and highly accurate surface reference polishing. SOLUTION: This tape polishing device is provided with a polishing head 20 having a pressing member 22 for pressing a polishing tape 10 to the polishing object surface 31 side of work 30 from a back face of the polishing tape 10 and having a polishing tape sending mechanism 25 provided with a supply reel 26 and a winding reel 28 for sending the polishing tape 10 along a part opposed to a polishing object surface 31 of the pressing member 22, a rotary mechanism 45 of the polishing head 20 for rotating the polishing head 20 with the axis 21 of the polishing head orthogonal to the polishing object surface 31 as the center and an optical work end point detecting monitor 60 arranged in a side part of the polishing head 20 so as to face to the work 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape polishing apparatus, and more particularly, to a polishing tape having an abrasive grain surface holding abrasive grains and a work having a planar surface to be polished. The present invention relates to a tape polishing apparatus that moves the polishing tape relative to the surface to be polished while bringing the polishing tape into contact with the surface to be polished and polishes the surface to be polished by feeding the polishing tape in a longitudinal direction.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have become more highly integrated, a highly accurate polishing technique in the manufacturing process thereof has become important. In particular, it is required that the interlayer insulating film, metal wiring, and the like deposited and formed when a device is formed on the wafer surface be polished with higher precision. On the other hand, in the conventional wafer polishing apparatus, the wafer is polished so that the surface to be polished can be pressed with a uniform pressure over the polishing surface formed by attaching a polishing cloth to the surface plate. A holding portion having an airbag function has been proposed.

[0003]

However, in the conventional wafer polishing apparatus, the polished surface is formed flat and has no flexibility. For this reason, it is difficult to uniformly polish the surface of a undulated wafer because of the difference in the coefficient of thermal expansion from silicon as a base material due to the formation of devices on the surface. In other words, there is a problem that a high portion caused by the undulation of the wafer is shaved more and cannot be uniformly polished.

Further, in this wafer polishing apparatus, polishing is performed using a polishing solution containing a chemical component for promoting polishing and free abrasive grains, and an interlayer insulating film or metal wiring on which the chemical component is deposited is formed. There has been a problem that the erosion occurs more than a predetermined amount.

[0005] To deal with this, it is conceivable to apply a technique of surface texturing of a hard disk (tape polishing technique). For example, JP-A-63-9917
It is conceivable to apply a processing technique using a polishing tape which considers tape floating due to a dynamic pressure effect described in No. 0 (polishing apparatus). As shown in FIG. 13, the hard disk 14 has a donut shape with an opening at the center, and does not require polishing of the central portion 15 of the circle. For this reason, it is possible to fix to the spindle at the opened central portion 15 and to rotate at high speed. The polishing tape 10 is wound around a cylindrical backup roller 16 and fed by a supply reel 26 and a take-up reel 28. This allows
The relative movement between the polished surface 14a and the polishing tape 10 can be obtained, and the polishing can be performed.

However, in the process of manufacturing a semiconductor device, it is necessary to process the entire surface of a circular wafer.
In other words, even if the wafer is rotated at a high speed about the axis passing through the center, the peripheral speed at the outer periphery is high, but the peripheral speed at the center is zero. Therefore, in the vicinity of the center, the speed of the relative movement with the polishing tape becomes small, and polishing is not possible. For this reason, there is also a problem that the technique of surface texturing relating to a hard disk cannot be directly applied to surface polishing in a manufacturing process of a semiconductor device.

An object of the present invention is to provide a tape polishing apparatus capable of performing more uniform and highly accurate surface reference polishing.

[0008]

To achieve the above object, the present invention has the following arrangement. That is, the present invention
A polishing tape having an abrasive grain surface in which abrasive grains are held, and a work having a planar polished surface are relatively moved while the abrasive grain surface and the polished surface are in contact with each other, and the polishing tape In a tape polishing apparatus for polishing the surface to be polished by feeding in the longitudinal direction, a pressing member for pressing the polishing tape from the back surface of the polishing tape to the surface to be polished,
A polishing head having a polishing tape feeding mechanism provided with a supply reel and a take-up reel for feeding the polishing tape along a portion of the pressing member opposed to the surface to be polished; A rotating mechanism of the polishing head for rotating the axis of the polishing head orthogonal to the axis of the polishing head, and an optical processing end point detection monitor provided on a side portion of the polishing head so as to face the work. .

Further, the pressing member is a pressing pad for pressing the polishing tape from the back surface of the polishing tape toward the surface to be polished, and the polishing tape feeding mechanism is arranged along a pressing surface of the pressing pad. By sending the polishing tape
Wafer-shaped work can be suitably polished.

[0010] Further, since the pressing surface of the pressing pad is circular, a stable rotational motion can be suitably obtained.

[0011] Further, by providing a work rotating mechanism for rotating the holding portion for holding the work about an axis parallel to the axis of the polishing head and separated by a predetermined distance, the entire surface of the work is preferably used. Can be polished. In addition, since the rotational angular velocity of the polishing head is higher than the rotational angular velocity of the work, the abrasive grain surface of the polishing tape can be suitably brought into contact with the surface to be polished, and the polishing can be accurately performed.

Further, the work surface to be polished is circular, and the diameter of the pressing surface is smaller than the diameter of the work surface, so that the optical processing end point detection monitor can appropriately face the work.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a tape polishing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view illustrating an embodiment of the internal structure of the tape polishing apparatus according to the present invention. FIG. 2 is a cross-sectional view showing a state in which the polishing head is rotated 90 degrees from the state shown in FIG. FIG. 3 is a plan view illustrating a rotating state of the polishing head of the embodiment of FIG.

A polishing tape 10 has an abrasive grain surface 12 on which abrasive grains are held. This polishing tape 10 is usually
Abrasive grains are dispersed and applied on a base film of polyester or the like via a paint composed of a binder resin and an additive. The polishing tape 10 is relatively moved with respect to the workpiece 30 having the planar polished surface 31, and the polishing is performed while the abrasive grain surface 12 is in contact with the polished surface 31.

A polishing head 20 has a pressure pad 22 at an end (lower end in this embodiment) and has a built-in polishing tape feed mechanism 25 for feeding the polishing tape 10 in the longitudinal direction. The pressure pad 22 presses the polishing tape 10 from the back surface of the polishing tape 10 toward the surface 31 to be polished. The pressing pad 22 is provided with a pressing means 40.
And its adjusting means. Pressurizing means 40
Any mechanism can be used as long as it can reciprocate the polishing head 20 and the entire pressure pad 22 or the pressing surface 23 thereof, and in this embodiment, move up and down. For example, a vertical movement mechanism using a cylinder device or a motor as a driving source, or a kind of expansion / contraction mechanism using an airbag system can be used. In the case of a cylinder device or an air bag system, the pressure of the polishing tape 10 by the pressure pad 22 can be adjusted by adjusting the pressure of the pressurized air supplied to the pressure chamber. In this embodiment, the pressure is applied from the polishing head 20 side. However, the vertical position of the polishing head 20 is fixed, and the polishing target surface 31 (wafer 3) is fixed.
It is also possible to make the 0) side movable in the vertical direction, and to apply pressure from the polished surface 31 side to the pressure pad 22 side.

In this embodiment, the pressing surface 23 of the pressing pad 22 is formed in a circular shape. According to this, the pressure pad 22 and the polishing head 20 including the same can perform a stable and well-balanced rotational motion, suitably corresponding to the later-described high-speed rotation of the polishing head 20. Further, the pressing force of the pressure pad 22 acts on the surface to be polished with high symmetry via the polishing tape, and a well-balanced polishing can be performed.

The polishing tape feeding mechanism 25 is provided with a supply reel 26 for feeding the polishing tape 10 along the pressing surface 23 of the pressing pad 22 and a take-up reel 28. The pressing surface 23 of the pressing pad 22 faces (opposes) the surface to be polished 31.
The overall shape is flat. That is, since the pressing surface 23 of the present embodiment is formed in a flat shape, the portion of the polishing tape 10 running following the pressing surface 23 also has a flat shape. The polishing tape 10 is fed in order to supply fresh abrasive grains 12 sequentially, and may be at a low speed.

Reference numeral 35 denotes a capstan drive motor. Three
A tape feed capstan 6 is driven by a capstan drive motor 35 via a belt 37 and the like.
Reference numeral 38 denotes a pinch roller, which sandwiches the polishing tape 10 with the tape feed capstan 36. In addition, the take-up reel 28 is configured such that the capstan drive motor 35 is also used, or another drive motor (not shown)
The polishing tape 10 is driven so as to be wound up. The supply reel 26 has a braking function, and is provided so as to apply a predetermined tension so that the polishing tape does not loosen. These mechanisms are for feeding the polishing tape 10 at a constant speed, and a known technique can be used.

Reference numeral 39 denotes a guide for feeding the polishing tape.
On both sides of the pressure pad 22, the surface to be polished 31
From each other. In this embodiment, since the surface 31 to be polished is positioned horizontally, the guide 39 for feeding the polishing tape is also provided in a state of extending in the horizontal direction so as to guide the polishing tape 10 horizontally.
The pair of polishing tape feeding guides 39, 39 suitably guides the polishing tape 10 so as to follow the pressing surface 23 and become flat. In addition, the guide 39 for feeding the polishing tape may be any one that feeds the polishing tape 10 in a slippery manner, and may be rotatably provided in a roller shape.

Reference numeral 45 denotes a rotating mechanism,
Is rotated about the axis 21 of the polishing head orthogonal to the surface 31 to be polished, so that the abrasive grain surface 12 rotates at high speed with respect to the surface 31 to be polished. Reference numeral 21a denotes a rotating shaft of the polishing head, which is rotatably provided on the base 50 via a bearing 46. Reference numeral 47 denotes a driving motor for the polishing head, which is a pulley 4 fixed to the rotating shaft 21a.
The polishing head 20 is driven to rotate at a high speed via the belt 8 and the belt 49. Thereby, a high-speed relative motion (relative speed) between the polishing head 20 (polishing tape 10) and the work 30 can be suitably obtained. The relative speed (mainly the rotation speed of the polishing head 20 in the present embodiment) may be high enough to suitably obtain the dynamic pressure effect described later.

Reference numeral 52 denotes a tip-sway-stopping guide, which guides the tip 20a of the polishing head 20 on the work side in order to prevent the tip of the polishing head 20 from swaying. The tip steadying guide portion 52 is provided at an end portion 55 a (a lower end portion in the present embodiment) of a tubular portion 55 of the base body 50 containing the polishing head 20. The tip steadying guide portion 52 of the present embodiment is similar to that of FIG.
As shown in the figure, the polishing head 20 is composed of three or more roller-shaped members 53 that come into contact with the outer periphery of the circular (cylindrical) polishing head 20. Note that four or more roller-shaped members 53 may be provided. What is called a bearing, a cam follower, or a bearing may be appropriately used as the roller-shaped member. According to this, it is possible to reduce the deflection of the polishing portion and to suitably cope with the high-speed rotation of the polishing head 20. Further, the advantage that uniformity and flatness can be improved by high-speed processing of the polishing tape 10 using fixed abrasive grains can be effectively obtained. The tip steadying guide 52 is not limited to this. For example, a ring-shaped bearing that includes the outer periphery of the polishing head 20 may be used.

Next, the positional relationship of the supply reel 26, the take-up reel 28, and the capstan drive motor 35 in the polishing head 20 will be described. As is clear from FIG. 1, in the polishing head 20 of the present embodiment, the take-up reel 2
8, the supply reel 26, and the capstan drive motor 35 are arranged in a line up and down in this order. The axis 21 of the polishing head is provided so as to pass through the centers of the supply reel 26 and the take-up reel 28. In other words, the centers of gravity of the supply reel 26 and the take-up reel 28, which are the main components, are arranged so as to be on the axis 21 of the polishing head. In this way, by keeping the axis 21 of the polishing head 20 and the centers of gravity of the supply reel 26 and the take-up reel 28, stable rotation can be obtained, and suitable for high-speed rotation. That is, when the polishing tape 10 is fed from the supply reel 26, the weight of the polishing tape 10 is reduced. However, since the center of gravity is at the center of rotation, the balance of rotation is not lost. When the take-up reel 28 takes up the polishing tape, the weight of the polishing tape increases, but since the center of gravity is at the center of rotation, the balance of rotation is not lost. Therefore, uniform and highly accurate polishing can be performed.

The axis 21 of the polishing head is provided so as to pass through the center of gravity of the motor driving the polishing tape feed mechanism 25. In this embodiment, the capstan drive motor 35 also serves as a rotation drive device for the take-up reel 28, and the center of gravity passes through the axis 21 of the polishing head. Since the center of gravity of the drive motor (capstan drive motor 35) is at the center of rotation in this manner, unbalanced rotation can be suitably prevented without requiring a special balancer to be mounted. . Therefore, uniform and highly accurate polishing can be performed.

Reference numeral 32 denotes a holding unit, which holds the work 30. As a means for holding the work 30, for example, a known technique such as vacuum suction by vacuum decompression, application using surface tension of water, adhesion, and electrostatic suction may be used. At this time, by providing a guide ring 32g having substantially the same thickness as the work on the outer peripheral portion of the work 31 on the holding portion 32, the contact force between the polishing tape and the work can be made uniform at the outer peripheral portion of the work. In addition, sagging of the outer peripheral portion of the work can be prevented. Numeral 34 denotes a work rotating mechanism, which rotates the holding unit 32 about an axis 33 of the holding unit which is parallel to the axis 21 of the polishing head and is separated from the holding unit 32 by a predetermined distance.
The work 30 rotates. For example, it is constituted by a drive mechanism for setting the rotational drive of a motor to a desired rotational speed via a speed reduction device. A processing tank 41 receives the liquid supplied for polishing.

According to the work rotating mechanism 34, the angular position of the work 30 can be changed so that the abrasive surface 12 of the polishing tape 10 can contact the entire surface 31 to be polished of the work 30. That is, the surface 31 to be polished can be rotated about the axis 33 perpendicular to the surface to be polished, and can be sequentially fed to the planar abrasive surface 12 of the polishing tape 10. According to the work rotation mechanism 34, the work 30 is rotated (rotated) at a relatively low speed. In this embodiment, at least the rotational angular velocity of the polishing head 20 is set to be higher than the rotational angular velocity of the work. Also,
The polishing speed and the like can be appropriately adjusted by appropriately adjusting the rotation speed of the work rotation mechanism 34. For example, according to the adjustment of the rotation speed, in relation to the rotation speed of the polishing head 20 (polishing tape), the pressing force of the polishing tape 10, and the like, it is necessary to perform adjustment so that the entire surface to be polished 31 is more uniformly polished. Can be.

Further, according to the present embodiment, the polished surface 31 of the work 30 is circular. That is, the work 3 of the present embodiment
Reference numeral 0 denotes a wafer whose base is formed of silicon or the like during an integrated circuit forming process for manufacturing a semiconductor device. It is a thin plate and is formed in a circular shape except for a part of the notch portion and the orientation flat portion.
The diameter of the pressing surface 23 is set smaller than the diameter of the polished surface 31 of the work 30. Further, the diameter of the pressing surface 23 is larger than the radius of the polished surface 31. Accordingly, when the work 30 is rotated (rotated) by the work rotating mechanism 34, the workpiece 30 is supplied so that the polished surface 31 of the work 30 sequentially contacts the abrasive grain surface 12 rotating at a high speed. Therefore, the entire surface to be polished 31 of the work 30 can be efficiently and suitably polished.

As the motion for feeding the work 30, in addition to the above-described rotational motion, a swinging motion, a turning motion that does not rotate, or the like can be used. Further, the present invention is not limited to the movement of the holding portion 32 of the work 30 as in the present embodiment, and the polishing head 20 rotating at a high speed may be moved. In other words, the work 30 and the polishing tape 10 are polished so that the entire surface to be polished 31 is uniformly polished.
What is necessary is just to set the locus | trajectory which moves relatively.

As shown in FIG. 2, reference numeral 60 denotes an optical processing end point detecting device.
It is provided facing. Optical processing end point detection device 60
In the case where the work 30 is in a wafer shape, the thickness of the work 30 is detected by detecting the reflected light from the front surface of the work 30 by emitting infrared rays and the reflected light transmitted through the work 30 and reflected on the back surface. Can be used. According to this, since the thickness of the work 30 can be detected in real time during polishing, the amount of polishing (progress of polishing) can be controlled based on the detected data. As described above, in order for the optical processing end point detection device 60 to appropriately monitor the polished surface 31 of the work 30 even during polishing, the optical processing end point detection device 60 needs to hold the shaft center 21 of the polishing head and the holder 32 on the work rotation mechanism 34. The axis 33 may be set so as to be separated from the axis 33 for a predetermined time, or may be set to be mutually movable. It is preferable that the pressure pad 22 (the pressing surface 23) is smaller than the work 30 (the surface to be polished 31) as shown in FIG. This is because the polishing head 20 and the rotation mechanism 34 of the workpiece are displaced from each other in the axial center, or the relative movement of the mutual axial center, causes the surface 3 to be detected to be the surface to be detected.
1 is likely to be suitably exposed in a state facing the optical processing end point detection device 60.

The tape polishing according to the present invention does not use an opaque polishing liquid containing free abrasive grains as in the prior art.
Is kept clean. In this embodiment, pure water is supplied as a working fluid, and the pure water exerts a dynamic pressure effect (fluid lubrication or elastic fluid lubrication) described later and an effect as a coolant. Pure water is, of course, a transparent liquid containing no abrasive grains. For this reason, the work 30 can be directly observed, the thickness thereof can be suitably measured, and the processing end point can be determined by the optical detection device that detects the reflected light as described above. As another method, it is also possible to use a light source including visible light, monitor the surface state based on a change in the amount of reflected light from the surface, and detect the polishing end point. The working liquid may contain another liquid, for example, a chemical component capable of corroding the polished surface 31 and improving the polishing rate. Even in this case, since it does not contain abrasive grains, it can be a liquid through which light can pass, and the optical processing end point detection device 60 can be suitably used. Thereby, polishing with an appropriate thickness can be performed.

Reference numeral 24 denotes a convex portion, which is provided on the pressing surface 23 of the pressing pad 22 so as to extend in a direction intersecting the relative movement direction of the polishing head 20 and the work 30 as shown in FIG. ing. The cross-sectional shape when cut along the relative movement direction of the convex portion 24 gradually becomes toward the direction opposite to the relative movement direction of the polishing head 20 with respect to the workpiece 30 (see the arrow F in FIG. 5). The projection height is increased so as to continue to the most protruding portion. In other words, the pressure pad 22 on the back of the polishing tape 10
With respect to the shape and the material, a fluid levitation force is generated between the polishing tape 10 and the work 30 such as a semiconductor wafer, and the polishing tape 10 can grind the polished surface 31 of the work 30 with a small contact force therebetween. Set as follows.

According to this, a dynamic pressure effect, in other words, an effect of fluid lubrication or elastic fluid lubrication occurs, and the polishing tape 10 is slightly lifted from the surface 31 to be polished while the tape main body of the polishing tape 10 is lifted. And the work 30 are relatively moved, and the abrasive surface 12 of the polishing tape 10
And can be suitably polished. In other words, the tape body of the polishing tape 10 is slightly floating, but the abrasive grains adhered to the surface (abrasive grain surface) of the tape body and fixed in a protruding state come into contact with the surface 31 to be polished. I do. In other words, the polishing tape 10 is floating and is in a state where the abrasive grains are in contact therewith. Then, the surface to be polished 31 is shaved by the grinding with the abrasive grains to be polished. Thereby, even the undulated polished surface 31 (surface) comes into contact with a small pressure following the undulation, and uniform and highly accurate surface reference polishing can be performed. Further, the floating effect enables the polishing tape 10 to be suitably fed. Further, in order to obtain the dynamic pressure effect suitably, the polishing tape 1
Of course, it is necessary to make the relative speed between 0 and the work 30 higher than a predetermined speed. For example, in the present embodiment, by rotating the polishing head 20 at a high speed, a dynamic pressure effect is generated such that a fluid (working liquid) is drawn between the abrasive surface 12 and the surface 31 to be polished.

Further, as shown in FIG. 5, the cross-sectional shape when cut along the relative movement direction of the convex portion 24 is preferably an arc-shaped cross-section, so that the convex surface 24p is suitably formed. Can be suitably levitated, and even the undulated polished surface 31 can be suitably and uniformly polished. Note that the cross-sectional shape is not limited to the present embodiment, and a liquid (fluid) such as pure water drawn in along with the movement of the polishing tape 10 causes the liquid between the abrasive grain surface 12 and the polished surface 31. Any form can be used as long as it can realize a state in which it enters a wedge shape (see the small arrow shown in FIG. 5). In other words, any shape may be used as long as it can generate a fluid levitation force on the polishing tape surface and gradually reduce the gap that becomes the introduction portion that can reduce the tape contact force. Therefore, the convex portion 24 is formed as the convex surface 24 as in this embodiment.
It is not limited to p, and may be a simple slope, a combination of a slope and a plane, or a plane with a step. For example, as shown in FIG. 6, a tapered flat type convex portion formed by a combination of a slope and a flat surface formed by a combination of a tapered portion 24t and a flat portion 24f can be used. In addition, as shown in FIG. 7, one having a step-shaped convex portion formed of a stepped flat surface formed by the step portion 24s can be used. In addition, as shown in FIG. 8, a convex portion formed of a soft material and having a deformable inclined surface 24e (a soft material inclined surface portion) can be used. FIG. 8A shows a state where the work 30 which is a workpiece is not pressed, and FIG. 8B shows a state where the work 30 is pressed. As shown in FIG. 8B, when the convex portion in the state of FIG. 8A is pressed against the work 30 via the polishing tape 10, the vertex side of the triangular cross section is deformed, and the portion is deformed. It becomes a plane (pressurization flattening part) almost parallel to the surface of 30,
As a result, the shape becomes the same as that of the taper flat type shown in FIG.
With these, the dynamic pressure effect can also be suitably obtained.

The convex portion 24 of the pressing surface 23 of the pressing pad 22 may be formed in an appropriate shape such as a spiral or a radial shape. In the embodiment shown in FIG. 4, the convex portions 24 are formed in a stripe shape extending radially, and a plurality of the convex portions 24 are provided at equally-spaced positions in the circumferential direction. The central part 23a is open. According to this, the convex portions 24 can be suitably arranged on the circular pressing surface 23. In addition, the polishing tape 10 positioned along the convex portion 24 rotating at a high speed and the polishing target surface 3
1, a dynamic pressure effect (fluid lubrication or elastic fluid lubrication) that causes the polishing tape 10 to float from the surface 31 to be polished suitably occurs. Then, the dynamic pressure effect is suitably generated at a plurality of locations on the circular pressing surface 23. Therefore, the surface to be polished can be efficiently polished. In addition, although four convex portions 24 are formed, the present invention is not limited to this, and more convex portions 24 are formed.
More than one book may be provided.

As shown in FIG. 9, the convex portions 24 may be formed in a state parallel to the tangential direction of the circle, and a plurality of the convex portions 24 may be provided at equal positions in the circumferential direction. The central part 23a is open. Further, as shown in FIG.
A may be formed along an arc-shaped line extending radially outward from the center of the circle, and a plurality of A may be provided at equally spaced positions in the circumferential direction. The central part 23a is open. By setting and arranging the shape of the convex portion 24 in this manner, the fluid is guided to the inner side where the peripheral speed due to the rotation is small and the levitation force cannot be obtained, and the floating of the polishing tape on the inner side is assisted. Thus, the dynamic pressure effect can be uniformly applied to the entire surface of the polishing tape.

Further, since the convex portions 24, 24A are provided with a soft material having high elasticity, the effect of the elastic fluid lubrication among the dynamic pressure effects can be suitably used. As a result, the polishing tape 10 can be floated appropriately, and the polished surface 31 can be copied more flexibly, and can be polished uniformly and with high precision. That is, when a strong pressing force is applied, the convex portions 24 and 24A made of the soft material are dented by the pressure, so that the pressing force is buffered and the polished surface 31 can be prevented from being damaged.

For the projections 24 and 24A, a fluoro rubber sponge or the like may be used for weather resistance, friction reduction and flexibility. Next, FIG. 11 and FIG.
Based on the above, a description will be given of a convex portion having another shape. FIG.
The convex portion 24B shown in FIG.
4 is provided with a protective sheet 70 for reducing friction. According to this, the effect of the elastic fluid lubrication can be suitably obtained, and the polishing tape 10 can be smoothly and suitably fed. In the convex portion 24C shown in FIG. 12, the surface side of the pressure pad 22 has a convex (corrugated) metal processing portion 22a.
It is provided as. Further, a surface layer thereon is formed of a sponge sheet 68 having a uniform thickness as an elastic portion. The protective sheet 70 is further provided on the outermost layer.
Is affixed. Also by this, the effect of the elastic fluid lubrication can be suitably obtained, and the polishing tape 10 can be smoothly and suitably fed. Further, according to this structure, there is an advantage that a reliable product can be easily manufactured.

A dressing member 65, as shown in FIG. 1, is provided for adjusting the abrasive grain surface 12 of the polishing tape 10 before it is supplied to the polishing section. The abrasive grain surface 12, which is the surface of the polishing tape 10, has large unevenness at the initial stage. For this reason, the dressing member 6 having a hardness, for example, made of a whetstone, a quartz material or the like.
If the initial dressing 5 is brought into contact with the contact 5, unnecessary protrusions of abrasive grains can be removed. Therefore, the uniformity of the abrasive grain surface 12 can be improved. Thereby, it is possible to prevent the surface to be polished 31 from being damaged, and it is possible to improve the uniformity of polishing.

Further, by appropriately adjusting the feed speed of the polishing tape 10, the amount of polishing of the surface to be polished 31 or the quality of polishing can be adjusted. If the feed speed is increased, a fresh abrasive grain surface 12 is rapidly supplied, so that the polishing amount per unit time can be increased. Also, if the feed rate is reduced, abrasive grains having good grinding efficiency are worn and reduced, so that a flat surface with less surface roughness can be finished. In addition, sending the polishing tape 10 means sending continuously, including sending intermittently, and the sending may be changed intermittently or continuously during the polishing process. For example, after polishing on a continuously supplied fresh surface, feed may be stopped and finish polishing may be performed. by the way,
Reference numeral 42 denotes a connection power supply and the like, for example, a capstan motor power supply, a dressing power supply, an end point detection power supply, a detection output device, a pressurized air supply device, and the like. Is omitted.

According to the tape polishing apparatus described above, in addition to the semiconductor device wafer as in this embodiment,
The present invention can be suitably applied to other fields in which the accuracy of flattening the surface to be polished is improved. For example, the surface of a substrate for a square liquid crystal display based on a thin glass material, and the surface of a hard and brittle thin material such as quartz can be suitably polished. As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and it goes without saying that many more modifications can be made without departing from the spirit of the invention. That is.

[0040]

According to the present invention, in polishing using a polishing tape, a work can be directly observed by an optical processing end point detecting device, its thickness can be measured, and the processing end point can be suitably judged. Therefore, according to the present invention, by performing suitable polishing using a polishing tape and performing processing with an appropriate polishing amount, it is possible to perform a more uniform and high-precision surface-based polishing.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating an embodiment of the internal structure of a tape polishing apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a state in which the polishing head is rotated 90 degrees from the state of FIG.

FIG. 3 is a plan view illustrating a rotating state of the polishing head of the embodiment in FIG. 1;

FIG. 4 is an explanatory diagram illustrating an example of a convex portion formed on a pressing surface of a pressing pad.

FIG. 5 is a cross-sectional view illustrating one cross-sectional shape of the protrusion according to the embodiment of FIG.

FIG. 6 is a cross-sectional view illustrating another cross-sectional shape of the convex portion.

FIG. 7 is a cross-sectional view illustrating another cross-sectional shape of the convex portion.

FIG. 8 is a cross-sectional view illustrating another cross-sectional shape of the convex portion.

FIG. 9 is an explanatory view for explaining another embodiment of the convex portion formed on the pressing surface of the pressing pad.

FIG. 10 is an explanatory diagram for explaining another embodiment of the convex portion formed on the pressing surface of the pressing pad.

FIG. 11 is an explanatory diagram illustrating another cross-sectional shape of the convex portion.

FIG. 12 is an explanatory diagram illustrating another cross-sectional shape of the convex portion.

FIG. 13 is a perspective view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Abrasive tape 12 Abrasive surface 20 Abrasive head 21 Abrasive head axis 22 Pressure pad 23 Pressing surface 24 Convex part 25 Abrasive tape feed mechanism 26 Supply reel 28 Take-up reel 30 Work 31 Polished surface 32 Holding unit 33 Holding unit Axis of work 34 work rotation mechanism 35 capstan drive motor 40 pressurizing means 45 rotation mechanism 50 base 52 tip steady rest guide section 60 optical processing detection device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshinobu Nishimoto 1650 Kiyono, Matsushiro-machi, Nagano-shi, Nagano F-term in Fujikoshi Machinery Co., Ltd. F-term (reference)

Claims (6)

[Claims] 1. A polishing tape having an abrasive grain surface holding abrasive grains and a work having a planar polished surface are relatively moved while the abrasive grain surface and the polished surface are in contact with each other. A tape polishing apparatus for polishing the surface to be polished by feeding the polishing tape in the lengthwise direction, comprising a pressing member for pressing the polishing tape from the back surface of the polishing tape to the surface to be polished, A polishing head having a polishing tape feed mechanism provided with a supply reel and a take-up reel for feeding the polishing tape along a portion of the member facing the surface to be polished, and a polishing head orthogonal to the surface to be polished. A polishing head rotating mechanism for rotating the polishing head about an axis of the polishing head, and an optical processing end point detection monitor provided on a side portion of the polishing head so as to face the work. Dress Place. 2. The pressing member is a pressing pad that presses the polishing tape from the back surface of the polishing tape toward the surface to be polished, and the polishing tape feeding mechanism is configured to move along the pressing surface of the pressing pad. 2. The tape polishing apparatus according to claim 1, wherein the polishing tape is fed at the same time. 3. The tape polishing apparatus according to claim 1, wherein the pressing surface of the pressure pad is circular. 4. A work rotating mechanism for rotating a holding portion for holding the work about an axis parallel to and axially separated from the polishing head by a predetermined distance. 4. The tape polishing device according to 2, 3 or 4. 5. The tape polishing apparatus according to claim 4, wherein a rotational angular velocity of said polishing head is higher than a rotational angular velocity of said work. 6. The tape polishing apparatus according to claim 3, wherein the surface to be polished of the work is circular, and the diameter of the pressing surface is smaller than the diameter of the surface to be polished.