Surface grinding device

Abstract

To provide a low-price plane polishing device which can provide a high plane smoothness of a polishing plane.SOLUTION: Because an adhering disc 20 remains fitted in an eccentric hole 34 formed in an adhering disc eccentric jig 30 rotationally driven by a jig rotation drive device 36, an autorotation drive device making the adhering disc 20 autorotate is unnecessary, so that a low-price plane polishing device 10 can be obtained. At the same time, a rotation direction regulator 44 allows the rotation in the same direction as the rotation of the adhering disc eccentric jig 30 of the adhering disc 20, so that the rotation in the reverse direction to that rotation. By a jig rotation suppressor 58, rotation force from a drive guide roller 42 transmitted to the adhering disc eccentric jig 30 is cut off temporarily over only predetermined rotation phase periods of the adhering eccentric jig 30, so that a high plane smoothness of a polishing plane can be obtained because an autorotation period and a revolution period of the adhering disc 20 are deviated and those periods are no longer synchronized.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a surface polishing apparatus used to mirror-polish one surface of a workpiece such as a semiconductor substrate, and to a technique that enables high flatness to be achieved with a simple apparatus. [Background technology]

[0002] When the workpiece is a semiconductor substrate such as a single crystal wafer of silicon, gallium arsenide, InP (indium phosphide), etc., it is desirable that after it is sliced ​​from the ingot, it be mirror-polished to a high degree of flatness using a surface polishing device.

[0003] Typically, when polishing one surface of a workpiece, a surface polishing apparatus 100 without an eccentric disk jig is used, as shown in Figures 9 and 10. In this surface polishing apparatus 100, when a disk 120 with a workpiece (workpiece) 116 attached to its underside is placed on a rotating polishing platen or polishing pad 112, a pair of free-rotating guide rollers 140 mounted on a guide roller fixing base 138 rotatably supports the disk 120. The disk 120 is rotated by a rotational force based on the difference in peripheral speed of the polishing platen or polishing pad 112, while the disk 120 is pressed against the polishing platen or polishing pad 112 by a load, for example, from a weight 122, thereby polishing. However, in this case, polishing of the outer periphery of one surface of the workpiece 120 is accelerated compared to the inner periphery, so that the workpiece tends to be polished thicker near the center of rotation and thinner at the outer periphery. This tendency becomes more pronounced when polishing is performed using a soft polishing pad or a slurry containing abrasive grains (loose abrasive grains).

[0004] In contrast, a surface finishing device can be considered that uses an eccentric carrier (carrier) rotated by a guide roller around a second rotational axis parallel to the first rotational axis of the polishing table, to polish a workpiece attached to the underside of the carrier. In this case, the carrier is fitted into an eccentric hole formed through the carrier. As the carrier eccentric jig is rotated, the carrier is rotated based on the difference in frictional force between the inner and outer peripheries of the carrier and the polishing table or polishing pad, resulting from the difference in peripheral speed between the inner and outer peripheries. This causes the carrier to rotate and revolve. In this case, the carrier is rotated based on the difference in frictional force between the inner and outer peripheries of the carrier and the polishing table or polishing pad. Since the rotation of the carrier is not controlled, a high level of flatness may not be reliably achieved.

[0005] For this reason, a surface polishing apparatus has been proposed that reliably rotates and revolves an adhesive disk with a workpiece (workpiece) attached to its underside. For example, at least one of a pair of guide rollers that receives an adhesive disk placed on a polishing table or polishing pad and moves together with the polishing table or polishing pad is rotated, and at the same time, a guide roller support base that rotatably supports the guide roller is revolved along a revolution path together with the guide roller. This reliably rotates and revolves the adhesive disk, thereby achieving high flatness on one polished surface of the workpiece. For example, the surface polishing apparatuses described in Cited Documents 1 and 2 are such apparatuses. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4342012 Publication [Patent Document 2] Patent No. 3511584 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the surface polishing apparatus described in References 1 and 2 requires the installation of a dedicated device for rotating and revolving the adhesive disk, which necessitates the modification of the polishing apparatus itself, resulting in the problem of high equipment costs.

[0008] It is also possible to consider a surface polishing apparatus in which the guide roller support base is reciprocated in a direction parallel to the line connecting the center of the polishing surface plate or polishing pad and the center of the attachment disk, instead of revolving along the revolution path together with the guide roller. However, although this type of surface polishing apparatus can achieve high flatness similar to the surface polishing apparatuses described in Patent Documents 1 and 2, it requires the installation of a dedicated device for rotating and reciprocating the attachment disk, which necessitates the modification of the polishing apparatus itself, resulting in the problem of high equipment costs.

[0009] SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inexpensive surface polishing apparatus which can obtain a highly flat polished surface.

[0010] In light of the above circumstances, the inventors have improved a surface finishing device that uses an eccentric application disc jig (carrier) that rotates along the predetermined revolution orbit to polish a workpiece attached to the underside of the application disc. They have discovered that a high level of flatness can be achieved on the polished surface without using a rotary drive device to rotate the application disc. Specifically, they have discovered that by providing a rotation direction restricting device that allows the application disc to rotate in the same direction as the rotation direction of the rotary application disc eccentric jig, and a device that shifts the rotation period of the application disc eccentric jig, i.e., the revolution of the application disc, and the rotation of the application disc, it is possible to achieve a high level of flatness equivalent to that of the applications described in References 1 and 2, without requiring expensive equipment costs. The present invention is based on this finding. [Means for solving the problem]

[0011] The gist of the first invention is (a) a surface polishing device that polishes one surface of a workpiece flat by holding a workpiece attached to the underside of a circular attachment disk in sliding contact with a polishing surface of a polishing table that rotates in one direction, the surface polishing device comprising: (b) a circular attachment disk eccentric jig that is placed on the polishing table and has an eccentric hole formed therethrough into which the attachment disk is rotatably fitted; and (c) a plurality of guide rollers that receive the attachment disk eccentric jig that attempts to move in a circumferential direction together with the polishing table and prevent the movement in the circumferential direction, (d) a jig rotation drive device that drives the application disc eccentric jig to rotate via a drive guide roller among several guide rollers so that the center line of rotation of the application disc revolves along a predetermined revolution trajectory; (e) a jig rotation suppression device that periodically suppresses the rotation of the application disc eccentric jig rotated by the drive guide roller for a predetermined period of time;

[0012] The gist of the second invention is that in the first invention, the rotation direction regulating device applies a predetermined relative rotational resistance between the application disc eccentric jig and the application disc, and when a relative rotational force exceeding the predetermined relative rotational resistance is generated, allows the application disc to rotate in the same direction as the application disc eccentric jig.

[0013] The gist of the third invention is that in the first or second invention, the rotation direction regulating device comprises serrated teeth formed on the outer peripheral surface of the application disc, and locking teeth that engage with the serrated teeth and allow rotation of the application disc in the rotational direction of the application disc eccentric jig, and prevent rotation of the application disc in the opposite direction to the rotation of the application disc eccentric jig.

[0014] The gist of the fourth invention is that in the third invention, the rotation direction regulating device is provided with a pressing force adjusting device that adjusts the rotational resistance of the application disc in the rotation direction of the application disc eccentric jig by changing the pressing force of the locking tooth against the serrated teeth.

[0015] The gist of the fifth invention is that in any one of the first to fourth inventions, the jig rotation suppression device blocks the rotational force transmission path transmitted from the drive guide roller to the application disc eccentric jig for a predetermined rotational phase period of the jig rotation drive device.

[0016] The gist of the sixth invention is that in the fifth invention, the jig rotation suppressing device is configured to suppress the rotation of the applying disk eccentric jig when the rotation force of the applying disk caused by sliding contact with the polishing surface plate exhibits a maximum value equal to or greater than a predetermined value among periodic changes accompanying the rotation of the applying disk eccentric jig. The aforementioned The jig rotation drive device and the applying disk eccentric jig are disconnected only during the rotation phase period of the applying disk eccentric jig.

[0017] The gist of the seventh invention is that in any one of the first to sixth inventions, the jig rotation suppression device is a notch cut out from the outer peripheral edge of the application disc eccentric jig at a portion that comes into contact with the drive guide roller when the rotation center of the polishing table, the rotation center of the application disc eccentric jig, and the rotation center of the application disc are located on a straight line. [Effects of the Invention]

[0018] According to the surface polishing apparatus of the first invention, the apparatus is equipped with a circular applying disc eccentric jig that is placed on the polishing table and has an eccentric hole formed therethrough into which the applying disc is rotatably fitted, a jig rotation drive device that has a plurality of guide rollers that receive the applying disc eccentric jig that attempts to move circumferentially together with the polishing table and prevent the circumferential movement, and that drives the applying disc eccentric jig to rotate so that the center line of rotation of the applying disc revolves along a predetermined revolution trajectory via a drive guide roller among the plurality of guide rollers, a rotation direction regulating device that allows rotation of the applying disc in the same direction as the rotation of the applying disc eccentric jig and prevents rotation of the applying disc in the opposite direction to the rotation of the applying disc eccentric jig, and a jig rotation suppressing device that periodically suppresses rotation of the applying disc eccentric jig rotated by the drive guide rollers for a predetermined period of time. This eliminates the need for a rotation drive device for rotating the application disc, resulting in an inexpensive surface polishing apparatus. At the same time, the rotation direction restricting device allows the application disc to rotate in the same direction as the application disc eccentric jig and prevents rotation in the opposite direction, and the jig rotation suppressing device periodically suppresses the rotation of the application disc eccentric jig, so that the rotation period and revolution period of the application disc are shifted and no longer synchronized, resulting in a high level of flatness of the polished surface.

[0019] According to the surface polishing apparatus of the second invention, the rotation direction regulating device applies a predetermined relative rotational resistance between the application disc eccentric jig and the application disc, and when a relative rotational force exceeding the predetermined relative rotational resistance is generated, allows the application disc to rotate in the same direction as the application disc eccentric jig, so that the application disc can be rotated stably in the same direction as the application disc eccentric jig.

[0020] According to the surface polishing apparatus of the third aspect of the present invention, the rotation direction regulating device comprises serrated teeth formed on the outer peripheral surface of the applying disc, and locking teeth that engage with the serrated teeth to allow rotation of the applying disc in the rotation direction of the applying disc eccentric jig and prevent rotation of the applying disc in the opposite direction to the rotation of the applying disc eccentric jig. This makes it possible, with a simple mechanism, to allow rotation of the applying disc in the same direction as the rotation of the applying disc eccentric jig.

[0021] According to the surface polishing apparatus of the fourth aspect of the present invention, the rotation direction restricting device includes a pressing force adjusting device that adjusts the rotation resistance of the applying disk in the rotation direction of the applying disk eccentric jig by changing the pressing force of the locking teeth against the saw-tooth teeth, thereby restricting excessive rotation of the applying disk in the same direction as the rotation of the applying disk eccentric jig, and allowing the applying disk to rotate stably.

[0022] According to the surface polishing apparatus of the fifth aspect of the invention, the jig rotation suppressing device blocks the rotational force transmission path from the drive guide roller to the applying disc eccentric jig for a predetermined rotation phase period of the jig rotation drive device. This temporarily suppresses the rotation of the applying disc eccentric jig and allows the rotation phase of the applying disc to advance, thereby reliably shifting the rotation period and revolution period of the applying disc.

[0023] According to the surface polishing apparatus of the sixth aspect of the invention, the jig rotation suppressing device isolates the jig rotation drive device from the applying disc eccentric jig only during the rotation phase of the applying disc eccentric jig when the rotational force of the applying disc, generated by sliding contact between the applying disc and the polishing surface plate, exhibits a maximum value equal to or greater than a predetermined value among the periodic changes that accompany the rotation of the applying disc eccentric jig. As a result, the rotational force from the jig rotation drive device is temporarily isolated only during the rotation phase of the applying disc eccentric jig when the rotational force of the applying disc is large, and the rotation phase of the applying disc is allowed to advance, thereby reliably staggering the rotation period and revolution period of the applying disc.

[0024] According to the surface polishing apparatus of the seventh aspect of the present invention, the jig rotation suppression device is a notch formed by cutting out a portion of the outer periphery of the applying disc eccentric jig that comes into contact with the drive guide roller when the rotation center of the polishing surface plate, the rotation center of the applying disc eccentric jig, and the rotation center of the applying disc are all aligned on a straight line. This simple mechanism causes the rotation period and revolution period of the applying disc to be shifted, causing them to become out of sync. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view conceptually showing the basic configuration of a surface polishing apparatus according to an application example of the present invention; [Figure 2] 2 is a schematic plan view showing an attachment disk, a disk eccentric jig, a jig rotation drive device, a rotation direction regulating device, and a jig rotation suppressing device provided in the surface polishing apparatus of FIG. 1. FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. 4 is a schematic diagram showing a plane of the adhesive disk of FIGS. 2 and 3. [Figure 5] FIG. 4 is a schematic diagram showing a cross section of the adhesive disk of FIGS. 2 and 3. [Figure 6] 3 is a schematic diagram illustrating the rotation direction restricting device of FIG. 2. FIG. [Figure 7] 4 is a schematic diagram showing a plan view of the joining disk eccentric jig of FIGS. 2 and 3. FIG. [Figure 8] 4 is a schematic diagram showing a cross section of the laminating disk eccentric jig of FIG. 2 and FIG. 3. [Figure 9] 3 is a plan view showing an adhering disc and a jig rotation drive device provided in a conventional surface polishing apparatus in which the adhering disc does not revolve, and corresponds to FIG. 2. FIG. [Figure 10] 9. FIG. 10 is a schematic diagram showing a cross section of the attachment disk taken along the line XX in FIG. 9, and corresponds to FIG. [Figure 11] 1 is a table showing the PV values ​​of the surfaces of the respective workpieces ground in a surface grinding test conducted by the present inventor. [Figure 12] 1 is a diagram showing the surface profiles of each workpiece polished in a plane search test conducted by the present inventor. [Figure 13] 10 is a schematic plan view corresponding to FIG. 2 showing another embodiment of the present invention. FIG. [Figure 14] FIG. 13 is a schematic cross-sectional view taken along the line XIII-XIII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0026] An application example of the present invention will be described in detail below with reference to the drawings. [Example]

[0027] FIG. 1 conceptually illustrates the essential components of a surface polishing apparatus 10 according to an embodiment of the present invention. In FIG. 1, the surface polishing apparatus 10 includes a polishing platen 12 rotatably supported about a vertical rotation centerline C1. The polishing platen 12 is driven by a platen drive motor 14 to rotate, for example, in one direction indicated by the arrow in FIG. 1. A sheet-shaped polishing pad 18, preferably containing abrasive grains, having the same diameter as the polishing platen 12 is attached to the upper surface of the polishing platen 12. In this embodiment, the upper surface of the polishing pad 18 functions as a planarized polishing surface against which a workpiece 16, such as a semiconductor substrate, is pressed.

[0028] At a position eccentric from the rotation center line C1 on the polishing surface plate 12, an attachment disk 20 is placed, with the workpiece 16 attached to its underside by suction, adhesive, or a holding frame, etc., so that the attachment disk 20 can rotate about a rotation center line C3 parallel to the rotation center line C1 and move in the direction of the rotation axis C3. A disk-shaped weight 22 is placed on the attachment disk 20 to increase the surface pressure on the workpiece 16 during polishing. The attachment disk 20 is rotated in the direction indicated by the arrow in Figure 1 by a rotational moment generated by the difference in frictional force between the inner and outer circumferential sides of the polishing surface plate 12 in the tangential direction, which is received from the polishing pad 18.

[0029] A drip nozzle 24 and a spray nozzle 26 are provided near the adhesive disk 20 of the surface polishing device 10, and a polishing liquid (lubricant) 28, such as an oxidizing or alkaline aqueous solution, delivered from a tank not shown is supplied onto the polishing table 12.

[0030] The surface polishing apparatus 10 may optionally be provided with an adjustment tool holder (not shown) that is rotatable about a rotation axis parallel to the rotation axis C1 of the polishing table 12 and that is movable in the direction of the rotation axis and in the radial direction of the polishing table 12, and an abrasive body adjustment tool (dresser or conditioner) such as a diamond wheel (not shown) that is attached to the underside of the adjustment tool holder, i.e., the surface facing the polishing pad 14. The adjustment tool holder and the abrasive body adjustment tool attached thereto are pressed against the polishing pad 18 while being rotated by an adjustment tool drive motor (not shown), and are moved back and forth in the radial direction of the polishing table 12, thereby adjusting the polishing surface of the polishing pad 18 and constantly maintaining the surface condition of the polishing pad 18 in a state suitable for polishing.

[0031] 2 and 3 show the applying disc eccentric jig 30 placed on the polishing platen 12, which are not shown in Fig. 1, a jig rotation drive device 36 fixed to the surface polishing apparatus 10 and which rotates the applying disc eccentric jig 30 about the revolution center line C2 parallel to the rotation center line C1, a rotation direction restricting device 44 which restricts the rotation direction of the applying disc 20 relative to the applying disc eccentric jig 30 to one direction, and a jig rotation suppressing device 58 which shifts the rotational synchronization of the applying disc 20 relative to the applying disc eccentric jig 30. Fig. 2 is a plan view, and Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2.

[0032] Fig. 4 is a plan view of the application disc 20, and Fig. 5 is a side view of the application disc 20. The application disc 20 integrally comprises a short cylindrical main body 20a to the bottom of which the workpiece 16 is fixed, and a flange 20b that protrudes from the upper end of the main body 20a toward the outer periphery and has a larger diameter than the main body 20a. Saw-tooth teeth 46 are formed continuously in the circumferential direction on the outer periphery of the flange 20b.

[0033] The applying disc eccentric jig 30 is disk-shaped with the revolution centerline C2 as its rotation centerline, and is provided with an eccentric hole 34 formed around a position eccentric from the revolution centerline C2 by a predetermined eccentric distance r so that the main body 20a of the applying disc 20 can be fitted into the applying disc 20 so as to be relatively rotatable and movable in the thickness direction. The center line of the eccentric hole 34 approximately coincides with the rotation centerline C3 of the applying disc 20. For example, the diameter of the eccentric hole 34 is larger than the radius of the applying disc eccentric jig 30, and the predetermined eccentric distance r is approximately ½ of the radius of the eccentric hole 34 or less.

[0034] The jig rotation drive device 36 has a guide roller fixed base 38 fixed to a frame (not shown) of the polishing processing device 10, and a pair of free-rotating guide rollers 40 and a drive guide roller 42 provided on the guide roller fixed base 36, and receives the applying disk eccentric jig 30 which is placed on the polishing table 12 and attempts to move circumferentially together with the polishing table 12, preventing the circumferential movement, keeping the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30, still, and drives the applying disk eccentric jig 30 to rotate around the revolution center line C2 at a constant speed, for example, via the drive guide roller 42. When the sticking disk eccentric jig 30 is rotated around the revolution center line C2, the rotation center line C3 of the sticking disk 20 in the eccentric hole 34 moves along a revolution locus K with a smaller diameter than the radius of the eccentric hole 34, and the sticking disk 20 is made to revolve around the revolution center line C2 while rotating around the rotation center line C3.

[0035] The free-rotating guide roller 40 is mounted on the guide roller fixed base 38 so as to be freely rotatable, and the drive guide roller 42 is mounted on the guide roller fixed base 38 so as to be rotatable in one direction by a drive motor (not shown). The drive guide roller 42 is mounted on the guide roller fixed base 38 so that its center of rotation is located on a straight line SL connecting the rotation center line C1 of the polishing surface plate 12 and the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30. The free-rotating guide roller 40 is mounted on the guide roller fixed base 38 so as to come into contact with a portion of the applying disk eccentric jig 30 that is downstream in the rotation direction of the polishing surface plate 12 from the straight line SL connecting the rotation center line C1 of the polishing surface plate 12 and the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30, and that is located on the inner side of the arc around the rotation center line C1 that passes through the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30.

[0036] 6, the rotation direction restricting device 44 includes sawtooth teeth 46 formed continuously on the outer peripheral surface of the flange portion 20b of the applying disc 20, and locking teeth 48 provided on the applying disc eccentric jig 30 that lock onto the sawtooth teeth 46. The rotation direction restricting device 44 allows rotation of the applying disc 20 in the rotation direction of the applying disc eccentric jig 30, and prevents rotation of the applying disc 20 in the opposite direction to the rotation of the applying disc eccentric jig 30. The rotation direction restricting device 44 also applies a predetermined relative rotational resistance between the applying disc eccentric jig 30 and the applying disc 20, and when a relative rotational force exceeding the predetermined relative rotational resistance is generated, allows rotation of the applying disc 20 in the same direction as the rotation of the applying disc eccentric jig 30.

[0037] The rotation direction restricting device 44 is equipped with a pressing force adjusting device 50 that adjusts the rotational resistance of the applying disk 20 in the rotational direction of the applying disk eccentric jig 30 by changing the pressing force of the locking teeth 48 against the sawtooth teeth 46. The locking teeth 48 are provided at the tip end of a leaf spring 52 whose base end is fixed to the applying disk eccentric jig 30, and the pressing force adjusting device 50 is equipped with an abutment member support device 56 that supports an abutment member 54 that abuts against the back surface of the leaf spring 52 so that the abutment member 54 can move in the longitudinal direction of the leaf spring 52. The more the abutment member 54 that abuts against the back surface of the leaf spring 52 is moved toward the tip side of the leaf spring 52, the greater the pressing force of the locking teeth 48 against the sawtooth teeth 46, and the greater the rotational resistance.

[0038] The jig rotation suppression device 58 suppresses the rotation of the applying disc eccentric jig 30 by interrupting the rotational force transmitted from the jig rotation drive device 36 to the applying disc eccentric jig 30 for a predetermined rotational phase period of the applying disc eccentric jig 30 so that the rotation of the applying disc 20 is out of synchronization with the rotation of the applying disc eccentric jig 30, and advances the rotation of the applying disc 20 by a predetermined amount relative to the rotation of the applying disc eccentric jig 30. The jig rotation suppression device 58 interrupts communication between the jig rotation drive device 36 and the applying disc eccentric jig 30 for a rotational phase period of the applying disc eccentric jig 30 during which the rotational force generated by the sliding contact of the applying disc 20 with the polishing surface plate 12 exhibits a maximum value equal to or greater than a predetermined value among the periodic changes that occur with the rotation of the applying disc eccentric jig 30, thereby temporarily suppressing the rotational drive of the applying disc eccentric jig 30 by the jig rotation drive device 36. Preferably, as shown in the application disc eccentric jig 30 in Figures 7 and 8, the jig rotation suppression device 58 is composed of a notch 60 cut out from the outer peripheral edge of the application disc eccentric jig 30 at a portion that comes into contact with the drive guide roller 42 when the rotation center line C1 of the polishing table 12, the revolution center line C2 which is the rotation center line of the application disc eccentric jig 30, and the rotation center line C3 of the application disc 20 are positioned on a straight line.

[0039] The application disc 20, which is placed on the polishing platen 12 and slides against the polishing platen 12, is subjected to a greater frictional force from the outer periphery of the polishing platen 12 than from the inner periphery, and is therefore caused to rotate in the same direction as the application disc eccentric jig 30, as shown in Figure 2. The rotational force that causes the application disc 20 to rotate increases or decreases in relation to the rotation phase of the application disc eccentric jig 30, and is greatest when the rotation center line C1 of the polishing platen 12, the revolution center line C2 which is the rotation center line of the application disc eccentric jig 30, and the rotation center line C3 of the application disc 20 are all aligned in a straight line.

[0040] [Experimental Example] The following describes experimental examples conducted by the present inventors. Two types of polishing tests (Comparative Example Test 1 and Comparative Example Test 2) were conducted on a common sample of workpiece under the following free-abrasive polishing conditions. One was conducted using a surface polishing apparatus without an eccentric disk attachment jig, as shown in FIGS. 9 and 10 , and the other was conducted using a surface polishing apparatus equipped with a rotation direction restricting device 44 and a jig rotation suppressing device 58, as shown in FIGS. 2 to 8 . In Comparative Example Test 1 and Example Test 1, a 5 mm-thick polyurethane foam pad was used as the polishing pad, and ceria slurry (5 wt%) was used as the polishing liquid. In Comparative Example Test 2 and Example Test 2, a 5 mm-thick semi-fixed abrasive pad was used as the polishing pad, and water was used as the polishing liquid. The semi-fixed abrasive pad is an abrasive-containing polishing pad made of epoxy resin or PES resin with closed or interconnected pores containing abrasive grains (ceria).

[0041] [Polishing test conditions] Surface polishing device: Lapmaster LP15 modified machine Workpiece: Synthetic quartz wafer (65mmφ) Work rotation speed: 60 rpm Polishing pad / polishing liquid: Polyurethane foam pad + ceria slurry (5 wt%) Polishing pad / polishing liquid: Pad containing abrasive grains (ceria) + water Polishing pad diameter: 300mmφ Polishing pad rotation speed: 60 rpm Polishing pressure: 20kPa Center distance between polishing pad and workpiece: 85 mm Polishing pad / revolution orbit center distance: 85 mm Distance between the center of revolution trajectory and the center of workpiece: 40 mm Polishing liquid flow rate: 10ml / min Dressing pressure, rotation speed, time: 25 kPa, 60 rpm, 120 sec

[0042] FIG. 11 is a table showing the PV values ​​of the workpiece surfaces polished by Comparative Example Test 1, Comparative Example Test 2, Example Test 1, and Example Test 2. The PV value is the difference (μm) between the highest and lowest points on the workpiece surface, measured using a laser interferometer. FIG. 12 shows the cross-sectional profiles of the workpieces polished by Comparative Example Test 1, Comparative Example Test 2, Example Test 1, and Example Test 2. The cross-sectional profiles were measured using a laser interferometer.

[0043] In FIG. 11, the PV value of the workpiece polished in Example Test 1 is significantly smaller than that of the workpiece polished in Comparative Example Test 1. The PV value of the workpiece polished in Example Test 2 is also significantly smaller than that of the workpiece polished in Comparative Example Test 2. In FIG. 12, the cross-sectional profile of the workpiece polished in Example Test 1 exhibits significantly higher flatness than that of the workpiece polished in Comparative Example Test 1. The cross-sectional profile of the workpiece polished in Example Test 2 exhibits significantly higher flatness than that of the workpiece polished in Comparative Example Test 2. These facts indicate that even when the polishing pad and polishing liquid are the same, when the workpiece is rotated and revolved and the synchronization of the rotation and revolution is desynchronized, a significantly higher flatness can be obtained on the polished surface of the workpiece than when the workpiece is rotated alone. When the rotation and revolution of the workpiece are desynchronized, the shape formed by wear on the portion of the polishing pad's upper surface against which the workpiece is pressed is suppressed from being transferred to the polished surface of the workpiece, resulting in a significantly smaller PV value of the workpiece and a significantly higher flatness in the cross-sectional profile of the workpiece.

[0044] In FIG. 11, the PV value of the workpiece polished in Comparative Example Test 2 is significantly smaller than that of the workpiece polished in Comparative Example Test 1. Furthermore, the PV value of the workpiece polished in Example Test 2 is significantly smaller than that of the workpiece polished in Example Test 1. In FIG. 12, the cross-sectional profile of the workpiece polished in Comparative Example Test 2 exhibited significantly higher flatness than that of the workpiece polished in Comparative Example Test 1. Furthermore, the cross-sectional profile of the workpiece polished in Example Test 2 exhibited significantly higher flatness than that of the workpiece polished in Example Test 1. These facts indicate that in the case of fixed-abrasive polishing using a semi-fixed abrasive pad as the polishing pad and water as the polishing liquid, a higher level of flatness can be achieved on the polished surface of the workpiece compared to free-abrasive polishing using a polyurethane foam pad as the polishing pad and ceria slurry as the polishing liquid, even with the same polishing rotational motion.

[0045] As described above, the surface polishing apparatus 10 of this embodiment includes a disc-shaped applying disc eccentric jig 30 that is placed on the rotating polishing table 12 and has an eccentric hole 34 formed therethrough into which the applying disc 20 is rotatably fitted, and a plurality of guide rollers (40, 42) that receive the applying disc eccentric jig 30 that attempts to move in the circumferential direction together with the polishing table 12 and prevent the circumferential movement, and the rotation center line C3 of the applying disc 20 is aligned with a predetermined axis via the drive guide roller 42 of the plurality of guide rollers. the jig rotation drive device 36 that rotates and drives the applying disc eccentric jig 30 so that it revolves along the orbital locus K of the applying disc 20, a rotation direction regulating device 44 that allows rotation of the applying disc 20 in the same direction as the rotation of the applying disc eccentric jig 30 and prevents rotation of the applying disc 20 in the opposite direction to the rotation of the applying disc eccentric jig 30, and a jig rotation suppressing device 58 that blocks the rotational force from the drive guide roller 42 that is transmitted to the jig rotation drive device 36 for only a predetermined rotation phase period of the jig rotation drive device 36. This eliminates the need for a rotation rotation drive device that rotates the applying disc 20 on its own axis, thereby providing an inexpensive surface polishing apparatus 10. At the same time, the rotation direction control device 44 allows the application disc 20 to rotate in the same direction as the application disc eccentric jig 30, and prevents rotation in the opposite direction, and the jig rotation suppression device 58 temporarily blocks the rotational force from the drive guide roller 42 transmitted to the application disc eccentric jig 30 for a specified rotation phase period of the application disc eccentric jig 30, so that the rotation period and revolution period of the application disc 20 are shifted and no longer synchronized, resulting in a high level of flatness of the polished surface.

[0046] Furthermore, according to the surface polishing apparatus 10 of this embodiment, the rotation direction regulating device 44 applies a predetermined relative rotational resistance between the application disc eccentric jig 30 and the application disc 20, and when a relative rotational force exceeding the predetermined relative rotational resistance is generated, it allows the application disc 20 to rotate in the same direction as the application disc eccentric jig 30, so that the application disc 20 can be rotated stably in the same direction as the application disc eccentric jig 30.

[0047] Furthermore, according to the surface polishing apparatus 10 of this embodiment, the rotation direction regulating device 44 comprises sawtooth teeth 46 formed on the outer peripheral surface of the applying disc 20, and locking teeth 48 that engage with the sawtooth teeth 46 to allow rotation of the applying disc 20 in the rotation direction of the applying disc eccentric jig 30 and prevent rotation of the applying disc 20 in the opposite direction to the rotation of the applying disc eccentric jig 30. This makes it possible to allow rotation of the applying disc 20 in the same direction as the rotation of the applying disc eccentric jig 30 with a simple mechanism.

[0048] Furthermore, according to the surface polishing apparatus 10 of this embodiment, the rotation direction regulating device 44 is equipped with a pressing force adjusting device 50 that adjusts the rotation resistance of the applying disk 20 in the rotation direction of the applying disk eccentric jig 30 by changing the pressing force of the locking teeth 48 against the saw-tooth teeth 46. This limits excessive rotation of the applying disk 20 in the same direction as the rotation of the applying disk eccentric jig 30, allowing the applying disk 20 to rotate stably.

[0049] Furthermore, according to the surface polishing apparatus 10 of this embodiment, the jig rotation suppression device 58 blocks communication between the jig rotation drive device 36 and the applying disc eccentric jig 30 only during the rotation phase of the applying disc eccentric jig 30 when the rotational force of the applying disc 20, generated by sliding contact between the applying disc 20 and the polishing surface plate 12, exhibits a maximum value equal to or greater than a predetermined value among the periodic changes that accompany the rotation of the applying disc eccentric jig 30. As a result, the rotational force from the jig rotation drive device 36 is temporarily blocked only during the rotation phase of the applying disc eccentric jig 30 when the rotational force of the applying disc 20 is large, and the rotation phase of the applying disc 20 is allowed to advance, so the rotation period and revolution period of the applying disc 20 are reliably shifted.

[0050] Furthermore, according to the surface polishing apparatus 10 of this embodiment, the jig rotation suppression device 58 is composed of a notch 60 formed by cutting out a portion of the outer circumferential edge of the applying disc eccentric jig 30 that comes into contact with the drive guide roller 42 when the rotation center line C1 of the polishing surface plate 12, the revolution center line C2 of the applying disc eccentric jig 30, and the rotation center line C3 of the applying disc 20 are all positioned on a straight line SL in a plan view. This simple mechanism causes the rotation period and revolution period of the applying disc 20 to be shifted, so that these periods no longer synchronize. [Example]

[0051] Next, another embodiment of the present invention will be described. In the following description, parts common to the above embodiment will be designated by the same reference numerals and will not be described again.

[0052] 13 and 14 are a plan view and a cross-sectional view taken along line XIV-XIV in FIG. 13 of another embodiment of the present invention, and correspond to the above-mentioned FIGS. 2 and 3. In FIG.

[0053] This embodiment differs from the previously described embodiment in that the positions of the free-rotating guide roller 40 and the drive guide roller 42 of the jig rotation drive device 36, which drives the application disc eccentric jig 30 to rotate around the revolution center line C2 parallel to the rotation center line C1, are different, but the rest is configured in the same way.

[0054] The drive guide roller 42 in this embodiment is provided rotatably around the same center line as the rotation center line C1 of the polishing platen 12. The free-rotating guide roller 40 is provided on the guide roller fixing base 38 so as to come into contact with a portion of the applying disk eccentric jig 30 that is downstream in the rotation direction of the polishing platen 12 from a straight line SL that connects the rotation center line C1 of the polishing platen 12 of the applying disk eccentric jig 30 and the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30, and that is located on the outer periphery of an arc around the rotation center line C1 that passes through the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30.

[0055] In this embodiment, similar to the jig rotation drive device 36 of the previously described embodiment, the applying disk eccentric jig 30, which is placed on the polishing platen 12 and tends to move circumferentially together with the polishing platen 12, is received and the circumferential movement is prevented, the revolution center line C2, which is the rotation center line of the applying disk eccentric jig 30, is held stationary, and the applying disk eccentric jig 30 is driven to rotate about the revolution center line C2 at a constant speed, for example, via the drive guide roller 42. Because the applying disk eccentric jig 30 is rotated about the revolution center line C2, the same effects as in the previously described embodiment can be obtained.

[0056] Although one embodiment of the present invention has been described above, the present invention can also be applied in other aspects.

[0057] For example, the jig rotation drive device 36 in the above-described embodiment had a pair of free-rotating guide rollers 40 and a drive guide roller 42, but it may also have guide rollers other than these, or may have multiple drive guide rollers.

[0058] Furthermore, the rotation direction regulating device 44 in the above-described embodiment was equipped with sawtooth teeth 46 formed on the outer peripheral surface of the flange portion 20b of the application disc 20 and locking teeth 48 provided on the application disc eccentric jig 30 so as to be able to engage with the sawtooth teeth 46, but the sawtooth teeth may be formed on the inner peripheral surface of the eccentric hole 34 of the application disc eccentric jig 30, and locking teeth that engage with the sawtooth teeth on the inner peripheral surface of the eccentric hole 34 may be provided on the application disc 20.

[0059] In addition, the jig rotation suppression device 58 of the above-mentioned embodiment may be configured to shift the rotation period and revolution period of the application disc 20 by controlling the electric motor that rotates the drive guide roller 42 to suppress the rotation transmitted from the drive guide roller 42 to the application disc eccentric jig 30.

[0060] Although not specifically exemplified, the present invention can be used with various modifications within the scope of the invention. [Explanation of symbols]

[0061] 10: Surface polishing device 12: Polishing plate 16: Work 20: Stick-on disc 34: Eccentric hole 30: Eccentricity jig for adhesive disk 36: Jig rotation drive device 42: Drive guide roller 44: Rotation direction control device 46: Serrated teeth 48: Locking teeth 58: Jig rotation suppression device 60:Notch C1: Center line of rotation C2: Center line of revolution C3: Center line of rotation

Claims

1. A surface polishing device that polishes one surface of a workpiece flat by holding the workpiece attached to the underside of a circular attachment disk in sliding contact with the polishing surface of a polishing table that rotates in one direction, a disc-shaped eccentric jig for a joining disc, which is placed on the polishing surface plate and has an eccentric hole formed therethrough into which the joining disc is rotatably fitted; a jig rotation drive device that has a plurality of guide rollers that receive the joining disk eccentric jig that attempts to move in a circumferential direction together with the polishing surface plate and prevent the movement in the circumferential direction, and that rotationally drives the joining disk eccentric jig via a drive guide roller among the plurality of guide rollers so that the joining disk revolves around the rotation center line along a predetermined revolution locus; a rotation direction restricting device that allows the application disc to rotate in the same direction as the application disc eccentric jig and prevents the application disc from rotating in the opposite direction to the application disc eccentric jig; a jig rotation suppressing device that periodically suppresses the rotation of the application disc eccentric jig rotated by the drive guide roller for a predetermined period of time. A surface polishing device characterized by:

2. The rotation direction restricting device applies a predetermined relative rotation resistance between the application disc eccentric jig and the application disc, and when a relative rotation force exceeding the predetermined relative rotation resistance is generated, allows the application disc to rotate in the same direction as the application disc eccentric jig.

2. The surface polishing apparatus according to claim 1.

3. The rotation direction restricting device is serrated teeth formed on the outer peripheral surface of the application disc; a locking tooth that is engaged with the saw-tooth tooth, allows rotation of the application disc in the rotation direction of the application disc eccentric jig, and prevents rotation of the application disc in the opposite direction to the rotation of the application disc eccentric jig; 3. The surface polishing apparatus according to claim 1 or 2.

4. The rotation direction restricting device includes a pressing force adjusting device that adjusts the rotation resistance of the applying disk in the rotation direction of the applying disk eccentric jig by changing the pressing force of the locking teeth against the saw-tooth teeth.

4. The surface polishing apparatus according to claim 3.

5. The jig rotation suppressing device blocks a rotational force transmission path from the drive guide roller to the joining disk eccentric jig for a predetermined rotation phase period of the jig rotation drive device.

5. The surface polishing apparatus according to claim 1, wherein the polishing surface is polished by a polishing roller.

6. The jig rotation suppressing device isolates the jig rotation drive device from the applying disc eccentric jig only during a rotation phase period of the applying disc eccentric jig during which the rotational force generated by the sliding contact of the applying disc with the polishing surface plate exhibits a maximum value equal to or greater than a predetermined value among periodic changes accompanying the rotation of the applying disc eccentric jig.

6. The surface polishing apparatus according to claim 5.

7. The jig rotation suppression device is a notch formed by cutting out a portion of the outer circumferential edge of the applying disc eccentric jig that comes into contact with the drive guide roller when the rotation center of the polishing surface plate, the rotation center of the applying disc eccentric jig, and the rotation center of the applying disc are positioned on a straight line.

7. The surface polishing apparatus according to claim 1, wherein the polishing surface is polished by polishing the surface of the polishing machine.

Images