Feeder

Abstract

To provide a feeding device that improves the overall yield of a polishing process, in which multiple wafers are polished one by one, without compromising the high precision of the wafer polishing process. [Solution] The micro-feeding device 40 includes a first rotating shaft 44 that rotates with a feed motor 42 as a drive source, a fourth gear 54 as a reciprocating part that is screwed with a first gear 51 of the first rotating shaft 44 at a predetermined pitch N so as to be able to move back and forth in the left-right direction (axial direction), and a second gear 52, a third gear 53, and a second rotating shaft 45 as variable parts that are driven by the forward rotation (one direction) of the first rotating shaft 44 and drive the fourth gear 54 at a rotational speed different from that of the first rotating shaft 44. The fourth gear 54 moves to the left while rotating at a different rotational speed with the second gear 52, the third gear 53, and the second rotating shaft 45 which are driven by the forward rotation of the first rotating shaft 44, and moves back in the axial direction when the first rotating shaft 44 reverses direction.

Description

Technical Field

[0001] The present invention relates to a feeding device that relatively moves forward and backward a semiconductor wafer as a workpiece toward a polishing device.

Background Art

[0002] Wafers, which are materials for semiconductor substrates, are generally manufactured by cutting a substantially cylindrical ingot made of silicon or the like into a plurality of thin disk shapes in a direction perpendicular to the length direction by a cutting machine such as a wire saw. Each wafer after cutting needs to be finely chamfered or polished by a polishing device at its periphery. Therefore, in a polishing process of polishing each wafer one by one, the support base on which the wafer is placed is relatively advanced toward the polishing device to polish the wafer, and after the polishing of the wafer is completed, the support base needs to be retracted from the polishing device to place the next wafer on the support base.

[0003] As a feeding device for moving the support base of the wafer used in the above polishing process forward and backward, for example, there is one described in Patent Document 1. This feeding device can achieve fine chamfering or other polishing processes of the wafer without causing chipping or cracking at the periphery of the wafer due to a collision with the polishing device by relatively moving the support base on which the wafer is placed toward the polishing device set by the control unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such feeding devices, the wafer feeding speed is controlled numerically, which leads to problems such as difficulty in recovery and procurement of replacement parts in the event of an electrical failure. Furthermore, in order to avoid such problems, if the feeding device is mechanically controlled using, for example, a drive motor and variable gear, instead of numerical control as described in Patent Document 1, the support stand on which the wafer is placed is moved toward the polishing device at an extremely low speed, thereby achieving precise polishing without causing chips or cracks on the edges of the wafer. However, the regression speed after polishing is slow, and it takes a considerable amount of time before the polishing of the next wafer can be started, which has a significant impact on the overall yield of the polishing process.

[0006] This invention has been made in view of the above problems, and aims to provide a feeding device that improves the overall yield of a polishing process in which multiple wafers are polished one by one without impairing the high precision of the wafer polishing process. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a feeding device that The device comprises a rotating shaft that rotates by a drive source, a reciprocating part screwed to the rotating shaft at a predetermined pitch so as to be able to move axially back and forth, and a variable part that moves in conjunction with the rotation of the rotating shaft in one direction and provides the reciprocating part with a rotational speed different from that of the rotating shaft. The forward and backward moving part is characterized by moving axially while rotating at different rotational speeds due to the variable part which is driven by the rotation of the rotation shaft in one direction, and moving backward in the axial direction as the rotation of the rotation shaft in the other direction. This feature allows for precise axial feeding of the workpiece during workpiece feeding using the feed device, achieved by the unidirectional rotation of the rotating shaft, enabling highly accurate processing of the workpiece. Furthermore, after the workpiece feeding operation is completed, the retractable part, which moves backward with the rotation of the rotating shaft in the other direction, can return the workpiece to its initial axial position with good yield.

[0008] The variable part is characterized by comprising a first gear that meshes with the rotating shaft, a second gear having a different number of teeth from the first gear and meshing with the reciprocating part, and a driven shaft that supports the first gear and the second gear. This feature allows for a simple configuration of the variable section and enables highly precise setting of the degree of minute feed progression.

[0009] The driven shaft or the second gear is characterized by being provided with a restricting portion that restricts rotation caused by the rotation of the rotating shaft in the other direction. This feature allows for reliable axial movement without the reciprocating parts rotating together when the rotating shaft rotates in another direction.

[0010] The forward and backward portion is characterized by advancing a predetermined distance in the axial direction with respect to the variable portion which is driven by multiple rotations of the rotation axis in one direction, and retracting a predetermined distance in the axial direction with respect to one rotation of the rotation axis in the other direction. This feature allows the workpiece to be returned to its initial position quickly and reliably by rotating the rotating shaft only once after the workpiece feeding operation is complete.

[0011] The rotating shaft is characterized in that it is detachably mounted to a case body having a bearing portion that supports the rotating shaft. This feature allows for variable axial movement of the reciprocating portion of the rotating shaft per revolution by appropriately selecting and mounting multiple rotating shafts with different pitches. [Brief explanation of the drawing]

[0012] [Figure 1] This is a front view showing a wafer chamfering apparatus as an embodiment of the present invention. [Figure 2] (a) is a schematic front view showing the microfeeding device in the origin position, and (b) is a schematic front view showing the microfeeding device in the feed position. [Figure 3] This is a left side view showing a micro-feed device. [Figure 4] It is a sectional view taken along the line A-A of FIG. 3. [Figure 5] (a) is a schematic sectional view taken along the line B-B of FIG. 4, and (b) is a schematic sectional view taken along the line C-C of FIG. 3. [Figure 6] (a) and (b) are diagrams for explaining the advancing movement amount of the fourth gear when the first rotating shaft rotates once in the forward rotation direction. [Figure 7] It is a diagram showing the number of teeth and pitch circle diameter of various gears. [Figure 8] It is a diagram showing the rotation modes of the first to fourth gears when the first rotating shaft rotates once in the forward rotation direction. [Figure 9] It is a diagram showing the rotation modes of the first to fourth gears when the first rotating shaft rotates once in the reverse rotation direction. [Figure 10] (a) is a diagram showing the rotational speeds of the first to fourth gears and the movement amount of the fourth gear when the first rotating shaft rotates once in the forward rotation direction in a fine feed device without a variable part, and (b) is a diagram showing the rotational speeds of the first to fourth gears and the movement amount of the fourth gear when the first rotating shaft rotates once in the forward rotation direction in a fine feed device with a variable part.

Embodiments for Carrying Out the Invention

[0013] Embodiments for carrying out the feed device according to the present invention will be described below based on examples.

Examples

[0014] The fine feed device 40 as a feed device according to an embodiment of the present invention will be described based on FIGS. 1 to 10. In the following description, the front side of FIG. 1 is defined as the front of the wafer chamfering device 1 including the fine feed device 40, the back side as the rear, the right side as the right, and the left side as the left for explanation.

[0015] As shown in FIG. 1, a wafer chamfering apparatus 1 for performing polishing processes such as chamfering the outer peripheral edge of a wafer W as a workpiece made of a semiconductor substrate material mainly includes a polishing apparatus 80 for polishing the outer peripheral edge of the wafer W, a fine feed apparatus 40 as an embodiment of the present invention described later, a wafer feed apparatus 20 for moving the wafer W toward the polishing apparatus 80, a base 10 for supporting the polishing apparatus 80 and the wafer feed apparatus 20, and a control apparatus (not shown) for controlling various apparatuses such as motors of the wafer feed apparatus 20 including the polishing apparatus 80 and the fine feed apparatus 40.

[0016] The polishing apparatus 80 has a bearing portion 11 erected on the upper portion of the base 10 and a lifting portion 12 provided so as to be movable in the vertical direction with respect to the bearing portion 11 via a linear guide 81. The bearing portion 11 is provided with a cylinder 82 capable of biasing the lifting portion 12 upward and a grinding wheel chamfering groove alignment stopper 83. The lifting portion 12 is provided with a grinding wheel shaft 85 having a chamfering grinding wheel 84 fixed to its tip and a grinding wheel shaft motor 86 for rotationally driving the grinding wheel shaft 85 around the axis. By moving the lifting portion 12 up and down, the vertical position adjustment of the chamfering grinding wheel 84 is enabled.

[0017] The wafer feed apparatus 20 mainly has a slide portion 22 provided so as to be slidably movable in the left - right direction with respect to the base 10 via a linear guide 21, a cylinder 23 for moving the slide portion 22 in the left - right direction, and a biasing means 24 for biasing the slide portion 22 toward the side opposite to the chamfering grinding wheel 84 (left side).

[0018] The slide section 22 has a workpiece axis 25 that can rotate around an axis oriented in the vertical direction. A wafer vacuum suction jig 26 for adsorbing and fixing the wafer W is provided at the upper part of the workpiece axis 25, and a workpiece axis motor 29 for rotating the workpiece axis 25 around its axis is provided at the lower part of the workpiece axis 25. Furthermore, the movement of the slide section 22 toward the chamfering wheel 84 is restricted when a diameter-determining stopper 28 contacts a touch switch 27 provided on the base 10. The diameter of the wafer W can be determined by adjusting the position of the movement restriction caused by contact with the touch switch 27 using the diameter-determining stopper 28.

[0019] The biasing means 24 includes a micro-feed link 30 that is rotatable about a pivot axis 30a facing the front-rear direction and located approximately in the center in the vertical direction, and a tension spring 31 whose one end 31a is locked to the micro-feed link 30 below the pivot axis 30a, and whose other end 31b is locked to a predetermined location on the base 10.

[0020] A cam follower 32, rotatably mounted on the upper part of the micro-feed link 30, can move toward and away from a stopper portion 33 located on the right side of the slide portion 22, and the tensile force of the tension spring 31 restricts the movement of the stopper portion 33 to the right. The biasing force of the tension spring 31 that biases the cam follower 32 to the left via the micro-feed link 30 is greater than the biasing force of the cylinder 23 that biases the slide portion 22 to the right.

[0021] On the other hand, the cam follower 34, which is rotatably provided at the lower part of the micro-feed link 30, can move toward and away from the stopper portion 43, which is the moving part of the micro-feed device 40, and is in constant contact with the stopper portion 43 due to the tensile force of the tension spring 31.

[0022] [Outline of the wafer chamfering process] The following outlines the wafer chamfering process of the wafer W using the wafer chamfering apparatus 1. As shown in Figure 2(a), in the initial state of the wafer chamfering apparatus 1, the microfeeding device 40 is positioned at the origin position, where the stopper portion 43 is at the far right position in the left-right direction (see Figure 4), and the microfeeding link 30 is biased in a counterclockwise direction around the pivot axis 30a when viewed from the front by the tensile force of the tension spring 31. In addition, the slide portion 22 is positioned at the origin position, where the stopper portion 33 is separated to the left from the cam follower 32, so that the wafer W fixed to the wafer vacuum suction jig 26 is separated to the left from the chamfering grinding wheel 84.

[0023] The following explains the process step by step: 1. First, the wafer W before polishing is centered and vacuum-fixed to the wafer vacuum suction jig 26. 2. Rotate the grinding wheel spindle 85 while discharging grinding fluid (not shown). 3. The cylinder 23 moves the slide portion 22 to the right, moving the workpiece axis 25 toward the chamfering wheel 84. 4. The stopper portion 33 of the slide portion 22 comes into contact with the cam follower 32. The tensile force from the tension spring 31 is greater than the biasing force from the cylinder 23 that biases the slide portion 22 to the right, thus restricting the movement of the slide portion 22 to the right. At this stage, the wafer W and the chamfering wheel 84 are not in contact. 5. While rotating the wafer W, the microfeeding device 40 is driven in the forward direction, and as described later, the stopper portion 43 is moved little by little to the left from the origin position (position shown by the solid line in Figure 4) toward the feeding position (position shown by the dashed line in Figure 4). As a result, as shown in Figure 2(a), the microfeeding link 30 rotates little by little clockwise when viewed from the front, and the cam follower 32 moves little by little to the right. This movement of the cam follower 32 to the right allows the slide portion 22 by the cylinder 23 to move to the right. 6. Continue step 5 until the diameter-setting stopper 28 contacts the touch switch 27. 7. When the diameter-setting stopper 28 comes into contact with the touch switch 27, the movement of the sliding part 22 is restricted while the cylinder 23 continues to apply a pressing force to the right. 8. After the touch switch 27 is turned ON, set the timer and rotate the wafer W at least once. 9. After the time limit is reached, the cylinder 23 is retracted to move the slide portion 22 towards the origin position on the left side. This causes the slide portion 22 to separate from the chamfering wheel 84, and the grinding process is completed. 10. The rotational drive of the work axis 25 is stopped, the micro-feed device 40 is driven in reverse, and the stopper section 43 is moved backward to the right from the feed position as described later, returning to the origin position (the rightmost position in the left-right direction). 11. Finally, turn off the vacuum suction, remove the polished wafer W from the wafer vacuum suction jig 26, and return to step 1 above.

[0024] [Configuration of the micro-feeding device] Next, the configuration of the fine feed device 40 will be explained based on Figures 3 to 5. Note that in Figures 2, 4, 6(b), and 8, some parts of the reciprocating mechanism are shown as moving slightly larger than they actually are in order to make the reciprocating movement easier to understand.

[0025] As shown in Figures 3 and 4, the micro-feed device 40 includes a case body 41 fixed to a predetermined location on the base 10, a feed motor 42 provided so as to protrude to the right of the case body 41, a stopper portion 43 provided inside the case body 41 so as to be able to move back and forth in the left-right direction, a first rotating shaft 44 facing left-right and supported on the front side inside the case body 41 so as to be able to rotate around an axis by the feed motor 42, a second rotating shaft 45 facing left-right and supported on the rear side inside the case body 41 so as to be able to rotate around an axis, and a first rotating shaft fixed to the right side of the first rotating shaft 44 so as not to rotate relative to it. The gear mainly comprises a gear 51, a second gear 52 mounted on the right side of the second rotating shaft 45 via a one-way clutch 46 so as to be rotatable relative to the second rotating shaft 45 in only one direction (the forward rotation direction described later), and meshing with the first gear 51, a third gear 53 mounted on the left side of the second rotating shaft 45 via a one-way clutch 47 so as to be rotatable relative to the second rotating shaft 45 in only one direction (the forward rotation direction described later), and a fourth gear 54 mounted on the left side of the first rotating shaft 44 so as to be rotatable relative to the second rotating shaft 45 and movable in the axial direction, and meshing with the third gear 53.

[0026] The first rotating shaft 44 is rotatable around its axis via ball bearings 56a and 56b on bearing portions 55a and 55b fixed to the bottom wall of the case body 41, but immovable in the axial direction. Its right end is connected to the drive shaft (not shown) of the feed motor 42 in a way that prevents relative rotation.

[0027] A male threaded portion 57 is formed on the outer circumferential surface of the left end of the first rotating shaft 44, and a female threaded portion 58 formed on the inner circumferential surface of the through hole of the fourth gear 54 is screwed into the male threaded portion 57. A recess 59 is also formed on the left end face of the first rotating shaft 44, and a compression spring 60 is housed in the recess 59. A biasing member 61 that rotates together with the first rotating shaft 44 is attached to the left end of the compression spring 60.

[0028] The stopper portion 43 has a substantially cylindrical insertion portion 43a that is inserted into a bearing portion 63a having a bearing hole 63 attached to the front left wall of the case body 41 by bolts 69, so as to be movable in the left-right direction and rotatable relative to an axis facing left-right, a flange portion 43b that protrudes outward from the right end of the insertion portion 43a and is fixed to the left side of the fourth gear 54 via bolts 68, and a non-rotating portion 43c which will be described later.

[0029] A recess 64 is formed in the center of the flange portion 43b, and a part of the biasing member 61 is housed in the recess 64 via a thrust bearing 65 so as to be rotatable relative to the axis. As a result, the stopper portion 43 and the fourth gear 54 integrated with the stopper portion 43 are constantly biased to the left relative to the male thread portion 57 of the first rotating shaft 44 by the compression spring 60, thereby preventing backlash from occurring between the male thread portion 57 of the first rotating shaft 44 and the female thread portion 58 of the fourth gear 54.

[0030] A recess 66 is formed on the left end face of the insertion portion 43a, and a cylindrical non-rotating portion 43c is provided within the recess 66 so as to be rotatable relative to the insertion portion 43a and the flange portion 43b via ball bearings 67a and 67b.

[0031] Furthermore, the first rotating shaft 44 is detachably mounted on the case body 41, which has bearing portions 55a and 55b that support the first rotating shaft 44. Specifically, by releasing the support provided by the bearing portions 55a and 55b, removing the bolt 68 from the fourth gear 54, and removing the bolt 69 from the front left wall of the case body 41, the first rotating shaft 44 can be removed from the case body 41 by pulling it axially towards the left of the case body 41 together with the stopper portion 43 and the bearing portion 63a.

[0032] The second rotating shaft 45 is rotatable around its axis via ball bearings 71a and 71b on left and right bearing portions 70a and 70b fixed to the bottom wall of the case body 41, but is immovable in the axial direction.

[0033] Furthermore, as shown in Figures 5(a) and (b), a biasing link 72 is rotatably provided above the first gear 51, second gear 52, third gear 53, and fourth gear 54 inside the case body 41, with respect to a vertically oriented pivot shaft 72a fixed to the upper part of the bearing portion 55a. The left end of a compression spring 73, whose right end is locked to the bearing portion 70b, is locked behind the pivot shaft 72a of the biasing link 72, and a guide roller 74 is rotatably supported at the front end of the biasing link 72.

[0034] The tensile force of the compression spring 73 biases the biasing link 72 clockwise in a plan view, thereby biasing the guide roller 74 to the right side of the fourth gear 54. An origin position detection sensor 35 capable of detecting the rear end 72b of the biasing link 72 is provided on the rear wall of the case body 41. When the origin position detection sensor 35 is in contact with or close to the rear end 72b of the biasing link 72 and detects it (origin position detection sensor 35; on; see Figure 5(b)), the control device of the wafer chamfering apparatus 1 determines that the fourth gear 54 and the stopper part 43 are located at the origin position on the right side of the figure. When the origin position detection sensor 35 does not detect the rear end 72b of the biasing link 72 (origin position detection sensor 35; off), the control device determines that the fourth gear 54 and the stopper part 43 are not located at the origin position, that is, they are located at the feed position on the left side of the figure. The drive control of the feed motor 42 is performed based on the determination result of the origin position detection sensor 35.

[0035] Next, as shown in Figure 6(a), the fourth gear 54, in which the female thread portion 58 is screwed into the male thread portion 57 of the first rotating shaft 44, is held in place so as not to rotate relative to the first rotating shaft 44. Then, as shown in Figure 6(b), when the first rotating shaft 44 is rotated 1 turn around its axis, the fourth gear 54 moves axially by N pitches in the direction of travel (leftward) (see Figure 10(a)). Note that the amount of forward and backward movement of the fourth gear 54 is referred to as "+N pitch" for movement in the direction of travel (leftward) and "-N pitch" for movement in the direction of backward (rightward).

[0036] As shown in Figure 7, in this embodiment, the first gear 51 has 88 teeth (Z=88T) and a pitch circle diameter of 110 mm (PCD=110 mm), the second gear 52 has 80 teeth (Z=80T) and a pitch circle diameter of 100 mm (PCD=100 mm), the third gear 53 has 72 teeth (Z=72T) and a pitch circle diameter of 99 mm (PCD=99 mm), and the fourth gear 54 has 80 teeth (Z=80T) and a pitch circle diameter of 110 mm (PCD=110 mm). Note that the number of teeth of each gear may be different from the above values, as long as the tooth ratio between the first gear 51 and the second gear 52 (for example, 11:10) and the tooth ratio between the third gear 53 and the fourth gear 54 (for example, 9:10) are the same as above.

[0037] The first gear 51 and the fourth gear 54, which are pivotally supported on the first rotating shaft 44, have the same pitch circle diameter of 110 mm, but the fourth gear 54 has fewer teeth than the first gear 51. Also, the second gear 52 and the third gear 53, which are pivotally supported on the second rotating shaft 45, have different pitch circle diameters, with the third gear 53 having a slightly smaller pitch circle diameter and fewer teeth than the second gear 52. Thus, the second gear 52 and the third gear 53, which constitute the variable part of the present invention, differ in the number of teeth and pitch circle diameter, and have fewer teeth and a smaller pitch circle diameter than the first rotating shaft 44.

[0038] Next, an example of the operation of the micro-feed device 40 will be explained based on Figures 8 to 10. In the following explanation, the rotational speeds of the first rotating shaft 44, the second rotating shaft 45, the first gear 51, the second gear 52, the third gear 53, and the fourth gear 54 will be referred to as "+n rotations (n ​​is an integer)" when rotating in the forward direction (clockwise when viewed from the right side) and "-n rotations (n ​​is an integer)" when rotating in the reverse direction (counterclockwise when viewed from the right side).

[0039] As shown in Figures 8 and 10(b), when the first rotating shaft 44 rotates +1 due to the drive of the feed motor 42, the first gear 51 rotates +1 along with the first rotating shaft 44. When the first gear 51 rotates +1, the second gear 52, the second rotating shaft 45, and the third gear 53 each rotate -1.1.

[0040] The fourth gear 54 rotates +0.99 times for every -1.1 rotations of the third gear 53. In other words, for every +1 rotation of the first rotation axis 44, the fourth gear 54 rotates a relative amount of +0.99 times, which is slightly less than +1 rotation, causing the fourth gear 54 to move by a pitch of +0.01N in the direction of travel. As a result, when the first rotation axis 44 rotates +1, the stopper portion 43, which is integrated with the fourth gear 54, moves by a pitch of +0.01N from the origin position (the rightmost position in the left-right direction) towards the leftward feed position (see the solid line in Figure 8).

[0041] Furthermore, as shown in Figure 10(b), when the first rotating shaft 44 rotates +100 rpm due to the drive of the feed motor 42, the first gear 51 rotates +100 rpm along with the first rotating shaft 44, while the second gear 52, the second rotating shaft 45, and the third gear 53 each rotate -110 rpm. The fourth gear 54 rotates +99 rpm due to the -110 rpm rotation of the third gear 53. In other words, relative to the +100 rpm rotation of the first rotating shaft 44, the fourth gear 54 rotates +99 rpm, which is less than +100 rpm, causing the fourth gear 54 to move +N rpm in the direction of travel.

[0042] On the other hand, as shown in Figures 9 and 10(b), when the first rotating shaft 44 rotates -1 unit due to the drive of the feed motor 42, the first gear 51 rotates -1 unit along with the first rotating shaft 44. When the first gear 51 rotates -1 unit, the second gear 52 rotates +1.1 units, but because the forward rotation of the second gear 52 is not transmitted to the second rotating shaft 45 by the one-way clutch 46, the second rotating shaft 45 and the third gear 53 remain stationary without rotating.

[0043] Furthermore, since the third gear 53 remains stationary and its forward rotation is restricted by the one-way clutch 47, the reverse rotation of the fourth gear 54, which meshes with the third gear 53, is restricted. Therefore, for every -1 rotation of the first rotating shaft 44, the reverse rotation of the fourth gear 54 is restricted, causing the fourth gear 54 to move -N pitches in the backward direction (see solid line in Figure 9). This allows the stopper portion 43, which is integrated with the fourth gear 54, to instantly return from the feed position to the origin position. Also, when the stopper portion 43 returns to the origin position in this way, the drive of the feed motor 42 stops.

[0044] In other words, when the first rotation axis 44 is reversed, the reverse rotation of the fourth gear 54 is restricted, so the fourth gear 54 does not rotate together with the first rotation axis 44, and therefore it can move backward a large amount with a much smaller amount of rotation than when it is rotating forward. That is, the amount of forward movement of the fourth gear 54 relative to the first rotation axis 44 when the first rotation axis 44 is rotated -n times (where n is an integer) is greater than the amount of forward movement when the first rotation axis 44 is rotated +n times.

[0045] Thus, when the first gear 51 rotates forward together with the first rotating shaft 44 due to the drive of the feed motor 42, the second gear 52, third gear 53, and second rotating shaft 45, which are variable parts that move in conjunction with the forward rotation of the first rotating shaft 44, drive the fourth gear 54 at a rotational speed different from that of the first rotating shaft 44. As a result, the fourth gear 54 rotates relative to the first rotating shaft 44, allowing the fourth gear 54 and the stopper part 43 integrated with the fourth gear 54 to move slightly toward the direction of travel. Furthermore, this allows the slide part 22 to move slightly toward the chamfering wheel 84, enabling precise chamfering and polishing of the wafer W without causing chipping or cracking of the wafer W's periphery due to collision with the chamfering wheel 84.

[0046] [Effects / Effects] As described above, in the micro-feeding device 40 as an embodiment of the present invention, a first rotating shaft 44 rotated by a feed motor 42 as a drive source, a fourth gear 54 and a stopper part 43 as an advancing and retracting part screwed with a predetermined pitch N to the first gear 51 of the first rotating shaft 44 so as to be able to move back and forth in the left-right direction (axial direction), and a second gear 52, a third gear 53 and a second rotating shaft 45 as variable parts that are driven by the forward rotation (one direction) of the first rotating shaft 44 and drive the fourth gear 54 at a rotational speed different from that of the first rotating shaft 44, the fourth gear 54 and the stopper part 43 move to the left while rotating at different rotational speeds due to the second gear 52, the third gear 53 and the second rotating shaft 45 which are driven by the forward rotation of the first rotating shaft 44, and retract in the axial direction when the first rotating shaft 44 reverses direction.

[0047] According to this, when the slide section 22 is being fed using the micro-feed device 40, the forward rotation of the first rotating shaft 44 enables fine axial feeding of the fourth gear 54, allowing for highly accurate processing of the slide section 22. Furthermore, after the feed operation of the slide section 22 is completed, the fourth gear 54 and the stopper section 43, which retract as the first rotating shaft 44 reverses, can be returned to their initial axial position with good yield.

[0048] Furthermore, since the rotational force of the feed motor 42, which acts as the drive source, is converted to allow the fourth gear 54 and the stopper portion 43 to move axially, fine feed progression can be easily performed simply by controlling the amount of rotational drive of the feed motor 42, without complicating the control of the drive source.

[0049] Furthermore, a first gear 51, which transmits the rotational force of the first rotating shaft 44 to the second gear 52 that constitutes the variable part, and a fourth gear 54 and a stopper part 43, which act as a reciprocating part to which rotational force is transmitted from the third gear 53 that constitutes the variable part, are attached to the first rotating shaft 44. In other words, the first rotating shaft 44, which transmits the driving force to the fourth gear 54 and the stopper part 43 that act as a reciprocating part, also serves as a guide means for the reciprocating movement of the fourth gear 54 and the stopper part 43. As a result, the rotating shaft, the variable part, and the reciprocating part can be compactly housed in the case body 41, thereby enabling miniaturization of the micro-feed device 40.

[0050] Furthermore, the variable section is composed of a second gear 52 (first gear) that meshes with the first gear 51 of the first rotating shaft 44, a third gear 53 (second gear) that has a different number of teeth from the second gear 52 and meshes with the fourth gear 54, and the first rotating shaft 44 as a driven shaft that supports the first gear 51 and the second gear 52. This allows the variable section to be easily constructed and enables highly accurate setting of the degree of fine feed progression.

[0051] Furthermore, one-way clutches 46 and 47 are provided on the second rotating shaft 45 or the third gear 53 (second gear) as restricting parts that restrict the rotation associated with the reverse rotation of the first rotating shaft 44. This ensures that the fourth gear 54 does not rotate together with the first rotating shaft 44 when it is reversed, and that it moves reliably in the axial direction.

[0052] Furthermore, the fourth gear 54 and the stopper portion 43 advance a predetermined distance in the axial direction (e.g., +N pitch) with the second gear 52, third gear 53, and second rotation shaft 45, which are driven by multiple forward rotations of the first rotation shaft 44, and regress a predetermined distance in the axial direction (e.g., -N pitch) with one reverse rotation of the first rotation shaft 44. As a result, after the wafer feeding operation of the wafer W is completed, the first rotation shaft 44 can be rotated only once to return to its initial position quickly and reliably.

[0053] Furthermore, since the first rotating shaft 44 is detachably mounted to a case body 41 having bearing portions 55a and 55b that support the first rotating shaft 44, the axial advancement and retraction dimension of the advancement and retraction portion per rotation of the first rotating shaft can be set to be variable by appropriately selecting and mounting multiple first rotating shafts with different pitches of the female screw portion 58.

[0054] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0055] For example, in the above embodiment, a configuration in which a fourth gear 54 and a stopper portion 43 are applied as an example of a reciprocating portion was illustrated, but the present invention is not limited thereto, and other components such as pulleys may be used as long as they are capable of moving back and forth, not just gears.

[0056] Furthermore, in the above embodiment, the variable part is exemplified as comprising a second gear 52 (first gear) that meshes with the first gear 51 of the first rotating shaft 44, a third gear 53 (second gear) having a different number of teeth from the second gear 52 and meshing with the fourth gear 54, and the first rotating shaft 44 as a driven shaft that supports the first gear 51 and the second gear 52. However, the present invention is not limited to this, and may have three or more gears. It may also have multiple driven shafts. Moreover, the variable part may be configured with a reduction mechanism or the like, which is composed of pulleys and components other than gears, such as a timing belt.

[0057] Furthermore, in the above embodiment, the number of teeth and pitch circle diameter of the first gear 51, second gear 52, third gear 53, and fourth gear 54 are set to the values ​​shown in Figure 7, illustrating a configuration in which the fourth gear 54 rotates +0.99 times when the first rotation axis 44 rotates +1 time. However, the present invention is not limited to this, and the number of teeth and pitch circle diameter of each gear can be changed in various ways. The number of teeth (tooth ratio) and pitch circle diameter of each gear can also be set to values ​​different from those shown in Figure 7, so that the fourth gear 54 rotates +0.99 times when the first rotation axis 44 rotates +1 time. Moreover, by changing at least one of the number of teeth (tooth ratio) and pitch circle diameter of each gear, the rotational speed of the fourth gear 54 when the first rotation axis 44 rotates +1 time can be changed. In other words, the fourth gear 54, which is the reciprocating part, can be driven at a rotational speed different from that of the first rotation axis 44.

[0058] Furthermore, in the above embodiment, a micro-feeding device 40 capable of feeding the wafer W toward the chamfering grinding wheel 84 was illustrated as an example of a feeding device. However, the present invention is not limited to this, and may also be applied to a feeding device capable of feeding workpieces other than wafers W.

[0059] Furthermore, in the above embodiment, the microfeeding device 40 was shown as being able to advance the slide portion 22 via the microfeeding link 30, but the present invention is not limited thereto, and the slide portion 22 may be able to advance without going through the microfeeding link 30.

[0060] Furthermore, in the above embodiment, the microfeeding device 40 was provided in a configuration that restricts the movement of the slide portion 22 toward the chamfering wheel 84 while allowing for fine movements. However, the present invention is not limited to this, and the slide portion 22 may be biased toward the chamfering wheel 84 to achieve fine feeding.

[0061] Furthermore, in the above embodiment, a configuration in which a one-way clutch 46 is applied was given as an example of a restricting part that restricts the rotation of the second gear 52 when the first rotating shaft 44 reverses. However, the present invention is not limited thereto, and the rotation of the second gear 52 may be restricted by providing a locking part that engages with the second gear 52 to restrict its rotation when the first rotating shaft 44 reverses, or a restricting pin that can restrict relative rotation with the second rotating shaft 45 when the first rotating shaft 44 reverses. [Explanation of symbols]

[0062] 1. Wafer chamfering machine 10 bases 20 Wafer feeder 22 Slide section 23 liters 24. Biasing means 25 Work axis 26. Wafer vacuum suction fixture 27 Touch switches 28 Diameter-determining stopper 29 Work Axis Motor 30 Fine Feed Links 31. Tension spring 32 Cam Followers 33 Stopper section 34 Cam Follower 40. Fine Feed Device 41 Case Body 42 Feed motor (drive source) 43 Stopper Department (Department of Advancement / Department of Retreat) 44. First axis of rotation (axis of rotation) 45. Second rotation axis (variable part, driven axis) 46, 47 One-way clutch (regulating part) 51 First gear 52. Second gear (variable part, first gear) 53 Third gear (variable part, second gear) 54. Fourth gear (forward / reverse section) 55a,55b Bearing part 57 Male screw part 58 Female thread section 80 Polishing equipment 84 Chamfering whetstone 85 Grinding wheel shaft 86 Grinding wheel shaft motor W wafer (workpiece)

Claims

1. The device comprises a rotating shaft that rotates by a drive source, a reciprocating part screwed to the rotating shaft at a predetermined pitch so as to be able to move axially back and forth, and a variable part that moves in conjunction with the rotation of the rotating shaft in one direction and provides the reciprocating part with a rotational speed different from that of the rotating shaft. The advancement and retraction section is characterized in that it advances axially while rotating at different rotational speeds due to the variable section which is driven by the rotation of the rotating shaft in one direction, and retracts axially as the rotating shaft rotates in the other direction.

2. The feed device according to claim 1, characterized in that the variable part comprises a first gear that meshes with the rotating shaft side, a second gear having a different number of teeth from the first gear and meshing with the advancing part, and a driven shaft that supports the first gear and the second gear.

3. The feeding device according to claim 2, characterized in that the driven shaft or the second gear is provided with a restricting part that restricts rotation due to the rotation of the rotating shaft in the other direction.

4. The feeding device according to any one of claims 1 to 3, characterized in that the advancing and retracting portion advances a predetermined distance in the axial direction by the variable portion which is driven by multiple rotations of the rotating shaft in one direction, and retracts a predetermined distance in the axial direction with one rotation of the rotating shaft in the other direction.

5. The feeding device according to claim 1, characterized in that the rotating shaft is detachably provided to a case body having a bearing portion that supports the rotating shaft.

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