JP2017001160A - Support unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable adjustment of rigidity against a load freely.SOLUTION: A support unit 1A capable of adjusting rigidity comprises: an upper plate 10 and a lower plate 11 forming a space S1 and provided in parallel; a connection part 120 and a connection part 121 for connecting left and right ends of the upper plate 10 and the lower plates 11 to each other; a first male screw 20 which is fitted to the space S1 and is a first support part moving left and right in a symmetrical manner; a second male screw 21 which is a second support part and is formed to have a rotation direction opposite to that of the first male screw; and rotating means 30 which is moving means for symmetrically moving the first male screw 20 and the second sale screw 21 left and right. The rotating means 30 simultaneously rotates and symmetrically moves the first male screw 20 and the second male screw 21 to change a distance between the first male screw 20 and the second male screw 21, and thereby the rigidity can be adjusted.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a support unit capable of adjusting rigidity against a load.

  In a grinding machine that grinds a plate-shaped workpiece by bringing a rotating grinding wheel into contact with the plate-shaped workpiece held by the chuck table, the grinding wheel is used to form a plate-shaped workpiece with a uniform thickness with high accuracy. Increased rigidity against pressing force.

  In addition, by adjusting the grinding surface of the grinding wheel and the holding surface of the chuck table to be parallel, it is possible to form a plate-like workpiece with a uniform thickness. There is a grinding device provided with an adjusting portion for adjusting the holding surface to be parallel to the holding surface (for example, see Patent Document 1). In the above grinding apparatus, even if the grinding wheel is pressed against the plate-like workpiece by pressing force, the plate-like workpiece can be ground to a uniform thickness with high accuracy by providing rigidity that can maintain the parallel state adjusted by the adjusting unit. It becomes possible.

  However, if the rigidity of the device is increased, the impact when the abrasive grains contained in the grinding wheel come into contact with the plate-like workpiece cannot be mitigated, and when grinding is performed at a high speed by increasing the rotation speed of the grinding wheel (for example, rough grinding) The cracks are likely to occur at the edge of the plate-like workpiece. And after rough grinding, when a plate-like workpiece is ground with a grinding wheel for finish grinding containing small abrasive grains, the abrasive grains are pressed against the plate-like workpiece and enter into a crack, and the plate-like workpiece is cracked starting from the crack. There is a case. Further, since the abrasive grains are strongly pressed against the plate-like workpiece and ground, the surface to be ground of the plate-like workpiece tends to be finally formed rough. In order to avoid such a phenomenon, it is connected to a grinding device (for example, see Patent Document 2) that supplies air to a spindle provided in the grinding means and adjusts the rigidity of the device by adjusting the pressure of the air, or a grinding wheel. There is a grinding apparatus (see, for example, Patent Document 3) that adjusts apparatus rigidity by sandwiching a rubber plate between a mount and a grinding wheel.

Japanese Patent No. 4416098 JP 2009-248267 A JP 2005-335014 A

  However, in the grinding device described in Patent Document 2, when the rigidity is lowered by lowering the air pressure, there is a problem that the spindle is swung between the spindle housing and the like. Further, the grinding apparatus described in Patent Document 3 has a problem that it is difficult to freely adjust the rigidity of the apparatus because it is difficult to adjust the hardness of the rubber plate. Such a problem may occur in other apparatuses other than the grinding apparatus as long as the processing apparatus is loaded.

  Therefore, when the apparatus includes an adjustment unit that adjusts the rigidity, there is a problem that the adjustment unit does not adversely affect other configurations of the apparatus and the adjustment unit can freely adjust the rigidity.

  The present invention for solving the above-described problems is a support unit capable of adjusting the rigidity against a load, and includes an upper plate and a lower plate that are arranged in parallel to form a gap, and the upper plate and the lower plate. A connecting part that connects the left and right ends, a first support part and a second support part that are fitted in the gap and move symmetrically to the left and right; the first support part and the second support part; Is a support unit that adjusts the rigidity by changing the distance between the first support part and the second support part.

  Further, the first support portion is a first male screw, and the second support portion is a second male screw formed so that the rotation direction is opposite to that of the first male screw, A central axis of the first male screw and the second male screw is formed with a polygonal-shaped rotary shaft insertion hole penetrating in the axial direction, and the lower surface of the upper plate and the upper surface of the lower plate are provided with the first A first female screw groove corresponding to one male screw and a second female screw groove corresponding to the second male screw, and the moving means simultaneously includes the first male screw and the second male screw. Rotating means for rotating, wherein the rotating means is a polygonal-shaped rotating shaft that is inserted into the rotating shaft insertion hole of the first male screw and the second male screw, and a rotating portion that rotates the rotating shaft. The rotating shaft is rotated by the rotating portion, and the first male screw and the second male screw are rotated simultaneously to form a pair. By moved, preferably shall adjust the rigidity by changing the distance between the first male screw and the second male screw.

  Alternatively, with the lower surface of the upper plate and the upper surface of the lower plate as slide surfaces, the first support portion and the second support portion are in contact with the slide surface and move symmetrically left and right, and the moving means is A first female screw nut coupled to the first support portion, and a second female screw nut coupled to the second support portion and formed so as to have a rotation direction opposite to that of the first female screw nut. A first ball screw for screwing the first female screw nut, a second ball screw for screwing the second female screw nut, and a rotation for simultaneously rotating the first ball screw and the second ball screw. The first ball screw and the second ball screw are simultaneously rotated by the rotating unit, and the first support unit and the second support unit are moved symmetrically. The rigidity is adjusted by changing the distance between the support part and the second support part. Preferable to set.

  The support unit according to the present invention is fitted in the gap, with an upper plate and a lower plate arranged in parallel to form a gap, a connecting portion that connects the left and right ends of the upper plate and the lower plate, and Since the first support portion and the second support portion that move symmetrically to the left and right, and the moving means that moves the first support portion and the second support portion symmetrically to the left and right, the moving means makes the first The rigidity can be adjusted by changing the distance between the support portion and the second support portion. Since the rigidity can be adjusted by the support unit, for example, when this support unit is mounted on a chuck table that holds a workpiece in the grinding apparatus, the processing conditions when grinding by the grinding apparatus, the grinding target, and Depending on the material of the wafer and the type of grinding wheel, etc., grinding can be performed in a state in which the grinding apparatus provided with the support unit is adjusted to the optimum rigidity. For example, when grinding a wafer with a grinding machine, reducing the rigidity at the start of wafer grinding reduces the impact of abrasive grains in the grinding wheel coming into contact with the wafer, causing chipping and cracking in the wafer. Can be prevented. After that, when the wafer is roughly ground at a high speed, the rigidity is increased, so that the grinding can be performed at a high load so that the wafer can be ground at a high speed. Further, for example, when the wafer is finish-ground after rough grinding, the surface to be ground of the wafer can be finished more smoothly by reducing the rigidity.

  Further, the first support part is a first male screw, the second support part is a second male screw formed so that the rotation direction is opposite to that of the first male screw, A central axis of the second male screw is formed with a polygonal column-shaped rotation shaft insertion hole penetrating in the axial direction, and the lower surface of the upper plate and the upper surface of the lower plate have a first corresponding to the first male screw. Each of the female screw groove and the second female screw groove corresponding to the second male screw, and the moving means is a rotating means for simultaneously rotating the first male screw and the second male screw, and the rotating means comprises: By providing a rotary shaft having a polygonal column shape to be inserted into the rotary shaft insertion hole of the first male screw and the second male screw, and a rotary unit for rotating the rotary shaft, the rotary shaft is rotated by the rotary unit. The first male screw and the second male screw are simultaneously rotated and moved symmetrically so that the first male screw and the second male screw are moved. By changing the distance between the Flip, it is possible to adjust the stiffness against the load. And since the rigidity can be adjusted by the support unit, for example, the grinding apparatus provided with the support unit is optimal depending on the processing conditions when grinding by the grinding apparatus, the material of the wafer to be ground and the type of grinding wheel, etc. Grinding can be performed with the rigidity adjusted.

  Further, with the lower surface of the upper plate and the upper surface of the lower plate as slide surfaces, the first support portion and the second support portion are in contact with the slide surface and moved symmetrically left and right, and the moving means is the first support portion. A first female screw nut that is coupled to the second support portion, a second female screw nut that is coupled to the second support portion and is formed to have a rotational direction opposite to that of the first female screw nut, and the first female screw nut The first ball screw to be rotated, the second ball screw to be screwed into the second female screw nut, and the rotating unit that simultaneously rotates the first ball screw and the second ball screw. The first ball screw and the second ball screw are rotated at the same time, and the first support portion and the second support portion are moved symmetrically so that the distance between the first support portion and the second support portion is increased. The rigidity can be adjusted by changing. And since the rigidity can be adjusted by the support unit, for example, according to the processing conditions when grinding by the grinding device, the material of the wafer to be ground, the type of grinding wheel, etc., a grinding device provided with the support unit is provided. Grinding can be performed with the optimum rigidity adjusted.

3 is a perspective view of a support unit according to Embodiment 1. FIG. It is a front view of the support unit of Embodiment 2. 6 is a plan view of a support unit according to Embodiment 2. FIG. It is a perspective view of the support unit of Embodiment 3. It is sectional drawing which shows the state which is grinding the wafer with the grinding apparatus provided with the support unit of Embodiment 2. FIG. It is sectional drawing which shows the state of the support unit at the beginning of grinding. FIG. 7A is a cross-sectional view showing a state in which the rigidity is lowered by the support unit. FIG. 7B is a cross-sectional view showing a state in which the rigidity is increased by the support unit. FIG. 8A is a cross-sectional view showing a state where rigidity is increased by the support unit. FIG. 8B is a cross-sectional view showing a state in which the rigidity is lowered by the support unit.

(Embodiment 1)
A support unit 1A shown in FIG. 1 is an embodiment of a support unit according to the present invention, and includes an upper plate 10 and a lower plate 11, and an upper plate 10 and a lower plate 11 that are arranged in parallel to form a gap S1. And the first male screw 20 and the second support part which are the first support part that fits in the gap S1 and moves symmetrically to the left and right. A second male screw 21 and a rotating means 30 which is a moving means for moving the first male screw 20 and the second male screw 21 symmetrically to the left and right are provided.

  Above the lower plate 11, the upper plate 10 is arranged in parallel with the longitudinal direction (X-axis direction) aligned so that the upper surface 11a of the lower plate 11 and the lower surface 10b of the upper plate 10 face each other. A gap S <b> 1 having a predetermined width is formed between 10 and the lower plate 11. The lower plate 11 and the upper plate 10 are formed of, for example, a steel plate or the like having a certain elasticity, and are formed in the same size. A width L1 of the gap S1 in the Z-axis direction is a distance from the upper surface 11a of the lower plate 11 to the lower surface 10b of the upper plate 10. The width L1 is determined and supported so that the first male screw 20 as the first support portion and the second male screw 21 as the second support portion can be fitted to the upper surface 11a and the lower surface 10b, respectively. It is determined by appropriately changing in consideration of the magnitude of rigidity adjusted by the unit 1A.

  For example, when the lower surface 10b of the upper plate is divided into two by the center line 10o extending in the short direction (Y-axis direction) of the upper plate 10, the first lower surface 10b in the −X direction from the center line 10o has the first A first female thread groove 13 corresponding to the male thread 20 is formed. A second female screw groove 14 corresponding to the second male screw 21 is formed on the lower surface 10b in the + X direction from the center line 10o. When the upper surface 11a of the lower plate 11 is divided into two by a center line 11o extending in the short direction (Y-axis direction) of the lower plate 11, the upper surface 11a in the −X direction from the center line 11o One female thread groove 13 is formed. A second female thread groove 14 is formed on the upper surface 11a in the + X direction from the center line 11o.

  At the left end (−X direction side end) and the right end (+ X direction side end) of the upper plate 10 and the lower plate 11 in the longitudinal direction, a connecting portion 120 and a connecting portion 121 are disposed, respectively. The left end is connected to the left end of the lower plate 11 by a connecting portion 120, and the right end of the upper plate 10 is connected to the right end of the lower plate 11 by a connecting portion 121. For example, a through hole 120a having a diameter equal to or larger than the diameter of the male screw 20 is formed in the central portion of the connecting portion 120, and the male screw 20 can enter and leave the gap S1 through the through hole 120a. For example, a through hole 121a having a diameter equal to or larger than the diameter of the male screw 21 is formed in the central portion of the connecting portion 121. The male screw 21 can enter and leave the gap S1 through the through hole 121a. As shown in FIG. 1, it is preferable that a female screw groove 120 b corresponding to the first male screw 20 and connected to the first female screw groove 13 is formed in the through hole 120 a. Further, it is preferable that a female screw groove 121b corresponding to the second male screw 21 and connected to the second female screw groove 14 is formed in the through hole 121a.

  The first male screw 20 and the second male screw 21 are made of, for example, a metal having a high elastic modulus, and have the same shape and size. The first male screw 20 includes a rotating shaft insertion hole 20a formed in a central axis whose axial direction is the X-axis direction, for example, in a quadrangular prism shape. The second male screw 21 includes a rotation shaft insertion hole 21a formed in a central axis whose axial direction is the X-axis direction, for example, in a quadrangular prism shape. The diameters of the first male screw 20 and the second male screw 21 are determined to be a size that can be fitted into the gap S1, and are determined by appropriately changing in consideration of the size of rigidity that is adjusted by the support unit 1A.

  The rotation means 30 includes a single polygonal column (quadrangular columnar) rotation shaft 300 that is inserted into the rotation shaft insertion hole 20a and the rotation shaft insertion hole 21a, and a rotation unit 301 that rotates the rotation shaft 300. For example, the rotation shaft 300 has an X-axis direction, and is formed in a quadrangular prism shape that fits in the rotation shaft insertion hole 20a and the rotation shaft insertion hole 21a. A rotating part 301 is connected to the tip of the rotating shaft 300. The rotating unit 301 is, for example, a pulse motor that rotates the rotating shaft 300 by a predetermined angle by a pulse signal sent from a control unit (not shown). In addition, the shape of the rotating shaft 300 is not limited to a quadrangular prism shape, and may be, for example, a triangular prism shape or a hexagonal prism shape. The rotating unit 301 is not limited to a pulse motor, and may be a servo motor having a detection mechanism for detecting a position and speed, or may be a handle that can be rotated manually by an operator.

  When the first male screw 20 and the second male screw 21 are simultaneously rotated by the rotating means 30, the second male screw 21 is formed to rotate in a direction opposite to the rotation direction of the first male screw 20. The That is, for example, the outer surface of the first male screw 20 is formed such that the first male screw 20 moves in the + X direction when the first male screw 20 rotates counterclockwise when viewed from the + X direction. A male thread 20b that is screwed into the first female thread groove 13 is formed. The second male screw 21 is formed on the outer surface of the second male screw 21 so that the second male screw 21 moves in the −X direction when the second male screw 21 rotates counterclockwise when viewed from the + X direction. A male thread 21b is formed to be screwed into the two female thread grooves 14.

  For example, when the rotating unit 301 rotates the rotation shaft 300 counterclockwise when viewed from the + X direction side, the first male screw 20 rotates and moves in the + X direction, and at the same time, the second male screw 21 rotates. The first male screw 20 moves in the −X direction by the same distance as the distance moved.

(Embodiment 2)
A support unit 1B shown in FIG. 2 is an embodiment of the support unit according to the present invention, and a part of the configuration of the support unit 1A of the first embodiment is changed. 2, parts that are configured in the same manner as the support unit 1A in FIG. The support unit 1B includes an upper plate 10 and a lower plate 11 that are arranged in parallel to form a gap S1, and a connecting portion 124 that connects the left and right ends of the upper plate 10 and the lower plate 11, respectively. A first male screw 20 that is a first support portion that fits in the gap S1 and moves symmetrically left and right, a second male screw 21 that is a second support portion, a first male screw 20 and a second male screw 21 Rotating means 30 which is a moving means for moving the right and left symmetrically.

  The rotating means 30 in the second embodiment is configured as a handle in which the rotating portion 301 is formed integrally with the rotating shaft 300 and is manually rotated by an operator, and other components are the support unit 1A in the first embodiment. It is the same as the rotation means 30 with which it comprises.

  As shown in FIG. 2, the connecting portion 124 has, for example, a longitudinal section formed in a half ring shape, and is arranged in a state of being integrated with the left and right ends of the upper plate 10 and the lower plate 11. In addition, a through hole 124 a having a diameter equal to or larger than the diameter of the rotating shaft 300 is formed in the central portion of the connecting portion 124, for example.

  For example, four screw holes (not shown) are formed in the upper plate 10 and the lower plate 11 in the thickness direction (Z-axis direction) along both sides of the first female screw groove 13 and the second female screw groove 14 shown in FIG. ) And penetrating toward the surface. 2 and 3, the pressing screw 16 is screwed into each screw hole from the upper surface 10a side with the spring 16a sandwiched between the upper surface 10a of the upper plate 10. Yes. Further, as shown in FIG. 3, each pressing screw 16 is disposed at a position that does not hinder the movement of the first male screw 20 and the second male screw 21 in the X-axis direction. Thereby, even if the first male screw 20 and the second male screw 21 are moved in the X-axis direction, the distance (gap S1) between the upper plate 10 and the lower plate 11 does not change. Further, for example, when the support unit 1B is disposed below the chuck table provided in the grinding apparatus, a load due to the weight of the chuck table is applied to the support unit 1B from the Z-axis direction. The support unit 1B may be used with the spring 16a removed from the support unit 1B.

  For example, the support column 15a is detachably mounted on the center portion of the upper surface 10a of the upper plate 10 and the support column 15b is detachably mounted on the center portion of the lower surface 11b of the lower plate 11, respectively. The support column 15a and the support column 15b are formed, for example, in a shape in which a column is integrated on a substantially square base, and the upper plate 10 and the force applied to the support unit 1B from the Z-axis direction are formed. The lower plate 11 can be centralized.

(Embodiment 3)
A support unit 1C shown in FIG. 4 is an embodiment of the support unit according to the present invention, and includes an upper plate 18 and a lower plate 19, and an upper plate 18 and a lower plate 19 that are arranged in parallel to form a gap S3. Are connected to the gap S3 with the connecting portion 27 that connects the left and right ends of each of them, and the lower surface 18b of the upper plate 18 and the upper surface 19a of the lower plate 19 that form the gap S3 as the slide surfaces. The first support portion 28 and the second support portion 29 that move symmetrically with each other, and the moving means 34 that moves the first support portion 28 and the second support portion 29 symmetrically left and right.

  Above the lower plate 19, the upper plate 18 is arranged in parallel with the longitudinal direction (X-axis direction) aligned so that the upper surface 19a of the lower plate 19 and the lower surface 18b of the upper plate 18 face each other. A gap S3 having a predetermined width is formed between the lower plate 19 and the lower plate 19. The upper surface 19a and the lower surface 18b serve as a slide surface where the first support portion 28 and the second support portion 29 are in contact with each other. The lower plate 19 and the upper plate 18 are made of, for example, a steel plate having a certain elasticity, and are formed in the same shape and size. For example, the upper surface 19a and the lower surface 18b are preferably processed so as to have a low friction coefficient. The width L3 of the gap S3 in the Z-axis direction is the distance from the upper surface 19a of the lower plate 19 to the lower surface 18b of the upper plate 18, and the first support portion 28 and the second support portion 29 are connected to the slide surface. It is determined so that it can be fitted to the upper surface 19a and the lower surface 18b, and is determined by appropriately changing the grinding rigidity adjusted by the support unit 1C.

  One connecting portion 27 is disposed at each of the left end (−X direction side end) and the right end (+ X direction side end) in the longitudinal direction (X-axis direction) of the upper plate 18 and the lower plate 19, respectively. The left end of the upper plate 18 is connected to the left end of the lower plate 19 by the connecting portion 27, and the right end of the upper plate 18 is connected to the right end of the lower plate 19 by the connecting portion 27.

  The first support portion 28 and the second support portion 29 are made of, for example, a metal having a high elastic modulus, both have a rectangular parallelepiped shape, and are formed in the same size that can be fitted into the gap S3.

  The moving means 34 includes, for example, a first female screw nut 340 that is coupled to the first support portion 28 and a second female portion that is coupled to the second support portion 29 and has a rotational direction opposite to that of the first female screw nut 340. Female screw nut 341, first ball screw 342 for screwing first female screw nut 340, second ball screw 343 for screwing second female screw nut 341, first ball screw 342 and second ball screw. And a rotating unit 344 that simultaneously rotates the H.343.

  For example, the first female screw nut 340 shown in FIG. 4 has a side surface coupled to the side surface of the first support portion 28, and the second female screw nut 341 has, for example, a second side surface. The support portion 29 is coupled to the side surface of the support portion 29. In addition, a first ball screw 342 is screwed into the first female screw nut 340, and a second ball screw 343 is screwed into the second female screw nut 341. It is preferable that the first ball screw 342 and the second ball screw 343 are formed to have the same length.

  The rotating unit 344 includes, for example, a spindle 344a whose axial direction is the X-axis direction, a pulse motor 344b that is connected to one end of the spindle 344a and rotationally drives the spindle 344a, a gear 344c that is connected to the other end of the spindle 344a, A gear 344d that meshes with the gear 344c and is connected to the first ball screw 342 and the second ball screw 343 is provided. A predetermined amount of a pulse signal is sent to the pulse motor 344b from a control unit (not shown), and the pulse motor 344b is turned into the gear 344c. , The first ball screw 342 and the second ball screw 343 are simultaneously rotated. For example, the gear 344d is preferably disposed on the center line 19o extending in the short direction (Y-axis direction) of the upper surface 19a of the lower plate 19. Further, the rotating unit 344 is not limited to one using a gear, and may be one using a belt pulley mechanism, for example.

  When the first ball screw 342 and the second ball screw 343 are simultaneously rotated by the rotating unit 344, the second female screw nut 341 rotates in a direction opposite to the rotation direction of the first female screw nut 340. Formed as follows. That is, for example, when the first ball screw 342 rotates counterclockwise when viewed from the + X direction, the first female screw nut 340 is formed to move in the + X direction. Further, when the second ball screw 343 rotates counterclockwise as viewed from the + X direction, the second female screw nut 341 is formed to move in the −X direction.

  For example, when the first ball screw 342 rotates counterclockwise when viewed from the + X direction side, as the first female screw nut 340 screwed into the first ball screw 342 moves in the + X direction, The first support portion 28 moves in the same direction as the first female screw nut 340 by the same distance. When the second ball screw 343 rotates counterclockwise when viewed from the + X direction side, the second female screw nut 341 that is screwed into the second ball screw 343 moves in the −X direction. The two support portions 29 move in the same direction as the second female screw nut 341 by the same distance.

  As an apparatus on which the support units 1A, 1B, and 1C shown in FIGS. 1 to 4 can be mounted, for example, there is a grinding apparatus 5 shown in FIG. The grinding device 5 shown in FIG. 5 is a device for grinding the wafer W held on the chuck table 53 by the grinding means 55, and includes, for example, a support unit 1B.

  On the base 50, the chuck table 53 is disposed in a state of being supported by a support unit 1B disposed on the lower side of the chuck table 53. The chuck table 53 has, for example, a circular outer shape, and includes a suction portion 530 that is made of a porous member and sucks the wafer W, and a frame body 531 that supports the suction portion 530 and is rotatable. The suction unit 530 communicates with a suction source (not shown), and the suction force generated by the suction of the suction source is transmitted to the holding surface 530a that is the exposed surface of the suction unit 530, so that the wafer on the holding surface 530a. W is sucked and held.

  A column 50a is erected on the base 50, and a grinding feed means 54 is disposed on the side surface in the -Y direction of the column 50a. The grinding feed means 54 is connected to a ball screw 540 having a vertical (Z-axis direction) axis center, a pair of guide rails 541 arranged in parallel to the ball screw 540, and the upper end of the ball screw 540, and the ball screw 540 is rotated. And a lifting holder 543 in which an inner nut 543a is screwed into the ball screw 540 and a side portion is in sliding contact with the guide rail 541. When the motor 542 rotates the ball screw 540, the lifting holder 543 is moved accordingly. Is guided by the guide rail 541 and reciprocated in the Z-axis direction, and the grinding means 55 held by the holder 543 is ground and fed in the Z-axis direction.

  The grinding means 55 includes, for example, a spindle 550 whose axial direction is the vertical direction (Z-axis direction), a motor 551 that rotationally drives the spindle 550, a circular mount 552 that is disposed at the lower end of the spindle 550, and a mount And a grinding wheel 553 detachably connected to the lower surface of 552. The grinding wheel 553 includes a wheel base 553a and a plurality of substantially rectangular parallelepiped-shaped grinding wheels 553b arranged in a ring shape on the bottom surface of the wheel base 553a. Then, as the spindle 550 is rotationally driven by the motor 551, the grinding wheel 553 is also rotated, and the grinding wheel 553b comes into contact with the wafer W to grind the wafer W.

  Under the chuck table 53, for example, three support units 1 </ b> B are disposed at a constant interval in the circumferential direction of the chuck table 53. In the present embodiment, for example, the three support units 1B are arranged so as to form an equilateral triangle. In FIG. 5, one support unit 1B and the pressing screw 16 and the spring 16a shown in FIG. 2 provided in each support unit 1B are omitted.

  For example, as shown in FIG. 5, the three support units 1 B arranged on the lower side of the chuck table 53 are arranged so that the support columns 15 a mounted on the upper plate 10 support the bottom surface of the chuck table 53. The -Z direction load applied by the grinding means 55 and the weight of the chuck table 53 are received via the support column 15a. That is, the load in the −Z direction and the weight of the chuck table 53 applied by the grinding means 55 mainly act on the upper plate 10 with the central portion of the upper plate 10 as an action point.

  As shown in FIG. 5, among the three support units 1 </ b> B that are disposed, one support unit 1 </ b> B has a support column 15 b that is mounted on the lower plate 11 and a base of the grinding device 5 via a support base 51. 50, and the drag received from the base 50 is received via the support column 15b. That is, the drag force from the base 50 mainly acts on the upper plate 10 with the central portion of the upper plate 10 as an action point.

  As shown in FIG. 5, for example, out of the three support units 1 </ b> B provided, the two support units 1 </ b> B have a support column 15 b mounted on the lower plate 11 via a tilt adjustment unit 52. 5 is disposed on the base 50 and receives the drag received from the base 50 via the support column 15b.

  The inclination adjusting unit 52 includes, for example, a screw part 520 having a vertical (Z-axis direction) axis center and screwed with the support column 15b, a coupling 521 connected to the screw part 520, and the coupling 521. When the motor 522 rotates the screw part 520 via the coupling 521, the support unit 1B reciprocates in the Z-axis direction along with the motor 522 connected to the screw part 520. Adjust the tilt relative to the horizontal plane.

  Hereinafter, the operation of the grinding device 5 and the operation of the support unit 1B when the wafer is ground by the grinding device 5 including the support unit 1B will be described with reference to FIGS. 2 and 5 to 8. 6 to 8, the configuration of the chuck table 53 is shown in a simplified manner.

  The wafer W shown in FIG. 5 is, for example, a semiconductor wafer having a circular outer shape, and on the surface Wa of the wafer W, a large number of devices are formed in a lattice-like area partitioned by division lines. The shape and type of the wafer W are not limited to the present embodiment.

  When grinding the wafer W, first, the wafer W having a protective tape (not shown) attached to the front surface Wa of the wafer is placed on the holding surface 530a of the chuck table 53 so that the back surface Wb is on the upper side. As the suction force generated by the suction source is transmitted to the holding surface 530a, the chuck table 53 sucks and holds the wafer W on the holding surface 530a.

  As the spindle 550 is driven to rotate by the motor 551, the grinding wheel 553 rotates. Further, the grinding means 55 is sent in the −Z direction by the grinding feed means 54, the grinding wheel 553 descends in the −Z direction, and the grinding wheel 553 b comes into contact with the back surface Wb of the wafer W to perform the grinding process. Done. Further, during grinding, as the chuck table 53 rotates, the wafer W held on the holding surface 530a also rotates, so that the grinding wheel 553b grinds the entire back surface Wb of the wafer W.

  In grinding the wafer W to a predetermined thickness, after performing rough grinding using a grindstone having relatively large abrasive grains, finish grinding is performed using a grindstone having smaller abrasive grains than the grindstone for coarse grinding. For example, during rough grinding, the grinding feed speed of the grinding means 55 and the rotational speed of the grinding wheel 553 are made relatively high and the rigidity is increased. After the wafer W approaches the desired thickness, the rigidity is lowered and finish grinding is performed to remove the damaged layer from the back surface Wb of the wafer W and reduce the surface roughness.

  First, the operation of the support unit 1B when the wafer W is roughly ground will be described below. At the start of grinding, for example, as shown in FIG. 6, the positions of the first male screw 20 and the second male screw 21 so that the distance between the first male screw 20 and the second male screw 21 is maximized. Determine. As shown in FIG. 7A, the support unit 1B in this state is against the grinding load F1 transmitted from the + Z direction transmitted through the support column 15a and the drag force F2 transmitted from the −Z direction through the support column 15b. Thus, the upper plate 10 and the lower plate 11 can be bent to the maximum extent. Accordingly, since the rigidity of the chuck table 53 with respect to the grinding load in the Z-axis direction is reduced, the impact when the grinding wheel 553 shown in FIG. 5 descends in the −Z direction and the grinding wheel 553a contacts the back surface Wb of the wafer W is mitigated. It is possible to prevent the wafer W from being chipped or cracked. Further, when an oxide film is formed on the back surface of the wafer, conventionally, the grinding feed rate is slowed to remove the oxide film, and after the oxide film is removed, the grinding feed rate is increased. By reducing the rigidity of the support unit, it is possible to grind the oxide film without reducing the grinding feed rate.

  When the grinding wheel 553b shown in FIG. 5 comes into contact with the wafer W and then the grinding force is increased by increasing the grinding feed speed of the grinding means 55 to increase the grinding load, the wafer W is roughly grounded as shown in FIG. Thus, for example, the rotating shaft 300 is rotated counterclockwise (arrow R1 direction) when viewed from the + Y direction by the rotating unit 301. The first male screw 20 and the second male screw 21 are simultaneously rotated by the rotation of the rotary shaft 300 in the direction of the arrow R1, the first male screw 20 moves in the + Y direction, and the second male screw 21 moves in the -Y direction. To do.

  For example, as shown in FIG. 7B, the first male screw 20 and the second male screw 21 are moved to just below the support column 15a and the support column 15b, so that the first male screw 20 and the second male screw 20 After the distance from the male screw 21 is minimized (for example, the first male screw 20 and the second male screw 21 are in contact with each other), the rotation of the rotating unit 301 is stopped. In the support unit 1B in this state, the upper plate 10 and the lower plate 11 are flexed against the grinding load F1 transmitted from the + Z direction transmitted through the support column 15a and the drag force F2 transmitted from the −Z direction through the support column 15b. Therefore, the force is not absorbed, that is, the rigidity of the chuck table 53 in the Z-axis direction is increased. Therefore, since the grinding load transmitted from the grinding wheel 553b shown in FIG. 5 to the wafer W does not escape, the grinding wheel 553b is more strongly pressed against the wafer W and ground at a high load, thereby enabling high-speed grinding.

  When performing final grinding of the wafer W after rough grinding, as shown in FIG. 8A, for example, the rotating unit 300 rotates the rotating shaft 300 in the clockwise direction (arrow R2 direction) when viewed from the + Y direction, as shown in FIG. The first male screw 20 and the second male screw 21 are simultaneously rotated by the rotation of the rotation shaft 300 in the arrow R2 direction, the first male screw 20 is moved in the -Y direction, and the second male screw 21 is moved in the + Y direction. To do.

  For example, as shown in FIG. 8B, after the first male screw 20 and the second male screw 21 are moved to maximize the distance between them, the rotation of the rotating unit 301 is stopped. In the support unit 1B in this state, the upper plate 10 and the lower plate 11 have the maximum resistance against the grinding load F1 transmitted from the + Z direction transmitted through the support column 15a and the drag force F2 transmitted from the −Z direction through the support column 15b. It becomes possible to bend to the limit. Accordingly, since the rigidity of the chuck table 53 in the Z-axis direction is reduced, it is possible to improve and finish the surface roughness of the back surface Wb of the wafer W.

  As described above, the support unit 1 </ b> B rotates the rotating shaft 301 by the rotating unit 300 to simultaneously rotate the first male screw 20 and the second male screw 21 to move symmetrically, thereby causing the first male screw 20 and the second male screw to move. The rigidity can be adjusted by changing the distance between the two. For this reason, it is possible to grind the wafer W in a state adjusted to an optimum rigidity in consideration of the processing conditions and processing method when the wafer W is ground by the grinding device 5 including the support unit 1B.

  In addition, the support unit which concerns on this invention is not limited to the said embodiment, In the range which can exhibit the effect of this invention, it can change suitably. For example, the grinding device 5 includes the support unit 1A or the support unit 1C instead of the support unit 1B, and the rotation unit 301 (or the rotation unit 344) made up of a pulse motor or the like is used when the grinding conditions change. You may enable it to rotate automatically by the control part which is not shown in figure. Further, the support unit may be disposed not inside the chuck table but inside the grinding means 55, for example.

Further, the rigidity may be adjusted according to the grinding feed speed. When the grinding feed rate is fast, the rigidity is high, and when the grinding feed rate is low, the rigidity is low.
Further, it may be adjusted according to the thickness of the wafer W. For example, the rigidity is reduced when the thickness of the wafer W reaches a predetermined thickness.

1A: Support unit 10: Upper plate 10a: Upper surface of upper plate 10b: Lower surface of upper plate 10o: Center line 11: Lower plate 11a: Upper surface of lower plate 11b: Lower surface of lower plate 11o: Center line S1: Gap L1: Width 120: Connection part 120a: Through hole 120b: Female screw groove 121: Connection part 121a: Through hole 121b: Female screw groove 13: First female screw groove 14: Second female screw groove 20: First male screw 20a: Rotating shaft insertion hole 20b: Male screw thread 21: Second male screw 21a: Rotating shaft insertion hole 21b: Male screw thread 30: Rotating means 300: Rotating shaft 301: Rotating part 1B: Support unit 124: Connecting part 124a: Through hole
15a: support column 15b: support column 16: pressing screw 16a: spring 1C: support unit
18: Upper plate 18a: Upper surface of upper plate 18b: Lower surface of upper plate
19: Lower plate 19a: Upper surface of lower plate 19b: Lower surface of lower plate 19o: Center line S3: Gap L3: Width 27: Connection portion 28: First support portion 29: Second support portion
34: Moving means
340: First female screw nut 341: Second female screw nut 342: First ball screw 343: Second ball screw 344: Rotating part
344a: Spindle 324b: Pulse motor 344c: Gear 344d: Gear 5: Grinding device 50: Base 50a: Column 51: Support base 52: Tilt adjustment part 520: Screw part 521: Coupling 522: Motor 53: Chuck table 530: Suction Part 530a: holding surface 531: frame body
54: Grinding feed means 540: Ball screw 541 Guide rail 542: Motor
543: Lifting holder: 543a: Nut 55: Grinding means 550: Spindle 551: Motor 552: Mount
553: Grinding wheel 553a: Wheel base 553b: Grinding wheel W: Wafer Wa: Wafer surface Wb: Wafer back surface F1: Grinding load F2: Drag

Claims (3)

A support unit capable of adjusting rigidity against load,
An upper plate and a lower plate that are arranged in parallel with a gap, a connecting portion that connects the left and right ends of the upper plate and the lower plate, and a symmetrical movement that fits into the gap and moves left and right. A first support portion, a second support portion, and a moving means for symmetrically moving the first support portion and the second support portion left and right;
A support unit that adjusts rigidity by changing a distance between the first support portion and the second support portion by the moving means. The first support portion is a first male screw, and the second support portion is a second male screw formed so that the rotation direction is opposite to that of the first male screw. A central axis of the male screw and the second male screw is formed with a polygonal-shaped rotating shaft insertion hole penetrating in the axial direction,
The lower surface of the upper plate and the upper surface of the lower plate are each provided with a first female screw groove corresponding to the first male screw and a second female screw groove corresponding to the second male screw,
The moving means is a rotating means for simultaneously rotating the first male screw and the second male screw,
The rotating means includes a polygonal column-shaped rotating shaft that is inserted into the rotating shaft insertion hole of the first male screw and the second male screw, and a rotating unit that rotates the rotating shaft,
By rotating the rotating shaft by the rotating unit and simultaneously rotating the first male screw and the second male screw to move symmetrically, the distance between the first male screw and the second male screw is increased. The support unit according to claim 1, wherein the rigidity is changed to adjust the rigidity. With the lower surface of the upper plate and the upper surface of the lower plate as slide surfaces,
The first support part and the second support part are in contact with the slide surface and move symmetrically left and right;
The moving means is
A first female thread nut coupled to the first support section; a second female thread nut coupled to the second support section and formed to have a rotational direction opposite to that of the first female thread nut;
A first ball screw into which the first female screw nut is screwed in; a second ball screw into which the second female screw nut is screwed; and a rotating unit that simultaneously rotates the first ball screw and the second ball screw. And comprising
The first ball screw and the second ball screw are simultaneously rotated by the rotating portion, and the first support portion and the second support portion are moved symmetrically to move the first support portion and the second support portion. The support unit according to claim 1, wherein the rigidity is adjusted by changing a distance between the support portion and the support portion.

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