Processing equipment

Abstract

To provide a processing device that is able to prevent an appropriate polishing process from being blocked by liquid adhering to a workpiece.SOLUTION: A processing device for processing a workpiece comprises: a chuck table having a holding surface for holding the workpiece; a grinding unit having a spindle on which a grinding wheel is mounted; a polishing unit having a spindle on which a polishing pad is mounted; a moving mechanism that moves a chuck table between a grinding region in which the workpiece is ground by the grinding wheel and a polishing region in which the workpiece is polished by the polishing pad, and a liquid removing unit that removes a liquid remaining on a processed-surface side of the workpiece when the chuck table moves between the grinding region and the polishing region.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a workpiece.

Background Art

[0002] In the manufacturing process of device chips, a wafer in which devices are formed in a plurality of regions partitioned by a plurality of streets (lines to be divided) arranged in a grid pattern is used. By dividing this wafer along the streets, device chips having devices are obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] In recent years, with the miniaturization of electronic devices, thin device chips have been demanded. Therefore, before dividing the wafer, a process of thinning the wafer using a grinding apparatus may be performed. The grinding apparatus includes a chuck table for holding the wafer and a grinding unit for performing grinding on the wafer. The grinding unit includes a spindle, and an annular grinding wheel provided with a grinding stone is attached to the tip of the spindle. By holding the wafer on the chuck table, rotating the chuck table and the grinding wheel, and bringing the grinding stone into contact with the wafer, the wafer is ground and thinned (see Patent Document 1).

[0004] Arc-shaped grinding marks (saw marks) are formed on the workpiece surface side of the wafer to be ground by the grinding stone along the rotation path of the grinding stone. When a wafer with grinding marks formed is divided to manufacture a device chip, the grinding marks remain on the device chip, and the flexural strength (bending strength) of the device chip decreases. Therefore, after grinding the wafer, a polishing process for removing the grinding marks is performed on the workpiece surface side of the wafer.

[0005] Polishing is performed using a polishing apparatus. The polishing apparatus comprises a chuck table for holding the wafer and a polishing unit for polishing the wafer. The polishing unit is equipped with a spindle, and a disc-shaped polishing pad is attached to the tip of the spindle. The wafer is held in the chuck table, and the wafer is polished by rotating the chuck table and the polishing pad while bringing the polishing pad into contact with the wafer.

[0006] Furthermore, grinding a wafer with a grinding machine and then polishing it with a polishing machine is time-consuming and requires effort to transport the wafer, which reduces the processing efficiency of the wafer. Therefore, a processing device equipped with both a grinding unit and a polishing unit (a grinding and polishing device) is sometimes used for wafer processing (see Patent Document 2). Using a grinding and polishing device makes it possible to perform grinding and polishing on the wafer continuously, improving processing efficiency. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2000-288881 [Patent Document 1] Japanese Patent Publication No. 2010-17798 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] When processing workpieces such as wafers using a grinding and polishing machine, the workpiece is first ground by a grinding unit, thinning it to a predetermined thickness. During this process, a liquid (grinding fluid) such as pure water is continuously supplied to the workpiece and the grinding wheel. This cools the workpiece and the grinding wheel, and washes away the debris (grinding dust) generated by grinding the workpiece. After grinding the workpiece is complete, it is then polished by a polishing pad. This polishing process removes any remaining grinding marks on the processed surface of the workpiece.

[0009] However, when a workpiece is subjected to grinding, some liquid, such as grinding fluid supplied in the previous grinding process, remains on the workpiece surface, and this liquid can adversely affect the grinding process. For example, when a workpiece is subjected to dry grinding, the remaining liquid may prevent proper friction between the workpiece surface and the grinding wheel, potentially hindering the grinding process. Similarly, when a workpiece is subjected to wet grinding, the remaining liquid may mix with the chemical solution (slurry) supplied during the grinding process, potentially reducing the chemical action acting on the workpiece surface.

[0010] This invention has been made in view of the above problems, and aims to provide a processing apparatus that can prevent proper polishing from being hindered by liquid adhering to the workpiece. [Means for solving the problem]

[0011] According to one aspect of the present invention, a processing apparatus for processing a workpiece is provided, comprising: a chuck table having a holding surface for holding the workpiece; a grinding unit having a spindle on which a grinding wheel is mounted; a polishing unit having a spindle on which a polishing pad is mounted; a moving mechanism for moving the chuck table between a grinding region where the workpiece is ground by the grinding wheel and a polishing region where the workpiece is polished by the polishing pad; and a liquid removal unit for removing any liquid remaining on the workpiece surface side of the workpiece when the chuck table moves between the grinding region and the polishing region.

[0012] Preferably, the liquid removal unit includes a contact member that contacts the workpiece surface to remove the liquid. Preferably, the contact member is an elastic member positioned to intersect the movement path of the chuck table. Preferably, the contact member is a rotatable sponge positioned to intersect the movement path of the chuck table. Preferably, the processing apparatus further includes a cover that covers the grinding area or polishing area, and the liquid removal unit is provided in the cover. [Effects of the Invention]

[0013] A processing apparatus according to one aspect of the present invention includes a liquid removal unit that removes any liquid remaining on the workpiece surface side of the workpiece when the chuck table moves between the grinding area and the polishing area. This allows the workpiece to be placed in the polishing area with the liquid removed, preventing the liquid from hindering proper polishing of the workpiece. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view showing the processing equipment. [Figure 2] This is a perspective view showing the polishing unit. [Figure 3] This is a plan view showing the chuck table and the moving mechanism. [Figure 4] Figure 4(A) is a side view showing an elastic member that contacts the front end of the workpiece, Figure 4(B) is a side view showing an elastic member that removes liquid adhering to the workpiece, and Figure 4(C) is a side view showing an elastic member that contacts the rear end of the workpiece. [Figure 5] Figure 5(A) is a side view showing a sponge that contacts the front end of the workpiece, Figure 5(B) is a side view showing a sponge that removes liquid adhering to the workpiece, and Figure 5(C) is a side view showing a sponge that contacts the rear end of the workpiece. [Figure 6] This is a perspective view showing the cover with the liquid removal section. [Modes for carrying out the invention]

[0015] Hereinafter, an embodiment of one aspect of the present invention will be described with reference to the attached drawings. First, an example of the configuration of the processing apparatus according to this embodiment will be described. Figure 1 is a perspective view showing a processing apparatus (grinding and polishing apparatus) 2 capable of performing grinding and polishing on a workpiece 11. In Figure 1, the X-axis direction (first horizontal direction, left-right direction) and the Y-axis direction (second horizontal direction, front-back direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, height direction, up-down direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0016] The processing apparatus 2 includes a base 4 that supports or accommodates each component of the processing apparatus 2. An opening 4a is provided on the upper side of the front end of the base 4. Inside the opening 4a, a transport unit 6 for transporting the workpiece 11 is provided. For example, a transport robot equipped with a robot hand (end effector) capable of holding the workpiece 11 is used as the transport unit 6.

[0017] A pair of mounting tables 8A and 8B are provided in front of the opening 4a. Box-shaped cassettes 10A and 10B are placed on mounting tables 8A and 8B, respectively. Cassettes 10A and 10B are containers capable of holding multiple workpieces 11, which are the objects to be processed by the processing device 2. When processing the workpieces 11 with the processing device 2, cassettes 10A and / or cassettes 10B containing the multiple workpieces 11 are set on mounting tables 8A and / or mounting tables 8B.

[0018] For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as silicon, and includes surfaces (first surface) 11a and back surfaces (second surface) 11b that are generally parallel to each other. The workpiece 11 is partitioned into a plurality of rectangular regions by a plurality of streets (division planned lines) arranged in a grid pattern so as to intersect each other. On the surface 11a side of the plurality of regions partitioned by the streets, devices such as IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode), and MEMS (Micro Electro Mechanical Systems) devices are formed respectively.

[0019] By dividing the workpiece 11 along the streets, a plurality of device chips each including a device are manufactured. Also, before dividing the workpiece 11, by grinding and polishing the workpiece 11 with the processing apparatus 2 to thin it, a thinned device chip can be obtained.

[0020] However, there are no restrictions on the type, material, shape, size, structure, etc. of the workpiece 11. For example, the workpiece 11 may be a substrate (wafer) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. Also, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of the devices formed on the workpiece 11, and the workpiece 11 may not have any devices formed thereon.

[0021] An alignment mechanism (positioning mechanism) 12 for aligning the workpiece 11 is provided diagonally behind the opening 4a. The alignment mechanism 12 includes a temporary placement table 14 on which the workpiece 11 is temporarily placed. The workpieces 11 housed in the cassettes 10A and 10B are transported onto the temporary placement table 14 by the transport unit 6. Then, the alignment mechanism 12 sandwiches the workpiece 11 and arranges it at a predetermined position.

[0022] A gate-shaped support structure 16 is provided on the side of the base 4, positioned to straddle the alignment mechanism 12. A transport unit 18 for transporting the workpiece 11 is mounted on the support structure 16. For example, the support structure 16 is provided with a ball screw type moving mechanism (not shown) that moves the transport unit 18 along the X-axis, Y-axis, and Z-axis directions, and the transport unit 18 is connected to the moving mechanism. The transport unit 18 also includes a suction pad (not shown) that holds the upper surface of the workpiece 11 by suction.

[0023] An opening 4b is provided behind the alignment mechanism 12. Inside the opening 4b are a plurality of chuck tables (holding tables) 20 for holding the workpiece 11, and a moving mechanism 22 for moving the chuck tables 20.

[0024] The upper surface of the chuck table 20 constitutes a holding surface 20a for holding the workpiece 11. The holding surface 20a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., formed inside the chuck table 20. The chuck table 20 is also connected to a rotational drive source (not shown), such as a motor, which rotates the chuck table 20 around a rotation axis that is approximately parallel to the Z-axis direction.

[0025] For example, the moving mechanism 22 includes a disc-shaped turntable on which the chuck table 20 is placed. The turntable is connected to a rotational drive source (not shown), such as a motor, which rotates the turntable around a rotation axis that is roughly parallel to the Z-axis direction. Multiple chuck tables (four in Figure 1) are arranged at roughly equal intervals (90° intervals) along the circumferential direction of the turntable.

[0026] The turntable rotates clockwise in a plan view (in the direction indicated by arrow R), positioning each chuck table 20 sequentially in the transport area A, grinding area B (first grinding area, rough grinding area), grinding area C (second grinding area, finish grinding area), and polishing area D. There are no restrictions on the type and configuration of the moving mechanism 22, as long as it is possible to position the chuck table 20 in the transport area A, grinding area B, grinding area C, and polishing area D.

[0027] The workpiece 11, which has been aligned by the alignment mechanism 12, is transported by the transport unit 18 to the chuck table 20 positioned in the transport area A. Then, with the workpiece 11 placed on the holding surface 20a of the chuck table 20, when the suction force (negative pressure) of the suction source is applied to the holding surface 20a, the workpiece 11 is held in place by the chuck table 20.

[0028] At the rear end of the base 4 (behind the chuck table 20 and the moving mechanism 22), a rectangular parallelepiped-shaped support structure 24 is provided, protruding upward from the upper surface of the base 4. On the front side (front side) of the support structure 24, a pair of moving mechanisms 26A and 26B are provided. Each of the moving mechanisms 26A and 26B is equipped with a pair of guide rails 28 arranged along the Z-axis direction on the front side of the support structure 24, and a flat moving plate 30 is slidably mounted on the guide rails 28.

[0029] A nut portion (not shown) is provided on the back side (rear side) of the movable plate 30. A ball screw 32, which is positioned between a pair of guide rails 28 along the Z-axis direction, is screwed into this nut portion. A pulse motor 34, which rotates the ball screw 32, is connected to the end of the ball screw 32. When the ball screw 32 is rotated by the pulse motor 34, the movable plate 30 moves along the guide rails 28 in the Z-axis direction.

[0030] A support member 36 is fixed to the front surface (front side) of the movable plate 30. The support member 36 fixed to the movable plate 30 of the movable mechanism 26A is positioned above the grinding area B and supports the rough grinding unit 38A that performs rough grinding on the workpiece 11. On the other hand, the support member 36 fixed to the movable plate 30 of the movable mechanism 26B is positioned above the grinding area C and supports the finish grinding unit 38B that performs finish grinding on the workpiece 11.

[0031] Each grinding unit 38A and 38B is equipped with a cylindrical housing 40. A cylindrical spindle 42 is housed in the housing 40. The tip (lower end) of the spindle 42 is exposed from the housing 40, and a disc-shaped wheel mount 44 made of metal or the like is fixed to the tip of the spindle 42. A rotational drive source, such as a motor, for rotating the spindle 42 is connected to the base (upper end) of the spindle 42.

[0032] A grinding wheel 46A for rough grinding is mounted on the underside of the wheel mount 44 of the grinding unit 38A. On the other hand, a grinding wheel 46B for finish grinding is mounted on the underside of the wheel mount 44 of the grinding unit 38B. Each of the grinding wheels 46A and 46B comprises an annular wheel base made of metal or the like, and a plurality of grinding wheels fixed to the underside of the wheel base.

[0033] Grinding wheels are formed by fixing abrasive grains, such as diamond or cBN (cubic boron nitride), with a binder (bonding material) such as metal bond, resin bond, or vitrified bond. For example, multiple rectangular grinding wheels are arranged in a ring shape at roughly equal intervals along the outer edge of the wheel base. The average particle size of the abrasive grains contained in the grinding wheel 46B is smaller than the average particle size of the abrasive grains contained in the grinding wheel 46A.

[0034] The grinding wheels 46A and 46B rotate around a rotation axis that is approximately parallel to the Z-axis direction, power transmitted from the rotation drive source via the spindle 42 and wheel mount 44. As a result, each of the multiple grinding wheels revolves along an annular rotation path (rotational trajectory) that is approximately parallel to the horizontal plane (XY plane).

[0035] The chuck table 20 holding the workpiece 11 is placed in grinding area B, and the grinding wheel is brought into contact with the workpiece 11 while the chuck table 20 and grinding wheel 46A are rotated, thereby performing rough grinding on the workpiece 11. Subsequently, the chuck table 20 holding the workpiece 11 is placed in grinding area C, and the grinding wheel is brought into contact with the workpiece 11 while the chuck table 20 and grinding wheel 46B are rotated, thereby performing finish grinding on the workpiece 11.

[0036] A cover 48 is attached to the base 4 to cover the grinding areas B and C. For example, the cover 48 is formed in a box shape and has a housing section (housing space) 48a capable of accommodating the chuck table 20. When the cover 48 is attached to the base 4, the grinding areas B and C are covered by the cover 48, and a processing chamber (grinding chamber) in which the workpiece 11 is ground is defined.

[0037] The upper surface of the cover 48 is provided with a pair of insertion holes 50A and 50B that connect the outside of the cover 48 to the housing section 48a. Insertion hole 50A is positioned to overlap with the grinding wheel 46A, and the grinding wheel 46A is inserted into insertion hole 50A. On the other hand, insertion hole 50B is positioned to overlap with the grinding wheel 46B, and the grinding wheel 46B is inserted into insertion hole 50B. This prevents interference between the grinding wheels 46A and 46B and the cover 48 when the grinding wheels 46A and 46B are raised or lowered.

[0038] The polishing area D is equipped with a polishing unit 52 for polishing the workpiece 11. After the grinding of the workpiece 11 by the grinding units 38A and 38B is completed, the chuck table 20 holding the workpiece 11 is positioned in the polishing area D, and the workpiece 11 is polished by the polishing unit 52. Details of the configuration and function of the polishing unit 52 will be described later (see Figure 2).

[0039] A cleaning unit 54 for cleaning the workpiece 11 is provided in front of the alignment mechanism 12. For example, the cleaning unit 54 includes a spinner table that holds and rotates the workpiece 11, and a nozzle for supplying cleaning fluid. As the cleaning fluid, a liquid such as pure water or a mixed fluid of a liquid (such as pure water) and a gas (such as air) can be used. The workpiece 11 is cleaned by holding it with the spinner table and supplying cleaning fluid to the workpiece 11 from the nozzle while rotating the spinner table.

[0040] The processing apparatus 2 includes a control unit (control unit, control device) 56 that controls the processing apparatus 2. The control unit 56 is connected to each component that makes up the processing apparatus 2 (transport unit 6, alignment mechanism 12, transport unit 18, chuck table 20, moving mechanism 22, moving mechanisms 26A, 26B, grinding units 38A, 38B, polishing unit 52, cleaning unit 54, etc.). The control unit 56 controls the operation of the processing apparatus 2 by outputting control signals to each component of the processing apparatus 2.

[0041] For example, the control unit 56 is composed of a computer and includes a calculation unit that performs calculations necessary for the operation of the processing device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the processing device 2. The calculation unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0042] Next, the polishing unit 52 will be described. Figure 2 is a perspective view showing the polishing unit 52. The polishing unit 52 is supported by a rectangular parallelepiped support structure 60 provided in or near the polishing area D (see Figure 1).

[0043] An X-axis movement mechanism 62 is provided on the surface side of the support structure 60 for moving the polishing unit 52 along the X-axis direction. The X-axis movement mechanism 62 comprises a pair of X-axis guide rails 64 fixed to the surface side of the support structure 60 and arranged along the X-axis direction. Rectangular parallelepiped X-axis movement blocks 66 are slidably mounted on the X-axis guide rails 64.

[0044] A nut (not shown) is provided on the back side of the X-axis movement block 66. An X-axis ball screw (not shown), which is positioned along the X-axis direction between a pair of X-axis guide rails 64, is screwed into this nut. An X-axis pulse motor 68, which rotates the X-axis ball screw, is connected to the end of the X-axis ball screw. When the X-axis pulse motor 68 rotates the X-axis ball screw, the X-axis movement block 66 moves along the X-axis guide rails 64 in the X-axis direction.

[0045] A Z-axis movement mechanism 70 is provided on the surface side of the X-axis movement block 66 to move the polishing unit 52 along the Z-axis direction. The Z-axis movement mechanism 70 includes a pair of Z-axis guide rails 72 fixed to the surface side of the X-axis movement block 66 and arranged along the Z-axis direction. A rectangular parallelepiped Z-axis movement block 74 is slidably mounted on the Z-axis guide rails 72.

[0046] A nut (not shown) is provided on the back side of the Z-axis movement block 74. A Z-axis ball screw (not shown), which is positioned along the Z-axis direction between a pair of Z-axis guide rails 72, is screwed into this nut. A Z-axis pulse motor 76, which rotates the Z-axis ball screw, is connected to the end of the Z-axis ball screw. When the Z-axis pulse motor 76 rotates the Z-axis ball screw, the Z-axis movement block 74 moves along the Z-axis guide rails 72 in the Z-axis direction.

[0047] A polishing unit 52 is mounted on the surface side of the Z-axis movement block 74. The polishing unit 52 has a cylindrical housing 78 fixed to the Z-axis movement block 74. A cylindrical spindle 80 is housed in the housing 78. The tip (lower end) of the spindle 80 is exposed from the housing 78, and a disc-shaped mount 82 made of metal or the like is fixed to the tip of the spindle 80. A rotational drive source, such as a motor, which rotates the spindle 80 is connected to the base (upper end) of the spindle 80.

[0048] A polishing pad 84 for polishing the workpiece 11 is mounted on the lower side of the mount 82. The polishing pad 84 has a disc-shaped base 86. The base 86 is made of metal or the like and is formed to be approximately the same diameter as the mount 82. A disc-shaped polishing layer 88 is fixed to the lower side of the base 86. The chuck table 20 holding the workpiece 11 is placed in the polishing area D (see Figure 1), and the workpiece 11 is polished by rotating the chuck table 20 and the polishing pad 84 while bringing the polishing layer 88 into contact with the workpiece 11.

[0049] Furthermore, a cover 90 that covers the polishing area D is attached to the base 4 (see Figure 1). For example, the cover 90 is formed in a box shape and has a housing section (housing space) 90a capable of accommodating the chuck table 20. When the cover 48 is attached to the base 4, the polishing area D (see Figure 1) is covered by the cover 48, and a processing chamber (polishing chamber) in which the workpiece 11 is polished is defined.

[0050] An oval-shaped through-hole 90b is provided on the upper side of the cover 90, connecting the outside of the cover 90 to the housing section 90a. The polishing unit 52 and the through-hole 90b of the cover 90 are connected via a connecting member 92. For example, the connecting member 92 is a flexible member made of a flexible elastic material such as rubber or resin, and is formed in a hollow, bellows-like shape.

[0051] The upper end of the connecting member 92 is fixed to the polishing unit 52 (for example, the Z-axis moving block 74 or the housing 78), and the lower end of the connecting member 92 is fixed to the upper surface of the cover 90 so as to cover the through hole 90b. A duct 94 is also connected to the cover 90 for discharging gas or mist-like liquid from the housing 90a.

[0052] When polishing the workpiece 11 with the polishing unit 52, the polishing pad 84 is positioned to overlap with the through hole 90b of the cover 90 and inserted into the through hole 90b. This prevents interference between the polishing pad 84 and the cover 90 when the polishing pad 84 moves up and down.

[0053] Next, the processing method for the workpiece 11 using the processing device 2 will be described with reference to Figures 1 and 2. In this embodiment, as an example, the case in which the back surface 11b of the workpiece 11 is a work surface (grinding surface, polishing surface) that is subjected to grinding and polishing will be described.

[0054] When processing the back surface 11b of the workpiece 11, a protective member may be fixed to the front surface 11a of the workpiece 11. For example, a film-like protective sheet (protective tape) made of resin or the like is attached to the front surface 11a of the workpiece 11 as a protective member. This protects the front surface 11a of the workpiece 11. Then, a cassette 10A or cassette 10B containing multiple workpieces 11 is placed on a mounting table 8A or mounting table 8B.

[0055] When the processing device 2 is in operation, first, the workpiece 11 contained in cassette 10A or cassette 10B is transported to the alignment mechanism 12 by the transport unit 6. Then, the alignment mechanism 12 aligns the workpiece 11. After that, the workpiece 11 is held by the transport unit 18 and transported to the chuck table 20 located in the transport area A.

[0056] The workpiece 11 is placed on the chuck table 20 such that its front surface 11a faces the holding surface 20a and its back surface 11b is exposed upwards. In this state, when the suction force of the suction source is applied to the holding surface 20a, the workpiece 11 is held in place by the chuck table 20.

[0057] Next, the moving mechanism 22 (turntable) rotates. This causes the chuck table 20 holding the workpiece 11 to enter the housing section 48a of the cover 48 and be positioned in the grinding area B. The workpiece 11 is also positioned below the grinding wheel 46A. Then, while rotating the chuck table 20 and the grinding wheel 46A, the grinding wheel 46A is lowered so that the grinding wheel comes into contact with the back surface 11b of the workpiece 11. As a result, the back surface 11b of the workpiece 11 is ground away by the grinding wheel 46A, and rough grinding is performed on the workpiece 11. When the workpiece 11 is thinned to a predetermined thickness, the rough grinding of the workpiece 11 is completed.

[0058] Once the rough grinding of the workpiece 11 is complete, the moving mechanism 22 (turntable) rotates. This causes the chuck table 20 holding the workpiece 11 to move within the housing section 48a of the cover 48 and be positioned in the grinding area C. The workpiece 11 is also positioned below the grinding wheel 46B. Then, while rotating the chuck table 20 and the grinding wheel 46B, the grinding wheel 46B is lowered so that the grinding wheel contacts the back surface 11b of the workpiece 11. As a result, the back surface 11b of the workpiece 11 is ground away by the grinding wheel 46B, and the workpiece 11 is given a finish grind. When the workpiece 11 is thinned to a predetermined thickness, the finish grinding of the workpiece 11 is complete.

[0059] During rough grinding and finish grinding of the workpiece 11, a liquid such as pure water (grinding fluid) is continuously supplied to the workpiece 11 and the grinding wheel. This cools the workpiece 11 and the grinding wheel, and washes away the debris (grinding chips) generated by grinding the workpiece 11.

[0060] When the back surface 11b of the workpiece 11 is ground, arc-shaped grinding marks (saw marks) are formed on the back surface 11b of the workpiece 11 along the rotation path of the grinding wheel. These grinding marks reduce the mechanical strength of the product obtained by processing the workpiece 11. Therefore, the grinding marks are removed by polishing the back surface 11b of the workpiece 11 after grinding.

[0061] Specifically, once the finish grinding of the workpiece 11 is complete, the moving mechanism 22 (turntable) rotates. As a result, the chuck table 20 holding the workpiece 11 moves out of the housing section 48a of the cover 48 and enters the housing section 90a of the cover 90 (see Figure 2), and is positioned in the polishing area D. In addition, the position of the polishing unit 52 is adjusted by the X-axis moving mechanism 62 (see Figure 2) so that the workpiece 11 and the polishing pad 84 overlap.

[0062] Then, while rotating the chuck table 20 and the polishing pad 84, the polishing pad 84 is lowered by the Z-axis movement mechanism 70 (see Figure 2), bringing the lower surface of the polishing layer 88 into contact with the back surface 11b of the workpiece 11. As a result, the back surface 11b of the workpiece 11 is polished.

[0063] The abrasive layer 88 is made of a resin such as polyurethane or a nonwoven fabric such as felt, and contains abrasive grains (fixed abrasive grains). As the abrasive grains, for example, silica with a particle size of 0.5 μm or more and 10 μm or less can be used. However, the material of the abrasive layer 88, the particle size and material of the abrasive grains can be appropriately selected according to the material of the workpiece 11, etc.

[0064] For example, the workpiece 11 is subjected to dry polishing. In this case, no liquid (polishing solution) such as slurry or pure water is supplied to the workpiece 11 during polishing. On the other hand, when the workpiece 11 is subjected to wet polishing, a polishing solution that does not contain abrasive grains is supplied to the workpiece 11 and the polishing pad 84. As the polishing solution, chemical solutions such as acidic polishing solutions and alkaline polishing solutions, or pure water can be used. As an acidic polishing solution, an acidic solution in which permanganate or the like is dissolved is used. As an alkaline polishing solution, an alkaline solution in which sodium hydroxide or potassium hydroxide is dissolved is used.

[0065] The polishing layer 88 does not necessarily have to contain fixed abrasive grains. In this case, a polishing solution containing abrasive grains is supplied to the workpiece 11 and the polishing pad 84. For example, the polishing solution may contain abrasive grains such as silica or alumina as free abrasive grains.

[0066] When the back surface 11b of the workpiece 11 is polished with the polishing pad 84, the back surface 11b of the workpiece 11 is flattened and polished to a mirror finish, and grinding marks remaining on the back surface 11b of the workpiece 11 are removed. The amount of polishing of the workpiece 11 (the difference in thickness of the workpiece 11 before and after polishing) is set appropriately according to the material of the workpiece 11, the depth of the grinding marks, etc.

[0067] Once the polishing of the workpiece 11 is complete, the moving mechanism 22 (turntable) rotates. This causes the chuck table 20 holding the workpiece 11 to move out of the housing section 90a (see Figure 2) of the cover 90 and be placed back in the transport area A. The workpiece 11 is then transported from the chuck table 20 to the washing unit 54 by the transport unit 18 and washed by the washing unit 54. After that, the workpiece 11 is stored in cassette 10A or cassette 10B by the transport unit 6.

[0068] Figure 3 is a plan view showing the chuck table 20 and the moving mechanism 22. In the processing process of the workpiece 11 by the processing apparatus 2 described above, after the workpiece 11 is ground in the grinding area C, the chuck table 20 moves from the grinding area C to the polishing area D, and the workpiece 11 is polished in the polishing area D. After grinding, liquid such as grinding fluid supplied during grinding adheres to the back surface 11b of the workpiece 11. If this liquid remains on the workpiece 11 during the polishing process, it may adversely affect the polishing process.

[0069] Therefore, the processing apparatus 2 according to this embodiment is provided with a liquid removal unit 100. The liquid removal unit 100 removes any liquid remaining on the workpiece surface of the workpiece 11 as the chuck table 20 moves between the grinding area C and the polishing area D. As a result, liquid is removed from the workpiece surface side of the workpiece 11 as the chuck table 20 moves from the grinding area C to the polishing area D, preventing the proper polishing of the workpiece 11 from being hindered by the liquid.

[0070] As shown in Figure 3, the liquid removal unit 100 is positioned in a location that overlaps with the movement path of the chuck table 20 from the grinding area C to the polishing area D. For example, the liquid removal unit 100 is a columnar member positioned along a direction intersecting the movement path of the chuck table 20 (the X-axis direction in Figure 3). The height of the liquid removal unit 100 (position in the Z-axis direction) is adjusted so that the liquid removal unit 100 contacts the back surface 11b of the workpiece 11 when the chuck table 20 moves from the grinding area C to the polishing area D.

[0071] After grinding the workpiece 11, when the chuck table 20 moves from the grinding area C to the polishing area D, the liquid removal unit 100 comes into contact with the back surface 11b of the workpiece 11 and wipes or absorbs any liquid adhering to the back surface 11b of the workpiece 11. As a result, the workpiece 11, with the liquid removed, is placed in the polishing area D.

[0072] There are no restrictions on the installation method of the liquid removal unit 100. For example, as shown in Figure 2, the liquid removal unit 100 is fixed to the rear end of the cover 90 (the entrance to the housing 90a) along the X-axis direction. In this case, by attaching the cover 90 to the base 4 (see Figure 1), the liquid removal unit 100 is positioned between the grinding area C and the polishing area D.

[0073] Next, the specific configuration of the liquid removal unit 100 will be described. The liquid removal unit 100 includes a contact member that contacts the workpiece surface side of the workpiece 11 to remove the liquid. For example, the liquid removal unit 100 includes an elastic member 102 (see Figures 4(A) to 4(C)) that contacts the workpiece 11, or a sponge 104 (see Figures 5(A) to 5(C)) that contacts the workpiece 11, as the contact member. In addition, liquid 13 such as grinding fluid that adhered during grinding remains on the back surface 11b side of the workpiece 11.

[0074] The elastic member 102 shown in Figures 4(A) to 4(C) is a plate-shaped member made of a flexible elastic material such as rubber or resin, and is formed, for example, in a rectangular shape. The elastic member 102 is positioned to intersect with the movement path of the chuck table 20 as it moves from the grinding area C to the polishing area D (see Figure 3). For example, the elastic member 102 is provided at the rear end of the cover 90 (see Figure 2) so that its length (longitudinal direction) is aligned with the X-axis direction. The length of the elastic member 102 is greater than the diameter of the workpiece 11.

[0075] The elastic member 102 is positioned such that its tip (lower end) is located slightly below the back surface 11b of the workpiece 11. For example, the height difference between the back surface 11b of the workpiece 11 and the tip of the elastic member 102 is set to 1 mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more.

[0076] Figure 4(A) is a side view showing the elastic member 102 that contacts the front end of the workpiece 11. When the chuck table 20 holding the workpiece 11 begins to move from the grinding area C towards the polishing area D (see Figure 3), first, the tip of the elastic member 102 contacts the front end of the workpiece 11 (the left end in Figure 4(A)). Then, the tip of the elastic member 102 is pressed by the workpiece 11 and elastically deforms, becoming bent.

[0077] Figure 4(B) is a side view showing an elastic member 102 that removes liquid 13 adhering to the workpiece 11. As the chuck table 20 moves, the tip of the elastic member 102 is elastically deformed and traces the back surface 11b of the workpiece 11. As a result, the liquid 13 adhering to the back surface 11b of the workpiece 11 is wiped away by the elastic member 102. In other words, the elastic member 102 functions as a wiper to remove the liquid 13.

[0078] Figure 4(C) is a side view showing the elastic member 102 in contact with the rear end of the workpiece 11. When the elastic member 102 reaches the rear end of the workpiece 11 (the right end in Figure 4(C)), the entire back surface 11b of the workpiece 11 is wiped by the elastic member 102, and the liquid 13 adhering to the back surface 11b of the workpiece 11 is removed. As a result, the workpiece 11 is placed in the polishing area D (see Figure 3) without any liquid 13 adhering to it.

[0079] The sponge 104 shown in Figures 5(A) to 5(C) is made of a water-absorbing material such as PVA (polyvinyl alcohol), urethane foam, polyethylene foam, or rubber sponge, and is formed, for example, in a cylindrical shape. A through hole (not shown) is provided in the center of the sponge 104, penetrating the sponge 104 in the longitudinal direction. A support shaft 106 is inserted into the through hole of the sponge 104 to support the sponge 104. As a result, the sponge 104 is supported by the support shaft 106, allowing it to rotate freely around the support shaft 106.

[0080] The sponge 104 is positioned to intersect the movement path of the chuck table 20 as it moves from the grinding area C to the polishing area D (see Figure 3). For example, both ends of the support shaft 106 are fixed to the lower ends of a pair of support members 108. The upper ends of the pair of support members 108 are fixed to both ends of the rear end of the cover 90 (see Figure 2). As a result, the sponge 104 is positioned so that its length is aligned with the X-axis direction. The length of the sponge 104 is greater than the diameter of the workpiece 11.

[0081] The sponge 104 is positioned such that its tip (lower end) is located slightly below the back surface 11b of the workpiece 11. For example, the height difference between the back surface 11b of the workpiece 11 and the tip of the sponge 104 is set to 1 mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more.

[0082] Figure 5(A) is a side view showing the sponge 104 in contact with the front end of the workpiece 11. When the chuck table 20 holding the workpiece 11 begins to move from the grinding area C towards the polishing area D (see Figure 3), first the outer circumference of the sponge 104 comes into contact with the front end of the workpiece 11 (the left end in Figure 5(A)). Then, the outer circumference of the sponge 104 is pressed by the workpiece 11 and elastically deforms, becoming compressed.

[0083] Figure 5(B) is a side view showing a sponge 104 that removes liquid 13 adhering to the workpiece 11. As the chuck table 20 moves, the sponge 104 rotates with its lower end deformed, tracing the back surface 11b of the workpiece 11. As a result, the liquid 13 is absorbed by the sponge 104. In other words, the sponge 104 functions as a water-absorbing member that absorbs the liquid 13.

[0084] Figure 5(C) is a side view showing the sponge 104 in contact with the rear end of the workpiece 11. As the sponge 104 rotates and reaches the rear end of the workpiece 11 (the right end in Figure 5(C)), the sponge 104 comes into contact with the entire back surface 11b of the workpiece 11, and the liquid 13 adhering to the back surface 11b of the workpiece 11 is absorbed and removed. As a result, the workpiece 11 is placed in the polishing area D (see Figure 3) without any liquid 13 adhering to it.

[0085] As described above, if the liquid 13 adhering to the workpiece 11 is removed by the liquid removal unit 100 while the chuck table 20 is moving from the grinding area C to the polishing area D, the drying process for the workpiece 11 after it reaches the polishing area D can be shortened or omitted. This makes it possible to quickly start polishing the workpiece 11 placed in the polishing area D, thereby improving the processing efficiency of the workpiece 11.

[0086] In the above description, an example was given in which the liquid removal unit 100 includes a contact member (elastic member 102 or sponge 104) that contacts the workpiece 11 to remove the liquid. However, the liquid removal unit 100 may remove the liquid without contacting the workpiece 11. For example, the liquid removal unit 100 may be a columnar (bar-shaped) nozzle that sprays a gas such as air. In this case, the liquid 13 adhering to the back surface 11b of the workpiece 11 is blown away and removed by the gas sprayed from the nozzle. However, if a contact member is used and the nozzle is omitted, components for supplying gas to the nozzle (valve, gas supply source, etc.) can also be omitted, thus simplifying the configuration of the liquid removal unit 100.

[0087] As described above, the processing apparatus 2 according to this embodiment includes a liquid removal unit 100 that removes the liquid 13 remaining on the workpiece surface side of the workpiece 11 when the chuck table 20 moves between the grinding area C and the polishing area D. This allows the workpiece 11 to be placed in the polishing area D with the liquid 13 removed, preventing the liquid 13 from hindering the proper polishing of the workpiece 11.

[0088] In the above embodiment, an example was described in which the liquid removal unit 100 is provided on the cover 90 that covers the polishing area D (see Figure 2), but there are no restrictions on the installation method of the liquid removal unit 100. For example, the liquid removal unit 100 can also be provided on the cover 48 that covers the grinding areas B and C.

[0089] Figure 6 is a perspective view showing the cover 48 on which the liquid removal section 100 is provided. One end of the front of the cover 48 (the grinding area B side) corresponds to the entrance of the housing section 48a into which the chuck table 20 enters. The other end of the front of the cover 48 (the grinding area C side) corresponds to the exit of the housing section 48a into which the chuck table 20 exits.

[0090] The liquid removal unit 100 is fixed to the other end (outlet) of the front end of the cover 48 along the X-axis direction. In this case, by attaching the cover 48 to the base 4 (see Figure 1), the liquid removal unit 100 is positioned between the grinding area C and the polishing area D.

[0091] The liquid removal unit 100 may be mounted on both the cover 48 and the cover 90. Alternatively, the liquid removal unit 100 may be supported by a dedicated support member provided on the base 4. For example, a support member may be installed between the cover 48 and the cover 90 mounted on the base 4, and the liquid removal unit 100 may be supported by this support member.

[0092] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of symbols]

[0093] 11 Workpiece 11a Surface (first side) 11b Back side (2nd side) 13 liquid 2. Processing equipment (grinding and polishing equipment) 4 base 4a,4b opening 6. Transport Unit 8A, 8B Mounting platform 10A, 10B Cassette 12. Alignment mechanism (positioning mechanism) 14 Temporary Placement Table 16 Support structure 18 Conveyor Unit 20 Chuck Table (Holding Table) 20a Holding surface 22 Moving mechanism 24 Support structure 26A,26B Moving mechanism 28 Guide rails 30 Mobile Plates 32 Ball screw 34 pulse motor 36 Support Member 38A, 38B Grinding Unit 40 Housing 42 spindles 44 Wheel Mount 46A, 46B Grinding Wheels 48 Cover 48a Storage area (storage space) 50A, 50B Insertion holes 52 Polishing Units 54 Washing Unit 56 Control Unit (Control Unit, Control Device) 60 Support structure 62 X-axis movement mechanism 64 X-axis guide rails 66 X-axis movement block 68 X-axis pulse motor 70 Z-axis movement mechanism 72 Z-axis guide rails 74 Z-axis movement block 76 Z-axis pulse motor 78 Housing 80 spindles 82 Mount 84 polishing pads 86 base 88 Polishing layer 90 Cover 90a Storage area (storage space) 90b through hole 92 Connecting member 94 duct 100 Liquid removal section 102 Elastic member 104 Sponge 106 Support shaft 108 Support Member

Claims

1. A processing device for processing a workpiece, A chuck table having a holding surface for holding the workpiece, A grinding unit having a spindle on which a grinding wheel is mounted, A polishing unit having a spindle on which a polishing pad is attached, A moving mechanism for moving the chuck table between a grinding area where the workpiece is ground by the grinding wheel and a polishing area where the workpiece is polished by the polishing pad, A processing apparatus characterized by comprising a liquid removal unit that removes any liquid remaining on the workpiece surface side of the workpiece as the chuck table moves between the grinding area and the polishing area.

2. The processing apparatus according to claim 1, characterized in that the liquid removal unit includes a contact member that contacts the workpiece surface side of the workpiece to remove the liquid.

3. The processing apparatus according to claim 2, characterized in that the contact member is an elastic member arranged to intersect the movement path of the chuck table.

4. The processing apparatus according to claim 2, characterized in that the contact member is a rotatable sponge positioned to intersect the movement path of the chuck table.

5. The system further comprises a cover that covers the grinding area or the polishing area, The processing apparatus according to any one of claims 1 to 4, characterized in that the liquid removal unit is provided in the cover.

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