Grinding device

Abstract

To provide a grinding device which enables unambiguous management of ending of lives of sponge parts and can stably maintain an effect for cleaning a support surface of a wafer.SOLUTION: A grinding device includes: carry-out means 15 which holds a wafer W which has been ground to carry out the wafer W from a chuck table 6; grinding surface cleaning means 11 which cleans a ground surface of the wafer W carried out by the carry-out means 15; and support surface cleaning means 12 which is disposed between the chuck table 6 and the grinding surface cleaning means 11 and cleans a support surface of the wafer W, which is supported by the chuck table 6, in a state that the wafer W is held by the carry-out means 15. The support surface cleaning means 12 includes: sponge parts 124 configured to contact with the support surface of the wafer W; a driving source 121 for rotating the sponge parts 124; and cleaning water supply parts 125 for supplying cleaning water L. The grinding device further includes a management part 110 which detects a load current value of the driving source 121 to manage lives of the sponge parts 124.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a grinding apparatus including a chuck table for supporting a wafer and a grinding means for grinding the wafer supported on the chuck table. [Background technology]

[0002] A wafer has multiple devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back side of the wafer is ground using a grinding machine to form it to a specified thickness, and then the wafer is divided into individual device chips using a dicing machine and laser processing machine. These chips are then used in electrical devices such as mobile phones and personal computers.

[0003] The grinding device is configured to include a chuck table that holds the wafer by suction, and grinding means that has a rotatably mounted grinding wheel with a ring-shaped grinding stone that grinds the top surface of the wafer held by suction on the chuck table, and can grind the wafer to the desired thickness with high precision.

[0004] Furthermore, when grinding the top surface (back surface) of a wafer, there is a problem in that grinding water containing contaminants seeps in from the outer periphery of the chuck table and contaminates the support surface on which the wafer is supported by the chuck table. To address this problem, the present applicant has proposed a grinding apparatus equipped with a cleaning means for cleaning the support surface of the wafer (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-054082 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as the sponge part that makes up the cleaning means wears out and becomes dirty over time, the cleaning effect decreases, and it becomes necessary to replace it with a new sponge part. However, there is no clear indicator for determining the replacement time, and it relies on the operator's sense, which makes it difficult to maintain a stable cleaning effect.

[0007] The present invention has been made in consideration of the above facts, and its main technical object is to provide a grinding device that makes it possible to uniquely manage the end of the life of the sponge part and can stably maintain the effect of cleaning the support surface of the wafer. [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problems, according to the present invention, there is provided a grinding apparatus comprising a chuck table for supporting a wafer, and grinding means for grinding the wafer supported on the chuck table, further comprising: carry-out means for holding the ground wafer and carrying it out of the chuck table; grinding surface cleaning means for cleaning the grinding surface of the wafer carried out by the carry-out means; and support surface cleaning means disposed between the chuck table and the grinding surface cleaning means for cleaning the support surface of the wafer supported on the chuck table while being held by the carry-out means, wherein the support surface cleaning means includes a sponge portion that contacts the support surface of the wafer, a drive source for rotating the sponge portion, and a cleaning water supply unit for supplying cleaning water, and further comprising a management unit that detects the load current value of the drive source and manages the life of the sponge portion.

[0009] The sponge portion may be a plurality of sponge portions arranged radially from the drive source, and may be cylindrical with a central axis corresponding to the rotation axis of the drive source. [Effects of the Invention]

[0010] The grinding apparatus of the present invention is a grinding apparatus comprising a chuck table for supporting a wafer and a grinding means for grinding the wafer supported on the chuck table, and further comprising a carrying means for holding the ground wafer and carrying it out of the chuck table, a grinding surface cleaning means for cleaning the grinding surface of the wafer carried out by the carrying means, and a support surface cleaning means disposed between the chuck table and the grinding surface cleaning means for cleaning the support surface of the wafer supported on the chuck table while being held by the carrying means. The support surface cleaning means includes a sponge portion that contacts the support surface of the wafer, a drive source for rotating the sponge portion, and a cleaning water supply unit for supplying cleaning water. The support surface cleaning means is equipped with a management unit that detects the load current value of the drive source and manages the life of the sponge portion. This makes it possible to uniquely manage the end of the life of the sponge portion by the management unit, and since there is no need to rely on the operator's sense regarding the life of the sponge portion, the effect of cleaning the support surface of the wafer W can be stably maintained. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view of a grinding device according to an embodiment of the present invention; [Figure 2] 2 is an enlarged perspective view showing a support surface cleaning means disposed in the grinding machine shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a perspective view of a wafer to be processed by the grinding apparatus of FIG. [Figure 4] FIG. 10 is a perspective view showing how the support surface of the wafer is cleaned by the support surface cleaning means. [Figure 5] 10(a) is a perspective view showing another embodiment of the support surface cleaning means, and FIG. 10(b) is a side view showing how the support surface of the wafer is cleaned by the support surface cleaning means shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The grinding apparatus of the present invention is a grinding apparatus equipped with a chuck table that supports a wafer, which is a workpiece, and grinding means that grinds the wafer supported on the chuck table. Below, an embodiment of a grinding apparatus configured based on the present invention will be described in more detail with reference to the attached drawings.

[0013] 1 shows a grinding apparatus 1 of this embodiment. The grinding apparatus 1 includes a roughly rectangular parallelepiped apparatus housing 2. A support wall 21 is erected on the rear end side of the illustrated apparatus housing 2. Two pairs of guide rails 22, 22 and 23, 23 extending in the vertical direction (Z-axis direction) are provided on the inner surface of this support wall 21. A rough grinding unit 3 as rough grinding means is mounted on one of the guide rails 22, 22 so as to be movable in the vertical direction, and a finish grinding unit 4 as finish grinding means is mounted on the other guide rails 23, 23 so as to be movable in the vertical direction.

[0014] The rough grinding unit 3 includes a unit housing 31, a wheel mount 33 disposed at the lower end of a rotating shaft 32 rotatably supported by the unit housing 31, a rough grinding wheel 34 mounted on the wheel mount 33 and having a plurality of grinding stones 35 arranged in an annular pattern on its underside, an electric motor 36 mounted on the upper end of the unit housing 31 for rotating the wheel mount 33 in the direction indicated by arrow R1, and a movable base 38 for supporting the unit housing 31 via a support member 37. A grinding water supply means (not shown) is connected to the upper end 32a of the rotating shaft 32, and grinding water L introduced from the upper end 32a is supplied via the rotating shaft 32 from the underside of the rough grinding wheel 34 to the location being ground by the grinding stones 35.

[0015] The movable base 38 is provided with guided grooves that slidably engage with the guide rails 22, 22 provided on the support wall 21, and the rough grinding unit 3 is supported so as to be movable in the vertical direction. The illustrated grinding apparatus 1 is equipped with a grinding feed mechanism 39 that raises and lowers the movable base 38 of the rough grinding unit 3 along the guide rails 22, 22. The grinding feed mechanism 39 is equipped with an externally threaded rod 391 that is rotatably supported and disposed in the vertical direction on the support wall 21 parallel to the guide rails 22, 22, a pulse motor 392 for driving the rotation of the externally threaded rod 391, and an internally threaded block (not shown) that is attached to the movable base 38 and threadably engages with the externally threaded rod 391, and the rough grinding unit 3 is moved in the vertical direction by driving the externally threaded rod 391 in the forward and reverse directions by the pulse motor 392.

[0016] The finish grinding unit 4 is configured in substantially the same manner as the rough grinding unit 3, and includes a unit housing 41, a wheel mount 43 disposed at the lower end of a rotating shaft 42 rotatably supported by the unit housing 41, a finish grinding wheel 44 attached to the wheel mount 43 and having a plurality of grinding stones 45 arranged in an annular pattern on its underside, an electric motor 46 attached to the upper end of the unit housing 41 for rotating the wheel mount 43 in the direction indicated by arrow R2, and a movable base 48 supporting the unit housing 41 via a support member 47. A grinding water supply means (not shown) is connected to the upper end 42a of the rotating shaft 42, and grinding water L introduced from the upper end 42a is supplied via the rotating shaft 42 from the underside of the finish grinding wheel 44 to the location being ground by the grinding stones 45.

[0017] The movable base 48 is provided with guided grooves that slidably engage with the guide rails 23, 23 provided on the support wall 21, and the finish grinding unit 4 is supported so as to be movable in the vertical direction. The grinding apparatus 1 is provided with a grinding feed mechanism 49 as elevating means for raising and lowering the movable base 48 of the finish grinding unit 4 along the guide rails 23, 23. The grinding feed mechanism 49 is provided with an externally threaded rod 491 that is rotatably supported and disposed in the vertical direction on the support wall 21 parallel to the guide rails 23, 23, a pulse motor 492 for driving the rotation of the externally threaded rod 491, and an internally threaded block (not shown) that is attached to the movable base 48 and threadably engages with the externally threaded rod 491, and the externally threaded rod 491 is driven to rotate forward and backward by the pulse motor 492, thereby moving the finish grinding unit 4 in the vertical direction.

[0018] The grinding machine 1 is equipped with a turntable 5 disposed on the front side of the support wall 21 so as to be substantially flush with the upper surface of the device housing 2. The turntable 5 is formed in a relatively large disk shape and is rotated appropriately in the direction indicated by arrow R3 by a rotation drive mechanism (not shown) within a drain pan 20 on the upper surface of the device housing 2. The turntable 5 is provided with three chuck tables 6, each of which serves as a holding means for holding a workpiece at an angle of 120 degrees. Each chuck table 6 is equipped with a rotation drive means (not shown) and is configured to be rotatable in the direction indicated by arrow R4. The holding surface of the chuck table 6 is formed in a disk shape using a porous material with air permeability, and is connected to a suction source (not shown).

[0019] The three chuck tables 6 arranged on the turntable 5 are moved sequentially from the workpiece carry-in / out area A → the rough grinding area B → the finish grinding area C → the workpiece carry-in / out area A by rotating the turntable 5 in the direction indicated by the arrow R3. A cleaning water supply nozzle 16 is arranged near the workpiece carry-in / out area A in the drain pan 20, for supplying cleaning water L (which can also be used as the grinding water L) to the upper surface of the chuck table 6 positioned in the workpiece carry-in / out area A.

[0020] The illustrated grinding apparatus 1 comprises a first cassette 7 disposed on one side of the workpiece carry-in / out area A and accommodating a plurality of wafers W, which are workpieces before grinding; a second cassette 8 disposed on the other side of the workpiece carry-in / out area A and accommodating a plurality of wafers W after grinding; a temporary placement table 9 disposed between the first cassette 7 and the workpiece carry-in / out area A and on which the wafers W are temporarily placed and centered; a grinding surface cleaning means 11 disposed between the workpiece carry-in / out area A and the second cassette 8 and cleaning the grinding surface (upper surface) of the wafer W; and a chuck table 6 moved to the workpiece carry-in / out area A and the grinding surface cleaning means 11. The workpiece carrying-in / out means includes a support surface cleaning means 12 for cleaning the support surface (lower surface) of the wafer W supported by the bull 6, a workpiece carrying-in / out means 13 for carrying out the wafer W stored in the first cassette 7 to the temporary placement table 9 and carrying out the wafer W cleaned by the grinding surface cleaning means 11 into the second cassette 8, a carrying-in means 14 for carrying the wafer W held on the temporary placement table 9 to the chuck table 6 positioned in the workpiece carrying-in / out area A, and a carrying-out means 15 for carrying out the ground wafer W placed on the chuck table 6 positioned in the workpiece carrying-in / out area A to the support surface cleaning means 12 and the grinding surface cleaning means 11 while holding the ground surface of the wafer W. The grinding surface cleaning means 11 includes a spinner table 111 that holds the wafer by suction and is rotated at high speed by a driving means (not shown), and a cleaning nozzle 112 that supplies cleaning water and air to the upper surface of the wafer W held on the spinner table 111.

[0021] Carry-in means 14 is capable of moving up and down in the vertical direction (Z-axis direction) and includes an arm member 141 that pivots in the direction indicated by arrow R5, and a suction unit 142 that is formed at the tip of arm member 141 and has a suction hole on the underside. Similarly, carry-out means 15 is capable of moving up and down in the vertical direction (Z-axis direction) and includes an arm member 151 that pivots in the direction indicated by arrow R6, and a suction unit 152 that is formed at the tip of arm member 151 and has a suction hole on the underside.

[0022] An operation panel 17 is provided on the front side of the device housing 2, and grinding instructions can be given to a control means 100 provided inside the device housing 2 using the operation panel 17. The control means 100 is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) for temporarily storing detected values, calculation results, etc., an input interface, and an output interface (details not shown). Each operating unit of the grinding device 1 described above is connected to the control means 100, and the control means 100 controls each operating unit to perform the grinding process described below.

[0023] 2 shows an enlarged view of support surface cleaning means 12, which is an example of the support surface cleaning means of the present invention. Support surface cleaning means 12 is disposed on drain pan 20 on a path taken when suction is applied to and the ground surface (upper surface) of wafer W held on chuck table 6 by suction unit 152 of carry-out means 15 from chuck table 6 positioned in workpiece carry-in / out area A and carried to ground surface cleaning means 11. Support surface cleaning means 12 includes a drive source 121 disposed on the underside of drain pan 20, a rotating shaft 122 that protrudes above drain pan 20 and is rotated by drive source 121, a sponge holding unit 123 disposed on the upper end of rotating shaft 122, a sponge unit 124 attached to sponge holding unit 123, and a cleaning water supply unit 125 that supplies cleaning water L.

[0024] In this embodiment, the sponge portions 124 are held by sponge holders 123 arranged radially from the drive source 121, and are configured to hold a plurality of (four in the illustrated embodiment) sponge portions 124, each having a substantially rectangular parallelepiped shape. Four cleaning water supply portions 125 are also formed along each sponge holder 123. A plurality of nozzle holes 125a for spraying cleaning water L (which can also serve as the grinding water L) are arranged on the upper surface of the cleaning water supply portions 125, and these nozzle holes 125a are connected to a cleaning water supply means (not shown), so that the cleaning water L is sprayed upward from the nozzle holes 125a. The material of the sponge portions 124 is not particularly limited, and may be, for example, a sponge made from sea sponge, loofah, or cotton; a sponge containing a nonwoven fabric made from a natural material such as cotton, linen, or wool; a synthetic sponge containing polyurethane, polyester, or nylon nonwoven fabric; or melamine. By operating the drive source 121, the sponge holding portion 123 is rotated in the direction indicated by the arrow R7 together with the cleaning water supply portion 125. The drive source 121 is an electric motor, and is driven by the control means 100. The load current value is detected by a management portion 110 (described in detail later) formed in the control means 100, which manages the life of the sponge portion 124.

[0025] The grinding device 1 of the embodiment has roughly the configuration as described above, and the functions, actions, and effects of the grinding device 1 will be described below.

[0026] 3 shows a wafer W to be processed by the grinding apparatus 1. The wafer W is, for example, a silicon wafer, and a plurality of devices D are formed on the front surface Wa of the wafer W, separated by planned division lines WL. A protective tape T is attached to the front surface Wa of the wafer W in advance as shown in the figure, and the wafer W is stored in a first cassette 7 with the back surface Wb, which is the grinding surface, facing upward.

[0027] When performing grinding using the grinding apparatus 1, first, the first cassette 7 containing a plurality of wafers W as described above is set in the grinding apparatus 1 shown in FIG. 1 , and an empty second cassette 8 is also set. Next, the turntable 5 is operated to position the chuck table 6, which does not hold a wafer W, in the workpiece carry-in / out area A. Next, the workpiece carry-in / out means 13 is operated to carry out the unprocessed wafer W from the first cassette 7 and place it on the temporary storage means 9, where it is centered. The centered wafer W is then sucked and transported by the suction part 142 of the carry-in means 14, and placed on the chuck table 6 positioned in the workpiece carry-in / out area A with the protective tape T facing downward.

[0028] Once the wafer W is placed on the chuck table 6, a suction source (not shown) is activated to generate negative pressure on the holding surface of the chuck table 6, thereby supporting the wafer W. Next, the turntable 5 is rotated 120 degrees in the direction indicated by the arrow R3 in FIG. 1, and the chuck table 6 supporting the unprocessed wafer W is moved toward the rough grinding area B.

[0029] Once the chuck table 6 supporting the wafer W is positioned in the rough grinding area B, rough grinding is performed. More specifically, the chuck table 6 is rotated in the direction indicated by the arrow R4 in FIG. 1 at, for example, 300 rpm. Simultaneously, the rough grinding unit 3 is operated to rotate the rough grinding wheel 34 in the direction indicated by the arrow R1 in the figure at, for example, 6000 rpm. Then, the grinding feed mechanism 39 is operated to lower the rough grinding unit 3, bringing the grinding wheel 35 into contact with the back surface Wb of the wafer W from above, and grinding is performed at a grinding feed rate of, for example, 1.0 μm / sec. At this time, the grinding water supply means (not shown) is operated to introduce grinding water L from the upper end 32a of the rotating shaft 32 and supply the grinding water L from the underside of the rough grinding wheel 34 toward the grinding wheel 35 and the back surface Wb of the wafer W. At the same time, grinding can be carried out while measuring the thickness of the wafer W using a contact or non-contact measuring gauge (not shown), and the back surface Wb of the wafer W is roughly ground to bring the wafer W to the desired thickness for rough grinding, thereby completing the rough grinding process.

[0030] As described above, once the rough grinding is completed, the turntable 5 is rotated another 120 degrees in the direction indicated by the arrow R3 in FIG. 1 , and the chuck table 6, which has undergone the rough grinding, is moved to the finish grinding area C, i.e., directly below the finish grinding unit 4. Once the chuck table 6 has been moved directly below the finish grinding unit 4, the rotary shaft 42 of the finish grinding unit 4 is rotated at, for example, 6000 rpm, while the chuck table 6 is rotated at, for example, 300 rpm. The manner in which the finish grinding is performed is substantially the same as the rough grinding described above, except that the grain size of the grinding wheel 45 is smaller than that of the grinding wheel 35 used in the rough grinding. That is, the grinding wheel 45 is brought into contact with the back surface Wb of the wafer W, and the grinding wheel 44 is fed downward at a grinding feed rate of, for example, 0.1 μm / sec. At this time, similarly to the rough grinding process, grinding water L is introduced from the upper end 42a of the rotating shaft 42 and supplied to the grinding surface, i.e., the back surface Wb, of the wafer W from the underside of the finish grinding wheel 44. At the same time, grinding can be carried out while measuring the thickness of the wafer W with a contact or non-contact measuring gauge (not shown), and the back surface Wb of the wafer W is ground to a desired thickness for finish grinding, completing the finish grinding process, and the grinding process consisting of the rough grinding process and the finish grinding process described above is completed.

[0031] In addition, when the above-mentioned rough grinding process is performed, if a wafer W that has been subjected to the rough grinding process is positioned in the adjacent finish grinding process area C, the above-mentioned finish grinding process can be performed simultaneously with the above-mentioned rough grinding process.

[0032] Once the above-described finish grinding is completed, the turntable 5 is rotated another 120 degrees in the direction indicated by R3, and the chuck table 6 supporting the wafer W for which finish grinding has been completed is positioned in the workpiece loading / unloading area A. Next, cleaning water L is sprayed from the cleaning water supply nozzle 16 onto the back surface Wb, which is the grinding surface of the wafer W, to clean the back surface Wb to some extent. Note that cleaning by the cleaning water supply nozzle 16 does not sufficiently clean the back surface Wb of the wafer W.

[0033] Here, the above-mentioned unloading means 15 is operated to position the lower surface of the suction part 152 of the unloading means 15 on the grinding surface (upper surface) of the wafer W positioned in the workpiece loading / unloading area A, and is lowered to approach the wafer W. Next, a negative pressure is generated on the lower surface of the suction part 152 of the unloading means 15, and the negative pressure generated on the holding surface of the chuck table 6 is released. As a result, the grinding surface of the wafer W supported on the chuck table 6 is sucked and held by the suction part 152 of the unloading means 15. Once the grinding surface of the wafer W has been sucked by the suction part 152, the unloading means 15 is raised to unload the wafer W from the chuck table 6.

[0034] The wafer W unloaded from the chuck table 6 is positioned on the support surface cleaning means 12 by rotating the arm member 151 of the unloading means 15 in the direction indicated by arrow R6 in Fig. 1. Next, the drive source 121 of the support surface cleaning means 12 is operated to rotate the sponge holding portion 123 in the direction indicated by arrow R7 at a predetermined speed (e.g., 10 rpm) and to spray a predetermined amount of cleaning water L (e.g., 1 L / min) from the spray holes 125a of the cleaning water supply portion 125, as shown in Fig. 4. Next, as shown in Fig. 4, the sponge unloading means 15 of the support surface cleaning means 12 is lowered a predetermined amount to bring the support surface of the wafer W, to which the protective tape T has been attached and which has been supported by the chuck table 6, into contact with the sponge portion 124 of the support surface cleaning means 12, and the arm member 151 of the unloading means 15 is swung in the direction indicated by arrow R6 at a predetermined speed (e.g., 5° / sec). The amount of pressure of the wafer W contacting the sponge portion 124 is adjusted to a position pressed 1.5 mm from the reference position where the wafer W contacts the sponge portion 124 during the first cleaning of the support surface after attaching a new sponge portion 124. Then, such cleaning of the support surface is carried out for a predetermined time (for example, 15 seconds).

[0035] As a result of the above, the support surface of the wafer W supported by the chuck table 6 is cleaned, and contaminants including contaminants adhering to the support surface of the wafer W to which the protective tape T is attached are removed.

[0036] Here, as described above, the control means 100 is formed with the management unit 110 that manages the life of the sponge portion 124, and detects the load current value from when the drive source 121 of the support surface cleaning means 12 starts operating until cleaning of the support surface of the wafer W is completed. The load current value of the drive source 121 increases due to frictional force generated when the support surface of the wafer W comes into contact with the sponge portion 124 of the rotating support surface cleaning means 12. However, for example, if the sponge portion 124 is contaminated with more than a predetermined amount of dirt or is worn down more than a predetermined amount, the load current value of the drive source 121 will fall below the expected allowable value compared to when the sponge portion 124 is brand new. The management unit 110 of the control means 100 stores as an initial value the load current value when the support surface of the wafer W is cleaned, using the position where the wafer W first contacts the sponge portion 124 after the sponge portion 124 is replaced with a new one as a reference position, and also stores in advance, through previous experiments, an allowable value (e.g., 95%) of the load current value of the drive source 121 when the load current value drops due to contamination or wear of the sponge portion 124 during cleaning of the support surface of the wafer W. If the load current value detected as described above drops below the allowable value compared to the load current value in a new state, even though the support surface of the wafer W is being cleaned by pressing it against the sponge portion 124 of the support surface cleaning means 12, it is determined that the life of the sponge portion 124 has expired. In this way, when the management unit 110 determines that the life of the sponge portion 124 has expired, it notifies the operator by an appropriate method that the life of the sponge portion 124 has expired. The method of notifying the operator that the life of the sponge portion 124 has come to an end can be realized, for example, by displaying on a display means (not shown), emitting an alarm sound, turning on an alarm lamp, or by a combination of these.

[0037] After the support surface cleaning means 12 has cleaned the support surface of the wafer W supported on the chuck table 6, i.e., the protective tape T side, the wafer W is transported by the carry-out means 15 to the ground surface cleaning means 11 described with reference to FIG. 1, and the protective tape T side of the wafer W is placed on the spinner table 111 and held by suction. Next, the spinner table 111 is rotated at high speed, and the cleaning nozzle 112 is oscillated over the back surface Wb (top surface), which is the ground surface of the wafer W, while cleaning water L is sprayed from the tip of the cleaning nozzle 112 toward the ground surface of the wafer W. In this way, cleaning with the cleaning water L sprayed from the cleaning nozzle 112 is carried out for a predetermined time, and the entire ground surface (top surface) of the wafer W is cleaned. Furthermore, after the ground surface of the wafer W is washed with cleaning water L, air is sprayed from the cleaning nozzle 112 toward the upper surface of the wafer W to dry the ground surface of the wafer W, thereby completing the cleaning of the wafer W by the ground surface cleaning means 11. As a result, the support surface (lower surface) and the ground surface (upper surface) of the wafer W are cleaned, and the entire wafer W becomes clean.

[0038] As described above, once the wafer W has been cleaned, the workpiece carrying-in / out means 13 then carries the wafer W out of the spinner table 111 of the grinding surface cleaning means 11, and stores the processed wafer W in a predetermined position in the second cassette 8. This completes the grinding of the wafer W by the grinding apparatus 1 of this embodiment.

[0039] According to the embodiment described above, the life of the sponge portion 124 of the support surface cleaning means 12 is managed primarily by the management unit 110. As a result, when the life of the sponge portion 124 has expired, the management unit 110 can inform the operator that the life of the sponge portion 124 has expired. Therefore, since it is not necessary to rely on the operator's intuition regarding the life of the sponge portion 124, the effect of cleaning the support surface of the wafer W can be stably maintained.

[0040] The support surface cleaning means of the present invention is not limited to the above-described embodiment. For example, instead of the support surface cleaning means 12 described above, a support surface cleaning means 12' shown in FIG. 5(a) may be provided in the grinding apparatus 1. The support surface cleaning means 12' shown in FIG. 5(a) is provided in the same position as the support surface cleaning means 12 described above and includes a drive source 121', a rotation shaft 122' driven by the drive source 121', a cylindrical sponge portion 124' having a central axis corresponding to the rotation shaft 122', and two cleaning water supply portions 125', 125' arranged along the longitudinal direction of the sponge portion 124'. As shown in the figure, the rotation shaft 122' is arranged horizontally and is rotated in the direction indicated by arrow R8 by the operation of the drive source 121'. When the sponge portion 124' is rotated, cleaning water L is sprayed from a plurality of nozzles 125' formed on the upper surface of the cleaning water supply portion 125'.

[0041] The support surface cleaning means 12' arranged as described above can also achieve the same effects as the support surface cleaning means 12. That is, when the chuck table 6 supporting the wafer W for which finish grinding has been completed is positioned in the workpiece loading / unloading area A, the unloading means 15 sucks and unloads the wafer W supported on the chuck table 6, and positions the support surface of the wafer W, i.e., the surface to which the protective tape T is attached, on the sponge portion 124' of the support surface cleaning means 12'. Then, as shown in FIG. 5(b), the drive source 121' of the support surface cleaning means 12' is operated to rotate the sponge portion 124' in the direction indicated by arrow R8 at a predetermined speed (e.g., 10 rpm), and a predetermined amount of cleaning water L (e.g., 1 L / min) is sprayed upward from the spray holes 125a' of the cleaning water supply portion 125'.

[0042] Next, the unloading means 15 is operated to lower the wafer W by a predetermined distance relative to the sponge portion 124' of the support surface cleaning means 12'. The support surface of the wafer W, to which the protective tape T has been attached and which has been supported by the chuck table 6, is brought into contact with and pressed against the sponge portion 124' of the support surface cleaning means 12', and the arm member 151 of the unloading means 15 is moved in the direction indicated by arrow R9 at a predetermined speed (e.g., 5° / sec) to clean the support surface. Even when the support surface of the wafer W is cleaned by the support surface cleaning means 12', the management unit 110 detects the load current value of the drive source 121', allowing the operator to know that the life of the sponge portion 124' has expired. Therefore, since it is not necessary to rely on the operator's intuition regarding the life of the sponge portion 124', the effect of cleaning the support surface of the wafer W can be stably maintained.

[0043] The grinding apparatus 1 described above is equipped with three chuck tables 6, a rough grinding unit 3, and a finish grinding unit 4, and after rough grinding is performed by the rough grinding unit 3, finish grinding is performed by the finish grinding unit 4. However, the above grinding apparatus 1 is merely an example, and the grinding apparatus of the present invention is not limited to the above-described embodiment. For example, the number of chuck tables may be other than three. For example, a grinding apparatus having only one chuck table may be used to perform only finish grinding on wafers that have been rough ground by another grinding apparatus. Furthermore, a grinding apparatus having four or more chuck tables may be used.

[0044] Furthermore, in the above-described embodiment, the management unit 110 is formed in the control means 100 that controls each operating unit of the grinding apparatus 1, but the present invention is not limited to this, and a computer for configuring the management unit 110 may be separately disposed apart from the control means 100 disposed in the grinding apparatus 1. In this case, the management unit 110 does not necessarily have to be configured in the grinding apparatus 1, and may be formed in an external computer connected via a network. [Explanation of symbols]

[0045] 1: Grinding device 2: Device housing 20: Drain pan 21:Supporting wall 22, 23: Guide rails 3: Rough grinding unit 31: Unit housing 32: Rotation axis 32a:Top end 33: Wheel mount 34: Rough grinding wheel 35: Grinding wheel 36: Electric motor 37: Support member 38: Mobile base 39: Grinding feed mechanism 4: Finish grinding unit 41: Unit housing 42: Rotation axis 42a:Top end 43: Wheel mount 44: Finishing grinding wheel 45: Grinding wheel 46: Electric motor 47: Support member 48: Mobile base 49: Grinding feed mechanism 5: Turntable 6: Chuck table 7: First Cassette 8: Second cassette 9: Temporary table 11: Grinding surface cleaning means 111: Spinner table 112: Cleaning nozzle 12, 12': Support surface cleaning means 121, 121': driving source 122, 122': Rotation axis 123: Sponge holder 124, 124': Sponge part 125, 125': Cleaning water supply section 125a, 125a': Ejection hole 13: Workpiece loading / unloading means 14: Means of transport 15:Export means 151: Arm member 152: Adsorption part 16: Cleaning water supply nozzle

Claims

1. A grinding apparatus comprising a chuck table for supporting a wafer and a grinding means for grinding the wafer supported on the chuck table, a carrying-out means for holding the ground wafer and carrying it out of the chuck table, and a ground surface cleaning means for cleaning the ground surface of the wafer carried out by the carrying-out means; a support surface cleaning means disposed between the chuck table and the grinding surface cleaning means for cleaning the support surface of the wafer supported on the chuck table while being held by the carrying-out means, the support surface cleaning means includes a sponge portion that contacts the support surface of the wafer, a drive source that rotates the sponge portion, and a cleaning water supply unit that supplies cleaning water; The grinding device includes a management unit that detects the load current value of the drive source and manages the life of the sponge unit.

2. 2. The grinding device according to claim 1, wherein a plurality of said sponge portions are disposed radially from said drive source.

3. 2. The grinding device according to claim 1, wherein the sponge portion is cylindrical and has a central axis corresponding to the rotation axis of the drive source.

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