Processing chamber cleaning method

Abstract

To clean the wide range of a processing chamber cover without needing a complex structure.SOLUTION: A grinding device 1 comprises: a chuck table 10; a grinding unit 201; a processing chamber cover 30 having first and second covers spaced apart from each other in a direction crossing a Z axis so as to cover at least a part of a processing space KA; and a nozzle 29 for supplying a fluid to the vicinity of a processing point. A method for cleaning the processing chamber KA comprises at least: a first cleaning step of positioning a grinding wheel 23 and a holding surface 101 relative to each other so as to set a gap between the grinding wheel 23 and the holding surface 101 to a distance D1, and cleaning the first cover by a fluid sprayed from the nozzle 29 and passed through the gap; and a second cleaning step of positioning the grinding wheel 23 and the holding surface 101 relative to each other so as to set a distance D2 shorter than the gap, and cleaning the second cover by the fluid sprayed from the nozzle 29 and collided with the grinding wheel 23 to bounce back.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for cleaning a processing chamber. [Background technology]

[0002] Grinding machines grind workpieces while supplying a grinding fluid, thereby preventing machining chips generated during grinding from adhering to and remaining on the workpiece, but machining chips that are sprayed into the machining chamber during grinding accumulate on the wall surface of the machining chamber cover, etc. If machining chips accumulated on the machining chamber cover fall onto the workpiece, there is a risk that the workpiece will be contaminated or that machining of the workpiece will be hindered, so techniques for cleaning the inside of the machining chamber and the machining chamber cover have been proposed (see Patent Documents 1 and 2).

[0003] Patent Document 1 describes a technology for cleaning the inside of a machining chamber cover by spraying grinding fluid supplied from a base of the grinding wheel onto the outer periphery of the grinding wheel using centrifugal force generated by the rotation of the grinding wheel. Patent Document 2 describes a technology for spraying cleaning water from a cleaning nozzle onto a mounter of a machining tool or onto blades attached to the machining tool, and cleaning the inside of the machining chamber with the splashed cleaning water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6129022 [Patent Document 2] Japanese Patent Publication No. 2023-028133 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, various cleaning techniques have been proposed, but new cleaning techniques are still needed. The present invention has been made in view of such a situation, and an object of the present invention is to provide a technique that enables cleaning of a wide area of ​​a processing chamber cover without requiring a complex configuration. [Means for solving the problem]

[0006] A method for cleaning a processing chamber according to one aspect of the present invention is a method for cleaning a processing chamber in a grinding apparatus including: a holding table having a holding surface for holding a workpiece; a grinding unit including a grinding wheel and a first moving unit for moving the grinding wheel in a first direction; a processing chamber cover including at least a first cover and a second cover that cover at least a part of a processing space in which the workpiece is processed by the grinding unit and are installed with a gap therebetween in a second direction intersecting the first direction; and a nozzle that supplies a fluid near a processing point, wherein the gap in the first direction between the grinding wheel and the holding surface is a gap that is formed by the fluid. The method includes at least a first cleaning step of spraying the fluid from the nozzle toward the first cover while the grinding wheel and the holding surface are positioned relative to each other so that the gap is a first distance that allows a body to pass through, and cleaning the first cover with the fluid that has passed through the gap; and a second cleaning step of spraying the fluid from the nozzle toward the first cover while the grinding wheel and the holding surface are positioned relative to each other so that the gap in the first direction between the grinding wheel and the holding surface is a second distance that is shorter than the first distance, and cleaning the second cover with the fluid that collides with the grinding wheel and rebounds. [Effects of the Invention]

[0007] According to the present invention, a wide area of ​​the processing chamber cover can be cleaned without requiring a complex configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a grinding device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the grinding apparatus according to the first embodiment when a first cleaning step is performed. [Figure 3] FIG. 4 is a cross-sectional view of the grinding device according to the first embodiment when a second cleaning step is performed. [Figure 4]FIG. 10 is a cross-sectional view of the grinding apparatus according to the second embodiment when a first cleaning step is performed. [Figure 5] FIG. 10 is a cross-sectional view of the grinding apparatus according to the second embodiment when a second cleaning step is performed. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment Fig. 1 is a perspective view of a grinding apparatus 1 according to this embodiment. The X-axis, Y-axis, and Z-axis directions shown in Fig. 1 are perpendicular to one another. The X-axis and Y-axis directions are approximately horizontal, and the Z-axis direction is the up-down direction (vertical direction).

[0010] The grinding apparatus 1 is a processing apparatus that performs grinding on workpieces and cleans processing chambers (processing chambers KA and KB) that have become contaminated with processing debris generated by grinding, using a processing chamber cleaning method described below. The grinding apparatus 1 is configured to perform a series of processes on the workpieces, including a carry-in process, a grinding process, a cleaning process, and a carry-out process, for example, fully automatically. The workpieces are, for example, wafers, and are carried into the grinding apparatus 1 while housed in a carry-in cassette 46. The wafers processed by the grinding apparatus 1 are, for example, semiconductor wafers made of silicon, gallium arsenide, or the like, but may also be ceramic, glass, or sapphire-based optical device wafers.

[0011] 1, the grinding apparatus 1 includes a chuck table 10 for holding a workpiece, grinding units 201 and 202 for grinding the workpiece held on the chuck table 10, a processing chamber cover 30 for defining processing chambers KA and KB, and a nozzle 29 for supplying a fluid to the vicinity of the processing point. The grinding apparatus 1 also includes a transport unit 40, a turntable 50, a cleaning unit 60, a control device 70, etc.

[0012] The chuck table 10 is a holding table having a holding surface 101 for holding a workpiece, and suction-holds the workpiece placed on the holding surface 101. The workpiece is placed on the holding surface 101 with the back side, on which no devices are formed, facing upward. The member constituting the holding surface 101 is made of porous ceramic or the like, and the chuck table 10 suction-holds the workpiece by generating a suction force on the holding surface 101 when a suction source (not shown) performs a suction operation. The chuck table 10 is also configured to be rotatable around the Z axis by power transmitted by a table rotation mechanism (not shown).

[0013] The chuck table 10 is movable by the rotation of the turntable 50. The turntable 50 is a disk-shaped table provided on the upper surface of the apparatus main body 2. Three chuck tables 10 are arranged on the turntable 50 at equal intervals of 120 degrees. When the turntable 50 rotates and the chuck table 10 is located at the carry-in / out position closest to the transport unit 40, the workpiece is carried in / out at that carry-in / out position. As the turntable 50 rotates, the chuck table 10 moves in the following order: carry-in / out position, rough grinding position, finish grinding position, and carry-in / out position. The rough grinding position and finish grinding position are located below the grinding unit 201 and grinding unit 202, respectively.

[0014] Grinding unit 201 performs rough grinding on the back surface of a workpiece before grinding, which is held on chuck table 10 positioned at the rough grinding position, to thin the workpiece. Grinding unit 202 performs finish grinding on the back surface of a workpiece that has been roughly ground and is held on chuck table 10 positioned at the finish grinding position, to thin the workpiece.

[0015] Grinding unit 201 and grinding unit 202 each include a grinding wheel 23 on which multiple grinding wheels 28 (see FIGS. 2 and 3) are arranged in a ring, and a moving unit 21 that moves grinding wheel 23 in the Z-axis direction. Each grinding unit grinds the back surface of the workpiece by having moving unit 21 move grinding wheel 23 in the Z-axis direction so that the grinding wheels 28 of the rotating grinding wheel 23 come into contact with the back surface of the workpiece held on chuck table 10. The multiple grinding wheels 28 may be arranged in an elliptical shape rather than a perfect circle on grinding wheel 23. That is, each grinding wheel 28 (grinding wheel) may be arranged along an elliptical locus rather than a perfect circle. The multiple grinding wheels 28 may also be arranged in a polygonal shape, such as a triangle, on grinding wheel 23. That is, the rotational loci formed by the grinding wheels 28 due to the rotation of the grinding wheel 23 do not necessarily have to be the same, and the rotational loci formed by at least some of the grinding wheels 28 may be different from the rotational loci formed by the other grinding wheels 28. Furthermore, the grinding wheel 23 may have a single grinding wheel that is continuous in the circumferential direction of the grinding wheel, rather than a plurality of grinding wheels.

[0016] The nozzle 29 is provided, for example, on the upper surface of the apparatus main body 2. While each grinding unit is grinding the workpiece, the nozzle 29 supplies a fluid grinding fluid near the processing point in a direction intersecting the Z direction (for example, a direction approximately perpendicular to the Z-axis direction). This allows grinding chips generated by grinding to be washed away along the back surface of the workpiece together with the grinding fluid. The processing point refers to the portion where the grinding stone 28 of the grinding wheel 23 comes into contact with the workpiece. When grinding is completed, each grinding unit separates the grinding stone 28 from the workpiece by having the moving unit 21 retract the grinding wheel 23 in the Z-axis direction.

[0017] The processing chamber cover 30 is a cover that covers at least a portion of the processing chamber (processing chamber KA, processing chamber KB), which is a processing space where a workpiece is processed by a grinding unit. The processing chamber cover 30 covers the two chuck tables 10 positioned at the rough grinding position and the finish grinding position, respectively, and the grinding wheels 23 of each grinding unit. A through hole 31 and a door 33 are provided on the upper surface of the processing chamber cover 30. The through hole 31 is for passing the spindle 24 (see FIGS. 2 and 3) of each grinding unit through. The door 33 opens an opening 34 to allow replacement of the grinding wheel 23 attached to the flange 25 (see FIGS. 2 and 3) of the spindle 24.

[0018] The machining chamber cover 30 further includes a partition wall 32 that separates the machining chamber KA for the grinding unit 201 from the machining chamber KB for the grinding unit 202, and side walls (side wall 35, side wall 36, side wall 37) that form the sides of each machining chamber. The partition wall 32 and the other side walls (side wall 35, side wall 36, side wall 37) are surfaces that are approximately parallel to the Z-axis direction. The partition wall 32 and the side wall 35 are spaced apart in the Y-axis direction and face each other, while the side wall 36 and side wall 37 are spaced apart in the X-axis direction and face each other.

[0019] When placed on the apparatus main body 2, the processing chamber cover 30 forms a gap below the side wall 37. By the rotation of the turntable 50, the chuck table 10 passes through the gap formed below the side wall 37 and moves from inside the processing chamber cover 30 to a loading / unloading position outside the processing chamber cover 30, or from the loading / unloading position into the processing chamber cover 30.

[0020] The transport unit 40 transports workpieces within the grinding device 1, transporting the workpieces before grinding onto the chuck table 10 positioned at the load / unload position, and recovering the ground workpieces positioned at the load / unload position from the chuck table 10. The transport unit 40 includes an unloading cassette 41, a transport mechanism 42, a temporary placement section 43, a load arm 44, a load arm 45, and a load cassette 46.

[0021] The loading cassette 46 and the unloading cassette 41 are cassettes of the same configuration, and store workpieces before and after grinding, respectively. The transport mechanism 42 transports the workpieces between the loading cassette 46 and the temporary rest section 43, and between the unloading cassette 41 and the cleaning unit 60. The temporary rest section 43 positions the center of the workpiece at the center of the temporary rest section 43 using multiple positioning pins that can advance and retreat relative to the center of the temporary rest section 43. The loading arm 44 transports the workpiece from the temporary rest section 43 to the chuck table 10, and the unloading arm 45 transports the workpiece from the chuck table 10 to the cleaning unit 60.

[0022] The cleaning unit 60 cleans the workpiece after grinding. The cleaning unit 60 has, for example, a spinner table that rotates at high speed, and cleans the workpiece by supplying a cleaning liquid to the workpiece held by the spinner table.

[0023] The control device 70 controls the operation of each part of the grinding device 1. The control device 70 is composed of, for example, a processor that executes various processes, and a storage unit (memory) that stores various parameters, programs, etc.

[0024] In the grinding apparatus 1 configured as described above, the processor of the control device 70 executes a program to perform a series of processes for processing the workpiece. Specifically, the transport mechanism 42 removes the workpiece to be ground from the loading cassette 46 and transports it to the temporary storage area 43. The workpiece positioned in the temporary storage area 43 is held by suction with the loading arm 44 and placed on the chuck table 10, which has been positioned in advance at the loading / unloading position, by the turntable 50. The workpiece placed on the chuck table 10 is held by suction on the holding surface 101 of the chuck table 10 and positioned below the grinding unit 201 by the rotation of the turntable 50. Thereafter, the grinding unit 201 roughly grinds the back surface of the workpiece while supplying grinding fluid to the rotating workpiece through the nozzle 29. After the rough grinding is completed, the turntable 50 rotates to position the workpiece below the grinding unit 202. Furthermore, grinding unit 202 finish-grinds the back surface of the workpiece while supplying grinding fluid to the workpiece, which is rotating due to the rotation of chuck table 10, through nozzle 29. When finish-grinding is completed, turntable 50 rotates to position the workpiece at the carry-in / out position. The ground workpiece positioned at the carry-in / out position is sucked and held by carry-out arm 45, and transported to cleaning unit 60, where it is cleaned. The cleaned ground workpiece is stored in carry-out cassette 41 by transport mechanism 42.

[0025] In the grinding apparatus 1, the processor of the control device 70 executes a program to perform the above-described series of processes for machining the workpiece, as well as a process for cleaning the machining chamber cover 30 using a machining chamber cleaning method described below. This cleaning method includes a first cleaning step and a second cleaning step. FIG. 2 is a cross-sectional view of the grinding apparatus 1 when the first cleaning step is performed. FIG. 3 is a cross-sectional view of the grinding apparatus 1 when the second cleaning step is performed. The machining chamber cleaning method used in the grinding apparatus 1 will be described below with reference to FIGS. 1 to 3.

[0026] The method for cleaning the machining chamber used in the grinding apparatus 1 is a method for cleaning the machining chamber in the grinding apparatus 1 that includes the chuck table 10, grinding units (grinding units 201 and 202) each including a grinding wheel 23 and a moving unit 21, a machining chamber cover 30, and a nozzle 29. In the following, an example will be described in which the machining chamber (machining chamber KA for the grinding unit 201) is cleaned when no workpiece is placed inside the machining chamber cover 30 in order to prevent machining debris washed away from the machining chamber cover 30 from adhering to the workpiece.

[0027] The timing of when the grinding apparatus 1 performs this cleaning process to clean the processing chamber is not particularly limited. This cleaning process to clean the processing chamber is not limited to after the grinding process, but may be performed before the grinding process, or both before and after the cutting process, in order to prevent processing debris from adhering to the processing chamber cover 30. As an example, the grinding apparatus 1 may clean the processing chamber cover 30 using the above-described cleaning method during the idle time after processing the final wafer. This allows the processing chamber cover 30 to be cleaned without affecting the cycle time required to perform the grinding process on the workpiece.

[0028] The grinding apparatus 1 first performs a first cleaning step. The first cleaning step, which constitutes a cleaning method, is performed in a state (hereinafter referred to as a first state) in which the grinding wheel 23 and the holding surface 101 are positioned relative to each other so that the gap between the grinding wheel 23 and the holding surface 101 in the Z-axis direction is a distance D1 that allows the fluid LA supplied from the nozzle 29 to pass through, as shown in FIG. 2 . The distance D1 is an example of the first distance, and is, for example, the distance between the holding surface 101 and the lower surface of the grinding stone 28, which is the part of the grinding wheel 23 closest to the holding surface 101. This first state may be, for example, a state in which the grinding process is completed and the grinding unit 201 is retracted, or a state in which the height of the grinding unit is adjusted by further raising or lowering the grinding unit 201 from the retracted state using the moving unit 21.

[0029] In the first state shown in FIG. 2, the grinding apparatus 1 supplies a fluid (grinding fluid) from the nozzle 29, similar to the grinding process. As shown in FIG. 2, the tip of the nozzle 29 is located inside the multiple grinding wheels 28 arranged in a circular ring on the grinding wheel 23. During grinding, the nozzle 29 is a nozzle (also referred to as an internal nozzle) that supplies the fluid sprayed from the nozzle 29 to the inner circumferential surfaces of the grinding wheels 28 near the processing point. Unlike during grinding, the fluid LA sprayed from the nozzle 29 in the first state travels straight and reaches the partition wall 32 (an example of a first cover) without colliding with the grinding wheels 28. This allows the partition wall 32 to be cleaned by the fluid LA. In other words, the first cleaning step is a process in which the fluid LA is sprayed from the nozzle 29 toward the partition wall 32 of the processing chamber cover 30 in the first state, and the fluid LA that passes through the gap of distance D1 cleans the partition wall 32.

[0030] The grinding apparatus 1 then performs a second cleaning step. The second cleaning step, which constitutes a cleaning method, is performed in a state (hereinafter referred to as the second state) in which the grinding wheel 23 and the holding surface 101 are positioned relative to each other so that the gap in the Z-axis direction between the grinding wheel 23 and the holding surface 101 is a distance D2 (second distance) that is shorter than the distance D1, as shown in Fig. 3. This second state is, for example, a state in which the grinding unit 201 is lowered from the position in the first state until the bottom surface of the grindstone 28 reaches a position that is sufficiently close to the holding surface 101 without contacting the holding surface 101, thereby reducing the gap.

[0031] In the second state shown in FIG. 3 , the grinding apparatus 1 supplies a fluid (grinding fluid) from the nozzle 29, similarly to during grinding and the first cleaning step. In the second state, the fluid LA sprayed from the nozzle 29 is supplied to the inner circumferential surface of the grinding wheel 28, substantially similarly to during grinding. Because the distance from the nozzle 29 to the grinding wheel 28 is relatively short, the fluid LA impinges on the grinding wheel 28 (grinding wheel 23) with sufficient pressure. As a result, the fluid LB that rebounds from the grinding wheel 28 (grinding wheel 23) travels straight ahead, passes through the gap between the grinding wheel 28 or below the grinding wheel 28, and reaches the side wall 35 (an example of a second cover) that faces the partition wall 32 (an example of a first cover). As a result, the side wall 35 is cleaned by the fluid LB. In other words, the second cleaning step is a process in which the fluid LA is sprayed from the nozzle 29 and cleans the side wall 35 with the fluid LB that rebounds after impacting the grinding wheel 28 (grinding wheel 23).

[0032] By cleaning the processing chamber cover 30 using the above-described cleaning method, the grinding apparatus 1 can prevent processing debris and the like from accumulating on the processing chamber cover 30. In particular, with the above-described cleaning method, it is possible to change the distance between the grinding wheel 23 and the holding surface 101 to switch the direction of travel of the fluid supplied from the nozzle 29 and clean multiple different surfaces of the processing chamber cover 30, and it is possible to clean a wide range of the processing chamber cover 30.

[0033] Furthermore, the nozzle 29 that supplies grinding water during grinding can be used as a nozzle for cleaning the machining chamber cover 30, and further, the moving unit 21 used for processing feed during grinding can be used as a mechanism for changing the distance between the grinding wheel 23 and the holding surface 101. Therefore, the grinding device 1 does not require a special configuration for supplying fluid that cleans the machining chamber cover 30, and does not require an additional drive mechanism for switching the direction of travel of the fluid.

[0034] Therefore, according to the above-described cleaning method, a wide area of ​​the processing chamber cover 30 can be cleaned without requiring a complex configuration. Furthermore, because the processing chamber cover 30 can be cleaned using the configuration of an existing grinding device, the above-described cleaning method can be implemented simply by modifying the control program of the existing grinding device without changing the physical device configuration. In other words, it is relatively easy to apply to existing grinding devices, and it is possible to obtain high technical effects while effectively utilizing the user's existing assets, resulting in high cost-effectiveness.

[0035] <Second embodiment> Fig. 4 is a cross-sectional view of the grinding device according to this embodiment when the first cleaning step is performed. Fig. 5 is a cross-sectional view of the grinding device according to this embodiment when the second cleaning step is performed. The grinding device according to this embodiment is similar to the grinding device 1 according to the first embodiment, except that it includes a nozzle 290 shown in Figs. 4 and 5 instead of the nozzle 29.

[0036] Nozzle 290 is an external nozzle whose tip is located outside grinding wheel 23, more specifically, outside the plurality of grinding stones 28 arranged in an annular shape on grinding wheel 23, and which supplies fluid jetted from nozzle 29 to the outer circumferential surfaces of grinding stones 28 during grinding. In this respect, nozzle 290 differs from nozzle 29, which is an internal nozzle.

[0037] The method for cleaning the machining chamber cover 30 used in the grinding apparatus according to this embodiment differs from the cleaning method according to the first embodiment in that fluid is supplied from a nozzle 290 instead of the nozzle 29. In other respects, it is the same as the cleaning method according to the first embodiment. In other words, the method for cleaning the machining chamber used in the grinding apparatus according to this embodiment is a method for cleaning the machining chamber in a grinding apparatus that includes a chuck table 10, a grinding unit including a grinding wheel 23 and a moving unit 21, a machining chamber cover 30, and a nozzle 290, and includes a first cleaning step and a second cleaning step.

[0038] The grinding apparatus according to this embodiment first performs a first cleaning step. The first cleaning step, which constitutes part of the cleaning method, is performed in a first state in which the grinding wheel 23 and the holding surface 101 are positioned relative to each other so that the gap between the grinding wheel 23 and the holding surface 101 in the Z-axis direction is a distance D1 that allows the fluid LA supplied from the nozzle 290 to pass through, as shown in FIG. 4 . This is the same as in the first embodiment. In the first state shown in FIG. 4 , the grinding apparatus according to this embodiment supplies fluid from the nozzle 290 in the same manner as during grinding. That is, in the first state, the fluid LA is sprayed from the nozzle 290 toward the side wall 35 of the processing chamber cover 30 (an example of a first cover), and the fluid LA that passes through the gap of distance D1 cleans the side wall 35.

[0039] The grinding apparatus according to this embodiment then performs a second cleaning step. The second cleaning step, which constitutes a cleaning method, is performed in a second state in which the grinding wheel 23 and the holding surface 101 are positioned relative to each other so that the gap between them in the Z-axis direction is a distance D2, which is shorter than the distance D1, as shown in FIG. 5 . This is the same as in the first embodiment. In the second state shown in FIG. 5 , the grinding apparatus according to this embodiment supplies fluid from the nozzle 290, as in the grinding process and the first cleaning step. That is, in the second state, the fluid LA is sprayed from the nozzle 290 toward the side wall 35 (an example of a first cover) of the processing chamber cover 30, and the fluid LB that collides with the grinding wheel 28 (the grinding wheel 23) and rebounds cleans the partition wall 32 (an example of a second cover).

[0040] The grinding device and cleaning method for the processing chamber cover 30 according to this embodiment can also prevent processing debris and the like from accumulating on the processing chamber cover 30, and can achieve the same effects as the grinding device 1 and cleaning method according to the first embodiment.

[0041] The embodiments of the present invention are not limited to the above-described embodiments, and may be variously modified, substituted, or altered without departing from the spirit and scope of the technical idea of ​​the present invention. Furthermore, if the technical idea of ​​the present invention can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea of ​​the present invention.

[0042] In the above-described embodiment, the second cleaning step is performed after the first cleaning step. However, the order in which the first and second cleaning steps are performed is not particularly limited. The second cleaning step, in which the machining chamber cover 30 is cleaned with fluid bounced off the grinding wheel 28, may be performed before the first cleaning step. Furthermore, the method for cleaning the machining chamber cover used in the grinding apparatus described above may include a third cleaning step, or even a fourth or subsequent cleaning step, in addition to the first and second cleaning steps. For example, the grinding apparatus 1 may be provided with another nozzle oriented in a different direction from the nozzle 29, and the third and subsequent cleaning steps may be performed using a nozzle different from the nozzle 29. Furthermore, the third and subsequent cleaning steps using a nozzle different from the nozzle 29 may be performed in parallel with the first or second cleaning step using the nozzle 29. Using multiple nozzles allows for cleaning a wider area.

[0043] In the above-described embodiment, an example was shown in which the nozzle supplied fluid in the Y-axis direction, but the direction of travel of the fluid supplied from the nozzle, i.e., the orientation of the nozzle, is not particularly limited. The nozzle may supply fluid in another direction that intersects with the Z-axis direction, such as the X-axis direction. When the nozzle supplies fluid in the Y-axis direction, the partition wall 32 and the side wall 35 are primarily cleaned, whereas when the nozzle supplies fluid in the X-axis direction, the side wall 35 and the side wall 37 are primarily cleaned.

[0044] In the above-described embodiment, the fluid is supplied from the nozzle under the same conditions as during grinding. However, the fluid may be supplied from the nozzle under different conditions during grinding and cleaning. If the flow rate or flow velocity of the fluid supplied from the nozzle is adjustable, the control device 70 may change the flow rate or flow velocity of the fluid supplied from the nozzle during cleaning (the first cleaning step and the second cleaning step) to a value different from the flow rate or flow velocity supplied during grinding. For example, the cleaning effect may be enhanced by increasing the flow rate or flow velocity of the fluid supplied from the nozzle during cleaning compared to the flow rate or flow velocity supplied during grinding. The flow rate or flow velocity may also be changed between the first cleaning step and the second cleaning step. For example, the fluid may be supplied at a higher flow rate or flow velocity during the second cleaning step so that the splashed liquid reaches the processing chamber cover 30 sufficiently.

[0045] In the above-described embodiment, an example was shown in which the nozzle was provided upright on the apparatus main body 2, but the nozzle may also be provided on the turntable 50. By providing the nozzle on the turntable 50, the orientation of the nozzle can be changed by rotating the turntable 50. This makes it possible to clean an even wider area of ​​the processing chamber cover 30. Furthermore, in the above-described embodiment, a grinding apparatus having a turntable 50 was exemplified, but the above-described cleaning method may also be applied to a grinding apparatus that does not have a turntable 50.

[0046] In each cleaning step, the grinding wheel 23 may or may not rotate. However, additional benefits can be obtained by performing the second cleaning step while the grinding wheel 23 is rotating. In the second cleaning step, in which the machining chamber cover 30 is cleaned with the fluid LB that bounces off the grinding wheels 28 of the grinding wheel 23, if the grinding wheel 23 is not rotating, the fluid supplied to the gaps between the annularly arranged grinding wheels 28 passes through without bouncing off the grinding wheels 28. In other words, if the grinding wheels 28 were positioned in the position where the fluid passed through, the fluid would not reach the part of the machining chamber cover 30 that would be directed by the bouncing fluid, and therefore the part is not cleaned. In contrast, by performing the second cleaning step while the grinding wheel 23 is rotating, the fluid supplied to any position around the grinding wheel 23 can be bounced back, allowing a wider area of ​​the machining chamber cover 30 to be cleaned.

[0047] Furthermore, because the grinding wheel 23 is rotating, the liquid fluid supplied from the nozzle 29 is more likely to turn into atomized fluid upon collision with the grinding wheel 28. The liquid fluid can reach a wider area of ​​the processing chamber cover 30 by diffusion, making it possible to clean a wider area of ​​the processing chamber cover 30. Furthermore, in the second cleaning step, by supplying fluid from the nozzle 29 to the rotating grinding wheel 23, the liquid is scattered inside the processing chamber cover 30 under substantially the same conditions as during grinding, making it easier for the fluid to reach areas where processing debris has adhered. This allows the fluid to efficiently reach areas inside the processing chamber cover 30 where processing debris is likely to adhere, enabling efficient cleaning.

[0048] In the above-described embodiment, an example in which the first cleaning step and the second cleaning step are performed has been shown, but the first cleaning step may be omitted and the second cleaning step may be performed instead. In this case, by performing the second cleaning step without rotating the grinding wheel 23, the fluid sprayed from the nozzle may clean the first cover through the gaps in the grinding wheel 28, and the fluid rebounded by the grinding wheel 28 may clean the second cover facing the first cover. [Industrial Applicability]

[0049] As described above, the cleaning method of the present invention can clean a wide area of ​​the machining chamber cover without requiring a complex configuration, and is therefore extremely useful for cleaning the machining chamber cover of a grinding machine. [Explanation of symbols]

[0050] 1: Grinding equipment 10: Chuck table 21: Mobile unit 23: Grinding wheel 28: Grindstone 29, 290: Nozzle 30: Processing chamber cover 32: Partition wall 35, 36, 37: Side wall 40: Transport unit 50: Turntable 60: Cleaning unit 70: Control device 101: Holding surface 201, 202: Grinding unit D1, D2: distance KA, KB: Processing room LA, LB: Fluid

Claims

1. a holding table having a holding surface for holding a workpiece; a grinding unit including a grinding wheel and a first moving unit that moves the grinding wheel in a first direction; a processing chamber cover covering at least a part of a processing space in which the workpiece is processed by the grinding unit, the processing chamber cover including at least a first cover and a second cover that are spaced apart in a second direction intersecting the first direction; a nozzle for supplying a fluid near a processing point; A method for cleaning a processing chamber in a grinding machine comprising: a first cleaning step of spraying the fluid from the nozzle toward the first cover while the grinding wheel and the holding surface are positioned relative to each other so that the gap between the grinding wheel and the holding surface in the first direction is a first distance that allows the fluid to pass through, and cleaning the first cover with the fluid that has passed through the gap; a second cleaning step of spraying the fluid from the nozzle while the grinding wheel and the holding surface are positioned relative to each other so that the gap in the first direction between the grinding wheel and the holding surface is a second distance shorter than the first distance, and cleaning the second cover with the fluid that collides with the grinding wheel and rebounds; A method for cleaning a processing chamber having at least the above.

2. The grinding wheel includes a plurality of grinding stones; In the second cleaning step, the nozzle supplies the fluid to the inner periphery of the grinding wheel. The method for cleaning a processing chamber according to claim 1 .

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