Cleaning procedure for cleaning a frame unit

Abstract

Cleaning method for cleaning a frame unit (11) comprising a fixed object (1), a band (7) attached to a lower surface (1b) of the fixed object (1), and an annular frame (9) to which an outer circumferential section of the band (7) is attached, wherein the cleaning method comprises: a holding step involving holding the frame unit (11) on a holding surface of a rotary table (8); a cleaning step for a fixed object comprising cleaning the fixed object (1) by ejecting a cleaning fluid (38a) from a cleaning nozzle (38) during a rotation of the rotary table (8) holding the frame unit (11) and a reciprocating movement of the cleaning nozzle (38) along a first path that runs above a center point of the holding surface and extends from above one end of an outer circumferential edge of the fixed object (1) to above another end of the outer circumferential edge of the fixed object (1); and a frame cleaning step separate from the cleaning step for a fixed object, with cleaning of the frame (9) by expelling the cleaning fluid (38a) from the cleaning nozzle (38) to the frame (9) during a rotation of the rotary table (8) and a back-and-forth movement of the cleaning nozzle (38) along a second path that includes an area above the frame (9).

Description

BACKGROUND OF THE INVENTION AREA OF THE INVENTION

[0001] The present invention relates to a cleaning method comprising cleaning a frame unit comprising a fixed object, a band attached to a lower surface of the fixed object, and an annular frame to which an outer circumferential section of the band is attached. DESCRIPTION OF THE RELATED STATE OF THE ART

[0002] In the manufacturing process of electronic component chips used in devices such as mobile phones, computers, and similar products, a multitude of intersecting planned process lines, also referred to as roads, are established on the top surface of a wafer made of semiconductor material. A component, such as an integrated circuit (IC), a large-scale integration (LSI), or similar device, is formed in each of the areas on the wafer's top surface, with the areas defined by the planned process lines. Individual component chips can be formed by subsequently cutting the wafer along the planned process lines.

[0003] The wafer is separated by a processing device, such as a cutting device that cuts the wafer with an annular cutting blade, a laser processing device that processes the wafer by irradiating it with a laser beam, or similar equipment. When the wafer is processed by the device, processing residues are generated and distributed across the top surface and circumference of the wafer. Therefore, the wafer is cleaned after processing to remove these residues. The processing device is, for example, equipped with a rotary cleaning device. After processing, the wafer is transported to the rotary cleaning device and cleaned by it (see, for example, JP 2000 – 33 346 A).The rotary cleaning device comprises: a rotary table that holds the object to be cleaned; a cleaning nozzle that ejects a cleaning fluid; and a fluid supply tube that feeds the cleaning fluid to the cleaning nozzle. The object to be cleaned is cleaned by moving the cleaning nozzle back and forth over an area from above one end of the object to be cleaned to above the other end of the object to be cleaned while rotating the rotary table that holds the object to be cleaned and ejecting the cleaning fluid from the cleaning nozzle.

[0004] An adhesive tape, bonded to an annular frame, is first applied to the lower surface of the wafer to be transported into the processing unit. The wafer is then transported into the processing unit and processed within a frame assembly in which the wafer, tape, and frame are integral components. A wafer identification mark or similar information may be placed on the upper surface of the annular frame to identify and manage the wafer (see, for example, JP H09-7977A). For example, the mark could be a barcode, and the processing unit obtains the wafer's identification information by reading the barcode. As a processing unit processes the wafer belonging to the frame assembly, processing residues are also distributed onto the mark located on the upper surface of the annular frame.If processing residues adhere to the marking, the processing device may be unable to read the identification information from it. To clean the frame by expelling the cleaning fluid during wafer cleaning, the rotary cleaning device accordingly moves the cleaning nozzle back and forth in an area extending from above one end of the frame to above the other.

[0005] JP 2008 - 16 673 A provides a rotary cleaning device comprising a water brush of a length covering the radius of a wafer to eject a cleaning fluid onto the wafer, in addition to a normal cleaning fluid ejection part which generates a cleaning fluid jet vertically with respect to a surface of the wafer on a rotary table to remove contaminants.

[0006] The rotary cleaning device of JP 2016 - 131 186 A includes a cleaning device for cleaning the surface of an object to be cleaned, wherein the cleaning device has a cleaning arm, a cleaning element for cleaning the object to be cleaned which is arranged at the tip of the cleaning arm by coming into contact with it, a pivoting device for pivoting the cleaning arm so that the cleaning element passes through the center of rotation of a rotary table, a motion device for moving the cleaning element forwards and backwards with respect to the object to be cleaned held on the rotary table, and a load meter for measuring the load when the cleaning element is brought into contact with the object to be cleaned by the motion device, and for sending the load to a controller.

[0007] JP 2017 - 92 379 A refers to a protective film coating process comprising a wafer support step in which a wafer is supported in an opening in an annular frame via an adhesive strip, a wafer holding step in which the wafer is held on a rotary table while being supported in the annular frame, a protective film coating step in which a protective film is covered with dripping water-soluble resin while the rotary table is rotated, and a water-soluble resin removal step in which the water-soluble resin spread on the top surface of the annular frame is removed.In the step of removing the water-soluble resin, the washing nozzle is positioned on the annular frame, washing water is supplied to the annular frame, an air nozzle is positioned downstream in the direction of rotation so that it lies next to the washing nozzle, air is supplied against the movement of the washing water and the washing water is discharged from the annular frame while the washing water is temporarily collected. SUMMARY OF THE INVENTION

[0008] The fluid supply tube of the rotary cleaning device includes a tubular shaft section that extends along the outside of the rotary table in a direction perpendicular to the upper surface of the rotary table, reaching a position higher than the height of the upper surface. The fluid supply tube further includes a tubular arm section with a length corresponding to the distance from the shaft section to the center of the rotary table, extending in a direction perpendicular to the direction of extension of the shaft section. One end of the arm section is connected to an upper end of the shaft section. The other end of the arm section is fitted with the downward-facing cleaning nozzle. The cleaning fluid is supplied to the cleaning nozzle via the shaft section and the arm section, and the cleaning fluid is expelled downwards from the cleaning nozzle.During cleaning, the cleaning nozzle is moved back and forth by rotating the fluid supply tube with the shaft section as its axis of rotation. Compared to cleaning only the wafer, cleaning the entire frame assembly, including the annular frame, increases the nozzle's travel distance per reversal and the time required for each reversal. Consequently, cleaning the entire frame assembly takes longer than cleaning only the wafer, thus reducing productivity when the frame is cleaned simultaneously with the wafer.

[0009] Accordingly, it is an object of the present invention to provide a cleaning method that can clean a frame unit in a relatively short time.

[0010] In accordance with one aspect of the present invention, a cleaning method is provided for cleaning a frame unit comprising a fixed object, a band attached to a lower surface of the fixed object, and an annular frame to which an outer circumferential section of the band is attached, wherein the cleaning method comprises: a holding step involving holding the frame unit on a holding surface of a rotary table;a cleaning step for a fixed object comprising cleaning the fixed object by ejecting a cleaning fluid from a cleaning nozzle during rotation of the turntable holding the frame unit and reciprocating the cleaning nozzle along a first path above a center point of the holding surface and extending from above one end of an outer circumferential edge of the fixed object to above another end of the outer circumferential edge of the fixed object; and a frame cleaning step separate from the cleaning step for a fixed object comprising cleaning the frame by ejecting the cleaning fluid from the cleaning nozzle to the frame during rotation of the turntable and reciprocating the cleaning nozzle (38) along a second path that includes an area above the frame (9).

[0011] Preferably, in the frame cleaning step, the fixed object is cleaned together with the frame by moving the cleaning nozzle back and forth along a second path, wherein the path runs above the center of the holding surface and extends from above one end of an outer circumferential edge of the frame to above another end of the outer circumferential edge of the frame.

[0012] In addition, during the frame cleaning step, the cleaning nozzle is preferably moved back and forth along a second path that only includes an area above the frame.

[0013] A cleaning method according to one mode or embodiment of the present invention is a cleaning method comprising cleaning a frame unit as the object to be cleaned, which has a fixed object, such as a wafer or the like, a band attached to a lower surface of the fixed object, and an annular frame to which an outer circumferential section of the band is attached. The cleaning method includes: a cleaning step for a fixed object comprising moving a cleaning nozzle back and forth along a first path extending from above one end of an outer circumferential edge of the fixed object to above another end of the outer circumferential edge of the fixed object, and a frame cleaning step comprising cleaning the frame by ejecting a cleaning fluid onto the frame.The cleaning force required for the fixed object, such as a wafer or similar item with components attached, differs from the cleaning force required for the frame on which identification information is located. In this case, the cleaning force is the force of a cleaning action, determined by the length of a cleaning cycle or similar factors. Due to the different cleaning forces required for the fixed object and the frame, if both are cleaned simultaneously in a single cleaning step, the frame will be cleaned with the higher cleaning force required for either the fixed object or the frame. In this case, the other component, which requires a lower cleaning force, will be excessively cleaned.

[0014] In contrast, the cleaning method according to one mode of the present invention can clean the fixed object and the frame with the cleaning forces required for each by performing the cleaning in two separate steps: the cleaning step for the fixed object and the frame cleaning step. This means that the time spent on excessive cleaning of either the fixed object or the frame, each requiring a low cleaning force, can be omitted, thereby reducing the time spent cleaning the frame assembly.

[0015] Consequently, the present invention provides a cleaning method that can clean a frame unit in a relatively short time.

[0016] The above and other tasks, features and advantages of the present invention and the manner of its implementation will become clearer by studying the following description and attached claims, with reference to the accompanying drawings, which show a preferred embodiment of the invention, and the invention itself will be best understood by this. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view that schematically represents a frame unit; Fig. Figure 2 is a perspective view that schematically depicts a cleaning device and the frame unit; Fig. 3 is a sectional view that schematically represents a holding step; Fig. Figure 4 is a sectional view that schematically illustrates a cleaning step for a fixed object; Fig. Figure 5 is a top view that schematically illustrates the cleaning step for a fixed object; Fig. Figure 6 is a top view that schematically illustrates an example of a frame cleaning step; Fig. Figure 7 is a top view that schematically illustrates another example of the frame cleaning step; and Fig. Figure 8 is a sectional view that schematically illustrates a drying step. DETAILED DESCRIPTION OF THE PREFERRED EXECUTION FORM

[0017] With reference to the accompanying drawings, an embodiment in accordance with one mode of the present invention is now described. A cleaning method in accordance with the present embodiment cleans a frame unit including a fixed object, such as a semiconductor wafer or the like. Fig. Figure 1 is a perspective view schematically representing a frame unit being cleaned by the cleaning procedure in accordance with the present embodiment. As in Fig. As shown in Figure 1, a frame unit 11 includes a fixed object 1, a band 7 attached to a lower surface 1b of the fixed object 1, and an annular frame 9 to which the circumference of the band 7 is attached. The fixed object is, for example, a disk-shaped wafer made of a semiconductor material such as silicon or the like, or of a substrate made of glass, sapphire, or the like. The material, shape, structure, and the like of the fixed object 1 are not limited. For example, a substrate made of a material such as ceramic, resin, metal, or the like, and a rectangular substrate can be used as the fixed object 1.

[0018] A multitude of intersecting planned process lines (paths) 3 are arranged on the side of an upper surface 1a of the fixed object 1. Components 5, such as ICs, LSIs, or similar, are formed in areas bounded by the planned process lines 3. Individual component chips can be formed when the fixed object 1 is cut along the planned process lines 3. Before a processing device processes the fixed object 1, the band 7, attached to the annular frame 9, is fastened to the lower surface 1b of the fixed object 1, so that the frame unit 11 is formed with the fixed object 1, the annular frame 9, and the band 7 integrally connected to each other. The fixed object 1 is supported by the frame 9 via the band 7 and is moved within the frame unit 11 into the processing device and processed by the processing device.The upper surface of frame 9, for example, is provided with a barcode that stores identification information for the fixed object as an entry 13 of the identification information. The processing device obtains the identification information by reading entry 13 of the identification information when it processes the fixed object 1.

[0019] The processing device that processes the fixed object 1 is, for example, a cutting device equipped with a ring-shaped cutting blade, a laser processing device equipped with a laser processing unit that applies a laser beam, or similar. The processing device processes the fixed object 1 along the planned process lines 3 and divides the fixed object 1 along the planned process lines 3. Fig. Figure 1 represents the fixed object 1 after it has been processed by the processing device. As in Fig. As shown in Figure 1, machining marks 3a are present on the fixed object 1 and the tape 7. Furthermore, machining residues generated during the machining process are scattered and adhere to the frame unit 11. If the machining residues adhere to the upper surface of the fixed object 1, they remain on the component chips formed by parts of the fixed object 1. Additionally, the machining residues adhering to the fixed object 1 and the tape 7 fall inside and outside the machining device, becoming a source of contamination. The machining residues can also adhere to the identification information mark 13, which is located on the upper surface of the frame 9, rendering it illegible.Accordingly, the machining residues are removed by supplying a cleaning fluid to the upper surface of the frame unit 11.

[0020] In an exemplary case where the laser processing device performs laser ablation on the fixed object 1 along the planned process lines 3, the upper surface of the fixed object 1 is first coated with a water-soluble resin. In this case, the processing residues generated by the processing adhere to the water-soluble resin. The processing residues can therefore be removed by removing the water-soluble resin from the upper surface of the fixed object 1. The water-soluble resin can be removed when the fixed object 1 is cleaned. However, the water-soluble resin is also spread onto and adheres to the upper surface of the belt 7 and the upper surface of the frame 9 when it is applied to the upper surface of the fixed object 1.Accordingly, not only the fixed object 1 but also the band 7 and the frame 9 are cleaned in order to reliably remove the water-soluble resin from the frame unit 11.

[0021] Next, a cleaning device is described which performs the cleaning process in accordance with the present embodiment. Fig. Figure 2 is a perspective partial sectional view schematically depicting a cleaning device 2 and the frame unit 11. The cleaning device 2 includes: a rotary table mechanism 4; a cleaning water intake mechanism 6 surrounding the perimeter of the rotary table mechanism 4; a cleaning mechanism 36 that cleans an object to be cleaned; and a drying mechanism 28 that dries the cleaned object. The rotary table mechanism includes: a rotary table 8; a motor 10 that rotates the rotary table 8 about an axis extending along a direction perpendicular to the upper surface of the rotary table 8; and a support mechanism 12 that supports the motor 10 so that it can move vertically. A porous element 8a, exposed upwards, is arranged at an upper section of the rotary table 8.A suction passage (not shown), connected at one end to a suction source (not shown) and at the other end to the porous element 8a, is arranged inside the rotary table 8. When the object to be cleaned is placed on the rotary table 8 and the suction source is activated, creating a vacuum on the object via the suction passage and the porous element 8a, the object is drawn to the rotary table 8 and held in place. This means that the upper surface of the rotary table 8 acts as a holding surface.

[0022] A lower section of the rotary table 8 is connected to an upper end of an output shaft 14. A lower end of the output shaft 14 is connected to the motor 10. The output shaft 14 transmits a rotational force to the rotary table 8, which is generated by the motor 10. The motor 10 is supported by the support mechanism 12. The support mechanism 12 includes a plurality of air cylinders 18 attached to the motor 10. Support legs 16 are connected to the lower sections of the respective air cylinders 18. When the air cylinders 18 are actuated simultaneously, the motor and the rotary table 8 can be raised or lowered. At the time of insertion or removal of the object to be cleaned, the rotary table 8 is raised to a predetermined insertion / removal position by actuating the support mechanism 12. At the time of cleaning the object to be cleaned, the rotary table 8 is lowered to a predetermined cleaning position.

[0023] The cleaning water intake mechanism 6 includes: a cylindrical outer circumferential wall 20a; an annular bottom wall 20b projecting radially inwards from a lower section of the outer circumferential wall 20a; and an inner circumferential wall 20c rising upwards from the inner circumferential side of the bottom wall 20b. The interior of the inner circumferential wall 20c forms a through-hole 22. The output shaft 14 passes through the through-hole 22.

[0024] The circumference of the output shaft 14 is provided with a cover element 46, which is sized to surround the inner circumferential wall 20c from the outer circumferential side of the inner circumferential wall 20c. The bottom wall 20b is provided with a drain opening 24. A drain passage 26 is connected to the drain opening 24. When cleaning fluid drips into the cleaning water intake mechanism 6, the cleaning fluid is discharged from the drain opening 24 through the drain passage 26 to the outside. When the rotary table 8 is lowered to the cleaning position, the inner circumferential wall 20c is surrounded by the cover element 46, thus preventing the cleaning fluid from being distributed to the side of the motor 10 via the through hole 22.

[0025] A tubular drying shaft section 34 of the drying mechanism 28 penetrates the bottom wall 20b. The drying shaft section 34 is a tubular element that extends along the outside of the rotary table 8 in a direction perpendicular to the upper surface of the rotary table 8. The drying shaft section 34 reaches a position higher than the height of the upper surface of the rotary table 8. A drying arm section 32 is connected to an upper end of the drying shaft section 34. A motor 34a (see Fig. The drying shaft section 34 is rotated by the motor 34a (or similar) and is connected to the base end of the drying shaft section 34. The drying shaft section 34 is rotated by the motor 34a in a perpendicular direction. The drying arm section 32 is a tubular element with a length corresponding to the distance from the drying shaft section 34 to the center of the rotary table 8 and extending in a direction perpendicular to the direction of extension of the drying shaft section 34. A downward-facing drying nozzle 30 is arranged at one end of the drying arm section 32. The drying mechanism 28 includes an air supply source not shown in the figure.The drying mechanism 28 has the function of removing the cleaning fluid that adheres to the object to be cleaned by allowing air to pass through the drying shaft section 34 and the drying arm section 32 and expelling the air from the drying nozzle 30 to the object to be cleaned which is held on the rotary table 8.

[0026] Furthermore, a tubular shaft section 42 of the cleaning mechanism 36 penetrates the bottom wall 20b. The shaft section 42 is a tubular element that extends along the outside of the rotary table 8 in a direction perpendicular to the upper surface of the rotary table 8. The shaft section 42 reaches a position higher than the height of the upper surface of the rotary table 8. An arm section 40 is connected to an upper end of the shaft section 42. A motor 42a rotates the shaft section 42 (see Fig. 3 and similar), is connected to the base end of the shaft section 42. The shaft section 42 is rotated about the vertical direction by the motor 42a. The arm section 40 is a tubular element with a length corresponding to the distance from the shaft section 42 to the center of the rotary table 8, and extending in a direction perpendicular to the direction of extension of the shaft section 42. A downward-facing cleaning nozzle 38 is arranged at one end of the arm section 40. The cleaning mechanism 36 includes a cleaning fluid supply source, which is not shown in the figure.The cleaning mechanism 36 has the function of removing machining residues or similar substances adhering to the object to be cleaned by allowing the cleaning fluid to pass through the shaft section 42 and the arm section 40, and then being expelled from the cleaning nozzle 38 onto the object to be cleaned, which is held on the rotary table 8. The shaft section 42 and the arm section 40 act as a feed passage that supplies the cleaning fluid.

[0027] Clamps 44, which hold the frame 9 of the frame unit 11, are arranged on the outer circumferential side of the upper section of the turntable 8. Weight portions of the clamps 44 are moved to the outer circumferential side by centrifugal force generated by the rotation of the turntable 8. Upper gripping sections of the clamps 44 thereby automatically fall to the inner circumferential side to grip the frame 9.

[0028] Each step of the cleaning procedure in accordance with the present embodiment is described in detail below. The cleaning procedure includes a holding step in which the frame unit 11 is held against the holding surface of the rotary table 8. Fig. Figure 3 is a sectional view that schematically illustrates the holding step. To perform the holding step, the rotary table 8 is first raised to the predetermined infeed / outfeed position by actuating the support mechanism 12. Then, the frame unit 11, including the fixed object 1, is transported to the cleaning device 2 after processing, and the frame unit 11 is positioned on the holding surface of the rotary table 8 via the conveyor belt 7. Subsequently, a vacuum is created by actuating the suction source of the rotary table mechanism 4 (not shown), drawing the frame unit 11 onto the rotary table 8 and holding it in place. Finally, the frame unit 11 is lowered to the predetermined cleaning position by actuating the support mechanism 12.

[0029] The cleaning procedure next performs a cleaning step for a fixed object, primarily cleaning the fixed object, and a frame cleaning step, primarily cleaning the frame 9. The cleaning step for a fixed object is described first. Fig. Figure 4 is a sectional view that schematically illustrates the cleaning step for a fixed object. As in Fig. As shown in Figure 4, the output shaft 14 is rotated by actuating the motor 10, thereby rotating the rotary table 8, which holds the frame unit 11. As the rotary table 8 rotates, the clamps 44 are actuated by the effect of centrifugal force, so that the frame 9 is gripped by the clamps 44. Next, the shaft section 42 is rotated by actuating the motor 42a, while a cleaning fluid 38a is expelled downwards from the cleaning nozzle 38. As the shaft section 42 rotates, the cleaning nozzle 38 moves along an arc-shaped path with the arm section 40 as its radius.

[0030] The movement of the cleaning nozzle 38 during the cleaning step for a fixed object is described with reference to Fig. 5 described. Fig. Figure 5 is a top view that schematically illustrates the cleaning step for an object to be cleaned. Fig. Figure 5 represents a movement path 38b of the cleaning nozzle 38 during the cleaning step for a fixed object. As in Fig. As shown in Figure 5, the cleaning nozzle 38 is moved back and forth along a path in the present step. This path runs above the center point of the holding surface of the rotary table 8 and extends from above one end of an outer circumferential edge of the fixed object 1 to above another end of the outer circumferential edge of the fixed object 1. During the cleaning step for a fixed object, the cleaning nozzle 38 moves back and forth above the fixed object 1 while ejecting the cleaning fluid 38a. Consequently, the upper surface of the fixed object 1 is primarily cleaned to remove, for example, machining residues adhering to the upper surface, a water-soluble resin applied to the upper surface, or similar substances.

[0031] Next, the frame cleaning step is described. As in the cleaning step for a fixed object described above, in the frame cleaning step the rotary table 8 is rotated, and the shaft section 42 is rotated by actuating the motor 42a, while the cleaning fluid 38a is expelled downwards from the cleaning nozzle 38. In the frame cleaning step, the frame is cleaned by expelling the cleaning fluid from the cleaning nozzle onto the frame. The movement of the cleaning nozzle 38 during the frame cleaning step is described with reference to Fig. 6 described. Fig. Figure 6 is a top view that schematically illustrates an example of the frame cleaning step. Fig. Figure 6 represents the movement path 38b of the cleaning nozzle 38 during the frame cleaning step. In the Fig. In the example shown in Figure 6, the cleaning nozzle 38 is moved back and forth along a path that includes an area above the frame 9. During the frame cleaning step, the cleaning nozzle 38 moves back and forth above the frame 9 while ejecting the cleaning fluid 38a. Therefore, primarily the upper surface of the frame 9 is cleaned to remove, for example, machining residues adhering to the identifier 13 of the identification information of the fixed object 1, where the identifier 13 is located on the upper surface of the frame 9.

[0032] A cleaning force required for the fixed object 1, such as a wafer or similar, on which the components 5 are formed, differs from a cleaning force required for the frame 9 on which the identification information 13 is located. In this context, a cleaning force is, for example, the force of a cleaning action, which is determined by the period over which a cleaning or similar process is carried out.

[0033] In a case where the cleaning forces required for the fixed object 1 and the frame 9 are not similar, for example, the entire upper surface of the frame unit 11 will be cleaned with the cleaning force required for the object to be cleaned, which requires a relatively high cleaning force when the frame unit 11 is cleaned in one cleaning step. In this case, the object to be cleaned, which requires a relatively low cleaning force, will be excessively cleaned.

[0034] On the other hand, the cleaning method, in accordance with the present embodiment, can clean the fixed object 1 and the frame 9 by performing the cleaning in two separate steps, each with the necessary cleaning forces: one for the cleaning step for the fixed object and one for the frame cleaning step. For example, if the cleaning force required for the fixed object 1 is higher than that required for the frame 9, the cleaning force achieved by the cleaning step for the fixed object is set relatively high by performing this step for a longer period than the frame cleaning step. In this case, the frame 9, which requires a relatively low cleaning force, can be cleaned with the appropriate force without being cleaned for an excessively long time.The time spent cleaning frame unit 11 can therefore be reduced.

[0035] The cleaning method according to the present embodiment can perform the frame cleaning step after the cleaning step for a fixed object. When the upper surface 1a of the fixed object 1 is cleaned, the machining residues adhering to the upper surface 1a, or similar substances, are carried outwards by the cleaning fluid. At this point, some of the machining residues may again adhere to the frame 9, which is arranged around the circumference of the fixed object 1. If the frame cleaning step is performed after the cleaning step for a fixed object has been performed, the machining residues adhering to the frame 9, or similar substances, can accordingly be removed by the cleaning fluid 38a. However, the present embodiment is not limited to this.

[0036] In addition, during the frame cleaning step, the fixed object 1 can be cleaned together by moving the cleaning nozzle 38 back and forth along the path that runs above the center of the holding surface and extends from above one end of an outer circumferential edge of the frame 9 to above another end of the outer circumferential edge of the frame 9. Fig. Figure 7 is a top view that schematically illustrates another example of the frame cleaning step. Fig. Figure 7 represents the movement path 38b of the cleaning nozzle 38. If the machining residues that re-adhere to the frame 9, or similar substances, are removed, it can be prevented in this case that the removed machining residues, or similar substances, repeatedly adhere to the upper surface of the fixed object 1. Furthermore, in this case, the execution time of the frame cleaning step is determined based on the cleaning force required for the frame 9. Then, the execution time of the cleaning step for a fixed object is determined based on a cleaning force obtained by subtracting the cleaning force of the fixed object 1, which is being cleaned in the frame cleaning step, from the cleaning force required for the fixed object 1.For example, assuming that the execution time of the cleaning step for a fixed object, which cleans the fixed object 1, is 150 seconds, and that the execution time of the frame cleaning step, which cleans the fixed object 1 and the frame 9, is 30 seconds, in this case the total time required to clean the frame unit 11 is 180 seconds. If the frame unit 11, which can be cleaned in this way, is actually cleaned in a single cleaning step without using the present embodiment, this step would require 311 seconds to clean the entire frame unit 11.

[0037] The cleaning method according to the present embodiment can clean the fixed object 1 and the frame 9 with the cleaning forces necessary for each, thus avoiding excessive cleaning. For example, in a case where the cleaning forces are set by a cleaning time, the cleaning method can eliminate time required for conventional excessive cleaning, thereby reducing the time needed to clean the frame unit 11. Furthermore, during the frame cleaning step, the cleaning nozzle 38 can be moved back and forth along a path that only covers the area above the frame 9.In this case, the respective cleaning steps for the fixed object 1 and the frame 9 can be carried out in accordance with the cleaning forces required for the fixed object 1 and the frame 9, respectively. This means that the cleaning force for each cleaning step can be determined without considering the cleaning force of the other cleaning steps, so that the execution time of each step, or similar parameters, can be easily determined.

[0038] After the cleaning step for a fixed object and the frame cleaning step have been carried out, a drying step is performed. The drying step is carried out with reference to Fig. 8 described. Fig.Figure 8 is a sectional view that schematically illustrates the drying step. In the drying step, the rotary table 8 is rotated, and the drying shaft section 34 is rotated by actuating the motor 34a, while air 30a is expelled downwards from the drying nozzle 30. As in the cleaning step for a fixed object and the frame cleaning step, the drying nozzle 30, which expels the air 30a, is moved back and forth to remove the cleaning fluid adhering to the upper surface of the frame unit 11 and to dry the frame unit 11. After the frame unit 11 has been dried, the rotary table 8 is raised to the predetermined infeed and outfeed position of the rotary table 8 by actuating the support mechanism 12, and the frame unit 11 is transported out of the rotary table 8.

[0039] It should be noted that the present invention is not limited to the description of the preceding embodiment, but can be modified and implemented in a variety of ways. For example, the preceding embodiment described a case in which the frame cleaning step is performed after the cleaning step for a fixed object has been performed. However, a mode of the present invention is not limited to this. For example, if the cleaning force required for the fixed object 1 is higher than the cleaning force required for the frame 9, the cleaning step for a fixed object can be performed after the frame cleaning step has been performed.If the frame cleaning step is performed after the cleaning step for a fixed object has been performed, the machining residues that adhere to the frame 9 as a result of the cleaning step for a fixed object are picked up by the cleaning fluid that is expelled to the edge of the frame 9 and similar areas during the frame cleaning step. The cleaning fluid, including the machining residues and similar substances, can then also spread onto the upper surface of the fixed object 1.

[0040] The sequence of the cleaning step for a fixed object and the frame cleaning step is selected according to the cleaning forces required for the fixed object 1 and the frame 9 or similar, the machining performed on the fixed object, and the size of the fixed object 1 and the frame 9 or similar. To more reliably remove machining residues or similar from the frame unit 11, the two steps can also be performed alternately several times, for example, by performing the frame cleaning step after performing the cleaning step for a fixed object and then performing the cleaning step for a fixed object again.

Claims

[1] Cleaning method for cleaning a frame unit (11) comprising a fixed object (1), a band (7) attached to a lower surface (1b) of the fixed object (1) and an annular frame (9) to which an outer circumferential section of the band (7) is attached, the cleaning method comprising: a holding step involving holding the frame unit (11) on a holding surface of a rotary table (8); a cleaning step for a fixed object comprising cleaning the fixed object (1) by ejecting a cleaning fluid (38a) from a cleaning nozzle (38) during a rotation of the rotary table (8) holding the frame unit (11) and a reciprocating movement of the cleaning nozzle (38) along a first path that runs above a center point of the holding surface and extends from above one end of an outer circumferential edge of the fixed object (1) to above another end of the outer circumferential edge of the fixed object (1); and a frame cleaning step separate from the cleaning step for a fixed object, with cleaning of the frame (9) by expelling the cleaning fluid (38a) from the cleaning nozzle (38) to the frame (9) during a rotation of the rotary table (8) and a back-and-forth movement of the cleaning nozzle (38) along a second path that includes an area above the frame (9). [2] Cleaning method according to claim 1, wherein The cleaning step is performed for a fixed object with a first cleaning force, and The frame cleaning step is carried out with a second cleaning person. [3] Cleaning method according to claim 1 or 2, wherein during the frame cleaning step the fixed object (1) is cleaned together with the frame (9) by moving the cleaning nozzle (38) back and forth along a second path which runs above the center point of the holding surface and extends from above one end of an outer circumferential edge of the frame (9) to above another end of the outer circumferential edge of the frame (9). [4] Cleaning method according to claim 1 or 2, wherein during the frame cleaning step the cleaning nozzle (38) is moved back and forth along a second path which includes only an area above the frame (9).

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