TWI893145B - Injectors, processing equipment and cleaning equipment - Google Patents

Abstract

[Question] An ejector is provided that suppresses the reduction in suction force when liquid has intruded into the interior of the ejector, and that can process or clean a processed object at a low cost. [Solution] An ejector is provided that generates suction force, the ejector comprising: an inlet pipe having a plurality of openings formed at a front end, from which a driving fluid is ejected; an outlet pipe having a receiving opening at a position facing the front end of the inlet pipe for receiving the driving fluid ejected from the openings; and a main body that surrounds the openings and the receiving opening and has a suction path for drawing external fluid into the interior.

Description

Injectors, processing equipment and cleaning equipment

The present invention relates to a sprayer for generating attraction, and a processing device and a cleaning device equipped with the sprayer.

Electronic devices such as personal computers and smartphones contain chips containing semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration). These chips are manufactured by slicing wafers with functional layers formed on the front surface of a semiconductor substrate made of silicon or silicon carbide.

After the wafer is processed to the desired thickness by, for example, grinding the back side, it is then cut along the predetermined separation lines to be separated. Furthermore, since the processing debris generated during the process adheres to the front side of the wafer and the individual chips manufactured from it, the wafer and the chips are often cleaned at appropriate times.

Each of a processing device for grinding or cutting a wafer and a cleaning device for cleaning the wafer and individual chips manufactured from the wafer includes a work clamp having a holding surface for holding the wafer.

When wafers and chips are processed, cleaned, or otherwise handled, external forces are applied to the workpieces. Generally, even in such situations, the worktable still attracts and holds the workpieces, preventing them from moving (see, for example, Patents 1 and 2). Prior Art Patent

Patent Document 1: Japanese Patent Application Publication No. 2009-246098 Patent Document 2: Japanese Patent Application Publication No. 2010-36275

Invention problem to be solved

A porous section is located on the front of the worktable to maintain negative pressure when sucking in the workpiece. The front of this porous section serves as the holding surface for the workpiece. Furthermore, this porous section is connected to the ejector, and the suction force generated by the ejector maintains a negative pressure within the porous section.

Ejectors are broadly divided into those using gas as the driving fluid to generate attractive forces, and those using liquid as the driving fluid. The former primarily utilizes Bernoulli's law, which states that the energy (momentum) of a non-viscous fluid can be retained. The latter primarily utilizes Newton's law of viscosity, which states that the frictional force generated by a viscous fluid corresponds to the velocity gradient between the fluid and the surrounding fluid.

However, while gases have lower viscosity than liquids, there are no non-viscous gases. Therefore, even if the driving fluid is a gas jet, friction will still occur between the gas and the surrounding fluid as it moves. Therefore, the driving fluid of a gas jet utilizes Bernoulli's theorem and Newton's law of viscosity to generate attractive forces.

Incidentally, the processing and cleaning of the above-mentioned object is generally carried out while supplying liquid. In order to securely hold the object, the size of the porous portion of the holding surface holding the object is often designed to be slightly larger than the size of the object.

Therefore, during processing or cleaning of the workpiece, an area near the outer edge of the porous portion's retaining surface may not be covered by the workpiece and may be exposed to the liquid. As a result, the liquid supplied to the workpiece may be drawn into the porous portion through this area due to the suction force generated by the ejector.

Furthermore, liquid attracted by the porous portion may sometimes pass through the communication passages and enter the interior of the ejector. In this case, there is a concern that friction will occur between the driving fluid and the liquid that has intruded into the ejector, hindering the flow of the driving fluid. Consequently, there is a concern that the ejector's suction force will be reduced, causing problems in processing or cleaning the substrate.

While there are some types of ejectors that minimize the negative impact of liquid intrusion, such ejectors are large devices with complex mechanisms and require large amounts of drive fluid. Therefore, using such ejectors in wafer manufacturing raises concerns about increased wafer manufacturing costs.

In view of the above, one object of the present invention is to provide an ejector that suppresses the reduction in suction force when liquid has intruded into the ejector, and that can process or clean a workpiece inexpensively. Another object of the present invention is to provide a processing device and a cleaning device equipped with such an ejector. Means for Solving the Problem

According to one aspect of the present invention, an ejector is provided, comprising: an inlet pipe having a plurality of openings formed at a front end, from which a driving fluid is ejected; an outlet pipe having a receiving port at a position opposite the front end of the inlet pipe for receiving the driving fluid ejected from the openings; and a main body surrounding the openings and the receiving port and having a suction path for drawing in external fluid.

Preferably, the driving fluid is a liquid.

According to another aspect of the present invention, a processing device can be provided, which is a processing device for processing a workpiece having a device formed on the front surface, and comprises: a work clamp having a holding surface for holding the workpiece; a processing unit that processes the workpiece held on the work clamp using a processing grindstone installed on the front end of the main spindle; the above-mentioned ejector; and a connecting path connecting the suction path of the ejector and the holding surface.

According to yet another aspect of the present invention, a cleaning device is provided for cleaning an object having a device formed on its front surface. The cleaning device comprises: a worktable having a holding surface for holding the object; a cleaning unit for cleaning the object held on the worktable; the aforementioned ejector; and a connecting passage connecting the ejector's suction passage and the holding surface. Effects of the Invention

According to one aspect of the present invention, an ejector is provided that ejects a driving fluid from multiple openings in an inlet pipe into the interior of a body. Compared to ejecting the driving fluid from a single opening, this ejector has a larger surface area of the flow path through which the driving fluid is expected to pass within the body. In other words, this ejector increases the contact area between the driving fluid and the surrounding fluid.

Therefore, according to one aspect of the present invention, the friction generated between the driving fluid and the surrounding fluid can be effectively increased. As a result, even in the event that liquid intrudes into the interior of the main body and obstructs the flow of the driving fluid, the adverse effects caused by the intruded liquid can be reduced. In other words, even in such a situation, a decrease in the attractive force of the ejector can be suppressed.

Furthermore, according to one aspect of the present invention, the desired suction force can be achieved without complicating or increasing the size of the apparatus, or significantly increasing the amount of the required driving fluid. As a result, the processed material can be processed or cleaned at a low cost.

In addition, according to another aspect of the present invention, a processing device or a cleaning device equipped with such an ejector can be provided. In these devices, as described above, the reduction in the attraction force of the ejector can be suppressed, and the processed object can be processed or cleaned in a low-cost manner.

Form used to implement the invention

FIG1 is a perspective view schematically showing an ejector 2 according to an embodiment, and FIG2 is a cross-sectional view schematically showing a portion of the ejector 2 shown in FIG1 .

The ejector 2 generates a suction force by flowing a driving fluid within a body 4 that is isolated from the outside. The driving fluid can be either a liquid or a gas. Examples of the driving fluid include liquids such as water, air, or inert gases such as argon and nitrogen.

The body 4 has walls 4a and 4b facing each other, and a suction passage 4c provided in the wall of the body 4 outside of the walls 4a and 4b. Furthermore, the wall 4a is provided so that one end of the inlet pipe 6 can be inserted, and the wall 4b is provided so that one end of the outlet pipe 8 can be inserted.

The inflow tube 6 provides a path for the driving fluid to flow into the interior of the main body 4. The outflow tube 8 provides a path for the fluid inside the main body 4 to flow out. The suction path 4c provides a path for sucking external fluid into the interior of the main body 4.

The other end of the inlet tube 6 is connected to a drive fluid supply source (not shown) for supplying drive fluid. Furthermore, one end of the inlet tube 6, located within the body 4, includes a portion 6a (functioning as a venturi tube) whose diameter decreases from the wall 4a of the body 4 toward the center and then increases.

One end of the inlet pipe 6 has a wall 6c with a plurality of openings (holes) 6b. Wall 6c has a predetermined thickness from one end (front end) of the inlet pipe 6 toward the local portion 6a. The front end of the inlet pipe 6 is generally circular, with a diameter approximately equal to the maximum diameter of the local portion 6a. In other words, wall 6c is generally cylindrical.

The shapes of the plurality of openings 6b are not limited to a specific shape. Furthermore, the shapes of the plurality of openings 6b at the front end of the inlet pipe 6 may all be the same or similar, or may differ from one another. However, from the perspective of uniformly spraying the driving fluid, the plurality of openings 6b at the front end of the inlet pipe 6 are preferably circular shapes with substantially equal diameters.

Furthermore, from the perspective of uniformly spraying the driving fluid, the plurality of openings 6b preferably maintain the shape of the front end of the inlet pipe 6 and extend through the wall 6c. For example, it is preferable that the thickness of the wall 6c is greater than the diameter of the front end of the inlet pipe 6, and the plurality of openings 6b maintain the shape of the front end of the inlet pipe 6 and extend through the wall 6c.

A socket 8a for the outflow pipe 8 is located opposite the front end of the inflow pipe 6. Socket 8a has a mortar-shaped bottom with an open bottom. The diameter of the socket 8a on the side facing the front end of the inflow pipe 6 is longer than the diameter of the front end of the inflow pipe 6.

Therefore, it can be imagined that the flow path of the driving fluid passing through the interior of the body 4 extends from each of the plurality of openings 6b to the receiving port 8a. In addition, the outflow pipe 8 located inside the body 4 includes a partial portion 8b whose diameter increases from the center of the body 4 as it approaches the wall 4b of the body 4.

The body 4 surrounds the plurality of openings 6b of the inlet pipe 6 and the receiving end 8a of the outlet pipe 8 to prevent fluid from entering or exiting outside the suction passage 4c, the inlet pipe 6, and the outlet pipe 8. In other words, the body 4 is sealed outside the suction passage 4c, the inlet pipe 6, and the outlet pipe 8.

Furthermore, the ejector 2 shown in Figures 1 and 2 may also include a recovery unit that circulates the driving fluid discharged from the front end 8c of the outflow pipe 8 to a driving fluid supply source (not shown). The ejector 2 having this recovery unit is advantageous in that the driving fluid can be reused.

In the ejector 2 shown in Figures 1 and 2 , driving fluid can be supplied to the inlet pipe 6 from a driving fluid supply source (not shown). The driving fluid supplied to the inlet pipe 6 is accelerated by the Venturi effect and ejected from each of the plurality of openings 6b provided at the front end toward the interior of the body 4. The driving fluid ejected into the interior of the body 4 flows from the receiving port 8a into the outlet pipe 8.

At this point, to offset the increased energy of the driving fluid due to its acceleration, the driving fluid's pressure decreases (Bernoulli's law), and friction occurs between the driving fluid and the surrounding fluid (Newton's law of viscosity). Consequently, the external fluid flows into the interior of the main body 4 through the suction passage 4c, and the surrounding fluid flows into the outflow pipe 8 along with the driving fluid. In short, the ejector 2 creates a negative pressure inside the main body 4 and generates a suction force through the suction passage 4c.

Here, the ejector 2 ejects the driving fluid from multiple openings 6b of the inlet pipe 6 into the interior of the body 4. This increases the surface area of the flow path through which the driving fluid can be expected to pass within the body 4, compared to an ejector that ejects the driving fluid from a single opening. In other words, the ejector 2 increases the contact area between the driving fluid and the surrounding fluid.

Therefore, in the ejector 2, the friction generated between the driving fluid and the surrounding fluid can be effectively increased. As a result, even in the event that liquid intrudes into the interior of the main body 4 and obstructs the flow of the driving fluid, the adverse effects caused by the intruded liquid can be reduced (specific examples of liquid intrusion into the interior of the main body 4 will be described later). In other words, even in such a situation, a decrease in the attractive force of the ejector 2 can be suppressed.

Furthermore, the ejector 2 can achieve the desired suction force without complicating or increasing the size of the device, or significantly increasing the amount of the required driving fluid. As a result, the material to be processed can be processed or cleaned at a low cost (specific examples of the processing or cleaning of the material to be processed will be described later).

Fig. 3 is a perspective view schematically showing the workbench base 18 and the work clamp 20 connected to the ejector 2 shown in Fig. 1 and Fig. 2, and Fig. 4 is a cross-sectional view thereof. Furthermore, the work clamp 20 is fixed to the workbench base 18 in a manner that allows it to be attached and detached.

An upwardly projecting annular protrusion 18b is provided on the top surface 18a of the table base 18. Concentrically with the inner side of protrusion 18b, an upwardly projecting annular protrusion 18c with a smaller diameter than protrusion 18b is provided on the top surface 18a. Furthermore, an upwardly projecting cylindrical positioning protrusion 18d is provided between protrusions 18b and 18c on the top surface 18a.

On the upper surface 18a, in an area further inward from the protrusion 18c, a circular groove 18e with a smaller diameter than the protrusion 18c is formed concentrically with the protrusion 18c. Furthermore, in an area further inward from the groove 18e on the upper surface 18a, a connecting passage 18f provided within the workbench base 18 is opened at one end. The other end of the connecting passage 18f is connected to the suction passage 4c of the main body 4 of the ejector 2 shown in Figures 1 and 2.

The worktable 20 comprises a frame 22 having a recessed portion 22a on its top surface, and a porous plate 24 secured to the recessed portion 22a of the frame 22 with an adhesive. The porous plate 24 functions as a porous portion that attracts and holds the workpiece, and its top surface 24a serves as a holding surface for attracting and holding the workpiece. For example, the frame 22 can be constructed of metal, and the porous plate 24 can be constructed of porous ceramics.

An annular recess 22c is formed on the lower surface 22b of the frame 22, corresponding to the raised portion 18b of the table base 18. An annular recess 22d is formed on the lower surface 22b, further inward of the recess 22c, corresponding to the raised portion 18c of the table base 18. In other words, recesses 22c and 22d are concentric.

A positioning recess 22e is formed in the area corresponding to the positioning protrusion 18d of the workbench base 18 (i.e., the area between recesses 22c and 22d). Furthermore, a circular recess 22f is formed in the area corresponding to the annular groove 18e (i.e., the area further inward of recess 22d). At the bottom of this recess 22f, one end of a connecting passage 22g, located within the frame 22, opens. The other end of connecting passage 22g opens at the bottom of recess 22a and communicates with the porous plate 24.

To secure the work clamp 20 to the table base 18, for example, an annular member 26 having a shape corresponding to the annular groove 18e of the table base 18 is inserted into the annular groove 18e of the table base 18. The annular member 26 is formed of, for example, a resin and is designed to be difficult to slide relative to the table base 18 and the work clamp 20. Furthermore, the annular member 26 is formed to a thickness (height) such that, when inserted into the groove 18e, it protrudes from the upper surface 18a.

After the annular member 26 is inserted into the groove 18e, the work clamp 20 is placed on the work clamp 18 so that the upper surface 18a of the work clamp 18 faces the lower surface 22b of the frame 22. At this time, the positions of the work clamp 20 and the work clamp 18 are adjusted so that the protrusion 18b, the protrusion 18c, and the positioning protrusion 18d are inserted into the recess 22c, the recess 22d, and the positioning recess 22e, respectively.

As described above, the shape of recess 22f corresponds to the shape of groove 18e, into which annular member 26 is inserted. Therefore, when the worktable 20 is placed on the worktable base 18, a portion of the annular member 26 protruding from the upper surface 18a is inserted into recess 22f. By inserting annular member 26 into groove 18e and recess 22f, positional deviation of the worktable base 18 relative to the worktable 20 can be suppressed.

After the work fixture 20 is placed on the workbench base 18, the communication path 18f and the communication path 22g are connected. Therefore, the suction path 4c of the main body 4 of the ejector 2 shown in Figures 1 and 2 is connected to the holding surface of the work fixture 20 (the upper surface 24a of the porous plate 24) through the communication path 18f and the communication path 22g.

In this state, if driving fluid is supplied to the inlet pipe 6 of the ejector 2 shown in Figures 1 and 2, the ejector 2 sets the suction passage 4c, the interior of the communication passage 18f, and the communication passage 22g to negative pressure, thereby sucking the porous plate 24. This allows the workpiece to be held on the holding surface of the work table 20 (the upper surface 24a of the porous plate 24).

Figure 5 is a cross-sectional view schematically showing a processing device that processes a workpiece 11 that has been sucked and held by the holding surface of the work clamp 20. Specifically, Figure 5 shows a cutting device 50 that cuts the workpiece 11 by forming a groove (half-cutting) in the workpiece 11 using a cutting unit 52.

The cutting device 50 shown in FIG. 5 includes the table base 18 and the work clamp 20 shown in FIG. 3 and FIG. 4 , and sucks and holds the workpiece 11 on the holding surface of the work clamp 20 .

The workpiece 11 is a disk-shaped wafer made of a semiconductor material such as silicon. Its front (top) surface is divided into a central device region and a peripheral residual region surrounding the device region. The device region is further divided into a plurality of regions by predetermined dividing lines (streaks) arranged in a grid pattern, and semiconductor devices such as ICs and LSIs are formed in each region.

The cutting device 50 shown in FIG5 further includes a worktable moving mechanism (not shown) and a cutting unit moving mechanism (not shown). The worktable moving mechanism can, for example, move the worktable base 18 and the worktable 20 in the machining feed direction (the front-to-back direction in FIG5 ). Furthermore, the cutting unit moving mechanism can, for example, move the cutting unit 52 in the indexing feed direction (the left-right direction in FIG5 ) and the cutting feed direction (the up-down direction in FIG5 ).

The cutting unit 52 includes a spindle 56 that rotates about an axis roughly parallel to the plane of the worktable 20. An annular cutting blade 58 is mounted on one end of the spindle 56, and a rotational drive source (not shown), such as a motor, is connected to the other end. The cutting blade 58 is rotated by the torque of the rotational drive source transmitted through the spindle 56.

The cutting blade 58 is a processing tool that cuts the workpiece 11 by a processing grindstone. Therefore, the cutting unit 52 can also be expressed as a unit that cuts the workpiece 11 by a processing grindstone installed at the front end of the spindle 56.

The cutting insert 58 may be a hub-type cutting insert, for example. The hub-type cutting insert is constructed by integrating an annular base made of metal or the like with an annular cutting edge formed along the outer periphery of the base. The cutting edge of the hub-type cutting insert may be formed using an electrocast grindstone, which is made by fixing abrasive grains (processing grindstone) composed of diamond and cubic boron nitride (cBN) or the like with a bonding material such as nickel plating.

Furthermore, as the cutting insert 58, a washer-type cutting insert composed of an annular cutting edge made by fixing abrasive grains (working grindstone) with a bonding material composed of metal, ceramics, resin, etc. may be used.

A cutting fluid supply nozzle 60 is provided near the cutting blade 58. The cutting fluid supply nozzle 60 supplies cutting fluid 17 to the workpiece 11 and the cutting blade 58 when the workpiece 11 is cut by the cutting blade 58. The cutting fluid 17 may be water, for example.

When cutting the workpiece 11 using the cutting unit 52, the workpiece 11 is first brought into contact with the upper surface 24a of the porous plate 24. Alternatively, the workpiece 11 can be attached to a dicing tape of the same size as the workpiece 11, and then brought into contact with the upper surface of the porous plate 24 through the dicing tape. Then, the driving fluid is supplied to the inlet pipe 6 of the ejector 2 shown in Figures 1 and 2.

The negative pressure generated in the ejector 2 acts on the holding surface (upper surface 24a of the porous plate 24) of the work clamp 20 through the suction passage 4c, the connecting passage 18f, and the connecting passage 22g. As a result, the workpiece 11 can be sucked and held on the work clamp 20.

Then, while the cutting blade 58 is rotated by the spindle 56, the table base 18 and the work clamp 20 are moved in the machining feed direction (the front-back direction in FIG. 5 ) so that the workpiece 11 contacts the cutting blade 58. Thus, the workpiece 11 is cut to form a groove.

As shown in FIG. 5 , when cutting the workpiece 11 sucked and held by the work clamp 20 , the cutting fluid 17 is supplied from the cutting fluid supply nozzle 60 to the workpiece 11 and the cutting blade 58 .

Here, as shown in FIG5 , cutting fluid 17 may sometimes penetrate through the porous plate 24 and enter the communication passage 18f and the communication passage 22g. Furthermore, because the communication passage 18f and the communication passage 22g are connected to the suction passage 4c of the main body 4 of the ejector 2 shown in FIG1 and FIG2 , there is a possibility that the cutting fluid 17 may intrude into the interior of the main body 4 of the ejector 2.

In contrast, the ejector 2 ejects the driving fluid from the plurality of openings 6b of the inlet pipe 6 into the interior of the body 4. This increases the surface area of the flow path through which the driving fluid is assumed to pass within the body 4, compared to ejectors that eject the driving fluid from a single opening. Consequently, the ejector 2 can effectively increase the frictional force generated between the driving fluid and the surrounding fluid.

As a result, even in the event that liquid intrudes into the interior of the main body 4 and obstructs the flow of the driving fluid, the cutting device 50 including the ejector 2 can still reduce the adverse effects caused by the intruded liquid. In other words, even in such a situation, the reduction in the suction force of the ejector 2 can be suppressed, and the probability of malfunction during cutting in the cutting device 50 can be reduced.

Furthermore, the ejector 2 is not a large device with a complicated mechanism, nor does it require a large amount of driving fluid. Therefore, the cutting device 50 having the ejector 2 can be used to cut the workpiece 11 at a low cost.

Furthermore, the processing device having a processing unit that can be equipped with the ejector 2 is not limited to the cutting device having a cutting unit for cutting as shown in Figure 5. The ejector 2 can also be equipped with, for example, a grinding device having a grinding unit that grinds the surface of the workpiece using a grinding stone mounted on the front end of a spindle.

In a grinding device, generally speaking, the surface of the workpiece is ground while liquid is supplied to the surface. Therefore, the ejector 2 is also suitable as an ejector mounted on such a grinding device.

Fig. 6 is a perspective view schematically showing a cleaning device 70 for cleaning an object 21 held by suction on a holding surface of a work clamp (or rotary table) 88. However, in Fig. 6, a portion of a component is removed for convenience, and a cross section of the component is shown.

6 shows a disk-shaped wafer with grooves formed in a grid pattern as the object to be cleaned 21, but the object to be cleaned by the cleaning device 70 is not limited to this object to be cleaned 21. Examples of the object to be cleaned by the cleaning device 70 include a disk-shaped wafer before such grooves are formed or a plurality of chips manufactured by dividing the wafer.

The cleaning device 70 includes a table rotating unit 84 that rotates a work table 88. The table rotating unit 84 includes a shaft 94 that rotates about an axis that is substantially parallel to the lead straight line. A cover member 126 that surrounds a portion of the side surface of the shaft 94 is connected to the side surface of the shaft 94.

The work clamp 88 is connected to one end of the shaft 94. A perforated plate 88a is provided on the front side of the work clamp 88. The axis of the shaft 94 is substantially perpendicular to the plane direction of the front surface of the perforated plate 88a.

Furthermore, a communication passage (not shown) is provided within the shaft 94, one end of which connects to the back surface of the porous plate 88a. The other end of this communication passage is connected to the suction passage 4c of the main body 4 of the ejector 2 shown in Figures 1 and 2. In other words, this communication passage connects the suction passage 4c with the porous plate 88a. Therefore, the ejector 2 is connected to the holding surface of the work clamp 88 (the upper surface of the porous plate 88a) through the suction passage 4c and this communication passage.

The other end of the shaft 94 is connected to a rotational drive source such as a motor (not shown) and a lift drive source such as an air cylinder (not shown). Therefore, the work clamp 88 rotates using the power of the rotational drive source transmitted through the shaft 94. Furthermore, the work clamp 88 is raised and lowered between an upper loading/unloading position, where the objects 21 are loaded and unloaded, and a lower cleaning position, using the power of the lift drive source.

A cleaning liquid receiving unit 86 is positioned around shaft 94. This unit comprises a cylindrical outer wall 100a, an annular bottom wall 100b extending radially inward from the lower portion of outer wall 100a, and a cylindrical inner wall 100c extending vertically upward from the inner circumference of bottom wall 100b. Shaft 94 passes inside inner wall 100c. The outer diameter of inner wall 100c is smaller than the inner diameter of cover member 126. When work clamp 88 is lowered to the cleaning position, cover member 126 surrounds inner wall 100c from the outer circumference.

A drain port 104 is provided on the bottom wall 100b and is connected to a downwardly extending drain channel (not shown). When cleaning liquid falls onto the cleaning liquid receiving unit 86, it is discharged from the drain port 104 through the drain channel to the outside. When the work clamp 88 is lowered to the cleaning position, the inner peripheral wall 100c is surrounded by the cover member 126, thereby preventing cleaning liquid from scattering downward through the through hole through which the shaft 94 passes.

A drying unit 108 is disposed on the inner side of the outer peripheral wall 100a. The drying unit 108 has a tubular shaft 114 that is inserted into the bottom wall 100b. The shaft 114 is a tubular member that extends on the outer side of the work clamp 88 in a direction generally perpendicular to the front of the work clamp 88. The upper end of the shaft 114 reaches a position higher than the front of the work clamp 88 and is connected to the arm 112. A rotational drive source (not shown), such as a motor, is connected to the lower end of the shaft 114 to rotate the shaft 114.

The arm 112 is a tubular member extending a length equal to the distance from the upper end of the shaft 114 to the center of the work clamp 88. The direction in which the arm 112 extends is generally perpendicular to the direction in which the shaft 114 extends. A downward-facing drying nozzle 110 is provided at the front end of the arm 112 (the end of the arm 112 not connected to the shaft 114). An air supply source (not shown) is connected to the shaft 114, and air is ejected from the drying nozzle 110 toward the front side of the work clamp 88 through the shaft 114 and arm 112.

On the inner side of the outer peripheral wall 100a, a cleaning unit 116 is arranged with the inner peripheral wall 100c between it and the drying unit 108. The cleaning unit 116 has a tubular shaft 122 inserted into the bottom wall 100b. The shaft 122 is a tubular member that extends on the outer side of the work clamp 88 in a direction approximately perpendicular to the front surface of the work clamp 88. The upper end of the shaft 122 reaches a position higher than the height of the upper surface of the work clamp 88 and is connected to the arm 120. A rotation drive source such as a motor that rotates the shaft 122 is connected to the lower end of the shaft 122.

Arm 120 is a tubular member extending a length equal to the distance from shaft 122 to the center of work table 88. The direction in which arm 120 extends is approximately perpendicular to the direction in which shaft 122 extends. A downward-facing cleaning nozzle 118 is provided at the front end of arm 120 (the end of arm 120 not connected to shaft 122). A cleaning liquid supply (not shown) is connected to shaft 122, and cleaning liquid is sprayed from cleaning nozzle 118 toward the front side of work table 88 via shaft 122 and arm 120.

When the cleaning device 70 cleans the object 21, the worktable 88 is rotated at high speed while the cleaning nozzle 118 sprays a cleaning liquid (typically a mixture of water and air) toward the object 21. Subsequently, the drying nozzle 110 sprays dry air toward the object 21 to remove the cleaning liquid.

Here, the cleaning liquid may sometimes penetrate the porous plate 88a of the work clamp 88 and enter the communication path provided inside the shaft 94. Moreover, because the communication path is connected to the suction path 4c of the main body 4 of the ejector 2 shown in Figures 1 and 2, the cleaning liquid may enter the interior of the main body 4 of the ejector 2.

In contrast, the ejector 2 ejects the driving fluid from the plurality of openings 6b of the inlet pipe 6 into the interior of the body 4. This increases the surface area of the flow path through which the driving fluid is assumed to pass within the body 4, compared to ejectors that eject the driving fluid from a single opening. Consequently, the ejector 2 can effectively increase the frictional force generated between the driving fluid and the surrounding fluid.

As a result, even in the event that liquid intrudes into the interior of the main body 4 and obstructs the flow of the driving fluid, the cleaning device 70 including the ejector 2 can still reduce the adverse effects caused by the intruded liquid. In other words, even in such a situation, the reduction in the suction force of the ejector 2 can be suppressed, and the probability of a malfunction occurring during cleaning in the cleaning device 70 can be reduced.

Furthermore, the ejector 2 is not a large device with a complicated mechanism, nor does it require a large amount of driving fluid. Therefore, the cleaning device 70 having the ejector 2 can be used to clean the object 21 at a low cost.

2: Injector 4: Main body 4a, 4b, 6c: Wall 4c: Suction path 6: Inlet pipe 6a, 8b: Partial portion 6b: Opening (hole) 8: Outlet pipe 8a: Socket 8c: Front end 11: Workpiece 17: Cutting fluid 18: Worktable base 18a: Top surface 18b, 18c, 18d: Protrusion 18e: Groove 18f, 22g: Connecting channel 20: Worktable 21: Workpiece 22: Frame 22a, 22c, 22d, 22f: Recess 22b: Bottom surface 22e: Positioning recess 24, 88a: Perforated plate 24a: Top surface (holding surface) 26: Ring member 50: Cutting device 52: Cutting unit 56: Spindle 58: Cutting blade 60: Cutting fluid supply nozzle 70: Cleaning device 84: Worktable rotation unit 86: Cleaning fluid receiving unit 88: Work clamp (or rotary table) 94: Shaft 100a: Outer wall 100b: Bottom wall 100c: Inner wall 104: Drain outlet 108: Drying unit 110: Drying nozzle 112, 120: Arm 114, 122: Shaft 116: Cleaning unit 118: Cleaning nozzle 126: Cover member

Figure 1 is a perspective view schematically showing an ejector according to an embodiment. Figure 2 is a cross-sectional view schematically showing a portion of the ejector shown in Figure 1. Figure 3 is a perspective view schematically showing a table base and a work clamp connected to the ejectors shown in Figures 1 and 2. Figure 4 is a cross-sectional view schematically showing a table base and a work clamp connected to the ejectors shown in Figures 1 and 2. Figure 5 is a cross-sectional view schematically showing a processing device for processing a workpiece held by suction and on a holding surface of a work clamp. Figure 6 is a perspective view schematically showing a cleaning device for cleaning a workpiece held by suction and on a holding surface of a work clamp (or rotary table).

2: Jet

4: Main body

4a, 4b, 6c: Wall

4c: Attraction Path

6: Inflow pipe

6a, 8b: Partial section

6b: Opening (hole)

8: Outflow pipe

8a: Socket

8c: Front-end

Claims (4)

An ejector generating a suction force is characterized by comprising: an inlet pipe having a plurality of openings formed at a front end, from which a driving fluid is ejected; an outlet pipe having a receiving opening at a position opposite the front end of the inlet pipe for receiving the driving fluid ejected from the openings of the inlet pipe; and a body surrounding the openings and the receiving opening and having a suction path for drawing in external fluid. The receiving opening is positioned further inward than a wall of the body. The inlet pipe includes a portion whose diameter decreases and then increases as it approaches the front end of the inlet pipe. The ejector of claim 1, wherein the driving fluid is a liquid. A machining device for machining a workpiece having a device formed on its front surface. The machining device is characterized by comprising: a worktable having a holding surface for holding the workpiece; a machining unit for machining the workpiece held on the worktable using a grinding stone mounted on the front end of a spindle; an ejector according to claim 1 or 2; and a connecting passage connecting the suction passage of the ejector to the holding surface. A cleaning device for cleaning an object having a device formed on its front surface. The cleaning device is characterized by comprising: a worktable having a holding surface for holding the object; a cleaning unit for cleaning the object held on the worktable; an ejector according to claim 1 or 2; and a connecting passage connecting the suction passage of the ejector to the holding surface.