Cleaning nozzle

Abstract

To provide a cleaning nozzle capable of efficiently propagating ultrasonic waves to an object via a cleaning liquid.SOLUTION: A cleaning nozzle for cleaning an object by supplying liquid to the object while propagating ultrasonic waves through the liquid includes a case having an internal space for storing the liquid therein, a supply port for supplying the liquid from an internal space toward the object, and a connection portion for connecting the internal space to a liquid supply source for supplying the liquid, a flat-plate type vibration plate provided in the internal space so as to face the supply port, and a plurality of transducers that impart ultrasonic vibrations to the vibration plate. The propagation of the ultrasonic waves imparted from the vibration plate to the liquid can be controlled by phased array control of the plurality of transducers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cleaning nozzle that supplies liquid to an object to clean the object. [Background technology]

[0002] A wafer on which a plurality of devices are formed is divided and diced to produce device chips each including a device. A package substrate is formed by mounting a plurality of device chips on a predetermined substrate and covering and sealing the mounted device chips with a resin layer (mold resin). A package device including a plurality of packaged device chips is manufactured by dividing and dicing this package substrate. The device chips and package devices are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] When dividing a workpiece such as a wafer or a package substrate into chips, the workpiece is processed by various processing devices. For example, a cutting device that cuts the workpiece with an annular cutting blade, a laser processing device that performs laser processing on the workpiece, etc. are used to divide the workpiece. Also, a grinding device is used to grind and thin the workpiece before division, thereby obtaining thin chips.

[0004] When a workpiece is processed by the above-mentioned processing device, the chips (chips) generated by the processing fly and adhere to the workpiece. Therefore, after the processing of the workpiece, a cleaning process is performed to clean the workpiece using a cleaning device. The cleaning device supplies a cleaning liquid (cleaning liquid) to the workpiece to wash away the chips adhering to the workpiece, thereby cleaning the workpiece.

[0005] However, when machining debris is firmly attached to the workpiece, the machining debris cannot be removed by simply supplying a cleaning liquid to the workpiece, and the workpiece may not be cleaned sufficiently. In response to this, a cleaning device equipped with a cleaning nozzle that applies ultrasonic vibrations to the cleaning liquid has been proposed (see Patent Document 1). For example, the cleaning nozzle is equipped with a vibration plate formed in a dome-shaped concave spherical shape, and ultrasonic vibrations are applied to the cleaning liquid by vibrating the vibration plate. By supplying the cleaning liquid to which ultrasonic vibrations have been applied to the workpiece, the machining debris is easily detached from the workpiece, and the workpiece is effectively cleaned. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2022-28313 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, when the vibration plate that applies ultrasonic vibration to the cleaning liquid is formed in a dome-shaped concave spherical shape, the ultrasonic waves can be converged near the supply port of the cleaning nozzle, and the ultrasonic waves can easily reach the object to be cleaned while maintaining their high intensity. However, it has been confirmed that when a concave spherical vibration plate is used, air is likely to accumulate near the concave spherical surface of the vibration plate. When air accumulates near the concave spherical surface of the vibration plate, an air layer is formed between the vibration plate and the liquid, and this air layer inhibits the transmission of ultrasonic waves from the vibration plate to the liquid. As a result, it becomes difficult for the ultrasonic waves to be properly transmitted to the object, and the cleaning efficiency of the object may decrease.

[0008] The present invention has been made in consideration of such problems, and has an object to provide a cleaning nozzle that can efficiently propagate ultrasonic waves to an object via a cleaning liquid. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a cleaning nozzle for cleaning an object by propagating ultrasonic waves through the liquid while supplying the liquid to the object, the cleaning nozzle comprising a case having an internal space for storing the liquid, a supply port for supplying the liquid from the internal space toward the object, and a connection portion connecting the internal space to a liquid supply source that supplies the liquid, a flat vibration plate provided in the internal space facing the supply port, and a plurality of transducers for imparting ultrasonic vibrations to the vibration plate, and the cleaning nozzle is capable of controlling the propagation of ultrasonic waves imparted to the liquid from the vibration plate by phased array control of the plurality of transducers.

[0010] Preferably, the cleaning nozzle is capable of converging ultrasonic waves applied from the vibration plate to the liquid on a straight line perpendicular to the supply port and passing through the center of the supply port. Preferably, the plurality of transducers are arranged in a lattice pattern. Preferably, the plurality of transducers are formed in a circular or annular shape and arranged concentrically. Effect of the Invention

[0011] A cleaning nozzle according to one aspect of the present invention is configured to be capable of controlling the propagation of ultrasonic waves applied from a flat vibration plate to a cleaning liquid by phased array control of a plurality of transducers, thereby enabling the ultrasonic waves to be efficiently propagated to a target object through the liquid. [Brief description of the drawings]

[0012] [Figure 1] FIG. [Diagram 2] FIG. 2 is a partially sectional front view showing the cleaning device. [Diagram 3] FIG. 2 is a cross-sectional view showing a cleaning nozzle. [Figure 4] 1 is a schematic diagram showing how ultrasonic waves propagate through liquid. FIG. [Diagram 5]FIG. 5(A) is a contour diagram showing the sound pressure of ultrasound generated by phased array control with the phase difference set to 0°, FIG. 5(B) is a contour diagram showing the sound pressure of ultrasound generated by phased array control with the phase difference set to 45°, FIG. 5(C) is a contour diagram showing the sound pressure of ultrasound generated by phased array control with the phase difference set to 90°, and FIG. 5(D) is a contour diagram showing the sound pressure of ultrasound generated by phased array control with the phase difference set to 135°. [Figure 6] FIG. 6(A) is a plan view showing a first specific example of a vibration imparting unit, FIG. 6(B) is a plan view showing a second specific example of a vibration imparting unit, and FIG. 6(C) is a plan view showing a third specific example of a vibration imparting unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment according to one aspect of the present invention will be described below with reference to the accompanying drawings. First, a configuration example of a cleaning device capable of mounting a cleaning nozzle according to this embodiment will be described. FIG. 1 is a perspective view showing a cleaning device 2 for cleaning an object 11. In FIG. 1, the X-axis direction (left-right direction, first horizontal direction) and the Y-axis direction (front-back direction, second horizontal direction) are perpendicular to each other. Also, the Z-axis direction (up-down direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0014] The object 11 corresponds to an object to be cleaned that is to be cleaned by the cleaning device 2. Specifically, the object 11 is an object to be processed by cutting, grinding, polishing, laser processing, etc. After the predetermined processing is performed on the object 11, the object 11 is cleaned by the cleaning device 2.

[0015] For example, the object 11 is a disk-shaped wafer made of a semiconductor material such as single crystal silicon, and has a first surface 11a and a second surface 11b that are generally parallel to each other. The object 11 is divided into a plurality of rectangular regions by a plurality of streets (planned division lines) arranged in a lattice pattern so as to intersect with each other. Furthermore, devices (not shown), such as ICs (Integrated Circuits), LSIs (Large Scale Integration), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices, are formed in each of the plurality of regions divided by the streets.

[0016] A plurality of device chips, each equipped with a device, are manufactured by dividing the object 11 along the streets by cutting, laser processing, etc. Also, if the object 11 is thinned by grinding or polishing before dividing the workpiece, a thinned device chip can be obtained.

[0017] However, there are no limitations on the type, material, size, shape, structure, etc. of the object 11. For example, the object 11 may be a wafer (substrate) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, etc. In addition, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of devices, and the object 11 does not necessarily have to have devices formed thereon.

[0018] Furthermore, the target object 11 may be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, a package substrate is formed by mounting a plurality of device chips on a predetermined substrate and covering and sealing the mounted device chips with a resin layer (mold resin). By dividing and singulating the package substrate, a package device including a plurality of packaged device chips is manufactured.

[0019] Various processing devices are used for processing the object 11. Examples of the processing devices include a cutting device that cuts the object 11, a grinding device that grinds the object 11, a polishing device that polishes the object 11, a laser processing device that performs laser processing on the object 11, and the like.

[0020] The cutting device includes a processing unit (cutting unit) that cuts the object 11. The cutting unit includes a spindle, and an annular cutting blade is attached to the tip of the spindle. The cutting blade is rotated and cuts into the object 11, thereby cutting the object 11.

[0021] The grinding device includes a processing unit (grinding unit) that grinds the object 11. The grinding unit includes a spindle, and an annular grinding wheel including a plurality of grinding stones is attached to the tip of the spindle. The object 11 is ground by bringing the grinding stones into contact with the object 11 while rotating the grinding wheel.

[0022] The polishing device includes a processing unit (polishing unit) that polishes the object 11. The polishing unit includes a spindle, and a disk-shaped polishing pad is attached to the tip of the spindle. The object 11 is polished by rotating the polishing pad and bringing it into contact with the object 11.

[0023] The laser processing device includes a processing unit (laser irradiation unit) that irradiates a laser beam onto the object 11. For example, the laser irradiation unit includes a laser oscillator and a condenser that condenses the laser beam emitted from the laser oscillator. The laser beam irradiated from the laser irradiation unit is condensed on the first surface 11a, the second surface 11b, or inside the object 11, whereby the object 11 is subjected to laser processing.

[0024] When the object 11 is processed by the processing device as described above, scraps (processing scraps) generated by the processing adhere to the object 11. After the processing of the object 11 is completed, the object 11 is transported to the cleaning device 2 and cleaned by the cleaning device 2. This washes away foreign matter such as processing scraps that are attached to the object 11. The cleaning device 2 may be mounted on the processing device, or may be installed independently of the processing device.

[0025] The cleaning device 2 includes a holding table (chuck table) 4 that holds the object 11, and a cleaning unit (cleaning mechanism) 14 that cleans the object 11. The upper surface of the holding table 4 is a flat surface that is roughly parallel to the horizontal plane (XY plane) and constitutes a holding surface 4a that holds the object 11. The object 11 held on the holding surface 4a of the holding table 4 is cleaned by the cleaning unit 14.

[0026] The holding table 4 includes a cylindrical frame (main body) 6 made of metal such as SUS (stainless steel), glass, ceramics, resin, or the like. A cylindrical recess (groove) 6b is provided in the center of the upper surface 6a of the frame 6. A disk-shaped holding member 8 made of a porous material such as porous ceramics is fitted into the recess 6b. The holding member 8 includes a large number of pores (flow paths) therein that communicate from the upper surface to the lower surface of the holding member 8.

[0027] The upper surface of the holding member 8 forms a circular suction surface 8a that sucks the target object 11. The depth of the recess 6b and the thickness of the holding member 8 are set to be approximately the same, and the upper surface 6a of the frame 6 and the suction surface 8a of the holding member 8 are disposed on approximately the same plane. The upper surface 6a of the frame 6 and the suction surface 8a of the holding member 8 form the holding surface 4a of the holding table 4. The holding surface 4a is connected to a suction source (not shown) such as an ejector via pores contained in the holding member 8, flow paths 6c (see FIG. 2) formed in the frame 6, valves (not shown), etc.

[0028] The frame 6 is supported by a cylindrical support shaft 10. The support shaft 10 is disposed along the Z-axis direction, and the center of the lower surface side of the frame 6 is fixed to the upper end of the support shaft 10. A rotation drive source 12 such as a motor that rotates the support shaft 10 is connected to the lower end side of the support shaft 10. When the rotation drive source 12 is operated, the holding table 4 and the support shaft 10 rotate around a rotation axis that is approximately parallel to the Z-axis direction.

[0029] A cleaning unit 14 is installed to the side of the holding table 4. The cleaning unit 14 includes a cylindrical support shaft 16 arranged along the Z-axis direction. A rotary drive source 18 such as a motor that rotates the support shaft 16 around a rotation axis roughly parallel to the Z-axis direction is connected to the base end (lower end) of the support shaft 16. Meanwhile, a columnar support arm 20 is connected to the tip end (upper end) of the support shaft 16. The support arm 20 is fixed to the support shaft 16 so as to be roughly parallel to the XY plane.

[0030] A cleaning nozzle 22 according to this embodiment is attached to the tip of the support arm 20. The cleaning nozzle 22 cleans the object 11 by supplying the liquid to the object 11 while propagating ultrasonic waves through the liquid.

[0031] When the rotary drive source 18 is operated to rotate the support shaft 16, the cleaning nozzle 22 rotates together with the support arm 20 around the rotation axis of the support shaft 16 along the XY plane. This allows the cleaning nozzle 22 to be positioned at a position where it overlaps with the holding surface 4a (supply position) and at a position where it does not overlap with the holding surface 4a (retracted position). The rotation path of the cleaning nozzle 22 is set so as to pass through the rotation axis of the holding table 4, for example.

[0032] 2 is a partial cross-sectional front view showing the cleaning device 2. The cleaning nozzle 22 cleans the object 11 by supplying a cleaning liquid (cleaning liquid) 24 to the object 11. For example, pure water is used as the liquid 24. The configuration of the cleaning nozzle 22 will be described in detail below.

[0033] The cleaning nozzle 22 includes a case (main body) 26 made of metal or the like. An internal space (storage section) 26a for temporarily storing the liquid 24 is provided inside the case 26. For example, the upper part of the internal space 26a is formed in a cylindrical shape, and the lower part of the internal space 26a is formed in a tapered truncated cone shape.

[0034] A supply port 26b that supplies the liquid 24 from the internal space 26a toward the target object 11 is provided on the lower surface side of the case 26. The supply port 26b corresponds to a circular area exposed on the lower surface side of the case 26, and is connected to the internal space 26a. The liquid 24 stored in the internal space 26a flows out from the supply port 26b at a predetermined flow rate.

[0035] A flow path 26c through which the liquid 24 flows and is supplied to the cleaning nozzle 22 is provided in the side wall of the case 26. One end of the flow path 26c is exposed at the side surface of the cleaning nozzle 22, and the other end of the flow path 26c is connected to the internal space 26a. However, there is no limitation on the position where the flow path 26c is provided.

[0036] The cleaning nozzle 22 also includes a connection part 28 connected to a liquid supply source 30 that supplies the liquid 24. The connection part 28 is configured with piping such as a pipe or a tube that is connected to the flow path 26c of the cleaning nozzle 22, and connects the liquid supply source 30 to the internal space 26a. Note that the connection part 28 may be provided with a valve or the like that adjusts the flow rate of the liquid 24 supplied to the flow path 26c.

[0037] A vibration imparting unit (ultrasonic irradiation unit) 32 is provided in the internal space 26a of the cleaning nozzle 22. The vibration imparting unit 32 imparts ultrasonic vibrations (vibrations at a frequency belonging to the ultrasonic band) to the liquid 24 by irradiating ultrasonic waves to the liquid 24 stored in the internal space 26a. An ultrasonic oscillator 34 that controls the application of ultrasonic vibrations from the vibration imparting unit 32 to the liquid 24 is connected to the vibration imparting unit 32. Details of the configurations and functions of the vibration imparting unit 32 and the ultrasonic oscillator 34 will be described later (see FIG. 3 and subsequent figures).

[0038] Furthermore, the cleaning device 2 includes a controller (control unit, control section, control device) 36 that controls the cleaning device 2. The controller 36 is connected to each component (the holding table 4, the rotation drive source 12, the rotation drive source 18, the cleaning nozzle 22, the liquid supply source 30, the vibration imparting unit 32, the ultrasonic oscillator 34, etc.) that constitutes the cleaning device 2. The controller 36 outputs a control signal to each component of the cleaning device 2 to operate the cleaning device 2.

[0039] For example, the controller 36 is configured by a computer. Specifically, the controller 36 includes a processing unit that executes processes such as calculations required for the operation of the cleaning apparatus 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the cleaning apparatus 2. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). When the cleaning apparatus 2 is mounted on a processing device, the controller of the processing device may have the function of the controller 36.

[0040] When cleaning the object 11 with the cleaning device 2, first, the object 11 is held by the holding table 4. For example, when cleaning the first surface 11a side of the object 11, the object 11 is placed on the holding table 4 so that the first surface 11a (surface to be cleaned) side is exposed upward and the second surface 11b side faces the holding surface 4a. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 4a, the object 11 is sucked and held by the holding table 4. On the other hand, when cleaning the second surface 11b of the object 11, the object 11 is held by the holding table 4 so that the second surface 11b is exposed upward.

[0041] Next, the rotary drive source 18 is operated to rotate the cleaning nozzle 22, and the cleaning nozzle 22 is positioned so as to overlap the object 11. Then, the rotary drive source 12 is operated to rotate the holding table 4, while supplying the liquid 24 from the supply port 26b of the cleaning nozzle 22 toward the object 11. As a result, the liquid 24 is supplied to the first surface 11a side of the object 11. At this time, the cleaning nozzle 22 may be reciprocated above the object 11 while supplying the liquid 24 to the object 11.

[0042] The liquid 24 supplied to the object 11 spreads radially toward the outer periphery of the object 11 due to the centrifugal force of the rotating object 11. As a result, the liquid 24 flows along the first surface 11a of the object 11, and foreign matter such as machining waste adhering to the first surface 11a side of the object 11 is washed away. In this manner, the object 11 is cleaned by the cleaning device 2.

[0043] When the liquid 24 is supplied from the cleaning nozzle 22 to the object 11, ultrasonic vibration is applied to the liquid 24 by the vibration applying unit 32. The ultrasonic vibration is transmitted to the first surface 11a side of the object 11 through the liquid 24 as a medium, and vibrates foreign matter adhering to the first surface 11a side. This makes it easier to remove foreign matter firmly adhering to the object 11. The vibration applying unit 32 will be described in detail below.

[0044] 3 is a cross-sectional view showing the cleaning nozzle 22 in which the vibration imparting unit 32 is housed in the internal space 26a of the case 26. The vibration imparting unit 32 includes a flat vibration plate 40 and a plurality of vibrators 42 that impart ultrasonic vibrations to the vibration plate 40.

[0045] For example, the vibration plate 40 is a disk-shaped member made of a metal such as SUS (stainless steel) and has a first surface (upper surface) 40a and a second surface (lower surface) 40b that are generally parallel to each other. The vibration plate 40 is installed in a region of the internal space 26a above the flow path 26c so as to face the supply port 26b.

[0046] For example, the case 26 is provided with an annular support member 44 formed along the side wall of the internal space 26a. The support member 44 is installed so as to protrude from the side wall of the internal space 26a toward the center of the internal space 26a, and the inner diameter of the support member 44 is smaller than the diameter of the vibration plate 40. The vibration plate 40 is placed on the support member 44 so that the first surface 40a faces upward and the second surface 40b faces downward. This allows the outer periphery of the vibration plate 40 to be supported by the support member 44. The first surface 40a and the second surface 40b are placed approximately parallel to the supply port 26b, and the second surface 40b faces the supply port 26b.

[0047] The multiple vibrators 42 are connected to the first surface 40a side of the vibration plate 40. For example, the vibrator 42 is a piezoelectric element that vibrates when a voltage is applied, and includes a piezoelectric ceramic such as lead zirconate titanate (PZT) and an electrode that applies a voltage to the piezoelectric ceramic. The multiple vibrators 42 are arranged so that their distances from the center of the vibration plate 40 are different.

[0048] Each of the transducers 42 is connected to an ultrasonic oscillator 34. The ultrasonic oscillator 34 oscillates ultrasonic waves to supply high-frequency power to the transducers 42. This causes each of the transducers 42 to vibrate at a frequency (20 kHz or higher) that belongs to the ultrasonic band. The high-frequency power supplied from the ultrasonic oscillator 34 to the transducers 42 may be set by the controller 36 controlling the ultrasonic oscillator 34, or may be set automatically by the ultrasonic oscillator 34.

[0049] When the liquid 24 is supplied from the liquid supply source 30 (see FIG. 2) to the internal space 26a via the connection portion 28 (see FIG. 2) and the flow path 26c, and the internal space 26a is filled with the liquid 24, the liquid 24 comes into contact with the vibration plate 40. When high-frequency power is supplied from the ultrasonic generator 34 to the transducers 42 in this state, the transducers 42 vibrate at a frequency belonging to the ultrasonic band, and the ultrasonic vibrations emitted by the transducers 42 each propagate through the vibration plate 40 and reach the liquid 24. As a result, ultrasonic waves are irradiated to the liquid 24 and propagate through the liquid 24, thereby imparting ultrasonic vibrations to the liquid 24.

[0050] In the cleaning nozzle 22 according to this embodiment, a flat vibration plate 40 is used, and the planar second surface 40b comes into contact with the liquid 24. As a result, air is less likely to remain between the vibration plate 40 and the liquid 24 compared to when a vibration plate formed in a dome-shaped concave spherical shape is used, and it is possible to prevent the transmission of ultrasonic vibration from the vibration plate 40 to the liquid 24 from being hindered by an air layer.

[0051] Furthermore, the cleaning nozzle 22 according to this embodiment is configured to be capable of controlling the propagation of ultrasonic waves applied from the vibration plate 40 to the liquid 24 by phased array control of the multiple transducers 42. As a result, even if the vibration plate 40 is flat, it is possible for the ultrasonic vibrations to efficiently reach the object 11 using the liquid 24 as a medium, making it easy to remove foreign matter adhering to the object 11.

[0052] Fig. 4 is a schematic diagram showing how ultrasonic waves propagate through the liquid 24. Fig. 4 shows the liquid 24 stored in the internal space 26a of the case 26, the vibration plate 40, and a plurality of transducers 42. Fig. 4 also shows a reference line 50 passing through the center of the internal space 26a. The reference line 50 is an imaginary straight line that is perpendicular to the supply port 26b and passes through the center of the supply port 26b and the center of the vibration plate 40.

[0053] When high-frequency power is supplied from the ultrasonic oscillator 34 to the multiple transducers 42, the multiple transducers 42 vibrate and impart ultrasonic vibrations to the vibration plate 40. The ultrasonic vibrations are then propagated to the liquid 24 via the vibration plate 40, and multiple ultrasonic waves 52 are irradiated from the vibration plate 40 to the liquid 24.

[0054] Here, the ultrasonic oscillator 34 controls the propagation of ultrasonic waves in the liquid 24 by phased array control of the multiple transducers 42. The phased array control is a control for adjusting the propagation direction, convergence position, etc. of ultrasonic waves by controlling the phase of ultrasonic vibrations emitted by the multiple transducers 42 for each transducer 42.

[0055] For example, the ultrasonic oscillator 34 supplies high-frequency power to the multiple transducers 42 so that the ultrasonic vibration emitted by the transducer 42 closer to the center (reference line 50) of the vibration plate 40 is delayed in phase. As a result, the ultrasonic waves 52 generated at positions closer to the center of the vibration plate 40 are delayed in phase. The multiple ultrasonic waves 52 are then synthesized to generate an ultrasonic wave (synthetic wave) 54 that propagates through the liquid 24 toward the supply port 26b and converges. The ultrasonic wave 54 propagates through the liquid 24 as a medium, thereby imparting ultrasonic vibration to the liquid 24.

[0056] When the multiple transducers 42 are controlled as described above, ultrasonic waves 54 propagating through the liquid 24 converge on the reference line 50. For example, the ultrasonic waves 54 converge at a convergence position (focus) 56 located at or near the supply port 26b. This makes it easier for the ultrasonic vibrations that have passed through the supply port 26b to reach the target object 11 (see FIG. 2) while maintaining high intensity.

[0057] The convergence position 56 of the ultrasonic waves 54 can be appropriately adjusted by controlling the phase difference of the ultrasonic vibrations emitted by the multiple transducers 42. For example, as shown in Fig. 4, the phase difference of the ultrasonic vibrations of the multiple transducers 42 is set so that the ultrasonic waves 54 converge at a convergence position 56 located outside the supply port 26b (closer to the target 11 than the supply port 26b). This allows the ultrasonic waves 54 to converge at a position closer to the target 11, making it easier to apply high-intensity ultrasonic vibrations to foreign matter adhering to the target 11.

[0058] Next, an example of ultrasonic wave propagation control by phased array control will be described with reference to Fig. 5(A) to Fig. 5(D). Here, the sound pressure of ultrasonic waves propagating through liquid when five transducers 42 are placed on a vibration plate 40 and phased array control is performed will be described.

[0059] 5(A) to 5(D) show contour diagrams 60A to 60D of the sound pressure [MPa] of ultrasonic waves propagating through liquid when four different types of phased array control are performed. In the contour diagrams 60A to 60D, the maximum value (positive value) of the ultrasonic sound pressure is displayed in white, and the minimum value (negative value) of the ultrasonic sound pressure is displayed in black.

[0060] 5(A) to 5(D), the numerical values ​​assigned to the transducers 42 indicate the phase difference (phase delay) of the ultrasonic waves with respect to 0° as the reference. Furthermore, a reference line 62 is an imaginary straight line that is perpendicular to the diaphragm 40 and passes through the center of the diaphragm 40, and corresponds to the reference line 50 (see FIG. 4). The contour diagrams 60B to 60D (FIGS. 5(B) to 5(D)) show the sound pressure of the ultrasonic waves when phased array control is performed so that the ultrasonic vibration of the transducers 42 closer to the reference line 62 has a greater phase delay.

[0061] 5(A) is a contour diagram 60A showing the sound pressure of ultrasonic waves generated by phased array control with a phase difference set to 0°. When there is no phase difference between the ultrasonic vibrations emitted by the multiple transducers 42, the ultrasonic waves (composite waves) propagate through the liquid along the reference line 62 but do not converge on the reference line 62. Therefore, the sound pressure of the ultrasonic waves is unlikely to increase or decrease on the reference line 62, and the intensity of the ultrasonic waves propagating through the liquid is low.

[0062] Fig. 5(B) is a contour diagram 60B showing the sound pressure of ultrasonic waves generated by phased array control with a phase difference set to 45°. Fig. 5(C) is a contour diagram 60C showing the sound pressure of ultrasonic waves generated by phased array control with a phase difference set to 90°. When the phase difference of ultrasonic vibrations emitted by multiple transducers 42 is set to 45° or 90°, the ultrasonic waves (composite waves) converge on or near the reference line 62. As a result, the sound pressure increases or decreases significantly on or near the reference line 62, taking maximum and minimum values, and the ultrasonic waves propagate through the liquid along the reference line 62 while maintaining high intensity.

[0063] 5(D) is a contour diagram 60D showing the sound pressure of ultrasonic waves generated by phased array control with a phase difference set to 135°. Even when the phase difference of ultrasonic vibrations emitted by multiple transducers 42 is set to 135°, the ultrasonic waves (composite wave) converge on or near the reference line 62. However, compared to when the phase difference is 45° or 90°, the ultrasonic waves converge at a position closer to the diaphragm 40, and therefore the intensity of the ultrasonic waves becomes weaker at positions farther from the diaphragm 40.

[0064] By controlling the propagation direction, convergence position, and the like of the ultrasonic waves 54 in the liquid 24 by the phased array control as described above (see FIG. 4), the ultrasonic waves 54 can easily reach the target object 11 via the supply port 26b, and ultrasonic vibration can be efficiently applied to the target object 11. Note that, although the case where the ultrasonic waves 54 propagate along the reference line 50 and converge at the convergence position 56 on the reference line 50 has been described in FIG. 4, the propagation control of the ultrasonic waves 54 is not limited to this. For example, the propagation direction of the ultrasonic waves 54 may be inclined with respect to the reference line 50. The convergence position 56 of the ultrasonic waves 54 can also be appropriately set according to the distance between the target object 11 and the cleaning nozzle 22.

[0065] Next, a specific example of the arrangement of the multiple vibrators 42 will be described. Each of the vibration imparting units 32A, 32B, and 32C shown in Fig. 6(A) to Fig. 6(C) corresponds to a specific example of the vibration imparting unit 32, and includes a disk-shaped vibration plate 40. In Fig. 6(A) and Fig. 6(B), a pattern is applied to a first surface 40a of the vibration plate 40 in order to clearly distinguish the vibration plate 40 from other components.

[0066] 6(A) is a plan view showing the vibration imparting unit 32A. The vibration imparting unit 32A includes annular partitions 70A, 70B, and 70C provided on the first surface 40a side of the vibration plate 40. The partitions 70A, 70B, and 70C are annular members made of the same or different material as the vibration plate 40, and are provided so as to protrude upward from the first surface 40a of the vibration plate 40.

[0067] The inner diameter of partition 70B is larger than the outer diameter of partition 70A, and the inner diameter of partition 70C is larger than the outer diameter of partition 70B. Partitions 70A, 70B, and 70C are concentrically arranged so that their centers overlap with the center of diaphragm 40. Partition 70C is arranged along the outer periphery of diaphragm 40.

[0068] The diaphragm 40 is divided into a plurality of regions 80A, 80B, and 80C by the partitions 70A, 70B, and 70C. The region 80A corresponds to a circular region inside the partition 70A and includes the center of the diaphragm 40. The region 80B corresponds to an annular region between the partitions 70A and 70B. The region 80C corresponds to an annular region between the partitions 70B and 70C. In other words, the regions 80A, 80B, and 80C correspond to a plurality of regions having different distances from the center of the diaphragm 40, and the first surface 40a of the diaphragm 40 is exposed in the regions 80A, 80B, and 80C.

[0069] The vibration imparting unit 32A also includes a plurality of vibrators 42A, 42B, and 42C. The vibrators 42A, 42B, and 42C are connected to the first surface 40a side of the diaphragm 40, respectively. The configurations, functions, and the like of the vibrators 42A, 42B, and 42C are the same as those of the above-mentioned vibrator 42 (see FIG. 3, etc.). The vibrator 42A is disposed in the region 80A, the vibrator 42B is disposed in the region 80B, and the vibrator 42C is disposed in the region 80C. Therefore, the vibrators 42A, 42B, and 42C are arranged so that their distances from the center of the diaphragm 40 are different.

[0070] There is no limit to the number and arrangement of the transducers 42A, 42B, and 42C in each of the regions 80A, 80B, and 80C. For example, as shown in FIG. 6A, in the region 80A, a plurality of transducers 42A having the same distance from the center of the diaphragm 40 and a plurality of transducers 42A having different distances from the center of the diaphragm 40 may be mixed. In the region 80B, a plurality of transducers 42B having the same distance from the center of the diaphragm 40 and a plurality of transducers 42B having different distances from the center of the diaphragm 40 may be mixed. Furthermore, in the region 80C, a plurality of transducers 42C having the same distance from the center of the diaphragm 40 and a plurality of transducers 42C having different distances from the center of the diaphragm 40 may be mixed.

[0071] The transducers 42A, 42B, and 42C are connected to an ultrasonic oscillator 34 (see FIG. 2, etc.). When high-frequency power is supplied from the ultrasonic oscillator 34 to the transducers 42A, 42B, and 42C, the transducers 42A, 42B, and 42C apply ultrasonic vibrations to the regions 80A, 80B, and 80C of the diaphragm 40, respectively.

[0072] Furthermore, when performing phased array control of the transducers 42A, 42B, 42C, the high frequency power supplied from the ultrasonic oscillator 34 to the transducers 42A, 42B, 42C is controlled so that a phase difference occurs in the ultrasonic vibrations emitted by the transducers 42A, 42B, 42C. Furthermore, a phase difference in the ultrasonic vibrations may be generated between the transducers 42A, 42B, and / or 42C that are at different distances from the center of the diaphragm 40.

[0073] Fig. 6(B) is a plan view showing vibration imparting unit 32B. Unlike vibration imparting unit 32A (see Fig. 6(A)), vibration plate 40 of vibration imparting unit 32B does not have an annular partition. However, vibration plate 40 of vibration imparting unit 32B is divided into areas 80A, 80B, and 80C by annular boundaries 72A and 72B.

[0074] Boundaries 72A and 72B correspond to imaginary dividing lines that divide diaphragm 40. The diameter of boundary 72A is smaller than the diameter of boundary 72B, and boundaries 72A and 72B are arranged concentrically so that their centers overlap with the center of diaphragm 40. Region 80A corresponds to a circular region inside boundary 72A and includes the center of diaphragm 40. Region 80B corresponds to an annular region between boundaries 72A and 72B. Region 80C corresponds to an annular region outside boundary 72B and includes the outer peripheral edge of diaphragm 40.

[0075] The vibration imparting unit 32B includes a plurality of vibrators 42A, 42B, and 42C. The vibrators 42A, 42B, and 42C are arranged in a lattice pattern and connected to the first surface 40a side of the vibration plate 40. That is, the vibrators 42A, 42B, and 42C are arranged at predetermined intervals along two mutually perpendicular directions (the up-down direction and the left-right direction in FIG. 6B). Note that, although FIG. 6B illustrates an example in which the vibrators 42A, 42B, and 42C are arranged in 14 rows and 14 columns, there is no limit to the number of rows and columns of the vibrators 42A, 42B, and 42C.

[0076] Transducer 42A is placed in region 80A, transducer 42B is placed in region 80B, and transducer 42C is placed in region 80C. Therefore, transducers 42A, 42B, and 42C are arranged so that they are at different distances from the center of diaphragm 40. In addition, in FIG. 6(B), the transducer placed on boundary 72A may be regarded as transducer 42A or transducer 42B. Furthermore, the transducer placed on boundary 72B may be regarded as transducer 42B or transducer 42C.

[0077] The transducers 42A, 42B, and 42C are each connected to an ultrasonic oscillator 34 (see FIG. 2, etc.). When high-frequency power is supplied from the ultrasonic oscillator 34 to the transducers 42A, 42B, and 42C, the transducers 42A, 42B, and 42C apply ultrasonic vibrations to the regions 80A, 80B, and 80C of the diaphragm 40, respectively.

[0078] Furthermore, when performing phased array control of the transducers 42A, 42B, 42C, the high frequency power supplied from the ultrasonic oscillator 34 to the transducers 42A, 42B, 42C is controlled so that a phase difference occurs in the ultrasonic vibrations emitted by the transducers 42A, 42B, 42C. Furthermore, a phase difference in the ultrasonic vibrations may be generated between the transducers 42A, 42B, and / or 42C that are at different distances from the center of the diaphragm 40.

[0079] Fig. 6(C) is a plan view showing the vibration imparting unit 32C. Similar to the vibration imparting unit 32A (see Fig. 6(A)), the vibration imparting unit 32C includes annular partitions 70A, 70B, and 70C provided on the first surface 40a side of the vibration imparting unit 40. The vibration imparting unit 32C's vibration imparting unit 40 is divided into a plurality of regions 80A, 80B, and 80C by the partitions 70A, 70B, and 70C.

[0080] The vibration imparting unit 32C includes transducers 42A', 42B', and 42C'. The configurations, functions, and the like of the transducers 42A', 42B', and 42C' are similar to those of the above-described transducer 42 (see FIG. 3, etc.). However, the shapes of the transducers 42A', 42B', and 42C' are different from those of the transducers 42A, 42B, and 42C shown in FIG. 6(A) and FIG. 6(B).

[0081] Specifically, transducer 42A' is formed in a circular shape corresponding to region 80A and is connected to region 80A. Transducer 42B' is formed in a ring shape corresponding to region 80B and is connected to region 80B. Transducer 42C' is formed in a ring shape corresponding to region 80C and is connected to region 80C. That is, transducer 42A' is placed inside partition 70A, transducer 42B' is placed between partitions 70A and 70B, and transducer 42C is placed between partitions 70B and 70C.

[0082] When the vibrators 42A', 42B', and 42C' are connected to the diaphragm 40 as described above, the vibrators 42A', 42B', and 42C' are arranged concentrically so that their centers overlap with the center of the diaphragm 40. In addition, the vibrators 42A', 42B', and 42C' are arranged so that their distances from the center of the diaphragm 40 are different.

[0083] In the vibration imparting unit 32C, the first surface 40a of the vibration plate 40 is covered by the vibrators 42A', 42B', 42C' and the partitions 70A, 70B, 70C. Therefore, the first surface 40a of the vibration plate 40 is not exposed. However, there may be gaps between the vibrators 42A', 42B', 42C' and the partitions 70A, 70B, 70C. Also, the partitions 70A, 70B, 70C may be omitted from the vibration imparting unit 32C.

[0084] The transducers 42A', 42B', 42C' are connected to the ultrasonic oscillator 34 (see FIG. 2, etc.). When high-frequency power is supplied from the ultrasonic oscillator 34 to the transducers 42A', 42B', 42C', the transducers 42A', 42B', 42C' apply ultrasonic vibrations to the regions 80A, 80B, 80C of the diaphragm 40, respectively. When performing phased array control of the transducers 42A', 42B', 42C', the high-frequency power supplied from the ultrasonic oscillator 34 to the transducers 42A', 42B', 42C' is controlled so that a phase difference occurs in the ultrasonic vibrations emitted by the transducers 42A', 42B', 42C'.

[0085] As described above, a vibration imparting unit 32 capable of phased array control is configured by connecting transducers to a plurality of regions at different distances from the center of the diaphragm 40. Although an example in which the diaphragm 40 is divided into three regions (regions 80A, 80B, and 80C) has been described in Fig. 6(A) to Fig. 6(C), the diaphragm 40 may be divided into four or more regions at different distances from the center of the diaphragm 40. In this case, a transducer is connected to each region.

[0086] As described above, the cleaning nozzle 22 according to this embodiment is configured to be capable of controlling the propagation of ultrasonic waves applied from the flat vibration plate 40 to the liquid 24 by phased array control of the multiple transducers 42. This allows the ultrasonic waves to be efficiently propagated to the object 11 via the liquid 24.

[0087] In the above embodiment, the vibration imparting unit 32 is described as having a disk-shaped vibration plate 40, but the vibration plate 40 may be composed of a plurality of independent vibration plates. For example, the vibration plate 40 may include a disk-shaped first vibration plate corresponding to the region 80A, an annular second vibration plate corresponding to the region 80B, and an annular third vibration plate corresponding to the region 80C. In this case, the first vibration plate, the second vibration plate, and the third vibration plate can be disposed separately from the other vibration plates.

[0088] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0089] 11 Object (object to be cleaned, object to be processed) 11a 1st page 11b Side 2 2. Cleaning equipment 4 Holding table (chuck table) 4a Holding surface 6 Frame (main body) 6a Top side 6b Recess (groove) 6c Flow Path 8 Retaining member 8a Suction surface 10 Support shaft 12 Rotational drive source 14 Cleaning unit (cleaning mechanism) 16 Support shaft 18 Rotational drive source 20 Support Arm 22 Cleaning nozzle 24 Liquid (cleaning fluid) 26 Case (main body) 26a Internal space (storage section) 26b Supply port 26c Flow Path 28 Connection 30 Liquid Source 32, 32A, 32B, 32C Vibration unit (ultrasonic irradiation unit) 34 Ultrasonic oscillator 36 Controller (control unit, control section, control device) 40 diaphragm 40a 1st side (top side) 40b 2nd side (bottom side) 42, 42A, 42B, 42C, 42A´, 42B´, 42C´ Transducers 44 Support member 50 Reference Line 52 Ultrasound 54 Ultrasound (synthetic wave) 56 Convergence position (focus) 60A, 60B, 60C, 60D Contour diagram 62 Reference Line 70A, 70B, 70C Partition 72A,72B Boundary 80A, 80B, 80C area

Claims

1. A cleaning nozzle that cleans an object by supplying the liquid to the object while propagating ultrasonic waves through the liquid, a case having an internal space for storing the liquid, a supply port for supplying the liquid from the internal space toward the object, and a connection portion for connecting the internal space to a liquid supply source for supplying the liquid; a flat vibration plate provided in the internal space so as to face the supply port; a plurality of vibrators for applying ultrasonic vibrations to the vibration plate; A cleaning nozzle characterized in that the propagation of ultrasonic waves applied from the vibration plate to the liquid can be controlled by phased array control of a plurality of the transducers.

2. 2. The cleaning nozzle according to claim 1, wherein the ultrasonic waves applied to the liquid from the vibration plate can be focused on a straight line perpendicular to the supply port and passing through a center of the supply port.

3. 3. The cleaning nozzle according to claim 1, wherein the plurality of vibrators are arranged in a lattice pattern.

4. 3. The cleaning nozzle according to claim 1, wherein the plurality of vibrators are formed in a circular or annular shape and are arranged concentrically.

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