Slurry mist spray nozzle and wet blasting device

Abstract

To apply more uniform fine polishing to a workpiece.SOLUTION: A slurry mist injection nozzle comprises: a casing (21) in which a high pressure air supply port (26) and a slurry mist injection port (28) are formed; and a slurry supply conduit (35) which is drawn into the casing (21) and in which a slurry supply port (37) is formed on a lateral face or an end face. In the slurry mist injection nozzle, an aperture area of the slurry mist injection port (28) is smaller than an aperture area of the high pressure air supply port (26).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a slurry mist injection nozzle, a wet blasting device, and a control method for a wet blasting device.

Background Art

[0002] Conventionally, a wet blasting device that injects a slurry obtained by mixing a liquid and an abrasive onto a workpiece by high-pressure air has been known.

[0003] For example, as shown in FIG. 10, a slurry mist injection nozzle included in the wet blasting device disclosed in Patent Document 1 is provided with a high-pressure air supply unit 1 and a slurry supply unit 2. The high-pressure air A supplied from the high-pressure air supply unit 1 and the slurry S supplied from the slurry supply unit 2 are mixed near the tip of the high-pressure air supply unit 1. The slurry S mixed with the high-pressure air A is injected from the slurry mist injection port 3 together with the high-pressure air A.

[0004] As shown in FIG. 11, a slurry mist injection nozzle included in the wet blasting device disclosed in Patent Document 2 is provided with slurry supply units 5 for supplying slurry S on both sides of a high-pressure air supply unit 4 that supplies high-pressure air A. The high-pressure air A supplied from the high-pressure air supply unit 4 and the slurry S supplied from the slurry supply unit 5 are mixed near the tip of the high-pressure air supply unit 4. The slurry S mixed with the high-pressure air A is injected from the slurry mist injection port 6 together with the high-pressure air A.

[0005] As shown in FIG. 12, a slurry mist injection nozzle included in the wet blasting device disclosed in Patent Document 3 is provided with a high-pressure air supply unit 7 for supplying high-pressure air A on the side surface of a slurry supply unit 8 that supplies slurry S. The high-pressure air A supplied from the high-pressure air supply unit 7 and the slurry S supplied from the slurry supply unit 8 are mixed near the tip of the slurry supply unit 8. The slurry S mixed with the high-pressure air A is injected from the slurry mist injection port 9 together with the high-pressure air A.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Application Publication No. 04-082668 [Patent Document 2] Japanese Patent Publication No. 2001-300363 [Patent Document 3] Japanese Patent Publication No. 2020-131303 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Incidentally, in recent years, there has been a demand for finer patterns to be formed on workpieces. Therefore, micro-polishing processes (such as surface roughening and pattern cutting) with surface roughness at the nano-order level are required. In order to achieve nano-order level surface roughness, it is necessary to uniformly spray a slurry containing abrasive with an average particle size of 2 μm (preferably an average particle size of 1 μm) or less onto the workpiece in a stable manner.

[0008] Incidentally, the slurry mist injection nozzles in typical wet blasting equipment utilize the ejector phenomenon to supply slurry into the slurry mist injection nozzle. As shown in Figures 10 to 12, in conventional wet blasting equipment, the opening area φB of the high-pressure air supply units 1, 4, and 7 is smaller than the opening area φA of the slurry mist injection ports 3, 6, and 9.

[0009] However, with such slurry mist spray nozzles, a pressure distribution occurs in the spray pressure of the high-pressure air supplied from the high-pressure air supply unit, resulting in uneven spray velocity of the slurry mist ejected from the slurry mist nozzle. Therefore, when fine abrasive material is used as the slurry, there is a problem in that the surface roughness of the workpiece after processing is not uniform due to the differences in the spray velocity of the slurry mist.

[0010] One aspect of the present invention aims to provide a slurry mist spray nozzle, a wet blasting apparatus, and a control method for the wet blasting apparatus that enable more uniform fine polishing of a workpiece. [Means for solving the problem]

[0011] To solve the above problems, a slurry mist spray nozzle according to one aspect of the present invention comprises a housing and a slurry supply conduit. The housing has a high-pressure air supply port and a slurry mist spray port formed therein. The slurry supply conduit is drawn into the interior of the housing, and a slurry supply port is formed on its side or end face. The opening area of ​​the slurry mist spray port is smaller than the opening area of ​​the high-pressure air supply port.

[0012] To solve the above problems, a wet blasting apparatus according to one aspect of the present invention comprises a slurry mist spray nozzle, a slurry supply device, and a high-pressure air supply device. The slurry mist spray nozzle comprises a housing and a slurry supply conduit. The housing has a high-pressure air supply port and a slurry mist spray port. The slurry supply conduit is drawn into the housing and has a slurry supply port formed on its side or end face. The slurry supply device has a slurry pressurizing tank and a high-pressure air supply unit, and supplies slurry into the housing via the slurry supply conduit connected to the slurry pressurizing tank. The slurry pressurizing tank contains the slurry. The high-pressure air supply device supplies high-pressure air for nozzle pressurization into the housing via the high-pressure air supply port and also supplies high-pressure air for slurry pressurization into the slurry pressurizing tank via the high-pressure air supply unit. The high-pressure air supply device then supplies high-pressure air for nozzle pressurization and high-pressure air for slurry pressurization such that the pressure of the high-pressure air for nozzle pressurization in the housing is higher than atmospheric pressure, and the pressure of the slurry in the slurry supply conduit is higher than the pressure of the high-pressure air for nozzle pressurization in the housing.

[0013] To solve the above problems, a control method for a wet blast apparatus according to one aspect of the present invention is a control method for a wet blast apparatus comprising a slurry mist spray nozzle, a high-pressure air supply device, and a slurry supply device. The slurry mist spray nozzle comprises a housing and a slurry supply conduit. The housing has a high-pressure air supply port and a slurry mist spray port formed therein. The slurry supply conduit is drawn into the interior of the housing, and a slurry supply port is formed on its side or end face. The slurry mist spray nozzle has an opening area of ​​the slurry mist spray port that is smaller than the opening area of ​​the high-pressure air supply port. The high-pressure air supply device supplies high-pressure air into the housing via the high-pressure air supply port. The slurry supply device supplies slurry into the housing via the slurry supply conduit. The pressure of the high-pressure air supplied by the high-pressure air supply device and the pressure applied to the slurry supplied by the slurry supply device into the housing are controlled so that the amount of slurry supplied in the slurry supply conduit approaches a target value. [Effects of the Invention]

[0014] According to one aspect of the present invention, a slurry mist spray nozzle, a wet blasting apparatus, and a control method for the wet blasting apparatus can be provided, which enable more uniform fine polishing of a workpiece. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing a wet blast apparatus according to Embodiment 1 of the present invention. [Figure 2] This is a schematic diagram illustrating the micro-polishing process applied to a circuit board. [Figure 3] This figure shows the external appearance of the slurry mist spraying nozzle equipped in the wet blasting apparatus shown in Figure 1. [Figure 4] This is a cross-sectional view along the line A-A shown in Figure 3. [Figure 5] This chart shows the control flow by the control device provided in the wet blasting apparatus according to Embodiment 1 of the present invention. [Figure 6]This is a diagram showing the appearance of the slurry mist injection nozzle according to Embodiment 2 of the present invention. [Figure 7] It is a cross-sectional view taken along the line B-B shown in FIG. 6. [Figure 8] This is a diagram showing the appearance of the slurry mist injection nozzle according to Embodiment 3 of the present invention. [Figure 9] It is a cross-sectional view taken along the line C-C shown in FIG. 8. [Figure 10] This is a schematic diagram showing a conventional slurry mist injection nozzle. [Figure 11] This is a schematic diagram showing a conventional slurry mist injection nozzle. [Figure 12] This is a schematic diagram showing a conventional slurry mist injection nozzle.

Mode for Carrying Out the Invention

[0016] 〔Embodiment 1〕 Hereinafter, an embodiment of the present invention will be described in detail.

[0017] <Overview of Wet Blasting Device> The wet blasting device 100 of the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing the wet blasting device 100. FIG. 2 is a schematic diagram showing the fine polishing process applied to the substrate.

[0018] The wet blasting device 100 includes a slurry processing device 10, a slurry supply device 30, a collection device 40, a blower device 50, a touch panel 60, a control panel 70, and a high-pressure air supply device (not shown).

[0019] The slurry processing apparatus 10 is a device that processes the surface of a workpiece by spraying slurry mist from a slurry mist spraying nozzle 20. The slurry processing apparatus 10 that performs micro-processing on an electronic circuit board, which is an example of a workpiece, will be described below. The slurry processing apparatus 10 can perform, for example, (i) pattern cutting processing, which involves cutting a thin film formed on the surface of a workpiece by spraying a fine mist-like slurry onto the surface of a glass, silicon wafer, ceramic, printed circuit board, etc., or (ii) micro-polishing processing, which is used to improve the adhesion of photoresist and vapor-deposited films, or to remove oxide films and organic films, etc. The slurry processing apparatus 10 comprises a container 11, a nozzle drive unit 14, a substrate transport conveyor 16, and a slurry mist spraying nozzle 20.

[0020] The container 11 is equipped with a processing chamber 12 for microfabrication of the substrate and a processing chamber hopper 13 located below the processing chamber 12. A slurry mist spray nozzle 20 is provided inside the processing chamber 12.

[0021] A nozzle drive unit 14 is provided within the processing chamber 12. The nozzle drive unit 14 drives the slurry mist spray nozzle 20. The nozzle drive unit 14 includes a nozzle drive motor, a guide rail, and a slider. The slurry mist spray nozzle 20 is driven along the direction of extension of the guide rail (left-right direction in the drawing) together with the slider driven by the nozzle drive motor.

[0022] A slurry mist spray nozzle 20 is provided inside the processing chamber 12. The slurry mist spray nozzle 20 sprays slurry mist onto substrates on the substrate transport conveyor 16. A high-pressure air supply conduit 15 is provided for the slurry mist spray nozzle 20. The high-pressure air supply conduit 15 is a conduit for supplying high-pressure air for nozzle pressurization from a high-pressure air supply device to the slurry mist spray nozzle 20. Details of the slurry mist spray nozzle 20 will be described later.

[0023] A substrate transport conveyor 16 is provided inside the processing chamber 12. The substrate transport conveyor 16 is located below the slurry mist spray nozzle 20. The substrate transport conveyor 16 is a transport mechanism for transporting substrates. In the drawing, the substrate moves in the front-back direction. Slurry mist is sprayed from the slurry mist spray nozzle 20 onto the substrate being transported by the substrate transport conveyor 16. As shown in Figure 2, the slurry mist M sprayed from the slurry mist spray nozzle 20 performs micro-polishing on the substrate W.

[0024] As shown in Figure 1, a processing chamber hopper 13 is provided at the bottom of the processing chamber 12. Most of the slurry mist sprayed from the slurry mist injection nozzle 20 is collected in the processing chamber hopper 13. The slurry mist collected in the processing chamber hopper 13 is stored in the slurry collection tank 41.

[0025] The slurry supply device 30 is a device that supplies slurry to the slurry mist injection nozzle 20. The slurry supply device 30 comprises a slurry pressurized tank 31, a slurry agitator 32, a slurry agitator motor 33, a pressurized air supply conduit 34, a slurry supply conduit 35, and a flow meter 36.

[0026] The slurry is contained within the slurry pressurized tank 31. The slurry is a mixed fluid obtained by mixing water, fine abrasive particles, and a dispersant. The slurry is placed in the slurry pressurized tank 31 in a pre-mixed state.

[0027] A slurry agitator 32 is provided inside the slurry pressurized tank 31. The slurry agitator 32 is driven by a slurry agitator motor 33 to agitate the slurry inside the slurry pressurized tank 31. It is desirable to agitate the slurry using the slurry agitator 32 to prevent the slurry from settling inside the slurry pressurized tank 31.

[0028] The slurry supply conduit 35 is connected to the slurry pressurized tank 31 on one end and to the slurry mist spray nozzle 20 on the other end. The slurry contained in the slurry pressurized tank 31 is supplied to the slurry mist spray nozzle 20 via the slurry supply conduit 35. A flow meter 36 is provided in the slurry supply conduit 35. The flow meter 36 is a sensor that detects the amount of slurry supplied to the slurry mist spray nozzle 20. The flow meter 36 transmits the detected data signal to the control device in the control panel 70.

[0029] The slurry pressurizing tank 31 is provided with a pressurizing air supply conduit 34. The pressurizing air supply conduit 34 is a conduit for supplying high-pressure air A2 for slurry pressurization from a high-pressure air supply device into the slurry pressurizing tank 31. By supplying high-pressure air A2 for slurry pressurization into the slurry pressurizing tank 31 via the pressurizing air supply conduit 34, the inside of the slurry pressurizing tank 31 becomes high-pressure. By making the inside of the slurry pressurizing tank 31 high-pressure, slurry is supplied from the slurry pressurizing tank 31 to the slurry mist spray nozzle 20 via the slurry supply conduit 35. The amount of slurry supplied to the slurry mist spray nozzle 20 is adjusted by increasing or decreasing the pressure of the high-pressure air A2 for slurry pressurization supplied from the high-pressure air supply device.

[0030] The collection device 40 comprises a slurry collection tank 41, a stirring air supply unit 42, conduits 43 and 45, and a diaphragm pump 44.

[0031] The slurry collection tank 41 is located at the bottom of the processing chamber hopper 13. The slurry collected in the processing chamber hopper 13 is contained in the slurry collection tank 41. The slurry collection tank 41 is equipped with an agitation air supply unit 42. The agitation air supply unit 42 supplies air from the high-pressure air supply unit into the slurry collection tank 41. By supplying air into the slurry collection tank 41, the slurry contained in the slurry collection tank 41 is prevented from settling.

[0032] Conduit 43 is connected to the slurry collection tank 41 on one end and to the diaphragm pump 44 on the other end. Conduit 45 is connected to the diaphragm pump 44 on one end and to the slurry pressurizing tank 31 on the other end. The slurry contained in the slurry collection tank 41 is supplied by the diaphragm pump 44 from the slurry collection tank 41 to the slurry pressurizing tank 31 via conduits 43 and 45.

[0033] The blower device 50 is a device that reduces the pressure inside the processing chamber 12. By creating negative pressure inside the processing chamber 12 using the blower device 50, the slurry mist sprayed from the slurry mist spray nozzle 20 is prevented from being discharged to the outside of the processing chamber 12. The blower device 50 comprises a mist collection cyclone 51, a blower 52, a cyclone conduit 53, a mist collection filter 54, and a blower conduit 55.

[0034] One end of the cyclone conduit 53 is connected to the top of the processing chamber 12, and the other end is connected to the mist collection cyclone 51. The mist collection cyclone 51 is a mechanism that classifies the slurry mist collected via the cyclone conduit 53. The classified abrasive and dispersant are contained in a tank located at the bottom of the mist collection cyclone 51. One end of the blower conduit 55 is connected to the top of the mist collection cyclone 51. A mist collection filter 54 is provided between the mist collection cyclone 51 and the blower conduit 55. The mist collection filter collects the slurry mist that is sent to the blower conduit. It is connected to the top of the mist collection cyclone 51, and the other end is connected to the blower 52.

[0035] When the blower 52 is activated, a portion of the slurry mist sprayed along with the air in the processing chamber is sucked in. The sucked-in slurry mist is sent to the mist collection cyclone 51 via the cyclone conduit 53. The slurry mist sent to the mist collection cyclone 51 is classified in the mist collection cyclone 51. The slurry mist that cannot be classified in the mist collection cyclone 51 is collected by the mist collection filter 54. The air sucked in by the blower 52 is discharged to the outside of the blower device 50 via the blower conduit. This reduces the pressure inside the processing chamber 12.

[0036] The high-pressure air supply device is a device that supplies high-pressure air to the slurry mist injection nozzle 20, the slurry pressurizing tank 31, and the slurry collection tank 41. The high-pressure air supply device comprises at least a high-pressure air supply unit and a high-pressure air supply pressure adjustment unit. The high-pressure air supply unit is, for example, a compressor. The high-pressure air supply pressure adjustment unit is, for example, an electro-pneumatic regulator. The high-pressure air supply pressure adjustment unit adjusts the amount of high-pressure air supplied from the high-pressure air supply unit. The high-pressure air supply pressure adjustment unit of the high-pressure air supply device is controlled by a control device described later. This controls the amount of high-pressure air A1 supplied to the slurry mist injection nozzle 20 for nozzle pressurization, high-pressure air A2 supplied to the slurry pressurizing tank 31 for slurry pressurization, and high-pressure air supplied to the slurry collection tank 41.

[0037] The touch panel 60 is located on the container 11. By operating the touch panel 60, the operator can make various settings related to the wet blasting device 100.

[0038] The control panel 70 is located in the container 11. The control panel 70 includes a control device. The control device controls various devices provided by the wet blasting apparatus 100. The control device is implemented by, for example, a personal computer (PC) or a PLC (programmable logic controller). The control device includes, for example, a processor such as a CPU (Central Processing Unit) or GPU (Graphic Processing Unit), memory such as ROM (Read Only Memory) or RAM (Random Access Memory), and an interface for communicating with various devices.

[0039] <Slurry Mist Spray Nozzle> The slurry mist spray nozzle 20 according to this embodiment will be described using Figures 3 and 4. Figure 3 is a diagram showing the external appearance of the slurry mist spray nozzle 20 provided in the wet blasting apparatus 100 shown in Figure 1. Figure 4 is a cross-sectional view along the line A-A shown in Figure 3. In describing the slurry mist spray nozzle 20 below, for the sake of convenience, we will define three coordinate axes, X (X1-X2), Y (Y1-Y2), and Z (Z1-Z2), as shown by the arrows in Figure 3 and other figures.

[0040] As shown in Figure 3, the slurry mist spray nozzle 20 comprises a housing 21, a high-pressure air buffer section 22, a high-pressure air tapered section 23, a straight section 24, a high-pressure air supply conduit 15, an opening 27, and a slurry supply conduit 35.

[0041] The housing 21 is a rectangular member with its longitudinal direction in the X direction. The housing 21 has a nozzle body 21A and a nozzle tip 21B. A high-pressure air supply conduit 15 is provided on the Z1 side of the housing 21 (nozzle body 21A). A high-pressure air supply port 26 is formed inside the nozzle body 21A, which connects to the high-pressure air supply conduit 15. Air A for nozzle pressurization is supplied from the high-pressure air supply conduit 15. 1 However, it is supplied to the inside of the housing 21 via the high-pressure air supply port 26.

[0042] A slurry mist nozzle 28 is formed on the Z2 side of the housing 21 (nozzle tip 21B). Slurry mist M is sprayed from the slurry mist nozzle 28 toward the workpiece W. The slurry mist nozzle 28 is formed in a rectangular shape along the X direction of the nozzle tip 21B. The opening area S3 of the slurry mist nozzle 28 is formed to be smaller than the opening area S1 of the high-pressure air supply port 26. In this embodiment, the high-pressure air A1 for nozzle pressurization flows from the high-pressure air supply port 26 toward the slurry mist nozzle 28 (Z direction).

[0043] Inside the housing 21, a high-pressure air buffer section 22, a tapered section 23, and a straight section 24 are formed. The high-pressure air buffer section 22, the tapered section 23, and the straight section 24 are passages through which the high-pressure air A1 for nozzle pressurization flows.

[0044] The high-pressure air buffer section 22 is a flow path connected to the high-pressure air supply port 26. The high-pressure air buffer section 22 is formed in the nozzle body 211A. The high-pressure air buffer section 22 is a flow path with the X direction as its longitudinal direction. The high-pressure air buffer section 22 is formed such that its cross-sectional area is larger than that of the high-pressure air supply port 26. Here, in this application, the cross-sectional area refers to the cross-sectional area in a direction perpendicular to the flow direction of the high-pressure air A1 for nozzle pressurization toward the slurry mist injection port 28. The cross-sectional area of ​​the high-pressure air buffer section 22 is constant in the flow direction of the high-pressure air A1 for nozzle pressurization. The high-pressure air A1 for nozzle pressurization supplied via the high-pressure air supply port 26 is buffered in the high-pressure air buffer section 22, which is a wide-area space.

[0045] The tapered section 23 is a flow path formed following the high-pressure air buffer section 22. The tapered section 23 is formed in the nozzle body 21A. The tapered section 23 is a flow path with the X direction as its longitudinal direction. In the Y direction (short direction), the tapered section 23 is formed such that the distance between the inner walls of opposing tapered sections 23 narrows as it approaches the slurry mist injection port 28. The tapered section 23 is formed such that the cross-sectional area of ​​the tapered section 23 decreases as it approaches the slurry mist injection port 28. With the above configuration, the flow of high-pressure air A1 for nozzle pressurization toward the slurry mist injection port 28 can be standardized. Therefore, the injection pressure of the slurry mist M injected from the slurry mist injection port 28 can be made even more uniform.

[0046] The straight section 24 is a flow path formed following the tapered section 23. The straight section 24 is formed at the nozzle tip 21B. The straight section 24 is a flow path with the X direction as its longitudinal direction. The cross-sectional area of ​​the straight section 24 is constant in the flow direction of the high-pressure air A1 for nozzle pressurization. The end of the straight section 24 in the flow direction of the high-pressure air A1 for nozzle pressurization forms the slurry mist injection port 28.

[0047] The cross-sectional area of ​​the flow path for the high-pressure air A1 for nozzle pressurization that flows inside the housing 21 is formed to be larger than or equal to the opening area S3 of the slurry mist injection port 28, from the high-pressure air supply port 26 to the slurry mist injection port 28. At the position where the slurry supply port 37 of the slurry supply conduit 35 is formed, the cross-sectional area of ​​the flow path for the high-pressure air A1 for nozzle pressurization is formed to be larger than the opening area S3 of the slurry mist injection port 28. With the above configuration, the pressure inside the housing 21 can be kept constant. Therefore, the injection pressure of the slurry mist M injected from the slurry mist injection port 28 can be made uniform.

[0048] A slurry supply conduit 35 is drawn into the housing 21 (flow channel). The slurry supply conduit 35 is drawn into the housing 21 through two openings 27 formed in the housing 21. The slurry supply conduit 35 is positioned inside the housing 21 so as to extend in the X direction.

[0049] The slurry supply conduit 35 is positioned so that its side faces the slurry mist nozzle 28. Multiple slurry supply ports 37 are formed on the side of the slurry supply conduit 35 along the slurry mist nozzle 28. As shown in Figure 4, the multiple slurry supply ports 37 are formed on the slurry supply conduit 35 so as to face the slurry mist nozzle 28. Slurry S is supplied into the housing 21 by being sprayed from the slurry supply ports 37. With the above configuration, multiple slurry supply ports 37 are formed along the rectangular slurry mist nozzle 28. Therefore, slurry mist M can be sprayed over a wide area from the slurry mist nozzle 28. This makes it possible to shorten the working time.

[0050] As shown in Figure 3, the opening area S2 of the slurry supply port 37 is formed to be smaller than the opening area S1 of the high-pressure air supply port 26. In this application, when multiple slurry supply ports are formed in the slurry mist injection nozzle 20, the opening area of ​​the slurry supply port is the total area obtained by adding up the areas of the multiple slurry supply ports. Therefore, the opening area S2 of the slurry supply port 37 is the total area obtained by adding up the areas of the multiple slurry supply ports 37. With the above configuration, the high-pressure air A1 for nozzle pressurization can maintain a state of uniform air pressure inside the housing 21. This makes it possible to equalize the injection pressure of the slurry mist M injected from the slurry mist injection port 28.

[0051] Furthermore, the opening area S2 of the slurry supply port 37 is formed to be smaller than the opening area S3 of the slurry mist injection port 28. In addition, with the above configuration, backflow of the slurry S supplied from the slurry supply port 37 within the housing 21 can be reduced. This makes it possible to perform more uniform fine polishing on the workpiece.

[0052] With the slurry mist injection nozzle 20 configured as described above, the opening area S3 of the slurry mist injection port 28 is smaller than the opening area S1 of the high-pressure air supply port 26. As a result, the high-pressure air A1 supplied via the high-pressure air supply port 26 for nozzle pressurization is buffered within the housing 21, and the air pressure inside the housing 21 is uniformly raised to a level higher than the ambient air pressure. Therefore, the injection pressure of the slurry mist M ejected from the slurry mist injection port 28 can be made uniform, and as a result, it becomes possible to perform more uniform fine polishing on the workpiece.

[0053] <Flow of slurry mist spray> Next, we will explain the process from the slurry mist spraying nozzle 20 to the spraying of slurry mist M towards the workpiece.

[0054] The control device controls the high-pressure air supply device so that the pressure inside the housing 21 of the slurry mist spray nozzle 20 reaches a preset pressure. High-pressure air A1 for nozzle pressurization is supplied from the high-pressure air supply device into the housing 21 of the slurry mist spray nozzle 20 (the flow path for high-pressure air A1 for nozzle pressurization) so that the pressure inside the housing 21 of the slurry mist spray nozzle 20 is higher than atmospheric pressure. As an example, the pressure of the high-pressure air A1 for nozzle pressurization inside the housing 21 is 0.02 to 0.4 MPa.

[0055] After the housing 21 of the slurry mist spray nozzle 20 is pressurized, slurry S is supplied into the housing 21 via the slurry supply conduit 35. At this time, high-pressure air A2 for slurry pressurization is supplied from the high-pressure air supply device to the slurry pressurization tank 31 so that the pressure of slurry S in the slurry supply conduit 35 is higher than the pressure of high-pressure air A1 for nozzle pressurization inside the housing 21. More specifically, high-pressure air A2 for slurry pressurization is supplied to the slurry pressurization tank 31 so that the difference between the pressure inside the slurry pressurization tank 31 and the pressure of high-pressure air A1 for nozzle pressurization inside the housing 21 is a preset differential pressure. As an example, high-pressure air A2 for slurry pressurization inside the housing 21 1 The pressure difference between the external pressure and the pressure inside the slurry pressurizing tank 31 is approximately 0.04 MPa.

[0056] The slurry S supplied into the housing 21 via the slurry supply conduit 35 is mixed with high-pressure air A1 for nozzle pressurization inside the housing 21. The slurry S mixed with high-pressure air A1 for nozzle pressurization is then sprayed as slurry mist M from the slurry mist nozzle 28.

[0057] According to the above configuration, the pressure of the slurry S supplied to the slurry supply conduit 35 can be made uniform. Therefore, the injection pressure of the slurry mist M injected from the slurry mist injection port 28 can be made uniform, and as a result, it becomes possible to perform more uniform fine polishing on the workpiece.

[0058] <Control method for wet blasting equipment> Next, using Figure 5, we will explain how to control the pressure of the high-pressure air A1 for nozzle pressurization and the high-pressure air A2 for slurry pressurization. Figure 5 is a flowchart showing the control flow by the control device provided in the wet blasting apparatus 100. The flowchart shown in Figure 5 is an example and is not limited to this.

[0059] The control device repeatedly performs the following steps S1 to S5 while performing a micro-polishing process on the workpiece. This allows the control device to control the pressure of the high-pressure air A1 supplied by the high-pressure air supply device for nozzle pressurization, and the pressure applied to the slurry S supplied by the slurry supply device 30 into the housing 21, so that the amount of slurry S supplied in the slurry supply conduit 35 approaches the target value.

[0060] First, the control device acquires detection data regarding the amount of slurry S supplied from the flow meter 36 (S1). Next, based on the detection data acquired in step S1, the control device determines whether the amount of slurry S supplied is greater than the target value (S2). If the amount of slurry S supplied is not greater than the target value (S2: NO), the control device proceeds to step S4. If the amount of slurry S supplied is greater than the target value (S2: YES), the control device controls the high-pressure air supply device to increase the pressure of the supplied high-pressure air A1 for nozzle pressurization and / or decrease the pressure of the supplied high-pressure air A2 for slurry pressurization (S3).

[0061] Next, the control device determines whether the amount of slurry S supplied is less than the target value based on the detection data acquired in step S1 (S4). If it determines that the amount of slurry S supplied is not less than the target value (S4: NO), the control device terminates control. If the amount of slurry S supplied is less than the target value (S4: YES), the control device controls the high-pressure air supply device to reduce the pressure of the supplied high-pressure air A1 for nozzle pressurization and / or increase the pressure of the supplied high-pressure air A2 for slurry pressurization (S5). After step S5, the control device terminates control.

[0062] According to the above configuration, the pressure inside the housing 21 can be made uniform, as can the pressure of the slurry S supplied to the slurry supply conduit 35. This makes it possible to make the injection pressure of the slurry mist M ejected from the slurry mist nozzle 28 uniform.

[0063] [Embodiment 2] Embodiment 2 of the present invention will be described below with reference to Figures 6 and 7. For the sake of clarity, components having the same function as those described in the above embodiment will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 6 shows the external appearance of the slurry mist injection nozzle 201. Figure 7 is a cross-sectional view along the line B-B shown in Figure 6.

[0064] The slurry mist injection nozzle 201 in Embodiment 2 differs from the slurry mist injection nozzle 20 in Embodiment 1 in that the slurry supply port 371 is formed on the end face of the slurry supply conduit 35.

[0065] As shown in Figure 6, the slurry mist spray nozzle 201 comprises a cylindrical housing 211. The housing 211 has a nozzle body 211A and a nozzle tip 211B. A high-pressure air supply conduit 15 is provided on the Z2 side (X2 side) of the nozzle body 211A. A high-pressure air supply port 261 is formed inside the nozzle body 211A, which connects to the high-pressure air supply conduit 15.

[0066] A slurry mist nozzle 281 is formed on the Z2 side of the nozzle tip 211B. The slurry mist nozzle 281 is formed in a circular shape at the Z2 end of the nozzle tip 211B. The opening area S6 of the slurry mist nozzle 281 is formed to be smaller than the opening area S4 of the high-pressure air supply port 261. In this embodiment, the high-pressure air A1 for nozzle pressurization flows in the direction (Z direction) from the high-pressure air supply port 261 toward the slurry mist nozzle 281.

[0067] A high-pressure air buffer section 221 is formed inside the nozzle body 211A. The high-pressure air buffer section 221 is connected to the high-pressure air supply port 261. The cross-sectional area of ​​the high-pressure air buffer section 221 is circular. The high-pressure air buffer section 221 is formed such that the cross-sectional area of ​​the high-pressure air buffer section 22 is larger than that of the high-pressure air supply port 26. 1 The cross-sectional area is constant in the flow direction of the high-pressure air A1 used for nozzle pressurization.

[0068] Inside the nozzle body 211A, a tapered section 231 is formed following the high-pressure air buffer section 221. The tapered section 231 has a circular cross-sectional area. The tapered section 23 is formed such that the cross-sectional area of ​​the tapered section 231 decreases as it approaches the slurry mist injection port 281. The tapered section 231 is formed in a hopper shape.

[0069] The nozzle tip 211B has a straight section 241 following the tapered section 231. The straight section 241 has a circular cross-sectional area. The cross-sectional area of ​​the straight section 241 is constant in the flow direction (Z direction) of the high-pressure air A1 for nozzle pressurization. 1 The end of the nozzle forms a slurry mist nozzle 281.

[0070] The cross-sectional area of ​​the flow path for the high-pressure air A1 for nozzle pressurization that flows inside the housing 211 is formed to be larger than or equal to the opening area S6 of the slurry mist injection port 281 from the high-pressure air supply port 261 to the slurry mist injection port 281. At the position where the slurry supply port 371 of the slurry supply conduit 35 is formed, the cross-sectional area of ​​the flow path for the high-pressure air A1 for nozzle pressurization is formed to be larger than the opening area S6 of the slurry mist injection port 281.

[0071] As shown in Figures 6 and 7, a slurry supply conduit 35 is drawn into the nozzle body 211A. One opening 271 is formed on the Z1 side of the nozzle body 211A. The slurry supply conduit 35 extends in the Z direction through the opening 271. The slurry supply conduit 35 is positioned within the nozzle body 211A so as to be concentric with the slurry mist injection port 281. The slurry supply conduit 35 is positioned so that its Z2 end face faces the slurry mist injection port 281. One slurry supply port 371 is formed on the Z2 end face of the slurry supply conduit 35. The slurry supply port 371 is circular in shape. The slurry supply port 371 is positioned so as to be concentric with the slurry mist injection port 281. Slurry supply conduit 35 It is formed in such a way. According to the above configuration, slurry mist M can be sprayed onto the workpiece more efficiently. As a result, it becomes possible to perform more uniform fine polishing on the workpiece.

[0072] As shown in Figure 6, the opening area S5 of the slurry supply port 371 is formed to be smaller than the opening area S4 of the high-pressure air supply port 261. Furthermore, the opening area S5 of the slurry supply port 371 is formed to be smaller than the opening area S6 of the slurry mist injection port 281.

[0073] [Embodiment 3] Embodiment 3 of the present invention will be described below with reference to Figures 8 and 9. For the sake of clarity, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 8 shows the external appearance of the slurry mist injection nozzle 202. Figure 9 is a cross-sectional view along the line C-C shown in Figure 8.

[0074] The slurry mist injection nozzle 202 in Embodiment 3 differs from the slurry mist injection nozzle 201 in Embodiment 2 in that multiple slurry supply ports 372 are formed in an annular shape on the end face of the slurry supply conduit 35.

[0075] As shown in Figure 8, the housing 21 1A slurry mist nozzle 282 is formed at the nozzle tip 212B. The slurry mist nozzle 282 is formed in an annular shape at the Z2 side end of the nozzle tip 212B. The opening area S8 of the slurry mist nozzle 282 is formed to be smaller than the opening area S4 of the high-pressure air supply port 261. In this embodiment, the high-pressure air A1 for nozzle pressurization flows in the direction (Z direction) from the high-pressure air supply port 261 toward the slurry mist nozzle 282.

[0076] As shown in Figures 8 and 9, the housing 21 1 (Nozzle body 211A) contains an opening 27 1 The slurry supply conduit 35 is drawn in through this. The slurry supply conduit 35 is positioned so that its Z2-side end face faces the slurry mist injection port 282. Multiple slurry supply ports 372 are formed on the Z2-side end face of the slurry supply conduit 35. 2 It is circular in shape. Multiple slurry supply ports 37 2 The slurry supply conduit 35 is formed in an annular shape on the Z2 side end face so as to be concentric with the slurry mist nozzle 282. With the above configuration, slurry mist M can be sprayed onto the workpiece more efficiently and over a wide area. As a result, it becomes possible to apply more uniform fine polishing to the workpiece over a wide area.

[0077] As shown in Figure 8, the opening area S7 of the slurry supply port 372 is equal to the high-pressure air supply port 26 1 It is formed to be smaller than the opening area S4. Also, the opening area S7 of the slurry supply port 372 is formed to be smaller than the opening area S8 of the annularly formed slurry mist injection port 282.

[0078] A tip rod portion 38 is provided at the Z2-side end face of the slurry supply conduit 35, extending toward the slurry mist nozzle 282. The tip rod portion 38 is provided concentrically with the slurry mist nozzle 282. As shown in Figure 9, the tip rod portion 38 extends to approximately the same position as the Z2-side end of the nozzle tip portion 212B. From the Z2-side end face of the slurry supply conduit 35, a tapered portion 23 1 Up to the end on the Z2 side, the tip rod portion 38 forms a cylindrical shape. The tip rod portion 38 located within the straight portion 242 is formed such that its diameter gradually increases as it approaches the slurry mist nozzle 282. That is, the tip rod portion 38 passing through the straight portion 242 has a shape that widens towards the slurry mist nozzle 282.

[0079] Straight section 24 formed at the nozzle tip 212B 2 The inner wall is formed such that its cross-sectional area gradually increases as it approaches the slurry mist nozzle 282. That is, the straight section 242 has a shape that widens towards the slurry mist nozzle 282. The flow path for the high-pressure air A1 for nozzle pressurization, formed by the straight section 242 and the tip rod section 38, is formed such that its cross-sectional area is constant in the flow direction (Z direction) of the high-pressure air A1 for nozzle pressurization. [Examples]

[0080] One embodiment of the present invention is described below.

[0081] In Example 1, ultrafine surface roughening was performed on a silicon wafer using the wet blasting apparatus 100 according to Embodiment 1 described above. In this example, abrasive slurry was prepared by adding white fused alumina powder with an average particle size of 0.5 μm to 0.7 μm and a dispersant to water and mixing for about 3 hours.

[0082] The prepared slurry was placed in a slurry pressurized tank 31, and the slurry mist M was sprayed onto a silicon wafer from a slurry mist spray nozzle 20. The slurry mist spray nozzle 20 had a width of 0.2 mm (Y direction) and a length of 150 mm (X direction).

[0083] The processing conditions for Example 1 are as follows. As shown below, after performing micro-polishing by changing the spray pressure conditions, the surface roughness of the processed surface was measured as the arithmetic mean roughness Ra and the ten-point mean roughness Rz as specified in JIS0601. • Distance from slurry mist spray nozzle 20 to the substrate: 30 mm • Movement speed of slurry mist spray nozzle 20: 8m / min • Movement range of slurry mist spray nozzle 20: 150mm • Silicon wafer transport speed (conveyor speed): 60 mm / min • Slurry injection volume: Approximately 0.7 liters / min • Injection pressure condition 1: Supply pressure to slurry mist injection nozzle 20: 0.05 MPa Supply pressure to slurry pressurized tank 31: 0.08 MPa • Injection pressure condition 2: Supply pressure to slurry mist injection nozzle 20: 0.1 MPa Supply pressure to slurry pressurized tank 31: 0.13 MPa • Injection pressure condition 3: Supply pressure to slurry mist injection nozzle 20: 0.15 MPa Supply pressure to slurry pressurized tank 31: 0.19 MPa • Injection pressure condition 4: Supply pressure to slurry mist injection nozzle 20: 0.2 MPa Supply pressure to slurry pressurized tank 31: 0.24 MPa The surface roughness after processing was measured using a Zygo laser interferometer (manufactured by Zygo Corporation).

[0084] Note that "distance from slurry mist spray nozzle 20 to substrate" refers to the distance from slurry mist spray port 28 to silicon wafer. Also, "supply pressure to slurry mist spray nozzle 20" refers to the pressure of the supplied high-pressure air A1 for nozzle pressurization, and "supply pressure to slurry pressurization tank 31" refers to the pressure of the supplied high-pressure air A2 for slurry pressurization.

[0085] The results of the machining roughness measurement were as follows: ·Before processing Ra:0nm Rz: 2.43nm ·Injection pressure condition 1 Ra: 1nm Rz: 5.68nm ·Injection pressure condition 2 Ra:3nm Rz:17.36nm ·Injection pressure condition 3 Ra:4nm Rz:32.76nm ·Injection pressure condition 4 Ra:6nm Rz:33.1 nm As described above, by changing the injection pressure, it was possible to create a uniform surface roughening process of any desired nano-order. [Examples]

[0086] An example of the present invention, specifically Example 2, is described below.

[0087] In this second embodiment, a pattern cutting process was performed on a silicon wafer using the wet blasting apparatus 100 according to the second embodiment described above. In this embodiment, abrasive slurry was prepared by adding white fused alumina powder with an average particle size of 0.5 μm to 0.7 μm and a dispersant to water and mixing for about 3 hours.

[0088] A photosensitive dry film for plating was laminated onto the tungsten thin film formation surface of a silicon wafer. Subsequently, the tungsten thin film formation surface of the silicon wafer was exposed to light and developed to form a photoresist pattern as shown in Figure 2.

[0089] The prepared slurry was placed in a slurry pressurized tank 31, and the prepared abrasive slurry was sprayed onto a silicon wafer patterned with dry film from a slurry mist spray nozzle 201, which is a round nozzle type with a slurry mist spray port 281 having a diameter of φ6 mm.

[0090] The processing conditions for Example 2 are as follows. Pattern cutting of a tungsten thin film was performed under the following conditions. • Distance from slurry mist spray nozzle 201 to the substrate: 30 mm • Movement speed of slurry mist spray nozzle 201: 8m / min • Movement range of slurry mist spray nozzle 201: 150 nm • Substrate transport speed (conveyor speed): 20 mm / min After processing, the dry film was peeled off, completing the pattern cutting process for the tungsten thin film.

[0091] Note that "distance from slurry mist spray nozzle 201 to substrate" refers to the distance from slurry mist spray port 281 to silicon wafer.

[0092] [Additional Notes] Generally, it is difficult to use abrasives with small average particle sizes in dry blasting equipment. For example, abrasives with an average particle size of 2 μm or less tend to aggregate, making it difficult to spray abrasives with an average particle size of 2 μm or less in dry blasting equipment. Furthermore, when recirculating and using sprayed abrasives with small average particle sizes, it is difficult to collect the sprayed abrasives with small particle sizes in dry blasting equipment. In contrast, with the wet blasting equipment described above, since the slurry with an average particle size of 2 μm or less is dispersed in water, it becomes possible to spray a slurry with an average particle size of 2 μm or less. Also, since the slurry with small average particle sizes is sprayed as a slurry mist together with water, it is possible to collect the sprayed slurry with small average particle sizes. This makes it possible to recirculate and use the slurry with small average particle sizes. Therefore, with the wet blasting equipment described above, it becomes possible to process the surface of a workpiece using a slurry with an average particle size of 2 μm or less.

[0093] Furthermore, in conventional wet blasting systems, pressure distribution occurred in the injection pressure of the high-pressure air within the slurry mist injection nozzle. Therefore, when using a slurry with a small average particle size, there was a problem in that the surface roughness of the workpiece after processing was not uniform due to differences in the injection speed of the slurry mist injected together with the high-pressure air. In contrast, with the wet blasting system of the present invention, the pressure of the high-pressure air within the slurry mist injection nozzle can be made uniform at a high pressure. Therefore, the injection pressure of the slurry mist injected from the slurry mist injection port can be made uniform. With the wet blasting system configured as described above, it is possible to perform more uniform surface processing on the surface of the workpiece at the nano-order level.

[0094] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0095] 10 Slurry processing device, 20 Slurry mist spray nozzle, 28 Slurry mist spray port, 21 Housing, 26 High-pressure air supply port, 31 Slurry pressurizing tank, 35 Slurry supply conduit, 37 Slurry supply port, A1 High-pressure air for nozzle pressurization, A2 High-pressure air for slurry pressurization

Claims

1. A housing having a high-pressure air supply port and a slurry mist spray port, The housing includes a slurry supply conduit that is drawn into the interior of the housing and has a slurry supply port formed on its end face, The opening area of ​​the slurry mist injection port is smaller than the opening area of ​​the high-pressure air supply port. The slurry supply conduit is positioned such that its end face faces the slurry mist nozzle. Multiple slurry supply ports are formed on the end face of the slurry supply conduit in an annular shape. A slurry mist spray nozzle characterized by the following features.

2. The slurry mist spray nozzle according to claim 1, characterized in that the opening area of ​​the slurry supply port is smaller than the opening area of ​​the high-pressure air supply port.

3. The slurry mist spray nozzle according to claim 2, characterized in that the opening area of ​​the slurry supply port is smaller than the opening area of ​​the slurry mist spray port.

4. The aforementioned enclosure is A slurry mist spray nozzle according to any one of claims 1 to 3, characterized in that it has a flow path through which high-pressure air flows, and the cross-sectional area of ​​the flow path is larger than or equal to the area of ​​the slurry mist spray port between the high-pressure air supply port and the slurry mist spray port.

5. The slurry mist spray nozzle according to claim 4, characterized in that the housing has a tapered portion in which the cross-sectional area of ​​the flow path decreases as it approaches the slurry mist spray port.

6. A slurry mist spray nozzle according to any one of claims 1 to 5, A high-pressure air supply device that supplies high-pressure air into the housing via the high-pressure air supply port, A wet blasting apparatus characterized by comprising a slurry supply device that supplies slurry into the housing via the slurry supply conduit.

7. The system further includes a control unit that controls the pressure of the high-pressure air supplied by the high-pressure air supply device and the pressure applied to the slurry supplied by the slurry supply device into the housing, so that the amount of slurry supplied in the slurry supply conduit approaches a target value. The wet blast apparatus according to feature 6.

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