Wafer cleaning device with bearing water lubrication

Abstract

The application provides a wafer cleaning device with bearing water lubrication, which comprises a box body, a cleaning assembly and a draining device. The box body is internally used for containing wafers and providing a space for wafer cleaning. The cleaning assembly comprises two horizontally arranged roll brushes located on both sides of the wafer. The roll brush has a driving end and a liquid inlet end. The roll brush rotates along its axial direction under the driving of the driving part located at the driving end, and performs rolling scrubbing on the wafer surface. The end of the liquid inlet end is connected with a liquid inlet end cover. The outer periphery of the liquid inlet end is provided with a bearing assembly. The bottom of the bearing assembly is provided with the draining device. The cleaning liquid is introduced into the liquid inlet end through the liquid inlet end cover. At least part of the cleaning liquid flows into the roll brush, and the remaining cleaning liquid is discharged by the draining device after passing through the bearing assembly. The draining device is arranged at the liquid inlet end of the roll brush, so that the fluid flows out from the bottom of the draining device after passing through the bearing assembly. The wafer pollution risk is reduced by preventing the cleaning liquid from flowing into the box body while achieving water lubrication of the bearing assembly.

Description

Technical Field

[0001] This invention belongs to the field of wafer manufacturing technology, and more specifically, relates to a wafer cleaning device for achieving water lubrication of bearings. Background Technology

[0002] The integrated circuit industry is the core of the information technology industry, playing a crucial role in promoting the digital and intelligent transformation and upgrading of the manufacturing industry. Chips are the carriers of integrated circuits, and chip manufacturing involves processes such as chip design, wafer fabrication, wafer processing, electrical measurement, dicing, packaging, and testing. Among these, chemical mechanical polishing (CMP) is a wafer fabrication process, a globally planarizing ultra-precision surface processing technology.

[0003] After chemical mechanical polishing (CMP), wafers require post-processing such as cleaning and drying. The purpose of wafer cleaning is to prevent contamination of semiconductor devices by trace ions and metal particles, ensuring the performance and yield of the semiconductor devices. Wafer cleaning methods include roller brush cleaning and megasonic cleaning, among which roller brush cleaning is more widely used. Based on the wafer's placement, roller brush cleaning can be divided into vertical roller brush cleaning and horizontal roller brush cleaning. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes a wafer cleaning apparatus for achieving water lubrication of bearings.

[0005] This invention provides a wafer cleaning apparatus for achieving water lubrication of bearings, comprising:

[0006] The enclosure, whose interior is used to house the wafers and provide space for wafer cleaning;

[0007] The cleaning assembly includes two horizontally arranged roller brushes located on both sides of the wafer. Each roller brush has a drive end and a liquid inlet end. The roller brushes rotate along their axial direction under the drive of a drive unit located at their drive end, and perform rolling scrubbing on the wafer surface.

[0008] The liquid inlet end is connected to the liquid inlet end cap, and a bearing assembly is arranged on the outer periphery of the liquid inlet end. A drainage device is arranged at the bottom of the bearing assembly. The cleaning liquid is introduced into the liquid inlet end through the liquid inlet end cap, at least part of the cleaning liquid flows into the roller brush, and the remaining cleaning liquid passes through the bearing assembly and is discharged by the drainage device.

[0009] In some embodiments, the roller brush includes a support shaft and a sponge wrapping the support shaft, the bearing assembly is sleeved on the outer periphery of one end of the support shaft, and the support shaft rotates under the drive of the drive member.

[0010] In some embodiments, the outer wall of the support shaft is provided with a plurality of liquid outlet holes, through which the cleaning fluid enters the sponge.

[0011] In some embodiments, the liquid inlet cap has an injection channel inside, the support shaft has an axially extending liquid inlet channel inside, and the outlet of the liquid inlet channel is connected to the injection channel.

[0012] A buffer chamber is provided between the liquid inlet channel and the liquid injection channel, and a liquid passage is formed between the buffer chamber and the bearing assembly, through which at least a portion of the cleaning fluid flows into the bearing assembly.

[0013] In some embodiments, the bearing assembly is located on the outer periphery of the end of the support shaft that extends beyond the housing.

[0014] In some embodiments, a sleeve is provided on the outer periphery of the bearing assembly to fix the bearing assembly to the outer periphery of the support shaft;

[0015] The drainage device is fixed to the bottom of the sleeve.

[0016] In some embodiments, a fixed end cap is provided on the side of the sleeve near the housing, and the sleeve is fixed to the side wall of the housing by the fixed end cap.

[0017] In some embodiments, a leakage slit is formed between the support shaft and the side wall of the housing, and a drainage slit is formed between the outer periphery of the bearing assembly and the drainage device, wherein the leakage slit is higher than the drainage slit;

[0018] The cleaning fluid passes through the bearing assembly to lubricate it with water, and then is discharged through the drainage slit by the drainage device.

[0019] In some embodiments, the interior of the housing is further provided with a drive assembly, which is used to define the vertical plane in which the wafer is located and drive the wafer to rotate.

[0020] In some embodiments, the driving assembly includes a driving wheel and a speed measuring wheel that contact the edge of the wafer. The driving wheel is used to define and drive the wafer to rotate along its axis in a vertical plane, and the speed measuring wheel is passively rotated under the drive of the wafer.

[0021] Compared with the prior art, the beneficial effects of the present invention include:

[0022] Based on the existing structure of wafer cleaning equipment, this invention rationally plans the water flow direction and water channel arrangement at the inlet end of the roller brush, allowing a portion of the cleaning fluid entering the roller brush to flow into the bearing assembly for water lubrication. Furthermore, to prevent residual cleaning fluid from flowing into the housing after water lubrication, this embodiment incorporates a drainage device at the inlet end of the roller brush. This allows the fluid to flow through the bearing assembly and exit from the drainage device at the bottom, achieving water lubrication of the bearing assembly while preventing cleaning fluid from flowing into the housing, thus reducing the risk of wafer contamination. Attached Figure Description

[0023] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0024] Figure 1 This diagram shows the internal structure of an existing wafer cleaning device;

[0025] Figure 2 A perspective view of the liquid inlet end of an existing roller brush is shown;

[0026] Figure 3 A three-dimensional cross-sectional view of the liquid inlet end of an existing roller brush is shown;

[0027] Figure 4 A planar cross-sectional view of the liquid inlet end of an existing roller brush is shown;

[0028] Figure 5 A schematic diagram of the cleaning components of an existing wafer cleaning apparatus is shown.

[0029] Figure 6 A simplified structural diagram of the roller brush in an existing wafer cleaning device is shown;

[0030] Figure 7 A planar sectional view of the liquid inlet end of a roller brush provided in an embodiment of the present invention is shown;

[0031] Figure 8 A perspective view of the liquid inlet end of a roller brush according to an embodiment of the present invention is shown;

[0032] Figure 9 A planar sectional view of the liquid inlet end of a roller brush provided in an embodiment of the present invention is shown;

[0033] Figure 10 A perspective sectional view of the liquid inlet end of a roller brush provided in an embodiment of the present invention is shown. Detailed Implementation

[0034] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0035] The accompanying drawings in this specification are schematic diagrams to aid in illustrating the concept of the invention, and schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly demonstrate the structure of the components in the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings. The technical solutions of the invention will be further described below through specific embodiments.

[0036] It should be understood that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In this invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)," and the wafer (W) is also called the substrate (Substrate), with the same meaning and actual function.

[0039] The working principle of chemical mechanical polishing is as follows: a polishing slurry composed of submicron or nano abrasive particles and a chemical solution flows between the wafer w and the polishing pad. The polishing slurry is uniformly distributed under the action of the transmission and centrifugal force of the polishing pad to form a liquid film between the wafer w and the polishing pad. The chemical components in the polishing slurry react with the wafer w, converting insoluble substances into soluble substances. Then, through the micromechanical friction of the abrasive particles, these chemical reactants are removed from the surface of the wafer w and dissolved into the flowing polishing slurry and carried away. In the alternating process of chemical film formation and mechanical film removal, surface material is removed to achieve surface planarization, thereby achieving the purpose of global planarization.

[0040] After chemical mechanical polishing, wafers need to undergo post-processing such as cleaning and drying. The purpose of this is to avoid contamination of semiconductor devices by trace ions and metal particles, and to ensure the performance and yield of semiconductor devices.

[0041] exist Figure 1 The illustrated embodiment provides a conventional wafer cleaning apparatus, comprising: a housing 100 having an internal cavity for cleaning a wafer w; a cleaning assembly 400 including roller brushes 410 located on both sides of the wafer w; a drive assembly 300 located below the cleaning assembly 400 and in contact with the edge of the wafer w, for supporting and limiting the rotation of the wafer w in a vertical plane; and a spray assembly for spraying cleaning fluid onto the surface of the wafer w.

[0042] Specifically, such as Figure 1 As shown, the cleaning assembly 400 includes two roller brushes 410, which are respectively disposed on the two side surfaces of the wafer w. The two roller brushes 410 rotate in opposite directions to perform rolling brushing on the surface of the wafer w. Particularly preferably, the rotation direction of the two roller brushes 410 is opposite to that of the wafer w surface, so that the roller brushes 410 generate an upward frictional force on the wafer w when rotating, thereby maximizing the relative speed between the roller brushes 410 and the wafer w in the area where the cleaning fluid falls, thus improving the cleaning effect.

[0043] exist Figure 6 In the illustrated embodiment, the roller brush 410 includes a support shaft 411 and a sponge 413 covering the outer periphery of the support shaft 411. Figure 5As shown, the roller brush 410 has a drive end 500 and a liquid inlet end 200. Driven by a drive unit located at its drive end 500, the roller brush 410 rotates along its axial direction, performing contact-type rolling scrubbing on the surface of the wafer w. A bearing assembly 240 is fitted around the outer periphery of the portion of the liquid inlet end 200 extending out of the housing 100. A sleeve 220 is disposed around the outer periphery of the bearing assembly 240 to fix the bearing assembly 240 to the outer periphery of the liquid inlet end 200 (e.g., ...). Figure 2 , Figure 3 and Figure 4 (As shown).

[0044] exist Figure 3 and Figure 4 In the embodiment shown, a liquid inlet cap 210 is provided at the end of the sleeve 220 away from the housing 100. A liquid injection channel 213 is provided inside the liquid inlet cap 210. The liquid injection channel 213 is connected to the support shaft 411 and liquid (cleaning liquid or rinsing liquid) is supplied to the inside of the support shaft 411 through the liquid injection channel 213.

[0045] like Figure 6 As shown, several liquid outlet holes 414 are evenly distributed on the support shaft 411 so that the cleaning fluid in the support shaft 411 can pass through the liquid outlet holes 414 to reach the sponge 413 and seep out from the sponge 413, thereby moisturizing the roller brush 410 and forming a liquid film on the surface of the sponge 413 to prevent the sponge 413 from directly contacting the wafer and causing contaminants on the sponge 413 to stick back and contaminate the wafer w.

[0046] like Figure 2 As shown, a fixed end cap 230 is provided at one end of the sleeve 220 near the housing 100. The fixed end cap 230 cooperates with the liquid inlet end cap 210 to fix the sleeve 220. Under the action of the bearing assembly 240, the liquid inlet end 200 of the roller brush 410 rotates inside the sleeve 220 while the sleeve 220, the liquid inlet end cap 210 and the fixed end cap 230 remain stationary.

[0047] like Figure 4 As shown, the liquid inlet cap 210 has an extended injection shaft 212 and an annular sidewall 214 surrounding the injection shaft 212 on one side, forming an annular groove 215 between the injection shaft 212 and the annular sidewall 214. The liquid inlet cap 210 has a vertical first passage inside, and the injection shaft 212 has a horizontal second passage inside. One end of the second passage is perpendicularly connected to the bottom end of the first passage to form an L-shaped injection channel 213, and the other end of the second passage is connected to the liquid inlet channel 412 of the support shaft 411.

[0048] The bottom of the liquid inlet cap 210 is also provided with a drain outlet 217. The drain outlet 217 is connected to the annular groove 215 through the third passage 216 inside the liquid inlet cap 210 to discharge the cleaning fluid that enters the annular groove 215. During the continuous supply of cleaning fluid to the support shaft 411, the cleaning fluid that seeps out from the gaps collects in the annular groove 215 and is discharged from the drain outlet 217 through the third passage 216, preventing the cleaning fluid from entering the housing 100.

[0049] The top of the sleeve 220 is provided with a ventilated air-sealing channel 222. One end of the air-sealing channel 222 is connected to the air inlet 221 on the sleeve 220, and the other end of the air-sealing channel 222 is connected to the bearing assembly 240. The air-sealing channel 222 can achieve air sealing in the gap between the bearing assembly 240, the support shaft 411 and the liquid injection shaft 212, thereby preventing the cleaning fluid from entering the housing 100 through the gap between the bearing assembly 240, the support shaft 411 and the liquid inlet end cap 210.

[0050] like Figure 1 As shown, the drive assembly 300 includes two drive wheels 310 and a speed measuring wheel 320. The speed measuring wheel 320 is located at the bottom edge of the wafer w, and the two drive wheels 310 are symmetrically arranged on both sides of the speed measuring wheel 320 with the speed measuring wheel 320 as the center.

[0051] During wafer cleaning, two drive wheels 310 rotate under the drive of their respective drive motors. The roller brushes 410 on both sides of wafer w contact the surface of wafer w and rotate around their axes. Under the action of friction, wafer w, vertically positioned in the gap between the two roller brushes 410, rotates around its axis. The rolling roller brushes 410 contact the rotating wafer w to remove contaminants from its surface. During wafer w's rotation, the speed measuring wheel 320 is passively rotated. A rear-mounted sensor calculates the number of rotations of the speed measuring wheel 320, thereby estimating the rotational speed of wafer w and monitoring its cleaning status.

[0052] Specifically, the spray assembly includes two spray bars (not shown in the figure) located above the cleaning assembly 400 and parallel to each other. Multiple nozzles are evenly distributed on the spray bars, and the cleaning liquid sprayed by the nozzles at least covers the contact area between the cleaning assembly 400 and the wafer w.

[0053] The above describes the structure of existing wafer cleaning equipment. As can be seen from the above, the structure of the inlet cap 210 in the existing wafer cleaning equipment prevents the cleaning fluid from entering the bearing assembly 240. The cleaning fluid enters the roller brush 410 directly through the injection channel 213, while the cleaning fluid seeping out from the gaps collects in the annular groove 215 before entering the bearing assembly 240 and is discharged through the outlet 217. Simultaneously, the design of the air-sealed channel 222 effectively prevents the cleaning fluid from entering the bearing assembly 240. Therefore, the existing wafer cleaning equipment cannot achieve water lubrication of the bearing assembly 240. After long-term use, insufficient lubrication of the bearing assembly 240 after roller brush 410 will affect the rotation of roller brush 410, thereby affecting wafer cleaning.

[0054] At least to solve the above-mentioned technical problems, embodiments of the present invention provide a method such as Figure 4-7 The wafer cleaning apparatus shown can achieve water lubrication of the bearing assembly 240. Specifically, the wafer cleaning apparatus provided in this embodiment includes:

[0055] The enclosure 100 has an interior space for accommodating the wafer w and providing space for cleaning the wafer w.

[0056] The cleaning assembly 400 includes two horizontally arranged roller brushes 410 located on both sides of the wafer w. Each roller brush 410 has a drive end 500 and a liquid inlet end 200. The roller brushes 410 rotate along their axial direction under the drive of a drive member located at their drive end 500 to perform rolling scrubbing on the surface of the wafer w.

[0057] The liquid inlet end 200 of the roller brush 410 is connected to the liquid inlet end cover 210. The outer periphery of the liquid inlet end 200 is equipped with a bearing assembly 240. After the cleaning fluid is introduced through the liquid inlet end cover 210, at least part of the cleaning fluid flows into the roller brush 410, and the remaining cleaning fluid passes through the bearing assembly 240 to lubricate the bearing assembly 240 with water.

[0058] A spray assembly, located above the cleaning assembly 400, is used to spray DIW and / or cleaning fluid onto the wafer w.

[0059] The drive component 300, located inside the housing 100, is used to define the vertical plane where the wafer w is located and drive the wafer w to rotate.

[0060] This embodiment is in Figure 2-4 Based on the existing structure of the wafer cleaning device, the water flow direction and water channel arrangement of the liquid inlet end 200 of the roller brush 410 are reasonably planned so that a portion of the cleaning fluid entering the roller brush 410 can flow into the bearing assembly 240 to lubricate the bearing assembly 240 with water.

[0061] The following is a brief description of the specific structure of the roller brush 410, the spray assembly, and the drive assembly 300:

[0062] Structural reference for roller brush 410 Figure 6 The roller brush 410 structure provided in this embodiment is the same as the existing roller brush 410 structure, including a support shaft 411 and a sponge 413 that wraps around the support shaft 411. The sponge 413 has a cylindrical structure and is made of a material with good water absorption, such as polyvinyl alcohol (PVA). The outer wall of the support shaft 411 has multiple liquid outlet holes 414. The cleaning liquid enters the sponge 413 through the liquid outlet holes 414 to moisturize the sponge 413.

[0063] It should be noted that this embodiment does not impose specific requirements or limitations on the number and arrangement of the liquid outlet holes 414. The design of the number of liquid outlet holes 414 needs to be adaptively adjusted according to the size of the support shaft 411 and the liquid outlet requirements. The arrangement of the liquid outlet holes 414 can be in a straight line with equal or unequal spacing along the radial direction of the support shaft 411, or in a single spiral or multiple spiral pattern with equal or unequal spacing along the outer periphery of the support shaft 411. The above is only an exemplary description. It is understood that other arrangement methods other than those described above also fall within the protection and disclosure scope of this embodiment.

[0064] Two roller brushes 410 are respectively positioned on both sides of the wafer w to be cleaned, and can roll around their own axes to contact and clean the surface of the wafer w. The roller brushes 410 soften after being filled with liquid to clean the wafer w, so it is necessary to keep the roller brushes 410 filled with liquid at all times during the cleaning process.

[0065] The roller brushes 410 located on both sides of the wafer w can move horizontally to move away from or towards the wafer w. When the roller brushes 410 move away from the wafer w, a certain gap is maintained between the roller brushes 410 and the wafer w, allowing the wafer w handling robot to grip the wafer w to remove the cleaned wafer w or place the uncleaned wafer w. When the roller brushes 410 move towards the wafer w, the roller brushes 410 come into contact with the wafer w and perform cleaning of the wafer w surface through contact.

[0066] The spray assembly may include multiple nozzles, the spray direction of which matches the rotation direction of the wafer w. The nozzles can spray at different angles toward the surface of the wafer w to ensure that the sprayed fluid fully covers the surface of the wafer w. When the spray assembly sprays the cleaning fluid, the cleaning fluid completely covers the surface of the wafer w.

[0067] Structural reference of drive component 300 Figure 1 The drive assembly 300 includes a drive wheel 310 and a speed measuring wheel 320 that are in contact with the edge of the wafer w. The drive wheel 310 is used to define and drive the wafer w to rotate along its axis in a vertical plane, and the speed measuring wheel 320 is passively rotated under the drive of the wafer w.

[0068] Two drive wheels 310 are symmetrically arranged on both sides of the speed measuring wheel 320, and abut against the lower edge of the wafer w to support the wafer w in the vertical direction. Driven by a drive motor, the two drive wheels 310 rotate, and under the action of friction, the wafer w rotates around its axis. The two drive wheels 310 are aligned in a straight line. The speed measuring wheel 320 is located below the two drive wheels 310. A sensor is mounted on the speed measuring wheel 320, which passively rotates under the rotation of the wafer w. The rotational speed of the wafer w is measured by a testing module to monitor the operating status of the wafer w in the wafer cleaning device.

[0069] The most significant difference between this embodiment and the wafer cleaning apparatus disclosed in the prior art lies in the structure of the liquid inlet end 200 of the roller brush 410, especially the structure of the liquid inlet end cover 210. The internal structure of the liquid inlet end cover 210 is described in detail below:

[0070] exist Figure 7 In the illustrated embodiment, a bearing assembly 240 is mounted on the support shaft 411. The bearing assembly 240 is sleeved on the outer periphery of the support shaft 411, thereby enabling the rotation of the support shaft 411. The bearing assembly 240 includes two bearings 241 placed side by side and a spacer 242 located between the two bearings 241.

[0071] A sleeve 220 is provided on the outer periphery of the bearing assembly 240 to fix the bearing assembly 240. A fixed end cap 230 is provided on the side of the sleeve 220 near the housing 100, and a liquid inlet end cap 210 is provided on the side of the sleeve 220 away from the housing 100. A liquid injection channel 213 is opened inside the liquid inlet end cap 210, and a through liquid inlet channel 412 is formed axially inside the support shaft 411. The outlet of the liquid inlet channel 412 is connected to the liquid injection channel 213, and cleaning fluid is injected into the support shaft 411 through the liquid injection channel 213 of the liquid inlet end cap 210.

[0072] The liquid inlet cap 210 has a horizontally extending injection shaft 212 and an annular groove 215 surrounding the injection shaft 212 on one side surface near the bearing assembly 240. The position of the injection shaft 212 corresponds to the position of the end of the support shaft 411, and the annular groove 215 communicates with the bearing assembly 240.

[0073] The injection channel 213 is an L-shaped channel formed by the connection of a first channel and a second channel. The inlet cap 210 has a longer first channel vertically connected inside, with the top of the first channel serving as the injection port 211. The injection shaft 212 has a shorter second channel horizontally connected inside. The bottom of the first channel and the end of the second channel are perpendicularly connected to form the L-shaped injection channel 213.

[0074] The support shaft 411 has a central through hole at one end near the liquid inlet end cap 210. The central through hole is coaxial with the liquid inlet channel 412 and the diameter of the central through hole is larger than the diameter of the liquid inlet channel 412, so that a stepped surface is formed between the central through hole and the liquid inlet channel 412.

[0075] At least a portion of the injection shaft 212 is inserted into the central through hole at one end of the support shaft 411, with a certain gap maintained between the end face of the injection shaft 212 and the bottom surface of the central through hole to form a buffer cavity 218. The central through hole of the support shaft 411 surrounds the outer periphery of the injection shaft 212 and extends into the annular groove 215. A certain gap is maintained between the end face of the support shaft 411 and the bottom surface of the annular groove 215 to connect the buffer cavity 218 and the annular groove 215, allowing the cleaning fluid to flow from the buffer cavity 218 into the annular groove 215, and then from the annular groove 215 into the area where the bearing assembly 240 is located.

[0076] Figure 7 In the embodiment shown, the cleaning fluid flow path is as follows: the cleaning fluid flows out from the outlet end of the injection channel 213 and enters the buffer chamber 218. The cleaning fluid is distributed in the buffer chamber 218. A portion of the cleaning fluid flows horizontally into the inlet channel 412 to wet the roller brush 410, and another portion of the cleaning fluid flows downward into the annular groove 215 and enters the gap of the bearing assembly 240 through the annular groove 215 to lubricate the bearing assembly 240 with water.

[0077] and Figure 2-4 Compared to existing wafer cleaning equipment, Figure 7 The provided wafer cleaning device can achieve water lubrication of the bearing assembly 240. Figure 2-4 The residual cleaning fluid in the existing wafer cleaning equipment will be discharged through the outlet 217 at the bottom of the inlet end cap 210, making it impossible to achieve water lubrication of the bearing assembly 240. Figure 7 In the provided embodiment, by setting a buffer cavity 218, the cleaning fluid injected into the liquid inlet end cap 210 can be distributed in a secondary manner, thereby achieving both moisturizing of the roller brush 410 and water lubrication of the bearing assembly 240.

[0078] but Figure 7 The provided wafer cleaning device also had problems during actual use. Specifically, after the cleaning fluid flowed through the bearing assembly 240, it continued to flow into the housing 100 through the natural gap (leakage slit 250) formed between the support shaft 411 and the fixed end cap 230. Figure 7 (The middle arrow indicates the direction of the cleaning fluid flow). Because the residual cleaning fluid after lubrication carries particles generated by the wear of the bearing assembly 240, it forms a contaminated fluid. After flowing into the housing 100, it will cause secondary contamination to the wafer w.

[0079] To ensure water lubrication of the bearing assembly 240 while preventing cleaning fluid after lubrication from entering the housing 100, this embodiment... Figure 7 Further improvements were made by incorporating a drainage device 270 at the bottom of the sleeve 220. This allows the lubricated cleaning fluid to drain out before seeping into the housing 100, preventing it from flowing into the housing 100 (e.g., ...). Figure 8-10 (As shown).

[0080] Therefore, the flow path of the cleaning fluid at the inlet end 200 of the roller brush 410 is as follows: Figure 9 As shown:

[0081] The cleaning fluid is introduced through the injection port 211 at the top of the first passage, flows out through the second passage and enters the buffer cavity 218 between the injection shaft 212 and the support shaft 411. Part of the cleaning fluid enters the inlet channel 412 of the support shaft 411 through the central through hole to moisturize the roller brush 410. Another part of the cleaning fluid flows downward into the annular groove 215 through the gap at the bottom of the buffer cavity 218, and enters the area where the bearing assembly 240 is located through the annular groove 215. The cleaning fluid passes radially through each bearing 241 along the bearing assembly 240 to lubricate the bearing 241 with water. The residual cleaning fluid after lubrication is discharged by the drainage device 270.

[0082] It should be noted that this embodiment does not impose specific requirements or limitations on the structure of the drainage device 270. For example, it can be a drainage pipe or a collection tank, or other structural components that can achieve the function of draining and draining liquid. At the same time, it is also necessary to ensure that the gap between the drainage device 270 and the bearing assembly 240 is of a certain width, so that the cleaning liquid can enter the drainage device 270 through the gap before entering the housing 100 after flowing through the bearing assembly 240, and be discharged by the drainage device 270.

[0083] The drainage device 270 should include at least a connector located below the sleeve 220 and a drain line mating with the connector, the connector being detachably connected to the sleeve 220. The drain line may optionally be equipped with a valve, such as a snap-fit ​​or other type of flow control valve, to control the inflow rate.

[0084] Specifically, the following combination Figure 8-10 The internal structure of the liquid inlet end 200 of the improved roller brush 410 is described in detail below:

[0085] exist Figure 8 In the illustrated embodiment, the drainage device 270 is located at the bottom of the sleeve 220 and can be integrally formed with or separate from the sleeve 220. A horizontal drainage slit 260 is formed between the inner circumferential surface of the sleeve 220 and the outer circumferential surface of the bearing assembly 240. The drainage slit 260 communicates with the drainage device 270, and the cleaning fluid flowing through the bearing assembly 240 flows into the drainage device 270 through the drainage slit 260.

[0086] exist Figure 9 In the indicated orientation, a portion of the fluid flows axially to the left along the bearing assembly 240, passing sequentially through the two bearings 241 to lubricate the balls within the bearings 241. The residual cleaning fluid after lubrication flows downwards under gravity, then flows horizontally to the right through the drainage slit 260 into the drainage device 270 and is discharged. This prevents the fluid from continuing to flow to the left into the housing 100 after passing through the bearing assembly 240, effectively preventing contaminated cleaning fluid from flowing into the housing 100 while achieving water lubrication.

[0087] Furthermore, in order to ensure that the cleaning fluid flows completely into the drainage device 270, this embodiment requires that the leakage slit 250 be higher than the drainage slit 260. After the cleaning fluid passes through the bearing assembly 240 to lubricate the bearing assembly 240 with water, it is discharged from the drainage device 270 through the drainage slit 260, and will not flow into the interior of the housing 100 through the leakage slit 250.

[0088] Based on this, this embodiment can also balance the inflow and outflow volumes by adjusting the ratio of the gap width of the drainage slit 260 to the gap width of the leakage slit 250. It is conceivable that the gap width of the drainage slit 260 should be greater than the gap width of the leakage slit 250. Utilizing the height difference between the drainage slit 260 and the leakage slit 250, the cleaning fluid is ensured to flow entirely out through the drainage slit 260 under its own gravity, preventing excess cleaning fluid from overflowing and entering the tank 100 through the leakage slit 250 due to excessive inflow.

[0089] The specific operation process of the wafer cleaning apparatus provided in this embodiment includes:

[0090] (1) The robot arm places the wafer w to be cleaned on the drive assembly 300. At this time, the roller brush 410 leaves a certain distance from the side of the wafer w to provide working space for the robot arm. Under the action of friction, the drive assembly 300 drives the wafer w to rotate around its axis. The spray assembly sprays cleaning liquid, such as acidic or alkaline cleaning liquid, toward the rotating wafer w.

[0091] (2) The roller brush 410 rolls around its axis and moves toward the position of the wafer w, so that the roller brush 410 contacts the surface of the wafer w; the roller brush 410 rolls and brushes the surface of the wafer w to remove contaminants from the surface of the wafer w, thereby achieving surface brushing of the wafer w.

[0092] (3) During the wafer cleaning process, cleaning fluid is injected into the liquid injection channel 213 of the liquid inlet end cap 210 through the liquid injection port 211. The cleaning fluid flows into the buffer cavity 218. Part of the cleaning fluid enters the liquid inlet channel 411 of the support shaft 411 and is discharged from the liquid outlet 414 into the sponge 413 to moisturize the roller brush 410. Another part of the cleaning fluid flows down into the annular groove 215 through the gap at the bottom of the buffer cavity 218 and enters the area where the bearing assembly 240 is located through the annular groove 215. The cleaning fluid passes through each bearing 241 radially along the bearing assembly 240 to lubricate the bearing 241 with water. The residual cleaning fluid after lubrication is discharged by the drainage device 270.

[0093] (4) After the wafer w is cleaned, the roller brush 410 moves toward the outside of the wafer w and separates from the surface of the wafer w; the spray assembly continues to spray cleaning fluid toward the rotating wafer w. After a period of time, the robot transfers the cleaned wafer w to the next process.

[0094] The applicant declares that the above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A wafer cleaning apparatus for achieving water lubrication of bearings, characterized in that, include: The enclosure, whose interior is used to house the wafers and provide space for wafer cleaning; The cleaning assembly includes two horizontally arranged roller brushes located on both sides of the wafer. Each roller brush has a support shaft, a drive end, and a liquid inlet end. The support shaft has a through-flow liquid inlet channel formed axially inside. The roller brushes rotate axially under the drive of a drive unit located at their drive end to perform rolling scrubbing on the wafer surface. The liquid inlet end is connected to the liquid inlet end cap, and a bearing assembly is provided on the outer periphery of the liquid inlet end. A drainage device is provided at the bottom of the bearing assembly. A central through hole is provided at one end of the support shaft near the liquid inlet end cap. The diameter of the through hole is larger than the diameter of the liquid inlet channel, so that a stepped surface is formed between the central through hole and the liquid inlet channel. The liquid inlet end cap has a horizontally extending injection shaft and an annular groove around the injection shaft on one side surface near the bearing assembly. At least part of the injection shaft is inserted into the central through hole at one end of the support shaft. A certain gap is maintained between the end face of the injection shaft and the bottom surface of the central through hole to form a buffer cavity. The liquid inlet end cap has an injection channel inside that penetrates the end face of the injection shaft. A certain gap is maintained between the end face of the support shaft and the bottom surface of the annular groove to connect the buffer cavity and the annular groove. A drainage slit is formed between the drainage device and the bearing assembly. The cleaning fluid is introduced into the buffer cavity through the injection channel. At least part of the cleaning fluid flows into the roller brush, and the remaining cleaning fluid flows from the buffer cavity into the annular groove and then into the area where the bearing assembly is located. It then passes radially through the bearing assembly for water lubrication and finally enters the drainage device through the drainage slit and is discharged from the drainage device.

2. The wafer cleaning apparatus according to claim 1, characterized in that, The roller brush includes a sponge that wraps around the support shaft, the bearing assembly is sleeved on the outer periphery of one end of the support shaft, and the support shaft rotates under the drive of the drive member.

3. The wafer cleaning apparatus according to claim 2, characterized in that, The outer wall of the support shaft has multiple liquid outlet holes, through which the cleaning fluid enters the sponge.

4. The wafer cleaning apparatus according to any one of claims 1-3, characterized in that, The bearing assembly is located on the outer periphery of the end of the support shaft that extends beyond the outside of the housing.

5. The wafer cleaning apparatus according to any one of claims 1-3, characterized in that, A sleeve is provided on the outer periphery of the bearing assembly to fix the bearing assembly to the outer periphery of the support shaft; The drainage device is fixed to the bottom of the sleeve.

6. The wafer cleaning apparatus according to claim 5, characterized in that, The sleeve is provided with a fixed end cap on the side near the box body, and the fixed end cap is used to fix the sleeve to the side wall of the box body.

7. The wafer cleaning apparatus according to any one of claims 1-3, characterized in that, A leakage slit is formed between the support shaft and the side wall of the housing. The leakage slit is higher than the drainage slit, so that after the cleaning fluid flows through the bearing assembly, it enters the drainage device through the drainage slit before entering the housing, and is discharged by the drainage device. Thus, the cleaning fluid will not enter the housing and cause secondary contamination to the wafer.

8. The wafer cleaning apparatus according to any one of claims 1-3, characterized in that, The housing is also equipped with a drive assembly, which is used to define the vertical plane where the wafer is located and drive the wafer to rotate.

9. The wafer cleaning apparatus according to claim 8, characterized in that, The drive assembly includes a drive wheel and a speed measuring wheel that contact the edge of the wafer. The drive wheel is used to define and drive the wafer to rotate along its axis in a vertical plane, and the speed measuring wheel is passively rotated under the drive of the wafer.

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