A grinding fluid supply device and method

Abstract

This invention discloses a grinding slurry supply device and method. The device includes a mixing tank and a supply tank sequentially arranged on a grinding slurry supply pipeline. The mixing tank is configured to rotate axially when driven. A protruding first stirring part is provided on the inner side wall of the mixing tank to provide stirring force to the grinding slurry in the mixing tank during rotation, so that the grinding particles in the grinding slurry are in a uniformly dispersed state. This invention can significantly enhance the stirring ability of the grinding slurry and effectively prevent the risk of clogging the grinding slurry supply pipeline, ensuring the stability of the grinding slurry flow rate during supply.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, and more particularly to a polishing fluid supply device and method. Background Technology

[0002] Existing polishing slurry supply systems involve a period of settling during the transfer of the slurry from the mixing tank to the supply tank, and again during its use within the supply tank. This allows polishing particles to easily aggregate into large particles, causing scratches on the wafer surface and abnormal polishing speeds during grinding. Methods to reduce this particle aggregation typically involve stirring the slurry in the tank and using a pump to circulate it, ensuring the slurry remains in a flowing state. Furthermore, filtration during the supply process reduces the impact of large particles on the process. However, due to the limited space within the tank, existing stirring methods are relatively weak and cannot achieve sufficient dispersion of the polishing particles. The circulation pump also has limitations in speed, requiring a considerable amount of time to achieve uniform particle dispersion, resulting in low efficiency. Additionally, prolonged use of the filter carries the risk of clogging, increasing pipeline pressure and causing unstable flow rates during slurry supply. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects in the prior art and to provide a grinding fluid supply device and method.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: The present invention provides a grinding fluid supply device, comprising a mixing tank and a supply tank sequentially disposed on a grinding fluid supply pipeline. The mixing tank is configured to rotate axially when driven. A first stirring part is provided on the inner side wall of the mixing tank for providing stirring force to the grinding fluid in the mixing tank during rotation, so that the grinding particles in the grinding fluid are in a uniformly dispersed state. Furthermore, the first stirring part includes a first spiral blade arranged circumferentially along the inner sidewall of the mixing tank. The first spiral blade is continuously distributed in at least one circle along the inner sidewall of the mixing tank, or the first spiral blade is discontinuously distributed in at least one circle along the inner sidewall of the mixing tank.

[0005] Furthermore, there are multiple first helical blades, which are arranged side by side in the same helical direction, or at least one of the multiple first helical blades is arranged in a helical direction opposite to that of the other first helical blades and intersects at the intersection.

[0006] Furthermore, a first filter section is provided on the bottom surface of the mixing tank. The first filter section is used to filter the grinding liquid that enters the first filter section under the stirring action when the mixing tank is rotated, targeting large particles or aggregated particles that exceed a certain size.

[0007] Furthermore, the first filtration unit includes a first filter screen box, with an inlet at one end of the first filter screen box facing the center of the mixing tank, and an inlet door that is elastically and unidirectionally open toward the other end of the first filter screen box. The first filter screen box will block and collect large particles or aggregated particles that exceed the mesh size in the grinding liquid that inertially enters through the inlet inside the first filter screen box.

[0008] Furthermore, an elastic element connects the entrance door to the other end inside the first filter box.

[0009] Furthermore, the mixing tank includes an outer tank and an inner tank nested together. The outer tank is fixedly installed, and the inner tank is used to contain the grinding liquid. The inner tank is configured to rotate axially when driven, and the first stirring part protrudes from the inner sidewall of the inner tank.

[0010] Furthermore, the liquid supply tank is configured to rotate axially when driven, and a second stirring part is provided on the inner side wall of the liquid supply tank. The second stirring part is used to provide stirring force to the grinding liquid in the liquid supply tank when rotating, so that the grinding particles in the grinding liquid are in a uniformly dispersed state. A second filtration part is provided on the bottom surface inside the liquid supply tank. The second filtration part is used to filter the grinding liquid that enters the second filtration part under the stirring action when the liquid supply tank rotates, targeting large particles or aggregated particles that exceed a certain size.

[0011] The present invention also provides a method for supplying polishing slurry, using the above-described polishing slurry supply device, comprising: When supplying grinding fluid, the mixing tank is rotated clockwise and counterclockwise alternately at a constant or variable speed. The first stirring part, which is protruding from the inner wall of the mixing tank, provides a variable centrifugal stirring force to the grinding fluid in the mixing tank during rotation, thereby breaking up the grinding particles that are in an agglomerated state in the grinding fluid. Alternatively, when supplying the grinding slurry, the mixing tank can be rotated alternately clockwise and counterclockwise at a constant or variable speed. This provides a varying centrifugal stirring force to the grinding slurry in the rotating mixing tank through a first stirring part protruding from the inner wall of the mixing tank, thereby breaking up the aggregated grinding particles in the grinding slurry. The supply tank can also be rotated alternately clockwise and counterclockwise at a constant or variable speed. This provides a varying centrifugal stirring force to the grinding slurry in the rotating supply tank through a second stirring part protruding from the inner wall of the supply tank, thereby breaking up the aggregated grinding particles in the grinding slurry.

[0012] Furthermore, it also includes: The grinding liquid is forced into a first filter section located on the bottom surface of the mixing tank by the impact force generated by the change in centrifugal stirring force generated by the rotation of the mixing tank and the grinding liquid therein. This filter section is used to filter and collect large particles or aggregated particles that exceed a certain size. Alternatively, the grinding liquid is forced into a second filter section located on the bottom surface of the supply tank by the impact force generated by the change in centrifugal stirring force generated by the rotation of the supply tank and the grinding liquid therein. This filter section is used to filter and collect large particles or aggregated particles that exceed a certain size.

[0013] As can be seen from the above technical solution, by providing a first stirring section (first spiral blade) on at least the inner wall of the mixing tank, the present invention can provide a stronger stirring force to the grinding liquid when the mixing tank rotates, which can significantly enhance the stirring ability of the grinding liquid, disperse the grinding particles in the grinding liquid that are in a state of aggregation, and make the grinding particles in the grinding liquid in a uniformly dispersed state. Furthermore, by providing a first filtration section (first filter screen) on at least the bottom surface of the mixing tank, large particles or aggregated particles in the grinding liquid that enter the first filtration section unidirectionally under the stirring action can be filtered and collected, further reducing particle aggregation in the grinding liquid. This effectively prevents the risk of clogging the grinding liquid supply pipeline and ensures the stability of the grinding liquid flow rate during supply. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an existing grinding fluid supply device.

[0015] Figure 2 This is a schematic diagram of an existing stirring device.

[0016] Figure 3 This is a schematic diagram of an existing circulation device.

[0017] Figures 4-5 This is a schematic diagram of a grinding fluid supply device according to a preferred embodiment of the present invention.

[0018] Figure 6 This is a schematic diagram of an inner and outer double-bucket structure of a mixing tank or supply tank according to a preferred embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the arrangement of a spiral blade and a filter screen box in an inner barrel according to a preferred embodiment of the present invention.

[0020] Figure 8 This is an enlarged structural schematic diagram of a filter screen box according to a preferred embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0022] refer to Figure 1 Existing grinding fluid supply devices generally include a raw material tank 6, a mixing tank 5, a supply tank 4, and a filter 3, which are sequentially arranged on the grinding fluid supply pipeline 1. The filter 3 is connected to the grinding machine platform through a delivery pipeline.

[0023] For example, chemical mechanical polishing (CMP) in chip manufacturing processes is characterized by high requirements for wafer surface morphology and a tendency to generate defects. The polishing slurry comes into direct contact with the wafer during the polishing process, removing the coating through chemical reactions and mechanical friction, while simultaneously suppressing polishing scratches and dents. The degree of particle aggregation in the polishing slurry affects the polishing speed and the amount of scratch defects during CMP; therefore, ensuring the stability of the polishing slurry is crucial in the polishing process.

[0024] The current process for preparing the polishing slurry is as follows: multiple raw materials are drawn from the raw material tank 6 to the mixing tank 5 for mixing, and additives are added. After mixing, the slurry is supplied to the supply tank 4, and then pumped by the transfer pump 2 and filtered by the filter 3 before being supplied to the polishing machine. However, the polishing slurry undergoes a certain period of settling during its transfer from the mixing tank 5 to the supply tank 4, and during its use in the supply tank 4. This allows the polishing particles to easily aggregate into large particles, causing scratches on the wafer surface and abnormal polishing speed during polishing. A common method to reduce this particle aggregation is to install a stirring device, including a stirring rod 7, in the mixing tank 5 to agitate the polishing slurry. Figure 2 As shown, a circulation device including a circulation pump 8 is installed in the supply tank 4 to keep the grinding fluid in the supply tank 4 in a flowing circulation state, such as... Figure 3 As shown, the liquid is filtered through filter 3 during the liquid supply process to reduce the impact of large particles on the process.

[0025] However, due to the limited space in the mixing tank 5 and the small size of the stirring rod 7, the stirring effect is weak, failing to achieve a good effect of fully dispersing the grinding particles. The circulation speed of the circulating pump 8 also has limitations, requiring a longer time to achieve uniform dispersion of the grinding particles, resulting in low efficiency. Furthermore, the filter 3 may become clogged with prolonged use, increasing pipeline pressure and causing unstable flow rates during the supply of grinding fluid.

[0026] To address the aforementioned problems, the present invention provides a grinding slurry supply device and method. By providing a first stirring part (first spiral blade) on at least the inner wall of the mixing tank, and by rotating the mixing tank alternately clockwise and counterclockwise at a constant or variable speed when supplying the grinding slurry, a stronger stirring force can be generated on the grinding slurry, which can significantly enhance the stirring ability of the grinding slurry, break up the grinding particles in the grinding slurry that are in a state of aggregation, and make the grinding particles in the grinding slurry in a uniformly dispersed state.

[0027] Furthermore, by setting a first filter section (first filter screen box) at least on the bottom surface of the mixing tank, the large or aggregated particles in the grinding liquid entering the first filter section can be filtered and collected by the changing centrifugal stirring force generated by the rotation of the mixing tank and the impact force caused by the difference in linear velocity between the mixing tank and the grinding liquid. This further reduces the aggregation of particles in the grinding liquid, thereby effectively preventing the risk of blockage of the grinding liquid supply pipeline and ensuring the stability of the flow rate when supplying the grinding liquid.

[0028] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] refer to Figure 4 A grinding fluid supply device of the present invention includes a mixing tank 15 and a supply tank 14 sequentially disposed on a grinding fluid supply pipeline 11.

[0030] The mixing tank 15 is configured to rotate about its vertical axis when driven. A protruding first stirring part 171 is provided on the inner side wall of the mixing tank 15. The first stirring part 171 is used to stir the grinding liquid in the rotating mixing tank 15, so that the grinding particles in the grinding liquid are in a uniformly dispersed state by the stirring force provided by the first stirring part 171. In some embodiments, the first stirring section 17 disposed within the mixing tank 15 includes a first helical blade 18 arranged circumferentially along the inner sidewall of the mixing tank 15. The first helical blade 181 protrudes from the inner sidewall of the mixing tank 15 toward the interior of the mixing tank 15. Figure 2Compared to the existing stirring rod 7 shown, the present invention provides a novel stirring device by providing a first stirring section 171 with a first helical blade 181 structure on the inner wall of the mixing tank 15, which together with the rotating mixing tank 15 body forms the present invention. When the mixing tank 15 is driven to rotate, the first helical blade 181 will rotate accordingly, which can generate a stronger stirring force on the grinding liquid in the mixing tank 15, thus greatly enhancing the stirring ability of the grinding liquid, thereby breaking up large or aggregated particles in the grinding liquid, so that the grinding particles in the grinding liquid are in a uniformly dispersed state.

[0031] In some embodiments, when the mixing tank 15 is driven accordingly, it can rotate at a constant speed or at a variable speed.

[0032] In some embodiments, when the mixing tank 15 is driven accordingly, it can rotate either clockwise or counterclockwise.

[0033] In some embodiments, when the mixing tank 15 is driven accordingly, it can rotate clockwise and counterclockwise alternately at a constant speed or a variable speed.

[0034] In some embodiments, the first helical blade 181 is continuously distributed in at least one ring along the inner sidewall of the mixing tank 15.

[0035] In some embodiments, the first helical blades 181 are discontinuously distributed circumferentially along the inner sidewall of the mixing tank 15 for at least one revolution. That is, it is equivalent to having at least one notch on the continuously distributed first helical blades 181, so that the first helical blades 181 form multiple independent blade segments along the helical direction.

[0036] In some embodiments, at least one notch exists on the inner diameter of the continuously distributed first helical blades 181, but the bottom of the notch facing the outer diameter of the first helical blades 181 maintains a certain distance greater than zero from the outer diameter of the first helical blades 181 (i.e., the inner wall of the mixing tank 15). That is, the first helical blades 181 are still continuously distributed on the inner wall of the mixing tank 15, but have notches along the inner edge of the inner diameter.

[0037] In some embodiments, the first helical blade 181 has a smooth surface. Alternatively, the surface of the first helical blade 181 has a continuous corrugated morphology along its orientation.

[0038] In some embodiments, the thickness of the first helical blade 181 may be equal or unequal along the direction of the first helical blade 181.

[0039] In some embodiments, the thickness of the first helical blade 181 may be equal or unequal along the direction between the outer and inner diameters of the first helical blade 181.

[0040] In some embodiments, the thickness of the outer diameter side of the first helical blade 181 is greater than the thickness of the inner diameter side. Alternatively, the thickness of the outer diameter side of the first helical blade 181 is less than the thickness of the inner diameter side.

[0041] In some embodiments, the thickness of the middle section between the outer diameter side and the inner diameter side of the first helical blade 181 is less than the thickness of the outer diameter side and the thickness of the inner diameter side. Alternatively, the thickness of the middle section between the outer diameter side and the inner diameter side of the first helical blade 181 is greater than the thickness of the outer diameter side and the thickness of the inner diameter side.

[0042] In some embodiments, the width (the distance between the outer diameter and the inner diameter) of the first helical blade 181 is equal or unequal at various points along the direction of the first helical blade 181.

[0043] In some embodiments, a plurality of protrusions are provided on the surface of the first helical blade 181 along the direction of the first helical blade 181.

[0044] In some embodiments, a plurality of through holes are provided on the surface of the first helical blade 181 along the direction of the first helical blade 181.

[0045] In some embodiments, a plurality of stirring heads are provided on the inner diameter edge of the first helical blade 181 along the direction of the first helical blade 181.

[0046] In some embodiments, there are multiple first helical blades 181, and the multiple first helical blades 181 are arranged side by side in the same helical direction (the same forward direction or the same reverse direction).

[0047] In some embodiments, there are multiple first helical blades 181, at least one of which is arranged in a helical direction opposite to that of the other first helical blades 181 and intersects at the junction. For example, there are two first helical blades 181, one of which protrudes from the inner wall of the mixing tank 15 in a clockwise helical direction, and the other protrudes from the inner wall of the mixing tank 15 in a counterclockwise helical direction. The two first helical blades 181 intersect on the inner wall of the mixing tank 15 and are integrally intersected at the junction.

[0048] refer to Figure 4In some embodiments, a first filter section 191 is further provided on the bottom surface of the mixing tank 15. The first filter section 191 is used to filter the grinding fluid entering the first filter section 191 under stirring action when the mixing tank 15 rotates, targeting large particles or aggregated particles exceeding a certain size, and collecting the filtered large particles or aggregated particles exceeding a certain size in the first filter section 191. This further reduces particle aggregation in the grinding fluid during the rotation and stirring process of the mixing tank 15 and the first stirring section 171, thus effectively preventing large particles or aggregated particles from entering the filter 13 through the supply pipe 11, causing blockage of the filter 13 during prolonged use, increasing the pressure in the grinding fluid supply pipe 11, and causing flow instability.

[0049] Reference Figure 8 In some embodiments, the first filter section 191 includes a first filter box 20. The first filter box 20 has an inlet at one end facing the center of the mixing tank 15, and an inlet gate 23 that resiliently opens in one direction towards the other end of the first filter box 20. A filter screen is covered on the side of the first filter box 20, and the mesh size (mesh size) of the filter screen defines the size of the abrasive particles in the abrasive liquid that can pass through the filter screen. During the rotation of the mixing tank 15, the first filter box 201 serves to block and collect large particles or aggregated particles exceeding the mesh size in the abrasive liquid that inertially enters the first filter box 201 through its inlet. The first filter box 201 forms an auxiliary filtration device (relative to filter 13) disposed in the mixing tank 15.

[0050] In some embodiments, a first filter box 201 is radially disposed on the bottom surface inside the mixing tank 15, and the end of the first filter box 201 with an inlet is at a distance greater than zero from the center of the mixing tank 15. Thus, the first filter box 201 can perform good filtration and collection functions when the mixing tank 15 rotates forward or backward. The other end of the first filter box 201, facing away from the inlet, is close to (or in contact with) the inner wall of the mixing tank 15.

[0051] In some embodiments, the shape of the first filter box 201 includes a polygonal box, such as a rectangular box (see reference). Figure 8 Triangular wire mesh cages, etc.

[0052] In some embodiments, an elastic member 24 is connected between the inlet gate 23 and the other end inside the first filter box 201. The elastic member 24 is set to a certain pre-compression state so that when the mixing tank 15 is stationary, the inlet gate 23 is pressed against the inlet of the first filter box 201 by the elastic force of the elastic member 24, thus closing the inlet. When the mixing tank 15 rotates, the impact force caused by the linear velocity difference between the rotational speed of the mixing tank 15 and the rotational speed of the grinding fluid inside causes the inlet gate 23 to elastically open unidirectionally toward the inside of the first filter box 201 due to the impact of the grinding fluid. Therefore, the grinding fluid can enter the first filter box 201 through the open inlet and then continue to flow out of the first filter box 201 through the filter screen under the action of inertia. During this process, the mesh size of the filter screen is used to block large particles or aggregated particles that exceed the mesh size of the filter screen inside the first filter box 201. Meanwhile, if the grinding fluid in the first filter box 201 flows towards the inlet, or if the impact force of the grinding fluid outside the inlet of the first filter box 201 on the inlet door 23 is less than the restoring elastic force of the elastic member 24, it will have a positive effect on the elastic stretching of the elastic member 24, so that the inlet door 23 can be closed, thereby achieving the function of filtering and collecting large particles or aggregated particles.

[0053] In some embodiments, the elastic element 24 includes a spring.

[0054] By using the first filter box 201, during the rotation of the mixing tank 15, the grinding liquid continuously flowing in and out of the first filter box 201 can generate a significant oscillating and scouring effect on the aggregated particles collected in the first filter box 201. This not only prevents the aggregated particles from continuing to accumulate, but also helps to disintegrate the aggregated particles and return them to a single state, thus playing a secondary auxiliary stirring role (relative to the first stirring part 171).

[0055] In some other embodiments, the first filter box 201 has a first inlet at one end facing the center of the mixing tank 15, and the first inlet has a first inlet door that elastically opens in one direction towards the other end of the first filter box 201. Simultaneously, the first filter box 201 has a second inlet at the other end facing away from the first inlet, and the second inlet has a second inlet door that opens in one direction towards the first inlet. An elastic member is connected at both ends to the inner sides of the first and second inlet doors, respectively. The first inlet is at a distance greater than zero from the center of the mixing tank 15, and the second inlet is close to the inner wall of the mixing tank 15 and is also at a distance greater than zero.

[0056] During the rotation of the mixing tank 15, the grinding fluid can enter the first filter box 201 through either the first inlet or the second inlet. However, since both the first inlet door and the second inlet door can only be opened in one direction into the first filter box 201, the grinding fluid entering the first filter box 201 cannot leave the first filter box 201 through either the first inlet or the second inlet. Instead, it can only be filtered through the filter screen, thus causing large particles and aggregated particles blocked by the filter screen to be collected in the first filter box 201 because they cannot pass through the filter screen.

[0057] The distance between the first inlet and the center of the mixing tank 15 generally needs to be greater than the distance between the second inlet and the inner wall of the mixing tank 15, so as to maximize the length of the first filter box 201 when it is arranged radially along the mixing tank 15, increase the internal volume of the first filter box 201, and enable the grinding liquid entering the first filter box 201 to generate sufficient oscillation, which is beneficial to prevent further accumulation of aggregated particles.

[0058] refer to Figure 6 and Figure 7 In some embodiments, the mixing tank 15 includes an outer tank 21 and an inner tank 22 that are axially nested together. The inner diameter of the outer tank 21 is larger than the outer diameter of the inner tank 22, and a gap greater than zero is required between the inner diameter of the outer tank 21 and the outer diameter of the inner tank 22. Preferably, the outer tank 21 and the inner tank 22 are coaxially nested together to form a double-tank structure of the mixing tank 15.

[0059] The outer barrel 21 is fixedly installed, and the inner barrel 22 is used to contain the grinding liquid. The inner barrel 22 is configured to rotate axially when driven. The first stirring part 171 (first spiral blade 181) protrudes from the inner side wall of the inner barrel 22. The first filter part 191 (first filter screen box 201) is provided on the bottom surface inside the inner barrel 22.

[0060] refer to Figure 5 In some embodiments, the liquid supply tank 14 is also configured to rotate about its vertical axis when driven, and a second stirring part 172 protrudes from the inner side wall of the liquid supply tank 14. The second stirring part 172 is used to stir the grinding liquid in the rotating liquid supply tank 14 so that the grinding particles in the grinding liquid are in a uniformly dispersed state by the stirring force provided by the second stirring part 172.

[0061] In some embodiments, the second stirring section 172 disposed within the liquid supply tank 14 includes a second helical blade 182 arranged circumferentially along the inner sidewall of the liquid supply tank 14. The second helical blade 182 protrudes from the inner sidewall of the liquid supply tank 14 toward the interior of the liquid supply tank 14. Figure 2Compared to the existing stirring rod 7 shown, the present invention provides a novel stirring device by providing a second filter section 19 with a second helical blade 182 structure on the inner wall of the liquid supply tank 14, which, together with the rotating liquid supply tank 14 body, forms a novel stirring device of the present invention. When the liquid supply tank 14 is driven to rotate, the second helical blade 182 will rotate accordingly, which can generate a stronger stirring force on the grinding liquid in the liquid supply tank 14, thus greatly enhancing the stirring ability of the grinding liquid, thereby breaking up large or aggregated particles in the grinding liquid, so that the grinding particles in the grinding liquid are in a uniformly dispersed state.

[0062] In some embodiments, when the liquid supply tank 14 is driven accordingly, it can rotate at a constant speed or at a variable speed.

[0063] In some embodiments, when the liquid supply tank 14 is driven accordingly, it can rotate either clockwise or counterclockwise.

[0064] In some embodiments, when the liquid supply tank 14 is driven accordingly, it can rotate alternately clockwise and counterclockwise in a constant speed or variable speed manner.

[0065] In some embodiments, the second helical blade 182 is continuously distributed in at least one ring along the inner sidewall of the liquid supply tank 14.

[0066] In some embodiments, the second helical blades 182 are discontinuously distributed circumferentially along the inner sidewall of the liquid supply tank 14 for at least one revolution. That is, it is equivalent to having at least one notch on the continuously distributed second helical blades 182, so that the second helical blades 182 form multiple independent blade segments along the helical direction.

[0067] In some embodiments, at least one notch exists on the inner diameter of the continuously distributed second helical blades 182, but the bottom of the notch facing the outer diameter of the second helical blades 182 maintains a certain distance greater than zero from the outer diameter of the second helical blades 182 (i.e., the inner wall of the liquid supply tank 14). That is, the second helical blades 182 are still continuously distributed on the inner wall of the liquid supply tank 14, but have notches along the inner edge of the inner diameter.

[0068] In some embodiments, the second helical blade 182 has a smooth surface. Alternatively, the surface of the second helical blade 182 has a continuous corrugated morphology along its orientation.

[0069] In some embodiments, the thickness of the second helical blade 182 may be equal or unequal along the direction of the second helical blade 182.

[0070] In some embodiments, the thickness of the second helical blade 182 may be equal or unequal along the direction between the outer and inner diameters of the second helical blade 182.

[0071] In some embodiments, the thickness of the outer diameter side of the second helical blade 182 is greater than the thickness of the inner diameter side. Alternatively, the thickness of the outer diameter side of the second helical blade 182 is less than the thickness of the inner diameter side.

[0072] In some embodiments, the thickness of the middle section between the outer diameter side and the inner diameter side of the second helical blade 182 is less than the thickness of the outer diameter side and the thickness of the inner diameter side. Alternatively, the thickness of the middle section between the outer diameter side and the inner diameter side of the second helical blade 182 is greater than the thickness of the outer diameter side and the thickness of the inner diameter side.

[0073] In some embodiments, the width (the distance between the outer diameter and the inner diameter) of the second helical blade 182 is equal or unequal at various points along the direction of the second helical blade 182.

[0074] In some embodiments, a plurality of protrusions are provided on the surface of the second helical blade 182 along the direction of the second helical blade 182.

[0075] In some embodiments, a plurality of through holes are provided on the surface of the second helical blade 182 along the direction of the second helical blade 182.

[0076] In some embodiments, a plurality of stirring heads are provided on the inner diameter edge of the second helical blade 182 along the direction of the second helical blade 182.

[0077] In some embodiments, there are multiple second helical blades 182, and the multiple second helical blades 182 are arranged side by side in the same helical direction (the same forward direction or the same reverse direction).

[0078] In some embodiments, there are multiple second helical blades 182, at least one of which is arranged in a helical direction opposite to that of the other second helical blades 182 and intersects at the junction. For example, there are two second helical blades 182, one of which protrudes from the inner wall of the liquid supply tank 14 in a forward helical direction, and the other protrudes from the inner wall of the liquid supply tank 14 in a counter-helical direction. The two second helical blades 182 intersect on the inner wall of the liquid supply tank 14 and are integrally intersected at the junction.

[0079] refer to Figure 5In some embodiments, a second filter section 192 is provided on the bottom surface of the supply tank 14. The second filter section 192 is used to filter large particles or aggregated particles exceeding a certain size from the grinding fluid entering the second filter section 192 under stirring action when the supply tank 14 rotates, and to collect the filtered large particles or aggregated particles exceeding a certain size in the second filter section 192. This further reduces particle aggregation in the grinding fluid during the rotation and stirring process of the supply tank 14 and the second filter section 192, thus effectively preventing large particles or aggregated particles from entering the filter 13 through the supply pipe 11, causing blockage of the filter 13 during prolonged use, increasing the pressure in the grinding fluid supply pipe 11, and causing flow instability.

[0080] Reference Figure 8 In some embodiments, the second filtration unit 192 includes a second filter box 202. The second filter box 202 has an inlet at one end facing the center of the supply tank 14, and an inlet gate 23 that resiliently opens in one direction towards the other end inside the second filter box 202. A filter screen is covered on the side of the second filter box 202, and the mesh size (mesh size) of the filter screen defines the size of the abrasive particles in the abrasive slurry that can pass through the filter screen. During the rotation of the supply tank 14, the second filter box 202 serves to block and collect large particles or aggregated particles exceeding the mesh size in the abrasive slurry that inertially enter the second filter box 202 through the inlet. The second filter box 202 forms an auxiliary filtration device (relative to filter 13) disposed in the supply tank 14.

[0081] In some embodiments, the second filter box 202 is radially disposed on the bottom surface inside the liquid supply tank 14, and the end of the second filter box 202 with an inlet is at a distance greater than zero from the center of the liquid supply tank 14. Thus, the second filter box 202 can perform good filtration and collection functions whether the liquid supply tank 14 rotates forward or backward. The other end of the second filter box 202, facing away from the inlet, is close to (or in contact with) the inner wall of the liquid supply tank 14.

[0082] In some embodiments, the second filter box 202 includes a polygonal shape, such as a rectangular shape (see reference). Figure 8 Triangular wire mesh cages, etc.

[0083] In some embodiments, an elastic member 24 is connected between the inlet gate 23 and the other end inside the second filter box 202. The elastic member 24 is set to a certain pre-compression state so that when the supply tank 14 is stationary, the inlet gate 23 is pressed against the inlet of the second filter box 202 by the elastic force of the elastic member 24, thus closing the inlet. When the supply tank 14 rotates, the impact force caused by the linear velocity difference between the rotational speed of the supply tank 14 and the rotational speed of the grinding fluid inside causes the inlet gate 23 to elastically open unidirectionally toward the inside of the second filter box 202 due to the impact of the grinding fluid. Therefore, the grinding fluid can enter the second filter box 202 through the open inlet and then continue to flow out of the second filter box 202 through the filter screen under the action of inertia. During this process, the mesh size of the filter screen is used to block large particles or aggregated particles that exceed the mesh size of the filter screen inside the second filter box 202. Meanwhile, if the grinding fluid in the second filter box 202 flows towards the inlet, or if the impact force of the grinding fluid outside the inlet of the second filter box 202 on the inlet door 23 is less than the restoring force of the elastic member 24, it will have a positive effect on the elastic stretching of the elastic member 24, so that the inlet door 23 can be closed, thereby achieving the function of filtering and collecting large particles or aggregated particles.

[0084] In some embodiments, the elastic element 24 includes a spring.

[0085] By using the second filter box 202, during the rotation of the liquid supply tank 14, the grinding liquid continuously flowing in and out of the second filter box 202 can generate a significant oscillating and scouring effect on the aggregated particles collected in the second filter box 202. This not only prevents the aggregated particles from continuing to accumulate, but also helps to disintegrate the aggregated particles and return them to a single state, thus playing a secondary auxiliary stirring role (relative to the second stirring section 172).

[0086] In some other embodiments, the second filter box 202 has a first inlet on the end facing the center of the liquid supply tank 14, and the first inlet has a first inlet door that elastically opens in one direction towards the other end of the second filter box 202. Simultaneously, the second filter box 202 has a second inlet on the other end facing away from the first inlet, and the second inlet has a second inlet door that opens in one direction towards the first inlet. An elastic element is connected at both ends to the inner sides of the first and second inlet doors, respectively. The first inlet is at a distance greater than zero from the center of the liquid supply tank 14, and the second inlet is close to the inner wall of the liquid supply tank 14 and is also at a distance greater than zero.

[0087] During the rotation of the liquid supply tank 14, the grinding liquid can enter the second filter box 202 through either the first inlet or the second inlet. However, since both the first inlet door and the second inlet door can only be opened in one direction into the second filter box 202, the grinding liquid that enters the second filter box 202 cannot leave the second filter box 202 through either the first inlet or the second inlet. Instead, it can only be filtered through the filter screen, so that large particles and aggregated particles blocked by the filter screen are collected in the second filter box 202 because they cannot pass through the filter screen.

[0088] The distance between the first inlet and the center of the liquid supply tank 14 generally needs to be greater than the distance between the second inlet and the inner wall of the liquid supply tank 14, so as to maximize the length of the second filter box 202 when it is arranged radially along the liquid supply tank 14, increase the internal volume of the second filter box 202, and enable the grinding liquid entering the second filter box 202 to generate sufficient oscillation, which is beneficial to prevent further accumulation of aggregated particles.

[0089] refer to Figure 6 and Figure 7 In some embodiments, the liquid supply tank 14 includes an outer tank 21 and an inner tank 22 that are axially fitted together. The inner diameter of the outer tank 21 is larger than the outer diameter of the inner tank 22, and a gap greater than zero is required between the inner diameter of the outer tank 21 and the outer diameter of the inner tank 22. Preferably, the outer tank 21 and the inner tank 22 are coaxially fitted together to form a double-tank structure of the liquid supply tank 14.

[0090] The outer barrel 21 is fixedly installed, and the inner barrel 22 is used to contain the grinding liquid. The inner barrel 22 is configured to rotate axially when driven. The second stirring part 172 (second spiral blade 182) protrudes from the inner side wall of the inner barrel 22. The second filter part 192 (second filter screen 202) is provided on the bottom surface inside the inner barrel 22.

[0091] refer to Figure 4 or Figure 5 In some embodiments, the polishing slurry supply device of the present invention includes a stock solution tank 16, a mixing tank 15, a supply tank 14, a delivery pump 12 and a filter 13 sequentially disposed on the polishing slurry supply pipeline 11, wherein the filter 13 is connected to the polishing machine platform through a delivery pipeline.

[0092] The grinding slurry supply device of the present invention can either have a first stirring section 171 and a first filtering section 191 separately installed in the mixing tank 15, and the first stirring section 171 and the first filtering section 191 rotate accordingly through the mixing tank 15 to stir and filter the grinding slurry in the mixing tank 15, or simultaneously have a second stirring section 172 and a second filtering section 192 installed in the supply tank 14, and the second stirring section 172 and the second filtering section 192 rotate accordingly through the supply tank 14 to stir and filter the grinding slurry in the supply tank 14.

[0093] In addition to the first line of defense where the first stirring part 171 and the first filtering part 191 in the mixing tank 15 rotate to stir and filter the grinding fluid in the mixing tank 15, the second stirring part 172 and the second filtering part 192 in the supply tank 14 rotate to stir and filter the grinding fluid in the supply tank 14. This serves as a second line of defense to prevent the grinding fluid particles in the grinding fluid supply pipeline 11 from accumulating, effectively preventing blockage of the grinding fluid supply pipeline 11, and ensuring a stable flow rate of the grinding fluid during supply. This effectively controls the overall macroscopic performance of the grinding fluid during supply.

[0094] The following detailed description of a grinding fluid supply method of the present invention, with reference to specific embodiments and accompanying drawings, provides a further detailed explanation.

[0095] In some embodiments, a grinding fluid supply method of the present invention uses the above-described, for example... Figure 4 (Also refer to) Figures 6-8 The grinding fluid supply device includes: When the grinding fluid is supplied to the grinding machine through the grinding fluid supply pipeline 11, the mixing tank 15 is rotated so that the first stirring part 171 (first spiral blade 181) protruding from the inner wall of the mixing tank 15 rotates along with it. The grinding fluid in the rotating mixing tank 15 is stirred by the rotating first stirring part 171. The stirring force provided by the first stirring part 171 disperses the grinding particles in the grinding fluid that are in a state of aggregation, so that the grinding particles in the grinding fluid are in a state of uniform dispersion.

[0096] In some embodiments, while waiting for liquid supply, the mixing tank 15 is rotated alternately clockwise and counterclockwise at a constant or variable speed, so as to provide a varying centrifugal stirring force to the grinding liquid in the rotating mixing tank 15 through the first stirring part 171, thereby providing a stronger stirring ability to better disperse the grinding particles in the grinding liquid that are in an agglomerated state.

[0097] Furthermore, the centrifugal stirring force generated by the rotation of the mixing tank 15 is utilized, and the impact force caused by the difference in linear velocity between the mixing tank 15 and the grinding liquid therein is used to make the grinding liquid enter the first filter section 191 (first filter screen box 201) located on the bottom surface of the mixing tank 15, so as to filter and collect large particles or aggregated particles that exceed a certain size.

[0098] Furthermore, during the rotation of the mixing tank 15, the grinding liquid continuously flowing in and out of the first filter screen box 201 generates a significant oscillating and scouring effect on the aggregated particles collected in the first filter screen box 201, so as to prevent the aggregated particles from continuing to accumulate, and also to facilitate the disintegration of the aggregated particles and their return to a single state, thus playing a secondary auxiliary stirring role.

[0099] In some embodiments, a grinding fluid supply method of the present invention uses the above-described, for example... Figure 5 (Also refer to) Figures 6-8 The grinding fluid supply device includes: When the grinding fluid is supplied to the grinding machine through the grinding fluid supply pipeline 11, the mixing tank 15 is rotated so that the first stirring part 171 (first spiral blade 181) protruding from the inner wall of the mixing tank 15 rotates along with it. The grinding fluid in the rotating mixing tank 15 is stirred by the rotating first stirring part 171. The stirring force provided by the first stirring part 171 disperses the grinding particles in the grinding fluid that are in a state of aggregation, so that the grinding particles in the grinding fluid are in a state of uniform dispersion.

[0100] At the same time, the liquid supply tank 14 is rotated so that the second stirring part 172 (second spiral blade 182) protruding from the inner wall of the liquid supply tank 14 rotates accordingly. The rotating second stirring part 172 stirs the grinding liquid in the rotating liquid supply tank 14. The stirring force provided by the second stirring part 172 disperses the grinding particles in the grinding liquid that are in a state of aggregation, so that the grinding particles in the grinding liquid are in a state of uniform dispersion.

[0101] In some embodiments, during the waiting period for liquid supply, the mixing tank 15 is rotated alternately clockwise and counterclockwise at a constant or variable speed. This provides a varying centrifugal stirring force to the grinding fluid within the rotating mixing tank 15 via the first stirring unit 171, thereby providing stronger stirring capabilities to better disperse aggregated grinding particles in the grinding fluid. Furthermore, by rotating the supply tank 14 alternately clockwise and counterclockwise at a constant or variable speed, a varying centrifugal stirring force is provided to the grinding fluid within the rotating supply tank 14 via the second stirring unit 172, thereby providing stronger stirring capabilities to better disperse aggregated grinding particles in the grinding fluid.

[0102] Furthermore, the varying centrifugal stirring force generated by the rotation of the mixing tank 15, combined with the impact force resulting from the difference in linear velocity between the mixing tank 15 and the grinding liquid within it, forces the grinding liquid into the first filter section 191 (first filter screen box 201) located on the bottom surface of the mixing tank 15, for filtration and collection of large particles or aggregated particles exceeding a certain size. Additionally, the varying centrifugal stirring force generated by the rotation of the supply tank 14, combined with the impact force resulting from the difference in linear velocity between the supply tank 14 and the grinding liquid within it, forces the grinding liquid into the second filter section 192 (second filter screen box 202) located on the bottom surface of the supply tank 14, for filtration and collection of large particles or aggregated particles exceeding a certain size.

[0103] Furthermore, during the rotation of the mixing tank 15, the continuously flowing grinding fluid into and out of the first filter box 201 creates a significant oscillating and scouring effect on the aggregated particles collected in the first filter box 201. This prevents further accumulation of the aggregated particles and facilitates their disintegration, allowing them to return to a single, unified state, thus providing secondary auxiliary stirring. Simultaneously, during the rotation of the supply tank 14, the continuously flowing grinding fluid into and out of the second filter box 202 creates a significant oscillating and scouring effect on the aggregated particles collected in the second filter box 202. This also prevents further accumulation of the aggregated particles and facilitates their disintegration, allowing them to return to a single, unified state, thus providing secondary auxiliary stirring.

[0104] In addition, by rotating the mixing tank 15 / supply tank 14 alternately clockwise and counterclockwise at a constant or variable speed, a non-constant centrifugal force can be generated, which can prevent the grinding liquid in the mixing tank 15 / supply tank 14 from stratifying.

[0105] This invention is applicable to the chemical mechanical polishing process for wafer surfaces in chip manufacturing. It can ensure the stability of the polishing slurry state during the polishing process, suppress polishing scratches and dents, and improve polishing efficiency.

[0106] This invention is also applicable to scenarios where mirror finishes are achieved on product surfaces using chemical mechanical polishing (CMP) processes.

[0107] In summary, by providing a first stirring section 171 (first spiral blade 181) on at least the inner wall of the mixing tank 15, the present invention can provide a stronger stirring force to the grinding liquid when the mixing tank 15 rotates, which can significantly enhance the stirring ability of the grinding liquid, disperse the grinding particles in the grinding liquid that are in a state of aggregation, and make the grinding particles in the grinding liquid in a uniformly dispersed state. Furthermore, by providing a first filter section 191 (first filter screen box 201) on at least the bottom surface of the mixing tank 15, large particles or aggregated particles in the grinding liquid that enter the first filter section 191 unidirectionally under the stirring action can be filtered and collected, further reducing the aggregation of particles in the grinding liquid, thereby effectively preventing the risk of blockage of the grinding liquid supply pipeline 11 and ensuring the stability of the flow rate of the grinding liquid during supply.

[0108] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A grinding slurry supply device, comprising a mixing tank and a supply tank sequentially disposed on a grinding slurry supply pipeline, characterized in that, The mixing tank is configured to rotate axially when driven. A protruding first stirring part is provided on the inner side wall of the mixing tank to provide stirring force to the grinding liquid in the mixing tank during rotation, so that the grinding particles in the grinding liquid are in a uniformly dispersed state. The bottom surface of the mixing tank is provided with a first filter section. The first filter section is used to filter the grinding liquid that enters the first filter section under the stirring action when the mixing tank is rotated, targeting large particles or aggregated particles that exceed a certain size. The first filtration unit includes a first filter screen box. The first filter screen box has an inlet at one end facing the center of the mixing tank. The inlet has an inlet door that opens elastically in one direction towards the other end inside the first filter screen box. The first filter screen box blocks and collects large particles or aggregated particles that exceed the mesh size in the grinding liquid that inertially enters through the inlet inside the first filter screen box.

2. The grinding fluid supply device according to claim 1, characterized in that, The first stirring section includes a first spiral blade arranged circumferentially along the inner wall of the mixing tank. The first spiral blade is continuously distributed in at least one circle along the inner wall of the mixing tank, or the first spiral blade is discontinuously distributed in at least one circle along the inner wall of the mixing tank.

3. The grinding fluid supply device according to claim 2, characterized in that, There are multiple first helical blades, which are arranged side by side in the same helical direction, or at least one of the multiple first helical blades is arranged in a helical direction opposite to that of the other first helical blades and intersects at the intersection.

4. The grinding fluid supply device according to claim 1, characterized in that, An elastic element connects the entrance door to the other end of the first filter box.

5. The grinding fluid supply device according to claim 1, characterized in that, The mixing tank includes an outer tank and an inner tank that are nested together. The outer tank is fixedly installed, and the inner tank is used to contain the grinding liquid. The inner tank is configured to rotate axially when driven, and the first stirring part protrudes from the inner side wall of the inner tank.

6. The grinding fluid supply device according to claim 1, characterized in that, The liquid supply tank is configured to rotate axially when driven. A second stirring part is protruding from the inner wall of the liquid supply tank. The second stirring part is used to provide stirring force to the grinding liquid in the liquid supply tank when rotating, so that the grinding particles in the grinding liquid are in a uniformly dispersed state. A second filtration part is provided on the bottom surface of the liquid supply tank. The second filtration part is used to filter the grinding liquid that enters the second filtration part under the stirring action when the liquid supply tank rotates, targeting large particles or aggregated particles that exceed a certain size.

7. A method for supplying polishing slurry, using the polishing slurry supply device according to any one of claims 1-6, characterized in that, include: When supplying grinding fluid, the mixing tank is rotated clockwise and counterclockwise alternately at a constant or variable speed. The first stirring part, which is protruding from the inner wall of the mixing tank, provides a variable centrifugal stirring force to the grinding fluid in the mixing tank during rotation, thereby breaking up the grinding particles that are in an agglomerated state in the grinding fluid. Alternatively, when supplying the grinding slurry, the mixing tank can be rotated alternately clockwise and counterclockwise at a constant or variable speed. This provides a varying centrifugal stirring force to the grinding slurry in the rotating mixing tank through a first stirring part protruding from the inner wall of the mixing tank, thereby breaking up the aggregated grinding particles in the grinding slurry. The supply tank can also be rotated alternately clockwise and counterclockwise at a constant or variable speed. This provides a varying centrifugal stirring force to the grinding slurry in the rotating supply tank through a second stirring part protruding from the inner wall of the supply tank, thereby breaking up the aggregated grinding particles in the grinding slurry.

8. The method for supplying grinding fluid according to claim 7, characterized in that, Also includes: The grinding liquid is forced into a first filter section located on the bottom surface of the mixing tank by the impact force generated by the change in centrifugal stirring force generated by the rotation of the mixing tank and the grinding liquid therein. This filter section is used to filter and collect large particles or aggregated particles that exceed a certain size. Alternatively, the grinding liquid is forced into a second filter section located on the bottom surface of the supply tank by the impact force generated by the change in centrifugal stirring force generated by the rotation of the supply tank and the grinding liquid therein. This filter section is used to filter and collect large particles or aggregated particles that exceed a certain size.

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