A polishing pad raw material mixing system

Abstract

The present application relates to a kind of polishing pad raw material mixing system, including at least one raw material barrel, mixing barrel and powder feeding device;Raw material barrel is equipped with first heating structure;Raw material barrel is communicated with mixing barrel by liquid delivery pipeline, and second heating structure is equipped on liquid delivery pipeline;Powder feeding device includes weighing machine, powder delivery pipeline and sealing element, weighing machine is used to hang powder bag, and the weight of powder bag is weighed, the bottom of powder bag is communicated with mixing barrel by powder delivery pipeline, and sealing element is sleeved on powder delivery pipeline, and the bottom of powder bag is abutted with sealing element.Compared with prior art, the above-mentioned polishing pad raw material mixing system is beneficial to improve the mixing sufficiency of raw material, ensure the uniformity of density, hardness and compression rate of polishing pad finished product, while avoiding the scattering of microsphere powder during feeding process, improving the efficiency and precision of microsphere feeding, and then improving the accuracy of raw material mixing ratio, improving the quality of polishing pad.

Description

Technical Field

[0001] This invention relates to the field of polishing preparation, and in particular to a polishing pad raw material mixing system. Background Technology

[0002] Polishing pads, also known as abrasive pads, have rough surfaces and are used to directly contact semiconductor surfaces to generate friction, mechanically removing the polishing layer from the semiconductor surface. Under the action of centrifugal force, polishing liquid is evenly sprayed onto the surface of the polishing pad to chemically remove the polishing layer from the semiconductor surface. At the same time, the reaction products are carried out of the polishing pad, thereby achieving nanoscale global planarization of the semiconductor processing surface, meeting the requirements of ultra-precision non-destructive surface processing of integrated circuit feature sizes below 0.35μm.

[0003] Polyurethane polishing pads are a commonly used type of polishing pad. They are generally prepared by mixing toluene diisocyanate prepolymer (TDI prepolymer), curing agent, and microspheres. During the preparation process, the various raw materials must first be mixed evenly, and then the mixture is poured and cured. Because TDI prepolymer is a colorless or pale yellow transparent liquid with a pungent odor at room temperature and has high viscosity, it is difficult to achieve thorough mixing with the curing agent and microspheres, thus affecting the density, hardness, and compressibility of the finished polishing pad. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a polishing pad material mixing system that promotes uniform mixing of various materials in the polishing pad.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A polishing pad material mixing system, comprising:

[0007] At least one raw material barrel, the raw material barrel being provided with a first heating structure, the raw material barrel being used to contain polyurethane prepolymer or curing agent;

[0008] A mixing tank, wherein the raw material tank is connected to the mixing tank via a liquid conveying pipe, and the liquid conveying pipe is provided with a second heating structure;

[0009] A powder feeding device includes a weighing machine, a powder conveying pipe, and a sealing element. The weighing machine is used to hang the powder bag and weigh the powder bag. The bottom of the powder bag is connected to the mixing tank through the powder conveying pipe. The sealing element is sleeved on the powder conveying pipe and abuts against the bottom of the powder bag.

[0010] In one embodiment, the polishing pad material mixing system includes a stirring assembly, the stirring assembly including a reflux pump, the inlet of the reflux pump being connected to the bottom of the mixing tank, and the outlet of the reflux pump being connected to the top of the mixing tank.

[0011] In one embodiment, the first heating structure includes a heating shroud with a flared opening, a light-emitting and heat-generating tube at the center of the heating shroud, a reflective coating on the inner wall of the heating shroud, the flared opening of the heating shroud being used to cover the at least one raw material tank, and the liquid delivery pipe passing through the heating shroud and communicating with the mixing tank.

[0012] In one embodiment, the seal includes a sealing portion forming a funnel-shaped opening around the powder conveying pipe, the funnel-shaped opening of the sealing portion being used to abut against the bottom of the powder bag.

[0013] In one embodiment, one end of the powder conveying pipe is provided with a hollow plug, which is located in the powder bag, and the plug has multiple through holes.

[0014] In one embodiment, the bottom of the plug is flared, and the bottom of the plug can extend into the flared opening of the sealing part and clamp the bottom of the powder bag.

[0015] In one embodiment, the seal includes a connecting portion connected to the sealing portion, the connecting portion being threadedly connected to the powder conveying pipe.

[0016] In one embodiment, the top of the plug is conical, and the through holes are distributed on the conical surface of the plug.

[0017] In one embodiment, the second heating structure includes a heating resistance wire that is spirally wound around the liquid delivery pipe.

[0018] In one embodiment, the mixing tank has a sandwich structure in its wall, and a heating pipe is provided inside the sandwich structure. The heating pipe is spirally arranged around the side wall of the mixing tank and is used to supply heating gas.

[0019] In one embodiment, the polishing pad raw material mixing system includes a support frame and a weighing module, wherein the weighing module is disposed between the support frame and the mixing barrel and is used to weigh the mixing barrel.

[0020] In one embodiment, the mixing tank is a closed mixing tank, and the top of the mixing tank is provided with an air inlet and an air outlet. The polishing pad raw material mixing system includes a gas generator, the outlet of which is connected to the air inlet, and delivers protective gas into the mixing tank to isolate moisture in the air.

[0021] In one embodiment, the polishing pad material mixing system includes a stirring paddle and a rotating motor, the stirring paddle being connected to the rotating motor and extending into the mixing tank.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The aforementioned polishing pad raw material mixing system employs a first heating structure to heat the polyurethane prepolymer or curing agent in the raw material tank, and a second heating structure to heat the polyurethane prepolymer or curing agent in the liquid delivery pipeline before it enters the mixing tank for mixing. Because the viscosity of the heated polyurethane prepolymer or curing agent decreases, it is easier for the polyurethane prepolymer or curing agent to mix evenly in the mixing tank, which helps improve the thoroughness of raw material mixing and ensures the uniformity of the density, hardness, and compressibility of the finished polishing pad. Simultaneously, a powder feeding device is provided to directly suspend the powder bag containing the microspheres. The weighing machine uses a powder conveying pipe to connect the powder bag and the polishing pad mixing tank, and uses a seal to ensure a sealed connection between the powder conveying pipe and the powder bag. During the addition process, microspheres can be directly added to the polishing pad mixing tank through the powder conveying pipe, and the weighing machine can display the weight change of the powder bag in real time. The amount of microspheres added can be obtained by measuring the weight change of the powder bag, which effectively reduces the workload of the microsphere addition process, avoids the microsphere powder from scattering during the addition process, improves the efficiency and accuracy of microsphere addition, and thus improves the accuracy of the raw material mixing ratio and the quality of the polishing pad.

[0024] 2. The mixing tank is equipped with a stirring component. The stirring component uses a reflux pump to stir and mix the raw materials in the mixing tank, which helps to fully mix the raw materials in the mixing tank, thereby improving the uniformity of the density, hardness and compressibility of the finished polishing pad.

[0025] 3. A horn-shaped heating cover is used to heat the raw material barrel. The heating cover is equipped with a light-emitting heating tube and a reflective coating. The reflective coating reflects the heat and infrared rays generated by the light-emitting heating tube onto the raw material barrel. The heating speed is fast and the raw material barrel is easy to install and disassemble.

[0026] 4. The sealing element is equipped with a sealing part, which is a funnel-shaped opening. It clamps the bottom of the powder bag by cooperating with the bottom of the funnel-shaped plug, preventing the microspheres from overflowing from the connection between the powder bag and the powder conveying pipe, and effectively avoiding the scattering of microsphere powder.

[0027] 5. The sealing element is connected to the powder conveying pipeline by a threaded connection. The sealing element can be moved by rotating the connection, which helps the sealing element and the plug to come closer to each other and clamp the powder bag. There is no need to set other structures to fix the relative position of the sealing element and the plug. The structure is simple and easy to disassemble and install the sealing element.

[0028] 6. The hollow plug on the powder conveying pipeline has a through hole, so the microsphere powder enters the powder conveying pipeline through the plug via the through hole. This is used to limit the rate at which the microsphere powder enters the powder conveying pipeline, avoid blockage of the opening of the powder conveying pipeline, and improve the microsphere dosing efficiency.

[0029] 7. A gas generator is installed on the mixing tank to supply protective gas into the mixing tank, thereby isolating the raw materials in the mixing tank from the air, preventing the moisture in the air from reacting with the polyurethane prepolymer to produce carbon dioxide gas, ensuring that the curing agent, microspheres and polyurethane prepolymer are fully mixed, and improving the quality controllability of the polishing pad. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a polishing pad material mixing system in one embodiment.

[0031] Figure 2 This is a perspective view of the heating cover in one embodiment.

[0032] Figure 3 This is a perspective view of a powder feeding device in one embodiment.

[0033] Figure 4 This is a cross-sectional view of the powder feeding device in the plug-in state in one embodiment.

[0034] Figure 5 This is a cross-sectional view of the powder feeding device in a clamping state in one embodiment.

[0035] Figure 6 This is a perspective view of the plug and seal in one embodiment.

[0036] Figure 7 This is a cross-sectional view of the plug and seal in one embodiment.

[0037] Reference numerals: 100, Polishing pad raw material mixing system; 10, Raw material barrel; 11, First raw material barrel; 12, Second raw material barrel; 13, Liquid conveying pipeline; 14, First heating structure; 141, Heating cover; 142, Light-emitting and heating tube; 143, Reflective coating; 15, Second heating structure; 20, Mixing barrel; 21, Weighing module; 22, Heating pipeline; 30, Stirring assembly; 31, Stirring paddle; 32, Rotary motor; 33, Return pump; 40, Gas generator; 50, Powder feeding device; 51, Fixed bracket; 511, Base plate; 512, Top plate; 513, Support plate; 52, Weighing machine; 53, Powder bag; 54, Powder conveying pipeline; 541, First switching valve; 542, Second switching valve; 55, Seal; 551, Connection part; 552, Sealing part; 56, Plug; 561, Through hole; 57, Vacuum pump; 58, Gas filter. Detailed Implementation

[0038] The polishing pad material mixing system 100 of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes, but the scope of protection of the present invention is not limited to the following embodiments.

[0039] like Figures 1 to 7 As shown, in one embodiment, a polishing pad raw material mixing system 100 is provided, including at least one raw material tank 10 and a mixing tank 20;

[0040] The raw material barrel 10 is equipped with a first heating structure 14 and is used to contain polyurethane prepolymer or curing agent. The raw material barrel 10 is connected to the mixing barrel 20 through a liquid conveying pipe 13 and is equipped with a second heating structure 15.

[0041] The aforementioned polishing pad raw material mixing system 100 uses a first heating structure 14 to heat the polyurethane prepolymer or curing agent in the raw material tank 10, and a second heating structure 15 to heat the polyurethane prepolymer or curing agent in the liquid conveying pipeline 13 before entering the mixing tank 20 for mixing. Since the viscosity of the polyurethane prepolymer or curing agent decreases after heating, the polyurethane prepolymer or curing agent is more easily mixed uniformly in the mixing tank 20, which helps to improve the fullness of raw material mixing and ensure the uniformity of density, hardness and compressibility of the finished polishing pad.

[0042] Specifically, such as Figure 3As shown, in one embodiment, the first heating structure 14 includes a heating cover 141 with a funnel-shaped opening. A light-emitting heating tube 142 is disposed at the center of the heating cover 141, and a reflective coating 143 is disposed on the inner wall of the heating cover 141. The funnel-shaped opening of the heating cover 141 is used to cover at least one raw material container 10. A liquid conveying pipe 13 passes through the heating cover 141 and communicates with a mixing container 20. The raw material container 10 is heated using the funnel-shaped heating cover 141. The heating cover 141 contains the light-emitting heating tube 142 and the reflective coating 143. The reflective coating 143 reflects the heat and infrared rays generated by the light-emitting heating tube 142 onto the raw material container 10, resulting in rapid heating and facilitating the installation and removal of the raw material container 10.

[0043] The raw material tank 10 includes a first raw material tank 11 for containing polyurethane prepolymer and a second raw material tank 12 for containing curing agent. Both the first raw material tank 11 and the second raw material tank 12 are located in a heating hood. The first raw material tank 11 and the second raw material tank 12 are respectively connected to the mixing tank 20 through liquid conveying pipes 13. A first fluid pump is provided between the first raw material tank 11 and the mixing tank 20, and a second fluid pump is provided between the second raw material tank 12 and the mixing tank 20. A first fluid valve is provided between the first fluid pump and the mixing tank 20, and a second fluid valve is provided between the second fluid pump and the mixing tank 20, for controlling the inflow of polyurethane prepolymer and curing agent.

[0044] Furthermore, the liquid delivery pipe 13 extends into the middle or bottom of the mixing tank 20, allowing the polyurethane prepolymer and curing agent to directly enter the middle or bottom of the mixing tank 20, achieving a closed-loop transfer between the raw material tank 10 and the mixing tank 20. This prevents the polyurethane prepolymer from coming into contact with moisture in the air and also prevents liquid from splashing into the mixing tank 20 and generating bubbles, thereby improving the mixing effect.

[0045] Furthermore, such as Figure 1 As shown, in one embodiment, the second heating structure 15 includes a heating resistance wire that is spirally wound around the liquid delivery pipe 13.

[0046] In this specific embodiment, the liquid conveying pipe 13 is a PFA plastic pipe with an operating temperature of -196℃ to 260℃, and the heating resistance wire has a heating temperature range of 25℃ to 150℃. Therefore, the liquid conveying pipe 13 has a wide applicable temperature range.

[0047] Specifically, such as Figure 1 As shown, in one embodiment, the mixing tank 20 has a sandwich structure in its wall, and a heating pipe 22 is provided within the sandwich structure. The heating pipe 22 is spirally arranged around the side wall of the mixing tank 20 and is used to supply heating gas. Heating the mixing tank 20 through the heating pipe 22 prevents the mixture from cooling and hardening during the stirring process, thus affecting the mixing effect.

[0048] In this specific embodiment, the mixing tank 20 is made of high-density polyethylene (HDPE), with a Teflon coating on the inner wall, and has a working temperature of 0℃~120℃. The heating temperature of the heating pipe 22 is 50℃~100℃.

[0049] Specifically, such as Figure 1 As shown, in one embodiment, the polishing pad raw material mixing system 100 includes a stirring assembly 30, which includes a stirring paddle 31 and a rotating motor 32. The stirring paddle 31 is connected to the rotating motor 32 and extends into the mixing tank 20.

[0050] The mixing tank 20 is a sealed tank body. The stirring paddle 31 includes a rotating shaft and a rotating paddle. One end of the rotating shaft is connected to the rotating motor 32, and the other end of the rotating shaft is movably inserted through the top of the mixing tank 20 and connected to the rotating paddle. A rotating bearing is provided between the rotating shaft and the mixing tank 20. A sealing cover is fitted on the rotating shaft. The sealing cover is used to seal the gap between the rotating shaft and the mixing tank 20.

[0051] Furthermore, such as Figure 1 As shown, in one embodiment, the polishing pad raw material mixing system 100 includes a stirring assembly 30, which includes a reflux pump 33. The inlet of the reflux pump 33 is connected to the bottom of the mixing tank 20, and the outlet of the reflux pump 33 is connected to the top of the mixing tank 20.

[0052] The mixing tank 20 has a mixture inlet at the top and a mixture outlet at the bottom. The inlet of the reflux pump 33 is connected to the mixture outlet, and the outlet of the reflux pump 33 is connected to the mixture inlet. The outlet of the reflux pump 33 is also connected to the casting mold for pouring the mixture into the casting mold. Therefore, a switch valve can be installed between the inlet and the mixture outlet of the reflux pump 33 to protect the reflux pump 33, and a three-way valve can be installed between the outlet of the reflux pump 33, the mixture inlet, and the casting mold to control the flow direction and opening / closing of the mixture.

[0053] A stirring component 30 is provided on the mixing tank 20. The stirring component 30 stirs and mixes the raw materials in the mixing tank 20 through the stirring paddle 31 and the reflux pump 33, which is conducive to the full mixing of the raw materials in the mixing tank 20, thereby improving the uniformity of the density, hardness and compressibility of the finished polishing pad.

[0054] Specifically, such as Figure 1As shown, in one embodiment, the mixing tank 20 is a closed mixing tank 20. The top of the mixing tank 20 is provided with an air inlet and an air outlet. The polishing pad raw material mixing system 100 includes a gas generator 40. The outlet of the gas generator 40 is connected to the air inlet, and a protective gas is supplied into the mixing tank 20 to isolate moisture in the air. The gas generator 40 is provided on the mixing tank 20 to supply protective gas into the mixing tank 20, thereby isolating the raw materials in the mixing tank 20 from the air, preventing moisture in the air from reacting with the polyurethane prepolymer to produce carbon dioxide gas, ensuring that the curing agent, microspheres and polyurethane prepolymer are fully mixed, and improving the quality controllability of the polishing pad.

[0055] The protective gases include inert gases such as nitrogen and argon.

[0056] In this specific embodiment, the air outlet is also connected to the gas generator 40. A gas switching valve is provided between the air inlet and the gas generator 40, and a gas switching valve is also provided between the air outlet and the gas generator 40. Therefore, the protective gas forms a gas circulation between the gas generator 40 and the mixing tank 20, completely isolating the air. The gas switching valve is used to control the opening and closing of the gas pipeline.

[0057] Specifically, such as Figure 1 As shown, in one embodiment, the polishing pad raw material mixing system 100 includes a support frame and a weighing module 21. The weighing module 21 is located between the support frame and the mixing tank 20 and is used to weigh the mixing tank 20. The weighing module 21 is used to weigh the weight of the raw materials added to the mixing tank 20 each time, thus allowing for precise control of the proportions of various raw materials and improving the quality of the polishing pad. The weighing module 21 includes a Mettler Toledo weighing module. Support ears are provided on both sides of the mixing tank 20, and the support ears are respectively connected to the support frame to keep the mixing tank 20 in a vertical position, facilitating the weighing of the raw materials added to the mixing tank 20 and also facilitating stirring and mixing.

[0058] Specifically, such as Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, in one embodiment, the polishing pad raw material mixing system 100 includes a powder feeding device 50, which includes a weighing machine 52, a powder conveying pipe 54, and a sealing element 55. The weighing machine 52 is used to hang the powder bag 53 and weigh the powder bag 53. The bottom of the powder bag 53 is connected to the mixing tank 20 through the powder conveying pipe 54. The sealing element 55 is sleeved on the powder conveying pipe 54 and abuts against the bottom of the powder bag 53.

[0059] The polishing pad raw material mixing system 100 is equipped with a powder feeding device 50. The powder bag 53 containing microspheres is directly suspended on the weighing machine 52. The powder bag 53 and the polishing pad mixing tank are connected by a powder conveying pipe 54, and a sealing element 55 is used to ensure a sealed connection between the powder conveying pipe 54 and the powder bag 53. During the feeding process, the powder feeding device 50 can directly feed microspheres into the polishing pad mixing tank through the powder conveying pipe 54. The weighing machine 52 can display the weight change of the powder bag 53 in real time. The amount of microspheres added can be obtained by the weight change of the powder bag 53, which effectively reduces the workload of the microsphere feeding process, avoids the microsphere powder from scattering during the feeding process, improves the efficiency and accuracy of microsphere feeding, and thus improves the accuracy of the raw material mixing ratio and the quality of the polishing pad.

[0060] Specifically, such as Figure 1 As shown, in one embodiment, the powder feeding device 50 includes a vacuum pump 57 and a gas filter 58. The inlet of the vacuum pump 57 is connected to the powder conveying pipeline 54. A first switching valve 541 is also provided on the powder conveying pipeline 54, located between the vacuum pump 57 and the powder bag 53. Meanwhile, the gas filter 58 is connected to the powder conveying pipeline 54 between the first switching valve 541 and the powder bag 53. A second switching valve 542 is provided between the gas filter 58 and the powder conveying pipeline 54.

[0061] Specifically, such as Figure 3 As shown, in one embodiment, the fixed bracket 51 includes a base plate 511, a top plate 512 and a support plate 513. The two ends of the support plate 513 are connected to the base plate 511 and the top plate 512 respectively. The weighing machine 52 is connected to the top plate 512 and is located between the base plate 511 and the top plate 512.

[0062] The weighing machine 52 includes a hanging scale, which includes a sensing body and a hook. One end of the sensing body is connected to the top plate 512, and the other end of the sensing body is rotatably connected to the hook. The hook is used to hang the powder bag 53.

[0063] Furthermore, such as Figure 4 , Figure 5 and Figure 6 As shown, in one embodiment, the seal 55 includes a sealing portion 552, which forms a funnel-shaped opening around the powder conveying pipe 54, and the funnel-shaped opening of the sealing portion 552 is used to abut against the bottom of the powder bag 53.

[0064] Furthermore, the flared opening of the sealing part 552 is spherical, and the radius of the sealing part 552 is equal to the bottom radius of the powder bag 53; the flared opening of the sealing part 552 can also be conical, and the generatrix of the cone of the sealing part 552 is tangent to the bottom of the powder bag 53.

[0065] The bottom of the plug 56 is flared, and the bottom of the plug 56 can extend into the flared opening of the sealing part 552 and clamp the bottom of the powder bag 53. The sealing part 55 is provided with the sealing part 552, which is a spherical or conical flared opening. By cooperating with the bottom of the flared plug 56, it clamps the bottom of the powder bag 53, preventing the microspheres from overflowing from the connection between the powder bag 53 and the powder conveying pipe 54, and effectively avoiding the scattering of microsphere powder.

[0066] In this specific embodiment, the sealing element 55 includes a connecting part 551 connected to the sealing part 552, and the connecting part 551 is threadedly connected to the powder conveying pipe 54. The sealing element 55 of the powder dispensing device 50 is provided with a connecting part 551 and a sealing part 552. The connecting part 551 is threadedly connected to the powder conveying pipe 54 for sealing, and the sealing part 552 is provided with a spherical or conical funnel-shaped opening. By cooperating with the bottom of the plug 56, it clamps the bottom of the powder bag 53 to prevent microspheres from overflowing from the connection between the powder bag 53 and the powder conveying pipe 54, effectively preventing the microsphere powder from scattering.

[0067] like Figure 4 and Figure 5 As shown, during the installation of the powder feeding device 50, the powder bag 53 is first suspended on the weighing machine 52, and then the plug 56 of the powder conveying pipe 54 is inserted into the bottom of the powder bag 53 (e.g., Figure 3 As shown), align the bottom of the plug 56 with the bottom of the powder bag 53, then move the seal 55 on the powder conveying pipe 54 until the flared opening of the seal 55 is aligned with the bottom of the powder bag 53. At this point, the seal 55 and the plug 56 tightly clamp the bottom of the powder bag 53 (as shown). Figure 4 As shown in the diagram, this effectively prevents microspheres from leaking out of the gap between the powder bag 53 and the powder conveying pipe 54, improving the sealing effect inside the powder bag 53. After installation, a vacuum pump 57 can be used to create a vacuum, allowing the microspheres in the powder bag 53 to enter the mixing tank 20 through the powder conveying pipe 54. The weight reduction of the powder bag 53 displayed on the weighing machine 52 at this time is the weight of the microspheres added. Therefore, for better sealing and weighing effects, the position of the plug 56 on the powder bag 53 and the position where the weighing machine 52 is suspended are preferably on the same vertical axis.

[0068] Furthermore, such as Figure 6 and Figure 7 As shown, in one embodiment, a hollow plug 56 is provided at one end of the powder conveying pipe 54. The plug 56 is located in the powder bag 53 and has multiple through holes 561 distributed on it.

[0069] Furthermore, the top of the plug 56 is conical, and the through holes 561 are distributed on the conical surface of the plug 56. The hollow plug 56 on the powder conveying pipe 54 has through holes 561. Firstly, the conical shape of the plug 56 can improve the efficiency of inserting the powder bag 53. Secondly, the through holes 561 on the conical surface facilitate the flow of microspheres along the top of the cone into the bottom of the plug 56, preventing the microspheres from clogging the plug 56 and the opening of the conveying pipe.

[0070] Among them, the through holes 561 are arranged in rows along the conical generatrix of the plug 56, and multiple rows of through holes 561 are distributed around the central axis of the plug 56.

[0071] In this specific embodiment, the central axis of the through hole 561 is inclined towards the side near the bottom of the plug 56, and the angle between the central axis of the through hole 561 and the generatrix of the plug 56 is 30°~60°. The plug 56 has a through hole 561 inclined towards the bottom, and the angle between the axis of the through hole 561 and the conical generatrix of the plug 56 is set to 30°~60°, which helps to improve the efficiency of the microspheres passing through the through hole 561, prevents the microspheres from clogging the through hole 561, and further improves the microsphere dosing efficiency.

[0072] Specifically, in one embodiment, the sealing portion 552 includes a plurality of elastic sheets surrounding the connecting portion 551, with a gap between adjacent elastic sheets. Since the sealing portion 552 includes a plurality of independent elastic sheets, the elastic sheets can move away from the central axis under the action of external force, thereby adapting to the different sizes of the bottom of the powder bag 53, ensuring that the sealing portion 552 fits tightly with the powder bag 53, and improving the sealing effect.

[0073] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and 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 this invention.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0077] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0078] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A polishing pad raw material mixing system, characterized in that, include: At least one raw material barrel (10) is provided with a first heating structure (14) and the raw material barrel (10) is used to contain polyurethane prepolymer or curing agent; A mixing tank (20) is provided, wherein the raw material tank (10) is connected to the mixing tank (20) via a liquid conveying pipe (13), and a second heating structure (15) is provided on the liquid conveying pipe (13); A powder feeding device (50) includes a weighing machine (52), a powder conveying pipe (54), and a sealing element (55). The weighing machine (52) is used to hang the powder bag (53) and weigh the powder bag (53). The bottom of the powder bag (53) is connected to the mixing tank (20) through the powder conveying pipe (54). The sealing element (55) is sleeved on the powder conveying pipe (54) and abuts against the bottom of the powder bag (53). The weighing machine (52) is connected to the top of the powder bag (53) and is used to obtain the amount of microspheres added to the mixing tank (20) by the weight change of the powder bag (53); One end of the powder conveying pipe (54) is provided with a hollow plug (56), the plug (56) is located in the powder bag (53), and the plug (56) has a plurality of through holes (561) distributed on it; The sealing element (55) includes a sealing part (552) and a connecting part (551) connected to the sealing part (552). The sealing part (552) forms a funnel-shaped opening around the powder conveying pipe (54). The funnel-shaped opening of the sealing part (552) is used to abut against the bottom of the powder bag (53). The bottom of the plug (56) is flared, and the bottom of the plug (56) can extend into the flared opening of the sealing part (552) and clamp the bottom of the powder bag (53) with the sealing part (552); The connecting part (551) is threadedly connected to the powder conveying pipe (54), the sealing part (552) includes an elastic sheet surrounding the connecting part (551), and the bottom of the plug (56) is in contact with the bottom of the powder bag (53). The top of the plug (56) is conical, and the through hole (561) is distributed on the conical surface of the plug (56). The polishing pad raw material mixing system (100) also includes a support frame and a weighing module (21). The weighing module (21) is located between the support frame and the mixing barrel (20) and is used to weigh the mixing barrel (20).

2. The polishing pad raw material mixing system according to claim 1, characterized in that, The polishing pad raw material mixing system (100) includes a stirring assembly (30), which includes a reflux pump (33). The inlet of the reflux pump (33) is connected to the bottom of the mixing tank (20), and the outlet of the reflux pump (33) is connected to the top of the mixing tank (20).

3. The polishing pad raw material mixing system according to claim 1, characterized in that, The first heating structure (14) includes a heating cover (141) with a flared opening. A light-emitting heating tube (142) is provided at the center of the heating cover. A reflective coating (143) is provided on the inner wall of the heating cover (141). The flared opening of the heating cover (141) is used to cover the at least one raw material tank (10). The liquid conveying pipe (13) passes through the heating cover (141) and communicates with the mixing tank (20).

4. The polishing pad raw material mixing system according to claim 1, characterized in that, The second heating structure (15) includes a heating resistance wire, which is spirally wound around the liquid delivery pipe (13).

5. The polishing pad raw material mixing system according to claim 1, characterized in that, The mixing tank (20) has a sandwich structure in its wall, and a heating pipe (22) is provided in the sandwich structure. The heating pipe (22) is spirally arranged around the side wall of the mixing tank (20) and is used to supply heating gas.

6. The polishing pad raw material mixing system according to claim 1, characterized in that, The mixing tank (20) is a closed mixing tank. The top of the mixing tank (20) is provided with an air inlet and an air outlet. The polishing pad raw material mixing system (100) includes a gas generator (40). The outlet of the gas generator (40) is connected to the air inlet to deliver protective gas into the mixing tank (20) to isolate moisture in the air.

7. The polishing pad raw material mixing system according to claim 1, characterized in that, The polishing pad raw material mixing system (100) includes a stirring paddle (31) and a rotating motor (32), the stirring paddle (31) being connected to the rotating motor (32), and the stirring paddle (31) extending into the mixing tank (20).

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