Wafer thinning machine cooling pipe assembly and processing technology thereof

Abstract

A wafer thinning machine cooling pipe assembly and its processing technology, the assembly includes a fluid module and two fluid pipes, the fluid pipes and the fluid module are assembled by interference fit, the fluid module is provided with a threaded column at the first end, the second end is respectively sealed and connected with the first port of the two fluid pipes by interference fit, the second port of each fluid pipe is provided with a plug, and a plurality of injection ports are arranged on the pipe wall section near the second port. Its processing technology includes laser blanking, CNC machining, bending forming, two times of stress relief by tempering, two times of wire cutting, two times of laser welding, M5 tapping, pressure seal test, fluid polishing, stainless steel passivation and cleaning, size detection and function test and assembly and other processes. The present case adopts a welding seam-free structure design and an interference fit laser welding assembly method, which fully guarantees the inner surface quality of the flow channel, realizes batch qualified production of the assembly with low manufacturing cost, and improves the processing efficiency of the wafer thinning machine.

Description

Technical Field

[0001] This invention relates to the field of semiconductor wafer thinning technology, specifically to a wafer thinning machine cooling tube assembly and its processing technology. Background Technology

[0002] In the semiconductor chip manufacturing process, the preparation of high-purity single-crystal silicon ingots begins with the purification and crystal pulling of polycrystalline silicon. First, industrial silicon (derived from SiO2) is purified into electronic-grade polycrystalline silicon (purity reaching 9 to 11 nines) through chemical vapor deposition or a modified Siemens process. Then, using the Czochralski (CZ) method or zone melting method, cylindrical single-crystal silicon ingots are slowly pulled in a crystal growth furnace guided by seed crystals. These ingots are then cut into thin wafers less than 1 mm thick using a diamond wire saw (i.e., the mainstream 8-inch and 12-inch wafers). These wafers are then thinned by back-side grinding using a wafer thinning machine to achieve the thickness and surface quality required for subsequent packaging. Cooling measures are indispensable during the thinning process. Continuous circulation and atomization of the grinding coolant through cooling pipe assemblies stabilizes the processing zone temperature within a narrow range of ±1℃. This prevents dimensional deviations caused by thermal deformation and ensures stable material performance, a prerequisite for normal equipment operation and achieving nanoscale processing precision. However, the cooling pipe assemblies equipped in existing wafer thinning machines suffer from systemic problems in their structural design and processing technology, severely restricting thinning quality and production efficiency. These cooling pipe assemblies employ a slot-type welding structure, using TIG welding (single-sided welding with double-sided forming), resulting in weld seams inside the fluid channels. This makes it impossible to avoid welding defects such as backside oxidation and weld beads, and also makes it difficult to control the surface roughness of the channels within the basic requirement of Ra1.6μm. Furthermore, the main material is often 304 stainless steel, further increasing the technological difficulty of CNC machining, die bending, welding deformation control, wire cutting, and fluid polishing. Key process indicators are generally out of control; for example, post-weld flatness is greater than 0.05mm, wire cutting accuracy is greater than 0.03mm, fluid polishing deformation is greater than 0.02mm, and die bending accuracy is greater than 0.1mm, all significantly deviating from the design tolerance range.

[0003] The aforementioned structural design and current process deficiencies not only make it impossible to repair defects in the inner wall of the pipe and result in surface roughness far below design values, directly affecting the spray stability of the coolant and inducing Karman vortex excitation and turbulent chattering that leads to temperature control failure, but also accelerate abnormal wear of the grinding wheels, causing fluctuations in thinning quality. Ultimately, the dilemma of cooling components being "theoretically feasible but practically difficult to manufacture" forces production lines to lower acceptance standards, resulting in persistently high product defect rates and continuously rising manufacturing costs and processing cycles. This has become a key bottleneck restricting the development and industrialization of nanoscale chips, urgently requiring fundamental breakthroughs in both structural design innovation and advanced manufacturing process improvements. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems and provide a wafer thinning machine cooling tube assembly and its processing technology.

[0005] The technical solution of this invention is: a cooling pipe assembly for a wafer thinning machine, comprising a fluid module and two fluid pipes, wherein the fluid pipes and the fluid module are assembled by an interference fit. The first end of the fluid module is provided with a threaded post for connecting an external liquid supply component, and the second end of the fluid module is respectively sealed to the first ports of the two fluid pipes by an interference fit. A plug is fixed at the second port of each fluid pipe, and several injection ports are opened on the pipe wall section of each fluid pipe near the second port. The injection ports are evenly spaced along the axial direction of the fluid pipe, and each injection port has a groove structure with a groove width of 0.18-0.23 mm, a groove length of 3.3-3.5 mm, and a groove depth of 1-1.03 mm.

[0006] Furthermore, in the aforementioned wafer thinning machine cooling pipe assembly, the fluid module has two parallel discharge channels for discharging coolant. Each discharge channel includes a first channel section and a second channel section connected in series along the coolant flow direction. The first channel section and the second channel section are smoothly connected by a variable diameter transition structure. The inlet end of the first channel section is configured as a liquid inlet that connects with the threaded column. The internal channel of the threaded column is connected to the first channel section and the second channel section to introduce external water into the discharge channel. The outlet end of the second channel section is configured as a liquid outlet that connects with the fluid pipe.

[0007] Specifically, the equivalent flow diameter of the first channel segment is defined as D1, and the equivalent flow diameter of the second channel segment is defined as D2, with D1 > D2.

[0008] Furthermore, in the aforementioned wafer thinning machine cooling pipe assembly, the fluid pipe is formed by bending with an integrated mold, including a first straight pipe section, a first elbow, a second straight pipe section, a second elbow, and a third straight pipe section. The first and third straight pipe sections are arranged vertically with a staggered vertical arrangement, and the second straight pipe section is inclinedly connected between the two. The outlet end of the first straight pipe section is fixedly connected to the inlet end of the second straight pipe section through the first elbow, and the outlet end of the second straight pipe section is fixedly connected to the inlet end of the third straight pipe section through the second elbow, so that the three straight pipe sections are connected in series to form a long-distance extended integrated drainage channel.

[0009] Furthermore, in the aforementioned wafer thinning machine cooling pipe assembly, the plug is a solid cylindrical plug, the plug is fixed to the second port of the fluid pipe by a press-fit interference fit, and the closed end face of the plug is recessed into the second port of the fluid pipe.

[0010] The present invention also provides a processing technology for a cooling tube assembly of a wafer thinning machine, comprising the following steps:

[0011] (1) Use laser cutting equipment to cut stainless steel raw materials to obtain module blanks of fluid modules and pipe blanks of fluid pipelines with predetermined outlines.

[0012] (2) The module blank of the fluid module is machined by turning and milling composite machining center to form a fluid module matrix with a first channel section and a second channel section, and the inner wall roughness and dimensional tolerance of the first channel section and the second channel section are controlled.

[0013] (3) Select a finely drawn tube with an inner surface roughness of less than Ra1.6 as the tube blank for the fluid pipeline, and perform wire cutting according to the design length.

[0014] (4) The blank of the fluid pipeline is placed in a bending die for a cold bending process to bend it into the target three-dimensional shape.

[0015] (5) Place the bent fluid pipe in a tempering furnace and perform stress-relief annealing at a temperature of 350-400°C to eliminate residual stress generated by cold bending and reduce the springback of stainless steel.

[0016] (6) The fluid pipe that has been bent into shape is cut with precise dimensions for the first time, and after being cleaned, dried and qualified, it is then welded with the plug by a robot laser for the first time.

[0017] (7) After the fluid module processed in step (2) is degreased, cleaned and dried, it is first robotic laser welded to the threaded column. The deformation of the weld flatness is less than 0.03mm. The drilling and tapping of the M5 threaded hole are completed. The thread qualification requirement must be passed by the thread go and no-go gauge inspection.

[0018] (8) The second channel section of the degreasing, cleaning and drying is press-fitted into the preset position inside the fluid pipeline in an interference fit manner. The interference fit is 0.01 to 0.04 mm. At the same time, the fluid module base is assembled with the assembled fluid pipeline to obtain a composite body to meet the welding size requirements.

[0019] (9) Perform a second robotic laser welding on the assembly prepared in step (8) and control the total deformation of the weld flatness to be less than 0.05 mm.

[0020] (10) The assembled body after welding is subjected to stress-relief annealing again to eliminate residual stress generated in the heat-affected zone of welding.

[0021] (11) Introduce pressurized medium into the assembly and maintain pressure to test the overall sealing performance.

[0022] (12) After welding the assembly, perform coordinate measuring machine (CMM) inspection to check whether the geometric tolerances meet the design requirements of the drawings.

[0023] (13) The assembly is positioned and cut using cutting equipment and special tooling molds to complete the second wire cutting, which meets the precise tolerance size requirements of the spray nozzle.

[0024] (14) Fluid polishing: The fluid flows through the threaded column, first channel section, second channel section and fluid pipe of the assembly at a set flow rate and pressure, and flows out from the nozzle to perform abrasive flow polishing on the inner wall of the channel in contact with the fluid, thereby reducing the surface roughness to meet the requirement of Ra1.6 or below.

[0025] (15) The polished assembly is immersed in a passivation solution to form a passivation film, followed by pure water cleaning and drying.

[0026] (16) Use a coordinate measuring machine or special inspection tool to check the key dimensions of the assembly to confirm that they meet the requirements of the drawings.

[0027] (17) Simulate actual working conditions and conduct performance tests on the combined body for spray fan angle, pressure resistance or atomization effect.

[0028] (18) After the qualified assembly is cleaned and vacuum-packed, the final cooling pipe assembly is obtained.

[0029] Preferably, in the above-mentioned wafer thinning machine cooling tube assembly processing technology, in steps (5) and (10): the stress-relief annealing temperature is 350-400℃, the holding time is 100-150min, and it is taken out after being cooled to 40-60℃ in the furnace, and the heating rate is controlled at 5-15℃ / min.

[0030] Preferably, in the above-mentioned wafer thinning machine cooling pipe assembly processing technology, in steps (6) and (13): wire cutting adopts slow wire EDM, and the cutting wire diameter is 0.15-0.25mm.

[0031] Preferably, in the above-mentioned wafer thinning machine cooling pipe assembly processing technology, in steps (7) and (9): the laser power of laser welding is 300W to 500W, the laser is a fiber laser, the welding speed is 4 to 8 mm / s, the protective gas is argon with a purity of 99.9% to 99.999%, and the gas flow rate is 20 to 30 L / min.

[0032] Preferably, in the above-mentioned wafer thinning machine cooling pipe assembly processing technology, in step (17): the selected polishing slurry is fluid-jet and atomized under a pressure of 0.1 to 0.2 MPa.

[0033] The terms "first," "second," etc., used in this document are only used to distinguish components or operations described with the same technical terms, and do not specifically indicate order or sequence, nor do they constitute a limitation on the scope of this application.

[0034] The terms “connection” or “location” used in this article refer to direct physical contact or indirect physical contact between two or more components or devices, and may also refer to the relationship between them in operation or action; and the terms “includes”, “includes”, “has” and other such terms used are all open-ended expressions, meaning that they include but are not limited to these.

[0035] Unless otherwise specified, the terms used herein generally have their conventional meanings in the art, the content of this case, and the relevant specific context. To facilitate a better understanding of this case by those skilled in the art, some of the terms used to describe this case will be explained below or elsewhere in the specification to provide additional guidance.

[0036] Compared with the prior art, the working principle and advantages of the present invention are as follows:

[0037] (1) Through structural improvement, the present invention completely eliminates the weld area inside the fluid pipe, so that the inner wall of the flow channel maintains continuity and consistency. The corresponding fluid polishing process can be fully applied to the entire inner surface, thereby controlling the surface roughness within the range required by the wafer thinning process and improving the fluid transmission quality.

[0038] (2) The fluid module and fluid pipe of the present invention are connected by interference fit, and precise positioning and fixing are achieved directly by radial extrusion without the need for additional seals, ensuring that the assembly dimensional tolerances between the components meet the design requirements; at the same time, all welding processes are laser welding, the heat input is concentrated and controllable, the deformation after overall welding is minimal, which meets the installation dimensional accuracy requirements of the cooling components and ensures the stable performance of the spraying effect and cooling performance.

[0039] (3) All component connection nodes of the present invention are laser welded, replacing the raw material tape or sealant used in traditional threaded connections. This fundamentally avoids the leakage risks caused by aging and creep of sealing materials, so as to accurately control the geometric dimensions and position of the plug end, so that the fluid ejected from the nozzle is evenly distributed in a fan shape and the effect is predictable, meeting the process requirements for cooling uniformity.

[0040] (4) The structural design of the present invention effectively avoids fluid-induced vibration during the operation of the fluid pipeline by optimizing the flow channel direction and support stiffness. Specifically, the structure can significantly suppress the generation of various vibration modes, including Karman vortex excitation, turbulent buffeting and fluid elastic instability, thereby ensuring the dynamic stability of the pipeline system during long-term continuous operation and avoiding problems such as loose connection, stress fatigue and jet deviation caused by vibration.

[0041] (5) Compared with existing similar structures, the present invention has a significant advantage in terms of manufacturing cost. Thanks to the integrated design of the structure and the simple assembly method of interference fit, the total manufacturing cost of the product is significantly reduced, and the quality reliability and consistency are high. The processing cycle is greatly shortened, and the cooling pipe assembly can achieve a high yield target of passing the assembly in one go.

[0042] (6) The present invention uses a laser welding robot to replace the traditional manual TIG welding, realizing full automation control, effectively avoiding common defects such as back oxidation, weld beads, and lack of fusion, ensuring the dimensional repeatability and heat input consistency of the weld, which not only greatly improves production efficiency, but also provides a reliable guarantee for mass production. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the cooling pipe assembly of the wafer thinning machine of the present invention.

[0044] Figure 2 This is an exploded view of the cooling pipe assembly of the wafer thinning machine of the present invention.

[0045] Figure 3 This is a partial cross-sectional structural diagram of the cooling pipe assembly of the wafer thinning machine of the present invention.

[0046] Figure 4 for Figure 1 Top view.

[0047] Figure 5 for Figure 3 Top view.

[0048] Figure 6 This is a process flow diagram of the cooling pipe assembly of the wafer thinning machine of the present invention.

[0049] The meanings of the labels in the attached figures are as follows: 1-Fluid module, 2-First channel section, 3-Second channel section, 4-Threaded column, 5-Fluid pipe, 51-First straight pipe section, 52-First elbow, 53-Second straight pipe section, 54-Second elbow, 55-Third straight pipe section, 6-Injection port, 7-Plug. Detailed Implementation

[0050] The technical solution of the present invention will now be described clearly, completely, and in detail with reference to the accompanying drawings, so as to make it easier to understand and master. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0051] like Figures 1-5 As shown, the present invention provides a cooling pipe assembly for a wafer thinning machine, including a fluid module 1 and two fluid pipes 5, wherein the fluid pipes 5 and the fluid module 1 are assembled by an interference fit.

[0052] According to the technical solution of the present invention, the first end of the fluid module 1 is provided with a threaded post 4 for connecting to an external liquid supply component, and the second end of the fluid module 1 is respectively sealed to the first ports of the two fluid pipes 5 by an interference fit. A plug 7 is fixedly provided at the second port of each fluid pipe 5, and several injection ports 6 are opened on the pipe wall section of each fluid pipe 5 near the second port. The injection ports 6 are evenly spaced along the axial direction of the fluid pipe 5, and each injection port has a groove-shaped structure with a groove width of 0.18–0.23 mm, a groove length of 3.3–3.5 mm, and a groove depth of 1–1.03 mm. The injection port 6 can serve as the final output channel for the fluid, used to spray the high-pressure fluid inside the fluid pipe 5 to the target area in a predetermined direction and flow rate to achieve targeted cooling, cleaning, or flushing functions.

[0053] Preferably, in the above structure: the plug 7 is a solid cylindrical plug, and the plug 7 is fixed to the second port of the fluid pipe 5 by a press-fit interference fit, and the closed end face of the plug 7 is recessed into the second port of the fluid pipe 5. This plug 7 is used to seal the second port of the fluid pipe 5 to prevent fluid from being directly discharged from the end, thereby forcing the fluid inside the pipe to change direction and spray outward from the injection port 6 opened on the pipe wall.

[0054] Preferably, in the above structure: the fluid pipeline 5 is formed by bending with an integral mold, including a first straight pipe section 51, a first elbow 52, ​​a second straight pipe section 53, a second elbow 54 and a third straight pipe section 55. The first straight pipe section 51 and the third straight pipe section 55 are arranged vertically with a staggered vertical arrangement. The second straight pipe section 53 is inclinedly connected between the two. The outlet end of the first straight pipe section 51 is fixedly connected to the inlet end of the second straight pipe section 53 through the first elbow 52. The outlet end of the second straight pipe section 53 is fixedly connected to the inlet end of the third straight pipe section 55 through the second elbow 54, so that the three straight pipe sections are connected in series to form a long-distance extended integral drainage channel.

[0055] Preferably, in the above structure: the fluid module 1 has two parallel discharge channels for discharging coolant. Each discharge channel includes a first channel section 2 and a second channel section 3 connected in series along the coolant flow direction. The first channel section 2 and the second channel section 3 are smoothly connected by a variable diameter transition structure. This variable diameter transition structure is used to gradually compress the channel cross-section as the fluid flows from the large diameter section to the small diameter section, thereby increasing the fluid velocity and outlet dynamic pressure to meet the requirements of jet or enhanced cooling. The inlet end of the first channel section 2 is configured as an inlet port that connects with the threaded column 4. The internal channel of the threaded column 4 is connected to the first channel section 2 and the second channel section 3 to introduce external water into the discharge channel. The outlet end of the second channel section 3 is configured as a drain port that connects with the fluid pipe 5.

[0056] Specifically, in the structure of the fluid module 1 described above, the equivalent flow diameter of the first channel segment 2 is defined as D1, and the equivalent flow diameter of the second channel segment 3 is defined as D2, with D1 > D2.

[0057] The following examples and comparative examples were conducted under exactly the same grinding reference conditions, with the only difference being whether or not the cooling component structure of the present invention was used.

[0058] like Figure 6 As shown, the processing technology of a wafer thinning machine cooling pipe assembly in this embodiment includes the following steps:

[0059] (1) The stainless steel raw material is cut by laser cutting equipment to obtain the module blank of fluid module 1 and the tube blank of fluid pipeline 5 with predetermined outline.

[0060] (2) The module blank of the fluid module 1 is machined by turning and milling composite machining center to form a fluid module 1 base with a first channel section 2 and a second channel section 3, and the inner wall roughness and dimensional tolerance of the first channel section 2 and the second channel section 3 are controlled.

[0061] (3) Select a finely drawn tube with an inner surface roughness of less than Ra1.6 as the tube blank for fluid pipeline 5, and perform wire cutting according to the design length.

[0062] (4) The blank of the fluid pipe 5 is placed in a bending die for a cold bending process to bend it into the target three-dimensional shape.

[0063] (5) Place the bent fluid pipe 5 in a tempering furnace and perform stress-relief annealing at 350°C for 120 min. After cooling to below 50°C in the furnace, remove the pipe and control the heating rate to below 10°C / min to eliminate residual stress generated by cold bending and reduce the springback of stainless steel.

[0064] (6) The fluid pipe 5 that has been bent into shape is subjected to a first wire cut with precise dimensions. The first wire cut is performed by slow wire EDM with a wire diameter of 0.2 mm. After being cleaned, dried and qualified, it is then laser welded to the plug 7.

[0065] (7) After cleaning and drying the fluid module 1 processed in step (2), perform the first robotic laser welding with the threaded column 4. The laser power of the first robotic laser welding is 300W to 500W, the laser is a fiber laser, the welding speed is 6mm / s, the shielding gas is argon with a purity of 99.99% or higher, the gas flow rate is 25L / min or higher, the welding flatness deformation is less than 0.03mm, and the drilling and tapping of the M5 threaded hole are completed. The thread qualification requirement must be passed by the thread go and no go gauge inspection.

[0066] (8) The second channel section 3 of the degreasing, cleaning and drying is press-fitted into the preset position inside the fluid pipe 5 in an interference fit manner. The interference fit is 0.02mm. At the same time, the fluid module 1 base is assembled with the assembled fluid pipe 5 to obtain a combined body to meet the welding size requirements.

[0067] (9) Perform a second robotic laser welding on the assembly prepared in step (8). The laser power of the second robotic laser welding is 350W, the laser is a fiber laser, the welding speed is 6mm / s, the shielding gas is argon with a purity of 99.99% or higher, the gas flow rate is 25L / min or higher, and the total deformation of the welding flatness is controlled to be less than 0.05mm.

[0068] (10) The assembled body after welding is subjected to stress-relief annealing again to eliminate the residual stress generated in the heat-affected zone of welding. The stress-relief annealing temperature is 350°C, the holding time is 120 min, and it is taken out after being cooled to below 50°C in the furnace. The heating rate is controlled below 10°C / min.

[0069] (11) Pressurized medium is introduced into the assembly and pressure is maintained to test the overall sealing performance. The pressurized medium for the 0.3MPa pressure sealing test is compressed air or nitrogen. The test pressure is twice the design working pressure and the pressure holding time is 15min. If no bubbles are produced when immersed in water, the sealing performance is deemed qualified.

[0070] (12) After welding the assembly, perform coordinate measuring machine (CMM) inspection to check whether the geometric tolerances meet the design requirements of the drawings.

[0071] (13) The assembly is positioned and cut using cutting equipment and special tooling molds to complete the second wire cutting. The second wire cutting uses slow wire EDM with a wire diameter of 0.2mm to meet the precise tolerance requirements of the nozzle.

[0072] (14) Fluid polishing: The fluid flows through the threaded column 4, the first channel section 2, the second channel section 3 and the fluid pipe 5 of the assembly at a set flow rate and pressure, and flows out from the nozzle 6 to perform abrasive flow polishing on the inner wall of the channel in contact with the fluid, thereby reducing the surface roughness to meet the requirement of Ra1.6 or below.

[0073] (15) The polished assembly is immersed in a passivation solution to form a passivation film, followed by pure water cleaning and drying.

[0074] (16) Use a coordinate measuring machine or special inspection tool to check the key dimensions of the assembly to confirm that they meet the requirements of the drawings. The dimension checks include the symmetry of fluid module 1 and fluid pipe 5 as 0.4 mm, the perpendicularity as 0.08 mm, the flatness as 0.06 mm, the total length as 72.5 mm, the bending angle as 135 degrees, and the width of each nozzle as 0.2 mm, and the plane of the nozzle end of the two fluid pipes 5 as 0.3 mm.

[0075] (17) Simulate the actual working conditions and conduct performance tests on the assembly for spray fan angle, pressure resistance or atomization effect. The selected grinding fluid is sprayed and atomized under a pressure of 0.15MPa.

[0076] (18) After the qualified assembly is cleaned and vacuum-packed, the final cooling pipe assembly is obtained.

[0077] The cooling pipe assembly prepared in the embodiment is installed on the taiko grinding wheel. The temperature control circulation unit, which is connected to the axial channel of the wafer thinning machine spindle, is turned on. The polishing fluid / cooling fluid is delivered to the annular liquid storage chamber of the guide distribution plate through the central hole of the spindle. Under pressure drive, the polishing fluid / cooling fluid is injected into the entrance of the grinding arc area where the taiko grinding wheel and the wafer are in contact through the injection port 6, so as to achieve all-round atomization cooling and temperature reduction.

[0078] A comparative example was selected. The conventional external nozzle cooling scheme, found in existing technologies, was employed. This involves fixing a coolant nozzle outside the spindle of the thinning machine and applying room-temperature coolant to the periphery of the grinding area via open spraying. In this comparative example, because the nozzle was far from the grinding arc zone, the coolant spraying process was severely interfered with by the centrifugal airflow generated by the high-speed rotation of the spindle. The coolant remained as large droplets after spraying, failing to achieve effective atomization. Some coolant was blown away before reaching the crystal surface, and heat exchange relied solely on the random adhesion of splashed droplets, resulting in a mediocre cooling effect.

[0079] Compared to the comparative example, the polishing slurry / cooling slurry in this embodiment is finely atomized after being ejected from the nozzle 6, without continuous liquid columns or large droplets, resulting in a uniform wetted state on the wafer surface and no dry polishing areas. This is beneficial for obtaining a smoother wafer polishing surface and is superior to the comparative example in terms of cooling efficiency.

[0080] The key technology of this invention lies in the combination of the seamless inner wall design of the fluid pipeline and the laser welding assembly method with a full interference fit for the cooling components. Figures 1-3 The focus is on showcasing the components and specific structures involved in the cooling system, including the fluid module, fluid piping, and interference fits between the components. Figure 3 and Figure 5 This paper demonstrates a laser-welded sealing structure that replaces traditional PTFE tape sealing, and how the geometric dimensions of the spray fan-shaped effect are adjusted by controlling the shape of the plug end. By employing interference fits throughout to ensure assembly dimensional tolerances, and using a laser welding robot to replace manual TIG welding for automated welding, the laser welding deformation is controlled to less than 0.05 mm. Simultaneously, a spray pressure of 0.15 MPa is designed, and the inner wall of the fluid pipe is polished to a surface roughness Ra≤1.6 μm, thus achieving one-time assembly qualification of the cooling pipe assembly. This avoids defects such as oxidation on the back of the weld and weld beads, while also eliminating the risk of leakage caused by aging of traditional PTFE tape seals. It ensures that the water spray effect meets cooling requirements and precisely controls wafer processing temperature variations within ±1℃. Furthermore, due to the seamless inner wall structure and precise dimensional control, vibration phenomena such as Karman vortex excitation, turbulent chattering, and fluid elastic instability are structurally eliminated, significantly improving product quality reliability and stability, reducing manufacturing costs compared to existing structures, and drastically shortening the processing cycle. For specific brands and models of laser welding robots, milling and turning machining centers, interference fit press fitting equipment, bending dies, wire cutting tooling fixtures, fluid polishing equipment, passivation cleaning fluid formulations, and sealing testing equipment, as well as other auxiliary components or measures, those skilled in the art can make conventional settings based on existing technologies. This case does not have any special requirements regarding the selection of models and their combined use.

[0081] Thus, by adopting the technical solution of this invention, through the systematic control of the entire process from raw materials, structural design, process logic, process parameters to testing standards, it solves many technical problems in the prior art, such as the inner wall weld of the cooling component, high roughness, poor flatness of the spray nozzle, large welding deformation and residual stress, and has significant technical progress and industrial applicability.

[0082] The technical solution, working process, and implementation effects of the present invention have been described in detail above. It should be noted that the described examples are only typical examples of the present invention. In addition, the present invention may have many other specific implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A cooling tube assembly for a wafer thinning machine, characterized in that: The system includes a fluid module (1) and two fluid pipes (5). The fluid pipes (5) and the fluid module (1) are assembled by an interference fit. The first end of the fluid module (1) is provided with a threaded post (4) for connecting to an external liquid supply component. The second end of the fluid module (1) is respectively sealed to the first port of the two fluid pipes (5) by an interference fit. A plug (7) is fixed at the second port of each fluid pipe (5). Several injection ports (6) are opened on the pipe wall section of each fluid pipe (5) near the second port. The injection ports (6) are distributed at equal intervals along the axial direction of the fluid pipes (5). Each injection port (6) is a groove structure with a groove width of 0.18-0.23 mm, a groove length of 3.3-3.5 mm, and a groove depth of 1-1.03 mm. The fluid module (1) has two parallel discharge channels for discharging coolant. Each discharge channel includes a first channel section (2) and a second channel section (3) connected in series along the coolant flow direction. The first channel section (2) and the second channel section (3) are smoothly connected by a variable diameter transition structure. The inlet end of the first channel section (2) is configured as an inlet port that connects with the threaded column (4). The internal channel of the threaded column (4) is connected to the first channel section (2) and the second channel section (3) to introduce external water into the discharge channel. The outlet end of the second channel section (3) is configured as a drain port that connects with the fluid pipe (5). The fluid pipeline (5) is formed by bending with an integrated mold and includes a first straight pipe section (51), a first elbow (52), a second straight pipe section (53), a second elbow (54) and a third straight pipe section (55). The first straight pipe section (51) and the third straight pipe section (55) are arranged vertically with an offset. The second straight pipe section (53) is inclinedly connected between the two. The outlet end of the first straight pipe section (51) is fixedly connected to the inlet end of the second straight pipe section (53) through the first elbow (52). The outlet end of the second straight pipe section (53) is fixedly connected to the inlet end of the third straight pipe section (55) through the second elbow (54), so that the three straight pipe sections are connected in series to form a long-distance integrated drainage channel.

2. The wafer thinning machine cooling tube assembly according to claim 1, characterized in that: Define the equivalent flow diameter of the first channel segment (2) as D1 and the equivalent flow diameter of the second channel segment (3) as D2, and set D1 > D2.

3. The wafer thinning machine cooling tube assembly according to claim 1, characterized in that: The plug (7) is a solid cylindrical plug. The plug (7) is fixed to the second port of the fluid pipe (5) by press-fit interference fit, and the closed end face of the plug (7) is sunk into the second port of the fluid pipe (5).

4. The processing technology of a wafer thinning machine cooling tube assembly according to any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Use laser cutting equipment to cut stainless steel raw materials to obtain module blanks of fluid module (1) and tube blanks of fluid pipe (5) with predetermined outlines. Step S2: The module blank of the fluid module (1) is machined by turning and milling composite machining center to form a fluid module (1) base with a first channel section (2) and a second channel section (3), and the inner wall roughness and dimensional tolerance of the first channel section (2) and the second channel section (3) are controlled. Step S3: Select a finely drawn tube with an inner surface roughness of less than Ra1.6 as the tube blank for the fluid pipeline (5), and perform wire cutting according to the design length; Step S4: Place the blank of the fluid pipe (5) into a bending die for one cold bending forming, so that it is bent into the target three-dimensional spatial shape; Step S5: Place the bent fluid pipe (5) in a tempering furnace and perform stress-relief annealing at a temperature of 350-400°C to eliminate residual stress generated by cold bending and reduce the springback of stainless steel. Step S6: The fluid pipe (5) that has been bent into shape is precisely cut into the first wire, and after being cleaned, dried and qualified, it is then welded to the plug (7) by a robot laser for the first time. Step S7: After cleaning and drying the fluid module (1) processed in step S2, perform the first robotic laser welding with the threaded column (4). The deformation of the welding flatness is less than 0.03mm. Complete the drilling and tapping of the M5 threaded hole. The thread qualification requirement must be passed by the thread go and no go gauge inspection. Step S8: Press the second channel section (3) of the degreasing, cleaning and drying into the preset position inside the fluid pipe (5) in an interference fit manner. The interference amount of the interference fit is 0.01~0.04mm. At the same time, assemble the fluid module (1) base body with the assembled fluid pipe (5) to obtain the assembly body to meet the welding size requirements. Step S9: Perform a second robotic laser welding on the assembly prepared in step S8, controlling the total deformation of the weld flatness to be less than 0.05mm; Step S10: The assembled body after welding is subjected to stress-relief annealing again to eliminate residual stress generated in the heat-affected zone of welding. Step S11: Introduce pressurized medium into the assembly and maintain pressure to test the overall sealing performance; Step S12: After welding the assembly, perform coordinate measuring machine (CMM) inspection to check whether the geometric tolerances meet the design requirements of the drawings; Step S13: Use cutting equipment and special tooling molds to position and cut the assembly, complete the second wire cutting, and meet the precise tolerance size requirements of the spray nozzle; Step S14: Fluid polishing: The fluid flows through the threaded column (4), first channel section (2), second channel section (3) and fluid pipe (5) of the assembly at a set flow rate and pressure, and flows out from the nozzle (6) to perform abrasive flow polishing on the inner wall of the channel in contact with the fluid, thereby reducing the surface roughness to meet the requirement of Ra1.6 or below. Step S15: Immerse the polished assembly in a passivation solution to form a passivation film, followed by rinsing with pure water and drying. Step S16: Use a coordinate measuring machine or special inspection tool to check the key dimensions of the assembly to confirm that they meet the requirements of the drawings; Step S17: Simulate actual working conditions and conduct performance tests on the assembly, including spray fan angle, pressure resistance, or atomization effect. Step S18: After cleaning and vacuum packaging the qualified assembly, the final cooling pipe assembly is obtained.

5. The processing technology of the wafer thinning machine cooling tube assembly according to claim 4, characterized in that, In steps S5 and S10: the stress-relief annealing temperature is 350-400℃, the holding time is 100-150min, and the furnace is cooled to 40-60℃ before being taken out, with the heating rate controlled at 5-15℃ / min.

6. The processing technology of the wafer thinning machine cooling tube assembly according to claim 4, characterized in that, In steps S6 and S13: the wire cutting adopts slow wire EDM, and the cutting wire diameter is 0.15-0.25mm.

7. The processing technology of the wafer thinning machine cooling tube assembly according to claim 4, characterized in that, In steps S7 and S9: the laser power for laser welding is 300W to 500W, the laser is a fiber laser, the welding speed is 4 to 8 mm / s, the shielding gas is argon with a purity of 99.9% to 99.999%, and the gas flow rate is 20 to 30 L / min.

8. The processing technology of the wafer thinning machine cooling tube assembly according to claim 4, characterized in that, In step S17: the selected grinding fluid is sprayed and atomized under a pressure of 0.1 to 0.2 MPa.

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