Pressure self-adaptive grinding device and method for large-size plane

Abstract

The pressure self-adaptive grinding device comprises a workbench assembly and a liquid supply assembly, a lower grinding disc is arranged on the workbench assembly, and the workbench assembly is connected with a rigid-flexible coupling parallel mechanism through a Z-axis rotating assembly and drives the rigid-flexible coupling parallel mechanism to rotate reversely relative to the lower grinding disc. The bottom of the rigid-flexible coupling parallel mechanism is connected with an upper grinding disc, the rigid-flexible coupling parallel mechanism comprises a rigid adjusting mechanism and a flexible adjusting mechanism, and the rigid adjusting mechanism comprises a rigid main shaft and rigid branch chains which are uniformly arranged in the circumferential direction; the flexible adjusting mechanism comprises a flexible rod piece, one end of the flexible rod piece is connected to the rigid branch chain, and the other end of the flexible rod piece is connected to the lifting platform. The lifting platform is connected to the mounting base through an air cylinder to move on the rigid main shaft. Multi-area pressure self-adaptive adjustment can be achieved, dynamic pressure compensation following the grinding process is achieved, the flexible rod piece is fast in response, the pressure compensation effect is good, the problems of eccentric wear and the like can be avoided, and the grinding quality is improved.

Description

Technical Field

[0001] This invention relates to the field of material surface treatment technology, and specifically to a pressure-adaptive grinding device and method for large-size flat surfaces. Background Technology

[0002] With the widespread application of large-size planar components such as photovoltaic silicon wafers, large-size semiconductors, and large optical lenses in new energy, electronic information, and high-end equipment, grinding technology has become a core and critical step in the processing of these components, combining precise thinning and surface finishing. In actual production scenarios, processing requirements present a dual core demand: on the one hand, grinding is needed to achieve precise thickness reduction of the workpiece (e.g., semiconductor wafers need to be thinned to the target thickness suitable for packaging, and optical lenses need to optimize optical transmission performance through thinning); on the other hand, it is necessary to simultaneously ensure high flatness and low surface roughness of the thinned workpiece surface.

[0003] Current mainstream grinding methods face several critical technical bottlenecks that urgently need to be addressed: First, the continuous frictional heat generated during grinding can cause thermal deformation of the upper and lower grinding discs, making it difficult for them to maintain a stable parallel state. This leads to localized stress concentration in the workpiece, which not only significantly increases the risk of fracture for large, hard, and brittle workpieces such as silicon wafers and optical glass, but also causes the thickness deviation to exceed the tolerance range, failing to meet the requirements for precise thinning. Second, the regional processing differences of large workpieces are significant. Traditional equipment lacks the ability to control pressure in multiple areas, and the pressure decreases exponentially from the center to the edge, resulting in poor thickness consistency after thinning and restricting the stability of surface grinding quality. Third, the grinding fluid plays a crucial role in different process stages (rough grinding thinning, fine grinding thinning, and finishing grinding). The type (e.g., high-concentration grinding fluid for efficient thinning, medium-concentration grinding fluid for precise thinning, and low-concentration grinding fluid for surface finishing), supply quantity, and supply method of the grinding fluid directly affect the thinning efficiency, final surface quality, and material loss. Therefore, there is an urgent need to provide a pressure-adaptive grinding device suitable for large-size flat surfaces. Through multi-region pressure adaptive control, it can simultaneously solve the problems of thickness uniformity, processing fracture risk, and precise adaptation of grinding fluid in different process stages during the thinning process of large-size workpieces, thereby meeting the industry's core needs for efficient, accurate, and high-quality thinning and grinding of large-size flat components.

[0004] Defects and shortcomings of existing technology:

[0005] (1) Traditional grinding equipment cannot achieve multi-zone pressure adaptive adjustment. The pressure decreases exponentially from the center to the edge, resulting in the thinning rate of the edge area being much higher than that of the center area during the thinning and grinding process of large workpieces. This not only causes poor overall thickness consistency of the workpiece and failure to meet the precision thinning tolerance, but also causes excessive surface roughness due to local over-grinding, which seriously affects the processing quality.

[0006] (2) Traditional grinding equipment can only achieve static pressure compensation and cannot follow the dynamic working conditions during the grinding process in real time: On the one hand, the frictional heat generated by long-term grinding will cause the grinding disc to accumulate thermal deformation and local expansion; on the other hand, the wear of the grinding pad and the deviation of the flatness of the upper and lower grinding discs will cause local stress concentration in the workpiece. These dynamic problems cannot be adapted by static pressure compensation, which makes large hard and brittle workpieces prone to breakage during the thinning grinding process, and the workpiece loss rate remains high.

[0007] (3) Most of the adaptive grinding devices currently used are based on active pressure control technology. They need to first detect the actual pressure distribution on the surface of the workpiece through precision detection methods (such as multi-point pressure sensors, optical surface shape detection, etc.), and then actively adjust the pressure in each area according to the detection data. Although this closed-loop control mode based on "detection-feedback-adjustment" can improve the problem of uneven pressure distribution and inability to respond dynamically in traditional equipment to a certain extent, it still has the following shortcomings:

[0008] ① Complex system and slow response: Relying on high-precision detection and real-time feedback, the system structure is complex, and there is an unavoidable time delay in the detection, calculation and execution stages. It is difficult to fully synchronize with the high-speed and dynamically changing grinding conditions (such as instantaneous wear of the grinding pad, thermal deformation fluctuations, etc.), resulting in adjustment lag and affecting the consistency of the workpiece thickness during grinding.

[0009] ② Over-reliance on high-precision detection and reliable feedback: Under complex working conditions such as slurry coverage and vibration interference, the detection signal is easily interfered with and may cause misadjustment, which may introduce surface shape errors or aggravate stress concentration.

[0010] ③ High cost and difficult maintenance: The multi-channel independent pressure regulation mechanism, precision sensing system and complex control algorithm significantly increase the equipment cost, and the high requirements for system maintenance and calibration also increase the cost.

[0011] (4) Different process stages such as coarse grinding thinning, fine grinding thinning, and finishing grinding have significant differences in the types of grinding fluids (such as high-concentration grinding fluid, medium-concentration grinding fluid, and low-concentration grinding fluid) and supply requirements. Traditional fluid supply systems lack the ability to quickly switch and accurately adapt, which not only reduces the thinning efficiency and surface quality stability, but also causes excessive consumption of grinding fluid and increases processing costs. Summary of the Invention

[0012] This invention provides a pressure-adaptive grinding apparatus and method for large-size flat surfaces to solve the problems existing in the prior art.

[0013] The technical solution for the grinding device in this application is as follows:

[0014] A pressure-adaptive grinding device for large-area flat surfaces includes a worktable assembly and a liquid supply assembly disposed on one side of the worktable assembly. The worktable assembly is a three-axis motion platform, on which a lower grinding disk is mounted and rotated by a servo motor. A Z-axis rotation assembly is connected to the Z-axis moving assembly of the three-axis motion platform. The Z-axis rotation assembly is connected to a rigid-flexible coupling parallel mechanism, the bottom of which is connected to an upper grinding disk. The rigid-flexible coupling parallel mechanism and the upper grinding disk are driven by the Z-axis rotation assembly to maintain opposite rotation relative to the lower grinding disk. The mechanism includes a rigid adjustment mechanism and a flexible adjustment mechanism. The rigid adjustment mechanism includes a rigid main shaft and rigid branches evenly arranged circumferentially. One end of the rigid main shaft is connected to the grinding disc via a ball joint, and the other end is connected to a mounting base. One end of the rigid branch is connected to the grinding disc via a ball joint, and the other end is connected to the slider of a lead screw drive pair. The lead screw drive pair is mounted on the mounting base. The flexible adjustment mechanism includes a flexible rod. One end of the flexible rod is connected to the rigid branch, and the other end is connected to a lifting platform. The lifting platform is mounted on the rigid main shaft and connected to the mounting base via a cylinder.

[0015] This invention designs a rigid-flexible coupling parallel mechanism, enabling the flexible adjustment mechanism to work in conjunction with the rigid adjustment mechanism to achieve adaptive pressure grinding in different areas of a large-size planar surface (multi-degree-of-freedom, multi-region adaptive independent pressure flexible adjustment). When the grinding disc experiences localized thermal expansion or the thickness of the large-size planar workpiece is inconsistent, the ball joint, through the translation of the three-axis motion platform in the X, Y, and Z axes and the slight rotation around these three axes, drives the upper grinding disc to follow the changes in the workpiece surface contour in real time. At this time, the flexible rod experiences uneven force, which can compensate for local pressure deviations. For example, in areas where the workpiece is thicker, the reaction force on the upper grinding disc increases, and the flexible rod, under this force, applies pressure to the rigid support, increasing the pressure of the rigid support on the upper grinding disc and thus increasing the grinding intensity. In areas where the workpiece is thinner, the reaction force on the upper grinding disc decreases, the force on the flexible rod decreases, and the pressure of the rigid support on the upper grinding disc decreases, reducing the grinding intensity. This addresses the problem of uneven thickness in large-size planar workpieces, reduces uneven grinding, and makes the grinding of large-size planar surfaces smoother.

[0016] This invention utilizes a cylinder-driven lifting platform and a lead screw drive to move a rigid support chain. Adjusting the positions of the lifting platform and the rigid support chain, and consequently adjusting the position and angle of the flexible rod, allows for control of varying flexibility strengths. Specifically, the cylinder-driven lifting platform adjusts the flexible pressure compensation value of the upper grinding disc on the lower grinding disc. Moving the lifting platform along the Z-axis towards the mounting base reduces the pressure compensation value of the flexible rod and increases its stiffness; moving the lifting platform along the Z-axis towards the fixed platform increases the pressure compensation value of the flexible rod and weakens its stiffness. Specifically, the lead screw drive moves the rigid support chain radially towards the center, reducing the pressure compensation value of the flexible rod and increasing its stiffness; moving the lead screw drive moves the rigid support chain radially outwards, increasing the pressure compensation value of the flexible rod and weakening its stiffness. One end of the rigid support chain is connected to the slider of the lead screw drive. The lead screw drive has a simple and reliable structure, facilitating precise adjustment of the rigid support chain's position. Furthermore, the rigid support chains are evenly distributed circumferentially to ensure uniform pressure application.

[0017] Preferably, in the aforementioned pressure-adaptive grinding device for large-area planes, the rigid branch includes an upper section and a lower section that are hinged to each other; the lower section is longer than the upper section; one end of the flexible rod is connected to the lower section. The longer lower section of the rigid branch can increase the range of the flexible pressure compensation threshold of the flexible rod.

[0018] Preferably, in the aforementioned pressure-adaptive grinding device for large-area flat surfaces, the liquid supply assembly includes multiple liquid supply channels. These channels are held by a y-axis rotating sleeve and mounted on a z-axis magnetic rotary joint. The z-axis magnetic rotary joint is connected to an x-axis moving unit, which is mounted on a base connected to a ground base. The multiple liquid supply channels can deliver grinding slurries of various concentrations. The y-axis rotating sleeve facilitates adjustment of the distance between the liquid supply channels and the lower grinding disc plane. Rotating the y-axis rotating sleeve adjusts the angle between the liquid supply channels and the lower grinding disc plane, thus adjusting the liquid supply angle. The z-axis magnetic rotary joint and the x-axis moving unit further adjust the position and angle of the liquid supply channels from multiple directions.

[0019] Preferably, in the aforementioned pressure-adaptive grinding device for large-size flat surfaces, a fixed platform is also provided on the rigid spindle. The fixed platform and the lifting platform are connected to the mounting base via auxiliary shafts evenly distributed along the circumference. The evenly distributed auxiliary shafts and the fixed platform are used to enhance the structural rigidity of the rigid-flexible coupling parallel mechanism and prevent local indentations from occurring in the rigid-flexible coupling parallel mechanism during the workpiece grinding process.

[0020] Preferably, in the aforementioned pressure-adaptive grinding device for large-area flat surfaces, the cylinders are a pair, each mounted on two non-adjacent auxiliary shafts. This structural arrangement allows for smoother adjustment of the lifting platform and greater stability of the rigid-flexible coupling parallel mechanism.

[0021] Preferably, in the aforementioned pressure-adaptive grinding device for large-size flat surfaces, the X-axis and Y-axis moving components of the worktable assembly are ball screw drive structures; the Z-axis moving component is a gear and rack drive structure. High-precision ball screws enable wide-range, high-precision positioning of the workpiece in the horizontal direction, with a repeatability of less than 3μm; precision gears and racks enable precise lifting and lowering in the Z-axis direction, with a repeatability of less than 3μm, and are more stable and reliable.

[0022] Preferably, in the aforementioned pressure-adaptive grinding device for large-size flat surfaces, the servo motors driving the upper and lower grinding discs to rotate are precision direct-drive motors. Precision direct-drive motors have a vertical loading force control accuracy of no more than 0.3N and a runout accuracy of no more than 2μm, exhibiting high precision and high reliability.

[0023] Preferably, in the aforementioned pressure-adaptive grinding device for large-area flat surfaces, a precision pressure sensor is installed inside the spindle of the Z-axis rotation assembly. This precision pressure sensor ensures that the pressure reaches the set multi-zone pressure reference value.

[0024] Regarding the grinding method, the technical solution of this application is as follows:

[0025] The pressure-adaptive grinding method for large-size flat surfaces, implemented using the aforementioned pressure-adaptive grinding device for large-size flat surfaces, includes the following steps: S1, the workpiece is adsorbed onto the lower surface of the upper grinding disc, and the three-axis motion platform is started, causing the upper grinding disc to be offset against the lower grinding disc; S2, according to the workpiece material, target thinning thickness, and machining accuracy requirements, process parameters are set according to different stages of rough grinding thinning, fine grinding thinning, and finishing grinding: setting the multi-region pressure reference value and flexible pressure compensation threshold of the rigid-flexible coupling parallel mechanism for different stages; setting the grinding fluid concentration, flow rate, supply angle, and distance between the fluid supply channel outlet and the lower grinding disc for different stages; setting the rotational speed of the upper and lower grinding discs; S3, starting the grinding device, causing the upper and lower grinding discs to rotate in opposite directions, grinding the workpiece in the order of rough grinding thinning, fine grinding thinning, and finishing grinding; after grinding is completed, the fluid supply channel stops supplying fluid, and the three-axis motion platform removes and unloads the workpiece.

[0026] This invention applies multi-regional pressure reference values ​​to the upper grinding disk through the Z-axis movement component of a pressure-adaptive grinding device for large-area flat surfaces. Flexible pressure compensation values ​​are applied to the upper grinding disk through the flexible rods of a rigid-flexible coupling parallel mechanism. During the grinding process, the flexible pressure compensation values ​​are adaptively adjusted in real time according to the local thermal expansion of the grinding disk or the thickness of the large-area flat workpiece, thereby improving grinding quality. To match different stages of the process, this invention delivers grinding fluid of different set concentrations to the lower grinding disk through multiple fluid supply channels, allowing the grinding process to automatically switch between different stages and improving the degree of automation in the grinding process.

[0027] The present invention uses an upper grinding disc to adsorb and fix large-sized planar workpieces, which can ensure the positioning stability of the workpieces during the grinding process.

[0028] As a preferred embodiment, in the aforementioned pressure adaptive grinding method for large-size flat surfaces, activating the Z-axis moving component allows the pressure of the upper grinding disc on the lower grinding disc to reach a set multi-zone pressure reference value; activating the cylinder and lead screw transmission pair causes the lifting platform to rise and fall, and the slider to drive the rigid support chain to move, allowing the flexible rod to reach a set flexible pressure compensation threshold.

[0029] Preferably, in the aforementioned pressure-adaptive grinding method for large-size flat surfaces, the multi-region pressure reference value is 0-3 kg / cm². 2 The flexible pressure compensation threshold is ±10-±40 g / cm. 2 The upper grinding disc rotates at a speed of 10 rpm to 300 rpm, and the lower grinding disc rotates at a speed of 20 rpm to 500 rpm. This pressure threshold and speed range enable high-precision grinding quality.

[0030] Preferably, in the aforementioned pressure-adaptive grinding method for large-size flat surfaces, the size of the flat surface ranges from 12 to 15 inches. The grinding apparatus and grinding method of the present invention are particularly suitable for 12-15 inch flat surfaces, and can achieve better grinding results compared to the prior art.

[0031] In summary, this invention achieves multi-zone adaptive pressure adjustment and dynamic pressure compensation throughout the grinding process. The rigid-flexible coupling parallel mechanism of this invention has a simple structure, fast response of the flexible rods, and good pressure compensation effect, avoiding problems such as uneven wear and improving grinding quality. This invention is particularly suitable for large-sized planar workpieces, with workpiece sizes ranging from 12 to 15 inches. The liquid supply component of this invention can provide grinding fluids of various concentrations, and the supply distance and angle are adjustable, further improving grinding quality. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the pressure-adaptive grinding device for large-size flat surfaces according to the present invention.

[0033] Figure 2 This is a schematic diagram of the rigid-flexible coupling parallel mechanism of the present invention connected to the grinding disc.

[0034] Figure 3 This is the present invention. Figure 2 Front view of the structure.

[0035] Figure 4 This is a schematic diagram of the inverted structure of the rigid-flexible coupling parallel mechanism of the present invention.

[0036] Figure 5 This is a schematic diagram of the liquid supply component of the present invention.

[0037] Figure 6 This is a schematic diagram of the structure of the workbench assembly connected to the lower grinding disc of the present invention.

[0038] Figure 7 This is a schematic diagram of the structure of the pressure adaptive grinding device for large-size flat surfaces of the present invention after installing the protective cover assembly, base, alarm light, and operation panel.

[0039] The labels in the attached diagram are as follows: 1-Rigid-flexible coupling parallel mechanism; 101-Motor; 102-Slider; 103-Guide rail; 104-Rigid support chain; 1041-Upper section; 1042-Lower section; 105-Rigid spindle; 106-Spherical hinge; 107-Bearing; 108-Cylinder; 109-Lifting platform; 110-Flexible rod; 111-Fixed platform; 112-Auxiliary shaft; 113-Mounting base; 114- 1-Lead screw; 2-Liquid supply assembly; 21-Liquid supply channel; 22-Y-axis rotating sleeve; 23-Z-axis magnetic rotary joint; 24-X-axis moving unit; 25-Base; 3-Worktable assembly; 31-X-axis moving assembly; 32-Y-axis moving assembly; 33-Z-axis moving assembly; 34-Z-axis rotating assembly; 4-Upper grinding disc; 5-Lower grinding disc; 6-Protective cover assembly; 7-Base; 8-Alarm light; 9-Operation panel. Detailed Implementation

[0040] The technical solution of the present invention will be further described in detail below through specific embodiments and with reference to the accompanying drawings, but this should not be construed as limiting the present invention. Contents not described in detail in the following embodiments are all common knowledge in the art or can be implemented using conventional technical means in the art.

[0041] For detailed embodiments of the present invention, please refer to the following: Figure 1-6 .

[0042] A pressure-adaptive grinding device for large-area flat surfaces includes a worktable assembly 3 and a liquid supply assembly 2 disposed on one side of the worktable assembly 3. The worktable assembly 3 is a three-axis motion platform, including an X-axis moving assembly 31, a Y-axis moving assembly 32, and a Z-axis moving assembly 33. The X-axis moving assembly 31 and the Y-axis moving assembly 32 of the worktable assembly 3 are ball screw transmission structures; the Z-axis moving assembly 33 is a gear and rack transmission structure. A lower grinding disc 5 is disposed on the worktable assembly 3, and the lower grinding disc 5 is driven to rotate by a servo motor, which is a precision direct drive motor. A Z-axis rotation assembly 34 is connected to the Z-axis moving assembly 33 of the three-axis motion platform. The lower end of the Z-axis rotation assembly 34 is connected to a rigid-flexible coupling parallel mechanism 1, which is driven by a servo motor, which is also a precision direct drive motor. A precision pressure sensor is installed inside the spindle of the Z-axis rotation assembly 34 to ensure that the pressure reaches the set multi-zone pressure reference value.

[0043] The lower end of the rigid-flexible coupling parallel mechanism 1 is connected to the upper grinding disk 4. The upper grinding disk 4 rotates in the opposite direction to the lower grinding disk 5. The lower surface of the upper grinding disk 4 can adsorb large-sized flat workpieces.

[0044] The rigid-flexible coupling parallel mechanism 1 includes a rigid adjustment mechanism and a flexible adjustment mechanism. The rigid adjustment mechanism includes a rigid main shaft 105 and rigid branches 104 evenly arranged circumferentially. In this embodiment, five rigid branches 104 are provided. One end of the rigid main shaft 105 is connected to the upper surface of the grinding disc 4 via a ball joint 106, and the other end is connected to the mounting base 113. One end of the rigid branches 104 is connected to the upper surface of the grinding disc 4 via a ball joint 106, and the other end is connected to the lead screw drive pair. The lead screw drive pair is connected to the mounting base 113. The lead screw drive pair includes a motor 101, a slider 102, a guide rail 103, a bearing 107, etc. The slider 102 is mounted on the lead screw 114. The two ends of the lead screw 114 are connected to the bearings 107. The upper side of the slider 102 is connected to the guide rail 103. The motor 101 drives the slider 102 to slide along the guide rail 103 through gear transmission. One end of the rigid support chain 104 is connected to the lower side of the slider 102. As the slider 102 moves, its position is adjusted.

[0045] The flexible adjustment mechanism includes a flexible rod 110, one end of which is connected to a rigid support chain 104, and the other end is connected to a lifting platform 109. The lifting platform 109 is connected to a mounting base 113 via cylinders 108, and can move up and down along a rigid main shaft 105 under the action of the cylinders 108. There is a pair of cylinders 108, located on two non-adjacent auxiliary shafts 112. Adjusting the position of the lifting platform 109 and the position of the rigid support chain 104 (the position of the slider) changes the pressure compensation strength of the flexible rod.

[0046] The rigid branch 104 includes an upper segment 1041 and a lower segment 1042 that are hinged to each other; the length of the lower segment 1042 is greater than that of the upper segment 1041; one end of the flexible member 110 is connected to the lower segment 1042. Specifically, in this embodiment, the length of the lower segment 1042 is twice the length of the upper segment 1041, and one end of the flexible member 110 is connected to the middle position of the lower segment 1042.

[0047] The liquid supply assembly 2 includes multiple liquid supply channels 21, four in this embodiment, capable of delivering four concentrations of grinding slurry. The liquid supply channels 21 are held by a y-axis rotating sleeve 22 and mounted on a z-axis magnetic rotary joint 23. The z-axis magnetic rotary joint 23 is connected to an x-axis moving unit 24, which is mounted on a base 25, which is connected to a base 7. The liquid supply channels 21 are retractable, allowing adjustment of their liquid supply distance and angle from the lower grinding disc 5.

[0048] A fixed platform 111 is also provided on the rigid spindle 105. The fixed platform 111 and the lifting platform 109 are connected to the mounting base 113 by auxiliary shafts 112 that are evenly arranged circumferentially. In this embodiment, there are five auxiliary shafts 112.

[0049] A pressure-adaptive grinding method for large-size flat surfaces, using the aforementioned pressure-adaptive grinding apparatus for large-size flat surfaces, includes:

[0050] S1, the workpiece is adsorbed onto the lower surface of the upper grinding disc 4, and the three-axis motion platform is started so that the upper grinding disc 4 is offset against the lower grinding disc 5.

[0051] S2, based on the workpiece material, target thinning thickness, and machining accuracy requirements, process parameters are set according to different stages of rough grinding thinning, fine grinding thinning, and finishing grinding: Multi-zone pressure reference values ​​and flexible pressure compensation thresholds are set for the rigid-flexible coupling parallel mechanism 1 at different stages; the Z-axis moving component 33 is activated, allowing the pressure of the upper grinding disc 4 on the lower grinding disc 5 to reach the set multi-zone pressure reference value; the cylinder 108 and the lead screw transmission pair are activated, causing the lifting platform 109 to rise and the slider 102 to drive the rigid support chain 104 to move, allowing the flexible rod 110 to reach the set flexible pressure compensation threshold. The multi-zone pressure reference value range is 0-3 kg / cm². 2 The flexible pressure compensation threshold range is ±10-±40 g / cm. 2 Set the concentration, flow rate, and supply angle of the polishing slurry at different stages, as well as the distance between the outlet of the slurry supply channel 21 and the lower polishing disc 5; set the rotation speed of the upper polishing disc 4 and the lower polishing disc 5, with the upper polishing disc 4 ranging from 10 rpm to 300 rpm and the lower polishing disc 5 ranging from 20 rpm to 500 rpm.

[0052] S3, start the grinding device, so that the upper grinding disc 4 and the lower grinding disc 5 rotate in opposite directions, and grind the workpiece in the order of rough grinding thinning, fine grinding thinning and finishing grinding. After the grinding is completed, the liquid supply channel 21 stops supplying liquid, and the three-axis motion platform moves the workpiece out and unloads it.

[0053] Specific embodiments of the method of the present invention:

[0054] Example 1 Workpiece: Silicon carbide wafer, workpiece size: 12 inches, target thinning thickness: 80 μm.

[0055] S1, adsorb the silicon carbide wafer onto the lower surface of the upper grinding disk 4, start the three-axis motion platform, and make the upper grinding disk 4 biased against the lower grinding disk 5.

[0056] S2 sets the multi-zone pressure reference value for different grinding stages, with coarse grinding and thinning at 1500 g / cm³. 2 Fine grinding and thinning: 1000g / cm 2 Fine grinding: 200g / cm 2 .

[0057] Setting flexible pressure compensation thresholds for different grinding stages, coarse grinding thinning: ±35 g / cm 2 Fine grinding and thinning: ±25g / cm 2 Fine grinding: ±15g / cm 2 .

[0058] Set the concentration, supply rate, supply angle, and distance between the supply channel 21 and the workpiece for different grinding stages. Rough grinding and thinning: High-concentration diamond abrasive slurry (20 wt%), supply rate 500 mL / min, supply angle 45°, supply distance 50 mm. Fine grinding and thinning: Medium-concentration silica abrasive slurry (10 wt%), supply rate 300 mL / min, supply angle 30°, supply distance 30 mm. Finishing grinding: Low-concentration polishing slurry (2 wt%), supply rate 150 mL / min, supply angle 15°, supply distance 20 mm.

[0059] Set the upper grinding disc speed to 60 rpm and the lower grinding disc speed to 65 rpm.

[0060] S3, start the grinding device, causing the upper grinding disc 4 and the lower grinding disc 5 to rotate in opposite directions, grinding the workpiece in the sequence of rough grinding thinning, fine grinding thinning, and finishing grinding. When the rough grinding thinning reaches the preset thickness, it automatically switches to the fine grinding thinning stage, and when the fine grinding thinning reaches the preset thickness, it automatically switches to the finishing grinding stage. After grinding is completed, the liquid supply channel 21 stops supplying liquid, and the three-axis motion platform removes and unloads the workpiece.

[0061] After grinding using the above process, the silicon carbide wafer is thinned to the target thickness, and the thickness uniformity is significantly improved, with its surface precision meeting the requirements.

[0062] Example 2 Workpiece: Sapphire wafer, workpiece size: 15 inches, target thinning thickness: 120 μm.

[0063] S1, the sapphire wafer is adsorbed onto the lower surface of the upper grinding disk 4, and the three-axis motion platform is started so that the upper grinding disk 4 is biased against the lower grinding disk 5.

[0064] S2 sets multi-zone pressure reference values ​​for different grinding stages; coarse grinding thinning: 1200 g / cm³ 2 Fine grinding and thinning: 800 g / cm 2 Fine grinding: 200 g / cm 2 ...

[0065] Setting flexible pressure compensation thresholds for different grinding stages, coarse grinding thinning: ±35 g / cm 2 ,

[0066] Fine grinding and thinning: ±25g / cm 2 Fine grinding: ±15g / cm 2 .

[0067] Set the concentration, supply rate, supply angle, and distance between the supply channel 21 and the workpiece for different grinding stages. Rough grinding and thinning: High-concentration boron carbide abrasive slurry (15 wt%), supply rate 450 mL / min, supply angle 45°, supply distance 50 mm. Fine grinding and thinning: Medium-concentration alumina abrasive slurry (8 wt%), supply rate 250 mL / min, supply angle 30°, supply distance 30 mm. Finishing grinding: Low-concentration silica polishing slurry (1 wt%), supply rate 120 mL / min, supply angle 15°, supply distance 20 mm.

[0068] Set the upper grinding disc speed to 70 rpm and the lower grinding disc speed to 75 rpm.

[0069] S3, start the grinding device, causing the upper grinding disc 4 and the lower grinding disc 5 to rotate in opposite directions, grinding the workpiece in the sequence of rough grinding thinning, fine grinding thinning, and finishing grinding. When the rough grinding thinning reaches the preset thickness, it automatically switches to the fine grinding thinning stage, and when the fine grinding thinning reaches the preset thickness, it automatically switches to the finishing grinding stage. After grinding is completed, the liquid supply channel 21 stops supplying liquid, and the three-axis motion platform removes and unloads the workpiece.

[0070] After the above-mentioned grinding process, the sapphire wafer is thinned to the target thickness, and the thickness uniformity is significantly improved, and its surface precision meets the requirements.

[0071] like Figure 7 As shown, the pressure adaptive grinding device for large-size flat surfaces of the present invention is mounted on the base 7. The present invention has a protective cover assembly 6 installed on the outside, an alarm light 8 installed on the upper part of the protective cover assembly 6, and an operation panel 9 installed on the front of the protective cover assembly 6.

[0072] The base 7 houses the grinding fluid supply and recovery tank, enabling clean production. It also considers human-machine interaction, facilitating movement and easy fixation. The base 7 is made of a rigid material, improving the stability of the device.

[0073] The protective cover assembly 6 is a fully enclosed protective cover. This protective cover is electrically connected to the main control system of the device of the present invention and is equipped with a safety interlock device. When the protective cover assembly 6 is not fully closed, the device of the present invention cannot start the grinding program, thereby ensuring operational safety.

[0074] Alarm light 8 is a multi-color audible and visual alarm light, located in a conspicuous position on the upper part of the protective cover assembly 6, used to provide real-time feedback on the equipment status: a solid green light indicates standby or normal operation; a flashing yellow light indicates a warning (such as low liquid supply pressure); a flashing red light accompanied by a buzzer indicates a malfunction (such as abnormal opening of the protective cover assembly 6). This design allows operators to remotely and intuitively monitor the equipment's operating status and process anomalies even away from noisy processing areas.

[0075] The front of the protective cover assembly 6 is equipped with an operation panel 9, which facilitates manual operation to set various grinding parameters.

[0076] The foregoing general description of the invention and its specific embodiments should not be construed as a limitation on the technical solution of the invention. Those skilled in the art, based on the disclosure of this application, can add, reduce, or combine the disclosed technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the invention, to form other technical solutions within the scope of protection of this invention.

Claims

1. A pressure adaptive lapping device for large size flat, characterized in that: The application relates to a pressure self-adaptive grinding device for large-size planes, which comprises a workbench assembly (3) and a liquid supply assembly (2) arranged on one side of the workbench assembly (3), the workbench assembly (3) is a three-axis motion platform, a lower grinding disc (5) is arranged on the workbench assembly (3) and driven to rotate by a servo motor; a Z-axis rotating assembly (34) is connected to a Z-axis moving assembly (33) of the three-axis motion platform, the Z-axis rotating assembly (34) is connected to a rigid-flexible coupling parallel mechanism (1), the bottom of the rigid-flexible coupling parallel mechanism (1) is connected to an upper grinding disc (4), and the rigid-flexible coupling parallel mechanism (1) and the upper grinding disc (4) are driven to keep reverse rotation relative to the lower grinding disc (5) by the Z-axis rotating assembly (34); the rigid-flexible coupling parallel mechanism (1) comprises a rigid adjusting mechanism and a flexible adjusting mechanism, the rigid adjusting mechanism comprises a rigid main shaft (105) and a plurality of rigid branch chains (104) which are uniformly arranged in a circumferential direction, one end of the rigid main shaft (105) is connected to the upper grinding disc (4) through a spherical hinge (106), and the other end is connected to a mounting base (113); one end of the rigid branch chain (104) is connected to the upper grinding disc (4) through the spherical hinge (106), and the other end is connected to a sliding block (102) of a screw transmission pair; the screw transmission pair is arranged on the mounting base (113); the flexible adjusting mechanism comprises a flexible rod (110), one end of the flexible rod (110) is connected to the rigid branch chain (104), and the other end is connected to a lifting platform (109); the lifting platform (109) is connected to the mounting base (113) through a gas cylinder (108) and can move up and down along the rigid main shaft (105).

2. The pressure-adaptive lapping device for large-sized flat surfaces according to claim 1, characterized in that: The rigid branch chain (104) comprises an upper segment (1041) and a lower segment (1042) which are hingedly connected to each other; the length of the lower segment (1042) is larger than that of the upper segment (1041); and one end of the flexible rod (110) is connected to the lower segment (1042).

3. The pressure-adaptive lapping device for large-sized flat surfaces according to claim 1, characterized in that: The liquid supply assembly (2) comprises a plurality of liquid supply flow channels (21), the liquid supply flow channels (21) are clamped by y-axis rotating sleeve heads (22) and arranged on z-axis magnetic rotating joints (23), the z-axis magnetic rotating joints (23) are connected to x-axis moving units (24), the x-axis moving units (24) are arranged on a base (25), and the base (25) is connected to a base (7).

4. The pressure-adaptive lapping apparatus for large-sized flat surfaces according to claim 1, characterized by: A fixed platform (111) is further arranged on the rigid main shaft (105), and the fixed platform (111) and the lifting platform (109) are connected to the mounting base (113) through auxiliary shafts (112) which are uniformly arranged in a circumferential direction.

5. A pressure adaptive lapping device for large size flat surfaces as claimed in claim 4 wherein: The gas cylinder (108) is a pair of gas cylinders arranged on two auxiliary shafts (112).

6. A pressure adaptive lapping device for large size flat surfaces as claimed in any one of claims 1 to 5, wherein: The X-axis moving assembly (31) and the Y-axis moving assembly (32) of the workbench assembly (3) are ball screw transmission structures; and the Z-axis moving assembly (33) is a gear and rack transmission structure.

7. Method for pressure adaptive lapping of large size flat surfaces, characterized in that: The pressure self-adaptive grinding device for large-size planes is used to realize the following steps: S1, a workpiece is adsorbed to the lower surface of the upper grinding disc (4), and the three-axis motion platform is started to offset the upper grinding disc (4) from the lower grinding disc (5); S2, according to the workpiece material, target thinning thickness and machining precision requirement, set process parameters according to different stages of rough grinding thinning, fine grinding thinning and finishing grinding: set the multi-region pressure reference value of the rigid-flexible coupling parallel mechanism (1) and the flexible pressure compensation threshold value at different stages; set the concentration, flow rate and supply angle of the grinding liquid at different stages, and the distance between the outlet of the liquid supply channel (21) and the lower grinding disc (5); set the rotating speed of the upper grinding disc (4) and the lower grinding disc (5); S3, start the grinding device, make the upper grinding disc (4) and the lower grinding disc (5) rotate in opposite directions, grind the workpiece according to the sequence of rough grinding thinning, fine grinding thinning and finishing grinding stages, and after grinding is completed, the liquid supply channel (21) stops supplying liquid, and the three-axis motion platform moves the workpiece out for unloading.

8. The pressure adaptive lapping method for large size flat according to claim 7, characterized in that: Start the Z-axis moving assembly (33), so that the pressure of the upper grinding disc (4) on the lower grinding disc (5) reaches the set multi-region pressure reference value; start the air cylinder (108) and the screw transmission pair, so that the lifting platform (109) lifts and the sliding block (102) drives the rigid branch chain (104) to move, so that the flexible rod (110) reaches the set flexible pressure compensation threshold value.

9. The pressure adaptive lapping method for large size flat according to claim 7, wherein: The multi-zone pressure reference value is 0-3 kg / cm 2 , and the flexible pressure compensation threshold is ±10-±40 g / cm 2 .

10. The pressure adaptive lapping method for large size flat according to claim 7, wherein: The size range of the large-size plane is 12-15 inches.

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