High-grinding-force polishing disc structure

Abstract

The invention provides a high-grinding-force polishing disc structure, and relates to the field of design of polishing pads for erbium-doped fluoride crystals. The polishing grid comprises a plurality of polishing subareas, each polishing subarea is internally provided with a polishing unit which is formed by separating a first grid flow channel and a second grid flow channel which are staggered, each polishing unit is in a parallelogram shape, and the polishing subareas on the polishing pad base body are formed in one of the polishing subareas in a circumferential array mode; the flow guide groove is formed in the polishing end face of the polishing pad base body; and the circular groove is formed in the center of the polishing pad base body, the polishing grids, the flow guide grooves and the circular groove communicate with one another, and polishing liquid is injected into the first flow guide flow channel and the second flow guide flow channel from the circular groove through a peristaltic pump and then evenly diffused into the first grid flow channel and the second grid flow channel through centrifugal force. The polishing grid adsorbs polishing liquid and enhances grinding force, the flow guide grooves synchronously discharge waste chips, dynamic balance is formed, and the situation that the polishing effect on crystals is affected by fragments is avoided.

Description

Technical Field

[0001] The invention relates to the field of polishing pad design for erbium-doped fluoride crystals, and in particular to a high-grinding-force polishing disc structure. Background Art

[0002] After the erbium-doped fluoride crystal is grown, it needs to be cut and ground to obtain the desired size and shape. The grinding process usually uses the chemical mechanical polishing (CMP) process.

[0003] The grids on existing polishing pads are mostly rectangular or regular hexagonal structures. Although they can provide a certain grinding force and polishing liquid storage space, the geometric symmetry of traditional polishing grids leads to rapid loss of fluid, short residence time of the polishing liquid, and frequent replenishment is required, which increases processing costs. In addition, the regularly arranged polishing grids are prone to form "dead zones" for polishing liquid flow. The uneven coverage of the liquid film in local areas causes fluctuations in grinding efficiency, reducing the polishing quality. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a high grinding force polishing disk structure. The technical problem to be solved by the present invention is: how to design a polishing grid shape with high polishing liquid adsorption capacity, dynamic polishing liquid control function and larger effective grinding area, so as to overcome the problems of fast fluid loss, uneven shear stress distribution and low processing efficiency of traditional rectangular or hexagonal grids.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a high-grinding force polishing disc structure, including a polishing pad base, and a transmission connection with the output end of a motor for driving the polishing pad base to rotate; a polishing grid, including a plurality of polishing partitions, each of which is provided with a polishing unit separated by staggered grid flow channels 1 and 2, the polishing unit is a parallelogram, and the polishing partition on the polishing pad base is obtained by a circular array in one of the polishing partitions; a guide groove is provided on the polishing end face of the polishing pad base; a circular groove is provided at the center of the polishing pad base, the polishing grid, the guide groove and the circular groove are connected, and the circular groove connected to the pump body is used to transport the polishing liquid to the guide groove and the polishing grid.

[0006] In a preferred embodiment, the polishing end surface of the polishing pad substrate is made of asphalt, and the hardness of the asphalt is between that of the polyurethane and ceramic composite materials.

[0007] In a preferred embodiment, one of the acute angles of the parallelogram-shaped polishing unit is between 60° and 70°.

[0008] In a preferred embodiment, the groove depth of the grid flow channel 1 is 1 mm, and the distance between two adjacent grid flow channels 1 in the same polishing partition is 2 mm-3 mm.

[0009] In a preferred embodiment, the groove depth of the second grid flow channel is 1 mm, and the distance between two adjacent second grid flow channels within the same polishing partition is 2 mm - 3 mm.

[0010] In a preferred embodiment, the diversion groove includes a first diversion flow channel and a second diversion flow channel. Both the first diversion flow channel and the second diversion flow channel are cross-shaped grooves formed on the polishing end face of the polishing pad substrate. The first diversion flow channel and the second diversion flow channel are designed to cross each other, and the angle between the first diversion flow channel and the second diversion flow channel is 45°. The area between the first diversion flow channel and the second diversion flow channel is the polishing partition.

[0011] In a preferred embodiment, the groove width of the first diversion flow channel is within 15 mm - 20 mm, the groove depth is 1 mm, and the surface roughness Ra of the inner wall is ≤ 10 μm.

[0012] In a preferred embodiment, the second diversion flow channel is divided into a shallow groove and a deep groove. The inner peripheral width of the shallow groove is smaller than the outer peripheral width, and the transition between the inner peripheral and outer peripheral parts of the shallow groove is not smooth. The deep groove is formed at the outer peripheral position of the shallow groove. The groove width of the deep groove is 15 mm - 20 mm, the groove depth is 1 mm, and the surface roughness Ra of the inner wall is ≤ 10 μm.

[0013] In a preferred embodiment, an included angle a is formed at the intersection of the inner periphery and the outer periphery of the shallow groove of the second diversion flow channel, and the angle of the included angle a is between 30° and 45°.

[0014] In a preferred embodiment, the ratio of the diameter of the circular groove to the diameter of the polishing pad substrate is 1:3, and the depth of the circular groove is greater than that of both the first diversion flow channel and the second diversion flow channel.

[0015] The technical effects and advantages of the present invention:

[0016] 1. The polishing grid increases the effective grinding area through a honeycomb structure, and at the same time utilizes the adsorption effect to extend the residence time of the polishing liquid.

[0017] 2. The polishing partitions are arranged in a 60° staggered manner to form a "micro-vortex effect", and the local shear stress can be increased by 15% - 20%, which is superior to traditional rectangular or hexagonal polishing units.

[0018] 3. The cross-shaped diversion groove: Based on fluid mechanics simulation, the groove width and inclination angle are optimized to achieve the centrifugal classification and discharge of waste chips. When the diversion groove with a groove width of 15 - 20 mm rotates at a speed of 100 rpm on the polishing pad substrate 10, the flow rate of the polishing liquid can reach 1.2 m / s, and the residence time of the grinding chips is shortened to less than 0.5 seconds, improving the polishing effect.

[0019] 4. Substrate selection: The polishing end face of the polishing pad substrate is made of an asphalt substrate, and its hardness is between that of polyurethane and ceramic composite materials, taking into account both flexibility and supportiveness. Brief Description of the Drawings

[0020] The disclosure of the present invention will be described with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings, the same reference numerals are used to refer to the same components. Among them:

[0021] Figure 1 is a structural diagram of the polishing pad of the present invention.

[0022] Figure 2 is Figure 1 an enlarged view of part A in

[0023] Figure 3 is a front view of the polishing pad of the present invention.

[0024] Figure 4 is Figure 3 an enlarged view of part B in

[0025] The reference numerals are as follows:

[0026] 10, polishing pad substrate; 20, polishing grid; 21, grid flow channel 1; 22, grid flow channel 2; 30, diversion groove; 31, diversion flow channel 1; 32, diversion flow channel 2; 40, circular groove. Detailed Embodiments

[0027] It is easy to understand that according to the technical solution of the present invention, without changing the essence of the present invention, those of ordinary skill in the art can propose various structural ways and implementation ways that can be mutually replaced. Therefore, the following detailed embodiments and the accompanying drawings are only illustrative descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction on the technical solution of the present invention.

[0028] The polishing pad mainly plays the roles of storing and transporting the polishing liquid, removing abrasive debris, and maintaining a stable polishing environment in the chemical mechanical polishing (CMP) process of erbium-doped fluoride crystals.

[0029] Embodiment 1

[0030] As Figures 1-3 , this structure includes a polishing pad substrate 10, a polishing grid 20, and a diversion groove 30. A power device for driving the entire structure to rotate is connected to the center of rotation of the polishing pad substrate 10. The power device is usually a motor, and the output shaft of the motor rotates synchronously with the polishing pad substrate 10. Since the technology of using a motor to drive the polishing pad substrate 10 to rotate is existing and mature, it will not be elaborated here.

[0031] The polishing end face of the polishing pad substrate 10 is made of asphalt material.

[0032] A polishing grid 20 is provided on the polishing end face of the polishing pad substrate 10.

[0033] The polishing grid 20 includes several polishing partitions. In each polishing partition, grid flow channels one 21 and grid flow channels two 22 are staggeredly arranged. The grid flow channels one 21 and the grid flow channels two 22 divide each polishing partition into several parallelogram-shaped polishing units.

[0034] Preferably, the layout form of the polishing partitions is obtained by taking one polishing partition as the basis and making a circular array with reference to the rotation center axis of the polishing pad substrate 10.

[0035] Among them, two adjacent polishing partitions are separated by a diversion groove 30.

[0036] The above design enables all the polishing units on the polishing pad substrate 10 to form honeycomb-shaped adsorption units during operation, enhancing the local storage capacity of the polishing liquid. At the same time, the contact frequency between the abrasive grains and the crystal in the polishing liquid is increased through the geometric shear effect.

[0037] Preferably, one of the acute angles of the polishing unit is 60° - 75°. This design can reduce the lateral diffusion rate of the polishing liquid on the entire polishing pad substrate 10 and enhance the concentration of the grinding force.

[0038] Preferably, the groove depth of the grid flow channels one 21 and the grid flow channels two 22 is 1 mm.

[0039] Preferably, in the same polishing partition, the distance between two adjacent grid flow channels one 21 is 2 - 3 mm, and the distance between two adjacent grid flow channels two 22 is 2 - 3 mm.

[0040] Compared with the existing products with the groove spacing designed to be more than 5 mm, through the reasonable design of the groove depth and groove spacing, this structure can improve the purpose of transporting the polishing liquid, ensure the high-frequency contact between the polishing unit and the crystal, and increase the surface removal rate of the crystal material by 30% - 40%.

[0041] Embodiment 2

[0042] Reference Figures 1-4 , on the basis of Embodiment 1, a circular groove 40 is further opened on the polishing surface of the polishing pad substrate 10. The circular groove 40 is used to quickly input the received polishing liquid into the diversion groove 30, and then, by using the centrifugal force and the siphon effect, the polishing liquid is timely transported into the grid flow channels one 21 and the grid flow channels two 22 to ensure the smooth progress of the entire polishing process.

[0043] Specifically, the diversion channels 30 include a first diversion channel 31 and a second diversion channel 32. The first diversion channel 31 is formed in a cross shape on the polishing surface of the polishing pad substrate 10, and the second diversion channel 32 is also formed in a cross shape on the polishing surface of the polishing pad substrate 10. The first diversion channel 31 and the second diversion channel 32 are arranged in a cross pattern, ensuring that the angle between adjacent first diversion channels 31 and second diversion channels 32 is 45°. The single polishing zones are located between the first diversion channel 31 and the second diversion channel 32. The first diversion channel 31, the second diversion channel 32 are connected to the corresponding first grid channel 21 and second grid channel 22 to form a multi-stage diversion network, which can accelerate the discharge of waste chips by centrifugal force during operation.

[0044] Preferably, the first diversion channel 31 is formed on the polishing end surface of the polishing pad substrate 10, with a groove depth of 1 mm, a groove width of 15 - 20 mm, and the surface roughness Ra of the groove inner wall ≤ 10 μm, so as to reduce the flow resistance and avoid the residue of the polishing liquid. The advantage of the consistent groove depth is that it can hold more polishing liquid, which is suitable for quickly transporting the polishing liquid from the central area to the peripheral zones, avoiding the problem of an overly thin local liquid film; under high-speed rotation conditions, the deep groove can increase the inertia of the liquid flow and resist the problem of the polishing liquid being thrown out due to centrifugal force; in addition, the deep groove can also serve as a temporary storage area for the polishing liquid to compensate for the instantaneous flow rate fluctuations caused by the zone switching.

[0045] Preferably, the second diversion channel 32 is divided into a shallow groove and a deep groove. The inner periphery of the shallow groove is close to the central axis of the polishing pad substrate 10, the outer periphery of the shallow groove is close to the edge of the polishing pad substrate 10, the inner periphery width of the shallow groove is smaller than the outer periphery width, the inner and outer peripheries of the shallow groove are not smoothly transitioned, and an angle ∠a within the range of 30° - 45° is set at the intersection of the inner and outer peripheries. The deep groove is formed at the outer periphery of the shallow groove, with a groove width of 15 mm - 20 mm, a groove depth of 1 mm, and the surface roughness Ra of the inner wall ≤ 10 μm, so as to reduce the flow resistance and avoid the residue of the polishing liquid carrying waste chips. The advantage of the combination of the deep groove and the shallow groove is that the deep groove is used in the outer area to accelerate the outward flow of the polishing liquid by centrifugal force, and at the same time buffer the impact of the liquid flow through the capacity of the deep groove. The shallow groove is used in the inner area to maintain the uniformity of the liquid film through the capillary effect.

[0046] Preferably, one side of the first grid channel 21 is parallel to one of the corresponding first diversion channel 31 or second diversion channel 32.

[0047] Preferably, chamfers are provided at the edges of the first diversion channel 31 and the second diversion channel 32 for the smooth transition of the polishing liquid.

[0048] The circular groove 40 is used to store the premixed polishing liquid and continuously penetrate it into the surrounding polishing grids through the capillary effect.

[0049] The circular groove 40 is connected to the automatic filling port of the peristaltic pump through a seal. By using a high-precision peristaltic pump, the closed-loop feedback system of the peristaltic pump is used to adjust the polishing liquid supply in real time to prevent the slurry from drying up or excessive accumulation. The peristaltic pump with a closed-loop feedback system is a prior art and will not be described in detail in this embodiment.

[0050] The output end of the peristaltic pump is connected to the circular groove 40 through a flexible pipe. The contact position between the flexible pipe and the circular groove 40 is generally sealed by a sealing joint. Since the polishing pad base 10 needs to rotate continuously, the two ends of the sealing joint selected here can rotate relatively. The two relatively rotatable joints are connected by a sealing bearing. There are such joints on the market, which are called central swivel joints or rotary joints. Since they are existing technologies, they will not be described in detail.

[0051] Preferably, the flow control accuracy of the high-precision peristaltic pump is ±1%, and the flow rate is designed to be 8-280 ml / min, which can improve the distribution uniformity of the polishing liquid by 50%.

[0052] Preferably, the groove depth of the circular groove 40 is greater than that of the guide channel 1 31 and the guide channel 2 32 .

[0053] Preferably, the circular groove 40 is located in the central area of ​​the polishing pad base 10 , and the ratio of the diameter of the circular groove 40 to the diameter of the polishing pad base 10 is 1:3.

[0054] The workflow of the above design can be briefly described as follows: the polishing liquid is injected from the circular groove 40 into the guide channel 1 31 and the guide channel 2 32 through the peristaltic pump, and then evenly diffused into the grid channel 1 21 and the grid channel 2 22 by centrifugal force. The polishing grid 20 absorbs the polishing liquid and enhances the grinding force, and the guide groove 30 simultaneously discharges waste chips to form a dynamic balance, thereby preventing the debris generated during the use of the polishing pad from affecting the polishing effect on the crystal.

[0055] In summary, the improvements of this application are:

[0056] 1. Parallelogram polishing unit: The honeycomb structure increases the effective grinding area and uses the adsorption effect to extend the residence time of the polishing liquid.

[0057] 2. Each polishing partition is staggered at 60° to form a "micro-vortex effect", which can increase the local shear stress by 15%-20%, which is better than traditional rectangular or hexagonal polishing units.

[0058] 3. The M-shaped guide groove 30: Based on fluid mechanics simulation, the groove width and inclination angle ∠a (30°-45°) are optimized to achieve centrifugal classification discharge of waste chips. When the guide groove 30 with a groove width of 15-20mm rotates at a speed of 100rpm on the polishing pad base 10, the polishing liquid flow rate can reach 1.2m / s, and the chip retention time is shortened to less than 0.5 seconds, thereby improving the polishing effect.

[0059] 5. Substrate selection: The polishing end face of the polishing pad substrate 10 is made of an asphalt substrate, and its Shore hardness (85 - 90) is between that of polyurethane (60 - 80) and ceramic composite materials, taking into account both flexibility and support.

[0060] The technical scope of the present invention is not limited to the content described above. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A structure of a high grinding force polishing disc, characterized in that, Comprising: A polishing pad substrate (10), which is in transmission connection with the output end of a motor for driving the polishing pad substrate (10) to rotate; A polishing grid (20), including a plurality of polishing partitions. Each polishing partition is provided with polishing units separated by intersecting grid flow channels one (21) and grid flow channels two (22). The polishing units are parallelograms, and the polishing partitions on the polishing pad substrate (10) are obtained by circular array of one of the polishing partitions; A diversion groove (30), which is opened on the polishing end face of the polishing pad substrate (10); A circular groove (40), which is opened at the center of the polishing pad substrate (10). The polishing grid (20), the diversion groove (30) and the circular groove (40) are communicated with each other. The circular groove (40) communicated with the pump body is used to convey the polishing liquid to the diversion groove (30) and the polishing grid (20); 2. The structure of a high grinding force polishing disc according to claim 1, wherein The material of the polishing end face of the polishing pad substrate (10) is asphalt, and the hardness of the asphalt is between that of polyurethane and ceramic composite materials; 3. A high grinding force polishing disc structure according to claim 1, characterized in that One of the acute angles of the parallelogram-shaped polishing unit is between 60° and 70°; 4. The structure of a high grinding force polishing disc according to claim 1, wherein, The groove depth of the grid flow channel one (21) is 1 mm, and the distance between two adjacent grid flow channels one (21) in the same polishing partition is 2 mm - 3 mm; 5. A high grinding force polishing disc structure according to claim 1 or 4, characterized in that, The groove depth of the grid flow channel two (22) is 1 mm, and the distance between two adjacent grid flow channels two (22) in the same polishing partition is 2 mm - 3 mm; 6. The structure of a high grinding force polishing disc according to claim 1, characterized in that, The diversion groove (30) includes a diversion flow channel one (31) and a diversion flow channel two (32). Both the diversion flow channel one (31) and the diversion flow channel two (32) are cross-shaped grooves opened on the polishing end face of the polishing pad substrate (10). The diversion flow channel one (31) and the diversion flow channel two (32) are designed to intersect with each other, and the angle between the diversion flow channel one (31) and the diversion flow channel two (32) is 45°. The area between the diversion flow channel one (31) and the diversion flow channel two (32) is the polishing partition; 7. A high grinding force polishing disc structure according to claim 6, characterized in that, The groove width of the diversion flow channel one (31) is between 15 mm and 20 mm, the groove depth is 1 mm, and the surface roughness Ra of the inner wall is ≤ 10 μm; 8. The structure of a high grinding force polishing disc according to claim 6, characterized in that, The diversion flow channel two (32) is divided into a shallow groove and a deep groove. The inner peripheral width of the shallow groove is smaller than the outer peripheral width, and the inner peripheral and outer peripheral parts of the shallow groove are not smoothly transitioned. The deep groove is opened at the outer peripheral position of the shallow groove. The groove width of the deep groove is 15 mm - 20 mm, the groove depth is 1 mm, and the surface roughness Ra of the inner wall is ≤ 10 μm; 9. The structure of a high grinding force polishing disc according to claim 7, characterized in that An included angle a is formed at the intersection of the inner periphery and the outer periphery of the shallow groove of the diversion flow channel two (32), and the angle of the included angle a is between 30° and 45°; 10. The structure of a high grinding force polishing disc according to claim 1, characterized in that, The ratio of the diameter of the circular groove (40) to the diameter of the polishing pad substrate (10) is 1:3, and the depth of the circular groove (40) is greater than that of both the diversion flow channel one (31) and the diversion flow channel two (32).

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