Laser processing system and method for convex point and annular groove structure on ceramic disk surface

Abstract

The invention proposes a laser processing system and a processing method for a convex point and annular groove structure on a ceramic disk surface, comprising a horizontally arranged horizontal X-direction linear drive mechanism and a horizontal Y-direction linear drive mechanism, a bearing platform connected to the X-direction and Y-direction linear drive mechanisms, a vertical Z-direction linear drive mechanism arranged above the bearing platform, a focusing field mirror and a positioning camera connected to the vertical Z-direction linear drive mechanism and arranged at the same height as the focal position; a two-dimensional scanning galvanometer, an optical path reflection lens, a beam expander, and a laser are arranged behind the focusing field mirror to form an optical path from the generation of the laser to the emission of the laser beam from the focusing field mirror; the invention adopts laser processing with the joint movement of the galvanometer and the platform and the superposition of multiple layers and gradient graphics to achieve large-scale multivariate compensation and target positioning, large-margin reverse precision uniform etching, and high efficiency and low damage balance, and is used for high-precision, high-quality, and high-efficiency etching processing of the surface structure of large-scale precision ceramic disk components, overcoming the problems of low efficiency, poor precision, high cost, high scrap risk, and poor versatility and flexibility of the existing method.

Description

Technical Field

[0001] The invention relates to the technical field of precision ceramic processing, and in particular to a laser processing system and a processing method for a ceramic disk surface structure. Background Art

[0002] Quality control in the semiconductor IC manufacturing process is a crucial link to ensure the yield rate of chip production, which runs through the entire integrated circuit manufacturing process, including front-end inspection, mid-end inspection and back-end measurement. Ceramic components are closely related to the precision of integrated circuit manufacturing processes, especially ceramic vacuum chucks, which are high-precision bearing mechanisms used to fix wafers in the semiconductor wafer inspection and measurement process, and are indispensable core key components in the quality control equipment of integrated circuit manufacturing.

[0003] There are many types of vacuum chucks. According to their materials, they can be divided into three types: aluminum alloy, alumina ceramic, and silicon carbide ceramic. According to their structures, they can be divided into three types: a combination of porous ceramics and a substrate, an integrated structure with a ring groove protrusion (ring chuck), and an integrated structure with a point protrusion (pin chuck). With the development of semiconductor manufacturing processes, the requirements for the accuracy of equipment for wafer inspection and measurement are getting higher and higher, and at the same time, the requirements for the accuracy and stability of the vacuum chuck of the wafer clamping system are also getting higher and higher. Therefore, the integrated structure series of ceramic vacuum chucks (especially silicon carbide ceramic vacuum chucks with point protrusions) have obvious advantages such as high flattening accuracy, strong adsorption force, good stability, small contact area with the wafer, and less back Paticle contamination. They have increasingly occupied the mid-to-high-end vacuum chuck market and gradually become the mainstream choice of the semiconductor wafer measurement / inspection industry.

[0004] Silicon carbide ceramics not only have the excellent mechanical properties of ordinary ceramics, but also have the best oxidation resistance among non-oxide ceramics, and the best high-temperature mechanical properties among current ceramic materials. Therefore, silicon carbide ceramics are increasingly used in pan-semiconductor related equipment, among which the silicon carbide vacuum chuck (Chuck) with thousands of small bumps or numerous concentric grooves on the surface is the most representative.

[0005] Thousands of coplanar circular small bumps or numerous concentric annular coplanar annular protrusions need to be prepared on a Chuck ceramic disk with a diameter of about 300mm. The purpose of designing these small bumps or annular protrusions is to be able to hold up and adsorb the wafer. The overall flatness of the adsorbed 12-inch wafer can reach 0.2μm; according to the shape of the wafer, the plane shape of the chuck can be freely adjusted; in order to improve the responsiveness of adsorption, the structure of the adsorption area or bumps can be specially made to better adsorb warped and deformed wafers. Usually, the diameters of these small circular bumps include about 2mm and 1mm. Now there is a trend towards smaller diameters, such as small circular bumps with a diameter of 0.2~0.4mm, and the target processing height of small circular bumps with a diameter of 0.4mm is about 0.2mm.

[0006] For the processing of such special structures as tiny bumps or annular protrusions on the surface of silicon carbide ceramics, the existing method mainly relies on CNC engraving and milling. However, due to the high hardness and brittleness of silicon carbide ceramics, not only is the efficiency extremely low and difficult to process, resulting in long processing time and high processing cost, but also the consistency of the bump diameter and the goodness of the bottom surface of the bump are very poor. When faced with small circular bumps with a diameter of 0.2~0.4mm, it is also very easy to break the bumps or even knock them off, resulting in uneven bumps on the entire chuck surface, resulting in an extremely low processing yield.

[0007] Another method is to achieve it through sandblasting. During sandblasting, a film corresponding to the size and position of the bump is attached to the surface of the ceramic suction cup, and then the surface of the ceramic suction cup is sandblasted. The sandblasting process removes a certain thickness of the position where the film is not attached, while the surface thickness of the position where the film is attached will not be removed, so a bump is formed at the position where the film is attached. This method has high requirements for the film. It must not only have good toughness, impact resistance and adhesion, but also achieve high flatness and development accuracy during film attachment, exposure and development. When facing small circular bumps with a diameter of 0.2~0.4mm, the adhesion of the film is extremely high. There is a great risk of the film falling off on a small bump in a certain area, causing the small bump to be incomplete during sandblasting, causing the entire chuck to be scrapped. In addition, this method is expensive, cumbersome and extremely inflexible. It is only suitable for the processing of single-specification, large-volume and high-value-added chuck products. In scenarios where the chuck specifications vary, the production and processing efficiency is low and the cost performance is not high. Summary of the invention

[0008] In response to the above-mentioned technical problems, the present invention proposes a method for processing the surface convex points and annular groove structures of a ceramic disk, which is used to solve the problems of low processing yield and low processing efficiency in the prior art for processing tiny convex points or annular protrusion structures on the surface of silicon carbide ceramic disks.

[0009] In order to achieve the above object, the technical solution of the present invention is achieved as follows: A laser processing system for a convex point and annular groove structure on a ceramic disk surface comprises a laser, an optical path reflective lens, a beam expander, a two-dimensional scanning galvanometer, a focusing field lens, a positioning camera, a bearing platform, a horizontal X-direction linear drive mechanism, a horizontal Y-direction linear drive mechanism, a vertical Z-direction linear drive mechanism, a motion controller, and a marble machine; the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are arranged horizontally and perpendicularly, and the bearing platform is connected to the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism so that the bearing platform can move along the X-direction and the Y-direction on a horizontal plane; the vertical Z-direction linear drive mechanism and the focusing The field mirror and the positioning camera are arranged above the carrying platform; the focal positions of the focusing field mirror and the positioning camera are arranged at the same height and are both connected to the vertical Z-direction linear drive mechanism, and the laser beam is vertically directed downward to the carrying platform, and the positioning camera observes the carrying platform vertically downward; a two-dimensional scanning galvanometer, an optical path reflection lens, a beam expander, and a laser are sequentially arranged behind the focusing field mirror to form an optical path for the laser beam to be emitted from the laser to the focusing field mirror; the control ends of the horizontal X-direction linear drive mechanism, the horizontal Y-direction linear drive mechanism, the vertical Z-direction linear drive mechanism, the laser, and the two-dimensional scanning galvanometer are all connected to a motion controller for realizing linkage control.

[0010] A method for processing a convex point and annular groove structure on a ceramic disk surface, comprising a laser processing system for the convex point and annular groove structure on the ceramic disk surface, and further comprising the following steps: S1. Build laser processing system; S2, mounting the ceramic disc to be processed on the carrying platform and positioning it according to the target; S3, setting a composite processing graphic with multiple layers of gradient overlay; S4, setting fill lines and outlines on the processing graphics of each layer in turn, and forming a 2D motion path of the laser spot by scanning the laser spot along the fill lines and outlines of the processing graphics of each layer in turn; S5, decomposing the 2D motion path of the laser spot to generate a linkage motion trajectory of a two-dimensional scanning galvanometer and / or a carrying platform; S6, carrying out laser etching rough processing, semi-finishing processing and finishing processing in sequence; S7, polishing and high flatness processing of the raised support parts on the surface of the ceramic disk; S8, using a solvent and pure water to clean or ultrasonically clean the ceramic disk processed in step S7, and then testing the accuracy of the cleaned ceramic disk.

[0011] Furthermore, the step S2 comprises the following steps: S21, adsorbing and fixing the ceramic disk to be processed on the carrying platform of the laser processing system; S22, controlling the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism through the motion controller to move the target on the upper surface of the ceramic disk on the carrying platform to the position directly below the positioning camera; S23, controlling the vertical Z-direction linear drive mechanism through a motion controller to make the positioning camera focus on the upper surface of the ceramic disk; S24, controlling the horizontal X-axis linear drive mechanism and the horizontal Y-axis linear drive mechanism through the motion controller to drive the carrying platform to move so that the position of the target on the upper surface of the ceramic disk corresponds to the position of the target on the processing drawing; S25. Repeat steps S22 to S24 to complete the correspondence between at least three targets on the upper surface of the ceramic disk and the target positions on the processing drawing to locate the position of the ceramic disk on the carrying platform.

[0012] Furthermore, the step S3 comprises: Import the contour line in the processing drawing into the laser, and set the closed area within the contour line that needs laser processing as the processing graphic; There are multiple processing graphics, and the multiple processing graphics are respectively arranged in multiple superimposed layers, and the inner contour of the processing graphics of each layer increases in sequence from small to large from top to bottom.

[0013] Furthermore, the step S4 comprises the following steps: S41, sequentially setting two groups of fill lines in each processing graphic of each layer, wherein the two groups of fill lines are respectively set along the X direction and the Y direction and cross each other vertically; S42, the laser spot scans along the filling line in the processing figure and the contour line of the processing figure in sequence to form a 2D motion path of the laser spot.

[0014] Furthermore, forming the laser spot 2D motion path in step S42 includes: While the laser spot is scanned in the horizontal plane by the movement of the two-dimensional scanning galvanometer, the ceramic disk is driven to move in the horizontal plane by controlling the movement of the carrying platform through the horizontal X-direction linear drive mechanism and / or the horizontal Y-direction linear drive mechanism. The movement of the two-dimensional scanning galvanometer is superimposed on the movement of the ceramic disk to form a 2D motion path of the laser spot relative to the ceramic disk.

[0015] Further, the step S5 includes the following two situations: When the processing pattern size does not exceed the maximum processing range of the two-dimensional scanning galvanometer, the carrier platform does not move, and only controls the movement of the two-dimensional scanning galvanometer to make the laser spot scan along the set 2D motion path of the laser spot, generating the motion trajectory of the two-dimensional scanning galvanometer; When the size of the processed graphics exceeds the maximum processing range of the two-dimensional scanning galvanometer, the carrier platform and the two-dimensional scanning galvanometer move synchronously, and the 2D motion path of the laser spot is the superposition of the motion trajectories of the two-dimensional scanning galvanometer and the carrier platform.

[0016] Furthermore, when the format of the processed pattern exceeds the maximum processable range of the two-dimensional scanning galvanometer, the step of generating the motion trajectory of the two-dimensional scanning galvanometer and / or the carrying platform includes: S51, reducing the size of the processed graphics in proportion to the maximum processable range of the two-dimensional scanning galvanometer, so that the reduced processed graphics are not larger than the maximum processable range of the two-dimensional scanning galvanometer; S52, then generate the motion trajectory of the two-dimensional scanning galvanometer and / or the carrying platform according to one of the following rules based on the 2D motion path of the laser spot: When the spacing between the fill lines and the outline lines of the reduced processing figure in the X and Y directions is greater than the motion resolution of the two-dimensional scanning galvanometer, the motion trajectory of the carrier platform is set to be a plurality of diagonal lines connected end to end; the carrier platform is made to move in a "W" shape at a uniform speed along the diagonal lines; then the 2D motion path of the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the motion trajectory of the two-dimensional scanning galvanometer; When the spacing of the fill lines and contour lines of the reduced processing graphics in the X direction is greater than the motion resolution of the two-dimensional scanning galvanometer, and the spacing in the Y direction is not greater than the motion resolution of the two-dimensional scanning galvanometer, the motion trajectory of the carrier platform is set to be a plurality of parallel straight lines along the X direction, and the straight line spacing is the spacing of the fill lines and contour lines of the processing graphics in the Y direction, so that the carrier platform moves in a serpentine uniform speed along the X direction, and then the 2D motion path synthesized by the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the motion trajectory of the two-dimensional scanning galvanometer; When the spacing of the fill lines and contour lines of the reduced processing graphics in the Y direction is greater than the motion resolution of the two-dimensional scanning galvanometer, and the spacing in the X direction is not greater than the motion resolution of the two-dimensional scanning galvanometer, the motion trajectory of the carrier platform is set to be a plurality of parallel straight lines along the Y direction, and the straight line spacing is the spacing of the fill lines and contour lines of the processing graphics in the X direction, so that the carrier platform moves in a serpentine uniform speed along the Y direction, and then the 2D motion path synthesized by the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the motion trajectory of the two-dimensional scanning galvanometer; When the spacing between the fill lines and the outline lines of the reduced processing graphics in the X and Y directions is not greater than the motion resolution of the 2D scanning galvanometer, the 2D scanning galvanometer is set not to move, the focusing field lens is fixed at a single point to emit light, and the 2D motion path of the laser spot is the motion trajectory of the carrier platform; S53, sending the 2D motion path of the laser spot and the motion trajectory generation rules of the two-dimensional scanning galvanometer and the carrying platform to the motion controller, controlling the two-dimensional scanning galvanometer and the carrying platform to move according to their generated motion trajectories, setting the laser spot to scan and process along the processing graphics of each layer from small to large in sequence; first scan the filling line in the processing graphics in the same layer, and then scan the contour line of the processing graphics.

[0017] Furthermore, step S6 includes the following steps: S61, Laser Etching Rough Processing: S611, set the laser power to 50~90w, the laser spot synthesis scanning rate to 500~1000mm / s, and the filling line spacing of the processed graphics to 30~50μm; S612, controlling the vertical Z-direction linear drive mechanism through the motion controller so that the laser beam emitted by the focusing field mirror is focused on the upper surface of the ceramic disk; S613, the laser emits light, controls the two-dimensional scanning galvanometer and the carrying platform to synchronize and link according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer according to the 2D motion path of the laser spot in S3 and S4 for laser processing, and stops when the processing depth reaches more than 80% of the target depth; S62, Laser Etching Semi-finishing: S621, set the laser power to 20~50w, the laser spot synthesis scanning rate to 200~500mm / s, and the filling line spacing of the processed graphics to 10~30μm; S622, the laser emits light, controls the two-dimensional scanning galvanometer and the carrying platform to synchronize according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer according to the 2D motion path of the laser spot in S3 and S4 for laser processing, and stops when the difference between the processing depth and the target depth is no greater than the single-pass processing depth; S63, laser etching finishing: S631, set the laser power to 1~15w, the laser spot synthesis scanning rate to 50~200mm / s, and the filling line spacing of the processed graphics to 2~10μm; S632, the laser emits light, controls the two-dimensional scanning galvanometer and the carrying platform to synchronize with each other according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer according to the 2D motion path of the laser spot in S3 and S4 for laser processing, and stops when the processing depth reaches the target depth tolerance range.

[0018] Furthermore, step S7 includes: placing the upper surface of the ceramic disc processed in step S6 with the surface facing downward on the polishing pad of the polishing machine, so that the circular protrusions and the raised supporting parts of the annular protrusions on the upper surface of the ceramic disc directly contact the polishing pad, and using a peristaltic pump to pour a polishing liquid containing diamond particles with a particle size of less than 10 μm into the contact area between the ceramic disc and the polishing pad; the polishing pad is driven by the polishing machine to rotate along its central axis, and the ceramic disc revolves along the central axis of the polishing pad, so that the polishing pad and the ceramic disc are squeezed and rubbed under the action of the polishing liquid, thereby achieving polishing and high flatness processing of the raised supporting parts on the surface of the ceramic disc.

[0019] Furthermore, the step S8 comprises: S8.1, the surface of the ceramic disk processed in step S7 is sequentially subjected to air blowing, organic solvent ultrasonic immersion, nitric acid and hydrofluoric acid mixed solution immersion, pure water ultrasonic immersion, nitric acid and sulfuric acid mixed solution boiling immersion, pure water ultrasonic immersion, hydrogen peroxide immersion, pure water ultrasonic immersion, and air blowing to complete the cleaning of the surface of the ceramic disk; S8.2. Place the standard wafer on the upper surface of the ceramic plate, support the standard wafer with the circular protrusion or annular protrusion, place the ceramic plate and the standard wafer together on a large-aperture plane interferometer, and test the flatness of the standard wafer. If the flatness of the standard wafer meets the index requirements, the ceramic plate is qualified; if the flatness of the standard wafer exceeds the index requirements, the ceramic plate is returned for rework.

[0020] Beneficial effects of the present invention: 1. The present invention innovatively adopts a laser processing method that combines the motion of a two-dimensional scanning galvanometer and a carrier platform, and superimposes multiple layers of gradually changing processing patterns, breaking through technical difficulties such as large-format multivariate compensation and target positioning, large-residue reverse precision uniform etching, and high-efficiency and low-damage balance, and realizes high-precision, high-quality, and high-efficiency processing of various specifications of 0.2-3mm bumps and special structures of ring grooves on the surface of 8-12-inch and above ceramic disks; and the method of the present invention can also be used for the processing of difficult-to-process silicon carbide vacuum chucks, opening up a new way to manufacture vacuum chuck products, not only with lower equipment and consumables costs and higher processing efficiency, but also achieving processing quality superior to foreign sandblasting technology; 2. The processing method of the convex point and annular groove structure on the surface of the ceramic disk provided by the present invention overcomes the problems of low efficiency, poor precision, high cost, high scrap risk, many process steps, poor versatility and flexibility of existing methods such as engraving and milling, sandblasting, etc., and achieves outstanding progress and great improvement in processing precision, processing quality and processing efficiency compared with the existing technology; 3. The processing method of the ceramic disk surface protrusion and annular groove structure provided by the present invention not only supports the research and development and manufacturing of ceramic vacuum chuck series products, but can also be expanded to the design and development of other ceramic functional components, promoting the development and upgrading of the field of high-end ceramic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a structural schematic diagram of the laser processing system of the present invention; Figure 2 It is a schematic diagram of the process of the present invention.

[0023] In the figure: 1. Carrying platform, 2. Positioning camera, 3. Laser, 4. Beam expander, 5. Optical path reflective lens, 6. Two-dimensional scanning galvanometer, 7. Focusing field lens. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The laser processing system of the convex point and annular groove structure on the surface of a ceramic disk described in Example 1 of the present invention comprises a laser 3, an optical path reflective lens 5, a beam expander 4, a two-dimensional scanning galvanometer 6, a focusing field lens 7, a positioning camera 2, a carrying platform 1, a horizontal X-direction linear drive mechanism, a horizontal Y-direction linear drive mechanism, a vertical Z-direction linear drive mechanism, a motion controller, and a marble machine. The laser 3 is an infrared nanosecond pulse laser.

[0026] Furthermore, the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are horizontally arranged and arranged vertically, and are interconnected with the carrying platform, so that the carrying platform can move freely in two-dimensional directions on the horizontal plane. Specifically, the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism can adopt a linear module or a telescopic cylinder or an electric push rod or other driving mechanisms in the prior art that can drive the driven part to perform linear motion. The working end of one of the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism is connected to the carrying platform 1, and the fixed end is connected to the working end of the other, and the fixed end of the other is fixedly arranged. And the driving directions of the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are both perpendicular to the horizontal direction, namely the X direction and the Y direction, so that the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism can drive the carrying platform 1 to perform two-dimensional movement in the X direction and the Y direction.

[0027] Furthermore, the vertical Z-direction linear drive mechanism, the focusing field lens 7, and the positioning camera 2 are arranged above the carrier platform 1, and the focal positions of the focusing field lens 7 and the positioning camera 2 are at the same height and fixedly connected to the vertical Z-direction linear drive mechanism, so that the laser beam is vertically directed downward toward the object platform, and the positioning camera vertically observes the object platform downward. The focusing field lens and the positioning camera are connected to the working end of the vertical Z-direction linear drive mechanism. Among them, the vertical Z-direction linear drive mechanism can also adopt a driving mechanism in the prior art such as a linear module, a telescopic cylinder, or an electric push rod that can drive the driven part to perform linear motion. In this embodiment, the driving direction is the vertical Z direction.

[0028] A two-dimensional scanning galvanometer 6, an optical path reflecting lens 5, a beam expander 4, and a laser 3 are sequentially arranged behind the focusing field lens to form an optical path for the laser beam to be emitted from the laser to the focusing field lens; the control ends of the horizontal X-direction linear drive mechanism, the horizontal Y-direction linear drive mechanism, the vertical Z-direction linear drive mechanism, the laser, and the two-dimensional scanning galvanometer are connected to a motion controller to realize linkage control of the above components.

[0029] In addition, a marble machine table is used to support and fix the components of the above-mentioned laser processing system and ensure the stability of each moving part.

[0030] The method for processing the surface convex point and annular groove structure of a ceramic disk described in Example 2 of the present invention takes the surface convex point and annular groove structure processing of a silicon carbide vacuum chuck as an example, and specifically comprises the following steps: Step 1: Build the laser processing system according to the structure of the above laser processing system.

[0031] Step 2: Install and position the ceramic disc to be processed: 2.1. The ceramic disk to be processed is fixed on the carrier platform of the laser processing system by adsorption and positioned according to the target; the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are controlled to move so that the target on the upper surface of the ceramic disk on the carrier platform (such as structural holes, boundary arcs, etc.) is moved to the position directly below the positioning camera; the vertical Z-direction linear drive mechanism is controlled by the motion controller to focus the positioning camera on the upper surface of the ceramic disk, and the image of the target observed by the camera is clear; the Z-direction position height at this time, that is, the height of the positioning camera from the upper surface of the ceramic disk, is also the focusing position height of the laser beam emitted by the focusing field mirror; the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are controlled by the motion controller to drive the current carrier platform to move in two dimensions on the horizontal plane, so that the position coordinates of the target on the upper surface of the ceramic disk on the carrier platform correspond to the position of the target on the processing drawing; 2.2. Repeat the above step 2.1 to complete the correspondence between at least three targets on the upper surface of the ceramic disk and the target positions and coordinates on the processing drawing, so as to locate and identify the actual position of the ceramic disk to be processed on the carrying platform according to the processing drawing.

[0032] Step 3: Set up the gradient composite processing graphics with multiple layers superimposed: 3.1. According to the processing drawing, import the contour line in the processing drawing into the laser, and define the closed area within the contour line that needs to be laser processed as the processing figure. Among them: when processing convex points, the outermost contour and the convex point contour and the closed area between them are the processing figures; when processing annular grooves, the annular groove contour and the closed area within the annular groove contour are the processing figures.

[0033] 3.2. To realize the controllable taper processing of circular frustum convex points, set multiple layers of processing graphics with a uniform size gradient from small to large. The setting method is: set multiple layers, set a processing graphic for each layer, and the inner contour of the processing graphics of each layer from top to bottom increases from small to large and uniformly. Among them: when processing convex points, the outermost contour of the processing graphics of each layer from top to bottom remains unchanged, and the contour diameter of the convex point gradually increases uniformly.

[0034] Step 4: Set fill lines and contour lines on the processed graphics, and scan the laser spot along the fill lines and contour lines to form a 2D motion path of the laser spot: Two groups of equally spaced fill lines are set in each processing graphic of each layer in turn, and the two groups of fill lines are set along the X direction and the Y direction respectively and cross vertically; the laser spot is scanned along the fill lines and contour lines in the processing graphics of each layer in turn to form a 2D motion path of the laser spot; Furthermore, in order to achieve large-scale processing far beyond the range of the two-dimensional scanning galvanometer, expand the processing format, or improve the processing efficiency, the synchronous linkage of the carrying platform and the two-dimensional scanning galvanometer and the integrated motion control technology are adopted, that is, a synchronous linkage control program of the carrying platform and the two-dimensional scanning galvanometer is set, and the movement of the two-dimensional scanning galvanometer makes the laser spot scan in the horizontal two-dimensional direction. At the same time, the movement of the carrying platform is controlled by the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism to drive the ceramic disk to be processed to move in the horizontal two-dimensional direction. The two movements are superimposed and synthesized to form a synthetic laser spot 2D motion path of the laser spot relative to the ceramic disk to be processed.

[0035] Step 5: Generate the scanning 2D scanning galvanometer motion trajectory and the carrier platform motion trajectory according to the 2D motion path of the laser spot: When the processing graphics format does not exceed the maximum processing range of the two-dimensional scanning galvanometer, the carrier platform does not move, and only the two-dimensional scanning galvanometer moves to make the laser spot scan along the set motion path. The motion trajectory of the two-dimensional scanning galvanometer is the 2D motion path of the laser spot. When the processing pattern exceeds the maximum processing range of the two-dimensional scanning galvanometer, the carrier platform and the two-dimensional scanning galvanometer are synchronously linked, and the motion trajectory of the two-dimensional scanning galvanometer and the motion trajectory of the carrier platform are superimposed to form a synthetic 2D motion path of the laser spot. At this time, the steps for generating the motion trajectory of the two-dimensional scanning galvanometer and the motion trajectory of the carrier platform include: 5.1. First, the processing pattern is proportionally reduced according to the maximum processing range of the two-dimensional scanning galvanometer. The reduced processing pattern is not larger than the maximum processing range of the two-dimensional scanning galvanometer. 5.2. Then, according to the synthesized 2D motion path of the laser spot, the motion trajectory of the two-dimensional scanning galvanometer and the carrying platform is generated according to one of the following rules: When the spacing between the fill lines and contour lines of the reduced processing graphics in the X and Y directions is greater than the motion resolution of the two-dimensional scanning galvanometer, the motion trajectory of the carrier platform is set to be multiple segments of end-to-end slash lines, and the intervals between the slash lines are small, that is, the angles between adjacent slash lines are very small. The carrier platform moves in one direction at a uniform speed along the multiple segments of end-to-end slash lines, so that the motion trajectory of the carrier platform is a plurality of "W"-shaped trajectories formed by multiple segments of end-to-end slash lines connected in sequence. Then, the 2D motion path of the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the motion trajectory of the two-dimensional scanning galvanometer; When the spacing of the fill lines and contour lines of the reduced processing graphics in the X direction is greater than the motion resolution of the two-dimensional scanning galvanometer, and the spacing in the Y direction is not greater than the motion resolution of the two-dimensional scanning galvanometer, the motion trajectory of the carrier platform is set to be a plurality of parallel straight lines along the X direction, and the straight line spacing is the spacing of the fill lines and contour lines of the processing graphics in the Y direction, that is, the carrier platform performs a serpentine uniform motion along the X direction, and then the 2D motion path of the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the motion trajectory of the two-dimensional scanning galvanometer; When the Y-direction spacing of the reduced processing graphics fill lines and contour lines is greater than the two-dimensional scanning galvanometer motion resolution, and the X-direction spacing is not greater than the two-dimensional scanning galvanometer motion resolution, the motion trajectory of the carrier platform is set to be a plurality of parallel straight lines along the Y direction, and the straight line spacing is the X-direction spacing of the processing graphics fill lines and contour lines, that is, the carrier platform performs a serpentine uniform motion along the Y direction, and then the 2D motion path of the laser spot is synchronously subtracted from the motion trajectory of the carrier platform to generate the two-dimensional scanning galvanometer motion trajectory; When the spacing between the fill lines and the outline lines of the reduced processing graphics in the X and Y directions is not greater than the motion resolution of the 2D scanning galvanometer, the 2D scanning galvanometer is set not to move, the focusing field lens is fixed at a single point to emit light, and the 2D motion path of the laser spot is the motion trajectory of the carrier platform; 5.3. Send the 2D motion path of the laser spot and the motion trajectory generation rules of the 2D scanning galvanometer and the carrying platform to the motion controller, control the 2D scanning galvanometer and the carrying platform to move according to their generated motion trajectories, set the laser spot to scan and process along the processing graphics of each layer from small to large, and scan the filling line in the processing graphics in the same layer first, and then scan the contour line of the processing graphics.

[0036] Step 6: Carry out laser etching rough processing: 6.1. Set the laser power to 50~90w, the laser spot synthesis scanning rate to 500~1000mm / s, and the processing pattern filling line spacing to 30~50μm; 6.2. Control the vertical Z-direction linear drive mechanism to focus the laser beam emitted by the focusing field mirror on the upper surface of the ceramic disk, and then the laser emits light. According to the current setting parameters, the two-dimensional scanning galvanometer and the carrying platform are controlled to synchronize and link according to the motion trajectory generated in step 5, so that the laser spot is repeatedly scanned layer by layer in sequence according to the 2D motion path of the laser spot set in steps 3 and 4. A large amount of material is quickly removed by laser, so as to achieve ultra-high efficiency etching rough processing of the surface processing area of ​​the ceramic disk; 6.3. After each processing, use a depth gauge to measure the etching depth. If the etching depth does not reach more than 80% of the target depth, continue to increase the number of processing passes; if the etching depth reaches more than 80% of the target depth, stop the current rough processing step.

[0037] Step 7: Perform laser etching semi-finishing: 7.1. Set the laser power to 20~50w, the laser spot synthesis scanning rate to 200~500mm / s, and the processing pattern filling line spacing to 10~30μm; 7.2. The laser emits light, and according to the current setting parameters, the two-dimensional scanning galvanometer and the carrying platform are controlled to synchronize and link according to the motion trajectory generated in step 5, so that the laser spot is scanned layer by layer repeatedly in sequence according to the 2D motion path of the laser spot set in steps 3 and 4. The laser processing optimizes and weakens the metamorphic layer, recondensation layer and laser spot scanning ablation lines left over from the rough processing, so as to achieve efficient and precise etching and semi-finishing of the surface processing area of ​​the ceramic disk; 7.3. After each pass of processing, use a depth gauge to measure the etching depth. If the difference between the etching depth and the target depth is greater than the single-pass etching depth in step 7.2, continue to increase the number of passes; if the difference between the etching depth and the target depth is not greater than the single-pass etching depth, stop the current semi-finishing step.

[0038] Step 8: Perform laser etching finishing: 8.1. Set the laser power to 1~15w, the laser spot synthesis scanning rate to 50~200mm / s, and the processing pattern filling line spacing to 2~10μm; 8.2. The laser emits light, and according to the current setting parameters, the two-dimensional scanning galvanometer and the carrying platform are controlled to synchronize and link according to the motion trajectory generated in step 5, so that the laser spot is repeatedly scanned layer by layer in sequence according to the 2D motion path of the laser spot set in steps 3 and 4. The laser processing completely eliminates the metamorphic layer and recondensation layer remaining on the surface, further weakens the laser spot scanning ablation texture, greatly reduces the roughness of the laser processing surface, and realizes ultra-high precision etching and finishing of the surface processing area of ​​the ceramic disk; 8.3. After each processing, use a depth gauge to measure the etching depth. If the etching depth does not reach the target depth tolerance range, continue to increase the number of processing passes; if the etching depth reaches the target depth tolerance range, stop the current finishing step.

[0039] Step 9: Polishing and high flatness processing of the raised support parts on the surface of the ceramic disk: The upper surface of the laser-processed ceramic disc is placed face down on the polishing pad of the polishing machine, so that the circular protrusions and the raised supporting parts of the annular protrusions on the upper surface of the ceramic disc directly contact the polishing pad. A peristaltic pump is used to pour polishing liquid containing diamond particles with a particle size of less than 10μm into the contact area between the ceramic disc and the polishing pad. Driven by the machine, the polishing pad rotates along its central axis, and the ceramic disc revolves along the central axis of the polishing pad. The two are squeezed and rubbed under the action of the polishing liquid to achieve polishing and high flatness processing of the raised supporting parts on the surface of the ceramic disc.

[0040] Step 10: Clean and inspect the ceramic plate: 10.1 After polishing, the surface of the ceramic disk is cleaned by air blowing, organic solvent ultrasonic immersion, nitric acid and hydrofluoric acid mixture immersion, pure water ultrasonic immersion, nitric acid and sulfuric acid mixture boiling immersion, pure water ultrasonic immersion, hydrogen peroxide immersion, pure water ultrasonic immersion, and air blowing in sequence to complete the cleaning of the surface of the ceramic disk.

[0041] 10.2 Place the standard wafer on the upper surface of the ceramic plate, start vacuum adsorption, and support the standard wafer with the circular convex point or the annular convex part. Place the ceramic plate and the standard wafer together on the large-aperture plane interferometer to detect the flatness of the standard wafer. If the flatness of the standard wafer meets the index requirements, the ceramic plate is qualified. If the flatness of the standard wafer exceeds the index requirements, the ceramic plate will be returned for rework.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that any modification to the technical solutions described in the aforementioned embodiments, or any equivalent replacement of some or all of the technical features therein, within the spirit and principles of the present invention, and such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A laser processing system for the convex point and annular groove structure on the surface of a ceramic disk, characterized in that: The invention comprises a laser (3), an optical path reflective lens (5), a beam expander (4), a two-dimensional scanning galvanometer (6), a focusing field lens (7), a positioning camera (2), a carrying platform (1), a horizontal X-direction linear drive mechanism, a horizontal Y-direction linear drive mechanism, a vertical Z-direction linear drive mechanism, and a motion controller; the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism are arranged horizontally and perpendicularly to each other, and the carrying platform (1) is connected to the horizontal X-direction linear drive mechanism and the horizontal Y-direction linear drive mechanism so that the carrying platform (1) can move in the X-direction and the Y-direction on a horizontal plane; the vertical Z-direction linear drive mechanism and the focusing field lens (7) and the positioning camera (2) are arranged above the carrying platform (1); The focal positions of the focusing field mirror (7) and the positioning camera (2) are arranged at the same height and are both connected to a vertical Z-direction linear drive mechanism, so that the laser beam is vertically directed downward toward the carrying platform (1), and the positioning camera (2) vertically observes the carrying platform (1) downward; a two-dimensional scanning galvanometer (6), an optical path reflection lens (5), a beam expander (4), and a laser (3) are sequentially arranged behind the focusing field mirror (7) to form an optical path for the laser beam to be generated from the laser (3) to be emitted from the focusing field mirror (7); and the control ends of the horizontal X-direction linear drive mechanism, the horizontal Y-direction linear drive mechanism, the vertical Z-direction linear drive mechanism, the laser (3), and the two-dimensional scanning galvanometer (6) are all connected to a motion controller for realizing linkage control.

2. A method for processing a convex point and annular groove structure on a ceramic disk surface, characterized in that: The laser processing system comprising the convex point and annular groove structure on the surface of the ceramic disk as claimed in claim 1 further comprises the following steps: S1. Build laser processing system; S2, mounting the ceramic disc to be processed on the carrying platform (1) and positioning it according to the target; S3, setting a composite processing graphic with multiple layers of gradient overlay; S4, setting fill lines and outlines on the processing graphics of each layer in turn, and forming a 2D motion path of the laser spot by scanning the laser spot along the fill lines and outlines of the processing graphics of each layer in turn; S5, decomposing the 2D motion path of the laser spot to generate a linkage motion trajectory of the two-dimensional scanning galvanometer (6) and / or the carrying platform (1); S6, carrying out laser etching rough processing, semi-finishing processing and finishing processing in sequence; S7, polishing and high flatness processing of the raised support parts on the surface of the ceramic disk; S8, using a solvent and pure water to clean or ultrasonically clean the ceramic disk processed in step S7, and then testing the accuracy of the cleaned ceramic disk.

3. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 2, characterized in that: The step S2 comprises the following steps: S21, adsorbing and fixing the ceramic disk to be processed on the supporting platform (1) of the laser processing system; S22, controlling the horizontal X-axis linear drive mechanism and the horizontal Y-axis linear drive mechanism through a motion controller to move the target on the upper surface of the ceramic disk on the carrying platform (1) to the position directly below the positioning camera (2); S23, controlling the vertical Z-direction linear drive mechanism through a motion controller so that the positioning camera (2) focuses on the upper surface of the ceramic disk; S24, controlling the horizontal X-axis linear drive mechanism and the horizontal Y-axis linear drive mechanism through a motion controller to drive the carrying platform (1) to move so that the position of the target on the upper surface of the ceramic disk corresponds to the position of the target on the processing drawing; S25, repeating steps S22 to S24, completing the correspondence between at least three targets on the upper surface of the ceramic disk and the target positions on the processing drawing, so as to locate the position of the ceramic disk on the carrying platform (1).

4. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 3, characterized in that: The step S3 comprises: Import the contour line in the processing drawing into the laser (3), and set the closed area within the contour line that needs to be laser processed as the processing pattern; There are multiple processing graphics, and the multiple processing graphics are respectively arranged in multiple superimposed layers, and the inner contour of the processing graphics of each layer increases in sequence from small to large from top to bottom.

5. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 4, characterized in that: The step S4 comprises the following steps: S41, sequentially setting two groups of fill lines in each processing graphic of each layer, wherein the two groups of fill lines are respectively set along the X direction and the Y direction and cross each other vertically; S42, the laser spot scans along the filling line in the processing figure and the contour line of the processing figure in sequence to form a 2D motion path of the laser spot.

6. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 5, characterized in that: The forming of the laser spot 2D motion path in step S42 includes: The laser spot is scanned in the horizontal plane by moving the two-dimensional scanning galvanometer (6), and the ceramic disk is driven to move in the horizontal plane by controlling the movement of the carrying platform (1) through the horizontal X-direction linear drive mechanism and / or the horizontal Y-direction linear drive mechanism. The movement of the two-dimensional scanning galvanometer (6) is superimposed on the movement of the ceramic disk to form a 2D movement path of the laser spot relative to the ceramic disk.

7. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 6, characterized in that: The step S5 includes the following two situations: When the size of the processed graphics does not exceed the maximum processable range of the two-dimensional scanning galvanometer (6), the carrier platform (1) does not move, and only controls the movement of the two-dimensional scanning galvanometer (6) so that the laser spot is scanned along a set 2D motion path of the laser spot, thereby generating a motion trajectory of the two-dimensional scanning galvanometer (6); When the format of the processed graphics exceeds the maximum processable range of the two-dimensional scanning galvanometer (6), the carrier platform (1) and the two-dimensional scanning galvanometer (6) move synchronously, and the 2D motion path of the laser spot is the superposition of the motion trajectories of the two-dimensional scanning galvanometer (6) and the carrier platform (1).

8. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to claim 7, characterized in that: When the size of the processed graphics exceeds the maximum processable range of the two-dimensional scanning galvanometer (6), the step of generating the motion trajectory of the two-dimensional scanning galvanometer (6) and / or the carrying platform (1) comprises: S51, reducing the size of the processed pattern in proportion to the maximum processable range of the two-dimensional scanning galvanometer (6), so that the reduced processed pattern is not larger than the maximum processable range of the two-dimensional scanning galvanometer (6); S52, then generating the motion trajectory of the two-dimensional scanning galvanometer (6) and / or the carrying platform (1) according to the 2D motion path of the laser spot according to one of the following rules: When the spacing between the fill lines and the outline lines of the reduced processing figure in the X-direction and the Y-direction is greater than the motion resolution of the two-dimensional scanning galvanometer (6), the motion trajectory of the carrier platform (1) is set to be a plurality of diagonal lines connected end to end, so that the carrier platform (1) moves in a "W" shape at a uniform speed along the diagonal lines; then the 2D motion path of the laser spot is synchronously subtracted from the motion trajectory of the carrier platform (1), so as to generate the motion trajectory of the two-dimensional scanning galvanometer (6); When the spacing in the X direction of the fill lines and the contour lines of the reduced processing graphics is greater than the motion resolution of the two-dimensional scanning galvanometer (6), and the spacing in the Y direction is not greater than the motion resolution of the two-dimensional scanning galvanometer (6), the motion trajectory of the carrier platform (1) is set to be a plurality of parallel straight lines along the X direction, and the straight line spacing is the spacing in the Y direction of the fill lines and the contour lines of the processing graphics, so that the carrier platform (1) performs a serpentine uniform motion along the X direction, and then the 2D motion path synthesized by the laser spot is synchronously subtracted from the motion trajectory of the carrier platform (1), so as to generate the motion trajectory of the two-dimensional scanning galvanometer (6); When the spacing between the fill lines and the contour lines of the reduced processing graphics in the Y direction is greater than the motion resolution of the two-dimensional scanning galvanometer (6), and the spacing between the fill lines and the contour lines in the X direction is not greater than the motion resolution of the two-dimensional scanning galvanometer (6), the motion trajectory of the carrier platform (1) is set to be a plurality of parallel straight lines along the Y direction, and the straight line spacing is the spacing between the fill lines and the contour lines of the processing graphics in the X direction, so that the carrier platform (1) performs a serpentine uniform motion along the Y direction, and then the 2D motion path synthesized by the laser spot is synchronously subtracted from the motion trajectory of the carrier platform (1), so as to generate the motion trajectory of the two-dimensional scanning galvanometer (6); When the spacing between the fill lines and the outline lines of the reduced processing graphics in the X and Y directions is not greater than the motion resolution of the two-dimensional scanning galvanometer (6), the two-dimensional scanning galvanometer (6) is set not to move, the focusing field lens (7) is fixed at a single point to emit light, and the 2D motion path of the laser spot is the motion trajectory of the carrier platform (1); S53, sending the 2D motion path of the laser spot and the motion trajectory generation rules of the two-dimensional scanning galvanometer (6) and the carrying platform (1) to the motion controller, controlling the two-dimensional scanning galvanometer (6) and the carrying platform (1) to move according to the motion trajectories generated by each, setting the laser spot to scan and process along the processing graphics of each layer from small to large in sequence; within the same layer, first scan the filling line in the processing graphics, and then scan the contour line of the processing graphics.

9. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to any one of claims 5 to 8, characterized in that: The step S6 comprises the following steps: S61, Laser Etching Rough Processing: S611, setting the power of the laser (3) to 50-90 W, the laser spot synthesis scanning rate to 500-1000 mm / s, and the filling line spacing of the processed pattern to 30-50 μm; S612, controlling the vertical Z-direction linear drive mechanism through a motion controller so that the laser beam emitted by the focusing field lens (7) is focused on the upper surface of the ceramic disk; S613, the laser (3) emits light, controls the two-dimensional scanning galvanometer (6) and the carrying platform (1) to be synchronously linked according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer according to the 2D motion path of the laser spot in S3 and S4 for laser processing, and stops when the processing depth reaches more than 80% of the target depth; S62, Laser Etching Semi-finishing: S621, setting the power of the laser (3) to 20-50 W, the laser spot synthesis scanning rate to 200-500 mm / s, and the filling line spacing of the processed pattern to 10-30 μm; S622, the laser (3) emits light, controls the two-dimensional scanning galvanometer (6) and the carrying platform (1) to be synchronously linked according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer according to the 2D motion path of the laser spot in S3 and S4 for laser processing, and stops when the difference between the processing depth and the target depth is no greater than the single-pass processing depth; S63, laser etching finishing: S631, setting the power of the laser (3) to 1-15 W, the laser spot synthesis scanning rate to 50-200 mm / s, and the filling line spacing of the processed pattern to 2-10 μm; S632, the laser (3) emits light, controls the two-dimensional scanning galvanometer (6) and the carrying platform (1) to be synchronously linked according to the motion trajectory generated in S5, so that the laser spot is repeatedly scanned layer by layer multiple times according to the 2D motion path of the laser spot in S3 and S4 to perform laser processing until the processing depth reaches within the target depth tolerance range and stops.

10. The method for processing the convex point and annular groove structure on the surface of a ceramic disk according to any one of claims 2 to 8, characterized in that: The step S7 comprises: placing the upper surface of the ceramic disc processed in step S6 downward on the polishing pad of the polishing machine, so that the circular protrusions and the raised supporting parts of the annular protrusions on the upper surface of the ceramic disc directly contact the polishing pad, and using a peristaltic pump to pour a polishing liquid containing diamond particles with a particle size of less than 10 μm into the contact area between the ceramic disc and the polishing pad; and driving the polishing pad to rotate along its central axis by the polishing machine, and the ceramic disc to revolve along the central axis of the polishing pad, so that the polishing pad and the ceramic disc are squeezed and rubbed under the action of the polishing liquid, thereby achieving polishing and high flatness processing of the raised supporting parts on the surface of the ceramic disc.

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