Method and system for machining semiconductor high-purity graphite parts based on pcd cutters

Abstract

The application relates to the technical field of machining, and discloses a semiconductor high-purity graphite part machining method and system based on a PCD cutter, the method comprising the following steps: generating edge rough machining instructions according to a three-dimensional model and a machining track of a graphite part to be machined; after edge rough machining is completed, starting precision compensation circulation until the deviation of the graphite part to be machined is smaller than a preset tolerance threshold; during the rough machining and the fine machining, when corners and deep groove regions of a graphite semi-finished product are machined, the graphite semi-finished product is subjected to impact-free machining; and after the machining is completed, the graphite finished product is subjected to ultrasonic cleaning and drying. The application can improve the machining efficiency of semiconductor high-purity graphite parts based on the PCD cutter.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a method and system for machining high-purity graphite semiconductor parts based on PCD cutting tools. Background Technology

[0002] High-purity graphite semiconductor parts are characterized by high brittleness, easy chipping, and susceptibility to microcracks, necessitating extremely stringent requirements for machining accuracy and surface quality. Existing machining methods typically employ conventional carbide tools or traditional milling processes. During the roughing stage at the edges, it is difficult to balance cutting efficiency with edge integrity, often resulting in chipped edges or burrs due to improper toolpath planning. In corner and deep groove areas, the lack of specialized feed control strategies tailored to the brittle nature of graphite leads to impact loads during tool entry and exit, causing dimensional deviations. Furthermore, existing processes lack effective real-time compensation mechanisms for tool wear and workpiece elastic recovery during machining, resulting in poor dimensional consistency and a high scrap rate in the finished parts.

[0003] The aforementioned problems result in low overall efficiency in the machining of high-purity graphite semiconductor parts using PCD tools, requiring multiple manual adjustments or rework, which severely restricts the mass production of high-purity graphite structural components in semiconductor equipment. Therefore, how to improve machining efficiency while ensuring machining quality, achieving impact-free and stable cutting in difficult-to-machine areas such as corners and deep grooves, and accurately compensating for tool wear and workpiece deformation has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] This invention provides a method and system for machining high-purity graphite semiconductor parts based on PCD cutting tools, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a method for machining high-purity graphite semiconductor parts based on PCD cutting tools, comprising:

[0006] Based on the 3D model and machining trajectory of the graphite part to be processed, generate edge roughing instructions; After completing the rough edge machining, start the precision compensation cycle until the deviation of the graphite part to be processed is less than the preset tolerance threshold. During the roughing and finishing processes, when processing reaches the corner and deep groove areas of the graphite semi-finished product, the graphite semi-finished product is subjected to non-impact processing. After processing is completed, the finished graphite product is ultrasonically cleaned and dried.

[0007] In a preferred embodiment, generating edge roughing instructions based on the three-dimensional model and machining trajectory of the graphite part to be processed includes: Extract the geometric information of all edges to be processed from the three-dimensional model of the graphite part to be processed. The geometric information includes the direction of the edge, the angle between adjacent surfaces, and the spatial coordinate range of the edge. The trajectory segments in the machining trajectory that correspond to the geometric information are selected, and the trajectory segments are identified as edge cutting segments; The edge cutting segment is divided into segments according to the cutting direction and cutting direction of the tool to generate an ordered sequence; For each sub-segment in the ordered sequence, a corresponding edge coarsening instruction is generated.

[0008] In a preferred embodiment, the edge roughing command includes: Before generating the roughing command, the edge cutting segment is divided into an outer open region and an inner closed region based on the edge and corner features in the three-dimensional model. For the outer open area, a unidirectional cutting command is generated that causes the PCD tool to cut in from the outside of the edge to the inside and out from the inside to the outside. For the closed area of ​​the inner corner, a circumferential cutting command is generated to make the PCD tool perform circumferential cutting along the equidistant offset line of the inner corner, and after each circumference is completed, it is offset inward by a preset cutting width. The unidirectional cutting command and the circumferential cutting command are combined to form an edge roughing command set.

[0009] In a preferred embodiment, the initiation of the accuracy compensation cycle includes: After completing the edge roughing, the PCD tool is controlled to move within the measurement range of a non-contact measuring device; Triggered by following a preset sampling path, multiple key dimensional features on the graphite semi-finished product are scanned sequentially to obtain the actual position data corresponding to each key dimensional feature; The actual location data is compared one by one with the corresponding theoretical location data in the three-dimensional model to generate a set of deviation values; Determine whether the deviation value exceeds a preset tolerance threshold. If it does, determine that a precision compensation loop needs to be started.

[0010] In a preferred embodiment, the accuracy compensation cycle includes: Identify the source type of the deviation value, which includes systematic deviations caused by tool radial wear and local deviations caused by workpiece elastic recovery; For the systematic deviation, an overall offset compensation vector is generated; for the local deviation, a local shaping compensation path is generated. The overall offset compensation vector is superimposed with the local shaping compensation path to form a corrected processing trajectory; Control the PCD tool to perform compensated cutting according to the corrected machining trajectory.

[0011] In a preferred embodiment, generating an overall offset compensation vector for the systematic deviation and a local shaping compensation path for the local deviation includes: Extract the actual position coordinates of all key dimensional features in the spatial coordinate system from the deviation values, and compare them point by point with the corresponding theoretical position coordinates to obtain a deviation distribution map. An overall trend analysis was performed on the deviation distribution map to identify regions where the deviations on all key dimensional features showed a consistent direction and magnitude, and the deviations corresponding to these regions were classified as the systematic deviations. Based on the direction and magnitude of the systematic deviation, a unified displacement is determined as the overall offset compensation vector. Subtract the deviation value corresponding to the overall offset compensation vector from the deviation distribution map to obtain the remaining local deviation map; In the remaining local deviation map, local regions where the absolute value of the deviation exceeds the preset tolerance threshold are identified, and the boundary contours of the local regions are extracted. Based on the boundary contour of the local region, a cutting path complementary to the surface morphology of the local region is generated as a local shaping compensation path.

[0012] In a preferred embodiment, the step of ensuring that the deviation of the graphite part to be processed is less than a preset tolerance threshold includes: After completing one compensation cut, the scanning and comparison of the multiple key dimensional features are repeated to obtain updated deviation values; The updated deviation value is compared with the preset tolerance threshold; If the updated deviation value is still greater than or equal to the preset tolerance threshold, then the correction processing step is performed again; If the updated deviation value is less than the preset tolerance threshold, the accuracy compensation loop is terminated, and the current graphite semi-finished product is output as a qualified workpiece.

[0013] In a preferred embodiment, when processing reaches the corner and deep groove areas of the graphite semi-finished product, performing impact-free processing on the graphite semi-finished product includes: When it is determined that the PCD tool has entered the transition section of the corner area, the interior angle of the corner and the direction change angle between the current feed direction of the PCD tool and the next segment of the trajectory are obtained; Based on the interior angle and the direction change angle, a deceleration starting point is determined, and the deceleration starting point is located at the arc entry position of one tool radius away from the corner vertex; Starting from the deceleration start point, the feed rate of the PCD tool is gradually reduced according to a stepped descent curve until the tool reaches the corner apex and the feed rate drops to a low-speed holding value. After the cutting tool completes the corner apex cutting at the low speed holding value, it gradually recovers to the normal feed speed according to the stepped upward curve.

[0014] In a preferred embodiment, when processing reaches the corner and deep groove areas of the graphite semi-finished product, performing impact-free processing on the graphite semi-finished product includes: Before the tool enters the deep groove area, obtain the ratio of groove depth to groove width in the deep groove, and determine whether layer cutting is required based on the ratio; If layered cutting is required, the total depth of the deep groove is divided into multiple cutting layers, and an independent surrounding cutting trajectory is generated for each layer. The tool is controlled to cut downwards layer by layer from the groove opening. After each layer of circumferential cutting is completed, the tool is raised to the groove opening plane in a non-cutting state, and then fed vertically to the starting depth of the next layer. During each layer of cutting, the radial depth of cut of the tool is controlled to not exceed a predetermined proportion of the tool diameter, and the tool is controlled to continuously perform circumferential cutting in the same direction within each layer.

[0015] To address the above problems, the present invention also provides a semiconductor high-purity graphite parts processing system based on PCD cutting tools, the system comprising: The edge roughing instruction generation module is used to generate edge roughing instructions based on the 3D model and machining trajectory of the graphite part to be processed. The precision compensation cycle control module is used to start the precision compensation cycle after the edge roughing is completed until the deviation of the graphite part to be processed is less than the preset tolerance threshold. The corner and deep groove non-impact processing module is used to perform non-impact processing on the graphite semi-finished product when processing the corner and deep groove areas during roughing and finishing processes. The ultrasonic cleaning and drying module is used to perform ultrasonic cleaning and drying on finished graphite products after processing.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention introduces a precision compensation loop, enabling automatic non-contact scanning and deviation comparison of key dimensional features of graphite semi-finished products after edge roughing. Based on the source type of the deviation, it generates an overall offset compensation vector and a local shaping compensation path. By superimposing these two to form a corrected machining trajectory, compensating cutting is performed, effectively eliminating systematic deviations caused by tool radial wear and local deviations caused by workpiece elastic recovery. Multiple compensation loops gradually converge the machining deviations to within a preset tolerance threshold, significantly improving the dimensional accuracy and consistency of high-purity graphite semiconductor parts, thereby increasing the finished product yield.

[0017] 2. When machining corner areas, this invention determines the deceleration starting point based on the interior angle and direction change angle, controlling the tool feed rate to gradually decrease to a low-speed holding value according to a stepped descent curve. After completing the corner apex cutting, the feed rate gradually recovers, avoiding graphite chipping caused by impact loads at the corner. In deep groove areas, layered cutting is performed based on the groove depth to groove width ratio. Each layer continuously cuts in the same direction, with the radial depth of cut controlled within a predetermined ratio. After each layer is cut, the tool is lifted and then vertically fed to the next layer. This impact-free machining method effectively ensures the integrity and surface quality of difficult-to-machine areas such as corners and deep grooves, reducing the risk of localized damage. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a method for processing high-purity graphite semiconductor parts based on PCD cutting tools according to an embodiment of the present invention. Figure 2 A functional block diagram of a semiconductor high-purity graphite parts processing system based on PCD cutting tools provided in an embodiment of the present invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] This application provides a method for machining high-purity graphite semiconductor parts using PCD cutting tools. The execution entity of this PCD-based high-purity graphite semiconductor part machining method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the PCD-based high-purity graphite semiconductor part machining method can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster. The server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms.

[0021] Reference Figure 1 The diagram shown is a schematic flowchart of a method for machining high-purity graphite semiconductor parts using a PCD tool according to an embodiment of the present invention. In this embodiment, the method for machining high-purity graphite semiconductor parts using a PCD tool includes: Based on the 3D model and machining trajectory of the graphite part to be processed, generate edge roughing instructions; In this embodiment of the invention, generating edge roughing instructions based on the three-dimensional model and machining trajectory of the graphite part to be processed includes: Extract the geometric information of all edges to be processed from the three-dimensional model of the graphite part to be processed. The geometric information includes the direction of the edge, the angle between adjacent surfaces, and the spatial coordinate range of the edge. The trajectory segments in the machining trajectory that correspond to the geometric information are selected, and the trajectory segments are identified as edge cutting segments; The edge cutting segment is divided into segments according to the cutting direction and cutting direction of the tool to generate an ordered sequence; For each sub-segment in the ordered sequence, a corresponding edge coarsening instruction is generated.

[0022] The edge roughing instructions include: Before generating the roughing command, the edge cutting segment is divided into an outer open region and an inner closed region based on the edge and corner features in the three-dimensional model. For the outer open area, a unidirectional cutting command is generated that causes the PCD tool to cut in from the outside of the edge to the inside and out from the inside to the outside. For the closed area of ​​the inner corner, a circumferential cutting command is generated to make the PCD tool perform circumferential cutting along the equidistant offset line of the inner corner, and after each circumference is completed, it is offset inward by a preset cutting width. The unidirectional cutting command and the circumferential cutting command are combined to form an edge roughing command set.

[0023] The geometric information of all edges to be processed is extracted from the 3D model of the graphite part to be processed. The geometric information includes the direction of each edge in space, the angle between the adjacent surfaces on both sides of the edge, and the spatial coordinate range occupied by the edge. The extraction process is completed by reading the preset edge feature identifier in the 3D model. Each edge to be processed in the 3D model is assigned an independent identifier in advance. Based on the identifier, the corresponding direction, angle and coordinate range information can be directly obtained.

[0024] The trajectory segments that correspond to the above geometric information in the machining trajectory are selected and identified as edge cutting segments. The machining trajectory is originally a series of continuous tool movement path points. By comparing the spatial position traversed by each trajectory segment with the coordinate range of the edge, and comparing the movement direction of the trajectory segment with the direction of the edge, when the two are consistent and the spatial range on both sides of the trajectory segment matches the spatial range of the adjacent surfaces on both sides of the edge, the trajectory segment is determined to be the cutting segment corresponding to the edge. All trajectory segments that are determined to be corresponding are uniformly included in the edge cutting segment set.

[0025] The edge cutting segment is divided into segments according to the tool's entry and exit directions to generate an ordered sequence. The entry direction refers to the direction of the tool axis relative to the workpiece surface when the tool enters the cutting state from the non-cutting state, and the exit direction refers to the direction of the tool axis when the tool exits the cutting state. Based on the change points of the entry and exit directions, the continuous edge cutting segment is cut into multiple sub-segments. Each sub-segment has a consistent entry and exit direction. These sub-segments are arranged according to their order in the machining trajectory to form an ordered sequence.

[0026] For each sub-segment in the ordered sequence, a corresponding edge roughing instruction is generated. Each sub-segment corresponds to an independent cutting action. The edge roughing instruction includes the starting coordinates, ending coordinates, tool axis direction, feed direction, and cutting depth information of the sub-segment. This information is written out line by line according to the instruction format that the CNC machine tool can recognize, resulting in a set of edge roughing instructions that correspond one-to-one with the sub-segments.

[0027] Before generating the above roughing instructions, the edge cutting segment is divided into an outer open region and an inner closed region based on the edge and corner features in the 3D model. The edge and corner features refer to the included angle between the two adjacent surfaces on both sides of the edge and the extension shape of these two surfaces in space. When the included angle is a convex angle and the two surfaces extend infinitely outward, the edge belongs to the outer open region. When the included angle is a concave angle and the two surfaces converge inward to form a closed space, the edge belongs to the inner closed region. Each edge cutting segment is classified according to this judgment rule.

[0028] For the open area at the outer edge, a one-way cutting command is generated that causes the PCD tool to cut in from the outside of the edge to the inside and out from the inside to the outside. The tool starts from the outside of the edge, that is, the tool starting point is located in the external space of the solid part defined by the edge. It cuts in along the direction perpendicular to the edge until the preset cutting depth is reached. After completing the cutting along the edge, it cuts out from the inside to the outside. That is, the tool withdraws to the external space of the solid along the direction perpendicular to the edge. The one-way cutting command defines this complete entry, cutting, and exit path.

[0029] For the closed area of ​​the inner corner, a circumferential cutting command is generated to make the PCD tool perform circumferential cutting along the equidistant offset line of the inner corner. After each circumferential cut, the tool is offset inward by a preset cutting width. The equidistant offset line is generated as follows: the first offset line is obtained by offsetting a fixed distance inward from the intersection line of the two adjacent surfaces of the inner corner as a reference. The tool center moves along the offset line. After completing one circumferential cut, the current offset line is offset inward by the same fixed distance to obtain the next offset line. The tool continues to perform circumferential cutting along the new offset line. The tool is offset inward once after each circumferential cut until the cutting covers the entire closed area of ​​the inner corner.

[0030] The above-mentioned unidirectional cutting commands and circumferential cutting commands are combined to form an edge roughing command set. The merging process is to arrange the unidirectional cutting commands corresponding to all open outer edge areas and the circumferential cutting commands corresponding to all closed inner corner areas in their natural order in the machining trajectory, and remove duplicate start and end actions, and finally obtain a complete command set. This command set can be directly used to control the PCD tool to perform edge roughing.

[0031] The beneficial effects are as follows: by extracting the geometric information of the edge to be processed from the 3D model and filtering out the corresponding trajectory segments in the machining path, the edge cutting segment is precisely matched with the actual edge of the part, avoiding over-cutting or under-cutting caused by misalignment between the tool path and the part edge. The edge cutting segment is divided into ordered sequences according to the infeed and outfeed directions, and a separate edge roughing command is generated for each sub-segment, ensuring the independent controllability of tool movements in different cutting sections. Based on the edge corner characteristics, the cutting segment is divided into an open outer edge region and a closed inner corner region. For the open outer edge region, a unidirectional cutting command is used, cutting from the outside in and then from the inside out, effectively preventing chipping on the outer edge. For the closed inner corner region, a circumferential cutting command is used, cutting around the edge along an equidistant offset line and shifting inward after each revolution, ensuring that the tool removes material evenly within the closed region, avoiding material accumulation or tool overload at the inner corner. The two types of commands are merged into an edge roughing command set, enabling continuous one-time machining of the outer edge and inner corner regions, improving the integrity and cutting stability of edge roughing.

[0032] After completing the rough edge machining, start the precision compensation cycle until the deviation of the graphite part to be processed is less than the preset tolerance threshold. In this embodiment of the invention, the initiation of the accuracy compensation loop includes: After completing the edge roughing, the PCD tool is controlled to move within the measurement range of a non-contact measuring device; Triggered by following a preset sampling path, multiple key dimensional features on the graphite semi-finished product are scanned sequentially to obtain the actual position data corresponding to each key dimensional feature; The actual location data is compared one by one with the corresponding theoretical location data in the three-dimensional model to generate a set of deviation values; Determine whether the deviation value exceeds the preset tolerance threshold. If it does, determine that a precision compensation loop needs to be started.

[0033] The accuracy compensation loop includes: Identify the source type of the deviation value, which includes systematic deviations caused by tool radial wear and local deviations caused by workpiece elastic recovery; For the systematic deviation, an overall offset compensation vector is generated; for the local deviation, a local shaping compensation path is generated. The overall offset compensation vector is superimposed with the local shaping compensation path to form a corrected processing trajectory; Control the PCD tool to perform compensated cutting according to the corrected machining trajectory.

[0034] For the systematic deviation, a global offset compensation vector is generated; for the local deviation, a local shaping compensation path is generated, including: Extract the actual position coordinates of all key dimensional features in the spatial coordinate system from the deviation values, and compare them point by point with the corresponding theoretical position coordinates to obtain a deviation distribution map. An overall trend analysis was performed on the deviation distribution map to identify regions where the deviations on all key dimensional features showed a consistent direction and magnitude, and the deviations corresponding to these regions were classified as the systematic deviations. Based on the direction and magnitude of the systematic deviation, a unified displacement is determined as the overall offset compensation vector. Subtract the deviation value corresponding to the overall offset compensation vector from the deviation distribution map to obtain the remaining local deviation map; In the remaining local deviation map, local regions where the absolute value of the deviation exceeds the preset tolerance threshold are identified, and the boundary contours of the local regions are extracted. Based on the boundary contour of the local region, a cutting path complementary to the surface morphology of the local region is generated as a local shaping compensation path.

[0035] The process of ensuring that the deviation of the graphite part to be processed is less than a preset tolerance threshold includes: After completing one compensation cut, the scanning and comparison of the multiple key dimensional features are repeated to obtain updated deviation values; The updated deviation value is compared with the preset tolerance threshold; If the updated deviation value is still greater than or equal to the preset tolerance threshold, then the correction processing step is performed again; If the updated deviation value is less than the preset tolerance threshold, the accuracy compensation loop is terminated, and the current graphite semi-finished product is output as a qualified workpiece.

[0036] After the roughing of the edges is completed, the PCD tool is controlled to move to the measurement range of a non-contact measuring device, which is a laser displacement sensor or an optical probe. Its measurement range refers to the spatial area in which the sensor can reliably collect the coordinates of the workpiece surface. The tool is moved to this area by the coordinate commands of the CNC machine tool so that the reference point on the tool is aligned with the detection origin of the measuring device.

[0037] The system triggers a sequential scanning of multiple key dimensional features on the graphite semi-finished product according to a preset sampling path, obtaining the actual position data corresponding to each key dimensional feature. The sampling path is a predetermined trajectory that passes through the spatial position of each key dimensional feature in sequence. During the scanning process, the measuring device continuously emits a probe beam and receives reflected signals. When the probe beam is aligned with the feature point, the current machine tool coordinates are recorded. The sum of the coordinate values ​​corresponding to all feature points is the actual position data.

[0038] The actual position data is compared one by one with the corresponding theoretical position data in the 3D model to generate a set of deviation values. The theoretical position data is the ideal coordinate value of each key dimension feature in space, which is directly read from the 3D model. The difference between the actual coordinate value and the theoretical coordinate value of each key dimension feature is the deviation value of that feature. The deviation values ​​of all features together form a set of deviation values.

[0039] Determine whether the deviation value exceeds the preset tolerance threshold. If it does, determine that the accuracy compensation loop needs to be started. The tolerance threshold is a preset allowable deviation range. For each critical dimension feature, check whether the absolute value of its deviation value is greater than the tolerance threshold corresponding to that feature. As long as the deviation value of any feature exceeds the threshold, it is determined that the accuracy compensation loop needs to be started.

[0040] Identify the source types of deviation values. These include systematic deviations caused by tool radial wear and local deviations caused by workpiece elastic recovery. Tool radial wear refers to the phenomenon that the outer circumference radius of the PCD tool gradually decreases during the cutting process. This wear causes the actual position of all machined surfaces to shift outward along the tool radial direction, resulting in deviations in all key dimensional features having the same direction and similar magnitude. This type of deviation is classified as systematic deviation. Workpiece elastic recovery refers to the deformation of graphite material under pressure during cutting. After the tool leaves, part of the material springs back, causing the actual size of the groove or inner corner to be inconsistent with the theoretical size. This type of deviation only occurs in local areas and is classified as local deviation.

[0041] For systematic deviations, an overall offset compensation vector is generated, and for local deviations, a local shaping compensation path is generated. The overall offset compensation vector is a unified direction and displacement. Applying this vector to the entire workpiece coordinate system can cause all machined surfaces to be translated as a whole to offset the positional offset caused by tool wear. The local shaping compensation path is a tool movement trajectory specifically for the local deviation area. Cutting along this trajectory can remove excess material generated by elastic recovery.

[0042] The overall offset compensation vector and the local shaping compensation path are superimposed to form a corrected processing trajectory. The superposition process is to first apply the overall offset compensation vector to each position point of the original processing trajectory to translate the entire trajectory, and then embed the local shaping compensation path at the position of the corresponding local deviation area in the translated trajectory to replace the original trajectory segment, thus obtaining a corrected processing trajectory that takes into account both overall translation and local shaping.

[0043] The PCD tool is controlled to perform compensatory cutting according to the corrected machining trajectory. The CNC machine tool reads each instruction in the corrected machining trajectory and drives the tool to complete the overall cutting and local shaping cutting after translation in sequence. During the cutting process, the tool simultaneously counteracts the effects of two deviation sources: tool wear and elastic recovery.

[0044] The actual position coordinates of all key dimensional features in the spatial coordinate system are extracted from the deviation values ​​and compared point by point with the corresponding theoretical position coordinates to obtain a deviation distribution map. The spatial coordinate system is a three-dimensional rectangular coordinate system with the machine tool zero point as the origin. Both the actual position coordinates and the theoretical position coordinates are represented in this coordinate system. Point by point comparison means that for each key dimensional feature, its actual coordinate value is subtracted from its theoretical coordinate value to obtain the deviation vector of that point. The deviation vectors of all feature points are drawn into a distribution map according to their spatial arrangement on the workpiece. The position of each point in the map corresponds to the spatial position of the feature point, and the direction and length of the arrow of each point correspond to the direction and magnitude of the deviation vector. This map is the deviation distribution map.

[0045] An overall trend analysis of the deviation distribution map is performed to identify regions where deviations on all key dimensional features exhibit consistent direction and magnitude. The deviations corresponding to these regions are classified as systematic deviations. The method of overall trend analysis is to observe whether all arrows in the deviation distribution map point in the same direction and have similar lengths. If the deviation arrows of multiple consecutive feature points in the map point in the same spatial direction and the difference in arrow length is within a predetermined range, then the region where these feature points are located is determined to be a region with consistent direction and magnitude, and the deviation values ​​corresponding to all deviation points in this region are classified as systematic deviations.

[0046] Based on the direction and magnitude of the systematic deviation, a uniform displacement is determined as the overall offset compensation vector. The average value of the deviation vectors of all feature points within the systematic deviation area is taken as the compensation direction, and the average value of the lengths of all deviation vectors is taken as the compensation distance. This direction and distance together constitute the overall offset compensation vector.

[0047] The remaining local deviation map is obtained by subtracting the deviation value corresponding to the overall offset compensation vector from the deviation distribution map. The deviation vector of each feature point in the deviation distribution map is subtracted from the overall offset compensation vector. If the feature point belongs to the systematic deviation region, the deviation value after subtraction approaches zero. If the feature point does not belong to the systematic deviation region, the remaining value after subtraction is the local deviation. The remaining results after subtracting all feature points are redrawn into a map to obtain the remaining local deviation map.

[0048] In the remaining local deviation map, local regions where the absolute value of deviation exceeds a preset tolerance threshold are identified, and the boundary contour of the local region is extracted. The absolute value of deviation refers to the positive value of the deviation vector length of each feature point in the remaining local deviation map. This length value is compared with the tolerance threshold. Feature points with a length value greater than the tolerance threshold are marked as local deviation points. All adjacent local deviation points are connected to form a local region. All local deviation points are surrounded by a closed curve along the outer edge of the local region. This closed curve is the boundary contour.

[0049] A cutting path complementary to the surface morphology of the local area is generated based on the boundary contour of the local area as a local shaping compensation path. The surface of the area enclosed by the boundary contour has a convex morphology caused by elastic recovery. The complementary cutting path means that the tool moves back and forth along the inside of the boundary contour line by line. The depth of each cut is equal to the height of the convex morphology at that position. The tool cuts into the workpiece surface at each position on the path until it reaches the theoretical surface height at that position, thereby completely removing the convex material.

[0050] After completing a compensation cut, the scanning and comparison of multiple key dimensional features are repeated to obtain updated deviation values. After the compensation cut is completed, the PCD tool moves back to the measurement range of the non-contact measuring device and rescans each key dimensional feature according to the same sampling path to obtain a new set of actual position data, which is then compared with the theoretical position data to obtain new deviation values.

[0051] The updated deviation value is compared with the preset tolerance threshold, and the absolute value of the updated deviation value of each key dimension feature is checked one by one to see if it is less than the tolerance threshold.

[0052] If the updated deviation value is still greater than or equal to the preset tolerance threshold, the correction machining step is executed again, that is, the deviation source type is identified again, the overall offset compensation vector and the local shape correction compensation path are generated, the correction machining trajectory is formed by superimposing them, and the compensation cutting is performed.

[0053] If the updated deviation value is less than the preset tolerance threshold, the accuracy compensation loop is terminated, and the current graphite semi-finished product is output as a qualified workpiece. A qualified workpiece refers to a graphite semi-finished product in which the deviation values ​​of all key dimensional features do not exceed the tolerance threshold. At this time, the accuracy compensation loop ends, and the workpiece can enter the subsequent processing or cleaning process.

[0054] The beneficial effect is that after rough machining of the edges, the PCD tool is controlled to move within the measurement range of the non-contact measuring device. Following a preset sampling path, key dimensional features are scanned to obtain actual position data, which is then compared with theoretical position data to generate deviation values. When the deviation exceeds the tolerance threshold, a precision compensation cycle is initiated. The type of deviation source is identified. Systematic deviations caused by radial tool wear are compensated by a global offset compensation vector to translate the workpiece coordinate system. Local deviations caused by workpiece elastic recovery are compensated by a local shaping compensation path that reciprocates along the boundary contour to remove protruding material. The two are superimposed to form a corrected machining trajectory for compensating cutting. After each compensation, the scan and comparison are repeated. If the updated deviation still exceeds the threshold, corrective machining is performed again until all key dimensional feature deviations are less than the tolerance threshold, resulting in a qualified workpiece. This process achieves separate compensation and cyclic convergence for deviations from two different sources, ensuring that the dimensional accuracy of the graphite semi-finished product is gradually improved until it meets the requirements, avoiding the continuous accumulation of deviations caused by tool wear or material springback.

[0055] During the roughing and finishing processes, when processing reaches the corner and deep groove areas of the graphite semi-finished product, the graphite semi-finished product is subjected to non-impact processing. In this embodiment of the invention, when processing reaches the corner area and deep groove area of ​​the graphite semi-finished product, performing non-impact processing on the graphite semi-finished product includes: When it is determined that the PCD tool has entered the transition section of the corner area, the interior angle of the corner and the direction change angle between the current feed direction of the PCD tool and the next segment of the trajectory are obtained; Based on the interior angle and the direction change angle, a deceleration starting point is determined, and the deceleration starting point is located at the arc entry position of one tool radius away from the corner vertex; Starting from the deceleration start point, the feed rate of the PCD tool is gradually reduced according to a stepped descent curve until the tool reaches the corner apex and the feed rate drops to a low-speed holding value. After the cutting tool completes the corner apex cutting at the low speed holding value, it gradually recovers to the normal feed speed according to the stepped upward curve.

[0056] When processing reaches the corner and deep groove areas of the graphite semi-finished product, the graphite semi-finished product undergoes non-impact processing, including: Before the tool enters the deep groove area, obtain the ratio of groove depth to groove width in the deep groove, and determine whether layer cutting is required based on the ratio; If layered cutting is required, the total depth of the deep groove is divided into multiple cutting layers, and an independent surrounding cutting trajectory is generated for each layer. The tool is controlled to cut downwards layer by layer from the groove opening. After each layer of circumferential cutting is completed, the tool is raised to the groove opening plane in a non-cutting state, and then fed vertically to the starting depth of the next layer. During each layer of cutting, the radial depth of cut of the tool is controlled to not exceed a predetermined proportion of the tool diameter, and the tool is controlled to continuously perform circumferential cutting in the same direction within each layer.

[0057] When the PCD tool is identified as entering the transition section of the corner region, the interior angle of the corner and the direction change angle between the current feed direction of the PCD tool and the next trajectory segment are obtained. The corner region refers to the position where the travel direction in the tool path changes. The transition section refers to the path segment before entering the corner arc from straight cutting. The interior angle refers to the angle formed by the intersection of two adjacent surfaces at the corner. The direction change angle refers to the angle between the current feed direction vector of the tool and the direction vector of the next trajectory segment after passing the corner. Both of these angle values ​​are directly read from the machining trajectory data.

[0058] A deceleration starting point is determined based on the interior angle and the direction change angle. This deceleration starting point is located at the arc entry position one tool radius away from the corner vertex. The method for determining the deceleration starting point is as follows: draw an arc with the corner vertex as the center and the tool radius as the radius. This arc intersects the extension line of the current feed direction of the tool at a point. This intersection point is the deceleration starting point. The tool starts to enter the arc entry path from this point.

[0059] Starting from the deceleration start point, the feed rate of the PCD tool is gradually reduced according to a stepped descent curve until the tool reaches the corner apex, at which point the feed rate drops to a low-speed holding value. The stepped descent curve means that the entire deceleration process is divided into multiple steps, with the feed rate remaining constant within each step, and the speed decreasing by a fixed difference between adjacent steps. Starting from the deceleration start point, the feed rate decreases by one step after each fixed distance or fixed time, decreasing sequentially until the feed rate equals the low-speed holding value when the corner apex is reached.

[0060] After the cutting tool completes the corner apex cutting at a low speed, it gradually recovers to the normal feed rate according to a stepped upward curve. The low speed holding value is the constant feed rate when the tool passes through the corner apex. This value is preset before the deceleration begins. After completing the corner apex cutting, the tool enters the exit corner path segment. The stepped upward curve means that the entire acceleration process is divided into multiple steps. The feed rate remains constant within each step, and the speed increases by a fixed difference between adjacent steps. After a fixed distance or fixed time, the feed rate increases by one step until it recovers to the normal feed rate.

[0061] Before the tool enters the deep groove region, the ratio of groove depth to groove width is obtained, and the need for layered cutting is determined based on the ratio. The deep groove region refers to a groove-shaped structure on the workpiece where the depth of the recess is greater than the width of the recess opening. The groove depth is the vertical distance from the groove opening plane to the groove bottom plane, and the groove width is the horizontal distance between the two side walls of the groove. The groove depth value is divided by the groove width value to obtain the ratio. This ratio is compared with a preset layered cutting threshold. When the ratio is greater than the threshold, layered cutting is required; otherwise, layered cutting is not required.

[0062] If layered cutting is required, the total depth of the deep groove is divided into multiple cutting layers, and an independent circular cutting trajectory is generated for each layer. The cutting layers are divided by dividing the total depth into several layers with equal depth intervals. Each layer has the same thickness, and a separate circular cutting trajectory is generated for each layer. This trajectory forms a closed loop along the inner wall contour of the groove on the depth plane of the corresponding layer.

[0063] The tool is controlled to cut downwards layer by layer, starting from the groove opening. After completing the circumferential cutting of each layer, the tool is raised to the groove opening plane in a non-cutting state, and then fed vertically to the starting depth of the next layer. Cutting downwards layer by layer means that the first layer, which is the layer closest to the groove opening, is executed first. After completion, the tool stops cutting and is raised vertically until the tool tip leaves the workpiece surface and reaches the groove opening plane. Then the tool moves horizontally to directly above the starting point of the next layer, and then feeds vertically downwards to the starting depth of the next layer. Then the circumferential cutting of that layer is executed. This process is repeated until all layers are cut.

[0064] During each layer of cutting, the radial depth of cut of the tool is controlled to not exceed a predetermined proportion of the tool diameter, and the tool is controlled to continuously perform circular cutting in the same direction within each layer. The radial depth of cut refers to the depth to which the tool cuts into the side wall of the workpiece in the radial direction. This depth value is limited to the value obtained by multiplying the tool diameter by a predetermined proportion, which is a fixed value. Continuous circular cutting means that the tool completes a full circle of cutting without interruption along the circular trajectory, without reversing or stopping midway. The same direction means that the circular travel direction of the tool in each layer remains consistent, such as always clockwise or always counterclockwise, and does not change with the number of layers.

[0065] The beneficial effects are as follows: In the corner area, the deceleration starting point at the arc entry position is determined by obtaining the interior angle and direction change angle. From this point, the feed rate is gradually reduced according to a stepped descent curve, so that the speed drops to a low and maintained value when the tool reaches the corner apex. After completing the corner cutting, the speed is gradually restored according to a stepped ascending curve. The feed rate transitions smoothly throughout the process, avoiding the impact load caused by sudden speed changes at the corner, and effectively preventing graphite corner chipping. In the deep groove area, the ratio of groove depth to groove width determines whether layered cutting is required. The total depth is divided into multiple cutting layers, and an independent circular cutting trajectory is generated for each layer. After each layer of cutting is completed, the tool is raised to the groove opening plane and then fed vertically to the starting depth of the next layer. This avoids groove wall damage caused by poor chip removal or radial force accumulation when the tool continuously cuts multiple layers in the deep groove. At the same time, the radial cutting depth of each layer is controlled to not exceed a predetermined proportion of the tool diameter, and continuous circular cutting in the same direction is maintained, ensuring uniform material removal and surface integrity of the deep groove sidewall.

[0066] After processing, the finished graphite product is ultrasonically cleaned and dried.

[0067] In this embodiment of the invention, the step of ultrasonically cleaning and drying the graphite product after processing includes: After processing, the finished graphite product is removed from the CNC machine tool's worktable and placed into the cleaning tank inside the ultrasonic cleaner. The tank contains cleaning fluid, either deionized water or a special graphite cleaning agent, with the fluid level completely submerging the graphite product. The ultrasonic cleaner is then started. The ultrasonic transducer inside the cleaner converts electrical energy into high-frequency mechanical vibrations. These vibrations propagate through the cleaning fluid and create a cavitation effect, forming countless tiny bubbles. These bubbles rapidly grow and burst under the action of ultrasound. The shock waves generated during the bursting act on the surface of the graphite product and its micropores, peeling off graphite dust and cutting residues adhering to the surface. After the set cleaning time, the ultrasonic cleaner is turned off. The finished graphite product is removed from the cleaning tank and rinsed with deionized water to remove residual cleaning fluid and the removed contaminants. The rinsed graphite product is placed on a rack inside the drying oven, which is equipped with a heating element and an air circulation fan. After closing the oven door, the heating element is activated to raise the internal temperature to the preset level. Simultaneously, the fan circulates the air inside the oven, continuously blowing hot air onto the surface of the graphite product to evaporate moisture. After the set drying time, the heating element and fan are turned off. The oven door is then opened, and the graphite product is removed after naturally cooling to room temperature, yielding a clean and dry finished graphite product.

[0068] The beneficial effects are as follows: By placing the finished graphite product in an ultrasonic cleaner, the high-frequency vibration generated by the ultrasonic transducer induces cavitation in the cleaning fluid. The shock waves generated by the instantaneous collapse of microbubbles act on the surface and micropores of the finished product, thoroughly removing graphite dust and cutting residue. Deionized water is then used to rinse away residual cleaning fluid and contaminants. Finally, in a drying oven, heating elements are used to raise the temperature, combined with a circulating fan driving hot air to continuously blow away moisture, allowing for complete evaporation. After natural cooling, a clean and dry finished graphite product is obtained. This process effectively removes fine particles adhering to the surface and micropores of the finished graphite product after processing, avoiding the risk of contamination to high-purity graphite semiconductor parts caused by residual dust during subsequent use. Simultaneously, the drying process ensures that the inside and surface of the finished product are free of moisture, meeting the stringent requirements of the semiconductor environment for cleanliness and dryness.

[0069] like Figure 2 The diagram shown is a functional block diagram of a semiconductor high-purity graphite parts processing system based on PCD cutting tools provided in an embodiment of the present invention.

[0070] The semiconductor high-purity graphite part processing system 100 based on PCD cutting tools described in this invention can be installed in an electronic device. Depending on the functions implemented, the semiconductor high-purity graphite part processing system 100 may include an edge roughing instruction generation module 101, a precision compensation cycle control module 102, a corner and deep groove impact-free processing module 103, and an ultrasonic cleaning and drying module 104. The module described in this invention can also be called a unit, referring to a series of computer program segments that can be executed by the processor of an electronic device and perform a fixed function, stored in the memory of the electronic device.

[0071] In this embodiment, the functions of each module / unit are as follows: The edge roughing instruction generation module 101 is used to generate edge roughing instructions based on the three-dimensional model and processing trajectory of the graphite part to be processed. The precision compensation cycle control module 102 is used to start the precision compensation cycle after the edge roughing is completed until the deviation of the graphite part to be processed is less than the preset tolerance threshold. The corner and deep groove non-impact processing module 103 is used to perform non-impact processing on the graphite semi-finished product when processing the corner and deep groove areas of the graphite semi-finished product during roughing and finishing processes. The ultrasonic cleaning and drying module 104 is used to perform ultrasonic cleaning and drying on the finished graphite product after processing is completed.

[0072] In the several embodiments provided by this invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0073] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0075] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0076] This application embodiment can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence is the theory, method, technology, and application system that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for machining high-purity graphite semiconductor parts based on PCD cutting tools, characterized in that, The method includes: Based on the 3D model and machining trajectory of the graphite part to be processed, edge roughing instructions are generated, including: Extract the geometric information of all edges to be processed from the three-dimensional model of the graphite part to be processed. The geometric information includes the direction of the edge, the angle between adjacent surfaces, and the spatial coordinate range of the edge. The trajectory segments in the machining trajectory that correspond to the geometric information are selected, and the trajectory segments are identified as edge cutting segments; The edge cutting segment is divided into segments according to the cutting direction and cutting direction of the tool to generate an ordered sequence; Before generating the roughing command, the edge cutting segment is divided into an outer open region and an inner closed region based on the edge and corner features in the three-dimensional model. For the outer open area, a unidirectional cutting command is generated that causes the PCD tool to cut in from the outside of the edge to the inside and out from the inside to the outside. For the closed area of ​​the inner corner, a circumferential cutting command is generated to make the PCD tool perform circumferential cutting along the equidistant offset line of the inner corner, and after each circumference is completed, it is offset inward by a preset cutting width. The unidirectional cutting command and the circumferential cutting command are combined to form an edge roughing command; For each sub-segment in the ordered sequence, a corresponding edge coarsening instruction is generated; After completing the rough edge machining, start the precision compensation cycle until the deviation of the graphite part to be processed is less than the preset tolerance threshold. During roughing and finishing processes, when machining reaches the corner and deep groove areas of the graphite semi-finished product, the graphite semi-finished product undergoes non-impact processing, including: When it is determined that the PCD tool has entered the transition section of the corner area, the interior angle of the corner and the direction change angle between the current feed direction of the PCD tool and the next segment of the trajectory are obtained; Based on the interior angle and the direction change angle, a deceleration starting point is determined, and the deceleration starting point is located at the arc entry position of one tool radius away from the corner vertex; Starting from the deceleration start point, the feed rate of the PCD tool is gradually reduced according to a stepped descent curve until the tool reaches the corner apex and the feed rate drops to a low-speed holding value. After the cutting tool is controlled to complete the cutting at the corner apex at the low speed holding value, it is gradually restored to the normal feed speed according to the step-like rising curve; It also includes obtaining the ratio of groove depth to groove width in the deep groove before the tool enters the deep groove area, and determining whether layered cutting is required based on the ratio; If layered cutting is required, the total depth of the deep groove is divided into multiple cutting layers, and an independent surrounding cutting trajectory is generated for each layer. The tool is controlled to cut downwards layer by layer from the groove opening. After each layer of circumferential cutting is completed, the tool is raised to the groove opening plane in a non-cutting state, and then fed vertically to the starting depth of the next layer. During each layer of cutting, the radial depth of cut of the tool is controlled to not exceed a predetermined proportion of the tool diameter, and the tool is controlled to continuously perform circumferential cutting in the same direction within each layer. After processing, the finished graphite product is ultrasonically cleaned and dried.

2. The method for machining high-purity graphite semiconductor parts based on PCD cutting tools as described in claim 1, characterized in that, The startup accuracy compensation loop includes: After completing the edge roughing, the PCD tool is controlled to move within the measurement range of a non-contact measuring device; Triggered by following a preset sampling path, multiple key dimensional features on the graphite semi-finished product are scanned sequentially to obtain the actual position data corresponding to each key dimensional feature; The actual location data is compared one by one with the corresponding theoretical location data in the three-dimensional model to generate a set of deviation values; Determine whether the deviation value exceeds the preset tolerance threshold. If it does, determine that a precision compensation loop needs to be started.

3. The method for machining high-purity graphite semiconductor parts based on PCD cutting tools as described in claim 2, characterized in that, The accuracy compensation loop includes: Identify the source type of the deviation value, which includes systematic deviations caused by tool radial wear and local deviations caused by workpiece elastic recovery; For the systematic deviation, an overall offset compensation vector is generated; for the local deviation, a local shaping compensation path is generated. The overall offset compensation vector is superimposed with the local shaping compensation path to form a corrected processing trajectory; Control the PCD tool to perform compensated cutting according to the corrected machining trajectory.

4. The method for machining high-purity graphite semiconductor parts based on PCD cutting tools as described in claim 3, characterized in that, For the systematic deviation, a global offset compensation vector is generated; for the local deviation, a local shaping compensation path is generated, including: Extract the actual position coordinates of all key dimensional features in the spatial coordinate system from the deviation values, and compare them point by point with the corresponding theoretical position coordinates to obtain a deviation distribution map. An overall trend analysis was performed on the deviation distribution map to identify regions where the deviations on all key dimensional features showed a consistent direction and magnitude, and the deviations corresponding to these regions were classified as the systematic deviations. Based on the direction and magnitude of the systematic deviation, a unified displacement is determined as the overall offset compensation vector. Subtract the deviation value corresponding to the overall offset compensation vector from the deviation distribution map to obtain the remaining local deviation map; In the remaining local deviation map, local regions where the absolute value of the deviation exceeds the preset tolerance threshold are identified, and the boundary contours of the local regions are extracted. Based on the boundary contour of the local region, a cutting path complementary to the surface morphology of the local region is generated as a local shaping compensation path.

5. The method for machining high-purity graphite semiconductor parts based on PCD cutting tools as described in claim 4, characterized in that, The process of ensuring that the deviation of the graphite part to be processed is less than a preset tolerance threshold includes: After completing one compensation cut, the scanning and comparison of the multiple key dimensional features are repeated to obtain updated deviation values; The updated deviation value is compared with the preset tolerance threshold; If the updated deviation value is still greater than or equal to the preset tolerance threshold, then the correction processing step is performed again; If the updated deviation value is less than the preset tolerance threshold, the accuracy compensation loop is terminated, and the current graphite semi-finished product is output as a qualified workpiece.

6. A semiconductor high-purity graphite part machining system based on PCD cutting tools, used to implement the semiconductor high-purity graphite part machining method based on PCD cutting tools as described in claim 1, the system comprising: The edge roughing instruction generation module is used to generate edge roughing instructions based on the 3D model and machining trajectory of the graphite part to be processed; The precision compensation cycle control module is used to start the precision compensation cycle after the edge roughing is completed until the deviation of the graphite part to be processed is less than the preset tolerance threshold. The corner and deep groove non-impact processing module is used to perform non-impact processing on the graphite semi-finished product when processing the corner and deep groove areas during roughing and finishing processes. The ultrasonic cleaning and drying module is used to perform ultrasonic cleaning and drying on finished graphite products after processing.

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