A drilling method, apparatus, and storage medium for preventing wire entanglement in back-drilling drill bits.

Abstract

This invention discloses a drilling method, apparatus, and storage medium for preventing drill bit wire entanglement in back-drilling holes. The drilling method for preventing drill bit wire entanglement in back-drilling holes includes: acquiring historical machining data of back-drilling holes; establishing a predictive model based on the historical machining data regarding the relationship between hole position accuracy, machining parameters, and the cumulative number of machined holes; determining a safe cumulative number of machined holes to prevent drill bit wire entanglement for the current back-drilling task, based on the predictive model and a hole position accuracy threshold; and controlling the drill bit to change tools when the cumulative number of machined holes reaches the safe cumulative number of machined holes, according to the safe cumulative number of machined holes. The technical solution provided by this invention can effectively predict and prevent drill bit wire entanglement in back-drilling holes while ensuring machining efficiency and reducing costs.

Description

Technical Field

[0001] The present invention relates to the field of printed circuit board manufacturing technology, and in particular to a drilling method, apparatus and storage medium for preventing wire entanglement in back-drilling drill bits. Background Technology

[0002] In the manufacturing process of high-speed signal transmission printed circuit boards (PCBs), back-drilling is commonly used to remove unwanted copper plating on the inner walls of through-holes and reduce signal loss and reflection during transmission. Back-drilling is a non-fully supported, suspended machining method. This weakens the rigidity of the drilling system, making the drill bit prone to trajectory drift and vibration without sufficient radial constraint. This is the physical root cause of deteriorated hole position accuracy. Insufficient hole position accuracy in back-drilling can induce drill bit wire entanglement, which in turn exacerbates hole wall damage and hole misalignment, creating a vicious cycle. Therefore, in high-end PCB manufacturing, improving back-drilled hole position accuracy is not only necessary to ensure electrical performance but also a core engineering approach to stabilize the drilling process, prevent drill bit wire entanglement, and reduce unplanned downtime.

[0003] Currently, solutions to the problem of wire entanglement in back drill bits mainly focus on process optimization and the application of auxiliary materials. Specifically, these include using segmented drilling and skip drilling techniques to reduce stress concentration, or introducing specially coated drill bits and lubricating materials to reduce the risk of wire entanglement. However, these existing methods have significant shortcomings: First, current solutions lack in-depth research into the correlation mechanism between drill bit wire entanglement and hole position accuracy, relying heavily on operator experience and making precise control difficult; second, while the use of auxiliary materials (such as special coatings or lubricants) can improve accuracy or alleviate wire entanglement to some extent, it significantly increases the complexity of the process and production costs.

[0004] Therefore, how to provide a method that can effectively predict and prevent back drill bit wire entanglement while ensuring processing efficiency and reducing costs has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a drilling method, apparatus, and storage medium for preventing back-drill bit wire entanglement, which can effectively predict and prevent back-drill bit wire entanglement while ensuring processing efficiency and reducing costs.

[0006] According to one aspect of the present invention, a drilling method for preventing wire entanglement in back-drilling drill bits is provided, comprising: Obtain historical processing data of back drilling, and establish a predictive model between hole position accuracy, processing parameters, and cumulative number of processed holes based on the historical processing data; For the current back drilling task, based on the prediction model and the hole position accuracy threshold, determine the safe cumulative number of holes to prevent drill bit wire tangling; Based on the safe cumulative number of holes processed, the drill bit is controlled to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed.

[0007] Optionally, before determining the safe cumulative number of holes to prevent drill bit wire tangling for the current back-drilling task based on the prediction model and the hole position accuracy threshold, the method further includes: The hole position accuracy threshold is determined based on the minimum hole position accuracy before the drill bit wire wrapping occurs.

[0008] Optionally, before determining the hole position accuracy threshold based on the minimum hole position accuracy before drill bit wire wrapping occurs, the method further includes: Collect process failure information for various back drill structures. The process failure information includes the drill bit wire winding rate corresponding to different hole position accuracy values ​​during the drilling of a preset number of back drill holes. Among them, the difference in hole diameter between the back drill hole and the corresponding metallized hole is different in different types of back drill structures. Based on the process failure information of each back-drilling structure, the relationship curve between the back-drilling hole position accuracy and the drill bit wire winding rate of each back-drilling structure was determined.

[0009] Optionally, determining the hole position accuracy threshold based on the minimum hole position accuracy before drill bit wire wrapping occurs includes: Based on the hole diameter difference of the back drill structure in the current back drill task, obtain the corresponding curve of the relationship between the back drill hole position accuracy and the drill bit wire winding rate. Based on the relationship curve between the back drill hole position accuracy and the drill bit wire winding rate, the minimum hole position accuracy at which the drill bit wire winding rate is equal to zero is determined, and the minimum hole position accuracy is determined as the hole position accuracy threshold.

[0010] Optionally, the step of establishing a predictive model between hole position accuracy, processing parameters, and the cumulative number of processed holes based on the historical processing data includes: Using statistical regression or machine learning methods, a predictive model is established based on the historical processing data to predict the relationship between hole position accuracy, processing parameters, and the cumulative number of processed holes.

[0011] Optionally, the prediction model between the hole position accuracy and the machining parameters and the cumulative number of machined holes is as follows: Cpk = F(D, K, T, R, N); Wherein, Cpk is the hole position accuracy, D is the back drill diameter, K is the material processing difficulty coefficient, T is the hole copper thickness, R is the depth-to-diameter ratio, and N is the cumulative number of holes processed; the processing parameters include the back drill diameter, the material processing difficulty coefficient, the hole copper thickness, and the depth-to-diameter ratio; the historical processing data includes historical data of each processing parameter for each back drilling task, historical data of the corresponding number of drilled holes, and historical data of hole position accuracy.

[0012] Optionally, controlling the drill bit to change tools when the cumulative number of machined holes reaches the safe cumulative number of machined holes, based on the safe cumulative number of machined holes, includes: Set the cumulative safe number of machined holes as the termination value of the drilling counter; When the cumulative number of machined holes reaches the termination value, a stop command will be automatically triggered and a tool change alarm will be issued.

[0013] Optionally, the tool change alarm includes at least one of the following alarm forms: audible alarm, visual alarm, and display screen notification alarm.

[0014] According to another aspect of the present invention, a drilling device for preventing wire entanglement in back-drilling drill bits is provided, comprising: The model building module is used to acquire historical processing data of back drilling and to build a predictive model between hole position accuracy, processing parameters and cumulative number of processed holes based on the historical processing data. The safe hole count determination module is used to determine the safe cumulative number of holes to prevent drill bit wire tangling for the current back drilling task, based on the prediction model and hole position accuracy threshold. The control module is used to control the drill bit to stop drilling after the cumulative number of holes processed reaches the safe cumulative number of holes processed, based on the safe cumulative number of holes processed.

[0015] According to another aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements a drilling method for preventing back-drill bit wire entanglement as described in any embodiment of the present invention.

[0016] This invention provides a drilling method, apparatus, and storage medium for preventing drill bit wire entanglement in back-drilling holes. The drilling method for preventing drill bit wire entanglement in back-drilling holes includes: acquiring historical processing data of back-drilling holes; establishing a prediction model based on the historical processing data regarding hole position accuracy, processing parameters, and the cumulative number of holes processed; determining a safe cumulative number of holes processed to prevent drill bit wire entanglement for the current back-drilling task, based on the prediction model and a hole position accuracy threshold; and controlling the drill bit to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed, according to the safe cumulative number of holes processed. The technical solution provided by this invention establishes a predictive model between hole position accuracy, machining parameters, and the cumulative number of machined holes. Based on the predictive model, hole position accuracy threshold, and machining parameters of the current back-drilling task, it calculates the corresponding safe cumulative number of machined holes through reverse engineering or iterative calculation. Once the cumulative number of machined holes reaches the safe cumulative number, the current tool is stopped from use. Preventative tool replacement is performed before the risk of wire entanglement occurs or before the wire entanglement rate exceeds a preset value. This allows for timely intervention before wire entanglement occurs or before the wire entanglement rate exceeds the preset value, preventing copper chip entanglement caused by asymmetric cutting at the source, thereby significantly reducing the wire entanglement rate of the drill bit. This method uses hole position accuracy Cpk as the core control indicator, prompting the process parameters to be adjusted towards a better range. This effectively improves the alignment accuracy between the back drill hole and the first drill hole (metallized copper block), ensuring stable electrical performance of high-speed signal transmission. The method enables on-demand tool changing, avoiding equipment downtime and workpiece scrap caused by sudden wire entanglement, and significantly improving the continuous operation time of the production line and the overall efficiency of the equipment. No additional materials or complex modifications are required, avoiding increased process complexity and cost. Therefore, while ensuring processing efficiency and reducing costs, it effectively predicts and prevents back drill bit wire entanglement, achieving coordinated control of back drill hole position accuracy and drill bit wire entanglement problems.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a drilling method for preventing wire entanglement in the drill bit during back drilling, provided by an embodiment of the present invention; Figure 2 This is a flowchart of another drilling method for preventing wire entanglement in the drill bit of a back-drilling hole, provided by an embodiment of the present invention; Figure 3 This is a graph showing the relationship between the number of boreholes and the accuracy of the borehole position, provided in an embodiment of the present invention. Figure 4 This is a flowchart of another drilling method for preventing wire entanglement in the drill bit of a back-drilling hole, provided by an embodiment of the present invention; Figure 5 This is a graph showing the relationship between hole position accuracy and drill bit wire winding rate for different drilling structures, provided in an embodiment of the present invention. Figure 6 This is a structural block diagram of a drilling device for preventing wire entanglement in the drill bit during back drilling, provided in an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] This invention provides a drilling method to prevent wire entanglement in the drill bit during back-drilling. Figure 1 This is a flowchart of a drilling method for preventing wire entanglement in the drill bit during back-drilling, provided by an embodiment of the present invention. (Refer to...) Figure 1 Drilling methods to prevent wire entanglement in back-drilling bits include: S110. Obtain historical machining data of back drilling, and establish a predictive model between hole position accuracy, machining parameters, and cumulative number of machined holes based on the historical machining data.

[0023] Specifically, historical processing data can be collected on the PCB back-drilling machine. This historical processing data includes various information for each back-drilling task, such as product design information, process control information, and quality inspection information. Product design information includes processing parameters such as material processing difficulty coefficient, back-drill diameter, back-drill hole depth-to-diameter ratio, and hole copper thickness. Quality inspection information includes at least hole position accuracy, and process control information includes at least the cumulative number of holes processed. Hole position accuracy refers to the degree of deviation between the actual geometric center position of the back-drilled hole and the target center position required by the design after back-drilling. The smaller the deviation, the higher the accuracy; the larger the deviation, the lower the accuracy. As described in the background art, decreased accuracy means drill bit trajectory drift, which can easily scrape the hole wall, generating copper wires and leading to wire entanglement.

[0024] Hole position accuracy is quantified by the offset of the back-drilled hole center relative to the target center, such as the center of a metallized hole. This data can be obtained through online or offline inspection equipment, such as a CCD vision positioning system. The calculation formula for hole position accuracy can be determined based on actual needs. Optionally, in this embodiment of the invention, hole position accuracy can be calculated based on the calculation formula of Cpk (Process Capability Index), and the hole position accuracy value is the Cpk value. That is, after obtaining the offsets of multiple back-drilled holes, the hole position accuracy Cpk value is determined based on the Cpk calculation formula.

[0025] S120. For the current back drilling task, based on the prediction model and hole position accuracy threshold, determine the safe cumulative number of holes to prevent drill bit wire tangling.

[0026] Specifically, before executing a new back-drilling task, the product design information and hole position accuracy threshold of the current back-drilling task are obtained. These parameters are then substituted into the prediction model to solve for or iteratively calculate the corresponding safe cumulative number of holes. The hole position accuracy threshold can be set according to actual needs. Lower hole position accuracy increases the number of drill bit entanglement events, resulting in a higher drill bit entanglement rate. The drill bit entanglement rate can be understood as the ratio of the number of events causing copper chip entanglement, leading to processing abnormalities or requiring intervention, to the total number of holes, given a specific number of holes. Therefore, the hole position accuracy threshold can be set based on the drill bit entanglement rate. In this embodiment of the invention, the hole position accuracy threshold can be set to be greater than the hole position accuracy at which a drill bit entanglement event occurs, thereby ensuring that no drill bit entanglement event occurs during the drilling of back-drilling holes within the safe cumulative number of holes using the current back-drilling tool.

[0027] S130. Based on the safe cumulative number of holes processed, control the drill bit to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed.

[0028] Specifically, once the cumulative number of machined holes reaches the safe cumulative number of machined holes, the current back drill tool will be discontinued. Preventive tool replacement can be performed before the risk of wire entanglement occurs or before the wire entanglement rate in the drill bit exceeds the preset value. This allows for timely intervention before wire entanglement occurs or before the wire entanglement rate in the drill bit exceeds the preset value, thus avoiding copper chip entanglement caused by asymmetric cutting at the source and significantly reducing the wire entanglement rate in the drill bit.

[0029] The drilling method for preventing drill bit wire entanglement in back-drilling holes provided by this invention establishes a predictive model between hole position accuracy, machining parameters, and the cumulative number of holes processed. Based on the predictive model, hole position accuracy threshold, and machining parameters of the current back-drilling task, the corresponding safe cumulative number of holes processed is calculated in reverse or iteratively. Once the cumulative number of holes processed reaches the safe cumulative number, the current tool is stopped from use. Preventative tool replacement is performed before the risk of wire entanglement occurs or before the wire entanglement rate exceeds a preset value. This allows for timely intervention before wire entanglement occurs or before the wire entanglement rate exceeds the preset value, preventing copper chip entanglement caused by asymmetric cutting at the source, thereby significantly reducing the drill bit wire entanglement rate. This method reduces costs and improves the alignment accuracy between the back drill bit and the first drilled hole (metallized copper block). It uses hole position accuracy (Cpk) as the core control indicator, prompting process parameters to be adjusted towards a better range. This effectively improves the alignment accuracy between the back drilled hole and the first drilled hole (metallized copper block), ensuring stable electrical performance for high-speed signal transmission. The method enables on-demand tool changing, avoiding equipment downtime and workpiece scrap caused by sudden wire entanglement, significantly improving the continuous operation time of the production line and overall equipment efficiency. No additional materials or complex modifications are required, avoiding increased process complexity and cost. Therefore, while ensuring processing efficiency and reducing costs, it effectively predicts and prevents back drill bit wire entanglement, achieving coordinated control of back drill hole position accuracy and drill bit wire entanglement problems.

[0030] Figure 2 This is a flowchart of another drilling method for preventing wire entanglement in the drill bit during back-drilling, provided by an embodiment of the present invention. (Refer to...) Figure 2 Drilling methods to prevent wire entanglement in back-drilling bits include: S210. Obtain historical processing data of back drilling, and use statistical regression or machine learning methods to establish a predictive model between hole position accuracy, processing parameters, and cumulative number of processed holes based on the historical processing data.

[0031] Specifically, the processing parameters include the back drill diameter, material processing difficulty coefficient, hole copper thickness, and depth-to-diameter ratio; historical processing data includes historical data for each processing parameter of each back drilling task, historical data for the corresponding number of holes, and historical data for hole position accuracy. Among them, the depth-to-diameter ratio is the ratio of the back drill hole depth to the diameter; the material processing difficulty coefficient is a quantitative parameter based on the influence of the physical and chemical properties of the board material (such as resin system, filler type, hardness, etc.) on drill bit wear, and this coefficient is determined by previous process experiments.

[0032] After obtaining historical processing data for back-drilled holes, statistical regression or machine learning methods are used to establish a predictive model relating hole position accuracy to processing parameters and the cumulative number of holes processed. Statistical regression is a classic modeling method based on mathematical statistics. Its core idea is to assume a known functional relationship between the dependent variable (hole position accuracy) and the independent variables (processing parameters, cumulative number of holes processed). It then uses historical observation data and parameter estimation techniques such as least squares to solve for the unknown coefficients in the model, ultimately obtaining an explicit mathematical expression. Machine learning is a data-driven modeling method in the field of artificial intelligence. It does not require pre-setting the specific functional form between the dependent and independent variables; instead, it automatically learns the complex mapping relationship from input to output from historical data through algorithms. It is particularly adept at handling nonlinear, high-dimensional, and interactive data. Commonly used regression algorithms include random forests, support vector regression, gradient boosting trees, and neural networks.

[0033] The established prediction model relating hole position accuracy to machining parameters and the cumulative number of machined holes is as follows: Cpk = F(D, K, T, R, N); Where Cpk is the hole position accuracy, D is the back drill diameter, i.e. the back drill hole diameter, K is the material processing difficulty coefficient, T is the hole copper thickness, R is the depth-to-diameter ratio, and N is the cumulative number of holes processed.

[0034] For example, after obtaining historical machining data of back-drilled holes, using machining parameters and the cumulative number of machined holes as inputs, and hole position accuracy as output, the prediction model between hole position accuracy and machining parameters and the cumulative number of machined holes, established using statistical regression or machine learning methods, is as follows: .

[0035] S220. Determine the hole position accuracy threshold based on the minimum hole position accuracy before the drill bit wire wrapping occurs.

[0036] Specifically, the lower the hole position accuracy, the more frequent the drill bit tangling events will occur, resulting in a higher drill bit tangling rate. Setting a hole position accuracy threshold higher than the hole position accuracy at which a drill bit tangling event occurs ensures that no drill bit tangling events will occur when drilling back drill holes within the safe cumulative number of holes using the current back drill tool. In this embodiment of the invention, the minimum hole position accuracy before drill bit tangling occurs is determined as the hole position accuracy threshold. By identifying the accuracy critical point before tangling occurs, this critical point is used as a control target to ensure that the drill bit always operates within a safe accuracy range. Since the drill bit is replaced before reaching the tangling trigger point, the transmission path from accuracy degradation to tangling is fundamentally cut off, keeping the drilling process in a stable and controllable state. Figure 3 This is a curve showing the relationship between the number of boreholes and the accuracy of hole positions, provided in an embodiment of the present invention. Figure 3There is a negative correlation between hole position accuracy and the number of back-drilled holes. Therefore, determining the minimum hole position accuracy before drill bit wire wrapping occurs as the hole position accuracy threshold can also avoid wasting drill bit life due to setting the hole position accuracy threshold too high. This maximizes the effective service life of a single drill bit while ensuring hole position accuracy, thereby reducing production costs.

[0037] S230. For the current back drilling task, based on the prediction model and hole position accuracy threshold, determine the safe cumulative number of holes to prevent drill bit wire tangling.

[0038] Specifically, the specific values ​​of each machining parameter and the hole position accuracy threshold of the current back-drilling task are substituted into the prediction model of hole position accuracy Cpk, and the corresponding cumulative number of machined holes is calculated in reverse or iteratively. Cpk = F(D, K, T, R, N) safe ); N safe The cumulative number of holes processed for safety is the upper limit of the safe number of holes to prevent wire tangling in this task.

[0039] S240. Based on the safe cumulative number of holes processed, control the drill bit to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed.

[0040] Specifically, the calculated N safe The control command is sent to the drilling machine and set as the termination value of the drilling counter for the back drilling tool. When the cumulative number of holes processed by this tool reaches N... safe When the machine is stopped, the CNC system automatically triggers a stop command and issues a tool change alarm, thus completing a preventative tool change before the risk of wire entanglement occurs. The tool change alarm includes at least one of the following: audible alarm, visual alarm, and display screen alert. The alarm type can be set according to actual needs.

[0041] The technical solution provided by this invention employs statistical regression or machine learning methods to establish a predictive model between hole position accuracy, processing parameters, and the cumulative number of processed holes based on historical processing data. Statistical regression methods offer advantages such as strong model interpretability, simple and efficient computation, and good adaptability to small samples. Machine learning methods, on the other hand, provide high predictive accuracy, adaptability to complex working conditions, and automatic identification of important variables and their interactions, eliminating the need for manually constructing complex polynomials or cross terms and reducing modeling difficulty. Furthermore, by defining the minimum hole position accuracy before drill bit wire entanglement occurs as the hole position accuracy threshold, and identifying the critical accuracy point before entanglement occurs, this threshold can be used as a control target to ensure that the drill bit always operates within a safe accuracy range. Simultaneously, it avoids wasting drill bit life due to excessively high hole position accuracy thresholds, maximizing the effective service life of a single drill bit while ensuring hole position accuracy, thus reducing production costs.

[0042] Figure 4 This is a flowchart of another drilling method for preventing wire entanglement in the drill bit during back-drilling, provided by an embodiment of the present invention. (Refer to...) Figure 4 Drilling methods to prevent wire entanglement in back-drilling bits include: S310. Obtain historical processing data of back drilling, and use statistical regression or machine learning methods to establish a predictive model between hole position accuracy, processing parameters, and cumulative number of processed holes based on the historical processing data.

[0043] S320. Collect process failure information for various back drill structures. The process failure information includes the drill bit wire winding rate corresponding to different hole position accuracy values ​​during the drilling of a preset number of back drill holes. Among them, the difference in hole diameter between the back drill hole and the corresponding metallized hole is different in different types of back drill structures.

[0044] S330. Based on the process failure information of each back drill structure, determine the relationship curve between the back drill hole position accuracy and the drill bit wire winding rate of each back drill structure.

[0045] Specifically, before determining the hole position accuracy threshold based on the hole position accuracy data at the time of drill bit wire entanglement, the process also includes: collecting process failure information for various back drill structures, and determining the relationship curve between the back drill hole position accuracy and the drill bit wire entanglement rate for each back drill structure based on the process failure information for each back drill structure. The process failure information includes the drill bit wire entanglement rate corresponding to different hole position accuracy values ​​during the drilling of a preset number of back drill holes; for different types of back drill structures, the difference in diameter between the back drill hole and the corresponding metallized hole is different.

[0046] For example, Figure 5 This is a graph showing the relationship between hole position accuracy and drill bit wire winding rate for different drilling structures, provided in an embodiment of the present invention. Figure 5 Examples show the relationship curves between back drill hole position accuracy and drill bit wire wrapping rate for a drill structure with a metallized hole diameter smaller than the back drill hole diameter by 8 mil (D-8mil); and the relationship curves between back drill hole position accuracy and drill bit wire wrapping rate for a drill structure with a metallized hole diameter smaller than the back drill hole diameter by 6 mil (D-6mil).

[0047] S340. Based on the hole diameter difference of the back drill structure in the current back drill task, obtain the corresponding curve of the relationship between the back drill hole position accuracy and the drill bit wire winding rate.

[0048] S350. Based on the relationship curve between back drill hole position accuracy and drill bit wire winding rate, determine the minimum hole position accuracy at which the drill bit wire winding rate is equal to zero, and set the minimum hole position accuracy as the hole position accuracy threshold.

[0049] Specifically, the steps for determining the hole position accuracy threshold based on the minimum hole position accuracy before drill bit wire entanglement occurs include: obtaining the relationship curve between the corresponding back drill hole position accuracy and the drill bit wire entanglement rate based on the hole diameter difference of the back drill structure in the current back drill task; determining the minimum hole position accuracy at which the drill bit wire entanglement rate is equal to zero based on the relationship curve between the back drill hole position accuracy and the drill bit wire entanglement rate, and setting the minimum hole position accuracy as the hole position accuracy threshold.

[0050] For example, in a new back-drilling task, the process parameters of the back-drilling structure, such as a material processing difficulty coefficient of 1.5, a back-drill hole diameter of 0.45 mm, a single-hole (metallized hole) diameter of 0.25 mm, a copper thickness of 55 µm, and an aspect ratio of 1.8, indicate that the back-drilling structure is a D-8 mil structure design with a single-hole diameter smaller than the back-drilling hole diameter of 8 mil. (Refer to...) Figure 4 The minimum hole position accuracy Cpk threshold, where the drill bit wire wrapping rate is 0, is 1.408. Therefore, the back drill hole position accuracy Cpk threshold for this back drill structure is 1.408. The corresponding safe cumulative number of machined holes N can then be calculated by reverse engineering or iterative calculation. safe =3279, such as Figure 3 As shown.

[0051] S360. For the current back drilling task, based on the prediction model and hole position accuracy threshold, determine the safe cumulative number of holes to prevent drill bit wire tangling.

[0052] S370. Based on the safe cumulative number of holes processed, control the drill bit to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed.

[0053] The technical solution provided by this invention collects process failure information for various back-drilling structures. Based on the process failure information for each back-drilling structure, it determines the relationship curve between the back-drilling hole position accuracy and the drill bit wire winding rate for each back-drilling structure. Then, based on the hole diameter difference of the back-drilling structures in the current back-drilling task, it obtains the corresponding relationship curve between the back-drilling hole position accuracy and the drill bit wire winding rate. Furthermore, based on the relationship curve between the back-drilling hole position accuracy and the drill bit wire winding rate, it determines the minimum hole position accuracy at which the drill bit wire winding rate is equal to zero, and sets this minimum hole position accuracy as the hole position accuracy threshold. Therefore, different hole position accuracy thresholds can be obtained for different back-drilling structures, thereby enabling more accurate and targeted cumulative drilling hole counts and further preventing drill bit wire winding.

[0054] In summary, this invention establishes a quantitative early warning mechanism: by establishing a quantitative relationship between the back-drilling hole position accuracy Cpk and the drill bit wire winding rate (e.g., Figure 5This invention shifts the focus from "experience-based judgment" to "data-driven early warning," eliminating the over-reliance on operator experience in traditional process adjustments and making decision-making more scientific, precise, and repeatable. It enables proactive prevention, transforming "post-event handling" into "pre-event early warning." Unlike existing technologies that primarily rely on remedial measures after wire entanglement occurs, this invention uses data monitoring to provide early warnings of risks, achieving a proactive shift in quality control. Furthermore, by monitoring the changing trend of hole position accuracy (Cpk), it can provide early warnings and intervention before wire entanglement actually occurs in the drill bit, enabling predictive tool changes, reducing unplanned downtime, and avoiding equipment downtime and workpiece scrap caused by sudden wire entanglement. This significantly improves the continuous operating time of the production line and the overall efficiency of the equipment.

[0055] Furthermore, this invention achieves linkage optimization of process parameters: by performing correlation analysis between back-drill hole position accuracy and drilling process parameters, it realizes the synergy between accuracy control and wire wrapping prevention; by quantitatively analyzing the relationship between hole position accuracy Cpk and parameters such as back-drill depth and hole limit, it can also provide data support for the systematic optimization of process parameters, which helps to establish a more stable and reliable drilling process window.

[0056] Furthermore, this invention requires no additional materials or complex modifications: the method is primarily based on process data monitoring and threshold management, eliminating the need for additional materials such as specially coated drill bits or lubricants, and avoiding major modifications to existing equipment, thus preventing increased process complexity and costs. It achieves synergistic optimization of quality, efficiency, and cost control.

[0057] This invention also provides a drilling device for preventing wire entanglement in the drill bit during back-drilling. Figure 6 This is a structural block diagram of a drilling device for preventing wire entanglement in back-drilling drill bits according to an embodiment of the present invention. (Refer to...) Figure 6 Drilling devices to prevent wire tangling in back-drilling bits include: The model building module 10 is used to acquire historical processing data of back drilling and to build a predictive model between hole position accuracy, processing parameters and cumulative number of processed holes based on the historical processing data. The safe hole count determination module 20 is used to determine the safe cumulative number of holes to prevent drill bit wire tangling for the current back drilling task, based on the prediction model and hole position accuracy threshold. The control module 30 is used to control the drill bit to stop drilling after the cumulative number of holes is reached, based on the safe cumulative number of holes.

[0058] The drilling device for preventing back-drill bit wire entanglement provided in the embodiments of the present invention can perform the drilling method for preventing back-drill bit wire entanglement provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0059] The present invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the drilling method for preventing wire entanglement in the back-drilling bit as described in any embodiment of the present invention. It has the same technical effects and will not be repeated here.

[0060] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A drilling method for preventing wire entanglement in the drill bit during back-drilling, characterized in that, include: Obtain historical processing data of back drilling, and establish a predictive model between hole position accuracy, processing parameters, and cumulative number of processed holes based on the historical processing data; For the current back drilling task, based on the prediction model and the hole position accuracy threshold, determine the safe cumulative number of holes to prevent drill bit wire tangling; Based on the safe cumulative number of holes processed, the drill bit is controlled to change tools when the cumulative number of holes processed reaches the safe cumulative number of holes processed.

2. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 1, characterized in that, Before determining the safe cumulative number of holes to prevent drill bit wire tangling for the current back-drilling task based on the prediction model and hole position accuracy threshold, the method further includes: The hole position accuracy threshold is determined based on the minimum hole position accuracy before the drill bit wire wrapping occurs.

3. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 2, characterized in that, Before determining the hole position accuracy threshold based on the minimum hole position accuracy before drill bit wire winding occurs, the method further includes: Collect process failure information for various back drill structures. The process failure information includes the drill bit wire winding rate corresponding to different hole position accuracy values ​​during the drilling of a preset number of back drill holes. Among them, the difference in hole diameter between the back drill hole and the corresponding metallized hole is different in different types of back drill structures. Based on the process failure information of each back-drilling structure, the relationship curve between the back-drilling hole position accuracy and the drill bit wire winding rate of each back-drilling structure was determined.

4. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 3, characterized in that, The step of determining the hole position accuracy threshold based on the minimum hole position accuracy before drill bit wire wrapping occurs includes: Based on the hole diameter difference of the back drill structure in the current back drill task, obtain the corresponding curve of the relationship between the back drill hole position accuracy and the drill bit wire winding rate. Based on the relationship curve between the back drill hole position accuracy and the drill bit wire winding rate, the minimum hole position accuracy at which the drill bit wire winding rate is equal to zero is determined, and the minimum hole position accuracy is determined as the hole position accuracy threshold.

5. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 1, characterized in that, The step of establishing a predictive model based on the historical processing data regarding the relationship between hole position accuracy, processing parameters, and the cumulative number of processed holes includes: Using statistical regression or machine learning methods, a predictive model is established based on the historical processing data to predict the relationship between hole position accuracy, processing parameters, and the cumulative number of processed holes.

6. The drilling method for preventing wire entanglement in the drill bit of a back-drilling hole according to claim 5, characterized in that, The prediction model relating hole position accuracy to machining parameters and the cumulative number of machined holes is as follows: Cpk = F(D, K, T, R, N); Wherein, Cpk is the hole position accuracy, D is the back drill diameter, K is the material processing difficulty coefficient, T is the hole copper thickness, R is the depth-to-diameter ratio, and N is the cumulative number of holes processed; the processing parameters include the back drill diameter, the material processing difficulty coefficient, the hole copper thickness, and the depth-to-diameter ratio; the historical processing data includes historical data of each processing parameter for each back drilling task, historical data of the corresponding number of drilled holes, and historical data of hole position accuracy.

7. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 1, characterized in that, The step of controlling the drill bit to change tools when the cumulative number of machined holes reaches the safe cumulative number of machined holes, based on the safe cumulative number of machined holes, includes: Set the cumulative safe number of machined holes as the termination value of the drilling counter; When the cumulative number of machined holes reaches the termination value, a stop command will be automatically triggered and a tool change alarm will be issued.

8. The drilling method for preventing wire entanglement in the drill bit during back-drilling according to claim 7, characterized in that, The tool change alarm includes at least one of the following alarm forms: audible alarm, visual alarm, and display screen notification alarm.

9. A drilling device for preventing wire entanglement in the drill bit during back-drilling, characterized in that, include: The model building module is used to acquire historical processing data of back drilling and to build a predictive model between hole position accuracy, processing parameters and cumulative number of processed holes based on the historical processing data. The safe hole count determination module is used to determine the safe cumulative number of holes to prevent drill bit wire tangling for the current back drilling task, based on the prediction model and the hole position accuracy threshold. The control module is used to control the drill bit to stop drilling after the cumulative number of holes processed reaches the safe cumulative number of holes processed, based on the safe cumulative number of holes processed.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by the processor, it implements the drilling method for preventing back-drilling drill bit wire entanglement as described in any one of claims 1-8.

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