Drilling control method, system and equipment suitable for circuit board

Abstract

The invention relates to the technical field of printed circuit manufacturing, in particular to a drilling control method, system and equipment suitable for a circuit board, distance characteristics are obtained according to the position of a next drill hole of a current drill hole in the circuit board and the distance between each circuit in the circuit board, and the drilling error tolerance of the next drill hole is obtained according to the distance characteristics; according to the method, the initial drilling feeding speed is adjusted according to the drilling error tolerance and the drilling protrusion degree, the feeding speed matched with the next drilling hole can be obtained, drilling is conducted at the feeding speed, the drilling precision can be improved, the drilling quality can be ensured, and therefore influences on the performance of the circuit board are avoided; according to the drilling error tolerance and the drilling deviation degree, the maximum tool retracting speed of the drilling is adjusted, the target tool retracting speed of the next drilling is obtained, the drilling precision can be improved, secondary damage to the drilling during tool retracting is avoided, the drilling quality is ensured, and therefore the influence on the performance of a circuit board is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit manufacturing, and particularly relates to a drilling control method, system and device applicable to a circuit board. Background Art

[0002] With the continuous development of electronic devices, higher requirements are also put forward for the manufacturing technology of circuit boards (i.e., PCB boards), especially in the drilling process. At present, the circuit board drilling technology is mainly mechanical drilling. Mechanical drilling is a contact drilling method, which realizes accurate positioning drilling through the combination of the movements of each axis. Before starting the processing, the user needs to first load the processing file and set the relevant processing process parameters. After starting the machine for processing, the X and Y axes start to run according to the processing instructions. At this time, the Z axis remains stationary at the set starting drilling position; when the X and Y axes move to the position of the first processing hole and are stable within the set position error range, then the motor in the Z axis direction drives the high-speed rotating spindle to process the circuit board downward according to the set processing parameters until it runs to the specified end drilling position and then retreats to the starting drilling position; the X and Y axes then move to the position of the next processing hole, and the Z axis runs downward for drilling, and so on to complete the processing of the entire circuit board.

[0003] The motion state of the Z axis during one processing process is as Figure 1 shown, Figure 1 In the two-dimensional coordinate system shown, the abscissa is time and the ordinate is speed. Among them: the AC segment is the idle stroke segment, point A is the starting point of the Z axis, and point C is the position point where the drill tip just touches the circuit board; in the idle stroke segment, it is required that the Z axis runs at the fastest speed to reduce the motion time; the CD segment is the drilling segment where the drill bit chips the circuit board. This stage is at a constant speed, and the displacement is determined by the thickness of the circuit board; the DE segment is the buffer segment, that is, decelerating from the constant speed segment to a speed of 0.

[0004] During the drilling process of the circuit board, it usually includes the downward movement stage of drilling and the upward movement stage of the return stroke (i.e., retracting the tool), and the motion state of the return stroke movement stage is usually acceleration - constant speed - deceleration or acceleration - deceleration. The complete motion state of the drilling and return stroke of the Z axis during one processing process is as Figure 2 shown, Figure 2 In the two-dimensional coordinate system shown, the abscissa is time and the ordinate is speed.

[0005] In the current mechanical drilling process, the circuit board drilling process usually adopts a constant drilling speed and rotation speed. Due to the unevenness of the actual board material of the circuit board, combined with the characteristics of the drill bit's uniform feed speed, a certain physical contact force will be generated between the circuit board and the drill bit. This will lead to different degrees of bulges in local areas on the surface of the circuit board. In addition, if the circuit board material is uneven, the bulge of the board caused by the drilling feed and retracting stages will have a risk of collision, affecting the smoothness of the operation. This will not only destroy the surface structure of the circuit board and cause the surface finish to decrease, but also cause stress concentration on the internal structure of the circuit board, endangering the stability of the internal wire and component connection. Therefore, from a process perspective, the existing circuit board drilling control method can destroy the drilling accuracy, resulting in rough hole walls and dimensional deviations; from a performance perspective, due to surface bulges and damaged internal structures, the electromagnetic shielding effectiveness of the circuit board is weakened, and the conductive performance is also hindered, making it difficult to ensure stable signal transmission. Therefore, the existing circuit board drilling control method is extremely unfavorable to the overall quality and performance assurance of the circuit board. Summary of the invention

[0006] In order to solve the technical problem that the existing circuit board drilling control method affects the performance of the circuit board, the purpose of the present invention is to provide a drilling control method, system and device suitable for circuit boards. The technical solution adopted is as follows: In a first aspect of the present invention, a drilling control method applicable to a circuit board is provided, comprising: The distance feature is obtained from the distance between the position of the next drill hole of the current drill hole in the circuit board and each circuit in the circuit board; Based on the distance feature, obtaining a drilling error tolerance of the next drilling hole; According to the drilling error tolerance and drilling prominence, the initial drilling feed speed is adjusted to obtain a target feed speed for the next drilling; the drilling prominence is used to characterize the overall prominence of multiple historical drillings, and the multiple historical drillings are obtained by drilling the same type of circuit board multiple times in history; According to the drilling error tolerance and the drilling deviation degree, the maximum drilling tool retraction speed is adjusted to obtain the target tool retraction speed for the next drilling; the drilling deviation degree is used to characterize the cumulative drilling angle deviations of the multiple historical drillings.

[0007] In an exemplary embodiment, the drilling control method applicable to a circuit board further includes: Performing multiple historical drillings on the same type of circuit board to obtain historical images of the drilling areas of each historical drilling; the historical images of the drilling areas include images obtained from the historical drillings along at least one shooting angle; Based on the relationship between the shadow appearing in the historical image of the drilling area due to the historical drilling bulge and the bulge height, the drilling bulge height in the historical image of the drilling area is obtained.

[0008] In an exemplary embodiment, the process of obtaining the drilling bulge degree includes: Obtain the average value and standard deviation of the drilling bulge heights in all the historical images of the drilling area, and respectively obtain the standard drilling bulge height and the standard bulge fluctuation degree; Based on the standard drilling bulge height and the standard bulge fluctuation degree, obtain the drilling bulge degree; the drilling bulge degree is directly proportional to the standard drilling bulge height and inversely proportional to the standard bulge fluctuation degree.

[0009] In an exemplary embodiment, the process of obtaining the drilling deviation degree includes: Based on the difference between the drilling bulge heights obtained from the historical drilling in the historical image of the drilling area along different shooting angles, obtain the bulge deviation amount of the historical drilling; Based on the bulge deviation amount of the historical drilling and the historical drilling diameter, obtain the drilling deviation angle; Based on the change trend of the drilling deviation angles of the historical drillings corresponding to all the historical images of the drilling area in time series, obtain the cumulative drilling deviation degree and the drilling deviation standard deviation; Obtain the standard drilling deviation angle, where the standard drilling deviation angle is the average value of the drilling deviation angles of the historical drillings corresponding to all the historical images of the drilling area; Based on the cumulative drilling deviation degree, the drilling deviation standard deviation and the standard drilling deviation angle, obtain the drilling deviation degree; the drilling deviation degree is directly proportional to the cumulative drilling deviation degree, directly proportional to the standard drilling deviation angle, and inversely proportional to the drilling deviation standard deviation.

[0010] In an exemplary embodiment, the process of obtaining the cumulative drilling deviation degree includes: performing a linear fit on the drilling deviation angles of the historical drillings corresponding to all the historical images of the drilling area in time series, and obtaining the angle between the slope of the fitted line and the time axis as the cumulative drilling deviation degree.

[0011] In an exemplary embodiment, the process of obtaining the target feed rate includes: Based on the drilling error tolerance and the drilling bulge degree, obtain the feed rate adjustment coefficient, where the feed rate adjustment coefficient is inversely proportional to the drilling error tolerance and directly proportional to the drilling bulge degree; Based on the initial drilling feed rate and the feed rate adjustment coefficient, obtain the feed rate reduction amount; Based on the initial drilling feed rate and the feed rate reduction amount, obtain the target feed rate.

[0012] In an exemplary embodiment, the process of obtaining the target retraction speed includes: Based on the drilling error tolerance and the degree of drilling deviation, a retraction speed adjustment coefficient is obtained. The retraction speed adjustment coefficient is directly proportional to the drilling error tolerance and inversely proportional to the degree of drilling deviation; Based on the maximum retraction speed of the drill and the retraction speed adjustment coefficient, the target retraction speed is obtained.

[0013] In an exemplary embodiment, the process of obtaining the distance feature includes: Obtain the shortest distance among the distances between the position of the next drill hole in the circuit board in each direction and each line in that direction; Obtain the target shortest distance, where the target shortest distance is the shortest distance among the shortest distances corresponding to each direction; Obtain the target average distance, where the target shortest distance is the average distance of the shortest distances corresponding to each direction; Calculate the average value of the target shortest distance and the target average distance to obtain the distance feature.

[0014] In a second aspect of the present invention, there is provided a drilling control system applicable to a circuit board, including: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-mentioned drilling control method applicable to the circuit board when the program instructions are executed.

[0015] In a third aspect of the present invention, there is provided a drilling control device applicable to a circuit board, including a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned embodiments of the drilling control method applicable to the circuit board are implemented.

[0016] The present invention has the following beneficial effects: Since the position of the next drill hole in the circuit board and the distances from the next drill hole to each circuit in the circuit board determine the error tolerance of the next drill hole, the error tolerance of the next drill hole can be obtained accordingly. Moreover, the error tolerance of the drill hole affects the feed speed and retraction speed of the next drill hole. Also, since the drill hole bulge is related to the feed speed of the drill bit, and the drill bits for drill holes with different error tolerances also have different feed speeds, the feed speed of the next drill hole can be obtained based on the error tolerance of the drill hole and the drill hole bulge, and a feed speed suitable for the next drill hole can be obtained. Drilling with this feed speed can improve the drilling accuracy, ensure the drilling quality, and thus avoid affecting the performance of the circuit board. Moreover, when the degree of drilling deviation is different, a suitable retraction speed is required to avoid causing secondary damage to the drill hole during the retraction process. Therefore, the retraction speed of the next drill hole can be obtained based on the error tolerance of the drill hole and the degree of drilling deviation, which can improve the drilling accuracy, avoid secondary damage to the drill hole during retraction, ensure the drilling quality, and thus avoid affecting the performance of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the motion state on the Z-axis during a single machining process provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the complete motion state of drilling and return stroke on the Z-axis during a single machining process provided by an embodiment of the present invention; Figure 3 is a flowchart of the steps further included in a drilling control method applicable to a circuit board provided by an embodiment of the present invention; Figure 4 is a flowchart for obtaining the drill hole bulge provided by an embodiment of the present invention; Figure 5 is a flowchart for obtaining the degree of drilling deviation provided by an embodiment of the present invention; Figure 6 is a core flowchart of the steps of a drilling control method applicable to a circuit board provided by an embodiment of the present invention; Figure 7 is a flowchart for obtaining the distance feature provided by an embodiment of the present invention; Figure 8 is a flowchart for obtaining the target feed speed provided by an embodiment of the present invention; Figure 9 is a flowchart for obtaining the target retraction speed provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and effects of the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs.

[0020] The hardware execution part of a drilling control method applicable to a circuit board provided in this embodiment includes an image acquisition device and a control device, and the image acquisition device is electrically connected to the control device. The image acquisition device is used to acquire an image of the drilling area and obtain the required data information based on the image of the drilling area.

[0021] In an exemplary embodiment, the image acquisition device selects a high-resolution (≥5 million pixels), global shutter CMOS camera with a frame rate ≥60fps (to adapt to high-speed drilling motion) and is equipped with a telecentric lens (to eliminate perspective distortion).

[0022] For each drilling, in order to obtain an image of at least one shooting angle of the drilling, at least one camera is set. When multiple cameras are set, the shooting angles of each camera are different. In an exemplary embodiment, four cameras are set, and these four cameras are used to achieve shooting of the drilling from four angles of up, down, left and right. Then, these four cameras are evenly arranged in a circle. Then, the first camera and the third camera are a pair of relatively arranged cameras, and the second camera and the fourth camera are a pair of relatively arranged cameras. The connection line between the first camera and the third camera is perpendicular to the connection line between the second camera and the fourth camera. And all these four cameras face inward and the shooting angles are all set obliquely downward, and the range of the obliquely downward angle is 30°-45°. It should be noted that the obliquely downward angles of these four cameras can be the same, so as to improve the monitoring accuracy. When the drilling is at the shooting center position of these four cameras, four drilling images with different shooting angles can be obtained.

[0023] In an exemplary embodiment, for the convenience of shooting, four cameras are integrated at the end of the drill moving arm or the fixing device of the drill bit. During installation, the drilling area is kept at the shooting center position of these four cameras. At the same time, it is connected to the main body of the drill bit device through an aluminum alloy bracket + shock pad to ensure rigid support and anti-vibration performance. In addition, a ring-shaped LED light source is selected and installed around the camera lens or on the side of the drill robotic arm to ensure that the light source can illuminate the surface of the circuit board well and provide uniform diffuse reflection illumination. The setting of the light source needs to meet the requirement that the illumination angle of the light source is consistent with the shooting angle of the camera, so as to facilitate subsequent processing.

[0024] Due to the non-uniformity of the circuit board and various error parameters during actual drilling, when drilling the circuit board, the raised conditions of the drilled holes obtained for the same type of circuit board are not exactly the same. Among them, the same type of circuit board refers to a circuit board with the same material and the same parameters. Moreover, when drilling in relatively fine parts, the errors generated may cause the raised part of the drilled hole to affect the surrounding circuits in the circuit board, thereby affecting the circuit stability. Therefore, first, analyze the raised height performance in the relevant historical data of historical drilling to obtain the drilling bulge degree and the drilling deviation degree. Among them, the drilling bulge degree is used to characterize the overall raised situation of multiple historical drillings. The multiple historical drillings are obtained by drilling the same type of circuit board multiple times in history. The drilling deviation degree is used to characterize the cumulative drilling angle deviation of multiple historical drillings.

[0025] In an exemplary embodiment, as Figure 3 shown, the drilling control method applicable to the circuit board provided in this embodiment further includes the following implementation process: Step S1: Continuously drill the same type of circuit board multiple times in history to obtain the historical images of the drilling areas of each historical drilling.

[0026] Preset a historical time period. Continuously drill the same type of circuit board multiple times within the historical time period, and each obtained drilling is defined as a historical drilling. Among them, the duration of the historical time period and the number of obtained historical drillings are set according to the actual situation.

[0027] Each time a historical drilling is obtained, use the above four cameras to obtain images of the historical drilling at four different shooting angles along four different shooting angles. Then, the historical image of the drilling area of the obtained historical drilling includes drilling images at four different shooting angles. Moreover, in an exemplary embodiment, the historical image of the drilling area is specifically a circular center area centered on the center of the drill hole and with a radius greater than the drill hole radius, so as to include all the shadows caused by the drilling bulge in the historical image of the drilling area, which is convenient for subsequent image processing. In an exemplary embodiment, the length greater than the drill hole radius can be 3 times the drill hole radius.

[0028] In an exemplary embodiment, when the drill bit of the drilling machine completely exits the hole and is delayed by 2 ms, a trigger signal is sent to start the camera to take pictures, realizing the synchronization mechanism between the trigger signal and the drilling action and avoiding motion blur.

[0029] The image obtained by shooting in this embodiment can directly be the image of the drilling area without pre-image preprocessing. As other implementation manners, an initial image can also be obtained first, median filtering or Gaussian filtering is used to eliminate the dust interference of the circuit board, and then ROI extraction is performed, and the detection area is located based on the drilling coordinates to obtain the historical image of the drilling area.

[0030] Step S2: According to the relationship between the shadow and the protrusion height that appears in the historical image of the drilling area due to the historical drilling protrusion, obtain the drilling protrusion height in the historical image of the drilling area.

[0031] First, edge detection (such as the Canny operator) is performed on the historical image of the drilling area to extract the drilling contour and the shadow boundary.

[0032] Since the camera shoots the drilling obliquely downward and with the effect of the light source, a shadow (i.e., the shadow formed by the drilling protrusion) will be generated at the edge of the drilling protrusion away from the light source. The generated shadow has a certain length in the direction of the light source irradiation, and this length is defined as the width of the shadow. Then, there is a geometric mathematical relationship between the width of the shadow, the protrusion height of the drilling, and the shooting angle. Then, according to the width of the shadow and the shooting angle, and performing mathematical operations based on the existing geometric relationship, the drilling protrusion height in the historical image of the drilling area can be obtained. Among them, there is a simple geometric relationship between the width of the shadow and the drilling protrusion height. Specifically: the drilling protrusion height is equal to the product of the tangent value of the angle between the light source and the horizontal plane and the width of the shadow. As other implementation manners, the drilling protrusion height can also be obtained by structured light three-dimensional reconstruction (for high-precision demand scenarios), which is applicable to high-precision scenarios and will not be elaborated here; or, the depth camera can also be used to detect the protrusion of the drilling, so as to obtain the protrusion height of the drilling.

[0033] Since four cameras are set to obtain four images with different shooting angles, then, for each historical drilling, four drilling protrusion heights will be obtained.

[0034] Then, according to the obtained drilling protrusion heights of each historical drilling, obtain the drilling protrusion degree and the drilling deviation degree.

[0035] In an exemplary embodiment, as Figure 4 shown, a specific obtaining process of the drilling protrusion degree includes: Step S3: Obtain the average value and standard deviation of the drilling protrusion heights in all historical images of the drilling areas, and respectively obtain the standard drilling protrusion height and the standard protrusion fluctuation degree.

[0036] First, for each historical drill hole, obtain four drilling protrusion heights based on the historical image of the drilling area of this historical drill hole, and calculate the average value of these four drilling protrusion heights as the drilling protrusion height of this historical drill hole. Thus, the drilling protrusion heights of each historical drill hole are obtained.

[0037] Calculate the average value of the drilling protrusion heights of all historical drill holes. This average value reflects the situation of the drilling protrusion heights of all historical drill holes, that is, it characterizes the overall situation of the drilling protrusion heights of the drill holes of this type of circuit board. Therefore, this average value is defined as the standard drilling protrusion height.

[0038] Calculate the standard deviation of the drilling protrusion heights of all historical drill holes. This standard deviation reflects the fluctuation situation of the drilling protrusion heights of all historical drill holes, that is, it characterizes the fluctuation situation of the drilling protrusion heights of the drill holes of this type of circuit board. Therefore, this standard deviation is defined as the standard protrusion fluctuation degree. It should be understood that as the circuit board drilling progresses, there will be a certain degree of wear on the drill bit tool, resulting in a certain difference in the drilling protrusion heights of historical drill holes. The drilling protrusion heights of historical drill holes are not exactly the same. Then, the standard deviation of the drilling protrusion heights of all historical drill holes is not 0.

[0039] Step S4: Obtain the drilling protrusion degree according to the standard drilling protrusion height and the standard protrusion fluctuation degree.

[0040] The standard drilling protrusion height represents the central tendency of the drilling protrusion heights of all historical drill holes, and the standard protrusion fluctuation degree represents the dispersion degree of the drilling protrusion heights of all historical drill holes. The drilling protrusion degree is an index that balances the relationship between the standard drilling protrusion height and the standard protrusion fluctuation degree, indicating the significance of the drilling protrusion height relative to the fluctuation degree of the drilling protrusion height, that is, the significance of the standard drilling protrusion height relative to the standard protrusion fluctuation degree. When the drilling protrusion degree is higher, it indicates a high mean value and low fluctuation. The average value of the drilling protrusion height is more significant relative to the fluctuation degree of the drilling protrusion height. The drilling protrusion heights of all historical drill holes are more concentrated, and the average value is more reliable and representative; on the contrary, when the drilling protrusion degree is lower, it indicates a low mean value and high fluctuation, indicating that the average value is not obvious relative to the fluctuation degree of the drilling protrusion height. The drilling protrusion heights of all historical drill holes are relatively dispersed, and the average value is less reliable and less representative. Therefore, the drilling protrusion degree is directly proportional to the standard drilling protrusion height and inversely proportional to the standard protrusion fluctuation degree.

[0041] In an exemplary embodiment, a specific calculation method of the drilling protrusion degree is given as follows: ; wherein, represents the drilling bulge degree; represents the standard drilling bulge height; represents the standard bulge fluctuation degree.

[0042] represents the normalization of , wherein the normalization method is set according to the actual situation, such as the sigmoid function.

[0043] During the PCB drilling process, the wear of the drill bit tool will cause slight deviations in the feed angle, and different feed angles will result in differences in the bulge amount of the drilling hole position (i.e., the concentricity deviation between the hole mouth and the hole bottom). It should be particularly noted that this deviation has the characteristic of progressive accumulation: during continuous drilling operations, with the gradual increase in the wear amount of the drill bit edge, the progressive deterioration of the spindle system accuracy, and the expansion of the fitting clearance of the positioning mechanism, the actual drilling position deviation will show a typical monotonically increasing trend. Therefore, it is necessary to obtain the drilling deviation degree to characterize this situation.

[0044] In an exemplary embodiment, as Figure 5 shown, a specific process for obtaining the drilling deviation degree includes: Step S5: Obtain the bulge deviation amount of the historical drilling based on the differences between the drilling bulge heights obtained from the historical drilling in the drilling area historical image along different shooting angles.

[0045] For each historical drilling, the four obtained drilling bulge heights respectively correspond to the first camera to the fourth camera, and the four cameras are arranged in sequence. Then: the first camera and the third camera are a pair of relatively set cameras, and there is a relative relationship between the shooting angles. The second camera and the fourth camera are a pair of relatively set cameras, and there is a relative relationship between the shooting angles. Correspondingly, there is a relative relationship between the first drilling bulge height and the third drilling bulge height, and there is a relative relationship between the second drilling bulge height and the fourth drilling bulge height. Then, calculate the absolute value of the difference between the first drilling bulge height and the third drilling bulge height to obtain the first absolute difference value; calculate the absolute value of the difference between the second drilling bulge height and the fourth drilling bulge height to obtain the second absolute difference value. Then calculate the absolute value of the difference between the first absolute difference value and the second absolute difference value. The result obtained is the bulge deviation amount, and the bulge deviation amount characterizes the bulge height difference of the historical drilling at the relative position angle. Thus, the bulge deviation amounts of each historical drilling are obtained.

[0046] Step S6: Obtain the drilling deviation angle based on the bulge deviation amount of the historical drilling and the historical drilling diameter.

[0047] Since the deviation of the protrusion angle of historical drill holes is usually caused by the deviation of the feed angle, the deviation angle of the drill hole is reflected according to the deviation amount of the protrusion of the historical drill hole. Thus, based on the deviation amount of the protrusion of the historical drill hole and the diameter of the historical drill hole, the deviation angle of the drill hole is obtained, and the calculation formula is: ; Among them, represents the deviation amount of the protrusion of the th historical drill hole, represents the diameter of the th historical drill hole (since the diameter of the historical drill hole is determined by the drill bit, therefore, the diameters of each historical drill hole are known values and the diameters of all historical drill holes are the same), represents the arctangent function.

[0048] represents the deviation angle of the th historical drill hole, which characterizes the deviation amount between the actual feed angle and the theoretical feed angle of the th historical drill hole.

[0049] Thus, the deviation angles of each historical drill hole are obtained.

[0050] Step S7: Based on the change trend of the deviation angles of the historical drill holes corresponding to all the historical images of the drilling areas in time series, the cumulative drill hole deviation degree and the standard deviation of the drill hole deviation are obtained.

[0051] Based on the chronological order of each historical drill hole, the deviation angles of each historical drill hole are arranged in time series to obtain a time series of drill hole deviation angles. Calculate the standard deviation of the drill hole deviation angles in the time series of drill hole deviation angles, which is defined as the standard deviation of the drill hole deviation and is used to characterize the fluctuation degree of the drill hole deviation angles. Based on the above description, during the PCB drilling process, the wear of the drill bit tool will cause a slight deviation in the feed angle, and different feed angles will result in differences in the protrusion amount of the drill hole positions. Correspondingly, the drill hole deviation angles in the time series of drill hole deviation angles are not completely equal and show an increasing trend. Then, the obtained standard deviation of the drill hole deviation is not 0.

[0052] Taking the time axis as the horizontal axis and the deviation angles of each historical drill hole as the vertical axis, perform a linear regression fitting on the time series of drill hole deviation angles to obtain a regression fitting line, and thus obtain the slope of the regression fitting line. Then, obtain the angle between the slope of the fitting line and the time axis (i.e., the included angle, also called the deviation angle), which is used as the cumulative drill hole deviation degree. The larger the cumulative drill hole deviation degree, the more obvious the change trend of the deviation angles of the historical drill holes in time series, and the more serious the cumulative drill hole deviation.

[0053] Step S8: Obtain the standard drilling deviation angle, which is the average of the drilling deviation angles of the historical drillings corresponding to the historical images of all drilling areas.

[0054] Calculate the average of the drilling deviation angles in the time series of drilling deviation angles, which is defined as the standard drilling deviation angle.

[0055] Step S9: Obtain the drilling deviation degree based on the cumulative drilling deviation, the standard deviation of drilling deviation, and the standard drilling deviation angle.

[0056] Involve the cumulative drilling deviation in obtaining the drilling deviation degree. The larger the cumulative drilling deviation is, the more serious the cumulative drilling deviation is, that is, the more serious the drilling deviation degree is. The drilling deviation degree is proportional to the cumulative drilling deviation. In an exemplary embodiment, a upper limit value of the cumulative drilling deviation is preset, and this upper limit value of the cumulative drilling deviation is the maximum allowable cumulative drilling deviation. Then, when the upper limit value of the cumulative drilling deviation is greater than the cumulative drilling deviation, calculate the ratio of the cumulative drilling deviation to the upper limit value of the cumulative drilling deviation, which is equivalent to normalizing the cumulative drilling deviation, and the obtained ratio is used as the influencing factor of the cumulative drilling deviation on the drilling deviation degree.

[0057] At the same time, the standard drilling deviation angle and the standard deviation of drilling deviation are also involved in obtaining the drilling deviation degree. The standard drilling deviation angle represents the central tendency of the drilling deviation angles of all historical drillings, and the standard deviation of drilling deviation represents the dispersion degree of the drilling deviation angles of all historical drillings. An index that balances the relationship between the standard drilling deviation angle and the standard deviation of drilling deviation is obtained according to the standard drilling deviation angle and the standard deviation of drilling deviation. Specifically, it is the ratio of the standard drilling deviation angle to the standard deviation of drilling deviation, which represents the significance of the drilling deviation angle relative to the standard deviation of drilling deviation. When the ratio of the standard drilling deviation angle to the standard deviation of drilling deviation is higher, it means high mean and low fluctuation, the average value of the drilling deviation angle is more significant relative to the standard deviation of drilling deviation, the drilling deviation angles of all historical drillings are more concentrated, the average value is more reliable and more representative; on the contrary, when it is lower, it means low mean and high fluctuation, indicating that the average value is not obvious relative to the standard deviation of drilling deviation, the drilling deviation angles of all historical drillings are relatively dispersed, the average value is less reliable and less representative.

[0058] Therefore, by integrating the ratio of the cumulative drilling deviation to the upper limit value of the cumulative drilling deviation and the ratio of the standard drilling deviation angle to the standard deviation of drilling deviation, and comprehensively analyzing these two parts, the drilling deviation degree is obtained. In an exemplary embodiment, the calculation formula of the drilling deviation degree is as follows: ; Where: represents the drilling deviation degree; Indicates the standard drilling deviation angle; Indicates the standard deviation of drilling deviation; Indicates the cumulative drilling deviation degree; Is the upper limit value of the preset cumulative drilling deviation degree.

[0059] Indicates the normalization of , where the normalization method is set according to the actual situation, such as the sigmoid function.

[0060] Adopt the method of taking and The average value of these two parts is used to achieve comprehensive analysis and obtain the degree of drilling deviation.

[0061] In the above, by drilling the same type of circuit board multiple times in the historical time period, the drilling bulge degree and the drilling deviation degree corresponding to the circuit board of this type are obtained. Next, when performing the current drilling on the same type of circuit board in combination with the obtained drilling bulge degree and drilling deviation degree, adaptive drilling control is performed according to the relevant situation of the next drilling of the current drilling. Among them, the circuit board of the current drilling belongs to the same type as the circuit boards drilled multiple times in the historical time period. Moreover, the drill bit parameters of the current drilling are also the same as those of the multiple drillings in the historical time period.

[0062] When drilling a circuit board, different drilling requirements are different, that is, there is a safety distance between the drilling and the surrounding circuits in the circuit board. When the circuits around the drilling are more complex, the tolerance for errors is smaller, that is, drilling errors cannot occur, because at this time, larger errors may cause the drilling and the surrounding circuits to not maintain a safe distance, thus affecting the performance of the circuit board.

[0063] This embodiment provides a drilling control method applicable to a circuit board, as Figure 6 shown, including: Step S100: Obtain a distance feature from the position of the next drilling of the current drilling in the circuit board and the distances from the various circuits in the circuit board.

[0064] When drilling the circuit board, when the current drilling is completed, the next drilling needs to be performed. According to the pre-determined design information of the circuit board and the path planning of each drilling, obtain the position of the next drilling in the circuit board. And, according to the pre-determined design information of the circuit board, the positions of the various circuits in the circuit board can be determined. Thus, according to the position of the next drilling in the circuit board and the positions of the various circuits in the circuit board, the positional relationship between the next drilling and the various circuits is obtained. Furthermore, a distance feature is obtained from the position of the next drilling in the circuit board and the distances from the various circuits in the circuit board. In an exemplary embodiment, as Figure 7As shown, the process of obtaining the distance feature includes: Step S101: Obtain the shortest distance between the position of the next drill hole on the circuit board in each direction and each circuit in that direction.

[0065] Step S102: Obtain the target shortest distance, which is the shortest distance among the shortest distances corresponding to each direction.

[0066] Step S103: Obtain the target average distance, which is the average distance of the shortest distances corresponding to each direction.

[0067] Step S104: Calculate the average value of the target shortest distance and the target average distance to obtain the distance feature.

[0068] Taking the position of the next drill hole as the center, diverge in multiple directions around. The number of settings for each direction and the directions are set according to the actual situation. In an exemplary embodiment, corresponding to four cameras, four directions of up, down, left, and right are set.

[0069] For any one direction, there will be circuits in that direction on the circuit board. Taking the position of the next drill hole as the starting point, make a ray in that direction, so that the ray intersects with each circuit in that direction to obtain intersection points. Then, obtain the distance between the position of the next drill hole on the circuit board and the intersection points of each circuit in that direction as the distance between the next drill hole and each circuit in that direction, and obtain the shortest distance from them as the shortest distance in that direction.

[0070] Determine the shortest distance from the shortest distances in each direction as the target shortest distance. Therefore, the target shortest distance is the shortest distance between the next drill hole and all the circuits on the circuit board. At the same time, calculate the average value of the shortest distances in each direction as the target average distance.

[0071] The target shortest distance characterizes the shortest distance between the next drill hole and the surrounding circuits, and the target average distance characterizes the overall level of the distance between the next drill hole and the surrounding circuits. Analyze the relevant features of the distance between the next drill hole and the surrounding circuits from two aspects. Then, conduct a comprehensive analysis of the target shortest distance and the target average distance. In this embodiment, a comprehensive analysis is carried out by calculating the average value of the target shortest distance and the target average distance to obtain the distance feature.

[0072] Step S200: Based on the distance feature, obtain the drilling error tolerance of the next drill hole.

[0073] The distance feature reflects the characteristic situation of the distance between the next drill hole and the surrounding circuits in the circuit board. The smaller the distance feature, the closer the distance between the next drill hole and the surrounding circuits as a whole, the more complex the situation of the next drill hole in the circuit board, and the smaller the error tolerance of the next drill hole, that is, the less likely there will be drilling errors. Then, the distance feature is proportional to the error tolerance of the next drill hole. In an exemplary embodiment, the distance feature is normalized, and the normalized result is the error tolerance of the next drill hole. Among them, the normalization method is set according to the actual situation, such as the sigmoid function.

[0074] Step S300: Adjust the initial drill feed speed according to the drill error tolerance and the drill protrusion degree to obtain the target feed speed of the next drill hole.

[0075] When the drill protrusion degree is larger, it means that the feed speed of the current drill bit is faster and the physical contact force between the drill bit and the circuit board is greater. Then, for a drill hole with a smaller drill error tolerance, the feed speed of the drill bit should be smaller to reduce the physical contact force between the drill bit and the circuit board, thereby reducing the protrusion degree of the next drill hole. Then, in an exemplary embodiment, as Figure 8 shown, the following gives a specific acquisition process of the target feed speed: Step S301: Obtain a feed speed adjustment coefficient according to the drill error tolerance and the drill protrusion degree.

[0076] The feed speed adjustment coefficient here is used to obtain the feed speed reduction amount. Then, when the drill protrusion degree is larger, the feed speed adjustment coefficient is larger, the feed speed reduction amount is larger, and the reduction amplitude of the feed speed is larger. Therefore, the feed speed adjustment coefficient is proportional to the drill protrusion degree. When the drill error tolerance is smaller, the feed speed adjustment coefficient is larger, the feed speed reduction amount is larger, and the reduction amplitude of the feed speed is larger. Therefore, the feed speed adjustment coefficient is inversely proportional to the drill error tolerance.

[0077] In an exemplary embodiment, the calculation formula of the feed speed adjustment coefficient is as follows: ; Among them, represents the feed speed adjustment coefficient, represents the drill error tolerance.

[0078] Step S302: Obtain the feed speed reduction amount according to the initial drill feed speed and the feed speed adjustment coefficient.

[0079] In an exemplary embodiment, the minimum allowable drilling feed rate is incorporated into the acquisition of the feed rate reduction amount to ensure the accuracy of the feed rate reduction amount. It should be understood that the initial drilling feed rate is greater than the minimum allowable drilling feed rate. The calculation formula for the feed rate reduction amount is as follows: ; wherein, represents the initial drilling feed rate; represents the minimum allowable drilling feed rate.

[0080] Step S303: Obtain the target feed rate according to the initial drilling feed rate and the feed rate reduction amount.

[0081] In an exemplary embodiment, the target feed rate is equal to the initial drilling feed rate minus the feed rate reduction amount difference.

[0082] Step S400: Adjust the maximum drilling retraction speed according to the drilling error tolerance and the degree of drilling deviation to obtain the target retraction speed for the next drilling.

[0083] When the degree of drilling deviation is greater, it indicates that the accuracy of the drilling feed angle and the drilling uniformity at different positions of the drilling decrease. At this time, when retracting the tool, it is necessary to reduce the retraction speed to avoid causing secondary damage to the drilling during the return stroke. Moreover, since the retraction speed is uniformly accelerated and then uniformly decelerated after reaching the speed peak, only the maximum drilling retraction speed needs to be adjusted.

[0084] In an exemplary embodiment, as Figure 9 shown, the following gives a process for obtaining the target retraction speed: Step S401: Obtain the retraction speed adjustment coefficient according to the drilling error tolerance and the degree of drilling deviation.

[0085] Among them, the retraction speed adjustment coefficient is used to adjust the maximum drilling retraction speed. The larger the retraction speed adjustment coefficient, the larger the adjusted retraction speed, that is, the smaller the reduction amplitude of the retraction speed. Then, when the degree of drilling deviation is greater, the reduction amplitude of the retraction speed needs to be larger, so the retraction speed adjustment coefficient should be smaller, and the retraction speed adjustment coefficient is inversely proportional to the degree of drilling deviation. When the drilling error tolerance is smaller, the reduction amplitude of the retraction speed needs to be larger, so the retraction speed adjustment coefficient should be smaller, and the retraction speed adjustment coefficient is directly proportional to the drilling error tolerance.

[0086] In an exemplary embodiment, the calculation formula for the retraction speed adjustment coefficient is as follows: ; wherein, Indicates the retraction speed adjustment coefficient.

[0087] Step S402: Obtain the target retraction speed based on the maximum retraction speed of the drill and the retraction speed adjustment coefficient.

[0088] In an exemplary embodiment, the product of the maximum retraction speed of the drill and the retraction speed adjustment coefficient is used as the target retraction speed for the next drill. Among them, the maximum retraction speed of the drill is the pre-set maximum retraction speed of the drill.

[0089] By using the above process, the target feed speed and target retraction speed for the next drill are obtained. Then, the obtained target feed speed and target retraction speed are output to the drill control system, so as to perform drill feed at the target feed speed and retract at the target retraction speed when processing the next drill, realizing the speed control of the feed and return stroke of the next drill.

[0090] It should be understood that the drill control method provided by the present invention can also be an adaptive regulation process, continuously obtaining and regulating the feed speed and retraction speed of the latest drill, dynamically optimizing the drill strategy, realizing the smooth progress of the circuit board drilling, improving the drilling accuracy, ensuring the drilling quality, and thus avoiding affecting the performance of the circuit board. Moreover, the drill control method provided by the present invention also has the following advantages: reducing the surface protrusions and hole wall roughness of the circuit board, improving the surface finish and dimensional accuracy, reducing the risk of internal stress concentration; avoiding circuit short-circuit or unstable signal transmission caused by drilling deviation, ensuring the electromagnetic shielding efficiency and conductivity; the dynamic regulation mechanism can adapt to the non-uniformity of different circuit board materials, the drill wear state and complex circuit layouts (such as high-density designs), expanding the application range of mechanical drilling; supporting the flexible switching between high-precision scenarios (such as micro-hole processing) and low-cost scenarios; reducing the wear of the drill and the spindle by reducing the physical contact force under abnormal working conditions (such as the impact caused by high-speed feed), extending the service life of the equipment; the error accumulation compensation mechanism delays the accuracy degradation of the positioning mechanism; combining historical data with real-time feedback to realize the self-learning optimization of process parameters, reducing the dependence on manual parameter adjustment; running at the fastest speed in the idle stroke section ( Figure 1 the AC section in it) to shorten the overall processing time.

[0091] This embodiment also provides a drill control system applicable to a circuit board, including: a memory and a processor; the memory is connected to the processor, and the memory is used to store program instructions; the processor is used to implement the steps in the drill control method embodiment applicable to the circuit board as described above when the program instructions are executed.

[0092] In an exemplary embodiment, the present invention provides a drilling control device applicable to a circuit board, including: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the above-described embodiment of the drilling control method applicable to a circuit board.

[0093] It should be noted that the above sequence of embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A drilling control method suitable for a circuit board, characterized in that: include: The distance feature is obtained from the distance between the position of the next drill hole of the current drill hole in the circuit board and each circuit in the circuit board; Based on the distance feature, obtaining a drilling error tolerance of the next drilling hole; According to the drilling error tolerance and drilling prominence, the initial drilling feed speed is adjusted to obtain a target feed speed for the next drilling; the drilling prominence is used to characterize the overall prominence of multiple historical drillings, and the multiple historical drillings are obtained by drilling the same type of circuit board multiple times in history; According to the drilling error tolerance and the drilling deviation degree, the maximum drilling tool retraction speed is adjusted to obtain the target tool retraction speed for the next drilling; the drilling deviation degree is used to characterize the cumulative drilling angle deviations of the multiple historical drillings.

2. A drilling control method suitable for circuit boards as claimed in claim 1, characterized in that: The drilling control method applicable to the circuit board also includes: Performing multiple historical drillings on the same type of circuit board to obtain historical images of the drilling areas of each historical drilling; the historical images of the drilling areas include images obtained from the historical drillings along at least one shooting angle; The drilling protrusion height in the historical image of the drilling area is obtained according to the relationship between the shadow appearing in the historical image of the drilling area due to the historical drilling protrusion and the protrusion height.

3. A drilling control method suitable for circuit boards as claimed in claim 2, characterized in that: The process of obtaining the drilling convexity includes: Obtaining the average value and standard deviation of the drilling bulge heights in all the historical images of the drilling area, and obtaining the standard drilling bulge height and the standard bulge fluctuation degree respectively; The drilling protrusion degree is obtained according to the standard drilling protrusion height and the standard protrusion fluctuation degree; the drilling protrusion degree is proportional to the standard drilling protrusion height and inversely proportional to the standard protrusion fluctuation degree.

4. A drilling control method suitable for circuit boards as claimed in claim 2, characterized in that: The process of obtaining the drilling deviation degree includes: Obtaining a convex deviation of the historical borehole according to a difference between the convex heights of the historical boreholes obtained along different shooting angles in the historical image of the drilling area; Based on the convex deviation amount of the historical drilling and the historical drilling diameter, the drilling deviation angle is obtained; Based on the time series change trend of the drilling deviation angle of the historical boreholes corresponding to the historical images of all drilling areas, the cumulative drilling deviation and the standard deviation of the drilling deviation are obtained; Obtaining a standard drilling deviation angle, where the standard drilling deviation angle is an average value of drilling deviation angles of historical drillings corresponding to historical images of all drilling areas; The drilling deviation degree is obtained according to the drilling cumulative deviation degree, the drilling deviation standard deviation and the standard drilling deviation angle; the drilling deviation degree is proportional to the drilling cumulative deviation degree, proportional to the standard drilling deviation angle, and inversely proportional to the drilling deviation standard deviation.

5. A drilling control method suitable for circuit boards as claimed in claim 4, characterized in that: The process of obtaining the cumulative drilling deviation includes: performing straight line fitting on the drilling deviation angles of historical drillings corresponding to all historical images of the drilling area in time series, and obtaining the slope of the fitting line and the angle of the time axis as the cumulative drilling deviation.

6. A drilling control method suitable for circuit boards as claimed in claim 1, characterized in that: The process of acquiring the target feed speed includes: According to the drilling error tolerance and the drilling protrusion, a feed speed adjustment coefficient is obtained, wherein the feed speed adjustment coefficient is inversely proportional to the drilling error tolerance and directly proportional to the drilling protrusion; Obtaining a feed speed reduction amount according to the initial drilling feed speed and the feed speed adjustment coefficient; The target feed speed is obtained according to the initial drilling feed speed and the feed speed reduction amount.

7. A drilling control method suitable for circuit boards as claimed in claim 1, characterized in that: The process of obtaining the target retracting speed includes: According to the drilling error tolerance and the drilling deviation degree, a tool retraction speed adjustment coefficient is obtained, wherein the tool retraction speed adjustment coefficient is proportional to the drilling error tolerance and inversely proportional to the drilling deviation degree; The target tool retracting speed is obtained according to the maximum tool retracting speed for drilling and the tool retracting speed adjustment coefficient.

8. A drilling control method suitable for circuit boards as claimed in claim 1, characterized in that: The process of acquiring the distance feature includes: Obtain the shortest distance between the position of the next drill hole in the circuit board and each circuit in the direction in each direction; Obtaining the shortest distance to the target, where the shortest distance to the target is the shortest distance among the shortest distances corresponding to each direction; Obtaining an average target distance, wherein the target shortest distance is the average distance of the shortest distances corresponding to each direction; The average of the shortest target distance and the average target distance is calculated to obtain the distance feature.

9. A drilling control system suitable for a circuit board, characterized in that it comprises: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is used to implement the drilling control method applicable to a circuit board as described in any one of claims 1 to 8 when the program instructions are executed.

10. A drilling control device suitable for circuit boards, characterized in that: A computer-readable storage medium is included, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the drilling control method embodiment applicable to a circuit board described in any one of claims 1 to 8 are implemented.

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