Drilling control method, system and equipment suitable for circuit boards

Abstract

The present invention relates to the technical field of printed circuit manufacturing, and particularly to a drilling control method, system, and device suitable for circuit boards. A distance feature is obtained by determining the distance between the position of a next hole drilled after a current hole in the circuit board and each circuit in the circuit board. A drilling error tolerance for the next hole is obtained based on the distance feature. An initial drilling feed speed is adjusted based on the drilling error tolerance and the drilling protrusion to obtain a feed speed suitable for the next hole. Drilling at this feed speed can improve drilling accuracy, ensure drilling quality, and thus avoid affecting the performance of the circuit board. A maximum drilling tool retraction speed is adjusted based on the drilling error tolerance and the degree of drilling deviation to obtain a target tool retraction speed for the next hole. This can improve drilling accuracy, avoid secondary damage to the hole during tool retraction, ensure drilling quality, and thus avoid affecting the performance of the circuit board.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit manufacturing, and in particular to a drilling control method, system and equipment suitable for circuit boards. Background Art

[0002] The continuous advancement of electronic devices has placed higher demands on circuit board (PCB) manufacturing technology, particularly in drilling processes. Currently, mechanical drilling is the primary method for drilling PCBs. Mechanical drilling is a contact-based method that achieves precise positioning through the combined motion of various axes. Before beginning processing, the user must load the processing file and set the relevant processing parameters. After the machine is started, the X and Y axes begin operating according to the processing instructions, while the Z axis remains stationary at the set drilling start position. Once the X and Y axes have reached the first drilling hole and stabilized within the set positional error range, the Z-axis motor then drives the high-speed spindle downward according to the set processing parameters, machining the PCB until it reaches the specified final drilling position and then returns to the drilling start position. The X and Y axes then move to the next drilling hole, while the Z axis drills downward. This repetitive process completes the entire PCB process.

[0003] The motion state on the Z axis during one processing process is as follows Figure 1 As shown, Figure 1 The horizontal axis of the two-dimensional coordinate system shown is time, and the vertical axis is speed. Segment AC is the idle travel segment, with point A being the Z-axis starting point and point C being the point where the drill tip just touches the circuit board. The idle travel segment requires the Z-axis to run at maximum speed to minimize motion time. Segment CD is the drilling segment where the drill cuts through the circuit board. During this stage, the speed is constant, and the displacement depends on the thickness of the circuit board. Segment DE is the buffer segment, which decelerates from the constant speed segment to zero speed.

[0004] The drilling process of the circuit board usually includes the downward movement phase of drilling and the upward movement phase of return (i.e., retraction). The motion state of the return motion phase is usually acceleration-constant speed-deceleration or acceleration-deceleration. The complete motion state of the Z-axis drilling and return motion in one processing process is as follows: Figure 2 As shown, Figure 2 The horizontal axis in the two-dimensional coordinate system shown is time and the vertical axis is speed.

[0005] In current mechanical drilling processes, circuit board drilling typically utilizes a constant drilling speed and rotational speed. Due to the inherent unevenness of the circuit board material, combined with the constant feed rate of the drill bit, a certain amount of physical contact force is generated between the circuit board and the drill bit. This, in turn, results in varying degrees of raised surfaces in localized areas of the circuit board surface. Furthermore, if the circuit board material is uneven, the raised surfaces caused by the drill during the feed and retract stages pose a risk of collision, impacting operational smoothness. This not only damages the circuit board's surface structure, resulting in a reduction in surface finish, but also creates stress concentration within the board's internal structure, compromising the stability of internal wiring and component connections. Therefore, from a process perspective, existing circuit board drilling control methods can compromise drilling accuracy, resulting in rough hole walls and dimensional deviations. From a performance perspective, these surface raised surfaces and damaged internal structures weaken the board's electromagnetic shielding effectiveness and compromise its electrical conductivity, making it difficult to ensure stable signal transmission. Consequently, existing circuit board drilling control methods are extremely detrimental to the overall quality and performance 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 solutions adopted are as follows:

[0007] In a first aspect of the present invention, a drilling control method applicable to a circuit board is provided, comprising:

[0008] A distance feature is obtained from the distance between the position of the next drill hole after the current drill hole in the circuit board and each circuit in the circuit board;

[0009] Based on the distance feature, obtaining a drilling error tolerance for the next drilling hole;

[0010] Adjusting the initial drilling feed rate based on the drilling error tolerance and the drilling prominence to obtain a target feed rate for the next drilling; the drilling prominence is used to characterize the overall prominence of multiple historical drillings, the multiple historical drillings being obtained by drilling the same type of circuit board multiple times;

[0011] 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 deviation of the multiple historical drilling holes.

[0012] In an exemplary embodiment, the drilling control method applicable to a circuit board further includes:

[0013] Performing multiple consecutive historical drillings on the same type of circuit board to obtain historical images of the drilling area of each historical drilling; the historical images of the drilling area include images obtained from at least one shooting angle of the historical drilling;

[0014] The drilling bulge height in the historical image of the drilling area is obtained based on the relationship between the shadow caused by the historical drilling bulge and the bulge height in the historical image of the drilling area.

[0015] In an exemplary embodiment, the process of obtaining the drilling protrusion includes:

[0016] Obtaining the average value and standard deviation of the drilling bulge heights in all historical images of the drilling area to obtain the standard drilling bulge height and the standard bulge fluctuation degree respectively;

[0017] 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.

[0018] In an exemplary embodiment, the process of obtaining the drilling deviation degree includes:

[0019] 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;

[0020] Based on the convex deviation amount and the historical drilling diameter of the historical drilling, the drilling deviation angle is obtained;

[0021] 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;

[0022] Obtaining a standard drilling deviation angle, where the standard drilling deviation angle is an average value of drilling deviation angles of historical boreholes corresponding to historical images of all drilling areas;

[0023] The drilling deviation degree is obtained according to the drilling cumulative deviation, drilling deviation standard deviation and standard drilling deviation angle; the drilling deviation degree is proportional to the drilling cumulative deviation, proportional to the standard drilling deviation angle, and inversely proportional to the drilling deviation standard deviation.

[0024] In an exemplary embodiment, the process of obtaining the cumulative deviation of the drilling includes: performing straight line fitting on the drilling deviation angles of the historical drilling corresponding to all historical images of the drilling area in the time series, and obtaining the slope of the fitting straight line and the angle of the time axis as the cumulative deviation of the drilling.

[0025] In an exemplary embodiment, the process of acquiring the target feed speed includes:

[0026] A feed speed adjustment coefficient is obtained according to the drilling error tolerance and the drilling protrusion, wherein the feed speed adjustment coefficient is inversely proportional to the drilling error tolerance and directly proportional to the drilling protrusion;

[0027] Obtaining a feed speed reduction amount according to the initial drilling feed speed and the feed speed adjustment coefficient;

[0028] The target feed speed is obtained according to the initial drilling feed speed and the feed speed reduction amount.

[0029] In an exemplary embodiment, the process of obtaining the target retraction speed includes:

[0030] 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;

[0031] The target retract speed is obtained according to the maximum retract speed of drilling and the retract speed adjustment coefficient.

[0032] In an exemplary embodiment, the process of acquiring the distance feature includes:

[0033] Obtain the shortest distance between the position of the next drill hole in the circuit board and each line in the direction in each direction;

[0034] 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;

[0035] Obtaining the average target distance, wherein the shortest target distance is the average distance of the shortest distances corresponding to each direction;

[0036] An average of the shortest target distance and the average target distance is calculated to obtain the distance feature.

[0037] In a second aspect of the present invention, a drilling control system suitable for a circuit board is provided, comprising: 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 suitable for the circuit board when the program instructions are executed.

[0038] In a third aspect of the present invention, a drilling control device suitable for a circuit board is provided, comprising a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the above-mentioned embodiment of the drilling control method suitable for a circuit board.

[0039] The present invention has the following beneficial effects: since the position of the next drill hole in the circuit board and the distance between each circuit in the circuit board determine the error tolerance of the next drill hole, the drilling error tolerance of the next drill hole is obtained accordingly, and the drilling error tolerance affects the feed speed and retraction speed of the next drill hole; and since the drilling protrusion is related to the feed speed of the drill bit, the feed speed of the drill bit for drilling holes with different error tolerances is also different. Therefore, the feed speed of the next drill hole is obtained according to the drilling error tolerance and the drilling protrusion, and the feed speed suitable for the next drill hole can be obtained. Using this feed speed for drilling can improve the drilling accuracy and ensure the drilling quality, thereby avoiding affecting the performance of the circuit board. Moreover, when the degree of drilling deviation is different, an adaptive retraction speed is required to avoid secondary damage to the drill hole during the retraction process. Therefore, according to the drilling error tolerance and the degree of drilling deviation, the retraction speed of the next drill hole is obtained, 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

[0040] Figure 1 This is a schematic diagram of the motion state on the Z axis during a machining process provided by an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the complete motion state of Z-axis drilling and return motion during a machining process provided by one embodiment of the present invention;

[0042] Figure 3 A flowchart of steps further included in a drilling control method for a circuit board provided by one embodiment of the present invention;

[0043] Figure 4 This is a flow chart for obtaining the drilling convexity provided by one embodiment of the present invention;

[0044] Figure 5 is a flowchart for obtaining the degree of drilling deviation provided by one embodiment of the present invention;

[0045] Figure 6 This is a flowchart of the core steps of a drilling control method applicable to a circuit board provided by one embodiment of the present invention;

[0046] Figure 7 is a flow chart of obtaining distance features provided by one embodiment of the present invention;

[0047] Figure 8 is a flow chart for obtaining a target feed speed provided by one embodiment of the present invention;

[0048] Figure 9 This is a flow chart for obtaining a target tool retraction speed provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific embodiments, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0051] The hardware execution portion of a drilling control method for a circuit board provided in this embodiment includes an image acquisition device and a control device, which are electrically connected to the control device. The image acquisition device is used to capture an image of the drilling area and obtain the required data information based on the image of the drilling area.

[0052] In an exemplary embodiment, the image acquisition device is a high-resolution (≥5 million pixels) global shutter CMOS camera with a frame rate ≥60fps (to accommodate high-speed drilling motion) and a telecentric lens (to eliminate perspective distortion).

[0053] For each borehole, at least one camera is provided to obtain an image of the borehole at at least one shooting angle. When multiple cameras are provided, each camera has a different shooting angle. In one exemplary embodiment, four cameras are provided to capture images of the borehole from four angles: top, bottom, left, and right. These four cameras are evenly spaced around a circle, with the first and third cameras forming a pair of opposing cameras, and the second and fourth cameras forming a pair of opposing cameras. The line connecting the first and third cameras is perpendicular to the line connecting the second and fourth cameras. Furthermore, all four cameras face inward and have their shooting angles set diagonally downward, ranging from 30° to 45°. It should be noted that the diagonal downward angles of the four cameras can be the same, thereby improving monitoring accuracy. When the borehole is at the center of the four cameras' shooting angles, four images of the borehole can be obtained from different shooting angles.

[0054] In an exemplary embodiment, in order to facilitate shooting, four cameras are integrated into the end of the drill's movable arm or the drill's fixing device. During installation, the drilling area is kept at the shooting center of the four cameras. At the same time, it is connected to the drill equipment body through an aluminum alloy bracket + shock-absorbing gasket to ensure rigid support and vibration resistance. In addition, a ring-shaped LED light source is selected and installed around the camera lens or on the side of the drill's mechanical arm to ensure that the light source can well illuminate the surface of the circuit board and provide uniform diffuse lighting. The setting of the light source needs to meet the following requirements: the illumination angle of the light source is consistent with the shooting angle of the camera, so as to facilitate subsequent processing.

[0055] Due to the unevenness of the circuit board and the various error parameters during actual drilling, the protrusions of the drilled holes obtained on the same type of circuit boards are not exactly the same when drilling the circuit boards. Among them, the same type of circuit boards refers to circuit boards with the same material and the same parameters. Moreover, when drilling more delicate parts, the errors generated may cause the protrusions of the drilled holes to affect the surrounding circuits in the circuit board, thereby affecting the stability of the circuits. Therefore, we first analyze the protrusion height performance in the relevant historical data of historical drilling to obtain the drilling protrusion degree and drilling deviation degree. Among them, the drilling protrusion degree is used to characterize the overall protrusion of multiple historical drillings. 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.

[0056] In an exemplary embodiment, Figure 3 As shown, the drilling control method applicable to a circuit board provided in this embodiment also includes the following implementation process:

[0057] Step S1: drilling the same type of circuit board multiple times in history to obtain a historical image of the drilling area of each historical drilling.

[0058] A historical time period is preset, and multiple consecutive drillings are performed on the same type of circuit board within the historical time period. The resulting drilled holes are defined as historical drilled holes. The length of the historical time period and the number of historical drilled holes are set based on actual conditions.

[0059] For each historical drill hole, the four cameras are used to capture four images of the historical drill hole at four different shooting angles. Thus, the resulting historical images of the drill hole area for the historical drill hole include the drill hole images captured at the four different shooting angles. Furthermore, in one exemplary embodiment, the historical images of the drill hole area specifically encompass a circle centered at the drill hole center and with a radius greater than the drill hole radius. This ensures that shadows cast by drill hole protrusions are fully included in the historical images of the drill hole area, facilitating subsequent image processing. In one exemplary embodiment, the length greater than the drill hole radius can be three times the drill hole radius.

[0060] In an exemplary embodiment, after the drill bit of the drilling machine completely exits the hole, there is a delay of 2ms, and a trigger signal is sent to start the camera shooting, thereby realizing a synchronization mechanism between the trigger signal and the drilling action to avoid motion blur.

[0061] The image captured in this embodiment can directly be an image of the drilling area without the need for preliminary image preprocessing. As another implementation, an initial image can be captured first, and then a median filter or Gaussian filter can be used to eliminate dust interference on the circuit board. ROI extraction can then be performed, and the detection area can be located based on the drilling coordinates to obtain a historical image of the drilling area.

[0062] Step S2: Obtain the drilling bulge height in the historical image of the drilling area 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.

[0063] First, edge detection (such as the Canny operator) is performed on the historical image of the drilling area to extract the drilling outline and shadow boundary.

[0064] Because the camera is angled downward to capture the borehole, coupled with the light source, a shadow (i.e., the shadow cast by the borehole protrusion) is created on the edge of the borehole protrusion away from the light source. This shadow has a certain length in the direction of the light source, defined as the shadow width. Therefore, the shadow width has a geometric relationship with the borehole protrusion height and the shooting angle. Based on the shadow width and shooting angle, and by performing mathematical operations based on this geometric relationship, the borehole protrusion height in historical images of the drilling area can be determined. The shadow width and the borehole protrusion height have a simple geometric relationship: specifically, the borehole protrusion height is equal to the product of the tangent of the angle between the light source and the horizontal plane and the shadow width. Alternatively, the borehole protrusion height can be obtained through structured light 3D reconstruction (for high-precision scenarios)—this method is suitable for high-precision scenarios and will not be further described here. Alternatively, the borehole protrusion height can be obtained by detecting the borehole protrusion using a depth camera.

[0065] Since four cameras are set up to obtain images at four different shooting angles, four drilling protrusion heights will be obtained for each historical drilling.

[0066] Then, the drilling protrusion degree and the drilling deviation degree are obtained according to the obtained drilling protrusion height of each historical drilling hole.

[0067] In an exemplary embodiment, Figure 4 As shown, a specific process for obtaining the drilling protrusion includes:

[0068] Step S3: Obtain the average value and standard deviation of the drilling bulge height in all historical images of the drilling area to obtain the standard drilling bulge height and standard bulge fluctuation degree respectively.

[0069] First, for each historical borehole, four borehole protrusion heights are obtained based on the historical image of the drilling area of the historical borehole, and the average of these four borehole protrusion heights is calculated as the borehole protrusion height of the historical borehole. In this way, the borehole protrusion height of each historical borehole is obtained.

[0070] The average value of the drilling protrusion heights of all historical drillings is calculated. This average value reflects the drilling protrusion heights of all historical drillings, that is, it characterizes the overall situation of the drilling protrusion heights of the drillings of this type of circuit board. Therefore, this average value is defined as the standard drilling protrusion height.

[0071] The standard deviation of the drill protrusion heights for all historically drilled holes is calculated. This standard deviation reflects the fluctuation in the drill protrusion heights for all historically drilled holes, specifically, the fluctuation in the drill protrusion heights for holes drilled on this type of circuit board. Therefore, this standard deviation is defined as the standard protrusion fluctuation degree. It should be understood that as circuit board drilling progresses, the drill bit wears, resulting in variations in the drill protrusion heights for historically drilled holes. Therefore, the standard deviation of the drill protrusion heights for all historically drilled holes is not zero.

[0072] Step S4: Obtaining the drilling protrusion degree according to the standard drilling protrusion height and the standard protrusion fluctuation degree.

[0073] The standard borehole prominence height represents the concentration trend of the borehole prominence heights across all historical boreholes, while the standard prominence fluctuation indicates the dispersion of the borehole prominence heights across all historical boreholes. The borehole prominence index is a metric that balances the relationship between the standard borehole prominence height and the standard prominence fluctuation. It indicates the significance of the borehole prominence height relative to the fluctuation of the borehole prominence height, that is, the significance of the standard borehole prominence height relative to the standard prominence fluctuation. A higher borehole prominence index indicates a higher mean and lower fluctuation. The average borehole prominence height is more significant relative to the fluctuation of the borehole prominence height, resulting in a more concentrated borehole prominence height across all historical boreholes and a more reliable and representative average. Conversely, a lower borehole prominence index indicates a lower mean and higher fluctuation. This indicates that the average borehole prominence height is less significant relative to the fluctuation of the borehole prominence height and that the borehole prominence height across all historical boreholes is more dispersed, making the average less reliable and less representative. Therefore, the borehole prominence index is directly proportional to the standard borehole prominence height and inversely proportional to the standard prominence fluctuation.

[0074] In an exemplary embodiment, a specific calculation method of the drilling protrusion is given as follows:

[0075] ;

[0076] in, Indicates the degree of drilling protrusion; Indicates the standard drilling protrusion height; Indicates the standard convex fluctuation degree.

[0077] Express Normalization, where the normalization method is set by the actual situation, such as the sigmoid function.

[0078] During the circuit board drilling process, wear on the drill bit can cause slight deviations in the feed angle. These different feed angles result in differences in the amount of hole projection (i.e., concentricity deviation between the hole opening and the bottom). It is particularly important to note that this deviation exhibits a progressively cumulative nature: during continuous drilling operations, with increasing wear on the drill bit edge, progressive degradation of the spindle system's accuracy, and increased clearance within the positioning mechanism, the actual drill position deviation exhibits a typical monotonically increasing trend. Therefore, it is necessary to characterize this situation by measuring the degree of drilling deviation.

[0079] In an exemplary embodiment, Figure 5 As shown in FIG, a specific process for obtaining the degree of drilling deviation includes:

[0080] Step S5: Obtain the convex deviation of the historical drilling hole according to the difference between the convex heights of the historical drilling holes obtained along different shooting angles in the historical image of the drilling area.

[0081] For each historical drill hole, the four drill hole protrusion heights obtained correspond to the first to fourth cameras, respectively, and the four cameras are arranged in order. Therefore, the first and third cameras form a pair of cameras positioned opposite each other, with their shooting angles being relative to each other; the second and fourth cameras form a pair of cameras positioned opposite each other, with their shooting angles being relative to each other. Accordingly, the protrusion height of the first drill hole is relative to the protrusion height of the third drill hole, and the protrusion height of the second drill hole is relative to the protrusion height of the fourth drill hole. Then, the absolute value of the difference between the protrusion heights of the first and third drill holes is calculated to obtain the first absolute value of the difference; the absolute value of the difference between the protrusion heights of the second and fourth drill holes is calculated to obtain the second absolute value of the difference. The absolute value of the difference between the first and second absolute values is then calculated to obtain the protrusion deviation value, which represents the difference in protrusion heights of the historical drill holes at relative positions and angles. This yields the protrusion deviation value for each historical drill hole.

[0082] Step S6: Based on the historical drilling convex deviation amount and the historical drilling diameter, the drilling deviation angle is obtained.

[0083] Since the convex angle deviation of historical drilling is usually caused by the deviation of the feed angle, the drilling deviation angle is reflected according to the convex deviation of historical drilling. Based on the convex deviation of historical drilling and the historical drilling diameter, the drilling deviation angle is obtained. The calculation formula is:

[0084] ;

[0085] in, Indicates the The convex deviation of the historical drilling hole, Indicates the The diameter of each historical borehole (since the diameter of a historical borehole is determined by the drill bit, the diameter of each historical borehole is a known value and the diameter of all historical boreholes is the same), Represents the inverse tangent function.

[0086] Indicates the The drilling deviation angle of the historical drilling hole represents the The deviation between the actual feed angle and the theoretical feed angle of a historical drilling.

[0087] Thus, the drilling deviation angle of each historical drilling hole is obtained.

[0088] Step S7: Based on the time-series variation trend of the drilling deviation angles of the historical drillings corresponding to the historical images of all drilling areas, the drilling cumulative deviation and the drilling deviation standard deviation are obtained.

[0089] Based on the chronological order of each historical drilling, the drilling deviation angles of each historical drilling are arranged in time sequence to obtain a drilling deviation angle time series. The standard deviation of the drilling deviation angles in the drilling deviation angle time series is calculated and defined as the drilling deviation standard deviation, which is used to characterize the degree of fluctuation of the drilling deviation angle. Based on the above description, during the circuit board drilling process, the wear of the drill tool will cause slight deviations in the feed angle. Different feed angles will produce differences in the amount of protrusion of the drill hole position. Correspondingly, the drilling deviation angles in the drilling deviation angle time series are not completely equal and have a tendency to gradually increase. Therefore, the obtained drilling deviation standard deviation is not 0.

[0090] Using the time axis as the horizontal axis and the drilling deviation angles of each historical drill hole as the vertical axis, a linear regression fit is performed on the drilling deviation angle time series to obtain a regression fit line, and thus the slope of the regression fit line. The angle between the slope of the fitted line and the time axis (i.e., the included angle, also called the deviation angle) is then calculated as the cumulative drilling deviation. A larger cumulative drilling deviation indicates a more pronounced trend in the drilling deviation angles of the historical drill holes over time, and a more severe cumulative drilling deviation.

[0091] Step S8: Obtain a standard drilling deviation angle, where the standard drilling deviation angle is an average value of drilling deviation angles of historical drillings corresponding to all historical images of the drilling area.

[0092] The average value of the drilling deviation angles in the drilling deviation angle time series is calculated and defined as the standard drilling deviation angle.

[0093] Step S9: Obtain the drilling deviation degree according to the drilling cumulative deviation, the drilling deviation standard deviation and the standard drilling deviation angle.

[0094] The cumulative drilling deviation is incorporated into the determination of the drilling deviation degree. A larger cumulative drilling deviation indicates a more severe cumulative drilling deviation, i.e., a more severe drilling deviation degree. The drilling deviation degree is proportional to the cumulative drilling deviation. In one exemplary embodiment, a preset upper limit for the cumulative drilling deviation is set as the maximum allowable cumulative drilling deviation. If the upper limit for the cumulative drilling deviation is greater than the cumulative drilling deviation, the ratio of the cumulative drilling deviation to the upper limit for the cumulative drilling deviation is calculated, which is equivalent to normalizing the cumulative drilling deviation. The resulting ratio serves as the influencing factor of the cumulative drilling deviation on the drilling deviation degree.

[0095] The standard borehole deviation angle and standard deviation of borehole deviation are also considered in the determination of borehole deviation. The standard borehole deviation angle represents the central tendency of the borehole deviation angles across all historical boreholes, while the standard deviation represents the dispersion of the borehole deviation angles across all historical boreholes. Based on the standard borehole deviation angle and standard deviation, an indicator is derived to balance the relationship between the standard borehole deviation angle and the standard deviation of borehole deviation. Specifically, the ratio of the standard borehole deviation angle to the standard deviation of borehole deviation indicates the significance of the borehole deviation angle relative to the standard deviation of borehole deviation. A higher ratio of the standard borehole deviation angle to the standard deviation of borehole deviation indicates a higher mean and lower volatility. The mean of the borehole deviation angle is more significant relative to the standard deviation of the borehole deviation, the borehole deviation angles across all historical boreholes are more concentrated, and the average is more reliable and representative. Conversely, a lower ratio indicates a lower mean and higher volatility. This means that the average is not significant relative to the standard deviation of the borehole deviation, the borehole deviation angles across all historical boreholes are more dispersed, and the average is less reliable and less representative.

[0096] Therefore, the ratio of the cumulative drilling deviation to the upper limit of the cumulative drilling deviation, and the ratio of the standard drilling deviation angle to the standard deviation of the drilling deviation are combined to perform a comprehensive analysis of these two parts to obtain the drilling deviation degree. In an exemplary embodiment, the calculation formula for the drilling deviation degree is as follows:

[0097] ;

[0098] in: Indicates the degree of drilling deviation; Indicates the standard drilling deviation angle; represents the standard deviation of drilling deviation; Indicates the cumulative deviation of drilling; It is the preset upper limit of the cumulative drilling deviation.

[0099] Express Normalization, where the normalization method is set by the actual situation, such as the sigmoid function.

[0100] Use and The average value of these two parts is used to achieve comprehensive analysis and obtain the degree of drilling deviation.

[0101] In the above, by drilling multiple holes on the same type of circuit board over a historical time period, the corresponding drill hole protrusion and drill hole deviation were obtained. Next, when drilling a hole on the same type of circuit board, adaptive drilling control was performed based on the relevant conditions of the next hole to be drilled. The circuit board being drilled currently is of the same type as the circuit boards that were drilled multiple times during the historical time period. Furthermore, the drill bit parameters for the current drilling are the same as those for the multiple drillings performed during the historical time period.

[0102] When drilling holes in circuit boards, different drilling requirements require a safe distance between the hole and the surrounding circuits. The more complex the circuitry surrounding the hole, the less tolerance there is for errors. This means that drilling errors are less likely to occur. Larger errors can prevent the hole from maintaining a safe distance from the surrounding circuits, impacting the board's performance.

[0103] This embodiment provides a drilling control method applicable to a circuit board. Figure 6 Shown, including:

[0104] Step S100: obtaining a distance feature from the position of the next drill hole after the current drill hole in the circuit board and the distance between each circuit in the circuit board.

[0105] When drilling a hole in a circuit board, the next hole needs to be drilled when the current hole is completed. The position of the next hole in the circuit board is obtained based on the predetermined design information of the circuit board and the path planning of each hole. Moreover, the position of each circuit in the circuit board can be determined based on the predetermined design information of the circuit board. Thus, based on the position of the next hole in the circuit board and the position of each circuit in the circuit board, the positional relationship between the next hole and each circuit is obtained. Furthermore, the distance feature is obtained based on the distance between the position of the next hole in the circuit board and each circuit in the circuit board. In an exemplary embodiment, as Figure 7 As shown in Figure 2, the process of obtaining distance features includes:

[0106] Step S101: Obtain the shortest distance between the position of the next drill hole in the circuit board and each circuit in each direction.

[0107] Step S102: Obtain the target shortest distance, which is the shortest distance among the shortest distances corresponding to various directions.

[0108] Step S103: Obtain the average target distance, where the shortest target distance is the average distance of the shortest distances corresponding to each direction.

[0109] Step S104: Calculate the average of the shortest target distance and the average target distance to obtain a distance feature.

[0110] The position of the next drill hole is taken as the center and diverges in multiple directions. The number of directions and the number of directions are set according to the actual situation. In an exemplary embodiment, four directions are set, corresponding to the four cameras.

[0111] For any direction, there will be a circuit in that direction on the circuit board. Starting from the location of the next drill hole, draw a ray in that direction so that it intersects with each circuit in that direction, obtaining an intersection point. Then, obtain the distance between the location of the next drill hole in the circuit board and the intersection point of each circuit in that direction as the distance between the next drill hole and each circuit in that direction. The shortest distance is then calculated as the shortest distance in that direction.

[0112] The shortest distance among the shortest distances in each direction is determined as the target shortest distance. Therefore, the target shortest distance is the shortest distance between the next drill hole and all traces on the board. The average of the shortest distances in each direction is calculated as the target average distance.

[0113] The target shortest distance represents the shortest distance between the next borehole and the surrounding lines, and the target average distance represents the overall level of the distance between the next borehole and the surrounding lines. The relevant characteristics of the distance between the next borehole and the surrounding lines are analyzed from two aspects. Then, a comprehensive analysis is performed on the target shortest distance and the target average distance. This embodiment performs a comprehensive analysis by calculating the average value of the target shortest distance and the target average distance to obtain the distance feature.

[0114] Step S200: Based on the distance feature, obtain the drilling error tolerance of the next drilling hole.

[0115] The distance feature reflects the characteristic of the distance between the next drilled hole and the surrounding circuits on the circuit board. The smaller the distance feature, the closer the next drilled hole is to the surrounding circuits overall, the more complex the next drilled hole is in the circuit board, and the smaller the error tolerance for the next drilled hole, that is, the less likely drilling errors will occur. Therefore, the distance feature is proportional to the drilling error tolerance of the next drilled hole. In one exemplary embodiment, the distance feature is normalized, and the normalized result is the drilling error tolerance of the next drilled hole. The normalization method is set according to the actual situation, such as a sigmoid function.

[0116] Step S300: adjusting the initial drilling feed speed according to the drilling error tolerance and the drilling protrusion to obtain the target feed speed for the next drilling.

[0117] When the drilling convexity is greater, it means that the current drill feed speed is faster and the physical contact force between the drill and the circuit board is greater. Therefore, for drilling holes with smaller drilling error tolerance, the drill feed speed should be slower to reduce the physical contact force between the drill and the circuit board, thereby reducing the convexity of the next drilling hole. Then, in an exemplary embodiment, if Figure 8 As shown, a specific process of obtaining the target feed speed is given as follows:

[0118] Step S301: Obtaining a feed speed adjustment coefficient according to the drilling error tolerance and the drilling protrusion.

[0119] The feed rate adjustment coefficient here is used to determine the feed rate reduction. Therefore, when the hole protrusion is greater, the feed rate adjustment coefficient increases, the feed rate reduction is greater, and the feed rate reduction amplitude is larger. Therefore, the feed rate adjustment coefficient is proportional to the hole protrusion. When the hole error tolerance is smaller, the feed rate adjustment coefficient increases, the feed rate reduction is greater, and the feed rate reduction amplitude is larger. Therefore, the feed rate adjustment coefficient is inversely proportional to the hole error tolerance.

[0120] In an exemplary embodiment, the calculation formula of the feed speed adjustment coefficient is as follows:

[0121] ;

[0122] in, Indicates the feed speed adjustment coefficient, Indicates the drilling error tolerance.

[0123] Step S302: Obtaining a feed speed reduction amount according to the initial drilling feed speed and the feed speed adjustment coefficient.

[0124] In an exemplary embodiment, the minimum allowable drilling feed rate is incorporated into the calculation of the feed rate reduction to ensure the accuracy of the feed rate reduction. 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 is as follows:

[0125] ;

[0126] in, Indicates the initial drilling feed rate; Indicates the minimum allowable drilling feed rate.

[0127] Step S303: Obtaining a target feed speed according to the initial drilling feed speed and the feed speed reduction amount.

[0128] In an exemplary embodiment, the target feed rate is equal to the initial drilling feed rate Feed rate reduction The difference.

[0129] Step S400: adjusting the maximum tool retraction speed for drilling according to the drilling error tolerance and the drilling deviation degree to obtain the target tool retraction speed for the next drilling.

[0130] When the drilling deviation is greater, the accuracy of the drilling feed angle and the uniformity of the drilling at different positions are reduced. In this case, when retracting the tool, it is necessary to reduce the retraction speed to avoid secondary damage to the drill hole during the return process. Moreover, since the retraction speed is uniformly accelerated and then uniformly decelerated after reaching the maximum speed point, it is only necessary to adjust the maximum retraction speed of the drilling tool.

[0131] In an exemplary embodiment, Figure 9 As shown, a process for obtaining the target retraction speed is given as follows:

[0132] Step S401: Obtaining a tool retraction speed adjustment coefficient according to the drilling error tolerance and the drilling deviation degree.

[0133] The retraction speed adjustment coefficient is used to adjust the maximum retraction speed of the drill. A larger retraction speed adjustment coefficient results in a greater adjusted retraction speed, meaning the reduction in retraction speed is smaller. Consequently, when the drilling deviation is greater, the reduction in retraction speed is greater, and the retraction speed adjustment coefficient should be smaller. The retraction speed adjustment coefficient is inversely proportional to the drilling deviation. When the drilling error tolerance is smaller, the reduction in retraction speed is greater, and the retraction speed adjustment coefficient should be smaller. The retraction speed adjustment coefficient is directly proportional to the drilling error tolerance.

[0134] In an exemplary embodiment, the calculation formula of the tool retraction speed adjustment coefficient is as follows:

[0135] ;

[0136] in, Indicates the retraction speed adjustment coefficient.

[0137] Step S402: Obtaining a target retraction speed according to the maximum retraction speed of drilling and a retraction speed adjustment coefficient.

[0138] In an exemplary embodiment, the product of the maximum drilling retraction speed and the retraction speed adjustment coefficient is used as the target retraction speed for the next drilling, wherein the maximum drilling retraction speed is a preset maximum drilling retraction speed.

[0139] The above process yields the target feed rate and target retract speed for the next hole. These are then fed to the drill control system, which then feeds the drill according to the target feed rate and retracts it according to the target retract speed during the next hole, achieving speed control for both the feed and retract strokes.

[0140] It should be understood that the drilling control method provided by the present invention can also be an adaptive control process, which continuously obtains and controls the latest drilling feed speed and retract speed, dynamically optimizes the drilling strategy, and realizes the smooth drilling of the circuit board. It can improve the drilling accuracy and ensure the drilling quality, thereby avoiding affecting the performance of the circuit board. Moreover, the drilling control method provided by the present invention also has the following advantages: reducing the surface protrusions of the circuit board and the roughness of the hole wall, improving the finish and dimensional accuracy, and reducing the risk of internal stress concentration; avoiding circuit short circuits or unstable signal transmission caused by drilling deviations, and ensuring electromagnetic shielding effectiveness and conductive performance; the dynamic control mechanism can adapt to the unevenness of different circuit board materials, the wear state of the drill bit and complex circuit layout (such as high-density design), and expand the scope of application of mechanical drilling; supporting flexible switching between high-precision scenarios (such as micro-hole processing) and low-cost scenarios; by reducing the physical contact force under abnormal working conditions (such as the impact caused by high-speed feed), the wear of the drill bit and the spindle is reduced, and the service life of the equipment is extended; the error accumulation compensation mechanism delays the deterioration of the positioning mechanism accuracy; combining historical data with real-time feedback to achieve self-learning optimization of process parameters and reduce reliance on manual parameter adjustment; under the premise of ensuring quality, through the idle stroke section ( Figure 1 The AC segment in the process runs at the fastest speed, shortening the overall processing time.

[0141] This embodiment also provides a drilling control system suitable for circuit boards, 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 above-mentioned drilling control method embodiment suitable for circuit boards when the program instructions are executed.

[0142] In an exemplary embodiment, the present invention provides a drilling control device suitable for a circuit board, comprising: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the above-mentioned drilling control method embodiment suitable for a circuit board.

[0143] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0144] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A drilling control method suitable for circuit boards, characterized in that: include: A distance feature is obtained from the distance between the position of the next drill hole after 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 for the next drilling hole; Adjusting the initial drilling feed rate based on the drilling error tolerance and the drilling prominence to obtain a target feed rate for the next drilling; the drilling prominence is used to characterize the overall prominence of multiple historical drillings, the multiple historical drillings being obtained by drilling the same type of circuit board multiple times; 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 deviation of the multiple historical drilling holes.

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 consecutive historical drillings on the same type of circuit board to obtain historical images of the drilling area of each historical drilling; the historical images of the drilling area include images obtained from at least one shooting angle of the historical drilling; The drilling bulge height in the historical image of the drilling area is obtained based on the relationship between the shadow caused by the historical drilling bulge and the bulge height in the historical image of the drilling area.

3. A drilling control method for a circuit board 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 historical images of the drilling area to obtain 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 and the historical drilling diameter of the historical drilling, 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 boreholes corresponding to historical images of all drilling areas; The drilling deviation degree is obtained according to the drilling cumulative deviation, drilling deviation standard deviation and standard drilling deviation angle; the drilling deviation degree is proportional to the drilling cumulative deviation, 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 linear fitting on the drilling deviation angles of historical drillings corresponding to all historical images of the drilling area in the 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 for a circuit board as claimed in claim 1, characterized in that: The target feed speed acquisition process includes: A feed speed adjustment coefficient is obtained according to the drilling error tolerance and the drilling protrusion, 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 for a circuit board as claimed in claim 1, characterized in that: The process of obtaining the target retraction 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 retract speed is obtained according to the maximum retract speed of drilling and the retract speed adjustment coefficient.

8. A drilling control method for a circuit board 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 the average target distance, wherein the shortest target distance is the average distance of the shortest distances corresponding to each direction; An 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 circuit boards, comprising: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is configured to implement the drilling control method applicable to a circuit board according to 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: The invention comprises a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the drilling control method applicable to a circuit board according to any one of claims 1 to 8.

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