Circuit board back drill stub control method, device and equipment and medium

Abstract

The invention relates to the technical field of circuit board processing, and discloses a circuit board back drilling stub control method, device and equipment and a medium, and the circuit board back drilling stub control method comprises the steps: carrying out the board thickness measurement of a circuit board, obtaining the original board thickness data, carrying out the difference analysis, and carrying out the piling and measurement processing according to the analysis result; obtaining a plate thickness data set corresponding to each pile; measuring and analyzing the target back drilling hole position to obtain grouped plate thickness data, calculating the influence degree of the plate thickness on the length of the back drilling stub, comparing the influence degree with a preset threshold value, and judging a back drilling depth adjusting scheme; and according to a judgment result, back drilling processing depth parameters of the whole or the partitions are calculated, and differentiated depth optimization control is achieved. According to the method, the stub range can be effectively reduced in multi-batch and high-layer PCB machining, the back drilling depth control precision is improved, and it is ensured that the stub length is stable and meets the high-specification signal integrity requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board processing, and in particular to a circuit board back-drilling residual stub control method, device, equipment and medium. BACKGROUND

[0002] High-speed circuit boards have high requirements for signal integrity, and in the design of transmission links, performance indicators such as transmission loss and impedance matching need to be met. For high multi-layer high-speed circuit boards, the via connecting the inner and outer layers not only needs to consider the conduction function, but also needs to consider the signal transmission performance. Back-drilling technology can reduce the redundant conduction section of the via connecting the inner and outer layers, thereby reducing transmission loss and improving impedance matching, and is widely used in the design and manufacture of high-speed printed circuit boards (PCBs). Back-drilling refers to, after the completion of hole plating, removing the residual conduction part in the via that has no function by means of secondary drilling, using the depth control function of the drilling machine, to reduce the length of the residual stub and the parasitic capacitance effect it causes, thereby improving the transmission characteristics of high-speed signals. The length of the via residual stub is directly related to impedance matching and transmission loss. The longer the residual stub length, the smaller the via impedance, the greater the deviation from the designed impedance value, and the greater the insertion loss. Under the transmission requirement of 25Gbps, the industry generally believes that a residual stub length of 0-0.30mm can meet the signal integrity requirements; while in high-speed data center products such as 112Gbps PAM4, the residual stub length requirement has become as strict as 0-0.20mm or even 0-0.15mm.

[0003] As the requirement for residual stub length continues to tighten, PCB manufacturers urgently need to improve the precision and consistency of back-drilling technology. However, the existing technology generally uses a unified set of back-drilling depth values to perform processing. When there is a difference in board thickness in high multi-layer boards, the difference in board thickness will directly affect the back-drilling residual stub, resulting in significant differences in the length of the residual stub at different positions in the same board, affecting impedance control and signal transmission performance. This contradiction is particularly prominent in products with a large number of layers and large differences in board thickness. The existing process lacks a mechanism for differentiating control based on the specific board thickness of the back-drilling position, limiting the precise control of the length of the residual stub. SUMMARY

[0004] Therefore, the embodiments of the present application provide a circuit board back-drilling residual stub control method, device, equipment and medium, which can effectively solve the problem that the existing back-drilling process leads to large differences in the length of the residual stub at different positions in the same circuit board under the condition of uneven board thickness in high multi-layer boards, and is difficult to stably meet the strict control requirements of the length of the residual stub.

[0005] In a first aspect, the embodiments of the present application provide a circuit board back-drilling residual stub control method, comprising: measuring the board thickness of the circuit board to obtain original board thickness data; The original board thickness data is used to perform a difference analysis on the circuit board, and the circuit board is then sorted and measured based on the analysis results to obtain a set of board thickness data for each stack. Based on the aforementioned plate thickness data set, the target back-drilled hole positions are measured and analyzed to obtain grouped plate thickness data; Based on the grouped plate thickness data, the degree of influence of plate thickness on the length of back-drilled residual pile is determined, and compared with a preset threshold to obtain the judgment result of the back-drilling depth adjustment scheme; Based on the determination results, the back drilling depth parameters are determined; Based on the back-drilling depth parameters, the circuit boards of the corresponding stacks are back-drilled to control the length of the back-drilling residual pile.

[0006] In some embodiments, the step of measuring the board thickness of the circuit board to obtain raw board thickness data includes: The circuit board is aligned based on the target back-drill hole coordinates and alignment target information. Non-contact laser measurement is performed on the circuit board that has been aligned, and the reflected signal is obtained at a position with a preset offset relative to the target back-drilled hole position. Based on the reflected signal, the plate thickness value of the target back-drilled hole position is obtained; The plate thickness value is matched with the corresponding target back drill hole coordinates to generate the original plate thickness data.

[0007] In some embodiments, the step of performing difference analysis on the circuit board based on the original board thickness data, and performing stacking and measurement processing on the circuit board based on the analysis results to obtain a set of board thickness data corresponding to each stack includes: The thickness values ​​at several measurement points of each circuit board are analyzed to obtain the average thickness of each circuit board. Calculate the average plate thickness range based on the average plate thickness; The average board thickness range is compared with a preset stacking threshold, and the circuit boards are stacked according to the comparison result. Point-to-point board thickness measurement is performed on any circuit board in each stack to generate a set of board thickness data corresponding to each stack.

[0008] In some embodiments, the step of measuring and analyzing the target back-drilled hole positions based on the plate thickness data set to obtain grouped plate thickness data includes: Based on the plate thickness data set, the plate thickness value of the target back drill hole position is extracted to form the plate thickness dataset of the target back drill hole position. The target back-drill hole position plate thickness dataset is classified according to the back-drilling parameters to obtain a hole position group set; For each group in the hole location grouping set, extract the corresponding plate thickness value sequence and calculate the plate thickness characteristic parameters of the group; The back-drilling parameters and corresponding plate thickness characteristic parameters of each group are associated to generate grouped plate thickness data.

[0009] In some embodiments, determining the degree of influence of the plate thickness on the length of the back-drilled residual pile based on the grouped plate thickness data, and comparing it with a preset threshold to obtain the determination result of the back-drilling depth adjustment scheme, includes: Extract the maximum thickness value, minimum thickness value, and thickness range of each group from the thickness characteristic parameters of the group; obtain the theoretical back-drilling depth and theoretical thickness of the corresponding group; The influence value of the residual pile length of the group is calculated based on the plate thickness range, the theoretical back drilling depth, and the theoretical plate thickness. Based on the influence value of the residual pile length and the preset threshold, a determination result for the back drilling depth adjustment scheme is generated.

[0010] In some embodiments, determining the back-drilling depth parameter based on the determination result includes: When the determination result is an overall adjustment scheme, extract the plate thickness characteristic parameters of all target back drill holes from the group plate thickness data of the corresponding group, calculate the overall average plate thickness, and combine the theoretical plate thickness and theoretical back drill depth to calculate the overall back drill processing depth parameters. When the determination result is an interval adjustment scheme, the position interval is divided according to the range of the maximum and minimum plate thickness values ​​in the corresponding group plate thickness data. The plate thickness characteristic parameters of each position interval are statistically analyzed, the average plate thickness of each position interval is calculated, and the back drilling processing depth parameters of each position interval are calculated in combination with the theoretical plate thickness and the theoretical back drilling depth.

[0011] In some embodiments, the step of back-drilling the circuit board in the corresponding stack based on the back-drilling depth parameters to control the back-drilling residual pile length includes: Obtain the back-drilling depth parameters, theoretical plate thickness, and theoretical back-drilling depth values ​​corresponding to the target back-drilling hole position; The back-drilling depth parameter is converted into a ratio with the theoretical plate thickness, and the ratio is multiplied by the theoretical back-drilling depth value to generate the corresponding back-drilling depth data. Based on the back-drilling depth data, the back-drilling equipment is controlled to perform back-drilling on the circuit board in the corresponding stack.

[0012] Secondly, embodiments of this application provide a circuit board back-drilling residual pile control device, comprising: The board thickness measurement module is used to measure the board thickness of the circuit board and obtain the raw board thickness data; The difference analysis module is used to perform difference analysis on the circuit board based on the original board thickness data, and to perform stacking and measurement processing on the circuit board based on the analysis results to obtain the board thickness data set corresponding to each stack. The hole position measurement module is used to measure and analyze the target back drill hole positions based on the plate thickness data set to obtain grouped plate thickness data; The comparison module is used to determine the degree of influence of the plate thickness on the length of the back drill residual pile based on the grouped plate thickness data, and compare it with a preset threshold to obtain the judgment result of the back drill depth adjustment scheme. The plate thickness acquisition module is used to determine the back drilling depth parameters based on the judgment result. The control module is used to perform back-drilling on the circuit board of the corresponding stack based on the back-drilling depth parameters, so as to control the length of the back-drilling residual pile.

[0013] Thirdly, embodiments of this application provide a back-drilling device, which includes a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the circuit board back-drilling residual pile control method of the first aspect described above.

[0014] Fourthly, embodiments of this application provide a computer-readable storage medium, wherein when the computer program is executed on a processor, it implements the circuit board back-drilling residual pile control method described in the first aspect.

[0015] The embodiments of this application have the following beneficial effects: By performing board thickness measurement on the circuit board to obtain the original board thickness data, and based on this, difference analysis is performed to achieve stacking according to board thickness differences and to construct the board thickness data set corresponding to each stack, eliminating the control deviation of residual posts caused by uneven board thickness between different circuit boards; based on the stacking, the target back-drilling hole positions are further refined for measurement and analysis to generate grouped board thickness data, and the influence of board thickness on the length of back-drilling residual posts is calculated, and the depth adjustment scheme is automatically determined in combination with the preset threshold; the back-drilling processing depth parameters are accurately calculated according to different schemes to achieve differentiated depth optimization for the whole or in sections, so that the length of back-drilling residual posts remains stable and consistent throughout the entire board. This method can significantly reduce the residual post range caused by uneven board thickness in the back-drilling processing of multilayer boards, ensure that the residual post length meets the stringent high-speed signal integrity requirements, and improve production consistency and yield. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart of a circuit board back-drilling residual pile control method according to an embodiment of this application is shown; Figure 2 Another flowchart of the circuit board back-drilling residual pile control method according to an embodiment of this application is shown; Figure 3 A schematic diagram of non-contact laser measurement is shown in the circuit board back-drilling residual pile control method of this application embodiment; Figure 4 This paper illustrates a schematic diagram of data with and without position intervals in the circuit board back-drilling residual pile control method according to an embodiment of this application. Figure 5 A schematic diagram of a circuit board back-drilling residual pile control method according to an embodiment of this application is shown.

[0018] Explanation of key component symbols: 10 - Plate thickness measuring instrument; 20 - Circuit board; 30 - Laser; 40 - Controller Detailed Implementation The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0019] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0021] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0022] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] Considering the problems of existing back-drilling processes leading to significant differences in the length of back-drilled studs at different locations within the same circuit board due to uneven thickness in multilayer boards, and the difficulty in consistently meeting stringent stud length control requirements, a circuit board back-drilling stud control method is proposed. By performing precise thickness measurement and difference analysis on the circuit board, combined with thickness stacking measurement processing and inter-section depth optimization, differentiated control of back-drilling processing depth is achieved, thereby effectively reducing the stud length difference and ensuring the integrity of high-speed signal transmission.

[0024] The following describes the method for controlling residual piles in the back drilling of the circuit board using some specific embodiments.

[0025] Figure 1 A flowchart illustrating a circuit board back-drilled residual stake control method according to an embodiment of this application is shown. Exemplarily, the circuit board back-drilled residual stake control method includes the following steps: Step S100: Measure the thickness of the circuit board to obtain the original thickness data.

[0026] Among them, board thickness measurement refers to using non-contact laser measurement equipment to perform board thickness detection on the selected target back-drilled hole position on the circuit board in order to obtain the thickness information corresponding to the hole position.

[0027] As an example, a plate thickness measuring instrument is used as the measuring device, and the coordinates of the target back-drilled hole and the alignment target information (common targets are alignment through holes) are imported into its control program. This allows the measuring system to first accurately align the coordinate data with the plate surface, and then automatically perform the plate thickness measurement operation to obtain the plate thickness value corresponding to the specific hole position. It is worth noting that the plate thickness measured in this embodiment is a coarse measurement, and several back-drilled points can be evenly distributed on the plate surface for measurement.

[0028] In an optional embodiment, step S100 includes the following sub-steps: S101, the circuit board is aligned based on the target back drill hole position coordinates and alignment target information.

[0029] Among them, alignment processing refers to using the visual recognition and position calibration functions of measuring equipment to ensure that the actual physical position of the circuit board is consistent with the coordinate frame of the target back drill hole.

[0030] As an example, hole position coordinates and target data can be imported into the control program of the plate thickness measuring instrument, and the target position on the plate surface (the common target is the alignment through hole) can be located using optical or laser recognition. The control system can then adjust the position of the measuring platform or optical system to achieve precise alignment between the plate surface coordinates and the equipment coordinates.

[0031] S102 performs non-contact laser measurement on the aligned circuit board and acquires the reflected signal at a position with a preset offset relative to the target back-drilled hole position.

[0032] Non-contact laser measurement refers to illuminating the surface area of ​​the target back-drilled hole with a laser beam and determining the measurement distance based on the phase, time difference, or interference characteristics of the reflected light signal. Since the target back-drilled hole is a through-hole structure, it is impossible to measure the plate thickness directly above it. Therefore, the laser measurement point is set at a preset offset relative to the center of the target back-drilled hole to ensure the acquisition of an effective reflected signal and accurate reflection of the plate thickness information of the hole area. In this embodiment, the preset offset is 1~5mm, preferably 3mm. This offset avoids the through-hole area and ensures that the measurement position is consistent with the actual plate thickness of the target back-drilled hole, thereby improving the accuracy of back-drilling depth control.

[0033] Demonstratively, a broadband light source emitting colored laser light is used, which is detected by lasers located above and below the board surface. During the measurement process, the board surface is suspended on the platform to avoid contact affecting measurement accuracy. The controller analyzes the collected reflected signals to obtain the raw data of the board thickness at the corresponding location.

[0034] S103, based on the reflected signal, obtain the plate thickness value of the target back-drilled hole position.

[0035] The plate thickness value refers to the material thickness value at that location, calculated by comparing the measurement distance difference between the upper and lower surfaces of the target back-drilled hole area.

[0036] As an example, the distance from the laser to the upper and lower surfaces of the plate is calculated based on the reflected signal, and the difference between the two is taken as the plate thickness of the hole position. During the measurement process, the equipment completes the thickness calculation one by one according to the target back-drilled hole position coordinates, and stores the results in the plate thickness recording unit corresponding to the hole position coordinates, forming a structured plate thickness data set.

[0037] S104: Match the plate thickness value with the corresponding target back drill hole coordinates to generate the original plate thickness data.

[0038] The original plate thickness data refers to the data set consisting of the target back drill hole coordinates and their corresponding plate thickness values.

[0039] As an example, the obtained target back-drilled hole plate thickness values ​​are stored in a data structure according to the hole position coordinates to form the original plate thickness dataset, which is used for subsequent stacking processing.

[0040] For example, such as Figure 2 As shown, the thickness is measured by a plate thickness measuring instrument 10. After importing data such as the coordinates of the back drill hole and the alignment target into the control program of the plate thickness measuring instrument 10, the plate thickness measuring instrument 10 can automatically measure the plate thickness by aligning the coordinate data with the plate surface using the alignment target. The measured plate thickness corresponds one-to-one with the back drill hole position, and the specific plate thickness data at the specific position can be recorded for subsequent optimization and adjustment of the back drill depth. The plate thickness measuring instrument obtains the plate thickness value at the specific position by emitting broadband light from a colored laser light source and processing the reflection of the light from the plate surface. The measurement method is that the plate surface of the circuit board 20 is suspended on the table, and lasers 30 are installed above and below the plate surface for detection. The controller 40 processes the plate thickness data through the reflected signal.

[0041] Step S200: Perform difference analysis on the circuit board based on the original board thickness data, and perform stacking and measurement processing on the circuit board based on the analysis results to obtain the board thickness data set corresponding to each stack.

[0042] The "grouping" process refers to grouping multiple circuit boards within the same production batch based on their thickness differences to reduce deviations in back-drilling residual stud length caused by thickness variations between different circuit boards. Thickness variation analysis involves measuring the thickness of all circuit boards in the batch at several points on the board surface using a thickness measuring instrument for comparison. All measurement points in the batch must be consistent to ensure data comparability.

[0043] For example, circuit boards laminated within the same production batch may have variations in thickness. If the same back-drilling depth control program is used directly for processing, it can lead to significant deviations in the length of the back-drilled studs between different boards within the batch. In severe cases, this could even drill through signal layer circuitry, causing an open circuit and resulting in circuit board product failure. For example... Figure 3 As shown, this embodiment obtains an independent set of board thickness data corresponding to each stack by sorting and measuring the circuit boards in the same batch according to their thickness. This reduces the difference in residual pile length between boards and improves the control accuracy of residual pile length.

[0044] In an optional embodiment, step S200 includes the following sub-steps: S201, analyze the thickness values ​​of several measurement points on each circuit board to obtain the average thickness of each circuit board.

[0045] The average board thickness refers to the average value obtained by summing the thickness values ​​of several measurement points on the same circuit board and dividing it by the number of measurement points. It is used to characterize the overall thickness level of the circuit board.

[0046] As an example, the thickness values ​​of all measurement points of the same numbered circuit board are selected from the original board thickness data, and the total thickness is obtained by performing an addition and accumulation operation. Then, the average board thickness of the circuit board is obtained by dividing by the total number of measurement points of the circuit board.

[0047] S202, calculate the average plate thickness range based on all average plate thicknesses.

[0048] The average board thickness range refers to the difference between the maximum and minimum values ​​of the average board thickness of all circuit boards, and is used to measure the range of thickness differences between different circuit boards.

[0049] As an example, the average board thickness values ​​of each circuit board are sorted according to their numerical values, and the average board thickness with the largest value and the average board thickness with the smallest value are selected and subtracted to obtain the average board thickness range; this range is used as a differential indicator to determine whether stacking is required.

[0050] S203, compare the average board thickness range with the preset stacking threshold, and stack the circuit boards according to the comparison result. Perform point-to-point board thickness measurement on any circuit board in each stack interval to generate the board thickness data set corresponding to each stack.

[0051] Among them, the stacking threshold refers to the critical value used to determine whether circuit boards need to be grouped according to thickness characteristics; interval division refers to the process of assigning samples to different thickness intervals based on the numerical range of the average board thickness. The stacking interval can be determined according to the product's residual length requirements. For example, when the residual length requirement is 0~0.2mm, it means that the standard is relatively strict, so the width of the stacking interval needs to be reduced to improve the consistency of residual length.

[0052] As an example, the calculated average board thickness range is compared with a preset stacking threshold. If the range is greater than the stacking threshold, the board thickness is divided into multiple intervals based on the distribution range of the average board thickness, using either an equidistant or adaptive method. The average board thickness value of each board is sequentially traversed and assigned to its corresponding interval. Then, point-to-point board thickness measurements are performed on any board belonging to each stack interval, and the measurements are summarized to obtain the board thickness data set corresponding to each stack. For example, when there are four stacks (A, B, C, and D), a board is extracted from A for point-to-point measurement to form the board thickness data set for stack A. A board is extracted from B for point-to-point measurement to form the board thickness data set for stack B.

[0053] Step S300: Based on the plate thickness data set, measure and analyze the target back-drilled hole positions to obtain grouped plate thickness data.

[0054] The board thickness dataset refers to the dataset generated after the circuit boards are stacked, by performing point-to-point thickness measurements on any board in each stack. This dataset contains the measurement coordinates and board thickness values ​​for each target back-drilling hole. The purpose of this step is to use the board thickness dataset, combined with back-drilling process parameters, to perform refined grouping analysis of the hole positions, providing fundamental data support for subsequent back-drilling depth adjustments.

[0055] As an example, the plate thickness value of each target back-drilled hole position is extracted from the plate thickness dataset to form a target back-drilled hole position plate thickness dataset. Then, the target back-drilled hole position plate thickness dataset is classified according to back-drilling parameters (including back-drilling diameter, theoretical back-drilling depth, etc.) to obtain a hole position group set. Next, for each group of the hole position group set, the plate thickness value sequence of all holes in the group is extracted, and plate thickness feature parameters including maximum plate thickness value, minimum plate thickness value, plate thickness range, and average plate thickness are calculated. Finally, the back-drilling parameters of each group are associated with the corresponding plate thickness feature parameters to generate grouped plate thickness data.

[0056] In an optional embodiment, step S300 includes the following sub-steps: S301, extract the plate thickness value of the target back drill hole position based on the plate thickness data set to form the plate thickness dataset of the target back drill hole position.

[0057] The target back-drill hole position plate thickness dataset refers to the data set obtained by extracting the plate thickness values ​​corresponding to each target back-drill hole position from the plate thickness data set and organizing them according to the hole position. This set only retains the plate thickness information related to back-drilling and removes the measurement point data that is not related to the hole position.

[0058] As an example, based on the target back drill hole position coordinate information, the plate thickness value at the corresponding position is retrieved from the plate thickness data set, and these values ​​are stored in the order of the hole position index to form the target back drill hole position plate thickness dataset.

[0059] S302, classify the target back-drill hole position plate thickness dataset according to the back-drill parameters to obtain the hole position group set.

[0060] Among them, back-drilling parameters refer to the key process indicators related to hole machining that are pre-set in the back-drilling process, including parameters such as back-drilling hole diameter and theoretical back-drilling depth; hole group set refers to the data set formed by dividing the target back-drilling holes into multiple groups according to different combinations of back-drilling parameters. The purpose of this step is to group target back-drilling holes with the same or similar machining conditions together to facilitate plate thickness characteristic analysis under the same conditions.

[0061] As an example, the holes in the target back-drilled hole position plate thickness dataset can be divided into several groups according to different combinations of back-drilled hole diameter and theoretical back-drilled depth. For example, holes with a diameter of X and a theoretical back-drilled depth of Y can be grouped into the same group, thereby obtaining a hole position group set.

[0062] S303, for each group in the hole location grouping set, extract the corresponding plate thickness value sequence and calculate the plate thickness characteristic parameters of the group.

[0063] Among them, the plate thickness characteristic parameters refer to statistical indicators used to describe the plate thickness distribution characteristics within the group, including the maximum plate thickness value, the minimum plate thickness value, the plate thickness range, and the average plate thickness. The purpose of this step is to quantify the plate thickness differences in each group, providing a basis for subsequent analysis of the impact of residual pile length.

[0064] As an example, the plate thickness values ​​of all holes can be read sequentially from each group to form a plate thickness value sequence; then, the maximum value, minimum value, range (difference between the maximum and minimum values) and average value of the sequence are calculated to obtain the plate thickness characteristic parameters of the group, and these parameters are stored in the group record.

[0065] S304 associates the back drilling parameters of each group with the corresponding plate thickness characteristic parameters to generate grouped plate thickness data.

[0066] Among them, the grouped plate thickness data refers to the comprehensive data set after the back drilling parameters and plate thickness characteristic parameters are matched one-to-one according to groups and stored. This data reflects the process conditions and plate thickness characteristics of each group. The purpose of this step is to determine the degree of influence of plate thickness differences on the length of the back drilling residual pile in subsequent steps.

[0067] As an example, a data structure is established for each group, and its back-drilling parameters, such as back-drilling diameter and theoretical back-drilling depth, are bound and stored with the calculated plate thickness characteristic parameters to finally generate the group plate thickness data.

[0068] Step S400: Based on the grouped plate thickness data, determine the degree of influence of plate thickness on the length of the back-drilled residual pile, and compare it with the preset threshold to obtain the judgment result of the back-drilling depth adjustment scheme.

[0069] Among them, the grouped plate thickness data refers to the statistical results obtained for each group after classifying the plate thickness values ​​of the target back drill hole position according to the back drill parameters (including back drill hole diameter and theoretical back drill depth); the degree of influence refers to the quantitative measurement of the deviation of the back drill residual pile length caused by the plate thickness difference within the group; the preset threshold refers to the judgment threshold set according to the product's control requirements for residual pile length (the threshold is smaller when the residual pile length requirement is 0~0.2mm).

[0070] As an example, the statistical results of each group in the grouped plate thickness data are read, and the impact value of the residual pile length of the group is calculated by using the plate thickness difference within the group and the theoretical back drilling depth and theoretical plate thickness of the group. The impact value is compared with a preset threshold. If it exceeds the threshold, it is determined to trigger the back drilling depth adjustment scheme of the sub-location interval; if it does not exceed the threshold, it is determined to be the overall back drilling depth adjustment scheme.

[0071] In an optional embodiment, step S400 includes the following sub-steps: S401, extract the maximum thickness value, minimum thickness value and thickness range of each group from the thickness characteristic parameters of the group.

[0072] Among them, the plate thickness characteristic parameter refers to the statistical index used to describe the plate thickness distribution within the group, including at least the maximum plate thickness value, the minimum plate thickness value, and the plate thickness range formed by the difference between the two.

[0073] As an example, the plate thickness value sequence within each group is sorted and scanned to extract the plate thickness value with the largest value and the plate thickness value with the smallest value, and the difference between the two is calculated as the plate thickness range of the group. The above three characteristic parameters are then associated with the group to facilitate the subsequent calculation of the influence value of the residual pile length.

[0074] S402, obtain the theoretical back-drilling depth and theoretical plate thickness of the corresponding group.

[0075] The theoretical back-drilling depth refers to the target back-drilling depth calculated based on the circuit board stack-up structure design; the theoretical board thickness refers to the design board thickness set according to the circuit board structure. Both are preset process parameters.

[0076] For example, for each group, the theoretical back-drilling depth corresponding to the group is determined according to its back-drilling parameters, and the theoretical plate thickness is read from the product structure design data. The two are matched with the plate thickness characteristic parameters obtained in step S401 to form the parameter combination required to calculate the influence value of the residual pile length.

[0077] S403, calculate the influence value of residual pile length for grouping based on plate thickness range, theoretical back drilling depth and theoretical plate thickness.

[0078] Among them, the influence value of residual pile length is used to quantitatively characterize the influence intensity of plate thickness difference within the group on the deviation of back-drilled residual pile length. Its calculation is based on the combined relationship between plate thickness range and process theoretical parameters; let the plate thickness range be (maximum plate thickness value - minimum plate thickness value), the theoretical back-drilling depth be Z0, and the theoretical plate thickness be H0, then the influence value can be expressed as: S = (Maximum plate thickness - Minimum plate thickness) × Z0 / H0 For example, for each group, the plate thickness range obtained in step S401 and the theoretical back drilling depth and theoretical plate thickness obtained in step S402 are called, and the residual pile length influence value S of the group is calculated by substituting it into the above expression, and S is recorded together with the group.

[0079] S404, based on the influence value of the residual pile length and the preset threshold, generate the judgment result of the back drilling depth adjustment scheme.

[0080] The determination result indicates the execution method of subsequent depth adjustment, including at least two types: overall back drilling depth adjustment scheme and position interval back drilling depth adjustment scheme; the preset threshold is the same as step S400, used to distinguish whether differentiated adjustment by position interval is required.

[0081] For example, the residual pile length influence value S obtained in step S403 is compared with a preset threshold for each group. When S is greater than the threshold, the judgment result of "back drilling depth adjustment scheme for different locations" is output; when S is less than or equal to the threshold, the judgment result of "overall back drilling depth adjustment scheme" is output.

[0082] Step S500: Determine the back drilling depth parameters based on the judgment result.

[0083] The determination result refers to the back drilling depth adjustment method obtained by comparing the plate thickness difference and preset thresholds through the previous steps. It includes at least two types: the overall back drilling depth adjustment scheme and the back drilling depth adjustment scheme for different positions and intervals. The back drilling processing depth parameter is used to guide the back drilling equipment to perform the corresponding processing action. It is the target processing depth calculated by combining the grouped plate thickness data and the process theory parameters.

[0084] As an example, when the determination result is an overall adjustment plan, the back drilling depth parameters of the entire group are calculated uniformly; when the determination result is a position interval adjustment plan, the back drilling depth parameters of each position interval are calculated separately.

[0085] In an optional embodiment, step S500 includes the following sub-steps: S501, when the determination result is the overall adjustment scheme, extract the plate thickness characteristic parameters of all target back drill holes from the group plate thickness data of the corresponding group, calculate the overall average plate thickness, and combine the theoretical plate thickness and theoretical back drill depth to calculate the overall back drill processing depth parameters.

[0086] Among them, the overall average plate thickness refers to the average value obtained after statistically analyzing the plate thickness values ​​of all target back-drilled holes within the same group, which is used to reflect the overall plate thickness level of the group; the theoretical plate thickness and the theoretical back-drilling depth are both preset process parameters, representing the design plate thickness and the design back-drilling depth, respectively.

[0087] As an example, the plate thickness values ​​of all target back-drilled holes are read from the target group, and the overall average plate thickness H_avg is calculated. The ratio of H_avg to the theoretical plate thickness H0 is directly multiplied by the theoretical back-drilling depth Z0 to obtain the overall back-drilling depth parameter Z=(H_avg / H0)×Z0. The above parameters need to be calculated independently for holes with different back-drilling diameters and different theoretical back-drilling depths.

[0088] S502, when the determination result is a segmented adjustment scheme, the position interval is divided according to the range of the maximum and minimum plate thickness values ​​in the corresponding group plate thickness data, the plate thickness characteristic parameters of each position interval are statistically analyzed, the average plate thickness of each position interval is calculated, and the back drilling processing depth parameters of each position interval are calculated in combination with the theoretical plate thickness and the theoretical back drilling depth.

[0089] Among them, the position interval refers to the plate thickness interval division within the group based on the difference between the maximum and minimum plate thickness values, which is used to achieve differentiated back drilling depth control in different thickness areas; the average plate thickness of the interval is the average value of the plate thickness values ​​of all hole positions within the position interval.

[0090] In one alternative approach, the division of the location interval is also related to the residual pile deviation value S calculated in the previous step: When S≤2×a specific value (for example, if the specific value is 0.05mm, then S≤0.1mm), the plate thickness is divided into two position intervals; When 2 × specific value < S ≤ 3 × specific value (e.g., 0.1 mm < S ≤ 0.15 mm), the plate thickness is divided into three position intervals; Other cases can be deduced similarly from this rule. To ensure traceability of subsequent processing, the location interval record should include fields such as location coordinates, back drill diameter, and back drill depth. For back drill holes with different back drill diameters and different theoretical back drill depths, interval division and depth calculation should be performed independently for each.

[0091] For example, the maximum plate thickness value H1 and the minimum plate thickness value H2 of the group are obtained. When the group is divided into two position intervals, the interval range can be set as [H2,H2+(H1-H2) / 2] and [H2+(H1-H2) / 2,H1]; When the location is divided into three intervals, the interval ranges can be set as [H2, H2 + (H1 - H2) / 3], [H2 + (H1 - H2) / 3, H2 + (H1 - H2) × 2 / 3], and [H2 + (H1 - H2) × 2 / 3, H1]. Then, the ratio of the average plate thickness H_i_avg to the theoretical plate thickness H0 for each interval is directly multiplied by the theoretical back-drilling depth Z0 to obtain the back-drilling depth parameter Z_i = (H_i_avg / H0) × Z0 for that interval. The interval range and the corresponding parameter are then archived together.

[0092] Step S600: Based on the back-drilling depth parameters, back-drilling is performed on the circuit boards of the corresponding stack to control the length of the back-drilling residual pile.

[0093] Among them, the back-drilling depth parameter is the target processing depth calculated by combining the plate thickness measurement data, theoretical plate thickness value and theoretical back-drilling depth value from the previous steps. It is used to guide the back-drilling equipment to accurately remove excess conductive material other than the conductive section in the hole, thereby ensuring that the length of the residual pile after back-drilling is within the process requirements. The length of the residual pile after back-drilling refers to the height of the conductive copper column remaining at the bottom of the hole after back-drilling. If it is too long or too short, it will affect the electrical performance and reliability.

[0094] In a demonstrative manner, the back-drilling depth parameters for each target hole are first loaded as input data into the processing control system before processing. Then, combined with the clamping and positioning information of the circuit board, the back-drilling equipment is driven to perform depth-controlled removal processing at the corresponding hole. Understandably, the back-drilling depth parameters are used to process all circuit boards within a single stack after grouping; however, for the back-drilling depth parameters of circuit boards in other stacks, it is necessary to select one circuit board within its stack for precise thickness measurement to obtain the corresponding back-drilling depth parameters.

[0095] In an optional embodiment, step S600 includes the following sub-steps: S601, obtain the back-drilling depth parameters, theoretical plate thickness, and theoretical back-drilling depth of the corresponding target back-drilling hole position.

[0096] Among them, the theoretical board thickness is the total thickness of the circuit board determined in the design stage; the theoretical back drill depth is the depth to which the conductive section inside the through hole is removed according to the design requirements.

[0097] As an example, the average board thickness H_avg of the target hole position is extracted from the board thickness measurement results or interval statistics results, and then the theoretical board thickness H0 and theoretical back drilling depth Z0 of the corresponding batch of circuit boards are read from the process database and bound at the hole position coordinate level.

[0098] S602 converts the back-drilling depth parameter to the theoretical plate thickness by ratio, and multiplies the ratio by the theoretical back-drilling depth value to generate the corresponding back-drilling depth data.

[0099] The ratio reflects the relative difference between the measured or corrected plate thickness and the designed plate thickness. The back-drilling depth data is the final depth command value executed by the direct drive equipment.

[0100] As an example, the machining depth of the target hole is calculated using the formula Z=(H_avg / H0)×Z0, and this data is recorded according to the hole number.

[0101] S603 controls the back-drilling equipment to perform back-drilling on the corresponding circuit board based on the back-drilling depth data.

[0102] Among them, back drilling equipment includes CNC drilling and milling machines equipped with a depth control unit, which can automatically stop cutting according to the input depth data when performing drilling operations.

[0103] As an example, the back-drilling depth data is sent sequentially to the CNC unit of the equipment. The equipment positions itself according to the hole coordinates and performs drilling operations at the corresponding depths until all target holes are processed, thus achieving precise control over the length of the back-drilled pile.

[0104] In one exemplary embodiment, a production batch of an 18-layer high-speed circuit board is selected and executed sequentially according to the above-described S100 to S600 processes, as follows: The circuit board requiring back drilling is placed on the platform of the board thickness measuring instrument. After importing the back drilling hole coordinates and alignment target data into the instrument's control program, the instrument aligns the coordinate data with the board surface using the alignment target (commonly an alignment through-hole) and then automatically measures the board thickness. The instrument uses a colored laser light source to emit a broadband light, which is then reflected off the board surface to obtain the thickness value at a specific location. The measurement method involves the circuit board surface being suspended on the platform, with lasers probing above and below the board surface. The controller processes the thickness data through the reflected signals.

[0105] After acquiring specific board thickness data, the software process the production batch by stacking it according to thickness differences. Because the circuit boards laminated within the same production batch have thickness variations, if the thickness differences between different boards are significant, using the same back-drilling depth control program data will cause large deviations in the back-drilling residual stud lengths of different boards within the batch, potentially even drilling through signal layer circuits and causing open circuits, leading to circuit board product failure. This application performs interval stacking based on board thickness within the same batch, which can reduce the differences in back-drilling residual stud lengths caused by thickness differences between boards, thereby improving the control accuracy of residual stud lengths. The stacking is performed by measuring the board thickness at nine evenly distributed points on the surface of all circuit boards in the batch using a board thickness measuring instrument to confirm whether stacking is necessary. All measurement points for thickness measurement in this batch are consistent. The board thickness measuring instrument automatically selects the same nine points for thickness measurement after target grabbing and alignment of each board.

[0106] Next, the thickness data of each board is analyzed. Optionally, the average value of the measurement points for each board is calculated. The average value is then compared, and the maximum and minimum values ​​of the average thickness for each board are selected. The thickness stacking interval is then set according to the product's residual stud length requirement, which is 0~0.2mm. Therefore, the thickness stacking interval is set to 0.05mm. The board thickness measuring instrument includes a laser engraving function, which can distinguish the measured circuit boards by engraving their board numbers. The engraved numbers correspond one-to-one with the board thickness data numbers stored in the controller, facilitating board selection or data traceability during stacking. This batch consists of 10 boards. After each board is measured, the board thickness measuring instrument automatically laser-engraves numbers from 1 to 10, and these board numbers correspond one-to-one with the board numbers in the recorded thickness data.

[0107] Table 1 shows the thickness data of 9 identical sites on each of the 10 plates tested in this batch. The average thickness of the plate at the 9 sites on each plate was calculated. The maximum value H1 of the average thickness was extracted as 2.414 mm, the minimum value H2 as 2.363 mm, and the range as 0.053 mm. When the range is greater than the set plate thickness stacking interval of 0.05 mm, stacking is required. The stacking interval is divided into two intervals: minimum value H2 ~ H2 + (H1 - H2) / 2 and H2 + (H1 - H2) / 2 ~ H1. In this case, it is divided into two intervals: 2.363 mm ~ 2.389 mm and 2.389 mm ~ 2.414 mm. Different stacks are distinguished as A, B, C, etc. According to the stacking calculation results, plates numbered 1, 2, 6, 9, and 10 are stack A, and plates numbered 3, 4, 5, 7, and 8 are stack B.

[0108]

[0109] Table 1 After completing the board thickness stacking step, a fine-grained thickness measurement is performed within each stack to determine if further segmentation is needed. For circuit boards from the same batch but with different serial numbers that require stacking due to significant thickness differences, a fine-grained thickness measurement is then performed to further optimize the point-to-point back-drilling depth. This fine-grained thickness measurement involves point-to-point measurement of all target back-drilling holes distributed across the board surface. By importing and analyzing data such as target back-drilling hole coordinates, hole diameters, and theoretical back-drilling depths, an automated moving detection system is created to determine the board thickness at the target back-drilling hole positions. The board thickness measuring instrument performs target grabbing and alignment on the circuit board to achieve automated thickness measurement. The circuit board thickness measurement must distinguish between the front and back sides; similarly, the target back-drilling hole coordinates and other data must also be distinguished between the front and back sides.

[0110] One board was randomly selected from both pile A and pile B to represent the fine-grained thickness measurement within that pile. The measurement data of board number 1 in pile A is used for illustration.

[0111] This example uses an 18-layer board (as shown in Table 2). The outer layer traces L1 or L18 are connected to different inner layer traces L3, L5, L7, L12, L14, or L16. Therefore, the theoretical back-drilling depths are different, and the back-drilling hole diameters also vary; in this case, there are two sizes: 0.35mm and 0.4mm. When processing board thickness data, it is necessary to distinguish between the back-drilling hole diameter and the different theoretical back-drilling depths. The theoretical back-drilling depth Z0 is calculated based on the board's stack-up structure design and is related to that design.

[0112] This product requires a back-drilled residual pile length of 0~0.2mm. Based on the product structure, the theoretical plate thickness H0 is calculated to be 2.384mm, and the theoretical back-drilling depth is shown in Table 2.

[0113]

[0114] Table 2 Obtain the board thickness data of the circuit board with board number 1 in pile A. The processing program extracts the maximum, minimum and range of the board thickness data corresponding to the back drill hole position under each different theoretical back drill depth and each different back drill hole diameter. First, it determines whether it is necessary to divide the position interval. Specifically, it determines whether it is necessary to divide the position interval for back drill depth optimization by calculating the influence of the board thickness range corresponding to the back drill hole position under the same theoretical back drill depth and back drill hole diameter on the back drill residual pile length. When the same board thickness range has different influence on the back drill residual pile length at different theoretical back drill depths, for example, the influence on the back drill residual pile length is small when the back drill depth is shallow.

[0115] The degree of influence on the length of the back-drilled pile can be defined by the deviation value S of the pile length. Specifically, the deviation value S = (H1-H2)*Z0 / H0; where H1 is the maximum board thickness under a certain theoretical back-drilling depth and back-drilling hole diameter, H2 is the minimum board thickness under the same theoretical back-drilling depth and back-drilling hole diameter; Z0 is the theoretical back-drilling depth of a certain back-drilling hole, and H0 is the theoretical board thickness. The theoretical back-drilling depth Z0 and the theoretical board thickness H0 are preset values ​​given based on the circuit board structure. The influence of the board thickness on the length of the pile is calculated based on these values.

[0116] Based on the calculation results, an interval is set for the degree of influence. When the degree of influence exceeds a certain specific value, the program is triggered to perform a back-drilling depth optimization command for different location intervals. The certain specific value is determined according to the product's residual pile length requirement. In this case, when the residual pile length requirement is 0~0.2mm, this specific value for the degree of influence of the residual pile length is set to 0.05mm.

[0117] Taking the A-stack plate number as 1, the back drill entry face is the front face, the back drill hole diameter is 0.4mm, the number of back drill holes is 33, the theoretical back drill depth Z0 is 2.028mm, and the theoretical plate thickness H0 is 2.384mm. (Data set, e.g.)Figure 4 Taking the example shown below, the measured plate thickness data is as follows: Figure 4 As shown in the section "Before Dividing the Position Intervals". The maximum plate thickness H1 is 2.465mm, and the minimum plate thickness H2 is 2.36mm. The residual pile deviation value S = (2.465-2.36)*2.028 / 2.384 = 0.089mm. The calculated residual pile deviation value S does not exceed twice the above specific value (0.05mm), that is, 0.05mm < S ≤ 0.1mm, so it is necessary to divide the plate thickness into two position intervals. Taking the maximum plate thickness measurement value H1 2.465mm and the minimum plate thickness measurement value H2 2.360mm, the back-drilled hole positions are divided into two position intervals according to the plate thickness 2.360mm < H ≤ 2.413mm and 2.413mm < H ≤ 2.465mm. The divided intervals are as follows. Figure 4 As shown in the "Divided position interval" section.

[0118] After dividing the location intervals, the back-drilling depth of the corresponding intervals needs to be optimized. The optimization rule for back-drilling depth is as follows: take the board thickness data of all points in the divided location intervals, calculate their average value H_avg, and the optimized back-drilling depth value Z = H_avg / H0*Z0, where Z0 is the theoretical back-drilling depth of a certain back-drilling hole, and H0 is the theoretical board thickness. Both the theoretical back-drilling depth Z0 and the theoretical board thickness H0 are preset values ​​given based on the circuit board structure. Figure 4 As shown in "Hole Position Interval 1": H_avg is 2.36mm, and H_avg for hole position interval 2 is 2.431mm. Therefore, the optimized back drill depth value Z for hole position interval 1 is Z=2.36 / 2.384*2.028=2.007mm, and the optimized back drill depth value Z for hole position interval 2 is Z=2.431 / 2.384*2.028=2.068mm.

[0119] Taking a data set with plate number 1 in pile A, the back drill entry face being the front, a back drill diameter of 0.4mm, 36 back drill holes, a theoretical back drill depth Z0 of 0.805mm, and a theoretical plate thickness H0 of 2.384mm as an example, the maximum plate thickness H1 is 2.50mm, and the minimum plate thickness H2 is 2.391mm. The residual pile deviation value S = (2.5 - 2.391) * 0.805 / 2.384 = 0.037mm. If the calculated residual pile deviation value is less than a specific value (0.05mm), it indicates that no position interval optimization is needed; only back drill depth optimization is required. Figure 4 As shown.

[0120] The back-drilling depth optimization rule is to take the board thickness data of all positions under a certain theoretical back-drilling depth and back-drilling hole diameter, calculate its average value H_avg, and the optimized back-drilling depth value Z=H_avg / H0*Z0, where Z0 is the theoretical back-drilling depth of a certain back-drilling hole, H0 is the theoretical board thickness, and the theoretical back-drilling depth Z0 and theoretical board thickness H0 are both preset values ​​given according to the circuit board structure. Figure 4 The thickness data H_avg for all 72 back-drilled hole positions shown is 2.442mm. Therefore, the optimized back-drilling depth value Z = 2.442 / 2.384*0.805 = 0.825mm.

[0121] The optimized back-drilling process parameter file is output as the back-drilling machining program file for all boards in stack A, including back-drilling face number, positioning target, back-drilling hole diameter, and optimized back-drilling depth information. The back-drilling process parameter file is imported into the back-drilling equipment, and the process is run to manufacture the back-drill. After the back-drill is manufactured, a cross-sectional slice of the back-drill hole is taken to observe the length of the residual pile, checking if it falls within the required range of 0~0.20mm. Table 3 shows the effect data of controlling the residual pile length after optimizing the back-drilling depth. After optimization, the residual pile length meets the requirements.

[0122]

[0123] Table 3 It is understandable that the B-stack circuit board also needs to have one board extracted from the stack for precise point-to-point thickness measurement. After performing the same data analysis and processing steps as the A-stack, the optimized depth back-drilling process parameter file is obtained for the B-stack circuit board processing and manufacturing. This will not be elaborated further here.

[0124] Figure 5 A schematic diagram of a circuit board back-drilling residual pile control device according to an embodiment of this application is shown. Exemplarily, the control device 100 includes: The board thickness measurement module 110 is used to measure the board thickness of the circuit board and obtain the raw board thickness data; The difference analysis module 120 is used to perform difference analysis on the circuit board based on the original board thickness data, and to perform stacking and measurement processing on the circuit board based on the analysis results to obtain the board thickness data set corresponding to each stack. The hole position measurement module 130 is used to measure and analyze the target back drill hole position based on the plate thickness data set to obtain grouped plate thickness data. The comparison module 140 is used to determine the degree of influence of the plate thickness on the length of the back drill residual pile based on the grouped plate thickness data, and compare it with a preset threshold to obtain the judgment result of the back drill depth adjustment scheme. The plate thickness acquisition module 150 is used to determine the back drilling depth parameters based on the determination result; The control module 160 is used to perform back-drilling on the circuit board of the corresponding stack based on the back-drilling depth parameters, so as to control the length of the back-drilling residual pile.

[0125] It is understood that the apparatus of this embodiment corresponds to the method of the above embodiments, and the options in the above embodiments are also applicable to this embodiment, so they will not be described again here.

[0126] This application also provides a back-drilling device, exemplary of which includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program to enable the back-drilling device to perform the functions of the various modules in the above-described method or apparatus.

[0127] The processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, including at least one of a Central Processing Unit (CPU), Graphics Processing Unit (GPU), Network Processor (NP), Digital Signal Processor (DSP), Application-Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application.

[0128] The memory can be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. The memory is used to store computer programs, and the processor can execute the computer programs accordingly after receiving execution instructions.

[0129] This application also provides a computer-readable storage medium for storing the computer program used in the aforementioned back-drilling device. For example, the computer-readable storage medium may include, but is not limited to, various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0130] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that, in alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0131] In addition, the functional modules or units in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0132] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a smartphone, personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0133] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for controlling residual studs in back-drilling of circuit boards, characterized in that, The method includes: The thickness of the circuit board is measured to obtain the original thickness data; The original board thickness data is used to perform a difference analysis on the circuit board, and the circuit board is then sorted and measured based on the analysis results to obtain a set of board thickness data for each stack. Based on the aforementioned plate thickness data set, the target back-drilled hole positions are measured and analyzed to obtain grouped plate thickness data; Based on the grouped plate thickness data, the degree of influence of plate thickness on the length of back-drilled residual pile is determined, and compared with a preset threshold to obtain the judgment result of the back-drilling depth adjustment scheme; Based on the determination results, the back drilling depth parameters are determined; Based on the back-drilling depth parameters, the circuit boards of the corresponding stacks are back-drilled to control the length of the back-drilling residual pile.

2. The circuit board back-drilling residual stake control method according to claim 1, characterized in that, The process of measuring the board thickness to obtain raw board thickness data includes: The circuit board is aligned based on the target back-drill hole coordinates and alignment target information. Non-contact laser measurement is performed on the circuit board that has been aligned, and the reflected signal is obtained at a position with a preset offset relative to the target back-drilled hole position. Based on the reflected signal, the plate thickness value of the target back-drilled hole position is obtained; The plate thickness value is matched with the corresponding target back drill hole coordinates to generate the original plate thickness data.

3. The circuit board back-drilling residual stake control method according to claim 1, characterized in that, The step involves performing a difference analysis on the circuit board based on the original board thickness data, and then performing stacking and measurement processing on the circuit board based on the analysis results to obtain a set of board thickness data corresponding to each stack, including: The thickness values ​​at several measurement points of each circuit board are analyzed to obtain the average thickness of each circuit board. Calculate the average plate thickness range based on the average plate thickness; The average board thickness range is compared with a preset stacking threshold, and the circuit boards are stacked according to the comparison result. Point-to-point board thickness measurement is performed on any circuit board in each stack to generate a set of board thickness data corresponding to each stack.

4. The circuit board back-drilling residual stake control method according to claim 1, characterized in that, The step involves measuring and analyzing the target back-drilled hole locations based on the plate thickness data set to obtain grouped plate thickness data, including: Based on the plate thickness data set, the plate thickness value of the target back drill hole position is extracted to form the plate thickness dataset of the target back drill hole position. The target back-drill hole position plate thickness dataset is classified according to the back-drilling parameters to obtain a hole position group set; For each group in the hole location grouping set, extract the corresponding plate thickness value sequence and calculate the plate thickness characteristic parameters of the group; The back-drilling parameters and corresponding plate thickness characteristic parameters of each group are associated to generate grouped plate thickness data.

5. The circuit board back-drilling residual stake control method according to claim 4, characterized in that, The step of determining the degree of influence of plate thickness on the length of the back-drilled residual pile based on the grouped plate thickness data, and comparing it with a preset threshold to obtain the determination result of the back-drilling depth adjustment scheme, includes: Extract the maximum thickness value, minimum thickness value, and thickness range of each group from the thickness characteristic parameters of the group; obtain the theoretical back-drilling depth and theoretical thickness of the corresponding group; The influence value of the residual pile length of the group is calculated based on the plate thickness range, the theoretical back drilling depth, and the theoretical plate thickness. Based on the influence value of the residual pile length and the preset threshold, a determination result for the back drilling depth adjustment scheme is generated.

6. The circuit board back-drilling residual stake control method according to claim 5, characterized in that, The step of determining the back-drilling depth parameters based on the determination result includes: When the determination result is an overall adjustment scheme, extract the plate thickness characteristic parameters of all target back drill holes from the group plate thickness data of the corresponding group, calculate the overall average plate thickness, and combine the theoretical plate thickness and theoretical back drill depth to calculate the overall back drill processing depth parameters. When the determination result is an interval adjustment scheme, the position interval is divided according to the range of the maximum and minimum plate thickness values ​​in the corresponding group plate thickness data. The plate thickness characteristic parameters of each position interval are statistically analyzed, the average plate thickness of each position interval is calculated, and the back drilling processing depth parameters of each position interval are calculated in combination with the theoretical plate thickness and the theoretical back drilling depth.

7. The circuit board back-drilling residual stake control method according to claim 1, characterized in that, The step of performing back-drilling on the circuit boards of the corresponding stack based on the back-drilling depth parameters to control the back-drilling residual pile length includes: Obtain the back-drilling depth parameters, theoretical plate thickness, and theoretical back-drilling depth values ​​corresponding to the target back-drilling hole position; The back-drilling depth parameter is converted into a ratio with the theoretical plate thickness, and the ratio is multiplied by the theoretical back-drilling depth value to generate the corresponding back-drilling depth data. Based on the back-drilling depth data, the back-drilling equipment is controlled to perform back-drilling on the circuit board in the corresponding stack.

8. A circuit board back-drilling residual pile control device, characterized in that, include: The board thickness measurement module is used to measure the board thickness of the circuit board and obtain the raw board thickness data; The difference analysis module is used to perform difference analysis on the circuit board based on the original board thickness data, and to perform stacking and measurement processing on the circuit board based on the analysis results to obtain the board thickness data set corresponding to each stack. The hole position measurement module is used to measure and analyze the target back drill hole positions based on the plate thickness data set to obtain grouped plate thickness data; The comparison module is used to determine the degree of influence of the plate thickness on the length of the back drill residual pile based on the grouped plate thickness data, and compare it with a preset threshold to obtain the judgment result of the back drill depth adjustment scheme. The plate thickness acquisition module is used to determine the back drilling depth parameters based on the judgment result. The control module is used to perform back-drilling on the circuit board of the corresponding stack based on the back-drilling depth parameters, so as to control the length of the back-drilling residual pile.

9. A back drilling device, characterized in that, The back-drilling device includes a processor and a memory, the memory storing a computer program, and the processor executing the computer program to implement the circuit board back-drilling residual pile control method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed on a processor, implements the circuit board back-drilling residual pile control method according to any one of claims 1-7.

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