Method for determining back-drilling depth, method for measuring thickness of circuit board, and method for generating object parameter

Abstract

Disclosed in the present application is a method for determining a back-drilling depth, comprising: acquiring theoretical thicknesses and actual thicknesses of a plurality of hole positions on a circuit board to be processed; comparing the theoretical thickness and the actual thickness of each hole position to determine first hole positions and abnormal hole positions; selecting a target hole position from the plurality of first hole positions, performing first search for a plurality of first hole positions adjacent to the target hole position, acquiring the actual thicknesses of the plurality of found first hole positions, and determining a corrected actual thickness of the target hole position; and, on the basis of the corrected actual thickness, the theoretical thickness and the theoretical back-drilling depth of the target hole position, determining the actual back-drilling depth of the target hole position. Further disclosed in the present application are a method for measuring the thickness of a circuit board, and a method for generating object parameters.

Description

A method for determining back drilling depth, a method for detecting circuit board thickness, and a method for generating object parameters.

[0001] This application claims priority to Chinese Patent Application No. 202411556276.8, filed on November 4, 2024, entitled "A method for determining back drilling depth, a method for detecting circuit board thickness and a method for generating object parameters", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the technical field of methods for manufacturing circuit boards, and in particular to a method for determining back-drilling depth, a method for detecting circuit board thickness, and a method for generating object parameters. Background Technology

[0003] With the continuous iteration and upgrading of technology, more and more intelligent devices are being applied to industrial manufacturing processes, such as circuit board processing equipment. These circuit board processing equipment have multiple spindle assemblies, which greatly improves processing efficiency.

[0004] Current circuit board drilling equipment obtains the actual thickness of the hole after bottom and top surface probing. Based on a preset theoretical thickness, the depth control value in the drill tape is corrected before depth-controlled drilling. However, the circuit board thickness directly determines the depth control value, requiring accurate thickness detection of the circuit board to be processed. Existing methods cannot effectively correct the depth control value for each hole. Secondly, this can lead to distortion of some thickness parameters, causing poor board processing or even scrapping. Finally, it cannot guarantee that the calculated actual depth control value for each circuit board to be processed matches the actual situation. Invention Overview

[0005] According to a first aspect of this disclosure, a method for determining back-drilling depth is provided, comprising: obtaining the theoretical thickness and actual thickness of multiple holes on a circuit board to be processed; comparing the theoretical thickness and actual thickness of each hole to determine a first hole and an abnormal hole; selecting a target hole from the multiple first holes, performing a first search on multiple first holes adjacent to the target hole, obtaining the actual thickness of the searched multiple first holes, and determining the corrected actual thickness of the target hole; and determining the actual back-drilling depth of the target hole based on the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth of the target hole.

[0006] In one embodiment of this disclosure, obtaining the actual thickness of a plurality of first holes and determining the corrected actual thickness of a target hole includes: determining the corrected actual thickness of the target hole based on the median or average of the actual thicknesses of the plurality of first holes.

[0007] In one embodiment of this disclosure, the actual thickness of the target hole is compared with the median or average value. When the actual thickness of the target hole is within a preset threshold range of the median or average value, the median or average value is determined as the corrected actual thickness of the target hole.

[0008] In one embodiment of this disclosure, when the actual thickness of the target hole is not within a preset threshold range of the median or average, a second search is performed on multiple first holes adjacent to the target hole to determine the corrected actual thickness of the target hole.

[0009] In one embodiment of this disclosure, the number of first holes found in the second search is greater than the number of first holes found in the first search.

[0010] In one embodiment of this disclosure, the range of the second search for the first hole is greater than the range of the first search for the first hole.

[0011] In one embodiment of this disclosure, comparing the theoretical thickness and actual thickness of each hole to determine the first hole and the abnormal hole includes: when the difference between the theoretical thickness and the actual thickness is within a preset threshold range, it is determined as the first hole; when the difference between the theoretical thickness and the actual thickness is not within the preset threshold range, it is determined as the abnormal hole.

[0012] In one embodiment of this disclosure, a plurality of first holes adjacent to the abnormal hole are searched for in the first step, the actual thickness of the plurality of first holes is obtained, and the corrected actual thickness of the abnormal hole is determined.

[0013] In one embodiment of this disclosure, the search is to expand outward from the target hole or abnormal hole as the center to query multiple first holes in order to determine the number and range of the multiple first holes found.

[0014] According to a second aspect of this disclosure, a method for detecting the thickness of a circuit board is provided, applied to a circuit board processing equipment, comprising: detecting the actual thickness of a plurality of holes on a circuit board to be processed; determining a first hole and an abnormal hole based on the difference between the actual thickness and the theoretical thickness of each hole; selecting a target hole among the plurality of first holes; performing a first search on a plurality of first holes adjacent to the target hole; obtaining the actual thickness of the searched plurality of first holes; and determining a corrected actual thickness of the target hole based on the median or average of the actual thicknesses of the searched plurality of first holes.

[0015] In one embodiment of this disclosure, a plurality of first holes adjacent to the abnormal hole are searched for the first time, and the actual thickness of the plurality of first holes is obtained. Based on the median or average of the actual thicknesses of the plurality of first holes, the corrected actual thickness of the abnormal hole is determined.

[0016] According to a third aspect of this disclosure, an object parameter generation method is provided, applied to a circuit board processing equipment. The method includes: obtaining basic object parameters, which include the theoretical thickness and actual thickness of multiple holes on a circuit board to be processed; comparing the theoretical thickness and actual thickness of each hole to determine first holes and abnormal holes; searching for first holes adjacent to each hole, and determining a corrected actual thickness of each hole based on the median or average of the actual thicknesses of the searched first holes; and generating target object parameters based on the corrected actual thickness and theoretical thickness of each hole.

[0017] In one embodiment of this disclosure, a plurality of first holes adjacent to each first hole are searched, and the corrected actual thickness of each first hole is determined based on the median or average of the actual thicknesses of the plurality of first holes searched.

[0018] In one embodiment of this disclosure, a plurality of first holes adjacent to each of the anomalous holes are searched, and the corrected actual thickness of each anomalous hole is determined based on the median or average of the actual thicknesses of the plurality of first holes searched.

[0019] The advantages of this method for determining back-drilling depth, detecting circuit board thickness, and generating object parameters are as follows: Firstly, it enables independent thickness correction for each hole on the circuit board to be processed, which can greatly improve the accuracy of the back-drilling depth for each hole. Secondly, it not only corrects the thickness of normal first holes but also corrects the thickness of abnormal holes, reducing back-drilling depth anomalies caused by thickness abnormalities, reducing back-drilling scrap rates, and improving product quality.

[0020] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0022] Figure 1 is a schematic diagram of the structure of a circuit board to be processed according to an embodiment of the present disclosure;

[0023] Figure 2 is a schematic diagram of the structure of a circuit board to be processed according to an embodiment of the present disclosure;

[0024] Figure 3 is a partial flowchart of a back drilling depth determination method provided in an embodiment of this disclosure;

[0025] Figure 4 is a partial flowchart of a method for detecting the thickness of a circuit board according to an embodiment of this disclosure;

[0026] Figure 5 is a partial flowchart of an object parameter generation method provided in an embodiment of this disclosure;

[0027] The one-to-one correspondence between the component names and reference numerals in the attached figures is as follows:

[0028] 10. Circuit board to be processed; 11. Sub-circuit board; 110. First hole position; 111. Abnormal hole position; 112. Target hole position. Implementation methods of this application

[0029] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless specifically stated otherwise, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present disclosure or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. It should be noted that similar reference numerals and letters denote similar items in the following drawings; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0030] The specific embodiments of this disclosure are described below with reference to the accompanying drawings. In this document, terms such as "upper," "lower," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, and not to limit the absolute position of these related parts. In this document, terms such as "first" and "second" are used only to distinguish them from each other, and not to indicate degree of importance, order, or prerequisite for each other's existence. In this document, terms such as "equal," "same," "synchronous," "in sequence," "consistent," "symmetrical," "replicated," and "center" are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0031] As a preamble to this application, current circuit board drilling equipment obtains the actual thickness of the hole after bottom and top surface probing. Based on a preset theoretical thickness, the depth control value in the drill tape is corrected before depth-controlled drilling. However, the circuit board thickness directly determines the depth control value, necessitating accurate thickness measurement of the circuit board to be processed. First, the actual thickness may vary between different areas of some circuit board materials; existing methods can only input a theoretical thickness into the drill tape, failing to adequately correct the depth control value for each hole. Second, the methods and environment of the detection device (thermal expansion and contraction, circuit board warping, uneven table surface) can cause discrepancies between the measured thickness and the actual thickness of some holes, resulting in distorted circuit board thickness measurements. Furthermore, the default data is considered completely accurate without correction, leading to distorted thickness parameters, causing poor board processing, or even scrapping. Finally, the thickness distribution within the same batch of circuit boards is unlikely to be uniform; current detection methods cannot guarantee that the calculated actual depth control value for each circuit board to be processed matches the actual situation.

[0032] Therefore, improving the accuracy of thickness detection for each hole on the circuit board to be processed, ensuring the accuracy of the actual thickness of each hole, and realizing differentiated detection or correction for multiple holes to improve the accuracy of back drilling depth are technical problems that technicians in this field need to solve.

[0033] Furthermore, in back-drilling processes, the back-drilling depth is a key technical parameter. One of the key factors affecting the back-drilling depth is the thickness of the circuit board to be processed. Accurately detecting the actual thickness of the circuit board, especially the actual thickness at each hole position, is crucial for improving depth control accuracy. Therefore, this disclosure provides a method for determining the back-drilling depth on a circuit board processing machine. This disclosure also provides a method for detecting the circuit board thickness on a circuit board processing machine. This disclosure further provides an object parameter determination method, applicable to circuit board processing machines, which, based on the original basic object parameters and combined with the corrected actual thickness of each hole position, generates new target object parameters for back-drilling of each hole position.

[0034] The circuit board processing equipment disclosed herein includes a base, a crossbeam, spindle assemblies, and a worktable. The worktable is mounted on the base, and a crossbeam is mounted above the worktable. At least one spindle assembly is slidably connected to the crossbeam, and each spindle assembly moves along a first direction on the crossbeam. The worktable is on the base and moves along a second direction. At least one processing station is provided on the worktable, and a circuit board to be processed is placed on each processing station. Each spindle assembly corresponds one-to-one with the circuit board to be processed at each processing station. A cutting tool held at the bottom of each spindle assembly moves along a third direction to process the corresponding circuit board to be processed. The first, second, and third directions are perpendicular to each other. In the context of this disclosure, the circuit board processing equipment can be implemented as a drilling device, a forming device, a milling machine, a drilling and milling integrated device, etc., and is not limited herein. In the embodiments of this disclosure, at least one spindle assembly is slidably connected to the crossbeam of the circuit board processing equipment. The number of spindle assemblies can be one, two, three, four, six, ten, twelve, etc., and the structure and function of each spindle assembly are basically the same, and is not limited herein.

[0035] At least one spindle assembly slides on the crossbeam of the circuit board processing equipment. Each spindle assembly includes a camera, a detection component, a spindle, and a base plate. The spindle, camera, and detection component are fixedly mounted on the base plate, and the spindle assembly moves along a first direction on the crossbeam via the base plate. In the spindle assembly, the camera is mainly used to detect the actual center coordinates of each hole, providing basic data for center position correction and compensation, thereby improving processing accuracy. The detection component is an electrical signal sensing and acquisition module that can detect the thickness at each hole of the circuit board to be processed. Specifically, the spindle assembly clamps a metal standard bar or a cutting tool to contact the respective metal layers at each hole of the circuit board to be processed. The detection component receives feedback pulse signals, thereby determining the actual thickness at each hole of the circuit board to be processed.

[0036] In the embodiments disclosed herein, the circuit boards to be processed are of different types, varying in material, size, thickness, hardness, etc., resulting in significant differences in physical properties among different types of circuit boards. However, these circuit boards are all fixed within a processing position on the worktable, and a high-speed spindle assembly clamps the cutting tool and moves it along a third direction to process the circuit board. Various methods exist for fixing the circuit board to the worktable, including but not limited to: pneumatic clamps, bakelite boards, and suction devices. These methods ensure that the circuit board is stably and reliably fixed within the processing position on the worktable, preventing displacement during the high-speed cutting tool's processing of the circuit board.

[0037] Each processing station on the worktable carries a circuit board 10 to be processed, as shown in Figure 1. Each circuit board 10 includes multiple sub-circuit boards 11, which have the same layout structure and are arranged in a matrix on the entire circuit board 10. Each sub-circuit board 11 includes multiple holes, which are arranged in a predetermined layout structure. The spindle assembly holds the cutting tool and processes the multiple holes on the sub-circuit board 11 sequentially according to a predetermined path and order. In the embodiments of this disclosure, the multiple holes on the circuit board 10 to be processed refer to the positions of through holes that require controlled depth processing, and each hole has a predetermined center coordinate; the thickness of the hole refers to the thickness of the board material of the circuit board 10 at the center coordinate of the through hole.

[0038] The circuit board 10 to be processed can be a multilayer board or a single-layer board. Here, "multilayer" and "single-layer" mainly refer to metal conductive layers. A multilayer board contains multiple metal conductive layers. Multilayer boards can integrate multiple circuit layouts, reducing the size of the circuit board 10, allowing it to accommodate more circuit layouts, increasing the scale of integrated circuits per unit area, and further reducing the size of the circuit board 10. Multilayer boards are widely used in the field of ultra-precision electronics. Multilayer circuit boards require selective electrical conduction between multiple circuit layers, which necessitates the use of back-drilling to process through-holes. Back-drilling is a secondary drilling process. After processing the through-hole on the front side and performing a copper plating process, a secondary drilling process is performed on the back side to remove excess copper layers. This achieves selective electrical conduction between some layers within the through-hole, with some layers conducting through the copper metal, and the remaining layers not conducting after the copper removal.

[0039] To this end, as shown in Figure 3, this disclosure provides a method for determining back-drilling depth, including: obtaining the theoretical and actual thicknesses of multiple holes on the circuit board 10 to be processed; comparing the theoretical and actual thicknesses of each hole to determine a first hole 110 and an abnormal hole 111; selecting a target hole 112 from the multiple first holes 110; performing a first search on multiple first holes 110 adjacent to the target hole 112; obtaining the actual thicknesses of the searched multiple first holes 110; and determining the corrected actual thickness of the target hole 112; and determining the actual back-drilling depth of the target hole 112 based on the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth. This method for determining back-drilling depth first accurately determines the actual thickness of the target hole 112, eliminating the influence of factors such as board deformation on the board thickness of each hole, thus improving the accuracy of the board thickness. On the other hand, while ensuring the accuracy of the actual thickness of each hole, the actual back-drilling depth of each hole can be accurately and differentially determined, reducing errors and improving back-drilling accuracy and yield.

[0040] In one embodiment of this disclosure, comparing the theoretical thickness and actual thickness of each hole to determine the first hole 110 and the abnormal hole 111 includes: determining the hole as the first hole 110 when the difference between the theoretical thickness and the actual thickness is within a preset threshold range, and determining it as the abnormal hole 111 when the difference is not within the preset threshold range. Multiple holes are distributed on the sub-circuit board 11, and the circuit board 10 to be processed at each hole has a predetermined board thickness. The thickness at different hole locations may vary. In practical applications, the slight difference between the actual thickness and the theoretical thickness of each hole directly affects the back-drilling depth.

[0041] Therefore, after obtaining the theoretical and actual thicknesses of multiple holes on the circuit board 10 to be processed, the actual and theoretical thicknesses of each hole are first compared. When the difference between the theoretical and actual thickness of any hole is within a preset threshold range, the hole is identified as the first hole 110, i.e., a qualified normal hole. At the first hole 110, the difference between the theoretical and actual thickness meets the standard for use as a sample. When the difference between the theoretical and actual thickness of any hole is not within the preset threshold range, the hole is identified as an abnormal hole 111. Abnormal holes 111 may be affected by factors such as measurement errors, board warping or deformation, and thermal expansion and contraction, resulting in a larger difference between the actual and theoretical thickness, which does not meet the standard for use as a sample. Firstly, multiple holes are screened to filter out abnormal holes 111, which helps improve the data accuracy of multiple first holes 110 in the sample, providing accurate samples for subsequent thickness search and correction, and further improving the accuracy of the actual thickness and back-drilling depth of each hole.

[0042] In one embodiment of this disclosure, obtaining the actual thickness of a plurality of first hole positions 110 and determining the corrected actual thickness of a target hole position 112 includes: determining the corrected actual thickness of the target hole position 112 based on the median or average of the actual thicknesses of the plurality of first hole positions 110. Specifically, among the plurality of first hole positions 110, any one first hole position 110 is selected as the target hole position 112 according to a predetermined path and order. For the plurality of first hole positions 110 on the sub-circuit board 11, by sequentially selecting any one first hole position 110 as the target hole position 112, the actual thickness of the first hole position 110 is determined sequentially, thereby determining the back drilling depth of the first hole position 110. This process is repeated multiple times, and the back drilling depth of each first hole position 110 is determined sequentially on the entire circuit board 10 to be processed.

[0043] After selecting the target hole position 112, a first search is performed on multiple first holes 110 adjacent to the target hole position 112 to obtain the actual thickness of these first holes 110. On the sub-circuit board 11, as shown in Figure 2, the first holes 110 are arranged at intervals according to the circuit board layout structure, and the spacing between any two adjacent first holes 110 is uncertain. When searching for multiple first holes 110 adjacent to the target hole position 112, a predetermined search range or number is set to ensure that the searched multiple first holes 110 meet the requirements of the sample collection standard. This search mainly involves first calculating and determining the center distance between multiple first holes 110 and the target hole position 112, and then selecting the multiple first holes 110 with the smallest distance as samples. In some optional embodiments of this disclosure, 10 or 20 first holes 110 adjacent to the target hole position 112 can be selected. Then, the actual thickness of these selected first holes 110 is obtained. The actual thickness of multiple samples near the target hole 112 is of great reference significance for the actual thickness of the target hole 112, especially on ultra-large scale circuit boards, where the spacing between each first hole 110 is very small and the thickness of multiple adjacent first holes 110 has a high degree of similarity.

[0044] After obtaining the actual thickness of multiple first holes 110 adjacent to the target hole 112, the average or median of the actual thickness of these selected first holes 110 is calculated. Specifically, after selecting 20 adjacent first holes 110, the average or median of the actual thickness values ​​of these 20 first holes 110 is calculated. This average or median is used as the parameter data for the actual thickness of the 20 first holes 110 adjacent to the target hole 112.

[0045] In one embodiment of this disclosure, the actual thickness of the target hole 112 is compared with the median or average value Px. When the actual thickness P of the target hole 112 is within a preset threshold range of the median or average value P0, the median or average value Px is determined as the corrected actual thickness of the target hole 112. Specifically, after determining the average value or median Px, it is compared with the actual thickness value P of the target hole 112. If P is within the threshold range of the Px value, the Px value is determined as the corrected actual thickness of the target hole 112. Finally, the actual back-drilling depth of the target hole 112 is calculated and determined using the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth of the target hole 112. For each first hole 110 on the circuit board 10 to be processed, the actual back-drilling depth is determined by the method of determining the corrected actual thickness of the target hole 112.

[0046] When the actual thickness P of the target hole 112 is not within the preset threshold range of the median or average value Px, a second search is performed on multiple first holes 110 adjacent to the target hole 112 to determine the corrected actual thickness of the target hole 112. For the target hole 112, it may be a first hole 110 in a recessed or raised area on the circuit board 10 to be processed. There may be issues with the actual thickness of one or more target holes 112 being too large or too small; a very small range may contain errors. Therefore, the search range is expanded a second time, searching multiple first holes 110 adjacent to the target hole 112 to obtain the actual thickness of 50 searched first holes 110. The average or median of these 50 first hole 110 values ​​is then calculated. This average or median Py is used as the parameter data for the actual thickness of the 50 first holes 110 adjacent to the target hole 112. The thickness P of the target hole 112 is compared with that of the actual thickness P. If P is within the threshold range of the Py value, the Py value is determined as the corrected actual thickness of the target hole 112. Finally, the actual back-drilling depth of the target hole 112 is calculated and determined using the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth of the target hole 112.

[0047] In some embodiments of this disclosure, the number of first hole positions 110 found in the second search is greater than the number of first hole positions 110 found in the first search; or, the range of the first hole positions 110 searched in the second search is greater than the range of the first hole positions 110 searched in the first search. The actual thickness of each hole position on the circuit board 10 to be processed may vary significantly. When multiple first hole positions 110 adjacent to the target hole position 112 are used as samples in the first search, if the median or average value Px differs significantly from the actual thickness P of the target hole position 112, or if P is not within the threshold range of Px, the search range is expanded, and multiple first hole positions 110 adjacent to the target hole position 112 are searched in the second search. The range and number of samples in the second search are greater than the range or number of samples in the first search, i.e., the range of the second search is greater than the range of the first search, searching for a larger range of samples, or the number of samples in the second search is greater than the number of samples in the first search, searching for a greater number of first hole positions 110. This reduces interference caused by local board warping or deformation of the circuit board 10 to be processed, improves the accuracy of correcting the actual thickness and the accuracy of back drilling depth, and reduces back drilling processing quality abnormalities.

[0048] In some embodiments of this disclosure, a first search is performed on multiple first holes 110 adjacent to the abnormal hole 111 to obtain the actual thickness of the searched multiple first holes 110 and determine the corrected actual thickness of the abnormal hole 111. The abnormal hole 111 may be caused by measurement errors, thermal expansion and contraction, or local deformation or warping of the board material. The abnormal hole 111 also needs to have its actual thickness corrected. Similar to the first hole 110, a first search is performed on multiple first holes 110 adjacent to the abnormal hole 111, and the corrected actual thickness of the abnormal hole 111 is determined based on the median or average of the actual thicknesses of the multiple first holes 110. Typically, the range and number of multiple first holes 110 searched adjacent to the abnormal hole 111 are greater than the range and number of multiple first holes 110 searched adjacent to the target hole 112 in the first search, to ensure the accuracy of the corrected actual thickness of the abnormal hole 111, reduce the number of searches, and improve efficiency.

[0049] In some embodiments of this disclosure, the search involves expanding outwards from the target hole position 112 or the abnormal hole position 111 to query multiple first hole positions 110; this determines the number and range of the searched first hole positions 110. As shown in Figure 2, multiple first hole positions 110 are distributed on multiple sub-circuits 11 on the circuit board to be processed 10. After selecting a first hole position 110 as the target hole position 112 according to predetermined rules and order, the search expands outwards from the center of the circle centered on the target hole position 112 to query multiple first hole positions 110. The first hole positions 110 closest to the center are then selected as the predetermined number of searched first hole positions 110. For the abnormal hole position 111, the search is also conducted outwards from the center using the same method. That is, during the search process, the radius of the search circle is continuously expanded to ensure that a predetermined number of first hole positions 110 can be captured. The target hole position 112 requires 20 first hole positions 110 as samples, and the abnormal hole position 111 requires 40 first hole positions 110 as samples. This search method, which expands outward from the center, can obtain multiple first holes 110 that are closest to the target hole 112 or the abnormal hole 111, thereby ensuring the accuracy of correcting the actual thickness.

[0050] As shown in Figure 4, this disclosure also provides a method for detecting the thickness of a circuit board, applied to a circuit board processing equipment. The method includes: detecting the actual thickness of multiple holes on the circuit board 10 to be processed; determining first holes 110 and abnormal holes 111 based on the difference between the actual thickness and the theoretical thickness of each hole; selecting a target hole 112 from among the multiple first holes 110; performing a first search on multiple first holes 110 adjacent to the target hole 112; obtaining the actual thickness of the searched multiple first holes 110; and determining the corrected actual thickness of the target hole 112 based on the median or average of the actual thicknesses of the searched multiple first holes 110. This method for detecting circuit board thickness first removes the interference of abnormal holes 111 to ensure the accuracy of the sample first holes 110, and then determines the corrected actual thickness of the target hole 112 based on the median or average thickness of the multiple first holes 110 adjacent to the target hole 112. This can reduce the interference of external factors and improve the accuracy of the thickness of each target hole 112 on the circuit board 10 to be processed.

[0051] In some embodiments of this disclosure, a plurality of first holes 110 adjacent to the abnormal hole 111 are searched first to obtain the actual thickness of the searched plurality of first holes 110. Based on the median or average of the actual thicknesses of the searched plurality of first holes 110, the corrected actual thickness of the abnormal hole 111 is determined. On the circuit board 10 to be processed, there are a plurality of first holes 110 and abnormal holes 111. Based on the actual thickness of the plurality of first holes 110, the corrected actual thickness of the abnormal hole 111 is determined by searching the median or average of the actual thicknesses of adjacent holes, which effectively reduces noise interference and improves the accuracy of the actual thickness of the abnormal hole 111.

[0052] As shown in Figure 5, this disclosure also provides an object parameter generation method applied to circuit board processing equipment. The object parameter generation method includes: obtaining basic object parameters, which include the theoretical and actual thicknesses of multiple holes on the circuit board 10 to be processed; comparing the theoretical and actual thicknesses of each hole to determine first hole 110 and abnormal hole 111; searching for first hole 110 adjacent to each hole, and determining the corrected actual thickness of each hole based on the median or average of the actual thicknesses of the searched first hole 110; generating target object parameters based on the corrected actual thickness and theoretical thickness of each hole. By comparing, searching, and determining the corrected actual thickness based on the basic object parameters of each hole on the circuit board 10 to be processed, the target object parameters are generated. The circuit board processing equipment retrieves the target object parameters to complete controlled-depth back-drilling, improving processing accuracy.

[0053] In some embodiments of this disclosure, the corrected actual thickness of each first hole 110 is determined based on the median or average of the actual thicknesses of a plurality of first hole positions 110 found adjacent to each first hole position 110; or, the corrected actual thickness of each abnormal hole position 111 is determined based on the median or average of the actual thicknesses of a plurality of first hole positions 110 found adjacent to each abnormal hole position 111. Whether it is a first hole position 110 or an abnormal hole position 111, the corrected actual thickness is determined based on the median or average of the actual thicknesses of adjacent first hole positions 110, improving accuracy and reducing interference errors.

[0054] The beneficial effects of this method for determining back-drilling depth, detecting circuit board thickness, and generating object parameters are as follows: (1) It can achieve independent thickness correction for each hole on the circuit board 10 to be processed, which can greatly improve the accuracy of the back-drilling depth of each hole. (2) It can not only correct the thickness of the normal first hole 110, but also correct the thickness of the abnormal hole 111, reduce the back-drilling depth abnormality caused by thickness abnormality, reduce the back-drilling scrap rate, and improve product quality.

[0055] Application Scenario 1

[0056] This embodiment takes a six-axis circuit board processing equipment as an example to explain in detail the specific application process of the back drilling depth determination method, the circuit board thickness detection method, and the object parameter generation method.

[0057] In this embodiment, the circuit board processing equipment includes a worktable, spindle assemblies, a crossbeam, and a base. The worktable is mounted on the base, and a crossbeam is mounted above the worktable. Six identical spindle assemblies are slidably mounted on the crossbeam, and each spindle assembly moves along a first direction on the crossbeam. The worktable is on the base and moves along a second direction. The worktable has six processing positions, and each processing position holds a circuit board 10 to be processed. The spindle assemblies move along a third direction to process the circuit board 10 to be processed on the corresponding processing position. In the above and below embodiments of this disclosure, the first direction, the second direction, and the third direction are perpendicular to each other.

[0058] In this embodiment, the circuit board processing equipment includes a control system. The control system has multiple built-in raw object parameters for processing circuit boards, and the circuit board to be processed 10 corresponds one-to-one with the object parameters. As shown in FIG1, in the raw object parameters, the circuit board to be processed 10 includes 20 sub-circuit boards 11, and each sub-circuit board 11 includes multiple holes. As shown in FIG2, the sub-circuit board 11 includes multiple first holes 110 and abnormal holes 111, which are arranged on the sub-circuit board 11 at predetermined intervals. The spindle assembly holds the cutting tool and performs back drilling on each first hole 110 and abnormal hole 111 on the circuit board to be processed 10.

[0059] In this embodiment, the spindle assembly includes a detection element, which is implemented as a CBD (Capacitive Board Detection) component. The spindle holds a standard bar to detect the conductivity of the metal on the surface of the circuit board 10 to be processed and the surface of the worktable, respectively detecting the board thickness at each hole of each circuit board 10. For the first hole 110 and abnormal hole 111 of each sub-circuit board 11 on the circuit board 10 to be processed, the CBD can detect the actual thickness, while the theoretical thickness is known. Obtaining the actual thickness and the theoretical thickness prepares for determining and correcting the actual thickness.

[0060] In the control system of the circuit board processing equipment, object parameters corresponding one-to-one with the circuit board 10 to be processed are preset. The appropriate object parameters are retrieved, and the spindle assembly is controlled to process each hole on the circuit board 10. To obtain the back drilling depth, an object parameter determination method is first applied to the circuit board processing equipment. Specifically, as shown in Figure 5, this object parameter determination method includes: obtaining basic object parameters, which include the theoretical and actual thicknesses of multiple holes on the circuit board 10; comparing the theoretical and actual thicknesses of each hole to determine the first hole 110 and abnormal hole 111; searching for the first hole 110 adjacent to each hole, and determining the corrected actual thickness of each hole based on the median or average of the actual thicknesses of the searched first hole 110s; and generating target object parameters based on the corrected actual thickness and theoretical thickness of each hole. In the object parameters, the first hole 110 and abnormal hole 111 of the circuit board 10 to be processed are corrected. Based on the median or average of the actual thickness of multiple first hole 110s found adjacent to each first hole 110 or abnormal hole 111, the corrected actual thickness is determined, which provides more accurate basic data for back drilling and improves the processing accuracy.

[0061] In the process of generating target object parameters, a method for detecting circuit board thickness is applied, as shown in Figure 4. Specifically, it includes: detecting the actual thickness of multiple holes on the circuit board 10 to be processed; determining the first hole 110 and abnormal hole 111 based on the difference between the actual thickness and the theoretical thickness of each hole; selecting a target hole 112 among the multiple first holes 110; searching multiple first holes 110 adjacent to the target hole 112 for the first time; obtaining the actual thickness of the searched multiple first holes 110; and determining the corrected actual thickness of the target hole 112 based on the median or average of the actual thicknesses of the searched multiple first holes 110.

[0062] On the circuit board 10 to be processed, the actual thickness of multiple holes is first detected using a CBD (Central Detector) and the actual thickness of each hole is compared with the theoretical thickness. If the difference between the two is greater than or equal to a threshold, the hole is identified as an abnormal hole 111; if the difference is less than the threshold, it is identified as the first hole 110. The threshold can be set to 10% of the theoretical thickness. After identifying the first hole 110, the abnormal hole 111 is filtered out to avoid interference from the abnormal hole 111 on the sample data, reduce data noise, and improve accuracy.

[0063] Next, following a predetermined path and order, each first hole position 110 is selected as the target hole position 112. The first search involves identifying the 20 first hole positions 110 closest to the target hole position 112, obtaining the actual thickness of these 20 first hole positions 110, and determining the corrected actual thickness of the target hole position 112 based on the median or average of these 20 actual thicknesses. These 20 first hole positions 110 are the 20 closest to the target hole position 112. The search method involves calculating the distance between these 20 positions and the center coordinates of the target hole position 112, sorting them according to the distance, selecting the 20 first hole positions 110 with the smallest distance, and obtaining the actual thickness of these 20 first hole positions 110. Based on these 20 actual thicknesses, the average value is calculated, and this average value is determined as the corrected actual thickness of the target hole position 112.

[0064] In this embodiment, as shown in FIG3, a method for determining back-drilling depth is also disclosed. This method for determining back-drilling depth can accurately calculate the back-drilling depth based on the detection of the board thickness at each hole position on the circuit board 10 to be processed, thereby improving the back-drilling processing accuracy. The method for determining back-drilling depth includes: obtaining the theoretical thickness and actual thickness of multiple holes on the circuit board 10 to be processed; comparing the theoretical thickness and actual thickness of each hole position to determine the first hole position 110 and the abnormal hole position 111; selecting a target hole position 112 among the multiple first hole positions 110; searching multiple first hole positions 110 adjacent to the target hole position 112 for the first time; obtaining the actual thickness of the searched multiple first hole positions 110; determining the corrected actual thickness of the target hole position 112; and determining the actual back-drilling depth of the target hole position 112 based on the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth of the target hole position 112.

[0065] In this embodiment, the actual thickness of multiple holes on the circuit board 10 to be processed is detected by CBD, and then the theoretical thickness is obtained. The actual thickness and theoretical thickness of the circuit board 10 to be processed at each hole are compared. When the difference between the actual thickness and the theoretical thickness is greater than or equal to a predetermined threshold, it is identified as an abnormal hole 111. When the difference between the actual thickness and the theoretical thickness is less than the predetermined threshold, it is identified as a first hole 110. In this embodiment, the predetermined threshold range is 10% of the theoretical thickness.

[0066] As shown in Figure 2, following the predetermined path and sequence, one of the multiple first holes 110 is selected as the target hole 112. Using the center coordinates of the target hole 112 as the center, multiple first holes 110 near the target hole 112 are searched to obtain the actual thickness of these first holes 110. The multiple first holes 110 are sorted according to their distance from the center coordinates of the target hole 112. The actual thickness of the 20 first holes 110 with the smallest distance is selected, and the average value P1 of the 20 actual thicknesses is calculated.

[0067] The actual thickness of the target hole 112 is P. The average value P1 is compared with the actual thickness P. If the actual thickness P is within the threshold range of the average value P1, P1 is determined as the corrected actual thickness of the target hole 112. If P is not within the threshold range of P1, a second search is performed on multiple first holes 110 adjacent to the target hole 112. In this embodiment, the threshold range of P1 is: upper limit P1 + 8% × P1, lower limit P1 - 8% × P1. That is, P1 is set with an upper and lower limit error range of 8%.

[0068] The second search involves multiple first holes 110 adjacent to the target hole 112, obtaining the actual thickness of each first hole 110. These first holes 110 are then sorted according to their distance from the center coordinates of the target hole 112. The 50 first holes 110 with the smallest distances are selected, and the average actual thickness P2 of these 50 first holes 110 is calculated. Similarly, the actual thickness P is compared with the average value P2 obtained in the second search. If P is within the threshold range of P2, P2 is determined as the corrected actual thickness of the target hole 112. If P is not within the threshold range of P2, a third search is performed on multiple first holes 110 adjacent to the target hole 112 until P and the average value meet the threshold range requirements. In this embodiment, the threshold range of the average value P2 obtained in the second search is: upper limit P2 + 10% × P2, lower limit P2 - 10% × P2. That is, P2 is set with an upper and lower limit error range of 10%.

[0069] It should be noted that both the first and second searches use the center coordinates of the target hole position 112 as the center to search for multiple first hole positions 110 adjacent to the target hole position 112. Multiple searches are performed to obtain multiple samples, reducing the impact of local warping or deformation of the board material 10 on the thickness. In the first search, the second search, and subsequent possible searches, each search obtains more first hole positions 110 than the previous search. In other words, each subsequent search expands the search range and obtains more first hole positions 110, which helps improve the accuracy of the samples.

[0070] In this embodiment, the abnormal hole position 111 also requires back drilling. However, the thickness of the abnormal hole position 111 may be significantly affected by various factors such as detection and local deformation of the board material, resulting in an abnormal thickness. Similar to the first hole position 110, the method of searching for multiple neighboring first hole positions 110 is used to obtain the average value of 40 neighboring first hole positions 110. This average value is determined as the corrected actual thickness of the abnormal hole position 111. However, the abnormal hole position 111 does not need to be compared or judged within a threshold range. It should be noted that, whether it is the first hole position 110 or the abnormal hole position 111, the abnormal hole position 111 is filtered out during the search process, and only the first hole position 110 is selected as the sample for obtaining the average value, thereby improving accuracy.

[0071] In this embodiment, after determining the corrected actual thickness of the target hole 112, the actual depth of the back drill can be determined based on the ratio of the corrected actual thickness to the theoretical thickness, the ratio of the actual depth of the back drill to the theoretical depth of the back drill, and a fixed coefficient K between the two ratios.

[0072] The back-drilling depth determination method, circuit board thickness detection method, and object parameter generation method described in this embodiment, on the one hand, enable independent thickness correction for each hole on the circuit board 10 to be processed, which can greatly improve the accuracy of the back-drilling depth for each hole. On the other hand, it not only corrects the thickness of the normal first hole 110, but also corrects the thickness of abnormal holes 111, reducing back-drilling depth abnormalities caused by thickness abnormalities, reducing back-drilling scrap rate, and improving product quality.

[0073] Application Scenario 2

[0074] This embodiment takes a 6-axis circuit board processing equipment as an example to explain in detail the specific application process of the back drilling depth determination method, the circuit board thickness detection method, and the object parameter generation method.

[0075] The circuit board processing equipment in this embodiment is the same as in Embodiment 1. The method for determining the back drilling depth, the method for detecting the circuit board thickness, and the method for generating object parameters are basically the same as in Embodiment 1. The difference from Embodiment 1 is that the median of the multiple actual thicknesses of the first hole positions 110 obtained by searching is calculated. In this embodiment, the median refers to the middle value of the multiple actual thicknesses arranged in order of size as the corrected actual thickness. That is to say, the median must be the actual thickness of a certain first hole position 110, and the average is the average of multiple actual thicknesses, not necessarily the actual thickness of a single hole position.

[0076] In this embodiment, during the initial search of multiple first holes 110 adjacent to the target hole 112, the multiple first holes 110 are sorted according to their distance from the center coordinates of the target hole 112. The 11 first holes 110 with the smallest distance are selected, and then sorted according to their actual thickness. The actual thickness of the 6th hole in the middle is selected as the median P3. Similar to Embodiment 1, the actual thickness P of the target hole 112 is compared with the median P3. If a threshold requirement is met, P3 is determined as the corrected actual thickness of the target hole 112. In this embodiment, the threshold range of the median P3 in the first search is: upper limit P3 + P3 × 5%, lower limit P3 - P3 × 5%, meaning the upper and lower limit error range of P3 is 5%. When the actual thicknesses P and P3 of the target hole 112 do not meet the threshold range, a second search is performed. The search range is expanded by using the center coordinates of the target hole 112 as the center and searching for multiple adjacent first holes 110. 99 first holes 110 are selected and sorted by spacing. These 99 first holes 110 are then sorted by actual thickness, and the actual thickness of the 50th first hole 110 is selected as the median P4. The actual thickness P and the median P4 are compared. If both meet the threshold requirement, P4 is determined as the corrected actual thickness of the target hole 112. In this embodiment, the threshold range of P4 is the same as that of P3: upper limit P4 + P4 × 5%, lower limit P4 - P4 × 5%, meaning the upper and lower limit error range of P4 is 5%.

[0077] In this embodiment, the actual thickness of the abnormal hole position 111 is also determined by searching and selecting the median, which will not be described in detail here.

[0078] Similar to Embodiment 1, this embodiment also determines the corrected actual thickness of the circuit board 10 at the target hole position 112 by sequentially selecting each first hole position 110 as the target hole position 112. Then, based on the ratio between the theoretical thickness at the target hole position 112 and the theoretical back-drilling thickness, the actual back-drilling depth at the target hole position 112 is determined. This method for determining back-drilling depth, detecting circuit board thickness, and generating object parameters can, on the one hand, enable independent thickness correction for each hole position on the circuit board 10 to be processed, greatly improving the accuracy of the back-drilling depth for each hole position. On the other hand, it can not only correct the thickness of normal first hole positions 110 but also correct the thickness of abnormal hole positions 111, reducing back-drilling depth abnormalities caused by thickness abnormalities, reducing back-drilling scrap rate, and improving product quality.

[0079] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for determining back-drilling depth, comprising: Obtain the theoretical and actual thicknesses of multiple holes on the circuit board to be processed; Compare the theoretical thickness and actual thickness of each hole location to determine the first hole location and abnormal hole locations; Select a target hole from a plurality of first hole positions, perform a first search on a plurality of first hole positions adjacent to the target hole position, obtain the actual thickness of the plurality of first hole positions searched, and determine the corrected actual thickness of the target hole position. The actual back-drilling depth of the target hole is determined based on the corrected actual thickness, theoretical thickness, and theoretical back-drilling depth of the target hole.

2. The method for determining back-drilling depth according to claim 1, wherein, The step of obtaining the actual thickness of the plurality of first holes found and determining the corrected actual thickness of the target hole includes: The corrected actual thickness of the target hole is determined based on the median or average of the actual thicknesses of the plurality of first holes found.

3. The method for determining back-drilling depth according to claim 2, wherein, The actual thickness of the target hole is compared with the median or average value. When the actual thickness of the target hole is within a preset threshold range of the median or average value, the median or average value is determined as the corrected actual thickness of the target hole.

4. The method for determining back-drilling depth according to claim 3, wherein, When the actual thickness of the target hole is not within the preset threshold range of the median or average, a second search is performed on multiple first holes adjacent to the target hole to determine the corrected actual thickness of the target hole.

5. The method for determining back-drilling depth according to claim 4, wherein, The number of the first holes found in the second search is greater than the number of the first holes found in the first search.

6. The method for determining back-drilling depth according to claim 4, wherein, The range of the second search for the first hole is greater than the range of the first search for the first hole.

7. The method for determining back-drilling depth according to claim 1, wherein, The step of comparing the theoretical thickness and actual thickness of each hole position to determine the first hole position and abnormal hole positions includes: When the difference between the theoretical thickness and the actual thickness is within a preset threshold range, it is determined to be the first hole position; When the difference between the theoretical thickness and the actual thickness is not within the preset threshold range, it is determined to be an abnormal hole position.

8. The method for determining back-drilling depth according to claim 1, further comprising: The first search is performed on multiple first holes adjacent to the abnormal hole position. The actual thickness of the multiple first holes found is obtained, and the corrected actual thickness of the abnormal hole position is determined.

9. The method for determining back-drilling depth according to any one of claims 1 to 8, wherein, The search is performed by taking the target hole or abnormal hole as the center and expanding outwards to search for multiple first holes, so as to determine the number and range of the multiple first holes found.

10. A method for detecting the thickness of a circuit board, applied to circuit board processing equipment, the method for detecting the thickness of the circuit board comprising: Inspect the actual thickness of multiple holes on the circuit board to be processed; Based on the difference between the actual thickness and the theoretical thickness of each hole, the first hole and the abnormal hole are determined; Select a target hole from among a plurality of first hole positions, perform a first search on a plurality of first hole positions adjacent to the target hole position, obtain the actual thickness of the plurality of first hole positions searched, and determine the corrected actual thickness of the target hole position based on the median or average of the actual thicknesses of the plurality of first hole positions searched.

11. The method for detecting the thickness of a circuit board according to claim 10, further comprising: The first search is performed on multiple first holes adjacent to the abnormal hole position to obtain the actual thickness of the multiple first holes found. Based on the median or average of the actual thicknesses of the multiple first holes found, the corrected actual thickness of the abnormal hole position is determined.

12. An object parameter generation method, applied to circuit board processing equipment, the object parameter generation method comprising: Obtain basic object parameters, including the theoretical and actual thicknesses of multiple holes on the circuit board to be processed; compare the theoretical and actual thicknesses of each hole to determine the first hole and abnormal holes; Search for the first hole adjacent to each of the aforementioned hole positions, and determine the corrected actual thickness of each hole position based on the median or average of the actual thicknesses of the multiple searched first hole positions. Target object parameters are generated based on the corrected actual thickness and theoretical thickness of each hole.

13. The object parameter generation method according to claim 12, further comprising: Search for multiple first holes adjacent to each first hole, and determine the corrected actual thickness of each first hole based on the median or average of the actual thicknesses of the multiple first holes found.

14. The object parameter generation method according to claim 12, further comprising: Search for multiple first holes adjacent to each of the anomalous holes, and determine the corrected actual thickness of each of the anomalous holes based on the median or average of the actual thicknesses of the multiple first holes found.

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