Intelligent measuring system and method for forming thickness of rigid-flex printed circuit board

Abstract

The present application belongs to the technical field of electronic circuit board manufacturing and detection, and relates to a soft and hard combination board forming thickness intelligent measurement system and method. The present application sets up a displacement sensor array on the outer side of the two opposite surfaces of the soft and hard combination board, obtains thickness data according to a grid layout, extracts the actual thickness mean value of the rigid area and the thickness distribution of the whole board, dynamically determines the dynamic tolerance of the rigid area, and constructs a reasonable interval of the thickness of the flexible area. The directly measured thickness of each point in the flexible area is compared with the reasonable interval, the measurement effectiveness is determined through the local thickness fluctuation value and the laser reflection signal strength, the points exceeding the reasonable interval are determined for effectiveness, and when invalid, the thickness mean value of the adjacent effective measurement points in the same flexible area is used as the final thickness, so that the thickness of the flexible area is accurately and reliably obtained, the measurement deviation problem caused by the material characteristics in the thickness measurement of the soft and hard combination board flexible area is effectively solved, and the measurement precision and reliability are significantly improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic circuit board manufacturing and detection, and relates to a soft and hard combination board forming thickness intelligent measurement system and method. BACKGROUND

[0002] The soft and hard combination board plays an irreplaceable role in modern high-end electronic equipment due to its support of rigid boards and flexibility of flexible areas. In the manufacturing process of the soft and hard combination board, accurate and reliable measurement of the forming thickness of the board is a key link to ensure product quality and long-term reliability.

[0003] In the manufacturing process of the soft and hard combination board, the flexible area is prone to slight warping or instantaneous deformation due to its soft material and susceptibility to external disturbances, and the surface is often covered with a covering film that is significantly different from the rigid area in reflection characteristics, making it difficult to stably and accurately obtain the thickness. However, in order to ensure the overall thickness uniformity and structural reliability of the product, high-precision measurement of the forming thickness of the flexible area is necessary.

[0004] The existing method mainly relies on multiple thickness measurements of the flexible area and statistical or threshold judgments based on these measurement values, but this method only stays in the measurement analysis of a single parameter dimension and fails to correlate and analyze the measurement data of the flexible area with the overall thickness reference of the board, which is susceptible to material characteristics, process fluctuations and external disturbances. Simply relying on multiple measurement values often cannot accurately reflect the true thickness uniformity, resulting in a lack of adaptability and reliability of the determination result, thereby affecting the accuracy of product quality evaluation. SUMMARY

[0005] In view of this, in order to solve the problems raised in the background art, a soft and hard combination board forming thickness intelligent measurement system and method are proposed.

[0006] The purpose of the present application can be achieved by the following technical solutions: The first aspect of the present application provides a soft and hard combination board forming thickness intelligent measurement system, comprising the following modules: a thickness acquisition module for extracting the measured thickness data of the rigid area of the current board and the measured thickness average value thereof, and the thickness distribution of the overall board, and extracting the direct measurement thickness of the corresponding point of the flexible area from the thickness distribution of the overall board.

[0007] A stability evaluation module is used to determine the dynamic tolerance of the rigid area of the current board based on the measured thickness data of the rigid area.

[0008] A deviation comparison module is used to construct a reasonable interval of the thickness of the flexible area based on the measured thickness average value of the rigid area and the dynamic tolerance, compare the direct measurement thickness of each point of the flexible area with the reasonable interval, and determine whether the point is in the reasonable interval.

[0009] A thickness decision module is configured to, if a point is in a reasonable interval, adopt the directly measured thickness of the point as the final thickness, if the point is out of the reasonable interval, determine the validity of the measurement according to the local thickness fluctuation value and the laser reflection signal strength of the region where the point is located, and if the measurement is determined to be invalid, adopt the thickness average of the adjacent valid measurement points in the same flexible region as the final thickness.

[0010] A flexible output module is configured to aggregate the final thicknesses of all points in the flexible region to form a flexible region thickness result.

[0011] The second aspect of the present application provides a soft and hard combined plate forming thickness intelligent measurement method, including the following steps: S1, extracting the measured thickness data of the rigid region of the current plate, the measured thickness average thereof and the thickness distribution of the whole plate, and extracting the directly measured thickness of the corresponding point of the flexible region from the thickness distribution of the whole plate.

[0012] S2, determining the dynamic tolerance of the rigid region of the current plate based on the measured thickness data of the rigid region.

[0013] S3, constructing a reasonable interval of the thickness of the flexible region based on the measured thickness average of the rigid region and the dynamic tolerance, comparing the directly measured thickness of each point of the flexible region with the reasonable interval, and determining whether the point is in the reasonable interval.

[0014] S4, if a point is in a reasonable interval, adopting the directly measured thickness of the point as the final thickness, if the point is out of the reasonable interval, determining the validity of the measurement according to the local thickness fluctuation value and the laser reflection signal strength of the region where the point is located, and if the measurement is determined to be invalid, adopting the thickness average of the adjacent valid measurement points in the same flexible region as the final thickness.

[0015] S5, aggregating the final thicknesses of all points in the flexible region to form a flexible region thickness result.

[0016] Compared with the prior art, the present application has the following beneficial effects: (1) the present application uses a dynamic tolerance calculation method of the thickness data of the rigid region, so that the system can adapt to the fluctuation of the thickness reference of the rigid region of the plate, and dynamically generate a determination tolerance range suitable for the flexible region. This method regulates the thickness detection process of the flexible region by applying dynamic constraints, selects credible measurement data, and thus realizes accurate detection of the thickness of the flexible region and effectively avoids the risk of misjudgment caused by overall thickness being too large or too small.

[0017] (2) The application identifies and filters out unreliable measurement data generated due to the variable surface characteristics of the flexible substrate through a double determination mechanism of local thickness fluctuation value and laser reflection signal intensity, and replaces it with the data of adjacent effective points. This process reduces the dependence on artificial experience judgment, improves the reliability of the thickness measurement results of the flexible area, and provides accurate data basis for the thickness uniformity evaluation of the rigid-flex printed circuit board, which helps to control the manufacturing quality of high-end electronic equipment. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a schematic diagram of the connection of each module of the intelligent measurement system of the formed thickness of the rigid-flex printed circuit board.

[0020] Figure 2 It is a content flow chart for determining the validity of measurement.

[0021] Figure 3 It is a step diagram of the intelligent measurement method of the formed thickness of the rigid-flex printed circuit board. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] Embodiment 1

[0024] Please refer to Figure 1 As shown in the drawings, the present application provides an intelligent measurement system of the formed thickness of the rigid-flex printed circuit board, which comprises a thickness acquisition module, a stability evaluation module, a deviation comparison module, a thickness decision module and a flexible output module. The connection relationship between the modules is: the thickness acquisition module and the stability evaluation module are connected, the thickness acquisition module and the deviation comparison module are connected, the stability evaluation module and the deviation comparison module are connected, the deviation comparison module and the thickness decision module are connected, and the thickness decision module and the flexible output module are connected.

[0025] a thickness acquisition module configured to extract measured thickness data and a measured thickness average of a rigid region of the current panel, and a whole-panel thickness distribution, and extract a directly measured thickness of a corresponding point of the flexible region from the whole-panel thickness distribution.

[0026] Considering the complex structure of the soft and hard combined panel and the fact that the flexible region is easily disturbed by measurement, the thickness stability of the rigid region is used as a reference to accurately construct the whole-panel thickness distribution by synchronously collecting the displacement data of the upper and lower surfaces of the panel and combining the region distribution map.

[0027] Further, the extraction of the measured thickness average of the rigid region of the current panel and the whole-panel thickness distribution comprises: arranging a pair of displacement sensor arrays corresponding in position on the outer sides of the two opposite surfaces of the soft and hard combined panel to be measured to form a measurement unit group; wherein each sensor is arranged in a grid in the X-Y plane parallel to the theoretical main plane of the panel.

[0028] The measurement axes of the two sensors in each measurement unit group are collinear, and the direction of the measurement axes is perpendicular to the theoretical main plane, and the displacement values of the side surfaces on which the sensors are located relative to a fixed reference surface along the measurement axes are synchronously collected.

[0029] The fixed installation coordinates of each sensor in the array are used as the X and Y positions of the measurement point, and the displacement values are combined to determine the position value of each measurement point along the measurement axis.

[0030] According to the process configuration file, a rigid and flexible region distribution map of the panel is obtained, a set of measurement points corresponding to the rigid region is determined, and for each measurement point in the set, the absolute value of the difference between the position values of the two opposite surfaces along the measurement axis is taken as the local thickness value of the point.

[0031] All local thickness values of the rigid region are arranged in ascending order, and the data of the first p% and the last p% are removed, and the remaining local thickness values are taken as the measured thickness data of the rigid region, wherein p is a preset outlier ratio and 0

[0032] For example, assuming that p=5%, the extreme values of the first 5% and the last 5% of the thickness data of the rigid region are removed to improve the robustness of the average value, and the implementer can adjust the value of p according to the process stability.

[0033] The arithmetic mean of the measured thickness data is calculated as the measured thickness average of the rigid region, and the thickness values of all measurement points of the whole panel form a whole-panel thickness distribution.

[0034] Considering that the measurement accuracy of the laser displacement sensor depends largely on the quality of the laser reflection signal, and that the flexible area is prone to abnormal enhancement or abnormal attenuation of the laser reflection signal due to its uneven surface material or deformation, such abnormal signals usually correspond to measurement interference such as mirror reflection, scattering or absorption, which will directly cause the calculated thickness data to be distorted.

[0035] Therefore, the intensity of the laser reflection signal is taken as a key criterion for data reliability, and the maximum and minimum values are removed, with the purpose of actively excluding these abnormal data points affected by interference, so as to ensure that the retained direct measurement thickness of the flexible area is derived from stable and reliable measurement results.

[0036] Further, the measurement point set corresponding to the flexible area is selected from the whole plate thickness distribution, and the laser reflection signal intensity of each point is recorded simultaneously; the maximum and minimum values of the laser reflection signal intensity in the set are calculated, and the measurement points with signal intensity equal to the maximum or minimum value are removed, and the thickness values of the remaining points are taken as the direct measurement thickness of the points corresponding to the flexible area.

[0037] For example, 4x4 laser displacement sensor arrays are arranged symmetrically on the upper and lower surfaces of the soft and hard combined board, forming 16 measurement units; each unit synchronously collects displacement values in the direction perpendicular to the board surface, and determines the spatial position of each point in combination with the preset coordinates; according to the rigid and flexible area map in the process file, 10 rigid area measurement points are identified, and the distance between the upper and lower surfaces is calculated as the local thickness; after sorting the 10 thickness values, the maximum and minimum values are removed, and the average value of the remaining 8 values is taken as the measured thickness average of the rigid area.

[0038] At the same time, 6 flexible area points are selected from the 16 points on the whole board, and the laser reflection signal intensity is recorded; the two points with the highest and lowest signal intensity are removed, and the thickness values of the remaining 4 points are taken as the direct measurement thickness of the flexible area.

[0039] Through the above operation, the thickness data basis for constructing a reasonable interval and subsequent effectiveness judgment can be obtained, providing conditions for the execution of the stability evaluation module.

[0040] The stability evaluation module is used to determine the dynamic tolerance of the rigid area of the current plate based on the measured thickness data of the rigid area.

[0041] Considering that the thickness of the rigid area of the soft and hard combined board is relatively stable during actual molding, but still has a certain degree of dispersion due to material batch, process fluctuation or environmental factors. In the traditional process, in order to simplify process control, a fixed tolerance range is generally set for thickness tolerance, so a fixed tolerance threshold is used, but it is difficult to adapt to the actual differences between different plates, which inevitably introduces the risk of misjudgment or omission.

[0042] Therefore, further, the method for obtaining the dynamic tolerance is: based on the measured thickness data of the rigid area, calculating the standard deviation, interquartile range or range of statistical quantities representing the degree of dispersion, and combining with the preset multiple such as 1.5 times the standard deviation to scale, to obtain the dynamic tolerance of the current plate.

[0043] Preferably, in an embodiment of the present application, the method for obtaining the dynamic tolerance is: according to the standard deviation σ of the measured thickness data, setting the dynamic tolerance as k·σ, wherein k is an empirical coefficient, usually between 1.0 and 2.0.

[0044] For example, if the standard deviation of the thickness of the rigid area is 0.02 mm, and k=1.5 is taken, then the dynamic tolerance is 0.03 mm; the implementer can adjust the value of k according to the measurement accuracy requirement.

[0045] Through the above operation, the tolerance parameter matched with the current plate state can be obtained, which provides a basis for the construction of a reasonable interval in the deviation comparison module.

[0046] The deviation comparison module is used to construct a reasonable interval of the thickness of the flexible area based on the measured thickness mean value and the dynamic tolerance of the rigid area, and compare the directly measured thickness of each point in the flexible area with the reasonable interval to determine whether the point is in the reasonable interval.

[0047] Considering that in the forming process of the rigid-flexible board, the thickness of the flexible area should theoretically be consistent with the rigid area or within a reasonable fluctuation range thereof, but due to factors such as flexible material characteristics, measurement interference or process fluctuation, the directly measured value may be abnormal. The traditional method generally presets a fixed threshold based on the product specification book, so the fixed threshold is used to judge whether the thickness of the flexible area is reasonable, but it is difficult to adapt to the actual thickness of the rigid area between different plates, and it is easy to cause misjudgment or omission.

[0048] Therefore, by taking the measured thickness mean value of the rigid area as a reference, and combining the tolerance dynamically generated based on the degree of dispersion thereof, a reasonable interval is constructed, which reflects the expected range of the thickness of the flexible area of the current plate.

[0049] Further, the specific content of the deviation comparison module includes: subtracting the dynamic tolerance from the measured thickness mean value of the rigid area to obtain the lower limit of the reasonable interval; adding the dynamic tolerance to the measured thickness mean value of the rigid area to obtain the upper limit of the reasonable interval, and the lower limit and the upper limit constitute the reasonable interval of the thickness of the flexible area.

[0050] For each measurement point in the flexible area, its directly measured thickness is compared with the lower limit of the reasonable interval and the upper limit of the reasonable interval respectively; if the thickness is less than the lower limit of the reasonable interval or greater than the upper limit of the reasonable interval, it is determined that the point is out of the reasonable interval, otherwise, it is determined that the point is in the reasonable interval.

[0051] The construction logic of the reasonable interval can be represented as: [μ-Δ, μ+Δ], where μ is the mean of the measured thickness of the rigid region, and Δ is the dynamic tolerance.

[0052] For example, if μ=0.80mm and Δ=0.03mm, the reasonable interval is [0.77mm, 0.83mm]; if the thickness of a flexible point is 0.85mm, it is determined to be out of range.

[0053] Through the above operation, potential abnormal points can be identified to provide input for effectiveness determination and correction in the thickness decision module.

[0054] The thickness decision module is used to adopt the directly measured thickness as the final thickness if a point is within the reasonable interval, and to determine the measurement effectiveness according to the local thickness fluctuation value and the laser reflection signal strength of the region where the point is located, and to adopt the mean thickness of adjacent valid measurement points in the same flexible region as the final thickness if the measurement is determined to be invalid.

[0055] Due to the influence of factors such as material deformation, surface reflection characteristic change and measurement interference during the forming process of the soft and hard combination board, some thickness measurement values may exceed the reasonable interval constructed based on the rigid region, but may not all be invalid abnormal values.

[0056] If all out-of-range points are simply removed or corrected, the real and valid local features may be damaged, affecting the accuracy and integrity of the final thickness result. Therefore, two dimensions of local thickness fluctuation value and laser reflection signal strength are introduced for joint effectiveness determination.

[0057] The local thickness fluctuation value reflects the uniformity of the thickness of the region around the point. If the fluctuation is severe, i.e., the standard deviation is an extreme value, it may indicate that there is measurement interference or structural abnormality. The laser reflection signal strength reflects the measurement signal quality. Extremely strong or weak reflection usually corresponds to unfavorable measurement conditions such as surface contamination and inclination.

[0058] By excluding points with both local fluctuation and reflection strength at extreme values, i.e., maximum or minimum, unreliable data caused by measurement noise or non-ideal surface state can be effectively identified and removed, while retaining out-of-range points with reasonable local consistency and good signal quality, thereby ensuring data robustness while avoiding excessive correction.

[0059] Further, as shown in Figure 2 The determination of measurement effectiveness includes: for the measurement points that exceed the reasonable interval, selecting adjacent measurement points in the same flexible region within a predetermined neighborhood radius centered on the measurement point, calculating the standard deviation of the thickness values of these points as the local thickness fluctuation value of the measurement point, and simultaneously obtaining the laser reflection signal strength of the measurement point.

[0060] Further, the maximum and minimum of the local thickness fluctuation value of all points beyond the reasonable interval and the maximum and minimum of the laser reflection signal intensity of all flexible region points are calculated; if the local thickness fluctuation value of the point is not equal to the extreme value of all fluctuation values and the laser reflection signal intensity is not equal to the extreme value of all signal intensities, it is determined that the point is measured effectively, otherwise it is determined to be invalid.

[0061] Since the local thickness fluctuation value is represented by calculating the standard deviation of the thickness of multiple adjacent measurement points in the neighborhood to represent the dispersion degree of the thickness distribution around the point, the statistical significance of the standard deviation depends on a sufficient number of samples. If the number of valid adjacent points in the neighborhood is less than two, when there is no other point in the neighborhood, the standard deviation cannot be calculated, and the local thickness fluctuation value is undefined; when there is only one point in the neighborhood, the standard deviation is always 0, which cannot reflect the true fluctuation and does not have the ability to distinguish, which is easy to cause misjudgment.

[0062] Therefore, if the number of adjacent measurement points in the preset neighborhood radius centered on the measurement point and belonging to the same flexible region is less than two, it is directly determined that the measurement point is invalid to avoid unreliable fluctuation value calculation.

[0063] For example, there is a measurement point P in a certain flexible region, and the direct measurement thickness of P is 0.18 mm, and the current reasonable interval is [0.20 mm, 0.24 mm], so P is beyond the reasonable interval. Then, 5 adjacent valid measurement points in the same flexible region are selected in a neighborhood with a radius of 3 mm centered on P, and the standard deviation of the thickness values of the 5 adjacent valid measurement points is 0.008 mm, which is taken as the local thickness fluctuation value of P. At the same time, the laser reflection signal intensity of P is recorded as 1250 a.u.

[0064] It should be noted that the value of the neighborhood radius should be greater than the minimum spacing of the sensor array to ensure that the neighborhood contains multiple valid measurement points, and at the same time, it should be less than the minimum feature size of the flexible region to avoid introducing interference data from other regions.

[0065] In a specific embodiment, the preset neighborhood radius is set to 5 mm, which corresponds to an array layout with a sensor spacing of 1 mm, and can cover about 20 adjacent measurement points.

[0066] Further, the maximum and minimum of the local thickness fluctuation value of all points beyond the reasonable interval and the maximum and minimum of the laser reflection signal intensity of all flexible region points are calculated; if the local thickness fluctuation value of the point is not equal to the extreme value of all fluctuation values and the laser reflection signal intensity is not equal to the extreme value of all signal intensities, it is determined that the point is measured effectively, otherwise it is determined to be invalid.

[0067] Considering the invalid points, if these points are directly discarded or replaced by global average values, large deviations may be introduced, which destroys the authenticity and continuity of the local thickness distribution. Therefore, when repairing the thickness of invalid points, the neighboring spatial range of the points is used to maintain the consistency of the local structural features.

[0068] To avoid including neighboring points that are valid but have significant thickness differences from the current point in the calculation, a local thickness continuity constraint is introduced, which only retains points with a thickness difference from other valid points in the neighborhood that does not exceed a dynamic tolerance. This tolerance itself is dynamically generated based on the actual fluctuation level of the current rigid region of the plate, which is process-adaptive, so it can reasonably define the physical boundaries of local continuity.

[0069] Further, when determined to be invalid, the thickness average of neighboring valid measurement points in the same flexible region is used as the final thickness, which specifically includes: selecting measurement points that have been determined to be valid within a predetermined neighborhood radius centered on the invalid point; further filtering the selected points to only retain points that satisfy the local thickness continuity constraint, i.e., the absolute value of the thickness difference between the point and other valid points in the neighborhood does not exceed the dynamic tolerance; calculating the arithmetic mean of the thickness of the filtered valid points as the final thickness of the invalid point.

[0070] For example, if there are 3 valid points in the neighborhood of an invalid point with thicknesses of 0.78mm, 0.79mm, and 0.82mm, and the dynamic tolerance is 0.03mm, then the pairwise difference between the three is ≤0.04mm, and if 0.04>0.03, then the 0.82mm point is removed, and the final average is .

[0071] Further, if the number of valid measurement points after filtering by the local thickness continuity constraint is zero, then calculate the arithmetic mean of all direct measurement thicknesses in the flexible region, and use this average as the final thickness of the invalid point.

[0072] Through the above operations, the measurement noise can be effectively suppressed while preserving the true thickness characteristics, providing reliable data for the flexible output module.

[0073] The flexible output module is used to aggregate the final thickness of all points in the flexible region to form the thickness result of the flexible region.

[0074] Specifically, the flexible output module includes: traversing all measurement points in the flexible region, collecting the final thickness data corresponding to each point one by one, and organizing and outputting according to the original coordinate position of each measurement point on the actual plate, thereby generating the complete thickness result of the flexible region.

[0075] Through the above operations, the intelligent and robust measurement of the thickness of the flexible region of the rigid-flexible combined board is completed.

[0076] Embodiment 2

[0077] Referring to Figure 3 As shown in the figure, the present application proposes a soft and hard combination plate forming thickness intelligent measurement method, comprising the following steps: S1, extracting the measured thickness data of the current plate rigid area and the measured thickness average value thereof and the whole plate thickness distribution, and extracting the direct measurement thickness of the corresponding point of the flexible area from the whole plate thickness distribution.

[0078] S2, based on the measured thickness data of the rigid area, determining the dynamic tolerance of the rigid area of the current plate.

[0079] S3, based on the measured thickness average value of the rigid area and the dynamic tolerance, constructing a reasonable interval of the thickness of the flexible area, comparing the direct measurement thickness of each point of the flexible area with the reasonable interval, and judging whether the point is in the reasonable interval.

[0080] S4, if a point is in the reasonable interval, the direct measurement thickness thereof is used as the final thickness, if it is out of the reasonable interval, the measurement effectiveness is determined according to the local thickness fluctuation value of the region where the point is located and the laser reflection signal strength, and when it is determined to be invalid, the thickness average value of the adjacent effective measurement point in the same flexible area is used as the final thickness.

[0081] S5, collecting the final thickness of all points of the flexible area to form the thickness result of the flexible area.

[0082] In summary, the present application constructs the reasonable interval of the flexible area by introducing the thickness average value of the rigid area and the dynamic tolerance, and verifies and intelligently corrects the effectiveness of the abnormal point by combining the double criteria of the local thickness fluctuation value and the laser reflection signal strength, realizes the accurate and anti-interference measurement of the soft and hard combination plate forming thickness, and improves the robustness and adaptability of the thickness detection.

[0083] The above embodiments can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When realized by software, the above embodiments can be realized in the form of a computer program product in whole or in part.

[0084] Those of ordinary skill in the art can realize that the algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0085] In addition, each function module in each embodiment of the present application can be integrated in one processing module, or each module can be physically present alone, or two or more modules can be integrated in one module.

[0086] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0087] Finally, the above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A smart measurement system for the forming thickness of a rigid-flex PCB, characterized in that, The method comprises the following steps: a thickness acquisition module is used to extract measured thickness data and a measured thickness average value of a rigid area of a current plate and a whole plate thickness distribution, and to extract a direct measurement thickness of a corresponding point of a flexible area from the whole plate thickness distribution; a stability evaluation module is used to determine a dynamic tolerance of the rigid area of the current plate based on the measured thickness data of the rigid area; a deviation comparison module is used to construct a reasonable interval of the thickness of the flexible area based on the measured thickness average value of the rigid area and the dynamic tolerance, to compare the direct measurement thickness of each point of the flexible area with the reasonable interval, and to determine whether the point is in the reasonable interval; a thickness decision module is used to adopt the direct measurement thickness of the point as a final thickness if the point is in the reasonable interval, to determine measurement effectiveness according to a local thickness fluctuation value of the area where the point is located and a laser reflection signal strength if the point is out of the reasonable interval, and to adopt a thickness average value of adjacent effective measurement points in the same flexible area as the final thickness if the measurement is determined to be invalid; a flexible output module is used to collect the final thickness of all points of the flexible area to form a flexible area thickness result; the extraction of the measured thickness average value of the rigid area of the current plate and the whole plate thickness distribution comprises the following steps: a pair of displacement sensor arrays corresponding in position are arranged on the outer sides of two opposite surfaces of a soft and hard combined plate to be measured to form a measurement unit group, wherein each sensor is arranged in a grid in an X-Y plane parallel to a theoretical main plane of the plate; the measurement axes of the two sensors in each measurement unit group are collinear, and the direction of the measurement axis is perpendicular to the theoretical main plane; and the displacement values of the side surfaces on which the sensors are located relative to a fixed reference surface along the measurement axis are synchronously collected; the fixed installation coordinates of the sensors in the array are used as the X and Y positions of the measurement points of the sensors, and the displacement values are combined to determine the position values of the measurement points along the measurement axis; a rigid and flexible area distribution map of the plate is obtained according to a process configuration file to determine a measurement point set corresponding to the rigid area; for each measurement point in the set, the absolute value of the difference between the position values of the two opposite surfaces of the measurement point along the measurement axis is used as the local thickness value of the measurement point; all local thickness values of the rigid area are arranged in ascending order, and the data of the first p% and the last p% are removed, and the remaining local thickness values are used as the measured thickness data of the rigid area, wherein p is a preset outlying proportion and 0 The determining measurement effectiveness comprises: for the measurement point exceeding the reasonable interval, selecting adjacent measurement points in the same flexible region within a preset neighborhood radius centered on the point, calculating the standard deviation of thickness values of the points in the neighborhood as the local thickness fluctuation value of the point, and simultaneously obtaining the laser reflection signal strength of the point; calculating the local thickness fluctuation values of all flexible region measurement points exceeding the reasonable interval to obtain the maximum value and the minimum value; calculating the laser reflection signal strengths of all flexible region measurement points to obtain the maximum value and the minimum value; if the local thickness fluctuation value of the point is not equal to the extreme value of all fluctuation values, and the laser reflection signal strength of the point is not equal to the extreme value of all signal strengths, it is determined that the point is measured effectively, otherwise it is determined to be invalid.

2. The system for intelligent measurement of the thickness of a rigid-flex printed circuit board according to claim 1, wherein The method for obtaining the directly measured thickness of the point corresponding to the flexible region comprises: In the process of synchronously obtaining the three-dimensional coordinates of the upper and lower surfaces of the plate by using the laser displacement sensor array, the laser reflection signal strength of each measurement point is synchronously recorded; According to the rigid-flexible region distribution map, the measurement point set located in the flexible region corresponding to the whole plate thickness distribution is screened; The maximum value and the minimum value of the laser reflection signal strengths of all the measurement points in the set are calculated; The measurement points with the laser reflection signal strength equal to the minimum value or equal to the maximum value in the set are removed, and the thickness value of the remaining measurement points is taken as the directly measured thickness of the point corresponding to the flexible region.

3. The system for measuring the thickness of a rigid-flex printed circuit board according to claim 1, wherein The method for obtaining the dynamic tolerance comprises: Based on the measured thickness data of the rigid region, the dynamic tolerance of the current plate is determined according to the discrete degree of the thickness distribution and combined with the preset multiple for scaling.

4. The system for measuring the thickness of a rigid-flex printed circuit board according to claim 1, wherein The specific content of the deviation comparison module comprises: The lower limit of the reasonable interval is obtained by subtracting the dynamic tolerance from the mean value of the measured thickness of the rigid region; The upper limit of the reasonable interval is obtained by adding the dynamic tolerance to the mean value of the measured thickness of the rigid region; The reasonable interval of the thickness of the flexible region is formed by the lower limit and the upper limit; For each measurement point in the flexible region, the directly measured thickness of the point is compared with the lower limit of the reasonable interval and the upper limit of the reasonable interval respectively; If the thickness is less than the lower limit of the reasonable interval or greater than the upper limit of the reasonable interval, it is determined that the point exceeds the reasonable interval, otherwise it is determined that the point is in the reasonable interval.

5. The intelligent system for measuring the thickness of a rigid-flex printed circuit board according to claim 4, wherein The calculation of the local thickness fluctuation value further comprises the following content: If the number of adjacent measurement points belonging to the same flexible region within the preset neighborhood radius centered on the measurement point is less than two, it is directly determined that the measurement of the measurement point is invalid.

6. The intelligent system for measuring the thickness of a rigid-flex printed circuit board according to claim 4, wherein When it is determined to be invalid, the thickness mean value of the adjacent valid measurement points in the same flexible region is taken as the final thickness, which comprises: Selecting the measurement points in the same flexible region within the preset neighborhood radius centered on the invalid point which have been determined to be valid; Further selecting the points satisfying the local thickness continuity constraint from the selected valid measurement points, wherein the local thickness continuity constraint is that the absolute value of the thickness difference between the point and other valid measurement points within the same preset neighborhood radius is not more than the dynamic tolerance; Calculating the arithmetic mean value of the thickness of the selected valid measurement points as the final thickness of the invalid point.

7. The system for intelligent measurement of the thickness of a rigid-flex printed circuit board according to claim 6, wherein The calculation of the arithmetic mean value of the thickness of the selected valid measurement points as the final thickness of the invalid point further comprises the following content: If the number of effective measurement points after the local thickness continuity constraint screening is zero, the arithmetic mean of all directly measured thicknesses in the flexible region is calculated, and the average value is taken as the final thickness of the invalid point.

8. A method for measuring the thickness of a rigid-flex printed circuit board, comprising the following steps performed by the system for measuring the thickness of a rigid-flex printed circuit board according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, extracting the measured thickness data and the measured thickness mean value of the rigid region of the current plate, and extracting the directly measured thickness of the corresponding point of the flexible region from the thickness distribution of the whole plate; S2, determining the dynamic tolerance of the rigid region of the current plate based on the measured thickness data of the rigid region; S3, constructing a reasonable interval of the thickness of the flexible region based on the measured thickness mean value and the dynamic tolerance of the rigid region, comparing the directly measured thickness of each point of the flexible region with the reasonable interval, and judging whether the point is in the reasonable interval; S4, if a point is in the reasonable interval, the directly measured thickness is taken as the final thickness, if it is out of the reasonable interval, the measurement effectiveness is determined according to the local thickness fluctuation value and the laser reflection signal strength of the region where the point is located, and when it is determined to be invalid, the thickness mean value of the adjacent effective measurement point in the same flexible region is taken as the final thickness; S5, the final thickness of all points in the flexible region is summarized to form the thickness result of the flexible region.

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