A PCB dielectric layer thickness measurement method, device, equipment and medium

Abstract

The application discloses a PCB board medium layer thickness measurement method, device and equipment and medium, including the following steps: obtaining the first thickness value of the target medium layer measured based on the capacitance test method; wherein, the target medium layer is the medium layer in the PCB board to be detected; obtaining the second thickness value of the sample medium layer measured based on the slice analysis; wherein, the sample medium layer is the medium layer in the sample PCB board, and the sample PCB board is the PCB board with the same structure as the PCB board to be detected and made based on the same process condition; obtaining the measurement thickness value of the target medium layer according to the first thickness value and the second thickness value; wherein, the measurement thickness value is the average value of the first thickness value and the second thickness value, and the application has the advantages of improving the measurement accuracy and realizing the non-destructive measurement of the PCB board to be detected.

Description

Technical Field

[0001] This application relates to the field of PCB board processing monitoring technology, and in particular to a method, device, equipment and medium for measuring the thickness of the dielectric layer of a PCB board. Background Technology

[0002] As the signal transmission rate of high-speed multilayer PCBs in the industry gradually increases, the requirements for signal stability also increase accordingly. In high-speed multilayer PCB manufacturing, poor impedance control can easily lead to signal loss, attenuation distortion, and signal noise during high-speed signal transmission and at the terminal. Dielectric layer thickness is one of the main factors affecting impedance; therefore, it is essential to strictly control the thickness of the dielectric layer between PCB layers to improve PCB impedance stability.

[0003] The thickness of the PCB dielectric layer cannot be effectively and accurately adjusted during the lamination process. Currently, the thickness of the PCB dielectric layer after lamination is mainly measured by destructive methods such as slicing. This measurement method is very one-sided, has low accuracy, and directly slicing the PCB board can easily cause product scrap. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, device, and medium for measuring the thickness of the dielectric layer of a PCB board, aiming to solve the technical problem of low accuracy in existing PCB dielectric layer thickness measurement methods.

[0005] To achieve the above objectives, this application provides a method for measuring the dielectric layer thickness of a PCB board, comprising the following steps: Obtain the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; Obtain the second thickness value of the sample dielectric layer based on slice analysis; wherein, the sample dielectric layer is the dielectric layer in the sample PCB board, and the sample PCB board is a PCB board with the same structure as the PCB board to be tested and manufactured under the same process conditions; The measured thickness value of the target dielectric layer is obtained based on the first thickness value and the second thickness value; wherein the measured thickness value is the average of the first thickness value and the second thickness value.

[0006] Optionally, obtaining a second thickness value of the sample medium layer based on slice analysis includes: Obtain the slice information of the sample PCB board to obtain the slice thickness value of the sample dielectric layer; Obtain a depth image after drilling at the target location on the sample PCB board, and obtain the predicted thickness value of the sample dielectric layer based on the depth image; wherein, the drilling depth must penetrate the sample dielectric layer, and the target location is the location where the thickness uniformity of the sample dielectric layer is concentrated. Based on the slice thickness value and the predicted thickness value, the second thickness value of the sample medium layer is obtained; wherein, the second thickness value is the average of the slice thickness value and the predicted thickness value.

[0007] Optionally, obtain the slice information of the sample PCB board to obtain the slice thickness value of the sample dielectric layer, including: Obtain the first slice information based on the first side slice of the sample PCB board; Based on the first slice information, obtain the first average thickness of the sample medium layer located on the first side; Obtain the second slice information based on the second side slice of the sample PCB board; wherein, the second side is the side of the sample PCB board adjacent to the first side. Based on the second slice information, obtain the second average thickness of the sample medium layer located on the second side. The slice thickness value of the sample medium layer is obtained based on the first average thickness and the second average thickness; wherein the slice thickness value is the average of the first average thickness and the second average thickness.

[0008] Optionally, a depth image is obtained after drilling at the target location on the sample PCB board, and the predicted thickness value of the sample dielectric layer is obtained based on the depth image, including: Obtain the first depth image after the first drilling at the target location on the sample PCB board; wherein, the first drilling only penetrates the upper substrate, and the upper substrate is a board material disposed on the top surface of the sample dielectric layer; Based on the first depth image, obtain the first borehole depth h1; Acquire a second depth image after the second drilling at the target location on the sample PCB board; wherein the second drilling penetrates the sample dielectric layer. Based on the second depth image, obtain the second borehole depth h2; Obtain the predicted thickness value H of the sample medium layer; where H = h2 - h1.

[0009] Optionally, the method for determining the target location includes: A first location point is obtained in the sample medium layer located on the first side; wherein the thickness of the sample medium layer at the first location point is closest to the average thickness of the first location point. A second location point is obtained in the sample medium layer located on the second side; wherein the thickness of the sample medium layer at the second location point is closest to the average thickness of the second location point. A first extension line is constructed into the sample medium layer starting from a first location point, and a second extension line is constructed into the sample medium layer starting from a second location point; wherein, the first extension line is parallel to the length direction of the second side, and the second extension line is parallel to the length direction of the first side. Obtain the intersection point of the first extension line and the second extension line within the sample medium layer; Construct a vertical line upwards from the intersection point, and use the intersection of the vertical line and the upper substrate as the target position.

[0010] Optionally, after obtaining the second thickness value of the sample medium layer measured based on slice analysis, the method further includes: Obtain the thickness difference between the second thickness value and the first thickness value; Determine whether the thickness difference is less than the preset theoretical difference; If yes, proceed to the next step; otherwise, return to obtain the first thickness value of the target dielectric layer measured by the capacitance test method.

[0011] Optionally, capacitance testing methods include: Select two capacitor plates of corresponding sizes and determine the effective area S of the two capacitor plates facing each other to form a parallel plate capacitor. Obtain the dielectric constant ε of the PCB board to be tested after lamination; The test capacitance C is obtained by testing the PCB board under test with a parallel plate capacitor. The first thickness value d is obtained based on the detection capacitance C; where d = εS / C.

[0012] To achieve the above objectives, this application also provides a PCB board dielectric layer thickness measuring device, comprising: The first acquisition module is used to acquire the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; The second acquisition module is used to acquire the second thickness value of the sample dielectric layer measured based on slice analysis; wherein, the sample dielectric layer is the dielectric layer in the sample PCB board, and the sample PCB board is a PCB board with the same structure as the PCB board to be tested and manufactured under the same process conditions. The third acquisition module is used to acquire the measured thickness value of the target dielectric layer based on the first thickness value and the second thickness value; wherein the measured thickness value is the average of the first thickness value and the second thickness value.

[0013] To achieve the above objectives, this application also provides a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0014] To achieve the above objectives, this application also provides a computer-readable storage medium storing a computer program, on which a processor executes the computer program to implement the above-described method.

[0015] The beneficial effects that this application can achieve are as follows: This application can measure the first thickness value of the target dielectric layer in the PCB board under test using the capacitance test method. However, considering the risk of data distortion and large measurement error due to relying solely on the capacitance test method, a second thickness value of the sample dielectric layer in the sample PCB board is also measured based on slice analysis. The average of the first and second thickness values ​​is output as the measured thickness value. Since the sample PCB board has the same structure and is manufactured under the same process conditions as the PCB board under test, the test results based on the sample PCB board can represent the thickness measurement of the target dielectric layer in the PCB board under test. At the same time, the average of the thickness values ​​obtained by the two different test methods can accurately characterize the measured thickness of the target dielectric layer in the PCB board under test, thereby overcoming the drawback of data distortion caused by unilateral test results. Furthermore, using the sample PCB board for slice analysis measurement eliminates the need to slice the PCB board under test, thus achieving non-destructive measurement of the PCB board under test, avoiding product scrapping, and ensuring measurement accuracy. This achieves two goals at once and can meet the current high-precision and high-requirement measurement requirements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a flowchart illustrating a method for measuring the dielectric layer thickness of a PCB board according to an embodiment of this application; Figure 2 This is a schematic diagram illustrating the principle of calculating the predicted thickness of the sample dielectric layer on a sample PCB board based on two drilling operations in an embodiment of this application. Figure 3 This is a schematic diagram illustrating the principle of determining the target position on a sample PCB board in an embodiment of this application.

[0018] Figure label: 110 - Sample dielectric layer, 120 - Upper substrate, 130 - Lower substrate, 140 - First side surface, 150 - Second side surface, 160 - First position point, 170 - Second position point, 180 - First extension line, 190 - Second extension line, 210 - Vertical line, 220 - Target position.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application. Example 1

[0024] Reference Figures 1-3 This embodiment provides a method for measuring the dielectric layer thickness of a PCB board, including the following steps: Obtain the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; Obtain the second thickness value of the sample dielectric layer 110 based on slice analysis; wherein, the sample dielectric layer 110 is the dielectric layer in the sample PCB board, and the sample PCB board is a PCB board with the same structure as the PCB board to be tested and manufactured under the same process conditions. The measured thickness value of the target dielectric layer is obtained based on the first thickness value and the second thickness value; wherein the measured thickness value is the average of the first thickness value and the second thickness value.

[0025] In this embodiment, the first thickness value of the target dielectric layer in the PCB board under test can be measured by capacitance testing. However, considering the risk of data distortion and large measurement error due to relying solely on capacitance testing, the second thickness value of the sample dielectric layer 110 in the sample PCB board is also measured based on slice analysis. The average of the first and second thickness values ​​is output as the measured thickness value. Since the sample PCB board has the same structure and is manufactured under the same process conditions as the PCB board under test, the test results based on the sample PCB board can represent the thickness measurement of the target dielectric layer in the PCB board under test. At the same time, the average of the thickness values ​​obtained by the two different test methods can accurately characterize the measured thickness of the target dielectric layer in the PCB board under test, thereby overcoming the drawback of data distortion caused by unilateral test results. Furthermore, using the sample PCB board for slice analysis measurement eliminates the need to slice the PCB board under test, thus achieving non-destructive measurement of the PCB board under test, avoiding product scrapping, and ensuring measurement accuracy. This achieves two goals at once and meets the current high-precision and high-requirement measurement requirements.

[0026] It should be noted that the basic structure of both the PCB board to be tested and the sample PCB board includes a dielectric layer, as well as an upper substrate 120 and a lower substrate 130 connected to the top and bottom surfaces of the dielectric layer, respectively. The dielectric layer in the middle is the object layer to be measured.

[0027] As an optional implementation, obtaining a second thickness value of the sample medium layer 110 based on slice analysis includes: Obtain the slice information of the sample PCB board to obtain the slice thickness value of the sample dielectric layer 110; Obtain a depth image after drilling at the target location 220 on the sample PCB board. Based on the depth image, obtain the predicted thickness value of the sample dielectric layer 110. The drilling depth must penetrate the sample dielectric layer 110, and the target location is the location where the thickness uniformity of the sample dielectric layer 110 is concentrated. Based on the slice thickness value and the predicted thickness value, the second thickness value of the sample medium layer 110 is obtained; wherein, the second thickness value is the average of the slice thickness value and the predicted thickness value.

[0028] In this embodiment, when calculating the second thickness value of the sample dielectric layer 110, measurement error is also taken into consideration. Here, the slice thickness value of the sample dielectric layer 110 is first obtained through the slice information of the sample PCB board. Then, after drilling at the target position 220 of the sample PCB board, a depth image can be acquired. Since the target position is the location where the thickness uniformity of the sample dielectric layer 110 is concentrated, the depth image after drilling at the target position 220 not only reflects the drilling depth, but also reflects the uniform thickness of the sample dielectric layer 110 from the side, i.e., the predicted thickness value. This avoids the situation where the thickness data measured by drilling at random positions of the sample dielectric layer 110 with non-uniform thickness is too large or too small, further improving the data accuracy. Finally, the average value of the slice thickness value and the predicted thickness value is output as the second thickness value. Therefore, this embodiment simultaneously characterizes the thickness of the sample dielectric layer 110 from two dimensions: sample PCB board slice measurement and depth image measurement. This can reduce the risk of large errors caused by a single measurement and further improve the measurement accuracy.

[0029] As an optional implementation, the slice information of the sample PCB board is obtained to obtain the slice thickness value of the sample dielectric layer 110, including: Obtain the first slice information based on the first side 140 slice of the sample PCB board; Based on the first slice information, the first average thickness of the sample medium layer 110 located on the first side 140 is obtained; Obtain the second slice information based on the second side 150 of the sample PCB board; wherein, the second side 150 is the side of the sample PCB board adjacent to the first side 140. Based on the second slice information, the second average thickness of the sample medium layer 110 located on the second side 150 is obtained; The slice thickness value of the sample medium layer 110 is obtained based on the first average thickness value and the second average thickness value; wherein the slice thickness value is the average of the first average thickness value and the second average thickness value.

[0030] In this embodiment, when calculating the slice thickness value, since there may be uneven thickness of the sample dielectric layer 110, in order to improve the measurement accuracy, slice measurements are performed from the first side 140 and the second side 150 adjacent to the sample PCB board, and the first slice information and the second slice information are obtained respectively, thereby obtaining the first average thickness and the second average thickness. Finally, the average of the first average thickness and the second average thickness is output as the slice thickness value of the sample dielectric layer 110. The obtained slice thickness value can accurately and effectively characterize the thickness distribution of the sample dielectric layer 110, thereby providing accurate measurement data to further improve the accuracy of the final measurement result.

[0031] It should be noted that when calculating the first average thickness and the second average thickness, multiple measurement points can be selected on the sample medium layer 110 on the corresponding side, the thickness of the sample medium layer 110 at the location of each measurement point can be calculated, and then the average value of the multiple thickness data can be output as the average thickness of the corresponding side.

[0032] As an optional implementation, a depth image is obtained after drilling at the target location 220 on the sample PCB board. Based on the depth image, the predicted thickness value of the sample dielectric layer 110 is obtained, including: Obtain the first depth image after the first drilling at the target position 220 on the sample PCB board; wherein, the first drilling only penetrates the upper substrate 120, and the upper substrate 120 is a board material disposed on the top surface of the sample dielectric layer 110. Based on the first depth image, obtain the first borehole depth h1; Acquire a second depth image after the second drilling at the target location 220 on the sample PCB board; wherein the second drilling penetrates the sample dielectric layer 110. Based on the second depth image, obtain the second borehole depth h2; Obtain the predicted thickness value H of the sample medium layer 110; where H = h2 - h1.

[0033] In this embodiment, when calculating the predicted thickness value, a hole is first drilled at the target position 220 of the sample PCB board. Since the first drilling only penetrates the upper substrate 120, the corresponding hole depth data (i.e., the first drilling depth h1) can be measured based on the first depth image of the sample PCB board after the first drilling. The first drilling depth h1 is the thickness of the upper substrate 120. Then, a second drilling is carried out based on the same target position 220. This time, only the sample dielectric layer 110 is drilled, and a second depth image with drilling depth information can be obtained, which yields the second drilling depth h2. h2 is the total thickness of the sample dielectric layer 110 and the upper substrate 120. Therefore, based on the depth image information after the two drillings, the first drilling depth h1 and the second drilling depth h2 can be accurately obtained. The difference between the two is the predicted thickness value H of the sample dielectric layer 110. This method is more accurate and effective than physical measurement, further improving the accuracy of the measurement data.

[0034] As an optional implementation, the method for determining the target location 220 includes: A first location point 160 is obtained in the sample medium layer 110 located on the first side 140; wherein the thickness of the sample medium layer 110 at the first location point 160 is closest to the first average thickness. A second location point 170 is obtained in the sample medium layer 110 located on the second side 150; wherein the thickness of the sample medium layer 110 at the second location point 170 is closest to the average thickness of the second thickness. A first extension line 180 is constructed into the sample medium layer 110 starting from the first position point 160, and a second extension line 190 is constructed into the sample medium layer 110 starting from the second position point 170; wherein, the first extension line 180 is parallel to the length direction of the second side 150, and the second extension line 190 is parallel to the length direction of the first side 140. Obtain the intersection point of the first extension line 180 and the second extension line 190 within the sample medium layer 110; A vertical line 210 is constructed upward from the intersection point, and the intersection point of the vertical line 210 and the upper substrate 120 is used as the target position 220.

[0035] In this embodiment, the positions closest to the first and second average thickness values ​​can be found in the sample dielectric layer 110 of the first side 140 and the second side 150, respectively, and marked as the first position point 160 and the second position point 170. Then, based on the first position point 160 and the second position point 170, the intersection point can be obtained by extending into the sample dielectric layer 110. The position of the intersection point is the position in the sample dielectric layer 110 that is relatively close to its uniform thickness. Therefore, a vertical line 210 is constructed upward from the intersection point. The intersection point of the vertical line 210 and the upper substrate 120 can be used as a relatively ideal target position 220, which provides a prerequisite for obtaining an accurate predicted thickness value in the future.

[0036] It should be noted that when finding the first location point 160, multiple evenly spaced measurement points can be selected on the first side 140 to obtain the thickness sample data of the sample medium layer 110 corresponding to the multiple measurement points. The average value of the multiple thickness sample data is the first thickness average value. The measurement point corresponding to the thickness sample data that is closest to the first thickness average value is selected as the target measurement point. Then, multiple alternative measurement points are selected on both sides of the target measurement point. The position of the alternative measurement points does not exceed the adjacent measurement points. The thickness sample data of the sample medium layer 110 corresponding to the alternative measurement points is obtained. Then, the point whose corresponding thickness sample data is closest to the first thickness average value is selected again from the target measurement point and alternative measurement points. This point is taken as the final first location point 160. Similarly, the method for finding the second location point 170 is the same. For example, five evenly spaced measurement points are selected on the first side 140 to measure the thickness data as a, b, c, d, and e respectively. The first average thickness m can be obtained as (a+b+c+d+e) / 5. Then, the point whose thickness sample data is closest to the first average thickness m among a, b, c, d, and e is selected. Taking measurement point b as an example, multiple candidate measurement points b1, b2, b3...bn are selected on both sides of measurement point b. The candidate measurement points are between measurement points a and c. The thickness sample data of the sample medium layer 110 corresponding to the candidate measurement points b1, b2, b3...bn are obtained. The point closest to the first average thickness is selected again. For example, if it is candidate measurement point b2, then b2 is marked as the first position point 160.

[0037] In other embodiments, the target position 220 can also be determined by constructing a reference coordinate system. First, the simulated point cloud data of the sample PCB board is obtained. The reference coordinate system is constructed with the geometric center of the sample PCB board as the origin. The coordinate information of the first position point 160 and the second position point 170 in the reference coordinate system is obtained, and the coordinate information of the target position 220 can be determined, which is accurate and efficient.

[0038] As an optional implementation, after obtaining the second thickness value of the sample medium layer 110 measured based on slice analysis, the method further includes: Obtain the thickness difference between the second thickness value and the first thickness value; Determine whether the thickness difference is less than the preset theoretical difference; If yes, proceed to the next step; otherwise, return to obtain the first thickness value of the target dielectric layer measured by the capacitance test method.

[0039] In this embodiment, after measuring the first thickness value and the second thickness value respectively, there may be a situation where one of the measurement results has an excessively large error. Under normal circumstances, the two measurement results should not differ much. Therefore, the authenticity of the first thickness value and the second thickness value is further checked here. That is, the thickness difference between the second thickness value and the first thickness value is compared with the preset theoretical difference. The theoretical difference is the difference between the two measurement results within the normal error range. If the thickness difference is less than the theoretical difference, it means that the two measurement results are normal and can proceed to the next step. If not, it means that one of the measurement results is distorted (the situation where both measurement results are distorted is extremely rare and will not be considered for the time being). In this case, the measurements are re-performed to further ensure the authenticity and validity of the measurement results and to ensure measurement accuracy.

[0040] As an optional implementation method, the capacitance test method includes: Select two capacitor plates of corresponding sizes and determine the effective area S of the two capacitor plates facing each other to form a parallel plate capacitor. Obtain the dielectric constant ε of the PCB board to be tested after lamination; The test capacitance C is obtained by testing the PCB board under test with a parallel plate capacitor. The first thickness value d is obtained based on the detection capacitance C; where d = εS / C.

[0041] In this embodiment, when performing capacitance testing, two capacitor plates of corresponding sizes are selected according to the testing requirements. The effective area S of the two capacitor plates facing each other can be determined, and the dielectric constant ε of the PCB board to be tested after pressing can be obtained (which can be obtained by consulting relevant technical manuals). When the parallel plate capacitor formed by the two capacitor plates is used to test the PCB board to be tested, the detection capacitance C can be obtained. The expression for the detection capacitance C is: C=εS / d, from which the first thickness value d=εS / C can be derived. Here, after multiple tests, data with obviously distorted test results can be removed, and the average value of the remaining test data is used as the first thickness value d, realizing non-destructive measurement, and the measurement data is accurate and effective. Example 2

[0042] Reference Figures 1-3 Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a PCB board dielectric layer thickness measuring device, comprising: The first acquisition module is used to acquire the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; The second acquisition module is used to acquire the second thickness value of the sample dielectric layer 110 measured based on slice analysis; wherein, the sample dielectric layer 110 is the dielectric layer in the sample PCB board, and the sample PCB board is a PCB board with the same structure as the PCB board to be tested and manufactured based on the same process conditions. The third acquisition module is used to acquire the measured thickness value of the target dielectric layer based on the first thickness value and the second thickness value; wherein the measured thickness value is the average of the first thickness value and the second thickness value.

[0043] The explanations and examples of each module in the device of this embodiment can be referred to the methods of the foregoing embodiments, and will not be repeated here. Example 3

[0044] Based on the same inventive concept as the foregoing embodiments, this embodiment provides a computer device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. Example 4

[0045] Based on the same inventive concept as the foregoing embodiments, this embodiment provides a computer-readable storage medium storing a computer program, and a processor executes the computer program to implement the above-described method.

[0046] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for measuring the thickness of the dielectric layer on a PCB board, characterized in that, Includes the following steps: Obtain the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; Obtaining a second thickness value of a sample dielectric layer based on slice analysis; wherein the sample dielectric layer is a dielectric layer in a sample PCB board, and the sample PCB board is a PCB board with the same structure and manufactured under the same process conditions as the PCB board to be tested; including: obtaining slice information of the sample PCB board to obtain a slice thickness value of the sample dielectric layer; obtaining a depth image after drilling a hole at a target location on the sample PCB board, and obtaining a predicted thickness value of the sample dielectric layer based on the depth image; wherein the drilling depth needs to penetrate the sample dielectric layer, and the target location is a location where the thickness uniformity of the sample dielectric layer is concentrated; obtaining a second thickness value of the sample dielectric layer based on the slice thickness value and the predicted thickness value; wherein the second thickness value is the average of the slice thickness value and the predicted thickness value; The step of obtaining slice information of the sample PCB board to obtain the slice thickness value of the sample dielectric layer includes: obtaining first slice information based on a slice of a first side of the sample PCB board; obtaining a first average thickness of the sample dielectric layer located on the first side based on the first slice information; obtaining second slice information based on a slice of a second side of the sample PCB board; wherein the second side is a side of the sample PCB board adjacent to the first side; obtaining a second average thickness of the sample dielectric layer located on the second side based on the second slice information; obtaining the slice thickness value of the sample dielectric layer based on the first average thickness and the second average thickness; wherein the slice thickness value is the average of the first average thickness and the second average thickness. The step of acquiring a depth image after drilling a hole at the target location on the sample PCB board, and acquiring a predicted thickness value of the sample dielectric layer based on the depth image, includes: acquiring a first depth image after drilling a hole for the first time at the target location on the sample PCB board; wherein the first drilling only penetrates the upper substrate, and the upper substrate is a board material disposed on the top surface of the sample dielectric layer; acquiring a first drilling depth h1 based on the first depth image; acquiring a second depth image after drilling a hole for the second time at the target location on the sample PCB board; wherein the second drilling penetrates the sample dielectric layer; acquiring a second drilling depth h2 based on the second depth image; and acquiring a predicted thickness value H of the sample dielectric layer; wherein H = h2 - h1. The method for determining the target location includes: obtaining a first location point in the sample medium layer located on the first side; wherein the thickness of the sample medium layer at the first location point is closest to the first average thickness; obtaining a second location point in the sample medium layer located on the second side; wherein the thickness of the sample medium layer at the second location point is closest to the second average thickness; constructing a first extension line into the sample medium layer starting from the first location point, and constructing a second extension line into the sample medium layer starting from the second location point; wherein the first extension line is parallel to the length direction of the second side, and the second extension line is parallel to the length direction of the first side; obtaining the intersection point of the first extension line and the second extension line in the sample medium layer; constructing a vertical line upward from the intersection point, and using the intersection point of the vertical line and the upper substrate as the target location; The measured thickness value of the target dielectric layer is obtained based on the first thickness value and the second thickness value; wherein the measured thickness value is the average of the first thickness value and the second thickness value.

2. The method for measuring the dielectric layer thickness of a PCB board as described in claim 1, characterized in that, After obtaining the second thickness value of the sample medium layer measured based on slice analysis, the method further includes: Obtain the thickness difference between the second thickness value and the first thickness value; Determine whether the thickness difference is less than a preset theoretical difference; If yes, proceed to the next step; otherwise, return to the step of obtaining the first thickness value of the target dielectric layer measured by the capacitance test method.

3. The method for measuring the dielectric layer thickness of a PCB board as described in claim 1, characterized in that, The capacitance testing method includes: Select two capacitor plates of corresponding sizes and determine the effective area S of the two capacitor plates facing each other to form a parallel plate capacitor. Obtain the dielectric constant ε of the PCB board to be tested after lamination; The PCB board under test is tested using the parallel plate capacitor to obtain the test capacitance C. The first thickness value d is obtained based on the detection capacitor C; where d = εS / C.

4. A PCB board dielectric layer thickness measuring device, characterized in that, include: The first acquisition module is used to acquire the first thickness value of the target dielectric layer measured by the capacitance test method; wherein, the target dielectric layer is the dielectric layer in the PCB board to be tested; The second acquisition module is used to acquire a second thickness value of the sample dielectric layer measured based on slice analysis; wherein the sample dielectric layer is a dielectric layer in a sample PCB board, and the sample PCB board is a PCB board with the same structure and manufactured under the same process conditions as the PCB board to be tested; the module includes: acquiring slice information of the sample PCB board to obtain a slice thickness value of the sample dielectric layer; acquiring a depth image after drilling a hole at a target position on the sample PCB board, and acquiring a predicted thickness value of the sample dielectric layer based on the depth image; wherein the drilling depth needs to penetrate the sample dielectric layer, and the target position is a position where the thickness uniformity of the sample dielectric layer is concentrated; acquiring a second thickness value of the sample dielectric layer based on the slice thickness value and the predicted thickness value; wherein the second thickness value is the average of the slice thickness value and the predicted thickness value; The step of obtaining slice information of the sample PCB board to obtain the slice thickness value of the sample dielectric layer includes: obtaining first slice information based on a slice of a first side of the sample PCB board; obtaining a first average thickness of the sample dielectric layer located on the first side based on the first slice information; obtaining second slice information based on a slice of a second side of the sample PCB board; wherein the second side is a side of the sample PCB board adjacent to the first side; obtaining a second average thickness of the sample dielectric layer located on the second side based on the second slice information; obtaining the slice thickness value of the sample dielectric layer based on the first average thickness and the second average thickness; wherein the slice thickness value is the average of the first average thickness and the second average thickness. The step of acquiring a depth image after drilling a hole at the target location on the sample PCB board, and acquiring a predicted thickness value of the sample dielectric layer based on the depth image, includes: acquiring a first depth image after drilling a hole for the first time at the target location on the sample PCB board; wherein the first drilling only penetrates the upper substrate, and the upper substrate is a board material disposed on the top surface of the sample dielectric layer; acquiring a first drilling depth h1 based on the first depth image; acquiring a second depth image after drilling a hole for the second time at the target location on the sample PCB board; wherein the second drilling penetrates the sample dielectric layer; acquiring a second drilling depth h2 based on the second depth image; and acquiring a predicted thickness value H of the sample dielectric layer; wherein H = h2 - h1. The method for determining the target location includes: obtaining a first location point in the sample medium layer located on the first side; wherein the thickness of the sample medium layer at the first location point is closest to the first average thickness; obtaining a second location point in the sample medium layer located on the second side; wherein the thickness of the sample medium layer at the second location point is closest to the second average thickness; constructing a first extension line into the sample medium layer starting from the first location point, and constructing a second extension line into the sample medium layer starting from the second location point; wherein the first extension line is parallel to the length direction of the second side, and the second extension line is parallel to the length direction of the first side; obtaining the intersection point of the first extension line and the second extension line in the sample medium layer; constructing a vertical line upward from the intersection point, and using the intersection point of the vertical line and the upper substrate as the target location; The third acquisition module is used to acquire the measured thickness value of the target dielectric layer based on the first thickness value and the second thickness value; wherein the measured thickness value is the average value of the first thickness value and the second thickness value.

5. A computer device, characterized in that, The computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a PCB board dielectric layer thickness measurement method as described in any one of claims 1-3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and the processor executes the computer program to implement a PCB board dielectric layer thickness measurement method as described in any one of claims 1-3.

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