Method for controlling thickness of copper on surface of PCB (Printed Circuit Board) and PCB
Through the laser system combined with the copper thickness measurement system, the precise control of the copper thickness on the surface of the PCB board is achieved, the problem of copper thickness is solved, the accuracy and production efficiency of the etching process are improved, the cost is reduced and environmental pollution is reduced.
Patent Information
- Application Number
- CN202510519794.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-24
- Publication Date
- 2025-07-18
AI Technical Summary
The prior art is difficult to efficiently and accurately control the copper thickness on the surface of PCB board, resulting in uneven copper thickness, affecting the accuracy and reliability of the etching process, and the chemical potency copper reduction process has the problem of polluting the environment.
The laser system is combined with the copper thickness measurement system, and the amount of copper to be reduced is calculated by measuring the current copper thickness value and the expected copper thickness, and the laser parameters are adjusted according to the copper foil material parameters to accurately reduce copper, so as to achieve automatic control of copper thickness.
It achieves a high consistency in the thickness of copper on the surface of the PCB board, improves the accuracy and reliability of the etching process, reduces artificial operation errors, reduces production costs, reduces environmental pollution, and is suitable for large-scale production.
Smart Images
Figure CN120343820A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of PCB board manufacturing, and specifically relates to a method for controlling the copper thickness of a PCB board surface and a PCB board. Background Art
[0002] With the development of multi-layer PCB boards, due to factors such as inner layer circuit design, different stack-up material combinations, and changes in lamination parameters, the surface copper foil thickness of the PCB is not on the same horizontal line, resulting in different copper thickness values at different points on the same PCB board after electroplating (such as Figure 1 the huge difference in copper thickness fluctuations between the left 1 and middle 2 regions in ). The uneven copper thickness poses a severe challenge to the circuit etching process and restricts the development of the etching process towards thinner line widths and smaller line spacings.
[0003] Currently, the main methods for controlling the copper thickness of PCB include electroless copper plating, electroplating process, and chemical solution copper reduction process. In the electroless copper plating process, traditional electroless copper plating methods have problems such as complex operation, long process, and inability to be fully automated. Slight operation errors are likely to cause the problem of no copper in the holes, resulting in board scrapping.
[0004] In the electroplating process, the quality of acid copper electroplating directly affects the quality of the electroplated copper layer and related mechanical properties, and has a certain impact on subsequent processing.
[0005] The current chemical solution copper reduction process has the problem of inconsistent removal of surface copper thickness. Moreover, the chemical solution reacts with the PCB board in a large area, and it is impossible to achieve copper reduction in a very small area or with high precision, and it is unable to well control the copper uniformity of the entire board surface, resulting in a large fluctuation in the copper thickness range on the surface of the same PCB board. In addition, the chemical solution generated by using the solution to remove copper has the problem of environmental pollution. Summary of the Invention
[0006] One of the purposes of the present invention is to avoid the deficiencies in the prior art and provide a method for controlling the copper thickness of a PCB board surface, which can efficiently and accurately control the copper thickness of the PCB board, and has the advantages of high automation and environmental protection.
[0007] Another purpose of the present invention is to provide a PCB board.
[0008] To achieve the above purpose one, the present invention provides the following technical solutions:
[0009] Provide a method for controlling the copper thickness of a PCB board surface, including the following steps:
[0010] Use a copper thickness measurement system to measure the copper thickness value Tx of the current area of the PCB board surface, and obtain the expected copper thickness T 预 of the PCB board. Subsequently, calculate the target copper amount, T目标 = T 预 + T 余 , T 余 is the safety margin, T 预 , T 余 > 0;
[0011] Calculate the copper amount to be subtracted △T, △T = Tx - T 目标 ,
[0012] When △T > 0, transmit the △T value and the copper foil material parameters of the PCB board surface to the laser system. The laser system adjusts the laser parameters according to the △T value and the copper foil material parameters and performs laser copper subtraction on the current area of the PCB board surface to obtain Tx. Tx is the copper thickness after copper subtraction. If T 余 ≥ Tx - T 目标 ≥ 0, it meets the copper thickness requirement; otherwise, it does not meet the copper thickness requirement;
[0013] When △T ≤ 0, there is no need to remove the copper amount on the current area of the PCB board surface.
[0014] In some embodiments, the copper thickness measurement system first divides the PCB board surface into several regions, and then measures the copper thickness of each region of the PCB board surface respectively.
[0015] The step of dividing into several regions includes:
[0016] Position and feed the PCB board into the copper thickness measurement system. The copper thickness measurement system identifies the identification code of the PCB board and correspondingly obtains the characteristic data of the current PCB board. The copper thickness measurement system divides the PCB board surface into several regions according to the characteristic data.
[0017] In some embodiments, the identification code of the PCB board includes a two-dimensional code or a positioning hole.
[0018] In some embodiments, the characteristic data includes graphic characteristic data. The copper thickness measurement system divides the PCB board into several regions according to the graphic characteristics.
[0019] In some embodiments, the copper thickness measurement system uses a measurement probe to obtain the copper thickness value Tx. When the spot R value of the measurement probe is greater than the area of the site to be detected, the copper thickness measurement system uses the estimation method to obtain the average value of the copper thickness values near the site as the actual copper thickness of the site.
[0020] In some embodiments, the measurement probe obtains the copper thickness value by means of capacitance thickness measurement, X-ray fluorescence or laser interference.
[0021] In some embodiments, the steps of performing laser copper subtraction on the current area of the PCB board surface include:
[0022] After completing the current laser copper reduction, the copper thickness measurement system measures the copper thickness value Tx of the PCB board surface in the current area again. If T 余 <Tx - T 目标 , then laser copper reduction is performed again; if Tx < T 预 , then the PCB board is reworked and electroplated again.
[0023] In some embodiments, the T 余 is 0.5 μm.
[0024] In some embodiments, the laser parameters include the number of laser guns, the spot route, the repetition frequency, the laser energy, and the laser defocus amount.
[0025] Advantages of the method for controlling the copper thickness of the PCB board surface according to the present invention:
[0026] By performing dot / line laser copper reduction on the PCB board surface through the laser system, the copper thickness of the entire board can be made highly consistent. This solves the problem of poor copper thickness uniformity in the traditional chemical copper reduction process, ensuring the accuracy and reliability of the etching process; throughout the process, the copper thickness measurement system and the laser system are used jointly to remove copper, with a high degree of automation. The laser system automatically adjusts the laser parameters according to the detected copper thickness and copper foil material parameters, reducing human operation errors and improving production efficiency; the laser system can automatically adjust the laser parameters according to the copper thickness to be removed and the copper foil material, achieving precise copper reduction. This precise control ability enables the copper thickness to reach the set value, ensuring the quality and performance of the PCB board; due to the high degree of automation and strong controllability, the present invention is suitable for large-scale production and application. This helps to improve production efficiency, reduce costs, and at the same time ensure the consistency of product quality; by precisely controlling the copper thickness, the present invention can improve the electrical conductivity, durability, and stability of the PCB board. This is particularly important for high-density interconnect (HDI) boards or high-frequency circuits. The laser copper reduction process can precisely remove the excess copper layer, reducing material waste. This not only reduces production costs but also improves resource utilization efficiency. Compared with the traditional chemical copper reduction process, the laser copper reduction process does not use chemical potions, can reduce environmental pollution, and also solves the disadvantage of poor copper reduction uniformity in the traditional chemical copper reduction process, which meets the requirements of modern manufacturing for environmental protection.
[0027] To achieve the second above-mentioned object, the present invention provides the following technical solution:
[0028] Provide a PCB board prepared by the above method for controlling the copper thickness of the PCB board surface. Description of the Drawings
[0029] Figure 1 is a schematic diagram of the copper thickness fluctuation in different areas of the PCB board.
[0030] Figure 2 It is a schematic diagram of the division of each region in Experimental Example 1.
[0031] Figure 3 It is a schematic diagram of the copper thickness measurement in the estimation region in Experimental Example 1.
[0032] Figure 4 It is a schematic diagram of the laser processing removal amount in Experimental Example 1.
[0033] Figure 5 It is a schematic diagram of the control method for the copper thickness on the PCB board surface in Experimental Example 1. Detailed implementation manners
[0034] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.
[0035] Embodiment 1
[0036] The control method for the copper thickness on the PCB board surface disclosed in this embodiment includes the following steps:
[0037] Measure the copper thickness value Tx of the PCB board surface in the current region using a copper thickness measurement system, and simultaneously obtain the expected copper thickness T 预 , and then calculate the target copper amount, T 目标 = T 预 + T 余 , where T 余 is the safety margin, and T 预 , T 余 > 0;
[0038] T 目标 is obtained by adding the safety margin to the expected copper thickness, that is, T 目标 = T 预 + T 余 .
[0039] Among them, since there will be detection errors when the copper thickness measurement system measures the copper amount, it will cause the problem that the laser system reduces too much copper and damages the PCB board. Therefore, a certain safety margin T 余 is reserved on the expected copper thickness to avoid the problem of damaging the PCB board.
[0040] Specifically, the copper thickness value Tx of the PCB board surface in the current area is obtained through a copper thickness measurement system, which is a known device commonly used for measuring copper thickness. Exemplarily, such as the Fischer copper thickness gauge PMP10, X-ray fluorescence spectrometer, etc. At the same time, the copper thickness measurement system is connected to the MES system, and the copper thickness measurement system can also obtain the target copper thickness T 目标 .
[0041] Calculate the copper amount to be subtracted △T, △T = Tx - T 目标 ,
[0042] The copper amount to be subtracted is obtained through the above calculation formula, so as to know the copper amount that needs to be subtracted from the copper thickness of the current PCB board surface. At the same time, it can be judged whether it is necessary to subtract copper according to the value of △T
[0043] When △T > 0, the △T value and the copper foil material parameters of the PCB board surface are transmitted to the laser system. The laser system adjusts the laser parameters according to the △T value and the copper foil material parameters and performs laser copper subtraction on the PCB board surface in the current area to obtain Tx, where Tx is the copper thickness after copper subtraction. If T 余 ≥Tx - T 目标 ≥0, then the copper thickness requirement is met; otherwise, the copper thickness requirement is not met
[0044] Tx is the copper thickness after copper subtraction. At this time, it is also necessary to judge whether the copper thickness after copper subtraction meets the requirements. Specifically, if T 余 <Tx - T 目标 , it means that the error between the copper thickness of the PCB board after copper subtraction and the target copper thickness is greater than T 余 , and it is still too thick and does not meet the requirements. In addition, if Tx is less than T 预 , it means that the copper thickness of the PCB board after copper subtraction is less than the expected copper thickness (less than the standard value) and does not meet the requirements. Therefore, only when T 余 ≥Tx - T 目标 ≥0 does the copper thickness requirement meet the copper thickness requirement
[0045] Specifically
[0046] When △T > 0, it means that the copper thickness of the current PCB board surface is too much and laser copper subtraction treatment needs to be carried out
[0047] The measured △T value and the copper foil material parameters of the PCB board surface are transmitted to the laser system. These parameters can be obtained through the automatic measurement equipment of the laser system and transmitted to the control unit of the laser system through a data interface (such as RS232, USB or network interface)
[0048] The laser system has an intelligent unit, which can automatically adjust parameters such as the power, pulse width, frequency and scanning speed of the laser according to the received △T value and copper foil material parameters, and according to the stored database. The specific adjustment method is as follows
[0049] Adjust the laser power according to the thickness of the copper foil (i.e., the △T value) and its material to ensure sufficient energy to remove the excess copper layer. For example, for thicker copper foils, higher laser power may be required.
[0050] Pulse width and frequency: Select appropriate pulse width and frequency according to the material characteristics of the copper foil. Shorter pulse width and higher frequency can reduce the heat affected zone and improve the precision of copper reduction.
[0051] Scanning speed: Adjust the scanning speed of the laser according to the △T value and the copper foil thickness. Too fast scanning speed may result in uneven copper reduction, while too slow scanning speed will reduce production efficiency.
[0052] The laser system performs laser copper reduction on the PCB board surface of the current area according to the adjusted parameters. The operation steps are as follows:
[0053] Use the vision positioning system (such as a CCD camera) of the laser system to accurately position the PCB board to ensure that the laser beam can accurately act on the area where copper reduction is required.
[0054] The laser beam scans the PCB board surface according to the preset path and parameters to remove the excess copper layer. During the copper reduction process, the copper layer thickness is monitored in real time to ensure the uniformity of copper reduction.
[0055] Real-time monitor the copper layer thickness through an on-line monitoring device (such as an optical sensor) to ensure that the copper thickness Tx after copper reduction meets the requirements.
[0056] When the monitored copper thickness value Tx reaches T 余 ≥Tx - T 目标 ≥0, the laser system automatically stops the copper reduction operation.
[0057] When △T ≤ 0, there is no need to remove the copper amount on the PCB board surface of the current area.
[0058] When △T ≤ 0, it means that there is no excess copper amount to be removed from the current copper amount of the PCB board, and there is no need to perform laser copper reduction anymore. Among them, when △T < 0, the PCB board will be reworked.
[0059] The copper thickness measurement system first divides the PCB board surface into several areas, and then controls the copper thickness of the PCB board surface in each area respectively.
[0060] The step of dividing into several areas includes:
[0061] Position and feed the PCB board into the copper thickness measurement system. The copper thickness measurement system identifies the identification code of the PCB board and correspondingly obtains the characteristic data of the current PCB board. The copper thickness measurement system divides the PCB board surface into several areas according to the characteristic data.
[0062] Since the PCB board has a certain area and different copper thickness requirements in different areas of the PCB board, dividing the PCB board into different areas can perform copper reduction treatment targeted, improving the accuracy and efficiency of copper reduction. Among them, the copper thickness measurement system is connected to the MES system, and the identity code of the PCB board is stored in the MES system. The copper thickness measurement system can call out the characteristic data of the PCB board by identifying the identity code of the PCB board, and then can divide the PCB board into different areas according to the characteristic data.
[0063] In this embodiment, the identity code of the PCB board includes a two-dimensional code or a positioning hole.
[0064] In this embodiment, the characteristic data includes graphic characteristic data, and the copper thickness measurement system divides the PCB board into several areas according to the graphic characteristics.
[0065] This graphic data can be CAD data or gerber data, and these data reflect the characteristics of the PCB board surface. To ensure the accuracy of area division, the PCB board surface needs to be divided according to the actual situation, and regular graphics cannot be used for division so as not to cause inaccurate division and inaccurate subsequent copper thickness measurement. Therefore, after area division, the boundary lines between adjacent areas will be irregular.
[0066] In this embodiment, the copper thickness measurement system uses a measurement probe to obtain the copper thickness value Tx. When the spot R value of the measurement probe is greater than the area of the site to be detected, the copper thickness measurement system uses the estimation method to obtain the average value of the copper thickness values near the site as the actual copper thickness of the site.
[0067] As Figure 3 shown, since the boundary lines between adjacent areas will be irregular, there will be dead corners. When the spot R value (resolution) of the measurement probe of the PCB board copper thickness measurement system is less than the area of the sites at the boundary in each divided area, the detection spot cannot detect the dead corners, so the estimation method is used, and the average value of the nearby copper thickness is used to represent the actual copper thickness of the area, as much as possible to ensure the accuracy of the measured copper thickness.
[0068] In this embodiment, the measurement probe obtains the copper thickness value by means of a capacitance thickness gauge, X-ray fluorescence or laser interference.
[0069] In this embodiment, the steps of laser copper reduction on the PCB board surface of the current area include:
[0070] After completing the current laser copper reduction, the copper thickness measurement system measures the copper thickness value Tx of the PCB board surface of the current area again. If T 余 <Tx - T 目标, then perform laser copper reduction again; if Tx < T 预 , then rework the PCB board and perform re - electroplating treatment.
[0071] After one copper reduction is completed, it is necessary to re - measure whether the copper reduction amount meets the standard. If Tx > T 目标 , and T 余 < Tx - T 目标 , it means that there is still an unqualified copper amount, and copper reduction treatment needs to be performed again. If Tx < T 预 , it means that the copper reduction is excessive, then rework the PCB board and perform re - electroplating treatment, and repair the PCB board again.
[0072] In this embodiment, the T 余 is 0.5μm. The T 余 value can be adjusted according to the actual situation.
[0073] In this embodiment, the laser parameters include the number of laser guns, the spot route, the repetition frequency, the laser energy, and the laser defocus amount.
[0074] Effect verification
[0075] To further illustrate the effect of controlling the copper thickness of the PCB board surface by the control method of the present invention, the following tests are carried out:
[0076] Test example 1
[0077] As Figure 5 shown, divide the PCB board with the copper thickness to be controlled into areas. First, the PCB board enters the copper thickness measurement system. The CCD camera of the copper thickness measurement system identifies the QR code and positioning holes of the board, and records the identity, surface number, and orientation information of the PCB board. At this time, the CAD or gerber data of the PCB board already exists in the copper thickness measurement system. The copper thickness measurement system divides the copper thickness measurement areas (BGA area, clock area, in - board area, board - edge area) according to the priority, and measures the BGA area (area A) > clock area (area B) > other in - board areas (area C) > board - edge area (area D) in the order of priority. The principle of area division is an irregular figure, and circular or standard figures cannot be used for division, otherwise the irregular figure cannot accurately divide the area. The combined repeated edges are exactly all the in - board or board - edge areas of the entire PCB board, and the in - board partition schematic diagram as shown in Figure 2 is obtained.
[0078] The measurement probe of the PCB board copper thickness measurement system, the resolution of the measurement probe is less than the minimum fillet R value of the boundary in each divided area. If the detection spot cannot detect the dead angle, the estimation method is used, and the average value of the nearby copper thickness is used to represent the actual copper thickness of the area ( Figure 3 ).
[0079] Measurement record of copper thickness of PCB board by the copper thickness measurement system. The MES system sets the target copper thickness T of the copper thickness 目标 (The expected copper thickness plus the safety margin, both the expected copper thickness and the safety margin have been recorded). The copper thickness measurement probe measures the copper thickness values Tx of different regions in order of priority, which are T1 A , T2 A …TN A ; T1 B , T2 B… TN B ,..., and so on, to obtain the measured copper thickness and target copper thickness values of each region in the following table. The target copper thicknesses TT1, TT2, TT3, TT4 of each region can be equal or unequal according to process requirements. The condition needs to be min{T1 x , T2 x ,…TN x}>TTi to ensure that there is enough copper thickness margin to be removed. It should be noted that the measurement range of the probe is generally large, reaching several square millimeters, which is much larger than the area of the laser spot of several hundred square micrometers. Therefore, the detected copper thickness margin is the average copper thickness. The target copper thickness is the expected copper thickness plus the safety margin. This is because there will be detection errors during the detection process. In order to prevent detection errors, a safety margin is added to the expected copper thickness (which can be understood as the standard copper thickness value) to obtain the target copper thickness. For example, in Table 1, by determining the expected copper thickness (not shown in the table) and the safety margin (not shown in the table), the target copper thickness can be obtained. The copper amount to be subtracted is the copper amount that the laser needs to remove.
[0080] Table 1
[0081]
[0082] The laser processing copper reduction system uses single-point laser focusing to process copper materials. The laser parameters are first determined according to information such as the type and roughness of the copper foil to determine the ablation threshold (the spot energy density within the Rayleigh length). After the laser sets the ablation threshold and the spot scans within the region, as Figure 4 shown, then adjust the Z focus to scan from top to bottom (the Z focus descent range), and the scanning range is the detected copper thickness ±2μm. After the laser processes all regions to the target copper thickness, it stops to obtain Tx. The target copper thickness is obtained by adding the expected copper thickness and the safety margin, making the copper thickness after reducing the copper slightly larger than the expected copper thickness to avoid the problem of over-reducing the copper.
[0083] After laser copper reduction processing, the regional partition remains unchanged. The probe measures the copper thickness of these regions again to detect whether the current copper thickness value Tx satisfies: T 余 ≥Tx - T 目标 ≥0. If T 余 <Tx - T 目标, then laser copper etching is carried out again. In this case, the out-of-tolerance area needs to be marked and laser copper etching is started. If Tx < T 预 , then mark this PCB and remove or reverse plate it in subsequent processes.
[0084] Among them, the detected surface copper thickness range Tx before copper etching is 10.3 - 12.5 (BGA area), 9.7 - 11.6 (clock area). At this time, the target thickness is the expected copper thickness + safety margin. Among them, the target copper thickness is 9.0μm and the safety margin is 0.5μm. Using laser copper etching, the copper thickness can be controlled within a specific range of 9.1 - 9.3 (BGA area), 9.1 - 9.3 (clock area). The results are shown in Table 2.
[0085] Table 2
[0086]
[0087] If the results after laser copper etching are all within the range of 9.5μm, it indicates that the requirements are met. As can be seen from Table 2, the present invention can efficiently and accurately control the copper thickness of the PCB, making the copper thickness reach the required range.
[0088] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps described in these embodiments do not limit the scope of the present application. At the same time, it should be understood that technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values.
[0089] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are usually based on the orientation or positional relationships, and are only for the convenience of describing the present application and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.
[0090] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures of the device. The exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used herein.
[0091] In addition, it should be noted that the use of terms such as "first", "second" etc. to define components is only for the convenience of differentiating the corresponding components. Without additional statement, the above terms have no special meaning, and thus should not be construed as limiting the scope of protection of this application.
[0092] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A method for controlling the copper thickness of a PCB board surface, characterized in that Including the following steps: Measure the copper thickness value Tx of the PCB board surface in the current area using a copper thickness measurement system, and obtain the expected copper thickness T of the PCB board 预 , then calculate the target copper amount, T 目标 = T 预 + T 余 , T 余 is the safety margin, T 预 , T 余 > 0; Calculate the copper amount to be subtracted △T, where △T = Tx - T 目标 , When △T > 0, the value of △T and the copper foil material parameters of the PCB board surface are transmitted to the laser system. The laser system adjusts the laser parameters according to the value of △T and the copper foil material parameters and performs laser copper reduction on the PCB board surface in the current area to obtain Tx. Tx is the copper thickness after copper reduction. If T 余 ≥ Tx - T 目标 ≥ 0, it meets the copper thickness requirement; otherwise, it does not meet the copper thickness requirement. When △T≤0, there is no need to remove the copper amount on the PCB board surface of the current area.
2. The method for controlling the copper thickness of the PCB board surface according to claim 1, wherein The copper thickness measurement system first divides the PCB board surface into several areas, and then measures the copper thickness of the PCB board surface in each area respectively; The step of dividing into several areas includes: Position the PCB board and feed it into the copper thickness measurement system. The copper thickness measurement system identifies the identification code of the PCB board and correspondingly obtains the characteristic data of the current PCB board. The copper thickness measurement system divides the PCB board surface into several areas according to the characteristic data.
3. The method for controlling the copper thickness of the PCB board surface according to claim 2, wherein, The identification code of the PCB board includes a two-dimensional code or a positioning hole.
4. The method for controlling the copper thickness of the PCB board surface according to claim 2, wherein, The characteristic data includes graphic characteristic data, and the copper thickness measurement system divides the PCB board into several areas according to the graphic characteristics.
5. The control method for the copper thickness of the PCB board surface according to claim 1, characterized in that The copper thickness measurement system uses a measurement probe to obtain the copper thickness value Tx. When the spot R value of the measurement probe is greater than the area of the site to be detected, the copper thickness measurement system uses the estimation method to obtain the mean value of the copper thickness values near the site as the actual copper thickness of the site.
6. The control method for the copper thickness of the PCB board surface according to claim 5, characterized in that, The measurement probe obtains the copper thickness value by means of capacitance thickness measurement, X-ray fluorescence or laser interference.
7. The control method for the copper thickness of the PCB board surface according to claim 1, wherein The step of laser copper removal on the PCB board surface of the current area includes: After completing the current laser copper reduction, the copper thickness measurement system measures the copper thickness value Tx of the PCB board surface in the current area again. If T 余 <Tx - T 目标 , then laser copper reduction is performed again; if Tx < T 预 , then the PCB board is reworked and electroplated again.
8. The method for controlling the copper thickness of the PCB board surface according to claim 1, wherein, The said T 余 is 0.5 μm.
9. The method for controlling the copper thickness of the PCB board surface according to claim 1, wherein, The laser parameters include the number of laser guns, the spot route, the repetition frequency, the laser energy, and the laser defocus amount.