PCB processing method and system

Abstract

According to the PCB processing method and system provided by the invention, the to-be-adjusted micro-area is determined by acquiring the dielectric constant distribution map and performing alignment with the design data, and the laser parameters are determined according to the deviation to perform local irradiation adjustment, so that the problem that the dielectric constant of a dielectric layer is locally uneven and is difficult to actively regulate and control in the prior art is effectively solved; therefore, active and spatially selective fine tuning or compensation of local dielectric constant distribution of a specific area on the PCB is realized, so as to reduce micro-area dielectric constant difference caused by inherent non-uniformity of materials and limitation of a traditional process; therefore, the time sequence offset caused by the mismatching of the effective dielectric constants of the differential signal pair is reduced, and finally the purposes of improving the transmission quality of the high-frequency and high-speed signal and improving the performance consistency and the production yield of the PCB product are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit board (PCB) manufacturing, and in particular to a PCB board processing method and system. Background Art

[0002] The material that constitutes the insulating dielectric layer of a PCB is typically a composite of a specific resin system and glass fiber cloth. Glass fiber cloth is composed of interwoven warp and weft yarns, with inherent interstices between the yarn bundles. During the lamination process, the semi-cured resin softens and flows under predetermined conditions of high temperature and high pressure, filling the gaps between the glass fiber cloth and the inner layer copper foil patterns, ultimately solidifying and forming the laminate. During the actual lamination process, various factors can lead to uneven resin distribution across microscopic areas. A deeper problem stems from the microstructure of the glass fiber cloth: even under ideal processing conditions, there are fundamental differences in material composition between areas where glass fiber bundles are concentrated and areas where the interstices between the yarns are filled with resin. The dielectric constant of glass fiber is significantly higher than that of commonly used resins. This localized fluctuation in dielectric constant, caused by microscopic inhomogeneities in material composition, is known in the industry as the "glass fiber effect" or "glass fiber weave effect."

[0003] Current approaches to improving the glass fiber effect in the PCB industry focus on improving the materials themselves, such as developing new glass fabric weave structures and optimizing resin formulations. However, these high-end materials are expensive, and their effectiveness remains limited under certain extreme performance requirements. More critically, these approaches primarily optimize materials during the material selection phase. During the actual PCB lamination process, there is a lack of a means to proactively monitor and specifically control the uniformity of local dielectric properties. Dielectric uniformity assessment of finished laminated boards often relies on small-batch spot tests using expensive equipment or predictions based on simulation combined with empirical evidence. This makes it impossible to accurately and non-destructively adjust the dielectric constant distribution of critical signal areas on each PCB in real-time, online or near-line. This is particularly true for small-batch, high-variety, high-value, high-end PCB products. Micro-area dielectric constant variations caused by factors such as the glass fiber effect can lead to product scrap or substandard performance if they cannot be effectively controlled or compensated for during the manufacturing process.

[0004] In view of the above problems, the existing technology is in urgent need of improvement. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present application provides a PCB board processing method and system that can actively and spatially selectively fine-tune or compensate the local dielectric constant distribution in specific areas of the PCB board, thereby reducing the dielectric constant differences in micro-areas caused by inherent material non-uniformity and limitations of traditional processes. This in turn reduces the timing offset of differential signal pairs caused by effective dielectric constant mismatch, ultimately achieving the goal of improving the quality of high-frequency and high-speed signal transmission, and enhancing the performance consistency and production yield of PCB products.

[0006] This application provides a PCB board processing method, the technical points of which are: Methods include: Obtaining a dielectric constant distribution map of a dielectric layer in a predetermined area of ​​a PCB board; the predetermined area is an area on a laminated PCB board that carries critical high-speed signals; Align the dielectric constant distribution map with the PCB design wiring data to identify the micro-area to be adjusted where the dielectric constant value deviates from the target range, and determine its physical coordinate position on the PCB board and the dielectric constant deviation value; A laser irradiation parameter is determined according to the dielectric constant deviation of the micro-region to be adjusted, and laser is applied to the micro-region to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted.

[0007] The above solution solves the problem in the prior art that the local dielectric constant of the PCB dielectric layer is uneven and difficult to actively control, and achieves precise and local adjustment of the dielectric constant of key areas.

[0008] To further solve the problem, the present application further proposes that, according to the above-mentioned PCB board processing method, laser light is applied to the micro-region to be adjusted based on laser irradiation parameters, so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted, including: The applied laser energy interacts with the dielectric layer resin in the micro-region to be adjusted, thereby changing the microstructure or chemical state of the dielectric layer resin, thereby causing the dielectric constant of the micro-region to be adjusted to move toward a target range.

[0009] Through the above scheme, the specific mechanism of laser adjustment of dielectric constant is clarified, and the feasibility and controllability of the scheme are improved.

[0010] To further solve the problem, the present application further proposes, based on the above-mentioned PCB board processing method, determining a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted, including: Obtaining the material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence model between the laser irradiation parameters and the dielectric constant change amount established in advance based on the modeling material characteristic parameters; Compare the actual material characteristic parameters with the modeled material characteristic parameters to determine the material difference parameters; Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model; Based on the dielectric constant deviation of the micro-region to be adjusted and using the corrected corresponding relationship model, the laser irradiation parameters are determined.

[0011] Through the above scheme, a laser parameter determination method that takes material differences into consideration is provided, thereby improving the accuracy and robustness of dielectric constant adjustment.

[0012] To further solve the problem, the present application further proposes that, according to the above-mentioned PCB board processing method, the correspondence model is corrected according to the material difference parameters to generate a corrected correspondence model, including: Analyze the nonlinear influence characteristics of material difference parameters on the corresponding relationship model; Based on the nonlinear influence characteristics, an adjustment function of the nonlinear relationship between the material difference parameters and the corresponding relationship model adjustment amount is constructed; The material difference parameter is input into the adjustment function to obtain the adjustment amount of the correspondence relationship model, and the correspondence relationship model is adjusted based on the adjustment amount to generate a corrected correspondence relationship model.

[0013] Through the above scheme, the model correction process is further refined, and the accuracy of parameter determination is improved through nonlinear functions.

[0014] To further solve the problem, the present application further proposes that, according to the above-mentioned PCB board processing method, laser is applied to the micro-area to be adjusted based on the laser irradiation parameters, and the method further includes: Analyze the target resin-poor area to identify a first sub-area where the glass fibers are densely distributed or the resin cover is thin; the target resin-poor area is an area with a high dielectric constant due to uneven distribution of glass fibers; For the first sub-region, an auxiliary medium is applied to the resin surface of the first sub-region using a trace material deposition technique; wherein the auxiliary medium is a protective layer having a reflective function for the selected laser wavelength, or an absorption enhancer capable of enhancing the resin's absorption of laser energy; adjusting the laser irradiation parameters used for irradiation according to the material properties of the applied auxiliary medium; the laser irradiation parameters include laser power, laser pulse width or laser scanning speed; The first sub-region is laser irradiated according to the adjusted laser irradiation parameters to form a microporous structure in the resin material.

[0015] Through the above scheme, a pretreatment scheme is provided for the resin-poor area, and a new way is provided for adjusting the dielectric constant of specific areas through auxiliary medium and micropore formation.

[0016] To further solve the problem, the present application further proposes that, according to the above-mentioned PCB board processing method, the first sub-region is laser irradiated according to the adjusted laser irradiation parameters to form a microporous structure in the resin material, and then the method further includes: Determine a sealing material having a dielectric constant lower than that of the resin substrate in the resin-poor area; the sealing material can form a protective layer with a barrier effect after curing; The micropores in the first sub-region are filled with a sealing material and then cured.

[0017] Through the above scheme, a filling scheme after the micropores are formed is provided, and the local dielectric properties are further optimized by using low dielectric constant materials.

[0018] To further solve the problem, the present application also proposes, based on the above-mentioned PCB board processing method, constructing an adjustment function for the nonlinear relationship between the material difference parameter and the corresponding relationship model adjustment amount based on the nonlinear influence characteristics, including: Obtaining a preset interval of laser irradiation parameters and a dielectric constant adjustment target value corresponding to a current adjustment operation; Based on a preset interval of the laser irradiation parameter and a target value for dielectric constant adjustment, determining a nonlinear influence characteristic description corresponding to a current adjustment operation from a predefined data structure; the predefined data structure storing a plurality of nonlinear influence characteristic descriptions, wherein each nonlinear influence characteristic description in the predefined data structure corresponds to a specific combination of a laser irradiation parameter interval and a target value for dielectric constant adjustment; Based on the description of nonlinear influence characteristics, an adjustment function is constructed to characterize the nonlinear relationship between material difference parameters and the adjustment amount of the corresponding relationship model.

[0019] Through the above scheme, a specific method for constructing a nonlinear adjustment function is provided, making the model correction process more systematic and operational.

[0020] To further solve the problem, the present application further proposes that, according to the above-mentioned PCB board processing method, laser light is applied to the micro-region to be adjusted based on laser irradiation parameters, so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted. Thereafter, the method further includes: The dielectric constant of the micro area to be adjusted is detected. If the dielectric constant still does not reach the target range, the laser irradiation parameters are determined again until the dielectric constant of the micro area to be adjusted reaches the target range.

[0021] Through the above scheme, a feedback mechanism is introduced to ensure that the dielectric constant adjustment reaches the target value, thereby improving the yield and consistency of processing.

[0022] To further solve the problem, this application also proposes a PCB board processing system, the technical points of which are: The system includes: An acquisition module is used to obtain a dielectric constant distribution map of a dielectric layer in a predetermined area of ​​a PCB board; the predetermined area is an area on the laminated PCB board that carries key high-speed signals; The determination module is used to align the dielectric constant distribution map with the PCB design wiring data, identify the micro-area to be adjusted whose dielectric constant value deviates from the target range, and determine its physical coordinate position on the PCB board and the dielectric constant deviation value; The irradiation processing module is used to determine a laser irradiation parameter according to the dielectric constant deviation of the micro-area to be adjusted, and apply laser to the micro-area to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-area to be adjusted to change the dielectric constant of the micro-area to be adjusted.

[0023] Through the above solution, a system for implementing the above method is provided, which facilitates automated and integrated production.

[0024] To improve the solution, this application also proposes that, according to the above-mentioned PCB board processing system, the irradiation processing module is also used to: Obtaining the material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence model between the laser irradiation parameters and the dielectric constant change amount established in advance based on the modeling material characteristic parameters; Compare the actual material characteristic parameters with the modeled material characteristic parameters to determine the material difference parameters; Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model; The laser irradiation parameters are determined based on the dielectric constant deviation of the micro-region to be adjusted and using the corrected corresponding relationship model.

[0025] Through the above solution, modules and functions for realizing accurate parameter determination in the system are provided.

[0026] In summary, the PCB processing method and system provided in this application effectively solves the problem in the prior art of difficulty in actively regulating the local unevenness of the dielectric constant of the dielectric layer by obtaining a dielectric constant distribution map, aligning it with the design data to determine the micro-area to be adjusted, and determining the laser parameters based on the deviation to perform local irradiation adjustment. This method and system achieves active and spatially selective fine-tuning or compensation of the local dielectric constant distribution in specific areas of the PCB board, thereby reducing the micro-area dielectric constant differences caused by inherent material heterogeneity and traditional process limitations, thereby reducing the timing offset of differential signal pairs caused by effective dielectric constant mismatch, ultimately achieving the purpose of improving the quality of high-frequency and high-speed signal transmission, and enhancing the performance consistency and production yield of PCB products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a flow chart of the steps of the PCB board processing method disclosed in an embodiment of the present invention; Figure 2 This is a schematic structural diagram of a PCB board processing system disclosed in an embodiment of the present invention; DETAILED DESCRIPTION Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this embodiment belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit this embodiment. The terms "including" and "having" and any variations thereof in the specification and claims of this embodiment and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this embodiment and the accompanying drawings are used to distinguish different objects, not to describe a specific order.

[0029] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] It should be noted that the “plurality” mentioned in this article refers to two or more.

[0031] The following is a detailed description of the implementation details of the technical solution of this embodiment: In the first aspect of this embodiment, a PCB board processing method is implemented. Figure 1 , Figure 1 1 is a flow chart of a PCB processing method disclosed in an embodiment of the present invention. The method comprises: S101, obtaining a dielectric constant distribution map of a dielectric layer in a predetermined area of ​​a PCB board; the predetermined area is an area on the laminated PCB board that carries key high-speed signals; S102, aligning the dielectric constant distribution map with the PCB design wiring data, determining the micro-area to be adjusted whose dielectric constant value deviates from the target range, and determining its physical coordinate position on the PCB board and the dielectric constant deviation value; S103, determining a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted, and applying laser to the micro-region to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted.

[0032] Among them, obtaining the dielectric constant distribution map of the dielectric layer in a predetermined area of ​​the PCB board refers to obtaining the spatial distribution of the dielectric constant of the insulating dielectric layer in a specific area of ​​the laminated PCB board through non-destructive testing means. It can be achieved by using scanning near-field microwave microscopy, terahertz time-domain spectroscopy or other high-resolution dielectric property scanning technologies. It is mainly used to obtain the actual dielectric property data of the key signal area; the predetermined area is the area on the laminated PCB board that carries key high-speed signals, which refers to a specific wiring area on the PCB board that has extremely high signal integrity requirements and is easily affected by uneven dielectric constants, such as the area below the high-speed differential signal line pair or adjacent areas, the purpose of which is to focus the detection and adjustment on the key parts that have the most direct impact on product performance; aligning the dielectric constant distribution map with the PCB design wiring data refers to accurately matching the actually measured dielectric constant distribution data with the original PCB design file (including wiring, stacking structure and other information) in space, the purpose of which is to establish the relationship between the actual dielectric performance deviation and the design layout, so as to determine which deviations are critical and need to be adjusted; determining the micro-area to be adjusted where the dielectric constant value deviates from the target range means identifying the tiny area where the dielectric constant value is significantly different from the design requirement or ideal value based on the alignment results, the purpose of which is to identify the micro-area where the dielectric constant value is significantly different from the design requirement or ideal value based on the alignment results. The purpose of the laser irradiation process is to accurately locate the specific location where the dielectric constant needs to be corrected; to determine the physical coordinate position and dielectric constant deviation value on the PCB board, which means recording the precise spatial coordinates of these micro-areas to be adjusted on the PCB board and the specific value and direction (higher or lower) of their dielectric constant deviation from the target value, with the purpose of providing positioning and parameter basis for subsequent precise laser processing; to determine a laser irradiation parameter based on the dielectric constant deviation of the micro-area to be adjusted, which means calculating or finding the laser processing parameter combination required to correct the deviation based on the degree and direction of the dielectric constant of the micro-area to be adjusted from the target value, with the purpose of ensuring that the laser processing can produce the desired effect. The dielectric constant change during the period; applying laser to the micro-area to be adjusted based on the laser irradiation parameters refers to using laser processing equipment to accurately apply laser energy to the micro-area to be adjusted according to determined parameters, with the purpose of initiating a physical or chemical change process of the dielectric layer material; allowing the applied laser to interact with the dielectric layer resin in the micro-area to be adjusted to change the dielectric constant of the micro-area to be adjusted refers to exchanging energy with the resin material in the dielectric layer through laser energy, resulting in changes in the microstructure, density or chemical bonds of the resin material, thereby causing a change in the overall dielectric constant of the area, with the purpose of achieving precise regulation of the local dielectric constant.

[0033] The core innovation of this application lies in aligning the dielectric constant distribution map of the key areas of the laminated PCB board with the PCB design wiring data, accurately locating and quantifying the dielectric constant deviation, and determining the laser irradiation parameters based on the deviation, thereby using the laser to selectively process specific micro-areas, achieving non-destructive fine-tuning of the local dielectric constant after lamination, effectively compensating for the glass fiber effect, and improving the integrity of high-speed signals.

[0034] The solution of this application obtains a dielectric constant distribution map of the critical high-speed signal areas on a laminated PCB board, providing a direct assessment of the actual dielectric performance of the finished board. This distribution map is necessary because traditional macroscopic testing cannot reveal dielectric constant fluctuations in microscopic areas. The acquisition of spatially resolved dielectric constant distribution data makes subsequent precise positioning and adjustment possible. This acquired dielectric constant distribution map is then aligned with the PCB design routing data. This alignment is necessary because the design data contains the precise locations of signal traces and the dielectric performance requirements. By combining this with actual measurement data, it is possible to identify dielectric constant deviations located below or adjacent to critical signal paths, where the deviation is significant enough to affect signal transmission. This alignment and analysis allows the identification of micro-areas to be adjusted where the dielectric constant value deviates from the target range, and their physical coordinates and dielectric constant deviation values ​​are determined. This provides the necessary location and quantitative information for subsequent local precision processing. The dielectric constant deviation of the micro-areas to be adjusted is then used to determine the laser irradiation parameters required to correct this deviation. The reason for determining parameters based on deviation is that different deviation values ​​require different levels of laser energy to achieve the target dielectric constant change, which reflects the targeted and precise nature of the adjustment. Finally, based on the determined laser irradiation parameters, laser light is applied to the micro-region to be adjusted, allowing the laser light to interact with the dielectric layer resin within the micro-region, thereby changing the dielectric constant of the micro-region. Applying laser light is the core means of achieving local changes in the dielectric constant. The interaction between laser energy and the resin can cause changes such as ablation, carbonization, structural rearrangement, or the formation of micropores in the resin, all of which affect the effective dielectric constant of the material. It is through this precisely controlled laser action that the dielectric constant that deviates from the target range can be adjusted to close to the target value, thereby compensating for dielectric non-uniformity caused by factors such as the glass fiber effect. The entire process forms a closed loop from detection, positioning, quantification, to precise processing, achieving localized and selective fine-tuning of the dielectric constant of key areas of laminated PCB boards.

[0035] In some preferred embodiments, a scanning near-field microwave microscope system can be used to obtain a dielectric constant distribution map of a predetermined area on a PCB. The system comprises a high-frequency signal source, a probe, and a scanning platform. The probe scans over the PCB surface, determining the local dielectric constant by measuring the microwave signal interaction between the probe and the dielectric layer. Simultaneously, a high-resolution camera captures an image of the PCB surface and performs image registration with the wiring layer image in the PCB design file to align the dielectric constant map with the designed wiring data. Using image processing and data analysis software, areas where the dielectric constant deviates from the design target value (for example, for a specific material, the target dielectric constant may be 3.4) by more than a certain threshold (e.g., ±0.05) are identified as micro-regions to be adjusted. The precise XY coordinates and specific dielectric constant deviation values ​​of these micro-regions are recorded. For example, if the measured dielectric constant of a micro-region is 3.55 and the target value is 3.4, the deviation is +0.15. Based on this +0.15 deviation, the required laser power, pulse width, and scanning speed are determined by consulting a pre-established relationship model between laser irradiation parameters and dielectric constant change. For example, a laser pulse with a specific energy density may be required. Subsequently, a laser processing system equipped with a high-speed galvanometer mirror precisely directs the laser beam to the physical coordinates of the microregion to be adjusted and scans and irradiates it according to the defined parameters. The laser energy acts on the resin on the surface of the dielectric layer, causing localized microstructural changes in the resin material, such as the formation of tiny pores, thereby reducing the effective dielectric constant in that area, bringing it closer to the target value of 3.4.

[0036] The present application further proposes that the step of applying laser light to the micro-region to be adjusted based on the laser irradiation parameters so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted includes: The applied laser energy interacts with the dielectric layer resin in the micro-region to be adjusted, thereby changing the microstructure or chemical state of the dielectric layer resin, thereby causing the dielectric constant of the micro-region to be adjusted to tend toward the target range.

[0037] The interaction of applied laser energy with the dielectric layer resin within the microregion to be adjusted refers to the absorption of energy carried by the laser beam by the dielectric layer resin, inducing physical or chemical changes. The thermal effect of the laser can cause localized heating, melting, vaporization, or carbonization of the resin, or the photochemical effect of the laser can cause molecular chains to break, crosslink, or form new chemical bonds. The purpose is to provide energy input to alter the microstructure or chemical state of the resin. Alterations in the microstructure or chemical state of the dielectric layer resin refer to internal changes in the dielectric layer resin under the action of laser energy. Alterations in the microstructure can involve the formation of micron- or sub-meter-scale pores or voids within the resin, or changes in the density of the resin molecular chains. Alterations in the chemical state can involve chemical reactions such as decomposition, polymerization, oxidation, and reduction of the resin molecules, generating new substances or altering the ratio of existing substances. The purpose is to alter the overall dielectric properties of the region by changing the material composition or structure. The dielectric constant approaches the target range, meaning that after laser exposure, the dielectric constant of the microregion to be adjusted approaches the preset target dielectric constant value. If the original dielectric constant is too high, it can be lowered through laser treatment; if the original dielectric constant is too low, it can be increased through other methods or laser-induced specific changes. The goal is to achieve or approach the design dielectric constant of the micro-area through local precision adjustment, thereby reducing dielectric constant deviation.

[0038] Based on the above understanding of the technical features, the solution of the present application achieves a change in the dielectric constant of the area by interacting the applied laser energy with the dielectric layer resin in the micro-area to be adjusted. Specifically, after the laser energy is absorbed by the resin, it can cause the microstructure or chemical state of the resin material to change. For example, by controlling the laser parameters, the resin can be locally vaporized or decomposed to form a micron-scale pore structure, and these pores are filled with air, thereby reducing the equivalent dielectric constant of the area. Alternatively, the laser energy can induce a specific chemical reaction in the resin, changing the polarity or molecular density of the resin, thereby affecting its dielectric constant. It is through this precise regulation of the microscopic structure or chemical composition of the resin material that the dielectric constant of the micro-area to be adjusted can change in the expected direction and tend towards the preset target range.

[0039] In some preferred embodiments, the present application is specifically implemented as follows. For a micro-region to be adjusted with a relatively high dielectric constant, an ultraviolet nanosecond laser with a wavelength of 355nm can be used. The laser beam is focused through an optical system, and the spot diameter is controlled to be on the order of tens of microns, and precisely aligned with the micro-region to be adjusted. The irradiation parameters such as laser power, pulse repetition frequency and scanning speed are set. When the laser pulse acts on the epoxy resin in the micro-region, the resin absorbs the ultraviolet light energy, photothermal decomposition or photochemical ablation occurs, gas is generated and micron-scale pores are formed. The presence of these pores reduces the effective material density of the area, thereby reducing the equivalent dielectric constant of the micro-region. By precisely controlling the total energy density of the laser irradiation, the porosity formed can be controlled, and then the decrease in the dielectric constant can be controlled so that it tends to the target range.

[0040] The above technical solution clearly defines the specific mechanism of using lasers to change the dielectric constant: adjusting the dielectric constant by changing the microstructure or chemical state of the dielectric layer resin. This allows for the establishment of a more precise control model based on material properties and laser parameters to guide actual operation. This allows for more accurate control of the interaction between the laser and the resin, enabling precise adjustment of the dielectric constant of the microregion to be adjusted, effectively moving it towards the target range. This avoids the potential for uncontrolled adjustment or PCB damage due to a lack of clear mechanistic guidance.

[0041] In some of the above-mentioned embodiments of the present application, it is proposed to determine a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted, and apply a laser to the micro-region to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted, so that the local dielectric constant can be fine-tuned. However, in its implementation process, the laser irradiation parameter is determined only according to the dielectric constant deviation, and the difference in material properties of the micro-region to be adjusted is not taken into account, resulting in inaccurate laser irradiation effect and inability to adjust the dielectric constant to the target range.

[0042] In this regard, the present application further proposes that the steps of determining a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted include: Obtaining the material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence model between the laser irradiation parameters and the dielectric constant change amount established in advance based on the modeling material characteristic parameters; Compare the actual material characteristic parameters with the modeled material characteristic parameters to determine the material difference parameters; Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model; Based on the dielectric constant deviation of the micro-region to be adjusted and using the corrected corresponding relationship model, the laser irradiation parameters are determined.

[0043] Among them, material characteristic parameters refer to the inherent properties of the material that affect the interaction effect between the laser and the dielectric layer resin, specifically the resin type, glass fiber content, degree of curing, absorption characteristics, etc., and their purpose is to quantify the actual material state of the micro-area to be adjusted; among them, modeling material characteristic parameters refer to the standard material property values ​​based on which the initial correspondence model is established, and their purpose is to provide a benchmark model; among them, the correspondence model between laser irradiation parameters and dielectric constant changes refers to a mathematical model or lookup table that describes the relationship between specific laser irradiation parameters and dielectric constant changes in the dielectric layer, and its purpose is to predict the change in dielectric constant under given laser parameters; among them, material difference parameters refer to the difference or degree of difference between the actual material characteristic parameters and the modeling material characteristic parameters, and its purpose is to quantify the deviation between the actual material and the model benchmark; among them, the corrected correspondence model refers to the model obtained by adjusting the original correspondence model according to the material difference parameters, and its purpose is to improve the accuracy of laser irradiation parameter determination.

[0044] The solution of the present application obtains the actual material characteristic parameters of the micro-area to be adjusted and compares them with the pre-established correspondence model based on the modeling material characteristic parameters to determine the difference parameters between the actual material and the model. It is precisely because of the identification and quantification of this material difference that the original correspondence model can be corrected according to the difference to generate a corrected correspondence model that reflects the actual situation. Based on the dielectric constant deviation of the micro-area to be adjusted and using this corrected model, the laser irradiation parameters can be determined. This method overcomes the limitation of relying solely on a general model and ignoring individual material differences, so that the subsequently applied laser can interact with the dielectric layer resin in the micro-area to be adjusted, thereby achieving adjustment of the dielectric constant. Combined with the method for determining the micro-area to be adjusted and its deviation, this solution can provide a reliable laser parameter, ensure the effectiveness of laser processing, and improve the success rate and accuracy of dielectric constant adjustment.

[0045] In one embodiment, specifically, obtaining the material characteristic parameters corresponding to the micro-region to be adjusted can be performed by performing micro-region spectral analysis on the micro-region to obtain the actual curing degree of the resin. The correspondence model between the laser irradiation parameters and the dielectric constant change, which is pre-established based on the modeling material characteristic parameters, can be a lookup table stored in a database, which records the dielectric constant change caused by different laser power and pulse width combinations under the standard resin curing degree. The actual material characteristic parameters (actual curing degree) are compared with the modeling material characteristic parameters (standard curing degree) to determine the material difference parameters, such as calculating the percentage difference between the two. Based on the material difference parameters, the correspondence model is corrected to generate a corrected correspondence model. Specifically, the dielectric constant change value in the original lookup table can be adjusted according to the percentage difference in the curing degree according to a preset correction formula or correction lookup table. Based on the dielectric constant deviation of the micro-area to be adjusted and using the corrected correspondence model, the laser irradiation parameters are determined. For example, if the dielectric constant of the micro-area to be adjusted needs to be reduced by 0.1, the laser power and pulse width combination that can produce a dielectric constant change close to -0.1 is searched in the corrected lookup table and determined as the laser irradiation parameter.

[0046] Through the above technical solution, when determining the laser irradiation parameters based on the dielectric constant deviation of the micro-region to be adjusted, the actual material characteristic parameters of the micro-region to be adjusted are taken into account, and the pre-established correspondence model is corrected based on these parameters. As a result, the determined laser irradiation parameters can reflect the actual material response to the laser, avoiding the parameter mismatch problem caused by material differences. The applied laser can change the dielectric constant of the micro-region to be adjusted, improving the accuracy and success rate of dielectric constant adjustment, thereby solving the problem of inaccurate dielectric constant adjustment caused by material characteristic differences.

[0047] In some of the above-mentioned embodiments of the present application, it is proposed to determine a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted, and apply a laser to the micro-region to be adjusted based on the laser irradiation parameter to change the dielectric constant of the micro-region to be adjusted. The determination of the laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted can be specifically by obtaining the material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence model between the laser irradiation parameters and the dielectric constant change amount established in advance based on the modeling material characteristic parameters, comparing the actual material characteristic parameters with the modeling material characteristic parameters, determining the material difference parameters, and based on the dielectric constant deviation of the micro-region to be adjusted, and using the correspondence model, determining the laser irradiation parameter. In this way, the applicable laser irradiation parameter can be determined according to the specific situation of the micro-region to be adjusted. However, in its implementation process, in actual applications, the material properties of the micro-region to be adjusted may be different, resulting in the pre-established correspondence model between the laser irradiation parameters and the dielectric constant change amount being inaccurate, thereby affecting the determination of the laser irradiation parameter, and further affecting the adjustment effect of the dielectric constant.

[0048] In this regard, the present application further proposes that the steps of correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model include: Analyze the nonlinear influence characteristics of material difference parameters on the corresponding relationship model; Based on the nonlinear influence characteristics, an adjustment function of the nonlinear relationship between the material difference parameters and the corresponding relationship model adjustment amount is constructed; The material difference parameter is input into the adjustment function to obtain the adjustment amount of the correspondence relationship model, and the correspondence relationship model is adjusted based on the adjustment amount to generate a corrected correspondence relationship model.

[0049] Among them, the material difference parameter refers to the difference or difference description between the material characteristic parameters of the actual micro-area to be adjusted and the modeling material characteristic parameters used to establish the initial correspondence model. It can be characterized by indicators such as material component ratio deviation, curing degree difference, moisture absorption rate difference, etc., and its purpose is to quantify the degree of deviation between the micro-area material to be adjusted and the standard material; the correspondence model refers to a mathematical model or lookup table that characterizes the relationship between laser irradiation parameters (such as power, pulse width, scanning speed, etc.) and the change in dielectric constant. It can take the form of polynomial functions, exponential functions, neural network models or discrete data tables, etc., and its purpose is to predict the required laser irradiation parameters based on the expected change in dielectric constant; the nonlinear influence characteristic refers to the influence of the material difference parameter on the correspondence model is not a simple linear proportional relationship, but presents a more complex influence pattern that varies with the parameter change rate, which can be fitted by experimental data. , physical model analysis or machine learning methods, the purpose of which is to accurately capture the complex effects of material differences on laser irradiation effects; the adjustment function of the nonlinear relationship refers to a mathematical function or algorithm, which takes material difference parameters as input and outputs the adjustment amount of the corresponding relationship model, and the function internally reflects the nonlinear relationship between the material difference parameters and the adjustment amount. It can be implemented by a nonlinear regression model, a piecewise function or an interpolation method based on a lookup table, and its purpose is to calculate the precise correction value of the corresponding relationship model according to the specific material difference parameters; the corresponding relationship model adjustment amount refers to the correction amount or correction method that needs to be made to the original corresponding relationship model to make it more suitable for the micro-area to be adjusted with specific material differences. It can be expressed as an offset of the model parameters, a coefficient adjustment of the model, or an offset or interpolation in the lookup table. Its purpose is to convert the nonlinear influence characteristics into specific correction instructions for the model.

[0050] The solution of this application analyzes the nonlinear influence characteristics of material difference parameters on the correspondence model. This is because the influence of material differences on the dielectric constant adjustment is often not a simple linear relationship. By analyzing the nonlinear influence characteristics, we can more accurately understand how material differences complexly affect the laser irradiation effect. Based on this nonlinear influence characteristic, an adjustment function is constructed to describe the nonlinear relationship between the material difference parameters and the correspondence model adjustment amount. This adjustment function can convert the complex nonlinear influence law into a calculable adjustment amount, providing a quantitative basis for subsequent model correction. The material difference parameters are input into the adjustment function to obtain the adjustment amount of the correspondence model, and the correspondence model is adjusted based on the adjustment amount to generate a corrected correspondence model. By substituting the actual measured material difference parameters into the adjustment function, the accurate model adjustment amount for the material characteristics of the current micro-region to be adjusted can be obtained, thereby correcting the original model and obtaining a corrected model that is more in line with the actual situation. This corrected correspondence model is used in the subsequent determination of laser irradiation parameters to more accurately predict the laser energy required to achieve the target dielectric constant change, thereby improving the accuracy of laser irradiation parameter determination. Compared with the basic solution that directly uses an uncorrected model, this method of nonlinear correction based on material differences can effectively address the common material batch differences or local non-uniformity problems in actual production. It makes the process of determining laser irradiation parameters based on dielectric constant deviation more robust and accurate, thereby improving the accuracy and success rate of dielectric constant adjustment, reducing the number of adjustment failures or poor results caused by material differences, and improving the yield and performance consistency of PCB board processing.

[0051] In some preferred embodiments, specifically, when the correspondence model is corrected based on the material difference parameters, a preset interval of the laser irradiation parameters and a target dielectric constant adjustment value corresponding to the current adjustment operation can be obtained. Based on the preset interval of the laser irradiation parameters and the target dielectric constant adjustment value, a nonlinear influence characteristic description corresponding to the current adjustment operation can be determined from a predefined data structure. The predefined data structure can store multiple nonlinear influence characteristic descriptions, and each nonlinear influence characteristic description in the data structure corresponds to a specific combination of a laser irradiation parameter interval and a target dielectric constant adjustment value. For example, the data structure can be a multidimensional lookup table, whose index dimension includes the laser irradiation parameter range and the expected dielectric constant variation range, and the values ​​in the table store nonlinear influence functions or parameters for different material difference parameters (such as resin content deviation). Based on the determined nonlinear influence characteristic description, an adjustment function can be constructed to characterize the nonlinear relationship between the material difference parameters and the adjustment amount of the correspondence model. For example, if the nonlinear impact characteristic description indicates that within the current parameter range and adjustment target, material differences (such as low resin content) will cause the change in dielectric constant to decrease, and this decrease is nonlinear, a function can be constructed that calculates an adjustment amount based on the material difference parameters (such as the percentage deviation of the resin content). This adjustment amount is used to increase the laser energy predicted by the original correspondence model. The actual measured material difference parameters are input into the constructed adjustment function to obtain the adjustment amount of the correspondence model, for example, the percentage or absolute value of the laser energy that needs to be increased is calculated. Finally, the original correspondence model is adjusted based on the adjustment amount, for example, the laser energy predicted by the original model is multiplied by an adjustment coefficient or an offset is added to generate a corrected correspondence model.

[0052] Through the above technical solution, the corresponding relationship model used to determine the laser irradiation parameters can be nonlinearly corrected according to the actual material differences in the micro-area to be adjusted, thereby improving the accuracy of the laser irradiation parameter determination, making the adjustment of the dielectric constant more precise, and effectively overcoming the influence of material property differences on the processing effect.

[0053] In some of the above-mentioned embodiments of the present application, it is proposed to apply laser to the micro-region to be adjusted based on laser irradiation parameters. The specific application of laser to the micro-region to be adjusted based on laser irradiation parameters can be achieved by controlling the output power, pulse width, scanning speed and other parameters of the laser, so that the laser energy acts accurately on the resin material in the micro-region to be adjusted, causing the microstructure or chemical state of the resin to change, such as forming micropores or changing the cross-linking density, thereby adjusting the dielectric constant of the area, so as to achieve precise control of the local dielectric constant of the PCB board. In the actual processing of the PCB board, due to factors such as the glass fiber effect, there may be some special areas, such as the target resin-poor area. These areas have a high dielectric constant due to the dense distribution of glass fibers or the thin resin covering layer. If these areas are directly irradiated with laser, the irradiation effect may be poor due to differences in material properties, or even adverse effects may occur.

[0054] In this regard, the present application further proposes applying laser to the micro-region to be adjusted based on laser irradiation parameters. Previously, the method further includes: Analyze the target resin-poor area to identify a first sub-area where the glass fibers are densely distributed or the resin cover is thin; the target resin-poor area is an area with a high dielectric constant due to uneven distribution of glass fibers; For the first sub-region, an auxiliary medium is applied to the resin surface of the first sub-region using a trace material deposition technique; wherein the auxiliary medium is a protective layer having a reflective function for the selected laser wavelength, or an absorption enhancer capable of enhancing the resin's absorption of laser energy; adjusting the laser irradiation parameters used for irradiation according to the material properties of the applied auxiliary medium; the laser irradiation parameters include laser power, laser pulse width or laser scanning speed; The first sub-region is laser irradiated according to the adjusted laser irradiation parameters to form a microporous structure in the resin material.

[0055] The target resin-poor area refers to a region within the dielectric layer of a PCB board where the resin content is relatively low due to uneven distribution of glass fibers, resulting in a locally high dielectric constant. This formation is related to the weave structure and lamination process of the glass fiber cloth. The first sub-region refers to a tiny area within the target resin-poor area where the glass fibers are particularly densely distributed or the resin coating is particularly thin. These areas exhibit more pronounced differences in material properties. Micro-material deposition technology is a technique that precisely applies a very small amount of material to a specific micro-area. This can be achieved through methods such as inkjet printing, micro-dispensing, and selective coating. Its purpose is to perform localized material modification or pretreatment on the target micro-area without affecting surrounding areas. The auxiliary medium refers to a material applied to the resin surface of the first sub-area. It can be a protective layer that reflects the selected laser wavelength, such as a dispersion of metal nanoparticles or ceramic particles. Alternatively, the auxiliary medium is an absorption enhancer that enhances the resin's absorption of laser energy, such as a dispersion of a specific dye or carbon material. Its purpose is to modify the absorption or reflection properties of the first sub-area to laser energy, thereby more precisely controlling the laser irradiation effect. Laser irradiation parameters are key process parameters used to control the interaction between the laser and the material. These include the laser's output power, the duration of the laser pulse (pulse width), and the speed at which the laser beam moves across the material's surface (laser scanning speed). These parameters are designed to control the laser's effect on the resin material by adjusting the energy input density and exposure time. Microporous structures are tiny voids formed within the resin material. These voids are created by the laser energy acting on the resin, inducing localized decomposition, vaporization, or structural rearrangement of the resin. Their purpose is to reduce the effective dielectric constant of that area.

[0056] This solution, based on the basic dielectric constant adjustment method, further considers the microscopic heterogeneity of material distribution within PCBs, particularly in areas with dense glass fiber distribution or thin resin coatings. This solution first analyzes the target resin-poor area to identify the first sub-regions where material properties differ most significantly. This allows subsequent treatment to focus on the micro-regions that truly require special attention. For these identified first sub-regions, the solution uses a micro-material deposition technique to apply an auxiliary medium to the resin surface. Applying the auxiliary medium is a critical step, and the choice of auxiliary medium (reflective protective layer or absorption enhancer) depends on the desired effect: a reflective layer reduces energy absorption and prevents excessive damage; an absorption enhancer improves energy utilization and promotes structural changes. After applying the auxiliary medium, the solution adjusts the laser irradiation parameters based on the material properties of the auxiliary medium. This parameter adjustment is customized to ensure the desired interaction between the laser energy and the material in the first sub-region treated with the auxiliary medium. Finally, the first sub-region is laser irradiated according to the adjusted laser irradiation parameters. The laser energy acts on the resin material, inducing local structural changes and forming a microporous structure. The introduction of micropores reduces the effective dielectric constant of this area. Through this series of steps, the solution achieves targeted and controllable dielectric constant adjustment of the target resin-poor area, especially the first sub-area within it, overcoming the challenges of material inhomogeneity that may be faced by direct irradiation, making the basic laser dielectric constant adjustment method more effectively applicable to areas with complex material distribution.

[0057] In some preferred embodiments, specifically, suppose that after dielectric constant mapping of a laminated PCB is performed, a region with a locally high dielectric constant is discovered beneath a high-speed signal trace. Further analysis confirms this as a target resin-poor region. High-resolution imaging or material analysis identifies a first subregion within this region, where the glass fiber bundles are particularly dense and the resin coverage is extremely thin. For this first subregion, a high-precision inkjet printer can be used to precisely spray an aqueous dispersion containing titanium dioxide nanoparticles onto the resin surface of the first subregion, forming a thin auxiliary dielectric protective layer. Titanium dioxide has a high reflectivity at commonly used ultraviolet or green laser wavelengths. After the auxiliary dielectric dries, the laser irradiation parameters originally planned for this region are adjusted based on the reflective properties of the titanium dioxide protective layer. For example, if a 10W ultraviolet laser power was originally planned, it might be adjusted to 8W. The pulse repetition frequency or scanning speed might also be fine-tuned to compensate for the loss of some laser energy due to reflection, ensuring a moderate effective energy density applied to the resin. The adjusted laser parameters are then used to scan and irradiate the first sub-area covered with the auxiliary medium. The laser energy penetrates the auxiliary medium and acts on the resin-poor area below, triggering localized decomposition of the resin material and forming tiny pores. These pores effectively lower the effective dielectric constant of the first sub-area, bringing it closer to the target value, thereby reducing its impact on signal transmission.

[0058] Through the above technical solution, targeted resin-poor areas on PCB boards, where the dielectric constant is high due to uneven distribution of glass fibers, particularly the first sub-area where the glass fibers are densely distributed or the resin cover is thin, are targeted and more effectively adjusted for the dielectric constant of these special areas through analysis and identification, application of an auxiliary medium, and adjustment of laser irradiation parameters based on the characteristics of the auxiliary medium. This overcomes the problem that direct laser irradiation of these areas may produce poor results or adverse effects due to differences in material properties, improves the accuracy and reliability of dielectric constant adjustment, thereby improving the performance of PCB boards in high-frequency and high-speed signal transmission, and reducing timing offset and signal integrity issues caused by localized dielectric constant unevenness.

[0059] In some of the above-mentioned embodiments of the present application, it is proposed to correct the correspondence model based on the material difference parameters to generate a corrected correspondence model. The correction can be specifically achieved by constructing an adjustment function of the nonlinear relationship between the material difference parameters and the corresponding relationship model adjustment amount. For example, you can try to use a simple nonlinear model, such as polynomial fitting or exponential function, and directly substitute the material difference parameters into these functions to calculate the adjustment amount. This can achieve a preliminary correction of the correspondence model. However, in its implementation process, since the influence of the material difference parameters on the correspondence model is usually nonlinear, simply using linear adjustment or a preset simple nonlinear model may not be able to accurately reflect this complex relationship, resulting in insufficient accuracy of the corrected correspondence model, which in turn affects the accuracy of the laser irradiation parameters and ultimately reduces the accuracy and effect of the dielectric constant adjustment.

[0060] Based on the nonlinear influence characteristics, an adjustment function of the nonlinear relationship between the material difference parameters and the corresponding relationship model adjustment amount is constructed, including: Obtaining a preset interval of laser irradiation parameters and a dielectric constant adjustment target value corresponding to a current adjustment operation; Based on a preset interval of the laser irradiation parameter and a target value for dielectric constant adjustment, determining a nonlinear influence characteristic description corresponding to a current adjustment operation from a predefined data structure; the predefined data structure storing a plurality of nonlinear influence characteristic descriptions, wherein each nonlinear influence characteristic description in the predefined data structure corresponds to a specific combination of a laser irradiation parameter interval and a target value for dielectric constant adjustment; Based on the description of nonlinear influence characteristics, an adjustment function is constructed to characterize the nonlinear relationship between material difference parameters and the adjustment amount of the corresponding relationship model.

[0061] Among them, the preset interval of laser irradiation parameters refers to the range of possible values ​​of laser parameters such as laser power, laser pulse width, laser scanning speed, etc., which can be pre-set according to different material types, thicknesses or desired processing effects, and its purpose is to limit the range of laser energy action in the current adjustment operation; the dielectric constant adjustment target value refers to the dielectric constant change expected to be achieved through laser irradiation or the dielectric constant value finally achieved, which can be determined based on the dielectric constant deviation of the micro-area to be adjusted, and its purpose is to clarify the dielectric performance state that needs to be achieved in this adjustment operation; the predefined data structure refers to a pre-established data set for storing and organizing descriptions of nonlinear influence characteristics, which can be implemented in the form of tables, databases, lookup tables or multidimensional arrays, etc. The purpose is to provide a way to quickly retrieve the nonlinear influence law under specific working conditions; the nonlinear influence characteristic description refers to the regular summary of how the material difference parameters nonlinearly affect the corresponding relationship model, which can be a set of mathematical model parameters, a specific function type, a rule set or a lookup table. Its purpose is to capture the complex nonlinear relationship between the material difference parameters and the adjustment amount of the corresponding relationship model; the adjustment function refers to a mathematical function or algorithm model, whose input is the material difference parameter and the output is the adjustment amount of the corresponding relationship model. It can be implemented in the form of polynomial function, exponential function, piecewise function, interpolation function based on lookup table or neural network model, and its purpose is to calculate the specific correction amount to the corresponding relationship model based on the material difference parameter.

[0062] The solution of this application obtains the preset laser irradiation parameter range and dielectric constant adjustment target value for the current adjustment operation. Based on these operating parameters, a nonlinear influence characteristic description corresponding to the current operation is determined from a predefined data structure. Based on this description, an adjustment function is then constructed to characterize the nonlinear relationship between the material difference parameter and the adjustment amount of the corresponding relationship model. This method can select or construct a nonlinear adjustment function that best reflects the influence of the material difference parameter on the corresponding relationship model under the current operating conditions, based on different laser irradiation parameter ranges and different dielectric constant adjustment amplitudes. This method is different from simply using a universal nonlinear function for adjustment. It takes into account the differences in material response under different operating conditions, making the constructed adjustment function more targeted and accurate. Applying this adjustment function constructed for specific operating conditions to calibrate the corresponding relationship model can significantly improve the accuracy of the calibration. The accurately calibrated corresponding relationship model can more accurately predict which laser irradiation parameters are required to achieve the desired dielectric constant change under specific material difference parameters. This method of constructing an adjustment function by refining the working conditions and selecting matching nonlinear characteristic descriptions is combined with the overall process of determining laser irradiation parameters based on dielectric constant deviation and correcting the corresponding relationship model based on material difference parameters in the basic scheme. This forms a more refined and accurate dielectric constant adjustment strategy, thereby improving the accuracy of laser irradiation parameter determination and ultimately enhancing the precision and effectiveness of dielectric constant adjustment.

[0063] In some preferred embodiments, the predefined data structure is a two-dimensional lookup table whose row index is the preset interval of laser irradiation parameters and the column index is the target value for dielectric constant adjustment. Each cell in the table stores a description of the nonlinear influence characteristics, such as the type of nonlinear function to be used (e.g., a quadratic polynomial, a cubic polynomial, or an exponential function) and the set of coefficients for that function. When a dielectric constant adjustment operation is required, the corresponding preset interval of laser irradiation parameters, such as [P_min, P_max], and the target value for dielectric constant adjustment, such as ΔDk, are first obtained. Then, the cell corresponding to the interval [P_min, P_max] and the target value ΔDk is searched in the predefined data structure. Assume that the found cell indicates that a quadratic polynomial function should be used to construct the adjustment function, and the coefficients a, b, and c of the quadratic polynomial are provided. Based on this information, an adjustment function f(x) = ax^2 + bx + c is constructed, where x represents the material difference parameter. The actual measured material difference parameter value of the micro-region to be adjusted is input into this function, and the adjustment amount for the corresponding relationship model is calculated.

[0064] Through the above technical solution, according to the preset interval of the laser irradiation parameters and the dielectric constant adjustment target value of the current adjustment operation, the corresponding nonlinear influence characteristic description is determined from the predefined data structure, and an adjustment function is constructed based on the description. This can enable the constructed adjustment function to more accurately reflect the nonlinear influence of the material difference parameters on the corresponding relationship model under the current working conditions, thereby achieving more precise correction of the corresponding relationship model, improving the accuracy of the laser irradiation parameter determination, and ultimately improving the accuracy and effect of the dielectric constant adjustment.

[0065] In high-frequency and high-speed applications, the material properties of the PCB's insulating dielectric layer, particularly the local uniformity of its dielectric constant (Dk) and dielectric loss (Df), become key factors affecting signal quality. Any slight local deviation in the dielectric constant can cause deviations in the characteristic impedance of the signal path, leading to signal reflections or inconsistent propagation speeds between the two lines of a differential signal pair, resulting in timing skew. During the production process, the company selected industry-recognized low-loss, high-speed substrate materials. These materials are typically composed of a specific resin system (such as modified epoxy resin, polyphenylene ether (PPO / PPE), etc.) and glass fiber cloth. While the glass fiber cloth provides the necessary mechanical support and dimensional stability for the PCB, its structure itself presents challenges. Glass fiber cloth is composed of interwoven warp and weft yarns, with inherent interstices between the yarn bundles. During the lamination process, the semi-cured resin (commonly known as PP sheet or prepreg) softens and flows under predetermined conditions of high temperature and high pressure, filling the gaps in the glass fiber cloth and the spaces between the inner layer copper foil patterns, ultimately solidifying and forming the finished product.

[0066] During the actual lamination process, a variety of factors can lead to uneven distribution of resin in microscopic areas. For example, the resin content of the PP sheet itself, the viscosity and flow characteristics of the resin, the heating rate during lamination, the pressure level, and the holding time, among other process parameters, will all affect the final filling state of the resin. A deeper problem stems from the microstructure of the glass fiber cloth: even under ideal process conditions, there are essential differences in material composition between areas where the glass fiber bundles are concentrated and areas where the gaps between the yarns are filled with resin. The dielectric constant of glass fiber (typically approximately 6 to 7) is significantly higher than that of commonly used resins (typically approximately 2.5 to 3.5). This fluctuation in the local dielectric constant caused by the inhomogeneity of the material composition at the microscale is known in the industry as the "glass fiber effect" or "glass fiber weave effect."

[0067] Glass fiber effect is particularly significant for wire pairs carrying high-speed differential signals. The two transmission lines for differential signals are typically designed to maintain strict parallelism and symmetry to ensure they experience the same electrical environment. However, in actual cabling, one transmission line may primarily pass through areas with denser glass fiber bundles (resin-poor areas), while the other may primarily pass through areas with more resin (resin-rich areas). The difference in effective dielectric constant between these two areas results in a slight difference in the actual signal propagation speed on the two transmission lines. This speed difference, accumulated over a certain transmission path length, results in significant timing skew. In high-speed backplanes or long-distance interconnects, this timing skew can severely degrade the common-mode rejection of differential signals, increase common-mode noise, reduce signal eye opening, increase bit error rates, and in extreme cases, even cause the entire high-speed link to fail. During trial production, the company discovered that even with expensive PP sheet materials featuring so-called "flattened" glass cloth or "spreading" technology, glass fiber effect persists at high frequencies (e.g., above 28 GHz), becoming a bottleneck restricting product performance.

[0068] The present application further proposes applying laser light to the micro-region to be adjusted based on laser irradiation parameters, so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted. Thereafter, the method further includes: The dielectric constant of the micro area to be adjusted is detected. If the dielectric constant still does not reach the target range, the laser irradiation parameters are determined again until the dielectric constant of the micro area to be adjusted reaches the target range.

[0069] The solution of this application effectively addresses the difficulty of precisely controlling the dielectric constant during a single laser irradiation by introducing a closed-loop control mechanism combining dielectric constant detection and parameter feedback adjustment. After laser application to the micro-region to be adjusted and initially changing its dielectric constant, the dielectric constant is immediately detected to obtain the current actual dielectric constant value. This actual value is then compared with a preset target range. This detection and comparison allows the system to accurately determine the effectiveness of the current adjustment and the degree of deviation from the target. If the detected dielectric constant still falls outside the target range, the laser irradiation parameter determination step is repeated using this deviation information. This means the system does not simply repeat the previous operation; instead, it intelligently adjusts the parameters for the next laser irradiation based on the current situation (i.e., the deviation from the target). For example, if the dielectric constant deviates significantly from the target, a higher laser energy may be set; if the deviation is smaller, a lower energy or a more refined scanning path may be set. This parameter adjustment based on real-time detection results makes each laser irradiation more targeted, gradually narrowing the gap between the dielectric constant and the target value. The above process of detection, comparison, parameter correction, and re-irradiation forms an iterative cycle that continues until the dielectric constant of the micro-area to be adjusted finally falls within the target range. It is through this iterative feedback adjustment that this solution can overcome the uncertainties caused by material non-uniformity and process fluctuations, achieving precise and reliable control of the dielectric constant of the micro-area to be adjusted. This adds an intelligent correction layer to the basic laser dielectric constant adjustment method, significantly improving the accuracy and success rate of adjustment, ensuring the uniformity of dielectric properties in key areas of the PCB board, and thus improving the quality of high-frequency and high-speed signal transmission.

[0070] In some preferred embodiments, after laser irradiation parameters are determined based on the dielectric constant deviation of the micro-region to be adjusted and laser light is applied, a non-contact microwave probe system can be used to measure the dielectric constant of the micro-region to be adjusted. This microwave probe system emits a microwave signal of a specific frequency and calculates the dielectric constant of the micro-region by measuring the reflection or transmission characteristics of the signal on the surface of the micro-region to be adjusted. After the measurement is completed, the measured dielectric constant value is compared with a preset target range (e.g., the target value ±0.05). If the measured value is still outside the target range, for example, above the upper limit of the target range, the system will consult a pre-established parameter adjustment lookup table or execute a parameter correction algorithm based on the deviation between the measured value and the upper limit of the target range to recalculate the laser power and scanning speed required for the next laser irradiation. For example, if the deviation is large, the laser power may be increased by a certain percentage; if the deviation is small, only the scanning speed may be fine-tuned. The laser system then performs a second laser irradiation on the micro-region to be adjusted based on the newly determined parameters. After the second irradiation, the dielectric constant is measured again. This process is repeated until the measured dielectric constant value falls within the target range, at which point the adjustment process ends.

[0071] Through the above technical solution, after laser dielectric constant adjustment is performed on the micro-area of ​​the PCB to be adjusted, a dielectric constant detection and iterative feedback adjustment mechanism based on the detection results are introduced. This enables dynamic correction of the adjustment process based on actual results, overcoming the impact of factors such as material non-uniformity and process errors on adjustment accuracy. Through multiple iterations, the dielectric constant of the micro-area to be adjusted can be accurately converged to the target range, significantly improving the accuracy and reliability of dielectric constant adjustment. This helps eliminate high-frequency signal timing offset and impedance mismatch problems caused by local dielectric constant deviation, thereby improving signal integrity and product yield of PCB boards in high-frequency and high-speed applications.

[0072] In addition, this application further proposes a PCB board processing system, such as Figure 2 , the system includes: An acquisition module 201 is configured to acquire a dielectric constant distribution map of a dielectric layer in a predetermined region of a PCB board; the predetermined region is a region on a laminated PCB board that carries critical high-speed signals; Determination module 202 is used to align the dielectric constant distribution map with the PCB design wiring data, determine the micro-area to be adjusted whose dielectric constant value deviates from the target range, and determine its physical coordinate position on the PCB board and the dielectric constant deviation value; The irradiation processing module 203 is used to determine a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted, and apply laser to the micro-region to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted.

[0073] The irradiation processing module 203 is also used to: obtain the material characteristic parameters corresponding to the micro-area to be adjusted, and the correspondence model between the laser irradiation parameters and the dielectric constant change amount established in advance based on the modeling material characteristic parameters; compare the actual material characteristic parameters with the modeling material characteristic parameters to determine the material difference parameters; correct the correspondence model according to the material difference parameters to generate a corrected correspondence model; determine the laser irradiation parameters based on the dielectric constant deviation of the micro-area to be adjusted and using the corrected correspondence model.

[0074] Furthermore, according to the material difference parameters, the correspondence model is corrected to generate a corrected correspondence model, including: analyzing the nonlinear influence characteristics of the material difference parameters on the correspondence model; constructing an adjustment function of the nonlinear relationship between the material difference parameters and the adjustment amount of the correspondence model based on the nonlinear influence characteristics; inputting the material difference parameters into the adjustment function to obtain the adjustment amount of the correspondence model, and adjusting the correspondence model based on the adjustment amount to generate a corrected correspondence model.

[0075] The above technical solution analyzes the nonlinear effects of material variation parameters on the correspondence model and constructs a nonlinear adjustment function based on this. This allows for more accurate calculation of the adjustment amount for the correspondence model, thereby generating a highly calibrated correspondence model. Using this calibrated model to determine laser irradiation parameters significantly improves the accuracy of laser irradiation parameter determination, thereby enhancing the precision and efficiency of dielectric constant adjustment for micro-areas on PCBs, effectively addressing dielectric property fluctuations caused by material batch or regional variations.

[0076] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0077] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A PCB board processing method, characterized in that: The method comprises: Obtaining a dielectric constant distribution map of a dielectric layer in a predetermined area of ​​a PCB board; the predetermined area is an area on the laminated PCB board that carries critical high-speed signals; Aligning the dielectric constant distribution map with the PCB design wiring data, determining the micro-area to be adjusted whose dielectric constant value deviates from the target range, and determining its physical coordinate position on the PCB board and the dielectric constant deviation value; According to the dielectric constant deviation of the micro-region to be adjusted, a laser irradiation parameter is determined, and based on the laser irradiation parameter, a laser is applied to the micro-region to be adjusted, so that the applied laser interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted.

2. The PCB processing method according to claim 1, wherein: The step of applying laser light to the micro-region to be adjusted based on the laser irradiation parameters so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted includes: The applied laser energy interacts with the dielectric layer resin in the micro-region to be adjusted, thereby changing the microstructure or chemical state of the dielectric layer resin, thereby causing the dielectric constant of the micro-region to be adjusted to tend toward the target range.

3. The PCB processing method according to claim 1, wherein: Determining a laser irradiation parameter according to the dielectric constant deviation of the micro-region to be adjusted includes: Obtaining material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence relationship model between laser irradiation parameters and dielectric constant variation established in advance based on the modeling material characteristic parameters; Compare the actual material characteristic parameters with the modeled material characteristic parameters to determine the material difference parameters; Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model; The laser irradiation parameters are determined based on the dielectric constant deviation of the micro-region to be adjusted and using the corrected corresponding relationship model.

4. The PCB processing method according to claim 3, wherein: Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model includes: Analyzing the nonlinear influence characteristics of the material difference parameters on the corresponding relationship model; Based on the nonlinear influence characteristics, constructing an adjustment function of the nonlinear relationship between the material difference parameter and the corresponding relationship model adjustment amount; The material difference parameter is input into the adjustment function to obtain an adjustment amount of the correspondence relationship model, and the correspondence relationship model is adjusted based on the adjustment amount to generate a corrected correspondence relationship model.

5. The PCB processing method according to claim 1, wherein: Before applying laser to the micro-region to be adjusted based on the laser irradiation parameters, the method further includes: Analyzing a target resin-poor area to identify a first sub-area where glass fibers are densely distributed or where the resin covering layer is thin; the target resin-poor area is an area with a high dielectric constant due to uneven distribution of glass fibers; For the first sub-region, an auxiliary medium is applied to the resin surface of the first sub-region using a trace material deposition technique; wherein the auxiliary medium is a protective layer having a reflective function for the selected laser wavelength, or an absorption enhancer capable of enhancing the resin's absorption of laser energy; Adjusting the laser irradiation parameters for irradiation according to the material properties of the applied auxiliary medium; the laser irradiation parameters include laser power, laser pulse width or laser scanning speed; The first sub-region is laser irradiated according to the adjusted laser irradiation parameters to form a microporous structure in the resin material.

6. The PCB processing method according to claim 5, characterized in that: After performing laser irradiation on the first sub-region according to the adjusted laser irradiation parameters to form a microporous structure in the resin material, the method further includes: Determining a sealing material having a dielectric constant lower than that of the resin substrate in the resin-poor area; the sealing material can form a protective layer with a barrier effect after curing; The micropores of the first sub-region are filled with the sealing material and then cured.

7. The PCB processing method according to claim 4, characterized in that: Constructing an adjustment function of a nonlinear relationship between the material difference parameter and the corresponding relationship model adjustment amount based on the nonlinear influence characteristic, including: Obtaining a preset interval of laser irradiation parameters and a dielectric constant adjustment target value corresponding to a current adjustment operation; Based on the preset interval of the laser irradiation parameter and the dielectric constant adjustment target value, determining a nonlinear influence characteristic description corresponding to the current adjustment operation from a predefined data structure; the predefined data structure stores a plurality of nonlinear influence characteristic descriptions, and each nonlinear influence characteristic description in the predefined data structure corresponds to a specific combination of a laser irradiation parameter interval and a dielectric constant adjustment target value; Based on the nonlinear influence characteristic description, an adjustment function is constructed to characterize the nonlinear relationship between the material difference parameter and the corresponding relationship model adjustment amount.

8. The PCB processing method according to claim 1, wherein: Applying laser light to the micro-region to be adjusted based on the laser irradiation parameters so that the applied laser light interacts with the dielectric layer resin in the micro-region to be adjusted to change the dielectric constant of the micro-region to be adjusted. Thereafter, the method further includes: The dielectric constant of the micro area to be adjusted is detected. If the dielectric constant still does not reach the target range, the laser irradiation parameters are determined again until the dielectric constant of the micro area to be adjusted reaches the target range.

9. A PCB board processing system, characterized in that: The system comprises: An acquisition module is used to obtain a dielectric constant distribution map of a dielectric layer in a predetermined area of ​​a PCB board; the predetermined area is an area on the laminated PCB board that carries key high-speed signals; a determination module, configured to align the dielectric constant distribution map with the PCB design wiring data, determine the micro-region to be adjusted whose dielectric constant value deviates from the target range, and determine its physical coordinate position on the PCB board and the dielectric constant deviation value; An irradiation processing module is used to determine a laser irradiation parameter according to the dielectric constant deviation of the micro-area to be adjusted, and apply a laser to the micro-area to be adjusted based on the laser irradiation parameter, so that the applied laser interacts with the dielectric layer resin in the micro-area to be adjusted to change the dielectric constant of the micro-area to be adjusted.

10. The PCB board processing system according to claim 9, characterized in that: The radiation processing module is further used for: Obtaining material characteristic parameters corresponding to the micro-region to be adjusted, and a correspondence relationship model between laser irradiation parameters and dielectric constant variation established in advance based on the modeling material characteristic parameters; Compare the actual material characteristic parameters with the modeled material characteristic parameters to determine the material difference parameters; Correcting the correspondence model according to the material difference parameter to generate a corrected correspondence model; The laser irradiation parameters are determined based on the dielectric constant deviation of the micro-region to be adjusted and using the corrected corresponding relationship model.

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