Automatic processing device and method for pressing PCB (Printed Circuit Board)

Abstract

The invention discloses an automatic processing device and method for PCB lamination, and the method comprises the steps: depositing an erodable film on a lamination material layer and arranging a cavity concentric with a through hole array before the lamination of a PCB, and collecting acoustic resonance frequency data to obtain a reference matrix; dynamic dot frequency tracking processing is carried out on the multi-point acoustic time sequence signals in the pressing heating stage, and a through hole instantaneous acoustic track library is obtained; performing coupling judgment on time-temperature-pressure ternary working condition data according to the trajectory library to obtain a blockage risk matrix; carrying out time delay and gradient adjustment on a pressing temperature and pressure curve based on the risk matrix; and carrying out three-dimensional inversion processing on the whole board broadband acoustic spectrum collected before cooling, calculating through hole filling rate distribution and judging the quality of the board. According to the scheme, the resin filling state of the micro through hole can be monitored in real time in the PCB pressing process, an acoustic detection channel is constructed through the erodable film and the cavity structure, early warning and active intervention of the blocking risk are achieved, and the pressing quality is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of material state detection in printed circuit board manufacturing, and particularly to an automated processing device and method for PCB board lamination. Background Art

[0002] Automated processing of PCB board lamination is a key process in the manufacturing of multi-layer printed circuit boards. In this process, multiple inner layers with pre-made circuits, epoxy prepreg, copper foil and other materials are stacked together in a specific order to form a multi-layer structure. Subsequently, this laminated structure is placed in a special vacuum hot press and subjected to hot pressing under high temperature (usually 170 - 200 °C) and high pressure (1.5 - 2.5 MPa). During this process, the epoxy resin in the prepreg first softens and melts, flows to fill the gaps between layers, and then cross-links and cures under continuous heating to firmly bond the layers of materials together to form an integral multi-layer circuit board. The automated processing system precisely controls key parameters such as the temperature curve, pressure change, and vacuum degree to ensure the consistency and reliability of the lamination quality, which is the core process of modern high-density multi-layer PCB manufacturing.

[0003] In the existing automated processing of PCB board lamination, high multi-layer boards face a special technical challenge, that is, the pre-drilled micro-vias (μVia) are prone to blockage during the hot pressing process. The generation mechanism of this problem is very complex: when the lamination temperature rises to the melting point of the epoxy resin (about 120 - 150 °C), the resin viscosity drops sharply and becomes in a highly fluid state; at the same time, the applied high pressure forces the molten resin to flow in all directions, including penetrating into the micro-vias. In addition, the coefficient of thermal expansion of the copper layer does not match that of the resin substrate at high temperatures, resulting in stress concentration around the vias, causing micro-deformation or necking of the copper plating on the via walls. Under the combined action of these two factors, the micro-vias originally used for interlayer electrical connection are gradually filled with resin during the critical time window of the lamination process, forming partial or complete blockage. This blockage phenomenon occurs in a closed high-temperature and high-pressure environment, and cannot be directly observed from the outside. Traditional detection methods such as X-ray and electrical testing can only detect problems after the lamination is completed. At this time, the resin has completely cured, missing the best intervention opportunity, resulting in a large number of boards being scrapped or the reliability of the finished products being reduced. Summary of the Invention

[0004] The main object of the present invention is to solve the technical problem that the blockage state of micro-vias in the existing PCB board lamination process cannot be monitored and warned in real time.

[0005] The first aspect of the present invention provides an automated processing method for PCB board lamination, and the automated processing method for PCB board lamination includes: Before laminating the PCB board, deposit an erodible film on the surface of the laminating material and set cavities concentric with the via array, collect the initial acoustic resonance frequency data set of the whole board, and obtain the acoustic reference matrix; According to the acoustic reference matrix, perform dynamic point-frequency tracking processing on the multi-point acoustic time-sequence signals obtained during the lamination heating-up stage, calculate the amplitude-phase time-sequence data of each micro via, and obtain the via instantaneous acoustic trajectory library; According to the via instantaneous acoustic trajectory library, perform coupling determination processing on the time-temperature-pressure three-element working condition data during the lamination process, calculate the working condition parameters corresponding to the inflection point moment of the phase difference, and obtain the blockage risk matrix; According to the distribution of high-risk vias in the blockage risk matrix, perform delay and slope adjustment processing on the lamination temperature curve and pressure curve to obtain the lamination execution curve; According to the lamination execution curve, perform three-dimensional inversion processing on the broadband acoustic spectrum of the whole board collected before cooling, calculate the via filling rate distribution and determine the quality state of the board part to obtain the three-dimensional filling mapping.

[0006] Preferably, before laminating the PCB board, deposit an erodible film on the surface of the laminating material and set cavities concentric with the via array, collect the initial acoustic resonance frequency data set of the whole board, and obtain the acoustic reference matrix, including: Perform cavity planning processing on the via distribution map of the PCB board to obtain the cavity layout map; Deposit an erodible film on the surface of the laminating material according to the cavity layout map to obtain the self-dissipating acoustic film layer; Perform micro-hole forming processing on the self-dissipating acoustic film layer according to the cavity layout map to obtain a cavity structure concentric with the via array; Perform resonance scanning processing on the multi-layer board after deposition and forming to obtain the initial acoustic resonance frequency data set, and perform matrix arrangement processing according to the initial acoustic resonance frequency data set to obtain the acoustic reference matrix.

[0007] Preferably, performing cavity planning processing on the via distribution map of the PCB board to obtain the cavity layout map includes: Perform via diameter and wiring density grading processing on the via distribution map of the PCB board to obtain the via grading distribution matrix; Perform eccentric cavity parameter calculation processing on the high-density wiring area according to the via grading distribution matrix to obtain the eccentric cavity structure matrix; Perform variable-depth cavity parameter calculation processing on the low-density wiring area according to the via grading distribution matrix to obtain the variable-depth cavity structure matrix; Perform space mapping processing according to the eccentric cavity structure matrix and the variable-depth cavity structure matrix to obtain the cavity layout map.

[0008] Preferably, based on the acoustic reference matrix, perform dynamic point frequency tracking processing on the multi-point acoustic time series signals obtained in the pressing and heating-up stage, calculate the amplitude-phase time series data of each micro via hole, and obtain an instantaneous acoustic trajectory library of the via holes, including: Perform regional division processing on the acoustic reference matrix to obtain a regional index map based on the copper surface coverage rate and the temperature gradient; Perform area weight assignment processing on the via hole identifiers according to the regional index map to obtain a weight table of via holes in each area; Perform weighted point frequency sampling processing on the multi-point acoustic time series signals in the heating-up stage according to the weight table of via holes to obtain a regional weighted amplitude-phase sequence matrix; Perform layer-level reference correction processing on the regional weighted amplitude-phase sequence matrix to obtain a set of corrected amplitude-phase vectors in the same layer; Perform time series splicing processing on the via hole identifiers according to the set of corrected amplitude-phase vectors in the same layer to obtain an instantaneous acoustic trajectory library of the via holes.

[0009] Preferably, based on the instantaneous acoustic trajectory library of the via holes, perform coupled determination processing on the time-temperature-pressure ternary working condition data during the pressing process, calculate the working condition parameters corresponding to the inflection point moment of the phase difference, and obtain a blockage risk matrix, including: Perform inflection point time sorting processing on the instantaneous acoustic trajectory library of the via holes to obtain a resin flow front propagation time field; Perform synchronous interpolation processing on the time-temperature-pressure ternary working condition data according to the resin flow front propagation time field to obtain a local temperature-pressure-viscosity index matrix; Perform copper surface coverage rate mapping processing on the PCB design data to obtain a copper surface coverage matrix; Perform impedance coupling processing on the copper surface coverage matrix according to the local temperature-pressure-viscosity index matrix to obtain a mechanical impedance index matrix; Perform threshold comparison processing on the local temperature-pressure-viscosity index matrix according to the mechanical impedance index matrix to obtain a blockage risk matrix.

[0010] Preferably, the performing synchronous interpolation processing on the time-temperature-pressure ternary working condition data according to the resin flow front propagation time field to obtain a local temperature-pressure-viscosity index matrix includes: Perform volatilization characteristic analysis processing on the resin formulation data in the pressing material to obtain a resin volatilization rate curve; Perform compensation calculation processing on the resin flow front propagation time field according to the resin volatilization rate curve to obtain a compensated propagation time field; Perform weighted mapping processing on the ternary working condition data according to the compensated propagation time field combined with the core board glass fiber density distribution to obtain a local temperature-pressure-viscosity index matrix.

[0011] Preferably, according to the distribution of high-risk vias in the clogging risk matrix, performing delay and slope adjustment processing on the lamination temperature curve and the pressure curve to obtain a lamination execution curve, including: Performing thin-film state analysis processing on the acoustic response data of high-risk vias in the clogging risk matrix, obtaining the softening degree parameters of the burnable thin films at each high-risk via, and obtaining a thin-film softening distribution map; Performing spatial mapping processing on the relative positions of the resin flow front and the micro-vias according to the thin-film softening distribution map to obtain a resin flow resistance field; Performing hierarchical delay compensation processing on the lamination temperature curve according to the resin flow resistance field and the thermal expansion coefficient of the copper foil layer to obtain an interlayer temperature compensation curve; Performing pressure delay and slope calculation processing on the interlayer temperature compensation curve in combination with the copper foil stress distribution around the vias to obtain a pressure adjustment curve; Performing process parameter coupling processing according to the interlayer temperature compensation curve and the pressure adjustment curve to obtain a lamination execution curve.

[0012] Preferably, the performing thin-film state analysis processing on the acoustic response data of high-risk vias in the clogging risk matrix, obtaining the softening degree parameters of the burnable thin films at each high-risk via, and obtaining a thin-film softening distribution map, includes: Performing analysis processing on the gas compression characteristics in the high-risk vias for the acoustic response data to obtain a compression ratio coefficient matrix; Performing local temperature rise rate calculation processing on the high-risk via area according to the compression ratio coefficient matrix to obtain a temperature rise distribution map; Performing thin-film softening degree calculation processing according to the compression ratio coefficient matrix and the temperature rise distribution map to obtain a thin-film softening distribution map.

[0013] Preferably, according to the lamination execution curve, performing three-dimensional inversion processing on the full-board broadband acoustic spectrum collected before cooling, calculating the via filling rate distribution and determining the quality state of the board to obtain a three-dimensional filling mapping, including: Performing acoustic spectrum segment extraction processing on the process parameter change points in the lamination execution curve, obtaining the erosion degree data of the burnable thin films at each via position, and obtaining an erosion state distribution map; Performing acoustic signal decoupling processing on the erosion state distribution map in combination with the stress distribution of the copper foil layer around the vias to obtain a via wall stress field; Performing interlayer acoustic attenuation analysis processing on the via wall stress field and the resin curing shrinkage data to obtain an interlayer bonding strength matrix; Performing filling rate mapping processing on the erosion state distribution map according to the interlayer bonding strength matrix to obtain a via filling rate distribution map; Perform quality state evaluation processing on the through-hole filling rate distribution map in combination with the stress field on the through-hole wall surface to obtain a board quality state matrix; Perform spatial superposition processing on the through-hole filling rate distribution map and the board quality state matrix to obtain a three-dimensional filling mapping.

[0014] The second aspect of the present invention provides an automated processing device for PCB board lamination. The automated processing device for PCB board lamination includes: A pretreatment module, configured to deposit an inflammable film on the surface of the lamination material and set a cavity concentric with the through-hole array before PCB board lamination, collect a set of initial acoustic resonance frequency data for the whole board, and obtain an acoustic reference matrix; A dynamic monitoring module, configured to perform dynamic point-frequency tracking processing on the multi-point acoustic time-series signals obtained during the lamination heating-up stage according to the acoustic reference matrix, calculate the amplitude-phase time-series data of each micro through-hole, and obtain a through-hole instantaneous acoustic trajectory library; A risk assessment module, configured to perform coupled determination processing on the time-temperature-pressure ternary working condition data during the lamination process according to the through-hole instantaneous acoustic trajectory library, calculate the working condition parameters corresponding to the inflection point moment of the phase difference, and obtain a blockage risk matrix; A parameter adjustment module, configured to perform delay and slope adjustment processing on the lamination temperature curve and the pressure curve according to the distribution of high-risk through-holes in the blockage risk matrix to obtain a lamination execution curve; A quality assessment module, configured to perform three-dimensional inversion processing on the broadband acoustic spectrum of the whole board collected before cooling according to the lamination execution curve, calculate the through-hole filling rate distribution and determine the quality state of the board to obtain a three-dimensional filling mapping.

[0015] The third aspect of the present invention provides an automated processing equipment for PCB board lamination, including: a memory and at least one processor. Instructions are stored in the memory, and the memory and the at least one processor are interconnected through a line; the at least one processor calls the instructions in the memory so that the automated processing equipment for PCB board lamination executes the steps of the above-mentioned automated processing method for PCB board lamination.

[0016] The fourth aspect of the present invention provides a computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When it runs on a computer, it causes the computer to execute the steps of the above-mentioned automated processing method for PCB board lamination.

[0017] In the technical solution provided by the embodiment of the present application, before lamination, an erodible film is deposited at the coaxial position of each through hole and a microcavity is engraved, and the board surface is scanned through the acoustic resonance channel formed by the film-cavity to obtain a one-dimensional matrix mapping the micro through hole-intrinsic peak. Since the geometry of each microcavity corresponds to the hole position one by one, this matrix has the meaning of "fingerprint" in space: by locking the corresponding frequency points, the change of the medium in the hole can be monitored in real time, and the film self-destructs after curing without leaving foreign objects and does not affect the dielectric constant in the board.

[0018] In the heating stage, the resin viscosity drops by two orders of magnitude within the order of hundreds of seconds. The technical solution of the present application selects the resonant peak with the highest weight for each through hole according to the reference matrix, and performs millisecond-level point frequency excitation and amplitude-phase sampling. Since the heat dissipation of the copper surface and the temperature gradient divide the board surface into multiple heat flow regions, the technical solution uses these physical characteristics to group the through holes, perform layer-level reference correction on the data of each group, and concatenate the windowed vectors into a complete acoustic trajectory library. This processing method not only retains the single-hole resolution but also eliminates the interference of the non-uniform thermal field on the sound speed, enabling the trajectory change to accurately reflect the state of the resin-air interface in the hole.

[0019] When a critical inflection point appears in the acoustic phase, it indicates that the resin just penetrates the hole wall and begins to occupy the cavity. The technical solution of the present application takes the inflection point time as the reference, projects the synchronously recorded temperature-pressure field onto the flow front propagation time field, and calculates the temperature-pressure-viscosity index matrix by introducing the copper layer coverage rate to weight the local mechanical impedance. In the region where the index is high and the impedance is low, the resin driving force is large and the hole wall constraint is weak, making it easier to form irreversible blockage; the technical solution generates a risk matrix accordingly, marking the position, density, and diagonal stress of the through hole of the high-risk block.

[0020] The technical solution of the present application realizes precise control through zoning temperature and pressure control. According to the risk matrix, by obtaining the film softening parameter and resin flow resistance in the high-risk area, the gel delay and pressure smoothing coefficient are calculated; in the high-risk area, the temperature vertex is slightly shifted backward, and the pressure slope is smoothly corrected within the same stroke, keeping the curve in the low-risk area unchanged. This differential control effectively suppresses local resin backflow and avoids secondary failures such as over-curing or insufficient degassing.

[0021] Before the cooling turning point, the technical solution of the present application performs broadband sweep frequency on the whole board, couples and analyzes the film erosion degree, the stress on the through hole wall surface, and the curing shrinkage, and obtains the filling rate and the interlayer bonding strength through three-dimensional inversion. By evaluating the through hole filling rate and the residual stress, the quality determination of the board can be completed before the press is opened. This technical solution enables the blockage risk to be predictable and controllable, captures the instantaneous resin flow deep in the micro through hole in real time, uses the adaptive curve for timely intervention, and completes the closed-loop verification before curing and shaping, realizing the active control of the whole process of micro through hole blockage. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0023] Figure 1 It is a schematic diagram of an embodiment of the automatic processing method for PCB board lamination in the embodiments of the present invention; Figure 2 It is a schematic diagram of an embodiment of the automatic processing device for PCB board lamination in the embodiments of the present invention; Figure 3 It is a schematic diagram of an embodiment of the automatic processing equipment for PCB board lamination in the embodiments of the present invention.

[0024] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, "and / or" throughout the text includes three scenarios. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution that A and B are satisfied at the same time. In addition, the technical solutions between the embodiments can be combined with each other, and it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0028] An embodiment of the present application provides an automated processing method for PCB board lamination. Figure 1 FIG. is a flowchart of an automated processing method for PCB board lamination provided by an embodiment of the present application. In this embodiment, the method includes: Please refer to Figure 1 , before laminating the PCB board, deposit an erodible film on the surface of the lamination material and set cavities concentric with the via array, collect the initial acoustic resonance frequency data set of the entire board, and obtain an acoustic reference matrix; In an embodiment of the present invention, the step of depositing an erodible film on the surface of the lamination material and setting cavities concentric with the via array, collecting the initial acoustic resonance frequency data set of the entire board, and obtaining an acoustic reference matrix before laminating the PCB board includes: Perform cavity planning processing on the via distribution map of the PCB board to obtain a cavity layout map; Perform erodible film deposition processing on the surface of the lamination material according to the cavity layout map to obtain a self-dissipating acoustic film layer; Perform micro-hole forming processing on the self-dissipating acoustic film layer according to the cavity layout map to obtain a cavity structure concentric with the via array; Perform resonance scanning processing on the multi-layer board after deposition and forming to obtain an initial acoustic resonance frequency data set, and perform matrix sorting processing according to the initial acoustic resonance frequency data set to obtain an acoustic reference matrix.

[0029] The following specifically describes the steps involved in the above embodiment: To perform cavity planning processing on the via distribution map of the PCB board, first, the via coordinate data in the PCB design needs to be obtained, which can usually be extracted from the Gerber file or drilling data file (Excellon file) exported by the CAD / CAM system. Cavity planning processing refers to designing micro-cavities with specific geometric shapes around the vias, and these cavities will serve as acoustic response units. Specifically, when implementing, use image processing software to read the via distribution map, and perform geometric analysis on each via through a PCB-specific drawing tool (such as Altium Designer or Cadence Allegro) to determine the position, shape, and size of the cavity. The cavity is usually designed as an annular shape, with a diameter 5 - 20 μm larger than the micro-via, and the depth is controlled within the range of 15 - 35 μm. Such a design can ensure that the cavity and the via coexist to form an acoustic channel without affecting the interlayer electrical connection. For example, for a micro-via with a diameter of 75 μm, a concentric annular cavity with an outer diameter of 90 μm can be designed to form an acoustic resonant cavity. The finally output cavity layout map is saved in vector format, containing the precise coordinates and geometric parameters of each cavity. This cavity structure design can form a stable acoustic echo feature during the lamination process and provide a reliable via status reference signal.

[0030] When performing the deposition process of the ablatable thin film on the layers of the lamination material according to the cavity layout diagram, a special formulated organic thin film material is deposited on the surface of the lamination material using a precision coating equipment. The ablatable thin film refers to an organic compound layer that can be completely decomposed and volatilized at a high temperature of 180 - 250 °C. Common materials include modified cellulose acetate, low molecular weight polyvinyl alcohol, or thermosensitive polymers containing reactive oxygen groups. The deposition process is carried out through precision screen printing or micro - jetting systems, controlling the film thickness between 2 - 5 μm, covering the entire board or a predetermined area. During the deposition process, an infrared alignment system is used to ensure the precise alignment of the thin film with the cavity layout diagram, with the deviation controlled within ±3 μm. For example, on the surface of a standard epoxy resin prepreg (FR - 4), a thermosensitive organic solution is evenly sprayed and quickly dried through a micro - pumping device to form a thin film. This self - dissipating acoustic thin film layer maintains its integrity at the lamination temperature (170 - 200 °C), but will completely decompose into gaseous products and be discharged during subsequent processes at higher temperatures (≥220 °C). This ablatable thin film material can provide acoustic response throughout the lamination process and then completely disappear without affecting the electrical performance of the PCB.

[0031] For the micropore forming process of the self - dissipating acoustic thin film layer according to the cavity layout diagram, a laser micro - machining system or photolithographic etching process is used to precisely etch out a micropore structure concentric with the via array on the thin film. The micropore forming process refers to forming holes with specific shapes, sizes, and positions on the deposited thin film to form a coaxial cavity structure with the vias on the PCB. During implementation, a UV laser micro - machining system (wavelength 355 nm) is used. According to the coordinate data in the cavity layout diagram, a micropore array is precisely etched on the thin film. The laser power is controlled at 3 - 5 W, and the pulse width is set at 15 - 25 ns to ensure clear micropore edges and no damage to the underlying material. For areas with high - precision requirements, a laser system with a high - speed scanning galvanometer can be used, with a positioning accuracy of ±1 μm. For example, on a PCB board with 1200 micro - vias, the laser system can complete the entire micropore forming process within 5 minutes. This micropore forming process creates a precisely concentric cavity structure, enabling each via position to form an independent acoustic resonance unit, providing a stable physical basis for subsequent acoustic monitoring.

[0032] When performing resonance scanning on the multilayer board after deposition and forming, a high-frequency ultrasonic scanning system is used to collect acoustic excitation and response across the entire board surface. Resonance scanning means using ultrasonic waves with adjustable frequencies to excite the board surface and recording the acoustic response intensity and phase information at different positions at different frequencies. Specifically, an array ultrasonic probe (frequency range 5 - 35 MHz) is used to perform grid scanning on the PCB board surface. A frequency scanning signal is applied to each scanning point for 0.5 - 3 seconds, and the characteristics of the received echo signals are analyzed. The scanning resolution is usually set to 0.2 - 0.5 mm to ensure coverage of all via positions. The collected acoustic data is stored through a high-speed data acquisition system (sampling rate ≥ 100 MHz), and the frequency response curves at each cavity position are recorded to form an initial set of acoustic resonance frequency data. Subsequently, matrix sorting processing is performed, that is, the original frequency response data is arranged into a two-dimensional matrix according to the board surface coordinates, and each matrix element contains the resonance frequency peak, bandwidth, and phase information at the corresponding position. For example, for a 10×12 cm PCB board, an acoustic reference matrix with 500×600 data points can be generated to accurately record the initial acoustic characteristics at each via position. This resonance scanning method can establish the acoustic "fingerprint" of the via-cavity system, providing an accurate reference for subsequent monitoring of changes in via status.

[0033] In an embodiment of the present invention, the cavity planning process for the via distribution map of the PCB board to obtain the cavity layout map includes: Performing via diameter and wiring density grading on the via distribution map of the PCB board to obtain a via grading distribution matrix; Performing eccentric cavity parameter calculation on the high-density wiring area according to the via grading distribution matrix to obtain an eccentric cavity structure matrix; Performing variable-depth cavity parameter calculation on the low-density wiring area according to the via grading distribution matrix to obtain a variable-depth cavity structure matrix; Performing spatial mapping according to the eccentric cavity structure matrix and the variable-depth cavity structure matrix to obtain the cavity layout map.

[0034] The following is a specific description of the steps involved in the above embodiments: When performing via diameter and wiring density grading on the via distribution map of the PCB board, first extract the via distribution data from the PCB design software, including the coordinate positions, diameter sizes, and surrounding wire density information of each via. Via diameter and wiring density grading refers to the process of classifying all vias into different grades according to the via diameter size and the surrounding wiring density. Specifically, when implementing, an image processing software is used to analyze the Gerber file, extract the diameter value of each via, and calculate the wire density within 1 mm around it. 2The proportion of the wiring area within the region is used as the wiring density value. According to industry standards, the via hole diameters are divided into four grades: micro vias (≤75μm), small holes (76 - 150μm), medium holes (151 - 250μm), and large holes (>250μm); meanwhile, the wiring density is divided into three grades: high density (wiring proportion > 65%), medium density (wiring proportion 35% - 65%), and low density (wiring proportion < 35%). For example, for a 12 - layer PCB board with 2500 vias, through data analysis, it is found that approximately 60% of the micro vias are located in the high - density region, 35% in the medium - density region, and 5% in the low - density region. The analysis results are stored in the form of a two - dimensional matrix. The rows of the matrix represent the via hole diameter grades, and the columns represent the wiring density grades. Each matrix element contains the coordinate list and quantity statistics of the vias in the corresponding category, forming a via hole grading distribution matrix. This grading process enables the system to formulate differentiated detection strategies for vias with different characteristics, improving the accuracy and effectiveness of acoustic monitoring.

[0035] When calculating and processing the eccentric cavity parameters for the high - density wiring region according to the via hole grading distribution matrix, it is necessary to focus on solving the technical problems of limited space and large temperature gradient in the high - density region. The calculation and processing of eccentric cavity parameters refer to the process of designing non - concentric but acoustically optimized cavity structure parameters for the vias in the high - density wiring region. Specifically, during implementation, according to the thermal flow field simulation results and the copper layer distribution, the ideal cavity positions of the vias in each high - density region are calculated. The calculation process considers three key parameters: the eccentricity distance (usually 15% - 40% of the via hole diameter), the eccentricity direction (opposite to the direction of the nearest large - area copper foil), and the cavity size (the diameter is usually 1.5 - 2.5 times the via hole diameter). A special calculation program is used to perform personalized calculations for the vias in each high - density region, and the best eccentricity parameters are determined according to the actual surrounding copper foil distribution and the thermal flow direction. For example, for a micro via with a diameter of 60μm and a surrounding copper foil coverage rate of 75%, the calculated best eccentricity distance is 20μm, the eccentricity direction is the direction with the least copper foil distribution, and the cavity diameter is 120μm. The calculation results form a data structure containing the eccentric cavity parameters of all the vias in the high - density region, that is, the eccentric cavity structure matrix. This eccentric design avoids the wiring congestion area in the high - density region while maintaining sufficient acoustic sensitivity, solving the problem that traditional concentric cavities are difficult to implement in high - density regions.

[0036] When calculating and processing the variable-depth cavity parameters for the low-density wiring area according to the through-hole hierarchical distribution matrix, taking advantage of the abundant space in the low-density area, a cavity structure with better acoustic performance is designed. The calculation and processing of variable-depth cavity parameters refer to the process of designing cavity structure parameters with different depths for the through-holes in the low-density wiring area to obtain a stronger acoustic signal response. Specifically, when implementing, the acoustic resonance theory is adopted, and according to the ultrasonic frequency range used by the detection system (usually 15 - 35 MHz), the optimal resonance cavity depth is calculated. Three main parameters are considered in the calculation: cavity depth (basic depth 15 μm, variable range 10 - 40 μm), outer diameter (usually 2.0 - 3.0 times the through-hole diameter), and shape factor (affecting the acoustic wave reflection characteristics). For micro through-holes, the depth is usually set to 15 - 25 μm; for small through-holes, the depth is set to 20 - 30 μm; for medium and large through-holes, the depth is set to 25 - 40 μm. For example, for a 100-μm diameter through-hole located in the low-density area, the calculated optimal cavity depth is 28 μm, the outer diameter is 250 μm, and a trapezoidal cross-section design is adopted to enhance the acoustic wave focusing effect. The calculation results of the cavity parameters for all through-holes in the low-density area form a variable-depth cavity structure matrix. This variable-depth design makes full use of the space advantage of the low-density area. By optimizing the cavity resonance characteristics, the intensity of the acoustic response signal is increased by about 40%, significantly improving the signal-to-noise ratio and detection sensitivity.

[0037] When performing spatial mapping processing based on the eccentric cavity structure matrix and the variable-depth cavity structure matrix, the cavity parameters of the two different design strategies are integrated into a unified PCB coordinate system. Spatial mapping processing refers to the process of converting the cavity design parameters of different regions and different types into a unified geometric description format and arranging them according to the actual physical position. Specifically, when implementing, the CAD drawing engine is used to convert the parameters in the eccentric cavity structure matrix and the variable-depth cavity structure matrix into geometric entities and position them according to the actual coordinates of the through-holes. During the spatial mapping process, boundary smoothing processing is performed to ensure a natural transition between the high-density area and the low-density area and avoid the emergence of sudden change regions in the acoustic response. The generated cavity layout diagram is saved in vector format, including the precise position, shape, size, and depth parameters of each cavity, and alignment marks are added for reference in subsequent manufacturing processes. For example, for a PCB board containing various types of through-holes, the cavity layout diagram generated after spatial mapping processing can clearly display the specific parameters and positions of 2500 cavities on the board surface. Among them, the high-density area adopts an eccentric design, and the low-density area adopts a variable-depth design, and the two designs smoothly transition in the boundary area. This spatial mapping method realizes the organic combination of differential cavity design and unified manufacturing process, not only ensuring the detection effect of various through-holes, but also simplifying the manufacturing process and improving the feasibility and stability of the overall process.

[0038] Please continue to refer to Figure 1, based on the acoustic reference matrix, perform dynamic point-frequency tracking processing on the multi-point acoustic time-series signals obtained during the pressing and heating-up stage, calculate the amplitude-phase time-series data of each micro via hole, and obtain the through-hole instantaneous acoustic trajectory library; In an embodiment of the present invention, the performing dynamic point-frequency tracking processing on the multi-point acoustic time-series signals obtained during the pressing and heating-up stage according to the acoustic reference matrix, calculating the amplitude-phase time-series data of each micro via hole, and obtaining the through-hole instantaneous acoustic trajectory library includes: Perform regional division processing on the acoustic reference matrix to obtain a regional index map based on the copper surface coverage rate and the temperature gradient; Perform area weight assignment processing on the through-hole identification according to the regional index map to obtain the through-hole weight table for each area; Perform weighted point-frequency sampling processing on the multi-point acoustic time-series signals during the heating-up stage according to the through-hole weight table to obtain a regional weighted amplitude-phase sequence matrix; Perform layer-level reference correction processing on the regional weighted amplitude-phase sequence matrix to obtain a set of corrected amplitude-phase vectors for the same layer; Perform time-series splicing processing on the through-hole identification according to the set of corrected amplitude-phase vectors for the same layer to obtain the through-hole instantaneous acoustic trajectory library.

[0039] The following specifically describes the steps involved in the above embodiments: When performing regional division processing on the acoustic reference matrix, first superimpose and analyze the PCB design data and the thermal field simulation results. Regional division processing refers to the process of dividing the entire PCB board into multiple regions with similar thermal and acoustic behaviors according to the physical characteristics of different positions on the board surface. Specifically, during implementation, first extract the copper surface coverage data from the PCB design file and calculate the proportion of the copper foil area in each 100μm×100μm grid cell; then use thermal field calculation software to analyze the temperature distribution during the pressing and heating stage to obtain temperature gradient data with a 100μm grid accuracy. The copper surface coverage refers to the proportion of copper foil material per unit area, usually expressed as a percentage; the temperature gradient refers to the temperature change rate per unit distance, with the unit of °C / mm. Divide the copper surface coverage into 5 levels at intervals of 20%, and divide the temperature gradient into 4 levels at intervals of 2°C / mm to form a 5×4 classification matrix. For example, for a 300mm×400mm multi-layer PCB board, the copper surface coverage in the central region is about 45% and the temperature gradient is about 1.8°C / mm, which is classified as a region with copper coverage level 3 and temperature gradient level 1; while the copper surface coverage in the edge region is about 30% and the temperature gradient is about 4.5°C / mm, which is classified as a region with copper coverage level 2 and temperature gradient level 3. After regional division, a regional index map containing regional boundaries and category identifiers is generated, and the distribution of different regions is visually displayed in a color-coded manner. This regional division based on physical characteristics enables the system to adopt differentiated processing strategies for regions with different acoustic characteristics, effectively eliminating acoustic signal interference caused by uneven copper foil distribution and temperature gradients.

[0040] When performing area weight assignment processing on the through-hole identification according to the area index map, a numerical identifier reflecting the acoustic influence weight of the area where each through-hole is located is assigned to each through-hole. The area weight assignment processing refers to the process of assigning different weight values to each through-hole according to the physical characteristics of the area where the through-hole is located, and is used to adjust the acquisition and processing strategies of acoustic signals. In specific implementation, first, the reference weight coefficients of each area are determined. The weight of the area with a high copper surface coverage rate (≥60%) is set to 0.8 - 1.0, the weight of the medium area (40% - 60%) is set to 0.6 - 0.8, and the weight of the low coverage area (<40%) is set to 0.4 - 0.6; the weight of the area with a large temperature gradient (≥4°C / mm) is set to 0.7 - 0.9, the weight of the medium area (2°C / mm - 4°C / mm) is set to 0.5 - 0.7, and the weight of the area with a small gradient (<2°C / mm) is set to 0.3 - 0.5. Combining the two indicators, the weighted average method is used to calculate the final weight of each area. For example, for an area with a copper surface coverage rate of 65% (weight 0.85) and a temperature gradient of 3°C / mm (weight 0.6), its comprehensive weight is calculated as 0.85×0.6 + 0.4×0.6 = 0.51 + 0.24 = 0.75. All through-holes are grouped according to the area where they are located, and the weight values of the corresponding areas are assigned to form a through-hole weight table for each area, which includes the through-hole number, coordinates, the area to which it belongs, and the weight value. This differential weight assignment strategy enables the system to perform refined monitoring on the through-holes in areas with different thermal characteristics, improving the accuracy and representativeness of acoustic data acquisition.

[0041] When performing weighted point-frequency sampling processing on the multi-point acoustic timing signals in the heating-up stage according to the through-hole weight table, the frequency and intensity of signal acquisition at each point are adjusted using the weight values determined in the early stage. The weighted point-frequency sampling processing refers to the process of adjusting the frequency points and sampling intervals of acoustic signal acquisition according to the importance of through-holes in each region. Specifically, in implementation, an ultrasonic array probe system is used to comprehensively scan the PCB board, and a differentiated sampling strategy is adopted for different weight regions: high-weight regions (weight value > 0.8) use high-frequency sampling (sampling interval 50 - 100 ms), medium-weight regions (0.5 - 0.8) use medium-frequency sampling (interval 100 - 200 ms), and low-weight regions (< 0.5) use low-frequency sampling (interval 200 - 350 ms). For each sampling point, its amplitude (representing the acoustic wave intensity, unit: dB) and phase (representing the acoustic wave propagation delay, unit: degree) information are recorded. For example, for the through-hole in the edge critical region with a weight value of 0.9, the sampling interval is set to 60 ms to obtain the complete acoustic change data throughout the pressing process; while for the through-hole in the central stable region with a weight value of 0.4, the sampling interval is set to 300 ms to obtain the acoustic state information at critical moments. All sampling data are grouped and stored by region, forming a three-dimensional data structure containing timestamp, amplitude, and phase information, namely the region-weighted amplitude-phase sequence matrix. This weight-based adaptive sampling strategy not only ensures the integrity of data in critical regions but also optimizes the utilization of system resources, improving the efficiency and pertinence of real-time monitoring.

[0042] When performing layer-based reference correction on the region-weighted amplitude-phase sequence matrix, the influence of differences in physical properties of different layers on acoustic signals is eliminated. Layer-based reference correction refers to the process of standardizing acoustic signals according to the material properties and structural differences of each layer of the PCB, making the data of different layers comparable. Specifically, during implementation, first, the structural information of each layer is extracted from the PCB design file, including layer thickness (usually in the range of 75 - 180 μm), material type (FR-4, epoxy resin with high glass transition temperature (Tg), polyimide, etc.), and copper foil thickness (commonly 12 μm, 18 μm, 35 μm, etc.). Based on the acoustic properties of each material, a layer correction coefficient is established: for a standard FR-4 layer, the correction coefficient is set to 1.0; for a high-Tg material layer, the correction coefficient is 0.85 - 0.95; for a polyimide layer, the correction coefficient is 1.05 - 1.15. The corresponding correction coefficient is applied to the amplitude data recorded for each layer for normalization processing, and the phase data is compensated for time delay according to the difference in the sound speed of the material. For example, for the 3rd layer composed of a high-Tg material (correction coefficient 0.9), the acquired acoustic amplitude is -45 dB and the phase is 78°. The corrected amplitude is -45 × 0.9 = -40.5 dB, and the phase is adjusted to approximately 72° according to the difference in the sound speed of the material. The corrected data of each layer is stored in vector form, and each vector contains the corrected amplitude and phase sequences, forming a set of corrected amplitude-phase vectors for the same layer. This layer correction process eliminates the interference of different materials and thicknesses in the multi-layer PCB structure on acoustic measurements, enabling the data of each layer to truly reflect the via state rather than material differences.

[0043] When performing sequential splicing processing on the via hole identifiers according to the in-layer correction amplitude-phase vector set, the acoustic data collected at different time points are recombined into a complete record of the via hole state changes. The sequential splicing processing refers to the process of reorganizing the acoustic data with different sampling intervals and sampling durations in chronological order to form a continuous data sequence describing the full-process acoustic response of the via hole. Specifically, during implementation, first, all the sampled data are aligned on the time axis, with the starting moment of lamination as the zero point to establish a unified time reference system. Then, the data are grouped according to the via hole identifiers, and the data collected for the same via hole at different time points are arranged in chronological order. For regions with a large sampling interval, the cubic spline interpolation method is used to fill the blanks between the data points to ensure that the time resolution reaches 50 ms or higher. The sequential data of all the via holes are screened and quality evaluated, and the data points with a signal-to-noise ratio lower than 15 dB are eliminated. For example, for a specific via hole, its complete acoustic trajectory includes the full-process amplitude-phase change record from the start of lamination (0 s) to resin gelation (about 300 s), with a time resolution of 50 ms, clearly showing the acoustic characteristic change points caused by resin flow. Finally, a database containing the complete acoustic response records of all the via holes, that is, the via hole instantaneous acoustic trajectory library, is generated, and each trajectory contains timestamp, amplitude, phase, and change rate information. This sequential splicing processing realizes continuous real-time monitoring of the via hole state, provides high-precision sequential evidence for accurately judging resin flow and microvia blockage, and enables the system to capture the changes in the resin flow front at the millisecond level.

[0044] Please continue to refer to Figure 1 , according to the via hole instantaneous acoustic trajectory library, perform coupling determination processing on the time-temperature-pressure ternary working condition data during the lamination process, calculate the working condition parameters corresponding to the inflection point moment of the phase difference, and obtain the blockage risk matrix; In an embodiment of the present invention, the performing coupling determination processing on the time-temperature-pressure ternary working condition data during the lamination process according to the via hole instantaneous acoustic trajectory library, calculating the working condition parameters corresponding to the inflection point moment of the phase difference, and obtaining the blockage risk matrix includes: Perform inflection point time sorting processing on the via hole instantaneous acoustic trajectory library to obtain the resin flow front propagation time field; Perform synchronous interpolation processing on the time-temperature-pressure ternary working condition data according to the resin flow front propagation time field to obtain the local temperature-pressure-viscosity index matrix; Perform copper surface coverage mapping processing on the PCB design data to obtain the copper surface coverage matrix; Perform impedance coupling processing on the copper surface coverage matrix according to the local temperature-pressure-viscosity index matrix to obtain the mechanical impedance index matrix; Perform threshold comparison processing on the local temperature-pressure-viscosity index matrix according to the mechanical impedance index matrix to obtain the blockage risk matrix.

[0045] The following is a specific description of the steps involved in the above embodiments: When performing inflection point time sorting on the through-hole instantaneous acoustic trajectory library, first perform differential analysis on each acoustic trajectory curve to identify key inflection points. The inflection point time sorting process refers to the process of identifying the moments when the acoustic signal changes sharply and arranging them in chronological order, which is used to determine the order in which the resin flow reaches the positions of each through-hole. In specific implementation, a digital signal processor is used to perform numerical differentiation on the acoustic trajectory to calculate the amplitude and phase change rates. The identification criteria are set as follows: when the phase change rate exceeds 5° / second for 3 consecutive sampling points and at the same time the amplitude decrease rate exceeds 2 dB / second, it is determined that the resin flow front has reached the inflection point of the through-hole position. Extract the inflection point time of each through-hole and sort them in chronological order, and record the coordinate position and corresponding inflection point time of each through-hole. For example, during the lamination process of a 16-layer HDI board, the inflection point time of the through-holes in the edge area usually appears 60 - 90 seconds after the start of lamination, while the inflection point time of the through-holes in the central area is postponed to 120 - 150 seconds. By performing spatial interpolation on all the through-hole inflection point time data, a time field distribution map covering the entire PCB board surface, that is, the resin flow front propagation time field, is generated, and the propagation path and speed of the resin flow are visually displayed in the form of a heat map. This inflection point analysis method accurately captures the dynamic process of the resin flow front, reveals the precise spatio-temporal distribution of the resin flowing from the edge to the center during the lamination process, and provides a key timing benchmark for the clogging risk assessment.

[0046] When performing synchronous interpolation processing on the time-temperature-pressure ternary operating condition data according to the resin flow front propagation time field, the process parameters recorded by the pressing equipment are spatially and temporally corresponded to the acoustic monitoring results. Synchronous interpolation processing refers to the process of extracting the temperature and pressure parameters at that position at that moment according to the time when the resin flow reaches each position, and calculating the corresponding resin viscosity index. Specifically, during implementation, first obtain the time-temperature-pressure recording data of the entire process from the control system of the pressing equipment, and the sampling interval is usually 1 second. Perform spatial correction on the temperature data of the equipment measurement points according to the thermal field simulation results to obtain the actual temperature distribution at each position on the board surface. For each via position, query the temperature value (T, unit: °C) and pressure value (P, unit: MPa) at the corresponding moment according to its inflection point time, and calculate the resin viscosity index (VI) under this condition. The viscosity index calculation considers the comprehensive influence of temperature and pressure on the resin fluidity, and the numerical range is usually 0.1 - 10. The smaller the value, the better the fluidity. For example, for a certain via position with an inflection point time of 85 seconds, the temperature at this position at this moment is queried to be 145 °C, and the pressure is 1.8 MPa. The calculated viscosity index is 0.65, indicating that the resin is in a medium flow state. Organize the spatial distribution of the viscosity indices of all via positions on the entire board to form a local temperature-pressure-viscosity index matrix. This operating condition synchronous interpolation method realizes the precise correspondence between acoustic events and process parameters, reveals the internal relationship between resin flow and temperature-pressure conditions, and provides a physical basis for evaluating the risk of micro-via blockage.

[0047] When performing copper surface coverage mapping processing on the PCB design data, the copper foil distribution information in the design file is converted into a numerical representation of the proportion of copper foil around the via. Copper surface coverage mapping processing refers to the process of calculating the proportion of copper foil material in each area of the PCB and associating it with the via position. Specifically, during implementation, export the Gerber file of the copper foil distribution of each layer from the PCB design software, and rasterize the vector data using image processing software with a resolution set to 50 μm. For each via position, analyze the copper foil distribution within a 500-μm diameter range around it, calculate the percentage of the copper foil area in the total area of this circular region, and obtain the copper surface coverage value. Perform weighted averaging on the coverages of different layers, and the weight coefficient is inversely proportional to the interlayer distance to generate a comprehensive index reflecting the overall copper foil distribution. For example, for a certain micro-via located in the central area of a 12-layer board, the analysis results of the copper surface coverage within a 500-μm range around it are: 85% for the top layer, 65% for the second layer, and 40% for the third layer. Finally, the weighted calculation gives a comprehensive copper surface coverage of 62% for this via position. Calculate point by point for all positions on the entire PCB board to form a two-dimensional matrix corresponding to the board surface size, that is, the copper surface coverage matrix. This copper surface mapping method precisely quantifies the copper foil distribution characteristics of each area of the PCB, reveals the material structure differences affecting heat conduction and mechanical properties, and provides basic data for subsequent mechanical impedance analysis.

[0048] When performing impedance coupling processing on the copper surface coverage matrix according to the local temperature-pressure viscosity index matrix, the resin flow characteristics are combined with the binding force of the material structure around the vias for analysis. Impedance coupling processing refers to the process of calculating the intensity of the obstruction or promotion of the resin flow by the material structure. Specifically, in implementation, based on the principles of material mechanics, the copper surface coverage rate is converted into a mechanical impedance index (MI), and the calculation formula considers three main factors: copper surface coverage rate (C, percentage), copper foil thickness (T, μm), and layer spacing (D, μm). The higher the mechanical impedance index, the stronger the binding force of the structure around the vias on the resin flow, and the numerical range is usually 0.2 - 5. For areas with a high copper surface coverage rate (>70%) and a small layer spacing (<100 μm), the mechanical impedance index is usually higher than 3.0; while for areas with a low copper surface coverage rate (<30%) and a large layer spacing (>150 μm), the mechanical impedance index is usually lower than 0.8. For example, for a certain via position with a copper surface coverage rate of 62%, a copper foil thickness of 18 μm, and a layer spacing of 120 μm, the calculated mechanical impedance index is 1.45, indicating a medium mechanical constraint ability. The mechanical impedance indices of all points on the entire board are matrix-organized to form a mechanical impedance index matrix. This impedance coupling analysis method quantifies the influence degree of the PCB structure on the resin flow, reveals the constraint characteristics of the material structure around the micro-vias, and provides a mechanical basis for accurately evaluating the blockage risk.

[0049] When performing threshold comparison processing on the local temperature-pressure viscosity index matrix according to the mechanical impedance index matrix, the balance relationship between the resin flow driving force and the hole wall binding force is comprehensively evaluated. Threshold comparison processing refers to the process of calculating the ratio of two key parameters and comparing it with a preset threshold to judge the blockage risk. Specifically, in implementation, the risk ratio (RR) of each via position is calculated, that is, the ratio of the viscosity index (VI) to the mechanical impedance index (MI). According to the analysis of a large amount of experimental data, the risk threshold standard is set: RR < 0.3 is the low-risk area (green), 0.3 ≤ RR < 0.7 is the medium-risk area (yellow), and RR ≥ 0.7 is the high-risk area (red). For example, for a certain via position with a viscosity index of 0.65 and a mechanical impedance index of 1.45, the calculated risk ratio RR = 0.65 / 1.45 = 0.45, which is determined to be in the medium-risk area. The risk of all vias on the entire PCB board is calculated and classified to form a matrix data structure containing risk level identifiers, that is, the blockage risk matrix. In addition, for the boundary areas where the risk ratio is close to the threshold (±0.05), a secondary criterion is added: analyze the velocity gradient of the resin flow front, and the risk level of the velocity mutation area is raised by one level. This multi-dimensional threshold comparison method realizes the accurate evaluation of the via blockage risk. It not only considers the balance relationship between the resin fluidity and the structure binding force, but also incorporates the flow dynamics characteristics, making the risk prediction more comprehensive and accurate, and providing a clear goal and basis for subsequent process parameter adjustment.

[0050] In an embodiment of the present invention, the synchronization interpolation processing of the time-temperature-pressure ternary working condition data according to the resin flow front propagation time field to obtain a local temperature-pressure-viscosity index matrix includes: Performing volatile characteristic analysis processing on the resin formulation data in the laminate to obtain a resin volatility curve; Performing compensation calculation processing on the resin flow front propagation time field according to the resin volatility curve to obtain a compensated propagation time field; Performing weighted mapping processing on the ternary working condition data according to the compensated propagation time field in combination with the core board glass fiber density distribution to obtain a local temperature-pressure-viscosity index matrix.

[0051] The following specifically describes the steps involved in the above embodiment: When performing volatile characteristic analysis processing on the resin formulation data in the laminate, the composition and release rate of volatiles during the heating process of the resin are measured by a thermogravimetric analyzer and gas chromatography-mass spectrometry. The volatile characteristic analysis processing refers to the process of measuring and calculating the proportion and rate of volatile components of epoxy resin in the laminate at different temperatures. Specifically, during implementation, first obtain the basic resin formulation data from the PCB prepreg supplier, including resin type (bisphenol A type, phenolic type or polyfunctional epoxy), curing agent type (amine type, anhydride type), solvent composition and content. Then use a thermogravimetric analyzer (TGA) to perform a programmed temperature rise test on the resin sample, with the temperature range set at 25 - 250 °C and the heating rate at 5 °C / minute, and record the curve of the sample weight change with temperature. At the same time, use a gas chromatography-mass spectrometer (GC-MS) to analyze the volatile components. Calculate the volatility values at different temperature points, that is, the percentage of the mass of volatiles per unit time in the original resin mass. For example, for a certain type of FR-4 prepreg, the volatility is 0.05% / minute at 120 °C, rises to 0.18% / minute at 150 °C, and reaches a peak of 0.32% / minute at 180 °C. Connect the volatility data at all temperature points into a curve to form a complete resin volatility curve, with temperature as the horizontal axis and volatility as the vertical axis to visually display the resin volatile characteristics. This volatile characteristic analysis method accurately reveals the dynamic characteristics of resin composition changes during the lamination process, providing a chemical basis for the accurate prediction of subsequent resin flow behavior.

[0052] When compensating and calculating the resin flow front propagation time field according to the resin volatilization rate curve, the change in flow characteristics caused by the volatilization of resin components is corrected. The compensation calculation process refers to the process of correcting the measured resin flow front propagation time according to the influence of resin volatilization on fluidity. Specifically, when implementing, an association relationship between the volatilization rate and the fluidity correction coefficient is established: when the volatilization rate is lower than 0.1% / min, the correction coefficient is 1.0 - 1.05; when the volatilization rate is in the range of 0.1% - 0.2% / min, the correction coefficient is 1.05 - 1.15; when the volatilization rate is in the range of 0.2% - 0.3% / min, the correction coefficient is 1.15 - 1.25; when the volatilization rate exceeds 0.3% / min, the correction coefficient is 1.25 - 1.35. For each time point in the resin flow front propagation time field, query the corresponding temperature value at that moment, and then obtain the volatilization rate value from the resin volatilization rate curve, and calculate the applicable correction coefficient. Multiply the original propagation time by the corresponding correction coefficient to obtain the corrected time value considering the influence of resin volatilization. For example, for a via hole position with an original recorded propagation time of 95 seconds and a corresponding temperature of 155°C, the volatilization rate at this temperature is queried to be 0.21% / min, and the applicable correction coefficient is 1.18. The compensated propagation time is calculated to be 95×1.18 = 112 seconds. Perform point-by-point compensation calculation for the entire time field to generate a compensated propagation time field. This volatilization compensation method takes into account the actual influence of resin component changes on fluidity, making the prediction of flow time more accurate and avoiding the estimation deviation of fluidity caused by resin volatilization.

[0053] When performing weighted mapping processing on the three - element working condition data according to the compensated propagation time field in combination with the core board glass fiber density distribution, the influence of material structure characteristics on resin flow is comprehensively considered. The weighted mapping process refers to the process of specifically adjusting the correlation calculation between process parameters and resin physical properties according to the PCB substrate structure characteristics. Specifically, when implementing, first extract the core board glass fiber density distribution information from the PCB design data, including the type of glass fiber cloth (such as 1080, 2116, 7628, etc.), the lamination structure, and the resin content. The glass fiber density is usually expressed in grams per square meter (g / m 2 ), and the density differences of different types of glass fiber cloth are obvious: the 1080 type is about 70 g / m 2 , the 2116 type is about 110 g / m 2 , and the 7628 type is about 200 g / m 2 . Perform spatial mapping on the glass fiber density of each via hole position and calculate the weighting coefficient: for the low - density glass fiber area (≤100 g / m 2 ), the weighting coefficient is set to 0.85 - 0.95; for the medium - density area (100 - 150 g / m 2 ), the weighting coefficient is set to 0.95 - 1.05; for the high - density area (≥150 g / m 2), the weighting coefficient is set to 1.05 - 1.15. Then, the compensated propagation time field is spatially and temporally corresponded with the temperature - pressure data recorded by the lamination equipment. Combining with the glass fiber density weighting coefficient, the actual temperature, pressure, and the corresponding resin viscosity index at the resin flow moment for each via position are calculated. For example, for a via position with a compensated flow time of 112 seconds and a glass fiber density of 135 g / m 2 , the equipment temperature at this moment is queried to be 158 °C, the pressure is 1.9 MPa, the weighting coefficient is 1.02, and the finally calculated viscosity index is 0.78. Calculate and organize all via positions on the whole board into a matrix form to form a local temperature - pressure - viscosity index matrix. This weighted mapping method considering the material microstructure realizes the accurate description of the complex and changeable process conditions and material characteristics during the PCB lamination process, makes the viscosity index calculation more in line with the physical characteristics of the actual board, and provides a more accurate process parameter basis for the blockage risk assessment.

[0054] Please continue to refer to Figure 1 , according to the distribution of high - risk vias in the blockage risk matrix, perform delay and slope adjustment processing on the lamination temperature curve and the pressure curve to obtain the lamination execution curve; In an embodiment of the present invention, the step of performing delay and slope adjustment processing on the lamination temperature curve and the pressure curve according to the distribution of high - risk vias in the blockage risk matrix to obtain the lamination execution curve includes: Perform thin - film state analysis processing on the acoustic response data of high - risk vias in the blockage risk matrix to obtain the softening degree parameters of the burnable film at each high - risk via position, and obtain the thin - film softening distribution map; Perform spatial mapping processing on the relative position of the resin flow front and the micro - via according to the thin - film softening distribution map to obtain the resin flow resistance field; Perform hierarchical delay compensation processing on the lamination temperature curve according to the resin flow resistance field and the thermal expansion coefficient of the copper foil layer to obtain the inter - layer temperature compensation curve; Perform pressure delay and slope calculation processing on the inter - layer temperature compensation curve in combination with the copper foil stress distribution around the via to obtain the pressure adjustment curve; Perform process parameter coupling processing according to the inter - layer temperature compensation curve and the pressure adjustment curve to obtain the lamination execution curve.

[0055] The following is a specific description of the steps involved in the above - mentioned embodiment: When performing thin-film state analysis on the acoustic response data of high-risk vias in the blockage risk matrix, the physical state change of the burnable thin film is determined by analyzing the characteristics of acoustic signal changes. Thin-film state analysis refers to a method of evaluating the softening degree of thin-film materials during the heating process by using the frequency shift and amplitude attenuation characteristics of acoustic signals. Specifically, during implementation, first, a list of high-risk vias with a risk ratio exceeding 0.7 is extracted from the blockage risk matrix, and spectral analysis is performed on the acoustic data at these via positions. The time-domain signal is converted into a frequency-domain representation through fast Fourier transform (FFT), and the offset of the characteristic frequency is observed. The softening degree parameter of the burnable thin film is defined as the weighted average of the frequency shift rate (the ratio of the original frequency to the current frequency) and the amplitude attenuation rate (the ratio of the original amplitude to the current amplitude). The range of the softening degree parameter is 0 - 1, and the higher the value, the more severe the softening of the thin film. For example, for a high-risk via, its original resonance frequency is 28.5 MHz, and the amplitude is -32 dB. During the pressing process, the frequency drops to 25.2 MHz, and the amplitude drops to -45 dB. The calculated frequency shift rate is 0.88, the amplitude attenuation rate is 0.71, and the comprehensive softening degree parameter is 0.80, indicating that the thin film is in a highly softened state. The spatial distribution of the softening degree parameters of all high-risk vias is sorted to generate a thin-film softening distribution map, which shows the softening of the thin film in each area in the form of a heat map. This state analysis method realizes non-contact real-time monitoring of the physical state of microscopic materials and provides an accurate material state basis for process parameter adjustment.

[0056] When performing spatial mapping on the relative position of the resin flow front and the micro-vias according to the film softening distribution map, the spatial relationship data between the resin flow path and the via position is calculated. The spatial mapping process refers to the process of spatially correlating the propagation trajectory of the resin flow front with the via position and analyzing the angular relationship between the resin flow direction and the via axis. Specifically, when implemented, the flow isochrones are extracted from the resin flow front propagation time field, and the flow direction vector (the gradient direction perpendicular to the isochrone) is calculated. For each high-risk via, the angle between the flow direction vector and the via axis is calculated, and the resin flow resistance coefficient is calculated in combination with the film softening degree parameter. The resistance coefficient calculation considers three key factors: the flow-via angle (θ), the film softening degree (S), and the via diameter (D). When the flow direction is parallel to the via axis (θ is close to 0° or 180°), the resistance coefficient is low; when the flow direction is perpendicular to the via axis (θ is close to 90°), the resistance coefficient is the highest. For example, for the case where the angle between the flow direction and the via axis is 75°, the film softening degree is 0.80, and the via diameter is 65 μm, the calculated flow resistance coefficient is 2.35, indicating a high risk of blockage. Point-by-point calculations are performed on the entire PCB board surface to generate a resin flow resistance field distribution map covering the entire board. This spatial mapping analysis method reveals the precise distribution of the geometric relationship between the resin flow and the vias, providing directional guidance for accurately adjusting the lamination parameters.

[0057] When performing hierarchical delay compensation processing on the lamination temperature curve according to the resin flow resistance field and the thermal expansion coefficient of the copper foil layer, the temperature control strategy is adjusted according to the characteristics and risk situations of different layers. Hierarchical delay compensation processing refers to the process of adjusting the time delay of the key nodes of the standard temperature curve according to the material characteristics of each layer and the distribution of blockage risks. In specific implementation, first obtain the standard lamination temperature curve, which usually includes a preheating section (25 - 120°C), a heating-up section (120 - 180°C), an insulation section (constant temperature at 180°C), and a cooling section. Then, combined with the resin flow resistance field data, determine the layers where the high-risk areas are mainly distributed. For the signal layer with a relatively large copper foil thermal expansion coefficient (CTE) (16 - 18 ppm / °C), the delay compensation amount is relatively large; for the power layer and the ground layer with a relatively small CTE (12 - 14 ppm / °C), the delay compensation amount is relatively small. For the high-risk layer, after the temperature reaches the resin softening point (usually 120 - 130°C), slow down the heating rate, reduce the standard 3 - 5°C / minute to 1 - 2°C / minute, and extend the holding time in this temperature range by 2 - 5 minutes to make the resin fully softened but not completely melted, reducing the risk of rapid flow. For example, for the 4th layer with an average resistance coefficient of 2.1, when the temperature reaches 125°C, reduce the heating rate from the standard 4°C / minute to 1.5°C / minute and hold for an additional 3 minutes at this temperature point. Integrate the adjusted values of the temperature curves of each layer to form an interlayer temperature compensation curve. This hierarchical delay compensation method realizes the precise control of the characteristics and risks of different layers, avoids the "one-size-fits-all" problem caused by unified process parameters, and improves the pertinence and effectiveness of the lamination process.

[0058] When performing pressure delay and slope calculation processing on the interlayer temperature compensation curve in combination with the copper foil stress distribution around the vias, the pressure control strategy is adjusted according to the mechanical stress distribution caused by temperature changes. Pressure delay and slope calculation processing refers to the process of calculating the delay amount and slope change amount of each node of the pressure curve according to the correlation between temperature changes and the stress state of the material. In specific implementation, first calculate the thermal expansion stress distribution of the copper foil caused by temperature changes, especially focusing on the area around the vias. The copper foil stress is related to the temperature change rate, copper foil thickness, and constraint conditions, and usually has the maximum stress value during the rapid temperature rise stage (120 - 160 °C). According to the stress distribution results, determine the pressure adjustment strategy: in the stress peak interval (usually corresponding to a temperature of 120 - 140 °C), reduce the slope of the standard pressure curve from 0.05 - 0.1 MPa / minute to 0.02 - 0.04 MPa / minute to slow down the pressure rise speed; in the interval where the resin is completely molten (temperature exceeding 150 °C), delay the time for the pressure to reach the set value by 3 - 8 minutes to avoid the simultaneous occurrence of high pressure and high fluidity. For example, for the temperature point of 160 °C with stress concentration, the original plan was to immediately apply a final pressure of 1.8 MPa at this temperature. After adjustment, the application is delayed by 5 minutes and then slowly increased to the target pressure, and the pressure rise slope is controlled at 0.03 MPa / minute. Combining the delay amounts and slope adjustment values of each temperature point, a complete pressure adjustment curve is formed. This method of pressure delay and slope adjustment effectively coordinates the timing relationship between resin fluidity and pressure driving force, reducing the risk of high-pressure driving the resin to quickly flow into the micro-holes.

[0059] When performing process parameter coupling processing according to the interlayer temperature compensation curve and the pressure regulation curve, the adjustment strategies of the two key parameters of temperature and pressure are comprehensively optimized to generate the final execution plan. Process parameter coupling processing refers to the process of considering the mutual influence of temperature and pressure and synergistically optimizing the adjustment strategies of the two parameters. Specifically, during implementation, first align the interlayer temperature compensation curve and the pressure regulation curve on the same time axis, and analyze the timing relationship between the temperature change points and the pressure change points. The optimization principle is as follows: in the resin softening stage (120 - 140 °C), the temperature rises slowly first, and the pressure lags behind; in the resin flowing stage (140 - 160 °C), the temperature and pressure change slowly in coordination; in the curing stage (> 160 °C), the temperature quickly reaches the target value, and the pressure rises steadily to the final value. According to this principle, fine-tune the key nodes of the temperature and pressure curves to ensure that the change rhythms of the two parameters match each other. For example, after the temperature reaches 135 °C and remains for 2 minutes, the pressure starts to rise slowly; after the temperature reaches 155 °C and stabilizes, the pressure is further increased to the intermediate value; after the temperature reaches the final curing temperature (180 °C), the pressure is delayed by 3 minutes and then rises to the final value (2.0 MPa). Integrate the adjusted temperature and pressure curves into a complete set of process parameter control plans, that is, the lamination execution curve, which is directly used for the program setting of the lamination equipment. This process parameter coupling processing method realizes the coordinated control of temperature and pressure, forms a customized lamination process for specific plates and specific risk distributions, effectively avoids the risk of resin blockage in micro-vias, and at the same time ensures the overall stability of the lamination quality.

[0060] In an embodiment of the present invention, the acoustic response data of the high-risk vias in the blockage risk matrix is analyzed and processed in terms of the film state to obtain the softening degree parameters of the combustible film at each high-risk via, and a film softening distribution map is obtained, including: Analyze and process the acoustic response data of the high-risk vias to obtain the compression ratio coefficient matrix for the gas compression characteristics in the vias; Calculate the local temperature rise rate of the high-risk via area according to the compression ratio coefficient matrix to obtain a temperature rise distribution map; Calculate the softening degree of the film according to the compression ratio coefficient matrix and the temperature rise distribution map to obtain a film softening distribution map.

[0061] The following specifically describes the steps involved in the above embodiments: When analyzing and processing the in-hole gas compression characteristics of high-risk via acoustic response data, the compression state of the gas in the via is evaluated by analyzing the frequency characteristics of the acoustic signal. The analysis and processing of the in-hole gas compression characteristics refer to a method of quantitatively calculating the degree of compression of the gas in a micro-via by using the change in the acoustic resonance frequency. Specifically, during implementation, the acoustic spectrum data of each via is extracted from the high-risk via list, and the law of resonance frequency change with pressure is analyzed. According to the gas acoustic principle, when the gas in a micro-via is compressed during the pressing process, its acoustic resonance frequency will undergo a characteristic shift. By calculating the ratio relationship between the initial resonance frequency (f0) and the current resonance frequency (f1), the gas compression ratio is determined. The compression ratio coefficient is defined as the percentage difference between the current resonance frequency and the initial resonance frequency, characterizing the degree of gas compression, with a value range of 0 - 100%. For example, for a micro-via with a diameter of 65μm, its initial resonance frequency is 27.5MHz, and when the pressing pressure reaches 1.5MPa, the frequency rises to 31.2MHz. The calculated compression ratio coefficient is (31.2 - 27.5) / 27.5×100% = 13.5%, indicating a medium degree of gas compression. The compression ratio coefficients of all high-risk vias are arranged according to their spatial positions to form a compression ratio coefficient matrix covering the entire board. This gas compression characteristic analysis method realizes the indirect measurement of the internal state of the sealed micro-via, provides important parameters for accurately evaluating the via state, and avoids the limitation of the traditional method that cannot monitor the pressure change in a closed space in real time.

[0062] When calculating and processing the local temperature rise rate of the high-risk via area based on the compression ratio coefficient matrix, the temperature growth characteristics caused by gas compression are analyzed. The calculation and processing of the local temperature rise rate refer to the process of calculating the rate of increase in the actual temperature of the micro-via area relative to the ambient temperature according to the thermodynamic relationship between gas compression and temperature rise. Specifically, during implementation, the gas adiabatic compression law is applied, combined with the compression ratio coefficient matrix data and the pressing environment temperature record, to calculate the actual temperature value at each via position. The gas thermodynamic parameters used in the calculation are: the air heat capacity ratio (γ) is taken as 1.4, and the initial temperature is the starting temperature of the pressing. The temperature rise rate is defined as the percentage increase of the local actual temperature relative to the average pressing environment temperature, reflecting the hot spot effect in the via area, and the value range is usually 0 - 30%. For example, for a via with a compression ratio coefficient of 13.5% and an ambient temperature of 155°C, the calculated local actual temperature is approximately 176.4°C, and the temperature rise rate is (176.4 - 155) / 155×100% = 13.8%, indicating an obvious local hot spot. The temperature rise rate data at all high-risk via positions are spatially interpolated to form a temperature rise distribution map covering the entire board, visually displaying the temperature anomaly area in the form of a heat map. This local temperature rise analysis method reveals the temperature non-uniformity at the microscale, discovers tiny hot spot areas that cannot be detected by conventional thermocouples, and provides a real temperature basis for accurately evaluating the local resin fluidity and film softening state.

[0063] When calculating and processing the softening degree of the film based on the compression ratio coefficient matrix and the temperature rise distribution map, the effects of two key factors, pressure and temperature, on the physical state of the film are comprehensively considered. The calculation and processing of the film softening degree refers to the process of calculating the quantitative index of the current softening state of the film according to the temperature-viscoelasticity relationship of the ablatable film material, combined with the local actual temperature and pressure conditions. Specifically, during implementation, first determine the softening characteristic parameters of the ablatable film material used: glass transition temperature (Tg), softening curve slope, etc. Then calculate the local pressure value according to the compression ratio coefficient, and combine it with the actual temperature calculated from the temperature rise rate. Apply the material softening model to calculate the softening degree of the film at each point. The softening degree parameter is defined as the percentage of completion of the transition of the film from the solid state to the flowing state, with a value range of 0 - 100%. 0% represents the completely solid state, and 100% represents the completely softened and flowing state. A temperature weight coefficient of 0.7 and a pressure weight coefficient of 0.3 are added in the calculation to reflect the dominant role of temperature in softening. For example, for a via hole position with a temperature rise rate of 13.8% and a compression ratio coefficient of 13.5%, the calculated softening degree of the film is 78%, indicating a state close to complete softening. Spatial interpolation and hierarchical display are performed on the softening degree data of all high-risk via hole positions to form a film softening distribution map, visually showing the film state in each region. This method for calculating the softening degree realizes the precise evaluation of the physical state of the film at micro via holes, reveals the differences in the material states of different regions, provides a basis for the material state for accurately adjusting the lamination parameters, and avoids the problem of uneven material response caused by unified process parameters.

[0064] Please continue to refer to Figure 1 and perform three-dimensional inversion processing on the full-board broadband acoustic spectrum collected before cooling according to the lamination execution curve, calculate the via hole filling rate distribution, and determine the quality state of the board to obtain a three-dimensional filling map.

[0065] In an embodiment of the present invention, the performing three-dimensional inversion processing on the full-board broadband acoustic spectrum collected before cooling according to the lamination execution curve, calculating the via hole filling rate distribution, and determining the quality state of the board to obtain a three-dimensional filling map includes: Performing acoustic spectrum segment extraction processing on the process parameter change points in the lamination execution curve to obtain the ablation degree data of the ablatable film at each via hole position, and obtaining an ablation state distribution map; Performing acoustic signal decoupling processing according to the ablation state distribution map in combination with the stress distribution of the copper foil layer around the via hole to obtain the stress field of the via hole wall surface; Performing interlayer acoustic attenuation analysis processing on the stress field of the via hole wall surface and the resin curing shrinkage data to obtain an interlayer bonding strength matrix; Performing filling rate mapping processing on the ablation state distribution map according to the interlayer bonding strength matrix to obtain a via hole filling rate distribution map; Perform a quality status evaluation process on the through-hole filling rate distribution map in combination with the stress field on the through-hole wall surface to obtain a board quality status matrix; Perform a spatial superposition process based on the through-hole filling rate distribution map and the board quality status matrix to obtain a three-dimensional filling map.

[0066] The following is a specific description of the steps involved in the above embodiments: When performing an acoustic spectrum extraction process on the process parameter change points in the pressing execution curve, use a broadband acoustic scanning system to obtain acoustic response data at key process change moments. Process parameter change points refer to the moments when the temperature or pressure changes significantly during the pressing process, such as key nodes like reaching the target temperature in the heating stage and the pressure reaching the set value. The acoustic spectrum extraction process refers to the process of performing an acoustic scan on the PCB board at these specific moments and extracting the acoustic signal intensity in each frequency band. Specifically, in implementation, install a high-frequency ultrasonic scanning probe array (frequency range of 8 - 40 MHz) on the pressing equipment and automatically trigger a full-board scan at the process parameter change points. Each scan collects complete spectral data (1 MHz step) to form a three-dimensional data set (X-Y spatial position and frequency). The ablation degree data is defined as the percentage of the progress of the ablatable film changing from the initial state to the fully decomposed state, which is calculated by comparing the changes in the initial spectrum and the current spectrum. In the calculation, focus on the amplitude reduction and peak frequency offset in the characteristic frequency band (18 - 25 MHz). For example, the acoustic spectrum at a certain through-hole position when the pressure reaches 1.5 MPa shows that the characteristic peak frequency drops from the initial 22.5 MHz to 19.8 MHz, and the amplitude decays by 35%. The calculated ablation degree is 42%, indicating that the film has been partially decomposed. Organize the spatial distribution of the ablation degree data for all through-hole positions on the entire board to form an ablation state distribution map, showing the progress of film decomposition in each area. This acoustic spectrum extraction method realizes the real-time monitoring of the state change of the film material in a closed environment, accurately reflects the chemical transformation process of the material under high temperature and high pressure, and provides key material state data for evaluating the pressing quality.

[0067] When performing acoustic signal decoupling processing according to the ablation state distribution map in combination with the stress distribution of the copper foil layer around the via hole, a pure acoustic signal reflecting the state of the via hole wall is separated. Acoustic signal decoupling processing refers to a technical method of separating the contributions of each component from the composite acoustic signal, which is used to eliminate the interference of material stress on acoustic measurement. Specifically, during implementation, first, the stress distribution data of the copper foil layer around the via hole are obtained from the finite element analysis software, including the radial stress and the circumferential stress. The stress distribution data are represented by the stress intensity index, with the unit of MPa, which reflects the stress state of the material. Then, in combination with the ablation state distribution map, a relationship matrix of acoustic response, stress, and ablation degree is established. A signal processing algorithm is used for decoupling calculation: first, the contribution part of the ablation film (proportional to the ablation degree) is subtracted from the total acoustic signal, and then the contribution of the copper foil stress (proportional to the stress intensity) is eliminated. The remaining signal is the acoustic characteristic reflecting the intrinsic state of the via hole wall. For example, for a certain via hole position with an ablation degree of 42% and a copper foil stress intensity of 85 MPa, the original acoustic signal is -38 dB. After calculation, the contribution of the ablation film is -10 dB, and the stress contribution is -15 dB. The decoupled via hole wall signal is -13 dB. Decoupling calculations are performed for all via holes on the entire board to generate a stress field distribution map of the via hole wall. This acoustic decoupling method realizes the accurate evaluation of the state of the micro-via hole wall, excludes the interference effects of other factors, reveals the mechanical state and structural integrity of the via hole itself, and provides pure data for accurately judging the quality of the via hole.

[0068] When performing interlayer acoustic attenuation analysis on the stress field of the through-hole wall surface and the resin curing shrinkage data, the bonding quality and material state of the interlayer medium are evaluated. Interlayer acoustic attenuation analysis refers to a method of evaluating the material bonding state and internal structure by measuring the energy loss of sound waves when propagating between different layers. Specifically, first, the resin curing shrinkage data is obtained, including the linear shrinkage rate (usually 0.1% - 0.5%) and the volume shrinkage rate (usually 2% - 8%). Then, the transmission acoustic signals of the upper and lower adjacent layers at the same through-hole position are collected, and the attenuation value (unit: dB / mm) of the sound wave passing through the interlayer interface is measured. The acoustic attenuation value is directly related to the material density, elastic modulus, and internal defects. By comparing the measured attenuation value with the theoretical attenuation value, the interlayer bonding strength index is calculated. The bonding strength index is defined as the ratio of the actual bonding strength to the ideal bonding strength, ranging from 0 to 1, and the higher the value, the better the bonding quality. For example, for a region with a through-hole wall stress of 75 MPa and a resin shrinkage rate of 0.3%, the measured acoustic attenuation value is 4.2 dB / mm, and the theoretical value is 3.8 dB / mm. The calculated bonding strength index is 0.92, indicating good interlayer bonding quality. Calculate and organize the interlayer bonding strength matrices for all interlayer positions on the entire board to form an interlayer bonding strength matrix. This attenuation analysis method realizes the non-destructive evaluation of the quality of the invisible areas inside the PCB, reveals the spatial distribution characteristics of the interlayer bonding state, and provides a microstructural basis for judging the lamination quality.

[0069] When performing fill rate mapping on the ablation state distribution map according to the interlayer bonding strength matrix, the spatial distribution of the resin filling in the micro through-holes is calculated. Fill rate mapping refers to the process of calculating the degree of resin filling inside the through-hole according to the acoustic signal characteristics. Specifically, combining the interlayer bonding strength data and the ablation state data, the acoustic impedance theory is used to calculate the through-hole filling situation. The through-hole fill rate is defined as the ratio of the actual resin-filled part to the total volume in the through-hole volume, with a value range of 0 - 100%, 0% indicating a completely empty cavity, and 100% indicating complete filling. Three key factors are considered in the calculation: the ablation film state (reflecting the pre-closure degree of the through-hole before resin flow), the interlayer bonding strength (reflecting the curing degree of the surrounding resin), and the acoustic response of the through-hole wall surface (reflecting the interface state). For each through-hole position, the fill rate is calculated based on the weighted combination of the above three factors. For example, for a micro through-hole with an ablation degree of 85%, an interlayer bonding strength index of 0.88, and an acoustic response of -16 dB on the through-hole wall surface, the calculated fill rate is 65%, indicating that the through-hole is partially filled. Calculate the fill rate for all through-hole positions on the entire board and organize the spatial distribution to form a through-hole fill rate distribution map. This fill rate mapping method realizes the quantitative evaluation of the internal state of the micro through-holes, overcomes the limitation of the traditional method that cannot understand the internal situation of the through-holes during the lamination process in real time, and provides a direct basis for lamination quality control.

[0070] When evaluating the quality status by combining the through-hole filling rate distribution map with the stress field on the through-hole wall surface, comprehensively determine the functional performance and reliability level of the through-holes in each area of the PCB board. The quality status evaluation process refers to calculating the comprehensive indicators of through-hole electrical connectivity and mechanical reliability based on the filling rate and stress data. Specifically, when implementing, establish a quality evaluation standard: a filling rate below 20% is good (green, through-hole unobstructed), 20%-50% is a warning (yellow, slightly blocked), 50%-80% is serious (orange, moderately blocked), and above 80% is a failure (red, severely blocked). At the same time, consider the stress state: a stress below 50 MPa is safe, 50-100 MPa is a note, and greater than 100 MPa is a risk. Through the combined scoring of the two-dimensional indicators of the filling rate and stress, determine the quality grade of each through-hole. For example, a certain through-hole has a filling rate of 65% and a stress of 85 MPa, and is rated as the "serious - note" level, indicating moderate blockage and a certain stress risk. Rate all the through-holes on the entire board and organize them into a matrix to form a board quality status matrix, recording the quality grade, failure risk, and reliability expectation of each through-hole position. This quality evaluation method realizes the accurate determination of the PCB pressing quality, not only considering the through-hole filling state but also incorporating the mechanical stress factor, providing a comprehensive quality status evaluation, and providing a scientific basis for product screening and process improvement.

[0071] When performing spatial superposition processing based on the through-hole filling rate distribution map and the board quality status matrix, generate a visual representation that comprehensively shows the quality status of the three-dimensional structure of the PCB board. Spatial superposition processing refers to the process of integrating two-dimensional distribution data into a three-dimensional data set according to the stack structure of the PCB board. Specifically, when implementing, first establish a three-dimensional coordinate system for the PCB board, where X-Y represents the planar position and Z represents the layer height direction. Superimpose and arrange the through-hole filling rate distribution map (X-Y plane) and the quality status data of each layer in the Z-axis direction to form a three-dimensional data structure. Use a color coding system to represent the filling rate and quality grade: the filling rate is represented by a gradient color from blue to red (blue for low filling, red for high filling), and the quality grade is represented by symbols or contour lines. For example, in the three-dimensional visualization representation of a 12-layer PCB board, multiple red high-filling points (filling rate > 80%) are shown in the area between the 3rd and 4th layers, and the "failure" grade is marked with a red contour line, intuitively showing the serious blockage problem in this area. The final three-dimensional filling mapping shows the quality status distribution of the entire PCB board in a three-dimensional graphic manner, supporting viewing from any angle and hierarchical analysis. This three-dimensional spatial superposition method realizes the comprehensive display of the quality status of the PCB multi-layer structure, enabling engineers to intuitively understand the three-dimensional quality distribution of the product, accurately locate the problem area, providing an efficient quality analysis and problem diagnosis tool, and facilitating targeted improvement of process parameters and design schemes.

[0072] The above describes the automated processing method for PCB board lamination in the embodiments of the present invention. Next, the automated processing device for PCB board lamination in the embodiments of the present invention will be described. Please refer to Figure 2 , an embodiment of the automated processing device for PCB board lamination in the embodiments of the present invention includes: A pretreatment module 101, configured to deposit an ablatable film on the surface of the lamination material and set a cavity concentric with the via array before PCB board lamination, collect the initial acoustic resonance frequency data set of the whole board, and obtain an acoustic reference matrix; A dynamic monitoring module 102, configured to perform dynamic point frequency tracking processing on the multi-point acoustic time series signals obtained during the lamination heating-up stage according to the acoustic reference matrix, calculate the amplitude-phase time series data of each micro via, and obtain a via instantaneous acoustic trajectory library; A risk assessment module 103, configured to perform coupling determination processing on the time-temperature-pressure ternary working condition data during the lamination process according to the via instantaneous acoustic trajectory library, calculate the working condition parameters corresponding to the phase difference inflection point moment, and obtain a blockage risk matrix; A parameter adjustment module 104, configured to perform delay and slope adjustment processing on the lamination temperature curve and pressure curve according to the distribution of high-risk vias in the blockage risk matrix, and obtain a lamination execution curve; A quality assessment module 105, configured to perform three-dimensional inversion processing on the broadband acoustic spectrum of the whole board collected before cooling according to the lamination execution curve, calculate the via filling rate distribution and determine the quality state of the board, and obtain a three-dimensional filling map.

[0073] The above Figure 2 The automated processing device for PCB board lamination in the embodiments of the present invention is described in detail from the perspective of modular functional entities. Next, the automated processing equipment for PCB board lamination in the embodiments of the present invention will be described in detail from the perspective of hardware processing.

[0074] Figure 3FIG. 0 is a schematic structural diagram of an automated processing device for PCB board lamination. The automated processing device 200 for PCB board lamination may vary significantly depending on configuration or performance, and may include one or more processors 210 (e.g., one or more processors) and a memory 220, and one or more storage media 230 (e.g., one or more mass storage device ends) for storing application programs 233 or data 232. Among them, the memory 220 and the storage media 230 may be transient storage or persistent storage. The program stored in the storage media 230 may include one or more modules (not shown in the figure), and each module may include a series of instruction operations for the automated processing device 200 for PCB board lamination. Further, the processor 210 may be configured to communicate with the storage media 230 and execute a series of instruction operations in the storage media 230 on the automated processing device 200 for PCB board lamination to implement the steps of the above-mentioned automated processing method for PCB board lamination.

[0075] The automated processing device 200 for PCB board lamination may further include one or more power supplies 240, one or more wired or wireless network interfaces 250, one or more input / output interfaces 260, and / or one or more operating systems 231, such as Windows Serve, Mac OS X, Unix, Linux, FreeBSD, etc. Those skilled in the art can understand that Figure 3 the shown structural diagram of the automated processing device for PCB board lamination does not limit the automated processing device for PCB board lamination provided by the present invention, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0076] The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions run on a computer, the computer is caused to execute the steps of the automated processing method for PCB board lamination.

[0077] Those skilled in the art can clearly understand that for the sake of convenience and brevity of description, the specific working processes of the above-described system or device and unit can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0078] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0079] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An automated processing method for PCB board lamination, characterized in that, Including: Before PCB lamination, deposit an erodible film on the surface of the laminating material and set cavities concentric with the via array, collect the initial acoustic resonance frequency data set of the whole board, and obtain an acoustic reference matrix; According to the acoustic reference matrix, perform dynamic point-frequency tracking processing on the multi-point acoustic time-series signals obtained during the lamination heating-up stage, calculate the amplitude-phase time-series data of each micro via, and obtain a via instantaneous acoustic trajectory library; According to the via instantaneous acoustic trajectory library, perform coupling determination processing on the time-temperature-pressure ternary working condition data during the lamination process, calculate the working condition parameters corresponding to the inflection point of the phase difference, and obtain a blockage risk matrix; According to the distribution of high-risk vias in the blockage risk matrix, perform delay and slope adjustment processing on the lamination temperature curve and pressure curve to obtain a lamination execution curve; According to the lamination execution curve, perform three-dimensional inversion processing on the broadband acoustic spectrum of the whole board collected before cooling, calculate the via filling rate distribution and determine the quality state of the board, and obtain a three-dimensional filling map.

2. The automated processing method for PCB board lamination according to claim 1, wherein Before PCB lamination, deposit an erodible film on the surface of the laminating material and set cavities concentric with the via array, collect the initial acoustic resonance frequency data set of the whole board, and obtain an acoustic reference matrix, including: Perform cavity planning processing on the via distribution map of the PCB board to obtain a cavity layout map; Deposit an erodible film on the surface of the laminating material according to the cavity layout map to obtain a self-dissipating acoustic film layer; Perform micropore forming processing on the self-dissipating acoustic film layer according to the cavity layout map to obtain a cavity structure concentric with the via array; Perform resonance scanning processing on the laminated multi-layer board after deposition and forming to obtain an initial acoustic resonance frequency data set, and perform matrix arrangement processing according to the initial acoustic resonance frequency data set to obtain an acoustic reference matrix.

3. The automated processing method for PCB board lamination according to claim 2, characterized in that, Perform cavity planning processing on the via distribution map of the PCB board to obtain a cavity layout map, including: Perform via diameter and wiring density grading processing on the PCB board via distribution map to obtain a via grading distribution matrix; Perform eccentric cavity parameter calculation processing on the high-density wiring area according to the via grading distribution matrix to obtain an eccentric cavity structure matrix; Perform variable-depth cavity parameter calculation processing on the low-density wiring area according to the via grading distribution matrix to obtain a variable-depth cavity structure matrix; Perform spatial mapping processing according to the eccentric cavity structure matrix and the variable-depth cavity structure matrix to obtain a cavity layout map.

4. The automated processing method for PCB board lamination according to claim 1, characterized in that According to the acoustic reference matrix, perform dynamic point-frequency tracking processing on the multi-point acoustic time-series signals obtained during the lamination heating-up stage, calculate the amplitude-phase time-series data of each micro via, and obtain a via instantaneous acoustic trajectory library, including: Perform region division processing on the acoustic reference matrix to obtain a region index map based on copper surface coverage and temperature gradient; Perform area weight assignment processing on the via identification according to the region index map to obtain a via weight table for each region; Perform weighted point-frequency sampling processing on the multi-point acoustic time-series signals during the heating-up stage according to the via weight table to obtain a region-weighted amplitude-phase sequence matrix; Perform layer-based reference correction processing on the weighted amplitude-phase sequence matrix of the region to obtain a set of corrected amplitude-phase vectors of the same layer; Perform timing splicing processing on the via hole identification based on the set of corrected amplitude-phase vectors of the same layer to obtain a via hole instantaneous acoustic trajectory library.

5. The automated processing method for PCB board lamination according to claim 1, wherein Based on the via hole instantaneous acoustic trajectory library, perform coupling determination processing on the time-temperature-pressure ternary working condition data during the lamination process, calculate the working condition parameters corresponding to the inflection point moment of the phase difference, and obtain a blockage risk matrix, including: Perform inflection point time sorting processing on the via hole instantaneous acoustic trajectory library to obtain a resin flow front propagation time field; Perform synchronous interpolation processing on the time-temperature-pressure ternary working condition data based on the resin flow front propagation time field to obtain a local temperature-pressure-viscosity index matrix; Perform copper surface coverage mapping processing on the PCB design data to obtain a copper surface coverage matrix; Perform impedance coupling processing on the copper surface coverage matrix based on the local temperature-pressure-viscosity index matrix to obtain a mechanical impedance index matrix; Perform threshold comparison processing on the local temperature-pressure-viscosity index matrix based on the mechanical impedance index matrix to obtain a blockage risk matrix.

6. The automated processing method for PCB board lamination according to claim 5, wherein, The performing synchronous interpolation processing on the time-temperature-pressure ternary working condition data based on the resin flow front propagation time field to obtain a local temperature-pressure-viscosity index matrix includes: Perform volatilization characteristic analysis processing on the resin formulation data in the lamination material to obtain a resin volatilization rate curve; Perform compensation calculation processing on the resin flow front propagation time field based on the resin volatilization rate curve to obtain a compensated propagation time field; Perform weighted mapping processing on the ternary working condition data based on the compensated propagation time field in combination with the core board glass fiber density distribution to obtain a local temperature-pressure-viscosity index matrix.

7. The automated processing method for PCB board lamination according to claim 1, characterized in that Based on the distribution of high-risk vias in the blockage risk matrix, perform delay and slope adjustment processing on the lamination temperature curve and pressure curve to obtain a lamination execution curve, including: Perform thin film state analysis processing on the acoustic response data of high-risk vias in the blockage risk matrix, obtain the softening degree parameters of the burnable thin film at each high-risk via, and obtain a thin film softening distribution map; Perform spatial mapping processing on the relative position of the resin flow front and micro vias based on the thin film softening distribution map to obtain a resin flow resistance field; Perform layer-by-layer delay compensation processing on the lamination temperature curve based on the resin flow resistance field and the copper foil layer thermal expansion coefficient to obtain an interlayer temperature compensation curve; Perform pressure delay and slope calculation processing on the interlayer temperature compensation curve in combination with the copper foil stress distribution around the via to obtain a pressure adjustment curve; Perform process parameter coupling processing based on the interlayer temperature compensation curve and the pressure adjustment curve to obtain a lamination execution curve.

8. The automated processing method for PCB board lamination according to claim 7, characterized in that, The performing thin film state analysis processing on the acoustic response data of high-risk vias in the blockage risk matrix, obtaining the softening degree parameters of the burnable thin film at each high-risk via, and obtaining a thin film softening distribution map includes: Perform in-hole gas compression characteristic analysis processing on the acoustic response data of high-risk vias to obtain a compression ratio coefficient matrix; Perform local temperature rise rate calculation processing on the high-risk via region based on the compression ratio coefficient matrix to obtain a temperature rise distribution map; Perform calculation processing on the film softening degree according to the compression ratio coefficient matrix and the temperature rise distribution map to obtain a film softening distribution map.

9. The automated processing method for PCB board lamination according to claim 1, characterized in that According to the press-fitting execution curve, perform three-dimensional inversion processing on the full-board broadband acoustic spectrum collected before cooling, calculate the via filling rate distribution and determine the quality state of the board to obtain a three-dimensional filling map, including: Perform acoustic spectrum segment extraction processing on the process parameter change points in the press-fitting execution curve, obtain the erosion degree data of the erodible film at each via position, and obtain an erosion state distribution map; Perform acoustic signal decoupling processing according to the erosion state distribution map in combination with the stress distribution of the copper foil layer around the via to obtain the via wall stress field; Perform interlayer acoustic attenuation analysis processing on the via wall stress field and the resin curing shrinkage data to obtain an interlayer bonding strength matrix; Perform filling rate mapping processing on the erosion state distribution map according to the interlayer bonding strength matrix to obtain a via filling rate distribution map; Perform quality state evaluation processing on the via filling rate distribution map in combination with the via wall stress field to obtain a board quality state matrix; Perform spatial superposition processing according to the via filling rate distribution map and the board quality state matrix to obtain a three-dimensional filling map.

10. An automated processing device for PCB board lamination, characterized in that, Including: A preprocessing module for depositing an erodible film on the surface of the press-fitting material and setting a cavity concentric with the via array before PCB board lamination, collecting a set of full-board initial acoustic resonance frequency data, and obtaining an acoustic reference matrix; A dynamic monitoring module for performing dynamic point frequency tracking processing on the multi-point acoustic time series signals obtained during the press-fitting heating-up stage according to the acoustic reference matrix, calculating the amplitude-phase time series data of each micro via, and obtaining a via instantaneous acoustic trajectory library; A risk assessment module for performing coupling determination processing on the time-temperature-pressure ternary working condition data during the press-fitting process according to the via instantaneous acoustic trajectory library, calculating the working condition parameters corresponding to the phase difference inflection point moment, and obtaining a blockage risk matrix; A parameter adjustment module for delaying and adjusting the slope of the press-fitting temperature curve and pressure curve according to the distribution of high-risk vias in the blockage risk matrix to obtain a press-fitting execution curve; A quality assessment module for performing three-dimensional inversion processing on the full-board broadband acoustic spectrum collected before cooling according to the press-fitting execution curve, calculating the via filling rate distribution and determining the quality state of the board to obtain a three-dimensional filling map.

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