Ceramic-based double-sided printed circuit board and manufacturing method thereof

Abstract

The present invention discloses a ceramic-based double-sided printed circuit board and a manufacturing method thereof, the method comprising dividing a key monitoring area and a conventional monitoring area according to the three-dimensional structure of a ceramic body, collecting temperature distribution parameters, gas composition parameters and optical characteristic parameters by heating in stages, and performing local spectrum and micro-area atmosphere analysis on high-risk areas to determine the formation time, temperature range and reaction intensity of a secondary phase, and then suppressing the secondary phase by regulating the atmosphere and temperature. The technical solution of the present invention can perform regional monitoring of a ceramic-based double-sided printed circuit board during sintering and metallization, use real-time data to judge and curb the diffusion or aggregation of secondary phases, significantly reduce the risk of interface defects and microcracks, and improve the yield of finished products, and is suitable for high-power, high-heat dissipation and high-reliability fields, thereby meeting the heat dissipation and reliability requirements of high-power devices.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board manufacturing, and in particular to a ceramic-based double-sided printed circuit board and a manufacturing method thereof. Background Art

[0002] Ceramic-based double-sided printed circuit boards refer to a type of circuit board made by depositing and forming metal conductor layers on the upper and lower surfaces of a ceramic material (such as alumina, aluminum nitride, etc.) as a substrate. Compared with traditional organic resin substrates, ceramic substrates have higher thermal conductivity, better high temperature resistance and better chemical stability, and are particularly suitable for high-power and high-reliability applications. The current mainstream preparation process usually includes sintering ceramic powder into a substrate, surface metallization (such as DBC, AMB or thick film slurry technology), and subsequent graphic etching or laser micromachining steps, thereby achieving high-precision circuit wiring and interconnection through holes on both sides of the ceramic substrate. However, as the ceramic formula becomes increasingly complex, the sintering temperature continues to increase, and the metallization layer has increasingly stringent requirements on the interface bonding performance, various undesigned crystalline phases or amorphous phases will appear in the ceramic interior or interface area during the preparation process due to factors such as additive ratio, temperature gradient and sintering atmosphere. These excess components are called "secondary phases".

[0003] Generally speaking, the secondary phase can be understood as an additional phase different from the main matrix phase (ceramic main crystal phase or metal main phase). It may be formed by chemical reactions of sintering aids or trace dopants at high temperatures, or it may be obtained by redistribution and crystallization of impurities in the raw materials themselves during the sintering process. The secondary phase is usually unevenly distributed and has a very low content. Once it accumulates at the ceramic-metal bonding surface, the inner wall of the through hole, or the local stress concentration area, it may affect the dielectric properties, mechanical strength and thermal expansion coefficient of the substrate, and even induce failure problems such as microcracks or decreased adhesion during subsequent service. Since the appearance of the secondary phase is often highly correlated with the key process parameters of sintering and metallization, it is difficult for existing technologies to ensure high density and high thermal conductivity while monitoring and inhibiting the generation and diffusion of such irregular phases in real time. Therefore, it has become one of the potential hidden dangers that need to be urgently solved in the field of ceramic-based double-sided printed circuit boards. Summary of the invention

[0004] The main purpose of the present invention is to solve the technical problem that it is difficult to monitor and effectively inhibit the secondary phase in real time during the sintering and metallization process of the existing ceramic-based double-sided printed circuit board, thereby causing the performance of the substrate to decline and the reliability of the hidden danger.

[0005] A first aspect of the present invention provides a method for manufacturing a ceramic-based double-sided printed circuit board, the method comprising:

[0006] The key monitoring area and the conventional monitoring area are obtained according to the preset three-dimensional structural characteristics of the ceramic body, and the initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters of the key monitoring area and the conventional monitoring area are collected during the staged heating process;

[0007] Analyzing the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk;

[0008] According to the risk level data, local spectral analysis and micro-area atmosphere analysis are performed on the area with high risk level to obtain crystal structure data, diffraction data and local gas concentration data, and the formation time point, temperature range and reaction intensity of the secondary phase are determined according to the crystal structure data, diffraction data and local gas concentration data;

[0009] According to the formation time point, temperature range and reaction intensity of the secondary phase, the atmosphere and temperature are controlled in the area with high risk level, and the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet the preset thresholds, it is determined that the secondary phase is effectively suppressed.

[0010] Optionally, the key monitoring area and the conventional monitoring area are divided according to the preset three-dimensional structural characteristics of the ceramic body, and initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters of the key monitoring area and the conventional monitoring area are collected during the staged heating process, including:

[0011] The monitoring area is divided according to the preset through-hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas;

[0012] Collecting local heating rate, organic decomposition product concentration and surface morphology characteristics of the first-level key monitoring area, the second-level key monitoring area, the third-level key monitoring area and the conventional monitoring area at the early stage of sintering at 400-800°C;

[0013] Collecting temperature gradient, volatile concentration of metal oxides and grain boundary characteristics of the primary key monitoring area, the secondary key monitoring area, the tertiary key monitoring area and the conventional monitoring area at the main phase sintering temperature stage of 1000-1400°C;

[0014] The local heating rate and the temperature gradient are used as initial temperature distribution parameters, the concentration of organic matter decomposition products and the concentration of metal oxide volatilization are used as initial gas composition parameters, and the surface morphology characteristics and the grain boundary characteristics are used as initial optical characteristic parameters.

[0015] Optionally, the monitoring area is divided according to the preset through-hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas, including:

[0016] Obtaining a preset chip power density, a preset through-hole density, and a preset metallization layer thickness of the ceramic body, defining a boundary range of a preset chip packaging area according to the preset chip power density, defining a boundary range of a preset through-hole distribution position according to the preset through-hole density, and defining a boundary range of a preset metallization layer distribution area according to the preset metallization layer thickness;

[0017] Calculate the overlapping area of ​​the preset chip packaging area, the preset through-hole distribution position and the preset metallization layer distribution area, and determine the region attribution of the overlapping area in the order of priority of the preset chip packaging area first, the preset through-hole distribution position second, and the preset metallization layer distribution area last;

[0018] According to the determined area affiliation, the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining area is divided into a conventional monitoring area.

[0019] Optionally, the initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters are analyzed to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk, including:

[0020] Performing deviation calculation on the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain a temperature deviation rate, a gas concentration deviation rate and an optical characteristic deviation rate, wherein the temperature deviation rate is the difference between the actual temperature and the standard temperature divided by the standard temperature, the gas concentration deviation rate is the difference between the actual concentration and the standard concentration divided by the standard concentration, and the optical characteristic deviation rate is the difference between the actual optical characteristic and the standard optical characteristic divided by the standard optical characteristic;

[0021] Performing time series correlation analysis on the temperature deviation rate, gas concentration deviation rate and optical property deviation rate, and calculating a dual-parameter deviation coupling degree and a three-parameter deviation coupling degree, wherein the dual-parameter deviation coupling degree is the ratio of the product of any two of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the corresponding two deviation rate detection time intervals, and the three-parameter deviation coupling degree is the ratio of the product of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the maximum interval of the three detection times;

[0022] The dual-parameter deviation coupling degree is compared with a first coupling threshold, and the three-parameter deviation coupling degree is compared with a second coupling threshold. When the three-parameter deviation coupling degree is greater than the second coupling threshold, it is determined to be a high risk; when the dual-parameter deviation coupling degree is greater than the first coupling threshold and the three-parameter deviation coupling degree is less than or equal to the second coupling threshold, it is determined to be a medium risk; when the dual-parameter deviation coupling degree is less than or equal to the first coupling threshold, it is determined to be a low risk.

[0023] Optionally, performing time series correlation analysis on the temperature deviation rate, the gas concentration deviation rate, and the optical property deviation rate to calculate a dual-parameter deviation coupling degree and a three-parameter deviation coupling degree includes:

[0024] The temperature deviation rate, gas concentration deviation rate and optical property deviation rate are segmented into time windows to obtain the deviation rate change trend in each time window, and the inflection point of the deviation rate change trend is selected as the deviation rate detection time mark point;

[0025] Determine, according to the deviation rate detection time mark point, a first detection time interval between the temperature deviation rate and the gas concentration deviation rate, a second detection time interval between the temperature deviation rate and the optical property deviation rate, and a third detection time interval between the gas concentration deviation rate and the optical property deviation rate;

[0026] The product of the temperature deviation rate and the gas concentration deviation rate is divided by the first detection time interval to obtain a first dual-parameter deviation coupling degree, the product of the temperature deviation rate and the optical property deviation rate is divided by the second detection time interval to obtain a second dual-parameter deviation coupling degree, the product of the gas concentration deviation rate and the optical property deviation rate is divided by the third detection time interval to obtain a third dual-parameter deviation coupling degree, and the maximum value among the first dual-parameter deviation coupling degree, the second dual-parameter deviation coupling degree and the third dual-parameter deviation coupling degree is selected as the dual-parameter deviation coupling degree;

[0027] The three-parameter deviation coupling degree is obtained by dividing the product of the temperature deviation rate, the gas concentration deviation rate and the optical characteristic deviation rate by the maximum value of the first detection time interval, the second detection time interval and the third detection time interval.

[0028] Optionally, the method of performing local spectral analysis and micro-area atmosphere analysis on a high-risk area according to the risk level data to obtain crystal structure data, diffraction data and local gas concentration data, and determining the formation time point, temperature range and reaction intensity of the secondary phase according to the crystal structure data, diffraction data and local gas concentration data includes:

[0029] Determine the high-risk area according to the risk level data, perform point-by-point scanning of the crystal structure of the determined high-risk area to obtain a fingerprint spectrum of the specific crystal structure, the offset and intensity of the diffraction peak, determine the crystal structure data according to the fingerprint spectrum, determine the diffraction data according to the offset and intensity, collect the micro-area atmosphere of the high-risk area, obtain the instantaneously released characteristic gas concentration, and use it as the local gas concentration data;

[0030] Performing a eutectic phase trend analysis on the diffraction data, performing a new phase generation trend analysis on the local gas concentration data, and determining a secondary phase formation time point according to the eutectic phase formation time point and the new phase generation time point;

[0031] Performing a temperature-raising interruption process on the temperature corresponding to the formation time point to obtain a local gas concentration attenuation curve, and determining a temperature range according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point;

[0032] The specific crystal structure fingerprint spectrum within the temperature range is integrated to obtain a first integral value, the diffraction peak within the temperature range is integrated to obtain a second integral value, the characteristic gas concentration within the temperature range is averaged to obtain an average concentration value, and a weighted calculation is performed based on the first integral value, the second integral value and the average concentration value to obtain the reaction intensity.

[0033] Optionally, performing a temperature-raising interruption process on the temperature corresponding to the formation time point to obtain a local gas concentration attenuation curve, and determining a temperature range according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point, comprises:

[0034] Collecting temperature data at the formation time point to obtain an initial temperature value, and regulating the heating rate according to the initial temperature value to obtain a temperature-time curve during the temperature reduction process;

[0035] The end point temperature of the temperature-time curve is controlled at a constant temperature to obtain gas concentration data in the constant temperature stage, and a gas concentration change curve is established according to the corresponding relationship between the gas concentration data and the acquisition time;

[0036] Performing differential calculation on the gas concentration change curve to obtain the gas concentration change rate per unit time, and determining the inflection point temperature according to the maximum change point of the gas concentration change rate;

[0037] The inflection point temperature is set as the upper limit of the temperature interval, and the initial temperature value is set as the lower limit of the temperature interval to obtain the temperature interval.

[0038] Optionally, the atmosphere and temperature of the high-risk area are controlled according to the formation time point, temperature range and reaction intensity of the secondary phase, and real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet preset thresholds, it is determined that the secondary phase is effectively suppressed, including:

[0039] Position mapping is performed on the formation time point of the secondary phase to obtain the spatial distribution characteristics of the high-risk area, the temperature control range is determined according to the temperature range of the secondary phase, and the atmosphere control parameters are determined according to the reaction intensity of the secondary phase;

[0040] Temperature control is performed on the high-risk area, the local temperature field is adjusted according to the temperature control range to obtain real-time temperature distribution parameters, the local atmosphere environment is adjusted according to the atmosphere control parameters to obtain real-time gas composition parameters, and the surface morphology of the high-risk area after control is scanned to obtain real-time optical characteristic parameters;

[0041] Performing gradient calculation on the real-time temperature distribution parameter to obtain a temperature deviation value, performing concentration calculation on the real-time gas composition parameter to obtain a gas concentration deviation value, and performing intensity calculation on the real-time optical characteristic parameter to obtain an optical characteristic deviation value;

[0042] The temperature deviation value, the gas concentration deviation value and the optical property deviation value are respectively compared with corresponding preset thresholds. When the three deviation values ​​are simultaneously smaller than the corresponding preset thresholds, it is determined that the secondary phase is effectively suppressed.

[0043] A second aspect of the present invention provides a ceramic-based double-sided printed circuit board, which is manufactured by the method for manufacturing the ceramic-based double-sided printed circuit board of the above embodiment.

[0044] This solution is based on finely dividing different areas of the ceramic substrate during the sintering and metallization process, and collecting multiple information such as temperature distribution, gas composition, and optical properties, so as to achieve dynamic control of the microscopic changes of the material. When the temperature or atmosphere conditions in a local area deviate significantly from the overall conditions, it often means that there is a possibility of generating non-designed crystal phases that are not conducive to subsequent performance. By focusing on monitoring and judging such areas, abnormal signals can be captured when the secondary phase is still in the embryonic or transitional stage.

[0045] On this basis, this solution uses more sophisticated spectral and atmosphere analysis methods to determine the intensity and growth range of the reaction, and then locally regulate these high-risk areas. For example, if a sudden increase in the concentration of a specific gas is detected around the through-hole, accompanied by abnormal reflection changes in the surface optical characteristics, it can be inferred that the additive or dopant has shown a tendency to over-decompose or phase change here. At this time, the temperature curve is adjusted accordingly, or the surrounding atmosphere conditions are temporarily changed (such as adding reducing gas or shortening the high-temperature insulation time), which can effectively suppress unnecessary secondary phase diffusion. Since this solution highly couples detection and regulation together, rather than unified inspection after the process is completed, it can timely perform differentiated treatment for different areas, and fundamentally solve the pain point of difficulty in real-time detection and blocking of secondary phases on the basis of high density and high thermal conductivity.

[0046] In this way, the overall performance of the resulting ceramic-based double-sided circuit board can take into account both high-temperature service requirements and through-hole metallization quality, ensuring thermal conductivity while avoiding adhesion degradation or microcracks caused by secondary phase aggregation. At the same time, the phased monitoring and data collection of the sintering atmosphere and temperature also provide an important reference basis for subsequent processes, which is conducive to the refinement of subsequent etching and metallization operations. In summary, this solution not only achieves higher reliability and stability at the internal structure level of the material, but also establishes a dynamic feedback mechanism for key parameters in the production process. By making full use of regional monitoring and local intervention methods, the core goal of effectively inhibiting the formation of secondary phases is ultimately achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0048] Figure 1 The figure is a schematic diagram of an embodiment of a method for manufacturing a ceramic-based double-sided printed circuit board in an embodiment of the present invention.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, "and / or" in the full text includes three solutions. Taking A and / or B as an example, it includes technical solution A, technical solution B, and technical solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, which must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0053] An embodiment of the present application provides a method for manufacturing a ceramic-based double-sided printed circuit board. Figure 1 A flow chart of a method for manufacturing a ceramic-based double-sided printed circuit board provided in an embodiment of the present application. In this embodiment, the method includes:

[0054] See also Figure 1 , according to the preset three-dimensional structural characteristics of the ceramic body, a key monitoring area and a conventional monitoring area are obtained, and initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters of the key monitoring area and the conventional monitoring area are collected during the staged heating process;

[0055] In one embodiment of the present invention, the key monitoring area and the conventional monitoring area are divided according to the preset three-dimensional structural characteristics of the ceramic body, and the initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters of the key monitoring area and the conventional monitoring area are collected during the staged heating process, including:

[0056] The monitoring area is divided according to the preset through-hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas;

[0057] Collecting local heating rate, organic decomposition product concentration and surface morphology characteristics of the first-level key monitoring area, the second-level key monitoring area, the third-level key monitoring area and the conventional monitoring area at the early stage of sintering at 400-800°C;

[0058] Collecting temperature gradient, volatile concentration of metal oxides and grain boundary characteristics of the primary key monitoring area, the secondary key monitoring area, the tertiary key monitoring area and the conventional monitoring area at the main phase sintering temperature stage of 1000-1400°C;

[0059] The local heating rate and the temperature gradient are used as initial temperature distribution parameters, the concentration of organic matter decomposition products and the concentration of metal oxide volatilization are used as initial gas composition parameters, and the surface morphology characteristics and the grain boundary characteristics are used as initial optical characteristic parameters.

[0060] Specifically, in this embodiment, when implementing the division of monitoring areas, it is necessary to first obtain power data related to the preset chip packaging area, and then calculate the power density. The power data can usually be obtained from the simulation results or device manuals in the circuit board design stage, and combined with the actual reserved packaging area on the ceramic body, the power density value can be obtained by dividing the total power by the packaging area. If the power density of a certain area is significantly higher than that of its surrounding area, it means that the area will bear greater heat exchange and more stringent heat dissipation requirements in the subsequent working state, so this high-power packaging area is set as a first-level key monitoring area when defining the monitoring area. This ensures that in the subsequent heating process, a more sophisticated and intensive temperature and gas monitoring method is adopted for this area, so as to timely capture the generation of unexpected phases that may lead to failure.

[0061] When setting the secondary key monitoring area, it is necessary to make a judgment based on the distribution position of the through holes and their quantity characteristics. The specific method is to input the CAD layout file of the ceramic body into the detection software, identify the XY coordinates and diameter range of the through holes, and count the distribution patterns of these through holes on the surface or inside of the substrate. If the number of through holes is relatively concentrated and the diameter is large, it means that there are obvious characteristics of heat conduction and local stress concentration in the sintering and subsequent metallization stages, and it is also prone to uneven heating or microcracks. Hidden dangers. Therefore, the area covered by such high-density or large-size through holes can be designated as a secondary key monitoring area, so that the local stress field and thermal gradient can be tracked more frequently during subsequent measurement and regulation.

[0062] When dividing the three-level key monitoring areas, it is necessary to refer to the preset metallization layer distribution area and its corresponding thickness information on the upper and lower surfaces. When obtaining this data, the metal deposition design file can be read to obtain which board surface positions and hole wall positions are deposited with a metal layer of a specific thickness. If the metal layer is thicker in certain locations, additional stress is likely to be generated during the sintering or metallization process, or challenges may arise in interface bonding, which poses a higher risk of secondary phase formation. For such locations, the key points of monitoring are concentrated on interface temperature changes and metal oxide volatilization, so they are set as three-level key monitoring areas. Other locations that do not have outstanding power density and do not have a special concentration of through holes are classified as conventional monitoring areas, and these areas can use lower frequency detection methods.

[0063] In the early stage of sintering at 400-800°C, the local heating rate, organic decomposition product concentration and surface morphology characteristics are collected for the above four types of monitoring areas. The local heating rate can be obtained by thermocouples or infrared thermometers installed in specific areas. For example, several thermocouples are arranged around each through-hole in the secondary key monitoring area to observe the temperature rise curve of the through-hole wall in real time. The concentration of organic decomposition products can be detected by connecting an external spectrometer to the gas sampling port. For example, the characteristic decomposition peaks produced by certain adhesives or organic solvents can be observed at the gas sampling port in the high-power packaging area. The surface morphology characteristics are mainly obtained by optical microscopy or scanning electron microscopy. The area can be temporarily removed after heating to 800°C, or photographed at the end of the set window period. For example, when an abnormal melting point or a large area of ​​particle appearance changes appear on the surface of a high-power packaging area, it means that there may be an unsuitable temperature environment or additive reaction in the area, which requires further attention.

[0064] At the main phase sintering temperature stage of 1000-1400°C, the temperature gradient, metal oxide volatile concentration and grain boundary characteristics are recorded for the same monitoring area. The temperature gradient can be collected by setting temperature measurement points at different vertical depths of the blank to obtain the temperature difference from the surface to the inside. If the temperature difference detected in the through-hole concentration area (i.e., the secondary key monitoring area) is greater than a certain set limit, it is inferred that stress imbalance may occur locally. The concentration of metal oxide volatiles can be quantitatively analyzed by a micro-sampling tube located in the through-hole or metallization layer area. If the characteristic oxide concentration is detected to increase significantly in certain monitoring areas, it means that volatilization or oxidation reactions have occurred at the metal interface there, which may cause secondary phase or interface defects. The grain boundary characteristics usually need to be observed on the blank cross section after the end of this temperature section. Under an electron microscope, it can be intuitively seen whether there is abnormal secondary phase accumulation between the grains. For example, if a large piece of undesirable crystal phase aggregation or grain boundary sharp cracks are observed in the metallization layer thickness area corresponding to the third-level key monitoring area, the sintering curve and atmosphere supply method of this area need to be evaluated immediately.

[0065] The local heating rate and temperature gradient are summarized as the initial temperature distribution parameters, which can reveal the heat load of different areas in different temperature sections. The concentration of organic decomposition products and the concentration of metal oxide volatilization are integrated into the initial gas composition parameters to reflect whether there are unexpected decomposition or oxidation reactions in these two key temperature sections. The surface morphology characteristics and grain boundary characteristics are summarized as initial optical property parameters to show the morphological evolution of the material structure at the microscopic level. In this way, all key data of each key monitoring area in the 400-800°C stage and the 1000-1400°C stage are saved in a partitioned manner, and can be compared one by one according to the chip packaging area, through-hole area and metallization area, so as to timely determine whether there are hidden dangers that require additional treatment. If it is observed that the gas concentration and temperature distribution in the first-level key monitoring area deviate from the baseline value synchronously, it can be further confirmed in combination with the surface or cross-sectional microscopic images, and the corresponding temperature curve correction or atmosphere adjustment operation can be taken in the subsequent high temperature or cooling period. Through this series of processes, the high-power packaging area, the through-hole concentration area and the metallization area can each receive targeted attention to avoid unnecessary reactions in any area during the sintering or metallization process, resulting in unfavorable phase generation or microcrack propagation.

[0066] In one embodiment of the present invention, the monitoring area is divided according to the preset through-hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas, including:

[0067] Obtaining a preset chip power density, a preset through-hole density, and a preset metallization layer thickness of the ceramic body, defining a boundary range of a preset chip packaging area according to the preset chip power density, defining a boundary range of a preset through-hole distribution position according to the preset through-hole density, and defining a boundary range of a preset metallization layer distribution area according to the preset metallization layer thickness;

[0068] Calculate the overlapping area of ​​the preset chip packaging area, the preset through-hole distribution position and the preset metallization layer distribution area, and determine the region attribution of the overlapping area in the order of priority of the preset chip packaging area first, the preset through-hole distribution position second, and the preset metallization layer distribution area last;

[0069] According to the determined area affiliation, the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining area is divided into a conventional monitoring area.

[0070] Specifically, in this embodiment, it is necessary to calculate the overlapping relationship between the preset chip packaging area, the preset through-hole distribution position, and the preset metallization layer distribution area. To achieve this process, the three sets of boundary information can be compared layer by layer in an electronic map-like coordinate system. Once it is detected that a part of the area is covered by multiple areas at the same time, the overlapping area is regarded as a higher level of potential risk area. Through superposition operations, those parts that have high power density, concentrated through-hole distribution, and a large metallization layer thickness can be accurately identified. If a triple overlap occurs somewhere, a higher monitoring priority will be given when the subsequent area is attributed.

[0071] In order to reasonably allocate the final ownership of each overlapping area, it is necessary to judge in the order of priority, with the preset chip packaging area first, the preset through-hole distribution position second, and the preset metallization layer distribution area last. This ensures that the high-power packaging area is always regarded as the most urgent risk point. If an overlapping area meets both high power and high through-hole density conditions, it will be prioritized as belonging to the chip packaging area. If there is still overlap with the metallization layer distribution area, it will also be retained under the corresponding priority ownership, but during actual monitoring, the attention here will be appropriately increased in the data collection frequency or control measures, so that the detection system can perceive microscopic changes in a timely manner and perform parameter corrections.

[0072] When all overlapping parts are processed in order of priority, the ownership of each area can be finally determined: the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and other parts are classified as conventional monitoring areas. The first-level key monitoring area will correspond to a more frequent temperature and gas collection frequency in the subsequent sintering and processing links, the second-level key monitoring area will continue to monitor the local heating rate and organic matter decomposition parameters, and the third-level key monitoring area will also pay special attention to the volatilization and bonding conditions between the metal and ceramic interface. Through this method of first obtaining key data and then classifying and superimposing it, and judging according to the established priority order when overlap occurs, each key area has formed an orderly and more targeted detection and control layout, which can effectively reduce the potential risk of secondary phase formation when the preset high power, many through-holes, thick metal layer and other conditions exist at the same time.

[0073] Please continue reading Figure 1 , analyzing the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk;

[0074] In one embodiment of the present invention, the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters are analyzed to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk, including:

[0075] Performing deviation calculation on the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain a temperature deviation rate, a gas concentration deviation rate and an optical characteristic deviation rate, wherein the temperature deviation rate is the difference between the actual temperature and the standard temperature divided by the standard temperature, the gas concentration deviation rate is the difference between the actual concentration and the standard concentration divided by the standard concentration, and the optical characteristic deviation rate is the difference between the actual optical characteristic and the standard optical characteristic divided by the standard optical characteristic;

[0076] Performing time series correlation analysis on the temperature deviation rate, gas concentration deviation rate and optical property deviation rate, and calculating a dual-parameter deviation coupling degree and a three-parameter deviation coupling degree, wherein the dual-parameter deviation coupling degree is the ratio of the product of any two of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the corresponding two deviation rate detection time intervals, and the three-parameter deviation coupling degree is the ratio of the product of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the maximum interval of the three detection times;

[0077] The dual-parameter deviation coupling degree is compared with a first coupling threshold, and the three-parameter deviation coupling degree is compared with a second coupling threshold. When the three-parameter deviation coupling degree is greater than the second coupling threshold, it is determined to be a high risk; when the dual-parameter deviation coupling degree is greater than the first coupling threshold and the three-parameter deviation coupling degree is less than or equal to the second coupling threshold, it is determined to be a medium risk; when the dual-parameter deviation coupling degree is less than or equal to the first coupling threshold, it is determined to be a low risk.

[0078] Specifically, in actual implementation, it is necessary to first compare the temperature distribution parameters, gas composition parameters and optical property parameters obtained in each monitoring area at different stages with the corresponding standard values. The standard values ​​are generally provided by the control samples that are stable in the previous test and do not produce secondary phases, and combined with the average value or credible interval obtained after repeated measurements. Subtract the measured temperature from the standard temperature and divide it by the standard temperature to get the temperature deviation rate. If this deviation rate is significantly higher, it means that the area has generated unexpected heat accumulation or insufficient heat dissipation under the specified conditions. Subtract the measured gas concentration from the standard concentration and divide it by the standard concentration to get the gas concentration deviation rate. If this value increases significantly, it indicates that the local chemical reaction is strong or the additive is over-decomposed. Subtract the measured optical properties from the standard optical properties and divide them by the standard optical properties to get the optical property deviation rate. If a large change is observed, it means that the surface reflectivity or grain boundary morphology is abnormal at the microstructural level.

[0079] In order to identify the coupling relationship of these deviation rates in the time dimension, it is necessary to set several detection time nodes in the control software, such as triggering a collection once when the temperature rises to 700°C or 1100°C, and recording the corresponding temperature deviation rate, gas concentration deviation rate and optical property deviation rate together with the sampling time. Next, the time series correlation analysis is carried out, and the dual-parameter deviation coupling is first calculated, that is, in the time period when any two deviation rates are collected at the same time, the product of the two deviation rates is divided by the value of the two detection time intervals. If both deviations increase rapidly and the interval is very short, the dual-parameter deviation coupling will increase significantly, indicating that this area has experienced thermal and chemical coordinated fluctuations in a short period of time. If the coordination of the optical property deviation rate is also considered at the same time, the product of the three will be divided by the maximum interval of the three detection times. The result is the three-parameter deviation coupling. When the temperature, gas and optical property deviations rise almost synchronously and the collection time is concentrated, the three-parameter deviation coupling will rise significantly, indicating that the internal organization or interface has been seriously disturbed under multiple effects. For example, if a chip packaging area shows a temperature deviation rate higher than 0.2, a gas concentration deviation rate higher than 0.3, and an optical property deviation rate higher than 0.25 during multiple tests between 800°C and 1000°C, and the maximum interval between the three tests is less than 5 minutes, then the three-parameter deviation coupling will exceed the equilibrium threshold, and it can be inferred that rapid secondary phase or interface defect growth may occur there.

[0080] In order to classify these coupling degrees, it is necessary to summarize the first coupling threshold and the second coupling threshold based on the test data of the previous stable process and the failed process. If the three-parameter deviation coupling exceeds the second coupling threshold, it is judged as high risk, because the temperature, gas and optical triple deviations have reached a concentrated and drastic level; if the two-parameter deviation coupling exceeds the first coupling threshold and the three-parameter deviation coupling does not break through the second coupling threshold, it is judged as medium risk, because there are only two types of deviations superimposed; if the two-parameter deviation coupling is lower than or equal to the first coupling threshold, it is judged as low risk, which reflects that there is no large-scale coordinated abnormality in the area. In this way, after each sintering stage or at the end of the critical temperature turning section, the comprehensive coupling results of the three-way data of thermocouple, gas detector and optical microscopy can be used to accurately identify which monitoring areas are on the edge of danger, and guide the subsequent degree of atmosphere adjustment or local cooling operation. If an area is judged as high risk many times, it means that there is an inherent defect tendency that cannot be ignored under the existing temperature curve or doping system, and targeted optimization must be carried out quickly. Through this multi-parameter coupling method, not only can the sudden changes of multiple physical quantities in a short period of time be quantitatively reflected, but also the parts most prone to failure can be found through lateral comparison of different areas, so that the stability of the entire ceramic-based double-sided printed circuit board during high-temperature sintering and metallization is significantly improved.

[0081] In one embodiment of the present invention, performing time series correlation analysis on the temperature deviation rate, the gas concentration deviation rate and the optical characteristic deviation rate to calculate the dual-parameter deviation coupling degree and the three-parameter deviation coupling degree includes:

[0082] The temperature deviation rate, gas concentration deviation rate and optical property deviation rate are segmented into time windows to obtain the deviation rate change trend in each time window, and the inflection point of the deviation rate change trend is selected as the deviation rate detection time mark point;

[0083] Determine, according to the deviation rate detection time mark point, a first detection time interval between the temperature deviation rate and the gas concentration deviation rate, a second detection time interval between the temperature deviation rate and the optical property deviation rate, and a third detection time interval between the gas concentration deviation rate and the optical property deviation rate;

[0084] The product of the temperature deviation rate and the gas concentration deviation rate is divided by the first detection time interval to obtain a first dual-parameter deviation coupling degree, the product of the temperature deviation rate and the optical property deviation rate is divided by the second detection time interval to obtain a second dual-parameter deviation coupling degree, the product of the gas concentration deviation rate and the optical property deviation rate is divided by the third detection time interval to obtain a third dual-parameter deviation coupling degree, and the maximum value among the first dual-parameter deviation coupling degree, the second dual-parameter deviation coupling degree and the third dual-parameter deviation coupling degree is selected as the dual-parameter deviation coupling degree;

[0085] The three-parameter deviation coupling degree is obtained by dividing the product of the temperature deviation rate, the gas concentration deviation rate and the optical characteristic deviation rate by the maximum value of the first detection time interval, the second detection time interval and the third detection time interval.

[0086] Specifically, in practice, the collected temperature deviation rate, gas concentration deviation rate and optical property deviation rate can be arranged in chronological order, and then these data can be divided into several time windows according to the key nodes in the heating or insulation process, and numerical fitting or differential analysis can be used in each time window to obtain the deviation rate change trend. By observing the process of the deviation rate from relatively stable to rapidly rising or falling from a high value to a lower level in each time window, a relatively smooth change curve can be obtained with the help of curve fitting tools or differential operations, and the inflection point can be set at the position where the maximum slope or minimum slope appears on the curve. The inflection point can correspond to the sudden decomposition of the additive in a certain temperature range, or it can correspond to the local structural transformation of a certain area under the change of atmosphere.

[0087] If the temperature deviation rate rises rapidly from an extremely low level to a peak value within a certain time window, an upward rapid fluctuation curve will appear in the image, and the inflection point usually appears at the moment when the slope of the curve changes suddenly, which is marked as the deviation rate detection time mark point. For example, if the temperature deviation rate curve in the window of 400°C to 600°C shows a single peak shape, the inflection point will be marked at the position where the curve rises to the highest point and bends, and then the time corresponding to the inflection point will be recorded, so as to be compared with the inflection point time of the gas concentration deviation rate or the optical property deviation rate in the subsequent coupling operation. After determining the inflection point, the detection time intervals between different deviation rates can be calculated, including the first detection time interval, the second detection time interval and the third detection time interval, which respectively represent the time difference between the temperature deviation rate and the gas concentration deviation rate, the temperature deviation rate and the optical property deviation rate, and the gas concentration deviation rate and the optical property deviation rate.

[0088] If the inflection points of the temperature deviation rate and the gas concentration deviation rate are observed to appear almost simultaneously within a certain temperature range, a minimum value will be obtained in the first detection time interval, which means that the two deviations are highly overlapped in time. In order to quantify the dual-parameter deviation coupling, it is necessary to divide the product of any two deviation rates by the corresponding detection time interval. For example, the temperature deviation rate is multiplied by the gas concentration deviation rate and divided by the first detection time interval to obtain the first dual-parameter deviation coupling. If the temperature deviation rate and the optical property deviation rate also rise synchronously at a close time point, the second detection time interval will become very short, and the resulting second dual-parameter deviation coupling value will be higher. The processing of the gas concentration deviation rate and the optical property deviation rate is similar to the previous two. The third dual-parameter deviation coupling is obtained by dividing their product by the third detection time interval, and then the maximum value of the three dual-parameter deviation couplings is selected to obtain the dual-parameter deviation coupling in the entire window.

[0089] The calculation method of the three-parameter deviation coupling is to multiply the temperature deviation rate, gas concentration deviation rate and optical property deviation rate, and divide them by the maximum value of the three detection time intervals. If the three deviation rates increase significantly at the same time or in a very short period of time, the three-parameter deviation coupling will be pushed to a higher level. This situation is usually related to the coupling of multiple reactions. If the three deviation rate curves are observed to rise suddenly in another window from 600°C to 800°C, and their inflection points fall at close time positions, a very small maximum detection time interval will be obtained in the time series correlation analysis, so that the three-parameter deviation coupling reaches a larger value, which often indicates that some local areas inside the ceramic-based double-sided printed circuit board are experiencing the superposition of heat accumulation, active species release and microscopic morphology mutation.

[0090] Through such subdivided windows and inflection point markings, we can not only focus on the typical response of each stage, but also amplify the deviation rate product when the detection time interval is very short, so as to identify the key time period of potential secondary phase generation or interface degradation. Each window will output a set of two-parameter deviation coupling and a three-parameter deviation coupling. If the coupling value of a window is significantly higher than that of other windows, it can be combined with the high-risk threshold in the process database to determine that abnormal changes have occurred in the heating or insulation process of this section, and then fine-tune the temperature curve or atmosphere supply plan for this section.

[0091] Please continue reading Figure 1 , according to the risk level data, performing local spectral analysis and micro-area atmosphere analysis on the area with high risk level, obtaining crystal structure data, diffraction data and local gas concentration data, and determining the formation time point, temperature range and reaction intensity of the secondary phase according to the crystal structure data, diffraction data and local gas concentration data;

[0092] In one embodiment of the present invention, the method of performing local spectral analysis and micro-area atmosphere analysis on a high-risk area according to the risk level data to obtain crystal structure data, diffraction data and local gas concentration data, and determining the formation time point, temperature range and reaction intensity of the secondary phase according to the crystal structure data, diffraction data and local gas concentration data includes:

[0093] Determine the high-risk area according to the risk level data, perform point-by-point scanning of the crystal structure of the determined high-risk area to obtain a fingerprint spectrum of the specific crystal structure, the offset and intensity of the diffraction peak, determine the crystal structure data according to the fingerprint spectrum, determine the diffraction data according to the offset and intensity, collect the micro-area atmosphere of the high-risk area, obtain the instantaneously released characteristic gas concentration, and use it as the local gas concentration data;

[0094] Performing a eutectic phase trend analysis on the diffraction data, performing a new phase generation trend analysis on the local gas concentration data, and determining a secondary phase formation time point according to the eutectic phase formation time point and the new phase generation time point;

[0095] Performing a temperature-raising interruption process on the temperature corresponding to the formation time point to obtain a local gas concentration attenuation curve, and determining a temperature range according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point;

[0096] The specific crystal structure fingerprint spectrum within the temperature range is integrated to obtain a first integral value, the diffraction peak within the temperature range is integrated to obtain a second integral value, the characteristic gas concentration within the temperature range is averaged to obtain an average concentration value, and a weighted calculation is performed based on the first integral value, the second integral value and the average concentration value to obtain the reaction intensity.

[0097] Specifically, after the high-risk areas are determined, the risk level data collected in the early stage is first used to find areas with high coupling in temperature, gas concentration and optical properties, and these locations are marked as targets that require in-depth analysis. In order to obtain more accurate microscopic information, a common spectral detection device can be used in the high-risk area to scan the crystal structure point by point, and the fingerprint spectrum of the specific crystal structure can be recorded during the scanning process. A fingerprint spectrum is an image that presents specific peak shapes and position information in a spectrum or diffraction pattern. The specific crystalline phase components of the material can be identified by comparing it with the spectra of known substances in the database. If an unfamiliar peak shape is observed at a certain position and the intensity is high, it indicates that there may be additional phase components at that location. Some devices can further provide diffraction angle information for the corresponding peak position. The user will accurately record the offset and peak intensity of these diffraction peaks to form diffraction data. For example, after the temperature range of 500°C to 800°C or higher ends, the ceramic substrate sample in the area can be scanned offline, and the board surface can be scanned step by step using an X-ray diffractometer. If a diffraction peak is found that deviates from the main crystal phase by several degrees and has obvious intensity, it proves that a phase that does not belong to the pre-designed formula has appeared in the microstructure of this high-risk area.

[0098] After completing the above crystal structure scan, in order to confirm the formation mechanism of the new phase, it is necessary to perform micro-area atmosphere collection operations on the same high-risk area. Micro-area atmosphere collection can use a small gas sampling probe to draw out local gas and introduce it into the gas analyzer during the heating or constant temperature stage, and combine spectral or chromatographic detection methods to obtain the instantaneous release of characteristic gas concentrations. If an increase in the content of specific metal oxide vapor or doping additive decomposition products is detected at a certain constant temperature stage, it means that the area is undergoing a significant chemical reaction, further confirming the activity of secondary phase formation. The numerical value obtained by the micro-area atmosphere collection is defined as the local gas concentration data, and mapped with the specific peaks detected in the fingerprint spectrum, it can be comprehensively judged what kind of chemical reaction or impurity aggregation caused the shift of the diffraction peak.

[0099] The trend analysis of the eutectic phase on the above diffraction data is a judgment process based on thermodynamics and kinetics. It is necessary to first identify the characteristic peaks that can characterize the eutectic phase on the diffraction pattern. If the peak position is significantly different from the main crystal phase or known dopants, the diffraction peak parameters of the eutectic system in the reference can be combined to determine whether the phase is in a eutectic state. If such diffraction peaks appear in a certain ceramic area at a relatively low temperature, it means that the area is quite sensitive to temperature and environmental changes, and it is easy to enter the secondary phase growth stage when the temperature is slightly increased. The trend analysis of new phase formation on local gas concentration data requires attention to the evolution of gas composition. If a large amount of new characteristic gases are detected during the gradual increase or maintenance of temperature, and it coincides with the appearance period of the diffraction peak in the fingerprint spectrum, it can be concluded that this area has formed a new phase under the action of active additives or dopants. After the above analysis obtains the specific time of eutectic phase formation and the time of new phase generation, the actual time point of the secondary phase can be recorded in the form of a timestamp, so as to clarify in which temperature range the polycrystalline phase or impurity deposition reaction occurred.

[0100] Next, in order to accurately measure the temperature range in which this secondary phase undergoes significant evolution, it is necessary to interrupt the temperature rise corresponding to the formation time point, that is, to pause the original temperature rise curve or reduce the temperature rise rate after the time point at which the secondary phase appears, so as to stabilize the reaction environment and observe the curve shape of the local gas concentration decaying with time. If the characteristic gas begins to decrease at an accelerated rate after a certain moment and continues to decline to a stable value, the inflection point recognition can be performed on the gas concentration decay curve to obtain the key temperature at which the gas composition falls from the peak value during this process, and this temperature is determined together with the temperature corresponding to the previous formation time point as the temperature range of the secondary phase, that is, the upper and lower limits of the most active reaction of this phase. For example, if a certain titanate ceramic system shows a significant diffraction peak shift at about 750°C and a high concentration of volatiles is detected, and then at about 790°C, the characteristic gas released begins to decay rapidly through micro-area collection, then 750°C-790°C can be defined as the reaction range of this secondary phase, and then measures such as auxiliary insulation or local cooling can be taken in this range to regulate it.

[0101] After completing the determination of the above temperature range, it is necessary to integrate the specific crystal structure fingerprint spectrum accompanying it to quantify how many peak areas or peak intensities appear in the range, and obtain a first integral value to represent the total amount of the phase generated in the spectral dimension. The diffraction peak can perform the same integral operation in the same range, and record the cumulative area of ​​the diffraction peak from nothing to something or from weak to strong in the temperature range to obtain a second integral value. As for the characteristic gas concentration in this range, the average value of multiple samplings can be used for statistics, and the average concentration value obtained can be included in the weighted calculation formula together with the first integral value and the second integral value to obtain a reaction intensity value. This value can reflect the activity and generation scale of the secondary phase in this temperature range, and provides an important reference for judging whether to make additional atmosphere adjustments, shorten the insulation time or increase the local pressure in this temperature range in the next step. If the reaction intensity is significantly higher, and microscopic observation shows that the phase is closely combined with the main grain boundary, it is even more necessary to carry out adaptive regulation immediately to avoid serious phase precipitation or interface peeling during subsequent high temperatures or service. If the reaction intensity remains at a low level, but rises rapidly in the next batch of monitoring, the low eutectic phase trend and the time of new phase generation can also be combined to determine that the area has a potential failure risk in the future heating link, thereby further improving the data sampling density at this location. It can be seen that by combining the three major processes of crystal structure point-by-point scanning, micro-area atmosphere collection and integral processing, not only can the initial morphology and activity of the secondary phase be clearly understood, but also its reaction matching degree with the external environment and the internal doping system can be judged, laying a solid foundation for subsequent metallization operations and the overall reliability of double-sided printed circuit boards.

[0102] In one embodiment of the present invention, the temperature corresponding to the formation time point is subjected to a temperature increase interruption process to obtain a local gas concentration attenuation curve, and the temperature interval is determined according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point, including:

[0103] Collecting temperature data at the formation time point to obtain an initial temperature value, and regulating the heating rate according to the initial temperature value to obtain a temperature-time curve during the temperature reduction process;

[0104] The end point temperature of the temperature-time curve is controlled at a constant temperature to obtain gas concentration data in the constant temperature stage, and a gas concentration change curve is established according to the corresponding relationship between the gas concentration data and the acquisition time;

[0105] Performing differential calculation on the gas concentration change curve to obtain the gas concentration change rate per unit time, and determining the inflection point temperature according to the maximum change point of the gas concentration change rate;

[0106] The inflection point temperature is set as the upper limit of the temperature interval, and the initial temperature value is set as the lower limit of the temperature interval to obtain the temperature interval.

[0107] Specifically, when collecting temperature data at the formation time point, it is necessary to first install a sensor device for measuring temperature in a high-risk area or a specific monitoring area, such as a thermocouple or an infrared temperature probe, and set a trigger instruction in the detection system. When the material or interface detects a signal of the appearance of a secondary phase, the temperature data is immediately read from the sensor device and recorded as the initial temperature value. If the initial temperature value is a certain value at this time, the control system will rate-regulate the heating program according to the value. In order to more intuitively show the actual change of temperature during the entire deceleration process, the process control software will plot the temperature record that changes over time into a temperature-time curve, and store the data in the database at a certain frequency to form a traceable numerical sequence.

[0108] If a conventional programmable furnace is used to control the heating rate at this stage, it is only necessary to issue instructions to the furnace after the initial temperature value to convert the heating curve from the original linear mode to a slower slope, thereby obtaining a deceleration process, and the temperature-time curve will show a gradually flat trajectory on the graphical interface. Then, constant temperature control is performed at the end temperature position of the curve to stabilize the furnace temperature at this end temperature, and no longer continue to increase or decrease. The gas concentration data of the constant temperature stage is collected through the gas analyzer, and the concentration values ​​at different sampling times are recorded using the data acquisition module. Then, the gas concentration change curve is established based on the corresponding relationship between the recorded time series and the gas concentration value.

[0109] If the concentration of volatile metal oxides is monitored to rise in the constant temperature stage and then slowly decrease after a few minutes in the actual scene, the discrete data points of these concentration changes over time can be connected into a continuous curve through the curve drawing program to further observe the inflection point and the rate of change. When performing differential calculations on the gas concentration change curve, it is necessary to use a finite difference or interpolation algorithm in the mathematical processing module to obtain the gas concentration change rate per unit time by selecting the difference between adjacent data points and dividing it by their time interval. When the slope of the curve changes sharply near a certain temperature point, it will show an obvious peak or valley value in the corresponding differential result, which is called the maximum change point, and this temperature is used as the inflection point temperature.

[0110] If it is found in a specific demonstration that after a certain material is kept at 650°C during the deceleration stage, the gas concentration initially increases with time, then begins to decrease after ten minutes, and a significant peak appears in the differential curve, then the corresponding temperature at this time can be determined as the inflection point temperature. Since the initial temperature value has been obtained in the previous text, the inflection point temperature can be set as the upper limit of the temperature range, and the initial temperature value can be regarded as the lower limit, so as to define a complete temperature range by means of upper and lower limits. If a certain aluminum nitride ceramic substrate detects the initial generation of secondary phase characteristics when the temperature is raised to about 640°C, and then in the process of controlling the heating rate and maintaining it at 700°C, it is found through continuous sampling that the gas concentration reaches the maximum change rate at 670°C, then 640°C can be set as the lower limit and 670°C as the upper limit, and it is determined that an important phase change or active reaction has occurred in this temperature range.

[0111] The significance of this step is that after accurately identifying the time point of secondary phase formation, the temperature can be further finely controlled, and in this process, the growth or disappearance process of the abnormal phase can be judged by using the decay or rising trend of gas concentration over time. When the inflection point temperature is found to be significantly deviated from the estimated range, it can be reasonably inferred that the reaction characteristics of the additives or impurities exceed the conventional process range, and in the subsequent links, measures such as local cooling, adjusting the atmosphere concentration or shortening the insulation time can be taken for this range. Through the above-mentioned whole set of processes, when the operator finds the risk of secondary phase, it can not only stop at simple warning, but also grasp the depth of the impact of temperature evolution on chemical composition over time, so as to obtain quantifiable and traceable technical basis in the sintering and metallization process of double-sided printed circuit boards, which is conducive to timely correction or optimization of temperature management solutions in key areas.

[0112] Please continue reading Figure 1 According to the formation time point, temperature range and reaction intensity of the secondary phase, the atmosphere and temperature of the area with high risk level are controlled, and the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet the preset thresholds, it is determined that the secondary phase is effectively suppressed.

[0113] In one embodiment of the present invention, according to the formation time point, temperature range and reaction intensity of the secondary phase, the atmosphere and temperature control are performed on the area with high risk level, and the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet the preset thresholds, it is determined that the secondary phase is effectively suppressed, including:

[0114] Position mapping is performed on the formation time point of the secondary phase to obtain the spatial distribution characteristics of the high-risk area, the temperature control range is determined according to the temperature range of the secondary phase, and the atmosphere control parameters are determined according to the reaction intensity of the secondary phase;

[0115] Temperature control is performed on the high-risk area, the local temperature field is adjusted according to the temperature control range to obtain real-time temperature distribution parameters, the local atmosphere environment is adjusted according to the atmosphere control parameters to obtain real-time gas composition parameters, and the surface morphology of the high-risk area after control is scanned to obtain real-time optical characteristic parameters;

[0116] Performing gradient calculation on the real-time temperature distribution parameter to obtain a temperature deviation value, performing concentration calculation on the real-time gas composition parameter to obtain a gas concentration deviation value, and performing intensity calculation on the real-time optical characteristic parameter to obtain an optical characteristic deviation value;

[0117] The temperature deviation value, the gas concentration deviation value and the optical property deviation value are respectively compared with corresponding preset thresholds. When the three deviation values ​​are simultaneously smaller than the corresponding preset thresholds, it is determined that the secondary phase is effectively suppressed.

[0118] Specifically, after the formation time point of the secondary phase is detected, the position of the time point is first mapped to determine the specific coordinate range of the high-risk area on the ceramic-based double-sided printed circuit board. When implementing this process, the monitoring area division data collected in the early stage can be called in the process control system, and combined with the temperature measurement node or optical detection node corresponding to the formation time point, they are marked on the material schematic diagram in the form of plane coordinates or three-dimensional coordinates. If it is found in a certain detection that the secondary phase indication appears around the through hole of a certain substrate when the temperature is raised to 900°C, the coordinate information corresponding to this time point can be recorded and overlapped with the previously delineated high-risk through-hole area to obtain the spatial distribution characteristics of the high-risk area. This spatial distribution feature can be regarded as a specific coordinate set or grid point set, and more accurate temperature and atmosphere control can be carried out for these coordinate points in the future.

[0119] After clarifying the coordinates of the high-risk area, the temperature control range can be set according to the temperature range of the secondary phase, and the atmosphere control parameters can be determined in combination with the reaction intensity of the secondary phase. The temperature range can refer to the lower and upper temperature limits of the secondary phase formation previously detected. If the lower temperature limit is 750°C and the upper temperature limit is 790°C, the temperature control range of this area can be set between 750°C and 790°C in the subsequent process, and the corresponding heating rate and cooling time can be specified in the system. The atmosphere control parameters can select the appropriate inert gas or reducing gas addition ratio based on the reaction intensity. If the reaction intensity value is in the medium range, the flow rate of the hydrogen-containing mixed gas can be increased to about 20% of the original set value, and the oxygen partial pressure in the furnace can be adjusted as appropriate to weaken the secondary phase growth in this area.

[0120] During this stage, when temperature control is performed on high-risk areas, the system will adjust the local temperature field according to the previously planned temperature control range, such as configuring an independently controllable auxiliary heating component or local cooling channel above the area to accurately match the required temperature curve, and then obtain real-time temperature distribution parameters through multiple thermocouples or infrared monitors, and compare these parameters with existing data to determine whether the implemented temperature correction is accurate. If the local temperature distribution is found to be discrete during this process, the heating or cooling power can be adjusted in time according to the monitoring feedback. At the same time, the atmosphere control parameters will be applied to the local gas supply or exhaust device in the furnace, and the gas analyzer will arrange several sampling ports around the area to obtain real-time gas composition parameters. If the gas composition parameters of the above-mentioned area are found to drop significantly after the inert gas flushing, it means that the active substances required for the secondary phase generation are locally diluted or discharged. In order to observe the microscopic conditions of the material surface, the temperature rise or fall can be stopped at an appropriate time, and the surface morphology of the area can be scanned using an optical microscope to generate real-time optical characteristic parameters, which will be transmitted to the control system for subsequent comparison.

[0121] After completing the above temperature control and atmosphere control, it is necessary to perform a gradient calculation on the real-time temperature distribution parameters by mathematical means to obtain a temperature deviation value to reflect the difference between the area and the target temperature curve, and then perform a concentration calculation on the real-time gas composition parameters to obtain a gas concentration deviation value to evaluate whether the current atmosphere adjustment controls the concentration of impurities or harmful components within a safe range. At the same time, perform an intensity calculation on the real-time optical characteristic parameters to obtain an optical characteristic deviation value to determine whether undesirable microcracks or high-reflection impurity deposition occur. If these three deviation values ​​are all below their respective corresponding preset thresholds, it can be concluded that the secondary phase in this area has been effectively suppressed. For example, if the temperature deviation value is less than 0.1, the gas concentration deviation value is less than 0.15, and the optical characteristic deviation value is less than 0.12, it indicates that after the current stage of temperature and atmosphere linkage adjustment, no new unfavorable secondary phases have appeared in the material. If any of the three deviation values ​​exceeds the threshold, the system will continue to execute the corresponding local control strategy, which may include reducing the local heating rate again or increasing the inert gas flow rate, so that the reaction conditions in this area are further close to the safe range. The entire process can manage the position information and temperature range of the formation time of the secondary phase, and combine it with the atmosphere control involved in the reaction intensity to form a dynamic closed-loop control of the high-risk area, so that the ceramic-based double-sided printed circuit board remains relatively stable and meets reliability requirements in the subsequent high-temperature stage or through-hole metallization process.

[0122] It should be noted that another embodiment of the present application further provides a ceramic-based double-sided printed circuit board, which is prepared by the manufacturing method of the ceramic-based double-sided printed circuit board of the above embodiment.

[0123] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a ceramic-based double-sided printed circuit board, characterized in that: include: The key monitoring area and the conventional monitoring area are obtained according to the preset three-dimensional structural characteristics of the ceramic body, and the initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters of the key monitoring area and the conventional monitoring area are collected during the staged heating process; specifically comprising: dividing the monitoring area according to the preset through hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas; the first-level key monitoring area, the second ... first-level key monitoring area, the second-level key monitoring area, the first-level key monitoring area, the second-level key monitoring area, the first-level key monitoring area, the second-level key monitoring area, the first-level key monitoring area, the second-level key monitoring area, the first-level key monitoring area, the second-level key monitoring area, The key monitoring area, the third-level key monitoring area and the conventional monitoring area collect local heating rate, organic decomposition product concentration and surface morphology characteristics at the early stage of sintering at 400-800°C; the temperature gradient, metal oxide volatile concentration and grain boundary characteristics are collected at the main phase sintering temperature stage of 1000-1400°C for the first-level key monitoring area, the second-level key monitoring area, the third-level key monitoring area and the conventional monitoring area; the local heating rate and the temperature gradient are used as initial temperature distribution parameters, the organic decomposition product concentration and the metal oxide volatile concentration are used as initial gas composition parameters, and the surface morphology characteristics and the grain boundary characteristics are used as initial optical property parameters; Analyzing the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk; According to the risk level data, local spectral analysis and micro-area atmosphere analysis are performed on the area with high risk level to obtain crystal structure data, diffraction data and local gas concentration data, and the formation time point, temperature range and reaction intensity of the secondary phase are determined according to the crystal structure data, diffraction data and local gas concentration data; According to the formation time point, temperature range and reaction intensity of the secondary phase, the atmosphere and temperature are controlled in the area with high risk level, and the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet the preset thresholds, it is determined that the secondary phase is effectively suppressed.

2. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 1, characterized in that: The monitoring area is divided according to the preset through hole distribution position, the preset metallization layer distribution area and the preset chip packaging area of ​​the ceramic body, wherein the preset chip packaging area is divided into a first-level key monitoring area, the preset through hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining areas are divided into conventional monitoring areas, including: Obtaining a preset chip power density, a preset through-hole density, and a preset metallization layer thickness of the ceramic body, defining a boundary range of a preset chip packaging area according to the preset chip power density, defining a boundary range of a preset through-hole distribution position according to the preset through-hole density, and defining a boundary range of a preset metallization layer distribution area according to the preset metallization layer thickness; Calculate the overlapping area of ​​the preset chip packaging area, the preset through-hole distribution position and the preset metallization layer distribution area, and determine the region attribution of the overlapping area in the order of priority of the preset chip packaging area first, the preset through-hole distribution position second, and the preset metallization layer distribution area last; According to the determined area affiliation, the preset chip packaging area is divided into a first-level key monitoring area, the preset through-hole distribution position is divided into a second-level key monitoring area, the preset metallization layer distribution area is divided into a third-level key monitoring area, and the remaining area is divided into a conventional monitoring area.

3. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 1, characterized in that: The initial temperature distribution parameters, initial gas composition parameters and initial optical characteristic parameters are analyzed to obtain risk level data of each area, wherein the risk level data includes high risk, medium risk and low risk, including: Performing deviation calculation on the initial temperature distribution parameters, the initial gas composition parameters and the initial optical characteristic parameters to obtain a temperature deviation rate, a gas concentration deviation rate and an optical characteristic deviation rate, wherein the temperature deviation rate is the difference between the actual temperature and the standard temperature divided by the standard temperature, the gas concentration deviation rate is the difference between the actual concentration and the standard concentration divided by the standard concentration, and the optical characteristic deviation rate is the difference between the actual optical characteristic and the standard optical characteristic divided by the standard optical characteristic; Performing time series correlation analysis on the temperature deviation rate, gas concentration deviation rate and optical property deviation rate, and calculating a dual-parameter deviation coupling degree and a three-parameter deviation coupling degree, wherein the dual-parameter deviation coupling degree is the ratio of the product of any two of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the corresponding two deviation rate detection time intervals, and the three-parameter deviation coupling degree is the ratio of the product of the temperature deviation rate, gas concentration deviation rate and optical property deviation rate to the maximum interval of the three detection times; The dual-parameter deviation coupling degree is compared with a first coupling threshold, and the three-parameter deviation coupling degree is compared with a second coupling threshold. When the three-parameter deviation coupling degree is greater than the second coupling threshold, it is determined to be a high risk; when the dual-parameter deviation coupling degree is greater than the first coupling threshold and the three-parameter deviation coupling degree is less than or equal to the second coupling threshold, it is determined to be a medium risk; when the dual-parameter deviation coupling degree is less than or equal to the first coupling threshold, it is determined to be a low risk.

4. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 3, characterized in that: The step of performing time series correlation analysis on the temperature deviation rate, the gas concentration deviation rate and the optical characteristic deviation rate to calculate the dual-parameter deviation coupling degree and the three-parameter deviation coupling degree includes: The temperature deviation rate, gas concentration deviation rate and optical property deviation rate are segmented into time windows to obtain the deviation rate change trend in each time window, and the inflection point of the deviation rate change trend is selected as the deviation rate detection time mark point; Determine, according to the deviation rate detection time mark point, a first detection time interval between the temperature deviation rate and the gas concentration deviation rate, a second detection time interval between the temperature deviation rate and the optical property deviation rate, and a third detection time interval between the gas concentration deviation rate and the optical property deviation rate; The product of the temperature deviation rate and the gas concentration deviation rate is divided by the first detection time interval to obtain a first dual-parameter deviation coupling degree, the product of the temperature deviation rate and the optical property deviation rate is divided by the second detection time interval to obtain a second dual-parameter deviation coupling degree, the product of the gas concentration deviation rate and the optical property deviation rate is divided by the third detection time interval to obtain a third dual-parameter deviation coupling degree, and the maximum value among the first dual-parameter deviation coupling degree, the second dual-parameter deviation coupling degree and the third dual-parameter deviation coupling degree is selected as the dual-parameter deviation coupling degree; The three-parameter deviation coupling degree is obtained by dividing the product of the temperature deviation rate, the gas concentration deviation rate and the optical characteristic deviation rate by the maximum value of the first detection time interval, the second detection time interval and the third detection time interval.

5. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 1, characterized in that: According to the risk level data, local spectral analysis and micro-area atmosphere analysis are performed on the area with high risk level to obtain crystal structure data, diffraction data and local gas concentration data, and the formation time point, temperature range and reaction intensity of the secondary phase are determined according to the crystal structure data, diffraction data and local gas concentration data, including: Determine the high-risk area according to the risk level data, perform point-by-point scanning of the crystal structure of the determined high-risk area to obtain a fingerprint spectrum of the specific crystal structure, the offset and intensity of the diffraction peak, determine the crystal structure data according to the fingerprint spectrum, determine the diffraction data according to the offset and intensity, collect the micro-area atmosphere of the high-risk area, obtain the instantaneously released characteristic gas concentration, and use it as the local gas concentration data; Performing a eutectic phase trend analysis on the diffraction data, performing a new phase generation trend analysis on the local gas concentration data, and determining a secondary phase formation time point according to the eutectic phase formation time point and the new phase generation time point; Performing a temperature-raising interruption process on the temperature corresponding to the formation time point to obtain a local gas concentration attenuation curve, and determining a temperature range according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point; The specific crystal structure fingerprint spectrum within the temperature range is integrated to obtain a first integral value, the diffraction peak within the temperature range is integrated to obtain a second integral value, the characteristic gas concentration within the temperature range is averaged to obtain an average concentration value, and a weighted calculation is performed based on the first integral value, the second integral value and the average concentration value to obtain the reaction intensity.

6. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 5, characterized in that: The temperature corresponding to the formation time point is subjected to a heating interruption process to obtain a local gas concentration attenuation curve, and a temperature range is determined according to the inflection point temperature of the attenuation curve and the temperature corresponding to the formation time point, including: Collecting temperature data at the formation time point to obtain an initial temperature value, and regulating the heating rate according to the initial temperature value to obtain a temperature-time curve during the temperature reduction process; The end temperature of the temperature-time curve is controlled at a constant temperature to obtain gas concentration data in the constant temperature stage, and a gas concentration change curve is established according to the corresponding relationship between the gas concentration data and the acquisition time; Performing differential calculation on the gas concentration change curve to obtain the gas concentration change rate per unit time, and determining the inflection point temperature according to the maximum change point of the gas concentration change rate; The inflection point temperature is set as the upper limit of the temperature interval, and the initial temperature value is set as the lower limit of the temperature interval to obtain the temperature interval.

7. The method for manufacturing a ceramic-based double-sided printed circuit board according to claim 1, characterized in that: According to the formation time point, temperature range and reaction intensity of the secondary phase, atmosphere control and temperature control are performed on the area with high risk level, and real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters in the control process are collected in real time. When the real-time temperature distribution parameters, real-time gas composition parameters and real-time optical characteristic parameters meet preset thresholds, it is determined that the secondary phase is effectively suppressed, including: Position mapping is performed on the formation time point of the secondary phase to obtain the spatial distribution characteristics of the high-risk area, the temperature control range is determined according to the temperature range of the secondary phase, and the atmosphere control parameters are determined according to the reaction intensity of the secondary phase; Temperature control is performed on the high-risk area, the local temperature field is adjusted according to the temperature control range to obtain real-time temperature distribution parameters, the local atmosphere environment is adjusted according to the atmosphere control parameters to obtain real-time gas composition parameters, and the surface morphology of the high-risk area after control is scanned to obtain real-time optical characteristic parameters; Performing gradient calculation on the real-time temperature distribution parameter to obtain a temperature deviation value, performing concentration calculation on the real-time gas composition parameter to obtain a gas concentration deviation value, and performing intensity calculation on the real-time optical characteristic parameter to obtain an optical characteristic deviation value; The temperature deviation value, the gas concentration deviation value and the optical property deviation value are respectively compared with corresponding preset thresholds. When the three deviation values ​​are simultaneously smaller than the corresponding preset thresholds, it is determined that the secondary phase is effectively suppressed.

8. A ceramic-based double-sided printed circuit board, characterized in that: The ceramic-based double-sided printed circuit board is prepared by the method for preparing a ceramic-based double-sided printed circuit board according to any one of claims 1 to 7.

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