Optimization of interface performance and connection method of diamond thermoelectric ceramics

Abstract

This invention discloses a method for optimizing and connecting the interface performance of diamond thermoelectric ceramics. The method includes: acquiring the current reaction time, film quality data, metal target sputtering power, and ceramic target sputtering power; calculating the current deposition composition ratio using a rate estimation method based on the film quality data, metal target sputtering power, and ceramic target sputtering power; finding the target deposition composition ratio corresponding to the current reaction time; calculating the difference between the current deposition composition ratio and the target deposition composition ratio; if the difference exceeds a first threshold, dynamically adjusting the sputtering power decrease rate of the metal target and the sputtering power increase rate of the ceramic target; estimating the predicted time to reach the next target deposition composition ratio and accumulating the predicted time; if the accumulated time exceeds the reaction time corresponding to the next target deposition composition ratio, increasing the ion beam incident angle adjustment frequency. This invention achieves precise composition control of metal-ceramic gradient films, effectively alleviating interfacial thermal stress.

Description

Technical Field

[0001] This invention relates to the field of diamond composite material processing technology, specifically to the optimization and bonding method of diamond thermoelectric ceramic interface performance. Background Technology

[0002] Diamond is widely used in semiconductor devices, ultraviolet detectors, quantum computers, surface acoustic wave devices, and high thermal conductivity electronic packaging materials. In practical research, to expand its application range, it is also combined with other materials to form composite materials, such as with thermoelectric ceramics.

[0003] However, during the bonding process, diamond has extremely high thermal conductivity but a very low coefficient of thermal expansion, while the coefficient of thermal expansion of thermoelectric ceramics differs greatly. This thermal expansion mismatch can lead to interfacial stress and even cracking at the bonding joint.

[0004] To overcome the interfacial failure problem caused by the difference in thermal expansion coefficients between diamond and thermoelectric ceramics, one existing approach is to add a transition layer between the two, such as using a functional thin film as a transition layer to connect with the thermoelectric ceramics.

[0005] Currently, magnetron sputtering is commonly used to deposit functional thin films on diamond substrates. However, existing thin film deposition processes often employ single-target sputtering or co-sputtering with multiple targets, and the sputtering power is typically fixed throughout the deposition process, lacking a mechanism for dynamic adjustment based on the substrate surface deposition state. This static power control method results in insufficient adaptability of the deposition process. Even if the preset reaction time is strictly achieved in the process, inherent fluctuations in the sputtering deposition rate and differences in deposition uniformity will ultimately lead to variations in the thickness, composition, or structure of the prepared thin film in different regions of the substrate and even between different batches, severely affecting the film's performance. Summary of the Invention

[0006] To address the problem that existing thin film deposition processes cannot be dynamically controlled based on the deposition state, this invention provides a method for optimizing and connecting the interface performance of diamond thermoelectric ceramics.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] In a first aspect, this application discloses a method for optimizing and connecting the interface performance of diamond thermoelectric ceramics, including the following steps:

[0009] Obtain current reaction time, thin film quality data, metal target sputtering power, and ceramic target sputtering power;

[0010] Based on the thin film quality data, sputtering power of the metal target, and sputtering power of the ceramic target, the current deposition composition ratio is calculated using the rate estimation method.

[0011] The target deposition component ratio corresponding to the current reaction time is matched using a predefined lookup table; wherein the lookup table characterizes the mapping relationship between reaction time and deposition component ratio.

[0012] Calculate the difference between the current depositional component ratio and the target depositional component ratio;

[0013] If the difference value exceeds a preset first threshold, the sputtering power decrease rate of the metal target and the sputtering power increase rate of the ceramic target will be dynamically adjusted.

[0014] The sputtering power of the adjusted metal and ceramic targets and the current reaction time are used to estimate the predicted time to reach the next target deposition component ratio through a deep learning model, and the current reaction time and the predicted time are added together to obtain the cumulative time.

[0015] If the cumulative duration exceeds the preset reaction time corresponding to the next target deposition component ratio, the frequency of ion beam incident angle adjustment is increased.

[0016] The sputtering power of the metal and ceramic targets and the frequency of the ion beam incident angle adjustment are fed back to the target end.

[0017] Secondly, this application also discloses a diamond thermoelectric ceramic reaction device, which includes a main cavity, a dual-target magnetron sputtering system, an auxiliary ion beam system, a quartz crystal thickness gauge, an atmosphere control mechanism, and a processor.

[0018] The dual-target magnetron sputtering system is used to sputter a metal target and a ceramic target into the main cavity;

[0019] An auxiliary ion beam system is used to dynamically bombard the deposition surface during the deposition process in the main cavity;

[0020] The quartz crystal thickness gauge is used to collect the film mass data inside the main cavity;

[0021] An atmosphere control mechanism is used to supply the main chamber with gases that assist the reaction;

[0022] The processor controls the operating status of the dual-target magnetron sputtering system, the auxiliary ion beam system, and the atmosphere control mechanism; when the processor is operating, it executes the steps of the diamond thermoelectric ceramic interface performance optimization and connection method described above.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. This application achieves precise, dynamic, and time-curve-controllable deposition of thin film composition in the co-sputtering process of diamond substrate and metal / ceramic target, which greatly reduces the differences in thin film composition in different regions of the substrate and different experiments, and ensures that the thin film composition reaches the expected level after the preset reaction time as much as possible; it achieves precise composition control of metal-ceramic gradient thin film, effectively alleviates interfacial thermal stress, and improves the interfacial bonding strength and thermal conductivity of composite materials.

[0025] 2. By controlling the relative speed of the power changes of the two targets, this application can more accurately control the trajectory of composition changes, which is beneficial to the formation of gradient thin films; it reduces the frequency of manual intervention and has good process adaptability and scalability. Attached Figure Description

[0026] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals refer to the same parts. Wherein:

[0027] Figure 1 This is a flowchart illustrating the diamond thermoelectric ceramic interface performance optimization and connection method described in this invention;

[0028] Figure 2 Based on Figure 1 A flowchart for obtaining the current deposition component ratio;

[0029] Figure 3 Based on Figure 1 A flowchart for introducing an auxiliary atmosphere based on the variation range of ceramic components;

[0030] Figure 4 Based on Figure 1 A flowchart for determining whether to perform periodic adjustments based on the current reaction time;

[0031] Figure 5 Based on Figure 1 A flowchart for dynamically adjusting the sputtering power of metal and ceramic targets;

[0032] Figure 6 Based on Figure 1 A flowchart for the preparation of composite materials;

[0033] Figure 7 Based on Figure 6 A flowchart for applying a pulsed electric field;

[0034] Figure 8 Based on Figure 6 A flowchart for performing thermal cycling tests and outputting test reports;

[0035] Figure 9This is a process flow diagram of a diamond thermoelectric ceramic reactor. Detailed Implementation

[0036] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0037] Application Overview

[0038] In existing technologies, magnetron sputtering is used to prepare a transition layer to address interfacial stress issues arising from the difference in thermal expansion coefficients between diamond and thermoelectric ceramics. However, this often employs a fixed-power single-target or co-sputtering mode, lacking a dynamic control mechanism. Due to fluctuations in sputtering rate and variations in deposition uniformity, the composition ratio of the thin film easily deviates from the preset value, resulting in insufficient interfacial bonding strength and affecting the stability of the composite material's properties.

[0039] To address the aforementioned issues, this research found that introducing a dynamic adaptive sputtering process can resolve deposition rate drift and sputtering variations caused by target consumption, plasma instability, and environmental factors. This ensures that even under suboptimal conditions, the sputtering process can approximate the target composition, forming a metal-ceramic gradient transition layer. Furthermore, a mapping relationship is established between reaction time and the target component ratio, and deep learning is used to predict time deviations, forming a closed-loop control system that enhances the predictability and early intervention capability of the process.

[0040] After introducing the basic concept of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Exemplary methods

[0042] like Figure 1 As shown, this paper introduces a method for optimizing and connecting the interface performance of diamond thermoelectric ceramics, which is used to form a metal-ceramic gradient thin film on the surface of a diamond substrate using a dual-target magnetron sputtering system and an auxiliary ion beam system. The method includes the following steps:

[0043] 100. Obtain current reaction time, thin film quality data, metal target sputtering power, and ceramic target sputtering power;

[0044] 200. Based on the thin film quality data, sputtering power of the metal target, and sputtering power of the ceramic target, calculate the current deposition composition ratio using the rate estimation method;

[0045] 300. Match the target sedimentary component ratio corresponding to the current reaction time using a predefined lookup table; whereby the lookup table characterizes the mapping relationship between reaction time and sedimentary component ratio;

[0046] 400. Calculate the difference between the current sedimentary composition ratio and the target sedimentary composition ratio;

[0047] 500. If the difference value exceeds the preset first threshold, the sputtering power decrease rate of the metal target and the sputtering power increase rate of the ceramic target will be dynamically adjusted.

[0048] 600. The sputtering power of the adjusted metal target and ceramic target and the current reaction time are used to estimate the predicted time to reach the next target deposition component ratio through a deep learning model, and the current reaction time and the predicted time are added together to obtain the cumulative time;

[0049] 700. If the cumulative duration exceeds the preset reaction time corresponding to the next target deposition component ratio, increase the ion beam incident angle adjustment frequency;

[0050] 800. Feedback to the target end on the adjusted sputtering power of the metal target and ceramic target, as well as the frequency of the ion beam incident angle adjustment.

[0051] It should be noted that the diamond substrate mentioned in this application is deposited by sputtering gradient thin films within a deposition chamber equipped with a vacuum system. Furthermore, a multi-target sputtering source system is used to provide independent metal and ceramic target sites, capable of providing and adjusting the sputtering power of both the metal and ceramic targets. An ion beam-assisted system is used to provide the ion beam, and the incident angle of the ion beam can be adjusted. A quartz crystal thickness gauge is used to provide thin film quality data. A processor is used for relevant data processing and judgment operations.

[0052] This application achieves real-time dynamic control of sputtering power, effectively suppressing compositional fluctuations. By establishing a time-composition mapping relationship and a deep learning prediction model, the precise layer-by-layer deposition of gradient films is ensured. Combined with intelligent adjustment of ion beam parameters, the interfacial bonding strength of the metal-ceramic gradient film is improved, providing a guarantee for reliable subsequent connection with thermoelectric ceramics.

[0053] To facilitate a further understanding of the scheme in this embodiment, step 200, calculating the current deposition composition ratio using a rate estimation method based on thin film quality data, metal target sputtering power, and ceramic target sputtering power, will be described in detail below. Figure 2 As shown, the specific steps are as follows:

[0054] 101. Extract the mass distribution of metal and ceramic targets from the thin film mass data, and obtain preliminary values ​​after calculating the ratio;

[0055] 102. By combining the sputtering power of the metal target and the sputtering power of the ceramic target to correct the initial value, the current deposition composition ratio is obtained.

[0056] The specific calculation process is as follows:

[0057] Extracting the mass distribution value of the metal sputtering material from thin film quality data. and the mass distribution value of ceramic target material Preliminary proportion estimate: .

[0058] To consider the impact of power on deposition rate for different target materials, a power normalization correction factor is introduced:

[0059]

[0060] in, This represents the unit power deposition correction factor for the metal target. This indicates the current sputtering power of the metal target. This represents the unit power deposition correction factor for ceramic targets. This indicates the current sputtering power of the ceramic target.

[0061] The initial quality estimate ratio Ratio to power A weighted average fusion is performed to obtain the current sedimentary composition ratio. : ; These are the weighting coefficients. ∈[0,1], used to adjust the influence of the film mass and power ratio on the final ratio, which can be set based on experience or dynamically optimized through machine learning methods.

[0062] In thin film deposition, the mass distribution ratio of metal to ceramic reflects the compositional proportions of the deposited material, but it does not consider the effect of the current sputtering power on the subsequent deposition rate. By acquiring the sputtering power of metal and ceramic in real time and incorporating the power parameter into the correction calculation, the calculated compositional proportions of the current deposition include both the actual composition of the deposited material and the expected impact of dynamic power adjustments on the subsequent composition. This dual data fusion mechanism effectively solves the compositional proportion prediction bias caused by neglecting dynamic power changes in traditional methods.

[0063] Step 200 has been described in detail above. The following section provides a detailed explanation of determining the ceramic component rising stage based on the current deposition composition ratio, and then implementing auxiliary atmosphere control. Figure 3 As shown, the specific steps are as follows:

[0064] 201. Obtain the sedimentary composition ratios from historical periods, and then linearly calculate the variation range of ceramic components by combining them with the current sedimentary composition ratios;

[0065] 202. Determine whether the change range is an increase. If so, determine that it is in the ceramic component rising stage, and introduce an auxiliary atmosphere with a corresponding flow rate according to the preset mapping relationship between the change range and the atmosphere volume.

[0066] 203. Continuously record the duration of introducing the auxiliary atmosphere. Stop introducing the atmosphere when the duration reaches the preset duration threshold.

[0067] The specific calculation process is as follows:

[0068] Calculate the variation range of ceramic components: ;in, This indicates the proportion of ceramic components deposited in the previous deposition cycle. This indicates the proportion of ceramic components deposited in the current cycle.

[0069] like (Minimum effective change threshold) is used to determine the rising stage of ceramic components. The mapping relationship between the change amplitude and the atmosphere flow rate (look up the table or fit the mapping relationship) is used to introduce the corresponding flow rate of auxiliary atmosphere. The table below is a comparison table of change amplitude and auxiliary atmosphere flow rate:

[0070] Table 1: Comparison of Variation Range and Auxiliary Atmosphere Flow Rate

[0071] Serial Number Variation ΔR (%) Auxiliary atmosphere flow rate Q (sccm) 1 0–0.5 0 2 0.5–1.0 5 3 1.0–2.0 10 4 2.0–3.0 15 5 3.0–4.0 20 6 4.0–5.0 25 7 ≥5.0 30

[0072] Record the cumulative import time each time it is imported. ,like If the duration threshold is reached, the introduction of auxiliary atmosphere will cease.

[0073] Based on this, the problem of uneven composition distribution caused by the lack of real-time atmosphere compensation for dynamic changes in ceramic composition during the formation of gradient films on diamond substrates was solved. By dynamically matching the gas flow rate with the ceramic growth rate, the continuity of elemental distribution in the gradient transition region was optimized. By quantitatively controlling the gas interaction time, the negative impact of excessive gas on film density was avoided, resulting in a more uniform composition gradient and more stable interfacial bonding performance in the final metal-ceramic gradient film.

[0074] The above describes in detail how to determine the auxiliary atmosphere control based on the current sedimentary composition. The following section details how to match the target sedimentary composition ratio corresponding to the current reaction time using a predefined lookup table. The specific steps are as follows:

[0075] Since the data in the lookup table is a discrete set of points, the target proportion value corresponding to any current duration t is calculated using an interpolation method.

[0076] If t lies between two known time points, that is: ;

[0077] The target sedimentary composition ratio is: ;in, Indicate duration The corresponding target depositional composition ratio, Indicate duration The corresponding target depositional component ratio.

[0078] The corresponding target depositional component proportions are obtained by representing the comparison table using a piecewise function:

[0079]

[0080] The above describes in detail the process of determining the target deposition component ratio based on the current reaction time. The following section details how to determine whether periodic adjustments should be made based on the current reaction time. Figure 4 As shown, the specific steps are as follows:

[0081] 301. Determine whether the current reaction time falls within the duration range of the periodic adjustment phase;

[0082] 302. If so, it is determined that the current periodic adjustment phase has been entered. The sputtering power of the metal target and the sputtering power of the ceramic target are periodically adjusted according to the preset adjustment range until the preset number of adjustments is reached.

[0083] 303. Otherwise, perform the operation to calculate the difference between the current sedimentary component ratio and the target sedimentary component ratio.

[0084] The specific calculation process is as follows:

[0085] First, determine whether the current reaction time t is in the periodic adjustment phase, i.e.

[0086]

[0087] in, , This indicates the start and end points of the time interval for the periodic adjustment phase.

[0088] When in the periodic adjustment phase (i.e.) =1), and the number of adjustments already performed. When the preset number of times is reached, the following periodic adjustment operation will be performed:

[0089] Metal target sputtering power: ;

[0090] in, Indicates the basic sputtering power of the metal target. This indicates the periodic adjustment range of the sputtering power of the metal target. This indicates the frequency of the periodic adjustment.

[0091] Ceramic target sputtering power: ;

[0092] in, Indicates the basic sputtering power of the ceramic target. This indicates the periodic adjustment range of the sputtering power of the ceramic target.

[0093] Phase difference between the two This allows for symmetrical adjustment, with one rise and one fall, and can be set to count after each complete positive and negative oscillation cycle (one full sine cycle). ← +1.

[0094] when =0, meaning not in the periodic adjustment phase, proceed to step 400. Calculate the difference between the current sedimentary component ratio and the target sedimentary component ratio. The specific calculation formula is as follows:

[0095]

[0096] in, Indicates the current composition ratio of the sediment. This indicates the proportion of the target sedimentary components.

[0097] This embodiment introduces a periodic adjustment mechanism to actively apply power fluctuations within a specific time window, effectively suppressing compositional deviations caused by random factors. Simultaneously, combined with dynamic adjustment of the difference value, a composite control strategy is formed, exhibiting higher adaptability compared to a single adjustment mode. This overcomes the problem that static sputtering power control cannot adapt to film compositional deviations caused by deposition rate fluctuations. The periodic adjustment mechanism actively intervenes in power parameters, forming alternating metal-ceramic deposition units during key deposition stages, effectively compensating for compositional shifts caused by inherent equipment fluctuations. Combined with dynamic adjustment of the difference value, dual control of the deposition process is achieved, improving the uniformity and batch consistency of gradient film composition.

[0098] The above describes the process of step 400 in detail. The following section provides a detailed explanation of step 500: if the difference value exceeds a preset first threshold, dynamically adjust the sputtering power decrease rate of the metal target and the sputtering power increase rate of the ceramic target. Figure 5 As shown, the specific steps are as follows:

[0099] 501. Determine whether the current sedimentary component ratio is higher than the target sedimentary component ratio;

[0100] 502. This increases the sputtering power decay rate of metal targets and decreases the sputtering power gain rate of ceramic targets;

[0101] 503. Otherwise, reduce the sputtering power decay rate of the metal target and increase the sputtering power gain rate of the ceramic target;

[0102] The adjustment range of sputtering power is proportional to the difference value, and the adjustment range of a single adjustment does not exceed the preset second threshold.

[0103] The specific calculation process is as follows:

[0104] like If the first threshold is reached, the adjustment logic will be triggered.

[0105] (1) The current deposition composition is too high (high proportion of ceramic components), that is:

[0106]

[0107] in, This indicates the range of power adjustment for a single sputtering operation on a metal target. This indicates the adjustment range of the sputtering power of the ceramic target in a single shot. This indicates the adjustment ratio coefficient. This represents the second maximum adjustable range (second threshold); where To mitigate the growth rate of ceramic sputtering targets, the adjustment factor is set as follows:

[0108]

[0109] in, This indicates the rate of decrease in sputtering power of the metal target. This indicates the rate of increase in sputtering power of the ceramic target.

[0110] (2) The current composition is too low (the proportion of ceramic components is low).

[0111]

[0112] The update rate is: .

[0113] For example: (i.e., the difference exceeds 3%) , Current differences =0.06 (6% higher than the target) then: ;

[0114] That is, the power reduction rate of metals is accelerating, while the power increase rate of ceramics is slowing down.

[0115] Based on this, the problem of lag in the adjustment of deposition component ratio caused by static power control is overcome, and dynamic matching of the thin film composition gradient with the preset target is achieved. Through real-time difference feedback and bidirectional rate adjustment mechanisms, the deposition ratio of metal and ceramic elements is ensured to always change along a predetermined trajectory, improving the interfacial bonding strength and thermal stress matching degree of the gradient thin film. At the same time, the single adjustment amplitude limitation mechanism effectively suppresses process parameter fluctuations, ensuring the stability and repeatability of the deposition process.

[0116] Step 500 has been described in detail above. The following section details step 600, which involves using a deep learning model to estimate the predicted time to reach the next target deposition composition ratio based on the adjusted sputtering power of the metal and ceramic targets and the current reaction time, and then summing the current reaction time with the predicted time to obtain the cumulative time. The specific process is as follows:

[0117] For example, prediction can be performed using time series networks based on LSTM or Transformer, or MLP structures, with the following input vector: ,in, Indicates the current reaction time. These represent the current sedimentary composition ratio and the next target sedimentary composition ratio, respectively.

[0118] The output is: the time required to predict the next target depositional composition ratio. ;in, This represents a function for a trained deep learning model, with parameters as follows: .

[0119] The final cumulative duration is: .

[0120] Step 600 has been described in detail above. Step 700, which involves increasing the ion beam incident angle adjustment frequency if the cumulative time exceeds the preset reaction time corresponding to the next target deposition component ratio, will be explained in detail below. The specific process is as follows:

[0121] like (If the preset reaction time corresponds to the next target deposition component ratio), then the ion beam incident angle adjustment and enhancement stage begins. The timeout ratio is calculated, and the adjustment frequency of the ion beam incident angle is increased according to the set linear or proportional strategy, for example, through the following calculation:

[0122]

[0123] or

[0124]

[0125] This is the frequency gain coefficient, preferably 0.5 to 1, set according to the response sensitivity.

[0126] in, This indicates the adjusted ion beam angle frequency. This indicates the current frequency of adjustment for the ion beam incident angle. This indicates the increment of the adjustment frequency. This indicates the maximum acceptable adjustment frequency.

[0127] The above describes step 700. The following section details the process following step 800, which involves sintering a diamond substrate with a metal-ceramic gradient film with a thermoelectric ceramic material to obtain a composite material after the accumulated time reaches a preset total time. Figure 6 As shown, the specific steps are as follows:

[0128] 601. Continuously accumulate the reaction time until the accumulated time reaches the preset total time, then stop the sputtering operation and heat-treat the diamond substrate with the metal-ceramic gradient film.

[0129] 602. The heat-treated diamond substrate and the thermoelectric ceramic material are sintered using a sintering device with a pulsed electric field applied;

[0130] 603. After the sintering time reaches the preset sintering duration, the desired composite material is obtained.

[0131] Specifically, after the metal-ceramic gradient thin film deposition is completed, the cumulative time is used to ensure the integrity of the film formation process and avoid discontinuities in the gradient structure due to insufficient reaction time. A step-by-step temperature control strategy is adopted during the heat treatment stage, such as stepped holding in the 300-500℃ range, to gradually release internal stress in the film. During sintering, the parameters of the pulsed electric field can be dynamically adjusted according to the material properties to achieve progressive diffusion of interfacial elements and stress buffering. The staged heat treatment and controlled sintering time prevent grain boundary weakening caused by over-sintering, ensuring the performance stability of the composite material under thermal cycling conditions.

[0132] The above describes in detail the sintering process of a diamond substrate with a metal-ceramic gradient film and a thermoelectric ceramic material. The following section details the sintering of the heat-treated diamond substrate and the thermoelectric ceramic material using a sintering apparatus with an applied pulsed electric field. Figure 7 As shown, the specific steps are as follows:

[0133] 701. Apply a pulsed electric field inside the sintering equipment;

[0134] 702. Real-time acquisition of current electric field parameters during the sintering period and pulsed electric field; electric field parameters include electric field strength, pulse frequency, duty cycle, etc.

[0135] 703. Match the adjustment parameters corresponding to the sintering time period according to the pre-set stage parameter adjustment table; the stage parameter adjustment table can be found in the table below:

[0136] Table 2 Examples of Stage-Based Parameter Adjustment

[0137] Sintering time (s) Electric field strength E (V / cm) Frequency f (Hz) Duty cycle D (%) 0–60 50 1000 20 60–120 70 900 25 120–180 90 800 30 ... ... ... ...

[0138] 704. Determine if the adjustment parameters are consistent with the current electric field parameters; otherwise, obtain the rate of change of conductivity at the material interface and compare it with the preset empirical threshold range. Based on the comparison results, make the following decision:

[0139] (1) If the rate of change of conductivity exceeds the empirical threshold range, it is determined that oxygen vacancies are generated too quickly, and the adjustment parameter is reduced;

[0140] (2) If the rate of change of conductivity is lower than the empirical threshold range, it is determined that the oxygen vacancy generation is too slow and the adjustment parameter is increased.

[0141] The specific calculation formula is as follows:

[0142] Dynamic adjustment is triggered when the electric field parameter set is inconsistent, and the rate of change of conductivity is acquired in real time. ;in, This indicates the current electrical conductivity value at the material interface. Indicates the sampling time.

[0143] Adjustments are made based on the comparison with the range of conductivity change rates. The judgment logic is as follows:

[0144] Scenario 1: Rate of change is too high (> upper limit) → Reduce electric field parameters

[0145]

[0146] Case 2: Rate of change too low (< lower limit) → Increase electric field parameters

[0147]

[0148] Scenario 3: Within a reasonable range → No adjustment

[0149] Keep current parameters

[0150] in, Indicates the current electric field strength. Indicates the current pulse frequency. Indicates the current duty cycle. , This represents the upper and lower limits of the empirical threshold range. , , This indicates the adjustment step size of the electric field parameters.

[0151] This embodiment achieves precise control of the interfacial oxygen vacancy generation rate during sintering, avoiding lattice distortion and decreased interfacial bonding caused by excessively high vacancy concentrations, while also preventing insufficient chemical bonding due to insufficient vacancy levels. By dynamically matching the electric field parameters with the requirements of the sintering stage, the interfacial atomic diffusion process is ensured to remain under control, thereby improving the thermal cycling stability and interfacial bonding strength of the composite material.

[0152] The process of applying a pulsed electric field has been described in detail above. The following section details the thermal cycling test performed on the obtained composite material and the output of the test report. Figure 8 As shown, the specific steps are as follows:

[0153] 801. The oxygen vacancy concentration distribution, metal / ceramic element ratio and lattice distortion rate of the composite material are obtained by point-by-point detection along the interface normal using laser-induced breakdown spectroscopy, and the gradient steepness is obtained by fitting a fitting function.

[0154] 802. Match the threshold number of iterations corresponding to the gradient steepness based on the preset iteration reference table;

[0155] 803. Perform thermal cycling tests on the composite material and accumulate the number of cycles. When the number of cycles reaches the cycle threshold, stop the test and output a test report consisting of test data. The test data includes the cycling temperature range, temperature change rate, single cycle time, cumulative number of cycles, and failure index records.

[0156] Laser-induced breakdown spectroscopy refers to the technique of generating plasma on the surface of a material using a high-energy laser pulse, and then determining the elemental composition and defect distribution by analyzing the wavelength and intensity of the emission spectrum. Specifically, it can be achieved by using a spectrometer with a wavelength range of 200-900nm combined with a Nd:YAG laser with a pulse energy of 50-200mJ, and is used for non-contact detection of interface microstructure parameters.

[0157] The specific calculation process is as follows:

[0158] To construct a fitting function, a joint fitting can be performed using either a polynomial or a Gaussian mixture model, i.e.:

[0159]

[0160] in, , , To normalize the fitted weight coefficients, This represents the oxygen vacancy concentration at position x along the interface normal direction. This indicates the proportional distribution of metallic and ceramic elements. This represents the lattice distortion rate.

[0161] Calculate gradient steepness: ;in, Represents the fitting function The derivative at position x; This represents the attribute function value corresponding to the i-th position. This represents the attribute function value corresponding to the (i+1)th position. , These represent the coordinates of the i-th and (i+1)-th detection points, respectively.

[0162] Use a preset loop count reference table to match the loop count threshold corresponding to the gradient steepness. See the table below for details:

[0163] Table 3: Reference Table for Number of Loops

[0164] If the current cumulative number of thermal cycles If this happens, the test will stop and a complete test report will be output.

[0165] This embodiment achieves a quantitative assessment of the reliability of composite material interfaces, avoiding insufficient testing or waste of resources by dynamically matching test number thresholds. Multi-dimensional parameter detection effectively captures the uniformity defects of the interface gradient structure, and gradient steepness calculation transforms complex interface characteristics into quantifiable indicators, providing precise termination conditions for thermal cycling tests and ensuring that the testing process covers the performance limits of the material in practical applications.

[0166] To facilitate understanding of the above embodiments, a specific experimental procedure from the above embodiments will be used as an example for explanation below:

[0167] This experiment requires the prepared diamond-thermoelectric ceramic composite interface structure to have high thermal conductivity (>1200W / m·K), high thermal cycling stability (no cracks after 1000 thermal cycles), stable interfacial electrical conductivity (change rate <5%), and gradient layer thickness <5µm.

[0168] Please refer to the table below for material and equipment configuration:

[0169] Table 4: Basic Experimental Parameter Configuration Table

[0170] project Parameter value Diamond substrate Thickness 500µm, diameter 20mm Ceramic sputtering material <![CDATA[Al2O3 (purity 99.99%)]]> Metal sputtering targets Ti (purity 99.995%) Dual-target sputtering power range <![CDATA[Ti:0–300W,Al2O3:0–200W]]> Ion beam energy range 0–500eV, adjustable incident angle Pulse sintering electric field Frequency 10–100Hz, duty cycle 20–80%, voltage 0–5kV

[0171] (1) Gradient thin film deposition control stage

[0172] Initial setup: Sputtering power: Ti = 250W, Al2O3 = 50W;

[0173] Thin film quality test results (first 5 minutes): Metal quality ;

[0174] Ceramic quality Preliminary sedimentation ratio: =0.4 / 3=13.3%. Assuming a weighting coefficient of 1, then the proportion of pre-deposited components... .

[0175] The target percentage (according to the mapping table) is 15%, and the difference is: =1.7% < (5%), without triggering sputtering power adjustment, only the cumulative duration is recorded.

[0176] Mid-game (30th minute): , .

[0177] Sputtering power: Ti = 120W, Al2O3 = 150W;

[0178] Current ratio: Target ratio = 50%; difference value =10%> Trigger adjustment:

[0179] The power decay rate of Ti is set to -5W per minute, and the power gain rate of Al2O3 is set to +5W per minute.

[0180] Predicted time to reach the goal: 5 minutes; estimated time of achievement: t=35min.

[0181] If the target ratio is not reached by the appointed time, the ion beam angle adjustment frequency is increased to 5Hz (originally 2Hz).

[0182] (2) Sintering stage

[0183] Sintering settings: initial electric field strength E = 3.5 kV / cm, frequency f = 60 Hz, duty cycle D = 60%, real-time monitoring of conductivity change rate: The empirical threshold range is [0.8, 1.2] μS / min. The current rate of change is too high, that is, oxygen vacancies are generated too quickly. Therefore, the electric field strength is reduced to 3.0 kV / cm.

[0184] (3) Laser-induced breakdown analysis + thermal cycling test

[0185] Maximum oxygen vacancy concentration distribution: ;

[0186] The metal / ceramic element ratio is -12.5% / μm, and the maximum lattice distortion rate is: Gradient steepness fitting results =0.52 / μm, corresponding to the recommended thermal cycling threshold of 800 cycles.

[0187] The output test report section can be referenced in the table below:

[0188] Table 5: Thermal Cycling Test Data Table

[0189] index Parameter value Cyclic temperature range -100℃～+250℃ heating rate 10℃ / min single cycle time 70min Total number of loops 800 times Failure indicators Crack length increase <2µm, thermal conductivity decrease <4%, electrical conductivity decrease <3.8%. Results and conclusions The interface has no delamination and the structure is intact, meeting the requirements.

[0190] In summary, this embodiment achieves precise compositional control of metal-ceramic gradient thin films by dynamically adjusting sputtering power, predicting deposition time, and coordinating the control of ion beam parameters. This effectively alleviates interfacial thermal stress and has the advantages of improving the interfacial bonding strength and thermal conductivity of composite materials.

[0191] Exemplary device

[0192] like Figure 9 As shown in the figure, this embodiment introduces a diamond thermoelectric ceramic reaction device, which includes a main cavity, a dual-target magnetron sputtering system, an auxiliary ion beam system, a quartz crystal thickness gauge, an atmosphere control mechanism, and a processor.

[0193] The dual-target magnetron sputtering system is used to sputter metal and ceramic targets into the main cavity;

[0194] The auxiliary ion beam system is used to dynamically bombard the deposition surface during the deposition process in the main cavity;

[0195] The quartz crystal thickness gauge is used to collect the film mass data inside the main cavity;

[0196] The atmosphere control mechanism is used to supply the main chamber with gases that assist the reaction;

[0197] The processor controls the operating status of the dual-target magnetron sputtering system, the auxiliary ion beam system, and the atmosphere control mechanism; when the processor is working, it executes the steps of the diamond thermoelectric ceramic interface performance optimization and connection method described above.

[0198] The main cavity refers to the vacuum reaction space that supports the diamond substrate and completes thin film deposition. It can be made of stainless steel or aluminum alloy and equipped with a vacuum pump assembly. An internal substrate heating stage and temperature sensor are installed to maintain the deposition temperature. The dual-target magnetron sputtering system is a deposition device capable of independently adjusting the sputtering power of the metal and ceramic targets. It can be implemented using magnetron sputtering targets with independent RF power supplies, changing the sputtering rate of the target material by adjusting the power supply. The auxiliary ion beam system can be implemented using a focused ion beam system, improving film compactness by adjusting the ion incident angle and energy density. The atmosphere control mechanism can be implemented using a mass flow controller and a gas mixer, controlling the degree of film oxidation by adjusting the oxygen or nitrogen flow rate. The processor can be implemented using an embedded system or an industrial computer, generating control commands by acquiring film quality data in real time and running preset algorithms.

[0199] This embodiment achieves dynamic optimization of the deposition process by integrating independent power adjustment of dual targets, dynamic ion beam bombardment, and coordinated atmosphere control, combined with the processor's closed-loop algorithm. This device, through a power reversal mechanism using metal / ceramic targets, can generate a nanoscale gradient transition layer, effectively mitigating the thermal expansion mismatch problem.

[0200] Based on this, this embodiment solves the problem of film thickness and composition differences caused by fixed sputtering power. Real-time monitoring and dynamic adjustment ensure consistent film performance across different regions and batches. The synergistic effect of ion beam bombardment and atmosphere control improves film density and interfacial bonding strength, while pulsed electric field sintering further optimizes the interfacial connection between diamond and thermoelectric ceramics. The resulting gradient transition layer reduces thermal stress concentration and enhances the thermal cycling stability of the composite material.

[0201] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A method for optimizing and connecting the interface properties of diamond thermoelectric ceramics, used to form a metal-ceramic gradient thin film on the surface of a diamond substrate using a dual-target magnetron sputtering system and an auxiliary ion beam system; characterized in that, It includes the following steps: Obtain current reaction time, thin film quality data, metal target sputtering power, and ceramic target sputtering power; Based on the thin film quality data, the sputtering power of the metal target, and the sputtering power of the ceramic target, the current deposition composition ratio is calculated using a rate estimation method. Specifically, this includes: extracting the mass distribution of the metal target and the ceramic target from the thin film quality data, calculating the ratio to obtain a preliminary value; and correcting the preliminary value by combining the sputtering power of the metal target and the sputtering power of the ceramic target to obtain the current deposition composition ratio. The target deposition component ratio corresponding to the current reaction time is matched using a predefined lookup table; wherein the lookup table characterizes the mapping relationship between reaction time and deposition component ratio. Calculate the difference between the current depositional component ratio and the target depositional component ratio; If the difference value exceeds a preset first threshold, the sputtering power decrease rate of the metal target and the sputtering power increase rate of the ceramic target are dynamically adjusted. Specifically, this includes: determining whether the current deposition component ratio is higher than the target deposition component ratio; if so, increasing the sputtering power decrease rate of the metal target and decreasing the sputtering power increase rate of the ceramic target; otherwise, decreasing the sputtering power decrease rate of the metal target and increasing the sputtering power increase rate of the ceramic target; wherein the adjustment range of the sputtering power is proportional to the difference value, and the single adjustment range does not exceed a preset second threshold. The sputtering power of the adjusted metal and ceramic targets and the current reaction time are used to estimate the predicted time to reach the next target deposition component ratio through a deep learning model, and the current reaction time and the predicted time are added together to obtain the cumulative time. If the cumulative duration exceeds the preset reaction time corresponding to the next target deposition component ratio, the frequency of ion beam incident angle adjustment is increased. The sputtering power of the metal and ceramic targets and the frequency of the ion beam incident angle adjustment are fed back to the target end.

2. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 1, characterized in that, Before calculating the difference between the current deposition component ratio and the target deposition component ratio, the process also includes determining whether the periodic adjustment phase has been reached based on the current reaction time and performing corresponding adjustment operations. The specific operations are as follows: Determine whether the current reaction time is within the duration range of the periodic adjustment phase; If so, it is determined that the current periodic adjustment phase has been entered, and the sputtering power of the metal target and the sputtering power of the ceramic target are periodically adjusted according to the preset adjustment range until the preset number of adjustments is reached. Otherwise, perform the operation of calculating the difference between the current deposition component ratio and the target deposition component ratio.

3. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 1, characterized in that, After calculating the current depositional composition ratio using the rate estimation method, the process further includes determining the rising stage of the ceramic components based on the current depositional composition ratio, and then performing auxiliary atmosphere control. The specific steps are as follows: The historical sedimentary composition ratios are obtained, and the variation range of ceramic components is linearly calculated by combining them with the current sedimentary composition ratios. Determine whether the change is an increase; if so, determine that it is in the ceramic component rising stage, and introduce an auxiliary atmosphere with a corresponding flow rate according to the preset mapping relationship between the change and the atmosphere volume. The duration of introducing the auxiliary atmosphere is continuously recorded. When the duration of introduction reaches a preset duration threshold, the introduction is stopped.

4. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 1, characterized in that, After feeding back the adjusted sputtering power of the metal target and ceramic target and the frequency of the ion beam incident angle to the target end, the process further includes sintering a diamond substrate with a metal-ceramic gradient film and a thermoelectric ceramic material to obtain a composite material after the accumulated time reaches a preset total time. The specific steps are as follows: The reaction time is continuously accumulated until the accumulated time reaches the preset total time. Then the sputtering operation is stopped and the diamond substrate with the metal-ceramic gradient film is heat-treated. The heat-treated diamond substrate and the thermoelectric ceramic material are sintered using a sintering device with a pulsed electric field applied. After the sintering time reaches the preset sintering duration, the desired composite material is obtained.

5. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 4, characterized in that, In the sintering of a heat-treated diamond substrate and a thermoelectric ceramic material using a sintering apparatus that applies a pulsed electric field, the specific steps for applying the pulsed electric field are as follows: Apply a pulsed electric field inside the sintering equipment; Real-time acquisition of the current electric field parameters of the sintering period and the pulsed electric field; Match the adjustment parameters corresponding to the sintering period according to the pre-set stage parameter adjustment table; Determine whether the adjustment parameter is consistent with the current electric field parameter; otherwise, obtain the rate of change of conductivity at the material interface and compare it with a preset empirical threshold range. Based on the comparison result, make the following decision: If the rate of change of conductivity exceeds the empirical threshold range, it is determined that oxygen vacancies are generated too quickly, and the adjustment parameter is reduced. If the rate of change of conductivity is lower than the empirical threshold range, it is determined that oxygen vacancy generation is too slow, and the adjustment parameter is increased.

6. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 4, characterized in that, After obtaining the desired composite material, a thermal cycling test is performed on the composite material, and a test report is generated. The specific steps are as follows: The composite material was subjected to laser-induced breakdown spectroscopy point-by-point detection along the interface normal to obtain the oxygen vacancy concentration distribution, metal / ceramic element ratio and lattice distortion rate, and the gradient steepness was obtained by fitting a fitting function. Match the threshold number of iterations corresponding to the gradient steepness according to the preset iteration reference table; The composite material is subjected to thermal cycling test, and the number of cycles is accumulated. When the number of cycles reaches the threshold, the test is stopped and a test report consisting of test data is output.

7. The method for optimizing and connecting the interface performance of diamond thermoelectric ceramics according to claim 6, characterized in that, The test data includes the cyclic temperature range, temperature change rate, single cycle time, cumulative number of cycles, and failure index records.

8. A diamond thermoelectric ceramic reactor, comprising: main cavity; A dual-target magnetron sputtering system for sputtering a metal target and a ceramic target into the main cavity; An auxiliary ion beam system is used to dynamically bombard the deposition surface during the deposition process in the main cavity; A quartz crystal thickness gauge is used to collect the film mass data inside the main cavity; An atmosphere control mechanism for supplying the main chamber with gases that assist the reaction; The processor is used to control the operating status of the dual-target magnetron sputtering system, the auxiliary ion beam system, and the atmosphere control mechanism. Its features are, When the processor is working, it executes the steps of the diamond thermoelectric ceramic interface performance optimization and connection method as described in any one of claims 1-7.

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