Semiconductor epi process lamp bulb life test apparatus and method

Abstract

The application discloses a semiconductor EPI process bulb life test device and a test method, and belongs to the technical field of fault prediction and health management, and comprises the following steps: collecting the resistance values of filaments in each bulb under different states through a resistance measurement module, acquiring an actual temperature change curve of the filaments, determining a nonlinear inflection point, and analyzing the aging characteristics of the filaments before and after the nonlinear inflection point; performing accelerated life test, adopting a double-voltage input cycle method to periodically load voltage on the filaments, and recording the resistance value change curves of the filaments under different voltage stress levels; and performing multidimensional test in cooperation with an execution device to simulate an actual use environment. In the technical scheme implementation process of the application, the resistance values of filaments in each bulb under different states are collected through the resistance measurement module, the temperature change curves of the filaments are acquired, then the nonlinear inflection point is determined, and the life is analyzed before and after the inflection point by using different methods, so that the current life of the bulb can be accurately acquired.

Description

Technical Field

[0001] This application relates to the field of fault prediction and health management technology, specifically to a semiconductor EPI process bulb life testing device and testing method. Background Technology

[0002] Semiconductor EPI (epitaxy growth) is a key process in semiconductor manufacturing. By growing thin film layers with the same lattice on the surface of a single crystal substrate, the electrical and optical performance of the device can be significantly improved. Its principle is based on high-temperature evaporation deposition technology. By adjusting parameters such as temperature and gas flow rate, the crystal quality and doping concentration can be precisely controlled. It is suitable for manufacturing optoelectronic devices such as lasers and LEDs.

[0003] EPI equipment consists of a reaction chamber and a heating system. Temperature control is fundamental to EPI equipment. The equipment uses a quartz or graphite boat as the reaction chamber, which is heated by the heating system to ensure that the material evaporates at high temperatures and forms an epitaxial layer on the substrate surface. The heating system typically uses light bulbs for heating. Multiple heating bulbs are arranged on the reaction chamber, and the temperature field inside the reaction chamber is precisely controlled by adjusting the power of each heating bulb. Since the heating bulbs are in a high-temperature environment for a long time, their lifespan directly affects the stability and maintenance cycle of the EPI equipment. Therefore, it is necessary to evaluate the lifespan of the bulbs to ensure the reliability and production efficiency of the equipment. In the current technology, the bulbs are usually managed by accumulating working time or replacing them periodically based on experience, thereby ensuring the normal operation of the EPI equipment.

[0004] However, in the implementation of the above technical solutions, due to the lack of a process for evaluating and testing the actual aging degree and performance degradation of the bulbs, it is easy for the aging degree and performance degradation of some bulbs during actual use to lack quantitative assessment. This makes it difficult to accurately grasp the timing of bulb replacement, and there is a risk of wasting resources due to premature replacement or causing equipment temperature control inaccurate due to delayed replacement.

[0005] Therefore, it is necessary to provide a semiconductor EPI process bulb life testing device and testing method to solve the above problems.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore may include information that does not constitute prior art. Summary of the Invention

[0007] Based on the aforementioned problems in the existing technology, the problem to be solved by this application is to provide a semiconductor EPI process bulb life testing device and testing method, which identifies the nonlinear inflection point in the actual temperature change process of the filament, and then uses different methods to conduct life testing in a targeted manner, thereby realizing bulb failure prediction and health management.

[0008] The technical solution adopted by this application to solve its technical problem is: a method for testing the lifespan of a light bulb using a semiconductor EPI process, comprising:

[0009] The resistance value of the filament in each bulb is collected by the resistance measurement module under different conditions, and the actual temperature change curve of the filament is obtained by combining the material temperature coefficient and the ambient temperature. The resistance value of the filament under different conditions includes cold resistance value and hot resistance value.

[0010] Based on the actual temperature change curve of the filament, its nonlinear inflection point is determined, and the aging characteristics of the filament before and after the nonlinear inflection point are analyzed.

[0011] Accelerated life testing was conducted by using a cyclic method with dual voltage inputs to periodically apply voltage to the filament and recording the filament resistance change curves under different voltage stress levels.

[0012] The collaborative execution device undergoes multi-dimensional testing to simulate the actual usage environment, with the execution device being an active heat dissipation module.

[0013] In the implementation of the technical solution of this application, the resistance value of the filament in each bulb under different states is collected by the resistance measurement module, and its temperature change curve is obtained. Then, the nonlinear inflection point is determined, and the lifespan before and after the inflection point is analyzed by different methods, so as to accurately obtain the current lifespan of the bulb.

[0014] Furthermore, the cold resistance value is the initial resistance value measured when the bulb is not powered on, and its temperature is the same as the ambient temperature; the hot resistance value is the resistance value measured after being powered on for a fixed time at rated power.

[0015] Furthermore, ambient temperature is introduced as a reference parameter. The ambient temperature during cold resistance measurement is used as the initial temperature reference. The actual temperature of the filament is obtained by using the correction factor corresponding to the average temperature and resistance fluctuation. The correction factor corresponding to the resistance fluctuation is the dynamic temperature change of the filament during operation.

[0016] Furthermore, the actual temperature of the filament is equal to the algebraic sum of the average temperature and the correction factor.

[0017] Furthermore, the nonlinear inflection point refers to the critical point at which the relationship between resistance and temperature changes changes from a linear relationship to a nonlinear relationship during the process of filament temperature change over time. Before this inflection point, the temperature change and resistance change of the filament are linearly related, and after this inflection point, the temperature change and resistance change of the filament are nonlinearly related.

[0018] Furthermore, the method for determining the nonlinear inflection point is as follows: by continuously sampling the temperature change curve, the second derivative between adjacent sampling points is calculated. When the second derivative undergoes a sudden change from positive to negative, it is determined to be the location of the nonlinear inflection point.

[0019] Furthermore, after determining the nonlinear inflection point, this point is used as the dividing point for analyzing the filament aging characteristics. Different methods are used to analyze the filament aging process before and after the nonlinear inflection point. Linear quantization analysis is used before the nonlinear inflection point, and a nonlinear resistance change model and thermodynamic aging equation are used for joint analysis after the nonlinear inflection point.

[0020] Furthermore, the quantitative analysis based on the linear change trend of resistance includes the following steps: establishing a linear fitting equation between resistance and time, calculating the slope of the fitting curve, which reflects the aging rate of the filament before the nonlinear inflection point; combining the initial resistance of the filament and the set lifespan threshold, calculating the remaining aging lifespan of the filament at this stage, using the linear extrapolation method, that is, calculating the time required to reach the lifespan threshold at the current aging stage based on the proportional relationship between the aging rate slope and the remaining lifespan.

[0021] Furthermore, the joint analysis using a nonlinear resistance change model and a thermodynamic aging equation includes the following steps: constructing a nonlinear fitting function between resistance and temperature, combining it with the thermodynamic aging equation, and deriving the aging rate function of the filament in the nonlinear stage.

[0022] A semiconductor EPI process bulb life testing device includes a test chamber with multiple mounting parts inside, each evenly distributed around the central axis of the test chamber. Each mounting part includes a guide rail fixed to the edge of the test chamber, and a slider slidably connected to the guide rail. The slider is adapted to slide along the guide rail, and a bulb holder is mounted on the slider for fixing the bulb. The bulb is mounted at the end of the bulb holder, and a power supply module is connected to the bulb holder via wires. The power supply module is mounted outside the test chamber. A voltage regulation unit and a test circuit are provided between the bulb holder and the power supply module. A heat dissipation hole is also provided at the bottom of the test chamber for cooling the bulb.

[0023] The beneficial effects of this application are as follows: This application provides a semiconductor EPI process bulb life testing device and testing method, which collects the resistance value of the filament in each bulb under different states through a resistance measurement module, obtains its temperature change curve, then determines the nonlinear inflection point, and uses different methods to perform life analysis before and after the inflection point, thereby accurately obtaining the current life of the bulb.

[0024] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is an overall schematic diagram of a semiconductor EPI process bulb life testing method according to this application;

[0027] Figure 2 This is a schematic diagram of the temperature change curve;

[0028] Figure 3 This is a schematic diagram of a semiconductor EPI process bulb life testing device according to this application;

[0029] The following are the labeling elements in the figure:

[0030] 1. Guide rail; 2. Slider; 3. Lamp holder; 4. Light bulb; 5. Heat dissipation holes. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0033] like Figure 1As shown, this application provides a method for testing the lifespan of a light bulb in a semiconductor EPI process. This method is applied in EPI equipment and mainly tests the lifespan of the light bulbs in its heating system. This allows for real-time monitoring of the luminous efficiency and aging status of the bulbs under different power conditions, ensuring the stable and continuous operation of the EPI equipment. Specifically, the testing method includes the following steps:

[0034] Step S1: Collect the resistance value of the filament in each bulb under different states through the resistance measurement module, and obtain the actual temperature change curve of the filament by combining the material temperature coefficient and the ambient temperature. The resistance value of the filament under different states includes the cold resistance value and the hot resistance value.

[0035] The lifespan of a light bulb is highly correlated with the temperature of its filament. However, in existing technologies, filament temperature monitoring typically relies on sensor testing. In EPI (Enhanced Power Input) devices, sensor placement is limited and it's difficult to cover all critical areas, resulting in blind spots in temperature monitoring and affecting the accuracy of filament temperature testing. Therefore, in this embodiment, a resistance measurement method is used to indirectly obtain the actual temperature of the filament. The resistance measurement module collects the filament's resistance values ​​in both cold and hot states, and calculates the actual filament temperature by combining the ambient temperature and the material temperature coefficient. Specifically, the cold-state resistance value is the initial resistance value measured when the bulb is not powered on, and its temperature is consistent with the ambient temperature. The hot-state resistance value is the resistance value measured after the bulb has been powered on for a fixed time at rated power. Taking tungsten filament as an example, the material temperature coefficient of tungsten filament is generally 0.0045 / ℃, meaning that for every 1℃ increase in the temperature of the tungsten filament, its resistance increases by 0.45%. By measuring the resistance changes in cold and hot states, the average temperature of the filament under operating conditions can be derived.

[0036] Specifically, since existing methods for calculating cold and hot resistance can only measure the average temperature of the filament and cannot obtain the actual absolute temperature value, this embodiment introduces ambient temperature as a reference parameter. The ambient temperature during cold resistance measurement is used as the initial temperature reference, and the actual filament temperature is obtained through a correction factor corresponding to the average temperature and resistance fluctuation. The correction factor for resistance fluctuation is due to the dynamic temperature change of the filament during operation caused by factors such as current and voltage fluctuations and changes in heat dissipation conditions, which approximately exhibits a sinusoidal waveform fluctuation. Therefore, the actual filament temperature, etc. The algebraic sum of the average temperature and the correction factor is used. Specifically, when the ambient temperature is 25℃, the cold resistance R0 is 10Ω, the hot resistance R1 is 14.5Ω, the material temperature coefficient α is 0.0045 / ℃, and the correction factor corresponding to the resistance fluctuation is equal to the product of ΔT and sin(wt), where ΔT represents the amplitude of the temperature fluctuation, which is calculated from the amplitude of the resistance fluctuation, and w represents the angular frequency, which is equal to 2πf, where f is the driving frequency. For example, when the AC power frequency is 50Hz, w is equal to 100π. Thus, the actual temperature change of the filament is calculated based on these parameters.

[0037] At different resistance values, the actual temperature of the filament will vary. By fitting these values ​​to a continuous temperature change curve, the dynamic temperature change trend of the filament throughout the entire working cycle can be obtained. This temperature change curve is shown below. Figure 2 As shown;

[0038] Resistance temperature measurement is generally used for temperature measurement of components with large heat capacity, such as motor windings. In this embodiment, it is introduced into filament temperature testing, which not only solves the problem of limited sensor deployment, but also improves the accuracy and response speed of temperature measurement. When it is applied to filament temperature testing, the ambient temperature is used as the reference parameter, and the correction factor corresponding to the resistance fluctuation is included in the calculation in combination with the temperature fluctuation amplitude, so as to accurately obtain the temperature change curve of the filament with resistance value. Compared with traditional sensor measurement, it not only eliminates the need to deploy temperature sensors, but also reflects the dynamic changes of filament temperature in real time, adapting to high-frequency fluctuating working environments.

[0039] Step S2: Based on the actual temperature change curve of the filament, determine its nonlinear inflection point and analyze the aging characteristics of the filament before and after the nonlinear inflection point.

[0040] In the aforementioned process, the temperature calculation method used is only applicable to the linear temperature range. When the temperature exceeds the nonlinear inflection point, due to the physical characteristics of the filament material itself, the relationship between temperature and resistance changes and no longer exhibits a linear relationship. The nonlinear inflection point refers to the point where the microstructure of the filament material changes at high temperatures, causing its temperature coefficient of resistance to become no longer constant, but gradually decreases as the temperature increases. At this time, the relationship curve between temperature and resistance shows a significant inflection point.

[0041] The nonlinear inflection point refers to the critical point where the relationship between resistance and temperature changes changes from linear to nonlinear during the process of filament temperature change over time. Before this inflection point, the temperature change and resistance change of the filament are linearly related; after this inflection point, the temperature change and resistance change of the filament are nonlinearly related. Specifically, the nonlinear inflection point is determined by continuously sampling the temperature change curve and calculating the second derivative between adjacent sampling points. When the second derivative changes abruptly from positive to negative, it is determined to be the location of the nonlinear inflection point.

[0042] In addition, it is necessary to verify the nonlinear inflection point by combining the physical properties of the filament material to prevent misjudgment due to data noise interference. For example, for tungsten filament, its nonlinear inflection point usually appears in the range close to the material recrystallization temperature. This range is generally a specific temperature threshold range. Therefore, by taking the recrystallization temperature range of tungsten filament as a theoretical reference value and cross-validating it with the actual measured resistance change curve, the location of the nonlinear inflection point can be accurately determined.

[0043] After determining the nonlinear inflection point, this point can be used as the dividing point for analyzing the filament aging characteristics. Different methods can be used to analyze the filament aging process before and after the nonlinear inflection point. Before the nonlinear inflection point, filament aging is mainly characterized by slow oxidation of the material and uniform degradation of the microstructure. This stage can be quantitatively analyzed through the linear change trend of the resistance value. After the nonlinear inflection point, due to irreversible physical changes such as recrystallization or grain growth within the material, the aging rate of the filament accelerates significantly. The aging characteristics at this point need to be analyzed jointly using a nonlinear resistance change model and a thermodynamic aging equation. Specifically:

[0044] Quantitative analysis based on the linear change trend of resistance includes the following steps: establishing a linear fitting equation between resistance and time, calculating the slope of the fitting curve, which reflects the aging rate of the filament before the nonlinear inflection point; combining the initial resistance of the filament and the set lifespan threshold, calculating the remaining aging lifespan of the filament in this stage. The calculation method adopts the linear extrapolation method, that is, based on the proportional relationship between the aging rate slope and the remaining lifespan, calculating the time required to reach the lifespan threshold in the current aging stage. For example, assuming the initial resistance of the filament is R0 and the resistance measured in the current aging stage is Rt, the linear extrapolation method can be expressed as: remaining lifespan = (Rt - R0) / slope.

[0045] The analysis by combining the nonlinear resistance change model with the thermodynamic aging equation includes the following steps: constructing a nonlinear fitting function between resistance and temperature, combining it with the thermodynamic aging equation, and deriving the aging rate function of the filament in the nonlinear stage.

[0046] Specifically, the nonlinear fitting function can be fitted using a polynomial or exponential function, and the thermodynamic equation is in the form of the Arrhenius equation, the basic expression of which is: aging rate = A × exp(-Ea / (R×T)), where A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and T is the thermodynamic temperature. After substituting the nonlinear fitting function into this equation, the aging rate variation law of the filament under different temperature conditions can be derived. The above method can be referred to Chinese invention patent with publication number CN119595137A, and will not be described in detail in this embodiment.

[0047] Step S3: Conduct accelerated life test by using a cyclic method with dual voltage input to periodically apply voltage to the filament and record the filament resistance change curves under different voltage stress levels.

[0048] Traditional bulb life tests only support unidirectional voltage loading, such as continuous voltage boosting. This method often fails to accurately reflect the impact of voltage fluctuations on filament aging during actual use. This embodiment employs a dual-voltage input cyclic loading method, including boosting and bucking cycles. By alternately applying different voltage stresses, it simulates the complex operating conditions of the bulb in real-world applications, thus more accurately assessing its aging behavior. Specifically, the boosting cycle involves gradually increasing the input voltage to a set upper limit, while the bucking cycle gradually decreases the voltage from that upper limit to a set lower limit. These two processes constitute a complete voltage cycle. During each cycle, the filament resistance change is monitored and recorded in real time, allowing for the plotting of resistance-time aging curves under different voltage stresses. These curves reflect the differences in filament aging rates at different voltage levels and provide fundamental data for subsequent aging model fitting.

[0049] The voltage change rate is kept consistent between the boost cycle and the buck cycle to ensure the symmetry of the test conditions. The voltage is controlled and regulated by a boost converter. The output voltage of the boost converter is dynamically adjusted by the controller according to the preset voltage change curve, thereby applying precise voltage stress to the filament. During the boost cycle, the controller gradually increases the duty cycle to increase the output voltage, while during the buck cycle, it gradually decreases the duty cycle to decrease the output voltage. After each voltage cycle, the system automatically saves the resistance change data of the current cycle and uploads it to the data processing center through the communication interface.

[0050] Step S4: Conduct multi-dimensional tests on the collaborative execution device to simulate the actual use environment, where the execution device is an active heat dissipation module.

[0051] In practical use, EPI equipment usually needs to be equipped with an active cooling module. When the bulb temperature is too high, the active cooling module is activated to reduce the ambient temperature around the bulb. However, in the aforementioned process, the test process did not consider the impact of heat dissipation conditions on bulb aging. Therefore, in this step, an active cooling module is introduced for collaborative testing. While the voltage is cyclically loaded, the working state of the cooling module is dynamically adjusted according to the current temperature of the filament to ensure that the bulb operates within the set temperature range.

[0052] The start / stop threshold of the active heat dissipation module is set according to the rated operating temperature of the bulb. When the filament temperature is detected to exceed the upper limit threshold, the heat dissipation module is activated to reduce the ambient temperature around the bulb through a fan or liquid cooling system. When the temperature drops back to the set lower limit, the heat dissipation module stops working, thereby simulating the effect of temperature fluctuations on bulb aging in real-world usage scenarios.

[0053] Example 2: Figure 3As shown, this application also proposes a semiconductor EPI process bulb life testing device. The device includes a test chamber with multiple mounting parts inside, each evenly distributed around the central axis of the test chamber. Each mounting part includes a guide rail 1 fixed to the edge of the test chamber. A slider 2 is slidably connected to the guide rail 1 and is adapted to slide along the guide rail 1. A bulb holder 3 for fixing the bulb is provided on the slider 2. A bulb 4 is provided at the end of the bulb holder 3. A power supply module is connected to the bulb holder 3 via wires. The power supply module is installed outside the test chamber (not shown in the figure). A voltage adjustment unit and a test circuit are provided between the bulb holder 3 and the power supply module. The voltage adjustment unit is used to adjust the voltage applied to the bulb according to the instructions output by the controller so that it follows a preset aging test curve. The test circuit is responsible for collecting the resistance change of the bulb in real time and feeding the collected data back to the controller to achieve closed-loop control. A heat dissipation hole 5 is also provided at the bottom of the test chamber for dissipating heat from the bulb 4.

[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for testing the lifetime of a semiconductor EPI process bulb, characterized by: The method comprises the following steps: Collecting resistance values of the filament in different states in each bulb through the resistance measurement module, and combining the material temperature coefficient and the environment temperature to obtain the actual temperature change curve of the filament, wherein the resistance values of the filament in different states include cold resistance value and hot resistance value; According to the actual temperature change curve of the filament, determining the nonlinear inflection point, and analyzing the aging characteristics of the filament before and after the nonlinear inflection point; the nonlinear inflection point refers to the critical point at which the resistance value and the temperature change are changed from linear relationship to nonlinear relationship in the process of the filament temperature change over time, before the inflection point, the temperature change and the resistance change of the filament are in linear relationship, and after the inflection point, the temperature change and the resistance change of the filament are in nonlinear relationship; The determination method of the nonlinear inflection point is: through continuous sampling of the temperature change curve, calculating the second derivative between adjacent sampling points, when the second derivative has a positive and negative mutation, it is determined that the position is the nonlinear inflection point; After determining the nonlinear inflection point, taking the point as the demarcation point for analyzing the aging characteristics of the filament, and using different methods to analyze the filament aging process before and after the nonlinear inflection point, using linear quantitative analysis before the nonlinear inflection point, and using nonlinear resistance change model and thermodynamic aging equation for joint analysis after the nonlinear inflection point; Performing accelerated life test, using a cycle method of double voltage input to periodically load voltage on the filament, and recording the resistance change curve of the filament under different voltage stress levels; Cooperating with the execution equipment to perform multi-dimensional test to simulate the actual use environment, wherein the execution equipment is an active heat dissipation module.

2. The method of claim 1, wherein: The cold resistance value is the initial resistance value measured when the bulb is not powered on, and its temperature is consistent with the environment temperature; the hot resistance value is the resistance value measured after being powered on for a fixed time under rated power.

3. The method of claim 1, wherein: The environment temperature is introduced as a reference parameter, the environment temperature during the measurement of the cold resistance value is taken as the initial temperature reference, and the actual temperature of the filament is obtained through the average temperature and the correction factor corresponding to the resistance fluctuation, wherein the correction factor corresponding to the resistance fluctuation is the temperature dynamic change of the filament in the working process.

4. The method of claim 3, wherein: The actual temperature of the filament is equal to the algebraic sum of the average temperature and the correction factor.

5. The method for testing the lifespan of a semiconductor EPI process bulb according to claim 1, characterized in that: The linear change trend of the resistance value includes the following steps: establishing a linear fitting equation of resistance value and time, calculating the slope of the fitting curve, which reflects the aging rate of the filament before the nonlinear inflection point; combining the initial resistance value of the filament and the set life threshold, calculating the remaining life of the filament in the aging stage, and the calculation method adopts linear extrapolation method, that is, according to the proportional relationship between the aging rate slope and the remaining life, calculating the time required to reach the life threshold under the current aging stage.

6. The method of claim 1, wherein: The joint analysis of the nonlinear resistance change model and the thermodynamic aging equation includes the following steps: constructing a nonlinear fitting function between resistance value and temperature, combining it with the thermodynamic aging equation, and deducing the aging rate function of the filament in the nonlinear stage.

7. The method for testing the lifespan of a semiconductor EPI process bulb according to claim 1, characterized in that: The method is applied to a semiconductor EPI process lamp bulb life test device, the device comprises a test cavity, a mounting portion is arranged in the test cavity, the number of the mounting portion is multiple, and each mounting portion is uniformly distributed around the center axis of the test cavity, the mounting portion comprises a guide rail (1), the guide rail (1) is fixed to the edge of the test cavity, a sliding block (2) is slidably connected to the guide rail (1), the sliding block (2) is suitable for sliding along the guide rail (1), a lamp holder (3) for fixing the bulb is arranged on the sliding block (2), an end of the lamp holder (3) is provided with a bulb (4), the lamp holder (3) is connected with a power supply module through a wire, the power supply module is installed outside the test cavity, a voltage adjusting unit and a test circuit are arranged between the lamp holder (3) and the power supply module, and a heat dissipation hole (5) is further formed in the bottom of the test cavity, and the heat dissipation hole (5) is used for heat dissipation of the bulb (4).

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