Thin film high temperature breakdown performance testing device and method

Abstract

The application provides a thin film high-temperature breakdown performance testing device and method. The method is applied to the thin film high-temperature breakdown performance testing device. The method comprises the following steps: fixing a test thin film and an aluminum foil on a grounded metal plate; in the oil injection process, the test thin film is not prone to wrinkles. A vacuum pump is started, and the pressure of a vacuum test box is reduced to below 100 Pa; the vacuum test box and the vacuum pump are used to avoid the influence of residual air on the test result. When the insulating oil covers the upper electrode of the cylinder, the vacuum pump is turned off. The insulating oil is heated to a preset temperature. The voltage between the upper electrode of the cylinder and the fixed lower electrode is increased to a target voltage. The attraction between the upper electrode and the lower electrode can be used to remove the air between the aluminum foil and the thin film, the aluminum foil and the grounded metal plate. The target voltage is maintained for a preset time, and the insulating oil between the upper electrode and the lower electrode can be fully removed. The influence of the insulating oil and the air on the test result is avoided to the greatest extent, and the accuracy of the thin film high-temperature breakdown performance test is improved.

Description

Technical Field

[0001] This application relates to the field of dielectric performance testing technology, and in particular to a device and method for testing the high-temperature breakdown performance of thin films. Background Technology

[0002] Testing the breakdown characteristics of polypropylene film is typically performed at room temperature. However, in actual use, capacitors experience significant internal temperature rises, with the hottest point often reaching 80°C. Since the measurement temperature differs from the hottest point temperature by approximately 60°C, it is necessary to measure the high-temperature breakdown characteristics of the polypropylene film used in capacitors.

[0003] Currently, the high-temperature breakdown characteristics of polypropylene film for capacitors are generally tested using two methods: oil bath heating and oven heating. However, when using oil bath heating, there is a lot of oil and residual air between the electrodes, which can easily affect the accuracy of the high-temperature breakdown characteristics test of polypropylene film. While oven heating avoids the influence of oil on the test results, the lack of oil as a constant temperature medium makes temperature control more difficult, thus affecting the accuracy of the test and leading to a large error in the high-temperature breakdown characteristics test of polypropylene film for capacitors. Summary of the Invention

[0004] The purpose of this application is to at least solve one of the aforementioned technical defects, particularly the technical defect that there is a large error in the testing of the high-temperature breakdown characteristics of polypropylene film for capacitors in the prior art.

[0005] In a first aspect, this application provides a method for testing the high-temperature breakdown performance of thin films, applied to a testing device for high-temperature breakdown performance of thin films. The device includes: a pressure relief valve, an oil tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder. The vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and a top cover plate. The fixed lower electrode includes a grounded metal plate and a fixing clamp. The method includes:

[0006] Pour the insulating oil into the storage tank;

[0007] The test film is laid flat on the upper surface of the aluminum foil, and the test film and the aluminum foil are fixed to the grounded metal plate by the fixing clamp;

[0008] Turn on the vacuum pump to reduce the pressure in the vacuum test chamber to below 100 Pa;

[0009] Open the pressure relief valve to allow the insulating oil in the oil storage tank to flow into the vacuum test chamber through the pipeline;

[0010] When the insulating oil covers the upper electrode of the cylinder, the vacuum pump is turned off; during the oil filling process, the pressure of the vacuum test chamber is kept below 100 Pa by the vacuum pump.

[0011] Activate the heating element to heat the insulating oil to the preset temperature;

[0012] Turn on the high-voltage power supply to raise the voltage between the upper cylindrical electrode and the fixed lower electrode to the target voltage and maintain it for a preset time; the target voltage is determined based on the current thickness of the test film.

[0013] After the preset time has elapsed, the voltage increase unit is determined, and the voltage between the upper cylindrical electrode and the lower fixed electrode is increased according to the voltage increase unit. When the test film breaks down, the breakdown voltage and breakdown location are recorded by a voltage recorder. If the current number of tests is not greater than the preset number, it is determined whether the preset conditions are met.

[0014] If the preset conditions are not met, the electrode on the cylinder is moved to any non-broken position of the test film, and the process returns to the step of starting the heating element to continue execution.

[0015] In one embodiment, determining the voltage rise unit includes:

[0016] Determine the range of film breakdown time and the estimated breakdown voltage of the test film;

[0017] Calculate the difference between the estimated breakdown voltage and the target voltage;

[0018] The quotient between the difference and the median of the film breakdown time range is used as the voltage rise unit.

[0019] In one embodiment, the film breakdown time ranges from 10 to 20 seconds.

[0020] In one embodiment, the preset condition is:

[0021] There were no unbroken areas in the test film;

[0022] or,

[0023] The breakdown voltages recorded by the voltage recorder show a decreasing trend as the number of tests increases.

[0024] In one embodiment, the method further includes:

[0025] If the preset conditions are met, the current test film is replaced with a new test film, the insulating oil in the vacuum test chamber is emptied, and the process returns to the step of laying the test film flat on the upper surface of the aluminum foil.

[0026] In one embodiment, a pressure gauge and a thermometer are used to monitor the pressure and temperature of the vacuum test chamber, respectively.

[0027] In one embodiment, the preset time is between 20 and 60 seconds.

[0028] Secondly, this application provides a thin film high-temperature breakdown performance testing device, the device comprising: a pressure relief valve, an oil storage tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder;

[0029] The pressure relief valve is connected to the oil storage tank;

[0030] The oil storage tank is connected to the vacuum test chamber;

[0031] The thermometer, the pressure gauge, and the voltage recorder are mounted on the top of the vacuum test chamber;

[0032] The vacuum pump is connected to the vacuum test chamber;

[0033] All of the above connections are made via pipes.

[0034] In one embodiment, the vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and an upper cover plate;

[0035] The positive terminal of the high-voltage power supply is connected to the upper electrode of the cylinder, and the negative terminal is connected to the fixed lower electrode.

[0036] The upper cover plate is located at the top of the vacuum test chamber;

[0037] The fixed lower electrode is placed at the bottom of the vacuum test chamber, and the cylindrical upper electrode is located above the fixed lower electrode, with a gap between the cylindrical upper electrode and the fixed lower electrode;

[0038] The upper electrode of the cylinder is connected to the voltage recorder;

[0039] The heating element is installed at the bottom of the vacuum test chamber.

[0040] In one embodiment, the fixed lower electrode includes a grounded metal plate and a fixing clamp;

[0041] The grounding metal plate is placed at the bottom of the vacuum test chamber and is connected to the zero potential line;

[0042] The fixing clamps are placed on both sides of the upper surface of the grounding metal plate and are used to fix the aluminum foil and film to the grounding metal plate.

[0043] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0044] This application provides a thin film high-temperature breakdown performance testing device and method. The method is applied to a thin film high-temperature breakdown performance testing device, which includes: a pressure relief valve, an oil storage tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder. The vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and a top cover plate. The fixed lower electrode includes a grounding metal plate and a fixing clamp. The method includes: laying the test film flat on the upper surface of aluminum foil, and fixing the test film and aluminum foil to the grounding metal plate using the fixing clamp; during the oil injection process, the test film can be fixed to the grounding metal plate and is less prone to wrinkles. The vacuum pump is turned on to reduce the pressure of the vacuum test chamber to below 100 Pa; the use of a vacuum test chamber and vacuum pump in conjunction with the thin film high-temperature breakdown performance testing method avoids the influence of residual air on the test results, thereby improving the accuracy of the thin film high-temperature breakdown performance test. The pressure relief valve is opened to allow the insulating oil in the oil storage tank to flow into the vacuum test chamber through a pipeline; using the insulating oil as a constant-temperature medium minimizes temperature changes and ensures the accuracy of the test results. When the insulating oil covers the upper cylindrical electrode, the vacuum pump is turned off; the heating element is started to heat the insulating oil to the preset temperature; the high-voltage power supply is started to increase the voltage between the upper cylindrical electrode and the fixed lower electrode to the target voltage. The attraction between the upper and lower electrodes can expel air between the aluminum foil and the film, and between the aluminum foil and the grounding metal plate. Maintaining the target voltage for the preset time effectively removes the insulating oil between the upper and lower electrodes without causing significant damage to the test film. This minimizes the influence of insulating oil and air on the test results, improving the accuracy of the high-temperature breakdown performance test of the film. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic flowchart of a method for testing the high-temperature breakdown performance of a thin film provided in an embodiment of this application;

[0047] Figure 2 This is a schematic diagram of the structure of a thin film high-temperature breakdown performance testing device provided in an embodiment of this application;

[0048] Figure 3 This is a schematic diagram of the structure of the fixed lower electrode provided in an embodiment of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] like Figure 1 As shown, this application provides a method for testing the high-temperature breakdown performance of thin films, applied to a testing device for high-temperature breakdown performance of thin films. The device includes: a pressure relief valve, an oil tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder; the vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and an upper cover plate; the fixed lower electrode includes a grounded metal plate and a fixing clamp; the method includes:

[0051] Step S101: Pour the insulating oil into the oil storage tank.

[0052] Insulating oil is a liquid used for insulation of electrical equipment. An oil storage tank is a container used to store insulating oil, with an opening at the top for connecting to pipelines.

[0053] In this step, when it is necessary to test the high-temperature breakdown performance of the test film, high-performance insulating oil needs to be poured into the energy storage tank of the film high-temperature breakdown performance testing device. It is understood that the film is an insulating dielectric material for a capacitor. Testing the breakdown performance of the film, i.e., testing the breakdown characteristics of the film, includes, but is not limited to, breakdown voltage, breakdown electric field strength, and breakdown current, etc.

[0054] Step S102: Lay the test film flat on the upper surface of the aluminum foil, and fix the test film and the aluminum foil to the grounded metal plate using a fixing clamp.

[0055] In this step, when the test film is laid flat on the upper surface of the aluminum foil, a fixing clamp is used to fix both sides of the test film and the aluminum foil to the grounding metal plate, so that the test film and the aluminum foil are fixedly laid flat on the grounding metal plate. In this way, the test film is less likely to wrinkle and will not change position due to the injection of oil, which helps to improve the accuracy of the high temperature breakdown performance test of the test film.

[0056] Step S103: Turn on the vacuum pump and reduce the pressure of the vacuum test chamber to below 100Pa.

[0057] A vacuum pump is a device used to extract gas to create a vacuum environment inside a container. It reduces the gas pressure inside the container by extracting the gas.

[0058] In the thin film high temperature breakdown performance testing device, the vacuum pump is connected to the vacuum test chamber through a pipeline. In this step, the vacuum pump is used to extract the air from the vacuum test chamber, so that the pressure of the vacuum test chamber is reduced to below 100 Pa.

[0059] Understandably, on the Earth's surface, standard atmospheric pressure is usually defined as 101.325 kilopascals (kPa), which is equivalent to one standard atmosphere. Environments below 100 Pa can be considered as low vacuum environments.

[0060] Step S104: Open the pressure relief valve so that the insulation in the oil storage tank flows into the vacuum test chamber through the pipeline.

[0061] A pressure relief valve is a device used to control and release excessive pressure. It monitors the pressure inside a system or equipment and opens when the pressure exceeds a set value, releasing excess gas or fluid into the environment.

[0062] In this embodiment, the pressure relief valve is used to control the pressure in the oil storage tank so that the insulating oil in the oil storage tank flows into the vacuum test chamber through the pipeline.

[0063] Step S105: When the insulating oil covers the upper electrode of the cylinder, turn off the vacuum pump.

[0064] During the oil filling process, a vacuum pump is used to ensure that the pressure in the vacuum test chamber does not exceed 100 Pa.

[0065] In this step, when the insulating oil covers the upper electrode of the cylinder, stop adjusting the pressure relief valve and turn off the vacuum pump. It is understood that during the oil filling process, the vacuum pump is operational to maintain the pressure in the vacuum test chamber below 100 Pa, and can be turned off when the insulating oil covers the upper electrode of the cylinder.

[0066] Understandably, a cylindrical electrode is an electrode structure in the shape of a cylinder, which can consist of a central electrode (usually a conductor rod or wire) and one or more peripheral electrodes (usually annular or cylindrical metal shells).

[0067] Step S106: Activate the heating element to heat the insulating oil to the preset temperature.

[0068] The heating element can be one of the following: heating wire, heating cable, heating plate, etc., which are elements that convert electrical energy or other forms of energy into heat energy.

[0069] In one embodiment, the preset temperature can be 80°C. The selection of the preset temperature depends on the testing requirements for the high-temperature breakdown performance of the thin film, and this application does not impose specific limitations on it. However, the preset temperature should not be set too high, as excessively high temperatures can easily damage the thin film.

[0070] Step S107: Turn on the high voltage power supply to raise the voltage between the upper cylindrical electrode and the fixed lower electrode to the target voltage and maintain it for a preset time.

[0071] The target voltage is determined based on the thickness of the current test film; the high-voltage power supply is an electrical device used to provide a higher voltage output. The fixed lower electrode is an electrode structure made of metallic material.

[0072] During a test of the high-temperature breakdown performance of the test film, the position of the lower electrode was fixed. When a certain position of the test film was broken down, the position of the breakdown was changed by moving the upper electrode on the cylinder.

[0073] Specifically, the process of determining the target voltage includes: when the thickness of the test film is greater than or equal to 10 micrometers, the target voltage of the test film is set to 500V; when the thickness of the test film is less than 10 micrometers, the product of the thickness of the test film and 50V / micrometer is used as the corresponding target voltage.

[0074] It is understandable that the voltage between the upper electrode of the cylinder and the fixed lower electrode is increased to the target voltage and maintained at the target voltage for a preset time. The breakdown voltage of the film is usually much greater than the target voltage. The purpose of maintaining the target voltage for the preset time is to fully remove the insulating oil between the upper and lower electrodes and make the upper and lower electrodes in close contact, while ensuring that the test film is not damaged.

[0075] Step S108: After the preset time has ended, determine the voltage increase unit, and according to the voltage increase unit, continue to increase the voltage between the upper cylindrical electrode and the fixed lower electrode. When the test film breaks down, record the breakdown voltage and breakdown location at this moment using a voltage recorder.

[0076] Here, the voltage increase unit refers to the step size of the voltage increase, that is, the voltage difference each time the voltage is increased.

[0077] In the thin film high-temperature breakdown performance testing device, the voltage recorder is connected to the cylindrical electrode. It can obtain the breakdown position at this time according to the position of the cylindrical electrode in the vacuum test chamber, and record the breakdown voltage corresponding to the breakdown position of the test film.

[0078] Step S109: If the current number of trials is not greater than the preset number of trials, then determine whether the preset conditions are met at this time.

[0079] The preset number of tests refers to the number of test points required for this high-temperature breakdown performance test of the experimental film. The preset number of tests can be set based on experience from previous tests, and this application does not impose specific restrictions on it.

[0080] Step S110: If the preset conditions are not met, move the electrode on the cylinder to any non-broken position of the test film and return to the step of starting the heating element to continue execution.

[0081] In this step, when moving the upper cylindrical electrode, the top cover of the vacuum test chamber needs to be opened, which will affect the temperature and pressure. Therefore, after moving the upper cylindrical electrode, a heating element is needed to heat the insulating oil to the preset temperature, and the voltage between the upper cylindrical electrode and the fixed lower electrode is adjusted to the target voltage through a high voltage, and then step S108 and subsequent steps are executed.

[0082] Step S111: If the preset conditions are met, replace the current test film with a new test film, empty the insulating oil in the vacuum test chamber, and return to the step of laying the test film flat on the upper surface of the aluminum foil to continue execution.

[0083] Understandably, the preset conditions are used to determine whether there are any unbroken areas on the film and whether the content of impurities, moisture, acid, and other substances in the insulating oil in the vacuum test chamber exceeds the specified standard limits. When the preset conditions are met, a new test film is used to replace the current test film, the insulating oil in the vacuum test chamber is emptied, and the new test film is fixed to the grounding metal plate according to the process of step S102, and then the steps after step S102 are executed.

[0084] When the current number of tests exceeds the preset number, the test of the high-temperature breakdown performance of the test film ends. The breakdown field strength can be calculated based on the recorded breakdown location and its corresponding breakdown voltage. Finally, the high-temperature breakdown performance of the test film can be analyzed using these data.

[0085] This application provides a thin film high-temperature breakdown performance testing device and method. The method is applied to a thin film high-temperature breakdown performance testing device, which includes: a pressure relief valve, an oil storage tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder. The vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and a top cover plate. The fixed lower electrode includes a grounding metal plate and a fixing clamp. The method includes: laying the test film flat on the upper surface of aluminum foil, and fixing the test film and aluminum foil to the grounding metal plate using the fixing clamp; during the oil injection process, the test film can be fixed to the grounding metal plate and is less prone to wrinkles. The vacuum pump is turned on to reduce the pressure of the vacuum test chamber to below 100 Pa; the use of a vacuum test chamber and vacuum pump in conjunction with the thin film high-temperature breakdown performance testing method avoids the influence of residual air on the test results, thereby improving the accuracy of the thin film high-temperature breakdown performance test. The pressure relief valve is opened to allow the insulating oil in the oil storage tank to flow into the vacuum test chamber through a pipeline; using the insulating oil as a constant-temperature medium minimizes temperature changes and ensures the accuracy of the test results. When the insulating oil covers the upper cylindrical electrode, the vacuum pump is turned off; the heating element is started to heat the insulating oil to the preset temperature; the high-voltage power supply is started to increase the voltage between the upper cylindrical electrode and the fixed lower electrode to the target voltage. The attraction between the upper and lower electrodes can expel air between the aluminum foil and the film, and between the aluminum foil and the grounding metal plate. Maintaining the target voltage for the preset time effectively removes the insulating oil between the upper and lower electrodes without causing significant damage to the test film. This minimizes the influence of insulating oil and air on the test results, improving the accuracy of the high-temperature breakdown performance test of the film.

[0086] In one embodiment, the preset condition is:

[0087] There were no unbroken areas in the test film;

[0088] or,

[0089] The breakdown voltages recorded by the voltage recorder show a decreasing trend as the number of tests increases.

[0090] When the preset conditions are met, there are three possible scenarios, as follows:

[0091] (1) There are no unbroken locations in the test film, and the breakdown voltages recorded by the voltage recorder do not show a decreasing trend as the number of tests increases.

[0092] (2) There are unbroken locations in the test film, and the breakdown voltages recorded by the voltage recorder show a decreasing trend as the number of tests increases.

[0093] (3) There are no unbroken locations in the test film, and the breakdown voltages recorded by the voltage recorder show a decreasing trend as the number of tests increases.

[0094] If the preset conditions are not met, there is only one possibility:

[0095] There were non-breakdown sites in the test film, and the breakdown voltages recorded by the voltage recorder did not show a decreasing trend with the increase of the number of tests.

[0096] Specifically, if the breakdown voltages recorded by the voltage recorder show a decreasing trend with the increase of the number of tests, it indicates that the insulating oil in the vacuum test chamber is contaminated and the insulation performance is lower than the specified standard. In this case, the test film and the insulating oil in the vacuum test chamber can be replaced. Conversely, if there are no non-breakdown locations in the test film, the test film and the insulating oil in the vacuum test chamber can also be replaced.

[0097] In one embodiment, determining the voltage rise unit includes:

[0098] Determine the range of film breakdown time and the estimated breakdown voltage of the test film;

[0099] Calculate the difference between the estimated breakdown voltage and the target voltage;

[0100] The quotient between the difference and the median of the film breakdown time range is used as the voltage rise unit.

[0101] The breakdown voltage estimate refers to the estimated breakdown voltage of the corresponding test film, which can be estimated and determined based on existing data.

[0102] Understandably, since the breakdown time of the test film needs to be controlled, it is necessary to calculate the voltage rise unit.

[0103] For example, assuming the film breakdown time ranges from 10 to 20 seconds and the thickness is 12 micrometers, the target voltage of the test film is 500V, and the estimated breakdown voltage of the test film is 800V. Then, the difference between the estimated breakdown voltage and the target voltage is 300V, and the median of the film breakdown time range is 15. At this time, the voltage rise unit can be obtained as 20V (300V / 15).

[0104] In one embodiment, a pressure gauge and a thermometer are used to monitor the pressure and temperature of the vacuum test chamber, respectively.

[0105] The pressure gauge and thermometer are installed on the top of the vacuum test chamber to monitor its pressure and temperature. This allows for adjustment of the vacuum pump and heating elements, ensuring accurate control of the chamber's pressure and temperature.

[0106] In one embodiment, the film breakdown time ranges from 10 to 20 seconds.

[0107] In one embodiment, the preset time is between 20 and 60 seconds.

[0108] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0109] The thin film high-temperature breakdown performance testing device provided in the embodiments of this application is described below.

[0110] like Figure 2 As shown, this application provides a thin film high-temperature breakdown performance testing device, the device including: a pressure relief valve, an oil storage tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder;

[0111] The pressure relief valve is connected to the oil storage tank;

[0112] The oil storage tank is connected to the vacuum test chamber;

[0113] The thermometer, the pressure gauge, and the voltage recorder are mounted on the top of the vacuum test chamber;

[0114] The vacuum pump is connected to the vacuum test chamber;

[0115] All of the above connections are made via pipes.

[0116] Specifically, one end of the pressure relief valve is connected to the oil storage tank via a pipeline, and the other end can be connected to a desiccant or nitrogen gas to stabilize the performance of the pressure relief valve.

[0117] The use of a vacuum test chamber and vacuum pump in conjunction with the high-temperature breakdown performance test method for thin films can minimize the influence of residual air on the test results, thereby improving the accuracy of the high-temperature breakdown performance test for thin films.

[0118] In one embodiment, the vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and an upper cover plate;

[0119] The positive terminal of the high-voltage power supply is connected to the upper electrode of the cylinder, and the negative terminal is connected to the fixed lower electrode.

[0120] The upper cover plate is located at the top of the vacuum test chamber;

[0121] The fixed lower electrode is placed at the bottom of the vacuum test chamber, and the cylindrical upper electrode is located above the fixed lower electrode, with a gap between the cylindrical upper electrode and the fixed lower electrode;

[0122] The upper electrode of the cylinder is connected to the voltage recorder;

[0123] The heating element is installed at the bottom of the vacuum test chamber.

[0124] like Figure 3 As shown, in one embodiment, the fixed lower electrode includes a grounded metal plate and a fixing clamp;

[0125] The grounding metal plate is placed at the bottom of the vacuum test chamber and is connected to the zero potential line;

[0126] The fixing clamps are placed on both sides of the upper surface of the grounding metal plate and are used to fix the aluminum foil and film to the grounding metal plate.

[0127] It is understandable that by fixing the test film and aluminum foil to the grounded metal plate with a fixing clamp, the test film and aluminum foil can be prevented from moving due to the injection of insulating oil into the vacuum test chamber, thus preventing test failure or inaccurate test results.

[0128] Those skilled in the art will understand that Figure 2 and Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the device to which the present application is applied. A specific thin film high temperature breakdown performance testing device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0129] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a…" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this document, the singular forms "a," "an," and "the" may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having” specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0130] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0131] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for testing the high-temperature breakdown performance of thin films, characterized in that, An apparatus for testing the high-temperature breakdown performance of thin films is provided, comprising: a pressure relief valve, an oil tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder; the vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and an upper cover plate; the fixed lower electrode includes a grounded metal plate and a fixing clamp; the method includes: Pour the insulating oil into the storage tank; The test film is laid flat on the upper surface of the aluminum foil, and the test film and the aluminum foil are fixed to the grounded metal plate by the fixing clamp; Turn on the vacuum pump to reduce the pressure in the vacuum test chamber to below 100 Pa; Open the pressure relief valve to allow the insulating oil in the oil storage tank to flow into the vacuum test chamber through the pipeline; When the insulating oil covers the upper electrode of the cylinder, the vacuum pump is turned off; during the oil filling process, the pressure of the vacuum test chamber is kept below 100 Pa by the vacuum pump. Turn on the heating element to heat the insulating oil to the preset temperature; Turn on the high-voltage power supply to raise the voltage between the upper cylindrical electrode and the fixed lower electrode to the target voltage and maintain it for a preset time; the target voltage is determined based on the current thickness of the test film. After the preset time has elapsed, the voltage increase unit is determined, and the voltage between the upper cylindrical electrode and the lower fixed electrode is increased according to the voltage increase unit. When the test film breaks down, the breakdown voltage and breakdown location are recorded by a voltage recorder. If the current number of tests is not greater than the preset number, it is determined whether the preset conditions are met. If the preset conditions are not met, the electrode on the cylinder is moved to any non-broken position of the test film, and the process returns to the step of starting the heating element to continue execution.

2. The method for testing the high-temperature breakdown performance of thin films according to claim 1, characterized in that, The determination of the voltage rise unit includes: Determine the range of film breakdown time and the estimated breakdown voltage of the test film; Calculate the difference between the estimated breakdown voltage and the target voltage; The quotient between the difference and the median of the film breakdown time range is used as the voltage rise unit.

3. The method for testing the high-temperature breakdown performance of thin films according to claim 2, characterized in that, The film breakdown time ranges from 10 to 20 seconds.

4. The method for testing the high-temperature breakdown performance of thin films according to claim 1, characterized in that, The preset conditions are: There were no unbroken areas in the test film; or, The breakdown voltages recorded by the voltage recorder show a decreasing trend as the number of tests increases.

5. The method for testing the high-temperature breakdown performance of thin films according to claim 1 or 4, characterized in that, The method further includes: If the preset conditions are met, the current test film is replaced with a new test film, the insulating oil in the vacuum test chamber is emptied, and the process returns to the step of laying the test film flat on the upper surface of the aluminum foil.

6. The method for testing the high-temperature breakdown performance of thin films according to claim 1, characterized in that, The pressure and temperature of the vacuum test chamber were monitored using a pressure gauge and a thermometer, respectively.

7. The method for testing the high-temperature breakdown performance of thin films according to claim 1, characterized in that, The preset time is between 20 and 60 seconds.

8. A thin film high-temperature breakdown performance testing device, characterized in that, The device includes: a pressure relief valve, an oil storage tank, a thermometer, a pressure gauge, a vacuum test chamber, a vacuum pump, and a voltage recorder; The pressure relief valve is connected to the oil storage tank; The oil storage tank is connected to the vacuum test chamber; The thermometer, the pressure gauge, and the voltage recorder are mounted on the top of the vacuum test chamber; The vacuum pump is connected to the vacuum test chamber; All of the above connections are made via pipes; the vacuum test chamber includes a heating element, a high-voltage power supply, a fixed lower electrode, a cylindrical upper electrode, and an upper cover plate; The positive terminal of the high-voltage power supply is connected to the upper electrode of the cylinder, and the negative terminal is connected to the fixed lower electrode. The upper cover plate is located at the top of the vacuum test chamber; The fixed lower electrode is placed at the bottom of the vacuum test chamber, and the cylindrical upper electrode is located above the fixed lower electrode, with a gap between the cylindrical upper electrode and the fixed lower electrode; The upper electrode of the cylinder is connected to the voltage recorder; The heating element is installed at the bottom of the vacuum test chamber; The fixed lower electrode includes a grounding metal plate and a fixing clamp; The grounding metal plate is placed at the bottom of the vacuum test chamber and is connected to the zero potential line; The fixing clamps are placed on both sides of the upper surface of the grounding metal plate and are used to fix the aluminum foil and film to the grounding metal plate.

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