Nondestructive continuous detection method and device for metal / glass sealing structure airtightness accelerated test

Abstract

This invention relates to a non-destructive continuous testing method and apparatus for accelerated testing of the airtightness of metal / glass sealed structures, belonging to the field of airtightness measurement technology. This invention addresses three major technical shortcomings of existing helium mass spectrometry backpressure methods: destructive testing leading to microcrack propagation, inability to continuously acquire water vapor data in a single test, and a disconnect between leakage rate criteria and the physical mechanism of airtightness failure. The invention includes: S1, encapsulating a temperature and humidity sensor within a metal / glass insulator sealed structure using an FPC sensor circuit board to construct a test chamber; transmitting the temperature and humidity electrical signals inside the test chamber to an external signal control board via lead posts; S2, placing the test chamber into an accelerated life test chamber, simultaneously applying temperature, humidity, and differential pressure stresses to the test chamber during the accelerated life test; S3, the signal control board calculates the water vapor content (IV) inside the test chamber in real time, determining airtightness failure when IV is ≥5000 ppm for three consecutive tests.

Description

Technical Field

[0001] This invention belongs to the field of airtightness measurement technology, specifically relating to a non-destructive continuous monitoring method and device for the sealing structure of electronic components in accelerated life testing, and is particularly suitable for the airtightness failure detection of metal / glass insulator sealing structures (such as sealed relays). Background Technology

[0002] The main failure modes of electronic components include, but are not limited to, open circuit, short circuit, functional failure, electrical parameter drift, and unstable failure. Based on existing research, the auxiliary effect of moisture in the hermetic failure of sealed relays and the multi-stress coupling effect are important reasons affecting the propagation of microcracks in glass insulators and further leading to moisture leakage. There are many methods for measuring hermeticity; the sealing tests of electronic components are divided into fine leak testing and coarse leak testing. Coarse leak testing uses various methods such as bubble methods, weighing methods, and staining methods. Fine leak testing methods include: helium mass spectrometry backpressure fine leak testing, radioactive isotope fine leak testing, and optical fine leak testing.

[0003] The most commonly used method for fine leak detection of components is helium mass spectrometry with back pressure. However, because the pressurization of the workpiece by the helium pressurization tank also has a certain impact on the glass insulator, there are several disadvantages to using helium mass spectrometry:

[0004] 1. Discontinuity: Single-scale testing cannot acquire dynamic data on water vapor changes under multi-stress coupling, making it difficult to establish a failure evolution model. Destructive testing results in limited water vapor detection data points and cannot achieve multi-stress coupling research, leading to its discontinuity. This invention is based on failure physics, not statistical physics. It does not fit data equations through a large number of data points, but instead accelerates the analysis of hermetic failure of sealed relays by combining failure modes with the three stresses of temperature, humidity, and pressure difference. In accelerated life testing, this invention can extend water vapor data for device failure at different time points at each stress point. Since hermetic failure is unpredictable and can only be predicted based on prior data and experience, if the water vapor content inside the sealed relay does not reach the failure water vapor content, the experiment is stopped when the sealed relay is tested with a helium mass spectrometer. Furthermore, the atmosphere inside the relay housing has exchanged with the outside environment, causing the internal water vapor content to change, making accurate and effective analysis impossible.

[0005] 2. Destructive Testing: The testing method involves damage. During leak rate detection, helium mass spectrometers apply high voltage and create a vacuum outside the metal / glass insulator seal. This high voltage is often far higher than normal atmospheric pressure, and even significantly higher than the pressure differential limit in accelerated life testing. This can damage the glass insulator in a short time. While this damage doesn't cause through-cracks, making a noticeable change in leak rate impossible in short-term leak rate detection, during longer storage or accelerated life testing, if microcracks in the glass insulator absorb moisture, it will significantly accelerate the propagation of these microcracks, leading to airtight failure of the metal / glass insulator seal. This hidden nature often leads to its being overlooked during helium mass spectrometry use.

[0006] 3. Inadequate Judgment Criteria: Even when the leak rate test passes, the internal moisture content may already exceed the standard (due to residual moisture or increased microcracks). In reality, airtightness failure is directly caused by excessive moisture content, leading to contact failure and other malfunctions. The current leak rate testing method results in insufficient rigor in testing the airtightness of metal / glass insulator sealing structures. Using a helium mass spectrometer for leak rate testing can lead to situations where the leak rate test passes, but the internal moisture content already exceeds the standard. This is partly due to residual moisture exceeding the standard during the encapsulation process, and partly due to increased microcracks in the glass insulator caused by lead post ramping, applied high voltage, etc., resulting in excessive internal moisture content even when the leak rate is within the standard. Since various failures that truly cause device failure, including electrical contact failure and contact adhesion, originate from airtightness failure due to excessive internal moisture content, this is problematic.

[0007] In summary, the shortcomings of the existing helium mass spectrometry back pressure method are that destructive testing leads to the propagation of microcracks, a single test cannot continuously obtain water vapor data, and the leakage rate criterion is disconnected from the physical mechanism of airtight failure, ultimately resulting in inaccurate assessment of sealing structure failure. Summary of the Invention

[0008] To address the three major technical shortcomings of existing helium mass spectrometry backpressure methods—destructive testing leading to microcrack propagation, inability to continuously acquire water vapor data in a single test, and a disconnect between leakage rate criteria and the physical mechanism of airtightness failure—this invention provides a non-destructive continuous testing method and apparatus for accelerated testing of the airtightness of metal / glass sealing structures.

[0009] On one hand, the present invention provides a non-destructive continuous testing method for accelerated testing of the airtightness of metal / glass sealing structures, the method comprising the following steps:

[0010] S1. The temperature and humidity sensor is encapsulated inside the metal / glass insulator sealing structure through the FPC sensor circuit board to construct a test cavity. The temperature and humidity electrical signals inside the test cavity are transmitted to the external signal group control board through the lead post.

[0011] S2. Place the test chamber into the accelerated life test chamber and apply temperature, humidity and pressure differential stress to the test chamber simultaneously during the accelerated life test.

[0012] S3, the signal group control board calculates the water vapor content (IV) inside the test chamber in real time. When IV is ≥5000 ppm for 3 consecutive times, the airtightness is determined to be faulty.

[0013] Preferably, the water vapor content IV inside the test chamber in step S3 is obtained by the following formula:

[0014]

[0015] In the formula,

[0016] To test the real-time relative humidity inside the chamber during accelerated life testing;

[0017] To test the real-time temperature inside the chamber during accelerated life testing;

[0018] This represents the saturated vapor pressure of water vapor at the current temperature.

[0019] The initial air pressure of the test chamber is set to atmospheric pressure.

[0020] To test the initial temperature inside the chamber before accelerated life testing;

[0021] This refers to the pressure difference between the acceleration chamber and the test chamber during accelerated life testing.

[0022] Preferably, the process of applying humidity stress to the test chamber during the accelerated life test in step S2 is as follows: a trace amount of liquid water is pre-added to the accelerated chamber, and the amount of liquid water added is calculated according to the following formula to ensure that it is entirely in the form of water vapor after the accelerated life test is carried out:

[0023]

[0024] In the formula, The gas constant is The molar mass of water, To increase the water vapor content inside the cavity during accelerated life testing.

[0025] Preferably, the process of applying differential pressure stress to the test chamber during the accelerated life test in step S2 is as follows: after adding a trace amount of liquid water, the accelerated chamber is pressurized or depressurized according to the preset differential pressure stress, and the pressurization or depressurization amount is calculated using the following formula:

[0026]

[0027] In the formula, This represents the charging or depressurization amount; a positive value represents charging and a negative value represents depressurization.

[0028] The initial air pressure of the acceleration chamber before the accelerated life test.

[0029] Preferably, the process of applying temperature stress to the test chamber during the accelerated life test in step S2 is as follows: after applying differential pressure stress, the accelerated chamber is placed in a constant temperature chamber, and temperature stress is applied by using the constant temperature chamber. The temperature of the entire device is raised through the constant temperature chamber. A small amount of liquid water is added to the accelerated chamber before vaporization to reach the preset temperature, humidity, and differential pressure. The temperature and humidity sensor installed in the accelerated chamber detects the temperature and humidity data in real time and transmits it to the signal group control board.

[0030] Preferably, in the accelerated experiment, any one of the stress factors—temperature stress, humidity stress, and differential pressure stress—has at least two levels.

[0031] On the other hand, the present invention provides a non-destructive continuous testing device for accelerated testing of the airtightness of metal / glass sealing structures. The device includes a test chamber, an acceleration chamber, and a control unit. The test chamber is placed inside the acceleration chamber, and the acceleration chamber provides the test chamber with temperature stress, humidity stress, and differential pressure stress.

[0032] Control unit: includes FPC signal transmission board 10 and signal group control board 14;

[0033] Test chamber: includes temperature and humidity sensor 7, FPC sensor circuit board 8 and metal / glass insulator sealing structure 9. Temperature and humidity sensor 7 is sealed in metal / glass insulator sealing structure 9 through FPC sensor circuit board 8 to construct test chamber; temperature and humidity electrical signals of test chamber are transmitted to signal group control board 14 through FPC signal transmission board 10.

[0034] Acceleration chamber: includes pressure vessel top cover 3, silicone rubber sealing structure 4, flanged pressure vessel 5, second temperature and humidity sensor 6, constant temperature chamber 13 and differential pressure stress loading unit; flanged pressure vessel 5 is placed in constant temperature chamber 13, pressure vessel top cover 3 seals the upper opening of flanged pressure vessel 5 through silicone rubber sealing structure 4, and second temperature and humidity sensor 6 is sealed inside the acceleration chamber.

[0035] The differential pressure stress loading unit includes a flange-type pressure transmitter 1, a stainless steel three-way valve 2, a sealing ball valve 11, a miniature air pump 12, and an explosion-proof plug 15. The pressure vessel tank top cover 3 has a central through hole, at which the sealing ball valve 11 is installed. One interface of the sealing ball valve 11 is connected to the stainless steel three-way valve 2. The other two interfaces of the stainless steel three-way valve 2 are connected to the flange-type pressure transmitter 1 and the miniature air pump 12, respectively. The miniature air pump 12 fills or evacuates air into the acceleration chamber to increase or decrease the air pressure in the acceleration chamber. The flange-type pressure transmitter 1 monitors the internal pressure of the acceleration chamber in real time. When the preset differential pressure stress is reached, the sealing ball valve 11 is closed, the flange-type pressure transmitter 1, the stainless steel three-way valve 2, and the miniature air pump 12 are disassembled, and the explosion-proof plug 15 is installed on the external interface of the sealing ball valve 11.

[0036] Preferably, the thickness of the FPC signal transmission board 10 is not less than 100μm, the bending radius is ≥5mm, one end of the FPC signal transmission board 10 is connected to the temperature and humidity sensor encapsulated in the test chamber by soldering, and the other end of the FPC signal transmission board 10 passes through the side wall of the acceleration chamber and is electrically connected to the external signal group control board 14.

[0037] The connection between the FPC signal transmission board 10 and the side wall of the acceleration chamber is sealed with silicone rubber. The sealing method is as follows: the FPC signal transmission board is first passed through the silicone rubber sealing ring at the connection. After the silicone rubber sealing ring is fixed to the groove of the pressure vessel tank top cover 3, liquid silicone rubber with a thickness of not less than 4mm is applied to both sides of the silicone rubber sealing ring for sealing protection. Vacuum silicone grease is applied to the contact surface between the FPC signal transmission board 10 and the silicone rubber sealing ring.

[0038] Preferably, the lower surface of the pressure vessel tank top cover 3 is provided with a groove for covering the tank body, and a silicone rubber ring is placed in the groove. When the cover is closed, it is squeezed and liquid silicone rubber is applied at the connection. Vacuum silicone grease is applied to the contact surface between the tank body and the silicone rubber ring, thereby maintaining a sealed structure around the perimeter.

[0039] Preferably, the method of providing humidity stress to the accelerated chamber is as follows: before installing the sealing ball valve 11, a small amount of liquid water is added to the interior through the central through hole of the pressure vessel tank top cover 3, so that it is completely vaporized and reaches the preset humidity during the accelerated life test.

[0040] The beneficial effects of this invention are as follows: It provides a method for non-destructively and continuously detecting the internal moisture content of metal / glass insulator sealing structures under accelerated life test conditions of high temperature, high humidity, and high pressure. This method overcomes several problems inherent in traditional leak rate detection methods, including helium mass spectrometry, such as the inability to perform non-destructive testing, the inability to perform continuous testing, and the lack of rigorous judgment criteria. By fully considering the influence of internal moisture content on microcracks in the glass insulator within the metal / glass insulator sealing structure from the perspective of failure physics, it can non-destructively, continuously, and accurately determine when an airtight failure occurs in the metal / glass insulator sealing structure. Specifically, this includes the following points:

[0041] 1. Overcoming the bottleneck of non-destructive continuous monitoring:

[0042] The device incorporates a built-in temperature and humidity sensor, utilizing lead-in posts and other structures within a metal / glass insulator sealing structure to transmit electrical signals. This avoids the destructive operations of traditional helium mass spectrometry, enabling continuous acquisition of moisture data throughout its entire lifespan. It solves the problems of requiring multiple stops for testing during accelerated life testing and the potential damage to the metal / glass insulator sealing structure. It effectively reduces the impact of other factors on accelerated life testing, shortening the accelerated life testing cycle for the airtightness of metal / glass insulator sealing structures from months or even years to just over a month.

[0043] 2. Multi-layer sealing design ensures stable signal transmission in high-pressure / high-temperature environments; by using FPC circuit boards and silicone rubber sealing components, the contradiction between signal transmission and cavity sealing under high-pressure environments is resolved. The FPC material ensures corrosion resistance under high temperature and high humidity conditions, while sufficient structural strength and bending resistance ensure that no significant deformation occurs when the flange is fixed, ensuring sealing performance of no less than 2 atmospheres.

[0044] While ensuring the airtightness of the accelerated life test device, it stably and accurately transmits the electrical signals of the temperature and humidity sensors. With the help of the water vapor and pressure control device, it precisely controls the water vapor and pressure inside the accelerated chamber through the evaporation of trace amounts of liquid water and pre-pressurization and depressurization. At the same time, it solves the problem that the overall structure needs to be pressure measured during the accelerated life test. This avoids the problem that the water vapor and pressure control structure is difficult to keep stable with trace amounts of water vapor and pressure at the same time. It can continuously detect the water vapor content and leakage status inside different chambers during the accelerated life test without damage.

[0045] 3. Scientific validity and acceleration of failure criteria:

[0046] Using a water vapor content of ≥5000 ppm as the criterion, it focuses on the physical nature of failure and reflects the physical mechanism of failure more directly than leak rate detection.

[0047] The three-stress coupling acceleration (temperature / humidity / pressure difference) method, compared with the traditional high temperature and high humidity accelerated life test, introduces the ultimate pressure difference that the metal / glass insulator sealing structure can withstand, which is expected to shorten the test cycle by more than 80%.

[0048] 4. Supports online early warning; the host computer software displays data in real time and triggers alarms (such as IV exceeding the threshold). Attached Figure Description

[0049] Figure 1 This is a flowchart of the non-destructive continuous testing method for accelerated testing of the airtightness of the metal / glass sealing structure described in this invention;

[0050] Figure 2 This is a schematic diagram of the non-destructive continuous testing device for accelerated testing of the airtightness of the metal / glass sealing structure described in this invention, which includes a flange-type pressure transmitter 1, a stainless steel three-way valve 2, a sealing ball valve 11, and a micro air pump 12.

[0051] Figure 3 This is a schematic diagram of the non-destructive continuous testing device for accelerated testing of the airtightness of the metal / glass sealing structure described in this invention. The flange-type pressure transmitter 1, stainless steel three-way valve 2, sealing ball valve 11, and miniature air pump 12 are disassembled and explosion-proof plugs are installed. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0055] Specific Implementation Method 1: The following is combined with... Figures 1 to 3 This embodiment describes a non-destructive continuous testing device for accelerated testing of the airtightness of a metal / glass sealing structure, comprising a test chamber, an acceleration chamber, and a control unit; the test chamber is placed inside the acceleration chamber, and the acceleration chamber provides the test chamber with temperature stress, humidity stress, and differential pressure stress;

[0056] Control unit: includes FPC signal transmission board 10 and signal group control board 14; signal group control board 14 is the data interaction and logic control center of the entire device, and its main function is to collect sensor data such as temperature and humidity, and realize the calculation and visualization of airtightness parameters.

[0057] Test Chamber: The test chamber is the core packaging unit of the sealed relay under test. Its main functions are: to achieve real-time acquisition of internal temperature and humidity of the seal, ensuring the internal structural sealing and withstanding high temperature, high humidity, and high pressure environments; and to communicate with external data systems through integrated flexible circuitry. It includes the following components:

[0058] Built-in temperature and humidity sensor 7: responsible for real-time monitoring of temperature and humidity data inside the test chamber;

[0059] FPC sensor circuit board 8: Provides fixing and connection support for the above sensors;

[0060] Metal / Glass Insulator Sealing Structure 9: Encapsulates the sealed structure under test, with lead posts and glass insulators, possessing a complete sealing physical structure;

[0061] FPC signal transmission board 10: It undertakes the task of circuit connection between signal acquisition sensor and external signal group control board, and has high temperature and flexibility characteristics, making it suitable for complex installation environment.

[0062] The combination of the above components ensures that internal signal acquisition and transmission can be completed without compromising the seal.

[0063] A temperature and humidity sensor 7 is encapsulated within a metal / glass insulator sealing structure 9 using an FPC sensor circuit board 8 to construct a test chamber. The temperature and humidity electrical signals of the test chamber are transmitted to a signal group control board 14 via an FPC signal transmission board 10. The metal / glass insulator sealing structure 9 includes, but is not limited to, any sealing device that can maintain the internal atmosphere and external atmosphere independently and enable the transmission of internal and external electrical signals, especially a sealed relay, which achieves sealing through a metal shell and a glass insulator, and transmits electrical signals between the FPC sensor circuit board and the FPC signal transmission board through lead posts. The electrical signals of the temperature and humidity sensor are transmitted through the FPC signal transmission board 10 to detect the temperature and water vapor inside the chamber and to detect the presence of gas leakage based on changes in water vapor. The temperature and humidity sensor 8 encapsulated inside the test chamber is used to detect the temperature and water vapor content inside the test chamber. Since the degree of gas leakage in the test chamber is very low, the total amount of gas leaking into the test chamber when the internal water vapor content reaches the failure criterion of 5000ppm is much smaller than the gas content of the test chamber itself. Therefore, the test chamber does not need to detect pressure.

[0064] Acceleration Chamber: The acceleration chamber structure is used to construct a controlled accelerated life test environment. Its main function is to apply stress conditions such as temperature, humidity, and air pressure to the outside of the test chamber, achieving environmental control and sealing during testing, and supporting pressurization and air intake operations. It includes the following components:

[0065] Flange-type pressure vessel tank 5: Provides a controlled, sealed environment to support the test chamber;

[0066] Silicone rubber sealing structure 4: forms a reliable seal at multiple connection interfaces and sealing points to prevent gas leakage;

[0067] Sealing ball valve 11 and stainless steel three-way valve 2: enable control of air intake and exhaust in the acceleration chamber;

[0068] Explosion-proof plug 15: Ensures safe venting under overpressure conditions;

[0069] Incubator 13: Provides a stable and controllable temperature environment for the chamber;

[0070] Flange-type pressure transmitter 1: Used to detect changes in air pressure inside a cavity;

[0071] Miniature air pump 12: works in conjunction with the air circuit system to complete the air extraction or pressurization process.

[0072] Specifically, it includes a pressure vessel top cover 3, a silicone rubber sealing structure 4, a flanged pressure vessel 5, a second temperature and humidity sensor 6, a constant temperature chamber 13, and a differential pressure stress loading unit; the flanged pressure vessel 5 is placed inside the constant temperature chamber 13, and the pressure vessel top cover 3 seals the upper opening of the flanged pressure vessel 5 through the silicone rubber sealing structure 4, accelerating the sealing of the second temperature and humidity sensor 6 inside the cavity.

[0073] The differential pressure stress loading unit includes a flange-type pressure transmitter 1, a stainless steel three-way valve 2, a sealing ball valve 11, a miniature air pump 12, and an explosion-proof plug 15. The pressure vessel tank top cover 3 has a central through hole, at which the sealing ball valve 11 is installed. One interface of the sealing ball valve 11 is connected to the stainless steel three-way valve 2. The other two interfaces of the stainless steel three-way valve 2 are connected to the flange-type pressure transmitter 1 and the miniature air pump 12, respectively. The miniature air pump 12 fills or evacuates air into the acceleration chamber to increase or decrease the air pressure in the acceleration chamber. The flange-type pressure transmitter 1 monitors the internal pressure of the acceleration chamber in real time. When the preset differential pressure stress is reached, the sealing ball valve 11 is closed, the flange-type pressure transmitter 1, the stainless steel three-way valve 2, and the miniature air pump 12 are disassembled, and the explosion-proof plug 15 is installed on the external interface of the sealing ball valve 11.

[0074] The test chamber with a temperature and humidity sensor, the accelerated chamber for accelerated life testing with heating, humidification and pressurization, and the FPC signal transmission board 10 are connected in an airtight manner. The connecting component that enables the airtight connection of the three components is a silicone rubber sealing structure. This component includes, but is not limited to, silicone rubber sealing rings that can pass through the circuit board, liquid silicone rubber, high airtight sealant, vacuum silicone grease, etc.

[0075] The FPC sensor circuit board 8, FPC signal transmission board 10, and sealing ball valve 11 must ensure that under the extreme accelerated stress applied in the accelerated life test, no damage or change occurs to their physical properties or electrical signal transmission performance by the end of the entire accelerated life test, especially corrosion caused by high temperature and high humidity, and bending caused by high pressure. The FPC signal transmission board has a multi-layer composite copper foil structure with an EMI anti-interference layer and upper and lower insulating protective films; the thickness of the FPC signal transmission board 10 is not less than 100μm, and the bending radius is ≥5mm. One end of the FPC signal transmission board 10 is connected to the temperature and humidity sensor encapsulated in the test chamber by soldering; the other end of the FPC signal transmission board 10 passes through the side wall of the accelerated chamber and is electrically connected to the external signal group control board 14.

[0076] The connection between the FPC signal transmission board 10 and the side wall of the acceleration chamber is sealed with silicone rubber. The sealing method is as follows: the FPC signal transmission board is first passed through the silicone rubber sealing ring at the connection. After the silicone rubber sealing ring is fixed to the groove of the pressure vessel tank top cover 3, liquid silicone rubber with a thickness of not less than 4mm is applied to both sides of the silicone rubber sealing ring for sealing protection. Vacuum silicone grease is applied to the contact surface between the FPC signal transmission board 10 and the silicone rubber sealing ring.

[0077] The pressure vessel tank top cover 3 has a groove on its lower surface for sealing the tank body. A silicone rubber ring is placed in the groove. When the cover is closed, it is squeezed and liquid silicone rubber is applied to the connection. Vacuum silicone grease is applied to the contact surface between the tank body and the silicone rubber ring to maintain a sealed structure around the tank.

[0078] The accelerated life test chamber is provided with humidity stress by adding a small amount of liquid water through the central through-hole of the pressure vessel top cover 3 before installing the sealing ball valve 11. This liquid water is then completely vaporized during the accelerated life test to reach the preset humidity. This is achieved using micro-syringes (pipettes) of different specifications.

[0079] The test chamber must have an internal volume sufficient to accommodate the temperature and humidity sensor and be airtight. A sealed relay itself can serve as the test chamber; the chamber itself must also be airtight. Temperature and humidity sensor sealing method: The temperature and humidity sensor is sealed to the metal / glass insulator sealing structure using methods including but not limited to soldering and reflow soldering. Electrical signals are transmitted through the lead posts encased in the glass insulator. Reflow soldering is particularly necessary when the temperature and humidity sensor requires connection or fixation via reflow soldering. The sealing process must ensure that it does not affect the airtightness of the metal / glass insulator sealing structure and that it does not affect the sensor's electrical signal transmission or test accuracy.

[0080] Specific Implementation Method Two: The non-destructive continuous testing method for accelerated testing of the airtightness of a metal / glass sealing structure described in this implementation method includes the following steps:

[0081] S1. The temperature and humidity sensor is encapsulated inside the metal / glass insulator sealing structure through the FPC sensor circuit board to construct a test cavity. The temperature and humidity electrical signals inside the test cavity are transmitted to the external signal group control board through the lead post.

[0082] S2. Place the test chamber into the accelerated life test chamber and apply temperature, humidity and pressure differential stress to the test chamber simultaneously during the accelerated life test.

[0083] S3, the signal group control board calculates the water vapor content (IV) inside the test chamber in real time. When IV is ≥5000 ppm for 3 consecutive times, the airtightness is determined to be faulty.

[0084] The accelerator chamber features temperature, humidity, and air pressure control. It utilizes a heating and pressurization system, and precisely calculates and adds water to create an accelerated aging environment. The chamber structure employs a flanged metal tank with sealing grooves, and incorporates multi-layered sealing with liquid silicone rubber and vacuum silicone grease. A reinforced silicone ring fixing structure further ensures stable sealing performance under long-term pressure. An internal temperature and humidity sensor monitors the chamber's humidity level in real time; any sudden changes or abnormal rates of humidity change promptly indicate an abnormality in the chamber's airtightness.

[0085] This technology encapsulates a miniature temperature and humidity sensor within a sealed relay cavity. The relay is then placed inside the accelerated life test chamber under heating, humidification, and pressurization. The sensor continuously monitors the internal moisture content, thereby assessing changes in sealing performance. Since microcrack propagation and moisture leakage are coupled, the degree of damage to the relay's glass insulator can be deduced from the humidity curve measured by the sensor, enabling non-destructive continuous testing. Humidity-leakage analysis of relay samples after microcrack propagation can reveal the microscopic mechanism of airtight failure of the seal under humidity stress. The sensor undergoes calibration before encapsulation within the sealed relay, and the detection data is output via an FPC signal transmission board, ensuring data transmissibility and system integrity while maintaining a sealed cavity.

[0086] In step S3, the water vapor content IV inside the test chamber is calculated based on the relative humidity transmitted from inside the test chamber, specifically as follows:

[0087]

[0088] In the formula,

[0089] To test the real-time relative humidity inside the chamber during accelerated life testing;

[0090] To test the real-time temperature inside the chamber during accelerated life testing;

[0091] This is the saturated vapor pressure of water vapor at the current temperature; the saturated vapor pressure of water vapor at any temperature can be obtained by looking up a table, and it is a known quantity.

[0092] The initial air pressure of the test chamber is set to atmospheric pressure.

[0093] To test the initial temperature inside the test chamber before accelerated life testing; the initial temperature must be higher than the dew point temperature of the test chamber.

[0094] This refers to the pressure difference between the acceleration chamber and the test chamber during the accelerated life test. The pressure inside the acceleration chamber is measured by the flange-type pressure transmitter 1 and is the preset pressure, while the pressure inside the test chamber can be considered as the initial air pressure. The pressure difference between the two can be calculated from the preset pressure and the initial air pressure.

[0095] The process of applying humidity stress to the test chamber during the accelerated life test in step S2 is as follows: a trace amount of liquid water is pre-added to the accelerated chamber. The amount of liquid water added is calculated according to the following formula to ensure that it is entirely in the form of water vapor after the accelerated life test is carried out:

[0096]

[0097] In the formula, The gas constant is The molar mass of water, To increase the water vapor content inside the cavity during accelerated life testing.

[0098] The process of applying differential pressure stress to the test chamber during the accelerated life test in step S2 is as follows: After adding a trace amount of liquid water, the accelerated chamber is pressurized or depressurized according to the preset differential pressure stress, and the pressurization or depressurization amount is calculated using the following formula:

[0099]

[0100] In the formula, This represents the charging or depressurization amount; a positive value represents charging and a negative value represents depressurization.

[0101] The initial air pressure of the acceleration chamber before the accelerated life test.

[0102] The process of applying temperature stress to the test chamber during the accelerated life test in step S2 is as follows: After applying differential pressure stress, the accelerated chamber is placed in a constant temperature chamber. Temperature stress is applied using the constant temperature chamber, and the temperature of the entire device is raised through the constant temperature chamber. A small amount of liquid water is added to the accelerated chamber before vaporization to reach the preset temperature, humidity, and differential pressure. The temperature and humidity sensors installed in the accelerated chamber detect the temperature and humidity data in real time and transmit them to the signal group control board.

[0103] In accelerated experiments, any one of the stress factors—temperature stress, humidity stress, and differential pressure stress—must be at least two levels.

[0104] Taking level 3 as an example:

[0105] For temperature stress: the level can be 85°C, 105°C, or 125°C.

[0106] For humidity stress: the level can be 2.4 × 10⁻⁶. 5 ppm, 2.6×10 5 ppm, 2.8×10 5 ppm.

[0107] For differential pressure stress: the level can be 50 kPa, 70 kPa, or 90 kPa.

[0108] The temperature and humidity sensor encapsulated in the accelerated life test chamber should be continuously monitored at a temperature not lower than the saturated vapor pressure corresponding to the accelerated life test chamber. This means that any trace amounts of liquid water added to the accelerated life test chamber must remain in a water vapor state after the accelerated life test. The temperature and humidity sensor encapsulated in the test chamber can be monitored simultaneously with the accelerated life test chamber at the same temperature, or monitored when the test chamber is cooled to its initial temperature before the accelerated life test. If the temperature and humidity sensor encapsulated in the test chamber is monitored at its initial temperature before the accelerated life test, the sensor must complete at least one heating-cooling cycle. During the accelerated life test, the heating and cooling rates must not exceed 5°C / min to avoid introducing additional temperature shocks. The heating temperature should be kept consistent with the accelerated life test temperature and maintained at the highest temperature for 1 hour to ensure that the temperature and humidity sensor has not absorbed any additional water vapor before the accelerated life test.

[0109] The following provides a complete workflow:

[0110] Phase 1: Sensor packaging and preprocessing;

[0111] 1. Leakage rate detection of the cover plate;

[0112] 2. The temperature and humidity sensor 7 is reflow soldered to the lead posts via the FPC sensor circuit board 8;

[0113] 3. Clean the welding area with anhydrous ethanol;

[0114] 4. The cover plate is pressed against the housing (not sealed);

[0115] 5. Dry at 110℃ for 8 hours (to reduce residual moisture);

[0116] 6. Evacuate and fill with dry inert gas;

[0117] 7. Metal / glass seal;

[0118] Phase 2: Accelerating preparation for cavity pre-tests;

[0119] 8. Accelerate the baking process by baking the cavity at 80℃ for ≥8 hours (drying treatment);

[0120] 9. Install the test chamber to the flanged pressure vessel tank 5;

[0121] 10. Silicone rubber sealing structure with multi-layer sealing:

[0122] 10.1 The FPC signal transmission board 10 has an opening through the silicone rubber ring;

[0123] 10.2 Coat with liquid silicone rubber ≥4mm thick;

[0124] 10.3 Curing time ≥ 48 hours;

[0125] 10.4 Cover with high-airtightness sealant + vacuum silicone grease;

[0126] 11. Injecting a trace amount of liquid water into the acceleration chamber:

[0127] 11.1 Calculate the required water volume (m);

[0128] 11.2 Add deionized water to the pipette;

[0129] 12. Pressure pre-regulation:

[0130] 12.1 Install pressure components (sealed ball valve 11 / flanged pressure transmitter 1 / stainless steel three-way valve 2 / miniature air pump 12);

[0131] 12.2 Calculate the required air pressure ;

[0132] 12.3 Adjust the air pump pressure to the target value;

[0133] Phase 3: Accelerated life testing is conducted;

[0134] 13. Remove the pressure assembly, close the sealing ball valve 11, and install the explosion-proof plug 15;

[0135] 14. The constant temperature chamber is heated to the target temperature (85 / 105 / 125℃).

[0136] 15. Start real-time monitoring:

[0137] Loop begins:

[0138] 15.1 Collect temperature and humidity data to ensure that at least one cycle of detection is completed every hour, that is, each sensor outputs at least one set of data per hour to ensure the continuity of accelerated life test data.

[0139] 15.2 Calculation of internal water vapor content IV:

[0140] 15.3 Data Transmission:

[0141] FPC signal transmission board 10 converts I²C to RS485 protocol;

[0142] Signal group control board 14 displays and stores data in real time;

[0143] 15.4 Failure Detection:

[0144] Yes (IV ≥5000 ppm for 3 consecutive times) → 16. Determine if the airtightness has failed;

[0145] No → Return to the beginning of the loop;

[0146] 16. Terminate the test and issue an alarm;

[0147] Phase 4: Post-experiment verification;

[0148] 17. Helium mass spectrometry re-detection leak rate (verification of failure criteria);

[0149] 18. Data Analysis:

[0150] Quantifying the impact of humidity / pressure difference on failure time;

[0151] Establish a microcrack propagation model.

[0152] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A non-destructive continuous testing method for accelerated testing of the airtightness of metal / glass sealed structures, characterized in that, The method includes the following steps: S1. The temperature and humidity sensor is encapsulated inside the metal / glass insulator sealing structure through the FPC sensor circuit board to construct a test cavity. The temperature and humidity electrical signals inside the test cavity are transmitted to the external signal group control board through the lead post. S2. Place the test chamber into the accelerated life test chamber and apply temperature, humidity and pressure differential stress to the test chamber simultaneously during the accelerated life test. S3. The signal group control board calculates the water vapor content (IV) inside the test chamber in real time. When IV is ≥5000 ppm for 3 consecutive tests, the airtightness is determined to be faulty. The process of applying humidity stress to the test chamber during the accelerated life test in step S2 is as follows: a trace amount of liquid water is pre-added to the accelerated chamber. The amount of liquid water added is calculated according to the following formula to ensure that it is entirely in the form of water vapor after the accelerated life test is carried out: In the formula, The gas constant is... The molar mass of water, To increase the water vapor content inside the cavity during accelerated life testing; The process of applying differential pressure stress to the test chamber during the accelerated life test in step S2 is as follows: After adding a trace amount of liquid water, the accelerated chamber is pressurized or depressurized according to the preset differential pressure stress, and the pressurization or depressurization amount is calculated using the following formula: In the formula, This represents the charging or depressurization amount; a positive value represents charging and a negative value represents depressurization. The initial gas pressure of the acceleration chamber before the accelerated life test; In step S3, the water vapor content IV inside the test chamber is obtained using the following formula: In the formula, To test the real-time relative humidity inside the chamber during accelerated life testing; To test the real-time temperature inside the chamber during accelerated life testing; This represents the saturated vapor pressure of water vapor at the current temperature. The initial air pressure of the test chamber is set to atmospheric pressure. To test the initial temperature inside the chamber before accelerated life testing; This refers to the pressure difference between the acceleration chamber and the test chamber during accelerated life testing.

2. The non-destructive continuous testing method for accelerated airtightness testing of metal / glass sealing structures according to claim 1, characterized in that, The process of applying temperature stress to the test chamber during the accelerated life test in step S2 is as follows: After applying differential pressure stress, the accelerated chamber is placed in a constant temperature chamber. Temperature stress is applied using the constant temperature chamber, and the temperature of the entire device is raised through the constant temperature chamber. A small amount of liquid water is added to the accelerated chamber before vaporization to reach the preset temperature, humidity, and differential pressure. The temperature and humidity sensors installed in the accelerated chamber detect the temperature and humidity data in real time and transmit them to the signal group control board.

3. The non-destructive continuous testing method for accelerated airtightness testing of metal / glass sealing structures according to claim 1, characterized in that, In accelerated testing, any one of the stress factors—temperature stress, humidity stress, and differential pressure stress—must be at least two levels.

4. A non-destructive continuous testing device for accelerated testing of the airtightness of metal / glass sealed structures, the device being used to implement the method described in any one of claims 1-3, characterized in that, The device includes a test chamber, an acceleration chamber, and a control unit; the test chamber is placed inside the acceleration chamber, and the acceleration chamber provides the test chamber with temperature stress, humidity stress, and differential pressure stress; Control unit: including FPC signal transmission board (10) and signal group control board (14); Test chamber: includes a first temperature and humidity sensor (7), an FPC sensor circuit board (8) and a metal / glass insulator sealing structure (9). The first temperature and humidity sensor (7) is sealed into the metal / glass insulator sealing structure (9) through the FPC sensor circuit board (8) to construct the test chamber; the temperature and humidity electrical signals of the test chamber are transmitted to the signal group control board (14) through the FPC signal transmission board (10). Acceleration chamber: includes pressure vessel top cover (3), silicone rubber sealing structure (4), flanged pressure vessel (5), second temperature and humidity sensor (6), constant temperature chamber (13) and differential pressure stress loading unit; the flanged pressure vessel (5) is placed in the constant temperature chamber (13), the pressure vessel top cover (3) seals the upper opening of the flanged pressure vessel (5) through the silicone rubber sealing structure (4), and the second temperature and humidity sensor (6) is sealed inside the acceleration chamber. The differential pressure stress loading unit includes a flange-type pressure transmitter (1), a stainless steel three-way valve (2), a sealing ball valve (11), a micro air pump (12), and an explosion-proof plug (15). The pressure vessel tank top cover (3) has a central through hole, at which the sealing ball valve (11) is installed. The sealing ball valve (11) is connected to one interface of the stainless steel three-way valve (2). The other two interfaces of the stainless steel three-way valve (2) are connected to the flange-type pressure transmitter (1) and the micro air pump (12) respectively. The micro air pump (12) fills or evacuates air into the acceleration chamber to realize the increase or decrease of air pressure in the acceleration chamber. The flange-type pressure transmitter (1) monitors the internal pressure of the acceleration chamber in real time. When the preset differential pressure stress is reached, the sealing ball valve (11) is closed. The flange-type pressure transmitter (1), the stainless steel three-way valve (2), and the micro air pump (12) are disassembled, and the explosion-proof plug (15) is installed on the external interface of the sealing ball valve (11).

5. The non-destructive continuous testing device for accelerated testing of the airtightness of metal / glass sealing structures according to claim 4, characterized in that, The thickness of the FPC signal transmission board (10) is not less than 100μm and the bending radius is ≥5mm. One end of the FPC signal transmission board (10) is connected to the temperature and humidity sensor encapsulated in the test chamber by soldering. The other end of the FPC signal transmission board (10) passes through the side wall of the acceleration chamber and is electrically connected to the external signal group control board (14). The connection between the FPC signal transmission board (10) and the side wall of the acceleration chamber is sealed with silicone rubber. The sealing method is as follows: the FPC signal transmission board (10) is first passed through the silicone rubber sealing ring at the connection. After fixing the silicone rubber sealing ring to the groove of the pressure vessel tank top cover (3), liquid silicone rubber with a thickness of not less than 4mm is applied to both sides of the silicone rubber sealing ring for sealing protection. Vacuum silicone grease is applied to the contact surface between the FPC signal transmission board (10) and the silicone rubber sealing ring.

6. The non-destructive continuous testing device for accelerated testing of the airtightness of metal / glass sealing structures according to claim 4, characterized in that, The pressure vessel tank top cover (3) has a groove on the lower surface to cover the tank body. A silicone rubber ring is placed in the groove. When the tank is closed, it is squeezed and liquid silicone rubber is applied at the connection. Vacuum silicone grease is applied to the contact surface between the tank body and the silicone rubber ring to maintain a sealed structure around the tank.

7. The non-destructive continuous testing device for accelerated testing of the airtightness of metal / glass sealing structures according to claim 4, characterized in that, The method of providing humidity stress to the accelerated chamber is as follows: before installing the sealing ball valve (11), a small amount of liquid water is added to the interior through the central through hole of the pressure vessel tank top cover (3) so that it is completely vaporized and reaches the preset humidity during the accelerated life test.

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