Helium mass spectrometer leak detector and helium leak detection method

Abstract

The application belongs to the technical field of vacuum leak detection, and particularly discloses a helium mass spectrometric leak detector and a helium spraying leak detection method. In the helium mass spectrometric leak detector, the sampling port of the mechanical pump is communicated with the first outlet of the mass spectrometric system, the second outlet of the cover body and the third outlet of the device to be detected through multiple pipelines. When the sampling signal is transmitted to the mechanical pump in the control terminal, the mechanical pump is in a working state to realize vacuumizing treatment on the first outlet, the second outlet, the third outlet and the pipeline, reduce the helium content in the air in the helium mass spectrometric leak detector, and reduce the influence of the helium in the air on the leak rate of the leak hole to be detected when helium is sprayed to the leak hole to be detected, thereby improving the accuracy of the leak hole detection leak rate.

Description

Technical Field

[0001] This invention relates to the field of vacuum leak detection technology, specifically to a helium mass spectrometer leak detector and a helium spray leak detection method. Background Technology

[0002] Vacuum devices operating in a vacuum environment have varying requirements for the vacuum level of the environment. Besides the performance of various vacuum pumps, the sealing between devices is also a crucial factor affecting the vacuum level. Since "absolute vacuum" cannot be obtained in nature, there will always be a certain number of leaks after devices are assembled. Therefore, before a vacuum device can operate, its vacuum operating environment must be leak-tested to ensure the required vacuum level and minimum permissible leak rate for normal operation.

[0003] Helium is widely used as a detection gas in instruments for leak detection in vacuum environments due to its small molecular size, light weight, ease of passage through tiny leaks, chemical stability, and non-toxicity. Furthermore, mass spectrometers offer high specificity and accuracy in qualitative and quantitative analysis of pure substances, allowing real-time determination of substance type and concentration. Therefore, cascading a mass spectrometer with the vacuum environment to be tested allows for the detection of helium levels flowing in through leaks. Through mathematical calculations, the leakage rate at the corresponding leak can be determined. Thus, helium mass spectrometry leak detectors have become essential instruments for detecting vacuum environments.

[0004] Existing helium mass spectrometry leak detectors are mostly of a separate structure, meaning the detection system containing the mass spectrometer and the helium sprayer are installed separately. This results in inconsistent helium amounts being sprayed onto different leak points during testing, leading to inaccurate detection results. Specifically, helium mass spectrometry leak detectors calculate the leak rate at each leak point based on the ion abundance at the corresponding mass-to-charge ratio of helium. However, the environment of each leak point and the amount of helium sprayed will affect the amount of helium entering the mass spectrometer to varying degrees. If external conditions change, the leak detection standards cannot be standardized, resulting in differences in the obtained ion abundance and inaccurate leak rates detected for each leak point. Summary of the Invention

[0005] Therefore, the present invention provides a helium mass spectrometer leak detector and a leak detection method to solve the problem of inaccurate detection of leak rates in the prior art.

[0006] Specifically, the present invention provides a helium mass spectrometer leak detector, comprising:

[0007] Mass spectrometry system;

[0008] The helium-spraying assembly includes at least a cover for covering the leak hole to be tested in the device under test.

[0009] The vacuum assembly includes at least a mechanical pump, which has a sampling port that is connected to a first outlet of the mass spectrometry system, a second outlet of the enclosure, and a third outlet of the device under test via multiple pipes.

[0010] A control terminal is communicatively connected to the mechanical pump and is used to transmit sampling signals to the mechanical pump to put the mechanical pump into operation.

[0011] Optionally, in the above-mentioned helium mass spectrometer leak detector, the helium injection assembly further includes:

[0012] A helium storage device, wherein the helium outlet of the helium storage device is connected to the second outlet of the enclosure through a first pipe for supplying helium to the enclosure;

[0013] A pressure reducing valve is installed in the first pipeline and is located between the cover and the helium storage device. The pressure reducing valve is communicatively connected to a control terminal.

[0014] A flow meter is installed in the first pipeline and is located on the side of the pressure reducing valve away from the helium storage element. The flow meter is communicatively connected to a control terminal.

[0015] A venting solenoid valve is installed on the first pipeline and is located near the cover. The venting solenoid valve is communicatively connected to a control terminal.

[0016] The first vacuum gauge is installed on the first pipeline and is located near the cover. The first vacuum gauge is communicatively connected to the control terminal.

[0017] Optionally, the above-mentioned helium mass spectrometer leak detector,

[0018] The sampling port of the mechanical pump is connected to the third outlet of the device under test through a second pipe;

[0019] The helium mass spectrometer leak detector also includes a leak detection component, which includes:

[0020] An isolation solenoid valve is installed on a second pipeline and is communicatively connected to a control terminal.

[0021] The second vacuum gauge is installed in the second pipeline and is located near the third outlet of the device under test. The second vacuum gauge is communicatively connected to the control terminal.

[0022] Optionally, the above-mentioned helium mass spectrometer leak detector,

[0023] The first and second pipes are connected by a third pipe;

[0024] The helium mass spectrometer leak detector also includes an auxiliary solenoid valve, which is installed in a third pipeline and is communicatively connected to a control terminal.

[0025] Optionally, the above-mentioned helium mass spectrometer leak detector,

[0026] The helium mass spectrometer leak detector also includes a venting solenoid valve, which is installed in the second pipeline and is communicatively connected to the control terminal.

[0027] Optionally, the above-mentioned helium mass spectrometer leak detector,

[0028] The sampling port of the mechanical pump is connected to the first outlet of the mass spectrometry system via a fourth pipe;

[0029] The vacuum pumping assembly also includes:

[0030] A molecular pump is installed in a fourth conduit and is located between the mass spectrometry system and the mechanical pump. The molecular pump is communicatively connected to a control terminal.

[0031] The system includes a pre-evacuation solenoid valve, a mass spectrometry solenoid valve, and a third vacuum gauge. All three are installed in a fourth pipeline. The pre-evacuation solenoid valve is located between the molecular pump and the mechanical pump. The mass spectrometry solenoid valve is located between the mass spectrometry system and the molecular pump. The third vacuum gauge is located near the first outlet of the mass spectrometry system. All three are communicatively connected to a control terminal.

[0032] Optionally, the aforementioned helium mass spectrometer leak detector further includes a coarse detection solenoid valve, a fine detection solenoid valve, and an ultra-fine detection solenoid valve arranged in parallel. The coarse detection solenoid valve is installed in the fifth pipeline. The coarse detection solenoid valve, the fine detection solenoid valve, and the ultra-fine detection solenoid valve are all communicatively connected to a control terminal. One end of the fifth pipeline is connected to the second pipeline, and the other end of the fifth pipeline is connected to the fourth pipeline. The other end of the fifth pipeline is located between the pre-pump solenoid valve and the mechanical pump. The fine detection solenoid valve is installed in the sixth pipeline. One end of the sixth pipeline is connected to the second pipeline, and the other end of the sixth pipeline is connected to the fourth pipeline. The other end of the sixth pipeline is located near the outlet of the molecular pump. The ultra-fine detection solenoid valve is installed in the seventh pipeline. One end of the seventh pipeline is connected to the second pipeline, and the other end of the seventh pipeline is connected to the fourth pipeline. The other end of the seventh pipeline is located near the inlet of the molecular pump.

[0033] A helium-spraying leak detection method, applied to the aforementioned helium mass spectrometer leak detector, wherein the helium-spraying leak detection method includes:

[0034] Step S1: Move the shield until it covers the leak to be tested, start the mechanical pump and molecular pump to evacuate the mass spectrometry system, the shield and the circuit containing the device under test;

[0035] Step S2: After the vacuum levels displayed by the first and second vacuum gauges have stabilized, helium is injected into the leak hole to be tested.

[0036] Step S3: The mass spectrometry system detects the leakage rate of the current leak in the test hole in real time and feeds it back to the control terminal. The control terminal records and plots the leakage rate curve, and then calculates the leakage rate.

[0037] Step S4: Repeat steps S1 to S3 until the leakage rate of all the leaks to be tested is completed.

[0038] Optionally, the above-described helium injection leak detection method further includes, during step S1 or step S3:

[0039] Step S5: Based on the vacuum level detected by the first vacuum gauge and the second vacuum gauge, open the coarse inspection solenoid valve, the fine inspection solenoid valve and the ultra-fine inspection solenoid valve in stages;

[0040] In step S5, a first threshold, a second threshold, and a third threshold are preset at the first vacuum gauge and the second vacuum gauge, respectively, as the starting conditions for the coarse inspection solenoid valve, the fine inspection solenoid valve, and the ultra-fine inspection solenoid valve.

[0041] Optionally, the above-described helium injection leak detection method, after completing step S4, further includes:

[0042] Step S6: The helium mass spectrometer leak detector is removed from the vacuum environment.

[0043] The technical solution provided by this invention has the following advantages:

[0044] The helium mass spectrometer leak detector provided by this invention includes a mass spectrometry system, a helium injection assembly, a vacuum pumping assembly, and a control terminal. The helium injection assembly includes at least a housing for covering the leak hole of the device under test (DUT). The vacuum pumping assembly includes at least a mechanical pump with a sampling port connected via multiple pipes to a first outlet of the mass spectrometry system, a second outlet of the housing, and a third outlet of the DUT. The control terminal is communicatively connected to the mechanical pump and transmits sampling signals to the mechanical pump to activate it.

[0045] This helium mass spectrometer leak detector connects the sampling port of the mechanical pump to the first outlet of the mass spectrometer system, the second outlet of the housing, and the third outlet of the device under test through multiple pipes. When the control terminal transmits the sampling signal to the mechanical pump, the mechanical pump is in operation to perform vacuum treatment on the first, second, and third outlets and the pipes, reducing the helium content in the air of the helium mass spectrometer leak detector. When helium is injected into the leak hole to be tested, the influence of helium in the air on the leak rate of the leak hole is reduced, thus improving the accuracy of leak detection. Attached Figure Description

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the structure of a helium mass spectrometer leak detector provided in Embodiment 1 of the present invention;

[0048] Figure 2 This is a flowchart illustrating the helium injection leak detection method provided in Embodiment 2 of the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Mass spectrometry system; 101-First outlet;

[0051] 21-Shell; 211-Second outlet; 22-Helium storage unit; 221-Helium outlet; 23-Pressure reducing valve; 24-Flow meter; 25-Ventilation solenoid valve; 26-First vacuum gauge;

[0052] 31-Mechanical pump; 311-Sampling port; 32-Molecular pump; 33-Pre-pump solenoid valve; 34-Mass spectrometer solenoid valve; 35-Third vacuum gauge;

[0053] 41-First pipe; 42-Second pipe; 43-Third pipe; 44-Fourth pipe; 45-Fifth pipe; 46-Sixth pipe; 47-Seventh pipe;

[0054] 51-Isolation solenoid valve; 52-Second vacuum gauge;

[0055] 61-Auxiliary solenoid valve; 62-Vent solenoid valve;

[0056] 71-Coarse inspection solenoid valve; 72-Fine inspection solenoid valve; 73-Ultra-fine inspection solenoid valve;

[0057] 81 - Standard leakage solenoid valve; 82 - Standard leakage orifice;

[0058] 9 - Device under test; 901 - Third outlet. Detailed Implementation

[0059] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0063] Example 1

[0064] This embodiment provides a helium mass spectrometer leak detector, such as Figure 1 As shown, the system includes a mass spectrometry system 1, a helium injection assembly, a vacuum pumping assembly, and a control terminal. The helium injection assembly includes at least a housing 21, which covers the leak point of the device under test (DUT) 9. The vacuum pumping assembly includes at least a mechanical pump 31, which has a sampling port 311. The sampling port 311 is connected to the first outlet 101 of the mass spectrometry system 1, the second outlet 211 of the housing 21, and the third outlet 901 of the DUT 9 via multiple pipes. The control terminal is communicatively connected to the mechanical pump 31 and is used to transmit sampling signals to the mechanical pump 31 to activate it.

[0065] The helium mass spectrometer leak detector provided in the above embodiment connects the sampling port 311 of the mechanical pump 31 to the first outlet 101 of the mass spectrometer system 1, the second outlet 211 of the housing 21, and the third outlet 901 of the device under test 9 through multiple pipes. When the control terminal transmits the sampling signal to the mechanical pump 31, the mechanical pump 31 is in working state to achieve vacuum treatment of the first outlet 101, the second outlet 211, the third outlet 901, and the pipes, thereby reducing the helium content in the air in the helium mass spectrometer leak detector. When helium is sprayed into the leak hole to be tested, the helium detected by the mass spectrometer system 1 is a portion of the helium sprayed into the leak hole to be tested, reducing the influence of the helium in the air on the leak rate of the leak hole to be tested and improving the accuracy of the leak detection rate.

[0066] It can be noted that, in the above embodiments, the mechanical pump 31 can be selected with a pumping speed range of 4L / s to 10L / s, depending on the requirements of the cleanliness of the detection environment, the detection speed, and the detection accuracy. Specifically, the mechanical pump 31 can be a dry vacuum pump, an oil vacuum pump, etc., but to ensure the accuracy of the detection results, a dry vacuum pump with strong anti-interference ability can be selected.

[0067] It can be noted that, in the above embodiments, to ensure the cleanliness of the helium mass spectrometer leak detector, filtration devices are provided at both the second outlet 211 and the third outlet 901. These devices may include reflux filters, circulation filters, air filters, and dust filters, which can be selected according to the specific application scenario. As one implementation method, an air filter is chosen to prevent dust and other substances from contaminating the instrument and to remove water vapor, thus avoiding corrosion of instrument components.

[0068] It can be noted that, in the above embodiments, in order to prevent the backflow of ambient gas into the helium mass spectrometer leak detector, a one-way air intake device, such as a one-way valve, can be added to the sampling port 311 of the mechanical pump 31.

[0069] It can be noted that the helium mass spectrometer leak detector provided in this embodiment uses a deformable, dense material to make the cover 21. For example, in this embodiment, a shape memory polymer, such as an epoxy-based shape memory polymer, a cyanate-based shape memory polymer, a polyimide-based shape memory polymer, or a styrene-based shape memory polymer, is used. Of course, in other alternative embodiments, silicone can also be used. This can adapt to the usage requirements of leaks in different shapes of devices under test 9 in different detection environments, ensuring that the leak under test is completely covered by the cover 21, obtaining a stable vacuum degree while maintaining the consistency of detection conditions.

[0070] like Figure 1As shown, the helium mass spectrometer leak detector provided in this embodiment includes a helium storage unit 22, a pressure reducing valve 23, a flow meter 24, a solenoid valve 25, and a first vacuum gauge 26 to realize the helium injection process for the leak to be tested. The second outlet 211 serves as the interface for helium to enter the enclosure 21. The helium outlet 221 of the helium storage unit 22 is connected to the second outlet 211 of the enclosure 21 via a first pipe 41 to supply helium to the enclosure 21. The pressure reducing valve 23 is installed in the first pipe 41 and is located between the enclosure 21 and the helium storage unit 22 to reduce the pressure of the helium flowing out of the helium storage unit 22. The pressure reducing valve 23 is communicatively connected to a control terminal. The flow meter 24 is installed in the first pipe 41 and is located away from the pressure reducing valve 23 from the helium storage unit. On one side of component 22, flow meter 24 is connected to control terminal; venting solenoid valve 25 is installed on the first pipe 41 and is located near the cover 21. Venting solenoid valve 25 is connected to control terminal and is used to control whether helium flows to cover 21 during helium injection; first vacuum gauge 26 is installed on the first pipe 41 and is located near cover 21. First vacuum gauge 26 is connected to control terminal and is used to display the vacuum level at cover 21.

[0071] It can be noted that in the helium mass spectrometer leak detector provided in this embodiment, the sampling port 311 of the mechanical pump 31 is connected to the third outlet 901 of the device under test 9 through the second pipe 42; the helium mass spectrometer leak detector also includes a leak detection component, which includes an isolation solenoid valve 51 and a second vacuum gauge 52. The isolation solenoid valve 51 is installed in the second pipe 42 and is communicatively connected to the control terminal. The isolation solenoid valve 51 is used to control whether air or helium inside the device under test 9 flows into the second pipe 42; the second vacuum gauge 52 is installed in the second pipe 42 and is located close to the third outlet 901 of the device under test 9. The second vacuum gauge 52 is communicatively connected to the control terminal and is used to display the vacuum level at the device under test 9.

[0072] Furthermore, in the helium mass spectrometer leak detector provided in this embodiment, the first pipe 41 and the second pipe 42 are connected through a third pipe 43; the helium mass spectrometer leak detector also includes an auxiliary solenoid valve 61, which is installed in the third pipe 43 and is communicatively connected to a control terminal, used to connect or disconnect the first pipe 41 and the second pipe 42.

[0073] Similarly, the helium mass spectrometer leak detector provided in this embodiment also includes a venting solenoid valve 62, which is installed in the second pipeline 42 and is connected to the control terminal for communication. It is used to open when the vacuum environment is removed, and then the cover 21 at the leak to be tested is removed.

[0074] like Figure 1As shown, in the helium mass spectrometer leak detector provided in this embodiment, the sampling port 311 of the mechanical pump 31 is connected to the first outlet 101 of the mass spectrometry system 1 through the fourth pipe 44. Simultaneously, to achieve a higher cleanliness of the helium detection environment, i.e., to make the helium detection environment closer to a vacuum environment, the vacuum pumping assembly also includes a molecular pump 32, a pre-evacuation solenoid valve 33, a mass spectrometry solenoid valve 34, and a third vacuum gauge 35. The molecular pump 32 is installed in the fourth pipe 44 and is located between the mass spectrometry system 1 and the mechanical pump 31. The molecular pump 32 is communicatively connected to the control terminal. The pre-evacuation solenoid valve 33, the mass spectrometry solenoid valve 34, and the third vacuum gauge 35... All vacuum gauges 35 are installed in the fourth pipe 44. The pre-evacuation solenoid valve 33 is located between the molecular pump 32 and the mechanical pump 31 and is used to control the extraction of air or residual helium. The mass spectrometry solenoid valve 34 is located between the mass spectrometry system 1 and the molecular pump 32 and is used to control the direction of helium flow into the test device 9 at the test leak during helium injection, and whether it flows into the mass spectrometry system 1. The third vacuum gauge 35 is located near the first outlet 101 of the mass spectrometry system 1 and is used to display the vacuum level at the mass spectrometry system 1. The pre-evacuation solenoid valve 33, the mass spectrometry solenoid valve 34 and the third vacuum gauge 35 are all connected to the control terminal.

[0075] It can be noted that the helium mass spectrometer leak detector provided in this embodiment can use a vacuum pump with a pumping speed range of 60L / s to 100L / s, depending on the requirements of the cleanliness of the detection environment, the detection speed, and the detection accuracy.

[0076] It can be noted that the helium mass spectrometer leak detector provided in this embodiment also includes a coarse detection solenoid valve 71, a fine detection solenoid valve 72, and an ultra-fine detection solenoid valve 73 arranged in parallel. The coarse detection solenoid valve 71 is installed in the fifth pipe 45. The coarse detection solenoid valve 71, the fine detection solenoid valve 72, and the ultra-fine detection solenoid valve 73 are all communicatively connected to the control terminal. One end of the fifth pipe 45 is connected to the second pipe 42, and the other end of the fifth pipe 45 is connected to the third pipe 43. The other end of the fifth pipe 45 is located between the pre-extraction solenoid valve 33 and the mechanical pump 31. The fine detection solenoid valve 72 is installed in the sixth pipe 46. One end of the sixth pipe 46 is connected to the second pipe 42, and the other end of the sixth pipe 46 is connected to the third pipe 43. The other end of the sixth pipe 46 is located near the outlet of the molecular pump 32. The ultra-fine detection solenoid valve 73 is installed in the seventh pipe 47. One end of the seventh pipe 47 is connected to the second pipe 42, and the other end of the seventh pipe 47 is connected to the third pipe 43. The other end of the seventh pipe 47 is located near the inlet of the molecular pump 32.

[0077] It should be noted that in the above embodiments, the first vacuum gauge 26 and the second vacuum gauge 52 are thin-film vacuum gauges, and the third vacuum gauge 35 is a composite vacuum gauge with a wide measurement range and high accuracy, such as an ionization and thermal Euler-type composite vacuum gauge.

[0078] It can be noted that the helium mass spectrometer leak detector provided in this embodiment also includes a standard leak solenoid valve 81 and a standard leak orifice 82. One end of the standard leak solenoid valve 81 is connected to the second pipe 42, and the other end of the standard leak solenoid valve 81 extends through a pipe to the standard leak orifice 82 for leak rate calibration.

[0079] Example 2

[0080] This embodiment provides a helium injection leak detection method, which is applied to the helium mass spectrometer leak detector provided in Embodiment 1.

[0081] like Figure 2 As shown, the helium injection leak detection method provided in this embodiment includes:

[0082] Step S1: Move the cover 21 until it covers the leak hole to be tested, start the mechanical pump 31 and the molecular pump 32 to perform vacuum treatment on the circuit where the mass spectrometry system 1, the cover 21 and the device under test 9 are located;

[0083] Step S2: After the vacuum levels displayed by the first vacuum gauge 26 and the second vacuum gauge 52 have stabilized, helium is injected into the leak hole to be tested.

[0084] Step S3: The mass spectrometry system 1 detects the leakage rate of the current leak in the test hole in real time and feeds it back to the control terminal. The control terminal records and plots the leakage rate curve, and then calculates the leakage rate.

[0085] Step S4: Repeat steps S1 to S3 until the leakage rate of all the leaks to be tested is completed.

[0086] It can be noted that the purpose of step S1 in the helium leak detection method provided in this embodiment is to perform vacuuming before helium detection, which specifically includes:

[0087] Step S101: Start the mechanical pump 31, mass spectrometer solenoid valve 34, pre-extraction solenoid valve 33, coarse inspection solenoid valve 71, fine inspection solenoid valve 72, ultra-fine inspection solenoid valve 73, auxiliary solenoid valve 61 and flow meter 24 to initially extract interfering or impurity gases from each pipeline and chamber.

[0088] Step S102: When the value of the third vacuum gauge 35 is less than 0.1 Pa, start the molecular pump 32 to further extract the interfering gas or impurity gas in each pipeline and chamber to improve the cleanliness of the helium detection environment until the vacuum level of the helium detection environment meets the requirements.

[0089] Step S103: Move the cover 21 until it covers the first leak hole to be tested. Then close the pre-vacuum solenoid valve 33, the fine inspection solenoid valve 72 and the ultra-fine inspection solenoid valve 73. Then open the coarse inspection solenoid valve 71, the isolation solenoid valve 51, the auxiliary solenoid valve 61 and the ventilation solenoid valve 25. The mechanical pump 31 performs vacuuming treatment on the device to be tested and the cover 21.

[0090] It should be noted that in the helium spray leak detection method provided in this embodiment, step S103 can be performed before step S101 or after step S102. As one implementation method, step S103 is performed after step S102 is completed.

[0091] It can be noted that the helium injection leak detection method provided in this embodiment further includes the following steps during step S1 or S3:

[0092] Step S5: Based on the vacuum level detected by the first vacuum gauge 26 and the second vacuum gauge 52, open the coarse inspection solenoid valve 71, the fine inspection solenoid valve 72 and the ultra-fine inspection solenoid valve 73 in stages.

[0093] In step S5, a first threshold, a second threshold, and a third threshold are preset at the first vacuum gauge 26 and the second vacuum gauge 52, respectively, as the activation conditions for the coarse inspection solenoid valve 71, the fine inspection solenoid valve 72, and the ultra-fine inspection solenoid valve 73.

[0094] Further, setting the first threshold > second threshold > third threshold, during step S1, the values ​​of the first vacuum gauge 26 and the second vacuum gauge 52 gradually decrease until they fall below the first threshold. At this point, the pre-extraction solenoid valve 33 and the coarse inspection solenoid valve 71 are activated, while the fine inspection solenoid valve 72 and the ultra-fine inspection solenoid valve 73 are closed, causing the helium mass spectrometer leak detector to enter the coarse inspection state. When the values ​​of the first vacuum gauge 26 and the second vacuum gauge 52 fall below the second threshold, the pre-extraction solenoid valve 33 and the fine inspection solenoid valve 72 are activated, while the coarse inspection solenoid valve 71 and the ultra-fine inspection solenoid valve 73 are closed, causing the helium mass spectrometer leak detector to enter the fine inspection state. When the values ​​of the first vacuum gauge 26 and the second vacuum gauge 52 fall below the third threshold, the pre-extraction solenoid valve 33 and the ultra-fine inspection solenoid valve 73 are activated, while the coarse inspection solenoid valve 71 and the fine inspection solenoid valve 72 are closed, causing the helium mass spectrometer leak detector to enter the ultra-fine inspection state.

[0095] It should be noted that in this embodiment, the values ​​of the first threshold, the second threshold, and the third threshold are not limited, and can be determined according to the actual helium detection requirements. As one implementation method, the first threshold is set to 1800 Pa, the second threshold to 300 Pa, and the third threshold to 50 Pa.

[0096] Of course, in this embodiment, if the actual requirement does not necessitate the helium mass spectrometer leak detector sequentially entering the coarse detection state, fine detection state, and ultra-fine detection state, a judgment condition should be added to the control terminal. For example, if the helium mass spectrometer leak detector maintains a certain helium detection state for a certain period of time, then step S2 is performed.

[0097] Furthermore, in this embodiment, the duration for which the helium mass spectrometer leak detector remains in a certain helium detection state is not limited, and can be adjusted according to actual needs. For example, if the helium mass spectrometer leak detector remains in a coarse detection state, fine detection state, or ultra-fine detection state for more than 5 seconds, step S2 is performed.

[0098] It can be noted that in the helium injection leak detection method provided in this embodiment, the purpose of step S2 is to inject helium, which specifically includes:

[0099] Step S201: The helium mass spectrometer leak detector is stably in a certain helium detection state;

[0100] Step S202: Close the auxiliary solenoid valve 61, open the pressure reducing valve 23 and flow meter 24, and supply helium to one side of the cover 21 according to the set flow value until the helium is sprayed towards the leak hole to be detected.

[0101] Step S203: Start the mass spectrometry system 1. The helium gas entering the device under test 9 at the leak detection point will pass through the third outlet 901 and then through the pipeline where the coarse detection solenoid valve 71, fine detection solenoid valve 72, or ultra-fine detection solenoid valve 73 is located, and enter the fourth pipeline 44 until it enters the helium detection port of the mass spectrometry system 1 to detect the leak rate of the leak detection point.

[0102] It should be noted that in this embodiment, the helium detection port and the first outlet 101 are the same interface; of course, in other optional embodiments, the helium detection port and the first outlet 101 are set separately.

[0103] Specifically, in the helium injection leak detection method provided in this embodiment, in step S203, the helium injection process is maintained for a period of time, that is, when the helium injection time before helium detection reaches the set value, the ventilation solenoid valve 25, flow meter 24 and pressure reducing valve 23 are closed. When the leak rate detected by the mass spectrometry system 1 is relatively stable, for example, when the numerical deviation of the leak rate within 5 seconds is 0.1%, the average leak rate during the stable period is taken as the leak rate value of the current leak to be tested. Since this value is a value that removes external interference, the detection result is more accurate.

[0104] Similarly, in this embodiment, if the selected device under test 9 has good pressure resistance, the condition for stopping helium injection can also be: when the reading of the first vacuum gauge 26 is greater than the reading of the second vacuum gauge 52, and the ratio of the reading of the first vacuum gauge 26 to the reading of the second vacuum gauge 52 is the fourth threshold, the solenoid valve 25, the flow meter 24 and the pressure reducing valve 23 are closed. When the leak rate detected by the mass spectrometry system 1 is relatively stable, for example, when the numerical deviation of the leak rate within 5 seconds is 0.1%, the average leak rate during the stable period is taken as the leak rate value of the current leak hole under test.

[0105] It should be noted that in this embodiment, the value of the fourth threshold is not limited. For example, the fourth threshold is 10, which means that the reading of the first vacuum gauge 26 is 10 times the reading of the second vacuum gauge 52.

[0106] It can be explained that, in the helium injection leak detection method provided in this embodiment, when performing step S4, after completing the leak rate detection of any leak hole to be tested, if it is necessary to detect the leak rate of the next leak hole to be tested, when the value of the first vacuum gauge 26 is less than 10 Pa, the coarse detection solenoid valve 71 is closed, and the pre-evacuation solenoid valve 33 and the venting solenoid valve 62 are opened, so that the cover 21 can be separated from the device under test 9. When the value of the first vacuum gauge 26 is 1 MPa (1 atmosphere), the venting solenoid valve 62, the auxiliary solenoid valve 61 and the ventilation solenoid valve 25 are immediately closed to avoid excessive pollution of the instrument interior by the atmospheric environment, which would cause errors in the detection results. Then, steps S1 to S3 are repeated until the leak rate detection of all leak holes to be tested is completed.

[0107] Furthermore, in this embodiment, after completing the detection of all leaks in any device under test 9, if it is necessary to replace the device under test 9, the replacement process is as follows: when the value of the first vacuum gauge 26 is less than 10 Pa, close the coarse inspection solenoid valve 71 and open the pre-extraction solenoid valve 33, the isolation solenoid valve 51 and the venting solenoid valve 62, so that the device under test 9 can be removed from the leak detection port and the cover 21 can be removed from the device under test 9. When the value of the first vacuum gauge 26 is 1 MPa (1 atmosphere), immediately close the isolation solenoid valve 51, the venting solenoid valve 62, the auxiliary solenoid valve 61 and the ventilation solenoid valve 25 to avoid excessive pollution of the instrument interior by the atmospheric environment, which would cause errors in the detection results. Then replace the next device under test 9, and then repeat steps S1 to S3 to complete the detection process of the device under test 9. Repeat this replacement process until all devices under test 9 have been tested.

[0108] It can be noted that, after completing step S4, the helium injection leak detection method provided in this embodiment further includes:

[0109] Step S6: The helium mass spectrometer leak detector is removed from the vacuum environment.

[0110] Specifically, the helium injection leak detection method provided in this embodiment includes step S6 as follows: after completing the leak rate detection of a certain leak hole to be tested, the mass spectrometry system 1, the precision detection solenoid valve 72, the ultra-precision detection solenoid valve 73 and the isolation solenoid valve 51 are closed, and the auxiliary solenoid valve 61 and the ventilation solenoid valve 25 are opened to extract the residual helium gas in the enclosure 21; after the extraction of residual helium gas is completed, if the molecular pump 32 is in working state, the molecular pump 32 is turned off. After the molecular pump 32 stops working, the pre-sampling solenoid valve, the auxiliary solenoid valve 61, the ventilation solenoid valve 25 and the mechanical pump 31 are closed.

[0111] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A helium mass spectrometer leak detector, characterized in that, include: Mass spectrometry system (1); The helium injection assembly includes at least a cover (21), a venting solenoid valve (25), a first vacuum gauge (26), and a helium storage unit (22). The cover (21) is used to cover the leak hole of the device under test (9). The venting solenoid valve (25) is installed on the first pipe (41) and is located on the side close to the cover (21). The venting solenoid valve (25) is connected to the control terminal. The first vacuum gauge (26) is installed on the first pipe (41) and is located on the side close to the cover (21). The first vacuum gauge (26) is connected to the control terminal. The helium outlet (221) of the helium storage unit (22) is connected to the second outlet (211) of the cover (21) through the first pipe (41) and is used to supply helium to the cover (21). The vacuum assembly includes at least a mechanical pump (31) and a third vacuum gauge (35). The mechanical pump (31) has a sampling port (311), which is connected to the first outlet (101) of the mass spectrometry system (1), the second outlet (211) of the enclosure (21), and the third outlet (901) of the device under test (9) through multiple pipes. The third vacuum gauge (35) is located close to the first outlet (101) of the mass spectrometry system (1). The pre-vacuum solenoid valve (33), the mass spectrometry solenoid valve (34), and the third vacuum gauge (35) are all connected to the control terminal. Leak detection assembly, the leak detection assembly includes a second vacuum gauge (52), the second vacuum gauge (52) is installed on the second pipe (42) and the second vacuum gauge (52) is set close to the third outlet (901) of the device under test (9), and the second vacuum gauge (52) is communicatively connected to the control terminal; A control terminal is connected in communication with the mechanical pump (31). The control terminal is used to transmit sampling signals to the mechanical pump (31) so that the mechanical pump (31) is in working state. The sampling port (311) of the mechanical pump (31) is connected to the third outlet (901) of the device under test (9) through the second pipe (42); The leak detection assembly also includes an isolation solenoid valve (51), which is installed on the second pipeline (42) and is communicatively connected to the control terminal. The first pipe (41) and the second pipe (42) are connected through the third pipe (43); The helium mass spectrometer leak detector also includes an auxiliary solenoid valve (61), which is installed in the third pipeline (43) and is connected to the control terminal. The sampling port (311) of the mechanical pump (31) is connected to the first outlet (101) of the mass spectrometry system (1) through the fourth pipe (44); The vacuum assembly also includes a molecular pump (32), a pre-vacuum solenoid valve (33), and a mass spectrometry solenoid valve (34). The molecular pump (32) is installed in the fourth pipe (44) and is located between the mass spectrometry system (1) and the mechanical pump (31). The molecular pump (32) is communicatively connected to the control terminal. The pre-vacuum solenoid valve (33) and the mass spectrometry solenoid valve (34) are both installed in the fourth pipe (44). The pre-vacuum solenoid valve (33) is located between the molecular pump (32) and the mechanical pump (31), and the mass spectrometry solenoid valve (34) is located between the mass spectrometry system (1) and the molecular pump (32). The helium mass spectrometer leak detector also includes a coarse detection solenoid valve (71), a fine detection solenoid valve (72), and an ultra-fine detection solenoid valve (73) arranged in parallel. The coarse detection solenoid valve (71) is installed in the fifth pipe (45). The coarse detection solenoid valve (71), the fine detection solenoid valve (72), and the ultra-fine detection solenoid valve (73) are all connected to the control terminal. One end of the fifth pipe (45) is connected to the second pipe (42), and the other end of the fifth pipe (45) is connected to the fourth pipe (44). The other end of the fifth pipe (45) is located between the pre-pump solenoid valve (33) and the mechanical pump (31). A valve (72) is installed in a sixth pipe (46), one end of which is connected to a second pipe (42), the other end of which is connected to a fourth pipe (44), and the other end of which is located near the outlet of the molecular pump (32). A super-precision inspection solenoid valve (73) is installed in a seventh pipe (47), one end of which is connected to a second pipe (42), the other end of which is connected to a fourth pipe (44), and the other end of which is located near the inlet of the molecular pump (32). Before helium detection, the mechanical pump (31), mass spectrometer solenoid valve (34), pre-extraction solenoid valve (33), coarse detection solenoid valve (71), fine detection solenoid valve (72), ultra-fine detection solenoid valve (73), auxiliary solenoid valve (61) and flow meter (24) are started to initially extract interfering or impurity gases from each pipeline and chamber. Then, the molecular pump (32) is started to further extract interfering or impurity gases from each pipeline and chamber to improve the cleanliness of the helium detection environment until the vacuum level of the helium detection environment meets the requirements.

2. The helium mass spectrometer leak detector according to claim 1, characterized in that, The helium injection assembly also includes: Pressure reducing valve (23), the pressure reducing valve (23) is installed in the first pipeline (41) and the pressure reducing valve (23) is located between the cover (21) and the helium storage device (22), the pressure reducing valve (23) is communicatively connected to the control terminal; A flow meter (24) is installed in the first pipeline (41) and is located on the side of the pressure reducing valve (23) away from the helium storage element (22). The flow meter (24) is communicatively connected to the control terminal.

3. The helium mass spectrometer leak detector according to claim 2, characterized in that, The helium mass spectrometer leak detector also includes a venting solenoid valve (62), which is installed in the second pipeline (42) and is connected to the control terminal.

4. A helium-spray leak detection method, applied to the helium mass spectrometer leak detector according to any one of claims 1-3, characterized in that, The helium injection leak detection method includes: Step S1: Move the cover (21) until the cover (21) covers the leak hole to be tested, start the mechanical pump (31) and molecular pump (32) to perform vacuum treatment on the circuit where the mass spectrometry system (1), cover (21) and device under test (9) are located; Step S2: After the vacuum levels displayed by the first vacuum gauge (26) and the second vacuum gauge (52) have stabilized, helium is injected into the leak hole to be tested; Step S3: The mass spectrometry system (1) detects the leakage rate of the current leak in the test hole in real time and feeds it back to the control terminal. The control terminal records and plots the leakage rate curve, and then calculates the leakage rate. Step S4: Repeat steps S1 to S3 until the leakage rate of all the leaks to be tested is completed.

5. The helium injection leak detection method according to claim 4, characterized in that, When performing step S1 or step S3, the following is also included: Step S5: Based on the vacuum level detected by the first vacuum gauge (26) and the second vacuum gauge (52), open the coarse inspection solenoid valve (71), the fine inspection solenoid valve (72) and the ultra-fine inspection solenoid valve (73) in stages; In step S5, a first threshold, a second threshold, and a third threshold are preset at the first vacuum gauge (26) and the second vacuum gauge (52), respectively, as the starting conditions for the coarse inspection solenoid valve (71), the fine inspection solenoid valve (72), and the ultra-fine inspection solenoid valve (73).

6. The helium injection leak detection method according to claim 5, characterized in that, After completing step S4, the following is also included: Step S6: The helium mass spectrometer leak detector is removed from the vacuum environment.

Images