Ion pump pumping speed measurement tool and measurement method

Abstract

The present application discloses an ion pump pumping speed measuring tool and a measuring method, which belongs to the field of ion pump performance testing, and its technical key points are: the ion pump pumping speed measuring tool comprises: a gas source, an air filling chamber component, a transition chamber component, and a test chamber component connected in sequence; the air filling chamber component is connected to a flow meter; the air filling chamber component, the transition chamber component, and the test chamber component are all connected to a molecular pump, the transition chamber component is also connected to a voltage-stabilizing ion pump, the ion pump to be tested is connected to the test chamber group, the air filling chamber component and the transition chamber component are connected through a first connecting pipe, and a first small hole and a first switch valve are arranged on the first connecting pipe; the transition chamber component and the test chamber component are connected through a second connecting pipe, and a second small hole and a second switch valve are arranged on the second connecting pipe. The technical solution of the present application can measure the pumping speed of the ion pump under ultra-high vacuum conditions.

Description

Technical Field

[0001] The present application relates to the field of ion pump performance testing, and more specifically, to an ion pump pumping speed measurement tool and a measurement method. Background Art

[0002] Both molecular pumps and ion pumps are vacuum pumps. However, ion pumps are a higher level vacuum obtaining device than molecular pumps. The two pumps have different principles and vacuum degrees. In a vacuum system equipped with an ion pump, first pre-pump the system with a fore pump, and after reaching the target vacuum, turn on the molecular pump; then, turn on the ion pump after the vacuum degree reaches the starting pressure of the ion pump.

[0003] For ion pumps, GB / T 25755-2010 "Measurement of performance parameters of vacuum technology sputtering ion pumps" and JB / T 4081-2011 "Vacuum technology sputtering ion pumps" point out that the saturation pumping speed of ion pumps should be within 1×10 -7 Pa-1×10 -3 Pa pumping speed test, specifically, need to be tested 3 times in each order of magnitude.

[0004] In the above specification, two test methods are proposed (see: http: / / www.360doc.com / content / 24 / 0808 / 11 / 51155580_1130756584.shtml):

[0005] First, the flow method. Install the test cover on the ion pump, and connect the test cover to the fine-tuning valve and the flow meter. First, evacuate and bake the test cover. Then, after the baking is completed, the ion pump starts to work. Adjust the air inlet control valve, put in 4SnPa·L of test gas, and test the volume flow rate of the test gas. This method directly tests the gas flow of the ion pump through the flow meter. The flow method is suitable for inlet pressure greater than 1×10 -4 Pa's situation.

[0006] Second, the small hole method. It indirectly calculates the volume flow rate of the molecular pump by measuring the pressure of the upper and lower chambers separated by the orifice plate. The small hole method is suitable for parameter measurement of low flow rate and small flow rate, and can achieve 1×10 -6 Pumping speed measurement in Pa.

[0007] In summary, the current difficulties in measuring the pumping speed of ion pumps are:

[0008] (1) The air pressure is 1×10 -5 Pa~1×10 -7 Pa, there is a lack of effective measurement methods. For both the flow method and the pinhole method, a fine-tuning valve is required to put the test gas in to adjust the vacuum degree in the test hood, but when the gas pressure is lower than 1×10- 5 Pa, the control accuracy of the fine-tuning valve is insufficient and the target vacuum degree is difficult to adjust.

[0009] (2) Low test efficiency. For the flow method and the small hole method, the opening of the fine-tuning valve needs to be adjusted during the test. In this process, it is very easy to adjust the flow too much, resulting in unqualified vacuum. Therefore, the opening size needs to be adjusted repeatedly. The pumping speed of the ion pump is slower than that of the molecular pump. Therefore, once the vacuum exceeds the test target value, every time the vacuum fails, the vacuum of the chamber needs to be pumped back to the starting vacuum (the starting vacuum must reach 10 -8 When the pressure is at the Pa level, the time required is basically more than 24 hours.

[0010] (3) It is difficult to measure the pumping speed of a low-pumping ion pump. For a low-pumping ion pump (such as 25L / 20L, etc.), the gas load control is not accurate and the gas load of the fine-tuning valve is too large, making it difficult to control the pressure at the target vacuum degree. During the inflation process, due to its low pumping speed, the vacuum degree of the cavity connected to the low-pumping ion pump does not change significantly, and the vacuum degree will gradually increase over time. It is almost impossible to measure the pumping speed of a low-pumping ion pump using this method, and it is even more impossible to fit the pumping speed curve under ultra-high vacuum.

[0011] Therefore, it is necessary to develop a new ion pumping speed measurement tool. Summary of the invention

[0012] The purpose of the present application is to provide an ion pump pumping speed measurement tool to address the deficiencies of the above-mentioned prior art.

[0013] Another object of the present application is to provide a method for measuring the pumping speed of an ion pump.

[0014] The technical solution of this application is as follows:

[0015] An ion pump pumping speed measuring tool is used to test the pumping speed of an ion pump to be tested; the ion pump pumping speed measuring tool comprises: an air filling chamber component, a transition chamber component, a test chamber component, and an air source;

[0016] The gas filling cavity assembly comprises: a gas filling cavity component, a flow meter, a gas filling cavity vacuum gauge component, a first molecular pump, and a first front stage pump; a gas filling cavity component is provided with a gas filling cavity inside; the flow meter and the gas filling cavity vacuum gauge component are respectively connected to the gas filling cavity; the first front stage pump, the first molecular pump, and the gas filling cavity component are connected in sequence;

[0017] The transition chamber component includes: a transition chamber component, a third switch valve, a transition chamber vacuum gauge component, a second molecular pump, a second front stage pump, and a voltage-stabilizing ion pump; a transition chamber is arranged inside the transition chamber component; the voltage-stabilizing ion pump and the transition chamber vacuum gauge component are respectively connected to the transition chamber component; the second front stage pump, the second molecular pump, the third switch valve, and the transition chamber component are connected in sequence;

[0018] Wherein, the test chamber assembly comprises: a test chamber component, a fourth switch valve, a test chamber vacuum gauge assembly, a third molecular pump, and a third front stage pump; a test chamber is arranged inside the test chamber assembly; the third front stage pump, the third molecular pump, the fourth switch valve, and the test chamber component are connected in sequence; the test chamber vacuum gauge assembly is connected to the test chamber component;

[0019] Among them, the connection relationship between the inflation chamber component, the transition chamber component, and the test chamber component is:

[0020] The inflatable cavity component is connected to the transition cavity component via a first connecting pipe, a first small hole is provided on the first connecting pipe, and a first switch valve is provided on the first connecting pipe;

[0021] The transition chamber component is connected to the test chamber component via a second connecting pipe, a second small hole is provided on the second connecting pipe, and a second switch valve is provided on the second connecting pipe;

[0022] Wherein, the gas source is connected to the flow meter.

[0023] Furthermore, the air-filled cavity vacuum gauge assembly includes more than two air-filled cavity vacuum gauges.

[0024] Furthermore, the transition chamber vacuum gauge assembly includes more than two transition chamber vacuum gauges.

[0025] Furthermore, the test chamber vacuum gauge assembly includes more than two test chamber vacuum gauges.

[0026] A method for measuring the pumping speed of an ion pump, using the aforementioned ion pump pumping speed measurement tool to measure the pumping speed of an ion pump to be measured; the method comprises the following steps:

[0027] It includes the following steps:

[0028] S1, the third switch valve and the fourth switch valve remain closed, the first switch valve and the second switch valve remain open, a certain amount of gas is introduced from the gas source into the inflation cavity through the flow meter, and then the flow meter is closed;

[0029] S2, the air pressures in the inflatable chamber, transition chamber, and test chamber are the same, and the third and fourth switch valves and the first to third fore-stage pumps are turned on;

[0030] S3, the vacuum degree of the inflatable chamber, the transition chamber, and the test chamber all reaches the molecular pump starting pressure, and the first to third molecular pumps are turned on;

[0031] S4, obtaining the background pressure of the transition chamber and the background pressure of the test chamber: when the vacuum of the transition chamber and the test chamber reaches the starting pressure of the ion pump, close the first switch valve, close the gas filling chamber and the transition chamber, and then turn on the voltage-stabilizing ion pump and the ion pump to be tested, and wait until the vacuum of the transition chamber and the test chamber reaches 10 -4 Pa ~10 -5 When the level reaches Pa, the second molecular pump and the third molecular pump are turned off;

[0032] S5, closing the first switch valve;

[0033] S6, inflate the air chamber: turn on the flow meter again, and the air source fills the air chamber with gas, and adjusts the opening of the flow meter so that the vacuum degree of the air chamber is stabilized at the target vacuum degree F1 of the air chamber;

[0034] S7, testing phase:

[0035] S7-1, close the second switch valve, open the first switch valve, and inflate the transition chamber with air from the inflation chamber. After the vacuum degree of the transition chamber reaches the target vacuum level of the transition chamber test and the vacuum degree of the transition chamber is stable for 30 minutes, close the first switch valve and the voltage-stabilizing ion pump;

[0036] S7-2, open the second switch valve. When the vacuum degree of the transition chamber drops to the vacuum level of the transition chamber test target vacuum level / 10, end the test and close the second switch valve. During the test, record the vacuum degree of the test chamber and the vacuum degree of the transition chamber during this level test.

[0037] A method for measuring the pumping speed of an ion pump, using the aforementioned ion pump pumping speed measurement tool to measure the pumping speed of an ion pump to be measured;

[0038] S1, the third switch valve and the fourth switch valve remain closed, the first switch valve and the second switch valve remain open, a certain amount of gas is introduced from the gas source into the inflation cavity through the flow meter, and then the flow meter is closed;

[0039] S2, the air pressures in the inflatable chamber, transition chamber, and test chamber are the same, and the third and fourth switch valves and the first to third fore-stage pumps are turned on;

[0040] S3, the vacuum degree of the inflatable chamber, the transition chamber, and the test chamber all reaches the molecular pump starting pressure, and the first to third molecular pumps are turned on;

[0041] S4, obtaining the background pressure of the transition chamber and the background pressure of the test chamber: when the vacuum of the transition chamber and the test chamber reaches the starting pressure of the ion pump, close the first switch valve, close the gas filling chamber and the transition chamber, and then turn on the voltage-stabilizing ion pump and the ion pump to be tested, and wait until the vacuum of the transition chamber and the test chamber reaches 10 -4 Pa ~10 -5 When the level reaches Pa, the second molecular pump and the third molecular pump are turned off;

[0042] S5, closing the first switch valve;

[0043] S6, inflate the air chamber: turn on the flow meter again, and the air source fills the air chamber with gas, and adjusts the opening of the flow meter so that the vacuum degree of the air chamber is stabilized at the target vacuum degree of the air chamber;

[0044] S7, testing phase:

[0045] S7-1, the first vacuum level test, includes the following steps:

[0046] First, close the second switch valve, open the first switch valve, and inflate the transition chamber with air from the inflatable chamber until the vacuum degree of the transition chamber reaches 10 -7 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0047] Next, open the second switch valve and the vacuum degree of the transition chamber reaches 10 -8 When the vacuum level reaches Pa, the first vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during the current level test;

[0048] S7-2, the second vacuum level test, includes the following steps:

[0049] First, open the first switch valve, inflate the transition chamber with gas from the inflatable chamber, start the voltage-stabilizing ion pump, and wait until the vacuum degree of the transition chamber reaches 10 -6 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0050] Next, open the second switch valve: the vacuum degree of the transition chamber reaches 10 -7 When the vacuum level reaches Pa, the second vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during the current level test;

[0051] S7-3, the third vacuum level test, includes the following steps:

[0052] First, open the first switch valve, inflate the transition chamber with gas from the inflatable chamber, start the voltage-stabilizing ion pump, and wait until the vacuum degree of the transition chamber reaches 10-5 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0053] Next, open the second switch valve: the vacuum degree of the transition chamber reaches 10 -6 When the vacuum level reaches Pa, the third vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during this level test.

[0054] Furthermore, the target vacuum degree of the gas filling chamber is in the range of [1×10 -5 Pa, 9×10 -5 Pa].

[0055] Furthermore, the volume flow rate q v The calculation is done using the following formula:

[0056] q V =C[(P 2-测试 -P 2min ) / (P 3-测试 -P 3min )-1];

[0057] Where C is the conductance of the second orifice;

[0058] Among them, P 2-测试 is the vacuum degree of the transition chamber recorded during the test;

[0059] Among them, P 3-测试 Is the test process with P 2-测试 Corresponding to the recorded vacuum degree of the test chamber;

[0060] Among them, P 2min is the background pressure of the transition chamber;

[0061] Among them, P 3min is the background pressure of the test chamber.

[0062] The beneficial effects of this application are:

[0063] First, although the specification provides the pinhole method and flow method to measure the flow rate of the ion pump, both methods require the adjustment of the fine-tuning valve to allow the gas to enter the test hood and select three measurement points for each level. However, this requirement is extremely demanding for the operator. When adjusting the fine-tuning valve, it is easy to have the problem of exceeding the level (for example, the target level is 10 -6 pa, if you can't control it, it will directly reach 10 -4pa), whenever this problem occurs, the test needs to be restarted. And each time the test is restarted, the preparation time required is basically more than 24 hours. Therefore, the primary problem solved by the ion pump pumping speed measurement tool proposed in this application is the problem of test efficiency.

[0064] Second, the present application uses a multi-stage cavity for pressure division. For this research and development goal, the following means are used to achieve it:

[0065] 2.1, Set up the inflation chamber. The inflation chamber is connected to the flow meter (the flow meter has a built-in fine-tuning valve), the flow meter is connected to the gas source, and the inflation chamber is equipped with a molecular pump to maintain the vacuum degree of the inflation chamber at 10 -4 Pa or 10 -5 Pa can basically keep the air-filled cavity in a relatively stable state, with fluctuations within an order of magnitude.

[0066] That is, the transition chamber is inflated by using the inflation chamber, thereby achieving stable control of the gas entering the transition chamber.

[0067] 2.2, the transition chamber is connected to a voltage-stabilizing ion pump. After opening the first switch valve of the gas filling chamber and the transition chamber, the gas pressure is divided to control the vacuum degree of the transition chamber to the required vacuum degree. -7 The pumping speed of the transition cavity ion pump is generally 10 -7 The Pa level maintains the vacuum degree and plays a role in maintaining the vacuum degree.

[0068] Different from the upper part of the test cover in GB / T 25755-2010 "Measurement of performance parameters of sputtering ion pumps using vacuum technology", the present application sets a voltage-stabilizing ion pump in the transition chamber, and its function is as follows: Under normal circumstances, after the gas enters the transition chamber from the gas-filled chamber in the state of molecular flow, the first switch valve between the two chambers is closed at this time. Because the gas has just entered the transition chamber and is unevenly distributed, the pressure should change to a certain extent at this time, and the vacuum measurement result is inaccurate (that is, it often causes a lag in monitoring, resulting in the first switch valve not being closed in time). By setting up a voltage-stabilizing ion pump, even if the first switch valve between the gas-filled chamber and the transition chamber is not closed in time, causing the pressure in the transition chamber to exceed the target level, this part of the gas can be pumped out by the voltage-stabilizing ion pump. For example, P 2min In 10 -8 Pa, at this time, we want to measure 10 -7 The pumping speed of the ion pump to be tested is 10 Pa. After the transition chamber is filled with gas, its vacuum degree also needs to be increased from 10 -8 Adjusted at 10 -7 Pa level, but the inflation time is a little longer, and the transition cavity becomes 10 -6 Pa, at this time the role of the voltage-stabilizing ion pump is reflected.

[0069] 2.3, a first switch valve is set between the inflation chamber and the transition chamber. By setting the first switch valve, one is to obtain P 2min and P 3min First, the inflation chamber and the transition chamber can be separated; second, when the inflation chamber is inflated into the transition chamber, the flow rate can also be controlled by the first switch valve.

[0070] 2.4, a second switch valve is set between the transition chamber and the test chamber. This is different from the practice of connecting the upper and lower parts of the test cover in GB / T 25755-2010 "Measurement of performance parameters of sputtering ion pumps using vacuum technology" (the two spaces are always connected during testing). This application has a second switch valve between the transition chamber and the test chamber. During testing, the second switch valve is in an open state. In the non-test state, the second switch valve is in a closed state to ensure that the transition chamber reaches a specified vacuum degree after being inflated, and its vacuum value is generally at the same order of magnitude as the pressure at which the pumping speed is measured.

[0071] Third, the test method of this application is for 1×10 -6 Pa~1×10 -8 Pumping speed of the ion pump to be tested in the Pa range:

[0072] Phase 1: Clean the inflation chamber, transition chamber, and test chamber and test the background of the transition chamber and test chamber:

[0073] The inflation chamber, transition chamber and test chamber are connected, and then the gas source introduces gas into the inflation chamber, and then the exhaust equipment is turned on (the molecular pump and ion pump need to reach the starting pressure before starting) to exhaust.

[0074] In the second stage, the gas source inflates the gas chamber: under the action of the flow meter and the first molecular pump, the gas pressure in the gas chamber is balanced at F1;

[0075] The inflatable cavity and the transition cavity are closed, the flow meter gas source is adjusted to inflate the transition cavity, and the first front pump and the first molecular pump are used to evacuate the inflatable cavity, so that the air pressure in the inflatable cavity is stabilized at 10 -4 Pa or 10 -5 Pa (i.e. the target vacuum degree F1 of the gas filling chamber is 1×10 -5 Pa~9×10 -4 Pa; preferably, 1×10 -5 Pa~9×10 -5 Pa range; can be set by the user according to the type of gas);

[0076] Phase 3, testing phase:

[0077] Specification GB / T 25755-2010: During the test, the gas source, the upper part of the test hood and the lower part of the test hood are always connected. During the test, the vacuum degree of the test chamber needs to be stable for 30 minutes and then recorded. The reason is that when the gas source, the upper part of the test hood and the lower part of the test hood are connected during the test, the vacuum degree of the test chamber is constantly fluctuating, so it needs to be stabilized before measurement.

[0078] This application adopts a new tooling design and abandons the above ideas.

[0079] First, the transition chamber is supplied with gas, which reaches the transition chamber test target vacuum level (10 -5 pa, 10 -6 pa, 10 - 7 pa): The transition chamber and the test chamber are closed first, and then the gas filling chamber and the transition chamber are connected, and the gas enters the transition chamber from the gas filling chamber; in this process, the vacuum degree of the transition chamber is achieved by a voltage-stabilized ion pump to reach the target vacuum level of the transition chamber test;

[0080] Secondly, the transition chamber and the test chamber are connected, and the recording of M2 (P 2-测试 )、M3(P 3-测试 The measured data obtained in this process is used to calculate the volume flow rate q v .

[0081] During the test, the vacuum level of the test chamber is from 10 -7 pa, 10 -6 pa, 10 -5 Each time, one vacuum level is tested, and the test is performed three times in total. -5 Pa~10 -7 Pumping speed test of the ion pump under test in Pa level.

[0082] The method of GB / T 25755-2010 can only obtain three numerical results at one vacuum level, but the present application is different and can obtain continuous results. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The present application is further described in detail below in conjunction with the embodiments in the accompanying drawings, but does not constitute any limitation to the present application.

[0084] Figure 1 It is a three-dimensional structural diagram of the ion pumping speed measurement tooling of the present application.

[0085] Figure 2 It is a three-dimensional structural diagram of the ion pumping speed measurement tooling of the present application from another perspective.

[0086] Figure 3It is a three-dimensional structural diagram of the ion pump speed measurement tooling of the present application from other perspectives.

[0087] Figure 4 It is a schematic diagram of the structural relationship of the ion pump pumping speed measurement tooling of the present application.

[0088] The reference numerals are as follows:

[0089] Ion pump pumping speed measurement tool 1000, ion pump to be tested 2000;

[0090] A gas filling cavity assembly 100, a gas filling cavity member 101, a flow meter 102, a gas filling cavity vacuum gauge assembly 103, a first molecular pump 104, and a first front stage pump 105;

[0091] A transition chamber assembly 200, a transition chamber component 201, a third switch valve 202, a transition chamber vacuum gauge assembly 203, a second molecular pump 204, a second front stage pump 205, and a voltage-stabilizing ion pump 206;

[0092] A test chamber assembly 300, a test chamber component 301, a fourth switch valve 302, a test chamber vacuum gauge assembly 303, a third molecular pump 304, and a third front stage pump 305;

[0093] A first switch valve 401 and a second switch valve 402;

[0094] A first small hole 501 and a second small hole 502 . DETAILED DESCRIPTION

[0095] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0096] <An ion pump pumping speed measurement tool>

[0097] An ion pump pumping speed measuring tool 1000 is used to test the pumping speed of an ion pump 2000 to be tested. The ion pump pumping speed measuring tool 1000 comprises: an air filling chamber component 100, a transition chamber component 200, a test chamber component 300, and an air source.

[0098] As for the gas filling chamber component 100, the gas filling chamber component 100 includes: a gas filling chamber component 101, a flow meter 102, a gas filling chamber vacuum gauge component 103, a first molecular pump 104, and a first front stage pump 105; the setting functions and connection relationships of the above components are as follows:

[0099] a, the inflatable cavity component 101 is provided with an inflatable cavity inside;

[0100] b. The first front stage pump 105, the first molecular pump 104, and the gas-filled cavity component 101 are connected in sequence, and the first front stage pump 105 and the first molecular pump 104 are used to pump air for the gas-filled cavity component 101;

[0101] c. The flow meter 102 is connected to the gas filling cavity component 101; the flow meter 102 is used to control the gas flow rate of the gas source entering the gas filling cavity;

[0102] d. The air-filling cavity vacuum gauge assembly 103 is connected to the air-filling cavity component 101 , and the air-filling cavity vacuum gauge assembly 103 is used to monitor the vacuum degree of the air-filling cavity inside the air-filling cavity component 101 .

[0103] For the transition chamber assembly 200, the transition chamber assembly 200 includes: a transition chamber component 201, a third switch valve 202, a transition chamber vacuum gauge assembly 203, a second molecular pump 204, a second front stage pump 205, and a voltage-stabilized ion pump 206; the arrangement functions and connection relationships of the above components are as follows:

[0104] a. A transition cavity is provided inside the transition cavity component 201;

[0105] b. The second front stage pump 205, the second molecular pump 204, the third switch valve 202, and the transition chamber component 201 are connected in sequence, and the second front stage pump 205 and the second molecular pump 204 are used to evacuate the transition chamber component 201;

[0106] c. The pressure-stabilizing ion pump 206 is connected to the transition chamber component 201;

[0107] d. The transition chamber vacuum gauge assembly 203 is connected to the transition chamber component 201 , and the transition chamber vacuum gauge assembly 203 is used to monitor the vacuum degree of the transition chamber inside the transition chamber component 201 .

[0108] For the test chamber assembly 300, the test chamber assembly 300 includes: a test chamber component 301, a fourth switch valve 302, a test chamber vacuum gauge assembly 303, a third molecular pump 304, and a third front stage pump 305; the setting functions and connection relationships of the above components are as follows:

[0109] a. A test cavity is provided inside the test cavity assembly 300;

[0110] b. The third front stage pump 305, the third molecular pump 304, the fourth switch valve 302, and the test chamber component 301 are connected in sequence, and the third front stage pump 305 and the third molecular pump 304 are used to evacuate the test chamber component 301;

[0111] c. The test chamber vacuum gauge assembly 303 is connected to the test chamber component 301, and the test chamber vacuum gauge assembly 303 is used to monitor the vacuum degree of the test chamber inside the test chamber component 301;

[0112] The connection relationship between the inflation chamber assembly 100, the transition chamber assembly 200, and the test chamber assembly 300 is:

[0113] a. The inflatable cavity component 101 is connected to the transition cavity component 201 via a first connecting pipe, a first small hole 501 is provided on the first connecting pipe, and a first switch valve 401 is provided on the first connecting pipe;

[0114] b. The transition chamber component 201 is connected to the test chamber component 301 via a second connecting pipe, a second small hole 502 is provided on the second connecting pipe, and a second switch valve 402 is provided on the second connecting pipe.

[0115] The connection relationship between the ion pump pumping speed measurement tool 1000 and the ion pump 2000 to be tested is: the ion pump 2000 to be tested is connected to the test chamber component 301.

[0116] It should be noted that the gas source is connected to the flow meter.

[0117] It should be noted that all parts, pipes, etc. need to be cleaned in advance before installation to ensure that oil, impurities, etc. on the inner surface are removed. After cleaning, high-temperature vacuum degassing is required. High-temperature degassing furnaces and other equipment can be used for degassing to remove the gas attached to the inner surface. Before using the molecular pump, it needs to be baked and degassed. All inner wall surfaces need to be mirror-polished to reduce the gas storage capacity of the material and reduce the amount of outgassing. Ion pumps are generally baked and degassed before leaving the factory and do not need to be baked again.

[0118]

[0119] A method for measuring the pumping speed of an ion pump comprises the following steps:

[0120] S1, the third switch valve and the fourth switch valve remain closed, the first switch valve 401 and the second switch valve 402 remain open, a certain amount (e.g., 4Sn·Pa·L) of gas is introduced from the gas source into the inflation chamber through the flow meter 102, and then the flow meter 102 is closed;

[0121] S2, the air pressures in the inflatable chamber, the transition chamber, and the test chamber are the same, and the third switch valve 202, the fourth switch valve, the first front stage pump 105, the second front stage pump 205, and the third front stage pump 305 are opened;

[0122] S3, the vacuum degrees of the chamber to be inflated, the transition chamber, and the test chamber all reach the molecular pump starting pressure, and the first molecular pump 104, the second molecular pump 204, and the third molecular pump 304 are turned on;

[0123] S4, wait until the vacuum degree of the transition chamber and the test chamber reaches the ion pump starting pressure (10 -2 Pa, close the first switch valve 401, close the gas filling chamber and the transition chamber, then turn on the voltage-stabilizing ion pump 206 and the ion pump to be tested 2000, and obtain the background pressure of the transition chamber (i.e., P 2min ) and the background pressure of the test chamber (i.e. P 3min );

[0124] The vacuum degree of the transition chamber and the test chamber is 10 -4 Pa ~10 -5 When the molecular pump reaches the Pa level, turn off the second and third molecular pumps (it should be noted that the valves before the molecular pumps need to be turned off before entering the 10 -6 When the molecular pump is not operated, it can only pump 10 -5 or 10 -6 Pa, and in 10 -7 When the molecular pump is in a relatively low vacuum state at the Pa level, it will affect the vacuum degree of the cavity, making the vacuum degree less than 10 -7 Pa or above, and affects the actual pumping speed test of the ion pump);

[0125] After the ion pump is turned on, the minimum vacuum degree of the transition chamber is the background pressure of the transition chamber (usually 10 -8 Pa level) (After the voltage-stabilized ion pump is turned on, the vacuum degree of the transition chamber will continue to decrease until it stabilizes at P 2min );

[0126] After the ion pump to be tested is turned on, the minimum vacuum degree of the test chamber is the background pressure of the test chamber (usually 10 -8 Pa level) (After the ion pump to be tested is turned on, the vacuum degree of the test chamber will continue to decrease until it stabilizes at P 3min );

[0127] S5, closing the first switch valve;

[0128] S6, inflation of the inflation chamber:

[0129] Open the flow meter 102 again, and fill the gas source into the gas filling chamber. Adjust the opening of the flow meter so that the vacuum degree of the gas filling chamber is stabilized at the target vacuum degree of the gas filling chamber (F1 is generally 1×10 -5 Pa~9×10 -5 Values ​​within the Pa range, such as 5×10 -5 Pa);

[0130] S7, testing phase:

[0131] S7-1, the first vacuum level test, includes the following steps:

[0132] First, close the second switch valve, open the first switch valve, and inflate the transition chamber until M2 reaches 10 -7 After the M2 reaches the pa level and is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0133] Next, open the second switch valve, M2 reaches 10 -8 When the vacuum level reaches Pa, the first vacuum level test is completed and the second switch valve is closed; during the test, record P 3-测试 and P 2-测试 ;

[0134] S7-2, the second vacuum level test, includes the following steps:

[0135] First, open the first switch valve, inflate the transition chamber with gas from the gas chamber, start the voltage-stabilizing ion pump, and wait until M2 reaches 10 -6 After the M2 reaches the pa level and is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0136] Next, open the second switch valve: M2 reaches 10 -7 When the vacuum level reaches Pa, the second vacuum level test is ended and the second switch valve is closed; during the test, record P 3-测试 and P 2-测试 ;

[0137] S7-3, the third vacuum level test, includes the following steps:

[0138] First, open the first switch valve, inflate the transition chamber with gas from the gas chamber, start the voltage-stabilizing ion pump, and wait until M2 reaches 10 -5 After the M2 reaches the pa level and is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed;

[0139] Next, open the second switch valve: M2 reaches 10 -6 When the vacuum level reaches Pa, the third vacuum level test is completed and the second switch valve is closed; during the test, record P 3-测试 and P 2-测试 .

[0140] It should be noted that a single test process takes about 45 minutes.

[0141] It should be noted that according to GB / T 25755-2010 "Measurement of performance parameters of vacuum technology sputtering ion pumps", for the pumping speed of the ion pump, at different P 2-测试The corresponding volume flow rate (i.e. pumping speed) q v It can be expressed as:

[0142] q V =C[(P 2-测试 -P 2min ) / (P 3-测试 -P 3min )-1], where C is the conductance of the second orifice.

[0143] It should be noted that the air-filling cavity vacuum gauge assembly includes more than two air-filling cavity vacuum gauges, which are distributed at different positions of the air-filling cavity, and the average value of the above monitoring values ​​is used as the vacuum degree of the air-filling cavity.

[0144] It should be noted that the transition chamber vacuum gauge assembly includes more than two transition chamber vacuum gauges, which are distributed at different positions of the transition chamber, and the average value of the above monitoring values ​​is used as the vacuum degree of the transition chamber.

[0145] It should be noted that the test chamber vacuum gauge assembly includes more than two test chamber vacuum gauges, which are distributed at different positions of the test chamber, and the average value of the above monitoring values ​​is used as the vacuum degree of the test chamber.

[0146] It should be noted that the settings of the first small hole and the second small hole comply with the requirements of GB / T 25755-2010 "Measurement of performance parameters of sputtering ion pumps using vacuum technology", which will not be elaborated here.

[0147] The physical meanings of the symbols in this application are:

[0148] F1: target vacuum degree of the inflation chamber;

[0149] M2: vacuum degree of transition chamber;

[0150] M3: vacuum degree of the test chamber;

[0151] P 2-测试 : The vacuum degree of the transition chamber recorded during the test;

[0152] P 3-测试 : The vacuum degree of the test chamber recorded during the test;

[0153] P 2min : background pressure of transition chamber;

[0154] P 3min : Background pressure of the test chamber;

[0155] C: conductance of the second orifice;

[0156] q v : Volume flow rate.

[0157] The above-mentioned embodiments are preferred implementation modes of the present application and are only used to facilitate the explanation of the present application. They are not intended to limit the present application in any form. Any person with ordinary knowledge in the relevant technical field, if they do not depart from the scope of the technical features of the present application, can make equivalent embodiments by making partial changes or modifications to the technical contents disclosed in the present application and do not depart from the technical features of the present application. All of these still fall within the scope of the technical features of the present application.

Claims

1. An ion pump pumping speed measuring tool, which is used to test the pumping speed of an ion pump to be tested; characterized in that: The ion pump pumping speed measurement tooling comprises: an air filling chamber component, a transition chamber component, a test chamber component, and an air source; The gas filling cavity assembly comprises: a gas filling cavity component, a flow meter, a gas filling cavity vacuum gauge component, a first molecular pump, and a first front stage pump; a gas filling cavity component is provided with a gas filling cavity inside; the flow meter and the gas filling cavity vacuum gauge component are respectively connected to the gas filling cavity; the first front stage pump, the first molecular pump, and the gas filling cavity component are connected in sequence; The transition chamber component includes: a transition chamber component, a third switch valve, a transition chamber vacuum gauge component, a second molecular pump, a second front stage pump, and a voltage-stabilizing ion pump; a transition chamber is arranged inside the transition chamber component; the voltage-stabilizing ion pump and the transition chamber vacuum gauge component are respectively connected to the transition chamber component; the second front stage pump, the second molecular pump, the third switch valve, and the transition chamber component are connected in sequence; Wherein, the test chamber assembly comprises: a test chamber component, a fourth switch valve, a test chamber vacuum gauge assembly, a third molecular pump, and a third front stage pump; a test chamber is arranged inside the test chamber assembly; the third front stage pump, the third molecular pump, the fourth switch valve, and the test chamber component are connected in sequence; the test chamber vacuum gauge assembly is connected to the test chamber component; Among them, the connection relationship between the inflation chamber component, the transition chamber component, and the test chamber component is: The inflatable cavity component is connected to the transition cavity component via a first connecting pipe, a first small hole is provided on the first connecting pipe, and a first switch valve is provided on the first connecting pipe; The transition chamber component is connected to the test chamber component via a second connecting pipe, a second small hole is provided on the second connecting pipe, and a second switch valve is provided on the second connecting pipe; Wherein, the gas source is connected to the flow meter; The gas-filled cavity vacuum gauge assembly includes more than two gas-filled cavity vacuum gauges; The transition cavity vacuum gauge assembly includes more than two transition cavity vacuum gauges.

2. The ion pumping speed measurement tool according to claim 1, characterized in that: The test chamber vacuum gauge assembly includes more than two test chamber vacuum gauges.

3. A method for measuring the pumping speed of an ion pump, characterized in that: Using the ion pump pumping speed measurement tool as claimed in claim 1 or 2 to measure the pumping speed of the ion pump to be measured; It includes the following steps: S1, the third switch valve and the fourth switch valve remain closed, the first switch valve and the second switch valve remain open, a certain amount of gas is introduced from the gas source into the inflation cavity through the flow meter, and then the flow meter is closed; S2, the air pressures in the inflatable chamber, transition chamber, and test chamber are the same, and the third and fourth switch valves and the first to third fore-stage pumps are turned on; S3, the vacuum degree of the inflatable chamber, the transition chamber, and the test chamber all reaches the molecular pump starting pressure, and the first to third molecular pumps are turned on; S4, obtaining the background pressure of the transition chamber and the background pressure of the test chamber: when the vacuum of the transition chamber and the test chamber reaches the starting pressure of the ion pump, close the first switch valve, close the gas filling chamber and the transition chamber, and then turn on the voltage-stabilizing ion pump and the ion pump to be tested, and wait until the vacuum of the transition chamber and the test chamber reaches 10 -4 Pa ~10 -5 When the level reaches Pa, the second molecular pump and the third molecular pump are turned off; S5, closing the first switch valve; S6, inflate the air chamber: turn on the flow meter again, and the air source fills the air chamber with gas, and adjusts the opening of the flow meter so that the vacuum degree of the air chamber is stabilized at the target vacuum degree of the air chamber; S7, testing phase: S7-1, close the second switch valve, open the first switch valve, and inflate the transition chamber with air from the inflation chamber. After the vacuum degree of the transition chamber reaches the target vacuum level of the transition chamber test and the vacuum degree of the transition chamber is stable for 30 minutes, close the first switch valve and the voltage-stabilizing ion pump; S7-2, open the second switch valve. When the vacuum degree of the transition chamber drops to the vacuum level of the transition chamber test target vacuum level / 10, end the test and close the second switch valve. During the test, record the vacuum degree of the test chamber and the vacuum degree of the transition chamber during this level test.

4. A method for measuring the pumping speed of an ion pump, characterized in that: Using the ion pump pumping speed measurement tool as claimed in claim 1 or 2 to measure the pumping speed of the ion pump to be measured; S1, the third switch valve and the fourth switch valve remain closed, the first switch valve and the second switch valve remain open, a certain amount of gas is introduced from the gas source into the inflation cavity through the flow meter, and then the flow meter is closed; S2, the air pressures in the inflatable chamber, transition chamber, and test chamber are the same, and the third and fourth switch valves and the first to third fore-stage pumps are turned on; S3, the vacuum degree of the inflatable chamber, the transition chamber, and the test chamber all reaches the molecular pump starting pressure, and the first to third molecular pumps are turned on; S4, obtaining the background pressure of the transition chamber and the background pressure of the test chamber: when the vacuum of the transition chamber and the test chamber reaches the starting pressure of the ion pump, close the first switch valve, close the gas filling chamber and the transition chamber, and then turn on the voltage-stabilizing ion pump and the ion pump to be tested, and wait until the vacuum of the transition chamber and the test chamber reaches 10 -4 Pa ~10 -5 When the level reaches Pa, the second molecular pump and the third molecular pump are turned off; S5, closing the first switch valve; S6, inflate the air chamber: turn on the flow meter again, and the air source fills the air chamber with gas, and adjusts the opening of the flow meter so that the vacuum degree of the air chamber is stabilized at the target vacuum degree of the air chamber; S7, testing phase: S7-1, the first vacuum level test, includes the following steps: First, close the second switch valve, open the first switch valve, and inflate the transition chamber with air from the inflatable chamber until the vacuum degree of the transition chamber reaches 10 -7 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed; Next, open the second switch valve and the vacuum degree of the transition chamber reaches 10 -8 When the vacuum level reaches Pa, the first vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during the current level test; S7-2, the second vacuum level test, includes the following steps: First, open the first switch valve, inflate the transition chamber with gas from the inflatable chamber, start the voltage-stabilizing ion pump, and wait until the vacuum degree of the transition chamber reaches 10 -6 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed; Next, open the second switch valve: the vacuum degree of the transition chamber reaches 10 -7 When the vacuum level reaches Pa, the second vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during the current level test; S7-3, the third vacuum level test, includes the following steps: First, open the first switch valve, inflate the transition chamber with gas from the inflatable chamber, start the voltage-stabilizing ion pump, and wait until the vacuum degree of the transition chamber reaches 10 -5 After the vacuum level of the transition chamber reaches the pa level and the vacuum degree is stable for 30 min, the first switch valve and the voltage-stabilizing ion pump are closed; Next, open the second switch valve: the vacuum degree of the transition chamber reaches 10 -6 When the vacuum level reaches Pa, the third vacuum level test is ended and the second switch valve is closed; during the test, the vacuum degree of the test chamber and the vacuum degree of the transition chamber are recorded during this level test.

5. The method for measuring the pumping speed of an ion pump according to claim 3 or 4, characterized in that: The target vacuum degree of the filling chamber is in the range of [1×10 -5 Pa, 9×10 -5 Pa].

6. The method for measuring the pumping speed of an ion pump according to claim 3 or 4, characterized in that: Volume flow rate q v The calculation is done using the following formula: q V =C[(P 2-测试 -P 2min ) / (P 3-测试 -P 3min )-1]; Where C is the conductance of the second orifice; Among them, P 2-测试 is the vacuum degree of the transition chamber recorded during the test; Among them, P 3-测试 Is the test process with P 2-测试 Corresponding to the recorded vacuum degree of the test chamber; Among them, P 2min is the background pressure of the transition chamber; Among them, P 3min is the background pressure of the test chamber.

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