Low gas consumption detection method of compressed nitrogen leak detector
By using hydraulic rods and sealing plates in the nitrogen leak detector, the detection space is reduced, and nitrogen is recovered by using the gas collector, the problem of helium waste is solved, achieving efficient use and low-cost detection of nitrogen.
Patent Information
- Application Number
- CN202111232424.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-10-22
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2041-10-22
AI Technical Summary
In the prior art, the remaining helium gas after detection by the pressure helium leak detector is directly discharged into the air, resulting in a large amount of helium waste and lacks effective methods for recycling and use of nitrogen.
The low-gas consumption detection method of the pressure nitrogen leak detector is adopted to reduce the detection space of the pressure vessel through the hydraulic rod and sealing plate, and nitrogen is recovered using the gas collector, and nitrogen charge is optimized through the nitrogen detector to reduce nitrogen waste.
The use of nitrogen is effectively reduced, and the recovery and reuse of nitrogen is realized, the detection cost is reduced, and the detection efficiency is improved.
Smart Images
Figure CN113959659B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor optoelectronic device technology, and in particular to a low-gas-consumption detection method for nitrogen pressure leak detectors. Background Technology
[0002] Leak testing, as an effective means of determining whether there is an air leak, is widely used in the field of semiconductor optoelectronic devices, or other fields that have leak testing requirements for semi-finished products or finished products. It is used to test the airtightness of sealed devices or other workpieces with airtightness requirements.
[0003] A search revealed Chinese patent CN101750192A, which relates to a method for testing workpieces with airtightness requirements, such as semiconductor optoelectronic devices. Specifically, it is a low-gas-consumption method using a helium pressure leak detector. The method involves the following steps: a. Before testing, a solid pad of a certain volume is placed at the bottom of the pressure vessel of the helium pressure leak detector; b. The device to be tested is placed into the pressure vessel and evacuated to -0.1 MPa; c. The helium cylinder valve is opened, and dry helium is introduced into the pressure vessel until the pressure meets the process requirements of the device; d. The pressure vessel is pressurized for 2 hours and then depressurized; e. The device is removed, purged under nitrogen for 2 minutes, and then placed in a helium mass spectrometer for leak rate testing. This invention is used for airtightness testing of small devices. Because it reduces the space inside the pressure vessel during testing, it reduces the amount of helium required, saving testing costs. Simultaneously, the time required for evacuation and helium introduction during testing is significantly shortened, thereby improving testing efficiency.
[0004] However, in practice, the above detection method reduces the internal space of the pressure vessel by placing solid pads, thereby reducing subsequent helium consumption. However, in practice, the size of the test device to be tested is not easy to determine, so multiple pads are needed to occupy the space of the pressure vessel. At the same time, the remaining helium after each test is directly discharged into the air, resulting in a large amount of helium waste. Therefore, a low-gas-consumption detection method for nitrogen pressure leak detectors is needed. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies where residual helium is directly released into the air after testing, resulting in a significant waste of helium. The invention proposes a low-gas-consumption detection method for nitrogen pressure leak detectors.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A low-gas-consumption method for nitrogen pressure leak detectors includes a detection device and a detection method. The detection device includes a pressure vessel, a support frame, a hydraulic rod, a sealing plate, an opening and closing valve, a pressure detector, an opening and closing door, a gas collector, a connecting pipe, and a nitrogen detector. The detection method includes the following steps:
[0008] Step 1: Before testing, introduce a small amount of nitrogen into the pressure vessel through the opening and closing valve, and then observe the change in pressure inside the pressure vessel using a pressure detector. If the pressure inside the pressure vessel does not change within two minutes, it proves that the pressure vessel has good sealing performance.
[0009] Step 2: Rotate the opening and closing door to open the pressure vessel, and then start the hydraulic rod. The hydraulic rod drives the sealing plate to move, reducing the detection space inside the pressure vessel.
[0010] Step 3: When the testing space inside the pressure vessel is compatible with the size of the testing device, place the device to be tested for sealing inside the pressure vessel, and then close the opening and closing door.
[0011] Step 4: Vacuum the air inside the pressure vessel by opening and closing the valve to maintain the air pressure inside the pressure vessel at -0.05 MPa. Then, open the nitrogen cylinder valve and fill the pressure vessel with dry nitrogen until the pressure value meets the process requirements of the device under test.
[0012] Step 5: After placing the test device inside the pressure vessel for two hours, start the gas collector. The gas collector will draw the gas inside the pressure vessel into its own chamber. Then, open the valve and open the door to remove the test device from the pressure vessel.
[0013] Step Six: After placing the testing device in the air for five minutes, the nitrogen content inside the testing device is detected using a nitrogen gas spectrometer.
[0014] Step 7: When conducting subsequent tests, before replenishing the pressure vessel with nitrogen from the nitrogen cylinder, the gas collected previously is first introduced into the pressure vessel through a gas collector. At this time, the nitrogen concentration inside the pressure vessel is detected by a nitrogen detector. Then, the nitrogen cylinder valve is opened, and dry nitrogen is introduced into the pressure vessel through the opening and closing valve until the pressure value meets the process requirements of the device under test.
[0015] The above technical solution further includes:
[0016] The support frame is installed outside the pressure vessel, the hydraulic rod is installed inside the support frame, the sealing plate is slidably connected to the inside of the pressure vessel, the output end of the hydraulic rod is connected to the outside of the sealing plate, and the opening and closing valve is installed outside the pressure vessel.
[0017] The pressure detector is installed inside the pressure vessel, the opening and closing door is installed inside the pressure vessel, the nitrogen detector is installed on the side of the sealing plate near the opening and closing door, the gas collector is installed inside the support frame, one end of the connecting pipe is connected to the gas collector, and the other end of the connecting pipe is connected to the inside of the pressure vessel.
[0018] During the five-minute period when the test device was exposed to air, a fan blew air onto the test device for two minutes.
[0019] When testing the subsequent testing equipment, since the gas inside the gas collector will be slightly less than the original gas, it is necessary to replenish the gas. The required pressure value for the process is 0.50±0.02Mpa.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0021] 1. In this invention, the combined use of the hydraulic rod and the sealing plate can effectively reduce the test space inside the pressure vessel, thereby reducing the amount of nitrogen gas that can be injected.
[0022] 2. In this invention, the test nitrogen gas inside the pressure vessel can be drawn into the pressure vessel through a connecting pipe using a gas collector. Then, the next device to be tested is placed inside the pressure vessel, and the gas collector is activated to discharge the gas inside the gas collector back into the pressure vessel, thus avoiding direct discharge of the test nitrogen gas and achieving the recovery of the test nitrogen gas. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the low-gas-consumption detection method for the nitrogen pressure leak detector proposed in this invention.
[0024] In the diagram: 1. Pressure vessel; 2. Support frame; 3. Hydraulic rod; 4. Sealing plate; 5. Opening and closing valve; 6. Pressure detector; 7. Opening and closing door; 8. Gas collector; 9. Connecting pipe; 10. Nitrogen detector. Detailed Implementation
[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0026] Example 1
[0027] Step 1: Before testing, place a solid pad of a certain volume at the bottom of the pressure vessel of the nitrogen pressure leak detector, place the device to be tested into the pressure vessel and evacuate to -0.05MPa pressure;
[0028] Step 2: Open the nitrogen cylinder valve and fill the pressure vessel with dry nitrogen until the pressure value meets the process requirements of the device under test (0.50±0.02Mpa). Hold the pressure in the pressure vessel for 2 hours and then release the pressure.
[0029] Step 3: Remove the device under test, blow it in air for 2 minutes, and then place it in a nitrogen mass spectrometer for leak rate testing;
[0030] The above embodiments do indeed reduce nitrogen consumption to some extent. However, due to the limited size of the testing device, a single pad cannot meet the needs of a large number of tests. In addition, the nitrogen is directly discharged to the outside during the depressurization process, resulting in a large amount of waste.
[0031] Example 2
[0032] Step 1: Before testing, a small amount of nitrogen gas is introduced into the pressure vessel 1 through the opening and closing valve 5. Then, the pressure inside the pressure vessel 1 is observed through the pressure detector 6. If the pressure inside the pressure vessel 1 does not change within two minutes, it proves that the sealing performance of the pressure vessel 1 is good. Then, the opening and closing door 7 is rotated. The opening and closing door 7 is now tightly fitted to the inside of the pressure vessel 1, thus opening the pressure vessel 1. Then, the hydraulic rod 3 is activated. The hydraulic rod 3 drives the sealing plate 4 to move. The sealing plate 4 is equipped with a rubber gasket on the outside. The rubber gasket plays a sealing role and reduces the test space inside the pressure vessel 1.
[0033] Step 2: When the testing space inside the pressure vessel 1 is compatible with the size of the testing device, place the device to be tested for sealing inside the pressure vessel 1, then close the opening and closing door 7, connect the opening and closing valve 5 to the external vacuum pump, and vacuum the air inside the pressure vessel 1 through the opening and closing valve 5 to keep the air pressure inside the pressure vessel 1 at -0.05Mpa. Then open the nitrogen cylinder valve and fill the pressure vessel 1 with dry nitrogen through the opening and closing valve 5 until the pressure value of 0.50±0.02Mpa meets the process requirements of the device under test.
[0034] Step 3: After placing the test device inside the pressure vessel 1 for two hours, depressurize it through the opening and closing valve 5, then open the opening and closing door 7, remove the test device from the pressure vessel 1, and expose the test device to the air for five minutes. During the five minutes of exposure to the air, blow air onto the test device using a fan for two minutes. Then, detect the nitrogen content inside the test device using a nitrogen gas spectrometer.
[0035] Through the above embodiments, the combined use of hydraulic rod 3 and sealing plate 4 enables real-time adjustment of the internal test volume of pressure vessel 1, thereby allowing the size of the testing device itself to be adjusted to the internal dimensions of pressure vessel 1, which is more convenient. Compared with embodiment one, the amount of nitrogen consumed in each test is lower.
[0036] Example 3
[0037] Step 1: Before testing, a small amount of nitrogen gas is introduced into the pressure vessel 1 through the opening and closing valve 5. Then, the pressure inside the pressure vessel 1 is observed through the pressure detector 6. If the pressure inside the pressure vessel 1 does not change within two minutes, it proves that the sealing performance of the pressure vessel 1 is good. Then, the opening and closing door 7 is rotated. The opening and closing door 7 is now tightly fitted to the inside of the pressure vessel 1, thus opening the pressure vessel 1. Then, the hydraulic rod 3 is activated. The hydraulic rod 3 drives the sealing plate 4 to move. The sealing plate 4 is equipped with a rubber gasket on the outside. The rubber gasket plays a sealing role and reduces the test space inside the pressure vessel 1.
[0038] Step 2: When the testing space inside the pressure vessel 1 is compatible with the size of the testing device, place the device to be tested for sealing inside the pressure vessel 1, then close the opening and closing door 7, connect the opening and closing valve 5 to the external vacuum pump, and vacuum the air inside the pressure vessel 1 through the opening and closing valve 5 to keep the air pressure inside the pressure vessel 1 at -0.05Mpa. Then open the nitrogen cylinder valve and fill the pressure vessel 1 with dry nitrogen through the opening and closing valve 5 until the pressure value of 0.50±0.02Mpa meets the process requirements of the device under test.
[0039] Step 3: After placing the test device inside the pressure vessel 1 for two hours, start the gas collector 8. The gas collector 8 will draw the gas inside the pressure vessel 1 into its interior. Then, open the opening and closing valve 5 and open the opening and closing door 7 to remove the test device from the pressure vessel 1. After placing the test device in the air for five minutes, blow air through the test device for two minutes using a fan. Then, use a nitrogen gas spectrometer to detect the nitrogen content inside the test device.
[0040] Step 4: When conducting subsequent tests, before replenishing the pressure vessel 1 with nitrogen from the nitrogen cylinder, the gas from the previous test is first introduced into the pressure vessel 1 through the gas collector 8. At this time, the nitrogen concentration inside the pressure vessel 1 is detected by the nitrogen detector 10. Then, the nitrogen cylinder valve is opened and dry nitrogen is introduced into the pressure vessel 1 through the opening and closing valve 5 until the pressure value meets the process requirements of the device under test (0.50±0.02Mpa).
[0041] In actual operation, this embodiment not only satisfies the real-time adjustment of the internal test volume of Embodiment 2, but also recovers the nitrogen gas consumed in the test and reuses it in the next test. Furthermore, by replenishing the nitrogen gas cylinders, subsequent tests are also accurate, achieving low gas consumption testing of the testing device.
[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A low gas consumption detection method for a nitrogen pressure leak detector, characterized in that: The invention comprises a detection device and a detection method, wherein the detection device comprises a pressure vessel (1), a support frame (2), a hydraulic rod (3), a sealing plate (4), an opening and closing valve (5), a pressure detector (6), an opening and closing door (7), a gas collector (8), a connecting pipe (9) and a nitrogen detector (10), and the detection method comprises the following steps: Step 1: Before the test, a small amount of nitrogen is introduced into the interior of the pressure vessel (1) through the opening and closing valve (5), and then the change of the internal air pressure of the pressure vessel (1) is observed through the pressure detector (6). If the internal air pressure of the pressure vessel (1) does not change within two minutes, it is proved that the sealing performance of the pressure vessel (1) is good; Step 2: Rotate the opening and closing door (7) to open the pressure container (1), and then start the hydraulic rod (3), which drives the sealing plate (4) to start moving, thereby reducing the detection space inside the pressure container (1); Step 3: When the detection space inside the pressure container (1) is adapted to the size of the test device, the device to be tested for sealing properties is placed inside the pressure container (1), and then the opening and closing door (7) is closed; Step 4: The air inside the pressure vessel (1) is vacuumized through the opening and closing valve (5) so that the air pressure inside the pressure vessel (1) is maintained at -0.05 MPa, and then the valve of the nitrogen cylinder is opened to fill the pressure vessel (1) with dry nitrogen through the opening and closing valve (5) to a pressure value that meets the process requirements of the device under test; Step 5: After the test device is placed inside the pressure vessel (1) for two hours, the gas collector (8) is started, and the gas collector (8) absorbs the gas inside the pressure vessel (1) into the inside, and then the opening and closing valve (5) is opened, and then the opening and closing door (7) is opened to take the test device out of the pressure vessel (1); Step 6: After the test device is exposed to air for five minutes, the nitrogen content inside the test device is detected by a nitrogen mass spectrometer; Step 7: When the subsequent test device is testing, before replenishing gas into the pressure vessel (1) through the nitrogen cylinder, the previous gas is first introduced into the pressure vessel (1) through the gas collector (8). At this time, the nitrogen concentration inside the pressure vessel (1) is detected by the nitrogen detector (10), and then the valve of the nitrogen cylinder is opened to fill the pressure vessel (1) with dry nitrogen through the opening and closing valve (5) to a pressure value that meets the process requirements of the device to be tested.
2. The low gas consumption detection method of the nitrogen pressure leak detector according to claim 1, characterized in that: The support frame (2) is installed on the outside of the pressure vessel (1), the hydraulic rod (3) is installed on the inside of the support frame (2), the sealing plate (4) is slidably connected to the inside of the pressure vessel (1), the output end of the hydraulic rod (3) is connected to the outside of the sealing plate (4), and the opening and closing valve (5) is installed on the outside of the pressure vessel (1).
3. The low gas consumption detection method of the nitrogen pressure leak detector according to claim 2, characterized in that: The pressure detector (6) is installed inside the pressure vessel (1), the opening and closing door (7) is installed inside the pressure vessel (1), the nitrogen detector (10) is installed on a side of the sealing plate (4) close to the opening and closing door (7), the gas collector (8) is installed inside the support frame (2), one end of the connecting pipe (9) is connected to the gas collector (8), and the other end of the connecting pipe (9) is connected to the inside of the pressure vessel (1).
4. The low gas consumption detection method of the nitrogen pressure leak detector according to claim 3, characterized in that: During the five minutes that the test device was in the air, the test device was blown with air by a fan for two minutes.
5. The low gas consumption detection method of the nitrogen pressure leak detector according to claim 4, characterized in that: When the subsequent test device is tested, since the gas inside the gas collector (8) will be slightly less than the original gas, it needs to be replenished with gas, and the pressure value required by the process is 0.50±0.02Mpa.