Vacuum leak detection system, gas control unit, and gas leak detection method

Abstract

The present invention relates to a vacuum leak detection system (10) comprising a test chamber unit (12) having a test chamber gas inlet (20) and a test chamber gas outlet (22), a gas detection unit (14) having a gas detection gas inlet (32) and a gas detection gas outlet (34), and a gas control unit (16) connecting the test chamber gas inlet (20) and the test chamber gas outlet (22) to the gas detection gas inlet (32) and the gas detection gas outlet (34), the gas control unit (16) being connected to the test chamber unit (12) and the gas detection unit (14) and having separate gas flow passages (48, 52, 54, 56, 60) for selectively connecting the gas inlets (20, 40) and gas outlets (22, 34) of the test chamber unit (12) and the gas detection unit (14). The gas control unit (16) has a third gas inlet (44) that opens to the atmosphere and is connectable to the gas inlet (20) of the test chamber via a gas flow passage (48) that passes through the gas control unit (16), and supplies the carrier gas introduced through the third gas inlet (44) to the test chamber unit (12).

Description

Technical Field

[0001] The present invention relates to a vacuum leak detection system, a gas control unit, and a gas leak detection method.

Background Art

[0002] Conventional helium vacuum leak detection devices such as INFICON's UL3000 (registered trademark) include a vacuum control unit incorporating a helium measurement device in the form of a mass spectrometer. This device includes a vacuum pump for connecting to a test chamber or a test object via a separate vacuum line. Here, the vacuum control unit, the helium mass spectrometer, and the vacuum pump form a unit within a common housing.

[0003] In another helium vacuum leak detection device, INFICON's LDC3000 (registered trademark), a sector-field mass spectrometer, and a turbomolecular pump flanged with a valve block form a helium detector unit incorporated in a test system. The test system consists of a test chamber, a pump stand, and a vacuum leak detector. The helium detector unit is connected to the vacuum test chamber and the pump stand in a gas-conducting manner via respective connection lines.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a vacuum leak detection system for a test gas that enables a flexible and controllable supply of the test gas from a test chamber to a gas detector.

Means for Solving the Problems

[0006] The vacuum leak detection system according to the present invention is defined by the features of independent claim 1. The gas control unit according to the present invention is defined by the features of independent claim 2.

[0007] According to this, the vacuum leak detection system includes three components: a test chamber unit having a gas inlet of the test chamber and a gas outlet of the test chamber, a gas detection unit having a gas inlet for gas detection and a gas outlet for gas detection, and a gas control unit connecting the gas inlets and gas outlets of the gas detection unit and the test chamber unit. The gas control unit is connected to the test chamber unit and the gas detection unit. The gas control unit is provided with a separate gas conduction path for selectively connecting the gas outlet of the test chamber to the gas inlet for gas detection and the gas outlet for gas detection.

[0008] The gas control unit can be connected to the test chamber unit and the gas detection unit of the vacuum leak detection system, and has a separate gas flow path for selectively connecting the gas inlets and gas outlets of the test chamber unit and the gas detection unit. In particular, a separate gas inlet of the gas control unit is connected to the gas inlet of the test chamber via a gas flow path passing through the gas control unit, and is provided to supply the carrier gas drawn through the separate gas inlet of the gas control unit to the test chamber unit. For this purpose, a vacuum pump existing in the gas control unit can be used. In particular, the gas control unit is configured to control the supply of the carrier gas to the test chamber unit. This means that the supply of the carrier gas can be opened and / or closed by the gas control unit, and / or the amount of the carrier gas can be changed. For this purpose, for example, a flow throttle having a variable passage and / or an individually controllable valve can be provided.

[0009] A modification of the present invention can include that the test chamber unit, the gas detection unit, and the gas control unit are designed as separate modules adapted to be detachably connected to each other. The three modules can be directly coupled to each other without the need for a separate vacuum line for connecting the modules. In this way, a common vacuum leak detection unit can be formed from the three modules, and this vacuum leak detection unit is also arranged, for example, in a common housing. The test chamber unit, the gas control unit, and / or the gas detection unit can be selectively exchanged with other modules so as to adapt the vacuum leak detection system to individual test conditions.

Brief Description of the Drawings

[0010]

Figure 1

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The figures show the embodiments in the form of schematic block diagrams.

[0012] The figure shows a vacuum leak detection system 10 including a test chamber unit 12, a gas detection unit 14, and a gas control unit 16.

[0013] The test chamber unit 12 includes a vacuum test chamber 18, which may be a rigid test chamber or a flexible test chamber in the form of, for example, a film chamber. The test chamber unit 12 has a gas inlet 20 of the test chamber and a gas outlet 22 of the test chamber, both of which are connected to the test chamber 18 so as to allow gas flow.

[0014] The gas detection unit 14 includes a gas detector 24, which is a quadrupole mass spectrometer in this embodiment, and the gas detector 24 is exhausted into the atmosphere via a two-stage vacuum pump 26. The gas detector 24 is connected to a gas inlet 32 for gas detection and a gas outlet 34 for gas detection so as to allow gas flow through a detection gas flow path 30 provided with a throttle 28.

[0015] The gas control unit 16 includes three gas inlets 36, 42, 44 and three gas outlets 38, 40, 46. The first gas inlet 36 is connected to the gas outlet 22 of the test chamber so as to allow gas flow through a removable connection. Correspondingly, the first gas outlet 38 is connected to the gas inlet 20 of the test chamber. Correspondingly, the second gas outlet 40 is connected to the gas inlet 32 for gas detection, and the second gas inlet 42 is connected to the gas outlet 34 for gas detection. The third gas inlet 44 and the third gas outlet 46 are each open to the atmosphere.

[0016] The third gas inlet 44 is gas-flow-connectable to the first gas outlet 38 via a carrier gas flow path 48. The carrier gas flow path 48 includes a selectively controllable valve V4 and a flow throttle 50 that generates a gas flow of, for example, 10 sccm. The flow throttle can be used to adapt the flow to the test chamber volume 18. Typically, a carrier gas flow of 10 sccm to 100 sccm is selected depending on the size of the test chamber volume 18. As used herein, selectively controllable means that each valve can be selectively opened and closed. For this purpose, the gas control unit 16 includes electronics (not shown). The carrier gas flow path 48 is bypassed via a bypass path 52, and the bypass path 52 also gas-flow-connects the third gas inlet 44 to the first gas outlet 38 and includes a selectively controllable valve V5 connected in parallel with the valve V4 and the throttle 50.

[0017] The first inlet 36 is gas-flow-connectable to the second gas outlet 40 via a test gas flow path 54 that includes a selectively controllable valve V2. Pressure measuring devices P2 and P3 are connected to the test gas flow path 54, and the pressure measuring device P2 measures the pressure on the downstream side of the valve V2 in the gas flow direction, while the pressure measuring device P3 measures the pressure on the upstream side of the valve V2 in the gas flow direction.

[0018] The second gas inlet 42 is gas-flow-connectable to the third gas outlet 46 via a return gas flow path 56 that includes a selectively controllable valve V3 and a vacuum pump 58. An exhaust gas flow path 60 that includes a selectively controllable valve V1 connects the test gas flow path 54 to the return gas flow path 56 between the valve V3 and the vacuum pump 58, upstream of the valve V2 in the direction of the gas flow. A pressure measuring device P1 indicated by reference numeral 62 is connected to the downstream side of the valve V1 in the gas flow direction in the exhaust gas flow path 60.

[0019] The measurement signals of the pressure measuring devices P1, P2, and P3 are sent to the control electronics of a gas control unit 16 (not shown). The control electronics controls the open / closed states of valves V1, V2, V3, V4, V5, and V6 and the operating state of the vacuum pump 58 according to the measured pressure values and possible further control parameters.

[0020] First, valve V1 is opened, at least valves V2 and V3, and possibly valves V4, V5, and V6 are closed, and the vacuum pump 58 operates to evacuate the test chamber 18. The gas from the test chamber 18 is exhausted to the third gas outlet 46 via the test gas flow path 54, the exhaust gas flow path 60, and the return gas flow path 56 and released into the atmosphere. In parallel, the vacuum pump 26 evacuates the gas detector 24.

[0021] When an appropriate pressure threshold is reached with the pressure measuring device P3 and / or P1, valves V2 and V3 are opened and valve V1 is closed. Optionally, valve V4 is also opened. Valve V5 is initially closed. In this operating state, the vacuum pump 58 sends the gas from the test chamber 18 through the open valve V2, through the test gas flow path 54, to the gas inlet 32 for gas detection, from where the gas flows through the flow throttle 28 to the mass spectrometer of the gas detector 24, through the gas outlet 34 for gas detection and the second gas inlet 42, the return gas flow path 56, and the open valve V3, and is sent to the third gas outlet 46, from where it is released into the atmosphere. Through the third gas inlet 44, an appropriate carrier gas flow enters the test chamber 18 through the open valve V4, via the carrier gas flow path 48, through the flow throttle 50. Here, the carrier gas is taken from the atmosphere around the gas control unit 16. Alternatively, it is also conceivable to connect a carrier gas source to the third gas inlet 44.

[0022] After the detection of gas leakage is completed, the throttle 50 can bypass through the bypass gas flow passage 52, and a corresponding large amount of gas can be drawn from the third gas inlet to flush the test chamber 18, the valves, and the gas flow passages. For this purpose, it is also possible to connect a suitable flushing gas source to the third gas inlet 44. For example, the flushing of the measurement chamber 18 to reduce contamination after measuring a very large leakage rate is carried out through the path leading to the pump 58 via the line section 52, valve V5, test chamber 18, and test gas flow passage 54, and then directly through the opened valve V1 and the exhaust gas flow passage 60. During this flushing period, the inlet area to the throttle 28 for gas detection is separated by the closed valves V2 and V3. The flushing of line 56 and the section between valves V2 and V3 is carried out through the throttle flushing gas inlet via valve V6. During this stage, valves V2 and V1 are closed. The flushing gas is led to the pump 58 via valves V6 and V3.

[0023] The gas flow passages 48, 52, 54, 56, and 60, and the corresponding valves V1 - V6, throttle, and pressure measuring devices P1 - P3 are arranged within a common integrated valve block disposed within the gas control unit 16, and this block is a solid element. The pressure measuring devices and the vacuum pump 58 can be connected to appropriate connectors of the valve block. The valves V1 - V6 can be arranged outside the valve block in a manner known per se and can be connected to the corresponding connectors of the respective gas flow passages.

[0024] Compared with conventional vacuum leak detection systems, the present invention can control the gas flow for evacuating the test chamber for gas leak detection and subsequent flushing of the gas flow path and test chamber with only one element, namely the gas control unit 16, providing a decisive advantage that there is no need to connect separate components to the test chamber and / or gas detector via separate hose lines. The carrier gas supply and the flushing gas supply are also directed not into the test chamber 18 via separate hose lines, but directly into the gas control unit 16. Here, the test chamber 18 has only two ports. There is no need for a separate port for the supply of carrier gas and / or flushing gas. Correspondingly, the gas detection unit 14 requires only two ports 32, 34, similar to the outlet for evacuating the mass spectrometer 24, without the need for separate ports for pumps, valves, pressure measuring devices, etc.

Claims

1. A test chamber unit (12) having a gas inlet (20) of the test chamber and a gas outlet (22) of the test chamber, A gas detection unit (14) having a gas inlet (32) for gas detection and a gas outlet (34) for gas detection, A gas control unit (16) connecting the gas inlet (20) of the test chamber and the gas outlet (22) of the test chamber to the gas inlet (32) for gas detection and the gas outlet (34) for gas detection, the gas control unit (16) being connected to the test chamber unit (12) and the gas detection unit (14), and having separate gas flow paths (48, 52, 54, 56, 60) for selectively connecting the gas inlets (20, 40) and the gas outlets (22, 34) of the test chamber unit (12) and the gas detection unit (14), A vacuum leak detection system (10) comprising: The gas control unit (16) has a third gas inlet (44) that opens to the atmosphere side and is connectable to the gas inlet (20) of the test chamber via a gas flow path (48) passing through the gas control unit (16), and supplies a carrier gas introduced through the third gas inlet (44) to the test chamber unit (12). A vacuum leak detection system characterized by this.

2. A test chamber unit (12) having a gas inlet (20) of the test chamber and a gas outlet (22) of the test chamber, A gas control unit (16) for a vacuum leak detection system, comprising a gas detection unit (14) having a gas inlet (32) for gas detection and a gas outlet (34) for gas detection, The gas inlet (20) of the test chamber and the gas outlet (22) of the test chamber are configured to be connected to the gas inlet (32) for gas detection and the gas outlet (34) for gas detection, For this purpose, it is connectable to the test chamber unit (12) and the gas detection unit (14), It has separate gas flow paths (48, 52, 54, 56, 60) for selectively connecting the gas inlets (20, 40) and the gas outlets (22, 34) of the test chamber unit (12) and the gas detection unit (14). The gas control unit (16) for the vacuum leak detection system has a third gas inlet (44) that opens to the atmosphere and is connectable to the gas inlet (20) of the test chamber via a gas flow path (48) that penetrates the gas control unit (16), and supplies carrier gas introduced via the third gas inlet (44) to the test chamber unit (12). A gas control unit for a vacuum leak detection system, characterized by this.

3. The gas control unit is a vacuum pump (58) that evacuates the test chamber unit (12), and is provided with a vacuum pump (58) that is connectable to the gas outlet (22) of the test chamber. The vacuum leak detection system according to claim 1 or the gas control unit according to claim 2, characterized by this.

4. The vacuum leak detection system (10) is modularized such that the test chamber unit (12), the gas detection unit (14), and the gas control unit (16) are separate modules detachably connected to each other. The vacuum leak detection system or gas control unit according to any one of claims 1 to 3, characterized by this.

5. The gas control unit (16) has a first gas inlet (36) connectable to the gas outlet (22) of the test chamber, a first gas outlet (38) connectable to the gas inlet (20) of the test chamber, a second gas outlet (40) connectable to the gas inlet (32) of the gas detection, and a second gas inlet (42) connectable to the gas outlet (34) of the gas detection. The first gas inlet (36) is connected to the second gas outlet (40) via a gas flow path (54) that penetrates the gas control unit (16). The vacuum leak detection system or gas control unit according to any one of claims 1 to 4, characterized by this.

6. The first gas outlet (38) and the second gas inlet (42) are not connected to each other via a gas flow path that penetrates the gas control unit (16). The vacuum leak detection system or gas control unit according to claim 5, characterized by this.

7. The gas control unit (16) has a third gas outlet (46) that opens to the atmosphere side, and the third gas inlet (44) is connected to the first gas outlet (38) via a gas flow path (48, 52) that penetrates the gas control unit (16). The third gas outlet (46) is connected to the second gas inlet (42) via a gas flow path (56) that penetrates the gas control unit (16). The vacuum leak detection system or gas control unit according to claim 5 or 6, characterized by this.

8. The gas flow path (56) connecting the second gas inlet (42) to the third gas outlet (46) has an individually controllable valve (V3) and a vacuum pump (58), and is connected to the gas flow path (54) connecting the first gas inlet (36) to the second gas outlet (40) via a branch path (60) of gas flow having an individually controllable valve (V1). The vacuum leak detection system or gas control unit according to claim 7, characterized by this.

9. The gas flow path (54) connecting the first gas inlet (36) to the second gas outlet (40) is provided with an individually controllable valve (V2). The vacuum leak detection system or gas control unit according to any one of claims 5 to 8, characterized by this.

10. The gas flow path (50) connecting the third gas inlet (44) to the first gas outlet (38) has an individually controllable valve (V4), a flow throttle (50) connected in series to the valve (V4), and a bypass branch portion (52) that bypasses the valve (V4) and the flow throttle (50) and has an individually controllable valve (V5). The vacuum leak detection system or gas control unit according to any one of claims 5 to 9, characterized by this.

11. The gas flow paths (48, 52, 54, 56, 60) of the gas control unit (16) are arranged in a common valve block. The vacuum leak detection system or gas control unit according to any one of claims 5 to 10, characterized by this.

12. The vacuum leak detection system or gas control unit according to any one of claims 5 to 11, wherein the test chamber unit (12) includes a vacuum chamber designed as a test chamber (18) in the form of a rigidity test chamber or a flexible film chamber.

13. The vacuum leak detection system or gas control unit according to any one of claims 5 to 12, wherein an auxiliary pump module connectable to the gas control unit (16) is provided to improve the exhaust capacity of the gas control unit (16).

14. A gas leak detection method using the vacuum leak detection system or gas control unit according to any one of claims 5 to 13, comprising: - Connecting a first gas inlet (36) to a vacuum pump (58), and exhausting the test chamber (18) of the test chamber unit (12) using the vacuum pump (58) of the gas control unit (16) through a gas flow path (54, 60, 56) connecting the vacuum pump (58) to a third gas outlet (46); - Supplying a carrier gas to the test chamber (18) through the third gas inlet (44), and while opening a gas flow path (48) connecting the third gas inlet (44) to the first gas outlet (38) to supply a mixed gas of the carrier gas and the leaked gas to the gas detection unit (14), blocking a branch path (60) of the gas flow connecting the first gas inlet (36) to the vacuum pump (58), and opening the gas flow path (54) connecting the first gas inlet (36) to the second gas outlet (40) and the gas flow path (56) connecting the second gas inlet (42) to the vacuum pump (58); characterized by comprising the above steps.

15. - Flushing the test chamber unit (12) and / or the gas detection unit (14) with gas sucked from the atmosphere around the gas control unit (16) through the third gas inlet (44). The method according to claim 14, further comprising the above step.

16. The gas flow path (54) connecting the first gas inlet (36) to the second gas outlet (40) and the gas flow path (56) connecting the second gas inlet (42) to the third gas outlet (46) are each closed while evacuating the test chamber (18) using the vacuum pump (58) of the gas control unit (16). The method according to claim 14 or 15, characterized in that.

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