JP2017072491A - Leakage inspection device and leakage inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method of micro leakage inspection using a gas or liquid having a molecule amount larger than helium.SOLUTION: The leakage inspection includes the steps of: placing a test subject S in a test subject vacuum chamber 21; after hermetically sealing the test subject vacuum chamber 21, evacuating by vacuum evacuation means 33; pressurizing and supplying a probe fluid from the exploration fluid pressure application/recovery system 1 to the device under test S; and measuring a partial pressure of the probe fluid leaked from the device under test S by a gas detection means 32. As the gas detecting means 32, a highly durable gas detecting means operable in an ultrahigh vacuum to a medium vacuum is used. A gas detection means operable in the vacuum region from an ultrahigh vacuum to 1 Pa order may be used depending on the connection configuration of vacuum evacuation means.SELECTED DRAWING: Figure 1(a)

Description

  The present invention is a leak inspection that quantitatively inspects leaks generated from defects in joints and seals such as welds and the like in various consumer and industrial parts and containers such as automobile parts, aircraft parts, and pharmaceuticals. The present invention relates to an apparatus and a leakage inspection method.

  For various parts that make up power generation facilities, gas and water supply facilities, as well as various parts of automobiles and aircraft, and containers for food and pharmaceuticals, etc., parts related to the transfer and storage of these fluids, structures such as containers themselves, welding, etc. It is necessary to inspect for leaks resulting from defects in the joint and seal. For the leak inspection method, the pressure foaming method, the underwater foaming method, the color check method, the ultrasonic method, the differential pressure method, the vacuum vessel method, etc. are used. Of these, the differential pressure method or the vacuum vessel is used to quantitatively inspect the leak. Use the law.

Patent Document 1 discloses a differential pressure method. In the differential pressure method, gas pressure is applied to the DUT and the master without leakage, the valve of the pressurization line is closed, and the pressure difference between the DUT and the master is measured with a differential pressure sensor after a certain period of time. Although the amount of leakage is estimated, the detection resolution of the leakage inspection device based on the differential pressure method is about 10 ⁻⁴ Pam ³ / s, so inspection of parts with an allowable leakage amount of more than 10 ⁻³ Pam ³ / s mainly. Used in

When the vacuum container method is used, it is possible to inspect the allowable leak amount of 10 ⁻³ Pam ³ / s or less. In the leak inspection by the vacuum container method, the test object is placed in the vacuum container, The exploration gas is introduced into the interior, and the leaked exploration gas is detected by a gas detector. In general, a helium leak inspection method using helium gas as the exploration gas is frequently used.
Patent Document 2 discloses a helium leak inspection apparatus, which includes a high vacuum exhaust vacuum pump for exhausting an analyzer and a rough exhaust apparatus for exhausting a test object, and leaks detected by a reverse diffusion method. In the detector, the configuration of the exhaust path from the vacuum pump for high vacuum exhaust and the support portion of the bearing of the rotor is simplified to simplify the device configuration.

In the helium leak inspection method in which leak detection is performed by the reverse diffusion method, the vacuum chamber of the device under test is evacuated in a short time of about 10 seconds from atmospheric pressure to a medium vacuum on the order of 10 Pa using a roughing pump, Helium gas and other residual gas are introduced between the high vacuum pump and the roughing pump on the detection side. At this time, a part of the light molecular helium gas having a small molecular weight reaches the helium detector by the reverse diffusion phenomenon and is detected. As a result, even if the vacuum chamber of the device under test is set to a medium vacuum on the order of 10 Pa, leakage inspection can be performed while maintaining the helium detector (mainly the magnetic field deflection type mass spectrometer) in a high vacuum state. It is possible to inspect for leaks. Here, in JIS Z 8126-1, medium vacuum is defined as a vacuum in a pressure range of 0.1 Pa to 100 Pa, and high vacuum is defined as a vacuum in a pressure range of 1 × 10 ⁻⁵ Pa to 0.1 Pa. Note that the ultra-high vacuum is defined as a vacuum in a pressure range of 1 × 10 ⁻⁹ Pa to 1 × 10 ⁻⁵ Pa.

  The leak inspection method using helium as the exploration gas has been severely restricted in recent years due to concerns about the exhaustion of helium as a resource and the ubiquitous production areas. In order to use the reverse diffusion phenomenon, it is conceivable to use hydrogen gas other than helium. However, since hydrogen gas may explode, hydrogen gas is mixed with other inert gases to reduce the hydrogen gas concentration to 3%. It is necessary to use a mixed gas less than the above, and the hydrogen released from the vacuum vessel of the leak inspection device is in the background, so there is a problem that a small amount of leak inspection is difficult. Is difficult. Therefore, it is appropriate to use a gas or liquid having a molecular weight larger than that of helium as the exploration fluid.

  In the leak inspection method using a gas or liquid whose molecular weight is higher than that of helium as the exploration fluid, the reverse diffusion phenomenon cannot be used. Therefore, it is necessary to evacuate the vacuum chamber under test to a high vacuum, Therefore, it is difficult to perform a leak inspection in a short time.

  Patent Document 3 relates to a method and an apparatus for a leak inspection apparatus using a high-pressure liquid as an exploration liquid in order to perform a high-pressure component leak inspection safely and at low cost. In leak inspection using liquid, the liquid evaporates when it leaks from the DUT. Since this liquid vapor has a molecular weight higher than that of helium, the exploration liquid vapor and residual gas are detected by a gas detector (for example, a quadrupole). A method of directly leading to a mass spectrometer (operating in a vacuum region of the order of 1 Pa or less) is adopted.

  By devising such as mirror-polishing the inner surface of the vacuum chamber of the device under test, for example, a vacuum evacuation time of 20 seconds for reaching 0.1 Pa from atmospheric pressure is realized for evacuation to high vacuum. As a result, when a small metal part having a small amount of adsorbed gas and contained gas is used as a test object, a short inspection time of, for example, about 60 seconds is achieved. If this technology is used, a highly efficient leak inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as an exploration fluid can be realized.

  As a means of ensuring high efficiency in the case of a leak inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as an exploration fluid, a gas detector operating in a vacuum region of the order of 1 Pa or less is used instead of a gas detector of about 10 Pa. It is conceivable to use a gas detector that can be operated even in a medium vacuum. As one of such gas detectors, there is a means for detecting light emission (referred to as discharge light emission) from an excited state of the gas by exciting the gas by ionization and radicalization by discharge. Patent Document 4 discloses a leak display device for a vacuum apparatus that employs a Penning discharge system as a system for exciting a gas, and includes a total pressure measurement mechanism using ion current measurement and a partial pressure measurement mechanism using emission intensity measurement of various gases. Has been.

  In Patent Document 5, a high-pressure discharge method or glow discharge method using an induction coil using a high-frequency power source is adopted as a mechanism for exciting gas, and a total pressure measuring mechanism and a partial pressure measuring mechanism by measuring emission intensity of various gases are provided. A leak inspection apparatus for containers such as fuel tanks is disclosed.

  Furthermore, there is a standard leak for calibrating the leak amount as another problem when implementing a leak inspection apparatus using a gas or liquid having a molecular weight larger than that of highly efficient helium as a search fluid. There is a standard leak of a gas such as a typical gas such as hydrogen, helium, nitrogen, or a refrigerant gas such as chlorofluorocarbon, but there is no standard leak of any liquid vapor. Patent Document 6 and Patent Document 7 involve one of the present inventors. For measuring the pressure in a microporous filter, a gas reservoir, a gas introduction system, a vacuum pump, and a gas reservoir whose conductance is calibrated in advance. The present invention relates to a reference minute gas flow rate introduction device composed of a vacuum gauge, a valve, and piping.

  By using this, not only an arbitrary gas but also a reference gas flow rate for liquid vapor such as water vapor or alcohol can be realized. Furthermore, in order to compare the amount of leakage due to the difference between exploration fluids, it is necessary to calibrate the leakage inspection apparatus using various gas types and liquid vapors. This can be achieved with the invention.

Japanese Patent Laid-Open No. 5-296687 Patent 2606568 International Publication WO2012 / 005199 JP 52-131780 A Japanese Patent No. 2926943 JP 2011-047855 A JP 2012-154720 A

  As helium is a resource-related concern about depletion and production sites are ubiquitous, there are significant restrictions on the use of helium as the exploration gas for leak inspection, and leak inspection of a large number of parts and containers at the manufacturing site. In Japan, leak inspection using exploration fluid other than helium is required from the viewpoint of continuation of stable leak inspection and cost. In addition, the use of hydrogen as the exploration gas requires the use of a mixed gas with a hydrogen gas concentration of less than 3% because there is a risk of explosion, and the hydrogen released from the vacuum vessel of the leak inspection device is in the background. Therefore, there is a problem that it is difficult to inspect a small amount of leakage. For this reason, the leak inspection method using hydrogen gas is also not suitable for leak inspection in a mass production line.

  In a leak test using a gas or liquid having a molecular weight higher than that of helium as the exploration fluid, the reverse diffusion phenomenon cannot be used. Therefore, it is necessary to evacuate the vacuum chamber of the device under test to a high vacuum. This makes it difficult to perform a leak inspection for a short time. In particular, when the parts and containers of the device under test are made of organic materials, the amount of released gas in vacuum is much larger than that of metal materials, and a large amount of released gas flows into the gas detector. Inspection is hindered.

  Patent Document 3 by the present inventors is an invention of a leak inspection apparatus using a high-pressure liquid as an exploration liquid. According to this, the vacuum chamber of the object to be tested is vacuumed from atmospheric pressure to high vacuum by polishing the inner surface. For example, when a small metal part with a small amount of adsorbed gas and contained gas is used as a test object, a short inspection time of about 60 seconds can be realized. If this technique is used, a highly efficient leak inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as a test fluid can be realized.

  However, when the specimen is made of an organic material or has a large surface area with a complex structure, the specimen has a large amount of adsorbed gas and contained gas. It takes several minutes to several tens of minutes to reach the vacuum, making it difficult to achieve a short inspection time. In addition, a mass spectrometer is used as a gas detector for detecting leaks in the exploration liquid. However, if this is used continuously in a vacuum environment of the order of 0.1 Pa, which is close to the maximum operating pressure, the sensitivity deteriorates and the leak is highly reliable. It becomes impossible to inspect. As described above, even if the technique of Patent Document 3 is used, there is a problem in realizing a highly efficient leak inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as a search fluid.

  Since Patent Document 4 or Patent Document 5 is a leak inspection apparatus equipped with a partial pressure measuring mechanism using a means for detecting discharge luminescence of gas as a gas detector that can be operated even in a medium vacuum of about 10 Pa, these technologies are disclosed. If used, the evacuation time can be greatly shortened, and there is a possibility of realizing a highly efficient leak inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as the exploration fluid.

However, in order to detect a minute leak of 10 ⁻⁵ Pam ³ / s or less, for example, when a vacuum pump with an effective pumping speed of 0.1 m ³ / s is used, the partial pressure of the exploration fluid of 10 ⁻⁴ Pa or less Need to be detected. For this purpose, it is effective to lower the background pressure of the gas detector to 10 ⁻⁴ Pa or less, and in a gas detector for detecting discharge luminescence, an ultrahigh vacuum from 10 ⁻⁴ Pa to 10 ⁻⁷ Pa. It is desired that the discharge is maintained even in the region and the partial pressure is detected.

In the case of the Penning discharge method disclosed in Patent Document 4, it is difficult to maintain a stable discharge at 10 ⁻⁴ Pa or less, and the discharge emission is weak, so a trace leakage detection of 10 ⁻⁵ Pam ³ / s or less is detected. Therefore, there is a problem that it is difficult to measure partial pressure. It is difficult to maintain the discharge in the following cases 10 ^-2 Pa of the high voltage application system or glow discharge method by inductive coupling through the use of high-frequency electric field as disclosed in Patent Document 5, since and discharge emission also weak 10 ^- There is a problem that it is difficult to measure a partial pressure for detecting a leak of ³ Pam ³ / s or less. Thus, when the partial pressure measurement technique by detecting the gas emission of Patent Document 4 or Patent Document 5 is used, there is a problem that it is difficult to inspect a small amount of leakage.

  In addition, the discharge emission of gas molecules is composed of a large number of emission spectra even in one gas molecule, and since various gases emitted from the inner surface of the device other than the exploration fluid and the test object exist as backgrounds, In order to perform partial pressure measurement for detecting an accurate amount of leakage, it is effective to measure a plurality of emission spectra in real time and compare and separate the exploration fluid and the background.

  In luminescence measurement for measuring partial pressure for leak detection in Patent Document 4 or Patent Document 5, one emission spectrum is extracted by limiting the wavelength with a filter or a diffraction grating, and measured with a photomultiplier tube. Since only the means to do so is disclosed, real-time measurement of a large number of light emissions is difficult, and accurate partial pressure measurement is considered difficult. As described above, a highly efficient leak inspection apparatus using a gas or liquid having a molecular weight higher than that of helium as an exploration fluid is realized even if the partial pressure measurement technique by detecting gas luminescence of Patent Document 4 or Patent Document 5 is used. There is a problem to make it.

Under such circumstances, in order to conduct a leak inspection using a gas or liquid having a molecular weight larger than that of helium as the exploration fluid with high efficiency and accuracy,
(1) Devise means to protect mass spectrometers that require high vacuum, which is a detector for exploration fluids,
Or
(2) Use a highly sensitive gas detector that can be operated from ultra-high vacuum to medium vacuum and that can handle trace leak detection.
It can be considered.

  Another problem when implementing a leak inspection device that uses a gas or liquid having a molecular weight higher than that of helium as the exploration fluid is leakage when using atmospheric component gases such as nitrogen, oxygen, argon, and carbon dioxide as the exploration gas. In the inspection, gas in the atmosphere becomes the background, raising the lower detection limit and hindering detection of a small amount of leakage. In particular, when the vacuum evacuation of the device under test vacuum chamber is evacuated to a medium vacuum of about 10 Pa, a large amount of atmospheric component gas remains. Therefore, it is necessary to perform a correction to make these atmospheric component background signals zero. is there.

  Patent Document 4 discloses that zero correction is performed, but a specific method thereof is not disclosed, and it is considered that zero correction of a general noise level employed in a helium leak inspection apparatus is performed. . On the other hand, Patent Document 5 does not disclose zero point correction.

  As a further problem when implementing a leak inspection device that uses a gas or liquid having a molecular weight higher than that of helium as the exploration fluid, it takes time to recover the liquid in the leak inspection when the liquid is the exploration fluid. In order to shorten the time, a method for inspecting leaks for a test object into which liquid has been introduced in advance will be adopted. It becomes a problem that the inspection becomes difficult.

  Furthermore, as another problem when implementing a leak inspection device that uses a gas or liquid whose molecular weight is larger than that of helium as the exploration fluid, the partial pressure data of the leaked exploration fluid molecules detected by the gas detector is leaked. Standard leak for changing to. That is, there is a problem that a gas standard leak product exists, but a liquid vapor standard leak product does not exist.

  Also, in order to ensure consistency and continuity with the conventional helium leak test, the results of the helium leak test are compared with the results of the leak test using a gas or liquid with a molecular weight higher than helium as the exploration fluid. Need to be verified. In order to perform such a comparative test with the same device, it is necessary to calibrate the gas detector using a plurality of gas species. However, since the helium standard leak uses the transmission phenomenon of quartz glass, It cannot be used for calibration. Capillary leak is difficult to correct for the difference in flow rate due to the difference in gas type because the gas flow characteristics change from molecular flow to intermediate flow and viscous flow. In addition, it is necessary to prepare a capillary leak and calibrate it using the capillary leak. Capillary leaks cannot generally be used for liquid vapor calibration.

  The present invention solves the above-mentioned problems of the prior art and the problems inherent in leak inspection using atmospheric component gases and liquids as exploration fluids, and uses a gas or liquid having a molecular weight higher than that of helium as the exploration fluid. Leaks that are highly efficient and capable of detecting trace leaks because inspections can be performed in a short period of time, even if the DUT is made of an organic material with a large amount of released gas or a complex structure. The object is to provide an inspection device.

  The present invention has been made to solve the above-mentioned problems, and the leak inspection apparatus according to the present invention 1 is a leak inspection apparatus for inspecting the amount of leakage of a test object, and can be sealed to arrange the test object. A test object vacuum chamber, exploration fluid supply means for pressurizing a gas or liquid search fluid having a molecular weight larger than helium into the test object, and a vacuum valve to the test object vacuum chamber A highly durable gas detecting means capable of operating from a connected ultra-high vacuum to a medium vacuum and capable of detecting a small amount of leakage, a vacuum exhaust means connected to the highly durable gas detecting means, and a vacuum chamber to be tested An exploration fluid standard leak that supplies the exploration fluid with a known amount of leakage connected via a vacuum valve, and the test object is attached to the inside of the test object vacuum chamber, and then the test object With the body vacuum chamber sealed The high-durability gas detection means detects the partial pressure of the exploration fluid leaked from the test object into which the exploration fluid is pressurized and introduced into the inside at an atmospheric pressure or higher by the exploration fluid supply means. The amount of leakage from the device under test is measured by

  A leak inspection apparatus according to a second aspect of the present invention is the leak inspection apparatus according to the first aspect of the present invention, wherein the highly durable gas detecting means has an excitation mechanism by cold cathode discharge using a magnetic field, and from a light emitting source by gas molecules excited by the excitation mechanism. Spectroscopic means for splitting light, optical detection means for separately and simultaneously detecting the intensity of the light split by the spectral means for each light wavelength, and converting it into an electrical signal, and the intensity of the wavelength of light unique to gas molecules And a data processing means for calculating the gas partial pressure based on the data stored in the database from the electrical signal, and a highly durable gas detection means comprising: It is.

  The leakage inspection apparatus according to the present invention 3 is the rough evacuation means for the vacuum evacuation means connected to the highly durable gas detection means to evacuate to a medium vacuum in the first or second aspect of the present invention, A medium vacuum is applied by the rough evacuation means in a state in which the vacuum chamber of the device under test is sealed.

  According to a fourth aspect of the present invention, there is provided the leak inspection apparatus according to any one of the first to third aspects, wherein the high durability gas detecting means is connected to the device under test vacuum chamber via the vacuum valve, and the roughing vacuum exhaust means is connected thereto. In addition, a roughing vacuum evacuation means for evacuating to a medium vacuum is connected to the device under test vacuum chamber via a vacuum valve, and the device under test is provided inside the device under test vacuum chamber. After the body is attached, the test object vacuum chamber is sealed and evacuated by the roughing vacuum evacuation means, and then measured by the highly durable gas detection means that maintains the vacuum at all times by switching the valve. The amount of leakage from the device under test is measured.

  According to the fifth aspect of the present invention, there is provided a leak inspection apparatus according to any one of the first and second aspects, wherein the vacuum exhaust means connected to the high durability gas detection means maintains the high durability gas detection means at a high vacuum at all times. High vacuum evacuation means for evacuating to a vacuum, and further, rough vacuum evacuation means for evacuating to a medium vacuum through a vacuum valve is connected to the vacuum chamber to be tested.

  A leakage inspection apparatus according to a sixth aspect of the present invention is the method according to any one of the first and second aspects, wherein the vacuum evacuation unit connected to the high durability gas detection unit is a high vacuum evacuation unit for evacuating to a high vacuum. A rough evacuation means for evacuating the DUT vacuum chamber to a medium vacuum through the vacuum valve, and a high vacuum evacuation means in parallel to the DUT vacuum chamber via the vacuum valve. The vacuum evacuation means connected to the vacuum chamber to be tested through a vacuum valve is set to two or more systems, and the specimen vacuum chamber and the highly durable gas detection means are in a high vacuum state and then inspected for leakage. It is a thing.

  A leak inspection apparatus according to a seventh aspect of the present invention is the leakage inspection apparatus according to any one of the fifth to sixth aspects, wherein a residual gas trapping means is connected in the middle of a vacuum pipe connecting the DUT vacuum chamber and the highly durable gas detector. is there.

  The leak inspection apparatus according to the present invention 8 is a leak inspection apparatus for inspecting a leakage amount of a test object, wherein a sealable test object vacuum chamber in which the test object is disposed, and helium in the test object are made from helium. Exploration fluid supply means for pressurizing a gas or liquid exploration fluid having a high molecular weight, and rough evacuation means for evacuating to a medium vacuum connected to the device under test vacuum chamber via a vacuum valve A residual gas trapping means connected to the vacuum chamber of the device under test via a vacuum valve, and an ultra-high vacuum connected to the residual gas trapping means to operate in a vacuum range of the order of 1 Pa and detect a minute amount of leakage. Gas detection means capable of high-vacuation means and rough evacuation means connected in series to the gas detection means, and a known leakage amount connected to the vacuum chamber to be tested via a vacuum valve. Providing the exploration fluid The exploration fluid standard leak is evacuated, and the exploration fluid is evacuated by the roughing evacuation means in a state where the vacuum chamber is sealed, and the exploration fluid is connected to the exploration fluid supply means. The amount of leakage from the device under test is measured by measuring the partial pressure of the exploration fluid that has leaked from the device under test with the gas detection means. .

  A leak inspection apparatus according to a ninth aspect of the present invention is a leak inspection apparatus for inspecting a leakage amount of a test object, wherein a sealable test object vacuum chamber in which the test object is arranged, and helium in the test object are made from helium. Exploring fluid supply means for pressurizing a gas or liquid exploration fluid having a high molecular weight, and rough evacuation for evacuating to a medium vacuum connected to the device under test vacuum chamber via a vacuum valve. Two or more vacuum evacuation means including a high vacuum evacuation means and a rough evacuation means connected in series via a vacuum valve, and an ultra-high height connected to the device under test vacuum chamber via a vacuum valve A gas detection means capable of operating from a vacuum to a vacuum range of the order of 1 Pa and capable of detecting a small amount of leakage, a high vacuum exhaust means and a rough exhaust means connected in series to the gas detection means, and the test object vacuum True in the room A known amount of leakage of the probe fluid exploration fluids standard leak supplies connected via a valve, it is those provided with the.

  A leak inspection apparatus according to a tenth aspect of the present invention is the leak inspection apparatus according to the ninth aspect of the present invention, wherein a residual gas trapping means is connected in the middle of a vacuum pipe connecting the device under test vacuum chamber and the gas detecting means.

  The leak inspection apparatus according to the eleventh aspect of the present invention uses the air component gas as the exploration fluid according to any one of the first to tenth aspects of the present invention, and measures the background air signal by the residual air component gas. And calculating the residual air gas component signal after t seconds using the fact that the residual air component gas decreases according to an exponential function, and measuring the residual air gas component signal after t seconds The background correction is performed by subtracting the calculated value of the residual air gas component from the value.

The leak inspection apparatus according to the twelfth aspect of the present invention provides the gas detector partial pressure signal at time t as P (t ) When the correction signal of the partial pressure signal is P _C (t), the zero point signal is P _0C , and the signal change rate is D (t), there is no leakage and the partial pressure signal P (t) is reduced or constant. Is set so that the correction signal P _C (t) is in the vicinity of the zero point signal P _0C, and when there is a leak and the partial pressure signal P (t) increases. the correction signal P _C (t) is set to the signal change rate D (t) to reproduce the original divided signal P (t) at the time of leakage determination time, the correction signal P _C a (t) It has a correction function of _{obtaining by} P _C (t) = P _0C + P (t) × D (t).

  The leak inspection apparatus according to the thirteenth aspect of the present invention includes, in any one of the first to twelfth aspects of the present invention, a micropore filter calibrated in advance as the exploration fluid standard leak.

  The leak inspection method according to the present invention 14 is a leak inspection method for inspecting a leak amount from a test object using a gas or liquid exploration fluid having a molecular weight larger than that of helium, and can be evacuated and sealed. Placing the device under test in a body vacuum chamber and sealing the device vacuum chamber; evacuating the device vacuum chamber in a sealed state; and inside the device under test. The exploration fluid supply means pressurizes the exploration fluid at a pressure higher than atmospheric pressure, and the partial pressure of the exploration fluid leaked from the test object can be operated from an ultra-high vacuum to a medium vacuum to detect a small amount of leakage. And measuring with a possible highly durable gas detection means.

  A leakage inspection method according to a fifteenth aspect of the present invention is the method according to the fourteenth aspect of the present invention, wherein the high-durability gas detecting means has an excitation mechanism by cold cathode discharge using a magnetic field, and from a light emitting source by gas molecules excited by the excitation mechanism. Spectroscopic means for splitting light, optical detection means for separately and simultaneously detecting the intensity of the light split by the spectral means for each light wavelength, and converting it into an electrical signal, and the intensity of the wavelength of light unique to gas molecules A highly durable gas detection means comprising a database storing the relationship between the gas partial pressure and a data processing means for calculating the gas partial pressure based on the data stored in the database from the electrical signal.

  The leak inspection method according to the present invention 16 is a leak inspection method for inspecting a leak amount from a test object using a gas or liquid exploration fluid having a molecular weight larger than that of helium, and can be evacuated and sealed. The test object is placed in a body vacuum chamber, an exploration fluid supply means is connected to the test object, and the test object vacuum chamber is sealed, and the test object vacuum chamber is sealed. A rough evacuation means connected to the device under test vacuum chamber is evacuated to a medium vacuum through a vacuum valve, and a residual gas trapping means connected to the device under test vacuum chamber and a high vacuum evacuation means are used. Maintaining a gas detection means capable of operating from a high vacuum to a vacuum range of the order of 1 Pa and capable of detecting a small amount of leakage in a high vacuum state, and the exploration fluid by the exploration fluid supply means inside the test object To the partial pressure of the probe fluid leaking from the test object introduced under pressure above atmospheric pressure measured by the gas detection means, it is made of.

  The leak inspection method according to the present invention 17 is the method according to any one of the present inventions 14 to 16, wherein an air component gas is used as the exploration fluid, and the background of the residual air component gas is measured when the background due to the residual air component gas is measured. Measure the partial pressure, calculate the residual air gas component after t seconds using the decrease in the residual air component gas according to an exponential function, and derive from the measured value of the residual air gas component after t seconds Background correction is executed by subtracting the calculated value.

In the leak inspection method according to the present invention 18, in any of the present inventions 14 to 17, when correcting the signal of the gas detector for detecting the leak amount, the partial pressure signal of the gas detector at time t is expressed as P (t ) When the correction signal of the partial pressure signal is P _C (t), the zero point signal is P _0C , and the signal change rate is D (t), there is no leakage and the partial pressure signal P (t) is reduced or constant. Is set so that the correction signal P _C (t) is in the vicinity of the zero point signal P _0C, and when there is a leak and the partial pressure signal P (t) increases. the correction signal P _C (t) is set to the signal change rate D (t) to reproduce the original divided signal P (t) at the time of leakage determination time, the correction signal P _C a (t) Correction is performed such that P _C (t) = P _0C + P (t) × D (t).

  The leak inspection method according to the present invention 19 includes a micropore filter that is calibrated in advance as a standard leak in any of the present inventions 14 to 18, and the leak amount is calibrated by the micropore filter.

  According to the leakage inspection apparatus using a gas or liquid having a molecular weight larger than that of helium as the exploration fluid of the present invention, the exploration above the atmospheric pressure is performed on the test object placed in the vacuum chamber of the test object that has been evacuated. By supplying the fluid to the inside of the DUT in a sealed state and measuring the partial pressure of the exploration fluid molecules that have leaked into the vacuum with a gas detector, it is possible to perform a micro leak inspection with high efficiency. Become. Thereby, a leak test can be carried out without using helium which is concerned about depletion. When an exploration liquid of 1.0 MPa or more is used, it is possible to carry out a micro leak inspection and a pressure resistance test under high pressure simultaneously with high efficiency. As a result, it is possible to inspect leaks of high-pressure products such as parts and containers of various energy sources whose fuel pressure is increasing.

It is the schematic diagram which showed an example of the structure of the leak test | inspection apparatus by the Example of this invention. It is the schematic diagram which showed the example of the other form of the structure of the leak test | inspection apparatus by the Example of this invention. It is the schematic diagram which showed an example of the magnetic field discharge light emission type | mold gas detector which is a highly durable gas detector used for the leak test | inspection apparatus by the Example of this invention. It is the schematic diagram which showed the structure of the leak test | inspection apparatus by the other Example of this invention. It is the schematic diagram which showed the structure of the leak test | inspection apparatus by other Example of this invention. It is the schematic diagram which showed the structure of the leak test | inspection apparatus by other Example of this invention. It is the schematic diagram which showed the structure of the leak test | inspection apparatus by other Example of this invention. It is the schematic diagram which showed an example of the standard leak used for the leak inspection apparatus by further another Example of this invention. It is the schematic diagram which showed an example which correct | amends the background signal of air component gas in the case of using air component gas as a search fluid. It is the schematic which showed an example of the time transition of the exploration fluid in case a leak test | inspection is carried out by carrying out the zero point correction | amendment of a background signal in a state without a leak, and introduce | transducing a search fluid into a to-be-tested object after that. It is the schematic diagram which showed an example of the time transition of the exploration fluid in the zero point correction | amendment in the case of carrying out a leak test | inspection of the to-be-tested body into which the exploration fluid was introduced previously.

Hereinafter, embodiments of the present invention will be described. As for the vacuum range, the above-mentioned JIS Z 8126-1 medium vacuum: 0.1 Pa to 100 Pa pressure range vacuum, high vacuum: 1 × 10 ⁻⁵ Pa to 0.1 Pa pressure range vacuum, ultra high vacuum The description will be made on the assumption that the pressure is in the range of 1 × 10 ⁻⁹ Pa to 1 × 10 ⁻⁵ Pa.

[Exploration fluid]
Hereinafter, embodiments of a highly efficient leak inspection apparatus and leak inspection method using a gas or liquid having a molecular weight larger than that of helium according to the present invention as a search fluid will be described with reference to the drawings. The leak inspection is performed by introducing the exploration fluid into the body under test, and examples of the exploration fluid gas include air component gases such as nitrogen, oxygen, argon, and carbon dioxide, and organic gases such as methane gas and butane gas. A mixed gas obtained by mixing these gases may be used. Such a gas having a molecular weight larger than that of helium can be applied to leak inspection of various parts and containers.

  On the other hand, since the exploration fluid liquid is desired to have properties such as being easy to pass through a leak hole and being easily vaporized, the molecular weight is 500 or less, the solidification pressure at room temperature is 1 MPa or more, and the saturated vapor pressure. Is preferably a liquid that satisfies the conditions of 100 Pa or more and latent heat of vaporization of 80 kJ / mol or less, alcohols such as methanol and ethanol, saturated hydrocarbons such as liquefied butane, ketones such as acetone, aromatics such as benzene, and Examples thereof include fluorocarbons which are inert liquids having a carbon-fluorine bond, and water. A mixed solution obtained by mixing these liquids may be used. Examples of the mixed solution include petroleum such as gasoline and light oil, which are fuels for automobiles and aircraft.

Since the liquid has a higher density than the gas, the liquid leak amount is larger than the gas leak amount for the same leak hole, and the liquid has a small amount of leak of 10 ⁻⁵ Pa or less. Suitable for inspection. Also, fuel, beverages, and pharmaceutical liquids that are energy sources can be applied to the exploration fluid.

[Embodiment 1]
1 and 3 to 6 are schematic views showing a configuration example according to an embodiment of a leak inspection apparatus according to the present invention. In any of the configuration examples, the leak inspection apparatus includes the exploration fluid pressurization / recovery system 1, a device vacuum system 2, and an inspection vacuum system 3.
FIGS. 1A and 1B are schematic diagrams illustrating a configuration example of a leakage inspection apparatus according to the first embodiment. Embodiment 1 will be described with reference to FIG. The exploration fluid pressurization / recovery system 1 in FIG. 1A is for introducing the exploration fluid F into the test object S by the exploration fluid pressurization supply device 11 and pressurizing it to an atmospheric pressure or higher. . This system includes an exploration fluid pressure supply device 11, an exploration fluid supply line 12 for supplying a pressurized exploration fluid F to the inside of the test object S, and the test object S and the exploration fluid supply after completion of the inspection. From the exploration fluid recovery device 13 for recovering the exploration fluid F remaining in the line 12, the evacuation line 14 for removing the exploration fluid F remaining after the recovery and the air introduced for the recovery, and valves 15 to 18 Composed.

A test object vacuum system 2 in FIG. 1A includes a test object vacuum chamber 21 in which a test object S is introduced and arranged, and a search fluid for quantifying a leak connected via a vacuum valve 22-a. And a standard leak 22-b. The inspection vacuum system 3 in FIG. 1A includes a gas detector 32 connected to a device under test vacuum chamber 21 via a vacuum valve 31 and a roughing pump 33 connected thereto. Here, as the gas detector 32, a highly durable gas detector using magnetic field discharge that can be operated from an ultrahigh vacuum to a medium vacuum on the order of 100 Pa and can detect a small amount of leakage of 10 ⁻⁷ Pam ³ / s is used. As described later in [High Durability Gas Detector Technology], this high durability gas detector is capable of measuring partial pressure for leak detection and measuring total pressure from atmospheric pressure to ultra-high vacuum.

For example, the leakage inspection in the first embodiment shown in FIG. 1A is performed as follows.
(1A) The test object S is introduced and arranged in the test object vacuum chamber 21 of the test object vacuum system 2 and connected to the search fluid supply line 12 of the search fluid pressurization / recovery system 1. Thereafter, the inside of the test object S is evacuated using the evacuation line 14 of the exploration fluid pressurization / recovery system 1. At the same time, the vacuum valve 31 is opened and evacuation of the device under test vacuum chamber 21 is started. Immediately after opening the vacuum valve 31, the gas detector 32 instantaneously becomes atmospheric pressure. Therefore, when using a highly durable gas detector, the partial pressure detection function by magnetic field discharge is temporarily stopped.

  (1B) After the pressure in the vacuum chamber 21 to be tested reaches a medium vacuum of, for example, 100 Pa, the partial pressure measurement of the gas detector 32 is activated, and background measurement, which is a leakage-free condition before introducing the exploration fluid, is started. . At this time, if the exploration fluid F is an air component gas, the air component background signal correction is performed using the evacuation data of the residual air component gas measured in advance with a test object having no leakage, and then noise is detected. Perform level background zero correction. On the other hand, in the case of exploration fluid other than air component gas, background zero correction of noise level is executed.

  (1C) Next, using the exploration fluid pressurization supply device 11 of the exploration fluid pressurization / recovery system 1, the exploration fluid F is pressurized and introduced into the specimen S and leaked from the specimen S A leak test is performed by measuring the partial pressure of F with the gas detector 32.

  (1D) After completion of the test for leakage of the test object, the valve 15 of the exploration fluid pressurization / recovery system 1 is closed to complete the introduction of the exploration fluid F, and at the same time the valves 16 and 17 are opened to collect the exploration fluid. The apparatus 13 is used to release the pressurization of the exploration fluid F and collect the exploration fluid F remaining in the test object S and the exploration fluid supply line 12. At this time, the vacuum valve 31 is closed and the gas detector 32 is maintained in a vacuum state. Finally, the specimen vacuum chamber 21 of the specimen vacuum system 2 is returned to the atmosphere, and the specimen S is taken out.

  (1E) Next, the exploration fluid supply line 12 is sealed and the evacuation procedure is performed, the vacuum valve 22-a is opened, and the exploration fluid having a known leakage amount is supplied from the exploration fluid standard leak 22-b. Measurement is performed by the gas detector 32. Using this standard leak measurement data, the measurement data of the exploration fluid F leaking from the test object S is calibrated, and the amount of leak is estimated.

  In (1B) of this leakage inspection step, the air component background signal correction for the residual air component gas is the content of claim 11, and the background zero correction of the noise level is the content of claim 12.

  In the leak test according to the configuration of FIG. 1A, the gas detector 32 is instantaneously at atmospheric pressure for each test, so there is contamination due to exposure to the atmosphere. There is a problem that the pressure measuring function needs to be stopped from operation every time it is inspected, and then it takes several seconds. When performing a leak inspection of a large number of test objects with high efficiency, it is desired to reduce the contamination of the gas detector 32 by the atmosphere and the operation-stop-operation time. In this case, as shown in FIG. 1B, the gas detector 32 is bypassed and connected to the roughing pump 33 by using the vacuum valve 31-1 to the vacuum valve 31-3 in the inspection vacuum system 3. It is effective.

  In the step of the leak inspection in the configuration of FIG. 1B, the vacuum valve 31-1 and the vacuum valve 31 are used when the device under test vacuum chamber 21 is evacuated from the atmospheric pressure in the above-described step [0058] (1A). -2 is closed and the gas detector 32 is kept in a vacuum state, the vacuum valve 31-3 is opened and evacuated. Next, when checking for leaks in (1B) to (1E), the vacuum valve 31-1 and the vacuum The valve 31-2 is opened and the vacuum valve 31-3 is closed to inspect the gas from the device under test vacuum chamber 21 and the exploration fluid gas leaked from the device under test S to the gas detector 32. The gas detector 32 is evacuated by closing the vacuum valve 31-1 and the vacuum valve 31-3 and opening the vacuum valve 31-2. Through such a procedure, the gas detector 32 can be maintained in a vacuum state at all times, and the partial pressure measurement function of the gas detector can be always in an operating state and can be protected from contamination by the atmosphere. is there.

  In the first embodiment, without using the exploration fluid pressurization / recovery system 1 shown in FIGS. 1 (a) and 1 (b), leakage inspection is performed using the test object S in which the exploration fluid F is introduced into the inside in advance. Is also possible. This is called leak inspection by the bombing method. In this case, in the above-described step (1A) of [0058], the test object S into which the exploration fluid has been previously introduced under pressure is placed in the test object vacuum chamber 21 and evacuated. Thereafter, air component background signal correction and noise level background zero correction are executed in step (1B), and leakage inspection is performed in step (1C). After completion of the leak inspection, the evacuation of the device under test vacuum chamber 21 is finished in step (1C), returned to the atmosphere, and the device under test S is taken out.

  Here, the background zero point correction according to claim 12 corrects the signal in the vicinity of the zero point obtained by the logical operation when there is no leakage and the signal is attenuated or the fluctuation is small. As it increases, the original signal is restored after a certain time. 13. In the leak inspection by the bombing method, the time transition of the signal is attenuated or the fluctuation is small when there is no leak, while the time transition of the signal increases for a certain time when there is a leak. The background zero correction function works effectively. Note that the leak inspection by the bombing method can also be performed in Embodiments 2 to 5 described later.

The first embodiment shown in FIGS. 1A and 1B has an advantage that the apparatus cost can be reduced, and a relatively large amount of leakage inspection of about 10 ⁻³ Pam ³ / s with a relatively small device under test. If so, the inspection time can be as high as several tens of seconds. In addition, the apparatus shown in FIG. 1B capable of protecting the gas detector 32 can be inspected many times. In the first embodiment, when the evacuation time is about several minutes, a leak inspection of about 10 ⁻⁵ Pam ³ / s was possible. From the above, Embodiment 1 is suitable for inspection of relatively large leaks for small parts.

[High durability gas detector technology]
In the leak inspection apparatus and the leak inspection method of the present invention, by using a highly durable gas detection means capable of operating from an ultra-high vacuum to a medium vacuum of 100 Pa and capable of detecting a small amount of leak of 10 ⁻⁷ Pam ³ / s. The micro leak inspection can be performed with high efficiency. As an example of such a highly durable gas detection means, there is one based on the magnetic field discharge emission gas analysis technology developed by one of the inventors of the present invention, which is filed as Japanese Patent Application No. 2015-0500346 (“evacuation monitoring device”). This will be described below.

FIG. 2 is a schematic diagram showing an example of a magnetic field discharge light emission type gas detector. An anode 41 is installed in the vacuum vessel 40, and two cylindrical magnets are installed outside the vacuum vessel 40 as magnetic field applying means 42 with the same polarity of N and N poles or S and S poles facing each other. To do. The vacuum vessel 40 is evacuated to a pressure of the order of 100 Pa or less, and a high voltage is applied to the anode 41 to generate a discharge between the anode 41 and the vacuum vessel 40 (cathode). Here, the electrons move in a high-density magnetic field by the magnets arranged to face each other and localize by spiral movement, and the discharge can be maintained up to an ultrahigh vacuum of the order of 10 ⁻⁷ Pa.

  Gas molecules in the vacuum vessel are excited by discharge, and discharge light emission L is generated. The discharge light emission L is guided to the atmospheric pressure side by the lens 43-1, the lens 43-2, and the optical window 44 and is condensed on the slit 45. The light emitted through the slit is converted into a parallel light beam using the lens 43-3 and the diffraction grating 46. Is incident on. The light is split by the diffraction grating, enters the light detection means 47, is converted into an electrical signal, and is detected.

  Here, the diffraction grating 46 uses a transmission diffraction grating. The light detecting means 47 uses a CMOS sensor in which a large number of solid-state imaging devices using complementary metal oxide semiconductors (CMOS) are arranged, and splits the light into wavelengths and receives the light to detect the light intensity. . Light emission inherent to gas molecules excited by discharge has a different emission wavelength for each gas type, so it is possible to detect discharge luminescence L for each gas type by detecting light emission for each light wavelength. It becomes. The diffraction grating 46 may be a reflection type diffraction grating, and the light detection means 47 may be a CCD sensor in which a large number of charge coupled devices (CCD) are arranged.

  Next, means for converting the discharge light emission of gas molecules into a partial pressure related to the leakage amount using a highly durable gas detector will be described. This gas detector is equipped with a vacuum gauge 48 for measuring the total pressure from ultra high vacuum to high vacuum and a vacuum gauge 49 for measuring the total pressure from medium vacuum to atmospheric pressure. Based on the data stored in the database from the electrical signal, the database storing the relationship between the emission intensity and gas partial pressure peculiar to the gas molecules, and measuring the total pressure and discharge luminescence L by these total pressure vacuum gauges in advance By using the data processing means for calculating the partial pressure, the discharge light emission L of the gas molecule of the exploration fluid used for the leak inspection is converted into the partial pressure.

  In actual leak inspection, in order to ensure that the influence of contamination and deterioration with time of the gas detector is sufficiently small, a fixed amount of exploration fluid is periodically introduced using the exploration fluid standard leak, and the gas detector Compensates for partial pressure measurement.

  If a conventional mass spectrometer type gas analyzer is operated at 0.1 Pa or higher, the oxygen gas of the air component or organic gas causes wear of the hot filament and deteriorates with time. It is necessary to operate. On the other hand, since the magnetic discharge type high durability gas analyzer is a cold cathode discharge method that does not use a hot filament, it can operate from an ultra-high vacuum to an intermediate vacuum region of 100 Pa and has high durability. Furthermore, since a highly durable gas analyzer is easy to maintain, it is easy to take measures against contamination by organic gases. Therefore, when a highly durable gas analyzer is applied to the leakage inspection apparatus of the present invention, it is possible to perform a highly efficient leakage inspection stably over a long period of time.

[Embodiment 2]
Next, the leakage inspection apparatus according to the second embodiment illustrated in FIG. 3 will be described. The exploration fluid pressurization / recovery system 1 and the inspection vacuum system 3 are the same systems as those shown in FIG. On the other hand, the device under test vacuum system 2 has a configuration in which a roughing pump 23-b is newly connected to the device under test vacuum chamber 21 via a vacuum valve 23-a with respect to FIG.

The leak test in the second embodiment shown in FIG. 3 is performed as follows, for example.
(2A) The test object S is introduced into the test object vacuum chamber 21 of the test object vacuum system 2 and connected to the search fluid supply line 12 of the search fluid pressurization / recovery system 1. Thereafter, the inside of the test object S is evacuated using the evacuation line 14 of the exploration fluid pressurization / recovery system 1. At the same time, the vacuum valve 23-a of the device under test vacuum system 2 is opened, and the vacuum evacuation of the device under test vacuum chamber 21 is started by the roughing pump 23-b. At this time, the vacuum valve 31 of the inspection vacuum system is closed, and the gas detector 32 is maintained in a medium vacuum state by the exhaust of the vacuum pump 33. As the gas detector 32, a highly durable gas detector using a magnetic field discharge capable of operating from an ultra-high vacuum to a medium vacuum on the order of 100 Pa and capable of detecting a small amount of leakage of 10 ⁻⁷ Pam ³ / s is used.

  (2B) After the pressure in the vacuum chamber 21 to be tested reaches a medium vacuum of, for example, 100 Pa, the vacuum valve 23-a is closed and the vacuum valve 31 is opened at the same time. Start a background measurement. At this time, if the exploration fluid F is an air component gas, the air component background signal correction is performed using the evacuation data of the residual air component gas measured in advance with a test object having no leakage, and then noise is detected. Perform level background zero correction. On the other hand, in the case of exploration fluid other than air component gas, background zero correction of noise level is executed.

  Thereafter, as in the second embodiment, (2C) the inspection fluid F is pressurized and introduced into the test object S and the leak inspection is executed. (2D) After the completion of the leak inspection of the test object F, Completion and collection of pressurization are performed, and (2E) calibration of the leak amount using the exploration fluid standard leak is performed.

The configuration of the leak inspection apparatus according to the second embodiment shown in FIG. 3 can protect the highly durable gas detector used for leak inspection by maintaining the gas detector 32 in a vacuum state all the time, and an added vacuum exhaust. Since the evacuation speed of the means can be freely selected, it has a feature that various test object leakage inspection apparatuses can be configured. From this, the second embodiment is capable of high-efficiency inspection of several tens of seconds and multiple times for leak inspection up to about 10 ⁻⁴ Pam ³ / s for test pieces of various shapes and sizes. Ensures continuous inspection.

[Embodiment 3 to Embodiment 5]
Embodiments 3 to 5 are embodiments for performing a high-efficiency leak inspection of about 10 ⁻⁷ Pam ³ / s on various test objects. In order to detect minute leaks with high accuracy, the gas detector is maintained in a vacuum environment of high vacuum or higher, and the background gas that reaches the gas detector from the vacuum chamber of the test object during inspection is about several seconds to 10 seconds. It is important to reduce the pressure in the gas analyzer to 0.1 Pa or less in a short time. Embodiments 3 to 5 will be described with reference to the drawings.

In addition, the gas detector used in Embodiments 3 to 5 uses magnetic field discharge that can be operated from an ultrahigh vacuum to a medium vacuum on the order of 100 Pa and can detect a small amount of leakage of 10 ⁻⁷ Pam ³ / s. Highly durable gas detectors and mass spectrometer type gas analyzers capable of operating from ultra-high vacuum to a vacuum range of the order of 1 Pa and capable of detecting a small amount of leakage of 10 ⁻⁷ Pam ³ / s are also available. A mass spectrometer type gas analyzer includes a quadrupole mass spectrometer.

  A leak inspection apparatus according to Embodiment 3 shown in FIG. 4 will be described. The exploration fluid pressurization / recovery system 1 and the DUT vacuum system 2 are the same as those shown in FIG. On the other hand, the configuration of the inspection vacuum system 3 is added to the configuration of FIG. 3 by connecting a residual gas trap 35 via a vacuum valve 31 between the vacuum chamber 21 to be tested and the gas detector 32, and gas. A high vacuum pump 34 is connected between the detector 32 and the roughing pump 33 and added.

For example, the leakage inspection in the third embodiment shown in FIG. 4 is performed as follows.
(3A) Using the exploration fluid pressurization / recovery system 1, the inside of the test object S is evacuated. At the same time, evacuation of the device under test vacuum chamber 21 is started. At this time, the vacuum valve 31 of the inspection vacuum system is closed, and the gas detector 32 is maintained in a high vacuum state of 10 ⁻⁵ Pa to 10 ⁻² Pa by the exhaust of the high vacuum pump 34. Thereby, the gas detector 32 can be operated in a clean vacuum environment that can detect a small amount of leak of 10 ⁻⁷ Pam ³ / s.

  (3B) After the pressure in the device under test vacuum chamber 21 reaches medium vacuum, for example, 10 Pa, the vacuum valve 23-a is closed and the vacuum valve 31 is opened at the same time. Start a background measurement.

  Since the main component of the residual gas in a medium vacuum of about 10 Pa is water vapor, it is effective to use, for example, a cooling trap as the residual gas trap 35. In this case, the background gas reaching the gas detector 32 can be greatly reduced. In the third embodiment, the exploration fluid F selects a gas or liquid that is not captured by the residual gas trap 35.

  In this step, if the exploration fluid F is an air component gas, air component background signal correction is executed, and then noise level background zero correction is executed. On the other hand, in the case of exploration fluid other than air component gas, background zero correction of noise level is executed.

  Thereafter, as in the second embodiment, (3C) the inspection fluid F is pressurized and introduced into the test object S, and the leak inspection is executed. (3D) After completion of the leak inspection of the test object F, Completion and collection of pressurized introduction are performed, and (3E) calibration of leak amount using the exploration fluid standard leak is performed.

A leak inspection apparatus according to Embodiment 4 shown in FIG. 5 will be described. The exploration fluid pressurization / recovery system 1 is the same system as that shown in FIG. On the other hand, the configuration of the device under test vacuum system 2 is such that a high vacuum pump 24-b and a roughing pump 24-c are connected to the device under test vacuum chamber 21 via a vacuum valve 24-a with respect to the configuration of FIG. The configuration of the inspection vacuum system 3 is added to the configuration of FIG. 3 by connecting a high vacuum pump 34 between the gas detector 32 and the roughing pump 33.
For example, the leakage inspection in the fourth embodiment shown in FIG. 5 is performed as follows.

  (4A) Using the exploration fluid pressurization / recovery system 1, the inside of the test object S is evacuated. At the same time, the vacuum valve 23-a connected to the device under test vacuum chamber 21 of the device under test vacuum system 2 is opened and evacuated from atmospheric pressure to a medium vacuum of about 100 Pa using the roughing pump 23-b, and then the vacuum valve 23-a is closed, and the vacuum evacuation by the roughing vacuum pump 23-b is finished. At the same time, the vacuum valve 24-a is opened, and the vacuum chamber 21 under test is evacuated to 0.1 Pa or less by the high vacuum pump 24-b. Allow to reach high vacuum. Thereby, the residual gas in the leak inspection is greatly reduced, and a trace leak inspection is made possible.

  (4B) After the pressure in the vacuum chamber 21 to be tested reaches 0.1 Pa or less, which is a high vacuum, the vacuum valve 24-a is closed, and the vacuum valve 31 is opened at the same time. Start the background measurement that is a condition. Since the air component gas is exhausted by high vacuum exhaust, it is almost unnecessary to execute the air component background signal correction in the background correction, and the noise level background zero point correction is executed.

  The subsequent steps are the same as in the second to third embodiments. (4C) The exploration fluid F is pressurized and introduced into the device under test S and the leak inspection is performed. (4D) After the end of the leak inspection of the device under test. Completes and recovers the pressurized introduction of the exploration fluid F, and executes (4E) calibration of the leak amount using the exploration fluid standard leak.

A leakage inspection apparatus according to Embodiment 5 shown in FIG. 6 will be described. This leak inspection apparatus has a residual gas trap 35 connected between a device under test vacuum chamber 21 and a gas detector 32 via a vacuum valve 31 in the inspection vacuum system 3 in the fourth embodiment shown in FIG. It is added. The leak inspection process of the fifth embodiment is the same as the leak inspection process of the fourth embodiment. According to the fifth embodiment, it is possible to perform a high-efficiency micro leak inspection of about 10 ⁻⁷ Pam ³ / s with respect to a large test object including a large amount of adsorbed gas and dissolved gas.

  Next, in the present invention, the “exploration fluid standard leak technology” for calibrating the partial pressure signal of the exploration fluid in the gas analyzer, and the inventive technology that plays an important role in detecting minute leaks with high efficiency, that is, the air component gas The “air component background signal correction technique” in the case of the exploration fluid and the “background signal zero point correction technique” for correcting the background signal that can also be used in the bombing method will be described below.

[Exploration fluid standard leak]
Patent Document 6 and Patent Document 7 relate to one of the present inventors, and relate to a reference micro gas flow rate introduction device using a micro pore filter whose conductance is calibrated in advance. An example of implementation of the exploration fluid standard leak technique will be described. FIG. 7 is a schematic diagram showing an example of the exploration fluid standard leak. The exploration fluid standard leak measures the pressure of the micropore filter 50, the exploration fluid gas reservoir 51, the exploration fluid container 52, the vacuum pump 53, and the gas reservoir with the conductance calibrated so that the molecular flow condition is established up to a high pressure of 10 ⁴ Pa It consists of a vacuum gauge 54, piping and valves. The exploration fluid gas reservoir 51 and the exploration fluid container 52 are kept at the same temperature.

The exploration fluid standard leak is used as follows.
(1) The exploration fluid gas reservoir 51 is evacuated using the vacuum pump 53.
(2) Open the valve of the exploration fluid container 52 and introduce the exploration fluid into the gas reservoir 51. Here, when the exploration fluid is liquid, the gas reservoir is filled with liquid vapor, and its pressure becomes equal to the saturated vapor pressure.
(3) The pressure in the gas reservoir 51 is lowered using the vacuum pump 52 until the molecular flow condition of the micropore filter 50 is satisfied, and is set to a desired pressure P, and a desired standard leak amount according to the following equation (1) the introduction of Q _S.

Here standard leak amount when the Q _S is the temperature ^{_{T 0 (Pa m 3 / s}} ), C S is calibrated conductance values of micropore filter at the temperature ^{_{T 0 (m 3 / s)}} , M N2 is The molecular weight of nitrogen gas, M is the molecular weight of the exploration fluid, T ₀ is the absolute temperature (K) during calibration, and T is the absolute temperature (K) during use. A microporous filter 50 having a calibrated conductance value in the range of 1 × 10 ⁻¹¹ m ³ / s to 1 × 10 ⁻⁸ m ³ / s as the conductance value in the molecular flow region can be manufactured. Therefore, when the pressure of the gas reservoir 51 is changed from 0.1 Pa to 10 ⁴ Pa, a standard leak amount Q _S of 1 × 10 ⁻¹² Pam ³ / s to 1 × 10 ⁻⁴ Pam ³ / s can be obtained. it can.

At a pressure of 10 ⁴ Pa or higher, the flow of the exploration fluid flowing through the microporous filter transitions from a molecular flow to an intermediate flow, so that the conductance of the microporous filter 50 changes, but increases depending on the pressure P of the gas reservoir 51. However, the change in conductance is highly reproducible with respect to the pressure P. Therefore, by measuring the conductance of the micropore filter with respect to the pressure of the gas reservoir 51 in advance and using a fitting function or the like, a standard leak using the micropore filter can be used even at a high pressure of atmospheric pressure or higher. By using this calibration technique, calibration using an arbitrary gas is possible.

  For liquid exploration fluids, it is difficult to calibrate highly adsorptive vapors such as oil vapor, but alcohols such as methanol, ethanol and liquefied butane, ketones such as acetone, aromatics such as benzene, Calibration using fluorocarbons, which are inert liquids having a carbon-fluorine bond, and water vapor is possible.

[Background signal correction of air component gas]
FIG. 8 shows the correction of the background signal of the residual air component gas that is executed when an air component gas such as nitrogen, oxygen, argon, carbon dioxide or the like is used as the exploration fluid and the pressure in the vacuum chamber under test is 1 Pa or higher in the medium vacuum. It is the schematic diagram which showed an example. The background signal correction of the air component gas will be described with reference to FIG.

(1) In the configuration of the leakage inspection apparatus shown in the first to fifth embodiments, the partial pressure signal P _A0 (60 in FIG. 8) of the air component gas when only the gas detector is evacuated is measured for a certain time. The standard deviation σ of the signal P _A0 is derived in advance.
(2) Next, at time t ₀ , the residual air component gas in the test object vacuum chamber is introduced into the gas detector without pressurizing the exploration fluid into the test object, and the residual air component gas partial pressure signal P _A is measured for a certain period of time until time t _S to obtain measurement data as indicated by 61 in FIG.
(3) It is known that the exhaust of residual air component gas decreases with an exponential function at a high pressure of about a medium vacuum. Therefore, P ₀ and α in the following equation (2) are obtained using the measurement data, and then the operation data P _AC of the residual air component gas partial pressure signal after time t _{S is} derived by the following equation.

P _AC = P ₀ EXP [−α · t] (2)
Here, P ₀ is an air component gas signal at time t ₀ , and α is a constant. The calculation data _PAC is as shown by the broken line 62 in FIG.
(4) Residual perform the following operations of (3) as a correction to the divided signal P _A of the air component gas, obtaining a correction amount pressure signal P _AR of the air component gas as shown in 63 of FIG.

P _AR = [P _A −P _AC ] + kσ (3)
In equation (3), kσ is added so that the correction signal P _AR does not become a negative value. Here, σ is the standard deviation of the partial pressure signal P _A0 of the air component gas obtained in (1). Also, if a negative correction signal for such spike noise appears is the correction amount-pressure signal P _AR and k?. Here, k is a constant of k = 1 to 10. Reference numeral 63 in FIG. 8 denotes an air component gas correction signal _PAR when k = 3.
(5) time when the pressure introducing exploration fluid into the test object when t _L, if there is a leak in the test object is leaking Yes signals 64 is detected by the correction amount pressure signal P _AR air component gas .
In FIG. 8, t ₀ : residual air component gas introduction time, t _S : background correction start time, t _L : exploration fluid pressurization introduction time.

[Background zero correction of exploration fluid gas]
The background zero correction of the exploration fluid gas for effectively detecting a small amount of leakage in the leak inspection will be described. In the leakage inspection apparatus as in the first to fifth embodiments, when there is no leakage from the test object, the partial pressure signal of the exploration fluid shows a tendency to decrease or become constant while fluctuating randomly.

  On the other hand, if there is a leak, the partial pressure signal of the exploration fluid increases monotonously unless the data acquisition interval is extremely shortened. Therefore, when the partial pressure signal of the exploration fluid is decreasing or has a constant tendency, the partial pressure signal is reduced by calculation. By performing a calculation process of returning to the original signal strength after a certain time, the difference between the divided voltage signals when there is a leak and when there is no leak is enlarged, and the leak determination can be made more reliably.

When the partial pressure signal of the exploration fluid of the gas detector at time t is P (t) and the zero point signal determined from the fundamental measurement lower limit of the gas analyzer is P _0C , the exploration fluid at time t The correction signal P _C (t) is obtained by the following equation (4).
P _C (t) = P _0C + P (t) × D (t) (4)
Here, 0 ≦ D (t) ≦ 1.

In the equation (4), D (t) is a signal change rate, and when there is no leakage and the divided signal P (t) tends to decrease or has a constant tendency, D (t) is set to a small value near 0 and there is leakage. divided signal P (t) is increased signal change rate D (t) in the case of monotonically increasing, in the leakage determination time t _G be a function, such as D (t) becomes 1.

As an example of the signal change rate D (t), there is the following equation (5). Here, C is a weight constant of about 10 to 1000, d (t) is a power signal change rate, Δt _LG is a time interval from the exploration fluid introduction time t _L of the gas detector to the leak determination time t _G , and Δt is a gas The analyzer measurement time interval, k _2, is a weight constant of 1 or more.
D (t) = C ^{(d (t) -1)} (5)
When P (t) ≦ P (t−Δt),
d (t) = d (t−Δt) −k ₂ Δt / Δt _LG (6)
When P (t)> P (t−Δt),
d (t) = d (t−Δt) + Δt / Δt _LG (7)

The exploration fluid partial pressure signal P (t) when there is no leakage fluctuates randomly, but P (t) is often less than or equal to the previous measurement value P (t−Δt). In this case, d (t) decreases by k ₂ Δt / Δt _LG as shown by the equation (6). P (t) becomes larger than the previous measurement value P (t-Δt), ( 7) equation shows, there is a case where d (t) is increased by Delta] t / Delta] t _LG, the effect of the weight constant k ₂ Thus, the increase in d (t) is suppressed, and d (t) remains at a value close to 0 at the determination time t _G. Accordingly, D (t) is approximately 1 / C from equation (5), and the correction signal P _C (t) in equation (4) is approximately 1 / C of the original divided voltage signal P (t) or zero signal P. _Decreases to _0C . This arithmetic processing also has an effect of reducing the variation of the correction signal P _C (t) to 1 / C or less of the variation of the original divided voltage signal P (t).

On the other hand, the partial pressure signal P (t) in the case of leakage increases monotonously and thus becomes larger than the previous measurement value P (t−Δt). At this time, as shown in equation (7), when d (t) increases by Δt / Δt _LG and P (t) continues to increase monotonously, as shown in equation (8), d (t the maximum value of) is from 1, when there is a leak, d (t) becomes 1 at the leak determination time t _G. Accordingly, D (t) is 1 from the equation (5), and in the equation (4), the correction signal P _C (t) is equal to P _0C + P (t), and when P _0C << P (t), the correction is performed. The signal P _C (t) substantially coincides with P (t).
By reducing the correction signal P _C (t) when there is no leak using this arithmetic processing, the difference from the correction signal P _C (t) when there is a leak is expanded, and the presence or absence of leak is more reliably detected. It becomes possible to judge.

FIG. 9 shows a time transition of background zero point correction in a normal leak test. The background zero correction is performed as follows. Here, the weight constant C is 100 and k ₂ is 2.
(1) Background zeroing is executed for the exploration fluid partial pressure signal 70 in a state where only the gas detector is evacuated. Although the deviation of the zero point correction signal 71 resulting from this calculation is smaller than the deviation of the original partial pressure signal 70, the signal zero point P _0C is obtained from the standard deviation σ of the correction signal 71.
(2) Leak inspection starts at time t ₀ , but at this time, when the exploration fluid is not introduced under pressure into the DUT, the background gas from the DUT vacuum chamber is introduced and there is no leak The exploration fluid partial pressure signal 72 is measured.
(3) When zero point correction is started at time t _S , the correction signal 73 can be made smaller by about one digit than the original signal compared to the exploration fluid partial pressure signal 72.
(4) At time t _L , the exploration fluid is pressurized and introduced into the DUT, and leakage detection is started. At this time, zero correction is started again. If there is a leak, exploration fluids correction signal 73 to reproduce the original leak signal when the increased leakage determination time t _G.
This background zero correction makes it possible to improve the signal / noise ratio by about one digit.
In FIG. 9, σ: standard deviation, P _OC : correction zero point, Δt _LG : correction execution time after restart, S / N: signal / noise ratio.

Since the background zero point correction increases the correction signal when the leakage increases, it can be used for the leakage inspection of the test object into which the exploration fluid is introduced in advance, that is, the leakage inspection by the bombing method. FIG. 10 shows the time transition of the background zero correction in the leak inspection of the bombing method. The leak inspection of the bombing method is executed as follows.
(1) The signal zero is performed in the same way as the normal inspection.
(2) The leak inspection is started at time t _{0. In} the bombing method, at this time, the leak start time t _L is simultaneously reached, and the exploration fluid leak signal 82 starts to increase.
(3) When leak zero correction is started at time t _S , the exploration fluid leak correction signal 83 is reset to the zero correction signal 81, and then increases to the original leak signal 82 during this time Δt _SG .
In FIG. 10, σ: standard deviation, P _OC : correction zero point, Δt _SG : correction execution time, S / N: signal / noise ratio.

[Example]
As an example of the present invention, argon gas and ethanol were selected as exploration fluids, and a leak test was performed using a leak test apparatus that embodies the first to fifth embodiments. The manufactured leak inspection apparatus will be described with reference to FIG.
In the exploration fluid pressurization / recovery system 1, gas pressurization can be applied up to 1 MPa and liquid pressurization up to 300 MPa. In the DUT vacuum system 2, the DUT vacuum chamber 21 used was a stainless steel vacuum vessel having an inner dimension of 400 mm × 400 mm × 300 mm and subjected to mirror polishing. In order to perform vacuum evacuation from the atmospheric pressure of the test object vacuum chamber 21 to the medium vacuum, the roughing vacuum pump 23-b has a roots pump with an exhaust speed of 2.8 × 10 ⁻¹ m ³ / s and an exhaust speed at the subsequent stage. An oil rotary pump of 8.0 × 10 ⁻² m ³ / s was connected to the device under test vacuum chamber 21 via the vacuum valve 23-a.

On the other hand, in order to perform vacuum evacuation from the medium vacuum to the high vacuum of the device under test chamber 21, the high vacuum pump 24-b includes a turbo molecular pump with an exhaust speed of 8.0 × 10 ⁻¹ m ³ / s and a subsequent stage. An oil rotary pump with an exhaust speed of 2.0 × 10 ⁻² m ³ / s was connected to the device under test vacuum chamber via a vacuum valve 24-a. In the inspection vacuum system 3, the gas detector 32 uses either a highly durable gas detector or a quadrupole mass spectrometer, and the high vacuum pump 34 is a turbo molecule having an exhaust speed of 2.2 × 10 ⁻¹ m ³ / s. An oil rotary pump having an exhaust speed of 9.1 × 10 ⁻³ m ³ / s was used as the roughing pump 33 in the pump and the subsequent stage. Further, a He gas circulation type cooling trap having a cooling temperature of 80 K was used as the residual gas trap 34.

Embodiments 1 to 5 were implemented using the manufactured leak inspection apparatus. The components used in each embodiment are shown in Table 1.
In the first embodiment, the roughing pump 33 is used for evacuation of the DUT vacuum system 2 and the inspection vacuum system 3, and a roots pump and an oil rotary pump are connected to the subsequent stage. Further, since the evacuation of the vacuum chamber 21 to be tested is a medium vacuum of 10 Pa to 100 Pa, the gas detector 32 is a highly durable gas detector.

  In the second embodiment, the roughing pump 23-b is used for evacuation of the vacuum chamber 21 of the test object vacuum system 2, and a roots pump and an oil rotary pump at the subsequent stage are used independently for this. . On the other hand, the vacuum pump 33 for evacuating the gas detector 32 of the inspection vacuum system 3 was an oil rotary pump. It is also possible to use a high-vacuum pump turbo molecular pump as the vacuum pump 33.

  In the third embodiment, a Roots pump and an oil rotary pump are used as a roughing pump 23-b for evacuation of the vacuum chamber 21 of the DUT 2 in the DUT vacuum system 2. A highly durable gas detector or a quadrupole mass spectrometer was used as the gas detector 32 of the inspection vacuum system 3. Regarding the vacuum evacuation of the inspection vacuum system 3, the high vacuum pump 34 used a turbo molecular pump, and an oil rotary pump was used as the roughing pump 33 in the subsequent stage. In addition, a cooling trap was connected as a residual gas trap 35 in front of the gas detector so that a quadrupole mass spectrometer could be used in the inspection vacuum system 3.

In the fourth embodiment, there are two systems for evacuating the test object vacuum chamber 21 of the test object vacuum system 2. One evacuation system used a Roots pump and a subsequent oil rotary pump as the roughing pump 23-b. The other exhaust system used a turbo molecular pump as the high vacuum pump 24-b and an oil rotary pump in the subsequent stage. A highly durable gas detector or a quadrupole mass spectrometer was used as the gas detector 32 of the inspection vacuum system 3. As for the vacuum evacuation of the inspection vacuum system 3, the high vacuum pump 34 is a turbo molecular pump, and an oil rotary pump is used as the roughing pump 33 in the subsequent stage.
The fifth embodiment adds a residual gas trap 35 in the inspection vacuum system 3 to the fourth embodiment.

  As shown in Table 1, the background correction of the air component gas used when the air component gas is selected as the exploration fluid for the signal correction is the first to the first embodiment in which the vacuum chamber under test reaches only about 10 Pa of medium vacuum. Although necessary for the third embodiment, it is not necessary for the fourth and fifth embodiments that reach a high vacuum of 0.1 Pa or less. On the other hand, the background zero correction functioned effectively in all the embodiments.

In the first to fifth embodiments, leakage inspection was performed using argon gas and ethanol as the exploration fluid, and the possibility of inspection of the specimen to be discharged with a large amount of gas, the leakage detection lower limit, and the inspection time were examined. The results are shown in Table 2.
In the case of the first embodiment, in the case of a small test piece that emits less gas, a detection limit of 10 ⁻⁴ Pam ³ / s and an inspection time of 20 seconds were possible.
In the second embodiment, the lower limit of the leak detection and the inspection time are the same as those in the first embodiment. However, since the gas detector can be evacuated at all times, it is possible to inspect a test object with a certain amount of gas emission. In the case of a device under test involving a large amount of gas release, it is desirable to use the apparatus configuration as in Embodiment 2 in order to protect it from contamination of the gas detector.

Embodiments 3 and 4 protect the gas detector in a high vacuum environment, and the gas from the vacuum chamber under test is also reduced, so the lower detection limit can be as low as 10 ⁻⁶ Pam ³ / s. Leak inspection was possible. Moreover, it can respond also to the test of the test object accompanied by a large amount of gas discharge. As for the leakage inspection time, the inspection time of the third embodiment is 20 seconds, but the inspection time of the fourth embodiment is a little longer, 30 seconds. However, it can be said that the inspection time of 30 seconds is sufficiently short. In the fourth embodiment, the inspection time becomes longer from the middle vacuum to the high vacuum by the high vacuum pump in the vacuum chamber under test.

In the fifth embodiment, because of the two effects of the high vacuum evacuation means of the test object vacuum chamber and the gas trapping means immediately before the gas analyzer, a low leak detection lower limit 10 even when a test object with a large amount of gas discharge is used. Inspection at ^-7 Pam ³ / s became possible. The reason why the lower limit of detection of ethanol leakage is low in all the embodiments is that the amount of leakage in liquid is larger than that in gas if it is near atmospheric pressure. This is because the liquid has a high density and flows through the leak hole in a viscous flow.

DESCRIPTION OF SYMBOLS 1 Exploration fluid pressurization / collection | recovery system 2 Test object vacuum system 3 Inspection vacuum system 11 Exploration fluid pressurization supply apparatus 12 Exploration fluid supply line 13 Exploration fluid collection | recovery apparatus 14 Vacuum exhaust line 15 Valve 16 Valve 17 Valve 18 Valve 21 Test object Body vacuum chamber 22-a valve 22-b Exploration fluid standard leak 23-a valve 23-b Rough pump 24-a valve 24-b High vacuum pump 24-c Rough pump 31 Valve 31-1 Valve 31-2 Valve 31-3 Valve 32 Gas detector 33 Roughing pump 34 High vacuum pump 40 Vacuum vessel 41 Anode 42 Magnetic field applying means 43-1 Lens 42-2 Lens 43-3 Lens 44 Optical window 45 Slit 46 Diffraction grating 47 Photodetecting means 48 Vacuum gauge 1 (high to ultra-high vacuum)
49 Vacuum gauge 2 (low to medium vacuum)
50 Micropore filter 51 Exploration fluid gas reservoir 52 Exploration fluid container 53 Vacuum pump 54 Vacuum gauge 60 Partial pressure signal P _AO of air component gas when only the gas detector is evacuated
61 divided signal P _A of residual air component gases
62 Calculation data P _{AC of} residual air component gas partial pressure signal
63 Corrected partial pressure signal P _{AR for} air component gas
Divided signal P _O exploration fluid gas when only the air component gas when there is a 64 leak correction amount pressure signal 70 gas analyzer was evacuated
71 Exploration fluid gas partial pressure correction signal when only gas analyzer is evacuated 72 Exploration fluid gas partial pressure signal P (t)
73 Exploration fluid gas zero correction signal P _C (t)
Divided signal P _O exploration fluid signal 75 exploration fluid gas when a leak was evacuated only exploration fluid zero-point correction signal 80 gas analyzer when there when there are 74 leaks
81 Exploration fluid gas partial pressure correction signal when only gas analyzer is evacuated 82 Exploration fluid gas partial pressure signal P (t)
83 Zero point correction signal P _C (t) for exploration fluid gas
F Exploration fluid L Discharge light emission S DUT Q _S Standard leak amount

Claims (19)

A leak inspection apparatus for inspecting a leakage amount of a test object, wherein a sealable test object vacuum chamber in which the test object is arranged, and a gas or liquid having a molecular weight larger than that of helium inside the test object Exploration fluid supply means that pressurizes the exploration fluid, and highly durable gas detection that can be operated from ultra-high vacuum to medium vacuum connected to the vacuum chamber of the device under test via a vacuum valve and capable of detecting a small amount of leakage A evacuation unit connected to the high durability gas detection unit, a probe fluid standard leak for supplying the probe fluid of a known leak amount connected to the vacuum chamber under test via a vacuum valve, Comprising
After the DUT is mounted inside the DUT vacuum chamber, the DUT vacuum chamber is evacuated by the evacuation means while the DUT vacuum chamber is sealed, and the exploration fluid is supplied to the inside by the exploration fluid supply means. The amount of leakage from the device under test is measured by measuring the partial pressure of the exploration fluid leaking from the device under pressure introduced at or above atmospheric pressure by the highly durable gas detecting means. Leak inspection device.   2. The leak inspection apparatus according to claim 1, wherein the highly durable gas detection means has an excitation mechanism by cold cathode discharge using a magnetic field, and splits light from a light source by gas molecules excited by the excitation mechanism. Spectroscopic means for detecting the intensity of light dispersed by the spectroscopic means separately and simultaneously for each wavelength of light and converting it into an electrical signal, and the intensity and gas content of the light wavelength peculiar to gas molecules. Leakage inspection comprising: a high-durability gas detection means comprising: a database storing a relationship with pressure; and a data processing means for calculating a gas partial pressure based on data stored in the database from the electrical signal apparatus.   3. The leak inspection apparatus according to claim 1, wherein the vacuum exhaust means connected to the high durability gas detection means is a rough exhaust means for exhausting to a medium vacuum, and the device under test Leakage inspection apparatus characterized in that a medium vacuum is created by the roughing exhaust means while the body vacuum chamber is sealed. 4. The leakage inspection apparatus according to claim 1, wherein the high durability gas detecting means is connected to the device under test vacuum chamber via the vacuum valve, and the roughing vacuum exhaust means is connected thereto. In addition, a roughing vacuum evacuation means for evacuating to the vacuum to the medium vacuum through the vacuum valve is connected to the device under test vacuum chamber,
After mounting the DUT inside the DUT vacuum chamber, the DUT vacuum chamber is sealed and evacuated by the roughing vacuum evacuation means, and then the valve is switched to maintain the vacuum at all times. A leakage inspection apparatus for measuring a leakage amount from the device under test by measuring with the highly durable gas detecting means.   3. The leakage inspection apparatus according to claim 1, wherein a vacuum exhaust means connected to the high durability gas detection means maintains a high vacuum so that the high durability gas detection means is always maintained at a high vacuum. Leakage characterized in that a high vacuum evacuation means for vacuum evacuation of the test object and a rough evacuation means for evacuation to a medium vacuum through a vacuum valve is connected to the vacuum chamber to be tested. Inspection device.   In the leak inspection apparatus according to any one of claims 1 to 2, the evacuation unit connected to the high durability gas detection unit is a high evacuation unit for evacuating to a high vacuum, A rough evacuation means for evacuating the DUT vacuum chamber to a medium vacuum through the vacuum valve and a high vacuum evacuation means in parallel through the vacuum valve to the DUT vacuum chamber. Two or more vacuum evacuation means connected to the DUT vacuum chamber via a vacuum valve are connected, and the DUT is inspected for leak after the DUT vacuum chamber and the highly durable gas detection means are in a high vacuum state. Leak inspection device.   7. The leak inspection apparatus according to claim 5, wherein a residual gas trapping means is connected in the middle of a vacuum pipe connecting the device under test vacuum chamber and the highly durable gas detector. Leak inspection device. A leak inspection apparatus for inspecting a leakage amount of a test object, wherein a sealable test object vacuum chamber in which the test object is arranged, and a search for a gas or liquid having a molecular weight higher than that of helium in the test object Exploration fluid supply means for supplying fluid under pressure, rough evacuation means for evacuating to a medium vacuum connected to the vacuum chamber under test through a vacuum valve, and vacuum under test chamber A residual gas trapping means connected via a vacuum valve; a gas detection means capable of operating from an ultrahigh vacuum connected to the residual gas trapping means to a vacuum region of the order of 1 Pa and capable of detecting a small amount of leakage; Exploration fluid standard for supplying the exploration fluid with a known leakage amount connected to the DUT vacuum chamber via a vacuum valve, and a high vacuum evacuation means and a rough evacuation means connected in series to the gas detection means Leak and And Bei,
A vacuum is created by the rough evacuation means in a state in which the vacuum chamber of the test object is sealed, and the exploration fluid is pressurized and introduced to the interior of the test object connected to the exploration fluid supply means at an atmospheric pressure or higher, A leakage inspection apparatus for measuring a leakage amount from the device under test by measuring a partial pressure of the exploration fluid leaking from the device under test by the gas detecting means.   A leak inspection apparatus for inspecting a leakage amount of a test object, wherein a sealable test object vacuum chamber in which the test object is arranged, and a search for a gas or liquid having a molecular weight higher than that of helium in the test object An exploration fluid supply means for supplying a fluid under pressure, a rough evacuation means for evacuating to a medium vacuum connected to the vacuum chamber of the device under test via a vacuum valve, and a vacuum valve in series. Two or more vacuum evacuation means including a connected high vacuum evacuation means and rough evacuation means, and operation from an ultra-high vacuum connected to the test object vacuum chamber via a vacuum valve to a vacuum region on the order of 1 Pa. A gas detection means capable of detecting a small amount of leakage, a high vacuum exhaust means and a rough exhaust means connected in series to the gas detection means, and a vacuum valve connected to the device under test vacuum chamber. Known Leak test apparatus, characterized by comprising a probe fluid standard leak supplying the exploration fluid leakage amount.   10. The leak inspection apparatus according to claim 9, wherein a residual gas trapping means is connected in the middle of a vacuum pipe connecting the device under test vacuum chamber and the gas detection means.   The leak inspection apparatus according to any one of claims 1 to 10, wherein an air component gas is used as the exploration fluid, and a signal of the residual air component gas is measured when a background signal due to the residual air component gas is measured. Measured and derived by calculating the residual air gas component signal after t seconds using the fact that the residual air component gas decreases according to an exponential function, the measured value of the signal of the residual air gas component after t seconds A leakage inspection apparatus that performs background correction by subtracting the calculated value of the residual air gas component from 12. The leak test apparatus according to claim 1, wherein when the signal of the gas detector for detecting the leak amount is corrected, the partial pressure signal of the gas detector at time t is P. (T) When the correction signal of the partial pressure signal is P _C (t), the zero point signal is P _0C , and the signal change rate is D (t), there is no leakage and the partial pressure signal P (t) decreases or When it becomes constant, the signal change rate D (t) is set so that the correction signal P _C (t) is in the vicinity of the zero point signal P _0C , there is a leak, and the divided voltage signal P (t) increases. time by setting the signal change rate D (t) as the correction signal P _C (t) to reproduce the original divided signal P (t) at the time of leakage determination time, the correction signal P _C (t ) _{Is obtained} by P _C (t) = P _0C + P (t) × D (t) Inspection device.   13. The leak inspection apparatus according to claim 1, further comprising a micropore filter calibrated in advance as the exploration fluid standard leak. A leakage inspection method for inspecting a leakage amount from a test object using a gas or liquid exploration fluid having a molecular weight larger than that of helium,
Placing the device under test in a vacuum chamber that can be evacuated and sealed, and sealing the device vacuum chamber;
Evacuating the device under test vacuum chamber in a sealed state;
The partial pressure of the exploration fluid leaked from the test object, which has been introduced by pressurizing the exploration fluid at atmospheric pressure or higher by the exploration fluid supply means, can be operated from ultrahigh vacuum to medium vacuum. Measure with a highly durable gas detection means that can detect a small amount of leakage with
A leakage inspection method characterized by comprising:   15. The leak inspection method according to claim 14, wherein the highly durable gas detection means has an excitation mechanism by cold cathode discharge using a magnetic field, and spectrally analyzes light from a light source by gas molecules excited by the excitation mechanism. Spectroscopic means for detecting the intensity of light dispersed by the spectroscopic means separately and simultaneously for each wavelength of light and converting it into an electrical signal, and the intensity and gas content of the light wavelength peculiar to gas molecules. Leakage inspection using a highly durable gas detection means comprising: a database storing a relationship with pressure; and a data processing means for calculating a gas partial pressure based on data stored in the database from the electrical signal Method. A leakage inspection method for inspecting a leakage amount from a test object using a gas or liquid exploration fluid having a molecular weight larger than that of helium,
Disposing the test object in a vacuum chamber that can be evacuated and sealed, and connecting the exploration fluid supply means to the test object so as to seal the test object vacuum chamber;
Evacuating to a medium vacuum by roughing exhaust means connected to the DUT vacuum chamber via a vacuum valve in a state where the DUT vacuum chamber is sealed;
The gas detection means capable of operating from ultra-high vacuum to a vacuum range of the order of 1 Pa and capable of detecting a small amount of leakage is maintained in a high vacuum state by means of residual gas capturing means and high vacuum exhaust means connected to the vacuum chamber of the device under test. To do
Measuring the partial pressure of the exploration fluid leaked from the test object into which the exploration fluid is pressurized and introduced at an atmospheric pressure or higher by the exploration fluid supply means into the test object, by the gas detection means;
A leakage inspection method characterized by comprising:   The leak inspection method according to any one of claims 14 to 16, wherein an air component gas is used as the exploration fluid, and when the background of the residual air component gas is measured, a fraction of the residual air component gas is measured. The pressure is measured, and the residual air gas component after t seconds is calculated and derived using the fact that the residual air component gas decreases according to an exponential function, and the measured value of the residual air gas component after t seconds A leakage inspection method comprising performing background correction by subtracting a calculated value. 18. The leak inspection method according to claim 14, wherein when the signal of the gas detector for detecting the leak amount is corrected, the partial pressure signal of the gas detector at time t is P (t). When the correction signal of the partial pressure signal is P _C (t), the zero point signal is P _0C , and the signal change rate is D (t), there is no leakage and the partial pressure signal P (t) decreases or becomes constant. The signal change rate D (t) is set so that the correction signal P _C (t) is in the vicinity of the zero point signal P _0C, and when there is a leak and the partial pressure signal P (t) increases, the leak The signal change rate D (t) is set so that the correction signal P _C (t) reproduces the original divided voltage signal P (t) at the determination time, and the correction signal P _C (t) is changed to P A leakage inspection method, wherein correction is performed such that _C (t) = P _0C + P (t) × D (t).   The leak inspection method according to any one of claims 14 to 18, further comprising a micropore filter calibrated in advance as a standard leak, wherein the leak amount is calibrated by the micropore filter. Method.