JP2005071692A - Residual gas detecting apparatus of vacuum tube device and method for evaluating reliability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a residual gas detecting apparatus which can suitably evaluate an influence on electron emitting capability of a cathode and the lifetime characteristics of the same by detecting discharge gases individually from a cathode ray tube when the vacuum tube device, such as the cathode ray tube, etc. is heated to a high temperature, and to provide a method for evaluating reliability which can evaluate the reliability for the cathode ray tube having different exhaust temperature, processing time, etc. and manufacturing steps. <P>SOLUTION: The method for evaluating the reliability includes a step of raising a temperature of a cathode ray tube 3 at a predetermined rate in a thermostatic oven 2, a step of guiding the residual gas released in the tube into a vacuum changer 5 in this case, and a step of detecting amounts of individual residual gas components by a mass spectrometer 8. The method further includes a step of detecting an amount of the residual gas component in the cathode ray tube 3 in a different manufacturing process, and a step of evaluating the reliability of the cathode ray tube by comparing this detected result. Thus, (1) when the residual gas of the cathode ray tube is examined, the problem that the amounts of the individual components cannot be measured; and (2) there is no suitable method of testing a lifetime caused by gas in the cathode ray tube in a short time, and the problem is overcome that the lifetime test of several thousands to several tens of thousands of hours is required. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a residual gas detection device and a reliability evaluation method for a vacuum tube device, and more particularly to a residual gas detection device for detecting a residual gas discharged at that time by raising the temperature of a cathode ray tube or a field electron emission device. The present invention relates to a method for evaluating the reliability of a vacuum tube apparatus based on a gas.

Conventionally, as this type of apparatus, for example, there have been the following.
When the cathode ray tube is raised to 150 ° C. to 250 ° C. and kept at this temperature for a certain time, the catalytic action of the getter changes the water vapor, carbon monoxide, and carbon dioxide into methane gas that is difficult for the getter to absorb. When the amount of methane gas produced is large and the absorption capacity of the getter is not sufficient, the gas in the tube remains even after the cathode ray tube is cooled. Therefore, by measuring the gas ratio while cooling, the life characteristics due to the gas in the cathode ray tube are evaluated (for example, Patent Document 1).

  In addition, there is also one in which graphite applied to the inner surface of a funnel glass of a cathode ray tube is formed on a metal sample piece, and the released gas is analyzed and evaluated when resistance heating is performed in a vacuum vessel (for example, see Non-Patent Document 1). .

JP-A-7-226159 (2nd page, FIG. 1) Masao Hashiba, Yuko Sugahata et al., “Vacuum” Vol. 41, No. 4, 1998, (pp. 440-447)

  As described above, in the conventional evaluation apparatus for a vacuum tube apparatus, the gas ratio of the cathode ray tube is measured to check the amount of methane gas generated by the catalytic action of the getter. Therefore, by measuring this methane gas, it is possible to know the total amount of water vapor, carbon monoxide, carbon dioxide, etc. remaining adsorbed or suspended in the tube, but the individual gas components and their component ratios are not clear. However, the degree of influence on the electron emission deterioration of the cathode differs depending on the type of gas component.

  S. Itoh et al., “J. Vac. Sci. Technol.” (Volume A5, No. 6, 1987, pp. 3430-3435) shows that carbon dioxide is emitted from the cathode as compared with carbon monoxide. Experimental results have been reported that the effect on degradation is about ten times as great.

  Methane, carbon monoxide, and carbon dioxide react with barium forming the cathode to degrade the electron emission ability, but gas is re-emitted from the cathode or new barium is generated by the reducing agent contained in the cathode. And the electron emission ability is restored. On the other hand, in the case of water vapor, barium hydroxide having a melting point lower than that of normal barium oxide is formed on the cathode and melts at the temperature of the operating conditions. In this case, the cathode is permanently destroyed without recovering the electron emission ability.

  As described above, it is necessary to know the gas species remaining in the tube and the amount thereof in order to evaluate the life characteristics of the cathode ray tube. However, in the conventional vacuum tube device evaluation device, the total amount of residual gas is reduced to methane. There is a problem that it is only measured as a quantity, and cannot be measured for the gas type and its quantity.

  Another evaluation apparatus for a conventional vacuum tube apparatus is one in which graphite to be applied to the inner surface of a funnel glass of a cathode ray tube is formed on a metal sample piece, and the emitted gas is analyzed when resistance heating is performed in a vacuum chamber. Although it is suitable for comparing or predicting to some extent the effects on reliability when adopting individual graphites in cathode ray tubes by comparing and measuring different graphites, they were actually used in cathode ray tubes. However, there is a problem that it is difficult to evaluate the reliability associated with various conditions such as the course of use.

  This is because the state of the surface applied to the metal of the sample piece and the surface applied to the funnel glass are not always the same. For example, if there is a difference in surface porosity due to the difference in wettability of the base, A difference appears. As a result, the gas emission amount at the time of measuring the sample piece is different from the actual gas emission amount of the cathode ray tube. In addition, although the sample piece can be processed in a pseudo manner by the manufacturing process of the cathode ray tube, it is difficult to make the heat treatment process including the atmosphere and the exhaust process with the exhaust conductance uniform considering the graphite surface area, After all, there was a problem that the amount of emission at the time of measurement was different between the test and the actual cathode ray tube. Even when the graphite is taken out from a cathode ray tube that has undergone a normal process and measured, it is once exposed to the atmosphere, so that it is affected by moisture adsorbed at this time.

  In addition, when the type of mask, frame material, etc. is different, or when evaluating the reliability of cathode ray tubes with different processes such as exhaust temperature and processing time, it is necessary to perform comparative measurements on all members used in the tube, There was a problem that time would be enormous. The measurement of each member here has the same problem as the above graphite.

  In general, there is no appropriate method for performing a life test due to gas in the cathode ray tube in a short time, and a life test of several thousand to several tens of thousands of hours is required.

  The object of the present invention is to solve the above-mentioned problems, and it detects the emission gas from the inside of the tube when the temperature of the vacuum tube device such as a cathode ray tube is raised, and the electron emission ability of the cathode A residual gas detection device that enables appropriate evaluation of the effects on life and life characteristics, and a reliability evaluation method that enables evaluation of the reliability of cathode ray tubes with different manufacturing processes such as exhaust temperature and processing time There is to do.

The residual gas detection device of the vacuum tube device of the present invention is a residual gas detection device of a vacuum tube device for detecting residual gas in the vacuum tube device.
The vacuum tube device is housed, and the vacuum tube device passes through a predetermined opening location of the vacuum tube device in a state of being isolated from the outside and a constant temperature means for heating the vacuum tube device so that the temperature of the vacuum tube device becomes a target temperature. An isolating means having a hollow portion connected to the internal space of the apparatus, an exhaust means for exhausting the hollow portion, a mass analyzing means for detecting the amount of gas components in the hollow portion,
And detecting the amount of the desired component of the gas released from the inside of the vacuum tube device into the hollow part in the process of raising the temperature of the vacuum tube device.

According to another aspect of the present invention, there is provided a method for evaluating the reliability of a vacuum tube device, wherein the residual gas detection device of the vacuum tube device is used to increase the temperature of the vacuum tube device and to determine the desired gas released from the internal space of the vacuum tube device to the hollow portion Detect the amount of ingredients,
The temperature of the vacuum tube apparatus is raised at a substantially constant rate, and the reliability of the vacuum tube apparatus is judged by determining the amount of a desired component of the gas detected at the time of temperature increase.

  According to the present invention, the residual gas when the temperature of the cathode ray tube is raised can be released from the inside of the tube, and each component and the amount of the emitted gas can be individually measured. In evaluating the reliability of the cathode ray tube. Detailed analysis is possible. Further, by analyzing the emitted gas component and its amount, the reliability of the cathode ray tube can be evaluated without performing a long-term life test.

Embodiment 1 FIG.
FIG. 1 is a main part configuration diagram schematically showing a main part configuration of a residual gas detection apparatus 1 of a vacuum tube apparatus according to Embodiment 1 of the present invention.

  In the figure, the thermostat 2 can accommodate the main part except for the neck part of the test cathode ray tube 3 in the inside thereof, and a heating / cooling unit 4 for changing the internal temperature inside the thermostat in the side part. Is arranged. The vacuum chamber 5 has a neck insertion portion 5a into which the neck portion 3a of the cathode ray tube 3 can be fitted. The neck insertion portion 5a seals a gap when the neck portion 3a of the cathode ray tube 3 is inserted. O-rings 6 are disposed at two locations in the insertion direction.

  The vacuum pump 7 as an exhaust means is arranged to exhaust the inside of the vacuum chamber 5, and an ion sputtering pump, a turbo molecular pump, an oil diffusion pump or the like is used. A mass spectrometer 8 serving as a mass analysis means includes an ion source including a mass filter (quadrupole) and the like, an analysis tube 8a including a mass filter and the like arranged in the vacuum chamber 5 and individual gas components in the vacuum chamber 5. Perform mass spectrometry. The straight lead-in terminal 9 as an action means opens the tip tube portion formed in the neck portion 3 a of the cathode ray tube 3 located in the vacuum chamber 5 by operating the operation portion 9 a extending outside the vacuum chamber 5. It is arranged to do. The vacuum chamber 5, the O-ring 6 and the straight lead-in terminal 9 correspond to isolation means, and the inside of the vacuum chamber 5 corresponds to a hollow portion.

  The temperature controller 10 inputs temperature data from a temperature control temperature sensor 11 that detects the temperature at a predetermined position of the cathode ray tube 3 accommodated in the thermostat 2, and the detected temperature is the temperature specified by the data processing device 13. Thus, the heating / cooling unit 4 is controlled. The data processing device 13 outputs a temperature designation signal for designating the temperature of the cathode ray tube 3 to the temperature controller 10 and detects the temperature at a predetermined position of the cathode ray tube 3 accommodated in the thermostat 2. Temperature data is input from the temperature sensor 12 and quantitative analysis data is input from the mass spectrometer 8. As will be described later, the temperature data of the cathode ray tube 3 at the time of raising the temperature of the cathode ray tube 3 and the amount data of each detected gas. Data processing is performed to obtain the mutual relationship with The constant temperature bath 2, the heating / cooling unit 4, the temperature control temperature sensor 11, and the temperature controller 10 correspond to a constant temperature means.

  In the above configuration, a method for measuring the residual gas in the cathode ray tube 3 will be described below with reference to the flowchart of FIG. 3 showing the processing procedure.

  First, the cathode ray tube 3 is set in the residual gas detection device 1 (step 1). At this time, the cathode ray tube 3 is held by a holding means (not shown) disposed in the thermostat 2 so that most of the cathode ray tube 3 is accommodated in the thermostat 2 except for a part of the neck portion 3a. And the vacuum chamber 5 is arrange | positioned so that the neck part 3a of the cathode ray tube 3 may be inserted in the neck insertion part 5a.

  For this reason, the vacuum chamber 5, the mass spectrometer 8, the vacuum pump 7, and the linear insertion terminal 9 are held by holding means (not shown) so as to be slidable in the directions of arrows A and B, for example. At this time, the gap between the neck portion 3a and the neck insertion portion 5a is filled by the O-ring 6, and the inside of the vacuum chamber 5 is sealed from the outside. The O-ring 6 is preferably made of a highly heat-resistant fluorine-based resin. Further, as shown in FIG.

  In order to prevent insulation and cracking of a stem pin (not shown) for applying a voltage to the electron gun of the cathode ray tube 3, a base and base silicone are attached to the neck end. It is assumed that it is previously removed with an organic solvent or the like. The tip tube portion formed in the neck portion 3a of the cathode ray tube 3 is cut in the vacuum chamber 5 as described later. For this reason, before setting the cathode ray tube 3, the tip tube cutting portion is previously set. It is preferable to make a scratch by scoring with a diamond cutter or the like.

  Next, the vacuum chamber 5 is evacuated by the vacuum pump 7 (step 2). At this time, the vacuum pump 7 uses an ion sputtering pump, a turbo molecular pump, an oil diffusion pump, or the like, and is used in combination with an auxiliary pump such as an oil rotary pump, if necessary. It is necessary to lower the background in order to increase the measurement sensitivity of the in-pipe gas. For this reason, at the time of this evacuation, the vacuum chamber 5 is once heated (a heating device is not shown), and the process of cooling the temperature to room temperature is performed again while the evacuation is continued.

  Next, the straight lead-in terminal 9 is moved, and the tip portion of the tip tube portion formed on the neck portion 3a of the cathode ray tube 3 is pressed and opened as previously described (step 3). At this time, by setting the inside of the vacuum chamber 5 at a lower pressure than the inside of the cathode ray tube 3, the residual gas in the cathode ray tube 3 at room temperature is led to the vacuum chamber 5, and the mass spectrometer 8 is led to this vacuum chamber 5. The amount of each gas is measured (step 4). In order to maintain the degree of vacuum in the vacuum chamber 5, the vacuum pump 7 is preferably operated during measurement.

  After measuring the residual gas in the tube at room temperature as described above, the temperature of the cathode ray tube 3 installed in the thermostat 4 is increased from room temperature to 300 ° C. at a constant rate, and the vacuum chamber is discharged from the cathode ray tube 3 during this temperature increase. The change in the amount of the desired component of the gas discharged into the gas 5 is checked to obtain its temperature dependency (step 5).

  For this reason, the temperature controller 10 controls the temperature of the cathode ray tube 3 by giving a command based on the relationship between the temperature detected by the temperature control temperature sensor 11 and the set temperature to the heating / cooling unit 4. For heating, an electric heater, an infrared lamp, or the like may be used, and a fan may be used in combination with air agitation.

  The data processing device 13 designates a set temperature so that the temperature controller 10 raises the temperature of the cathode ray tube 3 from room temperature to 300 ° C. at a constant rate, and at each predetermined temperature rise of the cathode ray tube 3, a mass spectrometer 8 is instructed to detect the amount of each component of the gas discharged into the vacuum chamber 5 in the meantime, and these quantitative analysis data are input. Then, the amount data of each component of the gas discharged into the vacuum chamber 5 received every time the temperature is increased and the temperature at that time are compared and stored, and presented to the observer in the form of a graph or the like. Thereby, the temperature dependence of the gas released from the cathode ray tube when the temperature is raised is obtained by a line graph or the like.

  The mass spectrometer 8 may continuously detect the amount of each released gas and sequentially send the amount analysis data to the data processor 13. In this case, the data processor 13 may The same temperature dependency can be obtained by performing data processing in correspondence with each quantitative analysis data to be detected and each detected temperature at the time of analysis detected by the temperature sensor 12 for temperature measurement.

  With the measurement method using the residual gas detection device 1 described above, the residual gas was detected for each of two types of cathode ray tubes having different manufacturing process times, and the reliability was evaluated.

  The cathode ray tube manufacturing process mainly includes a panel manufacturing process (phosphor screen coating, heat treatment, etc.), a mask manufacturing process (welding, heat treatment, etc.), a funnel manufacturing process (graphite coating, etc.), and a frit sealing process (panel-funnel). Sealing), an electron gun sealing process, an exhaust (heating) process, a base attaching process, a getter flash process, an aging process (cathode activation), a conditioning process (improvement of withstand voltage), and the like.

  For example, the amount of gas remaining in the tube depends on the heat treatment time for heat treating the organic material used for the panel phosphor screen in the panel manufacturing process or the exhaust time in the exhaust (heating) process. The There are now two types: a standard cathode ray tube manufactured by taking these steps over a standard manufacturing process time, and a comparative cathode ray tube manufactured by reducing these times by, for example, about 4% of the standard manufacturing process time. In the cathode ray tube, residual gas was detected by the measurement method using the residual gas detection device 1 described above, and the reliability was comparatively evaluated. The standard manufacturing process time referred to here is a manufacturing process time that allows the standard cathode ray tube manufactured thereby to obtain the expected performance in the life test.

  As a result, the comparative cathode ray tube, which has a shorter manufacturing process time than the standard cathode ray tube with the standard manufacturing process time, has about 5 times as much hydrogen released at the time of temperature rise, about 3 times as much as methane, and about 1 time as carbon monoxide. .2 times, carbon dioxide was about 1.5 times larger. In addition, calculation of the ratio of this discharge amount was performed by comparing the total discharge amount for each gas individually.

  On the other hand, as a result of conducting a life test of the cathode ray tube manufactured under the same conditions as the sample used in this evaluation, a difference was seen between 2,000 and 4,000 hours, and a comparative cathode ray tube having a short manufacturing process time was The radiation capacity deteriorated to less than half of the initial value in about 10,000 hours, whereas the cathode ray tube of the standard manufacturing process time did not deteriorate at this point.

  The above results show that cathode ray tubes with a short manufacturing process time such as evacuation and heat treatment have a larger amount of gas remaining in the tube than the cathode ray tube with the standard manufacturing process time, which affects the cathode during operation. It is shown to degrade the electron emission ability. Then, it is shown that reliability can be evaluated without performing a long life test by analyzing the emitted gas when the temperature of the cathode ray tube is raised.

  As described above, according to the residual gas detection device of the first embodiment, it is possible to analyze the type of residual gas in the cathode ray tube and the amount of each residual gas. Further, by analyzing the residual gas of the cathode ray tube thus obtained, it is possible to evaluate its reliability without performing a long-term life test.

  In the present embodiment, the residual gases in the two cathode ray tubes, the standard cathode ray tube and the comparative cathode ray tube, are detected and compared with each other, and the reliability of both is evaluated. The amount of each component of the residual gas of the standard cathode ray tube that cleared the above is obtained in advance, and by using this as the reference value, the amount of each component of the residual gas of the comparative cathode ray tube is obtained and compared with the above standard value. By examining it, the reliability of the comparative cathode ray tube can be evaluated.

Embodiment 2. FIG.
FIG. 2 is a main part configuration diagram schematically showing a main part configuration of the residual gas detection device 21 of the vacuum tube apparatus according to the second embodiment of the present invention.

  The residual gas detection device 21 of the second embodiment is mainly different from the residual gas detection device 1 of the first embodiment described above in that an oil bath is used to raise the temperature of the cathode ray tube 3 and the heating is performed by an electric heater or the like. It is a point that is done by. Therefore, in the residual gas detection device 21, the same reference numerals are given to the portions common to the residual gas detection device 1 of the first embodiment described above, description thereof will be omitted, and different points will be described mainly.

  In the figure, the thermostatic chamber 22 can accommodate the main part except the neck part of the test cathode ray tube 3 in the inside thereof, and the inside is filled with the silicone oil 25. Thereby, the main part of the accommodated cathode ray tube 3 is immersed in the silicone oil 25. A heating unit 24 such as an electric heater for applying heat to the silicone oil 25 is disposed in the vicinity of the bottom inside the thermostatic chamber 22. Here, the constant temperature bath 22, the silicone oil 25, and the heating unit 24 are collectively referred to as an oil bath 26.

  Although not shown in the figure, it is preferable that a fin for stirring the silicone oil 25 heated by the heating unit 24 is disposed in the thermostatic chamber 22. Moreover, the thermostat 22, the heating unit 24, the temperature sensor 11 for temperature control, and the temperature controller 23 correspond to a thermostat. Although not shown, it is preferable to further have a local exhaust facility for removing steam from the oil bath. Although formaldehyde may be generated at 150 ° C. or higher, in this case, it is safer by exhaust.

  The temperature controller 23 inputs temperature data from a temperature control temperature sensor 11 that detects the temperature at a predetermined position of the cathode ray tube 3 accommodated in the thermostat 2, and the detected temperature is the temperature specified by the data processing device 13. Thus, the heating unit 24 is controlled.

  As described above, the residual gas detection device 21 of the vacuum tube device of the type in which the cathode ray tube 3 is heated by the oil bath 26 allows the two types of cathode rays, the standard cathode ray tube and the comparative cathode ray tube defined in the description of the first embodiment. The tube was subjected to the same comparative evaluation as in the first embodiment by the method for measuring the residual gas in the cathode ray tube 3 based on the flowchart shown in FIG.

  As a result, the comparative cathode ray tube, which has a shorter manufacturing process time than the standard cathode ray tube with the standard manufacturing process time, has about 7 times as much hydrogen released at the time of temperature rise, about 5 times as much as methane, and about 1 time as carbon monoxide. The result was .8 times larger than that of carbon dioxide.

  This result is about 5 times to about 7 times hydrogen, about 3 times to about 5 times, about 5 times to about 5 times the evaluation result performed using the residual gas detection device 1 of the vacuum tube device described in the first embodiment, Carbon monoxide is about 1.5 times to about 1.8 times, carbon dioxide is about 1.5 times to about 5.5 times, and the detection amount of each gas increases, and the analysis sensitivity is high. This difference in sensitivity is due to the uniformity of the temperature of each part of the cathode ray tube at the time of temperature rise in the residual gas detection device 21 of the second embodiment using an oil bath as compared to the residual gas detection device 1 of the first embodiment. Because it became higher.

  The reason will be described. The same temperature measuring temperature sensor 12 as the temperature measuring temperature sensor 12 is attached to 10 positions of the cathode ray tube determined at random, and the temperature is raised in the thermostatic chamber 2 of the first embodiment, and the constant temperature of the second embodiment. The temperature variation in each part when the temperature was raised in the tank 22 was compared. When the control temperature sensor 11 rises to 50 ° C., 100 ° C., 150 ° C., and 200 ° C., the standard deviation of 10 measured values measured at 10 locations of the cathode ray tube 3 is measured in the thermostatic chamber 2 And when measured in a thermostatic chamber 22. As a result, the temperature chamber 2 of the first embodiment is about three times as large as the temperature chamber 22 of the second embodiment at each temperature, and it is better to use an oil bath like the temperature chamber 22 of the second embodiment. It was found that the temperature could be increased uniformly.

  On the other hand, the gas adsorbed other than the getter in the cathode ray tube is desorbed when the temperature rises and is exhausted by the vacuum pump 7 while repeatedly colliding with the inner wall of the tube, and detected by the mass spectrometer 8. However, if the temperature of the cathode ray tube 3 is uneven and low, the desorbed gas tends to be re-adsorbed there, and the amount of emission is reduced, so that the analysis sensitivity becomes dull. In the second embodiment, as described above, the oil bath using silicone oil as the heat medium is employed to uniformly raise the temperature of the cathode ray tube 3 and suppress such re-adsorption, thereby reducing the amount of released residual gas. The amount of detection by the mass spectrometer 8 is increased and the analysis sensitivity is increased.

  As described above, the reliability of the cathode ray tube can be evaluated without analyzing a long-term life test by analyzing the gas emitted when the temperature of the cathode ray tube is raised. By raising the temperature with an oil bath, the amount of released residual gas can be increased as compared with the first embodiment. As a result, the analysis sensitivity becomes higher, and the accuracy of reliability evaluation can be further increased.

  In the present embodiment, for example, the heater input power as a heating unit is controlled to increase the temperature at a constant rate, but a copper pipe is installed in the oil bath to pass a cooling medium, or silicone oil Cooling means such as circulating the air may be provided. When one evaluation is completed, when the next evaluation is performed, it is necessary to lower the oil heated to 300 ° C. to room temperature. With such a cooling means, the working efficiency can be improved.

Embodiment 3 FIG.
Embodiment 3 describes an example of a method for evaluating the reliability of a vacuum tube device according to the present invention.

  That is, the residual gas detection device 21 of the vacuum tube device employing the oil bath shown in FIG. 2 is used to measure the residual gas in the cathode ray tube 3 by the method for measuring the residual gas in the cathode ray tube 3 based on the flowchart shown in FIG. In the second embodiment, a cathode ray tube that has undergone normal manufacturing processes such as a getter flash process, an aging process (cathode activation), and a conditioning process (improvement of withstand voltage) is used as the measurement sample. In this embodiment, the cathode ray tube at the stage after the exhaust (heating) step before the getter flash is used. Since all other measurement conditions are the same as those of the evaluation method performed in the above-described second embodiment, the overlapping description will be omitted here, and different points in the description will be mainly described below.

  The cathode ray tube manufacturing process mainly includes a panel manufacturing process (phosphor screen coating, heat treatment, etc.), a mask manufacturing process (welding, heat treatment, etc.), a funnel manufacturing process (graphite coating, etc.), and a frit sealing process (panel-funnel). ), An electron gun sealing process, an exhaust (heating) process, a base attaching process, a getter flash process, an aging process (cathode activation), and a conditioning process (withstand voltage improvement).

  The cathode ray tube used as a measurement sample in the third embodiment is a cathode ray tube that has been subjected to the exhaust (heating) step before the getter flash step as described above, and the amount of gas remaining in the tube depends on the left and right. For example, there are two types of cathode ray tubes in which the heat treatment time for heat treatment of the organic material used for the panel phosphor screen in the panel manufacturing process or the exhaust time in the exhaust (heating) process is different.

  That is, there are two types: a standard cathode ray tube manufactured by taking these processes over a standard manufacturing process time, and a comparative cathode ray tube manufactured by reducing these times by, for example, about 4% of the standard manufacturing process time. In the cathode ray tube, residual gas was detected by the measurement method using the residual gas detector 21 described in the second embodiment, and the reliability was compared and evaluated.

  As a result, the comparative cathode ray tube having a shorter manufacturing process time than the standard cathode ray tube having a standard manufacturing process time is about 30 times as much hydrogen released at the time of temperature rise, about 9 times as much as methane, and about 10 times as much as carbon monoxide. Doubled, carbon dioxide was about 15 times larger. This result is about 7 times to about 30 times hydrogen, about 5 times to about 9 times methane, about 1.8 times to about 10 times carbon monoxide, and about 10 times that of the evaluation result in the second embodiment. Carbon dioxide is about 5.5 times to about 15 times higher in analytical sensitivity.

The reason why the analysis sensitivity is thus increased will be described below.
In a normal cathode ray tube that has undergone manufacturing processes such as a getter flash process, an aging process (cathode activation), and a conditioning process (improvement of withstand voltage), the gas absorbed by the getter is not released. The adsorbed gas will be evaluated. These gases are desorbed as the temperature rises, but repeatedly collide with the inner wall of the tube, and if absorbed by the getter at this time, they do not go out of the tube and are not detected by the mass spectrometer.

  In addition, the absorption by the getter at this time was found to be caused by gas adsorption on the surface and internal diffusion. For this reason, as the temperature rises, the getter absorption rate increases, and it becomes more difficult to get out of the tube, making it difficult to detect with a mass spectrometer. Therefore, as the temperature rises, the desorbed gas increases in the tube, while the amount of gas adsorbed on the getter increases, and the amount of gas released outside the tube decreases accordingly.

  On the other hand, since the cathode ray tube in which the getter film is not formed is used in the third embodiment, the residual gas in the tube desorbed as the temperature rises is directly released outside the tube without being absorbed by the getter. The amount of release increases, and the amount detected by the mass spectrometer 8 is increased to increase the analysis sensitivity.

  As described above, it is possible to evaluate the reliability of the cathode ray tube without performing a long-term life test by analyzing the gas emitted when the temperature of the cathode ray tube is raised. As described above, the cathode ray tube according to the third embodiment. According to this evaluation method, since the residual gas in the tube desorbed with the temperature rise goes out of the tube without being absorbed by the getter, the amount of released residual gas can be increased compared to the case of the second embodiment. it can. As a result, the analysis sensitivity becomes higher, and the accuracy of reliability evaluation can be further increased.

  In the above-described embodiment, the apparatus using the cathode ray tube as a sample and the evaluation method are shown. However, the present invention is not limited to this, and the apparatus is configured using another vacuum tube apparatus such as a field electron emission device as a sample. It is also possible to evaluate its reliability.

  Further, in the above-described embodiment, the gas analysis is performed by the mass spectrometer. However, the ionization vacuum gauge may be provided in the vacuum chamber 5, and the pressure data of the in-pipe residual / released gas can be measured. In this case, it is also useful as a vacuum chamber exhaust and ultimate pressure monitor before analysis, that is, before opening the cathode ray tube.

  In the above-described embodiment, since the cathode ray tube 3, the vacuum pump 7, and the mass spectrometer 8 are connected to one vacuum chamber 5, the entire vacuum chamber including the mass spectrometer is replaced every time the cathode ray tube is replaced. Will be exposed to the atmosphere. Therefore, the vacuum chamber may be divided by a gate valve, and the gate may be closed when the cathode ray tube is replaced so that the mass spectrometer is always kept at a high vacuum level. Further, the cathode ray tube side may be preliminarily evacuated by another vacuum pump, and then the gate may be opened to perform gas analysis in the tube. In this case, the heating and evacuation time of the vacuum chamber is shortened and the cathode ray tube replacement process is performed. It can be shortened and the life of the mass spectrometer can be extended.

  In the above-described embodiment, the temperature sensor 11 is used for temperature control, the temperature sensor 12 is used for temperature measurement, and data processing is performed to obtain the relationship between the temperature and the gas release amount. The temperature measured by the temperature control temperature sensor 11 may be input to the data processing device 13 for data processing.

  In the above-described embodiment, the O-ring is used to connect the vacuum tube device and the mass spectrometer while maintaining a vacuum, but it may be hardened with an adhesive such as an epoxy resin.

  Furthermore, in the above-described embodiment, the total emission amount for each gas of the emission gas is compared and evaluated with a mass spectrometer for cathode ray tubes having different manufacturing processes. However, the total emission amount for each gas using a known constant flow gas. It is possible to take various aspects such as quantifying the emission gas by pricing the value, and if the standard of the gas emission amount of the standard manufacturing process is defined, the absolute evaluation of the gas inside the cathode ray tube can also be performed It is.

It is a principal part block diagram which shows typically the principal part structure of the residual gas detection apparatus 1 of the vacuum tube apparatus of Embodiment 1 by this invention. It is a principal part block diagram which shows typically the principal part structure of the residual gas detection apparatus 21 of the vacuum tube apparatus of Embodiment 2 by this invention. 4 is a flowchart showing a processing procedure of a method for measuring a residual gas in the cathode ray tube 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Residual gas detection apparatus of vacuum tube apparatus, 2 Constant temperature bath, 3 Cathode ray tube, 3a Neck part, 4 Heating / cooling unit, 5 Vacuum chamber, 5a Neck insertion part, 6 O-ring, 7 Vacuum pump, 8 Mass spectrometer, 8a Analytical tube, 9 Straight line introduction terminal, 10 Temperature controller, 11 Temperature sensor for temperature control, 12 Temperature sensor for temperature measurement, 13 Data processing device, 21 Residual gas detection device for vacuum tube device, 22 Constant temperature bath, 23 Temperature controller, 24 Heating unit, 25 silicone oil, 26 oil bath.

Claims (8)

In the residual gas detection device of the vacuum tube device for detecting the residual gas in the vacuum tube device,
A thermostatic means for housing the vacuum tube device and heating at least the vacuum tube device so that the temperature of the vacuum tube device becomes a target temperature;
Isolation means having a hollow portion connected to the internal space of the vacuum tube device through a predetermined opening location of the vacuum tube device in a state isolated from the outside,
Exhaust means for exhausting the hollow portion;
Mass spectrometry means for detecting the amount of the gas component in the hollow part;
Have
A residual gas detection device for a vacuum tube device, wherein the amount of a desired component of gas released into the hollow portion is detected from the inside of the vacuum tube device in the process of raising the temperature of the vacuum tube device. 2. The vacuum tube apparatus residual according to claim 1, wherein the constant temperature means obtains temperature information of a predetermined location of the vacuum tube apparatus and heats the vacuum tube apparatus so that the temperature information corresponds to the target temperature. Gas detection device. 3. The residual gas detection device for a vacuum tube device according to claim 1 or 2, wherein the constant temperature means heats the vacuum tube device through the silicone oil in a state where the vacuum tube device is immersed in silicone oil. The residual gas detection device for a vacuum tube device according to any one of claims 1 to 3, wherein the isolation means includes an action means for opening the opening location. 2. The isolation means includes an insertion portion for inserting a part of the vacuum tube device, and an O-ring for filling a gap when a part of the vacuum tube device is inserted into the insertion portion. The residual gas detection apparatus of the vacuum tube apparatus in any one of thru | or 3. The residual gas detection device for a vacuum tube device according to any one of claims 1 to 5, wherein the temperature of the vacuum tube device is increased and the amount of a desired component of gas released from the internal space of the vacuum tube device to the hollow portion is detected. And
Reliability evaluation of the vacuum tube device characterized by determining the reliability of the vacuum tube device by raising the temperature of the vacuum tube device at a substantially constant rate and determining the amount of a desired component of the gas detected at the time of the temperature rise Method. 7. The reliability evaluation method for a vacuum tube device according to claim 6, wherein the reliability of the vacuum tube device is determined by obtaining and comparing the amounts of the individual desired components of the vacuum tube devices having different manufacturing processes. 8. The reliability evaluation method for a vacuum tube device according to claim 6, wherein the reliability of the vacuum tube is determined by obtaining the amount of each desired component of the vacuum tube device having no getter function therein.

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