JP4277442B2 - Evaluation method of gas discharge display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for evaluating a gas discharge display device by analyzing an impure gas contained in a gas discharge display device typified by an AC plasma display panel (hereinafter also referred to as an AC type PDP).
[0002]
[Prior art]
FIG. 5 is a diagram illustrating an example of the configuration of an AC type PDP, in which 20 represents a front panel, 30 represents a back panel, and 40 represents an AC type PDP. The front panel 20 includes a front substrate 21, a transparent electrode 24 formed on the front substrate 21, a metal electrode 25 formed on the transparent electrode 24, and the front substrate so as to avoid the transparent electrode 24 in order to improve the contrast of the PDP. The black stripes 26 formed on the substrate 21, the dielectric 22 formed on the front substrate 21 so as to cover them, and the dielectric 22 are protected from the discharge environment, and the discharge assists the discharge by emitting secondary electrons during the discharge. It is comprised from the MgO film | membrane 23 which functions as a film | membrane. The back panel 30 includes a back substrate 31, a metal electrode 36 formed on the back substrate 31 and functioning as an address electrode, and a base layer 32 formed on the back substrate 31 so as to cover the metal electrode 36 (this base layer 32 This functions as a reflection layer for preventing the diffusion of impurities from the back substrate 31 and efficiently extracting visible light emitted by excitation of the phosphor, etc.). Partition walls 35 (hereinafter also referred to as ribs) formed by upper layer ribs 33 and lower layer ribs 34 provided for separation into two, and red phosphors 37 formed between the ribs for regularly emitting three primary colors. (R), a green phosphor 37 (G), and a blue phosphor 37 (B).
[0003]
In the conventional AC type PDP 40, the front panel 20 and the back panel 30 are bonded together, and a predetermined discharge cell is formed between the transparent electrode 24 on the front panel 20 side or the metal electrode 25 and the W electrode (address electrode) 36 on the back panel 30 side. The discharge gas filled in the discharge space 38 (the discharge gap formed between the front panel 20 and the back panel 30 is about 100 to several hundred μm) is performed by selecting and performing the sustain discharge between adjacent electrodes of the front panel. When excited, the phosphor is further excited by the ultraviolet light obtained by this excitation to obtain visible light emission. The pressure of the discharge gas varies depending on the discharge gap length and the type of gas to be filled, but the discharge gap length is usually about 4000 to 7000 Pa. As the gas species, for example, Ne—Xe gas or Ne—Xe—He gas is used.
[0004]
The discharge space in the AC type PDP has a narrow discharge gap of about 100 to several hundred μm, and plasma is generated in this narrow space, so that a large stress is applied to the phosphor and the protective film constituting the inner wall of the discharge space. This is a cause of shortening the life of the panel. For this reason, it is an urgent issue to extend the life of the panel. To that end, it is necessary to clarify the phenomenon in the panel that contributes to the life, especially the importance of component analysis of gas in the discharge space. Has been attracting attention.
[0005]
A PDP is formed by bonding a front panel and a back panel so that a discharge gap is 100 μm to several hundreds μm, and is characterized by having a very narrow discharge space. How to properly extract the gas to be analyzed from the state space is an important point in obtaining accurate information. Normally, the PDP and the gas analyzer are connected by a thin pipe with an inner diameter of several millimeters. However, in the analysis of moisture that has been pointed out to affect the reliability of the PDP, the surface adsorption of these pipe inner surfaces The effect of this is great, and how to suppress this effect is important. For this reason, shorten the piping as much as possible, minimize the use of connecting parts such as valves and joints that cause leaks, and place the piping in a high vacuum state with a turbo molecular pump before analysis. In some cases, the temperature is raised using a tape heater or the like to promote cleaning.
[0006]
A conventional gas analysis method will be described with reference to the drawings. Conventional PDP gas analysis methods are roughly divided into two as shown in FIGS. FIG. 6 is a diagram showing a non-destructive gas analysis method of a panel in an exhaust process using a partial pressure gauge, and FIG. 7 is a seal disclosed in Asian Display Seoul '98, Proceedings pp-639-642. -It is one structural example of the apparatus which analyzes the gas component in PDP which the exhaust process was complete | finished and discharge gas was enclosed.
[0007]
In the gas analysis using the partial pressure gauge attached to the conventional exhaust device, as shown in FIG. 6, the PDP 40 in a state where the front panel 20 and the back panel 30 are bonded together has an exhaust pipe formed in the back panel 30 in advance. After being formed in the exhaust hole portion, it is set in the exhaust furnace 41 and heated according to a predetermined exhaust temperature rising profile, and a turbo molecular pump (hereinafter also referred to as TMP) 48 and a vacuum pump (hereinafter referred to as TMP) through the exhaust pipe. Evacuated by 49). The valve 46 is opened during roughing, and the valves 44 and 45 are opened during steady exhaust. The partial pressure gauge 47 is attached in the pipe and can continuously monitor the state of exhaust gas at a predetermined vacuum level or lower. The degree of vacuum is monitored by a low vacuum monitor means 42 such as a Bourdon tube and a high vacuum monitor means 43 such as a BA gauge, and when a predetermined pressure is reached, the partial pressure gauge 47 is turned on to perform gas analysis.
[0008]
FIG. 8 shows an example of gas analysis data in the PDP exhaust process using a partial pressure gauge attached to a conventional exhaust apparatus.
As shown in FIG. 8, the exhaust furnace enters a high temperature keep state at 350 ° C. after about 1 hour from the start of exhaust, and most of the large amount of water, CO, and CO ₂ contained in the panel before exhaust is in the panel. It is discharged outside, and the apparent degree of vacuum is reduced almost simultaneously with the 350 ° C. high temperature keep. Apparently, since the vicinity of the PDP is exposed to a high temperature state, the degree of vacuum at this time is only at a predetermined position of the piping, and does not necessarily accurately reflect the internal state of the PDP. It is.
However, the result of FIG. 8 suggests that most of the gas released from the PDP is H ₂ O in the exhaust process.
[0009]
Next, a destructive gas analysis method for the panel by collecting gas from the PDP after completion of the conventional exhaust process and the result will be described.
PDP30, which has been evacuated and sealed and filled with a predetermined discharge gas, is a Hitachi review VOL. 53 NO. 2 1971 P.M. 39 As in the method disclosed in FIG. 2B, a part of the back panel is processed and thinned, and the glass pipe 17 is covered with an epoxy seal 71 or the like so that there is no gap as shown in FIG. Attach to 2. Then, the magnetic hammer 72 is disposed in the pipe 17 so that the gas can be guided to the analyzer by breaking the thinned groove portion 10, and then fixed at a predetermined position by the magnet 73.
[0010]
In FIG. 7, the discharge gas of the PDP 30 containing impure gas is analyzed by the quadrupole mass analyzer 57, but the impure gas (mainly gas adsorbed on the surface) present in the pipe is removed for analysis. In order to reduce the influence of the above as much as possible, it is important to make the piping and the like as high a vacuum as possible before taking out the gas from the PDP 30. Therefore, in addition to the turbo molecular pump 53 and the rotary pump 54, some piping is provided with baking means. Reference numerals 65 and 66 denote baking areas. 58 is a pressure regulating valve provided with a predetermined conductance so that the gas pressure in the quadrupole mass analyzer 57 is substantially constant, and serves as an orifice.
[0011]
FIG. 9 shows the analysis result of the released gas from the PDP analyzed by such an analysis method. From FIG. 9, in the conventional destructive gas analysis method of the panel by collecting gas from the PDP after completion of the exhaust process, the gas components in the panel are mainly composed of CO and H ₂ , and H ₂ O is one of these. It looks as if there is only about / 4 to 1/5.
[0012]
[Problems to be solved by the invention]
In the gas analysis in the panel in the conventional AC type PDP in which a gas extracted by destroying a part of the PDP is analyzed using a quadrupole mass spectrometer, the above-described moisture is hardly detected, and a partial pressure gauge is used. It did not agree with the gas analysis results in the exhaust. In addition, the result obtained by performing the gas analysis after connecting the discharge means to the PDP in the configuration shown in FIG. 7 and discharging it under normal discharge conditions is almost the same, and the water is the main component of the exhaust gas. The analysis result that it was a component was not obtained. However, since AC type PDP is generally manufactured using a plurality of steps of applying paste and baking, the moisture in the atmosphere or the panel is absorbed in the heating-to-cooling cycle, and the moisture is absorbed in the panel. There is a high possibility that it has been brought in, and the result shown in FIG. Therefore, the present inventors considered that such an analysis result was obtained due to the strong moisture adsorption action of MgO formed on the front panel in the PDP.
FIG. 11 is a view of the PDP as seen from the front panel side. In the figure, 80 is an upper surface of a rib formed on the back panel, W is an address electrode formed on the back panel, and X and Y are an X electrode and a Y electrode formed on the front panel, respectively. Reference numeral 81 denotes discharge traces formed on the MgO film after lighting for a long time, and it is considered that the main discharge of the PDP is mainly generated in this region. As can be seen from FIG. 11, MgO formed on the entire surface of the front panel has a wide portion that does not contribute to discharge, and this portion is considered to be an adsorption site for moisture and other impure gases. . The inventors of the present application think that the behavior of the impurity gas (especially moisture) in the panel can be accurately grasped by substantially reducing the amount of the impurity gas adsorbed by MgO, and arrived at the present invention. It is what.
[0013]
[Means for Solving the Problems]
An evaluation method for a gas discharge display device according to the present invention includes a pair of opposing discharge substrates, and is configured to be capable of enclosing a discharge gas therein, in a state in which a discharge gas of a predetermined pressure is encapsulated. Using a gas discharge display panel provided with at least a pair of electrodes for applying a voltage to the discharge gas to discharge, under a state in which the discharge gas adjusted to 1000 Pa or less is sealed in the gas discharge display panel, Discharge is performed by at least a pair of electrodes, and then the discharged gas after discharge is taken out of the gas discharge display panel for gas analysis.
[0014]
In the method for evaluating a gas discharge display device according to the present invention, the gas analyzer used for gas analysis may be a quadrupole mass spectrometer.
[0015]
In the gas discharge display device evaluation method according to the present invention, the gas discharge display panel may be a plasma display panel.
[0016]
In the gas discharge display device evaluation method according to the present invention, the gas discharge display panel may have an MgO film.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
FIG. 1 is a diagram showing an example of an evaluation apparatus for a gas discharge display device according to the present invention.
In FIG. 1, 1 is a front panel of a PDP, 2 is a back panel of a PDP, 3 is a terminal part fitting means of the back panel, 4 is a terminal part fitting means of the front panel, 5 is a discharging means, and 6 is a low vacuum monitor. Means 7 is a variable leak valve (hereinafter also referred to as VLV), 8 is a high vacuum monitoring means, 9 is a valve 1, 10 is a turbo molecular pump (hereinafter also referred to as TMP), 11 is a vacuum pump (hereinafter also referred to as VP), 12 Is a variable leak valve (VLV), 13 is a high vacuum monitoring means, 14 is a quadrupole mass analyzer (hereinafter also referred to as QMS), 15 is a turbo molecular pump (TMP), 16 is a vacuum pump (VP), 17-19 Is piping.
[0018]
Next, according to the gas analysis flow of FIG.2 (b), an example of the analysis procedure of the evaluation method of the gas discharge display apparatus which concerns on this invention is demonstrated. First, a PDP that is exhausted and sealed by a normal process and has a discharge gas having a predetermined pressure is prepared. And, for example, Hitachi review VOL. 53 NO. 2 1971 P.M. 2 (b) disclosed in Fig. 39 (a part of the back panel is processed and thinned, and a glass tube is attached thereto with the above-mentioned resin, and the thinned portion is broken to supply gas to the analyzer. In the same manner as in the above, the device is connected to each other as shown in FIG. After the connection is completed, predetermined power is supplied from the discharging means 5 to the terminal portion connecting means 3 on the back panel and the terminal portion connecting means 4 on the front panel, and a discharge occurs in the PDP. As a result of this discharge, H ₂ O, CO ₂ or the like existing on or near the surface of the MgO film or phosphor is struck by sputtering, released into the discharge space of the PDP, and taken into the discharge gas. It becomes a shape.
[0019]
At this time, in order to remove as much as possible the impure gas adsorbed on the inner wall or the like of the pipe 17 or the like, the pipe or the like is evacuated prior to analysis. When the discharge of the PDP is completed, the high vacuum monitoring means 8 confirms that the piping system is in a high vacuum state, and then closes each valve.
[0020]
Next, a gas introduction method from the PDP back panel to the gas analysis system will be described. FIG. 10 is a diagram showing the connection relationship between the groove 70 provided in the back panel 2 of the PDP and the pipe 17. The pipe 17 is covered with an epoxy seal 71, which is a high vacuum sealant, so as to cover the groove 70. The back panel 2 is connected with good sealing properties. A magnetic hammer 72 is set on the pipe 17 and is held hollow by a magnet 73.
When the discharge of the PDP is completed, the magnet 73 is moved away from the pipe, the magnetic hammer 72 directly hits the groove 70, a part of the back panel of the PDP is destroyed, and the discharge gas of the PDP is introduced into the analysis system. At this time, the low vacuum monitoring means 6 shown in FIG. 1 is operating.
[0021]
After the discharge gas of the PDP is taken out to the pipe 17, the high vacuum monitoring means 8 is turned off, and then the VLV 7 is opened to introduce the discharge gas into the pipe 18. Then, the gas pressure is confirmed by the low vacuum monitoring means 6, and the VLV 7 is closed when the pressure is lowered by 200 Pa from the pressure before the VLV 7 is opened. The PDP discharge gas to be analyzed by the above operation is introduced into the pipe 18.
[0022]
Next, after operating the high vacuum monitoring means 13, the VLV 12 is slowly opened, and analysis is performed while the high vacuum monitoring means 13 monitors the degree of vacuum of the pipe 19. When the gas analysis is completed, all the valves are closed, the turbo molecular pump 10, the vacuum pump 11, the turbo molecular pump 15, and the vacuum pump 16 are operated, and the vacuum gas is exhausted to exhaust the impure gas existing in the pipes 18 and 19. Exhaust.
[0023]
If the PDP continues to be discharged, the high vacuum monitor means 8 and the high vacuum monitor means 13 confirm that the pipes 18 and 19 are in a high vacuum state, and then close the valves. Subsequently, the high vacuum monitor 8 is turned off, the VLV 7 is opened, the PDP discharge gas is introduced into the pipe 18, and gas analysis is performed in the same manner as described above.
[0024]
The series of operations described above are continued until the PDP discharge stops or becomes unstable. In this way, the analysis of the PDP discharge gas is performed by the QMS 14.
[0025]
3 and 4 show the analysis results of the discharge gas components of the PDP evaluated by the above-described method. Fig. 3 (a) shows an analysis result for a panel that is considered to have a long exhaust time and relatively little impurities in the panel. Fig. 3 (b) shows that the exhaust time is short and a large amount of impurities remain in the panel. Shows the analysis results for the expected panel. FIG. 4 shows a comparison between the data when the PDP is discharged under normal discharge conditions and analyzed by gas and the amount of moisture (H ₂ O) in the discharge gas analyzed by the evaluation method according to the present invention.
[0026]
3 (a) and 3 (b) shows that the difference in impurities contained in the discharge gas due to the difference in exhaust time from the results obtained when the discharge gas pressure is approximately 1000 Pa or less is mostly moisture. . On the other hand, it can be seen that when the discharge gas pressure is about 1000 Pa or more, there is no clear difference in the composition of the impure gas depending on the exhaust time of the panel.
[0027]
Embodiment 2
In the first embodiment, the method of analyzing until the discharge is stopped while reducing the pressure of the discharge gas by 200 Pa using a normal PDP panel in which the pressure of the discharge gas is 4000 to 7000 Pa has been described. However, it is of course possible to prepare and analyze a panel in which the pressure of the discharge gas is initially set to 1000 Pa or less.
FIG. 4 shows the relationship between the amount of moisture contained in the discharge gas and the PDP exhaust time, and the conventional gas analysis method for discharge and gas evaluation according to the present invention when the discharge gas pressure is 700 Pa. It is obtained by the method and the analysis results of both are compared. From FIG. 4, in the conventional method (indicated by a circle in the figure), even when the exhaust time (350 ° C. keep time in exhaust) changes, the amount of water contained in the PDP discharge gas hardly changes, and FIG. It turns out that it does not correspond with the result obtained by analyzing the gas component in the exhaust_gas | exhaustion process shown in. On the other hand, the results obtained by the gas analysis method according to the present invention indicated by Δ in FIG. 4 indicate that the panel has a longer exhaust time (350 ° C. keep time in exhaust) and the amount of water contained decreases. Since the tendency agrees well with the result obtained by analyzing the gas components in the exhaust process shown in FIG. 8, it reflects the state of the discharge gas in the PDP with relatively high accuracy. I think that the.
[0028]
According to the first and second embodiments, the PDP is not discharged under the optimal discharge conditions (discharge gas pressure: 4000 to 7000 Pa), but the discharge is slightly lower than the optimal discharge conditions (discharge gas pressure: 1000 Pa or less). ), It was found that the impure gas in the panel, particularly the water content, can be monitored with good reproducibility. It is thought that the reason why water does not appear to be released into the discharge gas in the conventional optimum discharge state may be due to the strong adsorption action of MgO used in the front panel of the PDP. In addition, when discharge is performed with the discharge gas pressure slightly lowered, the sputtering effect is enhanced and the cleaning effect of the MgO surface is enhanced, and the discharge space is in a low vacuum state. Since the dissociation property of the impure gas from the gas is improved, it is considered that the above-described effects are caused by the synergistic action of these actions.
[0029]
In the present invention, the discharge of the PDP is a discharge between the back panel and the front panel. However, the discharge of the PDP is not limited to such a discharge, and only the front panel is discharged like a normal sustain discharge. However, the same effect can be obtained. It is also possible to discharge alternately between the three electrodes, the XY electrode of the front panel and the W electrode of the back panel, and plasma is generated in the discharge space, resulting in a sputtering effect. Similar effects can be obtained. Furthermore, the excitation of the discharge space of the PDP can be performed not only by supplying power to the PDP but also by irradiating, for example, microwaves or ultraviolet rays from the outside. Needless to say, the excitation effect of the PDP is further improved by adding.
[0030]
Furthermore, in the evaluation method of the gas discharge display device according to the present invention, the discharge gas pressure was reduced by 200 Pa, but the discharge gas pressure reduction method is not limited to such a method, and every 100 Pa. Needless to say, it may be lowered or may be lowered every 50 Pa, and the same result can be obtained.
[0031]
【The invention's effect】
As described above, according to the present invention, the PDP was discharged at a slightly lower gas pressure than the optimal discharge state, and then the analysis was performed using QMS, which was hardly detected in the past. Impurity gas contained in the PDP centered on moisture can be analyzed, and there is an effect that an abnormality in the PDP manufacturing process can be detected and the exhaust process can be optimized.
[Brief description of the drawings]
FIG. 1 is a diagram showing an apparatus configuration used in an evaluation method for a gas discharge display apparatus according to the present invention.
FIG. 2 is a chart for explaining an evaluation method for a gas discharge display device according to the present invention.
FIG. 3 is a diagram showing an evaluation result obtained by the method for evaluating a gas discharge display device according to the present invention.
FIG. 4 is a diagram showing evaluation results obtained by the PDP evaluation method according to the present invention.
FIG. 5 is a diagram showing the structure of an AC type PDP.
FIG. 6 is a diagram showing an apparatus configuration for gas analysis in a conventional PDP exhaust process.
FIG. 7 is a diagram for explaining an apparatus configuration in a conventional PDP discharge gas analysis method;
FIG. 8 is a diagram showing an analysis result obtained by a gas analysis method in a conventional PDP exhaust process.
FIG. 9 is a diagram showing analysis results obtained by a gas analysis method using a conventional PDP discharge gas analyzer.
FIG. 10 is a diagram showing a panel destruction method for gas extraction in the evaluation method for a flat type gas discharge display device according to the present invention.
FIG. 11 is a diagram showing discharge traces formed on the MgO film of the AC type PDP.
[Explanation of symbols]
1 PDP front panel, 2 PDP back panel,
3 Electrode terminal connection on the back panel side,
4 Front panel side electrode terminal connection, 5 discharge means,
6 Low vacuum monitoring means, 7 Variable leak valve (VLV),
8 High vacuum monitoring means, 9 valves,
10 turbo molecular pump (TMP), 11 vacuum pump (VP),
12 variable leak valve (VLV), 13 high vacuum monitoring means,
14 quadrupole mass analyzer, 15 turbo molecular pump (TMP),
16 Vacuum pump (VP), 17 piping, 18 piping, 19 piping,
20 front panel, 21 front substrate, 22 dielectric,
23 protective film (MgO), 24 transparent electrode, 25 metal electrode,
26 Black stripe, 30 back panel, 31 back substrate,
32 Underlayer, 33 Upper rib, 34 Lower rib, 35 Bulkhead (rib),
36 W electrode (address electrode), 37 (R) red phosphor,
37 (G) green phosphor, 37 (B) blue phosphor, 38 discharge space,
40 PDP, 41 exhaust furnace, 42 low vacuum monitoring means,
43 High vacuum monitoring means, 44 valves, 45 valves, 46 valves,
47 High vacuum monitor, 48 Turbo molecular pump (TMP),
49 Vacuum pump (VP), 51 valve, 52 valve,
53 turbo molecular pump, 54 rotary pump, 55 valve,
56 valve, 57 mass analyzer, 58 pressure regulating valve, 59 vacuum gauge,
60 valves, 61 turbo molecular pumps, 62 rotary pumps,
63 valve, 64 calibration gas, 65 baking area,
66 baking area, 70 groove, 71 epoxy seal,
72 magnetic hammer, 73 magnet

Claims (4)

A pair of opposing discharge substrates is provided, and a discharge gas can be enclosed therein, and a voltage is applied to the discharge gas in a state where the discharge gas is sealed at a predetermined pressure. A gas discharge display panel having at least a pair of electrodes is used, and the discharge is performed by the at least a pair of electrodes in a state where the gas for discharge adjusted to 1000 Pa or less is sealed in the gas discharge display panel. Then, a method for evaluating a gas discharge display device, wherein the discharge gas after the discharge is taken out of the gas discharge display panel and subjected to gas analysis. The method for evaluating a gas discharge display device according to claim 1, wherein the gas analyzer used for the gas analysis is a quadrupole mass spectrometer. The method for evaluating a gas discharge display device according to claim 1, wherein the gas discharge display panel is a plasma display panel. The gas discharge display panel evaluation method according to any one of claims 1 to 3, wherein the gas discharge display panel includes an MgO film.

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