JP4869822B2 - Method for manufacturing plasma display panel - Google Patents

Description

The present invention relates to the production how suppress the plasma display panel that protective layer made of magnesium oxide which is formed on the front plate to produce a compound reacts with moisture and carbon dioxide in the atmosphere.

  In general, the plasma display panel manufacturing process includes a process of manufacturing a front panel and a process of assembling the front panel and a rear panel manufactured in a separate process.

  In the step of producing the front plate, after a predetermined electrode is formed on the glass substrate used for the front plate, a dielectric layer is formed for the purpose of protecting the electrode. This dielectric layer is vulnerable to ion bombardment caused by discharge, and this ion bombardment shortens the life of the plasma display panel. In addition, since the dielectric layer has low efficiency of secondary electron emission necessary for plasma discharge, the discharge voltage becomes high. Therefore, magnesium oxide (MgO) that is resistant to ion bombardment and has excellent secondary electron emission properties is formed on the surface of the dielectric layer as a protective layer. The protective layer made of MgO is formed by sputtering or the like in a vacuum chamber. After the front plate is produced in this way and the protective layer is formed, the front plate is taken out from the vacuum chamber.

  In the assembly process, first, the front plate manufactured as described above and the back plate manufactured in a separate process are overlapped and sealed by sealing the peripheral portion thereof. Next, the atmosphere in the panel formed by sealing the front plate and the back plate is exhausted, and then the light emission (discharge) gas is filled in the panel.

In such a process, after the front plate is taken out of the vacuum chamber, the protective layer formed on the front plate is exposed to the air in the clean room until the rear plate is superimposed on the front plate. Since the protective layer is made of MgO, it easily reacts with moisture (H ₂ O) and carbon dioxide (CO ₂ ) in the air, and MgO on the surface portion of the protective layer is hydroxylated by reaction with H ₂ O. It changes to magnesium [Mg (OH) ₂ ], and changes to magnesium carbonate (MgCO ₃ ) by reaction with CO ₂ . If these compounds are still present, problems such as unstable display will occur. Applying a voltage higher than the actual drive to the panel to generate a strong plasma, the surface of the protective layer Aging is performed to remove the above compound.

However, the aging process takes a long time (about 20 hours). For this reason, conventionally, a method for shortening the time has been proposed (see, for example, Patent Document 1). In Patent Document 1, a second protective film that is easily removed by aging is formed on the surface of the protective layer.
JP-A-11-149865

  However, in the said patent document 1, the process of forming a 2nd protective film on the surface of a protective layer is needed. Moreover, although the time required for aging is shortened, the aging step is essential.

The present invention has been made in view of such circumstances, and it is not necessary to form a second protective film on the surface of the protective layer, and an aging step can be eliminated, or the time required for aging can be greatly increased. providing a plasma display panel manufacturing how that can be shortened to its purpose.

In order to achieve the above object, the present invention is a method of manufacturing a plasma display panel having a front plate and a back plate, and a protective layer made of magnesium oxide serving as a constituent member is formed on the front plate. The process from forming the protective layer to sealing the back plate to the front plate on which the protective layer is formed is performed in a clean room in which a moisture concentration sensor and a carbon dioxide concentration sensor are installed , and the atmosphere in the clean room is A method for manufacturing a plasma display panel that maintains an atmosphere in which the concentrations of moisture and carbon dioxide are both controlled to 50 ppm by volume or less is required by a device that operates in response to signals from the moisture concentration sensor and the carbon dioxide concentration sensor. Let ’s do it.

In order to eliminate the aging step, the present inventor has conducted research on suppressing the reaction between a protective layer made of magnesium oxide and moisture and carbon dioxide in the air. As a result, the atmosphere in the clean room where the process from the formation of the protective layer to the sealing of the back plate to the front plate on which this protective layer is formed is controlled to have a moisture and carbon dioxide concentration of 50 ppm by volume or less. If the atmosphere is maintained, only this, no magnesium hydroxide or magnesium carbonate is produced on the surface of the protective layer, or even if it is produced, the aging process can be made unnecessary, or aging can be avoided. The inventors have found that the time required can be greatly shortened and have reached the present invention.

A method of manufacturing a plasma display panel of the present invention, the atmosphere in the clean room for performing the steps up to seal the rear plate to the front plate the protective layer is formed from a protective layer formed, either the concentration of water and carbon dioxide In addition , by maintaining the atmosphere controlled to 50 ppm by volume or less , magnesium hydroxide and magnesium carbonate are not generated on the surface of the protective layer made of magnesium oxide, or even if they are generated, the amount can be extremely small. As a result, the aging process can be eliminated or the time required for aging can be greatly shortened.

In particular, the device operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor is an artificial air production device of the following (A), and the artificial air production device is connected to the moisture concentration sensor and the carbon dioxide concentration. is activated in response to a signal from the sensor, the liquid nitrogen below liquid nitrogen tank and a liquid oxygen below the liquid oxygen tank, is vaporized by supplying the following mixer, an artificial air consisting of nitrogen gas and oxygen gas After producing a predetermined amount and raising the temperature of the artificial air with the following heater, supplying it to the upper part of the clean room, the atmosphere in the clean room has a moisture and carbon dioxide concentration of 50 ppm by volume. in maintaining the controlled atmosphere below, low liquid nitrogen and liquid acid than the concentration in the atmosphere in the concentration of water typically cleanroom In addition, since such liquid nitrogen and liquid oxygen contain only a very small amount of carbon dioxide (1 ppm by volume or less), artificial air obtained therefrom is used in a clean room. By supplying, it is possible to easily control the water and carbon dioxide concentrations in the atmosphere of the clean room to 50 ppm by volume or less .
(A) Artificial air provided with a liquid nitrogen tank, a liquid oxygen tank, a mixer connected to both tanks, and a temperature raising device provided between the mixer and the upper part in the clean room Manufacturing equipment.

Further, the device operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor is the adjusted air supply device of (B) below, and the adjusted air supply device is connected to the moisture concentration sensor and the carbon dioxide concentration. Operates according to the signal from the sensor , collects air from the atmosphere with the following compressor and pressurizes it, then cools the compressed air with the following cooler to condense the moisture contained in the compressed air. After the separation, moisture and carbon dioxide are further adsorbed by the following adsorption tower, a predetermined amount of adjusted air from which moisture and carbon dioxide have been removed is produced, and the adjusted air is supplied to the upper part in the clean room. the atmosphere in the clean room, if the concentration of water and carbon dioxide is maintained in an atmosphere both controlled to below 50 ppm by volume is clean The concentration of moisture and carbon dioxide contained in the conditioned air supplied to the room can be set lower than the concentration of moisture and carbon dioxide in the normal clean room atmosphere. Both the water and carbon dioxide concentrations can be easily controlled to 50 ppm by volume or less .
(B) Adsorption that adsorbs moisture and carbon dioxide provided between a compressor installed in the atmosphere, a cooler connected to the compressor, and the cooler and the upper part in the clean room A regulated air supply device comprising a tower.

Further, the device operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor is an air circulation device of (C) below, and the air circulation device is connected to the moisture concentration sensor and the carbon dioxide concentration sensor. After the air in the clean room atmosphere is sucked from the lower part of the clean room by the following compressor, the moisture and dioxide contained in the air are separated by the pressure swing adsorption type gas separator below. A predetermined amount of air from which carbon is adsorbed and from which moisture and carbon dioxide have been removed is produced, and the air is supplied to the upper part of the clean room, so that the atmosphere in the clean room has both moisture and carbon dioxide concentrations. When maintaining an atmosphere controlled to 50 ppm by volume or less, empty the clean room. The while circulating in the air circulation device, it is Ru easy to control both below 50 ppm by volume concentrations of water and carbon dioxide in the atmosphere in the clean room.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device.

And the said apparatus operated with the signal from the said moisture concentration sensor and the said carbon dioxide concentration sensor is the artificial air manufacturing apparatus of the following (A), and the air circulation apparatus of the following (C), The following of the said artificial air manufacturing apparatus A portion between the temperature-raising device and the upper portion in the clean room is connected to a portion between the pressure swing adsorption type gas separation device of the air circulation device and the upper portion in the clean room. The manufacturing apparatus and the air circulation apparatus are operated in accordance with signals from the moisture concentration sensor and the carbon dioxide concentration sensor. In the artificial air manufacturing apparatus, the liquid nitrogen in the following liquid nitrogen tank and the liquid oxygen in the following liquid oxygen tank are used. Is supplied to the following mixer and vaporized to produce a predetermined amount of artificial air composed of nitrogen gas and oxygen gas. After the temperature is raised, the air circulation device sucks the air in the clean room atmosphere from the lower part of the clean room with the following compressor, and then the moisture contained in the air with the pressure swing adsorption gas separation device shown below. And a predetermined amount of air from which moisture and carbon dioxide have been removed are adsorbed, and this air is heated at the connecting portion between the artificial air production device and the air circulation device. Mixing with the artificial air heated in a vessel and supplying it to the upper part of the clean room, the atmosphere in the clean room is changed to an atmosphere in which the concentration of water and carbon dioxide is both controlled to 50 ppm by volume or less. When maintaining, according to the signals from the moisture concentration sensor and carbon dioxide concentration sensor installed in the clean room, Serial artificial air producing apparatus and an air circulation device appropriately operates the, can easily be controlled either below 50 ppm by volume concentrations of water and carbon dioxide in the atmosphere in the clean room.
(A) Artificial air provided with a liquid nitrogen tank, a liquid oxygen tank, a mixer connected to both tanks, and a temperature raising device provided between the mixer and the upper part in the clean room Manufacturing equipment.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device.

Further, the devices operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor are the following regulated air supply device (B) and the following air circulation device (C), and the adjusted air supply device described below. The part between the adsorption tower and the upper part in the clean room is connected to the part between the pressure swing adsorption type gas separation device of the air circulation device and the upper part in the clean room, and these adjusted air supplies The apparatus and the air circulation device are operated in response to signals from the moisture concentration sensor and the carbon dioxide concentration sensor, and the adjusted air supply device collects air from the atmosphere with the following compressor and boosts the pressure. The compressed air thus cooled is cooled by the following cooler to condense and separate the water contained in the compressed air. A predetermined amount of adjusted air from which moisture and carbon dioxide have been removed is adsorbed, and in the air circulation device, the air in the clean room is sucked from the lower part in the clean room with the following compressor, A pressure swing adsorption type gas separation device adsorbs moisture and carbon dioxide contained in the air, and produces a predetermined amount of air from which moisture and carbon dioxide have been removed. By mixing with the conditioned air produced by the conditioned air supply device at the connection portion with the air circulation device and supplying it to the upper part of the clean room, the atmosphere in the clean room is adjusted to have a concentration of moisture and carbon dioxide. When maintaining an atmosphere controlled to 50 volume ppm or less in all cases, the moisture concentration installed in the clean room In response to signals from the sensor and the carbon dioxide concentration sensor, the adjusted air supply device and the air circulation device are appropriately operated to control the water and carbon dioxide concentrations in the clean room atmosphere to 50 ppm by volume or less. Easy to do.
(B) Adsorption that adsorbs moisture and carbon dioxide provided between a compressor installed in the atmosphere, a cooler connected to the compressor, and the cooler and the upper part in the clean room A regulated air supply device comprising a tower.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this.

FIG. 1 shows a first embodiment of a method of manufacturing a plasma display panel according to the present invention. In this embodiment, in the manufacturing process of a plasma display panel having a front plate and a back plate, from the formation of a protective layer made of magnesium oxide (MgO) in the production of the front plate, the back plate is sealed to the front plate The process up to this step is performed in a clean room 5 in an atmosphere in which the concentrations of moisture (H ₂ O) and carbon dioxide (CO ₂ ) are both controlled to 50 ppm by volume or less . Therefore, a vacuum chamber 6 for forming the protective layer and a sealing device 7 for sealing the back plate to the front plate taken out from the vacuum chamber 6 are installed in the one clean room 5. An artificial air production device 3 and an air circulation device 4 are connected to the clean room 5. In the clean room 5, one or more workers 1 are working. In addition to the artificial air production device 3 and the air circulation device 4, the clean room 5 has a conventionally known air conditioning facility (see FIG. 5) necessary for the clean room 5 that maintains the atmosphere in the clean room 5 in an appropriate clean state. Not shown).

The artificial air production apparatus 3 includes a liquid nitrogen tank 31, a liquid oxygen tank 32, a mixer 33 connected to both tanks, and a space between the mixer 33 and the ceiling space 51 of the clean room 5. The temperature rising device 34 provided is provided, and these are connected by piping. Then, liquid nitrogen is supplied from the liquid nitrogen tank 31 and liquid oxygen is supplied from the liquid oxygen tank 32 to the mixer 33, whereby the liquid nitrogen is vaporized by the mixer 33, and nitrogen gas and oxygen gas are used. Artificial air is to be produced. The artificial air is heated to a predetermined temperature (about room temperature) by the heating device 34 and then supplied to the ceiling space 51 of the clean room 5. The liquid nitrogen and liquid oxygen have H ₂ O concentration and CO ₂ concentration lower than those in a normal clean room atmosphere. By supplying artificial air obtained from these, H ₂ in the clean room 5 is supplied. It is easy to control the O and CO ₂ concentrations low. Further, from the viewpoint of suppressing the reaction between the protective layer made of MgO and H ₂ O and CO ₂ , the lower the concentration of H ₂ O and CO ₂ contained in the liquid nitrogen and liquid oxygen, the more preferable. Examples of the quality include those of the second grade (moisture of 10.7 vol ppm or less) or the first grade (moisture of 5.3 vol ppm or less) defined in JIS K 1107 (2005). The quality of oxygen is JIS. Examples are those specified in K 1101 (2006) (water content of 20.7 ppm by volume or less).

  The oxygen gas concentration of the artificial air is preferably controlled to about 20% by volume (the remainder is nitrogen gas), which is the same as that of the atmosphere. This control can be performed by adjusting the amounts of liquid nitrogen and liquid oxygen supplied to the mixer 33 with a valve or the like.

The air circulation device 4 is connected between the underfloor space 52 of the clean room 5 and a pipe downstream of the temperature riser 34 of the artificial air production device 3, and in order from the underfloor space 52 side, the compressor 41 and And a pressure swing adsorption (PSA) type gas separation device 42 that adsorbs H ₂ O and CO ₂ in the air, and these are connected by piping. Then, by operating the compressor 41, air in the atmosphere in the clean room 5 is sucked from the underfloor space 52, and H ₂ O and CO ₂ in the air are adsorbed by the PSA gas separation device 42. The artificial air introduced into the piping of the artificial air production apparatus 3 and heated by the heater 34 is introduced into the ceiling space 51 of the clean room 5. Here, the adsorption tower 42a in the PSA gas separator 42 is a container filled with an adsorbent that adsorbs H ₂ O and CO _2. Examples of the adsorbent include activated alumina and synthetic zeolite. And the mixture, activated carbon, zeolite, molecular sieve and the like. In FIG. 1, reference numeral 42b is a switching valve for switching the air supplied to the adsorption tower 42a. Further, H ₂ O and CO ₂ adsorbed by the PSA gas separation device 42 are included in the exhalation of the worker 1, and air that enters from the outside of the clean room 5 when the worker 1 enters and exits the clean room 5. The amount is a little.

The above clean room 5, the outlet near the like of the vacuum chamber 6 which is installed therein, and H ₂ O concentration sensor for measuring of H ₂ O concentration in the atmosphere in the clean room 5 (not shown), CO ₂ A CO ₂ concentration sensor (not shown) for measuring the concentration is installed. These sensors are connected to the artificial air production device 3 and the air circulation device 4, and the amount of artificial air produced by the artificial air production device 3 and the air circulation device 4 are circulated according to signals from the sensors. The amount of circulating air can be adjusted appropriately. Thereby, the both are H ₂ O concentration and CO ₂ concentration in the atmosphere in the clean room 5 adapted to be controlled below 50 vol ppm. Further, a HEPA filter 53 is disposed on the ceiling of the clean room 5, and the artificial air produced by the artificial air production device 3 and the circulating air that has passed through the air circulation device 4 are particles contained therein. Fine particles are adsorbed to the HEPA filter 53 and then supplied to the atmosphere in the clean room 5. The floor of the clean room 5 is formed with small vents communicating the atmosphere in the clean room 5 and the underfloor space 52 so that air in the atmosphere of the clean room 5 is introduced into the underfloor space 52. It has become.

  In the embodiment of the plasma display panel manufacturing method of the present invention, for example, each step is performed as follows.

First, in accordance with signals from the H ₂ O concentration sensor and the CO ₂ concentration sensor installed in the clean room 5, the artificial air production device 3 and the air circulation device 4 are operated appropriately (intermittently or continuously), and the clean room 5 The atmosphere inside is controlled so that the H ₂ O concentration and the CO ₂ concentration are both set to 50 ppm by volume or less .

On the other hand, in the production of the front plate, a predetermined electrode is first formed on a glass substrate in another clean room (the H ₂ O concentration and CO ₂ concentration are unlimited) prior to the formation of the protective layer in the vacuum chamber 6. Then, a dielectric layer that covers the electrode forming surface together with the electrodes is formed.

And after positioning the board | substrate with which the dielectric material layer was formed in the predetermined position of the vacuum chamber 6 installed in the said clean room 5, the vacuum chamber 6 is sealed. Next, the inside of the vacuum chamber 6 is depressurized (for example, about 1.3 × 10 ⁻⁴ Pa (absolute pressure)), and sputtering or the like is performed in this state, whereby the protective layer made of MgO is formed on the surface of the dielectric layer. To prepare a front plate. Then, the front plate is taken out from the vacuum chamber 6, and then the back plate is sealed to the front plate using the sealing device 7. In this step, since the protective layer on the front plate is exposed to an atmosphere in which both the H ₂ O concentration and the CO ₂ concentration are set to 50 ppm by volume or less , magnesium hydroxide [Mg ( OH) ₂ ] and magnesium carbonate (MgCO ₃ ) are not produced, or if any, are negligible.

Next, in another clean room (the H ₂ O concentration and CO ₂ concentration are unlimited), the air in the panel with the front plate and the rear plate sealed is exhausted, and then light emission (discharge) is performed in the panel. Fill with gas. And in the said process (process from formation of a protective layer to sealing with a front board and a backplate), when Mg (OH) ₂ and MgCO ₃ are not produced | generated on the surface of a protective layer, the said aging process Is not necessary, but when these compounds are produced in a very small amount, if necessary, aging is performed by applying a voltage to the panel to generate plasma to remove the Mg (OH) ₂ and MgCO ₃ . And the underlying protective layer is exposed. The time required for this aging [removal of Mg (OH) ₂ , MgCO ₃ ] is very short because the generation of these Mg (OH) ₂ and MgCO ₃ is very short (paragraph of Patent Document 1). According to the description of [0023], it can be very short (about several minutes to several tens of minutes).

  Thereafter, the drive circuit board is attached to the panel formed as described above, inspected, and the plasma display panel is completed.

  FIG. 2 shows a second embodiment of the plasma display panel manufacturing method of the present invention. In this embodiment, the air in the clean room 5 is released from the underfloor space 52 to the atmosphere without providing the air circulation device 4 (see FIG. 1) in the first embodiment. The rest is the same as in the first embodiment, and the same reference numerals are given to the same parts.

Also in the second embodiment, the artificial air production device 3 is operated appropriately (intermittently or continuously) in accordance with signals from the H ₂ O concentration sensor and the CO ₂ concentration sensor installed in the clean room 5, The atmosphere in the clean room 5 can be controlled so that both the H ₂ O concentration and the CO ₂ concentration are set to 50 ppm by volume or less . Thereby, Mg (OH) ₂ and MgCO ₃ are not generated on the surface of the protective layer, or even if they are generated, it can be extremely small. Even if it is performed, the time required for the aging can be very shortened.

FIG. 3 shows a third embodiment of the plasma display panel manufacturing method of the present invention. In this embodiment, in place of the artificial air production apparatus 3 (see FIG. 1) in the first embodiment, adjusted air obtained by removing H ₂ O and CO ₂ from the air in the atmosphere is supplied to the clean room. A regulated air supply device 8 is connected to the clean room 5. The rest is the same as in the first embodiment, and the same reference numerals are given to the same parts.

More specifically, the adjusted air supply device 8 includes a compressor (compressor or the like) 81 installed in the atmosphere, a cooler (aftercooler or the like) 82 connected to the compressor 81, and the cooler. 82 and an adsorption tower 83 provided between the space 51 above the ceiling of the clean room 5 and these are connected by piping. The adsorption tower 83 is filled with an adsorbent that adsorbs H ₂ O and CO ₂ , and examples of the adsorbent include a mixture of activated alumina and synthetic zeolite, activated carbon, zeolite, molecular sieve, and the like. . The adjusted air supply device 8 is connected to an H ₂ O concentration sensor and a CO ₂ concentration sensor installed in the clean room 5, and the adjustment air supply device 8 adjusts according to a signal from each sensor. The amount of air can be adjusted appropriately together with the amount of circulating air circulated by the air circulation device 4. Thereby, the both are H ₂ O concentration and CO ₂ concentration in the atmosphere in the clean room 5 adapted to be controlled below 50 vol ppm.

And by operating the said compressor 81, air is extract | collected from air | atmosphere and pressure | voltage rises, Then, it introduce | transduces into the space 51 on the ceiling of the clean room 5 through the said cooler 82 and the adsorption tower 83. Yes. That is, since the compressed air pressurized by the compressor 81 contains a large amount of moisture at a high temperature, the compressed air is cooled to a predetermined temperature (about room temperature) by the cooler 82, thereby containing the contained moisture. Are condensed and separated. Further, the subsequent adsorption tower 83 adsorbs H ₂ O and CO ₂ , thereby almost removing H ₂ O and CO ₂ . The adjusted air from which most of the H ₂ O and CO ₂ have been removed is supplied to the clean room 5. The adjusted air is air obtained by removing most of H ₂ O and CO ₂ from air in the atmosphere, and includes argon and the like in addition to nitrogen and oxygen.

Also in the third embodiment, according to the signals from the H ₂ O concentration sensor and the CO ₂ concentration sensor installed in the clean room 5, the adjusted air supply device 8 and the air circulation device 4 are appropriately (intermittently or continuously). And the atmosphere in the clean room 5 can be controlled so that both the H ₂ O concentration and the CO ₂ concentration are set to 50 ppm by volume or less . Thereby, Mg (OH) ₂ and MgCO ₃ are not generated on the surface of the protective layer, or even if they are generated, it can be extremely small. Even if it is performed, the time required for the aging can be very shortened.

  FIG. 4 shows a fourth embodiment of the plasma display panel manufacturing method of the present invention. In this embodiment, the air in the clean room 5 is released from the underfloor space 52 to the atmosphere without providing the air circulation device 4 (see FIG. 2) in the second embodiment. Other than that, the second embodiment is the same as the second embodiment, and the same parts are denoted by the same reference numerals.

Also in the fourth embodiment, according to the signals from the H ₂ O concentration sensor and the CO ₂ concentration sensor installed in the clean room 5, the adjusted air supply device 8 is operated appropriately (intermittently or continuously), The atmosphere in the clean room 5 can be controlled so that both the H ₂ O concentration and the CO ₂ concentration are set to 50 ppm by volume or less . As a result, Mg (OH) ₂ and MgCO ₃ produced on the surface of the protective layer are not present at all or can be negligibly small. As a result, the aging process is not required or aging is performed. However, the time required for the aging can be extremely shortened.

FIG. 5 shows a fifth embodiment of the plasma display panel manufacturing method of the present invention. In this embodiment, the air in the atmosphere in the clean room 5 is circulated by the air circulation device 4 without providing the artificial air production device 3 (see FIG. 1) in the first embodiment. The PSA type gas separation device 42 provided in the circulation device 4 adsorbs H ₂ O and CO ₂ in the circulation air.

Also in the fifth embodiment, the air circulation device 4 is operated appropriately (intermittently or continuously) in accordance with signals from the H ₂ O concentration sensor and the CO ₂ concentration sensor installed in the clean room 5, so that the clean room 5 can be controlled so that both the H ₂ O concentration and the CO ₂ concentration are set to 50 ppm by volume or less . As a result, Mg (OH) ₂ and MgCO ₃ produced on the surface of the protective layer are not present at all or can be negligibly small. As a result, the aging process is not required or aging is performed. However, the time required for the aging can be extremely shortened.

In each of the above embodiments, the process from the formation of the protective layer in the vacuum chamber 6 (the completion of the front plate) to the sealing of the front plate and the rear plate in the sealing device 7 is performed in one clean room 5. The process before and after that was performed in a separate clean room. However, the present invention is not limited to this. All processes are performed in one clean room, and the entire atmosphere in the clean room is adjusted to the concentration of H ₂ O and CO ₂ . May be controlled to 50 ppm by volume or less , and in the clean room, the above steps (from the formation of the protective layer to the sealing of the front plate and the back plate) part The enclosure is enclosed in an airtight manner, and the enclosed portion is defined as a partial clean room 5, and the atmosphere in the partial clean room 5 is controlled such that the concentrations of H ₂ O and CO ₂ are both controlled to 50 ppm by volume or less. It may be.

  In each of the above embodiments, one or more workers 1 are working in the clean room 5 that performs the above steps (from the formation of the protective layer to the sealing of the front plate and the back plate). It is not limited to this, The worker 1 does not need to exist.

Furthermore, in the first and second embodiments (see FIGS. 1 and 2), the concentrations of H ₂ O and CO ₂ contained as the liquid nitrogen tank 31 and the liquid oxygen tank 32 in the artificial air production apparatus 3 are low. In the case where those having a high concentration are used, an adsorption tower or a PSA type gas separation for adsorbing H ₂ O and CO ₂ to a pipe downstream of the temperature riser 34 of the artificial air production apparatus 3 is used. A device may be provided.

Further, in the third and fourth embodiments (see FIGS. 3 and 4), the conditioned air supply unit 8 is provided with the adsorption tower 83 as to adsorb H ₂ O and CO _2, the adsorption tower Instead of 83, a PSA type gas separation device may be provided.

It is explanatory drawing which shows typically 1st Embodiment of the manufacturing method of the plasma display panel of this invention. It is explanatory drawing which shows typically 2nd Embodiment of the manufacturing method of the plasma display panel of this invention. It is explanatory drawing which shows typically 3rd Embodiment of the manufacturing method of the plasma display panel of this invention. It is explanatory drawing which shows typically 4th Embodiment of the manufacturing method of the plasma display panel of this invention. It is explanatory drawing which shows typically 5th Embodiment of the manufacturing method of the plasma display panel of this invention.

  5 Clean room

Claims (6)

A method of manufacturing a plasma display panel comprising a front plate and a back plate, wherein a protective layer made of magnesium oxide as a constituent member is formed on the front plate, and the protective layer is formed from this protective layer formation The process until the back plate is sealed to the front plate is performed in a clean room in which the moisture concentration sensor and the carbon dioxide concentration sensor are installed , and the atmosphere in the clean room is changed from the moisture concentration sensor and the carbon dioxide concentration sensor. A method for manufacturing a plasma display panel, characterized in that an atmosphere that controls the concentration of water and carbon dioxide to 50 ppm by volume or less is maintained by a device that operates in response to a signal . The device operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor is an artificial air production device of the following (A), and the artificial air production device is connected to the moisture concentration sensor and the carbon dioxide concentration sensor. is activated in response to the signal, the liquid nitrogen below liquid nitrogen tank and a liquid oxygen below the liquid oxygen tank, is vaporized by supplying the following mixer, a predetermined amount of artificial air consisting of nitrogen gas and oxygen gas After manufacturing and raising the temperature of the artificial air with the following temperature riser, supplying the upper part in the clean room, the atmosphere in the clean room has a concentration of moisture and carbon dioxide of 50 ppm by volume or less . The method of manufacturing a plasma display panel according to claim 1, wherein the plasma display panel is maintained in a controlled atmosphere.
(A) Artificial air provided with a liquid nitrogen tank, a liquid oxygen tank, a mixer connected to both tanks, and a temperature raising device provided between the mixer and the upper part in the clean room Manufacturing equipment. The device that operates in response to signals from the moisture concentration sensor and the carbon dioxide concentration sensor is a regulated air supply device of (B) below, and the regulated air supply device is connected to the moisture concentration sensor and the carbon dioxide concentration sensor. The air is sampled from the atmosphere with the following compressor and pressurized, and the compressed air that has been pressurized is cooled with the following cooler to condense and separate the water contained in the compressed air. After that, moisture and carbon dioxide are further adsorbed by the following adsorption tower to produce a predetermined amount of adjusted air from which moisture and carbon dioxide have been removed , and the adjusted air is supplied to the upper portion of the clean room to thereby prepare the inside of the clean room. Purazumade according to claim 1, wherein the atmosphere, both the concentration of water and carbon dioxide to maintain a controlled atmosphere to below 50 ppm by volume Manufacturing method of the spray panel.
(B) Adsorption that adsorbs moisture and carbon dioxide provided between a compressor installed in the atmosphere, a cooler connected to the compressor, and the cooler and the upper part in the clean room A regulated air supply device comprising a tower. The device operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor is the air circulation device of (C) below, and this air circulation device is connected to the signals from the moisture concentration sensor and the carbon dioxide concentration sensor. After the air in the atmosphere of the clean room is sucked from the lower part of the clean room by the following compressor, the moisture and carbon dioxide contained in the air are removed by the pressure swing adsorption type gas separator described below. A predetermined amount of air from which moisture and carbon dioxide have been removed is produced by adsorption, and the air is supplied to the upper part of the clean room, so that the atmosphere in the clean room has a water and carbon dioxide concentration of 50 volumes. the plasma display panel of claim 1 wherein maintaining the ppm being controlled below ambient The method of production.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device . The devices operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor are the following artificial air production device (A) and the following air circulation device (C), and the following temperature rise of the artificial air production device And a part between the upper part in the clean room and a part between the pressure swing adsorption type gas separation device of the air circulation device and the upper part in the clean room are connected, and these artificial air production devices And the air circulation device are operated in response to signals from the moisture concentration sensor and the carbon dioxide concentration sensor. In the artificial air production device, liquid nitrogen in the following liquid nitrogen tank and liquid oxygen in the following liquid oxygen tank are , Supply to the following mixer to vaporize, produce a predetermined amount of artificial air consisting of nitrogen gas and oxygen gas, and heat the artificial air with the following heater In the above air circulation device, the air in the atmosphere in the clean room is sucked from the lower part in the clean room by the following compressor, and then the moisture and carbon dioxide contained in the air in the pressure swing adsorption gas separation device below A predetermined amount of air from which moisture and carbon dioxide have been removed is produced, and this air is raised at the connecting portion between the artificial air production device and the air circulation device using the temperature riser of the artificial air production device. Claims that the atmosphere in the clean room is maintained in an atmosphere in which the concentrations of moisture and carbon dioxide are both controlled to 50 ppm by volume or less by mixing with the warm artificial air and supplying it to the upper part of the clean room. Item 2. A method for producing a plasma display panel according to Item 1.
(A) Artificial air provided with a liquid nitrogen tank, a liquid oxygen tank, a mixer connected to both tanks, and a temperature raising device provided between the mixer and the upper part in the clean room Manufacturing equipment.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device. The devices operated by signals from the moisture concentration sensor and the carbon dioxide concentration sensor are the following regulated air supply device (B) and the following air circulation device (C), and the following adsorption tower of the regulated air supply device And a portion between the upper portion in the clean room and a portion between the pressure swing adsorption gas separation device of the air circulation device and the upper portion in the clean room are connected to each other. The air circulation device is operated in response to signals from the moisture concentration sensor and the carbon dioxide concentration sensor, and the adjusted air supply device collects air from the atmosphere with the following compressor to increase the pressure, and the pressure is increased. After cooling the compressed air with the following cooler and condensing and separating the water contained in the compressed air, the moisture and carbon dioxide are further removed with the following adsorption tower. A predetermined amount of adjusted air from which moisture and carbon dioxide have been removed is produced, and in the air circulation device, the air in the clean room is sucked from the lower part in the clean room by the following compressor, and then the pressure swing described below. An adsorption gas separation device adsorbs moisture and carbon dioxide contained in the air to produce a predetermined amount of air from which moisture and carbon dioxide have been removed. Mixing with the conditioned air produced by the conditioned air supply device at the connection portion with the device, and supplying it to the upper part of the clean room, the atmosphere in the clean room has both moisture and carbon dioxide concentrations. 2. The method of manufacturing a plasma display panel according to claim 1, wherein the atmosphere is controlled to 50 ppm by volume or less.
(B) Adsorption that adsorbs moisture and carbon dioxide provided between a compressor installed in the atmosphere, a cooler connected to the compressor, and the cooler and the upper part in the clean room A regulated air supply device comprising a tower.
(C) Air provided with a compressor connected to the lower part of the clean room, and a pressure swing adsorption type gas separation device that adsorbs moisture and carbon dioxide provided between the compressor and the upper part of the clean room. Circulation device.

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