JP4674415B2 - Vacuum container manufacturing method and image display device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a vacuum vessel and a method for manufacturing an image display device including a method for manufacturing a vacuum vessel.
[0002]
[Prior art]
Conventionally, in the process of manufacturing a vacuum vessel, for the sealing process and exhaust / baking process performed using a furnace, the temperature increase and decrease in the furnace are repeated for each process, There was a problem that heat efficiency was bad and productivity was very bad. As an example, a description will be given based on a thermal profile in a method of manufacturing a gas discharge display panel (PDP) which is one of devices using a vacuum vessel.
[0003]
This is shown as a prior art in Japanese Patent Laid-Open No. 09-306346. FIG. 7 shows this thermal profile.
[0004]
In this sealing and exhaust / baking method, as the sealing step A ′, a thermoplastic sealing material, for example, frit glass is heated to a temperature at which the frit glass is melted, for example, 410 ° C. In order to perform a leak check for confirming arrival reliability, the temperature is once returned to normal temperature (20 ° C.) (step B ′).
[0005]
Thereafter, the containerized PDP is heated again to 350 ° C. for degassing and the inside of the container is evacuated and evacuated (step C ′).
[0006]
When sealing, exhausting and baking are performed by applying this conventional method, the temperature of the PDP becomes 350 ° C. to 20 ° C. (normal temperature: a temperature at which manual leak check is possible) during the sealing process A ′. include duration a ₁ to the exhaust because step in the C 'includes the time required C ₁ until the temperature of the PDP is 350 ° C. from 20 ° C., the time required for one cycle of the sealing evacuation step An inefficient portion exists in T ′, which causes the entire process to be lengthened.
[0007]
Therefore, as means for solving the above problems, in Japanese Patent Laid-Open No. 09-306346, as shown in FIG. 8, the temperature of the PDP heated to, for example, 410 ° C. in order to perform the sealing step A ″ is The device configuration is such that the leak check process B ″ is started when the temperature capable of being sealed, for example, 350 ° C. is reached.
[0008]
According to this PDP sealing / exhaust / baking process, the time A ₁ until the temperature of the PDP that has completed the sealing process A ″ is lowered from 350 ° C. to 20 ° C. as compared with the prior art mentioned above, The time C ₁ is reduced until the temperature of the PDP that has completed the leak check process B ″ reaches the exhaustable temperature (350 ° C.) again.
[0009]
Japanese Patent Application Laid-Open No. 11-0797768 and Japanese Patent Application Laid-Open No. 2000-243280 each disclose a process for continuously performing sealing and exhaust / bake processes.
[0010]
The thermal profile is shown in FIG. 9 and FIG.
[0011]
[Problems to be solved by the invention]
In the above conventional example, as shown in FIGS. 8, 9, and 10, the thermal profile in the exhaust / baking process continuously performed after the sealing process is maintained at a constant temperature at the maximum temperature. Is.
[0012]
This is thought to be due to the conventional attempt to cope by simply combining the thermal profiles when sealing and exhausting / baking are performed separately as shown in FIG.
[0013]
As described above, continuous sealing and evacuation / baking can minimize losses during the temperature-falling and heating-up processes compared to separate cases, resulting in shorter process times. However, for the purpose of the exhaust / baking process, that is, for the purpose of releasing the gas existing inside the panel in advance by evacuating the panel while heating, the above-mentioned exhaust / baking process. The inventor has experimentally confirmed that there is room for further improvement in the thermal profile.
[0014]
The present invention seeks to achieve further efficiency of the sealing and exhaust / baking processes by improving the thermal profile of exhaust / baking as described above.
[0015]
[Means for Solving the Problems]
In order to solve such a problem, the present invention adopts the technical configuration described below.
[0016]
That is, the method for manufacturing a vacuum container according to the present invention (Claim 1) is to exhaust and bake by starting the exhaust from the point where the exhaustable temperature is reached in the temperature decreasing process in the sealing process at the time of manufacturing the vacuum container. A method for manufacturing a vacuum vessel in which the temperature of the vacuum vessel is continuously lowered during the evacuation / baking step, and moisture is sufficiently degassed from the evacuable temperature. The temperature decrease gradient to the temperature is the temperature decrease gradient from the melting temperature of the thermoplastic sealing material in the sealing step to the exhaustable temperature, and the temperature decrease from the sufficiently degassed temperature to the end of the exhaust / baking step. It is characterized by being gentler than the gradient .
[0021]
The manufacturing method of an image display device according to the present invention (Claim 2 ) is a manufacturing method of an image display device including a manufacturing process of a vacuum container, wherein the manufacturing process of the vacuum container is from the manufacturing method of a vacuum container according to Claim 1. It is characterized by becoming.
[0022]
Here, the image display device is preferably a plasma display panel.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
In the method of manufacturing a vacuum vessel according to the present invention, in a process in which sealing and evacuation / baking are performed continuously, the thermal profile during the evacuation / baking period is not constant at the maximum temperature, but the temperature is lowered. Therefore, the time as a total process is shortened.
[0024]
As a result of investigating the correlation between the thermal profile of the exhaust / baking period and the gas release from the panel at that time, the sealing process and the exhaust / baking process are continuously performed during the exhaust / baking period. The gas discharge state is based on experimental confirmation that the gas discharge state is different from the gas discharge state in the exhaust / bake period when each is performed separately.
[0025]
The sealing process A and the exhaust / baking process will be described in detail using the correlation between the thermal profile and the degree of vacuum in the process of continuously performing the conventional sealing process and the exhaust / baking process shown in FIG. In the exhaust / baking period Ba in the case where B is continuously performed, gas discharge does not continue during the period of maintaining the temperature Tb1, but gas is released in the initial stage of entering the exhaust / baking period. However, the behavior of the change in the degree of vacuum, which is considered that gas is generated, is not observed even in the period of maintaining the maximum temperature Tb1 thereafter.
[0026]
This is because when the sealing step and the exhaust / baking step are performed separately, the panel temperature once falls to room temperature under atmospheric pressure after the sealing period, so that the gas adheres to the panel during that time, As a result, the gas is released during the exhaust / bake period in the next exhaust / bake process. Therefore, during the evacuation / baking period, sufficient degassing is performed by keeping the panel temperature constant at a maximum temperature at which the frit glass as the sealing material does not remelt in order to sufficiently degas the gas. Although it is necessary, in the process of entering the exhaust / baking process continuously from the sealing process, the sealing period in the sealing process is up to the melting temperature of the glass frit, for example 450 ° C, even in the atmosphere. Since most of the gas physically and chemically attached to the panel at this point is released, the subsequent degassing during the exhaust and baking period is performed against the remaining small amount of gas. It is thought to be a thing.
[0027]
In such a situation, it is not always necessary to maintain the maximum temperature as the thermal profile of the exhaust / bake period in a process in which the sealing process and the exhaust / bake process are performed continuously. If the thermal process in the exhaust and baking period is applied, the efficiency of the entire process can be improved.
[0028]
Below, the specific example of the manufacturing method of the vacuum vessel concerning this invention is demonstrated in detail.
[0029]
(First embodiment)
FIG. 2 shows a thermal profile and a vacuum degree of the vacuum container at that time in a series of processes of a sealing process and an exhaust / bake process in the vacuum container manufacturing method according to the present invention.
[0030]
When the structure of the vacuum container is a combination of glass in a container shape by frit glass, first, in the sealing period Aa in the sealing process A, the melting temperature Ta of a so-called thermoplastic sealing material such as frit glass, For example, the frit glass is melted by heating to 450 ° C., and then the temperature is lowered (Ab) to solidify the frit glass, and the glass constituting the vacuum vessel is airtightly bonded as described above.
[0031]
Then, evacuation of the inside of the container is started from the time when the frit glass solidification temperature Tb1 is reached, and the process proceeds to the evacuation / baking step B continuously. Then, during the evacuation / baking period Ba in the evacuation / baking process B, the vacuum vessel temperature is gradually lowered without being kept constant.
[0032]
Here, the temperature at which the evacuation starts is not limited to Tb1 and may be lower than that. However, if the evacuation is started from Tb1, the time of the evacuation / baking period can be lengthened. From the aspect of degassing effect, it is convenient.
[0033]
The temperature gradient of the temperature drop is determined by the gas release state determined by the correlation with the size of the vacuum vessel, the gas content, and the capacity of the vacuum evacuation device, but the main part of the released gas is theoretically sufficiently desorbed. It is desirable that the temperature drop be such that the degassing situation is considered to have settled until the change in the degree of vacuum is reached until the temperature Tb2 is assumed to be gas. For this purpose, for example, during the exhaust and baking period, It is effective to make the temperature decrease gradient between Tb1 and Tb2 gentler than the temperature gradient in other temperature ranges.
[0034]
Specifically, when the main component of the gas released in the exhaust / baking period is water, the release temperature varies depending on the manner of existence in the vacuum vessel, but assuming chemical adsorption, which is a method of existence with a high release temperature. What is necessary is just to consider it as 350 degreeC as Tb2.
[0035]
Therefore, the actual thermal profile is that the degassing status during the exhaust / baking period has settled, that is, the vacuum degree has not deteriorated, and the vacuum vessel temperature is 350 ° C. by the time when there is almost no change from the subsequent vacuum degree. It is desirable to decide so that it does not become below.
[0036]
For example, in FIG. 2, the panel temperature drop profile in the exhaust / baking period Ba is normally set smaller than the temperature drop gradient set in the temperature drop period Ab in the sealing process A and the temperature drop period Bb in the exhaust / bake process B. The vacuum vessel temperature was kept from falling below 350 ° C. until it was considered that the degassing effect was sufficiently obtained.
[0037]
From the change in the vacuum degree of the vacuum vessel shown in FIG. 2 together with the thermal profile, the degassing has settled, that is, the vacuum vessel temperature has dropped below 350 ° C. until the degree of vacuum disappears and the vacuum degree is recovered and stabilized. It can be seen that the degassing inside the vacuum vessel was performed in the same manner as in the past, and as a result, the reliability of the vacuum degree of the vacuum vessel was obtained in the same manner as in the past.
[0038]
Moreover, since the temperature is lowered as a thermal profile during exhaust and baking, the time required for the total process can be shortened and productivity can be improved compared to the conventional process indicated by the broken line in FIG. .
[0039]
(Second Embodiment)
FIG. 3 shows a thermal profile in a series of processes of the sealing step A and the evacuation / baking step B and the vacuum degree of the vacuum vessel at that time in the vacuum vessel manufacturing method according to the present invention.
[0040]
Compared to the case of the first embodiment, after the panel temperature reaches the frit solidification temperature Tb1 in the temperature lowering process Ab of the sealing process A, the inside of the panel is evacuated and evacuated and baked. However, the temperature gradient during the evacuation / baking period and during the temperature drop Bb is the same as the temperature drop Ab during the sealing process A. As shown in FIG. This process is possible when the gas is fast enough.
[0041]
As described above, the total process time is further shortened as compared with the first embodiment.
[0042]
(Third embodiment)
An image display device was manufactured using the method for manufacturing a vacuum container in the embodiment described above.
[0043]
FIG. 5 is a schematic structural diagram of what is called a field emission display (FED), which is one type of image display apparatus.
[0044]
The manufacturing method of the image display apparatus according to the present invention will be described with reference to FIG. Reference numeral 10 denotes a vacuum vessel, and the manufacturing method thereof is the same as the manufacturing method of the vacuum vessel shown in the first and second embodiments, but the field emission is generated inside the vacuum vessel 10 before the sealing step for forming the vacuum vessel. A step of disposing a type electron-emitting device 11, a step of disposing a control electrode 12 for controlling emitted electrons on the front plate 1a side when viewed from the electron-emitting device, and light emission by collision of electrons on the inner surface of the front plate 1a A step of applying the phosphor 13 is added.
[0045]
And it assembles to a container structure with the above structure, Then, sealing, exhaust, and baking are performed with the manufacturing method of the vacuum container of the 1st Embodiment of this invention and 2nd Embodiment. Then, the exhaust pipe (not shown) is chipped off to form a vacuum container.
[0046]
As described above, it is possible to manufacture an FED which is a method of image display. However, the manufacturing method of the vacuum container according to the present invention is used as a manufacturing method of the vacuum container 10, and the reliability of the internal vacuum degree is increased. As a result, a method of manufacturing an image display device that can improve the reliability of image characteristics as an image display device can be realized.
[0047]
Another example of a method for manufacturing an image display device is a plasma display panel (PDP). The schematic structure is shown in FIG.
[0048]
The method for manufacturing the container 10 is the same as the method for manufacturing the vacuum container shown in the third and fourth embodiments, but the step of forming the rib 21 for partitioning the interior of the back plate 1b and between the ribs. A difference is that a process of applying the phosphor 22 is added and a process of sealing a discharge gas such as a mixed gas of neon and xenon is added to the inside of the vacuum vessel after evacuation and getter activation.
[0049]
As described above, it is possible to manufacture a PDP which is a method of image display. However, the manufacturing method of the vacuum container according to the present invention is used as a manufacturing method of the vacuum container 10, and the reliability of the internal vacuum degree is increased. As a result, a method of manufacturing an image display device that can improve the reliability of image characteristics as an image display device can be realized.
[0050]
【The invention's effect】
According to the present invention, in a method of manufacturing a vacuum vessel having a thermal process in which sealing, exhaust and baking are continuously performed, getter action is strengthened, and impure gas released into the discharge space during storage and operation of the panel is increased. Since the absorption capacity is enhanced, a panel having a good and stable discharge characteristic and a long life can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing a thermal profile in a series of processes of a sealing process, an exhaust / bake process, and a degree of vacuum of a vacuum container at that time in a conventional vacuum container manufacturing method. FIG. 3 is a diagram showing a thermal profile in a series of processes of a sealing process and an exhausting / baking process and a vacuum degree of the vacuum container at that time in the manufacturing method of the vacuum container according to the first embodiment. FIG. 4 is a diagram showing a thermal profile in a series of processes of a sealing process, an exhaust / bake process, and a vacuum degree of the vacuum container at that time in the vacuum container manufacturing method according to the second embodiment. FIG. 5 is a diagram showing a thermal profile in a series of processes of a sealing process and an exhaust / bake process and a vacuum degree of the vacuum container at that time in the container manufacturing method. FIG. 5 is a third embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of an image display device (FED) for explaining a method for producing an image display device. FIG. 6 is an image for explaining a method for producing an image display device according to a third embodiment of the invention. FIG. 7 is a schematic cross-sectional view of a display device (PDP). FIG. 7 is a diagram showing a thermal profile in a series of steps of sealing, evacuation and baking in a conventional vacuum vessel manufacturing method. FIG. 9 is a diagram showing a thermal profile in a series of steps of sealing, exhausting and baking in FIG. 9 is a diagram showing a thermal profile in a series of steps of sealing, exhausting and baking in a conventional vacuum vessel manufacturing method. FIG. 10 is a diagram showing a thermal profile in a series of steps of sealing, exhausting and baking in a conventional vacuum vessel manufacturing method.
A Sealing process Aa Sealing period Ab Cooling period B Exhaust / baking process Ba Exhaust / baking period Bb Cooling period Ta Sealing temperature Tb1 Exhaust / baking possible temperature Tb2 Temperature at which moisture is sufficiently degassed

Claims (3)

In the temperature-decreasing process in the sealing process at the time of vacuum vessel manufacturing, by starting the exhaust from the point where the exhaustable temperature is reached, the process proceeds to the exhaust / baking process continuously, and also during the exhaust / baking process A vacuum vessel manufacturing method in which the temperature drop of the vacuum vessel is continued ,
A temperature decrease gradient from the exhaustable temperature to a temperature at which moisture is sufficiently degassed is a temperature decrease gradient from the melting temperature of the thermoplastic sealing material in the sealing step to the exhaustable temperature, and the sufficient degassing. A vacuum vessel manufacturing method characterized by being gentler than a temperature drop gradient from a gas temperature to the end of the exhaust / bake process . In the manufacturing method of an image display apparatus including a vacuum chamber of the manufacturing process, the vacuum chamber of the manufacturing process consists of the production method of the vacuum container according to claim 1, a method of manufacturing an image display device, characterized in that. The method for manufacturing an image display device according to claim 2 , wherein the image display device is a plasma display panel .

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