JP2012104228A - Method for manufacturing image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an image display device, capable of increasing efficiency in a sealing and exhaust step for sealing an in-panel space between a front plate and a back plate by a seal layer, and reducing impurity gas remaining in the in-panel space, to thereby achieve more stabilized display characteristics.SOLUTION: A method for manufacturing an image display device, includes: heating a back face plate 8 and a front face plate 1 facing each other and having a seal material layer 18 formed at a position to be sealed by a seal layer in an outer peripheral edge region of either of the back face plate 8 or the front face plate 1, to reach a top keep temperature T set to be a temperature at which the seal material layer is melted; retaining the top keep temperature for a prescribed period of time; while retaining the top keep temperature, evacuating a space between the front face plate and the back face plate to a vacuum, and degassing the front face plate and the back face plate; in the middle of the retention period of the top keep temperature, starting to press-bond the seal material layer to the front face plate and the back face plate; and after the retention period is finished, reducing the temperature.

Description

  The present invention relates to a method for manufacturing an image display device in which display elements are arranged in a panel internal space between a front plate and a back plate, and more particularly to a method for manufacturing an image display device including a step of sealing the panel internal space with a seal layer.

  Conventionally, in the process of manufacturing an image display device, in the sealing process and the exhaust process performed using a furnace, the temperature increase and the temperature decrease in the furnace are repeated for each process. For this reason, there are problems that the efficiency of the heat process is poor and the productivity is very poor. Such a problem will be described based on a temperature profile in a method for manufacturing a gas discharge display panel (abbreviated as plasma display panel, PDP), which is an example of an image display device.

  First, the configuration of an AC surface discharge type PDP, which is a typical PDP, will be described with reference to FIGS. FIG. 8 is a perspective view showing a part of the PDP with the front plate 1 and the back plate 8 separated. FIG. 9 shows a state in which the front plate 1 and the back plate 8 of FIG. 8 are combined, and is a cross-sectional view along the direction crossing the scan electrode 3 and the sustain electrode 4 in FIG.

  The front plate 1 has a configuration in which display electrode pairs 5 including scan electrodes 3 and sustain electrodes 4 that perform surface discharge are arranged in parallel on the surface of a transparent and insulating front substrate 2. Scan electrode 3 and sustain electrode 4 are each composed of transparent electrodes 3a, 4a and bus electrodes 3b, 4b formed thereon. A front dielectric layer 6 is formed so as to cover the display electrode pair 5, and a protective film 7 is formed thereon.

  On the other hand, the back plate 8 has a configuration in which address electrodes 10 for writing image data are arranged on the surface of a transparent and insulating back substrate 9 and the upper part thereof is covered with a back dielectric layer 11. On the back dielectric layer 11, ribs 12 are formed, which are formed of, for example, low melting point glass and form partition walls. The ribs 12 have a cross beam shape formed by vertical ribs 12a formed extending in a direction parallel to the address electrodes 10 and horizontal ribs 12b formed in a direction orthogonal thereto. Each pixel is defined by a region surrounded by the vertical ribs 12a and the horizontal ribs 12b. A red phosphor layer 13r, a green phosphor layer 13g, and a blue phosphor layer 13b corresponding to the address electrodes 10 are formed on the side surfaces of the ribs 12 and the surface of the back dielectric layer 11 in each pixel region by coating. Has been.

  The front plate 1 and the back plate 8 face each other so that the display electrode pair 5 and the address electrode 10 are orthogonal to form a matrix. A space surrounded by the vertical ribs 12a and the horizontal ribs 12b between the front plate 1 and the back plate 8 is a discharge space 14 of each pixel. Corresponding to each discharge space 14, the display electrode pair 5 and the address electrode 10 are three-dimensionally crossed to form a discharge cell 15. A black stripe 16 is formed between the display electrode pair 5 of the front plate 1 so as to face the upper portion of the lateral rib 12b.

  The front dielectric layer 6 is generally formed by printing and baking a low melting point glass layer. The protective film 7 is provided to prevent the front dielectric layer 6 from being sputtered by plasma discharge, and is required to be a material excellent in sputtering resistance. Further, for the purpose of lowering the discharge voltage, the protective film 7 is made of MgO, which is an active material, or CaO, SrO, SrCaO, which are more active materials.

  The internal space between the front plate 1 and the back plate 8 is sealed with a sealing material such as a low-melting glass frit in the outer peripheral edge region of the opposing surface (not shown), and neon in the discharge space 14 of each pixel. A discharge gas composed of a mixed gas of (Ne) and xenon (Xe) is enclosed. In the following description, the internal space between the front plate 1 and the back plate 8 including the discharge space 14 of each pixel is referred to as a panel internal space. For example, a discharge gas having a Xe ratio of 10% is used, and the discharge gas is sealed at a pressure of about 450 Torr (about 60 kPa).

  In the process of sealing between the front plate 1 and the back plate 8, a temperature rise (about 400 to 500 ° C.) for melting the glass frit is required, and time and energy are required in the manufacturing process. In addition, after the sealing step, before the discharge gas is sealed, the panel interior space is exhausted.

  In Patent Document 1, in order to perform the sealing process, for example, when the temperature of the panel heated to 450 ° C. reaches a sealable temperature, for example, 350 ° C., the leak check and the exhaust process are started. It is disclosed. Also, Patent Document 2 and Patent Document 3 disclose that the sealing and the exhausting process are continuously performed. An example of the temperature profile in that case is shown in FIG.

  Here, with reference to FIG. 10, the temperature profile of the conventional sealing and exhaust process will be described. First, the temperature of the panel is increased at a certain rate (about 5 ° C./minute) from the temperature increase start time t0 in the sealing step, and reaches the top keep temperature T1 in the sealing step at time t1. The top keeping temperature T1 is a temperature at which a low-melting glass frit (for example, containing bismuth oxide as a main component) used as a bonding material for a sealing material layer for sealing the front plate and the back plate of the PDP is melted. In order to sufficiently transfer heat to the low melting point glass frit, the panel is maintained at the temperature T1 from time t1 to t1a. After time t1a, the panel temperature is decreased at a constant rate, and the exhaust temperature T2 is reached at time t2. The exhaust temperature T2 is equal to or lower than the temperature at which the low melting point glass frit is cured. At the exhaust temperature T2, the panel interior space can be exhausted without deforming the low-melting glass frit. While the panel is kept at the temperature T2 from the time t2 to the predetermined exhaust end time t2a, the space in the panel is exhausted. Thereafter, the temperature is lowered while controlling the panel temperature from the exhaust end time t2a, and the room temperature is reached at time t3.

JP 09-306346 A JP-A-11-0797768 JP 2000-243280 A

  As described above, in the temperature profile of the conventional sealing / exhaust process, the sealing process and the exhaust process are performed at different processing temperatures (temperature T1 for the sealing process and temperature T2 for the exhaust process). Therefore, when the temperature control in the furnace and the stability of the panel temperature are taken into account, there has been a problem that the entire process takes a long time.

  A conventional PDP sealing and exhausting process under the above temperature profile will be described with reference to FIGS. FIG. 11 is a schematic view when the PDP is viewed from the front surface on the front plate 1 side. The PDP is provided with a sealing material layer 18 made of a low melting point glass frit for bonding the front plate 1 and the back plate 8 around the display area 17. In the sealing process, the front plate 1 and the back plate 8 are pressure-bonded and sealed in a state where the low melting point glass frit of the sealing material layer 18 is melted, thereby generating a sealing property between the front plate 1 and the back plate 8. Let

  FIG. 12 is a schematic cross-sectional view for explaining a conventional sealing method of the PDP, and shows a configuration before sealing in the A-A ′ cross section of the PDP shown in FIG. 11. However, since FIG. 12 illustrates the sealing method, elements unnecessary for the description of the sealing method, such as scan electrodes, address electrodes, dielectric layers, and protective films, are not shown.

  The front plate 1 and the back plate 8 are overlapped and fixed with a sealing clip 19 in a state where mutual position adjustment (alignment) is performed, and are placed on a support bar 20. In this state, when the top-keeping temperature T1 of the sealing process shown in FIG. 10 is reached, the low-melting glass frit of the sealing material layer 18 is melted, and the pressure of the sealing clip 19 causes the pressure between the front plate 1 and the back plate 8. By deforming and closely contacting, the front plate 1 and the back plate 8 are sealed. When the panel temperature falls from the top keep temperature T1 to a temperature at which the low melting point glass frit is cured (exhaust temperature T2 in FIG. 10), the sealing of the front plate 1 and the back plate 8 is completed.

  13A and 13B are schematic views for explaining a conventional exhaust method of the PDP. 13A is a cross-sectional view showing a state in the exhaust process in the A-A ′ cross section shown in FIG. 11, and FIG. 13B is a front view showing a state seen from the front side of the front plate 1 side. A space between the front plate 1 and the back plate 8 after sealing is divided into minute discharge spaces by lattice-like ribs 12 having a height of several hundreds of μm.

  Each discharge space is filled with a discharge gas suitable for PDP (for example, a mixed gas of Ne and Xe). If the discharge gas contains an impurity gas other than the discharge gas, the discharge characteristics of each discharge cell become unstable, causing problems such as an increase in discharge voltage and a decrease in voltage margin. Therefore, after the sealing process, in order to remove the impure gas in the panel interior space and make it cleaner, there is an exhaust process aimed at evacuating the panel interior space and degassing the front plate 1 and the back plate 8. To be implemented. The impure gas mentioned here corresponds to nitrogen or oxygen (atmosphere) existing in the panel internal space, water or carbon dioxide adsorbed on the front plate 1 or the back plate 8.

  In the conventional exhaust method, as shown in the cross-sectional view of FIG. 13A, an exhaust head 22 attached to a sealing / exhaust device is connected to an exhaust pipe 21 provided on the back plate 8 of the PDP, thereby evacuating the space in the panel. I do. As described above, in the vacuum exhaust, it is necessary to remove as much of the impurity gas in the panel inner space as possible.

  However, since the front plate 1 and the back plate 8 are partitioned by the ribs 12 for every minute space, the exhaust conductance is small. Further, as shown in the plan view of FIG. 13B, the impurity gas flow 23 during exhausting is concentrated in the direction of the exhaust pipe 21. For this reason, in order to exhaust the PDP panel space sufficiently without exhausting unevenness and affecting the discharge characteristics, it is necessary to exhaust for a long time.

  As described above, in the conventional sealing / exhaust process, since the sealing process and the exhaust process have different processing temperatures, the time as a temperature profile becomes long, and the exhaust conductance of the space in the panel is increased. There is a problem that the time required for the exhausting process becomes long because the exhaust gas is small and the exhaust unevenness easily occurs.

  The present invention improves the productivity of the panel by improving the efficiency of the sealing / exhaust process for sealing the space in the panel between the front plate and the back plate with the sealing layer, and reduces the impurity gas remaining in the space in the panel. It is an object of the present invention to provide a method for manufacturing an image display device capable of making display characteristics more stable.

  In the method for manufacturing an image display device of the present invention, a space in a panel between a front plate and a back plate is sealed with a seal layer, and a display element provided on at least one of the front plate and the back plate is attached to the panel internal space. In order to solve the above problems, a sealing / exhausting step for sealing the space between the front plate and the back plate with the seal layer and exhausting the space in the panel includes the sealing. A top-keeping temperature set to a temperature at which the sealing material layer is melted by heating the panel including the back plate and the front plate in which a sealing material layer is formed at a position to be sealed by a layer facing each other in a furnace. Is performed during the top-keep temperature holding step, the top-keep temperature holding step for holding the top-keep temperature, and the top-keep temperature holding step. Sealing is started in the middle of the period of the exhaust and degassing process for degassing the face plate and the back plate and the top keeping temperature holding step, and the sealing material layer is pressure-bonded between the front plate and the back plate And a temperature lowering step for lowering the temperature after completion of the top-keep temperature holding step.

  According to the above configuration, sealing and exhaust can be sufficiently performed simultaneously at the top keeping temperature in the sealing and exhaust process, and baking with temperature control after the sealing process is unnecessary. As a result, the sealing / exhaust process is made more efficient, and the impurity gas remaining in the panel space is reduced, and the display characteristics of the panel become more stable.

The figure which shows the temperature profile in the sealing and exhaust process in the manufacturing method of PDP which concerns on embodiment of this invention Sectional drawing which shows typically the structure of the sealing and exhaust apparatus for enforcing the manufacturing method of PDP which concerns on Embodiment 1 of this invention Sectional drawing for demonstrating the process of sealing and exhaustion in the manufacturing method of the PDP Sectional drawing for demonstrating the process of sealing and exhaustion following FIG. 3A Sectional drawing for demonstrating the effect | action in the exhaust_gas | exhaustion process in the manufacturing method of PDP which concerns on embodiment of this invention Plan view for explaining the operation in the exhaust process Sectional drawing which shows the structure of the sealing and exhaust apparatus 24a for enforcing the manufacturing method of PDP which concerns on Embodiment 2 of this invention, and its operation | movement. Sectional drawing which shows operation | movement in the process following FIG. 5A. Sectional drawing which shows the operation | movement in the sealing and exhaust process for enforcing the manufacturing method of PDP which concerns on Embodiment 3 of this invention Sectional drawing which shows operation | movement in the process following FIG. 6A. The figure which shows the discharge voltage of PDP produced by the sealing and exhaust process in the manufacturing method of PDP of this invention The perspective view which showed a part of PDP of the prior art example in the state which isolate | separated the front board and the back board Sectional drawing which shows the state by which the front board and back board of FIG. 8 were united. A diagram showing a typical example of a temperature profile in a conventional sealing / exhaust process The top view seen from the front plate side which shows the conventional sealing structure of PDP Schematic sectional view showing the conventional sealing method of PDP Schematic cross-sectional view for explaining a conventional exhaust method of PDP Plan view for explaining a conventional exhaust method of PDP

  In the manufacturing method of the image display device according to the present invention, the vacuum exhaust between the front plate and the back plate constituting the image display device and the degassing of the front plate and the back plate are performed during the top keep temperature period of the sealing and exhaust process. Processing and further sealing of the front plate and the back plate is performed, and after the sealing, the time is reduced as a total process by lowering the temperature without performing baking with temperature control. This is based on experimental confirmation of the temperature profile of the sealing / exhaust process and the method of sealing / exhaust, and the relationship between the temperature profile and the display characteristics of the panel produced by the method of sealing / exhaust. .

  The manufacturing method of the image display device of the present invention can take the following aspects based on the above configuration.

  That is, it is preferable that the back plate and the front plate are positioned relative to each other so that there is a gap between the sealing material layer and the back plate or the front plate before the sealing step.

  In this case, in the period before the sealing step, the back plate and the front plate are overlapped with each other and the process is performed only from below, and when the sealing step is started, the back plate It can be set as the structure which makes the force which presses a face plate and the said front plate mutually act.

  Alternatively, in a period prior to the sealing step, the back plate and the front plate are supported by separate support members, thereby providing a gap between the back plate and the front plate. During this period, support by the support member with respect to the back plate or the front plate arranged at the top may be excluded.

  Further, when the sealing material layer is formed so that the upper surface has an uneven shape, and the back plate and the front plate are overlapped with each other, a gap is formed between the sealing material layer and the back plate or the front plate. It can be set as the structure to do.

In any one of the manufacturing methods described above, it is preferable that the sealing and exhausting step is performed in a vacuum atmosphere. In that case, it is preferable that the sealing / evacuation step is performed in a vacuum vessel, and the pressure in the vacuum vessel is 1 × 10 ⁻³ Pa or less at the top keep temperature.

  Further, in the sealing step, the front plate and the back plate are biased toward each other by a spring, whereby the seal material layer can be pressure-bonded between the front plate and the back plate.

  The sealing step is preferably started after 50 minutes or more have passed since the panel temperature reached the top-keep temperature. This method is particularly applied when the image display device is a plasma display panel.

  In addition, the sealing material layer may be formed of a low melting point glass frit.

  Hereinafter, a method for manufacturing an image display device according to an embodiment of the present invention will be described with reference to the drawings. The following embodiment relates to a method of manufacturing a PDP as an example of an image display device, but can be similarly applied to other image display devices.

(Embodiment 1)
A temperature profile of the sealing / exhaust process in the method of manufacturing the PDP according to the first embodiment will be described with reference to FIG. However, this temperature profile is common to each embodiment, and is similarly applied to each of the following embodiments.

  FIG. 1 shows an example of a temperature profile in a PDP sealing / exhaust process. First, the temperature of the panel is increased at a predetermined constant rate (about 5 ° C./min) from the temperature increase start time t0, and the top keep temperature T1 is reached at time t1 (temperature increase step S1). The top keeping temperature T1 is set to a temperature at which a low-melting glass frit (for example, containing bismuth oxide as a main component) that is a bonding material used for a sealing material layer for sealing the front plate and the back plate of the PDP is melted. Is done.

  At this top keep temperature T1, in order to perform exhaust between the front plate and the back plate, degassing treatment of the front plate and the back plate, and further sealing, the panel is kept at the temperature T1 for a predetermined time t1 to t1b. Hold (temperature holding step S2). After the time t1b, the panel temperature is lowered without performing the baking temperature control (temperature lowering step S3). The room temperature is reached at time t3b.

  Note that the time t4 shown in FIG. 1 is a time for starting the application of pressure to the front plate and the back plate in order to seal the front plate and the back plate. Therefore, from the time t4 to the time t3b after the time t1b. The sealing process is performed up to the middle of the temperature lowering process S3, which will be described later in detail.

  As described above, in the temperature profile of the sealing / exhaust process in the embodiment of the present invention, the sealing process and the exhaust process are performed at the same temperature (top keep temperature T1). Therefore, the time required for temperature control in the furnace and stabilization of the panel temperature is shortened, and the lead time of the entire process can be shortened. As an example, when the top-keeping temperature T1 is set to 450 ° C. for an 11 mm size panel, the time t0 to t1 is 100 minutes, the time t1 to t1b is 100 minutes, the time t4 to t1b is 10 minutes, The entire sealing and exhausting process could be processed in 300 minutes with t1b to t3b being about 100 minutes. However, it is necessary to adjust the top keep temperature T1 and the time of each process according to the size of the panel, the size of the discharge cell, and the material used for the panel. For example, when the protective film is formed of MgO in the PDP, the sealing process is started after 50 minutes or more have passed since the panel temperature reached the top keeping temperature, that is, the time t1 to t1b is set to 50 minutes or more. Is preferred.

  Next, other requirements for carrying out the manufacturing method of the present embodiment will be described in detail with reference to the drawings.

  FIG. 2 is a cross-sectional view schematically showing the configuration of the sealing / exhaust device 24 for carrying out the PDP manufacturing method according to the present embodiment. The sealing / exhaust device 24 is configured in a vacuum container shape that can be evacuated. FIG. 2 schematically shows the positional relationship between the front plate 1 and the back plate 8 constituting the PDP, the support bar 20 attached to the device, and the sealing spring 26 in the vacuum atmosphere 25 of the sealing / exhaust device 24. It is shown. The front shape of the PDP is the same as that of the conventional example shown in FIG. 11, and FIG. 2 shows an A-A 'cross section of the PDP shown in FIG. 11 as an example. However, the support bar 20 and the sealing spring 26 are arranged in the same configuration not only on the A-A ′ cross section but also on necessary portions on the long side and the short side of the PDP.

  The front plate 1 and the back plate 8 installed in the sealing / exhaust device 24 are supported from the back plate 8 side by the support rod 20 in a state where the mutual position adjustment (alignment) is performed. At this time, the front plate 1 is placed on the back plate 8 only by its own weight, and is not fixed by a fixing tool such as the sealing clip 19 as in the conventional example shown in FIG. The sealing spring 26 is used for pressing the front plate 1 at the time of sealing, but is disposed above the front plate 1 side during a period before the sealing process is started.

The sealing spring 26 can be moved up and down, and is in a raised position so that no pressure is applied to the front plate 1 during the period of time t0 to t4 (before sealing) shown in FIG. On the other hand, during the period of time t4 to t3b shown in FIG. 1 (after the start of sealing), the front plate 1 is lowered and pressed. The shape of the sealing spring 26 is shown as a U-shaped leaf spring in FIG. 2, but it is necessary for sealing without damaging the PDP, such as a circular or elliptical leaf spring, or a coil spring. Any shape can be used as long as pressure can be applied. In the present embodiment, in order to seal and exhaust an 11 mm size panel, the inside of the sealing / exhaust device 24 can be evacuated to a level of 10 ⁻³ Pa at room temperature. However, the degree of vacuum in the apparatus may be adjusted according to the size of the panel, the size of the discharge cell, and the reliability and specifications after completion of the panel.

  3A and 3B are cross-sectional views for explaining a sealing / exhaust process according to the present embodiment. FIG. 3A schematically shows a state in the period of time t0 to t4 shown in FIG. 1 (before sealing), and FIG. 3B schematically shows the state in the period of time t4 to t3b (after starting sealing). In FIG. 3A, as in the state shown in FIG. 2, the front plate 1 and the back plate 8 are placed on the support bar 20 in an aligned state, and the sealing spring 26 applies pressure to the front plate 1. It has risen to a position where it will not join. In FIG. 3B showing the next step, the sealing spring 26 is lowered at the timing of time t4, and a pressure 27 is applied to the sealing material layer 18 from the front plate 1 side. Due to the pressure, the shape of the sealing material layer 18 melted at the top keeping temperature T <b> 1 is deformed and tightly adheres to the front plate 1 and the back plate 8, thereby generating a sealing property in the panel internal space.

  When the panel temperature is lowered from the time t1b in FIG. 1 in a state where the sealing space is generated in the panel internal space, the low melting point glass frit of the sealing material layer 18 is cured and the sealing is completed.

  Next, the manufacturing method of the PDP according to the present embodiment makes it possible to manufacture by the temperature profile of the sealing / exhaust process shown in FIG. 1, and also reduces the impure gas in the panel inner space, thereby reducing the display characteristics of the PDP. The reason why becomes more stable will be explained.

  4A and 4B are views for explaining the action of the process of exhausting the space in the panel in the method for manufacturing a PDP according to the present invention. FIG. 4A is a cross-sectional view of the PDP, and a schematic plan view of the flow of impure gas in the panel space at time t0 to t4 of the sealing / exhaust process shown in FIG. FIG. 4B).

  In the exhaust method of the present invention, as shown in the cross-sectional view of FIG. 4A, in addition to the exhaust pipe 21 provided on the back plate 8, a gap formed between the front plate 1 and the sealing material layer 18 on the back plate 8 is also used. Can be exhausted. At the time t0 to t4 of the sealing / exhaust process, the front plate 1 is superposed on the back plate 8 only by its own weight, and therefore the adhesion between the front plate 1 and the back plate 8 by the sealing material layer 18 is insufficient. , The sealing of the space in the panel does not occur. Therefore, by evacuating the inside of the sealing / exhaust device 24, the impure gas in the panel space is also exhausted from the gap formed between the front plate 1 and the sealing material layer 18 on the back plate 8. Further, as shown in the plan view of FIG. 4B, the planar flow direction 28 of the impure gas in the exhaust does not concentrate toward the exhaust pipe 21, and the outer periphery from the long side and the short side of the PDP. It becomes uniform toward.

  Furthermore, the temperature of the panel at the time t1 to t4 in the temperature holding step S2 is the top keeping temperature T1 for melting the low melting point glass frit of the sealing material layer 18, so that the impure gas in the space in the panel, the front plate 1, The impure gas adsorbed on the back plate 8 can be desorbed at a higher temperature than the exhaust temperature T2 in the conventional exhaust process.

  As described above, in the sealing / exhaust method according to the present invention, sealing and exhausting (vacuum exhausting of the internal space of the panel and the front plate 1) are performed at times t1 to t1b of the top keeping temperature T1 in the sealing / exhausting process. , Degassing of the back plate 8). Therefore, if the time t1 to t1b held at the top keep temperature T1 is longer, the panel interior space can be sufficiently exhausted, and the cleanness of the panel interior space after exhaust is improved. According to the experiment, it was confirmed that the display characteristics equivalent to those of the panel manufactured with the conventional temperature profile can be obtained by setting the time t1 to t1b to 100 minutes in order to seal and exhaust the 11 mm size panel. did. However, the keeping time of the exhaust temperature T2 in the temperature profile according to the conventional method was set to 6 hours.

  As described above, according to the sealing / exhaust method according to the PDP manufacturing method of the present embodiment, the sealing and exhausting can be sufficiently performed simultaneously at the top keep temperature in the sealing / exhaust process. Accordingly, unlike the conventional sealing / exhaust process, temperature control and baking time control with baking are not required in the exhaust process after the sealing process. Further, the impurity gas remaining in the panel internal space is reduced, and the display characteristics of the panel become more stable.

(Embodiment 2)
5A and 5B are cross-sectional views showing the configuration and operation of a sealing / exhaust device 24a for carrying out the PDP manufacturing method according to Embodiment 2 of the present invention. In the present embodiment, although the first embodiment is the basis, the installation position of the front plate 1 in the sealing / exhaust process is improved so that the exhaust effect is further improved. That is, in the sealing / exhaust device 24a, in addition to the support rod 20 for the back plate 8, a support rod 29 for the front plate 1 is also provided.

  FIG. 5A is a time period from time t0 to t4 (before sealing) in the temperature profile shown in FIG. 1, and FIG. 5B is a time period from time t4 to t3b (after the start of sealing). The state of the face plate 1, the back plate 8, the support rods 20, 29, and the sealing spring 26 is schematically shown.

  As shown in FIG. 5A, the support rod 29 for the front plate 1 supports the front plate 1 at a raised position where it does not contact the back plate 8 during the period of time t0 to t4 (before sealing). Next, as shown in FIG. 5B, during the period of time t4 to t3b (after the start of sealing), the support bar 29 for the front plate 1 is lowered and the front plate 1 is placed on the back plate 8. Thereafter, the sealing spring 26 is lowered and pressure is applied to the front plate 1 to pressure-bond the sealing material layer 18.

  As shown in FIG. 5A, by arranging the front plate 1 at a position not in contact with the back plate 8 during the period of time t0 to t4 (before the sealing step), between the front plate 1 and the back plate 8, A larger exhaust conductance than the exhaust process in the first embodiment can be ensured. Therefore, the exhaust efficiency at time t0 to t4 is improved. As a result, even when sealing and exhausting with the same temperature profile, a larger exhaust effect than in the first embodiment can be obtained.

(Embodiment 3)
6A and 6B are cross-sectional views showing a sealing / exhaust process for carrying out a method of manufacturing a PDP according to Embodiment 3 of the present invention. In the present embodiment, the shape of the sealing material layer 30 made of the low melting point frit glass provided on the back plate 8 is improved so that the exhaust effect is further obtained while being based on the first embodiment. Yes. That is, the top surface shape of the sealing material layer 30 is provided with irregularities.

  6A is a time period from time t0 to t4 (before sealing) in the temperature profile shown in FIG. 1, and FIG. 6B is a time period from time t4 to t3b (after the start of sealing). The state of the face plate 1, the back plate 8, the support bar 20, and the sealing spring 26 is schematically shown. However, FIGS. 6A and 6B show a configuration in a cross section taken along line B-B ′ in FIG. 11.

  Since the top surface shape of the sealing material layer 30 is uneven, as shown in FIG. 6A, in the state where the front plate 1 is superposed on the back plate 8 by its own weight only at time t0 to t4, the sealing material layer Due to the 30 irregularities, a sufficient exhaust conductance can be secured between the front plate 1 and the back plate 8. Therefore, the exhaust efficiency at time t0 to t4 is improved. As a result, even when sealing and exhausting with the same temperature profile, a larger exhaust effect than in the first embodiment can be obtained.

  In addition, as a method of providing unevenness on the shape of the upper surface of the sealing material layer 30, when screen printing is used, printing is performed twice on a concave surface and a convex surface, and when a dispenser is used, the scanning speed of the dispenser is strong or weak. A method such as attaching can be used.

  FIG. 7 is a diagram showing changes in the discharge voltage (minimum sustain voltage Vsmn, lighting start voltage Vf1) for the PDP produced by the temperature profile of the sealing / exhaust process according to the embodiment of the present invention as described above. is there. It is expressed as a time transition with respect to the aging time on the horizontal axis. The vertical axis represents the discharge voltage ratio, which is the temperature profile of the sealing / exhaust process according to the embodiment of the present invention with respect to the discharge voltage of the PDP (A) manufactured using the temperature profile of the conventional seal / exhaust process. It is expressed as the ratio of the discharge voltage of the produced PDP (B). In addition, since the sealing process of A and B is both a vacuum atmosphere and the sealing method is the same, the difference between A and B is only the temperature profile of the sealing / exhaust process.

  Immediately after the start of aging, the discharge characteristics are unstable and an error is likely to occur in the evaluation. Therefore, there was a characteristic that the ratio of Vf1 was about 5%. However, the ratio of Vsmn and Vf1 was several percent after aging 2 hours. And after 6 hours, it was confirmed to be stable within 1%. This is because the PDP is manufactured by the sealing method according to the present invention, and even if the temperature profile of the sealing / exhaust process is changed from the conventional temperature profile, the discharge voltage of the PDP (currently, about 150 V is the lower limit for Vsmn). ) Shows almost no difference.

  As described above, it was confirmed that the time required for the sealing / exhaust process can be greatly shortened by producing the PDP by the temperature profile of the sealing / exhaust process according to the present invention and the sealing / exhaust method.

  According to the manufacturing method of the image display device of the present invention, the sealing / exhaust process can be made more efficient, and the impure gas remaining in the panel inner space can be reduced to make the display characteristics more stable. Especially useful for the manufacture of plasma displays.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Front substrate 3 Scan electrode 3a, 4a Transparent electrode 3b, 4b Bus electrode 4 Sustain electrode 5 Display electrode pair 6 Front dielectric layer 7 Protective film 8 Back plate 9 Back substrate 10 Address electrode 11 Back dielectric layer 12 Rib 12a Vertical rib 12b Horizontal rib 13r Red phosphor layer 13g Green phosphor layer 13b Blue phosphor layer 14 Discharge space 15 Discharge cell 16 Black stripe 17 Display area 18, 30 Sealing material layer 19 Sealing clips 20, 29 Support rod 21 Exhaust Pipe 22 Exhaust head 23 Impure gas flow 24 Sealing / exhaust device 25 Vacuum atmosphere 26 Sealing spring 27 Pressure 28 Flow direction

Claims (9)

An image display device comprising a step of sealing a panel inner space between a front plate and a rear plate with a seal layer, and sealing a display element provided on at least one of the front plate and the rear plate in the panel inner space. A manufacturing method comprising:
Sealing between the front plate and the back plate by the sealing layer, sealing and exhausting process for exhausting the space in the panel,
A top panel set to a temperature at which the sealing material layer is melted by heating the panel including the back plate and the front plate in which a sealing material layer is formed at a position to be sealed by the sealing layer, facing each other in a furnace. A temperature raising step to reach the keep temperature;
A top-keep temperature holding step for holding the top-keep temperature;
Performed during the top-keep temperature holding step, evacuation between the front plate and the back plate, and an exhaust / degas treatment step of degassing the front plate and the back plate;
A sealing step in which the sealing material layer is pressure-bonded between the front plate and the back plate, starting from the middle of the period of the top-keep temperature holding step;
A method of manufacturing an image display device, comprising: a temperature lowering step of lowering the temperature after the top keep temperature holding step.   The image display according to claim 1, wherein the back plate and the front plate are positioned relative to each other so that a gap exists between the sealing material layer and the back plate or the front plate before the sealing step. Device manufacturing method. In a period prior to the sealing step, the back plate and the front plate are overlapped with each other and the process is performed only from below,
The method for manufacturing an image display device according to claim 2, wherein when starting the sealing step, a force pressing the back plate and the front plate against each other is applied. In the period prior to the sealing step, by supporting the back plate and the front plate by separate support members, a gap is provided between the back plate and the front plate,
3. The method for manufacturing an image display device according to claim 2, wherein during the period after the sealing step, support by the support member for the back plate or the front plate disposed in the upper part is excluded.   The sealing material layer is formed so that an upper surface has an uneven shape, and a gap is formed between the sealing material layer and the back plate or the front plate when the back plate and the front plate are overlapped with each other. Item 3. A method for manufacturing an image display device according to Item 2.   The method for manufacturing an image display device according to claim 1, wherein the sealing / exhausting step is performed in a vacuum atmosphere. The method for manufacturing an image display device according to claim 6, wherein the sealing / evacuation step is performed in a vacuum vessel, and the pressure in the vacuum vessel is 1 × 10 ⁻³ Pa or less at the top keep temperature.   2. The image display device according to claim 1, wherein, in the sealing step, the sealing material layer is pressure-bonded between the front plate and the back plate by biasing the front plate and the back plate toward each other with a spring. Production method.   The method for manufacturing an image display device according to claim 1, wherein the sealing step is started after 50 minutes or more have passed since the temperature of the panel reached the top keep temperature.

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