JP5173504B2 - Sealing panel manufacturing method and plasma display panel manufacturing method using the same - Google Patents

Description

The present invention relates to a manufacturing method of the sealing panel and the manufacturing how the plasma display using the same.

Conventionally, a plasma display panel (hereinafter referred to as “PDP”) has been widely used in the field of display devices, and recently, a large screen, high quality and low price PDP is required.
In general, a PDP has a front substrate and a rear substrate bonded together with a sealing material, and a discharge gas is sealed inside. As the PDP, a three-electrode surface discharge type in which a sustain electrode and a scan electrode are formed on a front substrate and an address electrode is formed on a rear substrate has become the mainstream. When a voltage is applied between the scan electrode and the address electrode to generate a discharge, the enclosed discharge gas is turned into plasma and ultraviolet rays are emitted. This ultraviolet light excites the phosphor formed on the back substrate to emit visible light.

Conventionally, low-melting glass has been used as a sealing material for both substrates, but recently, a technique using a resin material has been proposed. By adopting a resin material as the sealing material, the heating conditions and cooling conditions at the time of panel sealing are alleviated, so that the panel manufacturing time can be greatly shortened.
On the other hand, when a thermosetting resin material is employed as the sealing material, CO ₂ , C ₆ H ₆ , other carbides, etc. contained in the resin material itself or components that easily evaporate due to heating during panel sealing Impurity gas and moisture may be released into the panel as outgas.

On the other hand, as shown in Patent Document 1, for example, a technique using an ultraviolet curable resin material as a sealing material for sealing each substrate has been proposed. According to this configuration, both substrates can be sealed by ultraviolet irradiation, and high temperature heating during sealing is not necessary. For this reason, the amount of outgas released from the sealing material can be reduced, and the manufacturing time of the panel can be shortened.
JP 2002-75197 A

However, even when an ultraviolet curable resin is used as the sealing material as described above, moisture or the like contained in the sealing material is released to the inside of the panel after the panel sealing, or the sealing material from the outside. There is a risk that moisture or the like may penetrate into the panel through the permeation.
As a result, when moisture enters the panel, the purity of the discharge gas sealed inside the panel gradually decreases and the discharge voltage increases, resulting in a problem of increased power consumption. In addition, there is a problem that it takes time to clean and age the PDP.

  Therefore, the present invention has been made to solve the above-described problems, and a method for manufacturing a sealing panel capable of reducing moisture released from the sealing material after application of the sealing material and the use thereof. The present invention provides a method for manufacturing a plasma display. Further, the present invention provides an ultraviolet curable resin that generates less moisture.

In order to achieve the above object, a method for manufacturing a sealing panel according to the present invention is a method for manufacturing a sealing panel in which a first substrate and a second substrate are bonded together with a sealing material, A coating step of coating the sealing material made of an ultraviolet curable resin on a surface of the substrate facing the first substrate, and prior to the coating step, the sealing material is at 35 ° C. or more and 85 ° C. or less. while heating, have a long degassing step of holding under a reduced pressure of not more than atmospheric 0.1 Pa 20 hours to 120 hours or less, the long time prior to the degassing step, heating said sealing material at 140 ° C. or higher while being characterized by Rukoto to have a high temperature degassing step of holding more than 10 minutes under a reduced pressure of not more than atmospheric 10kPa least 100 Pa.
According to this configuration, in the long-time degassing step, the ultraviolet curable resin to be a sealing material is heated for a long time in a reduced pressure atmosphere, so that the sealing material is applied to the second substrate before being applied. The low vapor pressure component (mainly moisture) contained in can be released. Thereby, it becomes possible to prevent the moisture contained in the sealing material from being released after the sealing material is applied, and it is possible to prevent the room and both substrates from being contaminated.
And by curing such a sealing material, polymerization inhibition due to moisture is reduced at the time of curing of the sealing material, and the curing polymerization reaction is performed efficiently, so that the sealing material has excellent film characteristics and less gas permeation. Can be formed. Thereby, it is possible to prevent moisture existing in the room from passing through the sealing material and entering the inside of the panel after the both substrates are sealed. Further, by removing the moisture contained in the sealing material, it becomes possible to prevent the moisture contained in the sealing material from being released toward the inside of the panel after sealing.
Here, during the degassing step for a long time, the sealing material is heated in a range of 35 ° C. or higher and 85 ° C. or lower in a reduced pressure atmosphere, and held for 20 hours or more and 120 hours or less, so that the sealing material is not cured properly In addition, the moisture contained in the sealing material can be efficiently removed. Therefore, moisture released from the sealing material after application of the sealing material can be reduced.

Further, according to the configuration of this, a long time prior to the degassing step, the sealing material with heating at 140 ° C. or higher, with a high temperature degassing step of holding more than 10 minutes under a reduced pressure of not more than atmospheric 10kPa least 100Pa Thus, the high vapor pressure component (mainly the resin material itself) contained in the sealing material can be efficiently released. On the other hand, by setting the pressure to 100 Pa or more, it is possible to prevent the sealing material from being hardened due to the reduced pressure.

In the application step, the sealing material is applied in a dry atmosphere having a dew point of −40 ° C. or less.
According to this configuration, when a sealing material is applied in a dry atmosphere with a dew point set to −40 ° C. or lower, moisture or the like is adsorbed again on the sealing material that has undergone the long-time degassing step. There is no. Therefore, since the sealing material from which moisture and the like are removed can be reliably applied to the second substrate, a sealing material with less gas permeation can be formed. Accordingly, it is possible to reliably prevent moisture from being released toward the inside of the panel after the both substrates are sealed.

In addition, the sealing material is held under a reduced pressure atmosphere or a dry atmosphere having a dew point of −40 ° C. or less between the long-time degassing step and the coating step.
According to this configuration, the above-described long-time degassing step is performed by maintaining the sealing material in a reduced pressure atmosphere or a dry atmosphere having a dew point of −40 ° C. or less between the long-time degassing step and the coating step. Moisture or the like is not adsorbed again on the sealing material that has undergone the above. Therefore, it is possible to form a sealing material with little gas permeation, and reliably prevent moisture from being released from the sealing material after sealing.

On the other hand, a method for manufacturing a plasma display panel according to the present invention is characterized by using the above-described method for manufacturing a sealing panel.
According to this configuration, by using the sealing panel manufacturing method described above, sealing is performed with a sealing material with less gas permeation, thereby preventing moisture or the like from entering the panel after sealing. Can do. Accordingly, the purity of the discharge gas can be maintained in a good state, and an increase in the discharge voltage can be prevented, so that a low-cost plasma display panel that realizes improved throughput and energy saving can be manufactured.

On the other hand, UV-curable resin according to the present invention is a UV-curable resin used as sealing material bonding the first substrate and the second substrate, prior to being applied as the sealing material, said sealing While the dressing is heated at 140 ° C. or higher, a high temperature degassing treatment is performed for 10 minutes or more in a reduced pressure atmosphere of 100 Pa or higher and 10 kPa or lower, followed by heating at 35 ° C. or higher and 85 ° C. or lower to 0.1 Pa. It is characterized in that a degassing treatment is performed for a long period of time that is maintained for 20 hours to 120 hours under the following reduced pressure atmosphere.
According to this configuration, moisture or the like contained in the ultraviolet curable resin can be released by subjecting the ultraviolet curable resin serving as the sealing material to degassing treatment for a long time in advance. This makes it possible to prevent moisture contained in the UV curable resin from being released, and to prevent contamination of the room and both substrates after applying the UV curable resin as a sealing material. Can do.
By curing such an ultraviolet curable resin, the polymerization inhibition due to moisture is reduced at the time of curing the ultraviolet curable resin, and the curing polymerization reaction is efficiently performed. Therefore, the film has excellent film characteristics and has little gas permeation. Can be formed.

According to the present invention, polymerization inhibition due to moisture is reduced when the sealing material is cured, and the curing polymerization reaction is efficiently performed. Therefore, it is possible to form a sealing material having excellent film characteristics and low gas permeation. Thereby, it is possible to prevent moisture existing in the room from passing through the sealing material and entering the inside of the panel. Further, by removing the moisture contained in the sealing material, it becomes possible to prevent the moisture contained in the sealing material from being released toward the inside of the panel after sealing.
Accordingly, the purity of the discharge gas can be maintained in a good state, and an increase in the discharge voltage can be prevented, so that a low-cost plasma display panel that realizes improved throughput and energy saving can be manufactured.

Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
Note that in this specification, the “inner surface” of a substrate refers to a surface facing both the surfaces of the substrate and the substrate that is paired with the substrate.

(Plasma display panel)
FIG. 1 is an exploded perspective view of a three-electrode AC type plasma display panel. The plasma display panel (hereinafter referred to as “PDP”) 100 includes a rear substrate 2 and a front substrate 1 which are disposed to face each other, and a plurality of discharge chambers 16 formed between the substrates 1 and 2.

  Display electrodes 12 (scanning electrodes 12 a and sustaining electrodes 12 b) are formed in stripes at predetermined intervals on the inner surface of the front substrate 1. The display electrode 12 is composed of a transparent conductive material such as ITO and a bus electrode. A dielectric layer 13 is formed so as to cover the display electrode 12, and a protective film 14 is formed so as to cover the dielectric layer 13. The protective film 14 protects the dielectric layer 13 from cations generated by the plasma of the discharge gas, and is made of an alkaline earth metal oxide such as MgO or SrO.

On the other hand, address electrodes 11 are formed in stripes on the inner surface of the back substrate 2 at predetermined intervals. The address electrodes 11 are arranged in a direction orthogonal to the display electrodes 12. The intersection of the address electrode 11 and the display electrode 12 is a pixel of the PDP 100.
A dielectric layer 19 is formed so as to cover the address electrode 11. A partition wall (rib) 15 is formed in parallel with the address electrode 11 on the upper surface of the dielectric layer 19 between the adjacent address electrodes 11. Further, phosphors 17 are disposed on the upper surface of the dielectric layer 19 and the side surfaces of the partition 15 between the adjacent partitions 15. The phosphor 17 emits red, green, or blue fluorescence.

FIG. 2A is a plan view of the PDP. The front substrate 1 and the back substrate 2 described above are bonded together by a sealing material 20 disposed at the peripheral edge between the substrates 1 and 2.
FIG.2 (b) is side surface sectional drawing in the AA line of Fig.2 (a). As shown in FIG. 2B, the discharge chamber 16 is formed between the adjacent barrier ribs 15 by bonding the front substrate 1 and the rear substrate 2 together. A discharge gas such as a mixed gas of Ne and Xe is sealed inside the discharge chamber 16.

  A DC voltage is applied between the address electrode 11 and the scan electrode 12a to generate a counter discharge, and an AC voltage is applied between the scan electrode 12a and the sustain electrode 12b to generate a surface discharge. Then, the discharge gas sealed in the discharge chamber 16 is turned into plasma, and vacuum ultraviolet rays are emitted. The phosphor 17 is excited by the ultraviolet rays, and visible light is emitted from the front substrate 1.

(Sealing material)
As the material of the sealing material 20 described above, it is necessary to adopt a material that can easily evaporate components, moisture, and impurity gas, and can ensure the panel bonding strength. As such a material, in this embodiment, an ultraviolet curable epoxy resin (cationic type) that does not require heating at the time of sealing and is cured by increasing the viscosity when irradiated with ultraviolet rays at room temperature is used. In addition to the cationic system, a radical system or the like can also be used, and general ultraviolet curable resins can be applied.

(PDP manufacturing method)
Next, the manufacturing method of PDP is demonstrated as a manufacturing method of the sealing panel of this invention. FIG. 3 is a flowchart of the PDP manufacturing method according to the present embodiment.
As shown in FIG. 3, the manufacturing process of the PDP is roughly divided into a degassing process (S40), a panel process (S50), and a module setting process (S52). The panel process (S50) is divided into a front substrate process (S60), a back substrate process (S70), and a panel forming process (S80).

FIG. 4 is a block diagram of a PDP manufacturing apparatus.
As shown in FIG. 4, in the PDP manufacturing apparatus 50, the rear end of the front substrate line 60, the rear end of the rear substrate line 70, and the front end of the paneling line 80 are connected via transfer chambers 55 and 56, respectively. Is. A UV curable resin set chamber 90 is connected to the coating chamber 79 of the back substrate line 70. The chambers provided in the manufacturing apparatus 50 are connected to each other via gate valves (not shown). The PDP manufacturing apparatus 50 is a consistent vacuum apparatus that continuously performs the range 50 surrounded by the two-dot chain line in the PDP manufacturing process shown in FIG. 3 in a vacuum or in a controlled atmosphere.

  The front substrate line 60 includes a front plate preparation chamber (evacuation chamber) 61 that receives the front substrate 1 on which the dielectric layer 13 is formed, a heating chamber 62 that heats the front substrate 1 to about 150 to 350 ° C., and an electron Cooling in which the front substrate 1 is temporarily put on standby before being transferred to the transfer chamber 56 while cooling the film formation chamber 64 for forming the protective film 14 by the beam evaporation method and the front substrate 1 after the protective film 14 is formed. A buffer chamber 66 is provided.

  On the other hand, the back substrate line 70 includes a back plate preparation chamber (evacuation chamber) 76 that receives the back substrate 2 on which the phosphor 17 is formed, a heating chamber 77 that heats the back substrate 2, and a back surface that has been heated and degassed. While cooling the substrate 2, a cooling / buffer chamber 78 for temporarily waiting the back substrate 2 in the previous stage of conveyance to the coating chamber 79 and a coating chamber 79 for coating the sealing material 20 are provided.

As shown in FIGS. 3 and 4, in the front substrate process (S60), first, a transparent electrode to be the display electrode 12 is formed (S62). Specifically, a transparent conductive film such as ITO or SnO ₂ is formed by sputtering or the like and patterned to form the display electrode 12. Next, in order to reduce the electrical resistance of the display electrode 12 made of a transparent conductive film, an auxiliary electrode (bus electrode) made of a metal material is formed by sputtering or the like (S63). Next, for the purpose of protecting each electrode and forming wall charges, the dielectric layer 13 is formed to a thickness of 20 to 40 μm by a printing method or the like.

  Thereafter, the front substrate 1 on which the dielectric layer 13 is formed is carried into the front plate preparation chamber 61 of the manufacturing apparatus 50, and the front plate preparation chamber 61 is evacuated. Subsequently, the front substrate 1 is transferred from the front plate preparation chamber 61 to the heating chamber 62, and the front substrate 1 is baked at about 150 to 350 ° C. with the inside of the heating chamber 62 held in a vacuum atmosphere (S64). Next, the front substrate 1 is transferred to the film formation chamber 64, and a protective film 14 having a thickness of 700 to 1200 nm is formed by electron beam evaporation or the like in order to protect the dielectric layer 13 and improve secondary electron emission efficiency. (S66). Then, the front substrate 1 is transported to the cooling / buffer chamber 66, and the front substrate 1 is cooled and kept waiting in front of the sealing chamber 82.

  On the other hand, in the back substrate process (S70), first, the address electrode 11 made of Ag, Cr / Cu / Cr or Al is formed (S72). Next, a dielectric layer 19 is formed to protect the address electrodes 11 (S74). Next, in order to increase the light emission area of the discharge space and the phosphor 17, the partition 15 is formed by a sandblast method or the like (S75). In the sand blasting method, a glass paste as a material of the partition wall 15 is applied on the back substrate 2, and after drying, a mask material is patterned, and an abrasive such as alumina or glass beads is sprayed at a high pressure to form the partition wall 15 having a predetermined shape. It is a method of forming. Next, the phosphor 17 is applied by a screen printing method or the like and dried (S76).

Thereafter, the back substrate 2 on which the phosphors 17 are formed is carried into the back plate preparation chamber 76 of the manufacturing apparatus 50 and the back plate preparation chamber 76 is evacuated. Subsequently, the back substrate 2 is transported from the back plate preparation chamber 76 to the heating chamber 77, and the back substrate 2 is heated and degassed at about 400 ° C. for about 30 minutes while the inside of the heating chamber 77 is held in a vacuum atmosphere. . Thereafter, the rear substrate 2 is transferred to the cooling / buffer chamber 78 to cool the rear substrate 2. Then, a gas having a low dew point, for example, a discharge gas such as a mixed gas of Ne and Xe (for example, Ne-4% Xe), N _2, or the like is introduced into the cooling / buffer chamber 78. At this time, the cooling / buffer chamber 78 is preferably maintained in a dry atmosphere having a dew point of −40 ° C. or lower. In this embodiment, the dry atmosphere is a gas atmosphere having a dew point of −40 ° C. or lower.

Here, the degassing process of this embodiment will be described. The degassing step of this embodiment is performed by a degassing apparatus provided separately from the manufacturing apparatus 50 (see FIG. 4) described above. FIG. 5 is a block diagram showing the degassing apparatus.
As shown in FIG. 5, the degassing apparatus 110 is degassed in the first degassing chamber 101, the second degassing chamber 102, the first degassing chamber 101 and the second degassing chamber 102. And a take-out chamber 103 for taking out the sealing material 20 subjected to the gas treatment. Each of the chambers 101 to 103 is connected via a gate valve.

As shown in FIG. 3, in the degassing step (S40), a first degassing step (S41: high temperature degassing step) for removing the high vapor pressure component (mainly the resin material itself) contained in the sealing material 20; Then, a second degassing step (S42: long-time degassing step) for removing low vapor pressure components (mainly moisture) contained in the sealing material 20 is performed. Thereby, prior to the sealing material application (S77) to be described later, the easily evaporating component of the resin material itself contained in the sealing material 20 or CO ₂ contained in the resin material, C ₆ H ₆ , other carbides, etc. Impurity gas and moisture are discharged in advance.

  First, in the first degassing step, about 2 g of the sealing material 20 is first filled in a tray made of aluminum, and the tray is thinly expanded so as to have a thickness of about 2 mm. Next, the tray is transported into the first degassing chamber 101, and the sealing material 20 is heated to about 180 ° C. in a state where the pressure in the first degassing chamber 101 is reduced to about 1 kPa by a rotary pump or the like. Hold for about 30 minutes. Then, the resin material itself contained in the sealing material 20 is easily evaporated, or out of the impurity gas and moisture contained in the resin material, the resin material itself is mainly released into the first degassing treatment chamber 101 as outgas. . In addition, it is preferable that the process conditions in a 1st degassing process hold | maintain for 10 minutes or more, heating at 140 degreeC or more in the pressure reduction atmosphere of 100 Pa or more and 10 kPa or less. As a result, the resin material itself contained in the sealing material 20 can be efficiently removed while preventing the sealing material 20 from being cured due to reduced pressure.

Thereafter, heating and exhaust are stopped, N ₂ is introduced into the first degassing chamber 101, and the first degassing chamber 101 is maintained at about atmospheric pressure. Then, when the temperature of the sealing material 20 is lowered to about 65 ° C., the tray in which the sealing material 20 is accommodated is conveyed to the second degassing treatment chamber 102. The transport line that connects the first degassing chamber 101 and the second degassing chamber 102 (not shown) is preferably N ₂ is dry atmosphere which is introduced to approximately atmospheric pressure.

Next, a second degassing process is performed on the sealing material 20 that has been subjected to the first degassing process (S42). First, the sealing material 20 is heated to about 35 ° C. and held for about 48 hours in a state where the inside of the second degassing treatment chamber 102 is evacuated to 1.0 × 10 ⁻³ Pa by a turbo molecular pump or the like. As a result, among the components that are easily evaporated of the resin material itself contained in the sealing material 20 or the impurity gas and moisture such as CO ₂ , C ₆ H ₆ , and other carbides contained in the resin material, mainly moisture is removed from the second material. The gas is discharged as outgas into the gas processing chamber 102. Note that the pressure in the second degassing treatment chamber 102 may be 0.1 Pa or less. The time condition and temperature condition of the second degassing process will be described in detail later.

Thereafter, the inside of the second degassing treatment chamber 102 is replaced with a dry gas (for example, N ₂ ) having a dew point of about −60 ° C., and the tray is transferred to the take-out chamber 103. The take-out chamber 103 is a glove box, and is held in a dry atmosphere with a dew point of about −60 ° C. The sealing material 20 that has been subjected to the second degassing process in the take-out chamber 103 is filled in a syringe for dispensing in the take-out chamber 103. Then, the syringe filled with the sealing material 20 is housed in a transport box that is evacuated (for example, 0.1 Pa or less) and transported to the UV curable resin set chamber 90.

Next, after the transport box is transported into the UV curable resin set chamber 90, a dry gas such as N ₂ is introduced into the UV curable resin set chamber 90, and the dew point in the UV curable resin set chamber 90 is set to −40 ° C. Lower to the extent. The UV curable resin set chamber 90 is a glove box, and after the dew point in the UV curable resin set chamber 90 is lowered to about −40 ° C., the syringe is taken out from the transport box. Subsequently, the gate valve between the coating chamber 79 and the UV curable resin setting chamber 90 is opened, and the dispenser is taken out from the coating chamber 79 to the UV curable resin setting chamber 90. Then, the syringe filled with the sealing material 20 is set in the dispenser in the UV curable resin setting chamber 90. Subsequently, the dispenser is returned to the coating chamber 79, and the gate valve between the coating chamber 79 and the UV curable resin setting chamber 90 is closed, whereby the setting of the sealing material 20 is completed.

  Subsequently, the back substrate 2 kept in the cooling / buffer chamber 66 is transferred to the coating chamber 79, and the sealing material 20 is applied to the inner surface of the back substrate 2 by the needle dispensing method in the coating chamber 79 (application process). ). Specifically, sealing is performed through a degassing step (S40) by a needle dispensing method in a state where the inside of the coating chamber 79 is maintained in a dry atmosphere (dew point −40 ° C. or lower) under the same conditions as in the cooling / buffer chamber 78. The material 20 is continuously applied to the peripheral edge of the back substrate 2. Thus, by applying the sealing material 20 in a dry atmosphere where the dew point is set to −40 ° C. or lower, moisture or the like is not adsorbed again on the sealing material 20 that has undergone the second degassing step. . Therefore, since the sealing material 20 from which moisture and the like have been removed can be reliably applied to the back substrate 2, the sealing material 20 with less gas permeation can be formed. Therefore, it is possible to reliably prevent moisture and the like from being released after the substrates 1 and 2 are sealed. In addition, you may hold | maintain not a dry atmosphere but a high vacuum atmosphere between a 2nd degassing process and an application | coating process. Further, a screen printing method or the like can be adopted as a method for applying the sealing material 20.

  Then, the above-described paneling process for bonding the front substrate 1 and the rear substrate 2 is performed (S80). In the panel forming step, the transfer chambers 55 and 56 are respectively set in a state where the front substrate 1 on which the protective film 14 is formed and the back substrate 2 on which the sealing material 20 is applied are held in a dry atmosphere. To the sealing chamber 82. Then, both the substrates 1 and 2 after sealing are conveyed to the take-out chamber 84 and taken out.

In the sealing chamber 82, first, after passing through an evacuation step (S81) for reducing the pressure in the sealing chamber 82 to about 1 × 10 ⁻⁴ Pa or less, a discharge gas is introduced into the sealing chamber 82 (see FIG. 4). A discharge gas introduction step (S82) is performed, and then an alignment step (S83) for both substrates 1 and 2 and a sealing step (S84) are performed. The time from the application process of the sealing material 20 to the evacuation process is preferably about 15 minutes. Further, the relationship between the atmospheric conditions in the coating process and the time conditions from the coating process to the vacuum evacuation process will be described in detail later. If necessary, a short aging step (S86) is performed. Further, a discharge gas may be introduced after the alignment step.

  In the discharge gas introduction step, a discharge gas such as a mixed gas of Ne and Xe (for example, Ne-4% Xe) is introduced into the reduced-pressure manufacturing apparatus 50. Next, in the alignment step, the alignment marks on the front substrate 1 and the rear substrate 2 are read by a CCD camera installed on the atmosphere side of the vacuum chamber, and the substrates 1 and 2 are aligned.

In the sealing step, the aligned substrates 1 and 2 are bonded together. Specifically, the sealing material 20 is cured by irradiating ultraviolet rays when the peripheral portions of both the substrates 1 and 2 are uniformly spread. For example, ultraviolet rays are irradiated under the condition of 6 W · s / cm ² using an ultraviolet irradiation device having a wavelength of 365 nm. Thereby, both the substrates 1 and 2 are sealed by the sealing material 20.

(Degassing condition investigation test)
Here, in order to obtain the optimum degassing conditions in the second degassing step described above, the inventor of the present application uses a sealing material subjected to the second degassing treatment under various conditions. A test was conducted to measure the value of neglected variation.

  First, the inventor of the present application conducted a test for measuring the discharge voltage and the standing fluctuation of a sample PDP (hereinafter referred to as PDP) manufactured by varying the temperature and time in the second degassing step.

  The PDP in this test is equivalent to the PDP 100 of the above-described embodiment, and a protective film 14 made of MgO is formed on the dielectric layer 13 on the front substrate 1 with a thickness of 400 nm. On the other hand, after the phosphor 17 is formed on the back substrate 2, it is baked at 400 ° C. for 30 minutes, and then the sealing material 20 is applied and transported in a dry atmosphere having a dew point of −50 ° C. or less. The time required for exhaust for replacement was about 15 minutes. The discharge gas was sealed at 400 Torr using Ne-4% Xe. Note that the PDP in this test was produced with a vacuum integrated device without taking it out into the atmosphere from the production of the protective film 14 to the enclosure of the discharge gas.

  As the degassing treatment of the sealing material used in this test, first, the first degassing treatment chamber 101 is subjected to a first degassing treatment at 180 ° C. in an atmosphere of 1 kPa for 30 minutes, and the impurity gas in the sealing material 20 is thus obtained. Then, a second degassing process was performed in the second degassing process chamber 102.

(Test 1)
The second degassing process in Test 1 was set at a constant temperature of 35 ° C. in a high vacuum atmosphere of 1.0 × 10 ⁻³ Pa, and the degassing time of the second degassing process was varied. And the test which measures the discharge start voltage at this time, a discharge maintenance voltage, and neglected variation was done. Note that the variation in standing indicates the variation in the discharge start voltage (Vf1) of the first cell between the PDP in the initial state and the PDP after being left in an atmosphere at a temperature of 70 ° C. for 72 hours. In the neglected variation measurement, the voltage change of Vf1 is the largest compared to Vfn, Vsmn, and the like.

  FIG. 6 is a graph showing the relationship between the discharge voltage with respect to the degassing time (hr) and the standing fluctuation (V (circle plot in FIG. 6)). In FIG. 6, Vfn (diamond plot in FIG. 6) is the discharge start voltage of the final cell, and Vsmn (square plot in FIG. 6) is the discharge sustain voltage of the final cell. Note that the discharge start voltage of the final cell is a drive voltage necessary to start discharge of all cells. Further, the discharge sustaining voltage of the last cell is a voltage at which the last cell is turned off when the drive voltage is gradually lowered from the state where all the cells are turned on.

  As shown in FIG. 6, the variation in neglect was 24 (V) in the PDP manufactured using the sealing material that was not subjected to the second degassing treatment at all, but it was left as the degassing time increased. The result was that the fluctuation was small. Furthermore, in the PDP manufactured using the sealing material that has been subjected to the second degassing treatment of 48 (hr), the uncontrolled fluctuation is 9 (V), which is less than half that in the case where the second degassing treatment is not performed. The result was obtained. Further, when the degassing time is 48 (hr) or more, the standing fluctuation slightly increases, but when the degassing time is 120 (hr), the leaving fluctuation is 12 (V), and the second degassing treatment is performed. It is about half of the case when not doing.

  Here, the fact that the neglected fluctuation is small indicates that the purity of the discharge gas sealed inside the panel does not decrease and the discharge start voltage does not increase even after leaving for 72 hours. In other words, since most of the moisture contained in the sealing material is removed by performing the second degassing process, it is considered that almost no moisture is released from the sealing material after the second degassing process. On the other hand, if the time of the second degassing treatment is too long, the standing fluctuation increases because components necessary for curing contained in the sealing material evaporate, and curing failure occurs during curing. It is thought that. From the above results, the optimum degassing time in the second degassing step is preferably about 20 (hr) to 120 (hr).

(Test 2)
Next, when the test conditions were set to a constant pressure of 1.0 × 10 ⁻³ Pa and time 48 (hr) and the degassing temperature was varied from 35 ° C. to 85 ° C., the same measurement method as described above was used. The method was tested.

  FIG. 7 is a graph showing the relationship between the discharge voltage (V) and the standing fluctuation (V (triangular plot in FIG. 7)) with respect to the degassing temperature (° C.). In FIG. 7, Vfn (diamond plot in FIG. 7) is the discharge start voltage of the final cell, and Vsmn (square plot in FIG. 7) is the discharge sustain voltage of the final cell.

  As shown in FIG. 7, it can be seen that the neglected variation also tends to decrease by increasing the temperature of the second degassing process. As a result, when the degassing temperature is 65 (° C.), the neglect fluctuation is about 4 (V). That is, it can be seen that, by performing the second degassing process, most of the moisture contained in the sealing material is released, so that almost no moisture is released from the sealing material after the second degassing process.

  On the other hand, when the degassing temperature is increased from 65 (° C.), it is understood that the standing fluctuation tends to increase. Specifically, when the degassing temperature is 75 (° C.), it slightly increases to 5 (V), and when it is 85 (° C.), it is 10 (V), which exceeds the value of the fluctuation of standing at 35 (° C.). As a result. This is because if the temperature of the second degassing process is too high, a large amount of components necessary for curing contained in the sealing material will evaporate, or the sealing material will start to cure due to high heat. It is thought that poor curing sometimes occurs. From the above results, it is considered that the optimum degassing temperature for the second degassing process is about 50 (° C.) to 70 (° C.).

  Thus, in the second degassing step, by holding the sealing material in a range of 50 ° C. or more and 70 ° C. or less in a reduced pressure atmosphere of 0.1 Pa or less, holding for 20 hours or more and 120 hours or less, The moisture contained in the sealing material 20 can be efficiently removed after preventing the curing failure of the sealing material 20. Therefore, the moisture released from the sealing material 20 after application of the sealing material 20 can be reduced.

(Test 3)
In Test 3, the coating atmosphere in the above-described sealing material application (S77) process and the time from the end of the sealing material application (S77) process to the evacuation (S81) process in the paneling process (S80) ( In the following, the test was performed in the same manner as the measurement method described above in a PDP produced by varying the exposure time). In addition, the conditions of the 2nd degassing process in Test 2 were set constant as pressure 1.0 * 10 <^-3> (Pa), time 48 (hr), and temperature 65 (degreeC). Moreover, the coating atmosphere in this test has shown the dew point in coating atmosphere.

  FIG. 8 is a graph showing the variation in standing (V) with respect to the exposure time (min) for each coating atmosphere. In addition, as an application atmosphere of Test 2, dew points were set to −50 (° C.) (diamond plot in FIG. 8), −60 (° C.) (triangle plot in FIG. 8), and −70 (° C.) (square plot in FIG. 8). Set.

  As shown in FIG. 8, it can be seen that the exposure fluctuation tends to increase as the exposure time becomes longer in each coating atmosphere. Furthermore, it can be seen that as the dew point becomes higher, the value of the neglected fluctuation at each exposure time becomes larger. Specifically, when the dew point is −70 (° C.) and the exposure time is 15 (min), the neglected variation is 4 (V), and further the neglected variation up to 60 (min) is 10 (V) or less. I was able to suppress it. Further, when the dew point is −60 (° C.) and the exposure time is 15 (min), the standing fluctuation is about 7 (V), and when it is 30 (min), it is 13 (V), and when it is 60 (min), 18 (V). On the other hand, when the dew point was −50 (° C.) and the exposure time was 15 (min), the standing fluctuation was 12 (V), and when it was 60 (min), it increased to 23 (V).

  From the above results, it can be considered that the optimum atmosphere for the coating atmosphere from the sealing material coating to the vacuum evacuation has a dew point of −50 ° C. or lower. In an atmosphere having a dew point of −50 ° C., it is preferable to set the time from application of the sealing material to evacuation within 10 minutes. When the dew point is −40 ° C., the amount of water is about 3.2 times that when the dew point is −50 ° C., so the process from application of the sealing material to exhaust can be performed in about 3 minutes. There is no practical problem.

(Accelerated test)
Next, the inventor of the present application conducted an acceleration test in a constant temperature and humidity atmosphere with a temperature of 70 ° C. and a humidity of 85%, and measured fluctuations in the discharge voltage of the PDP. Note that the PDP used in this test uses a sealing material that has been subjected to a second degassing treatment at 65 ° C. for 48 hours in a high vacuum atmosphere of 1.0 × 10 −3 Pa after the first degassing treatment. It is sealed.
FIG. 9 is a graph showing the variation of the discharge voltage (V) with respect to the acceleration test time (hr). Vf1 (diamond plot in FIG. 9) is the discharge start voltage of the first cell, and Vfn (open diamond plot in FIG. 9) is the discharge start voltage of the final cell. Vsm1 (square plot in FIG. 9) is the discharge sustain voltage of the first cell, and Vsmn (open square plot in FIG. 9) is the discharge sustain voltage of the final cell.

As shown in FIG. 9, although both the discharge start voltage Vf and the discharge sustain voltage Vsmn tend to increase slightly, the increase amount is small and is about 8 (V) even after leaving for 1080 (hr), and there is no practical problem. Results were obtained. That is, it can be seen that the PDP using the sealing material subjected to the second degassing treatment has less moisture intrusion into the panel even when exposed to a constant temperature and humidity atmosphere for a long time. This is considered to be because the moisture contained in the sealing material could be released by performing the second degassing treatment. That is, it is considered that a sealing material with less gas permeation could be formed because polymerization inhibition due to moisture was reduced during curing of the sealing material and the curing polymerization reaction was efficiently performed.
In addition, although not shown in figure, when PDP produced using the sealing material which has not performed 2nd degassing process was exposed to the same atmosphere, after about 72 hours, it stopped lighting. This is presumably because the moisture present in the constant temperature and humidity atmosphere penetrates the sealing material and enters the inside of the PDP panel, and the purity of the discharge gas is reduced.

As described in detail above, the method for manufacturing the PDP in the present embodiment includes an application step of applying the sealing material 20 made of an ultraviolet curable resin to the surface of the back substrate 2 facing the front substrate 1. Prior to the coating step, the second degassing step is employed.
According to this configuration, in the second degassing step, the ultraviolet curable resin to be the sealing material 20 is heated in a reduced pressure atmosphere for a long time, so that the sealing material 20 is applied to the back substrate 2 before being sealed. The low vapor pressure component (mainly moisture) contained in the dressing 20 can be released. As a result, it becomes possible to prevent the moisture contained in the sealing material 20 from being released after the sealing material 20 is applied, so that the sealing chamber 82 and both the substrates 1 and 2 are contaminated. Can be prevented.
Then, by curing the sealing material 20, the polymerization inhibition due to moisture is reduced when the sealing material 20 is cured, and the curing polymerization reaction is efficiently performed. The dressing 20 can be formed. Thereby, it is possible to prevent moisture existing in the sealing chamber 82 from passing through the sealing material 20 and entering the inside of the panel after the both substrates 1 and 2 are sealed. Further, by removing the moisture contained in the sealing material 20, it is possible to prevent the moisture contained in the sealing material 20 from being released toward the inside of the panel after sealing.

  In addition, by holding the sealing material 20 in a high vacuum atmosphere or a dry atmosphere between the second degassing step and the coating step, moisture or the like is again added to the sealing material 20 that has undergone the second degassing step. There is no adsorption. Therefore, the sealing material 20 with little gas permeation can be formed, and it is possible to reliably prevent moisture from being released from the sealing material 20 after sealing.

  And since PDP100 produced using the manufacturing method of a sealing panel is sealed with the sealing material 20 with little gas permeation | transmission, it can prevent that a water | moisture content etc. penetrate | invade inside a panel after sealing. it can. Accordingly, the purity of the discharge gas can be maintained in a good state, and an increase in the discharge voltage can be prevented, so that a low-cost plasma display panel that realizes improved throughput and energy saving can be manufactured.

  The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and configurations described in the embodiments are merely examples, and can be changed as appropriate.

  For example, in the above embodiment, the present invention is applied to a plasma display panel. However, the present invention can also be applied to an organic EL (electroluminescence) display panel or a field emission display panel.

The organic EL display panel has a configuration in which a functional layer such as a light emitting layer is sandwiched between an anode and a cathode, and uses light emitted from the light emitting layer as display light as it is.
The field emission display panel emits electrons from an electron emission source (emitter) arranged for each pixel in a vacuum and strikes a phosphor to emit light. Examples of the field emission display panel include a field emission display (FED) including a protruding electron-emitting device, and a surface-conduction electron-emitter display (SED) including a surface-conduction electron-emitting device.

  As described above, even when the present invention is applied to an organic EL or a field emission display panel, sealing with a sealing material with less gas permeation prevents moisture or the like from entering the panel after sealing. be able to. Therefore, it is possible to provide an organic EL or a field emission display panel having excellent display characteristics.

For example, in the present embodiment, the transfer line between the first degassing chamber and the second degassing chamber in the degassing apparatus is maintained in a dry atmosphere. There is no problem even if it is exposed to the atmosphere for a short time (about 1 hour) after completion.
In this embodiment, the case where the degassing apparatus and the integrated vacuum apparatus are provided separately has been described. For example, a configuration in which the degassing apparatus is connected to the UV curable resin set chamber of the integrated vacuum apparatus. Is also possible. In this case, it is possible to adopt a configuration in which the dispenser is automatically filled with the degassed sealing material.
In the present embodiment, the case where the first degassing process and the second degassing process are performed as the degassing process has been described. However, only the second degassing process (long-time degassing process) is performed. It may be.

It is a disassembled perspective view of a 3 electrode AC type plasma display panel. (A) is a top view of PDP, (b) is side surface sectional drawing in the AA of (a). It is a flowchart of the manufacturing method of PDP which concerns on this embodiment. It is a block diagram of the manufacturing apparatus of PDP. It is a block diagram of a degassing processing apparatus. It is a graph which shows the relationship between the discharge voltage (V) with respect to degassing time (hr), and neglected fluctuation | variation (V). It is a graph which shows the relationship between the discharge voltage (V) with respect to degassing temperature (degreeC), and neglected fluctuation | variation (V). It is a graph which shows the leaving variation (V) with respect to exposure time (min) for every application atmosphere. It is a graph which shows the fluctuation | variation of the discharge voltage (V) with respect to acceleration test time (hr).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front substrate 2 ... Back substrate 20 ... Sealing material S40 ... Degassing process S77 ... Sealing material application process S84 ... Sealing process S41 ... 1st degassing process (high temperature degassing process process) S42 ... 2nd degassing Process (long-time degassing process)

Claims (4)

The first substrate and the second substrate are a manufacturing method of a sealing panel bonded with a sealing material,
An application step of applying the sealing material made of an ultraviolet curable resin to a surface of the second substrate facing the first substrate;
Prior to the coating step, there is a long-time degassing step in which the sealing material is heated at 35 ° C. or higher and 85 ° C. or lower and held in a reduced pressure atmosphere of 0.1 Pa or lower for 20 hours or longer and 120 hours or shorter,
Prior to the long-time degassing step, the sealing material has a high-temperature degassing step in which the sealing material is heated at 140 ° C. or higher and held in a reduced pressure atmosphere of 100 Pa or higher and 10 kPa or lower for 10 minutes or longer. Panel manufacturing method.   The method for manufacturing a sealing panel according to claim 1, wherein in the application step, the sealing material is applied in a dry atmosphere having a dew point of −40 ° C. or less.   The said sealing material is hold | maintained in a reduced pressure atmosphere or a dry atmosphere whose dew point is -40 degrees C or less between the said long time degassing process and the said application | coating process. Manufacturing method for sealing panels.   A method for manufacturing a plasma display panel, wherein the method for manufacturing a sealing panel according to any one of claims 1 to 3 is used.

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