JP5173444B2 - Sealing panel manufacturing method and plasma display panel manufacturing method using the same - Google Patents

Description

  The present invention relates to a method for manufacturing a sealing panel and a method for manufacturing a 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 used as the sealing material, moisture or impurity gas (hereinafter referred to as “high vapor pressure component”) contained in the resin material itself is easily evaporated by heating during panel sealing. ) May be released inside the panel.

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. Therefore, it is said that the release of the high vapor pressure component contained in the sealing material can be reduced, and the manufacturing time of the panel can be shortened.
JP 2002-75197 A

  By the way, since both substrates are sealed in a sealing chamber filled with a discharge gas, it is necessary to evacuate the chamber (the preparation chamber or the sealing chamber) in which the rear substrate is arranged before sealing. Due to this evacuation, there is a problem in that high vapor pressure components contained in the ultraviolet curable resin of the sealing material are released into the room and adhere to the room or the back substrate surface to be contaminated. Furthermore, when both substrates are sealed, there is a problem that the high vapor pressure component detached from the back substrate adheres to the protective film of the front substrate and the front substrate is also contaminated. As a result, 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 is released into the room after application of the sealing material, easily evaporating components of the sealing material itself or moisture contained in the sealing material. there is provided a method of manufacturing a sealed panel can be reduced impurity gases, etc., and preparation how the plasma display panel using the same.

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, the opposing surfaces of the first substrate in the substrate, a coating step of applying the sealing material made of an ultraviolet curable resin, prior to pre-Symbol coating step, heating a predetermined time the sealing material in a reduced pressure atmosphere have a degassing step, using said degassing step the sealing material which has undergone, after the coating step, in a vacuum or in a controlled atmosphere, and the said first substrate second substrate The method further includes a panel forming step of bonding .
According to this configuration, in the degassing step, the ultraviolet curable resin to be the sealing material is heated in a reduced-pressure atmosphere, so that the component of the sealing material itself that easily evaporates or moisture or impurity gas contained in the sealing material Is released before the sealing material is applied to the second substrate, and then the coating process is performed using the sealing material that has undergone the degassing process. Thereafter, a paneling process for bonding the first substrate and the second substrate is performed in a vacuum or in a controlled atmosphere. Thereby, in the paneling process, even when exposed to a vacuum or a controlled atmosphere , the sealing material itself easily evaporates after application of the sealing material, or moisture or impurity gas contained in the sealing material. it is capable ing be prevented from being released from the sealing material. As a result, when the paneling process is performed, it is possible to prevent the room in a vacuum or a controlled atmosphere and both substrates disposed in the room from being contaminated. In addition, as described above, by using an ultraviolet curable resin as the sealing material, high temperature heating at the time of sealing is not necessary, so that the aging time after sealing can be greatly shortened. Accordingly, throughput improvement and energy saving can be realized.

The degassing step is characterized in that the sealing material is heated at 140 ° C. or higher and held for 10 minutes or more in a reduced pressure atmosphere of 100 Pa to 10 kPa.
According to this configuration, the temperature in the degassing step is set to 140 ° C. or more, the pressure is set to 10 kPa or less, and the time is set to 10 minutes or more, so that the moisture or impurity gas contained in the sealing material itself or the sealing material is efficiently used. It can be released well. 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 degassing step, the pressure in the chamber is adjusted by supplying a dry gas into the chamber while evacuating the chamber in which the sealing material is disposed.
According to this configuration, the exhaust speed can be made constant regardless of the degassing conditions. Therefore, moisture and impurity gas contained in the sealing material itself or the sealing material can be efficiently released.

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, it is possible to manufacture a low-cost plasma display panel that realizes throughput improvement and energy saving.

On the other hand, the ultraviolet curable resin according to the present invention is an ultraviolet curable resin used as a sealing material for bonding the first substrate and the second substrate, and is applied in a reduced pressure atmosphere before being applied as the sealing material. After degassing for heating for a predetermined time , the first substrate and the second substrate are applied, and the first substrate and the second substrate are bonded together in a vacuum or in a controlled atmosphere. It is used for this purpose .
According to this configuration, after the facilities previously degassed ultraviolet curable resin as a sealing material is applied to the second substrate, in a vacuum or in a controlled atmosphere, and the first substrate and the second substrate Therefore, after sealing, it is possible to prevent components that easily evaporate from the sealing material itself or moisture or impurity gas contained in the sealing material from being released from the sealing material. to be able to ing. As a result, a paneling process for bonding the first substrate and the second substrate is performed, and the chamber in a vacuum or controlled atmosphere and both substrates disposed in the chamber are contaminated. Can be prevented. In addition, as described above, by using an ultraviolet curable resin as the sealing material, high temperature heating at the time of sealing is not necessary, so that the aging time after sealing can be greatly shortened. Accordingly, throughput improvement and energy saving can be realized.

Further, in the degassing treatment, 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. As described above, by performing the degassing treatment with the pressure set to 10 kPa or less and the time set to 10 minutes or more, moisture or impurity gas contained in the sealing material itself or 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.

  According to the present invention, it is possible to prevent the components that are likely to evaporate in the sealing material itself after application of the sealing material or the release of moisture, impurity gas, and the like contained in the sealing material. It is possible to prevent the substrate from being contaminated. In addition, as described above, by using an ultraviolet curable resin as the sealing material, high temperature heating at the time of sealing is not necessary, so that the aging time after sealing can be greatly shortened. Accordingly, throughput improvement and energy saving can be realized.

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 method for manufacturing the PDP according to the first embodiment. The manufacturing process of the PDP is roughly divided into three steps: 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).

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 and fired (S64). Next, in order to protect the dielectric layer 13 and improve the secondary electron emission efficiency, the protective film 14 is formed to a thickness of 700 to 1200 nm by an electron beam evaporation method or the like (S66).

  FIG. 4 is a block diagram of a PDP manufacturing apparatus. 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 to the transfer chamber 55. 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., A film forming chamber 64 for forming the protective film 14 by the electron beam evaporation method and a buffer chamber 66 for temporarily waiting the front substrate 1 after the protective film 14 is formed are provided.
Further, the back substrate line 70 is provided with a back plate preparation chamber (vacuum exhaust chamber) 76 for receiving the back substrate 2 coated with the sealing material 20.

In the back substrate step (S70) shown in FIG. 3, 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 at about 500 ° C. after drying (S76).
Next, the sealing material 20 is apply | coated to the inner surface of the back substrate 2 (application | coating process). Specifically, the sealing material 20 that has been subjected to a degassing step (S40) to be described later is continuously applied to the peripheral portion of the back substrate 2 by a needle dispensing method. Note that a screen printing method or the like can be employed 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 process, first, after performing a vacuum exhausting process (S81) in which the inside of the sealing chamber 82 is depressurized to about 1 × 10 ⁻⁴ Pa or less, a discharge for introducing a discharge gas into the sealing chamber 82 (see FIG. 4). A 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. If necessary, a short aging step (S86) is performed. Further, a discharge gas may be introduced after the alignment step.

  In the paneling process, as shown in FIG. 4, the front substrate 1 on which the protective film 14 is formed and the rear substrate 2 on which the sealing material 20 is applied are held in a vacuum or in a controlled atmosphere. In this state, it is transferred to the sealing chamber 82 via the transfer chamber 55. Then, both the substrates 1 and 2 after sealing are conveyed to the take-out chamber 84 and taken out.

  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 process)
Here, the degassing process of this embodiment will be described.
In the above-described evacuation process, components that are easily evaporated in the sealing material 20 itself evaporate from the sealing material 20, and moisture and impurity gases (H ₂ , N ₂ , CO, CO _2, etc.) contained in the sealing material 20 are used. ) May be detached from the sealing material 20. The high vapor pressure component separated from the sealing material 20 stays in the back plate preparation chamber 76 and adheres to the inner surface of the back substrate 2 or adheres to the inside of the sealing chamber 82 that is the transfer destination of the back substrate 2. There is a case. Further, when the substrates 1 and 2 are sealed, there is a problem that the high vapor pressure component detached from the back substrate 2 adheres to the protective film 14 of the front substrate 1 and the front substrate 1 is also contaminated.

  Therefore, in this embodiment, prior to the application of the sealing material (S78), the sealing material 20 is degassed (S40), and the high vapor pressure component contained in the sealing material 20 is released in advance.

The degassing process is performed, for example, with a vapor deposition apparatus in a reduced pressure atmosphere while performing a heat treatment for a predetermined time. Specifically, first, about 2 g of the sealing material 20 is filled in a tray (hearth) made of aluminum, and thinly spread in the tray. Next, the tray is heated to about 180 ° C., and the deposition chamber (chamber) is decompressed to about 1 kPa by a rotary pump and held for about 30 minutes. Then, the high vapor pressure component contained in the sealing material 20 is released into the vapor deposition chamber. On the other hand, the degassed sealing material 20 remains in the tray. Then, the remaining sealing material 20 is supplied to a dispenser and the above-described coating process is performed. Note that in the degassing step, it is preferable to adjust the pressure in the deposition chamber by supplying a dry gas such as N ₂ gas or Ar gas while reducing the pressure in the deposition chamber. Thereby, compared with the case where the exhaust speed is adjusted without introducing gas, the exhaust speed in the vapor deposition chamber at the time of depressurization becomes constant, and the degassing process can be performed efficiently.

(Degassing condition investigation test)
The inventor of the present application conducted a test for measuring the amount of high vapor pressure component released from the sealing material by the degassing process in order to obtain the optimum degassing conditions in the above-described degassing step.

(Test 1)
First, the inventor of the present application performs heat treatment on the sealing material before the degassing treatment and the sealing material after the degassing treatment, and the amount of the high vapor pressure component released from both at this time. Compared. In this test, the amount of high vapor pressure component released was measured as a change in weight of the sealing material, and the evaporation rate was calculated from this change in weight. In the degassing treatment in this test, the inside of the vapor deposition chamber was heated at 150 ° C. and held for 30 minutes under a reduced pressure atmosphere of 1 kPa.

FIG. 5 shows the evaporation rate (mg / cm ² · min) under each test condition. The conditions of the heat treatment in this measurement test are (1) pressure 30 Pa · temperature 80 ° C., (2) pressure 1 kPa · temperature 100 ° C., and (3) pressure 2 kPa · temperature 150 ° C.

As shown in FIG. 5, the evaporation rate (release amount) of the high vapor pressure component was greatly reduced after the degassing treatment was performed on the sealing material for each condition as compared to before the degassing treatment. . Specifically, (3) When heat treatment is performed under conditions of pressure 2 kPa and temperature 150 ° C., the degassing process is performed, so that the evaporation rate of the impurity gas is reduced to about 1/3 compared to before the degassing process. I was able to. Further, (2) even when heat treatment was performed under conditions of a pressure of 1 kPa and a temperature of 100 ° C., it could be reduced to about 1/37 compared to before degassing. Further, (1) When heat treatment is performed at a pressure of 30 Pa and a temperature of 80 ° C., the evaporation rate before degassing is 0.038 mg / cm ² · min, whereas the evaporation rate after degassing is 0 It was reduced to about .0001 mg / cm ² · min and about 1/380.

  Based on the above results, the degassing process is performed prior to the sealing material application process, which significantly releases high vapor pressure components when the sealing material is exposed to a high-temperature reduced-pressure atmosphere after the application process. Can be reduced. That is, it is possible to prevent the front substrate and the protective film formed on the front substrate from being contaminated by the high vapor pressure component released from the sealing material when sealing both the substrates. In addition, in PDP100 after a product (refer FIG. 1), since PDP100 does not become 80 degreeC or more, sufficient effect is anticipated.

(Test 2)
Next, the inventor of the present application conducted a test for measuring the degree of contamination of the substrate by the high vapor pressure component contained in the sealing material by changing the temperature, pressure, and time in the degassing step.

  In this test, as a means for evaluating the contamination of the substrate, the degree of contamination was evaluated from the change in the contact angle under each test condition. As an evaluation method, first, degassing treatment for 30 minutes is performed in a reduced pressure atmosphere at a pressure of 1 kPa in a temperature range of 40 ° C to 200 ° C. Next, the degassed sealing material is applied on a glass substrate (hereinafter referred to as a back substrate) as a sample of the back substrate, and a distance of about 10 cm is provided immediately above the back substrate to be a sample of the front substrate. A clean glass substrate (hereinafter referred to as a front substrate) is disposed oppositely. And after reducing pressure to about 20 Pa with a scroll pump, the contact angle with the pure water in the surface of the front substrate opposingly arranged was measured. In addition, the glass substrate of the sample used for this test is a glass substrate whose contact angle with the pure water in the initial state after washing | cleaning is about 4 degrees.

FIG. 6 is a graph showing the change of the contact angle (°) with respect to the heat treatment temperature (° C.).
As shown in FIG. 6, it can be seen that the contact angle tends to decrease as the degassing temperature increases. Specifically, when the degassing temperature was 40 ° C., the contact angle increased to about 12 °, but the degassing temperature suddenly decreased from around 80 ° C. When the temperature is 140 ° C. or higher, the contact angle is about 4 °. That is, since most of the high vapor pressure component contained in the sealing material is released by performing the degassing treatment at a temperature of 140 ° C. or higher, the high vapor pressure component is hardly released from the sealing material after the degassing treatment. I understand that. As a result, even after the sealing material is applied to the back substrate and then the pressure in the room is reduced, the high vapor pressure component does not adhere to the room or the front substrate disposed oppositely. On the other hand, in the range where the temperature of the degassing process exceeded 200 ° C., a location where the sealing material began to harden due to high heat was confirmed. From the above results, the optimum temperature condition in the degassing step is preferably about 140 ° C. or higher and 200 ° C. or lower.

Next, when the test conditions were set to be constant at a temperature of 150 ° C. and a time of 30 minutes and the pressure was changed from 10 Pa to 100000 Pa, the test was performed by the same method as the evaluation method described above.
FIG. 7 is a graph showing a change in contact angle (°) with respect to pressure (Pa).
As shown in FIG. 7, when the pressure was 100000 Pa, the contact angle increased to about 5.5 °, but in the range of 10 Pa to 10000 Pa, almost no change in the contact angle with increasing pressure was confirmed. However, it can be seen that the contact angle tends to gradually increase in the pressure range of 10,000 Pa or more. On the other hand, when the pressure was less than 100 Pa, a location where the sealing material began to harden due to reduced pressure was confirmed. From the above results, the optimum pressure condition in the degassing step is preferably about 100 Pa or more and 10,000 Pa or less.

Furthermore, when the test conditions were set constant at a pressure of 1 kPa and a temperature of 150 ° C., and the treatment time was changed from 0 to 120 minutes for the degassing treatment, the test was performed in the same manner as the evaluation method described above.
FIG. 8 is a graph showing changes in contact angle (°) with respect to processing time (minutes).
As shown in FIG. 8, when the treatment time is 0 minute, that is, when the degassing treatment is not performed, the contact angle is 11.7 °, but when the treatment time is 3 minutes, the contact angle is 6.8 °. In the case of 5 minutes, it turns out that it is decreasing rapidly with 5.2 degrees. Furthermore, the contact angle is about 4.8 ° in the range where the degassing treatment time is 10 minutes or more. That is, it can be seen that the high vapor pressure component contained in the sealing material is surely released by performing the degassing treatment with a treatment time of 10 minutes or longer. As a result, even after the sealing material is applied to the back substrate and then the pressure in the room is reduced, the high vapor pressure component does not adhere to the room or the front substrate disposed oppositely. On the other hand, in the range where the heat treatment time exceeded 120 minutes, the location where the sealing material began to harden due to the long-time degassing treatment was confirmed. From the above results, the optimum heat treatment time condition in the degassing step is preferably about 10 minutes to 120 minutes.

  From the above results, the optimum degassing conditions of the degassing step in this embodiment are in the range of 10 minutes to 120 minutes in a reduced pressure atmosphere at a temperature of 140 ° C. to 200 ° C. and a pressure of 100 Pa to 10,000 Pa. It is preferable to set it.

(Test 3)
In addition, the inventor of the present application creates a sample PDP by setting the processing conditions of the degassing step to various conditions in the above-described PDP manufacturing method, and performs a contact angle measurement test on the front substrate after each step. Went.

FIG. 9 is a flowchart showing a method for manufacturing the sample PDP.
As shown in FIG. 9, the sample PDP manufacturing method is the same as the above-described PDP manufacturing method, the degassing step (S100), the sealing material coating step (S101), the vacuum exhausting step (S102), and the discharge gas injection. It is created through the process (S103), the overlaying process (S104), and the ultraviolet irradiation process (S105). Then, the sample PDP prepared by the above-described method was left in the atmosphere at a temperature of 72 ° C. for 72 hours (S106). The vacuum evacuation step was performed with the glass substrates facing each other with a distance of about 10 cm, and the pressure was reduced to about 20 Pa by a scroll pump at room temperature for 1 minute. In the discharge gas injection step, Ne-4% Xe was introduced as a discharge gas at 400 Torr.

  The contact angle was measured after the vacuum evacuation step, after the ultraviolet irradiation step (sealing), and after standing at 70 ° C. for 72 hours. In addition, about the measurement after ultraviolet irradiation, it measured by dividing PDP of the sample sealed and bonded together. The glass substrate used in this test was a glass substrate having a contact angle with pure water of about 4 ° in the initial state after cleaning.

  Here, Table 1 below shows the test conditions of the degassing step in this test. Note that “no degassing” in condition 1 indicates that no degassing treatment was performed.

FIG. 10 shows the change in the contact angle (°) for each measurement as a result of testing based on each test condition shown in Table 1.
First, after evacuation, in the case of Condition 1, the contact angle increased to 10 °. Similarly, in the case of Condition 2, the contact angle increased to 10 ° after evacuation, and the high vapor pressure component contained in the sealing material could not be degassed. As a result, the released high vapor pressure component adheres to the room or the front substrate and is contaminated.

  Further, after sealing, in the case of Condition 1, the contact angle increased to 35 °, and in the case of Condition 2, the contact angle increased to 25 °. In these cases, it is considered that the high vapor pressure component contained in the sealing material evaporates and is discharged while the discharge gas is injected up to 400 Torr. As a result, the released high vapor pressure component was adhered to the room or the surface of the front substrate and contaminated.

  Furthermore, after leaving the sample PDP after ultraviolet irradiation (after sealing) at 72 ° C. for 72 hours, in the case of condition 1, the contact angle was 35 °, which was not changed after ultraviolet irradiation. In the case of 2, the contact angle increased to 28 °. These are the front substrate disposed oppositely by the high vapor pressure component adhering to the surface of the back substrate after the vacuum exhausting step and the discharge gas injecting step described above or the high vapor pressure component evaporating from the cured sealing material. It is considered that the front substrate was contaminated due to adhesion.

  On the other hand, in the case of condition 3, the contact angle for each measurement was 4.7 ° after evacuation, 4.9 ° after sealing, and 4.8 ° after leaving at 70 ° C. for 72 hours. There wasn't. Thereby, the high vapor pressure component contained in the sealing material can be surely reduced in the PDP manufacturing process by performing the degassing treatment at 150 ° C. for 30 minutes in the reduced pressure atmosphere of 1 kPa. .

As described in detail above, the PDP manufacturing method according to the present embodiment includes the 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. And it was set as the structure which has the degassing process which heats the sealing material 20 for a predetermined time in a pressure-reduced atmosphere prior to an application | coating process.
According to this configuration, in the degassing step, the ultraviolet curable resin to be the sealing material 20 is heated in a reduced-pressure atmosphere, so that the high vapor pressure component contained in the sealing material 20 is removed from the sealing material 20 on the back surface. It can be discharged before being applied to the substrate 2. As a result, it becomes possible to prevent the high vapor pressure component contained in the sealing material 20 from being released after the sealing material 20 is applied, and the indoor (back plate preparation chamber 78 and sealing chamber 82) or both. It is possible to prevent the substrates 1 and 2 from being contaminated.
Moreover, since the high temperature heating at the time of sealing becomes unnecessary by using an ultraviolet curable resin for the sealing material 20, the aging time after sealing can be shortened significantly.

In addition, by reducing the pressure while supplying a dry gas such as N ₂ into the vapor deposition chamber in the degassing step, the exhaust speed can be made constant regardless of the degassing conditions. Therefore, the high vapor pressure component contained in the sealing material 20 can be efficiently released.
As described above, according to the present embodiment, it becomes possible to eliminate the need for cleaning the inside of the panel in the sealing step, and the aging time after sealing can be greatly shortened, so that the throughput is improved. In addition, energy saving can be realized and the low-cost PDP 100 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.
Thus, even when the present invention is applied to an organic EL or a field emission display panel, it becomes possible to prevent the high vapor pressure component contained in the sealing material from being released, and the indoor and both substrates are contaminated. Can be prevented.

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 graph which shows the evaporation rate (mg / cm < ² > * min) in each test condition. It is the graph which showed the change of the contact angle (degree) with respect to heat processing temperature (degreeC). It is the graph which showed the change of the contact angle (degree) with respect to pressure (Pa). It is the graph which showed the change of the contact angle (degree) with respect to processing time (minutes). It is a flowchart which shows the manufacturing method of sample PDP. It is a graph which shows the change of the contact angle (degree) for every measurement.

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

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;
A degassing step of heating the sealing material in a reduced pressure atmosphere for a predetermined time prior to the coating step;
After performing the coating step using the sealing material that has undergone the degassing step, a panel forming step of bonding the first substrate and the second substrate in a vacuum or in a controlled atmosphere is further performed. A method for producing a sealing panel, comprising:   2. The method for manufacturing a sealing panel according to claim 1, wherein in the degassing step, the sealing material is heated at 140 ° C. or higher and held in a reduced pressure atmosphere of 100 Pa to 10 kPa for 10 minutes or more.   3. The degassing step includes adjusting a pressure in the chamber by supplying a dry gas into the chamber while evacuating the chamber in which the sealing material is disposed. The manufacturing method of the sealing panel of description.   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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