JP2007265768A - Method of manufacturing plasma display panel and its manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique of manufacturing a plasma display panel capable of preventing foaming of a sealing material in sealing, and of surely removing impurities, particularly a CH-based contaminant. <P>SOLUTION: This method of manufacturing a plasma display panel has a sealing process for sealing a front plate and a back plate for the plasma display panel in vacuum by using a sealing material and by heating them at a predetermined temperature. The manufacturing method includes: a first degassing process S2 for executing evacuation by heating the back plate with the sealing material arranged thereon at a temperature higher than that in the sealing process S6 in a vacuum treatment vessel before the sealing process S6; and a second degassing process S3 for executing evacuation by heating the back plate at a temperature higher than that in the sealing process S6 by introducing O<SB>2</SB>gas into the vacuum treatment vessel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for manufacturing a plasma display panel in which a panel is manufactured in a vacuum.

A plasma display panel (hereinafter referred to as “PDP” as appropriate) is configured by stacking a front substrate and a rear substrate, which are two glass plates on which electrodes are formed, in parallel.
A sustain electrode and a display electrode are provided on the front substrate, and a transparent dielectric layer is provided so as to sandwich the sustain electrode and the display electrode between the front substrate. A protective film is formed on the transparent dielectric layer.

  On the other hand, an address electrode is provided on the rear substrate, and a number of small rooms (cells) are provided by a partition. These cells have red (R), green (G), and blue (B), respectively. A phosphor is applied.

  Here, a mixed gas of Ne—Xe is sealed in the gap between the front substrate and the rear substrate. When a voltage is applied to this small cell, gas discharge between the display electrode and the address electrode occurs. The generated ultraviolet rays emit red (R), green (G), and blue (B) phosphors applied to the cells, and color display is performed.

In recent years, due to diversification of PDP applications, development of products with large screens, high quality, and low prices has been demanded. In particular, from the viewpoint of realizing low price products, the manufacturing process of PDPs has been simplified. Is desired.
Conventionally, when manufacturing a PDP, an aging process for continuously lighting the entire panel after the sealing and exhaust processes is performed in order to stabilize the discharge voltage.
Since this aging process takes a long time, it has been proposed to seal the front substrate and the back substrate in a high vacuum in order to omit this step.

However, when sealing the whole substrate and the back substrate in a high vacuum, the sealing material foams and bubbles are generated, and the surface of the sealing material is roughened due to the generation of the bubbles. There was a problem that a leak occurred at the landing part.
Heating in vacuum is effective for degassing impurity gases such as H ₂ O, CO ₂ , and CO, but remains in the dielectric layer, ribs, phosphor, sealing material, and the like. Removal of impurities including carbon is insufficient, and these impurity gases remain in the panel after sealing, so that the discharge characteristics of the PDP are deteriorated (e.g., a long time is required for discharge voltage increase or panel aging) ) Was a problem.

On the other hand, it has been proposed to suppress foaming of the sealing material by degassing while introducing a predetermined gas into the vacuum chamber (see, for example, Patent Document 1). Is necessary.
JP 2000-315457 A

  The present invention has been made in order to solve the above-described problems of the conventional technology. The object of the present invention is to prevent foaming of the sealing material at the time of sealing, as well as impurities, particularly CH-based ones. It is an object of the present invention to provide a plasma display panel manufacturing technique that can reliably remove contaminants.

In order to achieve the above object, the invention according to claim 1 is a sealing step in which a front substrate and a rear substrate for a plasma display panel are sealed at a predetermined temperature by using a sealing material in a vacuum. A plasma display panel manufacturing method comprising: heating the back substrate on which the sealing material is disposed at a temperature higher than the temperature in the sealing step in a vacuum processing tank before the sealing step. A first degassing step in which vacuum evacuation is performed, and a second in which oxidization gas is introduced into the vacuum processing tank and the back substrate is heated at a temperature higher than the temperature in the sealing step to perform vacuum evacuation. Degassing step. In the present invention, for example, O ₂ gas can be used as the “oxidizing gas”.
According to a second aspect of the present invention, in the first aspect of the invention, the partial pressure of the oxidizing gas in the vacuum processing chamber is controlled to be 2 kPa to 20 kPa.
Invention of Claim 3 is a plasma display panel manufacturing apparatus which has a plurality of vacuum processing tanks, and manufactures a plasma display panel by sequentially processing and transporting the front substrate and the rear substrate in vacuum. The method according to claim 1 is used as a vacuum processing tank, and a degassing processing tank for degassing the back substrate is provided, and the degassing processing tank is configured to introduce an oxidizing gas. And a pressure adjusting means for controlling the partial pressure of the introduced oxidizing gas and a heating means for heating the back substrate, and the back substrate degassed in the degassing treatment tank is It is comprised so that it may convey to the sealing tank which seals a front substrate and the said back substrate.

  In the case of the present invention, in the first degassing step, the rear substrate on which the sealing material is disposed is heated at a temperature higher than the temperature in the sealing step and evacuated to form a dielectric film or the like on the rear substrate. Impurities in the contained sealing material are discharged to the outside of the sealing material with foaming.

  And in a 2nd degassing process, by introduce | transducing oxidizing gas in a vacuum processing tank, the pressure in a vacuum processing chamber rises and foaming of a sealing material stops. Then, by heating the back substrate at a temperature higher than the temperature in the sealing step and performing evacuation, CH-based contaminants contained in the dielectric film and the like of the back substrate and the sealing material are removed by combustion. The surface portion of the sealing material that has become uneven due to foaming is flattened.

  Thus, according to the present invention, since the front substrate and the rear substrate are sealed after the degassing step performed by heating at a temperature higher than the sealing temperature, the sealing material is foamed during sealing. In addition, since the front substrate and the rear substrate can be sealed with a sealing material having a flat surface, there is no leakage at the sealing portion, and the front substrate and the rear substrate are securely sealed. Can do.

Furthermore, according to the present invention, impurities, in particular, CH-based contaminants can be reliably removed, so that an aging process is not required, and the manufacturing cost of the PDP can be reduced.
On the other hand, according to the plasma display panel manufacturing apparatus of the present invention, each processing step including the above-described degassing step can be performed consistently and efficiently in a vacuum, and the aging process is not required. Cost can be greatly reduced.

  According to the present invention, the aging process becomes unnecessary, and the manufacturing cost of the PDP can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an embodiment of a PDP manufacturing apparatus of the present invention, FIG. 2 is an internal configuration diagram of a degassing treatment chamber of the PDP manufacturing apparatus, and FIG. 3 is a manufacturing of a plasma display panel of the present invention. It is process drawing explaining the procedure of embodiment of a method.

  As shown in FIG. 1, the PDP manufacturing apparatus 1 of the present embodiment carries a front plate (front substrate) 20 and a back plate (rear substrate) 21 to produce a PDP 22, and a vacuum exhaust system (not shown) is used. Each has an MgO film forming chamber 2, a degassing processing chamber (degassing processing tank) 3, an alignment chamber 4, a sealing / cooling chamber (sealing tank) 5, and a gas sealing / sealing chamber 6. Yes.

  The MgO film forming chamber 2 forms an MgO film by vapor deposition on the transparent dielectric layer provided on the front plate 20, and the alignment chamber 4 is connected to the subsequent stage via a valve 7.

The degassing chamber 3 performs a degassing process to be described later on the back plate 21 on which the sealing material is disposed. The degassing chamber 3 is connected to the alignment chamber 4 through the valve 8 and is processed in the degassing chamber 3. The rear plate 21 is carried into the alignment chamber 4.
The alignment chamber 4 performs positioning when sealing the front plate 20 and the rear plate 21, and a sealing / cooling chamber 5 is connected to the subsequent stage via a valve 9.

The sealing / cooling chamber 5 performs cooling after the sealing material is heated and melted to bond the front plate 20 and the back plate 21 together.
A gas filling / sealing chamber 6 is connected to the subsequent stage of the sealing / cooling chamber 5 via a valve 10.
The gas sealing / sealing chamber 6 is for sealing a gas in a space formed between the front plate 20 and the back plate 21 and then blocking the gas sealing to produce the PDP 22.

As shown in FIG. 2, the degassing treatment chamber 3 of the present embodiment is configured to introduce O ₂ gas as an oxidizing gas from a gas source (not shown) and to control the partial pressure by the pressure adjusting means 24. Yes. In this case, for example, the partial pressure of the O ₂ gas is controlled to a predetermined pressure by controlling the amount of O ₂ gas introduced by a mass flow controller (not shown) and adjusting the exhaust speed of the atmosphere in the degassing treatment chamber 3.

  Then, the back plate 21 on which the sealing material 23 is arranged is placed on the support base 25 in the degassing treatment chamber 3. A heating unit 26 is provided inside the support base 25, and the heating unit 26 is configured to adjust the temperature by a temperature control unit 27.

A method of manufacturing the PDP 22 using the PDP manufacturing apparatus 1 of the present embodiment having such a configuration will be described with reference to FIGS.
First, in step S1, the sealing material 23 is temporarily fired on the back plate 21 in the atmosphere, for example, at 380 ° C. for 30 minutes.
In step S2, the back plate 21 is carried into the degassing chamber 3 and the back plate 21 and the sealing material 23 are heated at a temperature higher than a sealing temperature described later while the degassing chamber 3 is evacuated. (First degassing step).

In the present invention, the pressure in the degassing treatment chamber 3 is not particularly limited, but from the viewpoint of performing degassing of the sealing material 23 as completely as possible, 1 kPa to 1.3 × 10 ^−3. Pa is preferable.

Moreover, the heating temperature of the back plate 21 and the sealing material 23 is not particularly limited, but from the viewpoint of surely foaming the sealing material 23, heating is performed at a temperature higher by 50 ° C. than the sealing temperature. Is preferred.
A higher heating temperature is more effective. For example, when the sealing temperature is 450 ° C., it is preferable to set the heating temperature to 480 ° C. to 500 ° C. in consideration of a practical temperature.

Furthermore, the heating time of the back plate 21 and the sealing material 23 is not particularly limited, but is preferably 20 minutes to 30 minutes from the viewpoint of sufficiently foaming the sealing material 23.
By this step S2, impurities inside the sealing material 23 are foamed, and the back plate 21 and the sealing material 23 are degassed.

In step S3, the back plate 21 and the sealing material 23 are heated at a temperature higher than the sealing temperature while introducing O ₂ gas into the degassing treatment chamber 3 and evacuating it (second degassing step).
Here, the partial pressure of the O ₂ gas in the degassing treatment chamber 3 is not particularly limited, but the foaming of the sealing material is surely stopped, and the CH-based pollutant is sufficiently removed by combustion. It is preferable to control so that it may become 2kPa-20kPa from the viewpoint to do.

Moreover, the heat treatment temperature of the back plate 21 and the sealing material 23 is not particularly limited, but from the viewpoint of sufficiently removing the CH-based contaminants at a temperature higher by 50 ° C. than the sealing temperature. It is preferable to heat.
A higher heat treatment temperature is more effective. For example, when the sealing temperature is 450 ° C., it is preferable to set the heat treatment temperature to 450 ° C. to 500 ° C. in consideration of a practical temperature.

Furthermore, the heat treatment time of the back plate 21 and the sealing material 23 is not particularly limited, but from the viewpoint of sufficiently removing the CH-based contaminants, it may be 20 minutes to 30 minutes. preferable.
By this step S3, the pressure in the degassing treatment chamber 3 is increased, the foaming of the sealing material 23 is stopped, the CH-based pollutant is burned and removed, and the sealing material becomes uneven by the foaming. The surface portion of 23 is flattened.

  On the other hand, in parallel with Steps S1 to S3 described above, in Step S4, an MgO protective film is formed on the transparent dielectric layer of the front plate 20 by vapor deposition in the MgO film forming chamber 2.

In step S5, the front plate 20 and the back plate 21 are carried into the alignment chamber 4, and the front plate 20 and the back plate 21 are positioned.
In step S6, the front plate 20 and the rear plate 21 are conveyed to the sealing / cooling chamber 5, and the sealing material is melted at a temperature of 450 ° C., for example, by heating the sealing material, and the front plate 20 and the rear plate 21 are attached. Together, a panel is produced (sealing). Thereafter, the panel is cooled in the sealing / cooling chamber 5 (step S7).

In step S8, the panel is transported to the gas sealing / sealing chamber 6 and, for example, a neon / xenon mixed gas is sealed in the space in the panel.
In step S9, in the gas sealing / sealing chamber 6, the sealing of the gas into the space in the panel is finished, and the space in the panel is sealed. Thereby, the target PDP 22 is obtained.

  As described above, according to the present embodiment, the front plate 20 and the rear plate 21 are sealed after the degassing step performed by heating at a temperature higher than the sealing temperature. Since the front material 20 and the rear plate 21 are sealed with the sealing material 23 having a flat surface, the dressing material 23 does not foam, so that no leak occurs in the sealed portion, and the front plate 20 and the rear plate. 21 can be securely sealed.

  As described above, according to the present embodiment, impurities, in particular, CH-based contaminants can be reliably removed, so that an aging process is not required, and the manufacturing cost of the PDP can be reduced.

  On the other hand, according to the plasma display panel manufacturing apparatus 1 of the present embodiment, each processing step including the above-described degassing step can be performed consistently and efficiently in a vacuum, and the aging process becomes unnecessary. The manufacturing cost of the PDP can be greatly reduced.

  Examples of the present invention will be described below together with comparative examples.

<Example>
First, the sealing material arrange | positioned on a backplate was baked for 30 minutes in air | atmosphere. In this case, the sealing material was heated so that the temperature was 380 ° C.
Next, the back plate was carried into the degassing chamber and the following processing was performed.

First, the chamber was evacuated and degassed for 30 minutes so that the pressure became 1.3 × 10 ⁻³ Pa or less. In this case, it heated so that the temperature of a backplate might be set to 500 degreeC.
Thereafter, O ₂ gas was introduced into the room while maintaining the temperature of the back plate at 500 ° C. At this time, the partial pressure of O ₂ gas in the room was adjusted to 2 kPa.
After degassing while maintaining this state for 30 minutes, the back plate was carried into the alignment chamber.

On the other hand, for the front plate, an MgO protective film was deposited on the transparent dielectric layer, and then this front plate was carried into the alignment chamber.
In the alignment chamber, the chamber was evacuated to 1.3 × 10 ⁻³ Pa or less, and the front plate and the back plate were positioned. In this case, the room temperature was controlled to be 250 ° C.

Subsequently, the front plate and the back plate were carried into the sealing / cooling chamber, and the following processing was performed.
First, the chamber is evacuated to 1.3 × 10 ⁻³ Pa or less, heated for 10 minutes so that the temperature of the sealing material is 450 ° C., and the front plate and the back plate are bonded together. A panel was formed.
Thereafter, the panel was cooled to room temperature in a sealing / cooling chamber.
Finally, this panel was carried into a gas sealing / sealing chamber, and after neon / helium mixed gas was sealed in the space in the panel, the space in the panel was sealed.

<Comparative Example 1>
All processes of the PDP manufacturing method were performed in the atmosphere without performing the degassing process of the back plate. In this case, the sealing temperature was the same as in the example.

<Comparative example 2>
A PDP was produced in the same manner as in the example except that the back plate was degassed at the same temperature as the sealing temperature without introducing O ₂ gas.

(Analysis method)
The variation of the discharge voltage (V) was measured for the PDP of the example and the comparative example.

FIG. 4 is a graph showing the change over time in the discharge voltage of the PDP manufactured according to the example and the comparative examples 1 and 2.
As understood from FIG. 4, Comparative Example 1 which was manufactured in the atmosphere and did not degas the back plate started from the start of discharge until the discharge start voltage (Vf) and the minimum discharge sustain voltage (Vsm) were stabilized. It takes about 10 hours.

Further, in Comparative Example 2 in which the back plate was degassed at the same temperature as the sealing temperature without introducing O ₂ gas, the discharge was started until the discharge start voltage (Vf) and the minimum discharge sustain voltage (Vsm) were stabilized. It takes about 5 hours.
On the other hand, in the example, both the discharge start voltage (Vf) and the minimum sustain voltage (Vsm) are stable at values near 200 V and 155 V, respectively, immediately after the start of discharge.

  As is clear from the above, according to the present invention, it is possible to obtain a PDP in which the discharge voltage is already stable and aging is not required immediately after assembly.

The schematic block diagram which shows embodiment of the PDP manufacturing apparatus of this invention Internal configuration diagram of degassing treatment chamber of the same PDP manufacturing apparatus Process drawing explaining the procedure of embodiment of the manufacturing method of PDP of this invention The graph which shows the time change of the discharge voltage of PDP manufactured by the Example and Comparative Examples 1 and 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... PDP manufacturing apparatus 2 ... MgO film-forming chamber 3 ... Degassing treatment chamber 4 ... Alignment chamber 5 ... Sealing / cooling chamber 6 ... Gas enclosure / sealing chamber 20 ... Front plate (front substrate) 21 ... Back plate (back) Substrate) 22 ... PDP 23 ... sealing material 26 ... heating means

Claims (3)

A plasma display panel manufacturing method comprising a sealing step in which a front substrate and a rear substrate for a plasma display panel are sealed in a vacuum by heating at a predetermined temperature using a sealing material,
Before the sealing step, a first degassing step of evacuating the back substrate on which the sealing material is disposed at a temperature higher than the temperature in the sealing step in a vacuum processing tank; ,
A plasma display panel manufacturing method comprising: a second degassing step of introducing an oxidizing gas into the vacuum processing tank and heating the back substrate at a temperature higher than the temperature in the sealing step to perform vacuum evacuation .   The method for manufacturing a plasma display panel according to claim 1, wherein the partial pressure of the oxidizing gas in the vacuum processing chamber is controlled to be 2 kPa to 20 kPa. A plasma display panel manufacturing apparatus that has a plurality of vacuum processing tanks and sequentially processes and conveys the front substrate and the rear substrate in a vacuum to manufacture a plasma display panel,
As the vacuum processing tank, using the method according to claim 1, comprising a degassing processing tank for performing a degassing process on the back substrate,
The degassing treatment tank is configured to introduce an oxidizing gas, and has a pressure adjusting means for controlling a partial pressure of the introduced oxidizing gas, and a heating means for heating the back substrate,
The plasma display panel manufacturing apparatus comprised so that the back substrate degassed in the said degassing processing tank may be conveyed to the sealing tank which seals the said front substrate and the said back substrate.

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