JP2005142139A - Manufacturing method of display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of manufacturing a display panel of high quality at low cost without prolonging time for manufacture. <P>SOLUTION: On the manufacturing method of the display panel sealing a discharge space S by heating a sealing layer 7 formed so as to surround a discharge space S between a pair of front base plate 1 and back base plate 4 facing each other, and softening and bonding the sealing layer 7 to the base plate by fusion at a temperature not lower than a prescribed temperature, an exhausting process exhausting from the discharge space S and a process of introducing replacement gas into the discharge space S are carried out while the temperature for heating the sealing layer 7 increases in order to bond the sealing layer 7 by fusion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a display panel.

  FIG. 1 is a longitudinal sectional view showing a panel structure of an AC drive type reflection type plasma display panel (PDP) which is an example of a display panel.

  On the inner surface side of the front substrate 1 of this PDP, row electrodes X and Y each composed of transparent electrodes Xa and Ya made of ITO and bus electrodes Xb and Yb made of thick film electrodes such as silver are paired. A row electrode pair (X, Y), a dielectric layer 2 covering the row electrode pair (X, Y), and a protective layer 3 made of MgO or the like covering the dielectric layer 2 are formed.

  Further, on the inner surface side of the rear substrate 4 facing the front substrate 1, it extends in a direction intersecting with the row electrode pair (X, Y) and is in the discharge space S at a position intersecting with the row electrode pair (X, Y). A column electrode D constituting the discharge cell C, a column electrode protective layer 5 covering the column electrode D, and phosphors color-coded in red, green and blue for each discharge cell C on the column electrode protective layer 5 The layer 6 and the partition (not shown) which divides the discharge space S for each discharge cell C are formed.

  Then, in the discharge space S formed between the front substrate 1 and the back substrate 4 and having the peripheral edge sealed by the sealing layer 7, a mixed gas with neon Ne containing 5 to 10% xenon Xe is discharged. It is sealed as a gas.

  The phosphor layer 6 emits light when excited by vacuum ultraviolet rays (wavelength 147 nm) emitted from the Xe gas by discharge.

  FIG. 2 is a process explanatory diagram showing a conventional manufacturing method of the PDP having the above-described configuration, and FIG. 3 is a diagram showing a relationship between a temperature change in the baking furnace and a process elapsed time in the conventional manufacturing method. is there.

  Next, a conventional manufacturing method will be described with reference to FIGS.

  First, in the front substrate manufacturing step s1 of FIG. 2, the row electrodes X and Y are formed on the front substrate 1 by a photolithography method or the like, and then the dielectric layer 2 is formed by a screen printing method or the like. The protective layer 3 is formed by forming a film.

  On the other hand, in the back substrate manufacturing step s2, the column electrode D is formed on the back substrate 4 by a photolithography method or the like, and then the column electrode protective layer 5 by the screen printing method or the like and the partition by the sandblast method or the like are sequentially performed. After being broken, the phosphor layer 6 is formed by filling and baking the phosphor paste between the partition walls.

  Next, a glass frit for sealing is applied to the peripheral portion of the surface of the back substrate 4 manufactured as described above facing the front substrate 1 and pre-baked at a temperature of about 400 ° C. Thus, the sealing layer 7 is formed (step s3).

  Then, the back substrate 4 and the front substrate 1 on which the sealing layer is formed are opposed and overlapped so that the row electrodes X and Y of the front substrate 1 are orthogonal to the column electrodes D of the back substrate 4. (Step s4) In this state, the front substrate 1 and the back substrate 4 are put into a baking furnace (step s5).

  Thereafter, as shown in FIG. 3, when the temperature in the baking furnace is increased and the temperature reaches the sealing temperature t1 (about 450 ° C.), the sealing step in which the sealing temperature t1 is set in advance. During the sealing step period p1, the sealing layer 7 formed on the back substrate 4 is welded to the front substrate 1 by heating, so that the space between the back substrate 4 and the front substrate 1 is maintained. The periphery of the discharge space S formed is sealed (step s6).

  After the elapse of the sealing process period p1, when the temperature of the baking furnace is lowered to a predetermined temperature t2 (about 350 ° C.) lower than the sealing temperature t1, the glass frit of the sealing layer 7 is solidified in advance. This temperature t2 is maintained during the set exhaust / baking process period p2.

  Then, in the exhaust / baking process period p2, the front substrate 1 and the rear substrate 4 are heated (baked) at the temperature t2, and the exhaust from the discharge space S is performed to evacuate the discharge space S ( Step s7).

  When the evacuation / baking process period p2 elapses, the discharge gas is introduced into the discharge space S at a predetermined pressure (400 to 600 Toor) in a state where the temperature in the baking furnace is lowered to near normal temperature ( Step s8) After the introduction of the discharge gas, the exhaust pipe used for introduction of the exhaust gas and the discharge gas is sealed with a burner or the like (step s9).

  Then, a drive pulse is applied between the pair of row electrodes X and Y of the front substrate 1 to generate a discharge for a predetermined time, thereby activating the protective layer 3 formed on the front substrate 1 and stabilizing the discharge. (Aging) is performed (step s10) (see, for example, Patent Document 1).

In the conventional display panel manufacturing method as described above, in the sealing step s6 for sealing the discharge space S by the sealing layer 7, the space between the front substrate 1 and the rear substrate 4 during the sealing step period p1. Is filled with an impurity gas released from the substrate by the atmosphere and heating, and the inner surface side of each substrate is exposed to an impurity gas such as H ₂ O and CO ₂ under a high temperature condition.

  This is a very unfavorable state for the display panel in the manufacturing process, and the front substrate 1 has a problem that the degassing process for MgO forming the protective layer 3 is hindered. This causes a problem that the fluorescent material forming the phosphor layer 6 deteriorates.

  In order to avoid the occurrence of such a problem, the exhaust time from the discharge space S in the exhaust / baking process period p2 is set to be sufficiently long, and sufficient degassing from the protective layer (MgO) 3 and the deteriorated phosphor It is conceivable to adopt a technique such as recovery of the layer 6 or a technique such as vacuum sealing that seals the discharge space S in a vacuum environment.

  However, if the evacuation / baking process period p2 is set to be long in order to perform sufficient evacuation, the manufacturing time becomes very long. Also, in order to perform vacuum sealing, since the apparatus for that is large, This increases the manufacturing cost.

JP 2000-30618 A

  An object of the present invention is to solve the problems in the manufacturing process of the plasma display panel as described above.

  In order to achieve the above object, a method for manufacturing a plasma display panel according to a first aspect of the present invention surrounds an internal space between a pair of substrates opposed to each other with a predetermined interval. In the method of manufacturing a display panel, which heats the sealing material positioned at a position, and softens the sealing material at a predetermined temperature or higher and welds the sealing material to the substrate, thereby sealing the internal space between the pair of substrates. In the process of raising the temperature for heating the sealing material to a predetermined temperature or higher, an exhaust process for exhausting from the internal space between the pair of substrates, and a process for introducing a replacement gas into the internal space after the exhaust process It is characterized by being performed.

  In order to achieve the above object, a method for manufacturing a plasma display panel according to a second invention encloses an internal space between a pair of substrates opposed to each other at a predetermined interval. In the method of manufacturing a display panel, which heats the sealing material positioned at a position, and softens the sealing material at a predetermined temperature or higher and welds the sealing material to the substrate, thereby sealing the internal space between the pair of substrates. In the process of sealing between the pair of substrates by welding the sealing material, a depressurizing step is performed to depressurize the internal space between the pair of substrates.

  The present invention heats a sealing material positioned so as to enclose an internal space between a pair of substrates opposed to each other with a predetermined interval, and softens the sealing material at a predetermined temperature or more to form a substrate. In a method for manufacturing a display panel that seals an internal space between a pair of substrates by welding to each other, in a process in which a temperature for heating the sealing material is increased to a predetermined temperature or more, The best embodiment is a display panel manufacturing method in which an exhaust process for exhausting air from the internal space and a replacement gas introduction process to the internal space after the exhaust process are performed.

  According to the display panel manufacturing method of this embodiment, the sealing material is positioned so as to surround the internal space between the pair of substrates opposed to each other with a predetermined interval, for example, the pair of substrates is accommodated. When the temperature in the baking furnace is raised, the sealing material positioned between the pair of substrates is heated and welded to the substrate, thereby sealing the internal space.

  At this time, after the start of the increase in the heating temperature of the sealing material, a required temperature (for example, the sealing material is reached) until reaching the temperature at which the sealing material is welded by heating and the gap between the substrates is sealed. When the temperature reaches a temperature at which softening and melting starts, the exhaust from the internal space between the pair of substrates is performed via an exhaust pipe connected to one of the pair of substrates, for example, Thereafter, a replacement gas is introduced into the interior space where the exhaust is performed.

As the replacement gas, a gas not containing H ₂ O and CO ₂ is used. For example, an inert gas, a mixed gas of inert gas and hydrogen gas or oxygen gas, oxygen gas, nitrogen gas, fluorine gas, chlorine Various gases such as a gas, a mixed gas of nitrogen gas and hydrogen gas or oxygen gas, a mixed gas of fluorine gas and hydrogen gas or oxygen gas, and a mixed gas of chlorine gas and hydrogen gas or oxygen gas are used.

  According to the display panel manufacturing method of this embodiment, it is possible to obtain the same effect as that of manufacturing a display panel using a vacuum sealing furnace, and to solve the problems in the conventional manufacturing method. I can do it.

That is, in the process of manufacturing the display panel, in the process of heating to seal the internal space between the pair of substrates, the exhaust in the internal space is exhausted before the heating temperature reaches the temperature for sealing the internal space. Since the impure gas discharged from the substrate side by the atmosphere and heating that fills the internal space is discharged, degassing from, for example, the MgO layer formed on the substrate is promoted, Since the inner surface side of each substrate is prevented from being exposed to an impure gas such as H ₂ O and CO ₂ under high temperature conditions, for example, the phosphor layer formed on the substrate is prevented from being deteriorated. The panel performance (discharge characteristics) of the display panel can be greatly improved.

  And according to said manufacturing method, after sealing internal space, the said effect is set without setting the process time which exhausts from this internal space to a long time, or using a large-scale vacuum sealing apparatus. In addition, since the conventional manufacturing apparatus can be implemented with simple changes and modifications, the manufacturing cost does not increase significantly.

Furthermore, after the exhaust process when the heating temperature is increased, the pressure in the internal space in the manufacturing process is set to a desired value by adjusting the pressure of the replacement gas not containing H ₂ O and CO ₂ introduced into the internal space. The pressure can be maintained, whereby the distance between the pair of substrates facing each other can be arbitrarily adjusted.

  In the above embodiment, the process of introducing the replacement gas into the internal space between the exhausted substrates is performed in the process of increasing the heating temperature of the sealing material. Even when the replacement gas is not introduced simply by reducing the pressure of the substrate, the expansion of the internal space between the substrates due to heating is suppressed, and a uniform image display surface is formed and the impurity gas generated by heating is discharged. It is possible to prevent the deterioration of the constituent parts.

  FIG. 4 is a process explanatory view showing a first example in the embodiment of the display panel manufacturing method according to the present invention, and FIG. 5 shows the temperature change in the baking furnace and the elapsed time in the manufacturing method of the example. FIG. 6 is a schematic configuration diagram of a baking furnace used in the manufacturing method of the same example.

  The manufacturing process of FIG. 4 will be described with reference to FIG.

  First, a row electrode pair (X, Y) is formed on the front substrate 1 by a photolithography method or the like, and a dielectric layer 2 is formed by a screen printing method or the like so as to cover the row electrode pair (X, Y). Further, a protective layer (MgO layer) 3 covering the back surface of the dielectric layer 2 is formed (front substrate manufacturing step S1).

  On the other hand, a column electrode D is formed on the back substrate 4 by a photolithography method or the like, a column electrode protective layer 5 covering the column electrode D is formed by a screen printing method or the like, and a sand blast method or the like is formed on the column electrode protective layer 5. A partition wall for partitioning the discharge space S is formed, and a phosphor layer 6 is formed by filling and baking the phosphor paste between the partition walls (back substrate manufacturing step S2).

  When the front substrate manufacturing step S1 and the back substrate manufacturing step S2 are completed as described above, a sealing glass frit is then applied to the peripheral portion of the surface of the back substrate 4 facing the front substrate 1. And the sealing layer 7 is formed by baking at the temperature of about 400 degreeC (process S3).

After that, the front substrate 1 and the rear substrate 4 are overlapped with each other so that the row electrode pair (X, Y) and the column electrode D formed on each of the front substrate 1 and the rear substrate 4 are orthogonal to each other (step S4). In this state, as shown in FIG. 6, it is put into the baking furnace H, and the exhaust pipe 10 is connected to the exhaust hole formed in the back substrate 4 and sealed (step S5).

  An exhaust pump 11, a replacement gas introduction system 12, and a discharge gas introduction system 13 are connected to the exhaust pipe 10.

  In this state, heating in the baking furnace H is started, and as shown in FIG. 5, the temperature in the baking furnace H is formed on the back substrate 4 before reaching the sealing temperature t1 (about 450 ° C.). When the temperature t2 (about 350 ° C.) at which the glass frit of the sealing layer 7 starts to melt is exceeded, the exhaust pump 11 is driven to form a primary space from the discharge space S formed between the front substrate 1 and the rear substrate 4. Exhaust is started (step S6).

  At this time, the glass frit of the sealing layer 7 is in a stage where it starts to melt, and the discharge space S is sealed, but its fluidity is low, and even if the primary exhaust of step S6 is performed, The sealing layer 7 is not pulled into the discharge space S due to the negative pressure in the discharge space S.

  However, as the temperature in the baking furnace H rises, the fluidity of the sealing layer 7 increases, so that drawing into the discharge space S occurs. At a temperature t4 (t2 <t4 <t1) at which the temperature rises, the exhaust by the exhaust pump 11 is stopped, and then the replacement gas is introduced into the discharge space S from the replacement gas introduction system 12 through the exhaust pipe 10. Performed (step S7).

  As the replacement gas introduced in this step S7, a gas not containing H 2 O and CO 2 is used. For example, an inert gas, a mixed gas of inert gas and hydrogen gas or oxygen gas, oxygen gas, nitrogen gas, fluorine Various gases such as gas, chlorine gas, mixed gas of nitrogen gas and hydrogen gas or oxygen gas, mixed gas of fluorine gas and hydrogen gas or oxygen gas, mixed gas of chlorine gas and hydrogen gas or oxygen gas are used. The

  Here, when a trace amount of hydrogen gas (about 3% or less) is mixed with the inert gas, the recovery effect of the phosphor layer 6 can be obtained, and a small amount of oxygen gas (about 20% or less) is added to the inert gas. When is mixed, an effect of improving the film quality of the protective layer (MgO layer) 3 can be obtained.

  In addition, the introduction pressure of the replacement gas in this step S7 only needs to secure a pressure that can prevent the melted sealing layer 7 from being drawn into the discharge space S, for example, about 1/100 to atmospheric pressure of the atmosphere. Set to

  After this step S7, when the temperature in the baking furnace H reaches the sealing temperature t1, it is maintained for a preset sealing step period P1, and during this sealing step period P1, the back substrate 4 The sealing layer 7 formed in this manner is welded to the front substrate 1 by heating, so that the periphery of the discharge space S formed between the rear substrate 4 and the front substrate 1 is sealed (step S8).

  When the temperature of the baking furnace H is lowered from the sealing temperature t1 to the temperature t2 (about 350 ° C.) at which the glass frit of the sealing layer 7 is solidified after the sealing process period P1 has elapsed, the temperature is set in advance. This temperature t2 is maintained during the exhaust / baking process period P2.

  Then, in the exhaust / baking process period P2, secondary exhaust for exhausting gas from the discharge space S is performed while the front substrate 1 and the rear substrate 4 are heated (baked) at the temperature t2, and the discharge space S is evacuated. A vacuum is applied (step S9).

  Next, when the evacuation / baking process period P2 elapses, the temperature in the baking furnace H is further lowered and the discharge gas is kept at a predetermined pressure (400 to 400) in the discharge space S in a state in which the temperature is close to room temperature t3. 600 Toor) (step S10), and after the introduction of the discharge gas is completed, the exhaust and the exhaust pipe used for introducing the discharge gas are sealed by a burner or the like (step S11).

  Then, a drive pulse is applied between the pair of row electrodes X and Y of the front substrate 1 to generate a discharge for a predetermined time, thereby activating the protective layer 3 formed on the front substrate 1 and stabilizing the discharge. (Aging) is performed (step S12).

  With the display panel manufacturing method as described above, it is possible to obtain the same effect as that of manufacturing a display panel using a vacuum sealing furnace, and to solve the problems in the conventional manufacturing method.

That is, in the manufacturing process, after the heating in the baking furnace H is started and before the sealing process period P1, the discharge space S is evacuated so that the atmosphere is filled in the discharge space S and the substrate side is heated. By discharging the impure gas released from the substrate, degassing from the protective layer (MgO layer) 3 is promoted, and the inner surface side of each substrate is impure gas such as H ₂ O, CO ₂ under high temperature conditions. As a result, the phosphor layer 6 is prevented from deteriorating, which can greatly improve the panel performance (discharge characteristics) of the display panel.

  The above manufacturing method can exert the above effects without setting the evacuation / baking process period P2 to a long time or using a large-scale vacuum sealing apparatus. In addition, in the conventional manufacturing apparatus, Since it can be implemented with simple changes and modifications, the manufacturing cost will not increase significantly.

  Further, by adjusting the pressure of the replacement gas introduced into the discharge space S after the primary exhaust, the pressure in the discharge space S in the manufacturing process can be maintained at a desired pressure. It is possible to arbitrarily adjust the distance between 1 and the back substrate 4.

  Note that, when the primary exhaust of the above step S6 is performed or when the replacement gas is exhausted in the step S9, the exhaust pump 11 is driven in advance so that the inside of the exhaust pipe 10 is evacuated, and the steps S6 and S9 are performed. If the valve connecting the exhaust pump 11 and the exhaust pipe 10 is released at the start of exhaust, exhaust is performed at once, and the process time can be shortened.

  FIG. 9 is a graph showing the relationship between the exhaust pressure and the voltage life of the PDP in the primary exhaust process S6.

As shown in FIG. 9, in the primary exhaust step S6, the lower the primary exhaust pressure, the longer the voltage life of the PDP. In particular, by setting the primary exhaust pressure to be 1 × 10 ⁻² Pa or less. The voltage life of the PDP can be greatly extended.

  FIG. 10 is a graph showing the relationship between the concentration of oxygen gas to be introduced and the accelerating voltage life of the PDP when oxygen gas is introduced as a replacement gas in the replacement gas introduction step S7.

  As shown in FIG. 10, in the replacement gas introduction step S7, the higher the concentration of oxygen gas introduced as replacement gas, the longer the voltage life of the PDP, and oxygen gas alone (concentration 100%) is introduced as replacement gas. As a result, the voltage life of the PDP can be maximized.

If the mixing ratio of O ₂ is increased, the acceleration voltage life of the panel is extended, but in this case, the initial characteristics of the panel may be deteriorated.

Therefore, in order to achieve both the acceleration voltage life and the initial characteristics of the panel, for example, it is desirable that the replacement gas is a mixed gas of N ₂ and O ₂ and the mixing ratio of O ₂ is 35% or less, preferably about 30%. .

  FIG. 7 is a diagram showing the relationship between the temperature change in the baking furnace and the process elapsed time in the second example of the embodiment of the display panel manufacturing method according to the present invention.

  In the first embodiment described above, after the front substrate 1 and the back substrate 4 overlapped in step S5 are put into the baking furnace H, the temperature in the baking furnace H is continuously raised to the sealing temperature t1. In this example, the primary exhaust of step S6 and the introduction of the replacement gas in step S7 are performed at this stage, but in this example, after the superposed front substrate 1 and back substrate 4 are put into the baking furnace H, When the temperature rises and reaches a temperature t5 (t2 <t5 <t1) that slightly exceeds the temperature t2 at which the glass frit of the sealing layer 7 starts to melt, the temperature rise is stopped and the preset period P0 is reached. Meanwhile, the inside of the baking furnace H is maintained at the temperature t5.

  In this period P0, a primary exhaust process from the inside of the discharge space S between the front substrate 1 and the rear substrate 4 and a subsequent replacement gas introduction process are performed.

  Then, after the period P0 ends, when the temperature in the baking furnace H is increased again and reaches the sealing temperature t1, the same steps as in the first example described above are performed thereafter.

  According to the second example, the primary exhaust process and the replacement gas introduction process from the inside of the discharge space S are performed under a constant temperature condition, so that the display panel can be manufactured more stably. Thereby, the quality of the display panel can be further improved.

  Also in this example, the type of the substitution gas introduced in the substitution gas introduction step, and the relationship between the concentration when oxygen gas is introduced as the substitution gas and the acceleration voltage life of the PDP (FIG. 10) are: This is the same as in the case of the first embodiment.

  Furthermore, the relationship between the exhaust pressure in the primary exhaust process and the voltage life of the PDP (FIG. 9) is the same as in the case of the first embodiment.

  FIG. 8 is a diagram showing the relationship between the temperature change in the baking furnace and the process elapsed time in the third example of the embodiment of the display panel manufacturing method according to the present invention.

  In the first and second embodiments described above, primary exhaust and replacement gas are introduced after the superposed front substrate 1 and rear substrate 4 are put into the baking furnace H. After the front substrate 1 and the back substrate 4 thus formed are put into the baking furnace H (see FIG. 6), the temperature in the baking furnace H is raised, and the temperature t2 at which the glass frit of the sealing layer 7 starts to melt is set. If it exceeds, the pressure in the discharge space S between the front substrate 1 and the back substrate 4 is a predetermined value between 1 / 100th atmospheric pressure and atmospheric pressure during the period until the sealing process period P1 ends. Depressurization is performed until pressure is reached.

  That is, the pressure in the discharge space S to be reduced is such that the glass frit is drawn into the discharge space S in a state where the glass frit forming the sealing layer 7 is dissolved and the discharge space S is blocked from the outside air. It is set to a value that does not exist.

  This pressure reduction is performed in a predetermined period after the temperature in the baking furnace H reaches the temperature t2 at which the glass frit of the sealing layer 7 starts to melt and until the sealing step period P1 ends. For example, this pressure reduction is performed between the time when the temperature t2 is reached and the time when the temperature t1 is reached or between the time when the temperature t2 is reached and the end of the sealing process period P1.

As this decompression method,
(1) The pressure is reduced directly from the discharge space S to a predetermined pressure by the exhaust pump 11 (see FIG. 6).
(2) With the valve of the exhaust pipe 10 connected to the discharge space S closed, the inside of the exhaust pipe 10 is reduced (exhaust) to a pressure lower than the reduced pressure of the discharge space S, and then the exhaust pipe 10 To reduce the pressure in the discharge space S,
There are methods.

  The other steps are the same as those in the first embodiment, and the same explanation is given in FIG.

  According to the above manufacturing method, it is possible to manufacture a display panel capable of forming a uniform image by improving a partial defect in electric characteristics of the display panel, uneven light emission, and the like.

  Further, the manufacturing time can be shortened, and sufficient degassing from the protective layer (MgO) 3 (see FIG. 1) is performed by the reduced pressure in the discharge space S during the sealing step, so that the phosphor layer 6 It is possible to obtain a technical effect that deterioration of the resin is suppressed.

  And it becomes possible to carry out this manufacturing method easily by simply changing the conventional apparatus without requiring a large-scale apparatus.

  In the above-described embodiments and the above-described embodiments, the sealing material for forming the sealing layer 7 (see FIG. 6) has a melting point higher than the melting point of the sealing material and has a required size (for example, discharge It is preferable to mix spherical or columnar beads (for example, glass beads) having the same particle size or length as the partition walls defining the space S.

  In this way, by incorporating beads such as heat-resistant glass into the sealing material forming the sealing layer 7, the sealing layer 7 is crushed even by decompression due to exhaust from the discharge space S. Can be prevented.

It is sectional drawing which shows the general structure of a display panel. It is process explanatory drawing which shows the manufacturing method of the conventional display panel. It is a figure which shows the temperature change in the baking furnace in the conventional manufacturing method. It is process explanatory drawing which shows the 1st Example in embodiment of the manufacturing method of the display panel by this invention. It is a figure which shows the temperature change in the baking furnace in the example. It is a schematic block diagram of the baking furnace used for the manufacturing method of the example. It is a figure which shows the 2nd Example in embodiment of the manufacturing method of the display panel by this invention. It is a figure which shows the 3rd Example in embodiment of the manufacturing method of the display panel by this invention. It is a figure which shows the relationship between the primary exhaust pressure and the voltage lifetime of PDP in the manufacturing method of the display panel by this invention. It is a figure which shows the relationship between the oxygen gas concentration introduce | transduced as replacement gas in the manufacturing method of the display panel by this invention, and the voltage life of PDP.

Explanation of symbols

1 ... Front substrate (substrate)
3 ... Protective layer 4 ... Back substrate (substrate)
7 ... Sealing layer 10 ... Exhaust pipe 11 ... Exhaust pump 12 ... Replacement gas introduction system 13 ... Discharge gas introduction system

Claims (20)

Heating a sealing material positioned so as to surround an internal space between a pair of substrates opposed to each other with a predetermined interval, and softening the sealing material at a predetermined temperature or more to weld it to the substrate In the manufacturing method of the display panel that seals the internal space between the pair of substrates,
In the process in which the temperature for heating the sealing material is raised to a predetermined temperature or higher, an exhaust process for exhausting air from the internal space between the pair of substrates, and introduction of a replacement gas into the internal space after the exhaust process A method of manufacturing a display panel, characterized in that a process is performed.   The display panel manufacturing method according to claim 1, wherein the exhausting step and the replacement gas introducing step are performed in a process in which a temperature for heating the sealing material is continuously increased.   The display panel manufacturing method according to claim 2, wherein the exhausting step and the replacement gas introducing step are performed when the heating temperature to be raised reaches a substantially softening start temperature of the sealing material.   When the heating temperature rises to a required temperature lower than the temperature at which the sealing material is welded to the substrate, the rise in the heating temperature is temporarily stopped, while the rise in the heating temperature is stopped, The method of manufacturing a display panel according to claim 1, wherein the step of introducing a replacement gas is performed.   The method for manufacturing a display panel according to claim 4, wherein the temperature at which the increase in the heating temperature is temporarily stopped is a substantially softening start temperature of the sealing material.   The display panel manufacturing method according to claim 4, wherein the heating temperature is maintained at the required temperature while the increase in the heating temperature is temporarily stopped and the exhaust process and the replacement gas introduction process are performed.   The internal space between the pair of substrates when the heating temperature is raised to a temperature at which the exhaust process is performed in a state where the exhaust member connected to the internal space between the pair of substrates is in a negative pressure state in advance. The method for manufacturing a display panel according to claim 1, wherein the exhaust process is performed by communicating the exhaust member with the exhaust member.   The method for manufacturing a display panel according to claim 1, wherein the replacement gas contains hydrogen gas.   The method for manufacturing a display panel according to claim 8, wherein a ratio of the hydrogen gas is 3% or less of a replacement gas.   The display panel manufacturing method according to claim 1, wherein the replacement gas contains oxygen gas.   The method for manufacturing a display panel according to claim 10, wherein a ratio of the oxygen gas is 20 percent or less of a replacement gas. The display panel manufacturing method according to claim 1, wherein an exhaust pressure in the exhaust process is 1 × 10 ⁻² Pascal or less.   The display panel manufacturing method according to claim 1, wherein a replacement gas having an oxygen gas concentration of 100 percent is introduced in the replacement gas introduction step. Heating a sealing material positioned so as to surround an internal space between a pair of substrates opposed to each other with a predetermined interval, and softening the sealing material at a predetermined temperature or more to weld it to the substrate In the manufacturing method of the display panel that seals the internal space between the pair of substrates,
A method of manufacturing a display panel, wherein a depressurizing step of depressurizing an internal space between the pair of substrates is performed in a process of sealing the pair of substrates by welding the sealing material.   15. In the decompression step, exhaust is performed from an internal space between a pair of substrates until the pressure in the internal space reaches a predetermined pressure between atmospheric pressure and a pressure approximately 1/100 of the atmospheric pressure. The manufacturing method of the display panel as described in any one of.   The method of manufacturing a display panel according to claim 14, wherein exhaust in the decompression step is performed in a process in which a temperature for heating the sealing material is continuously increased.   The method for manufacturing a display panel according to claim 14, wherein exhaust in the decompression step is performed after the heating temperature reaches a substantially softening start temperature of the sealing material.   The display panel manufacturing method according to claim 14, wherein a sealing layer having a height substantially equal to a distance between the pair of substrates is formed by the sealing material, and a granular material having a high melting point is mixed in the sealing layer. Method.   19. The method of manufacturing a display panel according to claim 18, wherein the particulate material is glass beads having a melting point higher than that of the sealing material.   The method for manufacturing a display panel according to claim 19, wherein the glass beads have a spherical or cylindrical shape.

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