JPH11149865A - Manufacture of plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a plasma display that aging time is shortened and has superior sputtering resistance performance during an operation, i.e., having a long life. SOLUTION: A manufacturing process for a plasma display panel consists of a forming process for a front substrate, a forming process for a back substrate, and assembling process. The forming process for the front substrate consists of a forming process (a) for a scanning/holding electrode, a forming process (b) for a dielectric layer, a forming process for a first protection coating, and a forming process for a second protection coating. The forming process for the back substrate consists of a forming process (e) for a data electrode, a forming process (f) for a bulkhead, and a forming process (g) for a phosphor. The assembling process consists of a sealing process (h), a discharge process, a discharge gas sealing process (j), and an aging process (k). The second protection coating is a coating that can be sputter more easily than the first protection coating, which is removed in the aging process (k).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a plasma display panel (hereinafter, referred to as PDP) used for displaying images on a television or a computer.

[0002]

2. Description of the Related Art A conventional process of manufacturing an AC type PDP is roughly divided into a process of forming a front substrate, a process of forming a rear substrate, and a process of assembling them. The step of forming the front substrate includes a step of forming a scan electrode and a sustain electrode, a step of forming a dielectric layer, and a step of forming a protective film. On the other hand, the step of forming the back substrate includes a step of forming a data electrode, a step of forming a partition, and a step of forming a phosphor. The assembling process includes a sealing process, an exhausting process, a discharge gas sealing process, and an aging process. When the aging process is completed, a panel is completed.

[0003] The step of forming a protective film is a step of forming a protective film on the dielectric layer in order to protect the dielectric layer from ion bombardment due to discharge. As a material of the protective film, magnesium oxide (Mg) formed by electron beam evaporation or the like is used.
O) is used. Since the MgO film formed by electron beam evaporation or the like under predetermined conditions is a highly crystalline and dense film, the dielectric layer formed on the scan electrode or the sustain electrode is subjected to ion collision during discharge. Sputtering and wear can be prevented by the MgO film.
Helium (He), neon (N
A mixture of two or more rare gases such as e), argon (Ar) and xenon (Xe) is generally used.

[0004]

However, such a conventional method of manufacturing an AC type PDP has a problem that the aging process requires a long time. That is, a protective film that is required to be a film having excellent sputter resistance is not easily cleaned in the aging step, which is the final step. In particular, when an MgO film is used as a protective film, the MgO film reacts with moisture in the air, carbon dioxide (CO ₂ ), etc. before the discharge gas sealing step, and magnesium hydroxide (Mg (OH) ₂ ) Magnesium carbonate (MgCO ₃ )
Such compounds precipitate on the surface of the MgO film. The purpose of aging is to remove such compounds and to obtain clean MgO
The surface is exposed on the surface of the MgO film. However, the MgO film formed by the conventional manufacturing method whose main purpose is to increase spatter resistance during operation of the AC type PDP requires a long time for the aging process. I was

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to reduce the time required for an aging process and to provide an AC type plasma having excellent spatter resistance during operation of a PDP, that is, a long life. It is an object to obtain a method for manufacturing a display panel.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a plasma display panel having two substrates disposed opposite to each other with a discharge space therebetween, wherein an electrode and a dielectric layer are sequentially formed on one of the substrates. Then, a first protective film is formed on the dielectric layer, and a second protective film that is more easily sputtered than the first protective film is formed on the first protective film. According to this manufacturing method, the second protective film is a film that is easily sputtered by aging, so that an AC plasma display panel having a short aging step and a long life can be obtained.

In another method for manufacturing a plasma display panel according to the present invention, a substrate formed on a surface of a substrate is transported above the target in a film forming chamber provided with the target. A first protective film and a second protective film are sequentially and sequentially formed on the layer, and a line connecting the center of the surface of the substrate and the surface of the target,
When the angle formed with the central axis of the substrate is a forming angle,
The forming angle at the time of forming the first protective film is set smaller than the forming angle at the time of forming the second protective film. According to this manufacturing method, the formation time of the first protective film and the second protective film can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

There are various types of AC-type PDPs, and an embodiment of the present invention will be described by taking a surface discharge AC-type PDP as an example.

FIG. 1 shows a surface discharge AC type PDP according to the present invention.
Shows the manufacturing process of the front substrate forming process,
The process is roughly divided into a rear substrate forming process and an assembling process. The front substrate forming step includes a scanning electrode / sustaining electrode forming step a, a dielectric layer forming step b, a first protective film forming step c, and a second protective film forming step d. On the other hand, the process of forming the back substrate includes a process e of forming a data electrode, a process f of forming a partition, and a process g of forming a phosphor. The assembling process includes a sealing process h, an evacuation process i, a discharge gas filling process j, and an aging process k. When the aging process k is completed, the panel is completed.

FIG. 2 is a partially cutaway perspective view of the AC type PDP before the aging step k.

Front substrate 1 made of a transparent material such as glass
A plurality of pairs of strip-shaped scanning electrodes 2 and sustaining electrodes 3 are formed in parallel with each other, and a dielectric layer 4 such as glass is formed to cover the scanning electrodes 2 and the sustaining electrodes 3. A first protective film 5 and a second protective film 6 are sequentially formed.

On a back substrate 7 made of glass or the like, strip-shaped data electrodes 8 are formed parallel to each other in a direction perpendicular to the scanning electrodes 2 and the sustaining electrodes 3. Partition walls 9 are formed between the data electrodes 8 in parallel with each other, and the phosphor 1 extends from above the data electrodes 8 to the side surfaces of the partition walls 9.
0 is formed.

The peripheral portions of the front substrate 1 and the back substrate 7 are sealed with glass frit, and a discharge space 11 formed between the front substrate 1 and the back substrate 7 has helium (H).
e), a mixed gas of at least one of neon (Ne) and argon (Ar) and xenon (Xe) is sealed.

By aging the AC-type PDP thus configured, the second protective film 6 is sputtered, and the completed AC-type PDP does not have the second protective film 6.

As the first protective film 5, a magnesium oxide (MgO) film formed by electron beam evaporation or the like is used. Since the MgO film thus formed is a dense film having high crystallinity, the MgO film protects the dielectric layer 4 from ion collision due to discharge during the operation of the AC PDP, and the dielectric layer 4 is sputtered by the ion collision. Wear can be prevented.

This AC type PDP is designed to view an image display from the front substrate 1 side which is a display surface side, and ultraviolet rays generated by a discharge between the scanning electrode 2 and the sustain electrode 3 in the discharge space 11 generate ultraviolet rays. The phosphor 10 is excited, and visible light from the phosphor 10 is used for display light emission.

Next, a method for forming the first protective film 5 and the second protective film 6 will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 3 shows a PD according to the present invention.
It is sectional drawing explaining the method of forming the protective film of P. The scanning electrode 2, the sustaining electrode 3, the dielectric layer 4, and the like formed on the front substrate 1 are omitted. The same applies to the drawings describing the manufacturing method described below. In FIG. 3, MgO
The film forming apparatus 20 includes a substrate heating chamber 21, a first film forming chamber 22,
It comprises a cooling chamber 23 and a second film forming chamber 24.
The front substrate 1 on which the dielectric layer 4 and the like are formed is first heated to a temperature of 200 ° C. or higher by the heater 25 in the substrate heating chamber 21 and sent to the first film forming chamber 22. First deposition chamber 2
In Step 2, about 5 mm is deposited on the dielectric layer 4 by a method such as electron beam evaporation.
A first protective film 5 made of a MgO film having a thickness of 000 mm is formed by an evaporation source (target) 26. During the formation of the MgO film, the temperature of the front substrate 1 (hereinafter referred to as the substrate temperature) is 20
Since the temperature is maintained at 0 ° C. or higher, the MgO film is dense and has good crystallinity.

Subsequently, after the front substrate 1 is cooled to room temperature in the cooling chamber 23, it enters the second film forming chamber 24, and the second protective film 6 is formed on the first protective film 5 by the evaporation source 27. . In the second film forming chamber 24, the substrate temperature is kept at about room temperature, so that the MgO film of the second protective film 6 has poor crystallinity and coarse film quality. For this reason, the second protective film 6 becomes a film that is easily sputtered by aging.

The front substrate 1 completed in this way is combined with the rear substrate 7 and aging is performed after the discharge gas is filled.

The MgO film is formed at a substrate temperature of 200.degree.
If it is formed about 00 °, the operating life (Mg
It is known that the time until the O film is sputtered by discharge and consumed is obtained. On the other hand, in aging, a load approximately 10 times that in normal operation is applied, and therefore, the rate of decrease of the MgO film due to aging is estimated to be about 1 / hour. Since the conventional technology requires an aging time of about 20 hours, the thickness of the MgO film to be removed by aging is about 20 °. This can be considered to be the thickness of the layer that is deteriorated by exposing the MgO film to the atmosphere. Therefore, when the second protective film 6 which is more easily sputtered than the first protective film 5 is formed on the first protective film 5 with a thickness of about 20 ° by the above-described method, the aging can be performed in a shorter time than in the conventional case, and the cleaning can be performed more cleanly. In addition, the first protective film 5 that is not easily sputtered can be exposed.

According to the experiments of the present inventors, the second protective film 6 formed by electron beam evaporation while maintaining the substrate temperature of the front substrate 1 at 30 to 40 ° C. can be aged for about 2 to 3 hours. Thus, the first protective film 5 was completely exposed. FIG. 4 shows an A fabricated according to the present embodiment.
FIG. 9 is a diagram illustrating a relationship between an aging time and an operating voltage of a C-type PDP together with a case of a conventional example. A solid line 28 is for the present embodiment, and a solid line 29 is for the conventional example.
Aging is completed when the operating voltage of the AC PDP converges to a constant value. It can be seen that in the case of the conventional example, aging required 20 hours or more, whereas in the case of the present embodiment, aging was completed within 3 hours.

(Embodiment 2) FIG. 5 shows a method for forming a protective film according to a second embodiment of the present invention.
The film forming apparatus 30 includes a substrate heating chamber 21, a film forming chamber 31, and a cooling chamber 32.

The front substrate 1 on which the dielectric layer 4 and the like are formed
First, in the substrate heating chamber 21, 200
It is heated to a temperature of not less than ° C. and sent to the film forming chamber 31. In the film forming chamber 31, after the first protective film 5 is formed on the dielectric layer 4 to a thickness of about 5000 ° by the evaporation source 33, the front substrate 1
Is once sent to the cooling chamber 32 and cooled to room temperature.
Subsequently, in the film forming chamber 31 again, the second protective film 6 is formed with a thickness of about 20 ° on the first protective film 5 by the deposition source 33. In this case, the transport speed of the front substrate 1 in the film forming chamber 31 is set faster than the transport speed of the front substrate 1 when forming the first protective film 5.

After the formation of the second protective film 6, the front substrate 1 is taken out without passing through the substrate heating chamber 21, and the step of forming the front substrate is completed.

As described above, in the present embodiment, the second protective film 6 which can be easily removed by aging can be formed with a thickness of about 20 °.
The aging time is greatly reduced, and a long-life AC PDP can be obtained.

(Embodiment 3) The third embodiment of the present invention uses the same MgO film forming apparatus as that of the first embodiment shown in FIG. 6 are different in the formation conditions.

That is, in the present embodiment, the second film forming chamber 2
By setting the atmosphere of 4 higher than the atmosphere of the first film forming chamber 22, the second protective film 6 which is more easily sputtered than the first protective film 5 is formed. Usually, the MgO film is formed in a reduced pressure atmosphere (air of up to 1 × 10 ⁻⁶ torr).
In forming the protective film of the AC type PDP, a slight amount of oxygen is introduced to keep the stoichiometry of the MgO film close to 1. This oxygen partial pressure is adjusted to a predetermined value (about 1 × 10 ⁻³ torr).
The MgO film formed in the above-described elevated atmosphere becomes a porous film and is easily removed by aging.

In this embodiment, as in the first embodiment, the temperature of the front substrate 1 is reduced to about room temperature when the second protective film 6 is formed.
Can be further reduced in spatter resistance.

(Embodiment 4) FIG. 6 is a sectional view for explaining a method of forming a protective film according to a fourth embodiment of the present invention. As shown in FIG. It comprises a film forming chamber 37 provided with the deposition-preventing plates 35a, 35b and 35c and an evaporation source 36, and a substrate heating chamber 21.
The evaporation source 36 is provided vertically below a slit 38a provided between the deposition-inhibiting plates 35a and 35b, and a slit 38b is provided between the deposition-inhibiting plates 35b and 35c. ing.

The front substrate 1 on which the dielectric layer 4 is formed is first heated to 200 ° C. by the heater 25 in the substrate heating chamber 21.
It is heated to the above temperature and sent to the film forming chamber 37. In the film forming chamber 37, an MgO film is formed by a method such as electron beam evaporation. First, when the front substrate 1 passes above the slit 38a, the MgO film is formed on the dielectric layer 4 by the evaporation source 36.
A first protective film 5 made of a film is formed to a thickness of about 5000 °. During this time, the front substrate 1 is continuously conveyed, but the front substrate 1 that has passed above the slit 38a is
5b, the deposition source 36 is isolated from the deposition source 36, and the deposition of the MgO film is temporarily stopped. Thereafter, the front substrate 1 passes above the slit 38b, and the second protective film 6 made of an MgO film is formed on the first protective film 5. Since the second protective film 6 is formed in a state in which the angle at which the vapor deposition source 36 is seen is shallow, the gap between the crystal grain boundaries is large. Such an MgO film is inferior in spatter resistance to a dense film formed above the slit 38a, and can be easily removed by aging, so that aging can be completed in a short time.

Further, in the present embodiment, since there is no need to cool the front substrate 1 between the formation of the first protection film 5 and the formation of the second protection film 6, the first protection film 5 and the second protection film Protective film 6
Can be shortened. Further, since the first protective film 5 and the second protective film 6 can be formed in the single film forming chamber 37, the production efficiency can be improved.

In the present embodiment, as shown in FIG. 7, an angle θ between a line segment 41 connecting the center 40 of the surface of the front substrate 1 and the surface of the vapor deposition source 36 and a central axis 42 of the front substrate 1 is formed. Is the forming angle, the forming angle θ at the time of forming the first protective film 5 is set smaller than the forming angle θ at the time of forming the second protective film 6, so that the second protective film 6 The gap between crystal grain boundaries is larger than that of the protective film 5, and the film is easily sputtered. In the above description, the first protective film 5 and the second protective film 6 are continuously formed in the same film forming chamber 37. However, the formation angle θ in the second film forming chamber 24 shown in FIG. It is also possible to increase the size and form the second protective film 6.

In each of the embodiments of the present invention, the method of forming the protective film by electron beam evaporation has been described, but sputtering may be employed. Also, the example of MgO as the material of the protective film has been described, but calcium oxide (C
Materials other than MgO, such as aO) and strontium oxide (SrO), can also be used.

[0036]

As described above, according to the present invention, the first protective film is formed on the dielectric layer covering the electrode, and the first protective film is more easily sputtered than the first protective film. By forming the second protective film, it is possible to provide a manufacturing method for greatly shortening the aging time and obtaining an AC type plasma display panel having a long operating life.

[Brief description of the drawings]

FIG. 1 is a process diagram of a method for manufacturing a plasma display panel according to the present invention.

FIG. 2 is a partially cutaway perspective view of a plasma display panel before an aging step according to the present invention.

FIG. 3 is a cross-sectional view illustrating a step of forming a protective film according to the first embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between aging time and operating voltage of a plasma display panel according to the present invention and a conventional manufacturing method.

FIG. 5 is a sectional view illustrating a step of forming a protective film according to a second embodiment of the present invention.

FIG. 6 is a sectional view illustrating a step of forming a protective film according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a formation angle when a protective film is formed in Embodiment 4 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 front substrate 2 scan electrode 3 sustain electrode 4 dielectric layer 5 first protective film 6 second protective film 7 back substrate 8 data electrode 9 partition 10 phosphor 11 discharge space 20, 30, 34 MgO film forming device 21 substrate heating chamber 22 First film forming chamber 23, 32 Cooling chamber 24 Second film forming chamber 26, 27, 33, 36 Evaporation source 31, 37 Film forming chamber 35a, 35b, 35c Deposition plate 38a, 38b Slit 40 Surface of front substrate Center 42 Center axis of front substrate

Claims (9)

[Claims] 1. A method of manufacturing a plasma display panel having two substrates disposed to face each other with a discharge space therebetween, wherein an electrode and a dielectric layer are sequentially formed on one substrate, and Forming a first protective film, and further forming a second protective film on the first protective film that is easier to sputter than the first protective film. 2. A substrate on which a dielectric layer is formed is heated to form a first protective film on the dielectric layer, and after cooling the substrate, a second protective film is formed on the first protective film. The method for manufacturing a plasma display panel according to claim 1, wherein a film is formed. 3. An atmosphere in a film forming chamber for forming a first protective film on a dielectric layer is controlled by a pressure of an atmosphere in the film forming chamber for forming a second protective film on the first protective film. 3. The method for manufacturing a plasma display panel according to claim 1, wherein the height is set to be higher. 4. The method according to claim 1, wherein the forming of the first protective film on the dielectric layer and the forming of the second protective film on the first protective film are performed in an atmosphere containing oxygen. 4. The oxygen partial pressure in the atmosphere of (1) is set higher than the oxygen partial pressure in the atmosphere when the first protective film is formed.
The method for manufacturing a plasma display panel according to any one of the above. 5. A first protective film is formed on a dielectric layer formed on a surface of a substrate in a film forming chamber provided with a target,
In the film forming chamber or a film forming chamber provided with a different target from the film forming chamber, a second protective film is formed on the first protective film, and the center of the surface of the substrate and the surface of the target are formed. When the angle formed between the line segment connecting the first protective film and the central axis of the substrate is defined as the forming angle, the forming angle when forming the first protective film is larger than the forming angle when forming the second protective film. The method for manufacturing a plasma display panel according to any one of claims 1 to 4, wherein the plasma display panel is set to be small. 6. A first protective film and a second protective film are formed on a dielectric layer formed on a surface of the substrate by transporting the substrate above the target in a film forming chamber provided with the target. Formed successively successively, when an angle between a line segment connecting the center of the surface of the substrate and the surface of the target and a central axis of the substrate is defined as a formation angle, when forming the first protective film, The method according to claim 1, wherein the forming angle is set to be smaller than the forming angle when the second protective film is formed. 7. The method for manufacturing a plasma display panel according to claim 1, wherein the first protective film is a magnesium oxide film. 8. The method according to claim 1, wherein the first protective film is formed by electron beam evaporation or sputtering.
8. The method for manufacturing a plasma display panel according to any one of items 7 to 7. 9. An electrode and a dielectric layer are sequentially formed on a substrate, a first protective film is formed on the dielectric layer, and a sputter is formed on the first protective film more than on the first protective film. Forming a second protective film that is easily formed, sealing the substrate and another substrate so as to oppose each other with a discharge space therebetween, and filling a discharge gas into the discharge space to constitute a plasma display panel;
A method of manufacturing a plasma display panel, comprising removing the second protective film by aging the plasma display panel.