JPH08293253A - Manufacture of plasma display panel - Google Patents

Abstract

PURPOSE: To stabilize the characteristics of a plasma display panel by covering electrode ends with conductive layers, then introducing a discharge gas during evacuation of an internal space, then causing a discharge within the space by application of voltages to the electrodes through the conductive layers, then re-evacuating the space, and then introducing and sealing the discharge gas inside the space. CONSTITUTION: A plurality of electrodes Y are arranged on a glass substrate 11 and entirely covered with heat-resisting protective layers 17, 50. The substrate 11 and another substrate 21 are opposed to each other with the ends 43 of the electrodes Y projecting from the edge of the substrate 21, and are integrated together to form an internal space 30. The space 30 is connected to an evacuation device to effect evacuation and baking. A current-carrying probe is attached to the conductive heat-resisting layer 50 at the ends 43, and when the temperature of the substrate 11 reaches 350 deg.C the evacuation is stopped, a discharge gas is introduced, and a discharge is caused by application of voltages to the electrodes Y to purify the space 30. After evacuation is performed again to expel impurities, the discharge gas is newly introduced and the space 30 is sealed.

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 PDP (plasma display panel). The PDP is a thin display device capable of high-speed display, and is attracting attention as a large color display device for high-definition video.
As the PDP market expands, the importance of technology for manufacturing PDPs with stable characteristics and high quality is increasing.

[0002]

2. Description of the Related Art FIG. 5 is a cutaway perspective view showing the appearance of a PDP. In FIG. 5, the PDP 1 is a pair of substrates (usually glass plates) 11 and 21 facing each other with the discharge space 30 in between.
It is a display panel having a structure based on.

A plurality of electrodes (not shown) are arranged at a predetermined pitch on the inner surfaces of one or both of the substrates 11 and 21.
The display area EH is defined by these electrodes. Further, the electrodes are led out from the discharge space to the edge portion of the substrate and connected to an external drive circuit by a flexible wiring board. In order to enable connection with the drive circuit, each substrate 11,
The size and the facing arrangement position of 21 are set such that both end edges of each of the pieces 21 project outward from the end edge of the other substrate.

In manufacturing the PDP 1, electrodes and other constituent members are separately provided on the front substrate 11 and the rear glass substrate 21, and then a frame-shaped low melting point is used as a sealing material on the surface of one substrate. The glass layer 40 is provided. Then, the two substrates 11 and 21 are overlapped and heated to about 400 to 450 ° C. while being pressed against each other. This allows
The substrates 11 and 21 are integrated by fusion to form the discharge space 30.
Is formed.

Following the integration of the glass substrates 11 and 21,
The discharge space 30 is evacuated and filled with discharge gas. For this reason, one substrate (usually the back side) 21 is provided with a through hole 25 having a diameter of about 5 mm in advance, and a glass tube (chip having a length of about several cm) is provided on the outer surface of the glass substrate 21 prior to evacuation. The tube 60 is fused. That is, the tip tube 60 is attached as a part of the pipe for connecting the discharge space 30 and the vacuum pump (or the discharge gas cylinder), and exhaust and gas filling are performed through the through hole 25 and the tip tube 60. After filling the discharge gas, the tip tube 60 is melted and cut so as to close the ventilation passage, and at that time, the discharge space 30 is completely sealed.

Among the PDPs manufactured as described above, in the AC type PDP which utilizes wall charges for discharge, the electrodes are covered with a dielectric (usually low melting point glass) with respect to the discharge space 30.

Conventionally, in manufacturing the AC type PDP 1, when the electrode is made of a metal thin film such as Cr / Cu / Cr, the end portion of the electrode (that is, the portion led to the outside of the discharge space 30) is included. The dielectric layer was provided so as to cover the entire electrode. Then, at a stage after the pair of substrates are integrated and the discharge space is sealed, the dielectric layer covering the ends of the electrodes is removed in order to enable conductive connection between the electrodes and the outside.

By covering the entire electrode with the dielectric layer in this manner, it is possible to prevent oxidation in the heat treatment for sealing the substrate. That is, the dielectric layer is 60
It has heat resistance to heat of about 0 ° C. and is used as an electrode protective layer for preventing deterioration of the electrode (metal thin film) due to heat at the manufacturing stage of PDP.

If the heat treatment is carried out with the electrodes exposed, it is necessary to carry out the treatment in an inert atmosphere, resulting in a significant decrease in productivity.

[0010]

By the way, in the PDP 1, it is desirable to reduce impurities remaining in the discharge space 30 as much as possible. If impurities such as water and carbon dioxide remain, the discharge characteristics become unstable and seizure easily occurs.

Conventionally, in order to improve the efficiency of cleaning the discharge space 30, the substrates 11 and 21 have been heated to about 350 ° C. and exhausted. However, it was difficult to remove impurities sufficiently with heat energy of about 350 ° C.

Therefore, it can be considered to physically and chemically remove the impurities by discharge (plasma). The cleaning by the discharge is more effective if it is performed especially during baking (vacuum heat treatment) in which the inner wall surface is in an active state.

However, in the prior art, since the entire electrode was covered with the dielectric layer (insulating layer) at the exhausting step, the inside could not be cleaned by electric discharge. The present invention has been made in view of this problem, and an object of the present invention is to manufacture a PDP having stable characteristics by cleaning the discharge space by discharge without degrading the electrodes.

[0014]

According to a first aspect of the present invention, as shown in FIGS. 1 and 2, a plurality of electrodes are arranged on a first substrate, and the entire electrodes are protected against heat. After being covered with a layer, the first substrate and the second substrate are arranged so as to face each other so that the end portions of the respective electrodes project from the end edges of the second substrate. Is formed into an internal space for discharge, and the internal space is evacuated in a state where the first and second substrates are heated. A layer having conductivity is formed as a layer of a portion covering the end portion of each electrode, and a discharge gas is introduced into the internal space at a stage of exhausting the internal space to improve the conductivity. Before applying a voltage to each of the electrodes through the layer having the first and second substrates in a heated state. After causing discharge within the interior space, it is again how the exhaust of the internal space by performing introducing a discharge gas, to completely seal the interior space.

According to a second aspect of the present invention, the conductive layer is formed so as to extend over the end portions of all the electrodes,
The voltage is applied to all the electrodes at once through the conductive layer to generate a discharge, and the internal space is completely sealed, and then the conductive layer is removed.

[0016]

In the course of manufacturing the PDP, the end portion of the electrode is separated from the outside air by the heat-resistant protective layer having conductivity, and deterioration due to chemical change (oxidation) during heating is prevented.

Since the electrodes can be electrically connected to the external power source through the heat-resistant protective layer having conductivity,
A discharge can be generated with the electrodes protected.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partial sectional view of a PDP 1 according to the present invention,
FIG. 2 is a plan view of a main part of the PDP 1. 3 is an exploded perspective view of the PDP 1 according to the present invention, showing one pixel EG
The basic structure of the part corresponding to is shown. In these figures, the same reference numerals are given to the constituent elements corresponding to FIG.

The PDP 1 is a surface discharge type PDP having a three-electrode structure in which a pair of display electrodes X and Y and an address electrode A correspond to a unit light emitting region EU of a matrix display as shown in FIG. It is called a reflective type after being classified.

The display electrodes X and Y for surface discharge are provided on the glass substrate 11 on the display surface H side (front side), and are covered with the dielectric layer 17 in the discharge space 30.
On the surface of the dielectric layer 17, a MgO film 18 having a thickness of about several thousand Å is provided. The discharge space 30 is the glass substrate 1
Sealing glass 40 for fusion bonding around the facing regions of 1, 21
(See FIG. 1).

Further, since the display electrodes X and Y are arranged on the display surface H side with respect to the discharge space 30, the surface discharge is made wide and the shielding of the display light is minimized. The transparent conductive film 41 has a wide width and a metal film 42 having a narrow three-layer structure (Cr / Cu / Cr) for compensating for the conductivity.

The metal film 42 of each of the display electrodes X and Y is led out to the end edge portion of the glass substrate 11 for connection with the driving system as shown in FIG. 1, and the tip (hatched in FIG. 1 is attached). The portion) is formed wide as the connection terminal 43 as shown in FIG.

On the other hand, the address electrode A for selectively emitting light in the unit light emitting area EU is a thick film electrode and is arranged on the rear glass substrate 21 at a constant pitch so as to be orthogonal to the display electrodes X and Y. It is arranged. Stripe-shaped barrier ribs 29 having a height of about 120 to 150 μm are provided between the address electrodes A, whereby the discharge space 30 is formed.
Are divided in the line direction for each unit light emitting region EU, and the gap size of the discharge space 30 is defined.

Further, the glass substrate 21 is covered with R (red), G (green), and B (blue) so as to cover the inner surface of the rear surface including the upper surface of the address electrode A and the side surface of the partition wall 29. A primary color phosphor 28 is provided. The phosphor 28 of each color is
When the surface discharge occurs, the discharge gas in the discharge space 30 is excited by the ultraviolet rays emitted to emit light. The PDP 1 is capable of full-color display by combining R, G, and B.

In manufacturing the PDP 1, the display electrode Y
Are protected by the dielectric layer 17 made of low melting point glass and the conductive heat-resistant layer 50. The conductive heat-resistant layer 50 is obtained, for example, by firing a silver paste or a conductive paste containing silver and lead glass as a main component, and covers the connection terminals 43 located outside the sealing material 40. In this embodiment, as shown in FIG. 2, the conductive heat-resistant layer 50 is formed so as to extend over the connection terminals 43 at the tips of all the metal films 42 constituting the display electrode Y.
This allows a voltage to be applied to each display electrode Y at once. The display electrode X is wholly protected by the dielectric layer 17.

After covering the display electrodes X and Y, the dielectric layer 1 is formed.
A MgO film 18 is formed on the surface of No. 7 by vacuum evaporation.
Then, the glass substrate 11 having the display electrodes X and Y, and the glass substrate 2 on the back side on which the address electrodes A and the like are separately provided.
1 and 1 are arranged so as to face each other so that the connection terminal 43 projects from the edge of the glass substrate 21, and are integrated. As a result, the discharge space 30 is formed inside. However, at this point, the discharge space 30 is in the atmospheric state.

Next, the discharge space 30 and the exhaust device are connected via a tip tube 60 (see FIG. 5), and vacuum exhaust and 35 are performed.
Baking (heat treatment) is performed at 0 ° C. At this time, a probe for energization is attached to the conductive heat-resistant layer 50 prior to heating.

When the temperature of the glass substrate 11 reaches 350 ° C., the exhausting is stopped and the discharge gas is introduced into the discharge space 30. As the discharge gas, for example, a mixed gas of neon, xenon, and oxygen is used. Also, the gas pressure is several tens to several hundreds T
It is an appropriate value within the range of orr.

A voltage pulse (200 V, 10 V) is commonly applied to all the display electrodes Y through the conductive heat resistant layer 50.
(kHz) is applied to generate a discharge for cleaning the discharge space 30 while the glass substrate 11 is kept heated. In this embodiment, in order to clean both the front wall surface and the rear wall surface of the discharge space 30, as shown in FIG.
And the address electrode A are connected to the power source 80, and the glass substrate 1
A discharge is generated in the opposite direction of 1, 21. Here, regarding the address electrodes A, by using a layer similar to the conductive heat-resistant layer 50 or a jig such as a stainless plate as the short-circuit conductor 55, the plurality of address electrodes A are collectively supplied to the power source 8.
Connect to 0.

The discharge is continued for a predetermined time, impurities such as water and carbon are liberated from the inner wall surface by the plasma action, and then exhaust is performed again to discharge the impurities together with the discharge gas. After that, a discharge gas is newly introduced to melt the tip tube 60 to completely seal the discharge space 30. Then, the conductive heat resistant layer 50 is removed using a nitric acid solution, and the display electrodes Y are electrically separated. This completes the assembly of PDP1.

In the above embodiment, the surface discharge type PDP is used.
However, the present invention is also applicable to a counter discharge type PDP. Further, the discharge gas can be introduced in parallel with the exhaust of the discharge space 30. In that case, for example, the tip tubes 60 may be attached to the diagonal corners of the discharge space 30, and one of them may be connected to an exhaust device and the other may be connected to a discharge gas supply source.

[0032]

According to the inventions of claim 1 and claim 2,
It is possible to manufacture a PDP with stable characteristics by cleaning the discharge space by discharge without changing the quality of the electrodes.

According to the second aspect of the present invention, connection with an external power source for causing discharge in the entire display area during manufacture becomes easy.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a PDP according to the present invention.

FIG. 2 is a plan view of an essential part of a PDP.

FIG. 3 is an exploded perspective view of a PDP according to the present invention.

FIG. 4 is a schematic diagram showing an example of a voltage application method.

FIG. 5 is an external view of a PDP.

[Explanation of symbols]

1 PDP 11 Glass Substrate (First Substrate) 22 Glass Substrate (Second Substrate) 17 Dielectric Layer (Heat Resistant Protection Layer) 30 Discharge Space (Internal Space) 43 Connection Terminal (End of Electrode) 50 Conductive Heat Resistance Layer (heat resistant protective layer, conductive layer) Y display electrode (electrode)

Claims (2)

[Claims] 1. A plurality of electrodes are arranged on a first substrate, and each of the electrodes is covered with a heat-resistant protective layer, and then the first electrode is formed.
The second substrate and the second substrate so as to face each other so that the end portions of the electrodes project from the edge of the second substrate, and the first and second substrates are integrated to form an interior for discharging. A method of manufacturing a PDP which forms a space and evacuates the internal space while heating the first and second substrates, wherein the end portion of each electrode is covered in the heat resistant protective layer. A layer having conductivity is formed as a layer of a portion to be formed, and a discharge gas is introduced into the internal space at a stage in the middle of exhausting the internal space, and each electrode is provided through the layer having conductivity. A voltage is applied to the first and second substrates to generate a discharge in the internal space where the first and second substrates are heated, and then the internal space is evacuated again to introduce a discharge gas. A method for producing a PDP, which comprises completely sealing 2. The conductive layer is formed so as to straddle the end portions of all the electrodes, and the voltage is collectively applied to all the electrodes via the conductive layer. The method of manufacturing a PDP according to claim 1, wherein the conductive layer is removed after the discharge is generated to completely seal the internal space.