JP3698452B2 - Aging method for plasma display panel - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a plasma display panel (PDP) having a multilayer metal film as an external connection member common to a plurality of display electrodes.
[0002]
A PDP is a thin display device that is excellent in visibility, relatively easy to enlarge, and capable of high-speed display. In particular, the surface discharge type PDP is suitable for color display using a phosphor, and has attracted attention as a display device for high vision. As the market for PDPs expands, higher reliability is required, and the importance of aging for stabilizing display operation is increasing.
[0003]
[Prior art]
FIG. 6 is a plan view showing a basic electrode structure of the surface discharge type PDP.
In the surface discharge type PDP of the matrix display system, a pair of display electrodes X and Y are arranged adjacent to each other on the same substrate for each display line L as shown in the figure, and a large number of them are orthogonal to the display electrodes X and Y. Address electrodes A are arranged.
[0004]
Usually, one display electrode Y is an individual electrode that is independent for each line in order to enable line-sequential screen scanning. On the other hand, the other display electrode X is electrically shared between the plurality of lines L by a strip-shaped connecting conductor 43 in order to simplify the drive circuit. The width of the connecting conductor 43 is sufficiently wider than the display electrodes X and Y.
[0005]
In each line L, a surface discharge cell C is defined for each unit light emitting region EU by the display electrodes X and Y. Then, the display electrode Y and the address electrode A are used to select whether each surface discharge cell C is turned on or not (address).
[0006]
In general, the display electrodes X and Y and the connecting conductor 43 are composed of a metal thin film having a multilayer structure represented by a three-layer structure of Cr / Cu / Cr, and are patterned by a photolithography method. Here, Cu (copper) is a main material for ensuring predetermined conductivity. Cr (chromium) is used as a base material for improving adhesion and as a coating material for preventing bubble generation and the like.
[0007]
When the display electrodes X and Y are arranged on the front substrate, the display electrodes X and Y are composed of a thick strip-shaped transparent conductive film and a thin strip-shaped metal thin film overlapping therewith.
In this case, the metal thin film has a role of supplementing the conductivity of the transparent conductive film.
[0008]
FIG. 7 is a diagram showing an aging method.
When manufacturing a PDP, a pair of substrates provided with predetermined components are arranged opposite to each other, the periphery is sealed, the interior is exhausted and filled with discharge gas, the assembly is completed, and then the discharge characteristics are stabilized. For aging.
[0009]
First, a plurality of metal plates 70 of appropriate sizes, which are jigs for energization, are overlapped on the connection conductor 43 on the substrate 11 and one end of the display electrode Y as shown in the figure. At this time, for the display electrode Y, the metal plate 70 is disposed so as to straddle each line. And each metal plate 70 is fixed to the board | substrate 11 using clamping means or pressing means, such as a clip.
[0010]
Next, each metal plate 70 is connected to an aging power source 80, and a predetermined aging voltage is commonly applied to the display electrodes X and Y of all lines. Thereby, all the surface discharge cells C (see FIG. 6) in the display area are uniformly lit. This state is continued for several tens of hours, for example.
[0011]
[Problems to be solved by the invention]
In the above aging, the aging efficiency can be increased by increasing the discharge current by setting the aging voltage higher.
[0012]
However, in the prior art, the temperature rise in the vicinity of the connection conductor 43 that shares the plurality of display electrodes X in the substrate 11 is remarkably increased, and thus the efficiency of aging due to the increase in discharge current is limited. there were. When the overheated state is reached, the substrate 11 is cracked or the protective tape covering the repair terminal used for repair when the display electrodes X and Y are disconnected is burnt.
[0013]
The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce heat generation at an electrical connection portion with the outside as much as possible.
[0014]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a multilayer structure in which a coating layer made of a second metal having a higher resistance than the first metal is formed on a main conductive layer made of the first metal, and a plurality of display electrodes are connected. A method for aging a plasma display panel in which a metal thin film is provided on a substrate, the planar shape of the metal thin film having a plurality of openings, and a surface roughness that contacts the main conductive layer at the openings. A metal plate having a thickness is superimposed on the metal thin film, and the plurality of display electrodes are collectively connected to an aging power source via the metal plate .
[0015]
The method of the invention of claim 2 is to the metal thin film and comb-shaped.
[0016]
[Action]
The main conductive layer is exposed at the end face of the opening in the metal thin film. For this reason, in the state where the conductor for connecting the display electrode to the external power source is placed on the metal thin film, the total of the placed conductor and the first metal of the main conductive layer is compared with the case where there is no opening. The contact area increases and the contact resistance between the metal thin film and the conductor decreases. Therefore, the amount of heat generated by the discharge current is reduced, and the limitation on the discharge current for avoiding overheating is relaxed.
[0017]
【Example】
FIG. 1 is a partial cross-sectional view of a PDP 1 according to the present invention. FIG. 2 is an exploded perspective view of the PDP 1 according to the present invention, and shows a basic structure of a portion corresponding to one pixel EG. In these drawings, components corresponding to those in FIGS. 6 and 7 are denoted by the same reference numerals regardless of differences in shape. The same applies to the other figures below.
[0018]
The PDP 1 of the present embodiment 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 in matrix display. It is called a reflection type.
[0019]
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 with respect to the discharge space 30. On the surface of the dielectric layer 17, an MgO film 18 having a thickness of about several thousand mm is provided as a protective film. The discharge space 30 is sealed with a sealing glass 31 (see FIG. 1) that fuses the periphery of the opposing region of the glass substrates 11 and 21.
[0020]
In addition, since the display electrodes X and Y are arranged on the display surface H side with respect to the discharge space 30, in order to widen the surface discharge and minimize the shielding of the display light, the display electrodes X and Y have a width made of a nesa film or the like. It is composed of a wide transparent conductive film 41 and a narrow metal film (bus electrode) 42 to supplement the conductivity. For example, when the line pitch is about 500 to 700 μm, the width of each transparent conductive film 41 is about 120 to 200 μm, and the width of the metal film 42 is about 50 to 70 μm. The metal film 42 of each display electrode X, Y is led out to the edge of the glass substrate 11 for connection with the drive system. As shown in FIG. 1, the metal film 42 constituting the display electrode X is integrated with a connection conductor 43 described later outside the sealing glass 11.
[0021]
On the other hand, the address electrodes A for selectively emitting light in the unit light emitting region EU are arranged on the glass substrate 21 on the back side at a constant pitch so as to be orthogonal to the display electrodes X and Y. Between each address electrode A, a stripe-shaped partition wall 29 having a height of about 120 to 150 μm is provided, whereby the discharge space 30 is partitioned for each unit light emitting region EU in the line direction, and the discharge space 30 The gap size is defined.
[0022]
The glass substrate 21 has three primary colors of fluorescence of R (red), G (green), and B (blue) so as to cover the inner surface of the rear surface side including the upper surface of the address electrode A and the side surface of the partition wall 29. A body 28 is provided. The phosphors 28 of the respective colors emit light when excited by ultraviolet rays emitted by the discharge gas in the discharge space 30 during surface discharge. The PDP 1 can display full color by a combination of R, G, and B.
[0023]
FIG. 3 is a diagram showing a planar shape of the connecting conductor 43, and FIG. 4 is a partial sectional view showing a layer structure of the connecting conductor 43.
The connection conductor 43 is a component for simplifying the drive circuit by electrically sharing the plurality of display electrodes X, and is disposed on the edge of the glass substrate 11 as an external connection terminal. Such a connecting conductor 43 is formed of a Cr / Cu / Cr thin metal film (thickness T is about 12,000 mm) as shown in FIG. 4 and is patterned simultaneously with the metal film 42 by photolithography. Has been. The thickness of the base layer 431 made of Cr and the uppermost coating layer 432 is about 500 to 2000 mm, and the thickness of the main conductive layer 432 made of Cu is about 8000 to 10,000 mm, for example.
[0024]
Now, the patterning shape (planar shape) of the connecting conductor 43 in the PDP 1 is a comb-teeth shape composed of comb teeth 43A arranged at equal intervals along the arrangement direction of the display electrodes X and connecting portions 43B connecting one ends thereof. That is, it is not a uniform solid shape in a plan view but a shape having a large number of openings (notches 430 between the comb teeth 43A) where no film exists. The metal film 42 of the display electrode X is connected to the edge of the connecting portion 43B on the side opposite to the comb tooth side.
[0025]
The width W of each comb tooth 43A is about 300 μm, and the interval between the comb teeth 43A (that is, the width of the notch 430) is also about 300 μm. The length L of the comb teeth 43A is about several millimeters.
[0026]
When aging the PDP 1, the connecting conductor 43 and a predetermined metal plate (for example, 0.7 mm thick stainless steel plate) 70 are overlapped and the predetermined number of display electrodes X are collectively connected to the aging power supply 80 in the same manner as in the past. . Further, the display electrode Y is also connected to the aging power source 80 using another metal plate 70. Then, discharge is generated in all the unit light emitting regions EU in the display surface H.
[0027]
At this time, the main conductive layer 432 is exposed at the side surface of each notch 430 of the connecting conductor 43. In addition, the coating layer 433 that is the upper layer of the main conductive layer 432 is sufficiently thin in view of the surface roughness of the metal plate 70. Therefore, the contact area between the main conductive layer 432 and the metal plate 70 is larger than when the notch 430 is not provided.
[0028]
Here, Cr of the coating layer 433 has a higher resistance than Cu of the main conductive layer 432.
That is, the value of the specific resistance ρ of Cr is 18.9 μΩcm (0 ° C.), which is about 10 times the value of the specific resistance ρ of Cu (about 1.7 μΩcm, 20 ° C.).
[0029]
That is, in the PDP 1, the contact resistance between the connection conductor 43 and the metal plate 70 is small compared with the case where the notch 430 is not provided, although the facing area between the connection conductor 43 and the metal plate 70 is small. .
[0030]
As a result, the amount of heat generated by the discharge current is reduced, and the limitation on the discharge current for avoiding overheating in the vicinity of the connecting conductor 43 is relaxed. Specifically, when the aging current was 1.8 A, the maximum temperature in the glass substrate 11 during aging in the PDP 1 was 55 ° C. On the other hand, in the PDP in which the shape of the connecting conductor 43 is a rectangle without the notch 430 and the other parts are the same as the PDP 1, the maximum temperature in the glass substrate 11 in the same aging is 70 ° C. .
[0031]
According to the above-described embodiment, heat generation due to contact resistance between the connecting conductor 43 and the metal plate 70 can be reduced, and particularly when the large PDP 1 is aged, cracking of the substrate due to overheating and scorching of the protective tape are prevented. be able to.
[0032]
In the above-described embodiment, the example in which the connecting conductor 43 is comb-shaped has been described. However, other shapes may be used as long as the main conductive layer 432 is exposed more in the arrangementable region. For example, as shown in FIG. 5, a connecting conductor 43b having openings 430b of various shapes such as a circle and a rectangle may be provided. In addition, various changes can be made to the material, number of layers, film thickness, dimensions of each part, electrode configuration, and the like of the connection conductor 43. Note that the present invention is not limited to a matrix display type PDP, and can also be applied to a segment display type PDP.
[0033]
【The invention's effect】
According to the first and second aspects of the present invention, since heat generation at the electrical connection portion with the outside is reduced, damage due to overheating can be prevented, and the discharge current is reduced by the amount that the thermal restriction is relaxed. Can be increased.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a PDP according to the present invention.
FIG. 2 is an exploded perspective view of a PDP according to the present invention.
FIG. 3 is a diagram showing a planar shape of a connecting conductor.
FIG. 4 is a partial cross-sectional view showing a layer structure of a connecting conductor.
FIG. 5 is a view showing a modification of the shape of a connecting conductor in a plan view.
FIG. 6 is a plan view showing a basic electrode structure of a surface discharge type PDP.
FIG. 7 is a diagram illustrating an aging method.
[Explanation of symbols]
1 PDP (Plasma Display Panel)
11 Glass substrate (substrate)
43, 43b Connecting conductor (metal thin film)
80 Aging power supply (external power supply)
430, 430b Opening 432 Main conductive layer 433 Coating layer X Display electrode

Claims (2)

A multi-layered metal thin film having a coating layer made of a second metal having a higher resistance than the first metal on the main conductive layer made of the first metal and connecting a plurality of display electrodes is provided on the substrate. An aging method for a plasma display panel,
The planar shape of the metal thin film has a shape having a large number of openings, and a metal plate having a surface roughness in contact with the main conductive layer in the openings is superimposed on the metal thin film, and the metal plate is interposed through the metal plate. A method for aging a plasma display panel, wherein a plurality of display electrodes are connected to an aging power source at once. The method for aging a plasma display panel according to claim 1, wherein the metal thin film has a comb shape.

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