JP2993263B2 - Plasma display panel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel used for an information display terminal or a flat panel television, and more particularly to a structure of a high definition and high brightness plasma display panel. 2. Description of the Related Art There are two types of plasma display panels: a monochrome panel that uses the emission color of Ne and a color panel that uses the emission color of a phosphor. Although the present invention is a technology common to both, here, a color plasma display panel is taken as an example. A color plasma display panel is a display that excites and emits a phosphor with ultraviolet rays generated by gas discharge to obtain visible light and performs a display operation, and can be classified into an AC type and a DC type according to a discharge method. AC
Among the molds, the reflection type AC surface discharge type is excellent in terms of luminance, luminous efficiency and life, so this is taken as an example. FIG. 4 is a plan view of a conventional reflective AC surface discharge plasma display panel. FIG. 3 shows a conventional reflection type AC shown by bb 'in FIG.
1 shows a sectional view of a surface discharge plasma display panel. In FIG. 3, a transparent electrode 31 is formed on a front substrate 30. A display discharge is obtained by applying a pulsed AC voltage of usually several tens of kHz to several hundreds of kHz between the adjacent transparent electrodes 31. When, for example, SnO ₂ is used for the transparent electrode 31, the sheet resistance is usually several tens of kHz. Since the resistance is as high as Ω / □, especially in a large panel or a high-definition panel, the electrode resistance becomes several tens of kΩ, and the voltage pulse does not sufficiently rise and driving becomes difficult. Therefore, a metal bus electrode 32 is formed on the transparent electrode 31 to reduce the resistance value of the electrode. The metal bus electrode 32 is, for example, A
1 thin film. The patterning of the metal bus electrode 32 uses photolithography. The insulating layer 33 is covered from above. The insulating layer 33 is a thick film of, for example, low melting point lead glass. The protective layer 34 is formed on the insulating layer 33.
The protective layer 34 is formed of, for example, an MgO thin film or a thick film. On the other hand, a write electrode 38 is provided on a rear substrate 39.
Is formed, and this is covered with an insulating layer 37. Further, a phosphor 36 of the emission color of each pixel is applied to a portion to be each pixel. The above-mentioned front substrate 30 is adhered to the above through a partition wall 35 and hermetically sealed, and a dischargeable gas, for example, a mixed gas of He and Xe is sealed therein at about 250 torr. When a pulsed AC voltage is applied between adjacent transparent electrodes 31, gas discharge occurs and plasma 40 is generated. The phosphor 36 is excited by the ultraviolet light 41 generated here, and visible light 52 is obtained through the front substrate 30. In the color plasma display panel having the above-described structure, the metal bus electrode is usually formed by photolithography of a thin film of Al or the like. Occurs. Generally, when a substance bonded to a dissimilar metal is immersed in an electrolytic solution, an electrochemical reaction occurs. In this case, the dissimilar metals are a transparent electrode and a metal bus electrode, and the electrolytic solution is a resist developing solution or an etching solution. For example, in the case of SnO ₂ and an Al thin film, when Al starts to dissolve in the electrolytic solution, a hydrogen generation reaction occurs, followed by reduction of SnO ₂ , resulting in corrosion of the electrode. It is difficult to suppress this reaction. Accordingly, the metal bus electrode is disconnected due to corrosion, and the yield is greatly reduced. In order to prevent this, it is necessary to increase the line width of the metal bus electrode. However, in order not to lower the aperture ratio of the discharge cells, the metal bus electrode needs to be hidden under the partition, and must be formed with a line width as narrow as possible. It is limited by the line width of the bus electrode and must be thick. Then, the aperture ratio of the discharge cells decreases. However, since the aperture ratio of the discharge cell greatly affects the discharge characteristics and the average surface luminance of the panel, a method capable of forming a metal bus electrode with a small line width with a high yield is required. [0006] The present invention provides a plasma display panel having a transparent electrode group formed on a transparent insulating substrate and a metal electrode formed on the transparent electrode. Forming an insulating layer between the transparent electrode and the metal electrode ; and forming an insulating layer between the transparent electrode and the metal electrode.
Pulse voltage is almost lost by capacitive coupling between poles
It is characterized by having a thickness that can be transmitted without any change. The electrochemical reaction that occurs when developing the resist or forming the metal bus electrode by etching suppresses the current caused by the local battery action by sandwiching a thin insulating film between the transparent electrode and the metal bus electrode. As a result, it was possible to prevent the electrode from being corroded during the development of the resist or the etching of the metal bus electrode. The transparent electrode and the metal bus electrode are coupled by a capacitor via a thin insulating film. The capacitance is large because the thickness of the insulating film is sufficiently small. Therefore, even if an insulating layer was inserted between the metal bus electrode and the transparent electrode, a sufficient current required for discharge could be passed. Next, an embodiment of the present invention will be described with reference to the drawings. Here, the reflection type AC surface discharge plasma display panel described in the conventional example will be described as an example.
This invention is common to all plasma display panels that use a _two- system, ITO, or ZnO-based transparent electrode and form a metal bus electrode on the transparent electrode to reduce the resistance.
FIG. 2 shows a plan view of one embodiment of the present invention. FIG. 1 is a sectional view taken along the line aa 'of FIG. In FIG. 1, the basic structure is the same as that of FIG. 3 described in the conventional example, except that the insulating layer 3 is formed on the transparent electrode 2. This insulating layer 3 is made of, for example, A
l ₂ O ₃ thin film is deposited about 300 angstroms.
The patterning of the metal bus electrode 4 formed thereon is performed as follows.
For example, a thin film of Al or the like is formed by photolithography, or a thick film of Ag or the like is formed by photolithography. By interposing the insulating layer 3 between the transparent electrode 2 and the metal bus electrode 4, corrosion of the electrode due to an electrochemical reaction during resist development or etching can be prevented. Therefore, there is no fear of disconnection, the line width can be reduced, and the yield is greatly improved. The contact between the transparent electrode 2 and the metal bus electrode 4 is based on capacitive coupling. The thickness of the insulating layer 3 is, for example, 300 angstroms, and the distance between adjacent transparent electrodes 2 for generating discharge is, for example, 200 μm. Since there is a large difference between these capacitances, the pulse voltage applied to the metal bus electrode 4 is applied between the adjacent transparent electrodes 2. Therefore, even if it is insulated against direct current, in the case of AC type PDP,
If the capacitance between the metal bus electrode 4 and the transparent electrode 2 that are insulated by the insulating layer 3 is sufficiently large, driving can be performed with almost no loss. As the insulating layer 3, a thin film of a light-transmitting substance such as an oxide such as SiO ₂ or a nitride other than Al ₂ O ₃ can be used. If the film thickness is sufficiently small, a thick film such as a low melting point lead glass may be used. The film thickness can be selected in such a range that the effect of the present invention is exhibited and that the increase in the driving voltage does not cause a practical problem. Although an insulating layer has been sandwiched between the transparent electrode and the bus electrode, the insulating layer does not necessarily have to be a perfect insulator, and a high-resistance substance has substantially no problem. The same effect can be obtained. As described above, the plasma display panel of the present invention can form a metal bus electrode for lowering the resistance of a transparent electrode while preventing corrosion of the electrode due to an electrochemical reaction. I was able to make a panel.

[Brief description of the drawings] FIG. 1 is a sectional view of one embodiment of the present invention. FIG. 2 is a plan view of one embodiment of the present invention. FIG. 3 is a sectional view of a conventional example. FIG. 4 is a plan view of a conventional example. [Explanation of symbols] 1,30 Front substrate 2,31 transparent electrode 3,5,9,33,37 insulating layer 4,32 metal bus electrode 6,34 protective layer 7,35 partition wall 8,36 phosphor 10,38 Writing electrode 11,39 Rear substrate 12,40 plasma 13,41 UV light 14,42 visible light 15,43 discharge cell

Claims (1)

(57) Claims: In a plasma display panel having a transparent electrode group formed on a transparent insulating substrate and a metal electrode formed on the transparent electrode, a portion between the transparent electrode and the metal electrode is provided . An insulating film is formed on the substrate, and the thickness of the insulating layer is 300 angstroms.
A plasma display panel, which is a little loss without transmission available-pulse voltage by capacitive junction between the transparent electrode and the metal electrode made of Al ₂ O ₃ thin film of about Strom.