JP2007200729A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide high-image-quality image display by suppressing displacement of an electron beam generated in the vicinity of a spacer. <P>SOLUTION: A conductive film 15 is formed on a surface of an adhesive member 14 for joining a back substrate 1 to a lower end part of the spacer 13, and the conductive film is connected to a scanning signal wire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flat-type image display device using electron emission into a vacuum formed between a front substrate and a back substrate, and in particular, includes a plurality of spacing members in the vacuum between the two substrates. The present invention relates to an image display apparatus.

  Conventionally, a color cathode ray tube has been widely used as a display device excellent in high luminance and high definition. However, with the recent improvement in image quality of information processing devices and television broadcasts, there is an increasing demand for flat image display devices (flat panel displays, FPDs) that have high brightness and high definition characteristics and are lightweight and space-saving. ing.

  As typical examples, liquid crystal display devices, plasma display devices and the like have been put into practical use. In particular, a self-luminous display device using electron emission from an electron source to a vacuum (for example, an electron emission image display device, a field emission image display device, or the like) that can increase the brightness. In addition, various flat image display devices such as organic EL displays characterized by low power consumption have been put into practical use.

  Among flat image display devices, a self-luminous flat panel display is known in which electron sources are arranged in a matrix.

  In a self-luminous flat panel display, the cold cathode has a Spindt type, surface conduction type, carbon nanotube type, metal-insulator-metal laminated MIM (Metal-Insulator-Metal) type, metal-insulator- An MIS (Metal-Insulator-Semiconductor) type or a metal-insulator-semiconductor-metal type electron source in which semiconductors are stacked is used.

  A flat-type image display device includes a rear substrate including the electron source, a front surface including a phosphor layer and an anode to which an acceleration voltage for projecting electrons emitted from the electron source to the phosphor layer is applied. 2. Description of the Related Art There is known a display panel including a substrate and a support that serves as a sealing frame that seals the opposing internal space of both substrates in a predetermined vacuum state. An image display device is operated by combining a drive circuit with this display panel.

  In an image display device having an MIM type electron source, a large number of first electrodes (for example, cathode electrodes, image signal electrodes) arranged in parallel in a second direction extending in the first direction and intersecting the first direction. ), An insulating film formed to cover the first electrode, and a number of second electrodes (for example, gates) extending in the second direction on the insulating film and arranged in parallel in the first direction. Electrode, scanning signal electrode) and a back substrate having an electron source provided near the intersection of the first electrode and the second electrode, the back substrate is made of an insulating material, and the electrode is placed on the substrate. Is formed.

  With this configuration, scanning signals are sequentially applied to the scanning signal electrodes in the first direction. On the substrate, the above-described electron source is provided in the vicinity of each intersection of the scanning signal electrode and the image signal electrode. These two electrodes and the electron source are connected by a feeding electrode, and current is supplied to the electron source. . A front substrate having a plurality of color phosphor layers and a third electrode (anode electrode, anode) is provided on the inner surface facing the rear substrate. The front substrate is formed of a light transmissive material suitable for glass. Then, both substrates are sealed by inserting a supporting body serving as a sealing frame at the inner peripheral edge of each bonding, and the inside formed by the rear substrate, the front substrate and the supporting member is evacuated to constitute an image display device. The

  As described above, the electron source is provided near the intersection of the first electrode and the second electrode, and the amount of electrons emitted from the electron source (on / off of emission) due to the potential difference between the first electrode and the second electrode. Control). The emitted electrons are accelerated by a high voltage applied to the anode of the front substrate, and are also colored by the color light according to the emission characteristics of the phosphor layer by exciting and exciting the phosphor layer of the front substrate. To do.

  Each electron source is paired with a corresponding phosphor layer to constitute a unit pixel. Usually, one pixel (color pixel, pixel) is composed of unit pixels of three colors of red (R), green (G), and blue (B). In the case of a color pixel, the unit pixel is also called a sub-pixel (sub-pixel).

  In the flat image display apparatus as described above, a plurality of spacing members (hereinafter referred to as spacers) are generally arranged and fixed in a display area surrounded by a support between the back substrate and the front substrate. The distance between the substrates is maintained at a predetermined distance in cooperation with the support. This spacer is generally formed of a plate-like body formed of an insulating material such as glass or ceramics, and is usually installed at a position where the operation of the pixel is not hindered for each of the plurality of pixels.

Further, the support serving as the sealing frame is fixed to the inner peripheral edge of the back substrate and the front substrate with a sealing member such as frit glass, and this fixing portion is hermetically sealed to form a sealing region. The degree of vacuum inside the display region formed by both the substrates and the support is, for example, about 10 ⁻³ to 10 ⁻⁵ Pa. Further, in a flat type image display device, a configuration in which the upper and lower end portions of a spacer are bonded and fixed to both substrates with a conductive adhesive member is disclosed in Patent Document 1 below.

Japanese Patent No. 3305166

  In the background art, an FPD has a structure having a frame-like support body that holds a distance between both substrates and a plurality of spacers arranged in a display region surrounded by the support body. The spacers are arranged in parallel on the scanning signal lines in the display area, for example. In such a spacer arrangement, electrons emitted from the electron source are accelerated by the anode applied voltage and collide with the phosphor layer to cause the phosphor layer to emit light. However, a part of the electrons charges the spacer, and this charging distorts the trajectory of the electrons emitted from the electron source, so that sufficient electrons cannot be projected into the fluorescent layer, resulting in insufficient excitation. There is. As a result, insufficient luminance and color reproducibility deteriorate. In addition, the charging of the spacer causes a deterioration in the withstand voltage characteristics between the two substrates, and there is a problem that becomes an impediment to extending the life.

  In this type of image display device, as one of the solutions to the problem due to the charging of the spacers, in Japanese Patent Application Laid-Open No. H11-228707, the spacers are frit glass and conductive frit glass on the metal back of the inner surface of the front substrate where there is no phosphor layer. By adhering and fixing via a conductive adhesive frit glass on the scanning signal electrode on the back substrate, the spacer can be prevented from being charged and the electric field distribution near the spacer can be made the same as the part without the spacer. A configuration is disclosed in which the electron beam is not displaced and a good display can be obtained.

  However, the image display device configured as described above has a problem in that minute electron beam displacement occurs in the vicinity of the spacer, and image quality defects cannot be reliably suppressed. Further, in the vicinity of the spacer, there is a problem that an image quality defect in which the amount of electron beam displacement changes irregularly depending on pixels occurs. The reason for this is that, in the pixels in the vicinity of the scanning signal electrode where the spacer is present, the path of the electron beam is displaced and is emitted from the phosphor layer, so that the emission luminance is partially reduced.

  Therefore, the present invention has been made to solve the above-described conventional problems, and an object of the present invention is to obtain a high-quality image display that suppresses the displacement of the electron beam generated in the vicinity of the spacer and hardly causes pixel defects. An image display device is provided.

  In order to achieve such an object, an image display device according to the present invention is arranged in parallel with a front substrate having a phosphor layer and an anode electrode on its inner surface, and extending in one direction and intersecting the one direction. A plurality of scanning signal wirings to which scanning signals are sequentially applied in the other direction, a plurality of image signal wirings extending in the other direction and arranged in parallel in one direction so as to intersect the scanning signal wirings, the scanning signal wirings and the image signals An electron source provided in the vicinity of each crossing portion of the wiring is provided on the inner surface, the rear substrate facing the front substrate with a predetermined interval, and inserted around the display area between the front substrate and the rear substrate, A support body that holds a predetermined interval, a plurality of interval holding members arranged in a display area between the front substrate and the rear substrate, and an end portion of the interval holding member and the front substrate and the rear substrate are bonded to each other. A support substrate and a front substrate. And the rear substrate are hermetically sealed through sealing members, respectively, and the interval holding member is arranged to extend in the same direction as the scanning signal wiring, overlapping the scanning signal wiring, A conductive film is formed on the surface of the adhesive member that joins the rear substrate and the end of the spacing member, and the conductive film is connected to the scanning signal wiring.

  Another image display device according to the present invention includes a black matrix film having a plurality of openings, a plurality of color phosphor layers arranged so as to close the openings and extend over the black matrix film, and the phosphor A front substrate having an anode electrode made of a metal thin film covering the layer and the black matrix film on the inner surface, and a parallel arrangement extending in one direction and crossing the one direction in the other direction, and sequentially applying scanning signals in the other direction A plurality of scanning signal wirings, a plurality of image signal wirings arranged in one direction so as to extend in the other direction and intersect the scanning signal wirings, and provided near the intersections of the scanning signal wirings and the image signal wirings A rear substrate having an electron source on the inner surface and facing the front substrate with a predetermined interval; and a support member that is inserted around the display area between the front substrate and the rear substrate and maintains the predetermined interval; Display area between the front and back substrates And a plurality of spacing members arranged to extend in the same direction as the scanning signal wiring, and adhesive members for joining the end portions of the spacing holding member to the front substrate and the back substrate, respectively. An image display device in which the end portion of the support and the front substrate and the rear substrate are hermetically sealed via sealing members, respectively, and the scanning signal wiring and the end portion of the spacing member are A conductive film is formed on the surface of the bonding member to be bonded, and the conductive film is connected to the scanning signal wiring.

  According to the present invention, by providing a conductive film on the surface of the adhesive member that joins the lower end surface of the spacing member and the rear substrate, it is difficult to charge even when irradiated with an electron beam, and the surrounding electric field is also less likely to be disturbed. Since the path change of the electron beam is small and goes straight and reaches a predetermined phosphor layer, it is possible to reliably prevent image quality defects and to obtain a high-quality image display.

  In addition, according to the present invention, conduction with the scanning signal wiring can be obtained substantially uniformly over the entire end face of the spacing member, the potential distribution becomes substantially uniform, and a good image with small displacement of the electron beam can be obtained. Therefore, it has an extremely excellent effect that a high-quality image display can be obtained.

  The best mode of the present invention will be described below in detail with reference to the drawings of the embodiments.

  1 and 2 are diagrams for explaining an image display device according to a first embodiment of the present invention. FIG. 1A is a plan view seen from the front substrate side, and FIG. FIG. 2 is a side view of a), and FIG. 2 is a schematic cross-sectional view cut along the line AA in FIG.

  1 and 2, reference numeral 1 is a back substrate, 2 is a front substrate, and these back substrate 1 and front substrate 2 are made of a glass plate having a thickness of several millimeters, for example, about 3 mm. Reference numeral 3 denotes a frame-like support, and this support 3 is composed of a glass plate or a frit glass sintered body having a thickness of several mm, for example, about 3 mm. Reference numeral 4 denotes an exhaust pipe, and the exhaust pipe 4 is fixed to the back substrate 1. The support 3 is inserted around a peripheral portion between the back substrate 1 and the front substrate 2 and is interposed between the back substrate 1 and the front substrate 2 and a sealing member (not shown) such as frit glass. It is airtight.

The space surrounded by the support 3, the back substrate 1, the front substrate 2, and the sealing member is exhausted through the exhaust pipe 4, and maintains a vacuum of, for example, 10 ⁻³ to 10 ⁻⁵ Pa. 5 is constituted. Further, the exhaust pipe 4 is attached to the back side of the back substrate 1 and communicates with a through hole 6 formed through the back substrate 1 so that the exhaust pipe 4 is sealed after the exhaust is completed. Reference numeral 7 denotes an image signal wiring. The image signal wiring 7 extends in one direction (Y direction) on the inner surface of the rear substrate 1 and is arranged in parallel in the other direction (X direction) and connected to the image signal driving circuit 8. ing. Reference numeral 9 denotes a scanning signal wiring. The scanning signal wiring 9 extends on the image signal wiring 7 in the other direction (X direction) intersecting therewith, and is arranged in parallel in one direction (Y direction). 10 is connected.

  Reference numeral 11 denotes an electron source. The electron source 11 is provided near each intersection of the scanning signal wiring 9 and the image signal wiring 7, and the scanning signal wiring 9 and the electron source 11 are connected by a connection electrode. Yes. An interlayer insulating film 12 is disposed between the image signal wiring 7 and the electron source 11 and the scanning signal wiring 9. The image signal wiring 7 is made of, for example, an Al / Nd laminated film, and the scanning signal wiring 9 is made of, for example, an Ir / Pt / Au laminated film.

  Reference numeral 13 denotes a spacer (also referred to as a partition wall) as a spacing member. The spacer 13 is made of, for example, a ceramic material, and has a semiconductive property in which, for example, a chromium oxide film having a low secondary electron emission efficiency is coated. It is made of ceramics and is formed into a rectangular thin plate shape. In this embodiment, every other line is placed upright on the scanning signal wiring 9, and the back substrate 1 and the front substrate 2 are fixed by the conductive adhesive member 14. ing. The spacer 13 is usually installed at a position that does not hinder the operation of each pixel.

  Ceramic spacers require a high-temperature pressure firing process using a press as a manufacturing process, and the process cost is high and it is difficult to make a long spacer. In addition, material costs are high. Therefore, by using glass as the spacer material, it can be made of an inexpensive material, and long production is also advantageous. Moreover, the surface flatness is good and the surface treatment is easy.

The spacer 13 has a resistance value of about 10 ⁶ to 10 ¹⁰ Ω · cm. The dimension of the spacer 13 is determined by the substrate dimension, the height of the support 3, the substrate material, the spacer spacing, the spacer material, etc. In general, the height is approximately the same as that of the support 3. The thickness is several tens of μm to several mm or less, and the length is about 20 mm to 200 mm, preferably about 80 mm to 120 mm.

  Further, the adhesive member 14 is configured to include, for example, an adhesive frit glass or a vitrifying component and a conductive member such as gold particles or silver particles having a size of, for example, about several nanometers to several tens of nanometers. The spacer 13 is bonded and fixed to the back substrate 1 and the front substrate 2 by the adhesive member 14. The thickness Sb of the adhesive member 14, that is, the dimension in which the spacer 13 is embedded in the adhesive member 14, depends on the composition of the adhesive member 14, but is several μm or more, preferably 5 to 40 μm from the viewpoint of securing adhesive fixation. The size is set to about 10 to 20 μm. If the thickness Sb is small, the inclination of the spacer 13 may occur. Conversely, if the thickness Sb is too large, a conductive film described later can be easily formed on the surface. On the other hand, on the front substrate 2 side, a high voltage may enter irregularly and adversely affect the trajectory of the electron beam.

  Reference numeral 15 denotes a conductive film, and the conductive film 15 is formed with a thickness of about 5 to 20 nm by, for example, sputtering of Au / Pt / Ir material. The conductive film 15 is also formed on the upper surface of the electron source, and also serves as an electrode material for the electron source. The conductive film 15 needs to be conductive and transmit electrons into the space. It combines the electrode material on the upper part of the electron source and imparts conductivity to the surface of the spacer adhesive member, and has the advantage that the device structure is simplified and the process can be simplified.

  The conductive film 15 is not formed on the back substrate 1, and the scanning signal wiring 9 including the adhesive member 14 after the adhesive member 14 that adheres and fixes the spacer 13 to the scanning signal wiring 9 is applied. It is formed on the interlayer insulating film 12 and the electron source 11. Therefore, the spacer 13 has a structure in which the lower end portion thereof is in contact with the conductive film 15 and is buried in the adhesive member 14 to be bonded and fixed.

  On the other hand, the upper end portion of the spacer 13 is fixedly arranged with an adhesive member 14 interposed between the phosphor layer 16 and the BM film 17 of the front substrate 2 on which the conductive BM (black matrix) film 17 is formed. Therefore, the spacer 13 is electrically connected between the scanning signal wiring 9 and the BM film 17 via the adhesive member 14 and is mechanically fixedly disposed.

  Reference numeral 19 denotes an anode power source for supplying an anode voltage of 5 kV to 20 kV to the BM film 17, reference numeral 20 denotes an electron beam emitted from the electron source 11, and reference numeral 21 denotes a region where the conductive film 15 is formed.

Next, a method for manufacturing a display panel on which the conductive film 15 is formed will be described with reference to a perspective view shown in FIG.
First, as shown in FIG. 3A, an opening H that emits the electron beam 20 from the electron source 11 is opened in the interlayer insulating film 12 formed on the back substrate 1 as shown in FIG. A conductive glass frit serving as the adhesive member 14 is applied onto the scanning signal wiring 9 on which the spacer 13 is disposed by using a printing method or a dispenser method. Next, the back substrate 1 is heated to about 300 ° C. to 500 ° C. which is about the melting point of the frit glass, the frit glass and the binder of the conductive paste are decomposed, and the gas from the frit is released to form the adhesive member 14.

  Next, as shown in FIG. 3C, after the adhesive member 14 is formed, a conductive film 15 is formed on the entire surface by, for example, Au / Pt / Ir material by sputtering. Next, as shown in FIG. 3 (d), the spacer 13 and a support (not shown) are arranged on the conductive film 15, the front substrate 2 with the adhesive member 14 applied on the inner surface is aligned, and again about 300 ° C. to 500 ° C. The frit glass is melted by heating to ° C., and the rear substrate 1, the front substrate 2, the spacer 13, and a support (not shown) are bonded and fixed to each other to complete the display panel.

  FIG. 4 is an enlarged plan view showing the positional relationship between the spacer 13 and the scanning signal wiring 9 as seen from above. As shown in FIG. 4, the spacer 13 is disposed within the electrode width of the scanning signal wiring 9, and the conductive adhesive member 14 whose entire surface is covered with the conductive film 15 protrudes outside the width of the spacer 13. The conductive film 15 is formed on the entire lower end portion of the spacer 13.

  In such a configuration, the conductive film 15 is also formed on the surface of the conductive adhesive member 14 by forming the conductive film 15 after forming the conductive adhesive member 14 on the scanning signal wiring 9, and the conductive adhesive member 14 can be reliably prevented from being charged. Further, the lower end portion that contacts the spacer 13 is covered with the conductive film 15, and good electrical continuity with the scanning signal wiring 9 is obtained through the conductive adhesive member 14. Further, the surface of the conductive film 15 is connected to the scanning signal wiring 9 from the lower end portion of the spacer 13 via the surface of the conductive adhesive member 14, and a good connection is obtained. In particular, the conductive film 15 continuous in the longitudinal direction at the lower end portion of the spacer 13 is in contact with the spacer 13, and the entire lower end portion of the spacer 13 can be connected to the scanning signal wiring 9.

  Finally, after the exhaust pipe 4 shown in FIG. 1B is evacuated and the inside of the display panel is evacuated and sealed, the image signal driving circuit 8 and the scanning signal driving circuit 10 are connected to connect the image display device. Complete.

  In the display panel manufactured in this way, as shown in an enlarged cross-sectional view of the main part in FIG. 5, the electron beam 20 emitted from the electron source 11 by the differential voltage between the scanning signal wiring 9 and the image signal wiring (not shown) during operation. Advances toward the conductive BM film 17 on the front substrate 2 to which a positive high voltage is applied by the anode power source 19 shown in FIG. Even if the electron beam 20 is scattered and the surface of the conductive adhesive member 14 on the side of the spacer 13 and the back substrate 1 is irradiated with the electron beam 20, the surface of the conductive adhesive member 14 is difficult to be charged. It goes straight and emits light by irradiating the phosphor layer 16 directly above the electron source 11. Since the electron beam 20 advances straight with high accuracy in the same manner in the phosphor layer 16 in the vicinity of the spacer 13 and in the distant phosphor layer, display defects are unlikely to occur.

  The image display apparatus configured as described above has a mutual conduction path by a conductive adhesive 14 bonded and fixed between the scanning signal wiring 9 and the lower end of the spacer 13 as shown in an enlarged sectional view of the main part in FIG. Therefore, even when the non-connection portion G occurs due to uneven dispersion of the conductive metal particles in the conductive adhesive material 14 and segregation of the frit glass, it is substantially uniformly reduced over the entire end portion of the spacer 13. The spacer 13 is electrically connected to the scanning signal wiring 9 by resistance.

  7, the surface of the adhesive member 14b that protrudes outward from the spacer overlapping portion 14a on the scanning signal wiring 9 of the conductive adhesive member 14 is also covered with the conductive film 15, as shown in an enlarged cross-sectional view of the main part. In addition, it is difficult to be charged even when irradiated with an electron beam, and the electric field is not easily disturbed in the peripheral part, so that the change in the path of the electron beam is easy to go straight and reaches a predetermined phosphor layer, thereby preventing poor image quality. it can. In the figure, 141 is a conductive metal particle, and 142 is a glass segregation part.

  FIG. 8 is an enlarged cross-sectional view of the main part showing the configuration of the spacer bonding portion for explaining the second embodiment of the image display device according to the present invention. Is omitted. In FIG. 8, the difference from the first embodiment is that a spacer conductive layer 21 made of, for example, Au / Pt / Ir material is formed on the lower end portion of the spacer 13 and the leg portion 13a including the peripheral portion thereof by a vacuum deposition method such as sputtering. Is formed by deposition.

  Further, a non-conductive adhesive member 22 made of only an adhesive frit glass not including a conductive member is applied on the scanning signal wiring 9, and spacer legs 13 a are embedded in the adhesive member 22. Then, the conductive film 15 is formed on the surfaces of the adhesive member 22, the spacer leg 13 a and the scanning signal wiring 9. Thus, the conductive layer 21 formed on the spacer leg 13a, the conductive film 15, and the scanning signal wiring 9 are connected.

  Even in such a configuration, the same effects as those of the first embodiment can be obtained. Further, in such a configuration, since an expensive conductive member such as Au or Ag is not used as the adhesive member 22, an electrical connection structure can be manufactured at a low cost. Alternatively, a metal thin film such as Al, Cr, Ni, Au, or an alloy thereof may be formed as the conductive layer 21 on the portion of the leg 13a of the spacer 13 that contacts the nonconductive adhesive member 22. Alternatively, the conductive layer 21 may be formed by a vacuum deposition method such as sputtering, an electroless plating method, or a metal paste printing and firing method.

  Further, in such a configuration, since the conductive film 15 is formed of a very thin film, the conductive film 15 is electrically conductive due to the deformation of the shape of the nonconductive adhesive member 22 when the spacer 13 is assembled according to the present embodiment. Even if the film 15 is partially broken, more reliable contact can be obtained by combining the spacer conductive layer 21.

  FIG. 9 is an enlarged cross-sectional view showing the main part of the structure of the display panel for explaining the third embodiment of the image display device according to the present invention. Omitted. In FIG. 9, the difference from each of the embodiments described above is that a metal back film 23 made of a vapor deposition film of an aluminum material is formed on the entire surface of the phosphor layer 16 and the BM layer 17 formed on the inner surface of the front substrate 2. The upper end portion of the spacer 13 is bonded and fixed on the metal back film 23 by the conductive adhesive member 14.

  The phosphor layer 16 disposed on the inner surface of the front substrate 2 includes a plurality of phosphor layers for red, green, and blue, and these are partitioned by a light-shielding BM (black matrix) film 17. Further, a metal back film (anode electrode) 23 made of a metal thin film is provided by, for example, a vapor deposition method so as to cover these to form a phosphor screen. The BM film 17 is set to a thickness of about several hundred μm, and the metal back film 23 is set to a thickness of about several tens to several hundreds of nm.

Here, as the phosphor layer 16, for example, Y ₂ O ₂ S: Eu (P22-R) as red, ZnS: Cu, Al (P22-G) as green, and ZnS: Ag, Cl (blue as blue) P22-B) can be used. With this phosphor screen configuration, electrons radiated from the electron source 11 are accelerated and projected onto the phosphor layer 16 constituting the corresponding pixel. As a result, the phosphor layer 16 emits light of a predetermined color and is mixed with the emission color of the phosphors of other pixels to form a color pixel of a predetermined color. In addition, although the BM film 17 is shown as a surface electrode, it may be a stripe electrode that intersects the scanning signal wiring 9 and is divided for each pixel column.

  In such a configuration, since the entire upper end portion of the spacer 13 and the metal back film 23 are in direct contact with each other, good conduction is obtained, and in particular, the connection in the longitudinal direction of the spacer 13 becomes substantially uniform. It is difficult for minute discharges to occur, and reliability is improved. Further, since the metal back film 23 can also be used as the conductive film with the spacer 13, the reliability can be improved without increasing the number of steps.

  The metal back film 23 may be a transparent conductive film such as ITO (Indium Tin Oxide), or a film having surface conductivity such as a conductive paste, instead of a vapor deposition film made of an aluminum material. In addition, when a transparent conductive film is used, the heat resistance is high, and even if the transparent conductive film is used in a high temperature process, the increase in surface resistance value is small. In addition, since the metal thin film such as Au has good conductivity and high electron beam transmittance, the utilization efficiency of the electron beam 20 is increased.

  10A and 10B are diagrams for explaining an example of an electron source that constitutes a pixel of the image display device of the present invention. FIG. 10A is a plan view, and FIG. 10B is an AA view of FIG. FIG. 10C is a cross-sectional view taken along the line BB ′ of FIG. 10A. This electron source is a MIM type electron source.

  The structure of this electron source will be described in the manufacturing process. First, the lower electrode DED (the image signal electrode 7 in each of the above embodiments), the protective insulating layer INS1, and the insulating layer INS2 are formed on the back substrate SUB1. Next, the interlayer film INS3, the upper bus electrode (scanning signal electrode 9 in each of the above embodiments) serving as a power supply line to the upper electrode AED, and the metal film serving as the spacer electrode for disposing the spacer 13 are sputtered, for example. The film is formed by a method or the like. Aluminum can be used for the lower electrode and the upper electrode, but other metals described later can also be used.

  As the interlayer film INS3, for example, silicon oxide, silicon nitride, silicon, or the like can be used. Here, silicon nitride is used and the film thickness is about 100 nm. When the protective insulating layer INS1 formed by anodic oxidation has a pinhole, the interlayer film INS3 fills the defect, and the upper bus electrode (metal film lower layer MDL and metal film upper layer MAL that becomes the lower electrode DED and the scanning signal electrode) The metal film intermediate layer MML plays a role of maintaining insulation between the three layers of the laminated film with copper (Cu) interposed therebetween.

  Note that the upper bus electrode is not limited to the above three-layer laminated film, and may have a larger number of layers. For example, as the metal film lower layer MDL and the metal film upper layer MAL, a metal material having high oxidation resistance such as aluminum (Al), chromium (Cr), tungsten (W), molybdenum (Mo), or an alloy containing them or a laminate thereof A membrane can be used. Here, an alloy of aluminum and neodymium (Al—Nd) was used as the metal film lower layer MDL and the metal film upper layer MAL. In addition, a laminated film of Al alloy and Cr, W, Mo or the like is used as the metal film lower layer MDL, and a laminated film of Cr, W, Mo or the like and Al alloy is used as the metal film upper layer MAL. By using a five-layer film in which the film in contact with Cu is a refractory metal, the refractory metal becomes a barrier film during the heating step in the manufacturing process of the image display device, so that alloying of Al and Cu can be suppressed. This is particularly effective for reducing the resistance of the wiring.

  When only the Al-Nd alloy is used as the metal film lower layer MDL and the metal film upper layer MAL, the film thickness of the Al-Nd alloy is such that the metal film upper layer MAL is thicker than the metal film lower layer MDL and the Cu of the metal film intermediate layer MML is made. Is as thick as possible to reduce the wiring resistance. Here, the metal film lower layer MDL is about 300 nm, the metal film intermediate layer MML is about 4 μm, and the metal film upper layer MAL is about 450 nm. Note that Cu in the metal film intermediate layer MML can be formed by electroplating or the like in addition to sputtering.

  In the case of the above five-layer film using a refractory metal, a multilayer film in which Cu is sandwiched between Mo that can be wet-etched with a mixed aqueous solution of phosphoric acid, acetic acid and nitric acid is used as the metal film intermediate layer MML, similarly to Cu. Is particularly effective. In this case, the film thickness of Mo sandwiching Cu is about 50 nm, the Al alloy of the metal film lower layer MDL sandwiching the metal film intermediate layer is about 300 nm, and the Al alloy of the metal film upper layer MAL is about 450 nm.

  Subsequently, the metal film upper layer MAL is processed into a stripe shape intersecting with the lower electrode DED by patterning a resist by screen printing and etching. In this etching process, for example, wet etching using a mixed aqueous solution of phosphoric acid and acetic acid is used. By not adding nitric acid to the etching solution, it is possible to selectively etch only the Al—Nd alloy without etching Cu.

  Also in the case of a five-layer film using Mo, it is possible to selectively etch only an Al—Nd alloy without etching Mo and Cu by not adding nitric acid to the etching solution. Although one metal film upper layer MAL is formed per pixel here, two metal film upper layers MAL may be formed.

  Subsequently, the same resist film is used as it is, or Cu of the metal film intermediate layer MML is wet-etched with a mixed aqueous solution of phosphoric acid, acetic acid and nitric acid, for example, using the Al—Nd alloy of the metal film upper layer MAL as a mask. Since the etching rate of Cu in an etching solution of a mixed aqueous solution of phosphoric acid, acetic acid, and nitric acid is sufficiently higher than that of an Al—Nd alloy, only Cu in the metal film intermediate layer MML can be selectively etched. . Also in the case of a five-layer film using Mo, the etching rate of Mo and Cu is sufficiently higher than that of an Al—Nd alloy, and it is possible to selectively etch only the three-layer film of Mo and Cu. . Other ammonium persulfate aqueous solutions and sodium persulfate aqueous solutions are also effective for etching Cu.

  Subsequently, the metal film lower layer MDL is processed into a stripe shape intersecting with the lower electrode DED by resist patterning and etching by screen printing. This etching process is performed by wet etching with a mixed aqueous solution of phosphoric acid and acetic acid. At that time, by shifting the resist film to be printed from the position of the stripe electrode of the metal film upper layer MAL, one end EG1 of the metal film lower layer MDL is projected from the metal film upper layer MAL, and the upper electrode is formed in a later step. A contact portion that secures connection with the AED. In addition, the other one end EG2 of the metal film lower layer MDL opposite to the one one end EG1 is over-etched using the metal film upper layer MAL and the metal film intermediate layer MML as a mask, and the metal film intermediate layer A recessed portion is formed so as to form a ridge in the MML.

  The upper electrode AED formed in a later step is separated by the metal film intermediate layer MML. At this time, since the metal film upper layer MAL is thicker than the film thickness of the metal film lower layer MDL, the metal film upper layer MAL is left on the Cu of the metal film intermediate layer MML even after the etching of the metal film lower layer MDL is finished. Can do. As a result, the surface of Cu can be protected, so that the upper bus electrode which is oxidation resistant even if Cu is used, and which separates the upper electrode AED in a self-aligned manner and serves as a scanning signal wiring for supplying power Can be formed. Further, in the case of a five-layer metal film intermediate layer MML in which Cu is sandwiched between Mo, even if the Al alloy of the metal film upper layer MAL is thin, Mo suppresses oxidation of Cu, so the metal film upper layer It is not always necessary to make MAL thicker than the film thickness of the metal film lower layer MDL.

Subsequently, the interlayer film INS3 is processed to open an electron emission portion. The electron emission portion includes one lower electrode DED in the pixel and two upper bus electrodes intersecting the lower electrode DED (a laminated film of a metal film lower layer MDL, a metal film intermediate layer MML, and a metal film upper layer MAL and an adjacent not shown) It is formed at a part of the intersection of the space sandwiched between the metal film lower layer MDL, the metal film intermediate layer MML, and the metal film upper layer MAL. This etching process can be performed, for example, by dry etching using an etching gas containing CF ₄ or SF ₆ as a main component.

  Finally, the upper electrode AED is formed. A sputtering method is used for this film formation. As the upper electrode AED, aluminum may be used, or a laminated film of iridium (Ir), platinum (Pt), and gold (Au) may be used, and the film thickness may be about 6 nm, for example. At this time, the upper electrode AED has a metal film intermediate at one end (the right side of FIG. 10C) of the upper bus electrode (laminated film of the metal film lower layer MDL, the metal film intermediate layer MML, and the metal film upper layer MAL). The layer MML and the metal film upper layer MAL are cut by the receding portion (EG2) of the metal film lower layer MDL due to the saddle structure. At the other end of the upper bus electrode (left side of FIG. 10C), the upper electrode AED is connected to the upper bus electrode (a laminated film of the metal film lower layer MDL, the metal film intermediate layer MML, and the metal film upper layer MAL). Has a structure in which the film is connected to the electron emission portion without being disconnected by the contact portion (EG1) of the metal film lower layer MDL and is fed to the electron emission portion.

  Next, FIG. 11 is an explanatory diagram of an equivalent circuit example of an image display device to which the configuration of the present invention is applied. A region indicated by a broken line in FIG. 11 is a display region 6. In this display region 6, n image signal electrodes 8 and m scanning signal wirings 9 are arranged so as to cross each other, and an n × m matrix. Pixels arranged in the same manner are formed. Each intersection of the matrix constitutes a sub-pixel, and one group of three unit pixels (or sub-pixels) “R”, “G”, and “B” in the figure constitutes one color pixel. The configuration of the electron source is not shown. The image signal wiring (cathode electrode) 7 is connected to the image signal driving circuit DDR at the image signal electrode lead-out terminal, and the scanning signal wiring (gate electrode) 9 is connected to the scanning signal driving circuit SDR at the scanning signal electrode lead-out terminal. . The image signal NS is input from the external signal source to the image signal driving circuit DDR, and the scanning signal SS is similarly input to the scanning signal driving circuit SDR.

  Accordingly, a two-dimensional full-color image can be displayed by supplying a video signal to the image signal wiring 7 that intersects the scanning signal wiring 9 that is sequentially selected. By using the display panel of this configuration example, an image display apparatus with a relatively low voltage and high efficiency is realized.

1A and 1B are diagrams for explaining an embodiment of an image display device of the present invention, in which FIG. 1A is a plan view seen from the front substrate side, and FIG. 1B is a side view of FIG. It is a schematic cross section along the AA line of FIG. It is a principal part perspective view explaining the manufacturing method of the display panel concerning this invention. It is a principal part enlarged plan view which shows the positional relationship of a spacer and scanning signal wiring. FIG. 4 is an enlarged cross-sectional view of a main part for explaining the effect of the configuration of Example 1. It is a principal part expanded sectional view which shows the adhesion structure of a spacer and scanning signal wiring. It is a principal part expanded sectional view which shows the adhesion structure by a conductive adhesive member. It is a principal part expanded sectional view of the spacer adhesion part which shows the structure of Example 2 of the image display apparatus by this invention. It is a principal part expanded sectional view which shows the structure of Example 3 of the image display apparatus by this invention. It is a figure explaining an example of the electron source which comprises the pixel of the image display apparatus of this invention. It is explanatory drawing of the equivalent circuit example of the image display apparatus to which the structure of this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Back substrate, 2 ... Front substrate, 3 ... Support body, 4 ... Exhaust pipe, 5 ... Display area, 6 ... Through-hole, 7 ... Image signal wiring, DESCRIPTION OF SYMBOLS 8 ... Image signal drive circuit, 9 ... Scan signal wiring, 10 ... Scan signal drive circuit, 11 ... Electron source, 12 ... Interlayer insulation film, 13 ... Spacer, 13a ... Spacer legs, 14 ... conductive adhesive, 15 ... conductive film, 16 ... phosphor layer, 17 ... conductive BM film, 19 ... anode power supply, 20 ... electrons Wire, 21 ... Spacer conductive layer, 22 ... Non-conductive adhesive member, 23 ... Metal back film, SUB1 ... Back substrate, SUB2 ... Front substrate, INS ... Insulating film (interlayer) Insulating film).

Claims (11)

A front substrate having a phosphor layer and an anode electrode on its inner surface;
A plurality of scanning signal wirings extending in one direction and arranged in parallel in the other direction intersecting the one direction and sequentially applying a scanning signal in the other direction, and extending in the other direction and intersecting the scanning signal wiring As described above, a plurality of image signal wirings arranged in parallel in the one direction, and an electron source provided in the vicinity of each intersection of the scanning signal wiring and the image signal wiring on the inner surface, and a predetermined distance from the front substrate. An opposing back substrate,
A support that is inserted around the display area between the front substrate and the rear substrate, and holds the predetermined distance;
A plurality of spacing members disposed in the display area between the front substrate and the back substrate;
An adhesive member for joining the end portion of the spacing member and the front substrate and the back substrate, respectively, and the end portion of the support and the front substrate and the back substrate are hermetically sealed via sealing members, respectively. An image display device comprising:
The spacing member is disposed so as to overlap with the scanning signal wiring and extend in the same direction as the scanning signal wiring, and a conductive film is formed on the surface of the adhesive member that joins the rear substrate and the end of the spacing holding member. An image display device formed, wherein the conductive film is connected to the scanning signal wiring.   The image display device according to claim 1, wherein the conductive film is disposed so as to extend from a lower end portion of the spacing member.   The image display device according to claim 1, wherein the adhesive member includes a conductive member and has conductivity. The image display device according to claim 1, wherein the spacing member has a resistance value of 10 ⁸ to 10 ⁹ Ω · cm.   The image display device according to claim 1, wherein the spacing member is made of a ceramic material and has a total length of 200 mm or less.   The image display device according to claim 1, wherein the spacing member is made of a glass material and has a total length of 200 mm or less.   The image display device according to claim 1, wherein the rear substrate includes a power supply electrode that connects the electron source and the scanning signal wiring. A black matrix film having a plurality of openings, a plurality of color phosphor layers arranged to cover the openings and extending to the black matrix film, and covering the phosphor layer and the black matrix film A front substrate having an anode electrode made of a metal thin film on its inner surface;
A plurality of scanning signal wirings extending in one direction and arranged in parallel in the other direction intersecting the one direction and sequentially applying a scanning signal in the other direction, and extending in the other direction and intersecting the scanning signal wiring As described above, a plurality of image signal wirings arranged in parallel in the one direction, an electron source provided near each intersection of the scanning signal wirings and the image signal wirings on the inner surface, A back substrate facing with a gap;
A support that is inserted around the display area between the front substrate and the rear substrate, and holds the predetermined distance;
A plurality of spacing members arranged to extend in the same direction as the scanning signal wiring so as to overlap the scanning signal wiring in the display region between the front substrate and the rear substrate;
An adhesive member for joining the end portion of the spacing member to the front substrate and the back substrate, respectively, and the end portion of the support body and the front substrate and the back substrate are respectively sealed via a sealing member. An image display device hermetically sealed,
An image display device, wherein a conductive film is formed on a surface of an adhesive member that joins the scanning signal wiring and an end of the spacing member, and the conductive film is connected to the scanning signal wiring.   The image display apparatus according to claim 8, wherein the conductive film is a metal thin film.   The image display apparatus according to claim 9, wherein the metal thin film uses a thin film material constituting an electron source. The image display device according to claim 9, wherein the metal thin film is made of an electron-transmitting thin film material constituting a surface of an electron source.

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