JP3697232B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is for a display panel that draws a plurality of wiring electrodes from the inside to the outside of a container and applies a drive signal through the wiring. Display device using substrate About.
[0002]
[Prior art]
Conventionally, as a display device, there are a gas discharge type such as a PDP (plasma display panel) and a type that irradiates a light emitting member such as an FED (field emission display) with an electron beam (electron beam irradiation type). Are known. Two types of electron-emitting devices for electron beam irradiation displays are known: a thermal electron source and a cold cathode electron source.
[0003]
Cold cathode electron sources include field emission devices (FE devices), metal / insulating layer / metal devices (MIM devices), surface conduction electron emitters, and the like.
[0004]
Since the above-described surface conduction electron-emitting device has a simple structure and is easy to manufacture, it has an advantage that it can be formed in large numbers over a large area. Various applications have been studied to take advantage of this feature. For example, it is applied to a display device such as a charged beam source or an image forming apparatus. As an example, in Japanese Patent Application Laid-Open Nos. 2000-251778 and 2000-251802 by the present applicant, an electron source substrate in which a large number of electron-emitting devices are connected to a matrix wiring and a counter substrate on which a phosphor is arranged are bonded together. An image forming apparatus having a high vacuum container (display panel) is disclosed.
[0005]
[Problems to be solved by the invention]
However, when constructing an image forming apparatus in which a high-vacuum container (display panel) is formed by bonding together an electron source substrate in which a large number of electron-emitting devices are connected by matrix wiring and a counter substrate on which a phosphor is disposed, as described above. There are the following problems in increasing the area and quality.
[0006]
First, a thick film paste made of metal and glass-based material is used as a wiring material in order to satisfy the required wiring resistance. It is necessary to make the width sufficiently small. Depending on the purpose of use of the display device, etc., it is desirable that the wiring width be about 70 μm or less for a high-definition display device that can be sufficiently utilized for general purposes.
[0007]
Further, as in the surface conduction electron-emitting device described in the above-mentioned JP-A-2000-251778, the opposing gap of the electrode pair (device electrode) is arranged in parallel with the column (Y) direction wiring (lower wiring), and the electron emitting portion When the electron source substrate is formed so that is formed in a line shape substantially parallel to the Y-direction wiring (lower wiring) 2, the edge of the Y-direction wiring is displayed in the display area due to the requirement for the trajectory control of emitted electrons. The height is required to be sufficiently high (for example, about 14 μm).
[0008]
Further, as described above, a sufficient height is required to sufficiently reduce the resistance value of the wiring.
[0009]
The “display area” means an orthogonal projection area of the image forming member such as fluorescence onto the wiring substrate, and the display panel is formed by arranging the electron source substrate as described above and the transparent substrate on which the phosphor is formed facing each other. In this case, a region facing the phosphor on the electron source substrate (wiring substrate) is equal to a region orthogonally projected to the wiring substrate of the image forming member (phosphor).
[0010]
As a result of examining specific means for realizing the formation of a wiring with a minimum line width and a sufficient height (thickness) in order to achieve both high definition and low resistance of the matrix wiring in the display region, As a forming method, it has been found that the transition from the conventional screen printing method to the photolithography method using a photo paste material is preferable. That is, in the conventional printed wiring, since the cross-sectional shape is a gentle semicircular shape, it is difficult to realize a high-definition wiring width while having a sufficient height. As a wiring shape having a narrow width and sufficient height (thickness), a rectangular wiring with a sharp edge is preferable, and a photolithography method using a photo paste is preferable to form a wiring with this shape. It was.
[0011]
However, when the thickness is increased in order to ensure the edge height of the wiring in the photo paste material for the purpose of reducing the wiring resistance and controlling the electron trajectory of the electron-emitting device as described above, the pattern edge is curled (patterned). There is a case where a problem occurs that a crack is easily generated in the substrate and the airtightness of the panel sealing portion on the outer periphery of the display region is lowered (leakage path is generated).
[0012]
The main object of the present invention is to improve such drawbacks, and an airtight container capable of maintaining a vacuum atmosphere and the like while achieving high brightness and high definition of an image display device and an image forming device using a wiring board. To achieve a higher quality image.
[0013]
[Means for Solving the Problems]
That is, the present invention Display device Has multiple wiring electrodes on the substrate. Wiring board to be connected to the wiring board Has wiring electrode A frame member located on the surface; Through the frame member Located facing the wiring board Counter substrate And having Display having an image forming member in an airtight container apparatus Because The average angle formed between the surface of the wiring board in contact with the wiring and the side surface of the wiring is: Orthographic projection area of the image forming member onto the wiring board At least part of Obtuse and and In the area where the frame member is placed Leave It is characterized by an acute angle.
[0014]
The present invention described above is The width of the wiring in the orthogonal projection area of the image forming member on the wiring board is smaller than the width of the wiring in the area where the frame member is disposed. It is particularly effective in cases.
[0021]
According to the present invention, a desired wiring height is secured in the display area to reduce wiring resistance, and when the configuration of the present invention is used as a signal supply wiring to an electron-emitting device, The trajectory of electrons can be controlled well. Further, it is possible to realize a wiring board free from edge curl and side cracks in the sealing portion outside the display area.
[0022]
In addition, in an image forming apparatus such as an image display apparatus using such a wiring board, it is possible to realize a highly airtight and reliable image forming apparatus capable of maintaining a vacuum and the like while improving luminous efficiency.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described in detail below. Prior to that, the relationship between the wiring shape and the airtightness in the sealing portion will be described in detail with reference to the drawings.
[0024]
FIG. 16 shows a part of the lead-out portion in a so-called matrix wiring board in which the X-direction wiring and the Y-direction wiring cross each other through an insulating layer, and the wiring is drawn from the image display region to the end of the substrate. It is the elements on larger scale when there is an edge curl in the wiring shape of a certain sealing part, and it originates in the pattern edge of the Y direction extraction wiring 12 and the crack (referred to as a side crack) generated in the substrate, along the wiring. It is the figure which represented typically the leak path (124, 126) formed.
[0025]
According to the study by the present inventor, it has been clarified that cracks generated in such a substrate are suppressed by forming an insulating layer. Therefore, in order to prevent the occurrence of such cracks, for example, it is conceivable to form an insulating layer at the panel sealing portion at the same time when forming the insulating layer at the intersection of the matrix wiring portion. Since this insulating layer pattern also has an effect of alleviating unevenness due to the wiring pattern, it is also effective in the case of vacuum formation through a resin O-ring as the vacuum container forming member 13.
[0026]
However, if there is a pattern edge gap, a leak path called a mouse hole 124 is created between the insulating layer and the vacuum tightness is reduced as in the case of a leak path caused by a crack generated in the substrate.
[0027]
On the other hand, with respect to the mouse hole due to the pattern edge, the leak path can be eliminated by using frit glass as the vacuum container forming member 13. However, even if frit glass is used, it cannot cope with a vacuum leak caused by a crack generated in the substrate. Considering the case where a resin O-ring is used as the vacuum container forming member 13, the leak path cannot be eliminated unless the angle formed with the substrate of the wiring cross section at the sealing portion is at least an acute angle.
[0028]
Further, according to the study by the present inventor, it has been found that the occurrence of the edge curl of the wiring and the substrate crack has a pattern width dependency in addition to the film thickness dependency. That is, in a wiring having a certain height (thickness), if the width of the wiring becomes large, the substrate is likely to crack and edge curl is likely to occur. Therefore, it is possible to some extent to prevent the occurrence of edge curl and substrate crack by narrowing the wiring width.
[0029]
However, as described above, in the lead-out wiring and the mounting terminal portion, the actual situation is that the line width must be wider than in the display area because of the requirement of wiring resistance.
[0030]
Therefore, rectangular wiring that achieves both reduction of wiring resistance and high definition of wiring patterns also has problems to be solved in realizing an airtight container, and it is necessary to reduce wiring resistance, realize high definition patterns, and form an airtight container. To meet all, further improvements are needed.
[0031]
As a result of comprehensive consideration of various conditions required as a wiring board for a display panel as described above, the present invention has been achieved in which the wiring shape is rectangular in the display region and the wiring shape is smoothed in the sealing portion. . In other words, in the display area, the average angle that the cross section of the wiring forms with the substrate (Average angle between the surface of the wiring board in contact with the wiring and the side surface of the wiring) Is an obtuse angle, and the cross-section of the wiring at the sealing portion where the frame member is disposed has a wiring shape in which the average angle formed with the substrate is an acute angle, thereby reducing the resistance of the wiring described above, increasing the definition, and airtightness. Allows realization of the container. Here, the average angle that the cross section of the wiring forms with the substrate is an obtuse angle. This is the relationship between the wiring having the cross sectional shape as illustrated in FIG. 18 and the substrate surface, and the cross section of the wiring is formed with the substrate. The acute angle is the relationship between the wiring having a cross-sectional shape as exemplified in FIG. 17 and the substrate surface.
[0032]
Here, in order to further explain the present invention, the relationship between the cross-sectional shape of the wiring in the sealing portion and the crack and leak path of the substrate will be described.
[0033]
17 and 18 schematically show an average angle formed by the wiring cross section with the substrate. If the average angle is an acute angle as shown in FIG. 17, substrate cracks are unlikely to occur, and conversely if the average angle is obtuse as shown in FIG. 18, substrate cracks are likely to occur. Further, the fact that the average angle is an acute angle is the direction opposite to the edge curl, which is also effective in realizing vacuum tightness.
[0034]
Furthermore, from the viewpoint of pattern stability, resistance value, and process conditions for obtaining the resistance value, in the wiring forming method that can be used at present, it is easy to make the average angle of the pattern edge obtuse in the photolithography process, and the average of the pattern edge in the screen printing process. The angle can be easily made acute. Also, as a combination of this, a thick film with an average average pattern edge angle of an acute angle is superimposed on an obtuse wiring whose average edge of the pattern edge is not large in the photolithographic process, and an acute pattern of the average edge of the pattern edge in the screen printing process. We found that wiring was obtained.
[0035]
The present invention has been made based on the above knowledge, and the configuration thereof will be specifically described below. In the following description, the cross-sectional shape of the wiring is made different between the image display area (a region orthogonally projected onto the substrate surface on which the wiring of the image forming member is formed) and the outside of the image display area including the sealing portion. Although a form will be described, this is a particularly preferable form considering the viewpoint of manufacturing and the like, and it is sufficient that the cross-sectional shapes of the wirings are respectively desired in the image display region and the sealing portion. Embodiments of the present invention will be described below.
[0036]
The present applicant has made a number of proposals regarding electron-emitting devices and their applications, and examples of applications such as image forming apparatuses using surface-conduction electron-emitting devices will be introduced below.
[0037]
Regarding the production of elements by the ink jet method, Japanese Patent Application Laid-Open No. 9-102271 and Japanese Patent Application Laid-Open No. 2000-251665 are disclosed in Japanese Patent Application Laid-Open No. 64-031332, Japanese Patent Application Laid-Open No. No. 326311 is described in detail. Further, the wiring forming method is described in detail in JP-A-8-185818 and JP-A-9-50757, and the driving method is described in detail in JP-A-6-342636.
[0038]
Further details are described in, for example, Japanese Patent Application Laid-Open No. 7-235255 and Japanese Patent Registration No. 2903295.
[0039]
The outline of the surface conduction electron-emitting device disclosed in the above publication will be briefly described below.
[0040]
As schematically shown in FIG. 15, the surface conduction electron-emitting device includes a pair of device electrodes 2 and 3 opposed to the substrate 1, and an electron-emitting portion 5 connected to the device electrode at a part thereof. The conductive film 4 is provided.
[0041]
The electron emission portion 5 includes a portion in which a part of the conductive film 4 is broken, deformed, or altered and a gap is formed, and a process called activation is performed on the conductive film in and near the gap. By performing, the deposit which has carbon and / or a carbon compound as a main component is formed. The deposit has a shape facing the gap with a narrower gap than the gap formed in the conductive film.
[0042]
FIG. 2 shows a configuration example of an electron source substrate in which a number of surface conduction electron-emitting devices are connected in a matrix. In FIG. 2, 21 is a substrate, 2 and 3 are element electrodes, 4 is a conductive film (element film), 5 is an electron emission portion, 24 is a Y-direction wiring (lower wiring), 25 is an insulating layer, and 26 is an X-direction. Wiring (upper wiring).
[0043]
In the electron source substrate, a plurality of Y direction wirings (lower wirings) 24 and a plurality of X direction wirings (upper wirings) 26 are formed on the Y direction wirings 24 via an insulating layer 25 on the substrate 21. Electron emitting devices including electrode pairs (element electrodes 2 and 3) are disposed in the vicinity of the intersections of the bidirectional wirings, and one of the electrode pairs (element electrode 3) is connected to the Y-directional wiring 24 and the other (elements). The electrode 2) is connected to the X-direction wiring 26 through a contact hole provided in the insulating layer 25.
[0044]
Hereinafter, an example of a method for manufacturing the electron source substrate will be briefly described with reference to FIGS.
[0045]
First, a plurality of electrode pairs (element electrodes 2 and 3) are formed on the substrate 21 (see FIG. 3).
[0046]
Next, a plurality of Y-directional wirings (lower wirings) 24 are formed in a line pattern so as to be in contact with one element electrode (element electrode 3) and to connect them (see FIG. 4). Although not shown, the end portion of the Y-direction wiring (lower wiring) 24 is used as a lead-out wiring to the external drive circuit, so that the line width is made larger. The Y-direction wiring (lower wiring) 24 functions as a signal electrode after being panelized as an image forming apparatus using the electron source substrate.
[0047]
Next, an insulating layer 25 is formed to insulate the upper and lower wirings (see FIG. 5). The insulating layer 25 covers an intersection with the Y-direction wiring (lower wiring) 24 formed earlier below the X-direction wiring (upper wiring), which will be described later, and the X-direction wiring (upper wiring) and the other side. A contact hole 27 is formed in a connection portion corresponding to each element so that an electrical connection with the element electrode (element electrode 2) is possible.
[0048]
Next, an X-direction wiring (upper wiring) 26 is formed on the previously formed insulating layer 25 (see FIG. 6). The X-direction wiring 26 intersects the Y-direction wiring 24 with the insulating layer 25 interposed therebetween, and is connected to the element electrode 2 at a contact hole 27 portion provided in the insulating layer 25. Although not shown, the lead-out wiring to the external drive circuit is also formed by the same method. Since the X-direction wiring 26 functions as a scanning electrode after being panelized as an image forming apparatus and requires a lower wiring resistance than the Y-direction wiring 24 that functions as a signal electrode, the line width is increased or the film thickness is increased. To be designed.
[0049]
Next, the conductive film 4 is formed between the device electrodes 2 and 3 by, for example, an ink jet method described in Japanese Patent Application Laid-Open Nos. 9-102271 and 2000-251665 (see FIGS. 2 and 7).
[0050]
Next, by applying a pulse voltage between the bidirectional wirings 24 and 26 and energizing the device electrodes 2 and 3, the conductive film 4 is locally destroyed, deformed, or altered, so that it has an electrically high resistance. An electron emission part (gap) in a proper state is formed (forming process). An example of the pulse voltage waveform is shown in FIG. At this time, as shown in FIGS. 2 and 15, the electron emission portion (gap) 5 is formed in the gap portion where the device electrodes 2 and 3 face each other substantially in parallel with the gap.
[0051]
Next, in the atmosphere of a gas containing carbon atoms, a pulse voltage is applied between the bidirectional wirings 24 and 26 and electricity is applied between the device electrodes 2 and 3 in the same manner as the above forming, whereby carbon or a carbon compound is obtained. A carbon film is deposited in the vicinity of the gap (activation step). An example of a voltage waveform used for activation is shown in FIG.
[0052]
Through the above-described steps, an electron source substrate in which a large number of surface conduction electron-emitting devices are connected to the substrate by matrix wiring is manufactured.
[0053]
Next, basic characteristics of the electron-emitting device manufactured by the device configuration and the manufacturing method as described above will be described with reference to FIGS.
[0054]
FIG. 9 is a schematic diagram of a measurement evaluation apparatus for measuring the electron emission characteristics of the electron-emitting device having the above-described configuration. In FIG. 9, 51 is a power source for applying an element voltage Vf to the element, 50 is an ammeter for measuring the element current If flowing through the electrode part of the element, and 54 is an emission current emitted from the electron emission part of the element. An anode electrode for capturing Ie, 53 is a high voltage power source for applying a voltage to the anode electrode 54, and 52 is an ammeter for measuring the emission current Ie emitted from the electron emission portion of the device.
[0055]
In measuring the device current If flowing between the device electrodes 2 and 3 of the electron-emitting device and the emission current Ie to the anode, a power source 51 and an ammeter 50 are connected to the device electrodes 2 and 3, and the electron-emitting device An anode electrode 54 to which a power source 53 and an ammeter 52 are connected is disposed above.
[0056]
In addition, the electron-emitting device and the anode electrode 54 are installed in a vacuum device 55. The vacuum device is equipped with devices necessary for the vacuum device such as an exhaust pump 56 and a vacuum gauge. The device can be measured and evaluated. The voltage of the anode electrode 54 was measured in the range of 1 kV to 10 kV, and the distance H between the anode electrode and the electron-emitting device was measured in the range of 2 mm to 8 mm.
[0057]
FIG. 10 shows a typical example of the relationship between the emission current Ie and the device current If measured by the measurement evaluation apparatus shown in FIG. 9 and the device voltage Vf. Although the emission current Ie and the device current If are significantly different in magnitude, in FIG. 10, the vertical axis is expressed in arbitrary units on a linear scale for qualitative comparison of changes in If and Ie.
[0058]
This electron-emitting device has three characteristics with respect to the emission current Ie.
[0059]
First, as is apparent from FIG. 10, when an element voltage higher than a certain voltage (referred to as threshold voltage, Vth in FIG. 10) is applied to this element, the emission current Ie increases rapidly. The emission current Ie is hardly detected below the threshold voltage Vth. That is, it can be seen that the characteristics as a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie are shown.
[0060]
Second, since the emission current Ie depends on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.
[0061]
Thirdly, the emitted charge captured by the anode electrode 54 depends on the time during which the device voltage Vf is applied. That is, the amount of charge trapped by the anode electrode 54 can be controlled by the time during which the element voltage Vf is applied.
[0062]
Next, the electron source substrate and the image forming apparatus according to the present invention will be described.
[0063]
The basic configuration of the electron source substrate of the present invention includes the configuration illustrated in FIG.
[0064]
The electron source substrate of the present invention has a plurality of Y-directional wirings (lower wirings) 24 on a substrate 21 and a plurality of X-directional wirings (upper wirings) 26 on the column-directional wirings 24 via an insulating layer 25. An electron-emitting device including an electrode pair (device electrodes 2 and 3) is disposed in the vicinity of the intersection of the two-way wirings. In particular, as shown in FIG. 3 opposing gap portions are arranged substantially parallel to the Y-direction wiring (lower wiring).
[0065]
A feature of the electron source substrate according to an embodiment of the present invention will be described with reference to FIG. 1. When a display panel is configured by facing a transparent substrate on which a light emitting material is formed, the light emitting material is formed. In the display area facing the area, at least the Y-direction wiring 24 has a cross-sectional shape as illustrated in FIG. 18 in which the average angle formed with the substrate is an obtuse angle. Outside the display area, the XY bidirectional wiring, That is, the X-direction lead wiring 11 and the Y-direction lead wiring 12 have a cross-sectional shape as illustrated in FIG. 17 where the average angle formed with the substrate is an acute angle.
[0066]
In the present invention, the average angle means an angle formed by a straight line (synthetic line) obtained by synthesizing the outline of the cross section of the wiring and the surface of the substrate. In the case of a wiring shape that narrows in the direction away from the substrate, an acute angle is formed with the substrate surface. In the case of a wiring shape in which the width of the wiring increases in the direction away from the substrate, the obtuse angle with the substrate surface. Form.
[0067]
In addition, if the average angle that the wiring forms with the substrate is an acute angle, the direction of stress applied to the edge at the contact portion of the wiring with the substrate is also an acute angle with respect to the substrate surface, and the wiring is When the average angle to be formed is an obtuse angle, the direction of stress applied to the edge at the contact portion of the wiring with the substrate also becomes an obtuse angle with respect to the substrate surface.
[0068]
A specific method for forming each wiring having the cross-sectional shape as described above will be described in detail in Examples below.
(1) A method in which at least the Y-direction wiring 24 is formed in the display area by a photolithographic method using a photo paste, and the XY bidirectional lead wirings 11 and 12 are formed by pattern printing by a screen printing method outside the display area.
(2) A pattern is formed by a photolithographic method using a photo paste for at least the Y direction wiring 24 in the display area and for both the XY bidirectional lead lines 11 and 12 outside the display area, and then at least outside the display area. A method of firing at the same time as an overcoat layer that burns at a temperature higher than the burning temperature of the organic component and lower than the softening point of the inorganic component.
Is preferred.
[0069]
Note that a photosensitive resin such as a photosensitive acrylic resin can be used as the overcoat layer.
[0070]
As described above, by controlling the cross-sectional shape of each wiring in the display area and outside the display area, the desired Y-direction wiring height can be secured in the display area and the trajectory control of emitted electrons can be performed satisfactorily. Outside the display area, it is possible to obtain an electron source substrate free from edge curl and side cracks in both direction wirings.
[0071]
Next, an example of the image forming apparatus of the present invention using the electron source substrate having the simple matrix arrangement as described above will be described with reference to FIG.
[0072]
In FIG. 12, 21 is the electron source substrate, 82 is a face plate having a fluorescent film 84 and a metal back 85 formed on the inner surface of a glass substrate 83, and 86 is a support frame. The electron source substrate 21, the support frame 86, and the face plate 82 are bonded with frit glass, and baked at 400 to 500 ° C. for 10 minutes or more to be sealed, thereby forming the envelope 90.
[0073]
In addition, by installing a support body (not shown) called a spacer between the face plate 82 and the electron source substrate 21, an envelope 90 having sufficient strength against atmospheric pressure even in the case of a large area panel. Can also be configured.
[0074]
FIG. 13 is an explanatory diagram of the fluorescent film 84 provided on the face plate 82. In the case of a monochrome film, the fluorescent film 84 is composed only of a fluorescent material. In the case of a color fluorescent film, the fluorescent film 84 is composed of a black conductor 91 and a fluorescent material 92 called a black stripe or a black matrix depending on the arrangement of the fluorescent materials. . The purpose of providing the black stripes and the black matrix is to make the mixed colors and the like inconspicuous by making the coating portions between the phosphors 92 of the three primary color phosphors necessary for color display black, It is to suppress a decrease in contrast due to external light reflection.
[0075]
A metal back 85 is usually provided on the inner surface side of the fluorescent film 84. The purpose of the metal back is to improve the luminance by specularly reflecting the light emitted from the phosphor toward the inner surface to the face plate 82 side, to act as an anode electrode for applying an electron beam acceleration voltage, etc. It is. The metal back can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like.
[0076]
When performing the above-mentioned sealing, in the case of a color, each color phosphor must correspond to the electron-emitting device, so that it is necessary to perform sufficient alignment by a method of abutting the upper and lower substrates.
[0077]
The degree of vacuum at the time of sealing is 10 ^-Five In addition to requiring a degree of vacuum of about Pa, a getter process may be performed to maintain the degree of vacuum after the envelope 90 is sealed. This heats a getter disposed at a predetermined position (not shown) in the envelope by a heating method such as resistance heating or high frequency heating immediately before or after sealing the envelope 90, This is a process for forming a deposited film. The getter usually contains Ba or the like as a main component, and maintains the degree of vacuum by the adsorption action of the deposited film.
[0078]
At this time, the electron source substrate of the present invention can eliminate edge curl and side cracks in the two-way lead-out wiring outside the display area, thereby preventing the occurrence of a leak path as shown in FIG. 16 and forming an image with high vacuum reliability. A device can be realized.
[0079]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to these examples.
[0080]
[Example 1]
This example is an example of manufacturing an electron source substrate in which a large number of surface conduction electron-emitting devices as shown in FIG. In FIG. 2, 21 is a substrate, 2 and 3 are element electrodes, 4 is a conductive film (element film), 5 is an electron emission portion, 24 is a Y-direction wiring (lower wiring), 25 is an insulating layer, and 26 is an X-direction. Wiring (upper wiring).
[0081]
2 shows only the display region of the electron source substrate. In the actually manufactured electron source substrate, as shown in FIG. 1, the Y-direction wiring 24 formed in the display region is outside the display region. The X direction wiring 26 is connected to the Y direction lead wiring 11, and the X direction wiring 26 is connected to the X direction lead wiring 11. Since the X direction wiring 26 functions as a scanning electrode after being paneled and requires a lower wiring resistance than the Y direction wiring 24 which functions as a signal electrode, the line width is increased or the film thickness is increased. .
[0082]
Hereinafter, a method for manufacturing the electron source substrate of the present embodiment will be described with reference to FIGS.
[0083]
(Element electrode formation)
As a sodium block layer on a 2.8 mm thick glass of PD-200 (manufactured by Asahi Glass Co., Ltd.) having a low alkali component as the substrate 21 ₂ A film having a thickness of 100 nm applied and fired was used.
[0084]
Then, on this glass substrate 21, first, titanium Ti (thickness 5 nm) is formed as an undercoat layer by sputtering, and ruthenium Ru (thickness 40 nm) is formed thereon, followed by applying a photoresist, exposure, development, The device electrodes 2 and 3 were formed by patterning by a series of photolithography methods called etching (see FIG. 3). In this embodiment, the distance L between the device electrodes is set to 10 μm, and the opposing length W is set to 100 μm.
[0085]
(Formation of Y direction wiring)
Regarding the wiring material of the X-direction wiring 26 and the Y-direction wiring 24 as the common wiring, it is desired that the resistance is low so that a substantially uniform voltage is supplied to a large number of surface conduction electron-emitting devices. Thickness, wiring width, etc. are appropriately set.
[0086]
The Y-direction wiring (lower wiring) 24 as the signal wiring was formed in a line pattern so as to be in contact with one element electrode 3 and to connect them by a photolithography method using a photo paste material. As a material, silver Ag photo paste ink DC-206 (manufactured by Dupont) was used, screen-printed, dried, exposed to a predetermined pattern and developed. Thereafter, the Y-direction wiring 24 was formed by firing at a temperature of about 480 ° C. (see FIG. 4). The Y-direction wiring 24 has a thickness of about 15 μm and a line width of about 50 μm.
[0087]
(Formation of insulating layer)
An insulating layer 25 is formed to insulate the upper and lower wirings. Electrical connection between the X-direction wiring (upper wiring) and the element electrode 2 so as to cover an intersection with the previously formed Y-direction wiring (lower wiring) 24 under the X-direction wiring (upper wiring) described later The contact hole 27 is formed in the connection portion corresponding to each element so as to be possible (see FIG. 5).
[0088]
Specifically, a photosensitive glass paste J1345 (manufactured by Dupont) containing PbO as a main component was screen-printed and then exposed and developed. This was repeated four times and finally baked at a temperature around 480 ° C. The insulating layer 25 has a total thickness of about 30 μm and a width of 150 μm.
[0089]
(Formation of X direction wiring)
On the insulating layer 25 formed earlier, Ag paste ink is screen-printed and dried, and the same process is performed again on the insulating layer 25. A wiring (upper wiring) 26 was formed (see FIG. 6). The X-direction wiring 26 intersects the Y-direction wiring 24 with the insulating layer 25 interposed therebetween, and is connected to the element electrode 22 at a contact hole 27 portion provided in the insulating layer 25.
[0090]
The X-directional wiring 26 functions as a scanning electrode after being panelized. The X-direction wiring 26 has a thickness of about 15 μm and a line width of about 300 μm.
[0091]
(Drawer wiring formation)
The lead wires 11 and 12 in both the X and Y directions for connecting to the external drive circuit were formed by the same method as the X-direction wire (upper wire) 26 described above (see FIG. 1). The lead wires 11 and 12 have a larger line width and are 100 μm to 500 μm depending on the location.
[0092]
As described above, in this embodiment, the Y-direction wiring 24 in the display area is formed by the photolithographic method using the photo paste, and the XY bidirectional wiring (lead-out wirings 11 and 12) outside the display area is also formed by the screen printing method. Therefore, the cross section of the Y-direction wiring 24 in the display area is an obtuse angle with respect to the substrate as shown in FIG. 18A, and the cross section of the XY bidirectional wiring (the lead wirings 11 and 12) outside the display area is FIG. As shown in a), a substrate having an XY matrix wiring having an acute angle with the substrate was formed.
[0093]
(Formation of conductive film)
Next, after sufficiently cleaning the substrate, the surface was treated with a solution containing a water repellent so that the surface became hydrophobic. This is so that the aqueous solution for forming a conductive film to be applied thereafter is disposed with an appropriate spread on the device electrode. As the water repellent used, dimethyldiethoxysilane was sprayed on the substrate by a spray method and dried with hot air at 120 ° C.
[0094]
Thereafter, a conductive film 4 was formed between the device electrodes 2 and 3. This process will be described with reference to the schematic diagram of FIG. In order to compensate for the planar variation of the individual element electrodes on the substrate 21, pattern displacement is observed at several locations on the substrate, and the amount of point displacement between the observation points is approximated by a straight line. In addition, by applying a conductive film forming material, the positional deviation of all the pixels is eliminated, and it is applied accurately at the corresponding position.
[0095]
In this example, for the purpose of obtaining a palladium film as the conductive film 4, first, 0.15% by weight of a palladium-proline complex is dissolved in an aqueous solution of water 85: isopropyl alcohol (IPA) 15 to prepare an organic palladium-containing solution. Obtained. In addition, some additives were added. The droplets of this solution were applied between the element electrodes by adjusting the dot diameter to 60 μm using an ink jet ejecting apparatus using a piezo element as the droplet applying means 71 (FIG. 7A).
[0096]
Thereafter, the substrate was heated and fired at 350 ° C. for 10 minutes in the air to form a conductive film 4 ′ made of palladium oxide (PdO) (FIG. 7B). A film having a dot diameter of about 60 μm and a maximum thickness of 10 nm was obtained.
[0097]
(Forming process)
Next, in this process called forming, the conductive film 4 ′ is energized to cause internal cracks, thereby forming the electron emission portion 5 (FIG. 7C).
[0098]
A specific method is to leave a lead wiring portion around the substrate 21 and cover the entire substrate with a hood-like lid to create a vacuum space between the substrate 21 and the external power supply. By applying a voltage between the bidirectional wirings 24 and 26 from the terminal portion of the wiring and energizing between the device electrodes 2 and 3, the conductive film 4 'is locally destroyed, deformed or altered, and electrically The electron emitting portion 5 in a high resistance state is formed. The hood-like lid and the substrate 21 are in contact with each other via a resin O-ring to form an airtight container.
[0099]
At this time, when energized and heated in a vacuum atmosphere containing a slight amount of hydrogen gas, the reduction is accelerated by hydrogen, and the conductive film 4 ′ made of palladium oxide PdO is changed to the conductive film 4 made of palladium Pd.
[0100]
At the time of this change, a crack (gap) is generated in part due to the reduction contraction of the film, but the position and shape of the crack are greatly influenced by the uniformity of the original film. In order to suppress variations in characteristics of a large number of elements, it is more desirable that the crack occurs in the central portion of the conductive film 4 and be as straight as possible.
[0101]
Electron emission occurs from the vicinity of the crack formed by this forming under a predetermined voltage, but the generation efficiency is still very low under the current conditions.
[0102]
The resistance value Rs of the obtained conductive film 4 is 10 ² To 10 ⁷ The value of Ω.
[0103]
In this embodiment, a pulse waveform as shown in FIG. 8B is used for forming processing, and T1 is set to 0.1 msec and T2 is set to 50 msec. The applied voltage was started from 0.1V and increased by about 0.1V step every 5 seconds. When the energization forming process was completed, the resistance value was obtained by measuring the current flowing through the element when the pulse voltage was applied, and the forming process was completed when the resistance was 1000 times or more that of the resistance before the forming process.
[0104]
(Activation process)
Similar to the above-described forming, a hood-like lid is covered to create a vacuum space between the substrate 21 and the pulse voltage is repeatedly applied between the device electrodes 2 and 3 through the bidirectional wirings 24 and 26 from the outside. . Then, a gas containing carbon atoms is introduced, and carbon or a carbon compound derived therefrom is deposited as a carbon film in the vicinity of the crack.
[0105]
In this example, trinitrile is used as a carbon source, and is introduced into the vacuum space through a slow leak valve. ^-Four Pa was maintained.
[0106]
FIG. 11 shows a preferred example of voltage application used in the activation process. The maximum voltage value to be applied is appropriately selected within a range of 10 to 20V.
[0107]
In FIG. 11A, T1 is a positive and negative pulse width of the voltage waveform, T2 is a pulse interval, and the voltage value is set to be equal in absolute value of positive and negative. In FIG. 11 (b), T1 and T1 ′ are the positive and negative pulse widths of the voltage waveform, T2 is the pulse interval, and T1> T1 ′, and the voltage value is set to have the same positive and negative absolute values. ing.
[0108]
At this time, the voltage applied to the device electrode 3 is positive, and the device current If flows in the direction from the device electrode 3 to the device electrode 2 is positive. After about 60 minutes, when the emission current Ie reached almost saturation, the energization was stopped, the slow leak valve was closed, and the activation process was completed. In the above-described forming and activation processes, the formation of an airtight container with a hood-like lid via an O-ring is sufficiently good, and the vacuum atmosphere during forming and the activation atmosphere (carbon atmosphere) during activation are sufficient. It was maintained.
[0109]
Through the above steps, an electron source substrate in which a large number of electron-emitting devices are connected to the substrate by matrix wiring can be manufactured.
[0110]
(Characteristic evaluation of electron source substrate)
The electron emission characteristics of the electron source substrate manufactured by the element configuration and the manufacturing method as described above were measured using an apparatus as shown in FIG. As a result, when the emission current Ie at a voltage of 12 V applied between the device electrodes was measured, an average of 0.6 μA and an electron emission efficiency of 0.15% were obtained. Also, the uniformity between elements was good, and the variation of Ie between the elements was as good as 5%.
[0111]
Next, an image forming apparatus (display panel) as shown in FIG. 12 was manufactured using the electron source substrate having the simple matrix arrangement manufactured as described above. FIG. 12 is partially cut away to show the interior.
[0112]
In this example, the electron source substrate 21, the support frame 86, and the face plate 82 were adhered by frit glass, and sealed at 480 ° C. for 30 minutes to obtain an envelope 90.
[0113]
In addition, by performing all of this series of steps in a vacuum chamber, it was possible to evacuate the inside of the envelope 90 from the beginning, and the steps could be simplified.
[0114]
In this way, a display panel as shown in FIG. 12 was manufactured, and a drive circuit consisting of the scanning circuit, control circuit, modulation circuit, DC voltage source, etc. of FIG. 14 was connected to manufacture a panel-like image display device. .
[0115]
In the image display device manufactured as described above, electrons are emitted by applying a predetermined voltage to each electron-emitting device in a time-sharing manner through the X-direction terminal and the Y-direction terminal, and the metal serving as the anode electrode through the high-voltage terminal Hv. A high voltage was applied to the back 85, the generated electron beam was accelerated, and collided with the fluorescent film 84 to display an image.
[0116]
In this embodiment, the height of the Y-direction wiring 24 arranged substantially parallel to the line-shaped electron emission portion 5 is sufficiently secured and the trajectory control of the emitted electrons can be performed satisfactorily, so that the light emission efficiency is high, Since the average angle formed by the cross section of the XY bidirectional wiring (lead wirings 11 and 12) outside the display area is an acute angle, edge curl and side cracks are not generated in the bidirectional wiring outside the display area. Thus, an image forming apparatus with high vacuum reliability was obtained.
[0117]
[Example 2]
In this embodiment, when the Y-direction wiring in the display area is formed, the X / Y bidirectional lead wiring outside the display area is also formed at the same time, and the X / Y bidirectional lead wiring is further coated with acrylic resin and fired at the same time. Produced an electron source substrate in the same manner as in Example 1. Only the wiring forming portion will be described below.
[0118]
(Formation of Y direction wiring)
The Y-direction wiring (lower wiring) 24 was formed in a line pattern so as to be in contact with one element electrode 3 and to connect them by a photolithography method using a photo paste material. As a material, silver Ag photo paste ink DC-206 (manufactured by Dupont) was used, screen-printed, dried, exposed to a predetermined pattern and developed. Thereafter, the Y-direction wiring 24 was formed by firing at a temperature of about 480 ° C. (see FIG. 4). The Y-direction wiring 24 has a thickness of about 15 μm and a line width of about 50 μm.
[0119]
Simultaneously with the formation of the Y-direction wiring, the X and Y both-direction extraction wirings 11 and 12 shown in FIG. 1 were also formed. The line widths of the X and Y lead-out lines 11 and 12 are 60 μm to 300 μm, although they vary depending on the location. However, after patterning the wiring, it was partially coated outside the display area using a photosensitive acrylic resin and baked simultaneously with the wiring.
[0120]
(Formation of insulating layer)
An insulating layer 25 is formed to insulate the upper and lower wirings. Electrical connection between the X-direction wiring (upper wiring) and the element electrode 2 so as to cover an intersection with the previously formed Y-direction wiring (lower wiring) 24 under the X-direction wiring (upper wiring) described later The contact hole 27 is formed in the connection portion corresponding to each element so as to be possible (see FIG. 5).
[0121]
Specifically, a photosensitive glass paste J1345 (manufactured by Dupont) containing PbO as a main component was screen-printed and then exposed and developed. This was repeated four times and finally baked at a temperature around 480 ° C. The insulating layer 25 has a total thickness of about 30 μm and a width of 150 μm.
[0122]
(Formation of X direction wiring)
On the insulating layer 25 formed earlier, Ag paste ink is screen-printed and dried, and the same process is performed again on the insulating layer 25. A wiring (upper wiring) 26 was formed (see FIG. 6). The X-direction wiring 26 intersects the Y-direction wiring 24 with the insulating layer 25 interposed therebetween, and is connected to the element electrode 22 at a contact hole 27 portion provided in the insulating layer 25. The X-direction wiring 26 has a thickness of about 15 μm and a line width of about 300 μm.
[0123]
In this embodiment, the Y-directional wiring 24 in the display area and the XY bidirectional lead-out wirings 11 and 12 outside the display area are both exposed and developed by a photolithographic method using a photo paste to form a pattern. An overcoat layer (photosensitive acrylic resin) that burns out at a temperature higher than the burning temperature of the organic component in the photo paste (silver Ag photo paste ink DC-206) and lower than the softening point of the inorganic component is formed on the wiring pattern. Then, by firing the wiring pattern and the overcoat layer at the same time, the cross-section of the Y-direction wiring 24 in the display area is an obtuse angle formed with the substrate as shown in FIG. As for the cross section of the wiring (lead wirings 11 and 12), a substrate having an XY matrix wiring having an acute average angle formed with the substrate as a whole was formed.
[0124]
Also in the electron source substrate of this example, while improving the light emission efficiency as in Example 1, it is possible to realize the element creation process of the electron source substrate and the improvement in the vacuum reliability of the image forming apparatus using the same. In addition, the lead-out wiring portion connected to the external drive circuit can be made high density, and the outer shape with respect to the image display area can be made more compact.
[0125]
[Example 3]
In this embodiment, the X and Y direction lead wires outside the display region are formed as the first wire by a photolithographic method using a photo paste, and the X and Y direction lead wires outside the display region ( An electron source substrate was prepared in the same manner as in Example 1 except that the second wiring layer was formed on the first wiring) by a screen printing method using a printing paste ink which was a non-photolitho paste. Only the wiring forming portion will be described below.
[0126]
(Formation of Y direction wiring)
The Y-direction wiring (lower wiring) 24 was formed in a line pattern so as to be in contact with one element electrode 3 and to connect them by a photolithography method using a photo paste material. As a material, silver Ag photo paste ink DC-206 (manufactured by Dupont) was used, screen-printed, dried, exposed to a predetermined pattern and developed. Thereafter, the Y-direction wiring 24 was formed by firing at a temperature of about 480 ° C. (see FIG. 4). The Y-direction wiring 24 has a thickness of about 15 μm and a line width of about 50 μm.
[0127]
Simultaneously with the formation of the Y direction wiring, the Y direction lead wiring 12 shown in FIG. 1 was also formed. The line width of the Y direction lead-out wiring 12 is 100 μm or less, although it varies depending on the location.
[0128]
(Formation of insulating layer)
An insulating layer 25 is formed to insulate the upper and lower wirings. Electrical connection between the X-direction wiring (upper wiring) and the element electrode 2 so as to cover an intersection with the previously formed Y-direction wiring (lower wiring) 24 under the X-direction wiring (upper wiring) described later The contact hole 27 is formed in the connection portion corresponding to each element so as to be possible (see FIG. 5).
[0129]
Specifically, a photosensitive glass paste J1345 (manufactured by Dupont) containing PbO as a main component was screen-printed and then exposed and developed. This was repeated four times and finally baked at a temperature around 480 ° C. The insulating layer 25 has a total thickness of about 30 μm and a width of 150 μm.
[0130]
(Formation of X direction wiring)
The X-direction lead wiring 11 outside the display area shown in FIG. 1 was first formed by a photolithography method using a photo paste material. As a material, silver Ag photo paste ink DC-206 (manufactured by Dupont) was used, screen-printed, dried, exposed to a predetermined pattern and developed. Thereafter, firing was performed at a temperature of about 480 ° C.
[0131]
Next, Ag paste ink is further screen-printed on the insulating layer 25 and the X-direction lead-out wiring 11 previously formed, and then dried. Firing was performed at a temperature of around 0 ° C. Next, Ag paste ink was further screen-printed on the Y-direction lead-out wiring and dried, and the same operation was performed again on the Y-direction lead wiring, followed by baking twice at a temperature of about 420 ° C. The X-direction wiring 26 formed thereby intersects the Y-direction wiring 24 with the insulating layer 25 interposed therebetween, and is connected to the element electrode 22 at a contact hole 27 portion provided in the insulating layer 25.
[0132]
The X-direction wiring 26 in the display area has a thickness of about 15 μm, the X-direction lead-out wiring 11 outside the display area has a thickness of about 30 μm, and the line width is 100 μm or less.
[0133]
In this embodiment, the cross section of the Y-direction wiring 24 in the display area has an obtuse angle with the substrate as shown in FIG. 18A, and outside the display area, the cross-section of the X and direction lead-out wiring is The board | substrate which has XY matrix wiring whose average angle formed with a board | substrate is an acute angle was formed.
[0134]
Also in the electron source substrate of this example, the improvement in luminous efficiency was ensured as in Example 1, and the airtightness due to the resin O-ring was sufficiently satisfied during forming and activation.
[0135]
The preferred embodiments of the present invention have been described above. The present invention is not limited to display devices using surface conduction electron-emitting devices, but can be applied to display devices using various electron-emitting devices such as FE elements and MIM elements. Further, the present invention is not limited to an electron beam excitation display device using an electron-emitting device, but can be applied to a display device using an airtight container such as a PDP. For example, in the case of a PDP, it is possible to form the back panel by applying the above-described embodiment to the address electrode and the lead portion described in JP-A-2001-189136, and to the display electrode and the lead portion as described above. It is also possible to form the front panel by applying the embodiment. In the PDP, it should be understood that the frit glass at the sealing portion also serves as the frame member. Further, the PDP panel type is not limited to the surface discharge type as described in JP-A-2001-189136, but can be applied to a counter discharge type, and the driving method is either AC type or DC type. Is also applicable.
[0136]
【The invention's effect】
As described above, according to the wiring board of the present invention, the cross-sectional shape of each wiring inside and outside the display area is controlled while ensuring the edge height of the desired wiring within the display area. As a result, it is possible to provide a wiring substrate for a display device that can realize an airtight container free from edge curl of wiring and side cracks of the substrate outside the display region (sealing portion) while achieving reduction in wiring resistance.
[0137]
And in an image forming apparatus using such a wiring board as an electron source substrate, it is possible to realize an image forming apparatus having high vacuum reliability as well as improving luminous efficiency, and obtaining a high-quality image by a higher density pixel array. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic plan view for explaining a wiring configuration of an electron source substrate of the present invention.
FIG. 2 is a plan view showing a basic configuration in a display region of an electron source substrate.
3 is a view for explaining a manufacturing process of the electron source substrate of FIG. 2; FIG.
4 is a view for explaining a manufacturing process of the electron source substrate of FIG. 2; FIG.
5 is a view for explaining a manufacturing process of the electron source substrate of FIG. 2; FIG.
6 is a diagram for explaining a manufacturing process of the electron source substrate of FIG. 2; FIG.
7 is a diagram for explaining a manufacturing process of the electron source substrate of FIG. 2; FIG.
FIG. 8 is a diagram illustrating an example of a forming voltage.
FIG. 9 is a view schematically showing an apparatus for measuring the characteristics of the electron-emitting device according to the present invention.
FIG. 10 is a diagram showing a device current and a relationship between a device current and a device current of a surface conduction electron-emitting device according to the present invention.
FIG. 11 is a diagram illustrating an example of an activation voltage.
FIG. 12 is a perspective view schematically showing a configuration example of an image forming apparatus according to the present invention.
FIG. 13 is a diagram schematically showing an example of a fluorescent film in the image forming apparatus according to the present invention.
FIG. 14 is a drive circuit diagram of the image forming apparatus according to the present invention.
FIG. 15 is a schematic view showing a configuration example of a surface conduction electron-emitting device.
FIG. 16 is a schematic diagram showing the formation of a leak path and its cause.
FIG. 17 is a schematic diagram for explaining an average angle at which the cross-sectional shape of the wiring forms with the substrate.
FIG. 18 is a schematic diagram for explaining an average angle at which the cross-sectional shape of the wiring forms with the substrate.
[Explanation of symbols]
1 Substrate
2 element electrodes
3 Device electrodes
4 Conductive film (element film)
5 Electron emission part
11 X direction lead wiring
12 Y direction lead wiring
13 Vacuum container forming member (sealing member)
21 Substrate (Electron source substrate)
24 Y-direction wiring
25 Insulating layer
26 X direction wiring
27 Contact hole
50 Ammeter for measuring element current If
51 Power supply for applying element voltage Vf to the element
52 Ammeter for measuring emission current Ie
53 High-voltage power supply for applying voltage to anode electrode
54 Anode electrode for capturing emission current Ie
55 Vacuum equipment
56 Exhaust pump
71 Droplet application means
82 Face plate
83 Glass substrate
84 Fluorescent membrane
85 metal back
86 Support frame
90 Envelope (Display panel)
91 Black conductor
92 Phosphor
101 Display panel
102 Scanning circuit
103 Control circuit
104 Shift register
105 line memory
106 Sync signal separation circuit
107 Information signal generator
122 Leak Pass
123 Insulating layer for vacuum container formation
124 mouse hole
125 Frit seal (frit glass)
126 Side crack

Claims (2)

It has a wiring board which have a plurality of wiring electrodes on the substrate, and a frame member positioned on the surface having the wiring electrodes of the wiring substrate and a counter substrate positioned to face the wiring board via the frame member A display device having an image forming member in an airtight container, wherein an average angle formed between a surface of the wiring board in contact with the wiring and a side surface of the wiring is a positive angle of the image forming member on the wiring substrate. at least in part in a obtuse, and the display device, wherein the frame member is Oite acute angle to the arrangement region of the projection area. Width of the wiring in the orthogonal projection area to the wiring substrate of the imaging member, a display device according to claim 1, wherein the frame member is smaller than the width of the wiring in the arrangement region .

Images