JP2001256907A - Image display device - Google Patents

Image display device

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Publication number
JP2001256907A
JP2001256907A JP2000070696A JP2000070696A JP2001256907A JP 2001256907 A JP2001256907 A JP 2001256907A JP 2000070696 A JP2000070696 A JP 2000070696A JP 2000070696 A JP2000070696 A JP 2000070696A JP 2001256907 A JP2001256907 A JP 2001256907A
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Japan
Prior art keywords
electrode
film
thin
electron source
layer
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2000070696A
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Japanese (ja)
Inventor
Toshiaki Kusunoki
Masakazu Sagawa
Mutsumi Suzuki
雅一 佐川
敏明 楠
睦三 鈴木
Original Assignee
Hitachi Ltd
株式会社日立製作所
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Application filed by Hitachi Ltd, 株式会社日立製作所 filed Critical Hitachi Ltd
Priority to JP2000070696A priority Critical patent/JP2001256907A/en
Publication of JP2001256907A publication Critical patent/JP2001256907A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide an image display device having high brightness and low power consumption, with an upper electrode film processed without using a photographic process and thin film type electron sources having high electron emitting efficiency in high yields. SOLUTION: The image display device comprises a first substrate having a plurality of thin film type electron sources for emitting electrons from the surface of an upper electrode when positive-polarity voltage is applied to the upper electrode, a frame member, and a second substrate having a fluorescent substance. Display elements are provided in a space encircled by the first substrate, the frame member and the second substrate, as a vacuum atmosphere. The first substrate has a plurality of bus electrodes for applying driving voltage to the upper electrode for the plurality of thin film type electron sources, at least one upper electrode for the thin film type electron sources, a resistance element provided between any two out of the plurality of bus electrodes and a first insulating layer having a first opening portion provided in an electron emission portion of each thin film type electron source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to a lower electrode, an electron acceleration layer (an insulating layer or
The present invention relates to an image display device having a three-layer structure of a semiconductor layer or a laminated film or a mixed film thereof and an upper electrode, and using a thin-film electron source that emits electrons in a vacuum.

[0002]

2. Description of the Related Art A thin-film electron source is based on a three-layer thin film structure consisting of an upper electrode, an electron accelerating layer (an insulating layer or a semiconductor layer, or a laminated film or a mixed film thereof), and a lower electrode. A voltage is applied between the upper electrode and the lower electrode to emit electrons from the surface of the upper electrode into a vacuum. For example, a thin-film electron source using an insulator as an acceleration layer, that is, a metal-insulator-metal stacked M
MIS (Metal-Insulator-Metal) type thin film type electron source, MIS (Metal-Insulator-Metal)
Insulator-semiconductor type thin film electron sources and the like are known. The MIM type thin film type electron source is described in, for example, Japanese Patent Application Laid-Open No. 7-65710.

FIG. 25 is a diagram for explaining the operation principle of the MIM type thin film type electron source. Upper electrode 13 and lower electrode 1
1, a drive voltage Vd is applied from a drive voltage source,
When the electric field in the insulating layer 12 is set to about 1 to 10 MV / cm, electrons near the Fermi level in the lower electrode 11 pass through the barrier due to a tunnel phenomenon, and the insulating layer 12 and the upper electrode 13
Into hot conduction electrons. These hot electrons are scattered in the upper electrode 13 in the insulating layer 12 and lose energy, but some hot electrons having energy equal to or more than the work function φ of the upper electrode 13 are emitted into the vacuum 20. Here, when a plurality of upper electrodes 13 and a plurality of lower electrodes 11 are orthogonal to each other to form a thin-film type electron source matrix, an electron beam can be generated from an arbitrary position. It can be used for a pattern electron source. Until now, gold (A
Electron emission is observed from a u-aluminum oxide (Al 2 O 3 ) -aluminum (Al) structure MIM (Metal-Insulator-Metal) structure or the like.

[0004]

The MIM type thin film type electron source emits hot electrons accelerated by the insulating layer 12 into the vacuum through the upper electrode 13. Therefore, the film thickness of the upper electrode 13 is reduced to about several nm in order to reduce scattering of hot electrons. On the other hand, in such an MIM type thin film type electron source, when the surface of the upper electrode 13 is contaminated with an organic substance or the like, hot electrons are scattered and the electron emission efficiency is reduced. In the conventional MIM type thin film type electron source, when processing the upper electrode 13 by a photo process, the surface of the upper electrode 13 is contaminated with a resist, and the electron emission efficiency has been reduced by about one digit. Therefore, in order to recover the electron emission efficiency, a cleaning step by ashing was required. This process requires careful attention so as not to damage the insulating layer 12 of the MIM type thin film type electron source due to charge-up or the like, and the yield during manufacturing is likely to be reduced.

When the MIM type thin-film type electron source matrix is used for an image display device, a substrate on which the MIM type thin-film type electron source matrix is formed and a face plate coated with a phosphor are joined by frit glass via a frame member. A display panel is created by laminating and sealing in a vacuum.
For a large display panel of about inches or more, a spacer needs to be provided to support the atmospheric pressure. Normally, the spacer is placed in a gap between the lower electrodes 11 or between the upper bus electrodes so as not to damage the MIM type thin film type electron source, so that precise position control is required. If the position control is insufficient, the MIM type thin film type electron source may be damaged, and the manufacturing yield is likely to be reduced.

Further, when a defect occurs in which the lower electrode 13 and the upper electrode 11 are short-circuited due to a defect in the manufacturing process, etc.
When the matrix driving is performed, the lower electrode 11 having a defective portion,
Other normal thin-film type electron sources on the wiring of the upper electrode 13 also cannot emit electrons because a sufficient driving voltage Vd is not applied, or the amount of emitted electrons is reduced, thereby causing line defects. In such a case, it cannot be used for an image display device or the like. When used in an image display device, it is necessary to form several hundred thousand to several million thin film type electron sources, and it is difficult to form a defect-free thin film type electron source matrix. Therefore, even when a defect occurs in the thin-film electron source, it is necessary to limit the point defect to a line defect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to process an upper electrode film without using a photolithography process and to obtain a high electron emission efficiency. An object of the present invention is to provide a thin-film electron source with high yield and provide an image display device with high luminance and low power consumption. Also,
Another object of the present invention is to provide a thin-film electron source that is hardly damaged even when a spacer is raised, to facilitate position control,
An object of the present invention is to provide a high-quality image display device in which spacers are not noticeable by improving the manufacturing yield of the image display device and optimizing the arrangement position of the spacers. Still another object of the present invention is to provide a thin-film type electron source matrix free from line defects and to improve the production yield of an image display device. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0008]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. That is, the present invention has a lower electrode and an upper electrode, and has a plurality of thin-film electron sources that emit electrons from the surface of the upper electrode when a positive voltage is applied to the upper electrode. A display element comprising: a first substrate, a frame member, and a second substrate having a phosphor, wherein a space surrounded by the first substrate, the frame member, and the second substrate has a vacuum atmosphere. An image display device comprising:
The first substrate includes a plurality of bus electrodes for applying a driving voltage to upper electrodes of the plurality of thin-film electron sources, at least one upper electrode of the thin-film electron sources, and any one of the plurality of bus electrodes. A resistance element provided between the bus electrode and
The thin-film electron source has a first insulating layer provided on the upper electrode and the resistance element, the first insulating layer having a first opening provided in an electron-emitting portion of each of the thin-film electron sources.

Further, the invention is characterized in that it has a spacer provided on the first insulating layer. Further, according to the present invention, the bus electrode includes a bus electrode lower layer and a bus electrode upper layer having a thickness larger than the bus electrode lower layer, and the resistance element has the same material as the bus electrode lower layer. It is characterized by being formed by using. Also, the present invention
The at least one thin-film type electron source has a first electrode having a second opening provided inside the first opening, and a first electrode having a second opening outside the first opening. And a second electrode provided between the first insulating layer and the first electrode. The upper electrode covers the second opening,
It is provided on the first electrode.

[0010] Further, in the present invention, the at least one thin-film electron source preferably has a first electrode having a second opening and a second electrode having a third opening provided on the first electrode. Having a fourth opening, and a second insulating layer provided between the first insulating layer and the second electrode, wherein the second insulating layer is The second opening is formed of a material different from that of the first insulating layer.
And the third opening is provided outside the fourth opening, and the upper electrode of the at least one thin-film type electron source is provided. The first opening so as to cover the second opening.
Characterized by being provided on the above-mentioned electrode.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted. An image display device according to an embodiment of the present invention uses a display panel in which a luminance modulation element for each dot is formed by a combination of a thin-film electron source matrix and a phosphor, and is driven by row electrodes and column electrodes of the display panel. It is configured by connecting circuits. Here, the display panel includes an electron source substrate on which a thin-film electron source matrix is formed and a fluorescent display panel on which a phosphor pattern is formed.

First, a method of manufacturing an example of a thin-film electron source constituting the thin-film electron source matrix according to the present embodiment will be described with reference to FIGS. 2 to 11, FIG. 2C is a plan view, and FIG.
Is a cross-sectional view of a principal part showing a cross-sectional structure taken along the line BB 'shown in FIG. 3C, and FIG. 3A is a cross-sectional view taken along the line AA' in FIG.
It is principal part sectional drawing which shows the cross-section along the cutting line. First, an insulating substrate 10 made of glass or the like is prepared, and a metal film for a lower electrode is formed on the substrate 10. Aluminum (Al; hereinafter, simply referred to as Al)
Called. ) Or an aluminum alloy (hereinafter simply referred to as an Al alloy). Here, neodymium (Nd;
Hereinafter, it is simply referred to as Nd. ) Was used at an atomic weight of 2%. The metal film is formed by, for example, a sputtering method and has a thickness of 300 nm.
And

After the formation of the metal film, a stripe-shaped lower electrode 1 as shown in FIG.
Form one. For this etching, for example, wet etching with a mixed aqueous solution of phosphoric acid, acetic acid, and nitric acid is used. Next, a method for forming the protective insulating layer 14 and the insulating layer 12 will be described with reference to FIGS. First, a portion serving as an electron emission portion on the lower electrode 11 is masked with a resist film 21, and the other portion is selectively anodized thickly to form a protective insulating layer 14. If the formation voltage is 100 V, the thickness is about 136 nm.
Is formed. Next, the resist film 21
Is removed, and the surface of the remaining lower electrode 11 is anodized. For example, if the formation voltage is 6 V, an insulating layer 12 having a thickness of about 10 nm is formed on the lower electrode 11.

Next, as shown in FIG. 5, an upper bus electrode film serving as a power supply line to the upper electrode 13 is formed by, for example, a sputtering method. Here, a laminated film is used as the upper bus electrode film, and the material of the upper bus electrode lower layer 15 is, for example, tungsten (W; hereinafter, simply referred to as W).
As a material of the upper bus electrode upper layer 16, for example, Al
An -Nd alloy was used. Further, the film thickness of the upper bus electrode lower layer film is reduced to several nm to several tens nm so that the upper electrode 13 to be formed later is not disconnected due to a step of the upper bus electrode lower layer 15. Was formed to be as thick as several hundred nm in order to make the film thickness sufficient and to use it as a stopper film when etching a passivation film to be formed later. Subsequently, as shown in FIG. 6, the upper bus electrode upper layer film is formed into the lower electrode 1 by a photo process and an etching process.
Processing is performed so as to be separated into a first electrode 22 of a wiring portion that is orthogonal to 1 and does not include an electron emission portion and a second electrode 23 of a contact portion that includes an electron emission portion. For this etching, for example, wet etching in a mixed aqueous solution of phosphoric acid, acetic acid, and nitric acid is used.

Subsequently, as shown in FIG. 7, W of the upper bus electrode lower layer film is processed so as to be a resistor 24 for connecting between the first electrode and the second electrode of the bus electrode upper layer 16.
The role of the resistor 24 will be described later. Next, as shown in FIG. 8, an insulating film serving as a passivation film 17 is formed on the entire surface of the substrate 10 where the thin film type electron source matrix is formed. As the passivation film 17, for example, a film generally used as a passivation film in a semiconductor device or the like can be used. That is, as materials, SiO, Si
Glass such as O 2 , phosphosilicate glass, borosilicate glass,
Si 3 N 4 , Al 2 O 3 , polyimide and the like can be used. As a film formation method, a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, a coating method, or the like can be used. For example, a sputtering method or a chemical vapor deposition method is used for film formation of SiO 2 , Al 2 O 3 , Si 3 N 4 and the like, and a vacuum evaporation method, glass such as phosphosilicate glass, borosilicate glass and the like is used for film formation of SiO. For example, a coating method or the like can be used for the kind and the polyimide. Here, a Si 3 N 4 film formed by a sputtering method was used. In addition, the film thickness is, for example, as large as about 0.3 to 10 μm.

Subsequently, as shown in FIG. 9, a region including an electron emission portion is opened in the passivation film 17 by a photolithography process and an etching process. For this processing, for example, a dry etching method using CF 4 or the like may be used. In the dry etching method using a fluoride-based etching gas such as CF 4, the insulator of the passivation film 17 is etched at a high selectivity with respect to the Al alloy of the upper electrode upper layer 16. Therefore, the passivation is performed using the upper electrode upper layer 16 as a stopper film. It is possible to process only the film 17. Subsequently, as shown in FIG. 10, the upper layer 16 of the upper bus electrode of the electron emission portion is wet-etched in a mixed aqueous solution of phosphoric acid, acetic acid and nitric acid. This etchant etches the Al alloy, but hardly etches the insulator used for the passivation film 17 and the W of the upper bus electrode lower layer 15.
Therefore, only the upper layer 16 of the upper bus electrode is etched with a high selectivity. Therefore, the upper bus electrode upper layer 16 recedes inward with respect to the passivation film 17, and the passivation film 17 having an eaves-like opening is formed.

Next, as shown in FIG. 11, W of the upper bus electrode lower layer 15 is etched by a photo process and an etching process to open an electron emission portion. At this time, by processing such that W of the upper bus electrode lower layer 15 extends toward the electron emission portion side from the upper bus electrode upper layer 16 and the passivation film 17, it is possible to make contact with the upper electrode 13 formed later. . For the etching, for example, a mixed aqueous solution of ammonia and hydrogen peroxide may be used. Finally, an upper electrode film is formed by, for example, sputtering. Also, the upper electrode 1
3, for example, iridium (Ir), platinum (P
t), a laminated film of gold (Au) is used, and the film thickness is several nm (4 nm in this embodiment).

FIG. 1 shows a thin-film electron source after the upper electrode film is formed. FIG. 1 is a diagram showing a schematic configuration of an example of a thin-film electron source constituting a thin-film electron source matrix according to the present embodiment. FIG. 1 (c) is a plan view, and FIG. Main part sectional view along the AA 'cutting line shown in FIG.
FIG. 2B is a cross-sectional view of a main part along a cutting line BB ′ shown in FIG. 1C. As shown in FIG. 1, in the thin film type electron source shown in FIG. 1, the formed thin upper electrode 13 is cut by an eave-shaped step at the opening of the passivation film 17 and separated for each thin film type electron source. At the same time, the upper bus electrode upper layer 16 and the passivation film 17 come into contact with the W of the upper bus electrode lower layer 15 extending to the electron emission portion side to supply power. Therefore, a photo step for processing the upper electrode 13 becomes unnecessary, and contamination by the resist is eliminated. Further, in the thin film type electron source of the present embodiment, components other than the electron emitting portion are covered with the thick passivation film 17, which is resistant to mechanical damage, and furthermore, the electron emitting portion has the thick passivation film 17. Is formed at the bottom of the opening, so that it is hard to receive mechanical damage. Therefore,
A thin-film electron source which is hardly damaged even when a spacer or the like is set up at the time of manufacturing a display device can be obtained. Further, in the thin film type electron source of the present embodiment, since the resistor 24 is covered with the passivation film 17, even if the film of the upper electrode 13 is formed uniformly on the entire surface of the substrate, it does not make electrical contact with the resistor 24. .
Therefore, the resistance value can be precisely controlled.

Here, the role of the resistor 24 will be described. The resistor 24 is provided for the purpose of preventing a point defect of the thin film type electron source matrix from becoming a line defect in the display device. FIG. 12 is a circuit diagram showing an equivalent circuit of a conventional thin film type electron source matrix. Row electrode (lower electrode 11) 3
A thin-film electron source 301 is formed at each intersection of 10 and a column electrode (upper bus electrode upper layer 16 and upper bus electrode lower layer) 311. Here, each thin-film electron source 301 is connected to the row electrode 31.
0 is directly connected to the column electrode 311. Therefore, for example, when the thin-film electron source 301 at the intersection (R2, C2) of the row electrode 310 of R2 and the column electrode 311 of C2 is short-circuited due to a manufacturing defect or the like, the row electrode 310 of R2
Since the column electrode 311 of C2 is short-circuited, even if an appropriate voltage is applied to both electrodes from the row electrode drive circuit 41 or the column electrode drive circuit 42, no voltage is applied. Therefore, all the elements on the row electrode 310 of R2 or all the elements on the column electrode 311 of C2 do not operate, resulting in a “line defect”.

FIG. 13 is a circuit diagram showing an equivalent circuit of the thin-film type electron source matrix of this embodiment. In the present embodiment, the resistor 24 is inserted between the column electrode 311 and the thin-film electron source 301. If the resistance value of the resistor 24 is set to be 10 times or more the output impedance of the column electrode drive circuit 42, even if the thin film type electron source 301 at (R2, C2) is short-circuited, the row electrode 310 of R2 and Since the resistance 42 between the C2 column electrode 311 and the output impedance of the drive circuit is sufficiently higher, a sufficient voltage is applied to both electrodes, and the other thin-film electron sources 301 on both electrodes operate normally. Of course, the thin-film electron source 301 at (R2, C2) does not operate. In this way, it is possible to prevent the “point defect” from becoming a “line defect”.

In the above-described manufacturing method, a total of six photo steps were required. It is preferable to reduce the number of photo steps as much as possible for cost reduction. Hereinafter, referring to FIGS. 14 to 19, the thin film type electron source according to the present embodiment in which the photolithography step is reduced by coating the upper layer 16 of the upper bus electrode film with an insulating film made of a material different from that of the passivation film 17 will be described. Another example of a method for manufacturing a thin-film electron source constituting a matrix will be described. 14 to 19, FIG. 14 (c) is a plan view, FIG. 14 (b) is a cross-sectional view of an essential part showing a cross-sectional structure taken along the line BB ′ shown in FIG. 14 (c),
FIG. 2A is a main part cross-sectional view showing a cross-sectional structure taken along the line AA ′ shown in FIG. First, similarly to the above-described manufacturing method, the lower electrode 11, the protective insulating layer 14, the insulating layer 12
To form Next, as shown in FIG.
An upper bus electrode film serving as a power supply line to the substrate and an insulating film 18 covering the upper bus electrode film are formed by, for example, a sputtering method. Here, W is used as the material of the upper bus electrode lower layer 15, an Al—Nd alloy is used as the material of the upper bus electrode upper layer 16, and SiO 2 is used as the insulating film 18. As in the case described above, the upper bus electrode lower layer film is formed to be as thin as about several nm to several tens of nm, and the upper bus electrode upper layer film is formed to be as thick as about several hundred nm, as in the case described above. The thickness of the insulating film 18 is arbitrary, but may be about 100 nm.

Subsequently, as shown in FIG.
Due to the etching process, the insulating film 18 and the upper bus electrode upper layer film are orthogonal to the lower electrode 11 and the first electrode 22 of the wiring portion not including the electron emission portion and the second electrode 22 of the contact portion where the electron emission portion is opened. The electrode 23 is processed. Etching is SiO 2
Insulating film is dry-etched using CF 4 , Al-N
For the upper layer film of the upper bus electrode of the d alloy, wet etching in a mixed aqueous solution of phosphoric acid, acetic acid, and nitric acid was used. Subsequently, as shown in FIG. 16, W of the lower layer of the upper bus electrode is connected to a resistor 2 connecting the wiring portion and the contact portion of the upper layer 16 of the upper bus electrode.
4 is processed to a portion extending from the upper bus electrode upper layer 16 to the electron emission portion side and serving as a contact portion with the upper electrode 13 to be formed later.

Next, as shown in FIG. 17, an insulating film to be the passivation film 17 is formed on the entire surface of the substrate 10 where the thin film type electron source matrix is formed. Passivation film 17
For example, a material generally used as a passivation film in a semiconductor device or the like can be used. That is, as a material, glass such as SiO, SiO 2 , phosphosilicate glass, borosilicate glass, Si 3 N 4 , Al 2 O 3 , and polyimide can be used. As a film formation method, a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, a coating method, or the like can be used. For example, SiO 2 , Al
Sputtering or chemical vapor deposition for the formation of 2 O 3 , Si 3 N 4, etc., vacuum deposition for SiO film formation, glass such as phosphosilicate glass and borosilicate glass, and spin coating for polyimide Can be used. However, it is desirable that the passivation film 17 be formed of a different material that can be selectively etched from the insulating film 18. Here, a Si 3 N 4 film formed by a sputtering method is used.
It is formed as thick as about 0.3 to 10 μm. Next, as shown in FIG. 18, an electron emission portion is formed on the passivation film 17 and a region including the periphery of the electron emission portion where the upper electrode 13 to be formed later contacts the upper bus electrode lower layer 15 by a photo process and an etching process. Open. This processing includes, for example, CF 4 ,
A dry etching method using a mixed gas of O 2 and N 2 may be used. By adding N 2 , the insulating film 18 made of SiO 2 and the passivation film 17 made of SiN 4 can be etched at a high selectivity, and the eaves structure of the insulating film 18 can be maintained. Finally, an upper electrode film is formed by, for example, sputtering. Also, the upper electrode 13
For example, iridium (Ir), platinum (P
t), a laminated film of gold (Au) is used, and the film thickness is several nm (4 nm in this embodiment).

FIG. 19 shows the thin-film electron source after the upper electrode film is formed. FIG. 19 is a diagram showing a schematic configuration of a thin-film electron source constituting the thin-film electron source matrix of the present embodiment. FIG. 19C is a plan view, and FIG. FIG. 3C is a cross-sectional view of a main part along a cutting line AA ′ shown in FIG. 3C, and FIG. 4B is a cross-sectional view of a main part along a cutting line BB ′ shown in FIG. As shown in FIG. 19, in the thin-film electron source shown in FIG. 19, the thin upper electrode 13 is cut at an eave-shaped step at the opening of the insulating film 18 and separated for each thin-film electron source. The upper bus electrode upper layer 16, the insulating film 18, and the W of the upper bus electrode lower layer 15 extending from the passivation film 17 to the electron emission portion side are configured to be supplied with power. Therefore, a photo step for processing the upper electrode 13 becomes unnecessary, and contamination by the resist is eliminated.

Further, in the thin film type electron source shown in FIG. 19, components other than the upper electrode 13 are covered with a thick passivation film 17, and are resistant to mechanical damage. In addition, since the electron emission portion is formed at the bottom of the opening of the thick passivation film 17, mechanical damage is less likely to occur. Therefore, a thin-film electron source which is hardly damaged even if a spacer or the like is set up at the time of manufacturing a display device can be obtained. Further, in the thin film type electron source shown in FIG. 19, since the resistor 24 is covered with the passivation film 17, even if the upper electrode film is uniformly formed on the entire surface of the substrate, it does not make electrical contact with the resistor 24. Therefore, the resistance value can be precisely controlled. In the thin-film electron source shown in FIG. 19, the insulating film 18 is increased by one layer, but is formed by continuous film formation with the upper bus electrode film, and the number of steps is small. On the other hand, since the number of photo steps can be reduced by one, cost reduction can be realized as a whole.

Although the present invention has been described for the case where it is applied to a metal-insulator-metal (MIM) thin-film electron source using an insulating layer as an electron acceleration layer, the present invention is not limited to this. Instead, a semiconductor layer, a laminated film thereof, or a mixed film is used as an electron acceleration layer. For example, a MOS type (metal-oxide-semiconducto) is used.
r), MIS type (metal-insulator-semiconductor), H
EED type (high-efficiency-electro-emission device,
Jpn.J.Appl. Phys., Vol 36, pL939, etc.), EL type (Electroluminescence, applied physics Vol. 63, No. 6)
, Page 592), and a porous silicon type (described in Applied Physics Vol. 66, No. 5, page 437, etc.). That is, the configuration of the upper electrode 13 and the like is the same even in the above-described thin film type electron source, so that the present invention can be naturally applied.

Hereinafter, the image display device according to the present embodiment will be described with reference to FIGS. Figure 1 above,
In the case where the thin-film electron source shown in FIG. 19 is used, an ashing step is unnecessary and electron emission efficiency is high, so that a display device with high luminance and low power consumption can be provided. Further, since the thin film type electron source is hardly damaged by the mechanical damage, the display device is hardly damaged even if the spacers are set up, and a high production yield can be provided. Further, since each thin-film electron source has the resistor 24, a thin-film electron source free from line defects can be realized, and a display device with a high production yield can be provided. Here, a description will be given mainly of a case where the above-described thin film type electron source shown in FIG. 1 is used. The method of manufacturing the display device is the same when the thin-film electron source shown in FIG. 19 is used.

FIG. 20 is a diagram showing a schematic configuration of the electron source substrate of the image display device according to the embodiment of the present invention. FIG.
(A) is a top view of the electron source board of this Embodiment,
FIG. 2B is a sectional view taken along line AA ′ shown in FIG. 2A, and FIG. 2C is a sectional view taken along line B-A shown in FIG.
FIG. 4 is a cross-sectional view of a principal part showing a cross-sectional structure along the line B ′. The electron source substrate according to the present embodiment is configured by forming a thin film type electron source in a matrix on the substrate 10 according to the above-described procedure. Although FIG. 20 shows a (3 × 3) dot thin film type electron source matrix composed of three lower electrodes 11 and three bus electrode upper layers 16 (or bus electrode lower layers 15), it is actually illustrated. Forms a thin film type electron source matrix corresponding to the number of display dots.

FIG. 21 is a diagram showing a schematic configuration of a fluorescent display panel of an image display device according to an embodiment of the present invention. FIG.
(A) is a top view of the fluorescent display panel of this Embodiment,
FIG. 2B is a sectional view taken along line AA ′ shown in FIG. 2A, and FIG. 2C is a sectional view taken along line B-A shown in FIG.
FIG. 4 is a cross-sectional view of a principal part showing a cross-sectional structure along the line B ′. The fluorescent display panel of the present embodiment has a light-transmitting substrate 11 made of glass or the like.
0, the red (R), green (G), and blue (B) phosphors (111 to 113) formed in the grooves of the black matrix 120, and formed thereon. And a metal back film 114 to be formed. Hereinafter, a method for manufacturing the fluorescent display panel of the present embodiment will be described. First, a black matrix 120 is formed over a substrate 110 in order to increase the contrast of a display device. The black matrix 120 is obtained by applying a solution obtained by mixing polyvinyl alcohol (PVA; hereinafter, simply referred to as PVA) and ammonium bichromate to the substrate 110, and irradiating ultraviolet rays to portions other than the portion where the black matrix 120 is to be formed. After exposure, unexposed portions are removed, a solution of graphite powder is applied thereto, and PVA is formed by lift-off.

Next, the red phosphor 111 is prepared by the following method.
To form After applying an aqueous solution of a mixture of PVA and ammonium bichromate to the red phosphor particles on the substrate 110, a portion where the phosphor is to be formed is exposed to ultraviolet light, and then the unexposed portion is removed with running water. . In this way,
The red phosphor 111 is patterned. The phosphor pattern is shown as a stripe pattern in FIG. 21, but this stripe pattern is an example, and other than that, for example, depending on the design of the display, for example,
Of course, an “RGBG” pattern in which one pixel is composed of four adjacent dots may be used. A green phosphor 112 and a blue phosphor 113 are formed by the same method. here,
As the phosphor, for example, the red phosphor 111 is Y 2 O 2 S:
Eu (P22-R), green phosphor 112 is ZnS: C
u, Al (P22-G), blue phosphor 113 is ZnS:
Ag (P22-B) may be used. Next, after filming with a film such as nitrocellulose, aluminum (Al) is deposited on the entire substrate 110 to a thickness of about 75 nm to form a metal back film 114. This metal back film 1
14 serves as an accelerating electrode. Thereafter, the substrate 110 is heated to about 400 ° C. in the air to thermally decompose an organic substance such as a filming film or PVA. Thus, the fluorescent display panel is completed.

FIG. 22 is a sectional view showing a schematic overall configuration of an image display device according to an embodiment of the present invention. 20A is a sectional view taken along line AA ′ shown in FIG. 20A, and FIG. 20B is a sectional view taken along line B-A shown in FIG.
FIG. 4 is a cross-sectional view of a principal part showing a cross-sectional structure along the line B ′. FIG.
As shown in FIG. 2, after assembling the electron source substrate, the fluorescent display panel, and the frame member 116 through the spacer 30 with the frit glass 11
Seal using 5. The height of the spacer 30 is set so that the distance between the electron source substrate and the fluorescent display panel is about 1 to 3 mm. The spacer 30 is provided on the passivation film 17 covered with the film of the upper electrode 13. The spacer 30 is made of, for example, a plate of glass or ceramic and is arranged between the bus electrode upper layer 16 (or the bus electrode lower layer 15).

In this embodiment, since most of the electron source substrate is covered with the passivation film 17, damage due to the erecting of the spacer 30 is unlikely to occur. Here, for the sake of explanation, the spacers 30 are all provided for each dot emitting R (red), G (green), and B (blue), that is, between the bus electrode upper layer 16 (or the bus electrode lower layer 15). In practice, the number (density) of the spacers 30 may be reduced and set approximately every 1 cm as long as the mechanical strength can withstand. Also, it may be set up between the lower electrodes 11. It should be noted that the effect of the present invention, which is less likely to be damaged even when a pillar-shaped spacer or a lattice-shaped spacer is used, can be naturally obtained.

The sealed panel is evacuated to a vacuum of about 10 -7 Torr and sealed. After the sealing, the getter is activated, and the inside of the display device is maintained in a vacuum. For example, in the case of a getter material containing barium (Ba) as a main component, a getter film can be formed by high-frequency induction heating. Thus, the image display device of the present embodiment is completed. In the image display device of the present embodiment, since the distance between the electron source substrate and the fluorescent display plate is as long as about 1 to 3 mm,
The acceleration voltage applied to the metal back film 114 is 3 to 6 KV
And high voltage. Therefore, as described above, a phosphor for a cathode ray tube (CRT) can be used as the phosphor.

FIG. 23 is a schematic diagram showing a state where a drive circuit is connected to the image display device of the present embodiment. The lower electrode 11 is driven by a lower electrode driving circuit 40, and the upper bus electrode layer 16 (or the lower bus electrode layer 15) is driven by an upper electrode driving circuit 50. An acceleration voltage of about 3 to 6 KV is constantly applied to the metal back film 114 from the acceleration voltage source 60. FIG. 24 is a timing chart showing an example of the waveform of the drive voltage output from each drive circuit shown in FIG. Here, the m-th lower electrode 11 is represented by Km, the n-th bus electrode upper layer 16 is represented by Cn, and the intersection of the m-th lower electrode 11 and the n-th bus electrode upper layer 16 is represented by (m, n). I do.

At time t0, no driving voltage is applied to any of the electrodes, so that no electrons are emitted, and thus the phosphor does not emit light. At time t1, the lower electrode 11 of K1
Then, a drive voltage of (−V1) from the lower electrode drive circuit 40 and a drive voltage of (+ V2) from the upper electrode drive circuit 50 are applied to the bus electrode upper layer 16 of (C1, C2). Lower electrode 11 and upper electrode 1 at intersections (1, 1) and (1, 2)
Since a voltage of (V1 + V2) is applied between the thin film type electron source at the intersection of these two points, if the voltage of (V1 + V2) is set to be equal to or higher than the electron emission start voltage. Will be released. The emitted electrons are accelerated by the acceleration voltage from the acceleration voltage source 60 applied to the metal back film 114, and then enter the phosphors (111 to 113) to emit light.

At time t2, the lower electrode 11 of K2
When a drive voltage of (−V1) is applied from the lower electrode drive circuit 40 to the upper electrode drive circuit 50 and a drive voltage of (+ V2) is applied from the upper electrode drive circuit 50 to the bus electrode upper layer 16 of C1. ) Lights up. In this manner, a desired image or information can be displayed by changing the signal applied to the upper layer 16 of the bus electrode. Further, by appropriately changing the magnitude of the driving voltage (+ V2) applied to the upper layer 16 of the bus electrode, an image having a gradation can be displayed. Here, the application of the inversion voltage for releasing the charges accumulated in the insulating layer 12 is performed by applying the drive voltage of (−V1) from the lower electrode drive circuit 40 to all of the lower electrodes 11 here. A drive voltage of (+ V3) is applied to the lower electrode 11 from the lower electrode drive circuit 40 and all upper electrode bus lines 15
, By applying a drive voltage of (−V3 ′) from the upper electrode drive circuit 50. In this case, (V3 + V
3 ') is set to be substantially equal to the voltage of (V1 + V2).

Here, for example, the output resistance of the upper electrode drive circuit 50 is changed by the resistance 24 added to each thin film type electron source.
Lower than the resistance value. As a result, even when the thin-film electron source is short-circuited due to the occurrence of a defect, a voltage is applied to the resistor 24, so that a voltage is applied to another normal thin-film electron source, and no line defect occurs. As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and can be variously modified without departing from the gist of the invention. Of course, it is.

[0038]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. (1) According to the image display device of the present invention, it is possible to improve luminance and reduce power consumption. (2) According to the image display device of the present invention, the arrangement of the spacers is facilitated, so that the production yield can be improved. (3) According to the image display device of the present invention, a point defect can be prevented from becoming a line defect, so that the production yield can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an example of a thin-film electron source constituting a thin-film electron source matrix according to the present embodiment.

FIG. 2 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 3 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 4 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 5 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 6 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 7 is a view for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 8 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 9 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 10 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 11 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 12 is a circuit diagram showing an equivalent circuit of a conventional thin-film electron source matrix.

FIG. 13 is a circuit diagram showing an equivalent circuit of the thin film type electron source matrix of the present embodiment.

14 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

15 is a view for explaining a method of manufacturing the thin-film electron source shown in FIG.

16 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

17 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

18 is a diagram for explaining a method of manufacturing the thin-film electron source shown in FIG.

FIG. 19 is a diagram showing a schematic configuration of another example of the thin-film electron source constituting the thin-film electron source matrix of the present embodiment.

FIG. 20 is a diagram illustrating a schematic configuration of an electron source substrate of the image display device according to the embodiment of the present invention.

FIG. 21 is a diagram illustrating a schematic configuration of a fluorescent display panel of the image display device according to the embodiment of the present invention.

FIG. 22 is a cross-sectional view illustrating a schematic overall configuration of an image display device according to an embodiment of the present invention.

FIG. 23 is a schematic diagram showing a state where a driving circuit is connected to the image display device of the present embodiment.

24 is a timing chart showing an example of a waveform of a driving voltage output from each driving circuit shown in FIG.

FIG. 25 is a diagram for explaining the operation principle of the MIM type thin film type electron source.

[Explanation of symbols]

10, 110: substrate, 11: lower electrode, 12: insulating layer,
13 upper electrode, 14 protective insulating layer, 15 lower bus electrode lower layer, 16 upper bus electrode upper layer, 17 passivation film, 18 insulating film, 20 vacuum, 21 resist film,
22 ... first electrode, 23 ... second electrode, 24 ... resistance, 3
0: spacer, 40: lower electrode drive circuit, 41: row electrode drive circuit, 42: column electrode drive circuit, 50: upper electrode drive circuit, 60: acceleration voltage source, 111: red phosphor, 112
... green phosphor, 113 ... blue phosphor, 114 ... metal back film, 115 ... frit glass, 116 ... frame, 301
... thin-film electron source, 310 ... row electrode, 311 ... column electrode

Continued on the front page (72) Inventor Masaichi Sagawa 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 5C031 DD09 DD17 5C036 EE01 EE08 EE14 EF01 EF06 EF09 EG01 EG12 EH06 EH08 5C094 AA10 AA22 BA32 BA34 CA19 CA24 CA25

Claims (5)

    [Claims]
  1. A first electrode having a lower electrode and an upper electrode, wherein the plurality of thin film electron sources emit electrons from the surface of the upper electrode when a positive voltage is applied to the upper electrode. A frame member, and a second substrate having a phosphor, wherein the first substrate has
    An image display device including a display element in which a space surrounded by the frame member and the second substrate is a vacuum atmosphere, wherein the first substrate is provided on an upper electrode of a plurality of thin-film electron sources. A plurality of bus electrodes for applying a driving voltage; an upper electrode of at least one of the thin-film electron sources; a resistive element provided between any one of the plurality of bus electrodes; An image display device comprising: a first insulating layer provided on an element and having a first opening provided in an electron-emitting portion of each of the thin-film electron sources.
  2. 2. The image display device according to claim 1, further comprising a spacer provided on the first insulating layer.
  3. 3. The bus electrode includes a bus electrode lower layer and a bus electrode upper layer having a thickness greater than that of the bus electrode lower layer. The resistor element is formed of the same material as the bus electrode lower layer. 3. The method as claimed in claim 1, wherein the first electrode is formed by using the first electrode.
    An image display device according to claim 1.
  4. 4. The at least one thin-film electron source,
    A first electrode having a second opening provided to be located inside the first opening; and a third opening provided to be located outside the first opening. And a second electrode provided between the first insulating layer and the first electrode, wherein the upper electrode of the at least one thin-film electron source is the second opening The image display device according to claim 1, wherein the image display device is provided on the first electrode so as to cover the first electrode.
  5. 5. The at least one thin-film electron source,
    A first electrode having a second opening; and a second electrode having a third opening provided on the first electrode.
    Having a fourth opening, and a second insulating layer provided between the first insulating layer and the second electrode, wherein the second insulating layer is The second opening is provided so as to be located inside the fourth opening, and the third opening is formed of a material different from the first insulating layer. An upper electrode of the at least one thin-film electron source is provided on the first electrode so as to cover the second opening; The image display device according to claim 1, wherein the image display device is a display device.
JP2000070696A 2000-03-14 2000-03-14 Image display device Pending JP2001256907A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000070696A JP2001256907A (en) 2000-03-14 2000-03-14 Image display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000070696A JP2001256907A (en) 2000-03-14 2000-03-14 Image display device

Publications (1)

Publication Number Publication Date
JP2001256907A true JP2001256907A (en) 2001-09-21

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6975075B2 (en) 2002-07-25 2005-12-13 Hitachi, Ltd. Field emission display
CN1301531C (en) * 2001-09-26 2007-02-21 株式会社日立制作所 Image display device
US7221086B2 (en) 2002-09-20 2007-05-22 Hitachi Displays, Ltd. Display device including a shield member

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1301531C (en) * 2001-09-26 2007-02-21 株式会社日立制作所 Image display device
US6975075B2 (en) 2002-07-25 2005-12-13 Hitachi, Ltd. Field emission display
US7221086B2 (en) 2002-09-20 2007-05-22 Hitachi Displays, Ltd. Display device including a shield member

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