JP2005108507A - Method for manufacturing electron emission element, electron source, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide methods for manufacturing an electron emission element, an electron source, and an image display device, where the methods can simplify production steps for the electron emission element, and can improve properties of the electron emission element. <P>SOLUTION: The method for manufacturing the electron emission element comprises a step for allocating a pair of electrodes on a substrate, a step for allocating a polymer film between the pair of the electrodes so as to connect them with each other, a step for lowering the resistance of the polymer film by emitting a light or energy beam to the polymer film, and a step for feeding an electric current through the film with lowered resistance obtained by the resistance-lowering of the polymer film to form a gap in the film with the lowered resistance. The step for lowering the resistance of the polymer film includes an operation to emit the energy beam for a specified period with the energy value decreased as time passes from the emission start. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an electron-emitting device, a method for manufacturing an electron source in which a large number of electron-emitting devices are arranged, and a method for manufacturing an image display device configured using the electron source.

  Conventionally, a surface conduction electron-emitting device is known as an electron-emitting device. The configuration, manufacturing method, and the like of the surface conduction electron-emitting device are disclosed in, for example, Patent Document 1.

  FIG. 24 schematically shows a configuration of a general surface conduction electron-emitting device disclosed in Patent Document 1 and the like. FIG. 24A is a plan view of the electron-emitting device, and FIG. 24B is a cross-sectional view of the electron-emitting device.

  In FIG. 24, reference numeral 241 denotes a base, 242 and 243 are a pair of electrodes disposed on the base 241 and face each other, 244 is a conductive film superimposed on the pair of electrodes 242 and 243, and 245 is between two conductive films 244. The second gap 246 is a carbon film covering the conductive film 244, and 247 is a first gap between the two carbon films 246.

  FIG. 25 schematically shows an example of an electron-emitting device manufacturing process having the structure shown in FIG. Hereinafter, an electron-emitting device creation process will be described with reference to FIG.

  First, a pair of electrodes 242 and 243 are formed on the base 241 (FIG. 25A).

  Subsequently, a conductive film 244 that connects the electrodes 242 and 243 is formed (FIG. 25B).

  Then, a “forming process” is performed in which a current is passed between the electrodes 242 and 243 to form the second gap 245 in a part of the conductive film 244 (FIG. 25C).

  Further, a voltage is applied between the electrodes 242 and 243 in a carbon compound atmosphere to form a carbon coating 246 on the base 241 and the conductive film 244 in the vicinity thereof in the second gap 245. “Activation” Step “is performed to form an electron-emitting device (FIG. 25D).

  On the other hand, Patent Document 2 discloses another method for manufacturing a surface conduction electron-emitting device.

  An image display device such as a flat display panel can be configured by combining an electron source composed of a plurality of electron-emitting devices and a light emitting member composed of a phosphor or the like produced by the manufacturing method as described above.

  In the above-described conventional element, in addition to the “forming process”, the “activation process” or the like is performed, so that the narrower first gap 247 is formed inside the second gap 245 formed by the “forming process”. A carbon coating 246 made of carbon or a carbon compound having a carbon atom is arranged to obtain good electron emission characteristics.

  In other words, in order to create an electron source or an image display device using a conventional electron-emitting device, a process of performing repeated energization in the “forming process” and “activation process” and a suitable atmosphere in each process are formed. There are many additional processes, such as a process to perform, and the management of each process has become complicated.

  In order to solve the above problems, the inventors have used a polymer film as an element film material, and an element and an element that can obtain good electron emission characteristics even if some of the steps required in the conventional element are omitted. The manufacturing process has been developed. As an element to which such an improvement is added, one disclosed in Patent Document 3 can be cited.

  A configuration example of this electron-emitting device is shown in FIG. FIG. 1A is a plan view of the electron-emitting device, and FIG. 1B is a cross-sectional view of the electron-emitting device.

  In FIG. 1, 1 is a base, 2 and 3 are a pair of electrodes arranged on the base 1 and facing each other, 4 'is a carbon film superimposed on the pair of electrodes 2 and 3, and 5 is between two carbon films 4'. It is a gap of. In this element, it is preferable to use a polymer film as a raw material of the carbon film 4 '.

  FIG. 2 schematically shows an example of an electron-emitting device manufacturing process having the structure shown in FIG. Hereinafter, an electron-emitting device creation process will be described with reference to FIG.

  First, a pair of electrodes 2 and 3 are formed on the substrate 1 (FIG. 2A), and then a polymer film 4 connecting the electrodes 2 and 3 is formed (FIG. 2B).

  Next, energy is applied to the polymer film 4 to perform a “resistance reduction process” for forming the carbon film 4 ′.

  In the process of processing the polymer film 4 into the carbon film 4 ′, if the whole is heated by an oven, a hot plate or the like, there may be a restriction from the viewpoint of the heat resistance of other members constituting the electron-emitting device. Therefore, as a more preferable low resistance treatment method, a method of selectively injecting energy into the polymer film 4 using the particle beam or light beam irradiation means 10 to form the carbon film 4 ′ is suitable. (FIG. 2 (c)).

  Then, a current is passed between the electrodes 2 and 3 to perform a “forming process” in which a gap 5 is formed in a part of the carbon film 4 ′, thereby forming an electron-emitting device (FIG. 2D).

  Since this electron-emitting device using the polymer film 4 does not perform the activation process as compared with the conventional device, the number of steps can be reduced and the device can be easily produced.

JP-A-8-32254 Japanese Patent Laid-Open No. 9-237571 JP 2002-150930 A

  The process of reducing the resistance of the polymer film in creating an electron-emitting device using the polymer film as an element film material is a process of applying thermal energy to the polymer film (heating), and the polymer film is a carbon film. It has been found that the reaction process that changes to Arrhenius is based on detailed studies by the inventors.

  FIG. 26 is a typical graph of reaction rate and reaction temperature when the resistance of the polymer film is reduced. The reaction rate is first order with respect to the reciprocal temperature, which is a typical Arrhenius type reaction.

Therefore, heating the polymer film is effective for performing the resistance reduction treatment of the polymer film in a short time.

  However, if it is heated too much, the electrode reaches the phase transition temperature before the resistance of the polymer film is lowered, and the electrode breaks down, resulting in defective electron emission. In the worst case, the device may be broken. It was.

  The present invention has been made in view of the above-described prior art. The object of the present invention is to prepare a polymer in a short time without destroying an electrode when producing a surface conduction electron-emitting device using a polymer film. An object of the present invention is to provide a technique for performing a resistance reduction process for a film.

  The present invention has been made in earnest to solve the above-described problems, and has the configuration described below.

That is, the manufacturing method of the electron-emitting device of the present invention includes:
Arranging a pair of electrodes on a substrate;
Arranging a polymer film so as to connect between the pair of electrodes;
Irradiating the polymer film with light or an energy beam to reduce the resistance of the polymer film;
Passing a current through the low resistance film obtained by reducing the resistance of the polymer film, and forming a gap in the low resistance film; and
Have
The step of reducing the resistance of the polymer film includes a step of irradiating the polymer film with an energy beam whose energy value decreases with time from the start of irradiation for a predetermined period.

The step of reducing the resistance of the polymer film includes:
Partially shielding the light or particle beam;
Scanning a light or particle beam;
Focusing the light or particle beam;
Have
It is preferable to perform a step of partially shielding the light or particle beam before the step of converging the light or particle beam.

  The step of reducing the resistance of the polymer film preferably includes a step of moving the substrate.

  The light or particle beam is preferably irradiated in a plurality of times.

  The particle beam is preferably an electron beam or an ion beam, the light is preferably laser light, and the light is light emitted from a xenon light source or a halogen light source. Is preferred.

  The polymer of the polymer film is preferably one of aromatic polyimide, polyphenylene oxadiazole, or polyphenylene vinylene.

  The method of manufacturing an electron source according to the present invention is characterized in that, in the method of manufacturing an electron source having a plurality of electron-emitting devices, the electron-emitting devices are manufactured by the method described above.

According to another aspect of the present invention, there is provided a method for manufacturing an image display apparatus, comprising: an electron source having a plurality of electron-emitting devices; and a light-emitting member that emits light when irradiated with electrons emitted from the electron source. The source is manufactured by the method described above.

  According to the manufacturing method of the present invention, the destruction of the element film and the electrode is suppressed by a simple process, the electron emission characteristic is sufficient and stable, the heat resistance is excellent, and the excellent electron emission characteristic is provided for a long time. An electron-emitting device that can be maintained across, an electron source using the electron-emitting device, and an image display device using the electron source can be provided with high yield.

  According to the present invention, it is possible to simplify the process for producing an electron-emitting device, and to manufacture an image display device excellent in display quality over a long period of time at low cost.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiments described below.

  Prior to the description of the low-resistance process, which is a feature of the present invention, the configuration of an electron-emitting device used in this embodiment and a method for producing the same will be described. Thereafter, the resistance reduction treatment process will be described in detail. An image display device using the electron-emitting device will also be described.

  First, the configuration of an electron-emitting device used in this embodiment and a method for producing the same will be described.

  FIG. 1 is a schematic view showing a configuration example of an electron-emitting device according to the present embodiment, FIG. 1 (a) is a plan view of the electron-emitting device, and FIG. 1 (b) is an electrode of the electron-emitting device. 2 is a cross-sectional view that passes between 2 and 3 and is substantially perpendicular to the surface of the substrate 1 on which the electrodes 2 and 3 are arranged.

  In FIG. 1, 1 is a substrate, 2 and 3 are electrodes, 4 'is a carbon film, and 5 is a gap. Reference numeral 6 denotes a gap between the carbon film 4 ′ and the substrate 1 and constitutes a part of the gap 5.

  The carbon film 4 ′ includes “a conductive film mainly composed of carbon”, “a conductive film mainly composed of carbon having a gap in part and electrically connecting a pair of electrodes”, “a pair of carbon films”. It can be referred to as “a conductive film mainly composed of carbon” or “a film obtained by subjecting a polymer film to a low resistance treatment”.

  In the electron-emitting device of the present embodiment configured as described above, when a sufficient electric field is applied to the gap 5, electrons tunnel through the gap 5, and a current (element current: If) ) Flows. Some of the tunnel electrons become emitted electrons (Ie) due to scattering.

  In the electron-emitting device according to the present embodiment, the gap 5 is arranged so as to be biased toward the vicinity of one electrode. In the example shown in FIG. 1A, the gap 5 is arranged along the edge of the electrode 2. As shown in FIG. 1B, the surface of the electrode 2 is exposed (exists) in at least a part of the gap 5.

  In the present invention, the above “exposure” naturally includes the case where the surface of the electrode 2 is completely exposed, but impurities, adsorbed substances of gas in the atmosphere, etc. are present on the surface of the electrode 2. It does not exclude the existing state or the attached (adsorbed) state.

In addition, it is assumed that the gap 5 is formed by an interaction such as thermal deformation or thermal strain between the electrodes 2 and 3, the carbon film 4 ′, and the substrate 1 during a “voltage application step” described later. Yes. Therefore, in the present invention, in the gap 5 after the “voltage application step”, a residue such as a carbon film that has been in contact with the surface of the electrode 2 before the “voltage application step” slightly appears on the surface of the electrode 2. Even in the attached state, it corresponds to the “exposure”. Further, at least in a cross-sectional TEM photograph or SEM photograph, this state also corresponds to “exposure” in the present invention unless the presence of a clear coating on the surface of the electrode 2 in the gap 5 is confirmed.

  When the gap 5 is formed as described above, the electric conduction characteristic (electron emission characteristic) of the electron-emitting device may be significantly asymmetric with respect to the polarity of the applied voltage applied between the electrodes 2 and 3. it can. When a voltage is applied with a certain polarity (forward polarity: the potential of the electrode 2 is made higher than the potential of the electrode 3) and when a voltage is applied with the opposite polarity (reverse polarity), for example, each voltage is 20V. When the comparison is made at a voltage of 10%, a difference of 10 times or more occurs in the current value. At this time, the voltage-current characteristics of the electron-emitting device of the present embodiment indicate that it is a tunnel conduction type under a high electric field.

  In addition, in the electron-emitting device of the above embodiment, very high electron emission efficiency can be obtained. In measuring the electron emission efficiency, an anode electrode is disposed on the element, and the electrode 2 on the side close to the gap 5 is driven so as to have a high potential with respect to the electrode 3. In this way, very high electron emission efficiency can be obtained. If the ratio (Ie / If) of the device current If flowing between the electrodes 2 and 3 and the emission current Ie trapped by the anode electrode is defined as the electron emission efficiency, this value is the same as the conventional “forming process” and “activity”. The value is several times as large as that of the surface conduction electron-emitting device formed by performing the “chemical treatment”. The present inventors speculate that the electrode material is exposed in the gap 5 in some form as one of several reasons why such a high electron emission efficiency can be obtained. ing.

  As will be described in detail later, the gap 5 is formed by arranging the polymer film 4 so as to connect the pair of electrodes 2 and 3, reducing the resistance of the polymer film 4, and applying the resistance reduction process. A voltage is applied to the obtained film (hereinafter referred to as “carbon film”. The carbon film is also referred to as a “low-resistance polymer film” or simply “conductive film”). It is formed by performing the “applying step”.

  Hereinafter, an example of a method for manufacturing the electron-emitting device of the present embodiment will be described with reference to FIGS.

  (1) The substrate 1, which is a substrate made of glass or the like, is sufficiently cleaned using a detergent, pure water, an organic solvent, or the like, and after depositing an electrode material by a vacuum deposition method, a sputtering method, etc., for example, using a photolithography technique. Electrodes 2 and 3 are formed on the substrate 1 (FIG. 2A).

The distance between the electrode 2 and the electrode 3 is set to 1 μm or more and 100 μm or less. Further, from the viewpoint of cost, as a member used for the substrate 1, relatively inexpensive glass such as soda lime glass, low alkali glass, and non-alkali glass, or glass obtained by forming SiO ₂ on the glass is used. Most of these glass have a strain point of less than 700 ° C.

  Here, as a material of the electrodes 2 and 3, a general conductive material can be used. Preferably, the material of the electrodes 2 and 3 is preferably a metal or a material containing a metal as a main component.

  (2) Next, the polymer film 4 is formed on the substrate 1 provided with the electrodes 2 and 3 so as to connect the electrodes 2 and 3 (FIG. 2B).

  As the film thickness of the polymer film, 1 nm or more and 1 μm or less are selected from the viewpoint of “low resistance treatment” described later, reproducibility of film formation, and the like.

  The “polymer” in the present invention means one having at least a bond between carbon atoms. And preferably, the molecular weight of the polymer of the present invention is 5000 or more, more preferably 10,000 or more.

  When heat is applied to a polymer having bonds between carbon atoms, dissociation and recombination of bonds between carbon atoms may occur and conductivity may increase. As a result of applying heat in this way, conductivity increases. This polymer is referred to as “pyrolytic polymer”.

  In the present invention, factors other than heat, such as decomposition recombination due to electron beams and decomposition recombination due to photons, are added to thermal recombination recombination to cause dissociation and recombination of bonds between carbon atoms, resulting in conductivity. Is also referred to as a pyrolytic polymer.

  However, in the present invention, the structural change of the polymer and the change of the conductive property due to heat and factors other than heat are collectively referred to as “modified”.

  In the pyrolytic polymer, it can be interpreted that the conductivity is increased by increasing the conjugated double bond between carbon atoms in the polymer, and the conductivity differs depending on the progress of the modification.

  Examples of the polymer that easily exhibits electrical conductivity by dissociation / recombination of bonds between carbon atoms, that is, the polymer that easily generates double bonds between carbon atoms include aromatic polymers. Therefore, in the present invention, it is preferable to use an aromatic polymer. Among them, in particular, aromatic polyimide is a more preferable material in the present invention because it is a polymer from which a pyrolytic polymer having high conductivity at a relatively low temperature can be obtained. In general, an aromatic polyimide is an insulator itself, but there are polymers having conductivity before thermal decomposition, such as polyphenylene oxadiazole and polyphenylene vinylene. These polymers are also polymers that can be preferably used in the present invention.

  As a method for forming the polymer film 4, various known methods, that is, a spin coating method, a printing method, a dipping method, or the like can be used. In particular, the printing method is a preferable method because the polymer film 4 can be formed at low cost. In particular, if an ink jet printing method is used, a patterning process can be eliminated and a pattern of several hundred μm or less can be formed. This is also effective for manufacturing an electron source having an electron-emitting device.

  When the polymer film 4 is formed, the polymer material solution may be applied with liquid droplets and dried. If necessary, the polymer material precursor solution may be applied with liquid droplets and heated to heat the polymer film. It is also possible to use a method of making it.

  In the present embodiment, as described above, an aromatic polymer is preferably used as the polymer material. However, since many of these are difficult to dissolve in a solvent, a method of applying a precursor solution is effective. It is. For example, a polyimide film can be formed by applying a polyamic acid solution, which is a precursor of aromatic polyimide, and heating.

  As the solvent for dissolving the polymer precursor, for example, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide and the like can be used, and n-butyl cellosolve, triethanolamine However, there is no particular limitation as long as the present invention can be applied, and the present invention is not limited to these solvents.

As shown in FIG. 1, for example, when it is desired to arrange the gap 5 on the electrode 2 side, the connection length between the electrode 2 and the polymer film 4 (or the carbon film 4 ′), the electrode 3 and the polymer film 4 (or carbon film 4 ′) may be formed so that the connection length differs depending on the shape of polymer film 4 (or carbon film 4 ′). For example, as shown in FIG. 1, the connection length (W1) between the polymer film 4 (or carbon film 4 ′) and the electrode 2, the polymer film 4 (or carbon film 4 ′), and the electrode 3 are used. The polymer film 4 is formed so as to have a different connection length (W2). In FIG. 1, W1 <W2 is set, and the gap 5 is formed on the electrode 2 side where W1 is set.

  In the present invention, the “connection length” (or “intersection length”) means “the polymer film 4 (or“ resistance reduction treatment ”described later) is applied to the ends (edges) of the electrodes (2, 3). The length (boundary) where the carbon film 4 ′) obtained in this way and the electrode (2, 3) are in contact with each other ”is indicated. Alternatively, the “connection length” (or “intersection length”) is “the electrodes (2, 3)” and the polymer film 4 (or the carbon film 4 obtained by performing the “low resistance treatment” described later). ') And the length of the portion (boundary) formed by contact with the substrate 1 ".

  In order to make the connection lengths different, a method can be used in which the polymer film 4 is patterned into a trapezoidal shape as shown in FIG. 1, for example. Alternatively, when the polymer film 4 is formed using an ink jet printing method, a method can be used in which a droplet is applied to one electrode by shifting the center position of the droplet. Or, after changing the surface energy of one electrode and the surface energy of the other electrode, a polymer material solution or a precursor solution of a polymer material is applied and heated, so that the polymer films have different connection lengths. 4 can also be formed. As described above, various methods can be appropriately selected as a method of varying the connection length.

In the present invention, when the position of the gap 5 is controlled as described above, the connection length is not limited to the method of making the connection different on the electrode 2 side and the electrode 3 side. Some of them are shown.
(A) The connection resistance or step coverage between the carbon film 4 ′ and the electrode 2 and the connection resistance or step coverage between the carbon film 4 ′ and the electrode 3 are made asymmetric.
(B) The degree of heat diffusion differs between the vicinity of the region where the carbon film 4 ′ and the electrode 2 are connected and the vicinity of the region where the carbon film 4 ′ and the electrode 3 are connected.
(C) The shapes of the electrodes 2 and 3 are made asymmetric.

  (3) Next, a “resistance reduction process” for reducing the resistance of the polymer film 4 is performed. The “resistance reduction process” is a process in which the polymer film 4 is made conductive and the polymer film 4 is changed to a carbon film 4 ′.

  As an example of this “resistance reduction treatment”, the resistance of the polymer film 4 can be reduced by heating the polymer film 4. The reason why the resistance of the polymer film 4 is reduced (conducted) by heating is to develop conductivity by dissociating and recombining bonds between carbon atoms in the polymer film 4.

  The “resistance reduction treatment” by heating can be achieved by heating the polymer constituting the polymer film 4 at a temperature equal to or higher than the decomposition temperature. The heating of the polymer film 4 is particularly preferably performed in an oxidation-inhibiting atmosphere such as an inert gas atmosphere or a vacuum.

  The above-mentioned aromatic polymer, especially aromatic polyimide, has a high thermal decomposition temperature, but it has high conductivity by heating at a temperature exceeding the thermal decomposition temperature, typically 700 ° C. to 800 ° C. or higher. Can be expressed.

However, when heating until the polymer film 4 that is a member constituting the electron-emitting device is thermally decomposed as in the present embodiment, the method of heating the whole by an oven, a hot plate, or the like, From the viewpoint of the heat resistance of other members that constitute the material, there are cases in which restrictions are imposed.

  Therefore, in the present embodiment, as shown in FIG. 2C, as a more preferable resistance reduction method, a particle beam such as an electron beam or an ion beam or a light irradiation means 10 such as a laser beam is used. By irradiating the polymer film 4 with a beam or light, the resistance of the polymer film 4 is reduced. In this way, it becomes possible to reduce the resistance of the polymer film 4 while suppressing adverse effects of heat on other members.

  Details of the low-resistance treatment method that is a feature of the present invention will be described later.

  (4) Next, the gap 5 is formed in the carbon film 4 '(FIG. 2D).

  The gap 5 is formed by applying a voltage (flowing current) between the electrodes 2 and 3. Note that the voltage to be applied is preferably a pulse voltage. By this voltage application step, a gap 5 is formed in a part of the carbon film 4 ′ whose resistance has been reduced. In driving the electron-emitting device at a low voltage, it is preferable to use a pulse voltage as the voltage applied in the voltage application step.

  This voltage application step can also be performed by applying a voltage pulse between the electrodes 2 and 3 simultaneously with the above-described resistance reduction process. Further, in order to form the gap 5 with good reproducibility, it is preferable to perform boosting forming that gradually increases the pulse voltage applied to the electrodes 2 and 3.

The voltage application step is preferably performed in a reduced pressure atmosphere, and preferably in an atmosphere having a pressure of 1.3 × 10 ⁻² Pa or less.

  Further, the voltage application step can be performed simultaneously with the above-described “resistance reduction process”.

  Note that the resistance value of the carbon film 4 ′ obtained through the aforementioned “resistance reduction treatment” may further decrease in the above-described “voltage application step”. The carbon film 4 ′ obtained by performing the “resistance reduction treatment” and the carbon film 4 ′ after the gap 5 is formed through the “voltage application process”, the electrical characteristics, film quality, etc. There is a case where there is a slight difference between the two, but in the present invention, they are not distinguished unless otherwise specified.

  More specifically, a carbon film that has undergone the “resistance reduction treatment” (“carbon film obtained by applying a resistance reduction treatment to the core film”) and a carbon film that has undergone the “voltage application step” ( If there is no particular difference in terms of carbon crystallinity from the carbon film with gaps), the expression “carbon film with gaps” and “reducing the resistance of polymer films” Although the expression “carbon film obtained by processing” is an expression that distinguishes process stages, it is not an expression that distinguishes as a film quality.

  Next, the voltage-current characteristic of the electron-emitting device obtained by the manufacturing method of the present embodiment is measured by the measuring apparatus shown in FIG. In FIG. 3, members using the same reference numerals as those used in FIG. 1 and the like indicate the same members.

  In FIG. 3, 84 is an anode electrode, 83 is a high voltage power source, 82 is an ammeter for measuring the emission current Ie emitted from the electron-emitting device, 81 is a power source for applying a drive voltage Vf to the electron-emitting device, Reference numeral 80 denotes an ammeter for measuring the element current If flowing between the electrodes 2 and 3.

  In measuring the device current If and the emission current Ie of the electron-emitting device, a power source 81 and an ammeter 80 are connected to the device electrodes 2 and 3, and a high-voltage power source 83 and an ammeter 82 are connected above the electron-emitting device. A connected anode electrode 84 is disposed.

  In addition, the electron-emitting device and the anode electrode 84 are installed in a vacuum device, and the vacuum device includes equipment necessary for the vacuum device such as an exhaust pump and a vacuum gauge (not shown), and a desired vacuum. The measurement and evaluation of the electron-emitting device can be performed below.

Note that the distance H between the anode electrode 84 and the electron-emitting device is 2 mm, and the pressure in the vacuum apparatus is 1 × 10 ⁻⁶ Pa.

  When the voltage-current characteristics of the electron-emitting device of this embodiment are measured by the measuring apparatus shown in FIG. 3, the characteristics of the device that exhibits good electron emission are as shown in FIG.

  That is, as shown in FIG. 4, the electron-emitting device has a threshold voltage Vth, and even if a voltage lower than this voltage is applied between the electrodes 2 and 3, electrons are not substantially emitted. By applying a voltage higher than this voltage, an emission current (Ie) from the element and an element current (If) flowing between the electrodes 2 and 3 start to be generated.

  Since the electron-emitting device has the characteristics shown in FIG. 4, a simple matrix drive is possible in which a plurality of electron-emitting devices are arranged in a matrix on the same substrate, and a desired device is selected and driven. It is.

  Next, the characteristic low resistance process of the present invention will be described in detail.

  In order to stably supply the user with the electron-emitting device, the electron source, and the image display device of the present invention at low cost, it is important to perform the above-mentioned “low resistance treatment” stably and at low cost. is there.

  For example, when forming an electron source or image display device having a diagonal length of about 40 inches, one million or more electron-emitting devices of the present invention are arranged on the same substrate, depending on the resolution. Therefore, shortening the resistance reduction processing time of each element is important for shortening the resistance reduction processing steps of all elements.

  As described in the prior art, the low resistance treatment of the polymer film is an Arrhenius type reaction (FIG. 26). Therefore, in order to process for a short time, it is necessary to heat the polymer film to a high temperature in a short time.

  However, in the conventional heating method, since the temperature of the polymer depends on the heat conduction of the substrate, the temperature does not rise in a short time. In addition, if the temperature is increased in a short time, there is a problem that the element electrode is destroyed.

  Hereinafter, the relationship between the energy beam irradiation and the polymer film temperature in the resistance reduction process will be described first. Thereafter, the relationship between the beam irradiation and the resistance reduction processing time is shown, and finally, the beam irradiation conditions that are the characteristics of the present invention will be described.

  FIG. 5 shows an irradiation power profile and a polymer film temperature profile during the low resistance treatment. When the beam irradiation is a rectangular wave as shown in FIG. 5A, the temperature of the polymer film shows a profile as shown in FIG. 5B.

  When a very thin (thickness L2) polymer film is arranged on a substrate (thickness L1), when irradiation power I1 is given with irradiation pulse width tpulse (= t2-t1), the temperature Tpoly of the polymer film is as follows: It can be estimated as follows.

That is,
Tpoly∝I1 / λ × SQRT (k × tpulse / π) (Equation 1)
k = λ / (ρ × C) (Expression 2)
tpulse = t2-t1 (Formula 3)
λ: Thermal conductivity of substrate ρ: Density of substrate C: Specific heat of substrate tpulse: Pulse irradiation time.

However,
Substrate thickness L1 >> 2 × SQRT (k × tpulse) (Formula 4)
Polymer film thickness L2 ≦ 2 × SQRT (k × tpulse) (Formula 5)
These conditions are necessary conditions.

Further, when the phase transition temperature (melting point or boiling point) of the device electrode is T2,
T2> Tpoly (Formula 6)
However, this is a necessary condition for the resistance reduction process without element destruction.

  In FIG. 5B, the maximum temperature of the polymer film is T1, and the relationship of T2> T1 is established, so that no element electrode destruction occurs.

  As can be seen from FIGS. 5B and (Equation 1), at the initial stage of pulse irradiation, the temperature of the polymer film is low, and time that does not substantially contribute to the resistance reduction treatment (Arrhenius type reaction) appears. Therefore, the processing time requires more time than the substantial resistance reduction processing. Naturally, this effect becomes more prominent as the processing time is shortened.

  FIG. 6 shows a case where the processing time is sufficiently long. FIG. 6A shows an irradiation power profile, and FIG. 6B shows a temperature profile of the polymer film.

  When the beam irradiation is a rectangular wave, the temperature of the polymer film shows a profile as shown in FIG. The pulse irradiation time was longer than that in FIG. 5 (pulse irradiation time: (t3-t1)> (t2-t1)).

  In FIG. 6, since the pulse irradiation is performed for a sufficiently long time, the temperature of the polymer film is constant T3. Also in this case, in the temperature profile at the initial stage of pulse irradiation, the time not contributing to the resistance reduction process appears in the initial stage of the beam irradiation as in FIG.

  Next, FIG. 7 shows a case where the irradiation power is increased as compared with the case of FIG. FIG. 7A shows an irradiation power profile, and FIG. 7B shows a temperature profile of the polymer film. Here, the temperature of the polymer film is shown for two types of irradiation power profiles.

  In the case of the irradiation profile [1], the temperature profile of the polymer film is [1] in FIG. 7B, and in the case of the irradiation profile [2], the temperature profile is [2] in FIG. 7B.

Compared to the case of FIG. 5, the irradiation power is set to I4 and I3 which are larger than I1, so that t4 (
It is possible to raise the temperature in a short time at the time of <t2).

  However, if the power is increased too much (irradiation power I3, irradiation profile [1]), the temperature of the polymer film becomes T3 (> T2), the device electrode is broken, and electrons are not emitted.

  After all, the resistance reduction treatment can be performed with the shortest pulse width (t4-t1) by adjusting the temperature of the polymer film, the resistance reduction time, and the irradiation power.

  Hereinafter, a method for determining the irradiation pulse width tpulse (= t4-t1) and the irradiation power I4 will be described.

From (Equation 1), the rectangular pulse and substrate temperature are
Tpoly∝I4 / λ × SQRT (k × tpulse / π) (Expression 7)
∝I4 × SQRT (tpulse) (Formula 7 ′)
However, from (Equation 4), the condition that the substrate thickness >> the thermal diffusion distance is a necessary condition.

Also, as shown in the prior art, the low resistance treatment is Arrhenius type,
1 / resistance reduction processing time ∝ EXP (−Ea / Tpoly) (Equation 8)
Ea: It becomes the activation energy for the low resistance treatment.

From (Equation 7 ′) and (Equation 8),
1 / resistance reduction processing time ∝ EXP (−Ea / SQRT (tpulse) / I4) (Equation 9)
It becomes.

Therefore,
Low resistance processing time ∝1 / EXP (−Ea / SQRT (tpulse) / I4) (Equation 9 ′)
It can be expressed.

  It can be seen that the longer the pulse irradiation time, the shorter the resistance reduction processing time.

However, between the highest temperature reached by the polymer film and the phase transition temperature T2 of the device electrode,
Tpoly <T2 (Expression 10) = (Expression 6)
This relationship is necessary.

  As described above, the values of the irradiation pulse width tpulse (= t4−t1) and the irradiation power I4 can be determined from (Expression 9 ′) and (Expression 10).

In summary,
(1) When energy irradiation is performed with a rectangular pulse, there is a time loss in the initial stage.
(2) When large energy is irradiated, good electron-emitting device characteristics cannot be obtained, and device electrode destruction may occur.
(3) If the resistance reduction process is performed with a large energy and a short rectangular pulse, good electron-emitting device characteristics cannot be obtained, and device electrode destruction may occur.

  Therefore, in the present invention, it is proposed to use an energy beam irradiation power profile as shown in FIG. 8A or an irradiation power profile as shown in FIG. 9A.

  After all, the characteristic point is to correct the delay in temperature rise at the initial stage of energy irradiation by increasing the initial irradiation value. However, if the irradiation value is as it is, excessive irradiation is performed as the temperature rises with time. Therefore, although the irradiation initial value is large, the irradiation value is reduced as the irradiation time elapses.

  First, the form of FIG. 8 will be described. FIG. 8A shows an irradiation power profile, and FIG. 8B shows a temperature profile of the polymer film.

  In FIG. 8, energy beam irradiation (power irradiation) is performed from time t0 to time t11. The irradiation power at t0 is set to initial I11, the irradiation power at time t11 is set to I12, and the irradiation ends at time t11.

Here, the irradiation powers I11 and I12 are
I11> I12
Have the relationship.

  Further, the peak temperature T11 of the polymer film is set to be a value (T11 <T2) smaller than the phase transition temperature T2 of the element electrode. Detailed conditions will be described later in Examples.

  Next, the form of FIG. 9 will be described. FIG. 9A shows an irradiation power profile, and FIG. 9B shows a temperature profile of the polymer film.

  In FIG. 9, power irradiation is performed from time t0 to t21. The irradiation power at t0 is set to the initial I25, and the power is gradually decreased gradually as I24 (time t24), I23 (time t23), I22 (time t22), and I21 (time t21). And irradiation is complete | finished at the time t21.

  Further, the peak temperature T21 of the polymer film is set to be a value (T21 <T22) smaller than the phase transition temperature T22 of the element electrode. Detailed conditions will be described later in Examples.

  In FIG. 9, since the irradiation power is controlled in detail as compared with the case of FIG. 8, the polymer film can be held at a higher temperature.

  The energy beam that can be used for the “resistance reduction process” of the present invention will be specifically described below.

(When performing electron beam irradiation)
In the case of irradiating an electron beam as an energy beam, the substrate 1 on which the polymer film 4 is formed is set in a reduced-pressure atmosphere (in a vacuum container) in which an electron gun is mounted. The polymer film 4 is irradiated with an electron beam from an electron gun installed in the container. The electron beam irradiation conditions at this time are preferably an acceleration voltage V _ac = 0.5 kV or more and 40 kV or less in consideration of the penetration depth of the electron beam into the polymer film 4 or the substrate 1.

The current density (j _d ) is determined from (Equation 1) by the thermal conductivity, specific heat, specific gravity of the selected substrate 1 and τ arbitrarily selected within a range of 10 seconds or less. _Normally used much in j d = 0.01mA / mm ² or more 10 mA / mm ² or less.

(When performing laser beam irradiation)
When irradiating a laser beam as an energy beam, the substrate 1 on which the polymer film 4 is formed is placed on the stage, and the polymer film 4 is irradiated with the laser beam. At this time,
In order to suppress oxidation (combustion) of the polymer film 4, the laser irradiation environment is preferably performed in an inert gas or in a vacuum, but depending on the laser irradiation conditions, it may be performed in the air. is there.

  As irradiation conditions of the laser beam at this time, it is preferable to irradiate using a semiconductor laser (790 to 830 nm), for example.

The laser irradiation energy is determined by the thermal conductivity, specific heat, specific gravity, and τ selected from the melting point / strain point of the substrate 1 from (Equation 1). The output of the laser light source is determined in consideration of the absorption factor (= 1− [transmittance] − [reflectance]) at the wavelength of the film 4 and the substrate 1. Usually, it is often used in the range of several hundreds mW / mm ² to several tens W / mm ² .

  Next, an image display apparatus using the electron-emitting device manufactured by the above manufacturing method will be described.

  FIG. 10 is a schematic view showing an example of an image display device using an electron-emitting device manufactured by the manufacturing method of the present invention. FIG. 10 is a view in which a part of a support frame 73 and a face plate 72 described later are removed in order to explain the inside of the image display device (airtight container 100). The drive circuit is not shown.

  In FIG. 10, reference numeral 71 denotes a rear plate as a base on which a large number of electron-emitting devices 102 are arranged. Reference numeral 72 denotes a face plate on which the light emitting member 76 is disposed. Reference numeral 73 denotes a support frame for maintaining a reduced pressure between the face plate 72 and the rear plate 71. Reference numeral 101 denotes a spacer arranged in order to maintain a gap between the face plate 72 and the rear plate 71.

  When the image display device is a display, the light emitting member 76 includes a phosphor film 75 and a conductive metal back 74.

  Reference numerals 62 and 63 denote wirings connected to apply a voltage to the electron-emitting device 102, respectively. Doy1 to Doyn and Dox1 to Doxm are external to the drive circuit and the like disposed outside the airtight container 100 and the decompression space of the airtight container 100 (the space surrounded by the face plate 72, the rear plate 71, and the support frame 73). This is a lead-out wiring for connecting the derived ends of the wirings 62 and 63.

  Next, an example of a method for manufacturing the image display device will be described below with reference to FIGS.

  (A) First, the rear plate 71 is prepared. The rear plate 71 is made of an insulating material, and glass is particularly preferably used.

  (B) Next, a plurality of pairs of the electrodes 2 and 3 described in FIG. 1 are formed on the rear plate 71 (FIG. 11). The electrode material may be a conductive material. In addition, as a method for forming the electrodes 2 and 3, various manufacturing methods such as a sputtering method, a CVD method, and a printing method can be used.

  In FIG. 11, for simplification of description, an example is used in which a total of 9 electrode pairs are formed, 3 sets in the X direction and 3 sets in the Y direction. It is set as appropriate according to the resolution of the display device.

(C) Next, the wiring 62 is formed so as to cover a part of the electrode 3 (FIG. 12). Although various methods can be used for forming the wiring 62, a printing method is preferably used. Among the printing methods, the screen printing method is preferable because it can be formed on a large-area substrate at low cost.

  (D) An insulating layer 64 is formed at the intersection of the wiring 62 and the wiring 63 to be formed in the next step (FIG. 13). Although various methods can be used for forming the insulating layer 64, a printing method is preferably used. Among the printing methods, the screen printing method is preferable because it can be formed on a large-area substrate at low cost.

  (E) A wiring 63 substantially orthogonal to the wiring 62 is formed (FIG. 14). Various methods can be used for forming the wiring 63, but preferably the printing method is used similarly to the wiring 62. Among the printing methods, the screen printing method is preferable because it can be formed on a large-area substrate at low cost.

  (F) Next, the polymer film 4 is formed so as to connect the electrodes 2 and 3 (FIG. 15). The polymer film 4 can be formed by various methods as described above, but an ink-jet method (droplet discharge method) can also be used to easily form a large area, as described above. The polymer film 4 having a desired shape may be formed by patterning.

  (G) Subsequently, as described above, “low resistance treatment” for reducing the resistance of each polymer film 4 is performed. The “resistance reduction process” is performed by irradiating a particle beam such as an electron beam or an ion beam, or irradiating a laser beam. This “resistance reduction treatment” is preferably performed in a reduced pressure atmosphere. By this step, the polymer film 4 is imparted with conductivity and changed to a carbon film 4 ′ which is a conductive film (FIG. 16).

  (H) Then, the gap 5 is formed in the carbon film 4 ′ obtained by the step (G). The gap 5 is formed by applying a voltage between the wirings 62 and 63. Thereby, a voltage is applied between the electrodes 2 and 3. The applied voltage is preferably a pulse voltage. By this voltage application step, a gap 5 is formed in a part of the carbon film 4 '(FIG. 17). The gap 5 is arranged close to the vicinity of the electrode 2.

  This voltage application step is performed by continuously applying a voltage pulse between the electrodes 2 and 3 simultaneously with the above-described resistance reduction processing, that is, during the irradiation of the electron beam or the laser beam. Can also be done. In either case, it is desirable that the voltage application process be performed in a reduced pressure atmosphere.

  (I) Next, prepared in advance are a face plate 72 having a metal back 74 made of an aluminum film and a phosphor film 75, and a rear plate 71 having undergone the above steps (A) to (H). Positioning is performed so that the metal back faces the electron-emitting device (FIG. 18A).

  A joining member 77 is disposed on the contact surface (contact region) between the support frame 73 and the face plate 72. Similarly, the joining member 77 is also disposed on the contact surface (contact region) between the rear plate 71 and the support frame 73. As the bonding member 77, a member having a vacuum holding function and an adhesion function is used, and specifically, frit glass, indium, an indium alloy, or the like is used.

  FIG. 18 illustrates an example in which the support frame 73 is fixed (adhered) to the rear plate 71 that has undergone the above-described steps (A) to (H) by the bonding member 77 in advance. ) Sometimes it is not necessary to be joined. Similarly, FIG. 18 shows an example in which the spacer 101 is fixed on the rear plate 71. However, the spacer 101 does not necessarily have to be fixed to the rear plate 71 in the present step (I).

  18 shows an example in which the rear plate 71 is disposed below and the face plate 72 is disposed above the rear plate 71 for the sake of convenience, either of them may be on the top.

  18 shows an example in which the support frame 73 and the spacer 101 are fixed (adhered) on the rear plate 71 in advance, but are fixed (adhered) at the next “sealing step”. Thus, it may be simply placed on the rear plate 71 or the face plate 72.

  (J) Next, a sealing step is performed. At least the bonding member 77 is heated while pressing the face plate 72 and the rear plate 71 that are arranged to face each other in the step (I) in the facing direction (FIG. 18B). The heating is preferably performed on the entire surface of the face plate 72 and the rear plate 71 in order to reduce thermal distortion.

The “sealing step” is preferably performed in a reduced pressure (vacuum) atmosphere or a non-oxidizing atmosphere. As a specific reduced pressure (vacuum) atmosphere, a pressure of 10 ⁻⁵ Pa or less, preferably 10 ⁻⁶ Pa or less is preferable.

  By this sealing step, the abutting portions of the face plate 72, the support frame 73, and the rear plate 71 are hermetically joined, and at the same time, the airtight container (image display device) shown in FIG. ) 100 is obtained.

Here, an example in which the “sealing step” is performed in a reduced pressure (vacuum) atmosphere or a non-oxidizing atmosphere is shown. However, you may perform the said "sealing process" in air | atmosphere. In this case, an exhaust pipe for exhausting the space between the face plate and the rear plate is provided in the hermetic container 100 separately, and the inside of the hermetic container 100 is reduced to 10 ⁻⁵ Pa or less after the “sealing step”. Exhaust. Thereafter, by sealing the exhaust pipe, an airtight container (image display device) 100 whose inside is maintained at a high vacuum can be obtained.

  In the case where the “sealing step” is performed in a vacuum, in order to maintain the inside of the airtight container (image display device) 100 at a high vacuum, a metal is interposed between the step (I) and the step (J). It is preferable to provide a step of covering the getter material on the back 74 (on the surface of the metal back 74 facing the rear plate 71). At this time, the getter material used is preferably an evaporation type getter for the purpose of simplifying the coating. Therefore, it is preferable to coat barium on the metal back 74 as a getter film. The getter coating step is performed in a reduced pressure (vacuum) atmosphere as in the step (J).

  In the example of the image display apparatus described here, the spacer 101 is disposed between the face plate 72 and the rear plate 71. However, when the size of the image display device is small, the spacer 101 is not necessarily required. Further, if the distance between the rear plate 71 and the face plate 72 is about several hundred μm, the rear plate 71 and the face plate 72 can be directly joined by the joining member 77 without using the support frame 73. In such a case, the joining member 77 also serves as an alternative member for the support frame 73.

  In this manufacturing method, after the step of forming the gap 5 of the electron-emitting device 102 (step (H)), the alignment step (step (I)) and the sealing step (step (J)) were performed. . However, the step (H) can also be performed after the sealing step (step (J)).

Further, as described above, when performing the “stabilization driving”, it is after the “sealing step” and the degree of vacuum inside the panel is 1.3 × 10 ⁻³ Pa or more. Done.

Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
In this example, the electron-emitting device manufactured by the manufacturing method shown in FIG. 2 was used. Details of the manufacturing process will be described below.

(Process 1)
A Pt film having a thickness of 100 nm was deposited on the substrate 1 made of glass by a sputtering method, and electrodes 2 and 3 made of the Pt film were formed by using a photolithography technique (FIG. 2A).

The distance between the electrodes 2 and 3 was 10 μm. As the substrate 1, “PD200” manufactured by Asahi Glass with 1 μm of SiO ₂ film was used. Each electrode 2 and 3 is connected to a wiring (not shown) for supplying a current. The wiring is disposed on the substrate 1.

(Process 2)
A polyamic acid solution, which is a precursor of aromatic polyimide, is applied to the entire surface of the substrate 1 by a spin coater diluted with an N-methylpyrrolidone solvent containing 3% triethanolamine, and the temperature is raised to 350 ° C. under vacuum conditions. Then, it was baked and imidized. Thereafter, a photoresist was applied, and exposure, development, and etching processes were performed to pattern the polyimide film in a trapezoidal shape across the device electrodes 2 and 3, thereby producing a polymer film 4 (FIG. 2B). ).

  At this time, the film thickness of the polymer film 4 which is a polyimide film was 30 nm. The shape of the polymer film 4 that is a polyimide film will be described with reference to FIG. 1. The short side W1 is 50 μm and the long side W2 is 100 μm.

(Process 3)
Next, the polymer film 4 was irradiated with an energy beam (low resistance treatment) using an Nd: YAG laser (beam diameter: 10 μm).

  FIG. 8A shows an irradiation energy profile. The laser power to be irradiated is decreased in proportion to time.

The set value of the laser power was set to be 150 W / mm ² (= I12) at the time t11 (50 msec) after irradiation of 150 W / mm ² (= I11) was started at the time t0 (0 sec).

  When the polymer film 4, which is a polyimide film, was subjected to the above “low resistance treatment” and the carbon film 4 ′ having conductivity was analyzed using an Auger Electron Spectrometer (AES), carbon was mainly used. It turned out that it changed into the film | membrane used as a component.

(Process 4)
After that, a voltage application step of forming a gap 5 in the film subjected to the resistance reduction treatment by applying a rectangular pulse of 20 V and a pulse width of 1 msec between the electrodes 2 and 3 by cooling was performed.

  When the electron emission characteristics of the device that had undergone the above steps (Step 1) to (Step 4) were examined, they were good.

Next, unlike the low resistance treatment of the present embodiment, a case where rectangular pulse energy is irradiated is shown as a comparative example.

<Comparative Example 1>
FIG. 5A shows an irradiation energy profile. As a set value of irradiation energy, irradiation of 150 W / mm ² was started at time t1 (0 sec), and irradiation was terminated at time t2 (50 msec).

  When the device was examined after the irradiation, the device electrode was sometimes destroyed.

<Comparative example 2>
The irradiation energy profile was changed, irradiation of 100 W / mm ² was started at time t1 (0 sec), and irradiation was terminated at time t2 (50 msec). The irradiation energy profile is shown in FIG.

  (Step 4) was performed on this device, but the gap 5 could not be formed and electron emission could not be observed.

<Comparative Example 3>
The irradiation energy profile was changed, irradiation of 100 W / mm 2 was started at time t1 (0 sec), and irradiation was terminated at time t2 (200 msec). The irradiation energy profile is shown in FIG.

  When (Step 4) was performed on this device, the gap 5 was formed, and when electron emission measurement was performed, good electron emission characteristics were obtained. However, as described above, the irradiation time is as long as 200 msec.

  As described above, it can be seen that the resistance can be reduced in a short time by using the method of this embodiment as compared with the comparative example.

[Example 2]
What is different from the first embodiment is the irradiation energy in the resistance reduction process. Here, a different part from Example 1 is described.

FIG. 9A shows an irradiation energy profile. The set value of the irradiation energy is 200 W / mm ² (= I25) at time t0 (0 sec), 150 W / mm ² (= I24) at time t24 (1 msec), and 100 W / mm at time t23 (5 msec). ² (= I23), time t22 to ^{(20msec) 70W / mm 2 (} = I22), is set to the time t21 (40msec) ^50W / mm 2 to (= I21) to allow irradiation respectively. That is, the irradiation energy gradually decreases with the passage of time.

  When (Step 4) was performed on this device, the gap 5 was formed, and when electron emission measurement was performed, good electron emission characteristics were obtained.

  By using the method of this embodiment, the resistance reduction treatment can be performed in a shorter time than in the case of Embodiment 1, and a good electron-emitting device can be produced.

[Example 3]
In this example, the image display apparatus schematically shown in FIG. 10 was produced. Reference numeral 102 denotes an electron-emitting device according to the present invention. A method for manufacturing the image display device of this embodiment will be described with reference to FIGS.

  FIG. 17 is an enlarged view of a part of an electron source including a rear plate 71, a plurality of electron-emitting devices of the present invention formed thereon, and wiring for applying a signal to each electron-emitting device. This is shown schematically.

  71 is a rear plate, 2 and 3 are electrodes, 5 is a gap, 4 'is a carbon film, 62 is a wiring in the X direction, 63 is a wiring in the Y direction, and 64 is an insulating layer between the wirings 62 and 63.

As the rear plate 71, “PD200” manufactured by Asahi Glass with 1 μm of SiO ₂ film was used.

  As shown in FIG. 10, reference numeral 72 denotes a face plate in which a phosphor film 75 and a metal back 74 made of Al are laminated on a glass substrate. Reference numeral 73 denotes a support frame. The rear plate 71, the face plate 72, and the support frame 73 form a vacuum hermetic container 100.

  Hereinafter, this embodiment will be described with reference to FIGS.

(Process 1)
A Pt film having a thickness of 100 nm was deposited on the rear plate 71, which is a glass substrate, by sputtering, and the electrodes 2 and 3 made of the Pt film were formed using a photolithography technique (FIG. 11). The distance between the electrodes 2 and 3 was 10 μm.

(Process 2)
Next, an Ag paste was printed by a screen printing method and heated and fired to form an X-direction wiring 62 (FIG. 12).

(Process 3)
Subsequently, an insulating paste was printed at a position where the wiring 62 in the X direction and the wiring 63 in the Y direction intersect with each other by screen printing, followed by heating and baking to form an insulating layer 64 (FIG. 13).

(Process 4)
Furthermore, the Ag paste was printed by screen printing and heated and fired to form the Y-direction wiring 63, and the matrix wiring was formed on the rear plate 71 (FIG. 14).

(Process 5)
N-methylpyrrolidone in which 3% triethanolamine is dissolved in a polyamic acid (Hitachi Chemical Industry Co., Ltd. product: PIX-L110) solution, which is a precursor of aromatic polyimide, on the rear plate 71 on which the matrix wiring is formed. It was applied to the entire surface by a spin coater diluted with a solvent, heated to 350 ° C. under vacuum and baked to perform imidization (FIG. 19B). Thereafter, a photoresist 8 is applied (FIG. 19C), exposure (not shown), development (FIG. 19D), and etching (FIG. 19E) are performed to form a polyimide film. A trapezoidal polymer film 4 was formed by patterning into a trapezoidal shape across the device electrodes 2 and 3 (FIG. 19F).

  At this time, the film thickness of the polymer film 4 made of a polyimide film was 30 nm. Further, the crossing length between the electrode 2 and the polymer film 4 (substantially equivalent to “the length of the boundary line between the electrode and the polymer film on the surface of the substrate 1 (rear plate 71)”) is set to 100 μm, The crossing length between the electrode 3 and the polymer film 4 was 150 μm. In addition, when the absorption coefficient of the wavelength near 800 nm of the rear plate 71 was measured, it was about 5%.

(Step 6)
Next, the rear plate 71 on which the electrodes 2 and 3 made of Pt, the wirings 62 and 63 of the matrix, and the polymer film 4 made of the polyimide film are formed is set on the stage, and each of the polymer films 4 is implemented. The energy under the conditions used in Example 1 was applied.

  At this time, the stage is moved so that each element is irradiated with the semiconductor laser that is the energy source, that is, the rear plate 71 that is the substrate 1 on which the element is arranged is moved, and each polymer film 4 is moved. Reduced resistance.

  The laser irradiation system of the present embodiment will be described in more detail with reference to FIGS.

FIG. 20A is a side view of an apparatus that performs a resistance reduction process, and FIG. 20B is a plan view of the apparatus. Reference numeral 301 denotes a pulse laser transmitter, 302 denotes a fiber for introducing the pulse laser into the chamber, 310 denotes a scanning optical system for irradiating the device with the pulse laser, 303 denotes a chamber envelope, and 304 denotes a chamber base. The chamber envelope 303 is connected to a vacuum exhaust system at the time of unillustrated, and exhausts the internal vacuum to 1e ⁻⁴ Pa.

  FIG. 20C shows the inside of the chamber envelope 303. The state which removed the chamber envelope 303 is shown typically. Reference numeral 306 denotes a substrate transfer system, and 305 denotes a rear plate. That is, in the chamber envelope 303, the rear plate 305 is moved by moving the substrate transfer system 306 that is a stage, and the desired resistance of the polymer film 4 is reduced.

  Next, the scanning optical system 310 will be described in detail with reference to FIG. Reference numeral 317 denotes an inlet for introducing a laser from the fiber, and 311 denotes a mask (details will be described later) for irradiating a specific element portion with the laser. Reference numerals 312 and 313 denote galvanometers for determining the light irradiation position, 312 denotes a galvanometer for the X axis, and 313 denotes a galvanometer for the Y axis. 314 is a condenser lens, 315 is a die lock mirror, and 316 is an inlet to the chamber.

  In the scan optical system 310, the laser can be irradiated only to a specific element through the mask 311 before the laser is condensed (converged) by the condenser lens 314.

  The mask 311 is made, for example, as shown in FIG. Reference numeral 321 denotes a mask portion, and 320 denotes a transmission hole.

  When such a mask 311 is used to irradiate the substrate with light, for example, the light is irradiated as shown in FIG. FIG. 23 shows a state in which light is irradiated only to the area 322 with the rear plate 71 created in (Step 5).

  As shown in FIG. 23, by using a mask 311, laser irradiation can be selectively performed on the element portion, and light irradiation on a thermally weak member (insulator or the like) can be avoided.

  When the resistance reduction process for the area 322 is completed, the substrate is moved using the substrate transport system 306 and set so that laser irradiation can be performed in another area. Each element is sequentially irradiated with laser to reduce the resistance of many elements.

Although FIGS. 20 to 23 show the 3 × 3 matrix array elements, the present invention is not limited to this and can be implemented in a similar manner with a larger number of elements.

(Step 7)
On the rear plate 71 manufactured as described above, the support frame 73 and the spacer 101 were adhered by frit glass as a joining member. Then, the rear plate 71 to which the spacer 101 and the support frame 73 are bonded is opposed to the face plate 72 (a surface on which the phosphor film 75 and the metal back 74 are formed, and a surface on which the wirings 62 and 63 are formed). (Fig. 18 (a)). Note that frit glass was previously applied to the contact portion of the face plate 72 with the support frame 73.

(Process 8)
Next, the face plate 72 and the rear plate 71 opposed to each other were sealed by heating and pressing at 400 ° C. in a vacuum atmosphere of 10 ⁻⁶ Pa (FIG. 18B). By this step, an airtight container 100 whose inside was maintained at a high vacuum was obtained. The phosphor film 75 is a film in which phosphors of the three primary colors (RGB) are arranged in a stripe shape.

  Finally, by applying a 25 V rectangular pulse between the electrodes 2 and 3 through the wirings 62 and 63 in the X and Y directions, a carbon film (carbon is obtained by applying a “low resistance treatment”). The gap 5 was formed in the conductive film 4 ′ as a main component (see FIG. 17), and the image display device of this example was manufactured.

  In the image display device completed as described above, a desired electron-emitting device is selected through the wirings 62 and 63 in the X and Y directions, a voltage of 22 V is applied, and an 8 kV voltage is applied to the metal back 74 through the high voltage terminal Hv. When a voltage was applied, a bright and good image could be displayed for a long time.

  As described above, in the first embodiment, the second embodiment, and the third embodiment, the case where the laser light source is used as the power source of the energy beam for the low resistance process has been described. However, the present invention is not limited to this. The present invention is also preferably implemented using a particle beam such as an electron beam or an ion beam. In addition, the present invention is preferably implemented even when a xenon lamp or a halogen lamp is used as the light source of the optical beam.

It is a figure which shows an electron emission element. It is a figure which shows the manufacturing process of an electron emission element. It is a figure which shows the manufacturing process of an electron emission element. It is a figure which shows the characteristic of an electron emission element. It is a figure which shows the irradiation power at the time of the resistance reduction process of an electron emission element, and the temperature of a polymer film. It is a figure which shows the irradiation power at the time of the resistance reduction process of an electron emission element, and the temperature of a polymer film. It is a figure which shows the irradiation power at the time of the resistance reduction process of an electron emission element, and the temperature of a polymer film. It is a figure which shows the irradiation power at the time of the resistance reduction process of the electron emission element which concerns on this invention, and the temperature of a polymer film. It is a figure which shows the irradiation power at the time of the resistance reduction process of the electron emission element which concerns on this invention, and the temperature of a polymer film. It is a figure which shows the airtight container of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an image display apparatus. It is a figure which shows the manufacturing process of an electron emission element. It is a figure which shows the apparatus which performs a resistance reduction process. It is a figure which shows a scanning optical system. It is a figure which shows a mask. It is a figure which shows the area of the laser irradiation on a rear plate. It is a figure which shows the conventional electron-emitting element. It is a figure which shows the manufacturing process of the conventional electron emission element. It is a figure which shows the reaction speed at the time of a resistance reduction process, and resistance reduction temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base | substrate 2, 3 Electrode 4 Polymer film 4 'Carbon film 8 Photoresist 10 Irradiation means 62, 63 Wiring 64 Insulating layer 71 Rear plate 72 Faceplate 73 Support frame 74 Metal back 75 Phosphor film 76 Light emitting member 77 Joining member 80 Ammeter 81 Power source 82 Ammeter 83 High voltage power source 84 Anode electrode 100 Airtight container 101 Spacer 102 Electron emitting element 301 Pulse laser transmitter 302 Fiber 303 Chamber envelope 304 Chamber base 305 Rear plate 306 Substrate transport system 310 Scan optical system 311 Mask 312,313 Galvanometer 314 Condensing lens 315 Die-lock mirror 316 Inlet 317 Inlet 320 Transmission hole 321 Mask part 322 Area

Claims (5)

Arranging a pair of electrodes on a substrate;
Arranging a polymer film so as to connect between the pair of electrodes;
Irradiating the polymer film with light or an energy beam to reduce the resistance of the polymer film;
Passing a current through the low resistance film obtained by reducing the resistance of the polymer film, and forming a gap in the low resistance film; and
Have
The step of reducing the resistance of the polymer film includes a step of irradiating the polymer film with an energy beam whose energy value decreases with time from the start of irradiation for a predetermined period of time. Device manufacturing method. The step of reducing the resistance of the polymer film includes:
Partially shielding the light or particle beam;
Scanning a light or particle beam;
Focusing the light or particle beam;
Have
2. The method of manufacturing an electron-emitting device according to claim 1, wherein a step of partially shielding the light or particle beam is performed before the step of converging the light or particle beam.   3. The method of manufacturing an electron-emitting device according to claim 2, wherein the step of reducing the resistance of the polymer film includes a step of moving the substrate.   A method for manufacturing an electron source having a plurality of electron-emitting devices, wherein the electron-emitting devices are manufactured by the method according to claim 1.   5. A method for manufacturing an image display apparatus, comprising: an electron source having a plurality of electron-emitting devices; and a light emitting member that emits light by irradiation of electrons emitted from the electron source. The electron source is manufactured by the method according to claim 4. A method for manufacturing an image display device.

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