JPH09223456A - Manufacture of surface conductive type electron emission element using laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence of heat or the like on a substrate in the manufacture of an electron emission element by varying the irradiation position of a laser beam for each of the first and second machining processes and machining the same line. SOLUTION: A sample 16 is set in an XY direction scanning mechanism 15, and the output of a laser oscillator 11 is set in the desirable value with a control computer 18. A control signal is sent to a position control mechanism 17 from the mechanism 15 so that the mechanism 15 moves according to a machining pattern, and the mechanism 15 is driven. At that time, a pulse laser beam is irradiated from the oscillator 11. This process is repeated to form a desirable trimming pattern. When machining is performed by using the laser beam of the illustrated output wave form, in a first machining, the wave form having machining pitch L1 and power Pw1 is used, and in a second machining, the wave form having machining pitch L2 and power Pw2 is used. Two wave forms are shifted by Lα. By shifting the wave forms and performing machining plural times, the total energy applied to the substrate can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a surface conduction electron-emitting device using laser light, and further to formation of an image forming apparatus using the electron-emitting device.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element. As an example of the FE type, W. P. Dyke & W.
W. Dolan, "Field Emission",
Advance in Electron Physi
cs, 889 (1956) or C.I. A. Spind
t, “Physical Properties of
thin-film field emission
cathodeswith mollybdenium ”
J. Appl. Phys. , 475248 (1976)
Etc. are known.

An example of the MIM type is C.I. A. Mead,
"The tune 1-emission ampl
ifier, J.M. Appl. Phys. , 32 646
(1961) and the like are known.

Examples of the surface conduction electron-emitting device type include:
M. I. Elinson, Radio Eng. Ele
ctron Phys. 10 (1965) and so on.
The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is applied to a thin film having a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, SnO by Elinson et al.
₂ using a thin film, using an Au thin film [G. Dit
tmer: "Thin Solid Films",
9, 317 (1972)], by In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.M. G. FIG. F
onstad: "IEEE Trans.ED Con
f. , 519 (1975)], by a carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, page 22 (19).
83)] etc. have been reported.

As a typical element structure of these surface conduction electron-emitting devices, the above-mentioned M. The Hartwell device configuration is shown in FIG. In the figure, 161 is an electron source substrate. Reference numeral 164 denotes a conductive thin film, which is made of a metal oxide thin film or the like formed by sputtering on an H-shaped pattern, and the electron emission portion 165 is formed by an energization process called energization forming described later. The element electrode spacing L in the figure is
0.5 to 1 mm, W'is set to 0.1 mm. Since the position and shape of the electron emitting portion 165 are unknown, they are shown as a schematic diagram.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 165 has generally been formed by conducting an energization process called energization forming in advance on the conductive thin film 164 before emitting electrons. That is, the energization forming is performed by applying a direct current voltage or a very slow rising voltage, for example, about 1 V / min to both ends of the conductive thin film 164 to locally break, deform or deteriorate the conductive thin film, That is, the electron emitting portion 165 is formed in a high resistance state. The electron emission unit 16
In No. 5, a crack is generated in a part of the conductive thin film 164, and electrons are emitted from the vicinity of the crack. In the surface conduction electron-emitting device that has been subjected to the energization forming process, a voltage is applied to the above-mentioned conductive thin film 164 and a current is passed through the device so that electrons are emitted from the above-mentioned electron-emitting portion 165.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arrayed and formed over a large area because it has a simple structure and is easy to manufacture. Therefore, various applications that can make full use of this feature are being researched. For example,
Display devices such as a charged beam source and an image display device are exemplified.

[0008]

FIG. 17 is a beam waveform diagram used in conventional laser processing, (a) is a graph showing a pulse shape, and (b) is a schematic diagram showing a beam trajectory. . In conventional processing using a pulsed laser, continuous processing was performed by overlapping beams. Therefore, the beam may be irradiated more than necessary.

Further, when the input power is reduced in order to reduce the influence on the substrate, there are cases where the processing cannot be completely performed.

Conventional conductive thin films have been formed by using vacuum film formation, photolithography, etching, etc. which are one of the usual semiconductor techniques, but surface conduction using laser light for trimming and the like. When manufacturing a type electron-emitting device, there is a concern that the heat may affect the substrate as described above.

The present invention has been made in view of the above circumstances,
The object of the invention is to provide a manufacturing method in which the influence of heat or the like on a substrate is reduced when a surface conduction electron-emitting device is manufactured using laser light.

[0012]

A method of manufacturing a surface conduction electron-emitting device using a laser beam according to the present invention uses a laser beam and a surface to be processed by relatively moving the laser beam and a workpiece. In the method of manufacturing a conduction type electron-emitting device, pulsed laser light is used as laser light, the first processing step and the second processing step are performed, and the irradiation position of the laser beam is changed for each processing step to be on the same line. To process.

The irradiation position of the laser beam may be changed for each processing step by shifting the processing start point in the first processing step and the second processing step, and the first processing step and the second processing step may be changed. By changing the relative movement speed with
The irradiation position of the laser beam may be changed for each processing step, and the Q of the laser may be changed between the first processing step and the second processing step.
The irradiation position of the laser beam may be changed for each processing step by changing the switch frequency.

Further, the second processing step may be performed with less irradiation energy than that of the first processing step.

Since the processing is divided into a plurality of times, the irradiation energy per one processing can be small and the damage to the work piece can be reduced.

Further, since the irradiation energy of the laser can be set for each processing, the irradiation energy can be finely adjusted and the optimum irradiation energy can be obtained.

Further, by changing the irradiation position of the laser beam, it is possible to perform processing with less residue.

[0018]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a laser processing machine according to an embodiment of the present invention, 11 is a laser oscillator, 12 is a total reflection mirror, 13 is a slit,
Reference numeral 14 is an objective lens, 15 is an XY scanning mechanism, 16 is a sample, 17 is a position control mechanism, and 18 is a control computer. The laser light emitted from the laser oscillator 11 is
The reflection mirror 12 illuminates the sample surface. On this occasion,
The laser light is shaped by the slit 13 and focused by the objective lens 14.

The sample 16 is fixed on the XY direction scanning mechanism 15 and can be controlled in the XY directions by the position control mechanism 17.

The control computer 18 uses the laser oscillator 1
1. A computer for controlling the position control mechanism 17, which can draw an arbitrary pattern according to a command from the control computer 18.

The operation of processing a sample using the laser processing machine having the above-described structure will be described.

The sample 16 is set in the XY scanning mechanism 15, and the output of the laser oscillator 11 is set to a desired value by the control computer 18.

Next, a control signal is sent from the control computer 18 to the position control mechanism 17 so that the XY scanning mechanism 15 moves according to the machining pattern, and the XY scanning mechanism 1 is moved.
5 is driven. At that time, laser light is emitted from the laser oscillator 11. By repeating this, a desired trimming pattern can be formed.

FIG. 2 is a laser output waveform diagram of the laser oscillator 11, where (a) is the first pulse shape and (b) is the pulse shape.
Is the first beam trajectory, (c) is the second pulse shape, and (d) is the second beam trajectory.

In the first machining, a machining pitch Ll and a waveform having a power of Pw1 were used for machining, and in the second machining, a machining pitch L2 and a waveform having a power of Pw2 were used for machining. The two waveforms are offset by Ld.

By thus shifting the pulse-shaped waveforms and processing them in multiple steps, the total amount of energy applied to the substrate can be reduced.

Here, an example in which the present invention is applied to an image display device using the surface conduction electron-emitting device will be described.

There are basically two types of surface conduction electron-emitting devices that can be used in the present invention: a planar surface conduction electron-emitting device and a vertical surface conduction electron-emitting device.

FIG. 6 is a schematic diagram showing the structure of a planar surface conduction electron-emitting device and a vertical surface conduction electron-emitting device to which the present invention can be applied. FIG. 6A is a planar surface conduction electron-emitting device. 2A is a schematic plan view of FIG. 1, FIG. 3B is a schematic cross-sectional view of FIG. 3A, and FIG. 3C is a schematic cross-sectional view of a vertical surface conduction electron-emitting device. In FIG. 6, 61 is an electron source substrate (insulating substrate), 62 and 63 are element electrodes, 64 is a conductive thin film, and 65.
Denotes an electron emission portion.

As the electron source substrate 61, quartz glass, N
Glass with low content of impurities such as a, soda lime glass, Si
A glass substrate having O ₂ formed on its surface and a ceramic substrate such as alumina are used.

As the material of the device electrodes 62 and 63, general conductors are used, and for example, Ni, Cr, Au and M are used.
In, a printed conductor composed of a metal or an alloy such as o, W, Pt, Ti, Al, Cu, Pd, a metal such as Pd, Ag, Au, RuO ₂ , Pd-Ag, or a metal oxide and glass, and In _2. It is appropriately selected from transparent conductors such as O ₃ —SnO ₂ and semiconductor conductor materials such as polysilicon.

The device electrode distance L is preferably several hundreds of angstroms to several hundreds of micrometers. Further, it is desirable that the voltage applied between the device electrodes is low, and since it is required to manufacture the device with good reproducibility, the preferred device electrode interval is several micrometers to several tens of micrometers.

The device electrode length W is from several micrometers to several hundreds of micrometers from the resistance value of the electrodes and electron emission characteristics, and the film thickness of the device electrodes 62 and 63 is from several hundreds of angstroms to several micrometers. preferable.

Not only the structure shown in FIGS. 6A and 6B, but also a structure in which the conductive thin film 64 and the opposing device electrodes 62 and 63 are laminated in this order on the electron source substrate 61 may be adopted. it can.

The conductive thin film 64 is preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the conductive thin film 64 is the step coverage of the device electrodes 62 and 63, and the device electrodes 62 and 63. Although it is appropriately set depending on the resistance value between them and the energization forming conditions described later, it is preferably several angstroms to several thousand angstroms, particularly preferably 10 angstroms to 500 angstroms. The sheet resistance value is 10 ^{3 to} 10 ⁷ Ω / □.

The material forming the conductive thin film 64 is P
d, Pt, Ru, Ag, Au, Ti, In, Cu, C
Metals such as r, Fe, Zn, Sn, Ta, W and Pd, Pd
O, SnO ₂ , In ₂ O ₃ , oxides such as PbO and Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB
₄ , boride such as GdB ₄ , TiC, ZrC, HfC, T
carbides such as aC, SiC, WC, TiN, ZrN, Hf
Examples thereof include nitrides such as N, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only a state in which the fine particles are dispersed and arranged but also a state in which the fine particles are adjacent to each other or overlap each other (islands). The particle size of the fine particles is from several angstroms to several thousand angstroms, preferably from 10 angstroms to 200 angstroms.

The electron emitting portion 65 is a high resistance crack formed in a part of the conductive thin film 64 and is formed by energization forming or the like. Further, the cracks may have conductive fine particles having a particle diameter of several angstroms to several hundred angstroms. The conductive fine particles contain at least part of the substance that constitutes the conductive thin film 64.

The electron emitting portion 65 and the conductive thin film 64 in the vicinity thereof may contain carbon or a carbon compound.

FIG. 6C is a schematic drawing showing the structure of a basic vertical surface conduction electron-emitting device. In FIG. 6C, the same members as those in FIGS. 6A and 6B are denoted by the same reference numerals, and 66 is a gap forming portion. The electron source substrate 61, the device electrodes 62 and 63, the conductive thin film 64, and the electron emitting portion 65 can be made of the same material as that of the above-mentioned plane type surface conduction electron emitting device, and the gap forming portion 66 is an insulating material. And the film thickness Ls of the gap forming portion 66 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above. The spacing is tens of micrometers rather than hundreds of angstroms. The distance can be controlled by the manufacturing method of the gap forming portion 66 and the voltage applied between the device electrodes, but is preferably several hundred angstroms to several micrometers.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, and one example thereof is schematically shown in FIG.

An example of the manufacturing method will be described below with reference to FIGS. 6 and 7. Also in FIG. 7, the same parts as those shown in FIG. 6 are designated by the same reference numerals as those shown in FIG.

The electron source substrate 61 is thoroughly washed with a detergent, pure water and an organic solvent, and after the element electrode material is deposited by the vacuum deposition method, the sputtering method, etc., the element is placed on the electron source substrate 61 by using, for example, the photolithography technique. The electrodes 62 and 63 are formed (FIG. 7A).

Electron source substrate 6 provided with device electrodes 62 and 63
1 is coated with an organometallic solution to form an organometallic thin film. As the organic metal solution, a solution of an organic metal compound containing a metal of the above-mentioned conductive thin film 64 as a main element can be used. The organic metal thin film is heat-fired and patterned by laser trimming, lift-off, etching, etc. to form the conductive thin film 64 (FIG. 7B). Although the method of applying the organic metal solution has been described here, the method of forming the conductive thin film 64 is not limited to this, and the vacuum deposition method, the sputtering method, the chemical vapor deposition method, the dispersion coating method, the dipping method, and the like. Method, spinner method, etc. can also be used.

Subsequently, a forming process is performed. As an example of a method of the forming step, a method by an energization process will be described. The energization forming is to energize between the device electrodes 62 and 63 from a power source (not shown) to locally break, deform or alter the conductive thin film 64 to form a site having a changed structure. The part where the structure is locally changed is called an electron emission part 65 (FIG. 7C). FIG. 8 shows an example of the voltage waveform of energization forming.

The voltage waveform is particularly preferably a pulse waveform,
There are a case where a voltage pulse having a constant pulse peak value is continuously applied (FIG. 8A) and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 8B). First, the case where the pulse peak value is a constant voltage (FIG. 8A) will be described.

In FIG. 8A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave ( The peak voltage at the time of energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes under a suitable vacuum degree, for example, in a vacuum atmosphere of about 10 ⁻⁵ Torr. The waveform applied between the electrodes of the element is not limited to the triangular wave,
A desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG. 8B are shown in FIG.
As in (a), the peak value of the triangular wave (peak voltage during energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere.

In the energization forming process in this case, the element current is measured at a voltage that does not locally destroy or deform the conductive thin film 64 during the pulse interval T2, for example, a voltage of about 0.1V, The resistance value is obtained, and when the resistance is 1 MΩ or more, the energization forming is completed.

Next, it is desirable to perform a process called an activation process on the element for which forming has been completed.

The activation step is, for example, 10 ^-4 to 10 ^-5.
Similar to energization forming, this is a process of repeatedly applying a voltage pulse with a constant pulse peak value at a vacuum degree of about Torr. Carbon or a carbon compound derived from an organic substance existing in a vacuum is deposited on a conductive thin film. , Element current I
f, a process of significantly changing the emission current Ie. In the activation process, while measuring the device current If and the emission current Ie,
For example, the process ends when the emission current Ie is saturated. Further, it is preferable that the applied voltage pulse is an operating drive voltage.

The carbon or carbon compound is graphite (indicating both single and polycrystalline) amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite), and its film thickness is , 500 angstroms or less, and more preferably 300 angstroms or less.

It is preferable that the electron-emitting device thus manufactured is operated and driven under an atmosphere of a vacuum degree higher than the vacuum degree in the energization forming step and the activation step. In addition, it is desirable to operate after heating at 80 ° C. to 150 ° C. in an atmosphere of a higher degree of vacuum.

The degree of vacuum higher than the degree of vacuum obtained by the energization forming step and the activation treatment is, for example, a degree of vacuum of about 10 ⁻⁶ or more, more preferably an ultrahigh vacuum system, and newly added carbon or carbon compound. Is a degree of vacuum that hardly deposits on the conductive thin film. By doing so, the device current If,
It becomes possible to stabilize the emission current Ie.

FIG. 9 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring the electron emission characteristics of the element having the configuration shown in FIG. 9, the same symbols as those in FIG. 6 indicate the same things. Further, 91 is a device voltage Vf for the electron-emitting device.
, 90 is an ammeter for measuring a device current If flowing through the conductive thin film 64 between the device electrodes 62 and 63, and 94 is a capture of the emission current Ie emitted from the electron emission portion of the device. Is an anode electrode, 93 is a high voltage power source for applying a voltage to the anode electrode 94, 92 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 65 of the device, 95 is a vacuum device, and 96 is It is an exhaust pump.

Next, the image forming apparatus of the present invention will be described.

The electron source substrate used in the image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate.

A ladder-type arrangement (hereinafter referred to as a ladder-type arrangement electron source substrate) in which the surface-conduction type electron-emitting devices are arranged in parallel in the array of the surface-conduction type electron-emitting devices, and both ends of each device are connected by wirings, A simple matrix arrangement (hereinafter referred to as a matrix-type arrangement electron source substrate) in which an X-direction wiring and a Y-direction wiring are connected to a pair of device electrodes of a surface conduction electron-emitting device, respectively. An image forming apparatus having a ladder type power supply substrate requires a control electrode (grid electrode) which is an electrode for controlling the flight of electrons from the electron-emitting device.

The structure of the electron source constructed based on this principle will be described below with reference to FIG. 101 is an electron source substrate, 102 is an X-direction wiring, 103 is a Y-direction wiring, 10
4 is a surface conduction electron-emitting device, and 105 is a wire connection. The surface conduction electron-emitting device 104 may be either the above-mentioned plane type or vertical type.

In the figure, the substrate used as the electron source substrate 101 is the above-mentioned glass substrate or the like, and its shape is appropriately set according to the application.

The m X-direction wirings 102 are Dxl and Dx.
2, ... Dxm, and the Y-direction wiring 103 is Dy
It consists of n wirings of 1, Dy2 ... Dyn.

Further, the material, the film thickness, and the wiring width are appropriately set so that a substantially uniform voltage is supplied to a large number of surface conduction elements. The m wirings in the X direction 102 and the n wirings in the Y direction 103 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers).

An interlayer insulating layer (not shown) is formed on the entire surface of the substrate 101 on which the X-direction wiring 102 is formed, or on a desired region. The X-direction wiring 102 and the Y-direction wiring 103 are drawn out as external terminals.

Further, the device electrodes (not shown) of the surface conduction electron-emitting device 104 are electrically connected to the m X-direction wirings 102 and the n Y-direction wirings 103 by the connection wire 105.

The surface conduction electron-emitting device may be formed either on the substrate or on an interlayer insulating layer (not shown).

The X-direction wiring 1 will be described in detail later.
Reference numeral 02 is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 104 arranged in the X direction according to an input signal.

On the other hand, a modulation signal (not shown) for applying a modulation signal for modulating each row of the surface conduction electron-emitting devices 104 arranged in the Y direction according to the input signal to the Y-direction wiring 103. It is electrically connected to the generating means.

Further, the drive voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element.

In the above structure, individual elements can be selected and driven independently by using only simple matrix wiring.

Next, an image forming apparatus using the matrix type arrangement electron source substrate manufactured as described above is shown in FIG.
This will be described with reference to FIGS. 11 is a basic configuration diagram of the image forming apparatus, FIG. 12 is a fluorescent film, and FIG.
Shows a block diagram of a drive circuit for displaying in accordance with an NTSC television signal, and represents an image forming apparatus including the drive circuit.

In FIG. 11, reference numeral 111 denotes an electron source substrate having an electron-emitting device formed on the substrate, and 110 denotes an electron source substrate 111.
Is a rear plate fixed to the glass plate, 113 is a face plate in which the fluorescent film 115 and the metal back 116 are formed on the inner surface of the glass substrate 114, and 112 is a support frame, and these members constitute the envelope 120.

In FIG. 11, the electron-emitting device 117 is shown in FIG.
Corresponds to the electron emitting portion 65 in. Reference numerals 118 and 119 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 120 is composed of the face plate 113, the support frame 112, and the rear plate 110 as described above. The rear plate 110 is mainly the electron source substrate 11.
1 is provided for the purpose of reinforcing the strength of the electron source substrate 111, the separate rear plate 110 is unnecessary when the electron source substrate 111 itself has sufficient strength, and the support frame 112 is directly provided on the electron source substrate 111. 113, support frame 11
2. The envelope 120 may be composed of the electron source substrate 111. Furthermore, by installing an atmospheric pressure resistant support member called a spacer between the face plate 113 and the rear plate 110, the envelope 120 having sufficient strength against atmospheric pressure can be obtained.

In FIG. 12, 122 and 127 are phosphors. In the case of monochrome, the fluorescent film is composed of only the phosphor, but in the case of a color fluorescent film, the black conductive materials 121 and 126 and the phosphors 122 and 12 called black stripes or black matrices are arranged depending on the arrangement of the phosphors.
7 is comprised. The purpose of providing the black stripes and the black matrix is to make the mixed colors and the like inconspicuous by blackening the separately applied portions between the phosphors 122, 127 of the three primary color phosphors, which are necessary for color display. This is to suppress the reduction in contrast due to the reflection of external light on the film 115. The material of the black stripe is not limited to a commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection. The method of applying the phosphor on the glass substrate 114 is monochrome,
Regardless of color, precipitation method and printing method are used.

A metal back 116 is usually provided on the inner surface side of the fluorescent film 115. The purpose of the metal back 116 is to improve the brightness by specularly reflecting the light to the inner surface side of the light emitted from the phosphor to the face plate 113 side, and to act as an electrode for applying an electron beam accelerating voltage. This is to protect the phosphor from damage due to collision of negative ions generated in the envelope. The metal back 116 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 115 after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like.

On the face plate 113, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 115 in order to further enhance the conductivity of the fluorescent film 115.

The envelope 120 is provided with an exhaust pipe (not shown) through
The degree of vacuum is set to about 0 ^-7 torr and sealing is performed. Further, a getter process may be performed in order to maintain the degree of vacuum after the envelope 120 is sealed. This is the envelope l2
A process of heating a getter arranged at a predetermined position (not shown) in the envelope 120 by a heating method such as resistance heating or high-frequency heating immediately before or after the sealing of 0 to form a vapor deposition film. Is. The getter usually has Ba as a main component, and due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵
The degree of vacuum of torr or 1 × 10 ⁻⁷ torr is maintained. The steps after the forming of the surface conduction electron-emitting device are appropriately set.

Next, referring to the block diagram of FIG. 13, a schematic structure of a drive circuit for displaying a television on the basis of an NTSC system television signal in an image forming apparatus constructed by using a matrix type electron source substrate will be described. explain. 131 is the display panel, and 132 is a scanning circuit, 133.
Is a control circuit, 134 is a shift register, 135 is a line memory, 136 is a synchronizing signal separation circuit, 137 is a modulation signal generator, and Vx and Va are DC voltage sources.

The functions of the respective parts will be described below. First, the display panel 131 has terminals Dox1 to Doxm and terminals Dox.
It is connected to an external electric circuit via y1 to Doyn and the high voltage terminal Hv. Of these, terminals Doxl to Dox
In m, an electron source provided in the image forming apparatus, that is, a group of surface conduction electron-emitting devices that are matrix-wired in a matrix of M rows and N columns is sequentially driven row by row (N elements). A scanning signal is applied.

On the other hand, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals Dy1 to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 [kV] from the DC voltage source Va, which is sufficient to excite the phosphor into the electron beam output from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

Next, the scanning circuit 132 will be described. The circuit includes M switching elements inside thereof (schematically shown by S1 to Sm in the figure), and each switching element is an output voltage of the DC voltage source Vx or 0.
One of [V] (ground level) is selected and electrically connected to the terminals Dox1 to Doxm of the display panel 131. Each of the switching elements S1 to Sm operates based on the control signal Tscan output by the control circuit 133, but can be actually configured by combining switching elements such as FETs.

It should be noted that the DC voltage source Vx is such that the driving voltage applied to an unscanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output a constant voltage such that

Further, the control circuit 133 has a function of matching the operations of the respective parts so that an appropriate display is carried out based on the image signal inputted from the outside. The synchronization signal Tsyn sent from the synchronization signal separation circuit 136 described below
Tscan, Tsft and T for each part based on c
mry control signals are generated.

The synchronizing signal separating circuit 136 is a circuit for separating the synchronizing signal component and the luminance signal component from the NTSC system television signal inputted from the outside, and can be constituted by using a frequency separating (filter) circuit. The sync signal separated by the sync signal separation circuit 136 is composed of a vertical sync signal and a horizontal sync signal, as is well known, but here it is shown as a Tsync signal for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience, but the signal is input to the shift register 134.

The shift register 134 performs serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and operates based on the control signal Tsft sent from the control circuit 133. . (That is, the control signal Tsft corresponds to the shift register 1
In other words, the shift clock is 34 shift clocks. ) The data of the image 1 line (corresponding to the driving data of the electron-emitting device N element) which is serial / parallel converted is Id.
It is output from the shift register l34 as N parallel signals 1 to Idn.

The line memory 135 is a storage device for storing data for one line of the image only for a required time, and stores the contents of Id1 to Idn as appropriate according to the control signal Tmry sent from the control circuit 133. The stored contents are output as Id1 to Idn and input to the modulation signal generator 137.

The modulation signal generator 137 outputs the image data I
A signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of d1 to Idn, the output signal of which is output from the display panel 13 through terminals Doyl to Doyn.
1 is applied to the surface conduction electron-emitting device.

The electron-emitting device according to the present invention has an emission current I
It has the following basic characteristics for e. That is, the electron emission has a clear threshold voltage Vth, and the electron emission occurs only when a voltage higher than Vth is applied.

For a voltage above the electron emission threshold value, the emission current also changes according to the change in the voltage applied to the device. Note that the value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may change by changing the material, configuration, and manufacturing method of the electron emitting element. I can say that.

That is, when a pulsed voltage is applied to this element, for example, when a voltage below the electron emission threshold is applied, no electron emission occurs but a voltage above the electron emission threshold is applied. Emits an electron beam. that time,
First, it is possible to control the intensity of the output electron beam by changing the peak value Vm of the pulse. Second, it is possible to control the total amount of charges of the electron beam output by changing the pulse width Pw.

Therefore, as a method of modulating the electron-emitting device according to the input signal, there are a voltage modulation method, a pulse width modulation method and the like. To implement the voltage modulation method, the modulation signal generator l37 has a fixed value. A circuit of a voltage modulation system is used which generates a voltage pulse of a length but appropriately modulates the peak value of the pulse according to the input data.

Further, in order to implement the pulse width modulation method, the modulation signal generator 137 generates a voltage pulse having a constant peak value, but a pulse which appropriately modulates the width of the voltage pulse according to the input data. A width modulation type circuit is used.

Through the series of operations described above, the image forming apparatus of the present invention can display a television using the display panel l31. Although not particularly described in the above description, the shift register l34 and the line memory 135 may be digital signal type or analog signal type, and the point is that serial / parallel conversion and storage of image signals are performed at a predetermined speed. It should be done.

When the digital signal system is used, it is necessary to convert the output signal DATA of the sync signal separation circuit 136 into a digital signal, which can be achieved by providing an A / D converter at the output section of 136. Further, in relation to this, the circuit used for the modulation signal generator 137 is slightly different depending on whether the output signal of the line memory 135 is a digital signal or an analog signal.

First, the case of digital signals will be described.
In the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 137, and an amplification circuit or the like may be added if necessary.

In the case of the pulse width modulation method, the modulation signal generator 137 compares the output value of the memory with the output value of the counter and the counter for counting the number of waves output from the oscillator, for example. It can be configured by using a circuit in which comparators (comparators) are combined.
If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator up to the drive voltage of the surface conduction electron-emitting device may be added.

Next, the case of an analog signal will be described.
In the voltage modulation method, for the modulation signal generator 137, for example, an amplifier circuit using a well-known operational amplifier may be used, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a well-known voltage controlled oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage to the drive voltage of the surface conduction electron-emitting device may be used if necessary. May be added.

In the image forming apparatus completed as described above, each of the electron-emitting devices has terminals outside the container Dox1 to Dox.
Electrons are emitted by applying a voltage through xm and Doy1 to Doyn, and a high voltage is applied to the metal back 116 or the transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam and collide with the fluorescent film 115. Then, an image can be displayed by exciting and emitting light.

The configuration described above is a schematic configuration necessary for producing a suitable image forming apparatus used for display and the like. For example, detailed portions such as materials of each member are not limited to the above-described contents. Is appropriately selected so as to be suitable for the use of the image forming apparatus. Further, although the NTSC system is given as an example of the input signal, the input signal is not limited to this, and PAL, SECA
Various methods such as the M method may be used, or a TV signal (for example, a high-definition TV such as the MUSE method) including a number of scanning lines may be used.

Next, the ladder type electron source substrate and the image forming apparatus using the same will be described with reference to FIGS. 14 and 15.

In FIG. 14, 140 is an electron source substrate, 1
41 is an electron-emitting device, and Dx1 to Dx10 of 142 are common wirings connected to the electron-emitting device. A plurality of electron-emitting devices 141 are arranged on the substrate 140 in parallel in the X direction. (This is called an element row). A plurality of this element row is arranged on the substrate to form a ladder type electron source substrate. By appropriately applying a drive voltage between the common wirings of each element row, each element row can be independently driven. That is, a voltage equal to or higher than the electron emission threshold may be applied to the element row that emits the electron beam, and a voltage equal to or lower than the electron emission threshold may be applied to the element row that does not emit the electron beam. In addition, the common wirings Dx2 to Dx9 between the respective element rows are, for example, Dx2 and Dx3.
May be the same wiring.

FIG. 15 is a view showing the structure of an image display device provided with a ladder-type electron source. Reference numeral 150 is a vacuum container, 151 is an electron source substrate in which common wiring between each element row is the same wiring, 152 is a grid electrode, 153 is a hole for passing electrons, 154 is a face plate, 155.
Is a fluorescent film, 156 is Dox1, Dox2 ... Doxm
, An external terminal 157 made of G1, G2, ... Gn connected to the grid electrode 152,
Reference numeral 158 is an electron-emitting device. The electron source substrate 1 is different from the image forming apparatus (FIG. 11) having the simple matrix arrangement described above.
The grid electrode 15 is provided between the 51 and the face plate 154.
It is equipped with 2.

A grid electrode 152 is provided between the substrate 151 and the face plate 154. The grid electrode 152 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device, and in order to pass the electron beam through the stripe-shaped electrode provided orthogonally to the ladder-shaped element rows, Circular holes 153 are provided one by one corresponding to each element. The shape and installation position of the grid are not necessarily those shown in FIG. 15, and a large number of passage openings may be provided in the form of a mesh as openings. Good.

The external container terminal 156 and the grid external container 157 are electrically connected to a control circuit (not shown).

In this image forming apparatus, the modulation signals for one image line are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time.
The irradiation of each electron beam to the phosphor can be controlled to display an image line by line. Further, according to the present invention, it is possible to provide an image forming apparatus suitable for not only a display device for television broadcasting but also a display device such as a video conference system and a computer. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum.

Further, not only surface conduction electron-emitting devices but also cold cathode electron sources such as MIM electron-emitting devices and field emission electron-emitting devices can be applied as electron-emitting devices.
Further, it can be applied to an image forming apparatus using a thermoelectron source.

[0107]

【Example】

(Embodiment 1) FIG. 1 is a view best showing the features of the present invention, and shows the constitution of a laser processing machine used in forming a conductive thin film of a surface conduction electron-emitting device. The configuration will be described below.

Reference numeral 11 is a laser oscillator. The laser light emitted from the laser oscillator 11 is reflected by the reflection mirror 12.
To irradiate the sample surface. At this time, the laser light is shaped by the slit 13 and focused by the objective lens 14.

The sample 16 is fixed on the XY-direction scanning mechanism 15 and can be controlled in the XY directions by the position control mechanism 17.

The control computer 18 uses the laser oscillator 1
1. A computer for controlling the position control mechanism 17, which can draw an arbitrary pattern by a command from the control computer 18.

In this embodiment, a matrix type arrangement electron source substrate having a surface conduction electron-emitting device manufactured by using the above-mentioned laser processing machine will be described as an example.

FIG. 3 is a schematic top view showing a processing pattern used in the present invention. FIG. 3A shows a state in which element electrodes are formed on a substrate by a printing method, and FIG. 3B shows a conductive thin film. The state processed by the laser processing machine is shown. Reference numeral 31 is an electron source substrate, 32 and 33 are device electrodes, and 34 is a laser mark.

First, as shown in FIG. 3A, the device electrodes 32 and 33 containing Pt as a main component were formed on the electron source substrate 31 by a printing method (in the electron-emitting device 104 of FIG. 10). Equivalent).

On top of that, organic palladium (Okuno Pharmaceutical Co., Ltd.)
Manufactured, ccp-4230) is applied to the entire surface, and the temperature is 2 at 300 ° C.
After firing for 0 minutes, a conductive thin film composed of a fine particle film containing Pd as a main component was produced.

Next, a YAG second harmonic laser beam machine with a Q switch (wavelength 532n) similar to the configuration shown in FIG.
m), the produced electron source substrate 31 was set (on the XY direction scanning mechanism 15), and the applied conductive thin film was processed (FIG. 3B).

FIG. 2 shows a laser oscillator 1 used in this embodiment.
It is a laser output waveform diagram of FIG.

In this embodiment, one pattern is drawn by drawing twice. Reference numeral 34 in FIG. 3 denotes a laser mark for drawing, and a conductive thin film 64 (FIG. 6) having both ends connected to the device electrodes 32 and 33 is formed for each device. In the first machining, a machining pitch of about 5 μm and a power of about 10 W are used for machining, and in the second machining, the same waveform is used for the machining position of 2.
It was shifted in the drawing direction of 5 μm (Ld) and the power was about 5 W.

The laser beam has a beam diameter on the surface of the sample that is a quadrangle with a side of about 10 μm, and the sample feed rate is 50 m.
m / sec.

Subsequently, energization forming was performed by applying a voltage as shown in FIG. At this time, as the forming voltage waveform, a pulse width Tl of 1 mse
c, the pulse interval T2 is a rectangular wave of 10 msec, and the peak value is 1
It was set to 5 V and performed in a vacuum atmosphere. By this energization treatment, the conductive thin film 64 (FIG. 6) was locally destroyed, deformed or altered, and the electron emitting portion 65 (FIG. 6) having a changed structure was obtained.

The matrix type arrangement electron source substrate having the surface conduction electron-emitting device is produced in this way, and is sealed with the face plate 113, the support frame 112, the rear plate 110, etc., as shown in FIG. An image forming apparatus was produced.

By processing the matrix type electron source substrate by using the laser beam machine of the present invention, the damage given to the electron source substrate was reduced and the electron source substrate could be manufactured in a short time.

(Example 2) In this example, a ladder type electron source substrate having a surface conduction electron-emitting device was produced using a laser beam machine having the same configuration as in Example 1. The manufacturing method will be described below.

First, as shown in FIG. 3A, device electrodes 32 and 33 containing Pt as a main component were formed on the electron source substrate 31 by a printing method (see the electron-emitting device 141 of FIG. 14). Equivalent).

On top of that, organic palladium (Okuno Pharmaceutical Co., Ltd.)
Manufactured, ccp-4230) is applied to the entire surface, and the temperature is 2 at 300 ° C.
After firing for 0 minutes, a conductive thin film composed of a fine particle film containing Pd as a main component was produced.

Next, a YAG second harmonic laser processing machine with a Q switch (wavelength 532n) having the same configuration as that shown in FIG.
m), the produced electron source substrate 31 was set (on the XY-direction scanning mechanism 15), and the coated conductive thin film was processed in the same pattern as in Example 1 (FIG. 3).
(B)).

FIG. 4 shows the laser oscillator 1 used in this embodiment.
2A is a laser output waveform diagram of FIG. 1, FIG. 1A is a first pulse shape diagram, and FIG. 1B is a second pulse shape diagram. In this embodiment, one pattern is drawn by drawing twice.

Laser Q-switch frequency is 10 kHz
Processing was performed using the waveform of. In the first processing, the scanning speed of the XY direction scanning mechanism 15 was set to about 50 mm / sec, the power was set to about 10 W, and the second processing was set to 25 mm / sec and the power was set to about 5 W. The beam diameter of the laser light on the surface of the sample was a quadrangle with one side of about 10 μm.

Subsequently, energization forming was performed by applying a voltage as shown in FIG. At this time, as the forming voltage waveform, a pulse width Tl of 1 mse
c, the pulse interval T2 is a rectangular wave of 10 msec, and the peak value is 1
It was set to 5 V and performed in a vacuum atmosphere. By this energization treatment, the conductive thin film 64 (FIG. 6) was locally destroyed, deformed or altered, and the electron emitting portion 65 (FIG. 6) having a changed structure was obtained.

A ladder-type arrangement electron source substrate having surface conduction electron-emitting devices is produced in this manner, and is sealed to the face plate 154, a support frame, a rear plate, etc. to form the image shown in FIG. The device was made.

By processing the ladder-type electron source substrate using the laser beam machine of the present invention, damage to the electron source substrate was reduced, and the electron source substrate could be manufactured in a short time.

(Example 3) In this example, a laser processing machine having the same configuration as in Example 1 was used to fabricate a matrix type arrangement electron source substrate having surface conduction electron-emitting devices.
The manufacturing method will be described below.

First, as shown in FIG. 3A, device electrodes 32 and 33 containing Pt as a main component were formed on the electron source substrate 31 by a printing method (in the electron-emitting device 104 of FIG. 10). Equivalent).

On top of that, organic palladium (Okuno Pharmaceutical Co., Ltd.)
Manufactured, ccp-4230) is applied to the entire surface, and the temperature is 2 at 300 ° C.
After firing for 0 minutes, a conductive thin film composed of a fine particle film containing Pd as a main component was produced.

Next, a YAG second harmonic laser beam machine with a Q switch (wavelength 532n) having the same configuration as that shown in FIG.
m), the produced electron source substrate 31 was set (on the XY-direction scanning mechanism 15), and the coated conductive thin film was processed in the same pattern as in Example 1 (FIG. 3).
(B)).

FIG. 5 shows the laser oscillator 1 used in this embodiment.
2A is a laser output waveform diagram of FIG. 1, FIG. 1A is a first pulse shape diagram, and FIG. 1B is a second pulse shape diagram.

In this embodiment, one pattern is drawn by drawing twice. The scanning speed of the XY direction scanning mechanism 15 is about 50.
mm / sec. In the first processing, the Q switch frequency was 10 kHz and the power was about 10 W, and in the second processing, it was 5 kHz and the power was about 5 W. The beam diameter of the laser light on the surface of the sample was a quadrangle with one side of about 10 μm.

Subsequently, energization forming was performed by applying a voltage as shown in FIG. At this time, as the forming voltage waveform, a pulse width Tl of 1 mse
c, the pulse interval T2 is a rectangular wave of 10 msec, and the peak value is 1
It was set to 5 V and performed in a vacuum atmosphere. By this energization treatment, the conductive thin film 64 (FIG. 6) was locally destroyed, deformed or altered, and the electron emitting portion 65 (FIG. 6) having a changed structure was obtained.

The matrix type arrangement electron source substrate having the surface conduction electron-emitting device is produced in this way, and is sealed to the face plate 113, the support frame 112, the rear plate 110 and the like, as shown in FIG. An image forming apparatus was produced.

By processing the matrix type electron source substrate by using the laser beam machine of the present invention, the damage to the electron source substrate was reduced and the electron source substrate could be manufactured in a short time.

[0140]

As described above, according to the present invention, damage to the substrate due to thermal strain during processing can be reduced, so that the durability of the image forming apparatus can be improved and the yield can be improved. There is an effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a laser processing machine according to an embodiment of the present invention.

FIG. 2 is a laser output waveform diagram of the laser oscillator 11 according to the embodiment of the present invention. (A) is the first pulse shape. (B) is the beam trajectory of the first time.
(C) is the second pulse shape. (D) is the beam trajectory of the second time.

FIG. 3 is a schematic top view showing a processing pattern used in the present invention. (A) shows a state in which element electrodes are formed on a substrate by a printing method. (B) shows a state in which the conductive thin film is processed by a laser processing machine.

FIG. 4 is a laser output waveform diagram of the laser oscillator 11 used in the second embodiment. FIG. 7A is a first pulse shape diagram. (B) is a second pulse shape diagram.

FIG. 5 is a laser output waveform diagram of the laser oscillator 11 used in the third embodiment. FIG. 7A is a first pulse shape diagram. (B) is a second pulse shape diagram.

FIG. 6 is a schematic diagram showing a configuration of a planar surface conduction electron-emitting device and a vertical surface conduction electron-emitting device to which the present invention can be applied. (A) is a schematic plan view of a planar surface conduction electron-emitting device. (B) is a typical sectional view of (a). (C) is a typical sectional view of a vertical surface conduction electron-emitting device.

FIG. 7 is a schematic front view showing an example of a method of manufacturing a surface conduction electron-emitting device. (A) shows the state where the element electrode is formed on the electron source substrate. (B) shows a state in which a conductive thin film is formed. (C) shows a state in which an electron emitting portion is formed on the conductive thin film.

FIG. 8 is a voltage waveform diagram of energization forming. (A)
FIG. 4 is a voltage waveform diagram in the case where voltage pulses having a constant pulse peak value are continuously applied. (B) is a voltage waveform diagram in the case of applying a voltage pulse while increasing the pulse crest value.

9 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring electron emission characteristics of an element having the configuration shown in FIG.

FIG. 10 is a schematic configuration diagram of an electron source substrate having a simple matrix arrangement.

FIG. 11 is a basic configuration diagram of an image forming apparatus using an electron source substrate having a simple matrix arrangement.

FIG. 12 is a schematic configuration diagram of a fluorescent film.

FIG. 13 is a block diagram of a drive circuit for displaying in accordance with an NTSC television signal.

FIG. 14 is a schematic configuration diagram of a ladder type electron source substrate.

FIG. 15 is a basic configuration diagram of an image forming apparatus using a ladder-type arrangement electron source substrate.

FIG. 16 is a schematic diagram showing a configuration of a conventional surface conduction electron-emitting device.

FIG. 17 is a laser output waveform diagram used in conventional laser processing. (A) is a pulse shape. (B) is a beam trajectory.

[Explanation of symbols]

 11 Laser Oscillator 12 Total Reflection Mirror 13 Slit 14 Objective Lens 15 XY Direction Scanning Mechanism 16 Sample 17 Position Control Mechanism 18 Control Computer 31, 61, 111, 161 Electron Source Substrate 32, 33, 62, 63 Element Electrode 34 Laser Trace 64, 164 Conductive thin film 65, 165 Electron emission part 90 Ammeter 91 Anode electrode 92 Ammeter 93 High voltage power supply 95 Vacuum device 96 Exhaust pump 101, 140, 151 Electron source substrate 102 X direction wiring 103 Y direction wiring 104 Surface conduction electron emission Element 105 Connection 110 Rear plate, 112 Support frame 113, 154 Face plate 114 Glass substrate 115, 155 Fluorescent film 116 Metal back 117, 141, 158 Electron emission element 118 X-direction wiring 119 Y-direction wiring 120 Enclosure 1 1, 126 Black conductive material 122, 127 Fluorescent substance 131 Display panel 132 Scanning circuit 133 Control circuit 134 Shift register 135 Line memory 136 Synchronous signal separation circuit 137 Modulation signal generator 142 Common wiring 150 Vacuum container 152 Grid electrode 153 Void 156, 157 Outer terminal 159 Hv terminal

Claims (5)

[Claims] 1. A method of manufacturing a surface conduction electron-emitting device, wherein laser light is used, and processing is performed by relatively moving the laser light and a workpiece, wherein pulsed laser light is used as the laser light. Manufacturing the surface conduction electron-emitting device using laser light, characterized in that the first processing step and the second processing step are performed, and the irradiation position of the laser beam is changed for each processing step to process on the same line. Method. 2. The method of manufacturing a surface conduction electron-emitting device using a laser beam according to claim 1, wherein the processing start points in the first processing step and the second processing step are shifted from each other, A method of manufacturing a surface conduction electron-emitting device using laser light, characterized in that the irradiation position of a laser beam is changed for each processing step. 3. The method for manufacturing a surface conduction electron-emitting device using a laser beam according to claim 1, wherein the relative moving speed between the first processing step and the second processing step is changed, A method of manufacturing a surface conduction electron-emitting device using laser light, characterized in that the irradiation position of a laser beam is changed for each processing step. 4. The method for manufacturing a surface conduction electron-emitting device using a laser beam according to claim 1, wherein the Q of the laser is used in the first processing step and the second processing step.
A method of manufacturing a surface conduction electron-emitting device using laser light, characterized in that the irradiation position of a laser beam is changed for each processing step by changing the switch frequency. 5. The method for manufacturing a surface conduction electron-emitting device using laser light according to claim 1, wherein the number of second processing steps is less than that of the first processing steps. A method for manufacturing a surface conduction electron-emitting device using a laser beam, which is characterized in that irradiation is performed.