JP4355928B2 - Manufacturing method of field emission cold cathode - Google Patents

Description

The present invention relates to the manufacture of a cold cathode in which uniform-shaped oriented carbon nanotube (hereinafter referred to as CNT) film is patterned on an electrode to obtain field electron emission with uniform intensity at a low voltage. The present technology can be applied to a thin image display device such as a field emission display (hereinafter referred to as FED).

CNT was discovered by Sumio Iijima in 1991 (see Non-Patent Document 1). The general shape is 0.5-100 nm in diameter and 1-100 μm in length, and is a very elongated hollow tube. Carbon material. In recent years, CNTs are expected to be applied as field electron emission type electron sources. A negative voltage is applied to the electrode on which the field electron emission type electron sources are arranged, and further heat is not emitted, so it is called a cold cathode. In particular, when CNT is used as an electron source of an image display device such as an FED, a large number of electrons are required because the amount of emitted electrons is insufficient from one CNT. Furthermore, since a unique electron source for illuminating each pixel of the FED is required, it is necessary to insulate each electron source and energize the control circuit.

Various methods are known for producing a field electron emission cold cathode using CNT, and there are a method of attaching CNT separately prepared to an electrode and a method of growing CNT directly on the electrode. Separately prepared CNTs can be attached to the electrode by mixing the CNT with a conductive paste and forming a pattern on the electrode by screen printing (for example, see Patent Document 1), mixing the CNT with a solvent or a binder, dropping and applying. Or a method of forming a CNT layer on an electrode by spraying (for example, see Patent Document 2), a method of mixing CNT with a solvent or a binder, and extruding the electrode through a metal mesh (for example, see Non-Patent Document 2), Examples include a method of forming a CNT layer on the filter surface by passing the CNT suspension through a filter, and transferring the CNT layer to an electrode (for example, see Non-Patent Document 3).

As a transfer method similar to the above-mentioned Non-Patent Document 3, although a manufacturing method of a field electron emission type cold cathode is not mentioned, an oriented CNT film is grown on a substrate, and the oriented CNT film is used as a second method. Also disclosed is a method of transferring to the substrate (for example, see Patent Document 3). Further, as a method for directly growing CNTs on an electrode, there is a method for growing CNTs vertically aligned on an electrode by attaching a catalyst to a predetermined position on the electrode substrate surface and performing CVD (for example, Patent Document 4, 5).

JP-A-11-260249 JP 2000-340098 A WO 00/73204 WO 00/30141 Publication JP 2001-15077 A S.Iijima, "Helical microtubules of graphite carbon", Nature, 354, p56-58 (1991) W.B.Choi et al., "Fully sealed high-brightness carbon-nanotube field-emission display", Applied Physics Letters, 75, 20, p3129-3131 (1999) W.A.de Heer et al., "A Carbon Nanotube Field-Emission Electron Source", Science, 270, p1179-1180 (1995)

As described in Patent Document 1 or 2 or Non-Patent Document 2, the method of mixing CNT with a solvent or a binder and adhering to the electrode increases the adhesion between the electrode and the CNT and makes it electrically conductive. Is the way. However, nanoscale substances such as CNTs tend to aggregate even if they are mixed with other fluid substances, and it is difficult to uniformly knead them. If CNT and other fluid substances are attached to the electrode in an unevenly mixed state, the density of the CNT contained in each electron source on the electrode is not constant, and irregularities occur on the surface of the electron source. As a result, the image display device becomes uneven. Here, there is a means of increasing the ratio of the solvent so that it is mixed as uniformly as possible. However, if the solvent remains in the electrode, it becomes a hindrance when performing field electron emission in a high vacuum, so use of the solvent is minimized. It is desirable.

In the transfer method of Non-Patent Document 3, the solvent is removed by filtration without using a binder. However, in this method, the CNT film on the filter is directly attached to a Teflon (registered trademark) sheet as an electrode, and is not suitable for pattern formation. There is also a problem with the adhesion between the electrode and the CNT.

In Patent Document 3, in order to obtain the above-mentioned FED field electron emission type cold cathode, it is necessary to pattern-form the oriented CNT films and insulate each of them to energize the control circuit. No method for forming an oriented CNT film pattern is disclosed.

  In addition, as disclosed in Patent Document 4 or 5, there is a method of patterning an oriented CNT film by performing CVD on the electrode substrate. However, the electrode substrate used in these methods is subjected to high temperature carbon deposition conditions. As a result, the material of the electrode substrate may deteriorate.

Here, in order to operate the image display apparatus using the field electron emission type cold cathode, it is advantageous to emit electrons with as low voltage and uniform intensity as possible. Therefore, the shape of the CNT electron source consisting of a large number of CNT electron sources used for field electron emission type cold cathodes is a unit in which a film oriented in the vertical direction with respect to the electrode and having a constant height is formed, and these are electrically connected to each other. What is insulated is preferable. If it is vertically aligned, the maximum electron emission intensity can be obtained in the vertical direction as the sum of a plurality of CNT electron sources.
If the surface height of each unit is constant and the surface is smooth without unevenness, uniform electron emission can be obtained in the planar direction. In the case of field electron emission, the closer the distance between the tip of the CNT and the anode, the lower the voltage for extracting electrons. Therefore, if the height of the electron source of each unit is constant, it is possible to maintain the uniformity of the distance even if the anode is installed close to the surface of the electron source, and the extraction voltage is used to obtain the same electron emission intensity. Can be lowered.

  In view of the above, the present invention provides an electron source based on a CNT film having a vertical alignment, a smooth surface, and a uniform density in manufacturing a field emission cold cathode using a plurality of CNTs as an electron source. It is an object of the present invention to provide a method for manufacturing a field emission cold cathode, which enables uniform electron emission at a low voltage by forming a pattern in a state where each unit has a constant height and is insulated from each other. To do.

  As means for solving the above problems, in the method of manufacturing a field emission cold cathode according to the present invention, a step of forming an oriented CNT film on a substrate surface and a pattern formation of a conductive binder on the electrode substrate surface A step of bonding the surface of the oriented CNT film and the surface of the conductive binder, a step of curing the conductive binder as required, and the conductive binder of the oriented CNT film; Only the bonded portion is peeled off from the manufactured substrate.

  That is, according to one aspect of the present invention, in the method of manufacturing a field emission cold cathode in which an oriented carbon nanotube film is formed in a pattern on the electrode substrate surface, (1) an oriented carbon nanotube film is produced on the base substrate surface And (4) patterning a conductive binder on the electrode substrate surface, and (5) bonding the surface of the oriented carbon nanotube film and the surface of the conductive binder, and then bonding the conductive binder The method of manufacturing a field emission cold cathode (Method A) includes a step of transferring the oriented carbon nanotube film by peeling the base substrate while leaving the oriented carbon nanotube film portion.

  In the method A, between the steps (1) and (4), (2) the surface of the oriented carbon nanotube film is bonded to the surface of a flexible substrate having a reversible adhesive surface, and then the reversible It is also preferable to intervene a step of transferring the oriented carbon nanotube film by peeling off the basic substrate while leaving the oriented carbon nanotube film adhered to the static adhesive surface. That is, another aspect of the present invention is a method of manufacturing a field emission cold cathode in which an oriented carbon nanotube film is formed in a pattern on the electrode substrate surface. (1) An oriented carbon nanotube film on the base substrate surface And (2) bonding the surface of the oriented carbon nanotube film to the surface of a flexible substrate having a reversible adhesive surface, and then attaching the oriented carbon nanotube film adhered to the surface of the flexible substrate. Leaving the base substrate peeled off and transferring the oriented carbon nanotube film; (4) patterning a conductive binder on the surface of the electrode substrate; and (5 ′) transferred to the flexible substrate. After adhering the surface of the oriented carbon nanotube film and the surface of the conductive binder, the flexible substrate is peeled off leaving the oriented carbon nanotube film part adhered to the conductive binder. Comprising the step of transferring the oriented carbon nanotube film Te, a field emission type cold cathode manufacturing method (B method).

  Further, in the method B, between the steps (2) and (4), (3) the surface of the oriented carbon nanotube film transferred to the first flexible substrate is replaced with the second reversible adhesive surface. After bonding to the surface of a flexible substrate having a surface, the first flexible substrate is peeled off, leaving the oriented carbon nanotube film adhered to the second flexible substrate surface, and the oriented carbon nanotube film is transferred. More preferably, an intervening step is interposed. That is, another aspect of the present invention is a method of manufacturing a field emission cold cathode in which an oriented carbon nanotube film is formed in a pattern on the electrode substrate surface. (1) An oriented carbon nanotube film on the base substrate surface And (2) an oriented carbon bonded to the surface of the flexible substrate after bonding the surface of the oriented carbon nanotube film to the surface of the flexible substrate having the first reversible adhesive surface. Removing the base substrate leaving the nanotube film and transferring the oriented carbon nanotube film; and (3) transferring the surface of the oriented carbon nanotube film transferred to the first flexible substrate to the second After adhering to the surface of a flexible substrate having a reversible adhesive surface, the first flexible substrate is peeled off and oriented while leaving the oriented carbon nanotube film adhered to the second flexible substrate surface. Carbon nano And (4) patterning a conductive binder on the surface of the electrode substrate, and (5 ′) the surface of the oriented carbon nanotube film transferred to the second flexible substrate. And bonding the surface of the conductive binder to the surface of the conductive binder, and then transferring the oriented carbon nanotube film by peeling off the second flexible substrate leaving a portion of the oriented carbon nanotube film adhered to the conductive binder. And a method of manufacturing a field emission cold cathode (Method C). The method C includes a method in which the step (3) is performed once, as well as a method in which the step (3) is performed a plurality of times.

  According to the method for producing a field emission cold cathode of the present invention, an electron source having a unit of a multi-walled CNT film having a thin outer diameter, a vertical alignment, a smooth surface, and a uniform density is provided. It is possible to manufacture a field emission cold cathode in which the surface of the unit is smooth and the pattern is formed in a state of being insulated from each other with a constant height. By using the cathode manufactured by the method of the present invention, it is possible to obtain an image display device that operates at a low voltage and has uniform luminance.

  The present invention is described in detail below. A method which is one of the present invention includes (1) a step of producing an oriented CNT film on the substrate surface, (4) a step of patterning a conductive binder on the electrode substrate surface, and (5) A step of bonding the surface of the oriented CNT film and the surface of the conductive binder, a step of curing the conductive binder as necessary, and only a portion of the oriented CNT film bonded to the conductive binder. It can implement by the process of peeling from the produced board | substrate.

First, (1) as a step of growing an oriented CNT film on the surface of a substrate for growth, an element or compound having no catalytic action alone was coated and a metal element having other catalytic action or a compound thereof was supported. By using the support substrate as a base substrate for CNT growth and decomposing the carbon compound, a CNT film oriented in a direction perpendicular to the substrate is grown on the surface of the base substrate for growth.

Here, as the support substrate, a substrate made of ceramics, quartz, silicon wafer or the like can be used, and among them, a ceramic substrate made of silica alumina, alumina or the like is preferable.

The element or compound which does not have a catalytic action by itself, that is, the inert substance is preferably aluminum or germanium, or an oxide thereof. Moreover, it is preferable that the method of coating | coated the element or compound (inert substance) which does not have a catalytic action by them alone is a vacuum evaporation method, an electrodeposition method, or a sputtering method. Further, the sol-gel method is preferable as a method that can be applied to a large area at a lower cost.
As a method of supporting the transition metal or transition metal compound having a catalytic action on the basic substrate for growth, a general metal supporting method such as an impregnation method, a dipping method, or a sol-gel method may be used. Can be employed on a large-area substrate. The metal species of the catalyst is preferably a heavy metal such as Fe, Co, Ni, or Mo.

The carbon compound used in forming the CNT film may be any carbon compound that generates CNTs in the presence of a suitable catalyst, such as saturated hydrocarbon compounds such as methane, ethane, and propane, ethylene, propylene, and acetylene. An unsaturated hydrocarbon compound such as benzene, toluene and the like, an oxygen-containing hydrocarbon compound such as methanol, ethanol, and acetone are preferable, and methane, ethylene, propylene, and acetylene are preferable. The carbon compound may be introduced in the form of a gas, mixed with an inert gas such as argon, or introduced as a saturated vapor in the inert gas. Also good. Further, a hetero element-containing nanotube can be obtained by mixing a compound containing a hetero element such as boron or nitrogen incorporated into the nanotube. As the decomposition reaction of the carbon compound, thermal decomposition is most common, a preferable reaction temperature is 400 to 1100 ° C. (more preferably 500 to 700 ° C.), and a preferable reaction pressure is 1 kPa to 1 MPa (more preferably 10 to 300 kPa). It is.

The outer diameter of the CNT constituting the oriented CNT film produced in the first step is 10 nm or less, which is advantageous for field electron emission. The film surface of the oriented CNT film is parallel to the substrate and the surface is smooth. Furthermore, the height of the oriented CNT film and the density of CNTs are constant.

  Next, (4) the conductive binder used in the process of patterning the conductive binder on the surface of the electrode substrate requires a function of mechanically bonding the electrode and the CNT and further electrically connecting them. . In addition, the field emission cold cathode emits electrons under a high vacuum, and the function of electron emission decreases when the degree of vacuum decreases. Therefore, the conductive binder preferably does not contain a volatile component. Or even if it contains a volatile component, after bonding an electrode and CNT, it is desirable to remove as much as possible by methods, such as drying, heating, or washing.

Here, in consideration of the above-described adhesive force and electrical conductivity, as well as fluidity that facilitates pattern formation, a conductive paste is preferable as the conductive binder. As the pattern forming method, the screen printing method is the simplest method. The conductive paste is usually composed of a conductive filler responsible for electrical conductivity, a polymer resin responsible for adhesion, and a volatile solvent responsible for fluidity. The conductive paste is classified according to the material used for the conductive filler. For the present invention, a conductive paste of metal such as gold, silver or copper, or carbon is suitable.

A low melting point metal is also used as a conductive binder that does not contain any volatile components. The low melting point metal is preferably one kind selected from the group consisting of indium, tin, lead, zinc and copper, or an alloy containing one or more kinds of these metals.

The conductive binder is attached in a desired pattern shape on the surface of the electrode substrate. The pattern shape can be arbitrarily formed by a known printing method or the like, and is preferably a block shape insulated from each other.
When a conductive paste is used as the conductive binder, pattern formation is performed on the surface of the electrode substrate in a fluid state, and the conductive paste is brought into contact with the surface of the oriented CNT film prepared in the first step. Depending on the curing characteristics, the contact surface is bonded by drying, pressure bonding, heating, or thermocompression bonding.
When using a low-melting-point metal as the conductive binder, the low-melting-point metal is previously cut into a predetermined size, arranged on the electrode surface, brought into contact with the surface of the oriented CNT film prepared in the first step, Crimp and bond the contact surface.

When the field emission cold cathode manufactured in the present invention is used as an electron source of an image display device such as an FED, a plate in which a conductive circuit is previously formed on the surface of an insulating plate is used as the electrode substrate. Is preferred. As the insulating plate, glass which is inexpensive even in a large area is preferable. Furthermore, if the pattern is formed on the surface of the electrode substrate so that the conductive binder adheres to the terminal of the pre-formed circuit, the oriented CNT film is adhered to the conductive binder in the next step, so that the pattern is formed. The oriented CNT film can be energized to the terminal of each conductive circuit. On the other hand, a method of forming a circuit so as to energize each patterned CNT film after the alignment CNT film is attached to the electrode substrate is very complicated.

In the last step (5), the oriented CNT film produced in the first step is attached on an electrode substrate having a conductive binder pattern formed on the surface. As a method of pasting, the surface of the oriented CNT film and the surface of the conductive binder are brought into contact with each other, and after drying, pressure bonding, heating, or thermocompression bonding, the contact surface is adhered, and then the orientation property is applied. This is done by peeling off the CNT film. Since the oriented CNT film is only physically on the basic substrate, the portion where the film surface is bonded to the conductive binder can be easily peeled off. On the other hand, since the part where the film surface did not adhere to the conductive binder remains without being peeled off, the oriented CNT film can be stuck as it is in the form in which the conductive binder is patterned.

Here, when the entire surface of the conductive binder is in contact with the surface of the oriented CNT film grown on the surface of the base substrate, the above-described A method may be used. However, the growth substrate is usually made of a non-deformable material such as ceramics or quartz. Therefore, if the electrode substrate surface used in the last step is curved, contact the entire surface of the conductive binder with the surface of the oriented CNT film obtained by the first method in the first step. It is difficult to let To compensate for this, an oriented CNT film transferred onto a deformable sheet is used.
That is, in the method A, (1) between the step of producing an oriented carbon nanotube film on the base substrate surface and (4) the step of patterning a conductive binder on the electrode substrate surface, (2) the orientation After the surface of the carbon nanotube film is bonded to the surface of a flexible substrate having a reversible adhesive surface, the oriented substrate is peeled off while leaving the oriented carbon nanotube film adhered to the reversible adhesive surface, and the oriented carbon A method B in which a step of transferring the nanotube film is interposed is also preferable.

(2) As a method for carrying out the process, the surface of the oriented CNT film grown on the surface of the base substrate for growth is brought into contact with the surface of a flexible substrate made of a deformable sheet, and drying, pressure bonding, heating, or By applying thermocompression bonding, the contact surfaces are adhered, and the oriented CNT film is peeled from the base substrate, thereby producing an oriented CNT film on the flexible substrate sheet.

As the flexible substrate sheet used here, a flexible substrate having a reversible adhesive surface can be used. The reversible adhesive surface only needs to have weak adhesiveness or adhesiveness on the surface, and the adhesive or adhesive is applied to the sheet entirely or in a pattern. In particular, a sheet printed with an EVA or acrylic adhesive is preferred. In addition, even a sheet that does not have adhesiveness or tackiness under a normal environment, or a sheet that exhibits adhesiveness or tackiness under a special environment such as a humid atmosphere or high temperature can be used.
As the flexible substrate material, a sheet that can be deformed when pressed against the electrode substrate can be used, and a single or multilayer sheet made of an adhesive resin, a thermosetting resin, a thermoplastic resin, or a water-soluble resin can be used. .

By using a deformable sheet, (5 ') the oriented carbon nanotube film is electrically conductive when bonding the surface of the oriented carbon nanotube film transferred to the flexible substrate and the surface of the conductive binder. The adhesive binder can be completely adhered to the electrode substrate, and can be satisfactorily adhered to the electrode substrate.
Specific examples of the flexible substrate include a single-layer sheet made of thermoplastic resin, a two-layer structure sheet of adhesive acrylic resin / thermoplastic resin, and an adhesive two-layer structure sheet of adhesive EVA / thermoplastic resin. Examples of the thermoplastic resin include polyolefin, polyester, polycarbonate, polyamide, and polyimide. Moreover, the sheet | seat which consists of a thermosetting resin illustrated by an epoxy resin and a phenol resin, and the sheet | seat which consists of water-soluble resin illustrated by polyvinyl alcohol can also be used. When a thermosetting conductive paste is used as the conductive binder in the step (5 ′), the sheet is preferably a sheet that can withstand the curing temperature. A multilayer sheet having two or more layers having a reversible adhesive surface can also be used.

In addition, between the steps (2) and (4) in the method B, (3) the surface of the oriented carbon nanotube film transferred to the first flexible substrate is replaced with the second reversible adhesive surface. After adhering to the surface of the flexible substrate having the reversible adhesive surface, the first flexible substrate is peeled off, leaving the oriented carbon nanotube film adhered to the reversible adhesive surface, and the oriented carbon nanotube film is formed into the second possible carbon nanotube film. A method of interposing a step of transferring to the surface of the flexible substrate (Method C) is also preferable.
As the flexible substrate having the first and second reversible adhesive surfaces, the same sheet as the flexible substrate having the reversible adhesive surface of the above-mentioned method B can be used, and the orientation in the step (3) In order to increase the transferability by making a difference in the adhesion with the carbon nanotube film, it is preferable to use different types of sheets. The flexible substrate having the second reversible adhesive surface is a heat-resistant sheet that can withstand the curing temperature when a thermosetting conductive paste is used as the conductive binder in the step (5 ′). It is preferable.

  The film surface of the oriented CNT film patterned on the electrode substrate by the method described above is parallel and smooth to the electrode surface, and the film thickness is constant. Further, the density of CNTs constituting the oriented CNT film is constant, and the outer diameter of each CNT is 10 nm or less, which is advantageous for field electron emission.

  As described above, according to the method for manufacturing a field emission cold cathode of the present invention, a field emission type cold cathode having an electron source of a large number of CNTs having a uniform density, a small outer diameter, and a vertical alignment is used. The field-emission type cold cathode enables uniform electron emission at a low voltage because the blocks are patterned in a state of being insulated from each other, and the surface of each block is parallel and smooth to the electrode substrate. A manufacturing method can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1 Method A [Step of Growing Oriented CNT Film]
A square silica alumina plate having a composition of 25% silica and 75% alumina and a thickness of 2 mm and a side of 75 mm was selected as a support substrate, and aluminum was coated by vapor deposition by a vacuum deposition method. At this time, the thickness of the aluminum thin film was 0.5 μm. Subsequently, it was immersed in a cobalt nitrate aqueous solution having a concentration of 0.2 mol / l for 2 hours. After raising the substrate, the substrate was baked in air at 400 ° C. for 3 hours to obtain a basic substrate. After firing, the base substrate was placed in a quartz tube furnace with the aluminum deposition side facing up horizontally. The tubular furnace was heated up to 700 ° C. while blowing argon at 1000 cm ³ / min in the horizontal direction. Then, while holding 700 ° C., and blown into a tubular furnace of propylene to argon 1000 cm ³ / min was mixed with 300 cm ³ / min. The propylene / argon mixed gas was allowed to flow for 20 minutes, and then the heating of the tubular furnace was stopped while switching to only argon, and the mixture was allowed to cool to room temperature. After completion of the reaction, the surface of the basic substrate was observed with a scanning electron microscope (SEM). As a result, it was confirmed that an oriented CNT film having a thickness of 100 μm was formed on the upper side of the basic substrate.
The film is made of CNTs oriented in the vertical direction, and has a constant thickness and a smooth surface. When this alignment film was observed with a transmission electron microscope (TEM), the CNT constituting the alignment film was a multilayer CNT having an outer diameter of 5 to 8 nm and about 5 to 7 layers.

[Step of patterning conductive binder on electrode substrate surface and step of transferring from the base substrate on which the oriented CNT film is grown to the electrode substrate surface]
A square copper plate having a thickness of 2 mm and a side of 100 mm was prepared as an electrode substrate. A conductive silver paste was patterned on the surface of the copper plate using screen printing. The conductive silver paste was applied to a thickness of 10 μm in a pattern as shown in FIG. Next, the oriented CNT film grown on the basic substrate described above and the surface of the conductive silver paste on the copper plate were brought into contact with each other and heated to 180 ° C. in an argon atmosphere. FIG. 2 is a cross-sectional view schematically showing this state. When the base substrate was peeled off from the copper plate after cooling, the orientation of the oriented CNT film could be retained and pasted only on the surface of the copper plate where the conductive silver paste was applied. This is shown in FIG. The thickness of the alignment film of each block was constant at the same thickness of about 100 μm as before the pasting, and the surface was smooth. In this way, an oriented CNT film could be patterned on the copper plate surface. Field electron emission measurement was performed using the copper plate produced in this example as a cold cathode. The measurement was performed under a vacuum of 10 ⁻⁶ Pa. FIG. 4 schematically shows an electrode as a cross-sectional view. FIG. 5 shows the measurement results, with the interelectrode distance L shown in FIG. 4 as the horizontal axis and the voltage when the current density of 10 mA / cm ² can be taken out as the vertical axis.

(Example 2) Method B FIGS. 6A to 6G are cross-sectional views showing stepwise steps of a method for manufacturing a field emission cold cathode according to this example. First, as shown in FIG. 6A, an oriented CNT film 3 having a height of 50 μm was grown on a base substrate 4 using a silica alumina plate as a supporting substrate in the same manner as in Example 1. Next, as shown in FIG. 6 (b), the surface of the oriented CNT film 3 and the surface of the adhesive sheet 9 (flexible substrate) made of adhesive acrylic resin / polyolefin are brought into contact with each other, and 2 Kg / Crimping was performed over cm ² . By pulling the adhesive sheet 9 and peeling off the base substrate 4 while leaving the oriented CNT film 3, the oriented CNT film 3 was produced on the surface of the adhesive sheet 9 by transfer (FIG. 6C). Separately, a glass plate 10 was prepared as an electrode substrate, and a conductive layer 11 was formed on the surface (FIG. 6D). Next, as shown in FIG. 6E, the conductive carbon paste 12 was screen-printed to a thickness of 15 μm on the surface of the conductive layer. Here, the surface of the prepared oriented CNT film 3 on the adhesive sheet 9 and the printed conductive carbon paste 12 were brought into contact as shown in FIG. 6 (f), and heated to 150 ° C. in an argon atmosphere. . After cooling, as shown in FIG. 6G, the field emission type in which the oriented CNT film is transferred by peeling the adhesive sheet 9 while leaving the oriented CNT film 3 adhered to the conductive carbon paste 12. A cold cathode was obtained.

Example 3 Method C In the same manner as in Example 1, an oriented CNT film having a height of 50 μm was grown on a base substrate having a silica alumina plate as a supporting substrate. Next, the surface of the oriented CNT film 3 is brought into contact with the surface of a water-soluble sheet (flexible substrate) made of polyvinyl alcohol that has been previously wetted in an atmosphere of 90% humidity for 1 hour, and is 2 Kg / cm with a press. Crimped over ² . After crimping and drying, the water-soluble sheet was pulled to leave the oriented CNT film, and the base substrate was peeled off to produce an oriented CNT film on the surface of the water-soluble sheet. Furthermore, the surface of the oriented CNT film transferred to the water-soluble sheet was brought into contact with the surface of the flexible substrate similar to the adhesive sheet used in Example 2, and was pressed with a press at 2 Kg / cm ² . . After the pressure bonding, the whole sample was placed in a 90% humidity atmosphere for 1 hour, and the water-soluble sheet was wetted and peeled off from the surface of the oriented CNT film, thereby producing an oriented CNT film on the surface of the adhesive sheet. Separately, an electrode substrate having a conductive layer formed on a glass plate was prepared, and a conductive silver paste was screen-printed to a thickness of 15 μm on the surface of the conductive layer. Here, the surface of the prepared oriented CNT film and the printed conductive silver paste were brought into contact with an adhesive sheet, and heated to 150 ° C. in an argon atmosphere. After cooling, the adhesive sheet was peeled off while leaving the oriented CNT film adhered to the conductive silver paste to obtain a field emission cold cathode having the oriented CNT film transferred thereto.

(Comparative Example 1)
First, an oriented CNT film was grown on a basic substrate in the same manner as in Example 1. Next, the grown oriented CNT film was peeled off from the base substrate using a plastic spatula. Next, CNT obtained by peeling, conductive silver paste and toluene were mixed at a weight ratio of 1: 8: 1 and carefully kneaded. The resulting mixture was patterned on the surface of a copper plate using screen printing. Thus, the copper plate which printed the pattern of the mixture on the surface was heated to 180 degreeC in argon atmosphere, and the volatile component was removed. The surface of each pattern on the obtained copper plate was severely uneven, and non-oriented CNTs were scattered unevenly in the silver particles. FIG. 7 shows the results of field electron emission measurement similar to that of Example 1 using the copper plate obtained in this comparative example as a cold cathode. The voltage when the current density of 10 mA / cm ² can be taken out is shown on the horizontal axis, and the vertical axis shows the distance L between the electrodes.

  In each example, constant field electron emission was uniformly obtained with a relatively low applied voltage. On the other hand, in the comparative example, a relatively high applied voltage was required to obtain constant field electron emission.

Copper plate screen-printed with conductive silver paste The schematic diagram which contacted the copper plate which screen-printed the electroconductive silver paste, and the film surface of the orientation CNT film | membrane which grew on the silica alumina plate. Oriented CNT film patterned on a copper plate Sectional view showing a field electron emission measuring device The graph which shows the field electron emission characteristic in Example 1 It is sectional drawing which shows the process of manufacturing the field electron emission cold cathode in Example 2, (a)-(g) has shown each process stepwise. The graph which shows the field electron emission characteristic in the comparative example 1

Explanation of symbols

1: Conductive silver paste 2: Copper plate 3: Oriented CNT film 4: Silica alumina plate 5: Cathode copper plate 6: Anode copper plate 7: Ammeter 8: DC power source 9: Adhesive sheet 10: Glass plate 11: Conductive layer 12 : Conductive carbon paste L: Distance between cathode and anode

Claims (17)

In the method of manufacturing a field emission cold cathode in which an oriented carbon nanotube film is formed in a pattern on the electrode substrate surface,
Producing an oriented carbon nanotube film on the base substrate surface;
After bonding the surface of the oriented carbon nanotube film to the surface of a flexible substrate having a reversible adhesive surface, the base substrate is peeled off leaving the oriented carbon nanotube film adhered to the surface of the flexible substrate. Transferring the oriented carbon nanotube film;
Forming a conductive binder pattern on the electrode substrate surface;
After bonding the surface of the oriented carbon nanotube film transferred to the flexible substrate and the surface of the conductive binder, the flexible substrate leaves the portion of the oriented carbon nanotube film bonded to the conductive binder. Including a step of peeling the oriented carbon nanotube film by peeling
Manufacturing method of field emission type cold cathode. In the method of manufacturing a field emission cold cathode in which an oriented carbon nanotube film is formed in a pattern on the electrode substrate surface,
Producing an oriented carbon nanotube film on the base substrate surface;
After the surface of the oriented carbon nanotube film is adhered to the surface of a flexible substrate having a first reversible adhesive surface, the oriented carbon nanotube film adhered to the surface of the first flexible substrate is left, Removing the base substrate and transferring the oriented carbon nanotube film;
After the surface of the oriented carbon nanotube film transferred to the first flexible substrate is bonded to the surface of the flexible substrate having a second reversible adhesive surface, the surface of the second flexible substrate Removing the first flexible substrate leaving the oriented carbon nanotube film adhered to and transferring the oriented carbon nanotube film;
Forming a conductive binder pattern on the electrode substrate surface;
After the surface of the oriented carbon nanotube film transferred to the second flexible substrate and the surface of the conductive binder are bonded, the first portion of the oriented carbon nanotube film bonded to the conductive binder is left, Peeling off the second flexible substrate and transferring the oriented carbon nanotube film,
Manufacturing method of field emission type cold cathode. The step of producing an oriented carbon nanotube film on the surface of the base substrate is carried out in the presence of a base substrate formed by supporting a catalyst made of a transition metal or a transition metal compound on a support substrate coated with an inert substance. The method of manufacturing a field emission cold cathode according to claim 1 or 2 , wherein a carbon nanotube film oriented in a direction perpendicular to the basic substrate is grown on the surface of the basic substrate by decomposing a carbon compound. The method for producing a field emission cold cathode according to claim 3 , wherein the inert substance coated on the support substrate is one selected from aluminum, germanium and oxides thereof. 4. The method of manufacturing a field emission cold cathode according to claim 3 , wherein the method of coating the support substrate with an inert substance is a vacuum deposition method, an electrodeposition method, a sputtering method, or a sol-gel method. The method for producing a field emission cold cathode according to claim 3 , wherein the method of supporting a catalyst made of a transition metal or a transition metal compound on a support substrate coated with an inert substance is an impregnation method, an immersion method, or a sol-gel method. . Carbon compounds, characterized in that a saturated hydrocarbon compound, an unsaturated hydrocarbon compound, an aromatic hydrocarbon compound is at least one mixture selected from the group consisting of oxygenated hydrocarbon compounds, according to claim 3 A method for producing a field emission cold cathode. The manufacturing method of the field emission cold cathode of Claim 1 or 2 whose outer diameter of the carbon nanotube which comprises an oriented carbon nanotube film | membrane is 10 nm or less. The step of bonding the surface of the oriented carbon nanotube film to the surface of the flexible substrate having a reversible adhesive surface causes the surface of the oriented carbon nanotube film to adhere to the reversible adhesive surface of the flexible substrate. The method for producing a field emission cold cathode according to claim 1 , wherein the field emission type cold cathode is bonded by drying, pressure bonding, heating or thermocompression bonding. 3. The method of manufacturing a field emission cold cathode according to claim 1, wherein the electrode substrate is a plate in which a conductive circuit is previously formed on the surface of an insulating plate. 3. The method of manufacturing a field emission cold cathode according to claim 1, wherein the step of patterning the conductive binder on the electrode substrate surface causes the conductive binder to adhere to the conductive circuit. The step of adhering the surface of the oriented carbon nanotube film and the surface of the conductive binder is performed by bringing the surface of the oriented carbon nanotube film and the surface of the conductive binder into contact with each other and drying, pressing, heating, or thermocompression bonding. and wherein the adhering the contact surface is subjected to field emission cold cathode method according to claim 1 or 2. The method of manufacturing a field emission cold cathode according to claim 1 or 2 , wherein the conductive binder is a conductive paste. The method for producing a field emission cold cathode according to claim 13 , wherein the conductive paste is a conductive silver paste, a conductive gold paste, a conductive carbon paste, or a conductive copper paste. The method for producing a field emission cold cathode according to claim 1 or 2 , wherein the conductive binder is a low melting point metal. The field emission type cold according to claim 15 , wherein the low melting point metal is one selected from the group consisting of indium, tin, lead, zinc and copper, or an alloy containing one or more of these. Manufacturing method of cathode. The manufacturing method of the field emission type cold cathode of Claim 1 or 2 whose flexible substrate which has a reversible adhesive surface is a resin sheet which apply | coated the adhesive to the surface.

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