WO2016111405A1 - Carbon nanotube paste for a high power field emission emitter and method of manufacturing the same - Google Patents

Carbon nanotube paste for a high power field emission emitter and method of manufacturing the same Download PDF

Info

Publication number
WO2016111405A1
WO2016111405A1 PCT/KR2015/000593 KR2015000593W WO2016111405A1 WO 2016111405 A1 WO2016111405 A1 WO 2016111405A1 KR 2015000593 W KR2015000593 W KR 2015000593W WO 2016111405 A1 WO2016111405 A1 WO 2016111405A1
Authority
WO
WIPO (PCT)
Prior art keywords
nano powder
cnt
paste
solvent
nano
Prior art date
Application number
PCT/KR2015/000593
Other languages
French (fr)
Inventor
Dae-Jun Kim
Dong-Il Kim
Kwan-Soo Park
Original Assignee
Vacuum Science & Instrument Co., Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vacuum Science & Instrument Co., Ltd filed Critical Vacuum Science & Instrument Co., Ltd
Publication of WO2016111405A1 publication Critical patent/WO2016111405A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H01J1/304—Field-emissive cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06—Cathodes
    • H01J35/065—Field emission, photo emission or secondary emission cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H01J1/304—Field-emissive cathodes
    • H01J1/3048—Distributed particle emitters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30403—Field emission cathodes characterised by the emitter shape
    • H01J2201/30434—Nanotubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30446—Field emission cathodes characterised by the emitter material
    • H01J2201/30453—Carbon types
    • H01J2201/30469—Carbon nanotubes (CNTs)
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30446—Field emission cathodes characterised by the emitter material
    • H01J2201/30484—Carbides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30446—Field emission cathodes characterised by the emitter material
    • H01J2201/30488—Nitrides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/30—Cold cathodes
    • H01J2201/304—Field emission cathodes
    • H01J2201/30446—Field emission cathodes characterised by the emitter material
    • H01J2201/30496—Oxides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00—Nanotechnology
    • Y10S977/902—Specified use of nanostructure
    • Y10S977/932—Specified use of nanostructure for electronic or optoelectronic application
    • Y10S977/939—Electron emitter, e.g. spindt emitter tip coated with nanoparticles

Definitions

  • the present invention relates to a carbon nanotube (CNT) paste and a method of manufacturing the CNT paste, and more particularly to a CNT paste for a high power field emission emitter, which is capable of maintaining high power characteristics even after being made as a CNT emitter and a method of manufacturing the CNT paste.
  • CNT carbon nanotube
  • An X-ray generator is used in various fields such as an industrial field, a medical field, a research field, etc.
  • the X-ray generator adopts a filament as an electron provider in general.
  • a carbon nanotube (CNT) has been adopted as the electron provider for a high value-added device with a sensitive control for medical appliances.
  • Field emission is performed by amplifying electric fields at the end of the CNT formed at a cathode to emit electrons to a vacuum space so that a prompt operation and high density current can be possible in comparison with a filament randomly emitting electrons through thermal energy. It is reported that a maximum current density of a single CNT reaches at 109A/cm 2 , and this is unrivaled excellent among characteristics of field emission devices.
  • each of emitters cannot be treated as a single emitter. Therefore, current density of emitters formed at a device cannot reach at that of the single CNT.
  • a packaging process that is the last process in manufacturing process of an X-ray generator is performed in vacuum, and high temperature process and contact with oxygen in the packaging process are main causes deteriorating characteristics of the CNT emitter.
  • the present invention provides a CNT paste for a high power field emission emitter, which is capable of maintaining high power characteristics even after being made as a CNT emitter and a method of manufacturing the CNT paste.
  • the present invention for solving the above technical problem presents a carbon nanotube (CNT) paste comprising first nano powder including insulating refractory material, second nano powder including metallic oxide material, solvent disgregating the first nano powder and the second nano powder, carbon nano tube disgregated in the solvent to operate as a field emission source, and organic binder included in the solvent for an attachment with an emitter electrode.
  • CNT carbon nanotube
  • the first nano powder may include at least one of silicon carbide (SiC), silicon nitride (Si 3 N 4 ) and spodumene (LiAlSi 2 O 6 ).
  • the second nano powder may include at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
  • the carbon nano tube may be added by about 5 ⁇ 15 % of weight of a mixture of the first nano powder and the second nano powder.
  • the first nano powder and the second nano powder may be mixed with the mixing ratio of about 10:1 ⁇ 20:1 by molar fraction.
  • the first nano powder and the second nano powder may be mixed with the mixing ratio of about 5:1 ⁇ 30:1 by weight.
  • the present invention for solving the above technical problem also presents a method of manufacturing a carbon nano tube (CNT) paste.
  • the method includes disgregating first nano powder having insulating refractory material and second nano powder having metallic oxide material in solvent, disgregating carbon nano tube in the solvent as a field emission source, and adding organic binder granting adhesiveness to the solvent
  • stable power characteristics can be obtained even after high temperature process for forming the CNT emitter is performed under atmosphere or in vacuum by adding the first nano powder including insulating refractory material and the second nano powder including metallic oxide material in forming the CNT paste.
  • FIG. 1 is a schematic cross-sectional view showing a field emission emitter manufactured by CNT paste according to an embodiment of the present invention.
  • FIG. 2 is a flow chart showing a process of manufacturing the CNT paste according to an embodiment of the present invention.
  • FIG. 3 is SEM photographs taken after surface processing of emitter with the CNT paste according to an embodiment of the present invention.
  • FIG. 4 is a graph showing output characteristics of the emitter with the CNT paste according to an embodiment of the present invention.
  • the present invention may have various modifications and shapes, but will be explained as an example referring to figures in detail.
  • first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.
  • FIG. 1 is a schematic cross-sectional view showing a field emission emitter manufactured by CNT paste according to an embodiment of the present invention.
  • carbon nanotube (CNT) paste 100 is spread on an emitter electrode 200 for forming a field emission emitter.
  • the CNT paste 100 may be spread on the emitting electrode 200 through a screen printing method or a dipping method.
  • the CNT paste 100 includes first nano powder 110 including insulating refractory material, second nano powder 120 including metallic oxide material, solvent disgregating the first nano powder 110 and the second nano powder 120, CNT disgregated in the solvent as a field emission source, and organic binder added to the solvent for attachment to an emitter electrode 200.
  • the solvent and the organic binder are removed through a thermal process. Therefore, the solvent and the organic binder are not shown in the figure.
  • the first nano powder 110 including the insulating refractory material is proof against high temperature in vacuum state or atmosphere.
  • the first nano powder 110 is not deteriorated in the high temperature to maintain the strength and to withstand chemical reaction.
  • the first nano powder 110 may include at least one of silicon carbide (SiC), silicon nitride (Si 3 N 4 ) and spodumene (LiAlSi 2 O 6 ).
  • the CNT paste 100 when the CNT paste 100 includes the first nano powder 110 with insulating refractory characteristic, the CNT paste 100 may have high temperature stability during a packaging process in a vacuum state or atmosphere.
  • the second nano powder 120 with metallic oxide material is superior to carbide in conductivity under high voltage.
  • the second nano powder 120 includes at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
  • the CNT paste 100 includes the second nano powder 120 that is superior to carbide in conductivity under high voltage, an absolute value and variation of contact resistance between CNT 130 and the emitter electrode 200 are lowered and current density of the field emission emitter may be raised.
  • the first nano powder 110 and the second nano powder 120 are uniformly mixed in the CNT paste 100 so that a surface with higher flatness may be obtained when the CNT paste 100 for forming emitter is surface treated.
  • the field emission characteristics of the CNT emitter may be changed. For example, after forming CNT paste 100 on the emitter electrode 200, a surface treatment using an adhesion of a roller or a tape is performed. Through this surface treatment, mixing ratio of the first nano powder 110 and the second nano powder 120 on the CNT emitter becomes different from the mixing ratio thereof in the CNT emitter to grant different arrangement regularity to a surface of the emitter and an inside of the emitter.
  • the mixing ratio of the first nano powder 110 and the second nano powder 120 which is capable of maximizing differences of attractive force between molecules induced by difference of structure and density of particles even though with same size, is required.
  • the first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 10:1 ⁇ 20:1 by molar fraction. Further, the first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 5:1 ⁇ 30:1 by weight.
  • the first nano powder 110 and the second nano powder 120 are mixed with different mixing ratio according to size of the CNT 130.
  • the above mixing ratio is in case of the CNT 130 has a size of about 5nm.
  • the size of the CNT 130 becomes bigger than 5nm, it is preferable to increase amount of the first nano powder 110.
  • the size of the CNT 130 becomes smaller than 5nm, it is preferable to increase amount of the second nano powder 120.
  • the CNT 130 is added by about 5 ⁇ 15 % of weight of a mixture of the first nano powder 110 and the second nano powder 120 to grant conductivity to the CNT paste 100 and to have effective field emission characteristics.
  • the CNT paste 100 includes too small amount of the CNT 130, the CNT 130 is scarcely formed on the emitter to deteriorate field emission.
  • the CNT paste 100 includes too much amount of CNT 130, the mixing and the disgregation of the CNT 130 are deteriorated to increase electric stress applied to the CNT 130 when field emission. Therefore, it is preferable to add the CNT 130 by about 5 ⁇ 15 % of weight of nano powder mixture, considering the mixing and the disgregation characteristics and field emission characteristics of the emitter.
  • the organic binder is added to the solvent with the first nano powder 110, the second nano powder 120 and the CNT 130 to grant adhesiveness to the emitter electrode 200.
  • the viscosity of the CNT paste 100 may be adjusted.
  • the organic binder may have the viscosity no less than about 100,000cps.
  • FIG. 2 is a flow chart showing a process of manufacturing the CNT paste according to an embodiment of the present invention.
  • a method of manufacturing CNT paste includes a step of disgregating the first nano powder 110 having insulating refractory material and the second nano powder 120 having metallic oxide material in solvent (step S10), a step of disgregating CNT 130 in the solvent (step S20), and a step of adding organic binder granting adhesiveness to the solvent (step S30).
  • the first nano powder 110 having insulating refractory material and the second nano powder 120 having metallic oxide material is disgregated in a solvent (step S10).
  • the first nano powder 110 is for improving stability of the CNT paste 100 in high temperature.
  • the first nano powder 110 may include at least one of silicon carbide (SiC), silicon nitride (Si 3 N 4 ) and spodumene (LiAlSi 2 O 6 ).
  • the second nano powder 120 is for reducing absolute value and variation of contact resistance between CNT 130 and the emitter electrode 200 to raise current density of the field emission emitter.
  • the second nano powder 120 may include at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
  • the first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 10:1 ⁇ 20:1 by molar fraction or with the mixing ratio of about 5:1 ⁇ 30:1 by weight in order to optimize adhesion in surface treating process for forming emitter.
  • the CNT 130 is disgregated in the solvent in which the first nano powder 110 and the second nano powder 120 are disgregated (step S20).
  • the CNT 130 operates as electron source in the CNT paste 100.
  • the CNT 130 is added by about 5 ⁇ 15 % of the weight of mixture of the first nano powder 110 and the second nano powder 120.
  • the weight of the first nano powder 110 added to the CNT paste 100 is 1, the weight of the second nano powder 120 added to the CNT paste 100 is about 0.03 ⁇ 0.2, and the weight of the CNT 130 added to the CNT paste 100 is about 0.05 ⁇ 0.15.
  • the organic binder is added to the solvent to form the CNT paste 100 (step S30).
  • the CNT paste 100 is spread on the emitter electrode 200, and a drying process, a thermal treatment process, a surface treatment process, etc. may be performed to form the CNT emitter.
  • FIG. 3 is SEM photographs taken after surface processing of emitter with the CNT paste according to an embodiment of the present invention
  • FIG. 4 is a graph showing output characteristics of the emitter with the CNT paste according to an embodiment of the present invention.
  • a surface flatness of CNT paste is improved and CNT are vertically erected with respect to the emitter electrode so that the CNT is arranged in a tip shape. That is, when the surface treatment process of the CNT paste is performed through adhesion of a roller or a tape, portions of which adhesive force is weak and unnecessary residues of paste are removed to improve surface flatness of the CNT paste to arrange the CNT in the tip shape.
  • the current density is improved after surface treating.
  • stable power characteristics can be obtained even after high temperature process for forming the CNT emitter is performed under atmosphere or in vacuum by adding the first nano powder 110 including insulating refractory material and the second nano powder 120 including metallic oxide material in forming the CNT paste100.

Abstract

The present invention provides a carbon nanotube (CNT) paste and a method of manufacturing the CNT paste. The carbon nanotube (CNT) paste includes first nano powder including insulating refractory material, second nano powder including metallic oxide material, solvent disgregating the first nano powder and the second nano powder, carbon nano tube disgregated in the solvent to operate as a field emission source, and organic binder included in the solvent for an attachment with an emitter electrode. Therefore, high power characteristics may be maintained even after high temperature process is performed for forming a CNT emitter.

Description

CARBON NANOTUBE PASTE FOR A HIGH POWER FIELD EMISSION EMITTER AND METHOD OF MANUFACTURING THE SAME
The present invention relates to a carbon nanotube (CNT) paste and a method of manufacturing the CNT paste, and more particularly to a CNT paste for a high power field emission emitter, which is capable of maintaining high power characteristics even after being made as a CNT emitter and a method of manufacturing the CNT paste.
An X-ray generator is used in various fields such as an industrial field, a medical field, a research field, etc. The X-ray generator adopts a filament as an electron provider in general. However, a carbon nanotube (CNT) has been adopted as the electron provider for a high value-added device with a sensitive control for medical appliances.
Field emission is performed by amplifying electric fields at the end of the CNT formed at a cathode to emit electrons to a vacuum space so that a prompt operation and high density current can be possible in comparison with a filament randomly emitting electrons through thermal energy. It is reported that a maximum current density of a single CNT reaches at 109A/cm2, and this is unrivaled excellent among characteristics of field emission devices.
When the CNT is applied to the emitter of devices such as an X-ray generator, hundred thousands or millions of CNTs are formed in a lump at a cathode.
However, in real case, each of emitters cannot be treated as a single emitter. Therefore, current density of emitters formed at a device cannot reach at that of the single CNT.
Additionally, a packaging process that is the last process in manufacturing process of an X-ray generator is performed in vacuum, and high temperature process and contact with oxygen in the packaging process are main causes deteriorating characteristics of the CNT emitter.
Therefore, the present invention provides a CNT paste for a high power field emission emitter, which is capable of maintaining high power characteristics even after being made as a CNT emitter and a method of manufacturing the CNT paste.
The present invention for solving the above technical problem presents a carbon nanotube (CNT) paste comprising first nano powder including insulating refractory material, second nano powder including metallic oxide material, solvent disgregating the first nano powder and the second nano powder, carbon nano tube disgregated in the solvent to operate as a field emission source, and organic binder included in the solvent for an attachment with an emitter electrode.
The first nano powder may include at least one of silicon carbide (SiC), silicon nitride (Si3N4) and spodumene (LiAlSi2O6).
The second nano powder may include at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
The carbon nano tube may be added by about 5 ~ 15 % of weight of a mixture of the first nano powder and the second nano powder.
The first nano powder and the second nano powder may be mixed with the mixing ratio of about 10:1 ~ 20:1 by molar fraction.
The first nano powder and the second nano powder may be mixed with the mixing ratio of about 5:1 ~ 30:1 by weight.
The present invention for solving the above technical problem also presents a method of manufacturing a carbon nano tube (CNT) paste. The method includes disgregating first nano powder having insulating refractory material and second nano powder having metallic oxide material in solvent, disgregating carbon nano tube in the solvent as a field emission source, and adding organic binder granting adhesiveness to the solvent
According to the present invention, stable power characteristics can be obtained even after high temperature process for forming the CNT emitter is performed under atmosphere or in vacuum by adding the first nano powder including insulating refractory material and the second nano powder including metallic oxide material in forming the CNT paste.
FIG. 1 is a schematic cross-sectional view showing a field emission emitter manufactured by CNT paste according to an embodiment of the present invention.
FIG. 2 is a flow chart showing a process of manufacturing the CNT paste according to an embodiment of the present invention.
FIG. 3 is SEM photographs taken after surface processing of emitter with the CNT paste according to an embodiment of the present invention.
FIG. 4 is a graph showing output characteristics of the emitter with the CNT paste according to an embodiment of the present invention.
The present invention may have various modifications and shapes, but will be explained as an example referring to figures in detail.
However, the specification and cases below are for showing embodiments of the present invention but only for examples. The present invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing a field emission emitter manufactured by CNT paste according to an embodiment of the present invention.
Referring to FIG. 1, carbon nanotube (CNT) paste 100 according to an embodiment of the present invention is spread on an emitter electrode 200 for forming a field emission emitter. For example, the CNT paste 100 may be spread on the emitting electrode 200 through a screen printing method or a dipping method.
The CNT paste 100 includes first nano powder 110 including insulating refractory material, second nano powder 120 including metallic oxide material, solvent disgregating the first nano powder 110 and the second nano powder 120, CNT disgregated in the solvent as a field emission source, and organic binder added to the solvent for attachment to an emitter electrode 200. The solvent and the organic binder are removed through a thermal process. Therefore, the solvent and the organic binder are not shown in the figure.
The first nano powder 110 including the insulating refractory material is proof against high temperature in vacuum state or atmosphere. The first nano powder 110 is not deteriorated in the high temperature to maintain the strength and to withstand chemical reaction. For example, the first nano powder 110 may include at least one of silicon carbide (SiC), silicon nitride (Si3N4) and spodumene (LiAlSi2O6).
As described above, when the CNT paste 100 includes the first nano powder 110 with insulating refractory characteristic, the CNT paste 100 may have high temperature stability during a packaging process in a vacuum state or atmosphere.
The second nano powder 120 with metallic oxide material is superior to carbide in conductivity under high voltage. For example, the second nano powder 120 includes at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
As described above, when the CNT paste 100 includes the second nano powder 120 that is superior to carbide in conductivity under high voltage, an absolute value and variation of contact resistance between CNT 130 and the emitter electrode 200 are lowered and current density of the field emission emitter may be raised.
The first nano powder 110 and the second nano powder 120 are uniformly mixed in the CNT paste 100 so that a surface with higher flatness may be obtained when the CNT paste 100 for forming emitter is surface treated.
According to a mixing ratio of the first nano powder 110 and the second nano powder 120, the field emission characteristics of the CNT emitter may be changed. For example, after forming CNT paste 100 on the emitter electrode 200, a surface treatment using an adhesion of a roller or a tape is performed. Through this surface treatment, mixing ratio of the first nano powder 110 and the second nano powder 120 on the CNT emitter becomes different from the mixing ratio thereof in the CNT emitter to grant different arrangement regularity to a surface of the emitter and an inside of the emitter.
In order to optimize the adhesion in the surface treatment, the mixing ratio of the first nano powder 110 and the second nano powder 120, which is capable of maximizing differences of attractive force between molecules induced by difference of structure and density of particles even though with same size, is required. In order for that, the first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 10:1 ~ 20:1 by molar fraction. Further, the first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 5:1 ~ 30:1 by weight.
On the other hand, it is preferable to mix the first nano powder 110 and the second nano powder 120 with different mixing ratio according to size of the CNT 130. For example, the above mixing ratio is in case of the CNT 130 has a size of about 5nm. When the size of the CNT 130 becomes bigger than 5nm, it is preferable to increase amount of the first nano powder 110. On the contrary, when the size of the CNT 130 becomes smaller than 5nm, it is preferable to increase amount of the second nano powder 120.
The CNT 130 is added by about 5 ~ 15 % of weight of a mixture of the first nano powder 110 and the second nano powder 120 to grant conductivity to the CNT paste 100 and to have effective field emission characteristics. When the CNT paste 100 includes too small amount of the CNT 130, the CNT 130 is scarcely formed on the emitter to deteriorate field emission. On the contrary, when the CNT paste 100 includes too much amount of CNT 130, the mixing and the disgregation of the CNT 130 are deteriorated to increase electric stress applied to the CNT 130 when field emission. Therefore, it is preferable to add the CNT 130 by about 5 ~ 15 % of weight of nano powder mixture, considering the mixing and the disgregation characteristics and field emission characteristics of the emitter.
The organic binder is added to the solvent with the first nano powder 110, the second nano powder 120 and the CNT 130 to grant adhesiveness to the emitter electrode 200. In this case, by adjusting the amount of the organic binder, the viscosity of the CNT paste 100 may be adjusted. For example, the organic binder may have the viscosity no less than about 100,000cps.
Hereinafter, a method of manufacturing the CNT paste according to an embodiment of the present invention will be explained.
FIG. 2 is a flow chart showing a process of manufacturing the CNT paste according to an embodiment of the present invention.
Referring to FIG. 1 and FIG. 2, a method of manufacturing CNT paste according to an embodiment of the present invention, includes a step of disgregating the first nano powder 110 having insulating refractory material and the second nano powder 120 having metallic oxide material in solvent (step S10), a step of disgregating CNT 130 in the solvent (step S20), and a step of adding organic binder granting adhesiveness to the solvent (step S30).
In order to manufacture the CNT paste, the first nano powder 110 having insulating refractory material and the second nano powder 120 having metallic oxide material is disgregated in a solvent (step S10).
The first nano powder 110 is for improving stability of the CNT paste 100 in high temperature. For example, the first nano powder 110 may include at least one of silicon carbide (SiC), silicon nitride (Si3N4) and spodumene (LiAlSi2O6). The second nano powder 120 is for reducing absolute value and variation of contact resistance between CNT 130 and the emitter electrode 200 to raise current density of the field emission emitter. For example, the second nano powder 120 may include at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
The first nano powder 110 and the second nano powder 120 may be mixed with the mixing ratio of about 10:1 ~ 20:1 by molar fraction or with the mixing ratio of about 5:1 ~ 30:1 by weight in order to optimize adhesion in surface treating process for forming emitter.
Then, the CNT 130 is disgregated in the solvent in which the first nano powder 110 and the second nano powder 120 are disgregated (step S20).
The CNT 130 operates as electron source in the CNT paste 100. For example, the CNT 130 is added by about 5 ~ 15 % of the weight of mixture of the first nano powder 110 and the second nano powder 120.
Therefore, when the weight of the first nano powder 110 added to the CNT paste 100 is 1, the weight of the second nano powder 120 added to the CNT paste 100 is about 0.03~0.2, and the weight of the CNT 130 added to the CNT paste 100 is about 0.05~0.15.
Then, the organic binder is added to the solvent to form the CNT paste 100 (step S30).
When the CNT paste 100 is completed, the CNT paste 100 is spread on the emitter electrode 200, and a drying process, a thermal treatment process, a surface treatment process, etc. may be performed to form the CNT emitter.
FIG. 3 is SEM photographs taken after surface processing of emitter with the CNT paste according to an embodiment of the present invention, and FIG. 4 is a graph showing output characteristics of the emitter with the CNT paste according to an embodiment of the present invention.
Referring to FIG. 3, through a surface treatment process of CNT paste, a surface flatness of CNT paste is improved and CNT are vertically erected with respect to the emitter electrode so that the CNT is arranged in a tip shape. That is, when the surface treatment process of the CNT paste is performed through adhesion of a roller or a tape, portions of which adhesive force is weak and unnecessary residues of paste are removed to improve surface flatness of the CNT paste to arrange the CNT in the tip shape.
Referring to FIG. 4, when the field emission emitter is formed by using the CNT paste according to the present invention, the current density is improved after surface treating.
As described above, stable power characteristics can be obtained even after high temperature process for forming the CNT emitter is performed under atmosphere or in vacuum by adding the first nano powder 110 including insulating refractory material and the second nano powder 120 including metallic oxide material in forming the CNT paste100.
It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (11)

  1. A carbon nanotube (CNT) paste comprising:
    first nano powder including insulating refractory material;
    second nano powder including metallic oxide material;
    solvent disgregating the first nano powder and the second nano powder;
    carbon nano tube disgregated in the solvent to operate as a field emission source; and
    organic binder included in the solvent for an attachment with an emitter electrode.
  2. The CNT paste of claim 1, wherein the first nano powder comprises at least one of silicon carbide (SiC), silicon nitride (Si3N4) and spodumene (LiAlSi2O6).
  3. The CNT paste of claim 1, wherein the second nano powder comprises at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
  4. The CNT paste of claim 1, wherein the carbon nano tube is added by about 5 ~ 15 % of weight of a mixture of the first nano powder and the second nano powder.
  5. The CNT paste of claim 1, wherein the first nano powder and the second nano powder are mixed with the mixing ratio of about 10:1 ~ 20:1 by molar fraction.
  6. The CNT paste of claim 1, wherein the first nano powder and the second nano powder are mixed with the mixing ratio of about 5:1 ~ 30:1 by weight.
  7. A method of manufacturing a carbon nano tube (CNT) paste, the method comprising:
    disgregating first nano powder having insulating refractory material and second nano powder having metallic oxide material in solvent;
    disgregating carbon nano tube in the solvent as a field emission source; and
    adding organic binder granting adhesiveness to the solvent.
  8. The method of claim 7, wherein the first nano powder comprises at least one of silicon carbide (SiC), silicon nitride (Si3N4) and spodumene (LiAlSi2O6).
  9. The method of claim 7, wherein the second nano powder comprises at least one of oxides of nickel (Ni), copper (Cu), zinc (Zn), magnesium (Mg), yttrium (Y), and zirconium (Zr).
  10. The method of claim 7, wherein the carbon nano tube is added by about 5 ~ 15 % of weight of a mixture of the first nano powder and the second nano powder.
  11. The method of claim 7, wherein the first nano powder and the second nano powder are mixed with the mixing ratio of about 10:1 ~ 20:1 by molar fraction, or with the mixing ratio of about 5:1 ~ 30:1 by weight.
PCT/KR2015/000593 2015-01-05 2015-01-21 Carbon nanotube paste for a high power field emission emitter and method of manufacturing the same WO2016111405A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR10-2015-0000702 2015-01-05
KR1020150000702A KR101663821B1 (en) 2015-01-05 2015-01-05 Carbon Nanotube Paste And Method For Manufacturing Thereof

Publications (1)

Publication Number Publication Date
WO2016111405A1 true WO2016111405A1 (en) 2016-07-14

Family

ID=56356084

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2015/000593 WO2016111405A1 (en) 2015-01-05 2015-01-21 Carbon nanotube paste for a high power field emission emitter and method of manufacturing the same

Country Status (3)

Country Link
JP (1) JP2016126993A (en)
KR (1) KR101663821B1 (en)
WO (1) WO2016111405A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102352861B1 (en) * 2017-08-03 2022-01-18 (주) 브이에스아이 Carbon nanotube paste and manufacturing method of carbon nanotube paste
KR102340337B1 (en) * 2017-08-16 2021-12-16 (주) 브이에스아이 A manufacturing method of compact cylindrical x-ray tube
CN113816719B (en) * 2021-10-09 2023-01-31 航天特种材料及工艺技术研究所 Phosphate group nano heat-insulating material and preparation method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050236951A1 (en) * 2004-04-22 2005-10-27 Tsinghua University Method for making a carbon nanotube-based field emission cathode device
US20070296322A1 (en) * 2006-06-23 2007-12-27 Tsinghua University Field emission element having carbon nanotube and manufacturing method thereof
US20080139073A1 (en) * 2006-12-07 2008-06-12 Electronics And Telecommunications Research Institute Method of manufacturing fine patternable carbon nano-tube emitter with high reliability
US20080299298A1 (en) * 2005-12-06 2008-12-04 Electronics And Telecommunications Research Institute Methods of Manufacturing Carbon Nanotube (Cnt) Paste and Emitter with High Reliability
US20120142836A1 (en) * 2009-07-28 2012-06-07 Mitsubishi Gas Chemical Company, Inc. Insulated ultrafine powder, method for producing same, and high dielectric constant resin composite material

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100354225B1 (en) * 2000-07-27 2002-09-27 삼성에스디아이 주식회사 Method for manufacturing emitter of field emission display device
KR101309537B1 (en) * 2012-04-06 2013-10-14 (주) 브이에스아이 Carbon nanotube paste and manufacturing method of carbon nanotube paste

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050236951A1 (en) * 2004-04-22 2005-10-27 Tsinghua University Method for making a carbon nanotube-based field emission cathode device
US20080299298A1 (en) * 2005-12-06 2008-12-04 Electronics And Telecommunications Research Institute Methods of Manufacturing Carbon Nanotube (Cnt) Paste and Emitter with High Reliability
US20070296322A1 (en) * 2006-06-23 2007-12-27 Tsinghua University Field emission element having carbon nanotube and manufacturing method thereof
US20080139073A1 (en) * 2006-12-07 2008-06-12 Electronics And Telecommunications Research Institute Method of manufacturing fine patternable carbon nano-tube emitter with high reliability
US20120142836A1 (en) * 2009-07-28 2012-06-07 Mitsubishi Gas Chemical Company, Inc. Insulated ultrafine powder, method for producing same, and high dielectric constant resin composite material

Also Published As

Publication number Publication date
KR101663821B1 (en) 2016-10-07
JP2016126993A (en) 2016-07-11
KR20160084153A (en) 2016-07-13

Similar Documents

Publication Publication Date Title
WO2016111405A1 (en) Carbon nanotube paste for a high power field emission emitter and method of manufacturing the same
KR100777113B1 (en) The fine patternable cnt emitter manufacturing method of with high reliability
CN102087947B (en) Field-emission electronic device
KR102461252B1 (en) Heat element structure, method of preparing the same, and heating device including the same
CN102082062A (en) Field emission display device
JP5926709B2 (en) Field electron emission film, field electron emission device, light emitting device, and method for manufacturing the same
JP5926750B2 (en) Field electron emission film, field electron emission device, light emitting device, and method for manufacturing the same
KR101533048B1 (en) Field electron emitter containing nucleic acid coated carbon nanotube and methode for manufactring the same
WO2015068992A1 (en) Transparent type flat panel x-ray generation apparatus and x-ray imaging system
WO2016144091A1 (en) Field emission element using graphite adhesive material and method for manufacturing same
JP2005197247A (en) Electron emission source forming composition of electron emission element and electron emission source manufactured therefrom
WO2015105260A1 (en) X-ray generator having anti-charging structure of triode electron emitting device
WO2012096499A2 (en) Horizontal field emission device
TWI494271B (en) Paste for electron emission source, electron emission source using the same and electron emission element and method for producing the same
WO2014007570A1 (en) Carbon nanotube structure, production method for same and field emission device using same
US7973460B2 (en) Composition for forming electron emitter, electron emitter formed using the composition, electron emission device having the emitter, and backlight unit having the emitter
JP2005521217A (en) Field electron emission materials and equipment
KR100571545B1 (en) Carbon paste composite of conducting carbon nano tube and making method of flexible film type Inorganic electroluminescence device using of
KR20100006524A (en) Method for producing a carbon nanotube field electron emitter and field electron emission device comprising the field electron emitter produced by the same
KR20030038044A (en) A carbon nanotube emitter composition for field emision device and preparation method of the same
KR20140142200A (en) Carbon nanotube paste for field emission device, Emitter using the same and Field emission device using the same
KR100932976B1 (en) Slurry composition for electron emission source formation of flat panel display device and electrode formation method using same
WO2018164302A1 (en) Electron-emitting material and preparation method therefor
KR20090044797A (en) Boron nitride nano tube paste composition, electron emission source using thereof, electron emission device employing the electron emission source, and backlight unit and electron emission display device employing the electron emission device
Yu-Kui et al. Thick Blending-Stacking-Layer Carbon Nanotube Cathode with Improved Stability and Balanced Electron Emission: Design Optimization and Experimental Fabrication

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15877126

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 09/11/2017)

122 Ep: pct application non-entry in european phase

Ref document number: 15877126

Country of ref document: EP

Kind code of ref document: A1