CN101009187A

CN101009187A - The method for making the carton nano tube electronic radiation source with the point matrix sequential electrophoresis sediment

Info

Publication number: CN101009187A
Application number: CN 200610002296
Authority: CN
Inventors: 郑奎文; 萧俊彦; 李协恒; 李裕安; 蔡金龙
Original assignee: Teco Electric and Machinery Co Ltd
Current assignee: Teco Electric and Machinery Co Ltd
Priority date: 2006-01-27
Filing date: 2006-01-27
Publication date: 2007-08-01

Abstract

A method of producing carbon nanometer tube electron emitter by dot matrix sequential electrophoresis aggradation provides a interleaving electrophoresis aggradation technique, it makes the electrophoresis aggradation cause form single pixel electric field only, so the electrophoresis area possesses electrophoresis aggradation effect; thereinto, several cathode electrodes of cathode plate is end-to-end arrangement, several position which is use to set electron emitter are set on the electron, several anode electron and cathode electron of the anode plate are arranged correspondingly, potential difference is provided in sequential mode between anode electron and cathode electron, when electrophoresis is proceeded, there is only one electric field between anode electron and cathode electron plate within unit time, so the aggradation effect is generated in this area to produce carbon nanometer tube electron emitter, the sequential voltage change of anode electron or cathode electron can realize electrophoresis aggradation of all pixel of cathode plate.

Description

The method of dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment

Technical field

The present invention relates to a kind of Field Emission Display, particularly a kind of with dot matrix type in proper order the electrophoresis carbon nano-tube make the electrophoretic deposition technique of each pixel electron emission source.

Background technology

Thereby Field Emission Display of the present invention is a kind of electric field that utilizes makes cathode electronics emission source (Cathode electron emitter) produce electronics, fluorescent powder by described electron excitation positive plate, it is luminous to make fluorescent powder produce photon, the characteristics of this display are that big I light, thin, effectively display area size is made according to manufacturing process and product demand, in addition, its visual angle problem that does not have flat liquid crystal display and had.

A kind of traditional three-electrode field transmitting display device, its structure mainly comprises positive plate and minus plate, be provided with eyelid retractor (spacer) between this positive plate and the minus plate, as the interval of vacuum area between positive plate and minus plate and as the support between positive plate and minus plate, this positive plate comprises anode substrate, anode conductive layer and fluorescent powder coating (phosphors layer); This minus plate then comprises cathode base, cathode conductive layer, electron emission source layer, dielectric layer and grid layer; Wherein provide potential difference on this grid layer so that electron emission source layer emitting electrons, by the high voltage that anode conductive layer provided, electron beam is quickened, thus make electronics that enough kinetic energy bumps (impinge) be arranged the fluorescent powder coating on the positive plate is so that thus it excites luminous.Therefore, in Field Emission Display, move, need to use vacuum equipment that the vacuum degree of display is remained at least 10 in order to make electronics ^-5Below the holder (torr),, should avoid the pollution in electron emission source and fluorescent material district simultaneously and poison so that electronics has enough mean free paths (mean free path).In addition, have enough energy with bump fluorescent material, between two plates, need appropriate gap, make electronics have enough accelerating spaces to clash into fluorescent powder, so that the fluorescent material physical efficiency fully produces luminescent effect for making electronics.

Wherein so-called electron emission source layer is a main component with carbon nano-tube (Carbon nanotubes), and carbon nano-tube is after being proposed (Nature354,56 (1991)) by Iijima in 1991 and possessing high characteristic electron, and it is used by multiple electronic building brick.Carbon nano-tube can have very high depth-to-width ratio (aspect ratio), its depth-to-width ratio is greater than more than 500, and has high rigidity, its young's modulus is many more than 1000GPn, and the tip of carbon nano-tube or fault location are exposing of atom magnitude, because it has above these characteristics, therefore be considered to a kind of desirable field electron emission source (electron field emitter) material, for example be used for the electron emission source on a kind of minus plate of Field Emission Display.Because carbon nano-tube possesses above-described physical characteristic, therefore also can be designed to multiple manufacturing process, as wire mark or film manufacturing process etc., to be used for the Butut electronic building brick.

And so-called minus plate manufacturing technology, be that carbon nano-tube is risen material on cathode conductive layer as electronics, its manufacture method is included in the chemical vapor deposition (CVD) method of direct growth carbon nano-tube on the interior negative electrode layer of each cathode pixels, or the method on a kind of cathode conductive layer that photosensitive type carbon nano-tube solution totemization can be made in each pixel, it also can be the method that spraying carbon nano-tube solution collocation guard is made, but according to the electron emission source structure of above-mentioned three-electrode field transmitting display device, carbon nano-tube to be made on the cathode electrode structure in each pixel, above-mentioned several manufacture method all is subjected to the restriction of cost of manufacture and stereochemical structure obstruction, especially for large-sized electron emission source, its uniformity will more be difficult to realize.

A kind of so-called electrophoretic deposition EPD (ElectrophoresisDeposition) technology has been proposed recently successively, open as the application for a patent for invention of the US2003/0102222 U.S., this invention is that carbon nano-tube is formulated as the alcohols aaerosol solution, and utilize magnesium, lanthanum, yttrium, aluminium plasma salt is as auxiliary salt (Charger), be made into electrophoresis solution, with cathode electrode substrate to be deposited, link to each other with electrode and be positioned in this electrophoresis solution, by providing direct current or alternating voltage in solution, to form electric field, the auxiliary salt ion that ionization goes out in solution is attached on the carbon nanotube dust, it forms electrophoretic force by electric field, to assist carbon nano-tube to be deposited on special electrodes, the carbon nano-tube one patterned can be deposited on the electrode thus, utilize above-mentioned electrophoretic deposition technique, can simply carbon nano-tube be deposited on the electrode layer, and can avoid the restriction structurally of three-electrode field transmitting display device cathode construction, so present technique has been widely used in the minus plate structure fabrication.

But; in traditional electrophoretic deposition method; for carbon nano-tube can only be deposited on the cathode electrode; and unlikelyly be deposited on the grid and cause conducting between grid and cathode electrode; form only at sacrifice layer or the protective layer treating to be exposed more than grid and dielectric layer by the cathode electrode layer region of Butut; carry out electrophoretic deposition again; and then described protective layer removed; to prevent that carbon nano-tube in the inessential zone is residual or to cause conducting; perhaps; another kind of conventional art i.e. No. 2001020093 Japanese patent laid-open publication gazette; be to form projection corresponding to the specific region of negative electrode at the anode electrode of electrophoresis; owing to be provided with this projection; therefore pairing cathode electrode forms a specific electric field; helping carbon nanotubes in solution is deposited in this specific region; and the carbon nano-tube that is deposited is easy to cohesion and concentrates on the specific electrodes layer region; or; the totem electrophoresis anode construction of a kind of easy making of being mentioned in the previous application of submitting to of applicant wherein provides the positive plate device in electrophoretic deposition zone in the active set.

Though present electrophoretic deposition mode has limited the electrophoretic deposition district, but described conventional method also needs to provide on cathode-anode plate simultaneously voltage to form electric field, therefore careful calculation Design need be carried out so that the electric field that forms can be realized effective compartmentalization effect, and its exploitativeness is restricted probably, especially resolve panel for height, the unit electrophoresis zone that can form will be littler, formed point-to-point electric field more is subject to the restriction of contiguous Electric Field Distribution and is difficult to produce a desired effect, promptly, though it is point-to-point electrophoretic deposition technique, but owing to be to produce electric field simultaneously, therefore reciprocation easily takes place in the electric field of neighbor, thereby loses the point-to-point electrophoretic deposition effect of matrix form easily.

Summary of the invention

Main purpose of the present invention is to improve the effect of dot matrix type structural region electrophoretic deposition, the present invention proposes a kind of alternating expression electrophoretic deposition technique, make only to concentrate in the electrophoresis time on the pixel electrophoretic deposition takes place, thereby the electrophoretic deposition compartmentalization is concentrated, and the design of positive plate and electric field that electrophoresis produced are oversimplified more, applicable current density improves when electrophoresis, on the large tracts of land panel is made, the consume of used instrument and equipment design cost and electric weight is reduced, and the fail safe of operation improves.

For achieving the above object, the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment of the present invention comprises:

The anode tap of supply unit is connected in a plurality of anode electrodes of positive plate, cathode terminal is connected in signal amplification unit, the output of signal amplification unit is connected on a plurality of cathode electrodes of minus plate, described a plurality of cathode electrode is vertical corresponding with a plurality of anode electrodes, the signal generation unit is connected in the input of described a plurality of signal amplification units again; Minus plate and positive plate are parallel corresponding being seated in the electrophoresis tank;

Then, the anode tap of supply unit exports voltage to a plurality of anode electrodes of described positive plate, and described signal generation unit will one of be imported in the described signal amplification unit with the pulse signal that formula in proper order produces, after signal amplification unit amplifies, make a cathode electrode in the minus plate be "on" position, and all the other cathode electrodes are no power, make between described cathode electrode and described anode electrode only single pixel form potential difference producing electric field, thereby on the position of cathode electrode preparation deposition electron emission source, form carbon nano-tube;

After above-mentioned steps, enter next cathode electrode energising, the cold state of all the other cathode electrodes in proper order, make with the dot matrix type circular sequence electrophoresis sediment formula carbon nano-pipe electronic emission source of finishing a plurality of cathode electrodes.

Description of drawings

Fig. 1 is a yin, yang pole plate schematic diagram of the present invention;

Fig. 2 is yin, yang pole plate of the present invention and electrophoresis equipment connection diagram;

Fig. 3 is a cathode and anode plate electrophoresis manufacturing process schematic diagram of the present invention;

Fig. 4 is that yin, yang pole plate of the present invention is connected simple and easy schematic diagram with electrophoresis equipment;

Fig. 5 is an another kind of cathode and anode plate electrophoresis manufacturing process schematic diagram of the present invention.

In the accompanying drawing, the list of parts of each label representative is as follows:

Minus plate 1,1a cathode electrode 11,11a

Positive plate

2,

2a anode electrode

21,21a

Scan-

type supply unit

3,3a

signal amplification unit

4,4a

Signal generation unit

5,5a electrophoresis tank 6,6a

Embodiment

About technology contents of the present invention and detailed description, existing accompanying drawings is as follows:

Fig. 1 and Fig. 2 are yin, yang pole plate of the present invention and the moon, pole plate and electrophoresis equipment connection diagram.As shown in the figure, dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment method of the present invention, mainly be to utilize the interleaved type scanning electrophoretic deposition technique that electric current is staggered on the pixel of the cathode electrode that is assigned to different sections, to make the carbon nano-pipe electronic emission source on the minus plate, this scan method can effectively reduce peak value (peak) electric current, and the method can be applied to pulse signal in the large-area panel making.

Said method is when making, be to get minus plate 1 earlier, the cathode electrode 11 that has any vertical layout of a bar or 32 on the minus plate 1, these a plurality of cathode electrodes 11 are the semi-finished product structure of finishing grid and sacrifice layer making, this sacrifice layer is used to protect the zone (as grid, dielectric layer etc.) that need not to carry out electrophoretic deposition can not produce sedimental residual, treat that again sacrifice layer being dialled film after electrophoretic deposition manufacturing process is finished removes, further, can on the semi-finished product substrate of minus plate 1, provide a * b or 32 * 32 pixels;

Get positive plate 2 then, positive plate 2 is anode electrodes 21 of making a plurality of landscape configuration on insulation board, it is vertical corresponding with a plurality of cathode electrode 11, can cooperate the pixel of minus plate 2 that b bar or 32 s' anode electrode 21 is provided, wherein insulation board can be a glass substrate, makes a plurality of anode electrodes 21 by wire mark or lithography process on glass substrate;

A plurality of anode taps 31 of scan-type supply unit 3 are connected on a plurality of anode electrodes 21 of positive plate 2, think that each anode electrode 21 provides pulse voltage in proper order, cathode terminal 32 then is connected on the input of each signal amplification unit 4, and the output of signal amplification unit 4 then is connected on each cathode electrode 11 of minus plate 1; In addition, another input with signal amplification unit 4 is connected with signal generation unit 5 again, to finish the connection that electrophoretic deposition is made, wherein scan-type supply unit 3 is used to each anode electrode 21 that delay (lag) pulse voltage in proper order is provided, signal generation unit 5 provides signal in proper order for each cathode electrode 11, and be connected with cathode electrode 11 by described a plurality of signal amplification units 4, signal amplification unit 4 is used to provide the amplifying signal that passes through voltage amplification.

Fig. 3 is the simple and easy schematic diagram that cathode and anode plate electrophoresis manufacturing process of the present invention and yin, yang pole plate are connected with electrophoresis equipment with Fig. 4.As shown in the figure, when minus plate 1, positive plate 2, scan-type supply unit 3, after

signal amplification unit

4 and 5 connections of signal generation unit are finished, to carry out the electrophoresis solution modulation of electrophoresis tank 6 inside: with ethanol is solvent, the electron emission source material powder of electrophoresis adopts a kind of carbon nano-tube of making by arc discharge, its average carbon length of tube is below 5 μ m, average carbon pipe caliber is below 100nm, carbon nano tube structure for a kind of multiple wall, it adds weight concentration is 0.1%～0.005% (being preferably 0.02%), auxiliary salt is selected the burning salt that can have conductivity behind the electrophoresis for use, as inidum chloride, and indium nitrate, or other similar salt, it is the inidum chloride salt of 0.1%～0.005% (being preferably 0.01%) that the present invention selects weight concentration for use, and weight concentration increases the glass dust etc. of adhesive force at least in being used to more than 5%;

Minus plate 1 and positive plate 2 are placed in the electrophoresis tank 6 accordingly, can keep the spacing of 3～5cm between the two.Wherein, the voltage presentation mode of scan-type supply unit 3 is for finishing the gross area electrophoresis one time with time one-period, electrophoresis is an example to finish a second once comprehensively, it is the voltage signal of b or 32 that scan-type supply unit 3 provides frequency to these a plurality of anode electrodes 21 successively in delay mode in proper order, each described anode tap is 120V with positive voltage, duty ratio (Duty)=1/b or 1/32 pulsed voltage provide to a plurality of anode electrode 21a of positive plate 2, and the continuity square-wave signal that signal generation unit 5 produces exports first signal amplification unit 4 to, after 4 pairs of signals of first signal amplification unit amplify, providing immediately to first cathode electrode 11 of minus plate 1 makes it form "on" position, this moment, remaining cathode electrode 11 formed the no power state, therefore in electrophoresis time, only form potential difference in the single pixel of first cathode electrode 11 and first anode electrode 21 and produce electric field, make on the position of cathode electrode 11 preparation deposition electron emission sources and form carbon nano-tube.Then form the state of next cathode electrode 11 conductings, all the other not conductings, form carbon nano-tube with relevant position in next pixel according to mode in proper order.Finish the electron emission source of cathode electrode 11 makes by this circular sequence electrophoresis sediment manufacture method.In view of the above, above-mentioned each cathode electrode 11 changes (or frequency multiplication is higher) in proper order for duty ratio=1/32 or 1/a, the frequency that each cathode electrode 11 is postponed P-SCAN is a or 32, in view of the above each pixel with frequency a * b 32 * 32 or its frequency multiplication mode carry out electrophoretic deposition, electrophoresis 15min operate time, one time electrophoresis can form the electron emission source structure that thickness is about the uniform thickness of 5～10um.

Fig. 5 is an another kind of cathode and anode plate electrophoresis manufacturing process schematic diagram of the present invention.Mainly be on minus plate 1a, to have a plurality of cathode electrode 11a among this embodiment, and have a plurality of anode electrode 21a on the positive plate 2a, the anode tap 31a of scan-type supply unit 3a is connected on a plurality of anode electrode 21a of positive plate 2a, think that each anode electrode 21a provides pulse voltage in proper order, and cathode terminal 32a is connected in signal amplification unit 4a input, and the output of signal amplification unit 4a is connected on a plurality of cathode electrode 11a of minus plate 1a again, again signal generation unit 5a is connected in the input of signal amplification unit 4a, then that described a plurality of cathode electrode 11a are vertical with anode electrode 21a corresponding and be placed among the electrophoresis tank 6a with keeping 3～5cm spacing, scan-type supply unit 3a provides voltage signal to each anode electrode 21a successively in the mode that postpones in proper order, postpone P-SCAN to each anode electrode 21a, it is the pulsed voltage of 120V that scan-type supply unit 3a provides positive voltage.At this moment, signal generation unit 5a produces the signal that exports a plurality of signal amplification unit 4a to, wherein first signal amplification unit 4a does not carry out the signal processing and amplifying, make first cathode electrode 11a of minus plate 1a form low-potential state, this moment, remaining cathode electrode 11a formed high potential state (promptly, cathode electrode equates with the current potential of anode electrode, no potential difference), therefore make at electrophoresis time that only single pixel forms potential difference with the generation electric field between first cathode electrode 11a and first anode electrode 21a, thereby cathode electrode 11a is prepared on the position that deposits electron emission source form carbon nano-tube, and then P-SCAN is to the pixel of next cathode electrode 11a.

After above-mentioned explanation, the advantage of dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment method of the present invention as can be known is as follows:

1, utilizes the staggered correspondence of electrode cable on the electrophoresis cathode-anode plate to dispose, make only to concentrate in the electrophoresis time on the pixel electrophoretic deposition takes place, thereby realize that the electrophoretic deposition compartmentalization is concentrated.

2, by the invention provides a kind of simpler electrophoresis anode plate design, avoided the reciprocation of complicated electric field in the conventional electrophoretic process, the electric field that electrophoresis is produced is oversimplified.

3, because but compartmentalization takes place for the unit electrophoresis, so applicable current density can improve during electrophoresis.

4, large tracts of land electrophoretic current amount is big, and instrument and equipment design cost and electric weight consume reduction, and the fail safe of operation improves.

The above is the preferred embodiments of the present invention only, is not to be used for limiting practical range of the present invention.Every equal variation and modification of being done in the present patent application claim includes in claim of the present invention.

Claims

1. the method for a dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment comprises:

A), a plurality of anode electrodes that connect positive plate with the anode tap of supply unit, the cathode terminal of supply unit is connected in the input of signal amplification unit, and the output of described signal amplification unit is connected on a plurality of cathode electrodes of minus plate, described a plurality of cathode electrode is vertical corresponding with described a plurality of anode electrodes, the signal generation unit is connected in the input of described a plurality of signal amplification units again;

B), the electrophoresis solution of modulated electrophoretic groove inside, described minus plate and described positive plate are parallel are seated in accordingly in the described electrophoresis tank;

C), the anode tap of described supply unit exports voltage to a plurality of anode electrodes of described positive plate, and described signal generation unit will one of be imported in the described signal amplification unit with the pulse signal that formula in proper order produces, after described signal amplification unit amplifies, make a cathode electrode in the described minus plate be "on" position, and all the other cathode electrodes are no power, thereby only single pixel forms potential difference with the generation electric field between cathode electrode described in the electrophoresis time and described anode electrode, thereby forms carbon nano-tube on the position of cathode electrode preparation deposition electron emission source;

D), after above-mentioned (c) step is finished, enter the energising of next cathode electrode, the cold state of all the other cathode electrodes in proper order, with the making of the dot matrix type circular sequence electrophoresis sediment formula carbon nano-pipe electronic emission source of finishing a plurality of cathode electrodes.

2. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described supply unit is the scan-type supply unit, the voltage system that is provided is for finishing a gross area electrophoresis with time one-period, described time one-period is preferably a second, and it is the pulsed voltage of 120V that the anode tap of described supply unit provides positive voltage.

3. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described positive plate is to make the anode electrode of doing a plurality of landscape configuration on insulation board.

4. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 3, wherein, described insulation board can be glass substrate, makes anode electrode by any one technologies such as wire mark or little shadows on glass substrate.

5. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1 wherein, has many cathode electrodes that vertically are provided with on the described minus plate.

6. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, described cathode electrode is for finishing the semi-finished product structure that grid and sacrifice layer are made.

7. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 6, wherein, it is residual that described sacrifice layer is used to protect the zone that need not to carry out electrophoretic deposition can not produce deposit.

8. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 6 wherein, is dialled film with described sacrifice layer again and is removed after electrophoretic deposition is finished.

9. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described minus plate is seated in the electrophoresis tank so that the spacing of 3～5cm is parallel accordingly with positive plate.

10. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described solution is solvent with ethanol, the electron emission source material powder of electrophoresis adopts a kind of carbon nano-tube of making by arc discharge, its average carbon length of tube is below 5 μ m, average carbon pipe caliber is a kind of carbon nano tube structure of multiple wall below 100nm, it adds weight concentration is 0.1%～0.005%.

11. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 10, wherein, described interpolation weight concentration is preferably 0.02%.

12. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described solution also includes auxiliary salt, and described auxiliary salt is selected the burning salt that can have conductivity behind the electrophoresis for use.

13. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 12, wherein, described burning salt is inidum chloride and indium nitrate.

14. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 12, wherein, it is 0.1%～0.005% inidum chloride salt that described auxiliary salt is selected weight concentration for use, and adds weight concentration increases adhesive force in being used to more than 5% glass dust.

15. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 14, wherein, the weight concentration of described auxiliary salt is preferably 0.01%.

16. the method for dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment as claimed in claim 1, wherein, described signal generation unit produces the output of continuity square wave.

17. the method for a dot matrix type making carbon nano-pipe electronic emission source with circular sequence electrophoresis sediment comprises:

C), the anode tap of described supply unit exports voltage to a plurality of anode electrodes of described positive plate, and described signal generation unit is imported the pulse signal that produces in described a plurality of signal amplification unit, make one of them signal amplification unit not amplify pulse signal in mode in proper order, thereby make a cathode electrode in the described minus plate be low-potential state, and all the other cathode electrodes are high potential state, promptly make described all the other cathode electrodes equate with the current potential of described anode electrode, no-voltage is poor, thereby make described one to be the cathode electrode of electronegative potential and to be between the anode electrode of high potential only single pixel and form potential difference producing electric field, thereby on the position of cathode electrode preparation deposition electron emission source, form carbon nano-tube;

D), after above-mentioned (c) step is finished, entering next cathode electrode in proper order is that electronegative potential, all the other cathode electrodes are the state of high potential, makes with the dot matrix type circular sequence electrophoresis sediment formula carbon nano-pipe electronic emission source of finishing a plurality of cathode electrodes.