Method of manufacturing carbon nanotube electron field emitters by dot-matrix sequential electrophoretic deposition

Abstract

A method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition forms an electric field for only one pixel in the electrophoretic deposition, so that only the electrophoretic area has the electrophoretic effect. Longitudinally aligned cathode electrodes of a cathode plate include a plurality of electron field transmitters at the depositing positions, and anode electrodes of an anode plate perpendicular to the cathode electrodes are preinstalled, and a switch unit provides a potential difference for each cathode or anode electrode by a sequential change, and only one alternating pixel having an electric field between the cathode and anode plates per unit time of the electrophoresis produces a deposition effect in the area for manufacturing a carbon nanotube electron field transmitter, and the sequential voltage change of each cathode or anode electrode is used to achieve the electrophoretic deposition effect for all pixels of the cathode plate.

1 . A method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition, comprising the steps of: 
 connecting an anode of a power supply to a plurality of anode electrodes of an anode plate, and connecting a cathode of the power supply to an input end of a switch unit, and connecting an output end of the switch unit to a plurality of cathode electrodes of a cathode plate such that the cathode electrodes and the anode electrodes are perpendicular with each other, and connecting a signal generator to an input end of the plurality of switch units;    preparing an electrophoresis solution in an electrophoresis tank, and placing the cathode plate and the anode plate which are parallel to each other in the electrophoresis tank;    an anode of a power supply outputting a voltage to the plurality of anode electrodes of the anode plate, and the signal generator producing a pulse signal outputted to the plurality of switch units, such that in the electrophoretic deposition, only one switch unit is electrically connected, and the rest of the switch units remain electrically disconnected, and one of the cathode electrodes of the cathode plate is electrically connected to allow only one pixel to produce a potential different and have an electric field between the cathode electrode and the anode electrode in an electrophoresis period, and the electrically connected cathode electrode forms a carbon nanotube at a position for depositing the electron field transmitter; and    the electrically connected switch unit counting the time, while the electrically connected cathode electrode is going through the electrophoretic deposition, and once the counted time is up, the electric power supplied to the cathode electrode will be disconnected to allow the next switch unit to be electrically connected and the rest of the switch units remain electrically disconnected, so as to proceed the electrophoretic deposition for the next cathode electrode sequentially.    
   
   
       2 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the power supply is a scanning power supply that supplies a voltage to complete the electrophoresis for a full area in the period of a cycle, such as completing a full electrophoresis in a second, and the voltage of a pulse voltage provided by the anode is equal to 120V.  
   
   
       3 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the anode plate includes a plurality of anode electrodes disposed transversally on an insulating board.  
   
   
       4 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 3 , wherein the insulating board is a glass substrate having the anode electrode produced on the glass substrate by a process selected from screen printing and lithography.  
   
   
       5 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the cathode plate includes a plurality of longitudinally aligned cathode electrodes.  
   
   
       6 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the cathode electrode is a semi-finished product structure having a finished gate and a manufactured sacrificial layer.  
   
   
       7 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 6 , wherein the sacrificial layer is intended for preventing a sediment such as a gate or a dielectric layer remained in a region without going through an electrophoretic deposition.  
   
   
       8 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 6 , further comprising the step of removing the film of a sacrificial layer after the electrophoretic deposition process is completed.  
   
   
       9 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the cathode plate and the anode plate are parallel to each other and have an interval of 3 cm to 5 cm, and the cathode plates and the anode plate are placed in the electrophoresis tank.  
   
   
       10 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the solution adopts ethanol as a solvent, and the phosphor powder material for the electron field transmitter of the electrophoresis employs carbon nanotubes produced by an electric arc discharge, and its average nanotube length is below 5 μm, and its average nanotube diameter is below 100 nm, and the carbon nanotube is a multiwalled carbon nanotube structure with a concentration in weight percentage equal to 0.1%˜0.005%.  
   
   
       11 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 10 , wherein the concentration in weight percentage is preferably equal to 0.02%.  
   
   
       12 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the solution further comprises a secondary salt which is a conducting metal oxide salt formed after the electrophoresis.  
   
   
       13 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 12 , wherein the metal oxide salt is one selected from the group of indium chloride, indium nitrate, and other salts such as a tin salt.  
   
   
       14 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 12 , wherein the secondary salt is indium chloride with a concentration in weight percentage equal to 0.1%˜0.005%, and a glass powder for increasing adhesiveness with a concentration in weight percentage greater than 5%.  
   
   
       15 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 14 , wherein the secondary salt selects a concentration in weight percentage preferably equal to 0.01%.  
   
   
       16 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the signal generator produces a continuous square wave output.  
   
   
       17 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the switch unit is a timer.  
   
   
       18 . The method of manufacturing carbon nanotube electron field emitters by do-matrix sequential electrophoretic deposition of  claim 1 , wherein the switch unit comprises a timer and a switch.