Method and apparatus for depositing films

Abstract

The disclosure relates to a method for depositing films on a substrate which may form part of an LED or other types of display. In one embodiment, the disclosure relates to an apparatus for depositing ink on a substrate. The apparatus includes a chamber for receiving ink; a discharge nozzle having an inlet port and an outlet port, the discharge nozzle receiving a quantity of ink from the chamber at the inlet port and dispensing the quantity of ink from the outlet port; and a dispenser for metering the quantity of ink from the chamber to the inlet port of the discharge nozzle; wherein the chamber receives ink in liquid form having a plurality of suspended particles and the quantity of ink is pulsatingly metered from the chamber to the discharge nozzle; and the discharge nozzle evaporates the carrier liquid and deposits the solid particles on the substrate.

What is claimed is: 
     
         1 . A method for depositing ink on a substrate, the method comprising:
 using a pulsating energy having a first frequency to meter a quantity of ink to a discharge nozzle, the ink defined by a plurality of solid particles in a carrier liquid;   receiving the metered quantity of ink at the discharge nozzle and evaporating the carrier liquid from the metered quantity of ink to provide a quantity of substantially solid ink particles;   dispensing the substantially solid ink particles from the discharge nozzle and depositing the substantially solid ink particles on the substrate; and   wherein at least a portion of the substantially solid ink particles are converted to a vapor phase during discharge from the discharge nozzle, directed to the substrate as a vapor, and condense on a surface of the substrate in substantially solid form.   
     
     
         2 . The method of  claim 1 , wherein the step of using the pulsating energy to meter the quantity of ink further comprises heating the quantity of ink with a plurality of heat pulses. 
     
     
         3 . The method of  claim 1 , wherein the step of using the pulsating energy to meter the quantity of ink further comprises activating a piezoelectric element to meter the quantity of ink. 
     
     
         4 . The method of  claim 3 , wherein the piezoelectric element is activated by providing a pulse of energy at a first frequency. 
     
     
         5 . The method of  claim 1 , wherein the step of dispensing the substantially solid ink particles from the discharge nozzle further comprises providing a plurality of conduits spanning from an inlet port of the discharge nozzle to an outlet port of the discharge nozzle, the plurality of conduits receiving the plurality of solid particles and the carrier liquid at the inlet port and heating the ink to be dispensed from the output port in substantially solid form 
     
     
         6 . The method of  claim 1 , wherein the step of dispensing the quantity of ink from the discharge nozzle in substantially solid form further comprises providing a discharge nozzle having a plurality of conduits separated by a plurality of partitions, each conduit having an opening surface area W which holds the relationship 1/20,000<W/D<¼, wherein D is the inlet port surface area of the discharge nozzle. 
     
     
         7 . The method of  claim 1 , wherein the solid ink particles are substantially solvent free. 
     
     
         8 . A method for depositing ink on a substrate, the method comprising:
 providing liquid ink to a chamber, the liquid ink defined by a plurality of suspended particles in a carrier liquid;   pulsatingly energizing a dispenser to meter a quantity of liquid ink from the chamber to a discharge nozzle, the quantity of liquid ink metered as a function of a frequency of at least one of a pulse amplitude, a pulse duration or a pulse frequency;   receiving the metered quantity of ink at a discharge nozzle, the discharge nozzle having a plurality of conduits for directing the metered quantity of ink;   heating the metered quantity of ink at the plurality of conduits to evaporate the carrier liquid; and   discharging the plurality of suspended particles from the discharge nozzle onto the substrate;   wherein the plurality of suspended particles are deposited on the substrate in substantially solid form.   
     
     
         9 . The method of  claim 8 , wherein the step of pulsatingly energizing the dispenser results in heating the chamber with a plurality of energy bursts. 
     
     
         10 . The method of  claim 8 , wherein the step of pulsatingly energizing the dispenser further comprises energizing a piezoelectric element. 
     
     
         11 . The method of  claim 8 , wherein the step of providing liquid ink to the chamber further comprises supplying ink from a reservoir to the chamber. 
     
     
         12 . The method of  claim 8 , wherein the step of receiving the metered quantity of ink at the discharge nozzle further comprises receiving the metered quantity of ink at an inlet to the conduit, transporting the metered quantity of ink through the conduit and substantially evaporating the carrier liquid as the metered quantity of ink is transported through the conduit. 
     
     
         13 . The method of  claim 8 , wherein the step of discharging the plurality of suspended particles from the discharge nozzle further comprises selectively heating the discharge nozzle to discharge the suspended particles. 
     
     
         14 . The method of  claim 13 , wherein the step of heating the discharge nozzle further comprises pulsatingly heating the discharge nozzle. 
     
     
         15 . The method of  claim 8 , wherein the step of discharging the plurality of suspended particles further comprises using a piezoelectric effect on the discharge nozzle to deposit the suspended particles onto the substrate. 
     
     
         16 . The method of  claim 15 , wherein using the piezoelectric effect further comprises mechanically stressing the discharge nozzle. 
     
     
         17 . The method of  claim 8 , wherein the step of pulsatingly energizing the dispenser further comprises controlling the quantity of dispensed ink by controlling at least one of duration, intensity, or frequency of the pulse energy.