VAPORIZING OR ATOMIZING OF ELECTRICALLY CHARGED DROPLETS
A vaporizing apparatus includes a chamber, a nozzle for dispersing a liquid into droplets, an electrode electrically isolated from the nozzle, and a heater for generating a vapor by applying heat to the droplets. The voltage source applies charges to the droplets by applying a voltage between the nozzle and the electrode. The vaporizing apparatus may be used to devices that deposit organic or inorganic thin films by chemical vapor deposition and/or atomic layer deposition processes, devices for supplying precursor materials that are deposited to form a thin film in organic light emitting diodes, devices that supply organic or inorganic precursor materials for encapsulation, and devices for supplying organic or inorganic polymer.
1 . A vaporizing apparatus comprising:
a nozzle having one end connected to a source of liquid to receive liquid and another end configured to disperse the receive liquid into droplets;
a chamber connected to the other end of the nozzle to receive the droplets; and
a signal line between a voltage source and the nozzle to apply a voltage signal to the nozzle,
wherein the nozzle is configured to electrically charge the droplets responsive to receiving the voltage signal via the signal line.
2 . The vaporizing apparatus of claim 1 , further comprising an electrode within the chamber electrically isolated from the node, a first voltage applied across the electrode and the nozzle.
3 . The vaporizing apparatus of claim 2 , wherein the voltage source a second voltage across the nozzle and an interior wall of the chamber.
4 . The vaporizing apparatus of claim 2 , wherein the voltage source applies the second voltage across the electrode and an interior wall of the chamber.
5 . The vaporizing apparatus of claim 1 , wherein the voltage source applies a DC signal or an AC signal to the nozzle.
6 . The vaporizing apparatus of claim 5 , wherein a frequency, pulse width, polarity and duty cycle of the AC signal is determined based on a flow rate of the liquid into the nozzle and a size of the chamber.
7 . The vaporizing apparatus of claim 2 , wherein the electrode is disposed at an outlet of the chamber located opposite to the nozzle.
8 . The vaporizing apparatus of claim 1 , further comprising a heater for generating vapor by applying heat to the droplets.
9 . The vaporizing apparatus of claim 8 , further comprising a charge neutralizer connected to an outlet of the chamber for neutralizing charges contained in the vapor.
10 . The vaporizing apparatus of claim 8 , further comprising a vapor reservoir connected to an outlet of the chamber for storing the vapor discharged from the chamber.
11 . The vaporizing apparatus of claim 8 , further comprising a feedback sensor configured to sense a polarity of the vapor discharged from the chamber, and send a feedback signal indicative of the polarity to the voltage source.
12 . A method of vaporizing a liquid, comprising:
injecting a liquid into one end of a nozzle from a source of the liquid;
generating a voltage signal at a voltage source;
generating droplets of a liquid at the other end of the nozzle by dispersing the liquid into a chamber; and
applying the voltage signal to the nozzle via a signal line to electrically charge the droplets.
13 . The vaporizing method of claim 14 , further comprising applying a first voltage across the nozzle and an electrode.
14 . The vaporizing method of claim 13 , further comprising a second voltage across the nozzle and an interior wall of the chamber.
15 . The vaporizing method of claim 12 , wherein the voltage signal is a DC signal or an AC signal.
16 . The vaporizing method of claim 12 , further comprising heating the droplets to generate vapor.
17 . The vaporizing method of claim 16 , further comprising controlling a polarity of the vapor by controlling a flow rate of the liquid through the nozzle.
18 . The vaporizing method of claim 16 , further comprising neutralizing charges of the vapor.
19 . The vaporizing method of claim 14 , further comprising:
generating a feedback signal at a sensor indicative of a polarity of the vapor; and
controlling the voltage signal based on the feedback signal.
20 . The vaporizing method of claim 16 , further comprising discharging the vapor to a surface of a substrate to form a layer on the surface of the substrate, wherein the vapor is electrically charged to selectively coat on the surface of the substrate depending on a polarity of the surface.
21 . An apparatus for coating a target surface, comprising:
an ejection apparatus for ejecting charged droplets or vapor of material onto a target surface;
a shadow mask placed between the ejection apparatus and the target surface to cover selective portions of the target surface, wherein the shadow mask is placed at a voltage potential to repel the charged droplets or vapor; and
at least one voltage source for charging the shadow mask and the droplets or vapor of material.
22 . The apparatus of claim 21 , wherein the ejection apparatus comprises a nozzle having one end connected to a source of liquid to receive liquid and another end configured to disperse the receive liquid into droplets.
23 . The apparatus of claim 21 , wherein the ejected material comprises at least one of photoresist and liquid polymer.
24 . A method for coating a target surface, comprising:
placing a shadow mask to cover a selected portion of the target surface;
placing shadow mask at a voltage potential by connecting the shadow mask to a voltage source; and
ejecting, onto the target surface, droplets or vapor of material charged with a polarity to receive repulsive force from the shadow mask.
25 . The method of claim 24 , further comprising:
injecting a liquid into one end of a nozzle from a source of the liquid;
generating a voltage signal at a voltage source;
generating droplets of a liquid at the other end of the nozzle by dispersing the liquid into a chamber; and
applying the voltage signal to the nozzle via a signal line to electrically charge the droplets.
26 . The method of claim 24 , wherein the ejected material comprises at least one of photoresist and liquid polymer.