JP2011181271A - Esd organic el device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ESD organic EL device and a method for improving a film forming rate into a large area by adjusting distances between a processed object and each nozzle part. <P>SOLUTION: Voltage is applied to a solution in which an organic material is solved, and spray liquid having charges generated by the application is sprayed toward the processed object. In application between the processed object and a mounting part mounting it, the plurality of nozzle parts having the solution and spray openings are used for spraying operation. The volatilization of solvent is promoted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ESD organic EL device and method for forming an organic material by an electrostatic spray method (ESD: Electrospray Deposition), and more particularly to an ESD organic EL device and method suitable for forming a large area.

  Although the current mainstream of semiconductors is silicon, organic EL (electroluminescence) is in the spotlight as the next generation semiconductor, and attention is focused on practical application to displays and lighting. In addition, vacuum evaporation of low-molecular organic EL materials is the mainstream as a method for manufacturing an organic EL display. In the future, in order to reduce the price, it is expected to produce a polymer organic EL material in the atmosphere (non-vacuum) by a coating (printing) process.

  A spin coater or slit coater has been used for large-area film formation of organic materials in a non-vacuum, but there is a problem that mixing occurs because the substrate is melted during lamination. For this reason, a large area film forming method in a non-vacuum which is less affected by the solvent has been awaited.

  The ESD method is a method for responding to this. The ESD method has been studied since around 1880 as one of non-vacuum film forming methods, and is applied in fields such as agricultural chemical spraying, liquid electrostatic coating machines, and thin film formation. Recently, Patent Document 1 discloses a technique applied to nanofibers. Patent Document 1 discloses a technique in which the raw material liquid deposited by periodically changing the polarity of the raw material liquid (supply liquid) with respect to one nozzle has an alternate polarity and is successfully deposited without mutual electrostatic repulsion. Disclosure.

JP 2009-13535 A

  Since the spray amount per nozzle in the ESD method is limited, in order to form a film with a large area and a short tact time, it is necessary to provide a plurality of nozzle portions. In general, it is known that the applied voltage required for the ESD method is proportional to the distance between the processing target and the nozzle portion. Here, in particular, when a plurality of nozzle portions are provided, it is desirable that the object to be processed and the nozzle portions be as close as possible in order to reduce the power required for spraying. On the other hand, when the distance between the object to be processed and the nozzle portion is reduced, the solvent of the spray liquid is not sufficiently volatilized, and there is a possibility that mixing with the underlayer and film thickness may vary after film formation.

  An object of the present invention is to provide an ESD organic EL device and method capable of adjusting a distance between a processing target and a nozzle unit and improving a film forming rate over a large area. is there.

  In order to achieve the object of the present invention, a voltage is applied to a solution in which an organic material is dissolved, a spray liquid having a charge generated by the application is sprayed toward a processing target, and the application is mounted on the processing target. The spraying is carried out with a plurality of nozzles having the solution and having a spraying port when promoting the vaporization of the solvent.

  In order to achieve the object of the present invention, in addition to the first feature, the promotion of volatilization is carried out by supplying a solvent volatilization promoting gas to the spray solution.

Furthermore, in order to achieve the object of the present invention, in addition to the second feature, the third feature is that the solvent volatilization promoting gas is caused to flow along the solution in the nozzle portion.
In order to achieve the object of the present invention, in addition to the second feature, the fourth feature is that the solvent volatilization promoting gas is an inert gas such as nitrogen or dry air.
Furthermore, in order to achieve the object of the present invention, in addition to the first feature, the fifth feature is that the promotion of volatilization is performed by heating the solution or the spray solution.

In order to achieve the object of the present invention, in addition to the second feature, the heating is performed by heating the solvent volatilization promoting gas, and the heated solvent volatilization promoting gas is supplied to the spray liquid. This is a sixth feature.
Furthermore, in order to achieve the object of the present invention, in addition to the sixth feature, the seventh feature is that the heating is performed by a lamp provided around the nozzle portion.

  In order to achieve the object of the present invention, in addition to the first feature, an eighth feature is to adjust the spray angle of the spray liquid.

  Furthermore, in order to achieve the object of the present invention, in addition to the first feature, the application is characterized in that a voltage having a different polarity is applied between adjacent nozzle portions.

  ADVANTAGE OF THE INVENTION According to this invention, the distance between a process target and a nozzle part can be adjusted, and the ESD organic EL apparatus and method which can improve the film-forming rate to a large area can be provided.

It is a figure which shows one Embodiment of the ESD organic electroluminescent apparatus of this invention. It is a figure which shows 1st Embodiment of the solvent volatilization acceleration | stimulation means of this invention, and has shown the part of the nozzle part, and the mounting part of a display substrate. It is a figure which shows 2nd Embodiment of the solvent volatilization acceleration | stimulation means of this invention, and has shown the part of the nozzle part, and the mounting part of a display substrate. It is a figure which shows one Embodiment of the spray angle adjustment means of this invention, and has shown the part of the nozzle part, and the mounting part of a display board. It is the figure which showed one Embodiment of the spraying part 10 which has a solvent volatilization acceleration | stimulation means and spray angle adjustment means of this invention. It is a figure which shows the 2nd Example using the alternating voltage from which the phase mutually shifted 180 degree | times as an applied voltage to a solution. It is a figure which shows the principle of ESD method. It is a figure explaining the electrostatic repulsion which generate | occur | produces between adjacent nozzle parts.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an ESD organic EL device 100 according to the present invention, and shows all the components used in the embodiments of each part of the present embodiment. Therefore, the component which is not implemented by embodiment of each part is also included.
The ESD organic EL device is roughly divided into a spray unit 10 for spraying an organic EL solution, and a processing target (display substrate, film, etc.) conveyed from another adjacent processing device (not shown). Receiving the information from the sensor in each part, the stage part 20 for mounting the substrate part, the mask part 30 for defining the processing part of the display substrate, the facility part 40 having facilities for supplying or driving necessary parts to each part It has the control apparatus 50 and the base 60 which control a facility part etc.

  The spray unit 10 includes a nozzle 11 having a metal capillary 11b that sprays a solution 12 in which an organic EL material (solute) is dissolved in a solvent from a spray port 11a, and a gas flow path 11c through which a gas 16 flows around the metal capillary. , A guard ring 13 that defines the spraying range of the spray liquid 12d sprayed with charge from the nozzle section provided in each nozzle section, a lamp 17 that warms the solution in the nozzle section, and measures the amount of solution in the nozzle section. A liquid amount sensor 14, a spray amount sensor 15 that measures the amount of spray from the nozzle unit 11, and a solution temperature sensor 18 that measures the temperature of the solution are included. In order to avoid complexity, only one nozzle unit 11 is shown in FIG.

  The stage unit 20 includes a stage 21 that is grounded and made of a conductor on which the display substrate P is placed, and an imaging unit 22 that images the alignment mark 23 on the display substrate P.

  The mask unit 30 includes a mask 31 for forming a film 31b at a desired position on the display substrate P placed on the stage 21, a collimator 32 for focusing the sprayed solution 12 on the opening 31a on the mask 31, and a display substrate. P has a substrate protection shutter 33 for preventing excessive spraying and liquid dripping at the start of film formation.

  The facility unit 40 generates a predetermined voltage to the solution supply source 12T that supplies the solution 12 to each nozzle unit 11 of the spray unit 10, the spray voltage generation source 11D that generates the spray voltage of each nozzle unit 11, and the guard ring 13. The guard ring voltage generation source 13D, the gas supply source 16T for supplying the gas 16 to the nozzle unit, the lamp power source 17D for supplying the necessary power to the lamp 17, the substrate position control drive unit 21K for moving the stage 21, and the position of the mask 31 A mask position driving unit 31K for adjustment, a collimator voltage generation source 32D for generating a voltage to be applied to the collimator 32, and a substrate protection shutter driving unit 33K for driving the 33 substrate protection shutter.

The control device 50 includes a control unit 51, a peripheral device 52 such as a recording device 52A for recording the operation results of the ESD organic EL device such as measurement results and normal / abnormal states of each unit, and a display device 52B for displaying them.
The control unit 51 includes various control programs 53P, information 53J such as measurement results and the operating state of the ESD organic EL device, and data 53 for controlling each unit, control data 53D such as conditions, the facility unit 40 and the surroundings. It has an interface 54 that exchanges signals with the device 52 and various sensors, and a control unit (CPU) 55 that manages and controls these interfaces. Each control means is composed of a component of the facility section, its control program, control data, and a control unit for controlling it. For example, the solvent volatilization promoting means described later includes a gas supply source 16T, a gas control program 16P, control data 53D necessary for gas control, and a control unit. The lamp heating means described later includes a lamp power source 17D, a solution temperature control program 17P, control data 53D necessary for solution temperature control, and a control unit. Further, the spray angle adjusting means includes a guard ring voltage source 13D, a spray range control program 13P, control data 53D necessary for spray range control, and a control unit. The same applies to other control means.

  The control program includes the solution supply source 12T based on the measurement results from the liquid amount sensor 14, the spray amount sensor 15, the solution temperature sensor 18 and the imaging means 22, the conditions built in the control data 53D, and the like. A solution supply program 12P for controlling and managing the amount of solution in the nozzle unit 11; a spray amount control program 11P for controlling the spray voltage generating source 11D to spray the solution 12 from the nozzle unit 11; and controlling the guard ring voltage generating source 13D for spraying. Spray range control program 13P for defining the range, gas control program 16P for controlling the gas supply source 16T to supply the necessary gas, solution temperature control program 17P for controlling the lamp 17 to control the solution 12 to a predetermined temperature, substrate A table for controlling the position control drive unit 21K to perform positioning and film formation by the alignment mark 23. A substrate position control program 21P for moving the substrate P at a constant interval or a constant speed, a mask position adjustment program 31P for controlling the mask position driving unit 31K to adjust the position of the mask 31, and a collimator voltage generation source 32D for controlling the spray liquid 12d. A spray liquid converging program 32P for converging and a substrate protection shutter drive unit 33K are controlled to have a display substrate protection program 33P for preventing excessive spraying and liquid dripping on the display substrate P.

  With the configuration shown in FIG. 1, nozzle portions are provided in a row corresponding to the width of the display substrate, the display substrate P is moved from the front side to the back side of the paper surface, and the solution 12 is sprayed continuously or intermittently. A pattern defined by the plurality of openings 31a is formed on the display substrate.

  First, the basic principle of ESD will be described with reference to FIG. When a positive (negative) voltage of several kV is applied to the metal capillary 11b, an electrostatic force having a surface tension or a positive charge acts on the liquid. When the electrostatic force increases and the surface tension is exceeded and Rayleigh splitting occurs, the solution 12 is distorted into a conical shape (referred to as a Taylor cone) 12a. The liquid injection breaks due to the instability of the positively charged liquid column 12b generated from the tip of the Taylor cone, and a droplet 12c having a positive charge is generated therefrom. The solvent of the droplets volatilizes (vaporizes) and the electrification density increases, and the droplets repeatedly break up due to electrostatic (Coulomb) repulsion. The dried particles are attracted to the grounded conductor 21a (stage 21 in FIG. 1) to form a thin film on the glass display substrate P provided on the conductor 21a. In the following description, the Taylor cone 12a, the liquid column 12b, and the liquid droplet 12c are collectively referred to as a spray liquid 12d. Although the voltage is applied to the metal capillary 11b in this figure, the voltage may be applied directly to the solution.

In order to shorten the distance between the display substrate (processing target) and the nozzle portion, a solvent volatilization promoting means for promoting the volatilization of the solvent of the droplets is necessary. This is because when the distance is shortened, the time for volatilizing the solvent is shortened and the volatilization becomes insufficient.
As the solvent volatilization promoting means, the solution 12 and the spray liquid 12d are heated.

FIG. 2 is a diagram showing a first embodiment of the solvent volatilization promoting means, and shows a nozzle portion 11 and a display substrate P mounting portion. FIG. 2 shows a multi-solution capillary 11b that can be sprayed separately to form a film with solutions 12A and 12B having two types of organic materials.
This embodiment will be described with reference to FIGS. In FIG. 2, the nozzle portion 11 has a metal capillary 11b, a gas flow path 11c for the solvent volatilization promoting gas 16, and a spray port 11a. A solvent volatilization promoting gas 16 having a predetermined speed and a predetermined flow rate is supplied from the gas supply source 16T shown in FIG. 1 to the gas flow path 11c of the nozzle portion and sprayed from the spray port.

The solvent volatilization promoting gas is heated to a predetermined temperature by the gas supply source 16T. Therefore, the solvent volatilization promoting gas warms the solution 12 while passing through the gas flow path 11c, and warms the spray liquid 12d after spraying. Therefore, the solvent volatilization promoting gas 16 has a function of heating means. When the temperature of the solution 12 or the spray liquid 12d is increased, the solvent is volatilized and the solute is dried.
On the other hand, the sprayed gas comes into contact with the Taylor cone 12a and the droplets 12c and is dried, and at the same time, the Taylor cone 12a and the droplets 12c are separated by the gas flow (shearing force) to promote drying. Therefore, the solvent volatilization promoting gas 16 also has a function of increasing the spray amount.

  The inner diameter ID of the 1 mm thick metal capillary 11b according to the present embodiment is 0.4 to 0.5 mm, and the outside of the gas flow path 11c is further increased by 0.15 mm. If it is 0.15 mm or more, the spray becomes unstable. Further, the gas flow rate GV at this time is about 2 L / min, and if it is small, the spray becomes unstable, and if it is large, the spray concentration decreases. In the case of an organic material, the gas temperature is used at 150 ° C. or lower in order to avoid deterioration of the organic material. In this embodiment, nitrogen is used as the solvent volatilization promoting gas. As other solvent volatilization promoting gases, inert gases other than nitrogen and dry air can be used.

  As described above, according to the present embodiment, for example, the distance L between the display substrate P and the nozzle portion can be reduced from about 150 mm to about 50 mm.

  Further, since the applied voltage between the display substrate P and the nozzle portion is proportional to the distance L, the applied voltage can be reduced to 1/3, and the spray voltage generating source 11D shown in FIG. This can contribute to downsizing and cost reduction of the ESD organic EL device.

  Furthermore, according to this embodiment, since nitrogen which is inert gas is used as gas, deterioration of an organic material can be reduced.

FIG. 3 is a diagram showing a second embodiment of the solvent volatilization promoting means. The difference of the second embodiment from the first embodiment is the following two points, and the other points are the same as those of the first embodiment.
The first point is that the solvent volatilization promoting gas is not heated.
The second point is that instead of heating with a solvent volatilization promoting gas, a lamp 17 is provided around the metal capillary 11b to heat the solutions 12A and 12B. The heating effect in this case is directly only the solution, but the temperature of the spray liquid 12d is also high. There is an advantage that the temperature control of the solution can be controlled more stably than the gas.

  Also in the second embodiment, the same effects as those of the first embodiment can be basically obtained.

  In the first and second embodiments described above, the solvent volatilization promoting gas is supplied along the capillary 11b. However, the solvent volatilization promoting gas may flow through the entire spray unit 10. In this case, the display substrate P and the mask 31 (see FIG. 1) are cooled as necessary.

In the above embodiment, the applied voltage between the display substrate and the nozzle portion can reduce the distance L, but generally the spray (film formation) area is reduced.
Therefore, a spray angle adjusting means for adjusting the spray angle is necessary.

  FIG. 4 is a view showing an embodiment of the spray angle adjusting means. FIG. 4 is a view in which a guard ring 12 for adjusting the spray angle is provided between the display substrate P and the nozzle portion 11 in the second embodiment of the solvent volatilization promoting means shown in FIG. A voltage having the same polarity as that of the spray liquid 12d is applied to the guard ring 13. When the voltage is increased, the spray liquid 12d is repelled and the spray angle is decreased. Conversely, when the voltage is decreased, the rebound is weakened and the spray angle is increased.

  Another method is to adjust the spray rate of the solvent volatilization promoting gas. That is, if the spraying speed is increased, the solvent volatilization promoting gas flows in parallel with the spray liquid 12d and presses the spray angle of the spray liquid. .

  According to the embodiment of the spray angle adjusting means described above, the spray angle can be adjusted, and in particular, the spray angle can be adjusted in order to maintain the uniformity of the film.

  By using both the solvent volatilization promoting means and the spray angle adjusting means described above, it is possible to provide an ESD organic EL device and method that can maintain film uniformity while improving the film formation rate.

  FIG. 5 is a view showing an embodiment of the spray unit 10 having the solvent volatilization promoting means and the spray angle adjusting means described above. FIG. 5A shows the configuration of the spray section when viewed from the paper surface side of FIG. 1, and FIG. 5B shows the arrangement of the nozzle section 11 when viewed from the top of the apparatus. The nozzle unit 11 may be a two-liquid type as shown in FIG. 2 or a one-liquid type as shown in FIG. As shown in FIG. 5 (a), the spray unit 10 arranges the nozzle units 11 in a column shape in the row direction corresponding to the width W of the display substrate P (six in this embodiment). Are arranged in a plurality of rows (4 rows in this embodiment) in the row direction, and a total of 24 are arranged in a matrix. For the description to be described later, reference numerals A1, A2,... Are attached to the columnar arrangement in the row direction in order from the top. FIG. 5A shows the state of the A1 column.

  In FIG. 5B, the white circle mark indicates the applied voltage V1, and the black circle mark indicates the nozzle portion 11 applied with the applied voltage V2. Further, the solvent 12 is supplied in the direction of the arrow 12k from the gas supply pipe 16h by the solution supply pipe 12h provided for the solution 12 in the unit of A1 to A4. When the solution is two liquids as shown in FIG. 2, the solution supply pipe 12h is a double pipe. Although the number of columns in the row direction is four in this embodiment, it may be one, or the number of columns may be further increased in some cases.

  By using the solvent volatilization promoting means shown in FIG. 2 or FIG. 3 in the spray unit 10 shown in FIG. 5, the distance L between the display substrate P and the nozzle unit 11 can be reduced, and the spray shown in FIG. To provide an ESD organic EL device and method capable of expanding the spraying range by using the angle adjusting means and maintaining the uniformity of the film while improving the film forming rate by increasing the density at which the nozzle portions are arranged. it can.

  In FIG. 5 (b), a plurality of nozzle portions are arranged in a matrix. As shown in FIG. 8, sprayed charged particles having the same polarity are electrostatically repelled between a plurality of adjacent nozzle portions, the amount of spray from the central nozzle portion is suppressed, and the spray liquid 12d is in the central portion. A non-existing or low-density region 12n is formed, and a region 12m that is difficult to form on the display substrate P is generated. Therefore, it is not possible to form a uniform film even if they are simply arranged in a matrix. Therefore, voltage application means for applying a voltage between adjacent nozzle portions is necessary so that electrostatic repulsion does not occur.

In the present embodiment, the applied voltage V1 and the applied voltage V2 are means for always applying different polarities. That is, by applying a voltage having a different polarity between the adjacent nozzle portions 11, the spray liquid 12d sprayed from each adjacent nozzle portion has a different polarity and suppresses or causes the occurrence of electrostatic repulsion with each other. There is no. Therefore, the spray liquid 12d having a constant profile can be stably obtained from each nozzle portion. FIG. 5 shows a state where a negative voltage is applied to the applied voltage V1 and a positive voltage is applied to the applied voltage V2. Further, as described with reference to FIG. 1, the suppression voltage applying means includes a spray voltage generator 11D, a spray amount control program 11P, control data 53D necessary for spray amount control, and a control unit.
As a result, in this embodiment, a uniform film having patterning by the mask 31 can be formed.

  Further, in the above embodiment, an example of four columns A1 to A4 is shown. As the number of columns increases, the moving speed of the display substrate can be increased, but only one column of A1 may be used.

Next, an example of the voltages V1 and V2 applied to the solution for forming a uniform film in the apparatus configured as described above will be described with reference to FIG. These waveform data are stored as control data 53D shown in FIG. 1, and are formed when an operator inputs a condition via the display device 52B or the like according to the processing content.
FIG. 6 shows an example of the applied voltages V1 and V2, and shows an example of using an AC voltage having a constant peak value that is 180 degrees out of phase with each other. 6A shows a rectangular wave voltage V having a constant peak value, and FIG. 6B shows a sine wave voltage V having a constant peak value. Various other applied voltage applications can be considered. For example, a DC pulse voltage having a constant peak value may be used. The use of AC voltage not only prevents electrostatic repulsion, but also sprays with different polarities alternate, so they accumulate while neutralizing the total charge on the substrate without repelling each other, so there is no charge up. A film can be formed. The AC frequency is preferably a low frequency. If it is several hundred Hz or more, the adhesion to the display substrate is lost. Preferably, it is 60 Hz or less.

  As described above, according to the embodiment of the present invention described above, since spraying can be performed using a plurality of nozzle portions, it is possible to form a film uniformly over a large area such as a display device. A pattern having a film formation can be formed.

  The present invention can be applied to manufacturing apparatuses such as organic thin film solar cells, organic EL lighting, digital signage, and organic sensors in addition to display apparatus manufacturing apparatuses.

DESCRIPTION OF SYMBOLS 10: Spray part 11: Nozzle part 11a: Spray port 11b: Metal capillary 11c: Gas flow path 11D: Spray voltage generation part 12: Solution 12a: Taylor cone 12b: Liquid column 12c: Droplet 12d: Spray liquid 12h: Solution Supply pipe 12T: Solution supply part 13: Guard ring 13D: Guard ring voltage generation part 14: Liquid quantity sensor 15: Spray quantity sensor 16: Gas supply source 16h: Gas supply pipe 17: Lamp 20: Stage part 21: Stage 21K: Substrate position control drive unit 22: Alignment mark imaging means 23: Alignment mark 30: Mask unit 31: Mask 31a: Mask opening 31K: Mask position drive unit 32: Collimator 32D: Collimator voltage generator 33: Substrate protection shutter 33K: Substrate protection shutter drive unit 40: Facility unit 50: Control Device 51: Control unit 52: Peripheral device 52A: Recording device 52B: Display device 53: Memory 53D: Data for controlling each unit, control data such as conditions 53P: Control program 53J: Operation of measurement results and ESD organic EL device Information such as status 54: Interface 55: Control unit (CPU)
60: Base 100: ESD organic EL device A1, A2...: Nozzle part column number P: Display substrate V1, V2: Applied voltage to solution V3, V4: Guard ring applied voltage.

Claims (14)

Applying a voltage to a solution in which an organic material is dissolved in a solvent, spraying a spray liquid having a charge generated by the application toward the processing target to generate the spray liquid, and a mounting section for mounting the processing target; In an ESD organic EL device having voltage application control means for performing the application between the mounting unit and controlling the application,
4. The ESD organic EL device according to claim 1, wherein the spray unit includes a plurality of nozzle units having the solution and spray ports, and further includes solvent volatilization promoting means for promoting volatilization of the solvent.   2. The ESD organic EL device according to claim 1, wherein the solvent volatilization promoting means is means for supplying a solvent volatilization promoting gas to the spray liquid.   3. The ESD organic EL device according to claim 2, wherein the solvent volatilization promoting means is means for supplying the solvent volatilization promoting gas to a gas flow path provided along the solution of the nozzle portion.   The ESD organic EL device according to claim 2, wherein the solvent volatilization promoting gas is an inert gas or dry air.   4. The ESD organic EL device according to claim 3, wherein the flow path has a width of 0.15 mm or less, and the flow rate of the solvent volatilization promoting gas is about 2 L / min.   The ESD organic EL device according to claim 1, wherein the solvent volatilization promoting means is a heating means for heating the solution or the spray liquid.   The ESD organic EL device according to claim 2, wherein the heating means is means for heating the solvent volatilization promoting gas.   The ESD organic EL device according to claim 6, wherein the heating means is a lamp provided around the nozzle portion.   The ESD organic EL device according to claim 1, further comprising a spray angle adjusting unit that adjusts a spray angle of the spray liquid.   The ESD organic EL device according to claim 1, wherein the voltage application control unit applies voltages having different polarities between adjacent nozzle portions. An ESD organic EL method in which a voltage is applied to a solution in which an organic material is dissolved, a spray liquid having an electric charge generated by the application is sprayed toward a processing target, and the application is performed with a mounting portion on which the processing target is mounted. In
The ESD organic EL method, wherein the spraying is performed by a plurality of nozzle portions having the solution and having a spraying port to promote volatilization of the solvent.   The ESD organic EL method according to claim 11, wherein the promotion of volatilization is performed by supplying a solvent volatilization promoting gas to the spray liquid.   The ESD organic EL method according to claim 12, wherein the solvent volatilization promoting gas is an inert gas or dry air.   The ESD organic EL method according to claim 11, wherein the promotion of volatilization is performed by heating the solution or the spray solution.

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