JPH0713170A - Spacer particle spraying method and spraying device of liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the spacer particle spraying method and spraying device of a liquid crystal display device capable of depositing spacer particles at always a uniform density on substrates without varying the spraying density between production lots. CONSTITUTION:The spacer particles 6 to be arranged between the substrates sealed with a liquid crystal of the liquid crystal display device are mixed with a volatile solvent to form a soln. contg. the spacer particles 6. The soln. contg. the spacer particles 6 is then blown from a nozzle 46 to the surface of the substrate 4 arranged within a spraying chamber 32 and the solvent in the soln. blown to the surface of the substrate 4 is allowed to evaporate. A washing liquid is supplied to a liquid feed pipe 44 for sending the soln. to the nozzle 46 after blowing of the soln. from the nozzle 46. An explosionproof gas is thereafter supplied to this liquid feed pipe 44. This explosionproof gas is blown from the nozzle 46 into the spraying chamber 32, by which the spacer particles 6 remaining in the pipe 44 and the nozzle 46 are blow out together with the washing liquid into the spraying chamber 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for spraying spacer particles of a liquid crystal display device, and more particularly, to a liquid crystal display device having no point defects.
The present invention relates to a spacer particle spraying method and a spraying device for depositing spacer particles on a surface of a substrate at a uniform density.

[0002]

2. Description of the Related Art In a liquid crystal display (LCD), liquid crystal is sealed between transparent glass substrates. In order to make the liquid crystal layer thickness uniform along the glass substrates, spacer particles having a substantially uniform particle size are arranged between the glass substrates.

Therefore, in the process of manufacturing an LCD, it is necessary to spray spacer particles on the surface of one glass substrate. There are a dry method and a wet method as a method of spraying spacer particles on the surface of one glass substrate. In the dry method, the spacer particles are applied to the surface of the glass substrate by spraying the spacer particles in a dried state on the surface of the glass substrate.

In the wet method, after the spacer particles are mixed with a solvent, the spacer particles are sprayed from the nozzle toward the glass substrate to volatilize the solvent and deposit only the spacer particles on the surface of the glass substrate. Compared with the dry method, the wet method has less variation in the dispersion density of the spacer particles on the surface of the glass substrate, and is therefore widely used in the manufacturing process of LCDs.

FIG. 4 shows a schematic view of a spacer particle spraying apparatus by a wet method. As shown in FIG. 4, the conventional spacer particle spraying device 2 has a spray chamber 8 in which one transparent glass substrate 4 constituting the LCD is installed. A heater 10 is installed in the spray chamber 8 to keep the spray chamber at a constant temperature. A nozzle 22 for spraying a solution in which spacer particles and a solvent are stirred and mixed by a stirrer 14 or the like in a mixing tank 12 onto the surface of the substrate 4 is attached to the upper part of the spray chamber 8.

A liquid feed pipe 16 for feeding the solution in the mixing tank to the nozzle 22 is connected to the mixing tank 12. A three-way valve 18 is attached in the middle of the liquid supply pipe 16. A return pipe 26 is connected to the three-way valve 18. A pump 28 is attached in the middle of the return pipe 26, and when the liquid supply to the nozzle 22 is stopped by the three-way valve 18 in order to stop spraying from the nozzle port 24 of the nozzle 22, mixing is performed. The solution in the tank 12 is configured to return to the inside of the mixing tank 12 through the return pipe 26 by the suction force of the pump 28.

[0007]

However, according to the spacer particle spraying method using the conventional spraying device 2 as described above,
Until the dispersion of the spacer particles on the glass substrate 4 is completed and the next glass substrate 4 is set in the dispersion chamber 8,
In order to stop spraying from the nozzle port 24 of the nozzle 22, the liquid supply to the nozzle 22 is stopped by the three-way valve 18. Therefore, there is a possibility that the solution remains in the flow path 20 from the three-way valve 18 to the nozzle port 24, the solution is dried, and the spacer particles are precipitated and condensed on the inner wall of the flow path 20. If spacer particles settle and condense on the inner wall of the channel, the nozzle may be clogged, and the next time the solution is sprayed from the nozzle,
There is a possibility that the dispersion density on the substrate 4 varies.
The dispersion of the dispersion density may cause non-uniform adhesion of the spacer particles 6 to be deposited on the surface of the substrate 4, and hinder the uniform thickness of the liquid crystal layer in the completed LCD.

When the spacer particles condensed in the flow path 20 are blown off by the spray from the nozzle opening 24 of the nozzle 22 and adhere to the substrate 4, a mass of spacer particles 6 adheres to the substrate 4. , There is a possibility that it may become a point defect of the completed LCD. Further, in the wet method, it has been the mainstream to use chlorofluorocarbon as a solvent, but from the viewpoint of environmental protection, there is a tendency to use an alcoholic solvent with the complete elimination of chlorofluorocarbon. Therefore, after spraying the spacer particles, it is necessary to replace the interior of the spray chamber 8 with an explosion-proof gas such as nitrogen gas. Therefore, the device 2
In addition, a new nitrogen gas replacement nozzle had to be provided, and a major remodeling of the device was necessary.

The present invention has been made in view of the above circumstances, and a liquid crystal display device in which the dispersion density does not vary between manufacturing lots and the spacer particles can always be adhered to the substrate at a uniform density. It is an object of the present invention to provide a spacer particle spraying method and a spraying device.

[0010]

In order to achieve the above object, a method for dispersing spacer particles in a liquid crystal display device according to the present invention comprises:
A step of mixing spacer particles, which are to be arranged between the substrates in which liquid crystal is sealed in the liquid crystal display device, with a volatile solvent to form a solution containing the spacer particles, and a surface of the substrate arranged in the spray chamber. And spray the solution containing the spacer particles from a nozzle to volatilize the solvent in the solution that is sprayed on the surface of the substrate, and after spraying the solution from the nozzle, blow the solution to this nozzle Supplying gas and spraying explosion-proof gas from the nozzle into the spray chamber.

In the method of the present invention, after the solution is sprayed from the nozzle, the cleaning liquid is flown in the liquid feed pipe for feeding the solution to the nozzle, and then the explosion-proof gas is introduced into the spray chamber through the liquid feed pipe and the nozzle. It is preferable to spray and wash the cleaning liquid remaining in the liquid supply pipe and the nozzle into the spray chamber.

In order to achieve the above object, the spacer particle sprinkling device of the present invention comprises mixing spacer particles, which are to be arranged between substrates in a liquid crystal display device in which liquid crystal is sealed, with a volatile solvent to form spacer particles. A mixing tank for forming a solution containing a spacer particle, a spraying chamber in which a substrate to be coated with spacer particles is to be installed, and a solution containing the spacer particle toward the surface of the substrate installed in the spraying chamber. A nozzle arranged so as to spray, a liquid sending pipe for sending the solution from the mixing tank to the nozzle, a valve means for controlling the liquid sending from the mixing tank to the liquid sending pipe, and this valve means, When the liquid supply to the liquid supply pipe is stopped, an explosion-proof gas is supplied to the liquid supply pipe, and an explosion-proof gas supply means for spraying the explosion-proof gas from the nozzle into the spray chamber is provided. .

In the device of the present invention, when the liquid supply to the liquid supply pipe is stopped by the valve means, before the explosion-proof gas is supplied from the explosion-proof gas supply means to the liquid supply pipe, It is preferable that the liquid supply pipe further includes a cleaning liquid supply means for supplying the cleaning liquid.

[0014]

In the spraying method using the spacer particle spraying device according to the present invention, after the solution is sprayed from the nozzle, the explosion-proof gas is supplied to the liquid feed pipe for sending the solution to the nozzle, and the explosion-proof gas is supplied from the nozzle. Since it is sprayed into the above spraying room,
By supplying this explosion-proof gas, the remaining solution is blown off into the liquid supply pipe and the flow path inside the nozzle.
Therefore, the spacer particles do not condense and clog the nozzle in the liquid supply pipe and the flow path inside the nozzle.
Therefore, there is no dispersion variation among manufacturing lots. Further, for the same reason, the condensed spacer particles are not deposited on the substrate, the point defects of the LCD are effectively prevented, and the manufacturing yield is improved. Furthermore, since the explosion-proof gas is blown into the spray chamber by using the spray nozzle, it is not necessary to modify the device such as newly providing an explosion-proof nozzle.

Further, even if the concentration of the spacer particles in the solution is increased, the nozzles are not clogged, so the spraying time can be shortened by the amount of the increased concentration. Furthermore, since it is not necessary to control the spraying interval, the solution can be stored while being set for a long time. This contributes to saving spacer solution.

Further, it is not necessary to regularly replace and clean the pipe and the nozzle, which contributes to cost reduction. Furthermore, even when spraying a solution in which the type of spacer particles, the type of solvent or the concentration of spacer particles is changed, it is not necessary to prepare multiple nozzles, and it is possible to spray with a single nozzle. No need to replace the nozzle each time, and no need to remove the nozzle or pipe for cleaning. Moreover, since a single nozzle is sufficient, it also contributes to cost reduction.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The spacer particle spraying method and spraying device for a liquid crystal display device according to the present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a schematic cross-sectional view of a spacer particle spraying device according to an embodiment of the present invention, FIG. 2 is a flowchart showing a manufacturing process of an LCD according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the LCD according to the present invention.

First, the structure of a liquid crystal display (LCD) that requires a spacer particle spraying step will be described. As shown in FIG. 3, in the LCD 11, the liquid crystal 13 is enclosed between the transparent glass substrates 4 and 5 arranged substantially in parallel by the spacer particles 6 having a substantially uniform particle diameter. Note that FIG.
Among them, reference numeral 7 indicates an alignment film, and reference numeral 9 indicates a peripheral sealant. The sealant 9 is made of, for example, an epoxy resin or an ultraviolet curable resin.

The spacer particles 6 are for keeping the substrates 4 and 5 substantially parallel to each other and for making the thickness of the liquid crystal layer enclosed between these substrates uniform, and to have an insulating property with a uniform particle size. It is composed of spherical materials. The particle diameter and the specific material of the spacer particles 6 are not particularly limited in the present invention,
The spacer particles 6 have a particle diameter of, for example, 1 to 7 μm, and specific materials include ceramics, alumina, plastics, silica and the like.

Such a spacer 6 is necessary in LCDs of all modes, and particularly in STN mode LCDs, it is required to control the thickness of the liquid crystal layer to about ± 0.1 μm or less. Is essential. The spraying method using the spraying device of this embodiment shown below is effective for all LCDs including this STN mode.

Next, a manufacturing process for manufacturing the LCD shown in FIG. 3 will be described with reference to FIG. As shown in FIG. 2, first, a pair of transparent glass substrates are prepared, an aligning agent for aligning liquid crystal molecules is applied to the surfaces of these substrates, and an alignment treatment is performed (step 60). Next, in step 62, a sealant is applied to the peripheral surface of one of the substrates. Also, on the surface of the other substrate, step 64
In, the spacer particles are sprayed. The present invention is an invention relating to the spraying of the spacer particles performed in step 64, and an embodiment of the spraying device and the spraying method thereof will be described later.

Then, the sealant is applied to the surface of one of the substrates in this way, spacer particles are dispersed on the surface of the other substrate, and then the substrates are bonded together to cure the sealant (step 66). The thickness of the liquid crystal layer and its accuracy are determined at this point. Therefore, if the dispersion density of the spacer particles varies within the same production lot, or if the dispersion density differs between production lots, uneven thickness of the liquid crystal layer or deviation from the set value will occur. . The method and apparatus of the present invention can eliminate such inconvenience.

After the laminating step of step 66,
In step 68, the liquid crystal is sealed, and in step 70, the liquid crystal sealing port is sealed. Next, FIG.
Based on the above, a spacer particle spraying device and a spraying method using the same according to one embodiment of the present invention will be described.

As shown in FIG. 1, the spraying device 30 according to this embodiment has a spraying chamber 32 in which one transparent glass substrate 4 constituting the LCD is installed. In the spray room 32,
A heater 34 is installed to keep the spray chamber at a constant temperature. The heater 34 keeps the inside of the spray chamber 32 at a predetermined temperature. The temperature in the spray chamber 32 is determined depending on the volatilization temperature of the solvent mixed with the spacer particles. For example, when ethanol is used as the solvent,
It is set to 100 ° C or lower.

A nozzle 46 for spraying a solution in which the spacer particles and the solvent are mixed in the mixing tank 36 onto the surface of the substrate 4 is mounted above the spraying chamber 32. The distance between the nozzle port 48 of the nozzle 46 and the substrate 4 is determined by factors such as the size of the substrate 4 and the ability of the nozzle. When the size of the substrate 4 is A4 size, for example, 50.
~ 150 cm.

A stirrer 38 for stirring and mixing the solution is attached to the mixing tank 12, and liquid feeding pipes 40 and 44 for feeding the stirred and mixed solution to the nozzle 46 are connected thereto. A first three-way valve 42 is mounted between the liquid feed pipe 40 and the liquid feed pipe 44. Although omitted in FIG. 1, the liquid supply pipe 40 is provided with a branch passage,
The return pipe 26 and the pump 28 shown in FIG. 4 may be mounted.

A branch pipe 50 is connected to the first three-way valve 42. A second three-way valve 51 is connected to the branch pipe 50. An explosion-proof gas supply pipe 52 and a cleaning liquid supply pipe 54 are connected to the second three-way valve 51. The first three-way valve 42 and the second three-way valve 51 are electromagnetic valves, for example. The first three-way valve 42 switches between communication between the pipes 40 and 44 and communication between the pipes 50 and 44. Second
The three-way valve 51 connects the pipes 50 and 52 and the pipe 5
The communication is switched to 0, 54.

The explosion-proof gas supplied from the explosion-proof gas supply pipe 52 is not particularly limited, but an inert gas such as nitrogen is used. Cleaning liquid supply pipe 5
The cleaning liquid supplied from No. 4 is not particularly limited, and pure water is used, for example. An exhaust pipe 56 is connected to the spray chamber 32. A solenoid valve 58 is attached to the exhaust pipe 56, and when sprayed from the nozzle 46, the solenoid valve 5 is attached.
8 is closed, and after the spraying is completed, the solenoid valve 58 is opened to exhaust the solvent gas in the spray chamber 32 from the exhaust pipe 56.

Next, a spraying method using the spraying apparatus of this embodiment will be described. Before spraying the spacer particles, the solution containing the spacer particles 6 is stirred and mixed in the mixing tank 36 by the stirrer 38. In that state, the three-way valve 42 closes the communication between the liquid supply pipes 40 and 44.
The volatile solvent mixed with the spacer particles 6 is not particularly limited, but an aqueous alcohol solution such as IPA (isopropenyl alcohol) can be used.

Then, the substrate 4 is mounted in the spray chamber 32,
Spacers are scattered in the following steps. First, the three-way valve 42 is controlled so that the liquid delivery pipes 40 and 44 are in communication. Further, a solenoid valve (not shown) attached to the nozzle port 48 of the nozzle 46 is also opened. At that time, high pressure air (for example, 1 to 5 kg / cm ² ) is directed from the periphery of the nozzle 46 toward the nozzle 46.
By spraying with, the solution blown out from the nozzle 48 is atomized.

The volatile solvent in the atomized solution is evaporated by the heater 34, and only the spacer particles 6 in the atomized solution sprayed from the nozzle port 48 are deposited on the glass substrate 4. In this state, after the spraying process from the nozzle 46 is performed for a certain time (spraying time), the nozzle 4
Close the solenoid valve of 6. Further, spacer particles that naturally fall for a certain time (settling time) are attached to the surface of the substrate 4, and then the substrate 4 is taken out from the spray chamber 32. The spraying density of the spacer particles on the surface of the substrate 4 is controlled by the spraying time and the sinking time, and the accuracy is ± 10%. After taking out the substrate 4 on which the spacer particles are dispersed, the substrate 4 of the next manufacturing lot is inserted into the dispersion chamber 32,
The same operation as above is performed to perform the spraying process.

When the interval period until the next spraying process is long, the spacer particles are precipitated and condensed in the liquid feeding pipe 44 from the first three-way valve 42 to the nozzle 46, and the dispersion density between lots varies. May not be maintained at an accuracy of ± 10%. Further, the spacer particles condensed in the pipe 44 are directly transferred to the substrate 4
May adhere to the surface of the LCD and become a point defect of the LCD.

However, in the method of this embodiment, since the following method is adopted, it is possible to eliminate the inconveniences such as the dispersion of the dispersion density and the point defect of the LCD.
That is, according to the method of the present embodiment, the substrate 4 after the spraying is completed.
After taking out from the spraying chamber 32, the first and second solenoid valves 42 and 51 are controlled, the communication between the pipes 40 and 44 is closed, and the pipes 50 and 44 are communicated with each other.
Connect between 0 and 54. As a result, the cleaning liquid flows from the cleaning liquid supply pipe 54 as the cleaning liquid supply means to the liquid supply pipe 44 through the branch pipe 50. At this time, the nozzle port 48 of the nozzle 46 is left open. A certain time,
The cleaning liquid is kept flowing in the liquid sending pipe 44 to clean the inside of the pipe 44 and the inside of the nozzle 46.

After that, the second three-way valve 51 is controlled, the communication between the pipes 54 and 50 is closed, and the explosion-proof gas supply pipe 52 as the explosion-proof gas supply means and the branch pipe are connected. Thereby, the nitrogen gas as the explosion-proof gas is supplied from the explosion-proof gas supply pipe 52 through the branch pipe 50 into the liquid sending pipe 44 and the nozzle 46. The nitrogen gas supplied into the liquid sending pipe 44 blows out the spacer particles remaining in the liquid sending pipe 44 and the nozzle 46 together with the cleaning liquid into the spray chamber 32 from the nozzle port 48. In this state, the valve 58 of the spray chamber 32 is opened, and the spray chamber 32 is evacuated through the exhaust pipe, so that the spray chamber is replaced with nitrogen gas to be in an explosion-proof state.

After that, the nozzle port 48 of the nozzle 46 is closed, and the inside of the liquid feed pipe 44 and the nozzle 46 is kept filled with nitrogen gas, and the process of spraying the substrate of the next manufacturing lot is waited. The mixing tank 36 and the first three-way valve 4
The liquid feed pipe 40 between the two is made as short as possible,
It is preferable that the solution does not become stagnant in this pipe.

In the spraying method using the spraying device 30 of this embodiment, after spraying the solution from the nozzle 46, the cleaning liquid is supplied to the liquid supply pipe 44 for sending the solution to the nozzle 46, and then the explosion-proof gas is supplied. However, since the explosion-proof gas is sprayed from the nozzle 46 into the spray chamber 32, the spacer particles remaining in the liquid supply pipe 44 and the flow path inside the nozzle 46 are introduced into the spray chamber 32 from the nozzle port 48 together with the cleaning liquid. Blow away. Therefore, the liquid sending pipe 44 and the nozzle 46
Spacer particles do not condense and clog the nozzle 46 in the internal flow path. Therefore, between production lots,
There is no dispersion variation. Further, for the same reason, the condensed spacer particles are not deposited on the substrate, the point defects of the LCD are effectively prevented, and the manufacturing yield is improved. Further, since the explosion-proof gas is blown out into the spray chamber using the spray nozzle 46, even if the volatile solvent is changed from CFC 113 to an alcohol solvent, the explosion-proof gas in the spray chamber 32 is treated to prevent the explosion-proof gas. There is no need to modify the device, such as installing new nozzles.

Furthermore, even if the concentration of the spacer particles in the solution is increased, the nozzle 46 is not clogged, and therefore the spraying time can be shortened by the amount of the increased concentration. Furthermore, since it is not necessary to control the spraying interval, the solution can be stored while being set for a long time. This contributes to saving spacer solution.

Further, it is not necessary to regularly replace and clean the pipe and the nozzle, which contributes to cost reduction. Further, even when a solution in which the type of spacer particles, the type of solvent or the concentration of spacer particles is changed is sprayed, it is not necessary to prepare a plurality of nozzles, and it is possible to spray with a single nozzle 46. For example, in this embodiment,
A branch valve is provided in the liquid feed pipe 40, a mixing tank for storing each solution is connected to the branch valve, and the branch valve is switched and controlled to selectively feed a plurality of types of solutions to the liquid feed pipe 44. No need to replace the nozzle each time, and it is not necessary to remove the pipe or nozzle for cleaning.

Next, the present invention will be described based on more concrete experimental examples, but the present invention is not limited to these experimental examples. In this experimental example, a glass substrate having a size of 350 × 300 mm was prepared as the substrate 4, and the glass substrate 4 was prepared as shown in FIG.
It was installed in the spray room 32 shown in FIG. As the spacer particles mixed in the mixing tank 36, plastic particles having a particle diameter of 6.0 μm were used. Further, as the volatile solvent, IPA
An alcohol aqueous solution having a ratio of pure water to 1: 1 was used. The concentration of the spacer particles in the mixed solution was 1% by weight.

The set temperature of the heater 34 provided in the spray chamber 32 was 50.degree. Pure water was used as the cleaning liquid supplied from the cleaning liquid supply pipe 54, and the supply time was 10 seconds. Further, nitrogen gas was used as the gas supplied from the explosion-proof gas supply pipe 52, and the supply time was 10 seconds. The spraying time and the sinking time of the spacer particles from the nozzle 46 are
The spacer particles were set to 100 particles / mm ² .

When the spraying treatment shown in the above-mentioned embodiment was carried out under such conditions, the spraying interval time was about 0.
Even when the time was changed to about 1 hour or about 2 hours, the dispersion density of the spacer particles could be suppressed to an accuracy of 100 ± 10 particles / mm ² . In addition, no point defect due to spacer condensation was found in the LCD manufactured using the substrate on which the spacer particles were dispersed in this manner.

The dispersion density is evaluated according to JIS Z90.
45-1962 "Test of difference between population mean and reference value". From the above experimental results, it was confirmed that the spraying method using the apparatus of this example can effectively prevent the dispersion of the spraying density between the production lots.

[0043]

As described above, according to the present invention, there is no dispersion variation among manufacturing lots. Further, the condensed spacer particles are not deposited on the substrate, the point defects of the LCD are effectively prevented, and the manufacturing yield is improved. Furthermore, since the explosion-proof gas is blown into the spray chamber by using the spray nozzle, it is not necessary to modify the device such as newly providing an explosion-proof nozzle.

Further, even if the concentration of the spacer particles in the solution is increased, the nozzle is not clogged, so that the spraying time can be shortened by the amount of the increased concentration. Furthermore, since it is not necessary to control the spraying interval, the solution can be stored while being set for a long time. This contributes to saving spacer solution.

Further, it is not necessary to regularly replace and clean the pipe and the nozzle, which contributes to cost reduction. Furthermore, even when spraying a solution in which the type of spacer particles, the type of solvent or the concentration of spacer particles is changed, it is not necessary to prepare multiple nozzles, and it is possible to spray with a single nozzle. No need to replace the nozzle each time, and no need to remove the nozzle or pipe for cleaning. Moreover, since a single nozzle is sufficient, it also contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a spacer particle spraying device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a manufacturing process of an LCD according to an embodiment of the present invention.

FIG. 3 is a schematic sectional view of an LCD according to an embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a spacer particle spraying device according to a conventional example.

[Explanation of symbols]

 4, 5 ... Substrate 6 ... Spacer particles 11 ... LCD 13 ... Liquid crystal 30 ... Spacer particle spraying device 32 ... Spraying chamber 34 ... Heater 36 ... Mixing tank 40, 44 ... Liquid delivery pipe 42 ... First three-way valve 46 ... Nozzle 48 ... Nozzle port 50 ... Branch pipe 51 ... Second three-way valve 52 ... Explosion-proof gas supply pipe 54 ... Cleaning liquid supply pipe

Claims (4)

[Claims] 1. A step of mixing spacer particles, which are to be arranged between substrates in which a liquid crystal is sealed in a liquid crystal display device, with a volatile solvent to form a solution containing the spacer particles, and the spacer particles are arranged in a spray chamber. A step of spraying a solution containing the spacer particles onto the surface of the substrate from a nozzle to volatilize the solvent in the solution sprayed on the surface of the substrate, and a method of spraying the solution from the nozzle and then sending the solution to this nozzle. A method for spraying spacer particles of a liquid crystal display device, comprising the step of supplying an explosion-proof gas to a liquid pipe and spraying the explosion-proof gas from a nozzle into the spray chamber. 2. After spraying the solution from the nozzle, a cleaning liquid is caused to flow in a liquid sending pipe for sending the solution to the nozzle, and then an explosion-proof gas is sprayed into the spray chamber through the liquid sending pipe and the nozzle to send the liquid. The method for spraying spacer particles of a liquid crystal display device according to claim 1, further comprising: blowing the cleaning liquid remaining in the pipe and the nozzle into the spray chamber. 3. A mixing tank in which spacer particles, which are to be arranged between substrates in which liquid crystal is sealed in a liquid crystal display device, are mixed with a volatile solvent to form a solution containing the spacer particles, and the spacer particles are coated on the surface. A spray chamber in which the substrate to be deposited is installed, a nozzle arranged to spray the solution containing the spacer particles toward the surface of the substrate installed in the spray chamber, and the mixing tank to the nozzle. A liquid sending pipe for sending the solution toward the liquid sending pipe, valve means for controlling the liquid sending from the mixing tank to the liquid sending pipe, and when the liquid sending to the liquid sending pipe is stopped by this valve means, A spacer particle-dispersing device for a liquid crystal display device, comprising: an explosion-proof gas supply means for supplying an explosion-proof gas to a liquid pipe and for spraying the explosion-proof gas from the nozzle into the spray chamber. 4. When the liquid supply to the liquid supply pipe is stopped by the valve means and before the explosion-proof gas is supplied to the liquid supply pipe from the explosion-proof gas supply means, the liquid supply pipe is supplied to the liquid supply pipe. The spacer particle sprinkling device of the liquid crystal display device according to claim 3, further comprising: a cleaning liquid supply unit for supplying a cleaning liquid.