JP2005103392A - Film formation method, electrooptical device, and manufacturing method of electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film formation method which enables the formation of a desired functional film. <P>SOLUTION: In the method for forming a functional film on a substrate 48 by delivering a liquid matter 2 with a liquid droplet delivery device, a silicone oil or a silane coupling agent is mixed into the liquid matter 2 before its delivering; thus, the silicone oil or the silane coupling agent, both having a boiling point higher than that of the solvent of the delivered liquid droplets 4, is adsorbed by the surface of the droplets 4. Since a film 6 of the silicone oil or the silane coupling agent is formed on the surface of the liquid droplets 4, the drying rate of the liquid droplets 4 by the evaporation of the low-boiling-point solvent is decreased; thus, the drying conditions of the liquid droplets 4 can be controlled, enabling the formation of a desired functional film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a film forming method, an electro-optical device, and a method for manufacturing an electro-optical device.

Examples of the device using the inkjet method include an organic EL device, a color filter, a metal wiring, and a microlens array. In these devices, a functional material is formed by discharging a liquid material containing a functional substance onto a substrate by an ink jet method and evaporating the solvent by heating or natural standing (see, for example, Patent Document 1). ).
JP 2002-371196 A

  Recently, a thin film with higher function and higher definition has been desired. For that purpose, it is necessary to operate the film forming process of the droplet. Control of the drying conditions of the droplets is an important factor for the operation of the film forming process. For example, if the drying conditions such as heat drying and reduced pressure drying can be controlled intentionally, it is possible to control the function, shape, etc. of the formed film.

  However, since the droplets ejected by the ink jet method are very small, the drying speed is high, and they may be naturally dried before the drying process. In this case, since the drying conditions of the droplets cannot be controlled, the function and shape of the formed thin film are naturally determined. Therefore, there is a problem that a desired film cannot be formed.

  Also, in film formation using the ink jet method, even if a plurality of minute droplets are arranged side by side and immediately subjected to a drying process, the previously ejected droplets are drying, so that each film There is a problem of unevenness. In addition, when a plurality of droplets are arranged close to each other, there is a problem that the drying speed changes due to the influence of vapor from adjacent droplets. These problems become more pronounced as the boiling point of the droplets is lower and the drying speed is faster.

  As a method for suppressing the drying speed of droplets, there is a method in which a moisturizing material (high boiling point solvent) is added to ink in advance. However, the ease of drying of the ink itself depends on the amount of the high-boiling solvent to be mixed, and if the mixing amount is increased, it becomes more difficult to dry, but the ratio of disadvantages such as high viscosity and low solubility increases. Furthermore, by using a mixed solvent, there are many problems such as film unevenness due to a difference in drying speed during film formation, and changes in physical properties of the film.

SUMMARY An advantage of some aspects of the invention is that it provides a film forming method and an electro-optical device manufacturing method capable of uniformly forming a desired film.
It is another object of the present invention to provide an electro-optical device having excellent display quality by providing a desired functional film.

In order to achieve the above object, a film forming method of the present invention is a film forming method in which a liquid is applied to form a film, and the solvent or dispersion medium of the liquid is applied to the surface of the applied liquid. A gas-liquid interfacial adsorbent having a higher boiling point and surface orientation with respect to the liquid is adsorbed.
According to this configuration, since a coating film of a high-boiling gas-liquid interface adsorbent is formed on the surface of the applied liquid material, the drying speed of the liquid material is reduced due to evaporation of the low-boiling solvent or dispersion medium. Can be made. Thereby, it becomes possible to control the drying conditions of the liquid, and a desired film can be formed.

The gas-liquid interface adsorbent is preferably silicone oil or a silane coupling agent.
According to this configuration, a high boiling point silicone oil or silane coupling agent film can be formed on the surface of the applied liquid. Thereby, even when the solvent or dispersion medium of the liquid material has a low boiling point, it becomes possible to control the drying conditions of the liquid material, and a desired film can be formed.

In addition, it is desirable that the gas-liquid interface adsorbent is mixed in advance with the liquid before application.
According to this configuration, the gas-liquid interface adsorbent film can be easily and reliably formed only on the surface of the applied liquid.

In addition, the concentration of the gas-liquid interface adsorbent in the liquid before application is preferably about 1.0 × 10 ⁻⁷ wt% or more and about 0.1 wt% or less with respect to the liquid.
According to this configuration, the gas-liquid interface adsorbent remaining after the film formation has little influence on the film properties.

The gas-liquid interface adsorbent may be applied in advance on the substrate to which the liquid material is applied. Further, the gas-liquid interface adsorbent may be sprayed on the surface of the applied liquid material.
Even with these configurations, a coating film of a high-boiling gas-liquid interface adsorbent can be formed on the surface of the applied liquid. Thereby, even when the solvent or dispersion medium of the liquid material has a low boiling point, it becomes possible to control the drying conditions of the liquid material, and a desired film can be formed.

Further, it is a film forming method in which a liquid material is sequentially applied to a plurality of adjacent regions to form a film, and the gas-liquid interface adsorbent is applied only to the surface of the liquid material applied to some of the regions. It is good also as a structure made to adsorb | suck.
Even when the gas-liquid interface adsorbent is adsorbed only on the surface of a part of the liquid, it is possible to prevent the influence of vapor from the liquid on other liquids, and other liquids. It becomes possible to prevent being affected by steam from the body. Therefore, a desired film can be formed.

Moreover, it is desirable that the gas-liquid interface adsorbent be adsorbed only on the surface of the liquid material applied in advance.
According to this configuration, the liquid material applied first and the liquid material applied later can be naturally dried equally, and a uniform film can be formed.

Moreover, it is good also as a structure which makes each said gas-liquid interface adsorbent adsorb | suck to the surface of the said liquid body apply | coated to each said area | region.
According to this configuration, it becomes possible to individually control the drying speed of each liquid material, and a desired film can be formed.

Here, the boiling point of the gas-liquid interface adsorbent adsorbed on the surface of the liquid material applied earlier is higher than the boiling point of the gas-liquid interface adsorbent adsorbed on the surface of the liquid material applied later. The boiling point is desirable.
According to this configuration, the liquid material applied first and the liquid material applied later can be naturally dried equally, and a uniform film can be formed.

On the other hand, the electro-optical device of the present invention is manufactured using the film forming method described above.
According to this configuration, it is possible to provide an electro-optical device having excellent display quality by including a desired functional film.

On the other hand, the manufacturing method of the electro-optical device of the present invention is a manufacturing method of an electro-optical device in which a liquid material is applied to a plurality of dot regions to form a functional film, on the surface of the applied liquid material, A gas-liquid interface adsorbent having a higher boiling point than the solvent or dispersion medium of the liquid and having surface orientation with respect to the liquid is adsorbed.
According to this configuration, since a coating film of a high-boiling gas-liquid interface adsorbent is formed on the surface of the applied liquid material, the drying speed of the liquid material is reduced due to evaporation of the low-boiling solvent or dispersion medium. Can be made. Thereby, it becomes possible to control the drying conditions of the liquid material, and an electro-optical device having a desired functional film can be manufactured.

The gas-liquid interface adsorbent is preferably silicone oil or a silane coupling agent.
According to this configuration, a high boiling point silicone oil or silane coupling agent film can be formed on the surface of the applied liquid. Thus, even when the liquid solvent or dispersion medium has a low boiling point, the drying conditions of the liquid can be controlled, and an electro-optical device having a desired functional film can be manufactured.

Moreover, it is good also as a structure which makes the said gas-liquid interface adsorbent adsorb | suck only to the surface of the said liquid apply | coated to a part of said dot area | region among each said adjacent dot area | region.
According to this configuration, it is possible to prevent the influence of vapor between a part of the liquid material and the other liquid material. Therefore, a desired film can be formed.

Moreover, it is good also as a structure which makes the said each gas-liquid interface adsorbent adsorb | suck to the surface of the said liquid body apply | coated to each said dot area | region.
According to this configuration, it becomes possible to individually control the drying speed of each liquid material, and a desired film can be formed.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS. In the first embodiment, a liquid material mixed with a gas-liquid interface adsorbent in advance is discharged, and a film of the gas-liquid interface adsorbent is formed on the surface of the discharged droplet.

[Inkjet ink]
In the case of forming a functional film using a droplet discharge device, a liquid material (ink jet ink) in which a functional film forming material is dissolved in a solvent is prepared, and the liquid material is placed on the substrate from the droplet discharge device. A functional film is formed by discharging and drying the discharged liquid. In the present embodiment, a liquid material in which a gas-liquid interface adsorbent is mixed in advance is produced. This gas-liquid interface adsorbent is a substance that forms a film by adsorbing on the free surface of gas and liquid.
FIG. 1 is a partially enlarged view of a side cross section of a nozzle portion of an ink jet head. When the liquid 2 in which the gas-liquid interface adsorbent has been mixed in advance is ejected from the ink jet head (hereinafter simply referred to as the head) 20, the gas-liquid interface adsorbent is adsorbed on the free surface of the droplet 4 attached to the substrate 48. Thus, the film 6 is formed.

  Particularly in this embodiment, a gas-liquid interface adsorbent having a boiling point higher than that of the solvent of the liquid 2 is employed. If the coating 6 of the gas-liquid interface adsorbent is formed on the surface of the droplet 4, the drying speed of the droplet due to evaporation of the low boiling point solvent can be reduced. As the high-boiling gas-liquid interface adsorbent, it is desirable to employ one having a boiling point about twice that of the solvent or one having a boiling point about 100 ° C. higher than that of the solvent. In addition, if a gas-liquid interface adsorbent having a boiling point equivalent to that of a high-boiling solvent used in conventional ink is employed, at least the same drying rate as in the conventional case can be secured. In addition, when it becomes possible to use a low-boiling solvent, it is possible to select a solvent suitable for producing a thin film to be obtained without being limited to the high-boiling solvent employed in conventional inks. . This makes it possible to create inks using solvents such as those with low boiling point but high solubility, low viscosity, low surface tension, etc. Can be improved.

Further, the mixing ratio of the gas-liquid interface adsorbent to the liquid 2 is preferably not less than the saturated adsorption concentration and not more than 0.1 wt%. The saturated adsorption concentration varies depending on the solubility in a solvent and the molecular weight, but is, for example, about 1.0 × 10 ⁻⁷ wt%. This is because if the mixing ratio of the gas-liquid interface adsorbent is too small, it is difficult to form a uniform film 6 on the surface of the droplet 4. Conversely, if the mixing ratio of the gas-liquid interface adsorbent is too large, the gas-liquid interface adsorbent remaining after the film formation increases, which may adversely affect the properties of the film.

  Silicone oil is used as one of the specific gas-liquid interface adsorbents. Silicone oil is a linear, low-polymerization silicone that exhibits fluidity at room temperature. Silicone refers to a polysiloxane having a repeating structure of siloxane bonds with silicon atoms and oxygen atoms, having an organic group such as an alkyl group or an annealing group. In addition, there are water-soluble and water-insoluble silicone oils in which the side chain functional groups are selectively changed. Polydimethylsiloxane, which is a typical silicone oil, is a substance represented by the following chemical formula.

  The boiling point of silicone oil varies depending on the degree of polymerization of siloxane bonds. Therefore, a silicone oil whose degree of polymerization is adjusted to have a boiling point higher than that of the solvent of the liquid 2 is employed. For example, the boiling point of silicone oil is about 300 ° C. Water (boiling point 100 ° C.), ethanol (boiling point 78 ° C.), xylene (boiling point 138.4 ° C. to 144.4 ° C.) or the like can be adopted as an ink solvent having a lower boiling point than the silicone oil.

As another specific gas-liquid interface adsorbent, a silane coupling agent is employed. A silane coupling agent is an organosilicon compound having a functional group that can chemically bond to both inorganic materials and organic materials that are generally unfamiliar. With a general formula of Y~CH ₂ SiX _3. X is a hydrolyzable substituent such as an alkoxy group or halogen. Y is a vinyl group, an epoxy group, an amino group or the like that easily reacts with organic matter.

  The boiling point of the silane coupling agent mainly depends on the molecular weight of Y in the general formula. Therefore, a silane coupling agent having a large molecular weight that has a higher boiling point than the solvent of the liquid 2 is employed. For example, the boiling point of octadecyltrimethoxysilane is about 170 ° C. As an ink solvent having a lower boiling point than this silane coupling agent, water (boiling point 100 ° C.), ethanol (boiling point 78 ° C.), xylene (boiling point 138 ° C. to 144.4 ° C.) or the like can be employed.

(Droplet discharge device)
The liquid material described above is discharged by a droplet discharge device. FIG. 2 is a perspective view of the droplet discharge device. The droplet discharge device 10 mainly includes a base 12, a first moving unit 14, a second moving unit 16, an electronic balance (not shown) as a weight measuring unit, a head 20, a capping unit 22, and a cleaning unit 24. Yes. The operation of the droplet discharge device 10 including the first moving means 14 and the second moving means 16 is controlled by the control device 23. In FIG. 2, the X direction is the left-right direction of the base 12, the Y direction is the front-rear direction, and the Z direction is the up-down direction.

  The first moving means 14 is directly installed on the upper surface of the base 12 with the guide rails 40, 40 aligned with the Y-axis direction. The first moving means 14 has a slider 42 that can move along the guide rails 40, 40. As a driving means for the slider 42, for example, a linear motor can be employed. Thereby, the slider 42 can be moved along the Y-axis direction, and can be positioned at an arbitrary position.

  A motor 44 is fixed to the upper surface of the slider 42, and a table 46 is fixed to the rotor of the motor 44. The table 46 is positioned while holding the substrate 48. That is, by operating a suction holding means (not shown), the substrate 48 is sucked through the hole 46A of the table 46, and the substrate 48 can be held on the table 46. The motor 44 is, for example, a direct drive motor. When the motor 44 is energized, the table 46 is rotated in the θz direction together with the rotor, so that the table 46 can be indexed (rotational indexing). The table 46 is provided with a preliminary discharge area for the head 20 to discard the liquid material or to perform trial driving (preliminary discharge).

  On the other hand, support columns 16A and 16A are erected on the rear side of the base 12, and a column 16B is installed on the upper ends of the support columns 16A and 16A. And the 2nd moving means 16 is provided in the front surface of the column 16B. The second moving means 16 has guide rails 62A and 62A arranged along the X-axis direction, and has a slider 60 movable along the guide rails 62A and 62A. As a driving means for the slider 60, for example, a linear motor can be employed. Thereby, the slider 60 can be moved along the X-axis direction and can be positioned at an arbitrary position.

  The head 20 is provided on the slider 60. The head 20 is connected to motors 62, 64, 66, 68 as swing positioning means. The motor 62 can move the head 20 in the Z-axis direction and can be positioned at an arbitrary position. The motor 64 can swing the head 20 in the β direction around the Y axis and can be positioned at any position. The motor 66 can swing the head 20 in the γ direction around the X axis and can be positioned at any position. The motor 68 can swing the head 20 in the α direction around the Z axis and can be positioned at an arbitrary position.

  As described above, the substrate 48 can be moved and positioned in the Y direction, and can be swung and positioned in the θz direction. The head 20 can be moved and positioned in the X and Z directions, and can be swung and positioned in the α, β, and γ directions. Therefore, the droplet discharge device 10 of the present embodiment can accurately control the relative position and posture between the ink discharge surface 20P of the head 20 and the substrate 48 on the table 46. .

(Inkjet head)
Here, a structural example of the head 20 will be described with reference to FIG. FIG. 3 is a side sectional view of the inkjet head. The head 20 discharges the liquid 2 from the nozzle 91 by a droplet discharge method. As a droplet discharge method, there are various known methods such as a piezo method in which a liquid material is discharged using a piezoelectric element as a piezoelectric element, and a method in which a liquid material is discharged by bubbles generated by heating the liquid material. Technology can be applied. Among them, the piezo method has an advantage that it does not affect the composition of the material because it does not apply heat to the liquid. Therefore, the above-described piezo method is adopted for the head 20 in FIG.

  A head body 90 of the head 20 is formed with a reservoir 95 and a plurality of ink chambers 93 branched from the reservoir 95. The reservoir 95 is a flow path for supplying the liquid material 2 to each ink chamber 93. A nozzle plate that constitutes an ink ejection surface is attached to the lower end surface of the head main body 90. In the nozzle plate, a plurality of nozzles 91 for discharging the liquid material 2 are opened corresponding to the respective ink chambers 93. An ink flow path is formed from each ink chamber 93 toward the corresponding nozzle 91. On the other hand, a diaphragm 94 is attached to the upper end surface of the head main body 90. The diaphragm 94 constitutes a wall surface of each ink chamber 93. Piezo elements 92 are provided outside the diaphragm 94 so as to correspond to the ink chambers 93. The piezo element 92 is obtained by holding a piezoelectric material such as crystal between a pair of electrodes (not shown). The pair of electrodes is connected to the drive circuit 99.

  When a voltage is applied from the drive circuit 99 to the piezo element 92, the piezo element 92 expands or contracts. When the piezo element 92 is contracted and deformed, the pressure in the ink chamber 93 is reduced, and the liquid 2 flows from the reservoir 95 into the ink chamber 93. Further, when the piezo element 92 expands and deforms, the pressure in the ink chamber 93 increases and the liquid material 2 is discharged from the nozzle 91. Note that the amount of deformation of the piezo element 92 can be controlled by changing the applied voltage. Further, the deformation speed of the piezo element 92 can be controlled by changing the frequency of the applied voltage. That is, by controlling the voltage applied to the piezo element 92, the discharge condition of the liquid 2 can be controlled.

  On the other hand, the droplet discharge device shown in FIG. 2 includes a capping unit 22 and a cleaning unit 24. The capping unit 22 is for capping the ink ejection surface 20P when the droplet ejection apparatus 10 is on standby to prevent the ink ejection surface 20P of the head 20 from drying. The cleaning unit 24 sucks the inside of the nozzles in order to remove clogging of the nozzles in the head 20. The cleaning unit 24 can also wipe the ink discharge surface 20P in order to remove dirt on the ink discharge surface 20P in the head 20.

[Film Formation Method]
Next, a method for forming a film on a substrate by discharging a liquid using the above-described droplet discharge device will be described with reference to FIG.

  First, a liquid 2 that is to be an inkjet ink is prepared. The liquid 2 is produced by dissolving the constituent materials of the film in a solvent and further mixing a gas-liquid interface adsorbent. The silicone oil mentioned above is employ | adopted as the gas-liquid interface adsorption agent. A silicone oil having a boiling point higher than that of the solvent of the liquid 2 is adopted by adjusting the degree of polymerization. Silicone oil is mixed in the liquid 2 at a ratio of 0.1 wt% or less. As will be described later, it is possible to use a low boiling point solvent as the solvent. In addition, since many low-boiling solvents have high solute solubility, it is possible to produce the liquid 2 containing a high concentration of solute.

Next, the manufactured liquid 2 is filled in the head 20. Specifically, the prepared liquid 2 is filled in a tank (not shown) and supplied to the head 20 by a pump or the like. As shown in FIG. 3, the liquid 2 supplied to the head 20 is distributed from the reservoir 95 to the ink chambers 93 and further filled into the nozzles 91.
Next, the head 20 and / or the substrate 48 shown in FIG. 2 is moved to a predetermined position, and the liquid material is discharged from the head 20 to the substrate 48. Then, as shown in FIG. 1, the silicone oil as the gas-liquid interface adsorbent is adsorbed on the free surface of the ejected droplet 4, and the coating 6 is formed.

  Next, the discharged droplet 4 is dried, and the film is baked. In general, the droplets 4 are dried by the evaporation of the solvent. Here, the lower the boiling point of the solvent, the higher the vapor pressure. Therefore, the lower the boiling point of the droplet 4, the faster the drying speed. In this case, the droplets may be naturally dried before the drying process. However, in the film forming method of the present embodiment, since the coating 6 of the high-boiling gas-liquid interface adsorbent is formed on the surface of the droplet 4, evaporation of the low-boiling solvent can be suppressed. Thereby, the drying speed of the droplet 4 can be reduced. Therefore, it becomes possible to control the drying conditions of the droplet 4, and a desired functional film can be formed into a desired shape.

  Further, the film 2 forming method described above makes it possible to produce the liquid 2 using a low boiling point solvent. Since many of the low boiling point solvents have low viscosity, the liquid 2 can be stably discharged. In addition, many low-boiling solvents have high solute solubility, and a liquid 2 containing a high concentration of solute can be produced. Thereby, since the film thickness after film formation becomes thick, it is not necessary to overprint the liquid material 2 by the droplet discharge device, and the throughput of the film formation process can be improved.

[Electro-optical device]
Next, an organic EL device that is an example of an electro-optical device manufactured by using the film forming method of the present embodiment will be described with reference to FIGS.

  FIG. 4 is a plan view schematically showing the configuration of the organic EL device. The organic EL device 200 of this embodiment is formed on the surface of the substrate 210. An image display area 204 is formed at the center of the surface of the substrate 210. In the image display area 204, a plurality of dot areas 208 are arranged in a matrix. In each dot region 208, a red light emitting element R, a green light emitting element G, or a blue light emitting element B is formed, and one pixel region is formed by a set of light emitting elements R, G, and B. An image can be displayed in the image display area 204 by controlling the light emission of each color light emitting element R, G, B. A scanning line driving circuit and the like for energizing the switching elements of the respective color light emitting elements R, G, and B are formed in the periphery of the image display area 204.

  FIG. 5 is a partially enlarged view of a side cross-section taken along line AB in FIG. As shown in FIG. 5, a circuit unit 220 is formed on the surface of the substrate 210, and pixel electrodes 240 corresponding to the light emitting elements R, G, and B are formed on the surface of the circuit unit 220. A thick film bank 245 made of an electrically insulating material is formed around each pixel electrode 240. A hole injection layer 250 and a light emitting layer 260 are sequentially formed on the surface of the pixel electrode 240 functioning as an anode. Further, an electron injection layer 270 and a common cathode 280 are formed on the entire surface of the light emitting layer 260 and the bank 245. Then, by applying a voltage between the pixel electrode 240 and the common cathode 280, the light emitting layer 260 emits light in each color. Note that a sealing substrate (not shown) is bonded to the end of the substrate 210, and the entire organic EL device 200 is hermetically sealed.

[Method of manufacturing electro-optical device]
Next, a method for manufacturing the electro-optical device according to this embodiment will be described with reference to FIGS. In FIG. 6 and FIG. 7, the description of the circuit portion and the like is omitted for easy understanding. Hereinafter, a method for forming the light emitting layer of the organic EL device by applying the above-described film forming method will be described.

  FIG. 6 is a first explanatory view of the method for manufacturing the organic EL device, and is a cross-sectional view taken along the line AB of FIG. The light emitting layer of the organic EL device is composed of an organic compound. As the organic compound, a polymer compound that can use a liquid phase process is preferably used as compared with a low molecular compound that requires a gas phase process. For example, MEHPPV (poly (3-methoxy 6- (3-ethylhexyl) paraphenylenevinylene) is used as a material for forming a red light-emitting layer, and polydioctylfluorene and F8BT (dioctylfluorene and benzothiadiazole) are used as a material for forming a green light-emitting layer. Polydioctylfluorene can be used as the blue light-emitting layer forming material.

  Therefore, first, a polymer that is a material for forming the red light emitting layer is dissolved in a solvent, and a gas-liquid interface adsorbent is mixed into the solution to prepare a liquid for the red light emitting layer. The silicone oil mentioned above is employ | adopted as the gas-liquid interface adsorption agent. As the silicone oil, one whose degree of polymerization is adjusted so as to have a higher boiling point than the solvent is employed. Silicone oil is mixed in the ink at a ratio of about 0.1 wt% or less. As the ink solvent, it is possible to use a non-polar solvent having a low boiling point such as toluene or xylene. In addition, since many low-boiling solvents have high solute solubility, it is possible to produce a liquid containing a high-concentration polymer compound. Similarly, a liquid for the green light emitting layer and a liquid for the blue light emitting layer are prepared.

  Then, as shown in FIG. 6A, the liquid material for the red light emitting layer is discharged to the formation region r of the red light emitting element by the droplet discharge device. Then, silicone oil is adsorbed on the surface of the discharged droplet 4r, and a coating 6r is formed. Here, since the boiling point of the silicone oil is set higher than the solvent of the droplet 4r, the drying rate of the droplet 4r due to the evaporation of the low boiling point solvent can be reduced. Therefore, it is possible to prevent the red light emitting layer from being naturally dried before forming the green light emitting layer and the blue light emitting layer.

  Next, as shown in FIG. 6B, the liquid material for the blue light emitting layer is discharged to the blue light emitting element forming region b by the droplet discharge device. Note that if a droplet is discharged to the adjacent region g following the discharge of the droplet to the region r, the drying speed of the other droplet may change due to the vapor pressure of the one droplet. Therefore, by discharging the droplet 4b to the region b separated from the region r, the drying speed of each droplet 4r, 4b can be controlled independently.

  Then, the silicone oil is adsorbed on the surface of the discharged droplet 4b, and the coating 6b is formed. Here, the boiling point of the silicone oil constituting the coating 6b is desirably lower than the boiling point of the silicone oil constituting the coating 6r. Since each droplet is uniformly dried in the drying step described later, it is desirable that each droplet before the drying treatment is equally naturally dried. Therefore, by lowering the drying speed of the droplet 4r discharged earlier than the drying speed of the droplet 4b discharged later, each droplet before the drying process can be naturally dried in the same manner. Because it can. As a result, a uniform light-emitting layer coating without film unevenness can be formed.

  Next, as shown in FIG. 6C, the liquid material for the green light emitting layer is discharged by the droplet discharge device to the formation region g of the green light emitting element. Then, silicone oil is adsorbed on the surface of the discharged droplet 4g, and a film 6g is formed. Similarly to the above, it is desirable that the boiling point of the silicone oil constituting the coating 6g is lower than the boiling point of the silicone oil constituting the coating 6r and the coating 6b. Thereby, it becomes possible to make each droplet before a drying process into the state dried naturally equally, and the film of a uniform light emitting layer can be formed.

  In addition, when performing a drying process immediately after discharge of the droplet 4g, it is not necessary to mix a silicone oil in the liquid for green light emitting layers. Even in this case, the vapor pressure from the droplets 4r and 4b is lowered by the coatings 6r and 6b, so that the droplet 4g is not affected. Further, although the vapor pressure from the droplet 4g does not decrease, the influence on the droplets 4r and 4b is blocked by the coatings 6r and 6b. Therefore, the drying speed of each droplet can be controlled independently. And each droplet before a drying process can be made into the state dried naturally.

  Then, as shown in FIG. 6 (d), the droplets 4r, 4g, 4b discharged to each region are dried (drying step). Thereby, the solvent of each droplet evaporates, and the red light emitting layer 260r, the green light emitting layer 260g, and the blue light emitting layer 260b are baked. Silicone oil may remain in the fired light emitting layers of the respective colors. However, the mixing ratio of the silicone oil to the liquid material for each color light emitting layer is a very small amount of about 0.1 wt% or less, and the function of each color light emitting layer is hardly adversely affected.

  In the electro-optical device manufacturing method described above, silicone oil is mixed in advance in the liquid for each color light emitting layer, and a film is formed on the surface of each discharged droplet, so that the drying conditions of each droplet are controlled. Is possible. Thus, it is sufficient to perform a single drying step after all the droplets have been ejected. Conventionally, since the drying conditions of the droplets could not be controlled, pre-baking was performed each time each droplet was ejected, and in addition, post-baking was performed after all the droplets were ejected. However, according to the above-described method for manufacturing an electro-optical device, it is sufficient to perform a single drying process, so that the throughput of the manufacturing process can be improved.

  FIG. 7 is a second explanatory view of the method for manufacturing the organic EL device, and is a cross-sectional view taken along the line CD of FIG. In the dot region 208 of FIG. 4, each light emitting element R, G, B is formed in a substantially rectangular shape. The light emitting element has a short side along the line AB in FIG. 4 and a long side along the line CD in FIG. In FIG. 7, a method for forming a light emitting layer in one dot region 208 will be described. First, in the same manner as described above, a polymer compound as a material for forming a light emitting layer is dissolved in a solvent, and a silicone oil is mixed into the solution to prepare a liquid.

  Then, as shown in FIG. 7A, the first droplets 4f and 4f are ejected from the droplet ejection device to both ends of the dot region 208. Then, the silicone oil is adsorbed on the surfaces of the discharged first droplets 4f and 4f, and the coatings 6f and 6f are formed. In this way, by discharging the plurality of first droplets 4f and 4f to the regions separated from each other, the possibility that the drying speed of the other droplet changes due to the vapor pressure of one droplet is reduced, and each liquid is reduced. The drying rate of the drops can be controlled independently.

  Next, as shown in FIG. 7B, the second droplet 4 s is ejected from the droplet ejection device to the center of the dot region 208. Then, silicone oil is adsorbed on the surface of the discharged second droplet 4s, and a coating 6s is formed. The boiling point of the silicone oil constituting the coating 6s is preferably lower than the boiling point of the silicone oil constituting the coating 6f, 6f. Thereby, it becomes possible to make each droplet before a drying process into the state dried naturally equally, and the film of a uniform light emitting layer can be formed.

Then, the first droplet 4f and the second droplet 4s ejected as described above wet and spread over the entire dot region 208, as shown in FIG. Then, the silicone oil adsorbed on the surface of each droplet is re-adsorbed on the free surface of the liquid material 5 that has spread and the film 7 is formed again. In addition, when the second droplet 4s spreads out immediately after ejection, it is not necessary to mix silicone oil into the second droplet 4s. Further, the same silicone oil as the first droplet may be mixed into the second droplet.
And as shown in FIG.7 (d), the liquid 5 which spreads wet is dried (drying process). Thereby, the solvent of the liquid 5 is evaporated and the light emitting layer 260 is formed.

In the electro-optical device manufacturing method described above, silicone oil is mixed in advance in the liquid material, and a film is formed on the surface of each discharged droplet. Thereby, it becomes possible to control the drying conditions of each droplet, and a uniform coating of the light emitting layer 260 can be formed for the entire dot region 208.
Note that the functional layers other than the light-emitting layer 260 shown in FIG. 5 can also be formed by using the above-described electro-optical device manufacturing method, whereby the manufacturing process throughput can be improved. In addition to the functional layer of the organic EL device, it is possible to improve the throughput of the manufacturing process by manufacturing color filters, metal wiring, microlens arrays, etc. using the droplet discharge method of each embodiment. It is.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, a gas-liquid interface adsorbent is applied on a substrate in advance, and a liquid material is discharged onto the substrate to form a film of the gas-liquid interface adsorbent on the surface of the discharged droplets. . Note that detailed description of portions having the same configuration as in the first embodiment is omitted.

FIG. 8 is an explanatory diagram of the film forming method of the second embodiment. As shown in FIG. 8A, in the film forming method of the second embodiment, the gas-liquid interface adsorbent 8 is applied in advance to the surface of the substrate 48 on which the functional film is formed. On the other hand, the film forming material is dissolved in a solvent to prepare a liquid.
Next, as shown in FIG. 8B, the produced liquid material is discharged onto the substrate 48 by a droplet discharge device. In addition, it is desirable to discharge ink before the gas-liquid interface adsorbent 8 applied on the substrate 48 is dried. Then, the gas-liquid interface adsorbent 8 applied on the substrate 48 flows into the inside of the droplet 4 discharged on the substrate 48 and is adsorbed on the surface of the droplet 4 to form the coating 6.

  Also by the film forming method of the second embodiment described above, the drying speed of the droplets 4 due to the evaporation of the low boiling point solvent can be reduced, so that it is possible to control the drying conditions of the droplets. Thereby, a desired film can be formed.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, a gas-liquid interface adsorbent is sprayed on the droplets 4 ejected on the substrate 48 to form a gas-liquid interface adsorbent coating 6 on the surface of the droplets 4. Note that detailed description of portions having the same configuration as in the first embodiment is omitted.

  FIG. 9 is an explanatory diagram of the film forming method of the third embodiment. In the film forming method of the third embodiment, first, a film forming material is dissolved in a solvent to prepare a liquid. Then, the produced liquid material is discharged onto the substrate 48 by the head 20. Next, a gas-liquid interface adsorbent is sprayed on the surface of the discharged droplet 4. As a result, the gas-liquid interface adsorbent is adsorbed on the surface of the droplet 4 to form the film 6. The gas-liquid interface adsorbent is sprayed by the gas-liquid interface adsorbent spraying means 130 provided in the droplet discharge device. The spray means 130 is preferably formed so that the gas-liquid interface adsorbent can be sprayed in a mist form. Thereby, a uniform film 6 can be formed on the surface of the droplet 4.

  Also by the film forming method of the third embodiment described above, the drying speed of the droplets due to the evaporation of the low boiling point solvent can be reduced, so that the drying conditions of the droplets can be controlled. Thereby, a desired film can be formed.

[Electronics]
Next, electronic devices formed using the film forming method of each embodiment will be described with reference to FIG. FIG. 10 is a perspective view of a mobile phone. In FIG. 10, reference numeral 1000 denotes a mobile phone body, and reference numeral 1001 denotes a display unit. The mobile phone 1000 includes a display unit 1001 formed using the film forming method of each embodiment. Therefore, the mobile phone 1000 that exhibits good display characteristics can be provided at low cost.

  The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and configurations described in the embodiments are merely examples, and can be changed as appropriate. For example, the case where a liquid material (inkjet ink) is applied using a droplet discharge device has been described above as an example, but the present invention can also be applied to a case where a liquid material is applied by other methods. Is possible. In addition, the case where a film is formed using a solution in which a solute is dissolved in a solvent has been described above as an example, but also when a film is formed using a dispersion liquid in which a dispersoid is dispersed in a dispersion medium. The present invention can be applied.

A plurality of inks were prepared, droplets were formed on the substrate, and the drying rates were compared.
Ethanol, xylene and water were employed as the dispersion medium, and polystyrene fine particles (particle size: 1.5 μm) were dispersed in each dispersion medium at a concentration of 0.1 wt%. In addition, each dispersion was prepared with and without silicone oil added. Silicone oil was added at a concentration of 0.1 wt% or less.

  As a result, in the dispersion using ethanol as a dispersion medium, the addition of silicone oil slowed the drying rate by a factor of 3 (it took 3 times longer to dry). Moreover, in the dispersion liquid which uses xylene as a dispersion medium, the drying rate became 1.5 times slower by adding silicone oil. Moreover, in the dispersion liquid which uses water as a dispersion medium, the drying rate became 1.2 times slower by adding silicone oil. From the above, it was confirmed that when using the above three types of dispersion media, the drying rate can be reduced by adding silicone oil.

It is explanatory drawing of the film | membrane formation method of 1st Embodiment. It is a perspective view of a droplet discharge device. It is side surface sectional drawing of an inkjet head. It is a top view which shows the structure of an organic electroluminescent apparatus typically. It is the elements on larger scale of the side surface cross section along the AB line of FIG. It is 1st explanatory drawing of the manufacturing method of an organic electroluminescent apparatus. It is 2nd explanatory drawing of the manufacturing method of an organic electroluminescent apparatus. It is explanatory drawing of the film formation method of 2nd Embodiment. It is explanatory drawing of the film formation method of 3rd Embodiment. It is a perspective view of a mobile phone.

Explanation of symbols

  2 liquid 4 droplet 6 coating 48 substrate

Claims (15)

A film forming method for forming a film by applying a liquid material,
A film characterized by adsorbing a gas-liquid interface adsorbent having a higher boiling point than the solvent or dispersion medium of the liquid material and having surface orientation to the liquid material on the surface of the applied liquid material Forming method. The film forming method according to claim 1, wherein the gas-liquid interface adsorbent is silicone oil or a silane coupling agent. The film forming method according to claim 1, wherein the gas-liquid interface adsorbent is mixed in the liquid before application. The concentration of the gas-liquid interface adsorbent in the liquid before application is about 1.0 × 10 ⁻⁷ wt% or more and about 0.1 wt% or less with respect to the liquid. Item 4. The film forming method according to Item 3. 3. The film forming method according to claim 1, wherein the gas-liquid interface adsorbent is applied in advance on a substrate to which the liquid material is applied. The film forming method according to claim 1, wherein the gas-liquid interface adsorbent is sprayed on a surface of the applied liquid material. A film forming method in which a liquid material is sequentially applied to a plurality of adjacent regions to form a film, and the gas-liquid interface adsorbent is adsorbed only on the surface of the liquid material applied to some of the regions. 7. The film forming method according to claim 1, wherein The film forming method according to claim 7, wherein the gas-liquid interface adsorbent is adsorbed only on the surface of the liquid material applied in advance. 7. The film forming method according to claim 1, wherein different gas-liquid interface adsorbents are adsorbed on the surface of the liquid material applied to each of the regions. The boiling point of the gas-liquid interface adsorbent adsorbed on the surface of the liquid material applied earlier is higher than the boiling point of the gas-liquid interface adsorbent adsorbed on the surface of the liquid material applied later. The film forming method according to claim 9. An electro-optical device manufactured using the film forming method according to claim 1. A method of manufacturing an electro-optical device that forms a functional film by applying a liquid material to a plurality of dot regions,
An electric-liquid interface adsorbent having a boiling point higher than that of the solvent or dispersion medium of the liquid and having surface orientation with respect to the liquid is adsorbed on the surface of the applied liquid. Manufacturing method of optical device. 13. The method of manufacturing an electro-optical device according to claim 12, wherein the gas-liquid interface adsorbent is silicone oil or a silane coupling agent. 14. The gas-liquid interface adsorbent is adsorbed only on the surface of the liquid material applied to a part of the dot areas among the adjacent dot areas. Manufacturing method of the electro-optical device. 14. The method of manufacturing an electro-optical device according to claim 12, wherein the different gas-liquid interface adsorbents are adsorbed on the surface of the liquid material applied to the dot regions.

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