JP4597490B2 - Method for manufacturing light emitting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an element (hereinafter referred to as a light emitting element) having a structure in which a thin film (hereinafter referred to as a light emitting layer) that emits light is sandwiched between an anode, a cathode, and a phenomenon called electroluminescence. In the technical field related to a display device (hereinafter referred to as a light-emitting device) provided on a substrate and the technical field related to an electronic device provided with the light-emitting device in a video display unit.
[0002]
[Prior art]
In recent years, development of a light emitting device called an organic EL panel or an organic light emitting diode (OLED) has been urgently developed as an image display. This is because a hole and an electron are recombined in a light emitting layer provided between an electrode for injecting holes (hereinafter referred to as an anode) and an electrode for injecting electrons (hereinafter referred to as a cathode). Thus, a light emission phenomenon called electroluminescence is generated, and image display is made possible by controlling on / off of the light emission.
[0003]
As a light emitting layer used in these light emitting devices, an organic thin film is mainly used. This organic thin film was mainly formed by depositing low molecular weight materials by vapor deposition, but recently, attention has been focused on polymer materials, and development of solution coating methods such as spin coating, ink jet, and printing has been developed. Actively progressing. In particular, the formation of an organic thin film by an ink jet method has already approached a practical level, and the basic technique is disclosed in a patent publication (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-12377
The ink-jet method is a technology that diverts the ink-jet method used in conventional printers to thin film formation, and instead of ink, the solute that is the material of the organic thin film is dissolved or dispersed in a solvent such as water or alcohol. This is a method of applying liquid droplets for each pixel. Naturally, since the droplets adhering onto the pixels (actually the pixel electrodes provided on each pixel) contain a large amount of solvent component, a process for volatilizing the solvent component to remove this (hereinafter referred to as firing process) Is required). That is, after applying droplets by the inkjet method, the entire pixel is heated to volatilize the solvent component, and the remaining solute (organic thin film material) is thinned.
[0006]
Since such a firing process is usually performed in an electric furnace, it causes a decrease in throughput. Further, if the solvent component does not readily evaporate at a low temperature and the solvent component remains in the thin film, it evaporates with time and causes a degassing phenomenon, leading to deterioration of the organic thin film, and further deterioration of the light emitting element. Furthermore, if the heating temperature is raised to completely remove the solvent component, the composition of the organic thin film having low heat resistance will be destroyed.
[0007]
As described above, the film forming method by the ink jet method is a low-cost and simple method and has an advantage that the throughput is fast, but it is a technology that leaves room for improvement in that a baking step is required.
[0008]
[Problems to be solved by the invention]
This invention is made | formed in view of the said problem, and makes it a subject to provide the technique which makes a baking process unnecessary in the method of forming a thin film by apply | coating a solution. Then, it is an object of the present invention to provide a method for manufacturing a light-emitting device with high throughput at a low cost by a simple method by applying the technology to the manufacture of the light-emitting device.
[0009]
[Means for Solving the Problems]
According to the present invention, at least one thin film constituting a light emitter is formed by spraying a solution containing a light emitting material toward a pixel electrode (anode or cathode) under reduced pressure and depositing the light emitter composition on the pixel electrode. It is characterized by forming. At this time, while the solution reaches the pixel electrode, the solvent in the solution is volatilized and the remaining phosphor composition is deposited on the pixel electrode to form at least one thin film constituting the phosphor. Furthermore, the pixel electrode may be heated (room temperature (typically 20 ° C.) to 300 ° C., more preferably 50 to 200 ° C. in consideration of heat resistance of the light emitter). The solution reaches the pixel electrode, and at the same time, the solvent in the solution starts to volatilize, and the remaining phosphor composition is deposited on the pixel electrode to form the phosphor. May be formed. In any case, the feature of the present invention is that at least one thin film constituting the illuminant is formed and at the same time the solvent component is volatilized, eliminating the firing step that has been conventionally required or shortening the firing step. It is.
[0010]
In the present invention, the light emitter is a carrier injection layer (a hole injection layer or an electron injection layer), a carrier transport layer (a hole transport layer or an electron transport layer), a carrier blocking layer (a hole blocking layer or an electron blocking layer). ), An organic compound or an inorganic compound that contributes to recombination of the light emitting layer and other carriers, or a laminate thereof. Moreover, a light-emitting body composition means the composition used as the material of these light-emitting bodies, and it is not ask | required that it is an inorganic compound if it is an organic compound. The luminous body composition is roughly classified into a luminous material and a carrier (hole or electron) transporting material.
[0011]
A light-emitting material is a material that generates a light-emitting phenomenon due to electroluminescence by injecting holes and electrons. Such a luminescent material can be found in both inorganic compounds and organic compounds, but in the method of applying a solution as in the present invention, it is preferable to use an organic compound. As the light-emitting material, a material that emits fluorescence by singlet excitation or a material that emits phosphorescence by triplet excitation may be used. In addition, the hole transporting material is a material that easily moves holes, and the electron transporting material is a material that easily moves electrons.
[0012]
Under reduced pressure refers to a pressure lower than atmospheric pressure, and in an atmosphere filled with nitrogen, a rare gas or other inert gas (hereinafter referred to as an inert atmosphere), 1 × 10 ² to 2 × 10. ^It may be ⁴ Pa (preferably 5 × 10 ^{2 to} 5 × 10 ³ Pa), or 1 to 5 × 10 ⁴ Pa (1 × 10 ² to 1 × 10 ³ Pa) in vacuum. By setting the pressure under reduced pressure, the solvent is volatilized from the droplets until the droplets injected into the atmosphere reach the pixel electrode, and the volume of the droplets decreases. When reaching the pixel electrode, almost all the solvent is volatilized, and at the same time, the film formation is completed. That is, it is superior to the prior art in that it does not require a heating step such as a baking step after application of the solution.
[0013]
In order to volatilize the solvent sufficiently before reaching the pixel electrode, a highly volatile solvent (that is, a solvent having a high vapor pressure) is preferably used as the solvent. This is because if the volatility is low, it is necessary to increase the time required for volatilization by increasing the distance between the pixel electrode and the solution injection port (nozzle tip), but if the distance is long, the ballistic error of the droplet is large. Because it becomes. Examples of the highly volatile solvent include alcohols such as methanol and ethanol.
[0014]
Further, if a solvent having a high boiling point is used without using a highly volatile solvent, it is possible to eliminate anxiety such as clogging of the nozzle tip due to drying of the droplet ejection port. At that time, if the pixel electrode is heated (room temperature (typically 20 ° C.) to 300 ° C., more preferably 50 to 200 ° C. is preferable considering the heat resistance of the light emitter), the liquid is applied to the pixel electrode. Volatilization is started as the droplets arrive, and the firing process can be completed at the same time as the droplets are ejected to other pixels. Of course, the film quality can be further improved by allowing the solvent to volatilize from the droplets until the droplets reach the pixel electrode by the above method and further heating the pixel electrode.
[0015]
As the solvent having a high boiling point, NMP (N-methylpyrrolidone), DMF (dimethylformamide), DMSO (dimethylsulfoxide), HMPA (hexamethylphosphoamide) and other polar solvents can be used. In addition, an aromatic solvent such as an alkylbenzene such as xylene (especially, a long-chain alkylbenzene such as dodecylbenzene is preferable) may be used even in a low polarity solvent. For example, a solvent in which tetralin and dodecylbenzene are mixed at 1: 1 can be used.
[0016]
Note that the present invention can be manufactured for both a passive matrix light-emitting device and an active matrix light-emitting device, and is not particularly limited to the form of the light-emitting device. In addition, the light-emitting material is not limited to an organic compound and can be implemented for an inorganic compound. In particular, when the present invention is implemented, it is effective when laminating organic compounds because a baking step is not particularly required after solution application.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment 1]
An embodiment of the present invention will be described with reference to FIG. FIG. 1A shows a state immediately after a solution containing a luminescent material is sprayed, and FIG. 1B shows that a thin film (luminescent layer) is formed by the luminescent material reaching the anode or the cathode. Represents a state.
[0018]
In FIG. 1A, 101 is an anode or cathode, 102 is an insulator that defines each pixel, and 103 is a carrier injection layer. The carrier injection layer 103 is a hole injection layer if 101 is an anode, and is an electron injection layer if it is a cathode. Reference numeral 104 denotes an enlarged head portion of an apparatus for applying a solution (hereinafter referred to as a solution applying apparatus), and a part thereof shows an internal structure. The head unit 104 includes a plurality of ejecting units 105a to 105c having a function of ejecting a solution containing a luminescent material, and piezoelectric elements (piezo elements) 106a to 106c are provided respectively. Moreover, each of the injection parts 105a-105c is filled with the solution 107a-107c containing a luminescent material.
[0019]
Here, the solution 107a containing a light emitting material contains a light emitting material that emits red light, the solution 107b containing a light emitting material contains a light emitting material that emits green light, and the solution 107c containing a light emitting material is blue. A luminescent material that emits light. These three kinds of luminescent materials constitute a pixel emitting red light, a pixel emitting green light, and a pixel emitting blue light, and these three pixels are regarded as one pixel unit (pixel unit).
[0020]
In FIG. 1 (A), only R (red), G (green), and B (blue) each corresponding to one injection unit is described, but a plurality of injection units (nozzles) are arranged in parallel. In consideration of throughput, it can be said that it is most desirable to arrange the pixels corresponding to the number of pixels (pixel number) corresponding to one row or one column of the pixel portion.
[0021]
The most characteristic point in the present invention is that the space 108 between the head portion 104 and the anode or cathode 101 is maintained at a reduced pressure, that is, a pressure lower than the atmospheric pressure. Specifically, it is 1 × 10 ² to 2 × 10 ⁴ Pa (preferably 5 × 10 ^{2 to} 5 × 10 ³ Pa) in an inert atmosphere, and 1 to 5 × 10 ⁴ Pa (1 × in vacuum). 10 ² to 1 × 10 ³ Pa). The solutions 107 a to 107 c containing the luminescent material filled in the ejection units 105 a to 105 c are pressed and pushed out by the volume change of the piezoelectric elements 106 a to 106 c and ejected toward the pixel electrode 101. Then, the ejected droplet 109 proceeds while volatilizing the solvent under reduced pressure, and the remaining luminescent material is deposited on the pixel electrode 101. As a result, the luminescent material is deposited intermittently.
[0022]
The thin film deposited in this way is thinned with the solvent components removed sufficiently without volatilizing the solvent by means such as heating, so that a light emitting layer with less problems such as deterioration over time due to degassing can be obtained. It is done. Even after the solution is applied with the above-described configuration, a baking step or the like is not required, and the throughput can be greatly improved, and deterioration of the luminescent material itself due to heating can be prevented. The feature of the present invention is that it does not require a baking step, but it is possible to obtain a light emitting layer with a small amount of degassing by sufficiently removing the solvent component even in combination with a baking step such as heat treatment in vacuum. The effect of the invention is not impaired.
[0023]
Thus, as shown in FIG. 1B, a light emitting layer 110a that emits red light, a light emitting layer 110b that emits green light, and a light emitting layer 110c that emits blue light are formed. Thereafter, a carrier transport layer, a carrier injection layer, and the like are formed as necessary, and then a counter electrode (a cathode for an anode and an anode for a cathode) is provided to complete a light emitting element.
[0024]
[Embodiment 2]
This embodiment is an example of applying a gel-like solution having a certain degree of viscosity rather than performing solution application by droplet ejection. FIG. 2A illustrates a state in which a solution containing a luminescent material is sprayed, and FIG. 2B illustrates a state in which injection of the solution containing a luminescent material is stopped. Note that the description of the first embodiment may be referred to for the same reference numerals used in FIG.
[0025]
In the present embodiment, as shown in FIG. 2A, a plurality of ejecting portions 205a to 205c each having a function of ejecting a luminescent material are provided on the head portion 204 of the solution coating apparatus, and each includes a piezoelectric element. (Piezoresistive elements) 206a to 206c are provided. Moreover, each of the injection parts 205a-205c is filled with the solution 207a-207c containing a luminescent material. At this time, similarly to FIG. 1A, the solution 207a containing a luminescent material contains a luminescent material that emits red light, and the solution 207b containing a luminescent material contains a luminescent material that emits green light, The solution 207c containing a light emitting material contains a light emitting material that emits blue light.
[0026]
However, in this embodiment, the viscosity of the solutions 207a to 207c containing the luminescent material is adjusted to be higher than the viscosity of the solutions 107a to 107c containing the luminescent material of the first embodiment. This is so that the solution containing the luminescent material is continuously applied, and as a result, the luminescent material is continuously deposited. Further, as shown in FIG. 2A, when the solutions 207a to 207c containing the light emitting material are applied, the light emitting material is applied by an inert gas such as nitrogen while the piezoelectric elements 206a to 206c are pushed down. It applies so that the solution 207a-207c containing may be pressurized and extruded.
[0027]
Note that the solvents 207a to 207c containing the light-emitting material start to volatilize the solvent immediately after exiting the ejection port, and reach the pixel electrode 101 while gradually reducing the volume. When reaching the pixel electrode 101, most of the solvent is volatilized and the remaining luminescent material is deposited to form a luminescent layer. Of course, the atmosphere in the space 108 is maintained at a reduced pressure as in the first embodiment.
[0028]
In addition, as shown in FIG. 2B, when the application of the solutions 207a to 207c containing the light emitting material is stopped, pressurization with an inert gas is stopped and the piezoelectric elements 206a to 206c are moved upward (in the direction of the arrows). And pushed up. If it carries out like this, since the solution containing a luminescent material will enter from a jet nozzle a little back, it can prevent drying of a solution.
[0029]
Further, by making the space 108 a solvent atmosphere at this time, drying of the solutions 207a to 207c containing the light-emitting material at the injection ports can be prevented. Further, in the present embodiment, an example in which the solution is guided into the ejection port using the piezoelectric elements 206a to 206c has been described, but the same can be performed by setting the space 108 in a pressurized state.
[0030]
Thus, as shown in FIG. 2B, a light emitting layer 210a that emits red light, a light emitting layer 210b that emits green light, and a light emitting layer 210c that emits blue light are formed. The light-emitting layer formed in this way is thinned with the solvent components removed sufficiently without volatilizing the solvent by means of heating or the like. can get. Even after the solution is applied with the above-described configuration, a baking step or the like is not required, and the throughput can be greatly improved, and deterioration of the luminescent material itself due to heating can be prevented.
[0031]
The feature of the present invention is that it does not require a baking step, but it is possible to obtain a light emitting layer with a small amount of degassing by sufficiently removing the solvent component even in combination with a baking step such as heat treatment in vacuum. The effect of the invention is not impaired. Thereafter, after forming a carrier transport layer, a carrier injection layer, and the like as necessary, a counter electrode (a cathode for an anode and an anode for a cathode) is provided to complete a light emitting element.
[0032]
In addition, the present invention can be applied to the manufacture of both a passive matrix light-emitting device and an active matrix light-emitting device, and is not particularly limited to the form of the light-emitting device. In addition, the light-emitting material is not limited to an organic compound and can be implemented for an inorganic compound. In particular, when the present invention is implemented, it is effective when laminating organic compounds because a baking step is not particularly required after solution application.
[0033]
[Embodiment 3]
An embodiment of the present invention will be described with reference to FIG. FIG. 3A shows a state immediately after a solution containing a luminescent material is jetted and the droplets reach the anode or cathode, and FIG. 3B shows that the luminescent material is fired on the anode or cathode. The thin film (light emitting layer) is formed. The solution coating apparatus in FIG. 3 is the same as that described in FIG. 1, and the description of the first embodiment may be referred to for the same reference numerals as those used in FIG.
[0034]
In FIG. 3A, injection units 105a to 105c each including piezoelectric elements (piezo elements) 106a to 106c are filled with solutions 307a to 307c containing a luminescent material. The solutions 307a to 307c containing a luminescent material use a luminescent material that emits red, green, or blue light as a solute, and have a high boiling point as a solvent (however, room temperature (typically 20 ° C.) to 300 ° C. Preferably, those which volatilize at a temperature of 50 to 200 ° C. are used. Therefore, the solutions 307a to 307c containing the light emitting material are very difficult to dry.
[0035]
A liquid pool 307a to 307c containing such a luminescent material is extruded by the piezoelectric elements 106a to 106c and ejected from the plurality of ejection units 105a to 105c, and a liquid pool immediately after reaching the anode or cathode 101 is represented by 309. ing. Of course, the space 108 between the head unit 104 and the anode or cathode 101 is maintained at a reduced pressure, that is, a pressure lower than the atmospheric pressure. Specifically, it is 1 × 10 ² to 2 × 10 ⁴ Pa (preferably 5 × 10 ^{2 to} 5 × 10 ³ Pa) in an inert atmosphere, and 1 to 5 × 10 ⁴ Pa (1 × in vacuum). 10 ² to 1 × 10 ³ Pa).
[0036]
At this time, the anode or cathode 101 is heated at room temperature (typically 20 ° C.) to 300 ° C., more preferably 50 to 200 ° C., and the liquid pool 309 immediately after reaching the anode or cathode 101 is obtained. Evaporates the solvent from the point of arrival. Note that although only one line of pixels is described in FIG. 3A, pixels in a plurality of lines are arranged in parallel in an actual pixel portion, and solutions 307a to 307c containing a light-emitting material are added to each pixel. It will be injected sequentially. Therefore, a certain time is required to apply the entire pixel, and this embodiment uses the certain time to finish the baking process.
[0037]
The thin film deposited in this way has almost completed the baking process when the entire pixel portion has been applied. Although the baking process itself is performed, the process time can be significantly reduced compared to the conventional method. is there. Thus, as shown in FIG. 3B, a light emitting layer 310a that emits red light, a light emitting layer 310b that emits green light, and a light emitting layer 310c that emits blue light are formed. Thereafter, a carrier transport layer, a carrier injection layer, and the like are formed as necessary, and then a counter electrode (a cathode for an anode and an anode for a cathode) is provided to complete a light emitting element.
[0038]
Note that when the solution is applied by an inkjet method using a solution containing a light-emitting material using a solvent having a high boiling point, the structure of this embodiment in which the entire pixel portion which is a formation portion is heated is described in the embodiment. Even when applied to the solution coating apparatus having the configuration of Embodiment 2 as well as 1, the same effect as that of the present embodiment can be obtained.
[0039]
[Embodiment 4]
In this embodiment, a technique for filling a phosphor composition without exposing it to the atmosphere when filling the head portion with the solution containing the phosphor composition shown in Embodiments 1 and 2 will be described. To do.
[0040]
FIG. 4 is a cross-sectional view of a container (canister can) for mounting (stock) a solution containing a phosphor composition on a solution coating apparatus. The container 351 is preferably formed of a material having sufficient confidentiality, particularly sufficient resistance to permeation of oxygen and moisture, and stainless steel, aluminum, or the like may be used. The inner surface is preferably mirror-finished. Furthermore, a silicon nitride film, a diamond-like carbon film, or other insulating film having a low oxygen permeability may be provided on the inner surface and / or the outer surface as necessary. This is for preventing deterioration of the solution 352 containing the phosphor composition provided inside the container 351.
[0041]
Reference numeral 353 denotes an inlet for introducing nitrogen, a rare gas, or other inert gas into the container 351, from which an inert gas is introduced to increase the internal pressure of the container. Reference numeral 354 denotes a lead-out port for sending the solution 352 containing the phosphor composition delivered by pressurization to the head portion of a solution coating apparatus (not shown). The inlet 353 and the outlet 354 may be formed of a material different from that of the container 351 or may be integrally formed.
[0042]
Note that reference numeral 356 denotes an introduction pipe connected to the introduction port 353. When an inert gas is actually introduced, the distal end of the introduction pipe 356 is connected to the introduction port 353 to introduce the inert gas. Similarly, the tip of the outlet tube 357 is connected to the outlet 354 to lead out the solution 352 containing the phosphor composition. In the figure, since it is removable, it is represented by a dotted line.
[0043]
Each head portion shown in the first embodiment and the second embodiment is attached to the extended tip of the outlet tube 357. In the case of the first embodiment, the solution 352 containing the phosphor composition can be intermittently ejected by vibrating the piezoelectric elements 106a to 106c in a state where the inside of the container 351 is pressurized with an inert gas. Become. Further, in the case of Embodiment 2, it is possible to apply continuously while the inside of the container 351 is pressurized with an inert gas, and when the pressurization is stopped, the solution 352 containing the phosphor composition is also ejected. Stop.
[0044]
Further, the present embodiment is characterized in that the solution 352 containing the phosphor composition is always transported in a state of being cut off from the atmosphere after being put into the container 351 and attached to the solution coating apparatus. That is, a manufacturer that manufactures the solution 352 containing the phosphor composition puts the solution 352 containing the phosphor composition into the container 351 and transports it without opening to the atmosphere while maintaining airtightness, and directly into the solution coating apparatus. It can be attached. This is a device made in view of the fact that the phosphor composition is weak in resistance to oxygen and moisture and easily deteriorates, and after purifying the phosphor composition, it maintains the purity as it is purified until it is applied. Therefore, it contributes to the suppression of deterioration of the phosphor composition, and thus to the improvement of the reliability of the light emitting device.
[0045]
Note that the container shown in FIG. 4 in this embodiment is an example suitable for transporting while maintaining the purity of the solution containing the phosphor composition, and limits the containers that can be used in the present invention. is not.
[0046]
[Embodiment 5]
This embodiment is characterized in that light in a long wavelength region is used for heating the entire pixel portion in Embodiment 3. The structure of this embodiment will be described with reference to FIGS. 5A is a top view illustrating a heating method in this embodiment, FIG. 5B is a cross-sectional view taken along line AA ′, and FIG. 5C is a line taken along BB. FIG.
[0047]
In FIG. 5A, reference numeral 601 denotes a substrate which transmits at least light having a wavelength longer than that of visible light (typically light having a wavelength longer than 300 nm), over which a thin film transistor, a pixel electrode, and the like are provided. It has been. The substrate 601 is transported in the direction of arrow 602 by a transport mechanism (not shown).
[0048]
In addition, a head portion 603 of a solution coating apparatus is installed above the surface side of the substrate 601, and the solution containing the phosphor composition is applied in the manner described in the first to third embodiments. The applied phosphor composition 604 is heated by light emitted from a lamp 605 (hereinafter, referred to as lamp light) disposed below the back side of the substrate 601, and the solvent is volatilized (baked). 606. That is, after the applied phosphor composition 604 is applied, it is fired sequentially with lamp light to form a thin film.
[0049]
That is, as the substrate 601 moves, the head portion 603 and the lamp 605 are scanned in a direction opposite to the moving direction of the substrate 601. Of course, the substrate 601 can be fixed and the head portion 603 and the lamp 605 can be scanned. At this time, the head 603 is always scanned first. As a result, the solution application by the head portion 603 and the subsequent baking process by the lamp light are performed almost simultaneously, and an effect equivalent to substantially reducing the baking process can be obtained.
[0050]
Note that light that can be used as lamp light is light having a wavelength that allows heating only without destroying the composition of the light emitter 606. Specifically, light having a wavelength longer than 400 nm, that is, infrared light. The above long wavelength light is good. For example, electromagnetic waves in a wavelength region from 1 μm to 10 cm from far infrared to microwave can be used. In particular, from the viewpoint of handling, it is preferable to use far infrared rays (typically a wavelength of 4 to 25 μm).
[0051]
In this example, the entire surface application is completed by one scan of the head unit 603. However, after the substrate 601 is reciprocated several times and overcoated several times, the lamp 605 is scanned. You can go. At this time, the lamp 605 may be turned off during the first several scans of the head unit 603, and the lamp 605 may be scanned and emitted in synchronization with the last scan of the head unit 603.
[0052]
As described above, by using a light source such as a lamp as a heating means in the firing process and irradiating light having a wavelength longer than infrared light, the phosphor composition can be applied and fired almost simultaneously. In other words, a process in which the firing step is omitted can be obtained. Thereby, the throughput of the manufacturing process of the light emitting device can be improved.
[0053]
[Embodiment 6]
Examples of the light emitters shown in Embodiments 1 to 5 include a light emitting layer, a hole injection layer, a hole transport layer, a hole blocking layer, an electron injection layer, an electron transport layer or an electron blocking layer, or a laminate thereof. Although these are mentioned, these may be comprised only with an organic compound, and the composite_body | complex (composite) which laminated | stacked the organic compound and the inorganic compound may be sufficient as it.
[0054]
Therefore, in this embodiment, an example in which a composite in which an organic compound and an inorganic compound are combined is used as a light emitter of the light emitting device of the present invention will be described. In addition, as a patent characterized by a hybrid structure in which an organic compound and an inorganic compound are laminated, there is US Pat. No. 5,895,932, which describes ultraviolet light (wavelength 380 nm) emitted from a diode made of an inorganic compound. ) To an organic compound Alq ₃ (Tris-8-quinolinolato aluminum complex) and take out light generated by a phenomenon called photoluminescence, and the light emitter described in the present embodiment, That is, it is a technical idea that is fundamentally different from composites.
[0055]
Among organic compounds, a high molecular weight organic compound (hereinafter referred to as an organic polymer) has high heat resistance and is easy to handle, so that it is used as a solute in a film forming method by solution coating. In this embodiment, an example in which a composite of an organic polymer and an inorganic compound is used as a light emitter will be described.
[0056]
As an example of laminating an organic polymer and an inorganic compound to form a light emitter, there are typically the following four patterns.
(A) Combination of a hole injection layer (or hole transport layer) made of an inorganic compound and a light emitting layer made of an organic polymer (b) Light emission made of an electron injection layer (or an electron transport layer) made of an inorganic compound and an organic polymer (C) A combination of a light emitting layer made of an inorganic compound and a hole injection layer (or hole transport layer) made of an organic polymer (d) A light emitting layer made of an inorganic compound and an electron injection layer made of an organic polymer ( Or an electron transport layer)
Moreover, as an example of forming a light emitter by mixing an organic polymer and an inorganic compound, there are typically the following three patterns.
(E) A combination in which an organic polymer having carrier transportability is used as a light-emitting layer, and an inorganic compound is mixed in the organic polymer. (F) Organic polymer and inorganic compound having carrier transportability of the same polarity (n-type or p-type) (G) A combination in which an organic polymer having carrier transportability is mixed with an inorganic compound having carrier acceptability.
Examples of the configuration (g) include a combination of an organic polymer having a hole transporting property and an inorganic compound having an electron accepting property. In this case, the inorganic compound having an electron-accepting property has a configuration in which electrons are received from the organic polymer, and as a result, holes are generated in the organic polymer, and the holes are transported to obtain transportability.
[0059]
In the structures (a) to (g), a p-type semiconductor material such as NiO (nickel oxide) can be used as a hole injection layer or a hole transport layer made of an inorganic compound, and an electron made of an inorganic compound. An n-type semiconductor material such as ZnO (zinc oxide) or TiO ₂ (titanium dioxide) can be used as the injection layer or the electron transport layer, and ZnS (zinc sulfide), CdS (as a light emitting layer made of an inorganic compound) can be used. Cadmium sulfide) can be used.
[0060]
For example, as an example of the configuration of the above (b), an example in which PPV (polyparaphenylene vinylene) is used as an organic polymer, CdS is used as an inorganic compound, and these are prepared by solution coating. In this case, when forming CdS, it is possible to apply CdS nano-particles (fine particles of several nm to several tens of nm; the same applies hereinafter) dispersed in a solvent. What is necessary is just to implement a process. Instead of CdS, an n-type semiconductor material such as ZnO or TiO ₂ or a p-type semiconductor material such as NiO may be used.
[0061]
Moreover, as an example of the structure of said (e), the example which uses PVK (polyvinylcarbazole) as an organic polymer, uses CdS as an inorganic compound, and produces these by solution coating is mentioned. In this case, CdS emits light with the light emission center. When CdS is formed, CdS fine particles can be dispersed and applied in a solvent, and the coating process of the present invention may be performed in this coating process. An inorganic compound such as ZnS can be used instead of CdS. Since these CdS and ZnS are inorganic compounds that can easily form nanoparticles, they are very suitable materials when solution coating is used as in the present invention.
[0062]
In addition, as an example of the configuration of (g), PC (polycarbonate) is used as an organic polymer, and TPD (triphenyldiamine), which is a hole-transporting inorganic compound, and Ti alkoxide are mixed with this PC. An example of forming a light-emitting body in which PC, TPD and TiO ₂ are mixed by applying hydrolysis and vacuum heating after coating is given. In this case, when CdS is formed, the fine particles of CdS can be dispersed and applied in a solvent, and the coating process of the present invention may be performed in this coating process.
[0063]
As described above, a composite phosphor can be manufactured by using various organic compounds and inorganic compounds, and the manufacturing method of the present invention can be carried out during the formation. It is.
[0064]
Note that the structure of the light emitter (composite) shown in this embodiment can be manufactured by any of the methods in Embodiments 1 to 3, and can be stored in the container shown in Embodiment 4. Is possible.
[0065]
[Embodiment 7]
In this embodiment, an example of a light-emitting device that can be manufactured by implementing the present invention will be described with reference to FIGS. In the pixel structure shown in FIG. 6A, 401 is a data signal line, 402 is a gate signal line, 403 is a power supply line, 404 is a thin film transistor for switching (hereinafter referred to as switching TFT, the same applies hereinafter), and 405 is for holding charge. 406 is a driving thin film transistor (referred to as driving TFT, hereinafter the same) 407 for supplying a current to the light emitting element, 407 is a pixel electrode connected to the drain of the driving TFT, and the pixel electrode 407 is a light emitting element. Functions as an anode. Reference numeral 412 denotes a counter electrode, and the counter electrode 412 functions as a cathode of the light emitting element.
[0066]
FIG. 6B shows a drawing corresponding to the cut surface at AA ′ at this time. In FIG. 6B, reference numeral 410 denotes a substrate, and a glass substrate, a quartz substrate, a plastic substrate, or other light-transmitting substrate can be used. A driving TFT 406 is formed on the base 410 using a semiconductor process. In addition, an insulator 408 patterned in a lattice shape is provided so as to cover the end portion of the pixel electrode 407 formed to be connected to the driving TFT 406 and at least the driving TFT and the switching TFT.
[0067]
On these pixel electrodes 407, light emitters 411a to 411c, a counter electrode 412 functioning as a cathode, and a passivation film 413 are provided. The light emitters 411a to 411c refer to a carrier injection layer, a carrier transport layer, a carrier blocking layer, a light emitting layer, an organic compound or an inorganic compound that contributes to recombination of carriers, or a laminate thereof. Known structures and materials may be used for the laminated structure and materials of the light emitters 411a to 411c.
[0068]
For example, as described in JP 2000-268967 A, JP 2000-294375 A, and the like, at least one of the light emitters has high resistance (resistivity is 1 to 1 × 10 ¹¹ Ω · cm). Inorganic hole injection layer (or inorganic hole transport layer) may be included. This inorganic hole injecting layer comprises, as a first component, an alkali metal element selected from Li, Na, K, Rb, Cs and Fr, an alkaline earth metal element selected from Mg, Ca and Sr, or La and A lanthanoid element selected from Ce is included, and an element selected from Zn, Sn, V, Ru, Sm and In is included as the second component. Further, at least one layer of the light emitters may include an inorganic electron transport layer having a high resistance (a resistivity of 1 to 1 × 10 ¹¹ Ω · cm). This inorganic hole injection layer is made of a metal element selected from Au, Cu, Fe, Ni, Ru, Sn, Cr, Ir, Nb, Pt, W, Mo, Ta, Pd and Co, or an oxide or carbide thereof. , Nitrides, silicides or borides. The main component of the inorganic hole injection layer may be silicon, germanium, or silicon germanium oxide. Thus, reliability as a light-emitting element can be increased by using a stable inorganic insulating film as a material for part of the light-emitting body.
[0069]
As the counter electrode 412, an aluminum film or a silver thin film containing an element belonging to Group 1 or Group 2 of the periodic table can be used. In the present embodiment, light emitted from the light emitters 411a to 411c is used. Therefore, the film thickness is desirably 50 nm or less. As the passivation film 413, a silicon nitride film, an aluminum nitride film, a diamond-like carbon film, or other insulating films that have high blocking properties against moisture and oxygen can be used.
[0070]
By implementing the present invention in manufacturing a light-emitting device having the above structure, it becomes possible to produce a light-emitting device with high throughput by a low-cost and simple method, and further improve the reliability of the light-emitting device. Can do.
[0071]
[Embodiment 8]
In this embodiment, an example of a light-emitting device that can be manufactured by implementing the present invention will be described with reference to FIGS. In the pixel structure shown in FIG. 7A, reference numeral 501 denotes a data signal line, 502 denotes a gate signal line, 503 denotes a power supply line, 504 denotes a switching TFT, 505 denotes a charge holding capacitor, 506 denotes a driving TFT, and 507 denotes a driving TFT. The drain electrode 508 is a pixel electrode connected to the drain electrode of the driving TFT, and the pixel electrode 508 functions as an anode of the light emitting element. The pixel electrode 508 is preferably made of a conductive film that is transparent to visible light so that light emitted from the light emitter can pass through, such as ITO (compound of indium oxide and tin oxide), indium oxide and zinc oxide. It is preferable to use an oxide conductive film such as the above compound. Reference numeral 512 denotes a counter electrode, and the counter electrode 512 functions as a cathode of the light emitting element.
[0072]
FIG. 7B shows a drawing corresponding to the cut surface at AA ′ at this time. In FIG. 7B, reference numeral 510 denotes a substrate, and a glass substrate, a quartz substrate, a plastic substrate, or another light-transmitting substrate can be used. A driving TFT 506 is formed on the base 510 using a semiconductor process. In addition, an insulator 509 patterned in a lattice shape is provided so as to cover the end portion of the pixel electrode 508 formed to be connected to the driving TFT 506 and at least the driving TFT and the switching TFT.
[0073]
On these pixel electrodes 508, light emitters 511a to 511c, a counter electrode 512 functioning as a cathode, and a passivation film 513 are provided. The light emitters 511a to 511c refer to a carrier injection layer, a carrier transport layer, a carrier blocking layer, a light emitting layer, an organic compound or an inorganic compound that contributes to carrier recombination, or a stacked body thereof. Known structures and materials may be used for the laminated structures and materials of the light emitters 511a to 511c.
[0074]
For example, as described in JP 2000-268967 A, JP 2000-294375 A, and the like, at least one of the light emitters has high resistance (resistivity is 1 to 1 × 10 ¹¹ Ω · cm). Inorganic hole injection layer (or inorganic hole transport layer) may be included. This inorganic hole injecting layer comprises, as a first component, an alkali metal element selected from Li, Na, K, Rb, Cs and Fr, an alkaline earth metal element selected from Mg, Ca and Sr, or La and A lanthanoid element selected from Ce is included, and an element selected from Zn, Sn, V, Ru, Sm and In is included as the second component. Further, at least one layer of the light emitters may include an inorganic electron transport layer having a high resistance (a resistivity of 1 to 1 × 10 ¹¹ Ω · cm). This inorganic hole injection layer is made of a metal element selected from Au, Cu, Fe, Ni, Ru, Sn, Cr, Ir, Nb, Pt, W, Mo, Ta, Pd and Co, or an oxide or carbide thereof. , Nitrides, silicides or borides. The main component of the inorganic hole injection layer may be silicon, germanium, or silicon germanium oxide. Thus, reliability as a light-emitting element can be increased by using a stable inorganic insulating film as a material for part of the light-emitting body.
[0075]
As the counter electrode 512, an aluminum film or a silver thin film containing an element belonging to Group 1 or Group 2 of the periodic table can be used. As the passivation film 513, a silicon nitride film, an aluminum nitride film, a diamond-like carbon film, or other insulating films having high blocking properties against moisture and oxygen can be used.
[0076]
By implementing the present invention in manufacturing a light-emitting device having the above structure, it becomes possible to produce a light-emitting device with high throughput by a low-cost and simple method, and further improve the reliability of the light-emitting device. Can do.
[0077]
[Embodiment 9]
In this embodiment mode, an example of a multi-chamber manufacturing apparatus that automates the steps from formation of a light emitter to sealing of a light emitting element is shown in FIG. In FIG. 8, 11 is a receiving substrate preparation chamber, 12, 14 a, 18, and 24 are transfer chambers (also referred to as common chambers) for transferring the substrate to be processed to each chamber (chamber), and 15, 17, and 21 are each transfer. A delivery chamber 29 for delivering the substrates between the chambers is an extraction chamber for processed substrates. Reference numeral 13 denotes a pretreatment chamber in which the electrode surface is previously cleaned or the work function is adjusted before the light emitter is formed.
[0078]
In addition, 16R, 16G, and 16B are emission layer deposition chambers corresponding to red, blue, and green, 16H is a hole injection layer (HIL) or hole transport layer (HTL) deposition chamber, and 16E is electron injection. This is a film formation chamber for a layer (EIL) or an electron transport layer (ETL). The present invention can be implemented by providing a solution coating apparatus which is a feature of the present invention in any one or a plurality of these film forming chambers. Note that in the case where it is necessary to use a spin coating method in order to form a hole injection layer, a hole transport layer, an electron injection layer, or an electron transport layer, a film formation chamber for spin coating may be provided separately.
[0079]
Reference numeral 19 denotes a film forming chamber for an oxide conductive film, 20 denotes a film forming chamber for forming a metal film to be a cathode, and 23 denotes a film forming chamber for forming an insulating film used as a passivation film. The film formation chamber 20 can be a film formation chamber by vapor deposition, but in the case of vapor deposition, there is a concern that the TFT and the luminescent material may be deteriorated by radiation such as X-rays and electron beams. It is desirable to use a film formation chamber by the method.
[0080]
Reference numeral 27 denotes a sealing substrate load chamber for stocking a sealing substrate for sealing, 25 denotes a dispenser chamber for forming a sealing material, and 26 denotes a light emitting device by bonding the substrate to be processed and the sealing substrate together. It is the sealing chamber for sealing. Since these sealing chambers and the like are provided, the manufacturing apparatus described in this embodiment can seal a light-emitting element without being exposed to the atmosphere even once, and realizes a highly reliable light-emitting device. This is an effective configuration.
[0081]
In the manufacturing apparatus of FIG. 8, each chamber is partitioned by a gate valve, and can be hermetically cut off from other chambers. Further, each chamber is connected to an evacuation pump so that a vacuum can be maintained or an inert gas can be introduced to create a reduced pressure atmosphere. As the vacuum pump, a magnetic levitation turbo molecular pump, a cryopump or a dry pump can be used. Further, it is desirable that the inert gas to be introduced is sufficiently purified in advance through a purifier or the like.
[0082]
In addition, the structure of the manufacturing apparatus shown in FIG. 8 is an example to the last, and does not limit this invention at all. This embodiment mode shows that a solution coating apparatus for carrying out the method for manufacturing a light emitting device according to the present invention can be combined with a multi-chamber manufacturing apparatus. Embodiment Modes 1 to 8 The present invention can also be implemented when a light-emitting device is manufactured in combination with any of the above structures.
[0083]
[Embodiment 10]
In this embodiment mode, FIG. 9 shows an example in which a solution coating apparatus used for carrying out the present invention is combined with an in-line manufacturing apparatus for performing steps from the formation of a light emitter to the formation of a cathode. FIG. 9A is a top view and FIG. 9B is a side view.
[0084]
9A and 9B, 41 is a load chamber for carrying in a substrate, 42 is an unload chamber for carrying out a substrate, 43 is a film forming chamber for forming a hole injection layer, and 44 is a hole. A film formation chamber for forming a transport layer, 45 a film formation chamber for forming a light emitting layer, 46 a film formation chamber for forming an electron injection layer, and 47 a film formation chamber for forming a metal film serving as a cathode. is there. An arrow 50 in the figure is the transport direction of the substrate 40, and a substrate that has already been processed is indicated by a dotted line. At this time, the substrate 40 is conveyed in an upright state, that is, in a state where the surface (surface to be processed) is parallel to the direction of gravity.
[0085]
Each of the film forming chambers 43 to 46 is a solution coating apparatus for carrying out the present invention, and head portions 43a, 44a, 45a, 46a are provided therein. Each of these head portions has the structure described in the first embodiment or the second embodiment, and a solution containing an organic compound or an inorganic compound is applied and a thin film is formed under reduced pressure. Of course, a mechanism for heating the substrate 40 at room temperature (typically 20 ° C.) to 300 ° C., more preferably 50 to 200 ° C., may be provided.
[0086]
In FIG. 9B, a side view of the film formation chamber (light emitting layer) 45 corresponds to a state in which the head portion moving along the substrate surface is viewed from above. An arrow 51 indicates the moving direction of the head portion 45a. The head moves from one end of the substrate 40 to the other end in parallel with the substrate surface, and solution application and thin film formation are performed. In addition, the distance (L) between the substrate 40 and the tip portion (jet port) of the head portion 45a is 2 to 20 mm.
[0087]
Further, at this time, nitrogen, rare gas or other fluorinated gas flows in the film forming chambers 43 to 46 from the top to the bottom in the direction perpendicular to the paper surface, and the substrate 40 and the head portions 43a to 46a. A laminar flow (laminar flow) is formed between them. At this time, the flowing inert gas can be heated instead of or in combination with the substrate. Of course, it is possible to create a vacuum without introducing an inert gas.
[0088]
The film formation chamber 47 is a chamber for forming a metal film to be a cathode by sputtering, and film formation is performed while the substrate 40 passes beside the rectangular target 47a. For example, a metal film containing an element belonging to Group 1 or Group 2 of the periodic table, such as an alloy film of aluminum and lithium, can be formed. The shape of the target 47a is not limited to this, but as a merit of placing the substrate 40 vertically, a high throughput can be ensured by using a linear, rectangular, oblong or other elongated target. The point that an apparatus area can be made small is mentioned.
[0089]
A feature of the present invention is that a thin film is formed at the same time as the application of a solution, so that a baking step or the like is unnecessary, but a baking step such as heating in a vacuum between the film forming chambers 43 to 47 is possible. May be provided. This is because if the solvent component is removed from the thin film such as the light emitting layer, the reliability is considered to be improved accordingly.
[0090]
[Embodiment 11]
In this embodiment mode, FIG. 10 shows an example in which a solution coating apparatus used for carrying out the present invention is combined with an in-line manufacturing apparatus for performing steps from formation of a light emitter to sealing of a light emitting element. 10A is a top view of the manufacturing apparatus, and FIG. 10B is a side view of the manufacturing apparatus.
[0091]
10A and 10B, 61 is a load chamber for carrying in a substrate, 62 is an unload chamber for carrying out a substrate, 63 is a film forming chamber for forming a hole injection layer, and 64 is a light emitting layer. , 65 is a film forming chamber for forming an electron injection layer, 66 is a film forming chamber for forming a metal film serving as a cathode, and 67 is a film forming a protective film having a passivation effect. It is a room. An arrow 70 in the figure is the direction in which the substrate 60 is transported, and a substrate that has already been processed is represented by a dotted line. At this time, the substrate 60 is transported in an upright state, that is, in a state where the surface (surface to be processed) is parallel to the direction of gravity.
[0092]
Each of the film forming chambers 63 to 65 is a solution coating apparatus for carrying out the present invention, and is provided with head portions 63a, 64a, and 65a. Each of these head portions has the structure described in the first embodiment or the second embodiment, and a solution containing an organic compound or an inorganic compound is applied and a thin film is formed under reduced pressure. Of course, a mechanism for heating the substrate 60 at room temperature (typically 20 ° C.) to 300 ° C., more preferably 50 to 200 ° C., may be provided.
[0093]
In FIG. 10B, a side view of the film formation chamber (light emitting layer) 64 corresponds to a state in which the head portion moving along the substrate surface is viewed from above. An arrow 71 indicates the moving direction of the head portion 64a. The head moves from one end of the substrate 60 to the other end in parallel with the substrate surface, and solution application and thin film formation are performed. In addition, the distance (L) between the substrate 60 and the tip portion (jet port) of the head portion 64a is 2 to 20 mm.
[0094]
Further, at this time, nitrogen, rare gas or other fluorinated gas flows in the film forming chambers 63 to 65 from the top to the bottom in the direction perpendicular to the paper surface, and the substrate 60 and the head portions 63a to 65a. A laminar flow (laminar flow) is formed between them. At this time, the flowing inert gas can be heated instead of or in combination with the substrate. Of course, it is possible to create a vacuum without introducing an inert gas.
[0095]
The film formation chamber 66 is a chamber for forming a metal film to be a cathode by sputtering, and film formation is performed while the substrate 60 passes by a rectangular target 66a. For example, a metal film containing an element belonging to Group 1 or Group 2 of the periodic table, such as an alloy film of aluminum and lithium, can be formed. The shape of the target 66a is not limited to this, but as a merit of placing the substrate 60 vertically, a high throughput can be secured by using a linear, rectangular, oblong or other elongated target. The point that an apparatus area can be made small is mentioned.
[0096]
The film formation chamber 67 is a chamber for forming an insulating film having a passivation effect by sputtering (preferably high frequency sputtering), and the substrate 60 passes by a rectangular target 67a as in the seventh embodiment. In the meantime, film formation is performed. For example, a highly dense silicon compound film such as a silicon nitride film or a silicon nitride oxide film can be formed. The shape of the target 67a is not limited to this, but as a merit of placing the substrate 60 vertically as in the seventh embodiment, a linear, rectangular, oblong or other elongated target is used. Therefore, it is possible to reduce the device area while ensuring a higher throughput.
[0097]
A feature of the present invention is that a thin film formation is performed at the same time as the application of the solution, so that a baking step or the like is unnecessary. However, a baking step such as heating in a vacuum between the film forming chambers 63 to 66 is possible. May be provided. This is because if the solvent component is removed from the thin film such as the light emitting layer, the reliability is considered to be improved accordingly.
[0098]
[Embodiment 12]
In the tenth embodiment and the eleventh embodiment, the case where the substrate is erected, that is, the case where the surface to be processed is transported in a state parallel to the direction of gravity has been described. This example will be described with reference to FIG.
[0099]
FIGS. 11A and 11B are diagrams illustrating a manufacturing process of a light emitter in this embodiment mode, in which a head portion 801 of a solution coating apparatus is scanned along the surface of a substrate 800. A solution containing a phosphor composition is ejected from the head portion 801 in the manner shown in the first to third embodiments, and the phosphor 802 is formed without any particular firing step. At this time, a feature of this embodiment is that the substrate 800 is installed with a certain inclination with respect to the direction of gravity. If this inclination is too small, the advantage of space-saving of the manufacturing apparatus is impaired, so 70-95 ° (more preferably 80-90 °) may be used.
[0100]
Another feature of the present embodiment is that a means for preventing drying of the ejection openings of the head unit 801 is taken after completion of a predetermined coating process on the entire substrate. That is, a storage portion 803 for storing the head portion 801 is installed under the substrate 800, and the inside thereof is filled with a gas obtained by volatilizing the solvent. A gas in which the solvent is volatilized (a gas containing a solvent component) is introduced from the introduction port 804 and then filled into the storage portion 803 through a plurality of openings 805 provided in the lower portion of the storage portion 803.
[0101]
The “gas in which the solvent is volatilized” is a solvent that can dissolve the light emitter to be formed, and is preferably the same as the solvent of the solution containing the light emitter composition ejected by the head portion 801. Of course, it is not necessary to limit to the same thing, What is necessary is just to change suitably according to the kind of light-emitting body which should be formed.
[0102]
Next, FIGS. 11C and 11D show the state of the head portion 801 at the time when the light emitter formation process is completed. As shown in FIGS. 11C and 11D, the head unit 801 is stored so as to be completely hidden inside the storage unit 803, and is exposed to an atmosphere of solvent gas. At this time, it is effective to provide a lid portion in the storage portion 803, and after the head portion 801 is stored, cover the storage portion 803 to suppress diffusion of the solvent component to the outside. Of course, since the head portion is fixed and scanned by a support material (not shown) or the like, it is natural to cover the head portion while avoiding this.
[0103]
As described above, the present embodiment is characterized in that after the step of forming a light emitter, the head portion is exposed to an atmosphere filled with a solvent capable of dissolving the light emitter to be formed. Since the phosphor composition is dissolved by the solvent at the ejection port of the head unit 801, clogging does not occur due to drying or the like. In other words, since it is in an environment where it does not dry even if the injection of the phosphor composition is stopped, there is no need to prevent continuous drying by constantly injecting the solution as in the conventional inkjet method, and the ratio of wasteful injection and discharge is reduced. Thus, the utilization efficiency of the phosphor composition can be improved.
[0104]
Note that this embodiment mode describes a case where the present invention is applied to a method for manufacturing a light-emitting device in which a solution is applied in a state where a substrate is erected, but the head portion is exposed to an atmosphere filled with the solvent component after application to prevent drying. Needless to say, this technical idea can also be applied to the case where the substrate is placed horizontally as in the prior art.
[0105]
In addition, this embodiment can be combined with a manufacturing apparatus including any of the configurations of Embodiments 4, 5, and 9 to 11, and is a light emitting device including any of the configurations of Embodiments 6 to 8. It can also be used for the manufacturing method.
[0106]
[Embodiment 13]
In this embodiment mode, a structure of a head portion of a solution coating apparatus used for a method for manufacturing a light-emitting device according to the present invention will be described with reference to FIGS. In addition, although this Embodiment is an aspect (it respond | corresponds to Embodiment 10 and 11) apply | coated in the state which stood the board | substrate, it cannot be overemphasized that it can implement also when a board | substrate is placed horizontally. Yes.
[0107]
In FIG. 12A, a substrate 901 is supported by a susceptor 902 made of a magnetic material, and is installed vertically (including an oblique case). And the head part 903 of a solution coating apparatus is provided close to the surface side of the substrate 901. At this time, an enlarged portion of the tip of the nozzle (injection port) 904 is indicated by a dotted line portion 905. The inside of the nozzle has a hollow structure, and a cap 906 fixed to the inside of the nozzle and a cap made of a magnetic body connected to the core 906 via an elastic body (a spring in this embodiment) 907 (hereinafter referred to as magnetic 908). The outer side of the hollow structure is filled with a solution 909 containing a phosphor composition.
[0108]
The magnetic cap 908 is selected from a material that exerts a repulsive force between the magnetic cap 908 and the susceptor 902 made of a magnetic material. In the case of FIG. 12A, the distance (X1) between the substrate 901 and the magnetic cap 908 is a distance at which repulsive force does not work effectively between the susceptor 902 and the magnetic cap 908, and the magnetic material And the distance determined by the thickness of the substrate. When the repulsive force does not work effectively between the susceptor 902 and the magnetic body cap 908, the magnetic body cap 908 is pushed by the elastic body 907 and packed at the tip of the nozzle 904, and the solution 909 containing the phosphor composition is formed. It is designed not to be jetted.
[0109]
On the other hand, after starting the solution application, the distance between the substrate 901 and the magnetic cap 908 is reduced to X2 as shown in FIG. This distance X2 is a distance at which a repulsive force is sufficiently exerted between the susceptor 902 and the magnetic cap 908, and the magnetic cap 908 compresses the elastic body 907 and is pushed into the hollow structure by the repulsive force. As a result, a space is secured at the tip of the nozzle 904, and the solution 909 containing the phosphor composition is injected. In this manner, the solution 909 containing the phosphor composition is applied to the surface of the substrate 901, and the solvent is volatilized under reduced pressure, or the solvent is volatilized by heating the substrate 901 to form the phosphor 910.
[0110]
As described above, it is possible to apply the internal solution when approaching a certain distance by using a magnetic material having a repulsive force acting as a cap on both the susceptor and the nozzle tip. Thus, the uniformity of the distance between the substrate and the head portion (strictly, the nozzle) can be ensured. This technique is particularly effective when a solution is applied on a substrate having irregularities.
[0111]
Note that this embodiment can be combined with a manufacturing apparatus including any of the configurations of Embodiments 4, 5, and 9 to 12, and is a light emitting device including any of the configurations of Embodiments 6 to 8. It can also be used for the manufacturing method.
[0112]
[Embodiment 14]
In this embodiment mode, as shown in Embodiment Modes 12 and 13, FIG. 13 shows an example of a multi-chamber manufacturing apparatus in a manufacturing apparatus of a light emitting device that carries and forms a film with a substrate standing. It explains using. Each chamber is connected to each other by a gate valve so as to maintain an airtight state.
[0113]
In FIG. 13, a carrier 702 for carrying a substrate is installed in a stock chamber 701. The stock chamber 701 is connected to the transfer chamber 703 via a gate valve, and the substrate mounted on the carrier 702 is transferred by the transfer arm 704 and installed on the substrate mount 705. At this time, the substrate is first placed on the pusher pin 706, and then the pusher pin 706 is lowered and placed on the substrate mounting base 705.
[0114]
The substrate mount 705 rises at 90 ° C. after fixing the substrate, moves to the inside of the load / unload chamber 707, and delivers the substrate to the susceptor 700. In FIG. 13, the portion of the susceptor 700 indicated by a dotted line is located at the time of substrate processing, but the substrate and the susceptor move together as the process progresses. It means that there is not at that time.
[0115]
The substrate delivered in the load / unload chamber 707 moves along the rail together with the susceptor 700 and is transferred to a common chamber 708 connected by a gate valve. A turntable 709 is provided in the common chamber 708. When the susceptor 700 is placed on the turntable 709, the turntable 709 rotates, and a chamber to be subjected to the next process connected to the common chamber via a gate valve is provided. select.
[0116]
The manufacturing apparatus in this embodiment includes a film formation chamber (HTL film formation chamber) 710 in which a hole transport layer (HTL) is formed as a chamber for processing, and a film formation chamber (light emission layer formation) in which a light emission layer is formed. A film formation chamber (ETL film formation chamber) 712 for forming an electron transport layer (ETL), and a film formation chamber (sputter film formation chamber) 713 for forming a conductive film by sputtering. . Each of the film formation chambers 710 to 712 for forming the light emitter is provided with the solution coating apparatus described in the first to third embodiments, and film formation of the light emitter composition by solution application such as ink jet is performed under reduced pressure. The chamber to be performed. Each chamber is provided with head portions 710a to 712a of a solution coating apparatus, and these head portions are scanned in the direction toward the paper surface (that is, the direction along the substrate surface) to form a film.
[0117]
A deposition chamber 713 in which a cathode is deposited by sputtering is provided with electrodes 714 and 715 and a target 716, all of which have a columnar shape or an elliptical shape. The substrate attached to the susceptor 700 is transported in the direction of the arrow, and film formation is performed when it passes by the target 716. At this time, the sputtering method may be either a DC (direct current) sputtering method or an RF (alternating current) sputtering method.
[0118]
Then, the substrate (susceptor) that has been processed in each chamber returns to the load / unload chamber 707 and is stored in the carrier 702 via the substrate mounting base 705 and the like. The process up to the formation of the cathode of the light emitting element is thus completed. Note that in this embodiment mode, the manufacturing apparatus that performs the process up to the cathode formation has been described. However, the number of chambers may be increased to complete the formation process of the passivation film (protective film) and the sealing process using a seal can or the like. . In addition, the structure of the light emitter is not limited to this embodiment mode, and can be applied to the formation of a composite as shown in Embodiment Mode 6. What is necessary is just to change the processing content and other changes.
[0119]
Note that this embodiment mode may have the configurations of Embodiment Modes 4 and 5 and can be used for manufacturing the light-emitting devices described in Embodiment Modes 7 and 8. Further, the structures of Embodiments 12 and 13 may be applied as the film formation chamber.
[0120]
[Embodiment 15]
In this embodiment mode, an entire structure of a light-emitting device manufactured according to the present invention will be described with reference to FIGS. FIG. 14 is a top view of a light-emitting device formed by sealing an element substrate on which a thin film transistor is formed with a sealing material, and FIG. 14B is a cross-sectional view taken along line BB ′ in FIG. FIG. 14C is a cross-sectional view taken along line AA ′ of FIG.
[0121]
On the substrate 81, a pixel portion (display portion) 82, a data line driving circuit 83, gate line driving circuits 84 a and 84 b and a protection circuit 85 provided so as to surround the pixel portion 82 are arranged so as to surround them. A sealing material 86 is provided. The pixel portion 82 includes a light-emitting element manufactured by implementing the present invention. As the sealing material 86, an ultraviolet curable resin, an epoxy resin, or other resin can be used, but it is desirable to use a material having as low a hygroscopic property as possible. Note that the sealing material 86 may be provided so as to overlap with part of the data line driving circuit 83, the gate line driving circuits 84a and 84b, and the protection circuit 85, or may be provided avoiding these circuits.
[0122]
Then, the sealing material 87 is bonded using the sealing material 86, and a sealed space 88 is formed by the substrate 81, the sealing material 86 and the sealing material 87. As the sealing material 87, a glass material, a metal material (typically stainless steel material), a ceramic material, or a plastic material (including a plastic film) can be used. Further, as shown in Embodiment Mode 8, sealing with only an insulating film is also possible.
When a material different from the substrate 81 is used as the sealing material 87, the adhesiveness of the sealing material 86 may be impaired due to the difference in thermal expansion coefficient. Accordingly, it is desirable to use the same material as the sealing material 87 that is the same material as the substrate 81 on which the transistor is formed. In other words, it is desirable to use a substrate having the same thermal expansion coefficient as the substrate 81. In this embodiment mode, glass is used as the material of the substrate 81 and the sealing material 87, and the sealing material 87 has the same thermal expansion coefficient by allowing the substrate 81 to pass the same thermal history as that in the thin film transistor manufacturing process.
[0124]
The sealing material 87 is previously provided with a moisture absorbent (barium oxide, calcium oxide or the like) 89 in the recess, and adsorbs moisture, oxygen, etc. inside the sealed space 28 to maintain a clean atmosphere. Plays a role in suppressing deterioration. This concave portion is covered with a fine mesh-shaped cover material 90, and the cover material 90 allows air and moisture to pass therethrough and does not allow the moisture absorbent 89 to pass therethrough. The sealed space 88 may be filled with a rare gas such as nitrogen or argon, and may be filled with a resin or liquid if inactive.
[0125]
A terminal portion 91 for transmitting signals to the data line driving circuit 83 and the gate line driving circuits 84 a and 84 b is provided on the substrate 81, and the terminal portion 91 is connected to the terminal portion 91 via an FPC (flexible printed circuit) 92. Thus, a data signal such as a video signal is transmitted. The cross section of the terminal portion 91 is as shown in FIG. 14B. The terminal portion 91 is provided on the side of the FPC 92 and the wiring having a structure in which the oxide conductive film 94 is stacked over the wiring 93 formed simultaneously with the gate wiring or the data wiring. The wiring 95 is electrically connected using a resin 97 in which a conductor 96 is dispersed. The conductor 96 may be a spherical polymer compound that is plated with gold or silver.
[0126]
In this embodiment, the protection circuit 85 is provided between the terminal portion 91 and the data line driving circuit 83, and when static electricity such as a sudden pulse signal enters between the two, the pulse signal is transmitted to the outside. Play a role of escape. At that time, a high voltage signal that enters instantaneously can be blunted by a capacitor, and other high voltage can be released to the outside by a circuit configured using a thin film transistor or a thin film diode. Needless to say, the protection circuit may be provided at another location, for example, between the pixel portion 82 and the data line driving circuit 83 or between the pixel portion 82 and the gate line driving circuits 84a and 84b.
[0127]
[Embodiment 16]
Although the thin film transistors shown in Embodiments 7 and 8 each have a top gate structure (specifically, a planar structure), each embodiment has a bottom gate structure (specifically, an inverted staggered structure). It is also possible.
[0128]
Needless to say, the present invention is not limited to a thin film transistor, and may be applied to a MOS transistor formed using a silicon well. Furthermore, the present invention may be applied to a case where a diode element (also referred to as a two-terminal element) typified by an MIM (Metal-Insulator-Metal) element or the like is used instead of a thin film transistor.
[0129]
In any case, even when the present invention is implemented in manufacturing an active matrix light emitting device, the original effect is not impaired by the structure of a switching element such as a transistor structure.
[0130]
[Embodiment 17]
An electronic device can be manufactured by incorporating a light-emitting device obtained by implementing the present invention into a display portion. Electronic devices include video cameras, digital cameras, goggle-type displays (head-mounted displays), navigation systems, sound playback devices (car audio, audio components, etc.), notebook-type personal computers, game devices, and portable information terminals (mobile computers, A mobile phone, a portable game machine, an electronic book, or the like), an image playback device including a recording medium (specifically, a display capable of playing back a recording medium such as a digital versatile disc (DVD) and displaying the image) Apparatus). Specific examples of these electronic devices are shown in FIGS.
[0131]
FIG. 15A illustrates a television which includes a housing 2001, a support base 2002, a display portion 2003, a speaker portion 2004, a video input terminal 2005, and the like. The present invention can be applied to the display portion 2003. Note that all information display televisions such as a personal computer, a TV broadcast reception, and an advertisement display are included.
[0132]
FIG. 15B illustrates a digital camera, which includes a main body 2101, a display portion 2102, an image receiving portion 2103, operation keys 2104, an external connection port 2105, a shutter 2106, and the like. The present invention can be applied to the display portion 2102.
[0133]
FIG. 15C illustrates a laptop personal computer, which includes a main body 2201, a housing 2202, a display portion 2203, a keyboard 2204, an external connection port 2205, a pointing mouse 2206, and the like. The present invention can be applied to the display portion 2203.
[0134]
FIG. 15D illustrates a mobile computer, which includes a main body 2301, a display portion 2302, a switch 2303, operation keys 2304, an infrared port 2305, and the like. The present invention can be applied to the display portion 2302.
[0135]
FIG. 15E illustrates a portable image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 2401, a housing 2402, a display portion A2403, a display portion B2404, and a recording medium (DVD or the like). A reading unit 2405, operation keys 2406, a speaker unit 2407, and the like are included. Although the display portion A 2403 mainly displays image information and the display portion B 2404 mainly displays character information, the present invention can be applied to the display portions A, B 2403, and 2404. Note that an image reproducing device provided with a recording medium includes a home game machine and the like.
[0136]
FIG. 15F illustrates a goggle type display (head mounted display), which includes a main body 2501, a display portion 2502, and an arm portion 2503. The present invention can be applied to the display portion 2502.
[0137]
FIG. 15G shows a video camera, which includes a main body 2601, a display portion 2602, a housing 2603, an external connection port 2604, a remote control receiving portion 2605, an image receiving portion 2606, a battery 2607, an audio input portion 2608, operation keys 2609, and the like. . The present invention can be applied to the display portion 2602.
[0138]
FIG. 15H illustrates a mobile phone, which includes a main body 2701, a housing 2702, a display portion 2703, an audio input portion 2704, an audio output portion 2705, operation keys 2706, an external connection port 2707, an antenna 2708, and the like. The present invention can be applied to the display portion 2703. Note that the display portion 2703 can suppress current consumption of the mobile phone by displaying white characters on a black background.
[0139]
As described above, the display device obtained by implementing the present invention may be used as a display unit of any electronic device. Note that a light-emitting device manufactured using any structure of Embodiments 1 to 3 and 6 to 8 may be used for the electronic device of this embodiment.
[0140]
【The invention's effect】
According to the present invention, it is possible to form a thin film almost simultaneously with the application of a solution containing a phosphor composition such as an organic compound or an inorganic compound without requiring a firing process, and the throughput in the manufacturing process of the light emitting device is greatly improved. Can do.
[0141]
In addition, since the solvent component in the formed thin film is sufficiently removed at the same time as the film formation, it is possible to avoid a problem that the light emitting layer itself deteriorates due to degassing after the light emitting element is completed. Can be increased.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a solution coating apparatus used for carrying out the present invention.
FIG. 2 is a cross-sectional view of a solution coating apparatus used for carrying out the present invention.
FIG. 3 is a cross-sectional view of a solution coating apparatus used for carrying out the present invention.
FIG. 4 is a cross-sectional view of a container for mounting a solution containing a phosphor composition in the solution coating apparatus used in the practice of the present invention.
FIGS. 5A and 5B illustrate a method for manufacturing a light-emitting device of the present invention. FIGS.
6A and 6B are a top view and a cross-sectional view illustrating a pixel structure of a light-emitting device obtained by implementing the present invention.
7A and 7B are a top view and a cross-sectional view illustrating a pixel structure of a light-emitting device obtained by implementing the present invention.
FIG. 8 is a top view of a manufacturing apparatus used for carrying out the present invention.
FIGS. 9A and 9B are a top view and a side view of a manufacturing apparatus used for carrying out the present invention. FIGS.
10A and 10B are a top view and a side view of a manufacturing apparatus used for carrying out the present invention.
11A to 11C illustrate a method for manufacturing a light-emitting device of the present invention.
FIG. 12 is a cross-sectional view of a solution coating apparatus used for carrying out the present invention.
FIG. 13 is a top view of a manufacturing apparatus used for carrying out the present invention.
FIG. 14 is a diagram showing the appearance of a light emitting device obtained by carrying out the present invention.
FIG. 15 is a diagram illustrating an example of an electronic device including a light-emitting device obtained by implementing the present invention.

Claims (4)

In a reduced-pressure atmosphere, a gel-like solution containing a phosphor composition is continuously ejected from an ejection port, and the solution is applied between insulators that define each pixel formed on the substrate, Forming a light emitting layer,
The application is performed using a solution application apparatus,
The solution coating apparatus includes a piezoelectric element and the ejection port,
By the state of depressing the piezoelectric element with pressurized with inert gas the solution, and injecting the solution,
A method for manufacturing a light-emitting device, wherein the injection is stopped by stopping pressurization by the inert gas and pushing up the piezoelectric element from the pushed- down state . In claim 1,
The method for manufacturing a light-emitting device, wherein the solution is ejected from a plurality of ejection ports. In claim 1 or claim 2,
The method for manufacturing a light-emitting device, wherein the light-emitting layer is at least one of a light-emitting layer that emits red light, a light-emitting layer that emits green light, and a light-emitting layer that emits blue light. In any one of Claims 1 thru | or 3,
The method for manufacturing a light-emitting device, wherein the atmosphere is a solvent atmosphere.

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