JP2004355975A - Manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a display device in which occurrence of defects of non-emission is prevented and the display quality can be improved. <P>SOLUTION: The total film thickness of a red color organic layer 16R, a green color organic layer 16G, and a blue color organic layer 16B are made in the order of the red color organic layer 16R, green color organic layer 16G, and blue color organic layer 16B from the thick side, and they are formed in the order from the color layer of the total film thickness. Thereby, occurrence of many defects of non-emission due to repeated contact with a vapor deposition mask 100 in the blue color organic layer 16B which becomes thinnest of the total film thickness when a resonator structure is introduced is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a display device, and more particularly, to a method for manufacturing a display device using an organic light emitting device.
[0002]
[Prior art]
Conventionally, when an evaporation mask is aligned in order to form an organic layer of an organic light emitting element for each color, the evaporation mask comes into contact with the previously deposited organic layer, causing damage to the organic layer or foreign matter in the evaporation mask. It is known that dark spots or non-light-emitting defects are more likely to occur in an organic layer that has been transferred to an organic layer, and as a result, an organic layer that has been deposited earlier than an organic layer that is deposited later. As a countermeasure, an organic layer is formed in order from a color having a low luminance in consideration of the fact that the luminance around a non-luminous defect becomes prominent when the luminance is high. Normally, when displaying all white, the luminance becomes higher in the order of green, red and blue, so that the organic layer is formed in the order of blue, red and green in the order of lower luminance. I have.
[0003]
By the way, with respect to the organic light emitting device, attempts have been made to control the light generated in the light emitting layer, for example, by improving the color purity of the emitted light or increasing the luminance by introducing a resonator structure (for example, See Patent Document 1.).
[0004]
[Patent Document 1]
International Publication No. 01/39554 pamphlet
[0005]
[Problems to be solved by the invention]
In an organic light-emitting device incorporating such a resonator structure, the total thickness of the organic layer is controlled according to the emission wavelength, and the order of red, green, and blue is from the thicker. However, when forming the organic layer, if the order of blue, red, and green is as low as the conventional one, the blue organic layer having a relatively thin total thickness comes into contact with the deposition mask many times. There is a problem that many non-light emitting defects may occur in the blue organic light emitting element.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a method for manufacturing a display device capable of preventing non-light-emitting defects from occurring and improving display quality.
[0007]
[Means for Solving the Problems]
The method for manufacturing a display device according to the present invention includes a substrate, a red organic light emitting element having a red organic layer including a red light emitting layer, a green organic light emitting element having a green organic layer including a green light emitting layer, and a blue light emitting layer. A display device comprising a blue organic light-emitting element having a blue organic layer, wherein the total thickness of the red organic layer, the green organic layer, and the blue organic layer is different from each other. The light-emitting layer, at least the green light-emitting layer of the green organic layer, and at least the blue light-emitting layer of the blue organic layer are arranged in order from the color having the largest total thickness of the red organic layer, the green organic layer, and the blue organic layer for each color. To form. Here, the “total film thickness” means a plurality of layers when the red organic layer, the green organic layer, and the blue organic layer have a laminated structure of a plurality of layers including a red light emitting layer, a green light emitting layer, and a blue light emitting layer. In the case of having only a red light emitting layer, a green light emitting layer, or a blue light emitting layer, it refers to a film thickness in the stacking direction of a red light emitting layer, a green light emitting layer, or a blue light emitting layer.
[0008]
In the method for manufacturing a display device according to the present invention, at least the red light emitting layer of the red organic layer, at least the green light emitting layer of the green organic layer, and at least the blue light emitting layer of the blue organic layer are formed of a red organic layer and a green organic layer. The layers are formed for each color in order from the color having the largest total film thickness of the layer and the blue organic layer. Therefore, the light emitting layer having the lightest color in the total film thickness is formed last, and the occurrence of non-light emitting defects is prevented.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
1 to 5 show a method for manufacturing a display device according to an embodiment of the present invention. First, as shown in FIG. 1A, a substrate 11 made of an insulating material such as glass is prepared, and a TFT 12 is formed on the substrate 11. Subsequently, as shown in FIG. 1A, for example, a flattening film 13 is formed by applying, exposing, developing, and firing polyimide. At the time of exposure, a contact hole 13A is formed.
[0011]
Next, as shown in FIG. 1B, a film made of, for example, chromium is formed on the flattening film 13 by, for example, a sputtering method so as to have a thickness of, for example, 100 nm to 150 nm. Subsequently, a resist (not shown) is formed by applying a resist, exposing and developing, and the chrome film is selectively etched using the mask to form the first electrode 14. After that, the mask is peeled off.
[0012]
Subsequently, as shown in FIG. 1C, an insulating film 15 for element isolation is formed on the first electrode 14 by applying, exposing, developing, and firing polyimide, for example, and light emission is performed. An opening 15A is formed corresponding to the region. The thickness T of the insulating film 15 can be, for example, 1 μm, and the width W of the opening 15A can be, for example, several tens μm to one hundred and several tens μm.
[0013]
After that, nitrogen (N ₂ Bake) in an atmosphere and oxygen (O ₂ 2.) Pre-treating the substrate 11 with plasma.
[0014]
Subsequently, as described in detail below with reference to FIGS. 2A to 3A, a red organic layer 16R including a red light emitting layer is formed at a position where the red organic light emitting element 10R is to be formed. The green organic layer 16G including the green light emitting layer is formed at the position where the green organic light emitting element 10G is to be formed, and the blue organic layer 16B including the blue light emitting layer is formed at the position where the blue organic light emitting element 10B is to be formed. As a constituent material of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, for example, a low molecular material can be used. In this case, the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are formed by evaporation. It is preferable to form each of the colors by an evaporation method using a mask.
[0015]
Here, in the present embodiment, when forming the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, the total thickness thereof is made different. This is because the red organic light emitting element 10R, the green organic light emitting element 10G, and the blue organic light emitting element 10B have a resonator structure as described later. That is, the total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is controlled according to the emission wavelength, and the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are arranged in order from the thicker. . In the present embodiment, the total thickness of the red organic layer 16R is, for example, 150 nm, the total thickness of the green organic layer 16G is, for example, 110 nm, and the total thickness of the blue organic layer 16B is, for example, 70 nm.
[0016]
Further, in the present embodiment, the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are formed in order from the color having the larger total thickness. This is to prevent the occurrence of many non-light emitting defects in the blue organic layer 16B having the smallest total film thickness when the resonator structure is introduced. That is, first, the red organic layer 16R having the largest total thickness is formed, the green organic layer 16G having the second largest total thickness is formed, and finally, the blue organic layer 16B having the smallest total thickness is formed. To form
[0017]
First, the substrate 11 is transported to the deposition chamber of the deposition apparatus without breaking the vacuum, and the deposition mask 100 is aligned as shown in FIG. On top of this, a red hole injection layer 16AR, a red hole transport layer 16BR, a red light emitting layer 16CR, and a red electron transport layer 16DR are sequentially stacked to form a red organic layer 16R. The red hole injection layer 16AR is a buffer layer for preventing a leak, and can be omitted as long as the leak does not cause a problem. The red hole transport layer 16BR is for increasing the efficiency of hole injection into the red light emitting layer 16CR. The red light-emitting layer 16CR generates light by recombination of electrons and holes when an electric field is applied, and emits light in a region corresponding to the opening 15A of the insulating film 15. The red electron transport layer 16DR is for increasing the efficiency of injecting electrons into the red light emitting layer 16CR. The vapor deposition mask 100 has a thickness of about several tens μm to several tens μm, and is made of a magnetizable material such as nickel (Ni) or an alloy containing nickel.
[0018]
As a constituent material of the red hole injection layer 16AR, for example, 4,4 ', 4 "-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA) or 4,4', 4" -tris (2- Using (naphthylphenylamino) triphenylamine (2-TNATA), the thickness can be, for example, 15 nm or more and 300 nm or less. As a constituent material of the red hole transport layer 16BR, for example, bis [(N-naphthyl) -N-phenyl] benzidine (α-NPD) is used, and the thickness can be, for example, 15 nm or more and 100 nm or less. As a constituent material of the red light emitting layer 16CR, for example, an 8-quinolinol aluminum complex (Alq ₃ ) Is mixed with 40% by volume of 2,6-bis [4- [N- (4-methoxyphenyl) -N-phenyl] aminostyryl] naphthalene-1,5-dicarbonitrile (BSN-BCN). The thickness can be, for example, 15 nm or more and 100 nm or less. As a constituent material of the red electron transport layer 16DR, for example, Alq ₃ And the thickness can be, for example, 15 nm or more and 100 nm or less.
[0019]
After that, the substrate 11 is transferred to another evaporation apparatus or evaporation chamber without breaking the vacuum, and as shown in FIG. 2B, the evaporation mask 100 is aligned, and the evaporation method using the evaporation mask 100 is performed. Thereby, a green organic layer 16G including a green hole injection layer 16AG, a green hole transport layer 16BG, a green light emitting layer 16CG, and a green electron transport layer 16DG is formed on the first electrode 14. The green hole injection layer 16AG is a buffer layer for preventing leakage, and can be omitted as long as the leakage does not hinder. The green hole transport layer 16BG is for increasing the efficiency of hole injection into the green light emitting layer 16CG. In the green light emitting layer 16CG, the recombination of electrons and holes occurs when an electric field is applied to generate light, and light is emitted in a region corresponding to the opening 15A of the insulating film 15. The green electron transport layer 16DG is for increasing the efficiency of injecting electrons into the green light emitting layer 16CG. In addition, the same thing as the thing used for formation of the red organic layer 16R may be used for the vapor deposition mask 100, and another thing may be used.
[0020]
As a constituent material of the green hole injection layer 16AG, for example, m-MTDATA or 2-TNATA is used, and the thickness can be, for example, 15 nm or more and 300 nm or less. As the constituent material of the green hole transport layer 16BG, for example, α-NPD is used, and the thickness can be, for example, 15 nm or more and 100 nm or less. As a constituent material of the green light emitting layer 16CG, for example, Alq ₃ And a thickness of, for example, 15 nm or more and 100 nm or less, which is obtained by mixing coumarin 6 with 3% by volume. As a constituent material of the green electron transport layer 16DG, for example, Alq ₃ And the thickness can be, for example, 15 nm or more and 100 nm or less.
[0021]
Subsequently, the substrate 11 is transported to another vapor deposition apparatus or vapor deposition chamber without breaking vacuum, and the vapor deposition mask 100 is aligned as shown in FIG. The blue organic layer 16B including the blue hole injection layer 16AB, the blue hole transport layer 16BB, the blue light emitting layer 16CB, and the blue electron transport layer 16DB is formed on the first electrode 14 by the method. The blue hole injection layer 16AB is a buffer layer for preventing a leak, and can be omitted as long as the leak does not cause a problem. The blue hole transport layer 16BB is for increasing the efficiency of hole injection into the blue light emitting layer 16CB. In the blue light emitting layer 16CB, the recombination of electrons and holes occurs when an electric field is applied, and light is generated. The blue light emitting layer 16CB emits light in a region corresponding to the opening 15A of the insulating film 15. The blue electron transport layer 16DB is for increasing the efficiency of injecting electrons into the blue light emitting layer 16CB. Note that the same evaporation mask as that used for forming the red organic layer 16R or the green organic layer 16G may be used, or another evaporation mask may be used.
[0022]
As a constituent material of the blue hole injection layer 16AB, for example, m-MTDATA or 2-TNATA is used, and the thickness can be, for example, 15 nm or more and 300 nm or less. As a constituent material of the blue hole transport layer 16BB, for example, α-NPD is used, and the thickness can be, for example, 15 nm or more and 100 nm or less. As a constituent material of the blue light emitting layer 16CB, for example, spiro 6Φ (spiro6Φ) is used, and the thickness can be, for example, 15 nm or more and 100 nm or less. As a constituent material of the blue electron transport layer 16DB, for example, Alq ₃ And the thickness can be, for example, 15 nm or more and 100 nm or less.
[0023]
In such an order, the deposition mask 100 is to be aligned or replaced on the red organic layer 16R to be formed first. However, since the total thickness of the red organic layer 16R is large, the adverse effect due to the contact with the deposition mask 100 is smaller than in the case where the blue organic layer 16B is first formed as in the related art.
[0024]
Thereafter, the substrate 11 is transported to another vapor deposition apparatus or vapor deposition chamber without breaking the vacuum, and as shown in FIG. 3B, for example, lithium fluoride (LiF) An electron injection layer 17 made of and a semi-permeable electrode 18A made of a magnesium (Mg) -silver (Ag) alloy are formed in order. The thickness of the electron injection layer 17 can be, for example, 1 nm, and the thickness of the translucent electrode 18A can be, for example, 10 nm.
[0025]
Subsequently, the substrate 11 is transported to another vapor deposition apparatus or vapor deposition chamber without breaking the vacuum, and as shown in FIG. 4A, the same as the vapor deposition mask used to form the semi-transparent electrode 18A. Using a vapor deposition mask (not shown), a transparent electrode 18B made of, for example, a compound containing indium (In), zinc (Zn), and oxygen (O) (IZO; Indium Zinc Oxide) is formed. The transparent electrode 18B is for lowering the electric resistance of the semi-transmissive electrode 18A, and the thickness thereof can be, for example, 100 nm. Thereby, the second electrode 18 in which the semi-transparent electrode 18A and the transparent electrode 18B are stacked is formed.
[0026]
After that, the substrate 11 is transported to another vapor deposition apparatus or vapor deposition chamber without breaking the vacuum, and as shown in FIG. 4B, for example, silicon nitride (SiN _x ) Is formed. The thickness of the protective film 19 can be, for example, 1 μm.
[0027]
Subsequently, as shown in FIG. 5, an adhesive layer 20 made of, for example, a thermosetting resin is formed on the protective film 19, and the sealing substrate on which the substrate 11 and the color filter 32 are formed is formed via the adhesive layer 20. The stop substrate 31 is bonded. At this time, it is desirable that the color filter 32 be aligned with the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B before the adhesive layer 20 is cured by heating or the like. As described above, a display device including the red organic light emitting element 10R having the red organic layer 16R, the green organic light emitting element 10G having the green organic layer 16G, and the blue organic light emitting element 10B having the blue organic layer 16B on the substrate 11 is completed. .
[0028]
The red organic light-emitting element 10R, the green organic light-emitting element 10G, and the blue organic light-emitting element 10B formed as described above have the first electrode 14 on the side of the red light-emitting layer 16CR, the green light-emitting layer 16CG, or the blue light-emitting layer 16CB. One end P1, the end face of the translucent electrode 18A on the side of the red light emitting layer 16CR, the green light emitting layer 16CG or the blue light emitting layer 16CB is a second end P2, and the red organic layer 16R, the green organic layer 16G or the blue organic layer 16B. Is used as a resonance portion, a resonator structure is provided that resonates light generated in the red light emitting layer 16CR, the green light emitting layer 16CG, or the blue light emitting layer 16CB and extracts the light from the second end P2 side. With such a resonator structure, light generated in the red light emitting layer 16CR, the green light emitting layer 16CG or the blue light emitting layer 16CB causes multiple interference, and acts as a kind of narrow band filter, thereby being extracted. This is preferable because the half width of the light spectrum can be reduced and the color purity can be improved. External light incident from the sealing substrate 31 can also be attenuated by multiple interference, and in combination with the color filter 32, external light in the red organic light emitting element 10R, the green organic light emitting element 10G, and the blue organic light emitting element 10B. Is preferable because the reflectance of the film can be extremely reduced.
[0029]
For this purpose, the optical distance L between the first end P1 and the second end P2 of the resonator is set so as to satisfy Equation 2, and the resonance wavelength of the resonator (the peak wavelength of the extracted light spectrum) It is preferable to match the peak wavelength of the spectrum of the light to be extracted. In practice, it is preferable that the optical distance L is selected so as to be a positive minimum value that satisfies Expression 2.
[0030]
(Equation 2)
(2L) / λ + Φ / (2π) = m
(Where L is the optical distance between the first end P1 and the second end P2, and Φ is the phase shift Φ of the reflected light generated at the first end P1. ₁ And the phase shift Φ of the reflected light generated at the second end P2 ₂ (Φ = Φ ₁ + Φ ₂ ), (Rad) and λ are peak wavelengths of the spectrum of light to be extracted from the side of the second end P2, and m is an integer where L is positive. Note that, in Expression 2, L and λ may have the same unit, but for example, the unit is (nm). )
[0031]
In this display device, when a predetermined voltage is applied between the first electrode 14 and the second electrode 18, a current is injected into the red light emitting layer 16CR, the green light emitting layer 16CG, or the blue light emitting layer 16CB, and holes and holes are removed. Light is emitted by recombination with electrons. This light is multiple-reflected between the first end P1 and the second end P2, passes through the second electrode 18, the color filter 32, and the sealing substrate 31, and is extracted. At this time, since the blue organic layer 16B having the smallest total thickness among the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is formed last, the blue color resulting from repeated contact with the deposition mask 100 is obtained. The organic layer 16B is prevented from being scratched or mixed with foreign matter. Therefore, generation of many non-light-emitting defects in the blue organic layer 16B is prevented.
[0032]
As described above, in the present embodiment, the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are formed for each color in order from the color having the largest total film thickness. The thinnest blue organic layer 16B is formed last, thereby preventing non-light emitting defects from occurring and improving display quality.
[0033]
[Modifications 1 to 3]
Hereinafter, Modification Examples 1 to 3 of the present embodiment will be described.
[0034]
In the present embodiment, when there is a layer having the same material or thickness among the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are common. May be formed. By doing so, the material is shared and the manufacturing process is simplified, so that the manufacturing efficiency can be increased and it is advantageous for establishing a mass production system. The following Modifications 1 to 3 are specific examples, but are not necessarily limited thereto.
[0035]
(Modification 1)
For example, as shown in FIG. 6A, the materials and thicknesses of the red hole injection layer 16AR, the green hole injection layer 16BR, and the blue hole injection layer 16AB are the same, and the red organic layer 16R and the green organic layer 16AR. A continuous hole injection layer 46A common to 16G and the blue organic layer 16B is formed. After that, as shown in FIG. 6B, a red hole transport layer 16BR, a red light emitting layer 16CR, and a red electron transport layer 16DR are formed, and a red organic layer 16R having the largest total film thickness is formed. Next, as shown in FIG. 7A, a green hole transport layer 16BG, a green light emitting layer 16CG, and a green electron transport layer 16DG are formed, and a green organic layer 16G having the second largest total thickness is formed. . Finally, as shown in FIG. 7B, a blue hole transport layer 16BB, a blue light emitting layer 16CB, and a blue electron transport layer 16DB are formed, and a blue organic layer 16B having the smallest total thickness is formed. The continuous hole injection layer 46A does not need to be formed on all of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, and it is sufficient that only necessary colors among them are common to at least two colors.
[0036]
(Modification 2)
Alternatively, the materials and thicknesses of the red electron transport layer 16DR, the green electron transport layer 16DR, and the blue electron transport layer 16DB may be the same. In this case, first, as shown in FIG. 8A, a red hole injection layer 16AR, a red hole transport layer 16BR, and a red light emitting layer 16CR of the red organic layer 16R having the largest total film thickness are formed. Next, as shown in FIG. 8B, a green hole injection layer 16AG, a green hole transport layer 16BG, and a green light emitting layer 16CG of the second thickest green organic layer 16G having the total thickness are formed. Subsequently, as shown in FIG. 9A, a blue hole injection layer 16AB, a blue hole transport layer 16BB, and a blue light emitting layer 16CB are formed among the blue organic layers 16B having the smallest total thickness. Finally, as shown in FIG. 9B, a continuous electron transport layer 46D common to the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is formed. The continuous electron transport layer 46D does not need to be formed on all of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, and it is sufficient that only necessary colors among them are common to at least two colors.
[0037]
(Modification 3)
Further, Modification 1 and Modification 2 may be performed in an overlapping manner. For example, a continuous hole injection layer 46A common to the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is formed. After that, the red hole transport layer 16BR and the red light emitting layer 16CR of the red organic layer 16R having the largest total film thickness are formed, and then the green hole transport layer of the second thickest green organic layer having the total film thickness is formed. A blue hole transport layer 16BB and a blue light emitting layer 16CB of a blue organic layer 16B having the smallest total thickness, and finally, a red organic layer 16R and a green light emitting layer 16CG. A continuous electron transport layer 46D common to the organic layer 16G and the blue organic layer 16B is formed.
[0038]
【Example】
Further, specific examples of the present invention will be described.
[0039]
A display device was manufactured in the same manner as in the above embodiment. At that time, the total thickness of the red organic layer 16R is 150 nm, the total thickness of the green organic layer 16G is 110 nm, and the total thickness of the blue organic layer 16B is 70 nm. An organic layer 16R, a green organic layer 16G, and a blue organic layer 16B were formed in this order for each color.
[0040]
As a comparative example with respect to the present embodiment, the present embodiment is different from the present embodiment except that the color is formed for each color in order from the color having the lowest luminance, that is, in the order of the blue organic layer 16B, the red organic layer 16R, and the green organic layer 16G. A display device was manufactured in the same manner.
[0041]
With respect to the obtained display devices of the example and the comparative example, the change with time of the non-light-emitting defect when continuously lit at a predetermined current value was examined. The result is shown in FIG. FIG. 10 shows the change over time of the non-light emitting defect of each color in the example and the comparative example, with the number of blue non-light emitting defects in the comparative example being continuously lit for 360 hours as 100.
[0042]
When the initial characteristics of this example and the comparative example were compared, the luminous efficiency and the chromaticity were equivalent, but the initial non-light-emitting defect was smaller in this example than in the comparative example. Further, when the non-light-emitting defects in the case of continuous lighting were compared with time, the non-light-emitting defects in blue in the comparative example increased remarkably, whereas the non-light-emitting defects in blue hardly increased in this example. But could be greatly improved. That is, it has been found that the non-light-emitting defect can be suppressed from increasing by forming the red organic layer, the green organic layer, and the blue organic layer in order from the color having the largest total thickness of each color.
[0043]
As described above, the present invention has been described with reference to the embodiment and the example. However, the present invention is not limited to the above-described embodiment and example, and can be variously modified. For example, in the above-described embodiment, a case has been described in which all of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are formed for each color in order from the color having the largest total film thickness. Of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, only layers having different materials or thicknesses are arranged in order from the color having the larger total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B. It is sufficient if it is formed separately.
[0044]
Specifically, for example, at least the red hole transport layer 16BR and the red light emitting layer 16CR of the red organic layer 16R, at least the green hole transport layer 16BG and the green light emitting layer 16CG of the green organic layer 16G, and the blue organic layer At least the blue hole transport layer 16BB and the blue light emitting layer 16CB of the 16B are formed for each color in order from the color having the largest total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B. Good. This is because the total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is actually the red hole transport layer 16BR and the red light emitting layer 16CR, the green hole transport layer 16BG, and the green light emitting layer 16CG, Also, by changing only the thicknesses of the blue hole transport layer 16BB and the blue light emitting layer 16CB, it may be possible to control the optical distance L to satisfy Equation 2. Further, the red hole injection layer 16AR, the green hole injection layer 16AG, or the blue hole injection layer 16AB, or the red electron transport layer 16BR, the green electron transport layer 16DG, or the blue electron transport layer 16DB is often omitted, or all of them are omitted. This is because the color is not necessarily provided in the organic light emitting element of the color.
[0045]
Further, by changing the total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B only by changing the thicknesses of the red light emitting layer 16CR, the green light emitting layer 16CG, and the blue light emitting layer 16CB, the optical distance L is reduced. 2, it is possible to control at least the red light emitting layer 16CR of the red organic layer 16R, at least the green light emitting layer 16CG of the green organic layer 16G, and at least the blue light emitting of the blue organic layer 16B. The layer 16CB may be formed for each color in order from the color having the largest total thickness of the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B.
[0046]
Furthermore, in the above-described embodiments and examples, the case where the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B are made of a low molecular material has been described. It can also be applied when used. Here, the polymer material has a molecular weight of 10,000 or more. In this case, for example, the red organic layer includes a red hole transport layer and a red light emitting layer, the green organic layer includes a green hole transport layer and a green light emitting layer, and the blue organic layer includes a blue hole transport layer and a blue light emitting layer. May be included. When a resonator structure is introduced, the total thickness of the red organic layer, the green organic layer, and the blue organic layer is changed by changing only the thicknesses of the red, green, and blue light emitting layers. It is possible to control so that the distance L satisfies Equation 2. Therefore, at least a red light emitting layer of the red organic layer, at least a green light emitting layer of the green organic layer, and at least a blue light emitting layer of the blue organic layer are formed as a total film of a red organic layer, a green organic layer, and a blue organic layer. It is sufficient to form each color in order from the thickest color.
[0047]
In addition, for example, the material and thickness of each layer described in the above embodiment, or the film forming method and the film forming conditions are not limited, and other materials and thicknesses may be used. The method and the film forming conditions may be used. For example, in the above-described embodiment, the first electrode 14, the red organic layer 16R, the green organic layer 16G and the blue organic layer 16B, and the second electrode 18 are sequentially stacked on the substrate 11 from the substrate 11 side. Although the case where light is extracted from the side of the sealing substrate 31 has been described, the stacking order is reversed, and the second electrode 18, the red organic layer 16R, the green organic layer 16G, and the blue The organic layer 16 </ b> B and the first electrode 14 may be sequentially stacked from the substrate 11 side, and light may be extracted from the substrate 11 side.
[0048]
Further, for example, in the above embodiment, the case where the first electrode 14 is an anode and the second electrode 18 is a cathode has been described. However, the anode and the cathode are reversed, and the first electrode 14 is a cathode, and the second electrode 18 is a cathode. 18 may be used as the anode. Further, while the first electrode 14 is a cathode and the second electrode 18 is an anode, the second electrode 18, the red organic layer 16R, the green organic layer 16G and the blue organic layer 16B, and the first electrode 14 are formed on the substrate 11. Can be stacked in order from the substrate 11 side, and light can be extracted from the substrate 11 side.
[0049]
In addition, in the above-described embodiment, the configurations of the red organic light emitting element 10R, the green organic light emitting element 10G, and the blue organic light emitting element 10B have been specifically described. However, it is not necessary to include all the layers. Other layers may be further provided. For example, between the first electrode 14 and the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B, chromium (III) oxide (Cr ₂ O ₃ ), ITO (Indium-Tin Oxide: mixed oxide film of indium (In) and tin (Sn)) or the like. Further, for example, the first electrode 14 may have a two-layer structure in which a transparent conductive film is laminated on a dielectric multilayer film or a reflective film such as Al. In this case, the end face of the reflection film on the light emitting layer side constitutes the end of the resonance part, and the transparent conductive film constitutes a part of the resonance part.
[0050]
Furthermore, in the above-described embodiment, the case where the second electrode 18 has the semi-transmissive electrode 18A and the transparent electrode 18B laminated in order from the side of the first electrode 14 has been described. A configuration having only the transmissive electrode 18A may be adopted.
[0051]
In addition, in the above-described embodiment, the semi-transmissive electrode 18A is used as one end, and the other end is provided at a position facing the semi-transmissive electrode 18A with the transparent electrode 18B interposed therebetween. A resonator structure serving as a portion may be formed. Further, after providing such a resonator structure, the red organic light-emitting element 10R, the green organic light-emitting element 10G, and the blue organic light-emitting element 10B are covered with a protective film 19, and the protective film 19 is covered with a transparent electrode 18A. It is preferable that the protective film 19 be made of a material having the same refractive index as the constituent material, since the protective film 19 can be a part of the resonance part.
[0052]
Furthermore, in the present invention, the second electrode 18 is constituted by the transparent electrode 18B, and the reflectance of the transparent electrode 18B at the end face on the side opposite to the red organic layer 16R, the green organic layer 16G, and the blue organic layer 16B is increased. The first light emitting layer 16R, the green light emitting layer 16G, and the blue light emitting layer 16B side of the first electrode 14 have the first end, the red organic layer 16R, the green organic layer 16G, and the blue organic layer of the transparent electrode 18B. The present invention can also be applied to a case where a resonator structure having the end face opposite to 16B as the second end is formed. For example, the transparent electrode 18B may be brought into contact with the atmosphere layer to increase the reflectance at the interface between the transparent electrode 18B and the atmosphere layer, and this interface may be used as the second end. Alternatively, the reflectance at the interface with the adhesive layer 20 may be increased, and this interface may be used as the second end. Further, the reflectance at the interface with the protective film 19 may be increased, and this interface may be used as the second end.
[0053]
【The invention's effect】
As described above, according to the display device manufacturing method of the present invention, at least the red light emitting layer of the red organic layer, at least the green light emitting layer of the green organic layer, and at least the blue light emitting layer of the blue organic layer , Red organic layer, green organic layer, and blue organic layer are formed for each color in order from the color having the largest total thickness. Can be prevented and display quality can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a method of manufacturing a display device according to an embodiment of the present invention in the order of steps.
FIG. 2 is a cross-sectional view illustrating a process following the process in FIG.
FIG. 3 is a sectional view illustrating a step following the step of FIG. 2;
FIG. 4 is a sectional view illustrating a step following FIG. 3;
FIG. 5 is a sectional view illustrating a step following FIG. 4;
FIG. 6 is a cross-sectional view illustrating a method of manufacturing a display device according to Modification Example 1 of the present invention in the order of steps.
FIG. 7 is a cross-sectional view illustrating a process following the process in FIG.
FIG. 8 is a cross-sectional view illustrating a method of manufacturing a display device according to Modification 2 of the present invention in the order of steps.
FIG. 9 is a cross-sectional view illustrating a process following the process in FIG.
FIG. 10 is a diagram illustrating a change over time in the number of non-light-emitting defects in an example of the present invention and a comparative example.
[Explanation of symbols]
10R: Red organic light emitting element, 10G: Green organic light emitting element, 10B: Blue organic light emitting element, 11: Substrate, 12: TFT, 13: Flattening film, 13A: Contact hole, 14: First electrode, 15: Insulating film , 16R: red organic layer, 16AR: red hole injection layer, 16BR: red hole transport layer, 16CR: red light emitting layer, 16DR: red electron transport layer, 16G: green organic layer, 16AG: green hole injection layer, 16BG: green hole transport layer, 16CG: green light emitting layer, 16DG: green electron transport layer, 16B: blue organic layer, 16AB: blue hole injection layer, 16BB: blue hole transport layer, 16CB: blue organic layer, 16DB ... blue electron transport layer, 17 ... electron injection layer, 18 ... second electrode, 18A ... semi-transparent electrode, 18B ... transparent electrode, 19 ... protective film, 20 ... adhesive layer, 31 ... sealing substrate, 32 ... color Filter, 100 ... deposition mask

Claims (8)

On the substrate, a red organic light emitting element having a red organic layer including a red light emitting layer, a green organic light emitting element having a green organic layer including a green light emitting layer, and a blue organic light emitting element having a blue organic layer including a blue light emitting layer A method for manufacturing a display device, wherein the total thickness of the red organic layer, the green organic layer, and the blue organic layer is different from each other,
At least the red light emitting layer of the red organic layer, at least the green light emitting layer of the green organic layer, and at least the blue light emitting layer of the blue organic layer, the red organic layer, the green organic layer and A method for manufacturing a display device, comprising forming a blue organic layer for each color in order from the color having the largest total thickness. The red organic light emitting element, the green organic light emitting element, and the blue organic light emitting element emit light generated in the red light emitting layer, the green light emitting layer, and the blue light emitting layer between a first end and a second end. 2. The method for manufacturing a display device according to claim 1, wherein the method has a resonator structure that resonates at a time. The sum of the phase shift of the reflected light generated at the first end and the phase shift of the reflected light generated at the second end is Φ, and the optical distance between the first end and the second end is Φ. 3. The method of manufacturing a display device according to claim 2, wherein the optical distance satisfies Equation 1 where L is a peak wavelength of a spectrum of light to be extracted from the side of the second end. .

4. The display device according to claim 3, wherein the total thickness of the red organic layer, the green organic layer, and the blue organic layer is, in order from a thicker one, a red organic layer, a green organic layer, and a blue organic layer. Manufacturing method. At least the red light emitting layer and the red hole transport layer of the red organic layer, at least the green light emitting layer and the green hole transport layer of the green organic layer, and at least the blue light emitting layer of the blue organic layer 2. The manufacturing method of a display device according to claim 1, wherein the blue hole transport layer is formed for each color in order from a color having a larger total thickness of the red organic layer, the green organic layer, and the blue organic layer. Method. A layer having the same material and thickness among the red organic layer, the green organic layer, and the blue organic layer is formed as a continuous layer common to at least two colors of the red organic layer, the green organic layer, and the blue organic layer. The method for manufacturing a display device according to claim 1, wherein: 2. The method according to claim 1, wherein the red organic layer, the green organic layer, and the blue organic layer are made of a low molecular material. The method according to claim 1, wherein the red organic layer, the green organic layer, and the blue organic layer are formed for each color by an evaporation method using an evaporation mask.

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