JP2002305077A - Organic EL device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process ink repellant processing of a surface simply without using plasma processing. SOLUTION: A surface treatment agent is transferred on a part of the surface of a bank of a substrate, which has the bank, by sticking an original sheet, to which the surface treatment agent is made to absorb or adhere, tightly to the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL (electroluminescence) element which is an electroluminescent element used for a display, a display light source and the like using an organic semiconductor film, and a technique for forming a thin film patterning substrate suitable for manufacturing the same. Related to

[0002]

2. Description of the Related Art In recent years, the development of light-emitting elements using organic substances as spontaneous light-emitting displays replacing liquid crystal displays has been accelerated. As an organic EL device using an organic substance,
Appl. Phys. Lett. 51 (12), 21
Sep. 1987, pp. 913, a method of depositing a low molecular weight film by a vapor deposition method;
pl. Phys. Lett. 71 (1), 7 July
A method of applying a polymer as shown on page 34 of 1997 is mainly reported.

As a means for colorization, in the case of a low-molecular material, a method of vapor-depositing and forming a different luminescent material on a desired pixel through a mask has been used. On the other hand, for polymer materials, colorization using an ink-jet method has attracted attention because it can be finely and easily patterned. The following known examples are known for forming an organic EL element by an ink-jet method. JP-A-7-23537
8, JP-A-10-12377, JP-A-10-15396
7, JP-A-11-40358, JP-A-11-5427
0, JP-A-11-339957.

[0004]

In the ink jet system, which can form thin films having different characteristics on the same substrate by coating, the different thin film materials are mixed on the substrate.
There is a problem that the discharged liquid material flows out to adjacent pixels.

[0005] In order to solve such a problem, a convex partition member (also called a "bank" or a convex portion) for partitioning different thin film regions is usually provided, and a liquid forming a different thin film is formed in a region surrounded by the partition member. A method of filling the material is employed. Filling of a liquid material by causing a difference between the surface characteristics of a partition member (hereinafter referred to as a bank) and the surface characteristics of a region surrounded by the bank, specifically, an affinity for a thin film material liquid (hereinafter referred to as ink). Is controlled.

If the surface of the bank shows an affinity (hydrophilicity) for the ink, the ink is easily surrounded by the adjacent bank even if the bank is filled with an amount of material exceeding the height of the bank. Spilled into the area. Conversely, if the surface of the bank shows a moderate incompatibility (ink repellency) with ink, the area surrounded by the adjacent bank due to the surface tension of the material even if the amount of material exceeds the height of the bank. The ink does not flow out.

When the ink repellency of the bank is strong, the liquid of the thin film material is repelled on the side walls of the bank, so that the thickness after the film formation is large at the center of the region surrounded by the bank and thin at the periphery. In this case, color unevenness in pixels occurs in the display element. In particular, a short circuit easily occurs in an EL element, which leads to a decrease in reliability.

In the case where the surface of the bank is subjected to an ink repellent treatment to give an affinity (ink-affinity) to its side surface, and more desirably, to a layer below the bank, a thin film material is provided to form a film. Although the thickness of the thin film does not decrease around the region surrounded by the bank, the ink is pulled to the side surface of the bank, so that the film thickness becomes larger at the skirt portion of the thin film, that is, at the portion in contact with the substrate. Reliability is improved.

The modification of the affinity (wettability) of the surface of the material constituting the upper layer of the bank with respect to the ink is mainly performed by controlling the surface free energy, and the ink is a liquid having a high surface free energy, for example, a liquid having a high surface free energy. For many aqueous solutions, the wettability of the ink on materials with high surface free energy is high.

At present, a generally used bank structure having the above-described function is a two-layer bank structure (two layers of a lower bank layer and an upper bank layer). Specifically, a bank structure in which an organic material is laminated on an inorganic material is used, and the inorganic material is subjected to a surface treatment that increases the affinity for the ink, while the affinity of the organic material is lowered. By applying the processing, ink is supplied to the area surrounded by the bank,
A thin film is formed. This two-layer structure is used for the convenience that the ink repellency and the ink affinity can be collectively applied to the surface by plasma treatment, and will be described below.

For the surface modification of organic substances, it is well known to carry out a plasma treatment.
There is one described in JP-A-3-308920.
The surface modification method described in this publication treats an organic substance surface using a mixed gas plasma containing a fluorine-based gas and an oxygen gas, and changes the mixing ratio of the mixed gas,
It controls the surface free energy of the organic substance.

Further, the glass or IT constituting the lower layer of the bank
A method of performing UV irradiation or oxygen plasma treatment to hydrophilize the surface of an inorganic material such as O (Indium Tin Oxide) is also a well-known method.

However, a method of providing a layer pattern made of an organic substance or an inorganic substance on the same substrate and imparting ink repellency to the surface of the organic substance or the surface of a member formed of the organic substance by a mixed gas plasma treatment is efficient. There is a problem that the ink repellency cannot be imparted, the ink repellency of the surface is transient, and the ink repellency deteriorates after a heating step or a lapse of time.

In view of the above, a method is employed in which oxygen gas plasma and fluorine gas plasma are continuously and uniformly processed over substantially the entire surface of a substrate on which a bank having a two-layer structure is formed. , While the lower layer of the bank has ink-philic surface characteristics, the organic material in the upper layer of the bank can have stable ink repellency,
Conventional processes have used a two-layer structure.

FIG. 7 is a schematic sectional view of an organic EL device manufactured by a conventional method.

Referring to FIG. 7A, in describing a conventional method of manufacturing an organic EL device, FIG.
(A) shows a step of forming a lower layer of a bank for separating between transparent pixel electrodes of an organic EL element.

When, for example, a bank forming surface 3 is formed of a pixel electrode such as ITO on a transparent substrate 1 having a pixel electrode 2 and functioning as a support and a surface for extracting light, it is generally used as an insulating film. Silicon oxide film (S
The lower film 5 is formed by using a known film forming process and an etching process, using iO ₂ ), a silicon nitride film, and amorphous silicon as materials.

Upper layer forming step (FIG. 7B): Next, a layer made of an organic material such as polyimide is applied and formed on the lower layer film 5, and a bank upper layer 6 is formed by lithography.

Surface treatment step (FIG. 7D): Next, the substrate surface is subjected to a continuous treatment of oxygen gas plasma and fluorine gas plasma treatment to form a region surrounded by a bank made of, for example, ITO or SiO _2. 4, the lower film 5, and
The affinity of the upper bank layer 6 made of an organic material for the thin film material liquid is adjusted, and the degree of affinity is adjusted so that the area surrounded by the bank> = the lower bank surface> the upper bank surface. To process.

Thin film forming step (FIGS. 7E and 7F):
A thin film layer is formed by filling a thin film material liquid 7 into the concave portion surrounded by the bank lower layer 5 and the upper layer 6, that is, the region 4 surrounded by the bank and the side surface of the bank lower layer 5, and after the filling, heat treatment or the like is performed. The solvent component is evaporated to form the thin film layer 8.

In the above method, in order to improve the reliability of the device, the upper bank layer 6 is formed on the lower bank layer 5 in a smaller size than the lower bank layer in order to prevent a short circuit with the upper electrode. There is a need. The reason for this is that by making the side wall of the bank upper layer 6 having high ink repellency smaller than that of the bank lower layer 5, the droplets are repelled, causing unevenness, and the peripheral portion of the final thin film layer 8 becomes thinner. This is to reduce the possibility.

For this purpose, it is necessary to use the conventional photolithography technique frequently, and there is much waste in terms of cost and time due to an increase in the number of steps.

In the above method, the surface of the bank is modified by
Since continuous processing of oxygen gas plasma and fluorine-based gas plasma is used, excessive plasma irradiation may cause damage to the substrate surface, particularly oxidation of the electrode surface.

The order of the affinity of the surfaces of the upper surface of the bank, the surface of the lower layer of the bank 5, and the surface of the region surrounded by the bank with respect to ink by the plasma treatment is set as "the region surrounded by the bank> = the lower surface of the bank". > Upper bank surface "
However, the selection of materials for the lower bank layer 5 and the upper bank layer 6 is largely restricted.

The fact that this restriction is large means that firstly, the restriction on the material relating to the adhesion between the upper bank layer 6 and the lower bank layer 5,
In addition, material restrictions on surface free energy change due to plasma treatment of lower bank layer 5 and upper bank layer 6
There are also restrictions on materials regarding the holding power of surface free energy change after plasma treatment.

On the other hand, as a conventional surface treatment technique using transfer without using plasma treatment, a micro contact printing (μCP) technique can be mentioned.
ew. Chem. , Int. Ed. Engl. 37, N
o. 18 pp. 550, 1998; Phys. Lett. B 102, No. 1
8 A surface treatment technique for transferring the pattern shape of a stamp (original plate) to a substrate has been reported, as in the method described on page 3324 of 1998.

Such a method is intended to transfer a pattern of an ink composition containing a surface treating agent onto a flat substrate corresponding to the irregular shape of the stamp, since the purpose is to treat the surface of the flat substrate. Therefore, this is different from the surface treatment of the substrate with irregularities that we invented this time.

The present invention has been accomplished under such circumstances.

An object of the present invention is to increase the number of steps in the above-described conventional method without impairing the function as a bank for preventing the situation where ink guaranteed to flow by the conventional method flows out of the bank. And a substrate surface treatment method for the purpose of simply and appropriately controlling wettability by solving problems such as concern about damage due to a plasma treatment process and restrictions on materials for forming a bank, and this surface treatment By providing a method for forming a thin film having stable characteristics without flatness and uniform thickness with high accuracy and fineness by utilizing the method, and a method for producing an organic semiconductor device having a good yield with the thin film. is there.

[0030]

According to the present invention, there are provided the following methods (1) to (7) for manufacturing an organic EL device.

(1) An organic layer having a structure in which a hole injection layer and a light emitting layer are sandwiched between an anode and a cathode on a substrate having a bank of a predetermined height and a coating area divided by the bank.
A method for manufacturing an EL element, wherein a part of the surface treatment agent is transferred by contacting an original plate that has absorbed or adhered a surface treatment agent for performing an ink repellent treatment to the substrate. A step of imparting ink repellency to a part of the surface of the bank; and an ink including a material for forming a hole injection layer and a light emitting layer in a region not imparted with ink repellency by the step. And a step of applying the composition.

In the present invention, the original plate for imparting ink repellency to a part of the surface of the bank has a surface treating agent absorbed or adhered to the surface, and is in contact with a part of the bank surface of the thin film patterning substrate. Thus, the original is transferred to a part of the bank surface.

The ink repellency of the bank surface is enhanced by the effect of the transferred surface treating agent, and the ink repellency is maintained semipermanently. In the surface treatment using transfer, the damage due to the process is small, and the treatment for the substrate can be performed collectively, so that the plasma treatment is not required, and the restriction on the material of the bank is also reduced. In addition, the device is small and the work time can be shortened. further,
Since the original plate that has absorbed the surface treatment agent can be reused, it is advantageous in terms of cost. According to such a method, a thin film patterning substrate having ink repellency using a much wider variety of bank materials than conventional ink repellency treatment methods by plasma continuous processing in a simple method, in a short time, at low cost, is used. Can be formed. That is, the present invention is suitable as a process for imparting ink repellency to a bank.

In the present invention, the original plate for transferring the surface treating agent may be flat or may have a pattern structure corresponding to the shape of the bank.

(2) The method for manufacturing an organic EL device according to (1), wherein the area to be coated divided into banks has ink affinity and the contact angle is 30 ° or less. According to the condition (2) of the present invention, it is possible to form a thin film layer having stable characteristics without flatness and uniform thickness and color unevenness.

When the ink is supplied to the substrate, the ink stays in a region having a high affinity with a high probability because the ink is a fluid. Therefore, in the present invention, the applied area has a high affinity for the ink, and the ink droplet has a contact angle of 30 °.
The materials are set under the following conditions. The material is set to a material having a high polarity surface free energy if the ink is a highly polar fluid, and a material having a low polarity if the ink is a low polarity fluid. The condition is set by forming in the region to be coated. However, since it usually includes a pixel electrode, a polar solvent is supplied to a coating region having a high polarity.

(3) The method for producing an organic EL device according to (1), wherein the contact angle of the material forming the bank with the ink is 20 ° to 50 °.

According to the condition (3) of the present invention, a sufficient film thickness can be obtained at the bottom of the coating region, that is, at the portion where the ink is in contact with the bank. It leads to improvement of sex.

As described above in the condition (2), the ink stays in the area to be coated and then is dried to form a thin film layer. In order to prevent a short circuit of the EL element, the member forming the bank is made of the ink. The material is set to have a contact angle of 20 to 50 ° with respect to the ink so as not to repel too much.

(4) By the step of imparting ink repellency, the ink repellency of the upper surface of the bank can be adjusted to 5 at the contact angle.
(1) The method for manufacturing an organic EL device according to (1), wherein the angle is 0 ° or more.

Under the condition (4), a multicolor and high-definition organic EL device can be easily obtained without mixing different light emitting layers.

(5) In the step of imparting ink repellency to at least the upper surface of the bank surface, at least a part of the surface of the bank is formed of an organic or inorganic oxide layer and transferred to the bank surface. (1) The method for manufacturing an organic EL device according to (1), wherein the ink repellent agent is a fluorine-based silane coupling agent.

According to the method (5), a region having desired ink repellency can be formed on at least a part of the upper surface of the bank surface.

(6) The method for producing an organic EL device according to (1), wherein the step of applying the ink composition is a dipping method or a spin coating method. According to the method (6), the ink can be easily applied to the application area.

(7) A method for producing an organic EL device, wherein the step of applying the ink composition according to claim 1 is an ink-jet method.

In the case of forming an element having a plurality of pixels by the method (7), the ink can be easily applied to the application area. According to the present invention, a high-performance EL device obtained by the above method is provided.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

The method of manufacturing an organic EL device by an ink-jet method means that an ink composition obtained by dissolving or dispersing a hole injecting / transporting material and a luminescent material constituting a device in a solvent is discharged from an ink-jet head to a transparent electrode substrate. In this method, a hole injection / transport layer and a light-emitting material layer are formed by patterning.

FIG. 1A is a sectional view of a substrate used for manufacturing an organic EL device by an ink-jet method. A transparent pixel electrode 12 made of, for example, ITO is patterned on a transparent glass substrate 10 or a substrate provided with a TFT.
_This is a structure in which _two banks 15 are provided. Bank 15
May be any of a circular shape, an elliptical shape, a square shape, and a stripe shape. However, since the ink composition has a surface tension, it is preferable that the square corners are rounded. The area surrounded by the banks (hereinafter
An EL material is formed on the application region 20 by an inkjet method.

FIGS. 1B and 1C show a step of transferring a surface treating agent 40 for treating the surface of the bank 15 with ink repellency. A surface treating agent 40 is applied to at least a part of the surface of the original plate 30 in order to treat the substrate 10 with an ink-repellent treatment. By bringing the original plate 30 into contact with the substrate surface, the surface treatment agent 40 applied to the surface of the original plate 30
Are transferred to the substrate side.

The shape of the original plate 30 is not particularly limited. The original plate 30 may be flat or have irregularities corresponding to the shape of the bank on the substrate, but there is no necessity for alignment with the substrate 10. For this reason, it is preferable that the surface is flat for simplification of the process.

(Surface Treatment Agent) As the surface treatment agent 40,
For example, a silane coupling agent (organosilicon compound) of a self-assembled compound characterized in that a terminal functional group of a molecule is selectively chemically adsorbed to a constituent atom of a substrate can be used. Here, the silane coupling agent is R2nS
iX4-n (n is a natural number, R2 is H, a substitutable hydrocarbon group such as an alkyl group), and X is -OR
3, -COOH, -OOCR3, -NH3-nR3n, -OC
N, halogen and the like (R3 is a substitutable hydrocarbon group such as an alkyl group).

The silane coupling agent is characterized in that it is chemically adsorbed to hydroxyl groups on the substrate surface, and is reactive to oxide surfaces of a wide range of materials such as metals and insulators. Can be suitably used. Among these silane coupling agents, in particular, R
1 and R3 is CnF2n + 1CmH2m (n, m are natural numbers) becomes the surface free energy of the modified solid surface by a compound having a fluorine atom such as a is lower than 20 mJ / m ^2, of a material having a polarity Because affinity becomes small,
It is preferably used.

The thickness of the transferred surface treatment agent 40 is preferably 10 nm or less, more preferably 5 nm or less, so as not to affect the size of the bank.

(Original Plate Forming Step) As the original plate 30, it is preferable to use an elastic body in order to enhance the adhesion to the substrate 10. For example, when the above-mentioned silane coupling agent or the like is used as the surface treatment agent 40, an elastic material of polydimethylsiloxane (PDMS), which is also a silane compound, can be used. The structural formula of this polymer is Si (CH ₃ ) ₃
—O— (Si (CH ₃ ) ₂ O) _n —Si (CH ₃ ) ₃ . n is a positive integer. By using this material, the surface treatment agent 40 can be absorbed or adhered to the surface of the molded elastic body.

For example, the reaction for forming an elastic body by reacting a liquid material may be either a condensation type or an addition type. In the condensation type having a linear shrinkage of about 0.5%, a polymer reacts. Since gas is generated in the process, it is more preferable to use an elastic material with an additional reaction mechanism having a linear shrinkage of about 0.1% in terms of pattern accuracy.

As shown in FIG. 1B, the surface treating agent 40
As a method of absorbing or adhering to the original plate 30, spin coating, dipping, or the like can be used. In this case, the surface treatment agent 40 uses a material dissolved in a liquid or a solvent.

(Transfer of Surface Treatment Agent) As shown in FIG. 1C, the surface treatment agent 40 is transferred by bringing the original plate 30 coated with the surface treatment agent 40 into contact with the substrate 10. Since the unevenness due to the bank 15 is formed on the substrate surface, the surface treatment agent 40 is transferred to the upper surface of the bank 15.

In order to improve the ink repellency of the bank surface,
After the transfer step, it is also preferable to use a step for fixing the surface treatment agent 40 to the substrate 10, specifically, a treatment such as a heat treatment or exposure to a reactive vapor. For example, in the case of a silane coupling agent, the reaction proceeds by heating the substrate to a high temperature or exposing the substrate to an environment of high humidity at room temperature.

In the present invention, at least a part of the upper surface of the bank (hereinafter referred to as the modified region 50) which has been subjected to the ink-repellent treatment by the surface modifying agent 40 is formed in the other unmodified region 5.
It is preferable to combine the substrate materials of the bank 15 and the coating target area 20 or to perform a surface treatment so that the degree of affinity for ink is lower than that of No. 5. By the treatment with the surface modifier 40, the contact angle of the ink to the modified region 50 is set to 50 ° or more, and the contact angle of the applied region 20 to the ink is set to 30 ° in order to prevent short-circuiting of the color unevenness of the EL element. It is preferable to set the following. By doing so, even if a large amount of ink is ejected compared to the thickness of the thin film layer, the ink does not overflow over the bank and is filled only in a predetermined area. In addition, since the thickness of the thin film layer is easily controlled by the ink being appropriately pulled on the side wall of the bank, the contact angle of the bank material to the ink is set to 20 to
The angle is preferably set to 50 °, whereby color unevenness and short circuit of the thin film layer can be prevented.

Referring to FIGS. 1D and 2F, a hole injection / transport layer 75 + a light emitting layer 85 by an ink-jet method.
Is shown.

In FIGS. 1D and 1E, an ink composition 70 containing a hole injecting / transporting material is ejected from an ink jet head 60 and pattern-coated. After the application, the hole injection / transport layer 75 is formed by solvent removal and / or heat treatment, or by a flow of nitrogen gas or the like.

As shown in FIGS. 2F and 2G, an ink composition 80 containing a luminescent material is subsequently applied on the hole injecting / transporting layer, and the solvent is removed and / or heat-treated, or a gas such as nitrogen gas is applied. The light emitting layer 85 is formed by the flow.

As shown in FIG. 2H, Ca, Mg, A
The cathode 90 is formed using a metal such as g, Al, or Li by a vapor deposition method, a sputtering method, or the like. Further, in consideration of protection of the element, a sealing layer 95 is formed of epoxy resin, acrylic resin, liquid glass, or the like, and the element is completed.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 FIG. 3 shows an original plate and a substrate used in this example.

A bank 115 is formed by etching a SiO ₂ layer by photolithography on a glass substrate 110 on which an ITO transparent electrode 112 has been patterned. The bank diameter (opening diameter of SiO ₂ ) is 28 μm,
The height is 2 μm. The opening of the bank is 44 μm.
This is a substrate on which these pixels are continuously arranged at a pitch of 70.5 μm.

The SiO 2 layer constituting the bank is 50
Shows a contact angle of ６０60 °.

As a material of the original plate 130, polydimethylsiloxane (PDMS) is used, and a resin material that is cured by an addition-type reaction mechanism and a curing agent are mixed to leave a flat original plate 130 having no pattern at room temperature for 24 hours.
Was formed. The matrix for forming a flat original plate having no pattern is not particularly limited as long as it has a flat surface.

A solution of a silane coupling agent octadecyltrichlorosilane (OTS) was applied as a surface treatment agent 140 on the original plate 130. Since the OTS reacts with water, it was diluted with a hexane solvent to obtain a 10 mM solvent, and the surface treatment agent 140 was applied to the original plate 130 by a spinner rotating at 3000 rpm for 30 seconds.

By bringing the original plate of PDMS coated with the surface treating agent into close contact with the glass substrate, a thin film of OTS as the surface treating agent was formed only on the upper surface of the bank on the glass substrate. The surface of the bank whose surface has been treated to have ink repellency by the transferred OTS shows a high contact angle of 90 ° or more with water.

In order to cause OTS as a surface treating agent to react with the substrate surface, a heat treatment was performed for 10 minutes in an oven heated to 110 ° C.

The ink compositions shown in Table 1 were prepared as ink compositions for the hole injection / transport layer.

[0074]

[Table 1] After the surface treatment of the substrate, 15 pl of the ink composition for the hole injection / transport layer shown in Table 1 was ejected from the head (MJ-930C manufactured by Epson Corporation) of the ink jet printing apparatus, and pattern coating was performed. The solvent was removed under vacuum (1 torr) at room temperature for 20 minutes. Subsequently, the same ink composition for a hole injecting / transporting layer was ejected in an amount of 15 pl to apply a pattern.
The solvent was removed under vacuum (1 torr) at room temperature for 20 minutes.
Hole injection / transport was formed by heat treatment for 0 minutes. As a result, a flat hole injection / transport layer having a thickness of 50 nm was obtained.

The compositions shown in Tables 2 and 3 were prepared as ink compositions for the light emitting layer.

[0076]

[Table 2]

[0077]

[Table 3] 1% are shown in Table 2 from the head of (wt / vol) concentration ink jet printing apparatus a light emitting layer ink composition (Epson MJ-930C), and 20pl ejected pattern casting while flowing the _{N 2} gas .

Next, 1% (wt / vol) shown in Table 3
Concentration of the light-emitting layer ink composition, ₂Do not let the gas flow
Apply 20pl pattern to the next pixel 70.5μm away
Clothed. As a result, blue and green light emitting layers were obtained.
Fig. 5 shows the fluorescence spectrum of the green light-emitting layer (ejected film product in Table 2)
It is shown in FIG.

As a cathode, 20 nm of Ca was deposited by evaporation, and
Was formed to a thickness of 200 nm by sputtering, and finally sealed with an epoxy resin.

The selected device showed uniform green emission as shown in the fluorescence spectrum.

(Modification 1) It is desirable that the original plate used in the present invention be flat. However, it is possible to adjust the area for surface treatment by forming irregularities on the original plate depending on the shape of the bank.

As shown in FIG. 5, it is also possible to form irregularities on the surface of the original plate 210 so that a portion corresponding to an area smaller than the size of the upper surface of the bank is formed as a convex portion. The original plate 230 coated with the surface treating agent 240 is aligned with and adhered to a part of the modified region 250 on the upper surface of the bank, so that only the modified region 250 can be surface-treated with ink repellency. When this original plate is used, since the ink repellency of the peripheral portion of the upper surface is not high, it is possible to avoid the thinning of the peripheral portion of the thin film layer due to the ink being repelled in the peripheral portion, and as a result, the reliability of the organic EL element is reduced. improves.

(Modification 2) As shown in FIG. 6, by preparing an original plate 330 having concaves and convexes in which the bank portion is a concave portion, the modified region 350 including the upper surface of the bank and a part of the side wall is further formed. Surface treatment can be performed to make the ink repellent. Unmodified region 35 surrounded by the modified region 350
5 is supplied with ink. At this time, the depth of the surface treatment of the side surface is adjusted by the depth of the unevenness of the original plate.

The substrate 310 surface-treated using such an original plate 330 has a high ink repellent property halfway along the bank side surface, so that the possibility of ink flowing out of the pixel is reduced.

As described above, according to this embodiment, a part of the upper surface of the bank on the substrate surface is treated to be ink-repellent by transferring the original plate coated with the surface modifier to the unevenness of the substrate. be able to. Thus, semi-permanent ink repellency can be imparted to at least a part of the upper surface of the bank without performing the plasma processing, while maintaining the ink affinity of the surface of the substrate.

Subsequently, by supplying an EL material by an ink-jet method to form an EL element, an EL element can be formed by a simple method in a short time and at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a manufacturing process of an organic EL device according to the present invention.

FIG. 2 is a view showing a manufacturing process of the organic EL element according to the present invention.

FIG. 3 shows a substrate and an original plate used in a surface treatment step according to the present invention.

FIG. 4 is a fluorescence spectrum of a thin film formed by an inkjet method according to the present invention.

FIG. 5 is a first modification of the substrate and the original plate used in the surface treatment step according to the present invention.

FIG. 6 is a second modified example of the substrate and the original plate used in the surface treatment step according to the present invention.

FIG. 7 is a cross-sectional view showing a manufacturing process of an organic EL element according to a conventional method.

[Explanation of symbols]

 1. Transparent substrate 2. 2. Pixel electrode 3. Bank formation surface 4. Area surrounded by banks Bank lower layer 6. Upper bank 7. 7. Thin film material liquid Thin film layer 10. Substrate 12. Transparent pixel electrode 15. Bank 20. Application area 30. Original plate 40. Surface treatment agent 50. Modified region 55. Unmodified region Inkjet head 70. 75. Ink composition containing hole injection / transport layer Hole injection / transport layer 80. 85. Ink composition containing light emitting layer Light emitting layer 90. Cathode 95. Sealing layer 110. Glass substrate 112. ITO transparent electrode 115. Bank 130. Original plate 140. Surface treatment agent 210. Substrate 212. Transparent electrode 215. Bank 230. Original plate 240. Surface modifier 250. Modified region 255. Unmodified region 310. Substrate 312. Transparent electrode 315. Bank 330. Original plate 340. Surface modifier 350. Modified area 355. Unmodified area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K007 AB04 AB11 AB18 BA06 CA01 CB01 DA01 DB03 EB00 FA01

Claims (8)

[Claims] 1. An organic EL device having a structure in which a hole injection layer and a light emitting layer are sandwiched between an anode and a cathode on a substrate on which a bank having a predetermined height and a region to be coated divided by the bank are formed. A method, wherein a part of the surface treatment agent is transferred to the substrate by contacting an original plate that has absorbed or adhered a surface treatment agent for performing an ink-repellent treatment on the substrate, thereby transferring the part of the bank. A step of imparting ink repellency to a part of the surface, and applying an ink composition containing a material for forming a hole injection layer and a light emitting layer to a region not imparted with ink repellency by the above step And a method for producing an organic EL device. 2. The method for manufacturing an organic EL device according to claim 1, wherein the application area divided into said banks has an ink-philic property and a contact angle is 30 ° or less. A method for manufacturing an organic EL device. 3. The method for manufacturing an organic EL device according to claim 1, wherein a contact angle of the bank with respect to ink of a material forming the bank is 20 ° to 50 °. Manufacturing method. 4. The method of manufacturing an organic EL device according to claim 1, wherein the step of imparting ink repellency causes the upper surface of the bank to have an ink repellency of 50 ° or more in contact angle. A method for manufacturing an organic EL device, comprising: 5. The method of manufacturing an organic EL device according to claim 1, wherein a part of the surface of the bank is formed of an organic or inorganic oxide layer, and the ink repellent treatment is transferred to the bank surface. A method for producing an organic EL device, wherein the agent is a fluorine-based silane coupling agent. 6. The method for manufacturing an organic EL device according to claim 1, wherein the step of applying the ink composition is a dipping method or a spin coating method. 7. The method according to claim 1, wherein the step of applying the ink composition according to claim 1 is an inkjet method.
Manufacturing method of L element. 8. An organic EL device obtained by using the method according to any one of claims 1 to 7.