JP2009259570A - Organic electroluminescent device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device having a functional layer with uniform film thickness, and therefore, capable of high-quality display without unevenness. <P>SOLUTION: The organic electroluminescent device is provided with light-emitting elements each consisting of a functional layer 15 containing a first electrode 11 and an organic light-emitting layer 17 and a second electrode 18 in a region superposing in plane view an opening 14a of a barrier rib formed with the opening, with at least one layer out of the functional layers 15 formed by a droplet discharge method. An opening shape of the opening 14a is formed in an oval or an elliptical shape, and the barrier rib has a slanted part 27a formed descending toward the opening 14a at an opening edge part at the corner of the opening 14a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence device and an electronic apparatus.

  In recent years, in the manufacture of organic electroluminescence devices (organic EL devices), a technique for forming a desired functional film by arranging a liquid material (functional liquid) containing a functional material at a predetermined position has been actively developed. . In particular, according to a droplet discharge method typified by an inkjet method, a minute functional liquid can be applied to a desired position in accordance with the resolution of an inkjet head to be used, so that a functional film with a fine pattern is formed. Therefore, it becomes possible to form a high-resolution and high-quality organic EL device.

By the way, in the manufacturing method using the droplet discharge method, it has been proposed to provide a partition (bank) around the area where the functional liquid is applied, and to partition each functional liquid. This is because the partition wall is provided to improve the positional accuracy at the time of ejection, and to prevent the applied functional liquid from being mixed with the functional liquid in other regions, thereby enabling good patterning.
In the manufacturing method using such a partition, in practice, an opening is formed in the partition, and the inside of the opening is used as a functional liquid application region, that is, a light emitting element formation region, and a first electrode (pixel electrode) is formed in the opening. To face.

In addition, the opening shape of the opening formed in the partition wall is generally rectangular (rectangular) at the beginning. However, since the liquid droplets (functional liquid) that are arranged to be discharged tend to be rounded by the surface tension when falling into the opening, the liquid droplets are sufficiently wetted and spread particularly at the corner (corner) of the opening. It will disappear. As a result, film thickness unevenness occurs in the resulting functional film, which causes a display defect (display unevenness) such as a difference in the amount of light emission within the film and a difference in brightness and hue. It was.
Therefore, in recent years, it has been proposed to improve the wettability of droplets by making the opening shape into an oval shape, that is, the shape of a track in athletics, thereby eliminating the corners (for example, Patent Documents). 1).
JP 2004-127552 A

However, in the case where droplets are ejected and arranged by the ink jet method (droplet ejection method) in the opening portion having the oval opening shape as described above, there are the following disadvantages.
The droplet diameter of the functional liquid ejected from the inkjet head is, for example, about 20 to 30 μm. On the other hand, the opening having an oval opening shape has a lateral width of the opening shape, that is, a short axis side. The maximum length is, for example, about 100 to 200 μm. Therefore, when an attempt is made to efficiently discharge and arrange droplets in such an opening, a plurality of nozzles (for example, 3 to 5 nozzles) in the nozzle row of the inkjet head are allocated for the opening, and liquid is discharged from these nozzles. While performing droplet discharge, the inkjet head is relatively scanned in the long axis direction of the opening shape, thereby discharging a predetermined amount of functional liquid into the opening.

  However, if the opening shape is rectangular, there is no problem with such a discharge method, but since it is oval, it is assigned to a curved portion in an oval shape, that is, a semicircular portion as it is. When liquid liquid is discharged with a plurality of nozzles, the droplets discharged from the nozzles are arranged in the openings, particularly at the corners of the ellipse, that is, at the portions corresponding to the corners of the rectangle circumscribing the ellipse. Without being disposed on the partition wall. Then, this droplet does not flow down into the opening but stays in the same position, thus causing a variation in the film thickness of the functional film. Further, in an extreme case, there is a possibility that the characteristics of the functional film of the previous opening after flowing down may be impaired by flowing down into the opening of another region.

  In order to cope with such a problem, when discharging to an elliptical curved portion (a semicircular portion), the discharge from the nozzles on the end side among a plurality of assigned nozzles is stopped. It is also possible. However, if the discharge from some of the nozzles is stopped in this way, there is a possibility that the total amount of the functional liquid that is discharged and arranged in the opening will vary, and the resulting functional film may be uneven in film thickness. In addition, if the presence or absence of ejection is controlled only for some of the nozzles, this control may affect the ejection operation of other nozzles, that is, the ejection volume and the accuracy of the ejection position, which may impair the characteristics of the resulting functional film. There is.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a functional liquid with high precision in an opening having an oval or elliptical opening, thereby providing a functional layer having a uniform thickness. Accordingly, an organic electroluminescence device capable of high quality display without unevenness and an electronic device including the same is provided.

  In order to solve the above problems, an organic electroluminescence device of the present invention includes a functional layer including a first electrode and at least an organic light emitting layer in a region overlapping with the opening of the partition wall in which the opening is formed in plan view, and a second layer. An organic electroluminescence device having a light emitting element composed of an electrode, wherein at least one of the functional layers is formed by a droplet discharge method, and the opening shape of the opening is formed in an oval or elliptical shape In addition, the partition wall is characterized in that an inclined portion that descends toward the opening is formed at an opening edge at the corner of the opening.

  According to this organic electroluminescence device, the functional layer is formed by the ink jet method (droplet discharge method) because the inclined portion that descends toward the opening is formed at the opening edge at the corner of the opening formed in the partition wall. ), The liquid droplets are not directly disposed in the opening, but are disposed on the opening edge of the corner portion. It flows along the inclined portion and flows into the opening. Therefore, without performing control such as stopping the discharge of a part of the nozzles assigned according to the discharge position, regular discharge is performed with a preset nozzle, so that the functional layer can be formed under a stable discharge operation. Formation can be performed. Therefore, it is possible to prevent the disadvantage that the liquid film stays on the partition wall, causing unevenness of the film thickness in the functional film in the opening, resulting in deterioration of display quality without performing complicated discharge control. .

  Moreover, in the said organic electroluminescent apparatus, it is preferable that the said inclination part has an inclination larger than opening edge parts other than the corner part of the said opening part. Moreover, it is preferable that the maximum height of the inclined portion is higher than the height of the opening edge other than the corner of the opening. Furthermore, it is preferable that the width of the inclined portion is wider than the droplet diameter of the functional liquid ejected to form at least one of the functional layers.

Further, in the organic electroluminescence device, a spacer material is provided at a position corresponding to a corner of the opening in the inside of the partition wall or below the partition wall, and the height difference due to the spacer material is reflected. It is preferable that the inclined portion is formed.
If it does in this way, it will become possible to form the formation position of a sloping part, its inclination, etc. in a desired state with a spacer material.

In the organic electroluminescence device, the spacer material is preferably made of wiring. In that case, the wiring may be an auxiliary second electrode provided inside the partition, or may be a power supply wiring provided below the partition.
In this way, the auxiliary second electrode and the power supply wiring are easily patterned without increasing the number of steps by patterning the inclined portion so as to reflect the height difference formed by these wirings. Can be formed.

In the organic electroluminescence device, the partition is preferably made of a resin material.
In this way, it becomes easy to form the partition wall relatively thick, and therefore, it becomes easy to form the slope of the inclined portion sufficiently large.

An electronic apparatus according to the present invention includes the organic electroluminescence device described above.
According to this electronic device, since the inconvenience that the display quality is deteriorated as described above is prevented and the organic electroluminescence device capable of high quality display without unevenness is provided, the electronic device itself is also of high quality. Display is possible.

  Hereinafter, the organic electroluminescence device (organic EL device) of the present invention will be described in detail with reference to the drawings. In the following drawings, the scale is appropriately changed for each layer and each member so that each layer and each member can be recognized on the drawing.

<First Embodiment>
FIG. 1 is a side sectional view showing a schematic configuration of a first embodiment of the organic EL device of the present invention, and reference numeral 1 in FIG. 1 denotes the organic EL device. The organic EL device 1 uses the light emitted from the functional layers 15 of a large number of organic EL elements 30 formed on the substrate 2 as the sealing substrate 20 on the side opposite to the substrate 2 on which the organic EL elements 30 are formed. This is a top emission type that is taken out from

The substrate 2 is made of a reflective material such as glass, quartz, resin, or metal, and an insulating film 3 made of, for example, SiO ₂ (silicon oxide) is formed on the surface (inner surface) thereof. . On the insulating film 3, driving TFTs (thin film transistors) 4 are provided corresponding to the individual organic EL elements 30. The driving TFT 4 includes a semiconductor layer 5 made of polysilicon or the like formed on the insulating film 3, and a gate electrode 6 disposed opposite to the channel region of the semiconductor layer 5 via a gate insulating film (not shown). I have. An interlayer insulating film 7 made of SiO ₂ or SiN is formed so as to cover the gate insulating film and the gate electrode 6.

  A source electrode 8 and a drain electrode 9 are formed on the interlayer insulating film 7 and are connected to a source region (not shown) and a drain region (not shown) of the semiconductor layer 5 through contact holes 7a and 7b, respectively. ing. The source electrode 8 is connected to a power supply wiring 103 formed on the interlayer insulating film 7. The power supply wiring 103 is arranged on the side of the pixel opening, that is, on the side of the driving TFT 4 in order to increase the aperture ratio of the pixel opening, and is 0.5 μm to 1.0 μm in thickness by Al or the like. It is formed to the extent. In the present embodiment, the power supply wiring 103 functions as a spacer material for forming an inclined portion described later.

  A flattening layer (organic flattening layer) 10 for flattening the substrate 2 is formed so as to cover the driving TFT 4 and the power supply wiring 103. The planarization layer 10 is formed of an organic material having heat resistance and insulation, such as an acrylic resin or a polyimide resin. The planarizing layer 10 is formed on the interlayer insulating film 7 to have a thickness of 1 μm or more so as to planarize the convex portions formed by the driving TFT 4 and the power supply wiring 103 and thereby reduce the overall irregularities. It is a thing. However, as described above, since the power supply wiring 103 is relatively thick with a thickness of about 0.5 μm to 1.0 μm, the height difference due to the thickness is not completely eliminated by the planarization layer 10 and remains to some extent. End up. Therefore, a difference in height due to the thickness of the power supply wiring 103 is still formed on the surface of the planarizing layer 10.

  A pixel electrode (first electrode) 11 that is an anode of the organic EL element 30 is formed on the planarizing layer 10 immediately above the driving TFT 4 and in the vicinity thereof. The pixel electrode 11 is made of a conductive material having reflectivity such as Al (aluminum). Alternatively, in order to adjust the work function, an electrode having a laminated structure in which the upper layer is made of transparent ITO and the lower layer is made of a reflective conductive material such as Al may be used. The pixel electrode 11 is connected to the drain electrode 9 through a contact hole 10 a that passes through the planarization layer 10 and reaches the drain electrode 9. The gate electrode 6 of the driving TFT 4 is connected to a switching TFT 112 described later, and is electrically connected to a storage capacitor cap that stores a pixel signal.

  A partition wall 14 including an inorganic partition wall 12 and an organic partition wall 13 formed on the inorganic partition wall 12 is formed on and around the periphery of the pixel electrode 11. In the partition wall 14, an opening (pixel opening) 14 a that partitions the pixel electrode 11 for each organic EL element 30 and exposes the upper surface (surface opposite to the substrate 2) of the pixel electrode 11 is formed. The end of the organic partition wall 13 (the part defining the opening 14a) is formed so as to be outside the end of the inorganic partition wall 12 (the part defining the opening 14a) when viewed from the opening 14a. Yes. As a result, the barrier rib 14 exposed in the opening 14 a is formed with a stepped stepped portion with the upper surface of the inorganic barrier rib 12 exposed at the boundary between the organic barrier rib 13 and the inorganic barrier rib 12 in the opening 14 a. Yes.

The inorganic partition wall 12 is formed of an insulating inorganic material such as SiO ₂ and has a lyophilic property because its surface has been subjected to lyophilic treatment and wettability has been improved. ing. The organic partition wall 13 is made of, for example, the same organic material as that of the planarization layer 10 and has a liquid repellency by the liquid repellency treatment on the surface thereof.

  The organic partition wall 13 is formed so as to cover the inorganic partition wall 12, and the opening shape thereof is the opening shape of the opening portion 14 a of the entire partition wall 14. In the present embodiment, the organic partition wall 13 has an inner surface of the opening portion 13a that is a tapered surface, and thus the opening shape on the upper surface side is the largest opening. Therefore, the opening shape of the opening in the present invention refers to the shape of the uppermost portion of the tapered surface. In addition, the opening shape of this opening (the opening shape of the opening 13a (14a)) is an oval shape (track shape) as shown in FIG. 2A in this embodiment. Moreover, the opening part 14a of such a partition 14 is arrange | positioned at matrix form. In the present embodiment, the power supply wiring 103 is arranged in a grid (vertically and horizontally) between the openings 14a arranged in a matrix as shown by a solid line in FIG. 2A. Formed and arranged.

  Here, in the present embodiment, the power supply wiring 103 is formed in a substantially rhombus shape in a plan view as shown in FIG. That is, in the central part of the four openings 14a arranged vertically and horizontally, the power supply wiring 103 arranged between the openings 14a and 14a has an intersection portion 103a with a constant width (adjacent openings). Corners of the respective openings 14a as compared to the vertical and horizontal intersections when it is assumed that the power supply wiring 103 located between the portions 14a extends in the vertical and horizontal directions. Overhangs in the direction. Here, in the present invention, the corner of the oval opening 14a is a curved portion (rectangular E) corresponding to the corner F of the rectangle E circumscribing the oval D as shown in FIG. (Region surrounded by the outer contour line of the ellipse and the outer contour line of the ellipse D) R1 to R4.

  Further, the power supply wiring 103 has a (shortest) distance between the edge of the power supply wiring 103 and the opening 14a adjacent thereto as compared with the distance d1 in the linear portion (the straight portion 103b) as shown in FIG. The distance d2 at the intersection 103a is shorter. With such a configuration, the organic partition wall 13 (partition wall 14) is formed with an inclined portion that descends toward the opening portion 14a on the upper surface portion, reflecting the height difference due to the thickness of the power supply wiring 103. .

  As shown in FIG. 3A, which is a cross-sectional view taken along the line AA in FIG. 2B, it is formed particularly at the opening edge at the corners (curved portions R1 to R4) of the opening 14a. The degree of inclination (inclination angle) of the inclined part 27a is larger than that of the inclined part 27b formed at the opening edge of the straight part of the opening 14a. That is, in the inclined portion 27a, as described above, the distance d2 between the edge of the power supply wiring 103 and the opening 14a is formed shorter than the distance d1 in the other portion (the straight portion 103b). The influence of the height difference due to the wiring 103 is further increased, and the inclination angle of the inclined portion 27a is increased accordingly. On the other hand, the inclined portion 27b formed at the opening edge portion in the straight portion of the opening portion 14a has a power supply wiring as shown in FIG. 3B, which is a cross-sectional view taken along the line BB in FIG. Since the distance d1 between the edge 103 and the opening 14a is relatively long, the degree of inclination (inclination angle) is smaller than that of the inclined part 27a.

  In addition, the opening which determines the opening shape of the partition 14 is the uppermost part in the inner surface of the opening 13a of the organic partition 13 having a tapered surface as described above. Specifically, FIGS. b) A position P at which the inner surface of the organic partition wall 13 changes from a substantially flat surface (tapered surface) to a curved surface, that is, a position P that intersects a perpendicular line indicated by a two-dot chain line in FIGS. The opening at. Therefore, the curved surface portion above this position is referred to as an opening edge portion, and the inclined portion is an inclined portion 27a (27b). The inclination angles of the inclined portions 27a and 27b are the positions of intersection lines (intersection points) between the inclined portions 27a and 27b and the upper surface of the partition wall 14 (organic partition wall 13), that is, the surface substantially parallel to the surface of the substrate 2. Is a position Q, it means an angle between a straight line connecting the position Q and the position P and the surface of the substrate 2.

  As shown in FIG. 1, a functional layer 15 is provided in the opening 14a of the partition wall 14 (organic partition wall 13) in which the inclined portions 27a and 27b are formed. The functional layer 15 includes a hole injection / transport layer 16 formed on the pixel electrode 11 side, and a light emitting layer (organic light emitting layer) 17 formed by being laminated thereon. . The hole injection / transport layer 16 is, for example, a 3,4-polyethylenedioxythiophene-polystyrene sulfonic acid (PEDOT-PSS) dispersion, that is, 3,4-polyethylenedioxythiophene using polystyrene sulfonic acid as a dispersion medium. And a liquid material such as a dispersion obtained by dispersing this in water is dried. The light emitting layer 17 is formed of a known light emitting material capable of emitting fluorescence or phosphorescence. In particular, when full-color display is performed, a material that emits light corresponding to each wavelength range of red, green, and blue is used.

  Here, examples of the material for forming the light emitting layer 17 include (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), and polyvinylcarbazole. Polysilanes such as (PVK), polythiophene derivatives, and polymethylphenylsilane (PMPS) are preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as. Further, a phosphorescent material such as Ir (ppy) 3 can also be used.

On the functional layer 15, a transparent common electrode (second electrode) 18 that is a cathode of the organic EL element 30 is provided so as to cover the functional layer 15 and the partition wall 14. The common electrode 18 is formed of an alkali metal or alkaline earth metal that is a low work function metal, or is formed of MgAg, LiF, ITO (indium tin oxide), or the like.
In addition, a sealing substrate 20 made of a transparent material such as glass or quartz is attached on the common electrode 18 via a light-transmitting adhesive layer 19.

  FIG. 4 is a schematic diagram showing a wiring structure of the organic EL device 1 of the present embodiment. As shown in FIG. 4, the organic EL device 1 includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting the scanning lines 101, and a plurality of power supply lines 103 extending in parallel to the signal lines 102. Are respectively wired, and pixel regions A are formed in the vicinity of the intersections of the scanning lines 101 and the signal lines 102.

Connected to the signal line 102 is a data side driving circuit 104 including a shift register, a level shifter, a video line, and an analog switch. A scanning side driving circuit 105 including a shift register and a level shifter is connected to the scanning line 101. Further, each of the pixel regions A is supplied with a switching TFT 112 to which a scanning signal is supplied to the gate electrode 6 (see FIG. 1) via the scanning line 101, and is supplied from the signal line 102 via this switching TFT 112. When the storage capacitor cap that holds the pixel signal, the driving TFT 4 to which the pixel signal held by the holding capacitor cap is supplied to the gate electrode 6, and the power supply wiring 103 through the driving TFT 4 are electrically connected Further, a pixel electrode 11 into which a driving current flows from the power supply wiring 103 and a functional layer 15 sandwiched between the pixel electrode 11 and the common electrode 18 are provided.
The pixel electrode 11, the common electrode 18, and the functional layer 15 constitute an organic EL element 30.

  According to such a configuration, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor cap, and the driving line is driven according to the state of the holding capacitor cap. The on / off state of the TFT 4 is determined. Then, current flows from the power supply wiring 103 to the pixel electrode 11 through the channel of the driving TFT 4, and further current flows to the common electrode 18 through the functional layer 15. Then, the functional layer 15 emits light according to the amount of current flowing through it.

  In order to manufacture the organic EL device 1 having such a configuration, first, as shown in FIG. 5A, an insulating film 3 is formed on a substrate 2, and a driving TFT 4 and a switching TFT 112 are formed on the insulating film 3. And the above-mentioned wirings and circuits are formed. That is, a semiconductor layer 5 such as polysilicon and a gate insulating film (not shown) covering the semiconductor layer 5 are formed on the insulating film 3, and a gate electrode 6 is formed thereon. Next, the semiconductor layer 5 is doped with impurities to form a source region, a drain region, and a channel region. Then, an interlayer insulating film 7 is formed so as to cover them, and contact holes 7a and 7b reaching the source region and the drain region of the semiconductor layer 5 through the interlayer insulating film 7 by photolithography are formed.

  Next, as shown in FIG. 5B, the power supply wiring 103 is formed on the interlayer insulating film 7. Specifically, Al is selectively formed by a vapor deposition method using a mask to form a lattice pattern as shown in FIG. At this time, as shown in FIG. 2B, the tolerance portion 103a is formed in a substantially rhombus shape by projecting to the vicinity of the corner of the opening 14a. For the formation of the power supply wiring 103, a known patterning method using a resist technique or an etching technique may be used instead of the mask vapor deposition method.

Next, a source electrode 8 and a drain electrode 9 are formed on the interlayer insulating film 7.
Next, as shown in FIG. 5C, an acrylic resin or the like is formed so as to cover them by a spin coating method or the like, and the planarization layer 10 is formed. When the planarization layer 10 is formed in this way, the height difference due to the height of the power supply wiring 103 is reduced to some extent, and the planarization layer 10 is still flattened. A difference (tilt) is formed.
Next, a contact hole 10 a that penetrates the planarization layer 10 and reaches the drain electrode 9 is formed by a known patterning method using a resist technique and an etching technique.

Next, as shown in FIG. 6A, the pixel electrode 11 is formed on the planarizing layer 10 and connected to the drain electrode 9 through the contact hole 10a.
Next, as shown in FIG. 6B, an insulating inorganic material layer 120 made of SiO ₂ or the like is formed so as to cover the pixel electrode 11 and the planarization layer 10. Then, the inorganic material layer 120 is patterned using a resist technique, an etching technique, or the like to form the opening 12a that partitions the pixel electrode 11 and exposes the upper portion of the pixel electrode 11, thereby forming the inorganic partition wall 12.

Next, as shown in FIG. 6C, an acrylic resin film or the like is formed by a spin coating method or the like so as to cover the pixel electrode 11 and the inorganic partition wall 12, and an organic material layer 130 is formed. Then, the organic material layer 130 reflects the height difference of the planarizing layer 10 that is the base, that is, the height difference due to the power supply wiring 103, and forms a height difference (inclination) particularly on the edge of the power supply wiring 103. ing.
Subsequently, the organic material layer 130 is patterned by a resist technique, an etching technique, or the like to form a tapered opening 13 a that exposes the pixel electrode 11. Thereby, the organic partition wall 13 is formed.

  At this time, the opening 13 a is formed to be slightly larger than the opening 12 a of the inorganic partition wall 12. As a result, the partition wall 14 is formed which includes the inorganic partition wall 12 and the organic partition wall 13 and has an opening portion 14 a including the opening portion 12 a of the inorganic partition wall 12 and the opening portion 13 a of the organic partition wall 13. Then, when the opening 13a of the organic partition wall 13, that is, the opening 14a of the partition wall 14 is formed in this way, the opening edge portion has an inclined portion 27a, as shown in FIGS. 27b is formed. However, for the reasons described above, the inclination angle of the inclined portion 27a at the corner of the opening 14a is larger than that of the inclined portion 27b at the straight portion other than the corner.

Next, the surface of the pixel electrode 11 is cleaned, and then oxygen plasma treatment is performed on the surface on which the pixel electrode 11, the inorganic partition wall 12, and the organic partition wall 13 are formed. Thereby, contaminants, such as an organic substance adhering to the surface, are removed and wettability is improved. Specifically, the substrate 2 is heated to a predetermined temperature, for example, about 70 to 80 ° C., and then plasma processing (O ₂ plasma processing) using oxygen as a reaction gas under atmospheric pressure is performed.

Next, the wettability of the upper surface and the inner surface of the organic partition wall 13 is lowered by performing a liquid repellent treatment. Specifically, plasma treatment (CF ₄ plasma treatment) using tetrafluoromethane as a reaction gas under atmospheric pressure is performed, and then the substrate 2 heated for the plasma treatment is cooled to room temperature, whereby organic The upper surface and side surfaces of the partition wall 13 are made liquid repellent, and the wettability is lowered.
In this CF ₄ plasma treatment, the exposed surface of the pixel electrode 11 and the inorganic partition wall 12 are also somewhat affected, but the metal that is the material of the pixel electrode 11 and the like, SiO ₂ that is the constituent material of the inorganic partition wall 12 and the like. Has poor affinity for fluorine, so that the wettability of the surface improved by the oxygen plasma treatment is maintained.
Next, the substrate 2 is heated to, for example, a temperature of about 200 ° C. to perform an annealing process.

  Next, as shown in FIG. 1, the hole injection / transport layer 16 is formed in the opening 14 a surrounded by the partition wall 14. In the step of forming the hole injection / transport layer 16, an ink jet method, which is a droplet discharge method, is particularly employed because the material for forming the hole injection / transport layer 16 needs to be selectively disposed in the opening 14 a. .

  FIG. 7A is a cross-sectional view of an inkjet head 301 provided in an apparatus (droplet ejection apparatus) that ejects droplets by an inkjet method. The inkjet head 301 is provided with a piezo element 322 adjacent to a liquid chamber 321 that stores a liquid material. The liquid material is supplied to the liquid chamber 321 via a liquid material supply system 323 including a material tank that stores the liquid material. The piezo element 322 is connected to the drive circuit 324, and a voltage is applied to the piezo element 322 via the drive circuit 324 to deform the piezo element 322. Accordingly, the liquid chamber 321 is deformed to increase the internal pressure, and the liquid droplet L is discharged from the nozzle 325. That is, by changing the value of the applied voltage, the distortion amount of the piezo element 322 is controlled, and the discharge amount of the liquid material is controlled.

  Further, as shown in FIG. 7B, the inkjet head 301 is of a multi-nozzle type in which a large number of discharge nozzles 325 are arranged in a row (or a plurality of rows) at regular intervals on the lower surface thereof. From the discharge nozzles 325, the liquid droplets L of the functional liquid (liquid material) that are the material for forming the functional layer 15 are discharged independently from each other as described above.

A dispersion of PEDOT-PSS, which is a material for forming the hole injection / transport layer 16, is ejected into the opening 14 a by the ink jet method using the ink jet head 301, thereby exposing the exposed surface of the pixel electrode 11. Arrange on top.
At that time, for example, the three adjacent discharge nozzles 325 among the many discharge nozzles 325 shown in FIG. 7B are used, and as shown in FIG. Is discharged. Then, the inkjet head 301 is scanned relative to the substrate 2, the ejection nozzle 325 is moved in the major axis direction of the oval opening 14 a, and the droplet L is ejected. By repeating such an operation a plurality of times (six times in FIG. 8A), the discharge of the material for forming the hole injection / transport layer 16 into one opening 14a is completed.

When the droplet L is discharged from the discharge nozzle 325 in this manner, as shown in FIG. 8A, the curved portion in the oval opening 14a, that is, the semicircular portion 14b having a semicircular shape. Then, the liquid droplets L1 are discharged from the three discharge nozzles 325 as they are, so that the liquid droplets L1 discharged from the discharge nozzle at the end are not arranged directly in the opening portion 14a, but the partition wall 14 ( It may be disposed on the organic partition wall 13), that is, on the opening edge of the corner. However, in the present invention, since the inclined portion 27a is formed on the opening edge portion, the droplet L1 discharged and disposed here surely flows down into the opening portion 14a. Therefore, by regularly discharging with a preset discharge nozzle 325, a set amount of liquid droplets L (material for forming the hole injection / transport layer 16) in the opening 14a can be obtained in a stable discharge operation. Can be arranged.
Thereafter, heat treatment (drying / firing treatment) is performed, for example, at 200 ° C. for about 10 minutes to form the hole injection / transport layer 16 having a thickness of about 20 nm to 100 nm.

  Next, a light emitting layer 17 is formed on the hole injection / transport layer 16. Also in the step of forming the light emitting layer 17, as in the step of forming the hole injecting / transporting layer 16, an ink jet method that is a droplet discharge method is performed. That is, droplets L are ejected from the material for forming the light emitting layer 17 onto the hole injection / transport layer 16 by an ink jet method. At that time, as in the hole injection / transport layer 16 forming step, the three ejection nozzles 325 adjacent to each other are used as shown in FIG. Then, the discharge nozzle 325 is moved in the long axis direction of the oval opening 14a, and the droplet L is discharged.

Then, also in this case, in the semicircular portion 14b in the oval opening portion 14a, the droplet L1 is not arranged directly in the opening portion 14a but is arranged on the partition wall 14 (organic partition wall 13). There is. However, since the inclined portion 27a is formed on the edge of the opening, the droplet L1 discharged and disposed here surely flows down into the opening 14a. Therefore, also in the step of forming the light emitting layer 17, the liquid droplets L (the material for forming the light emitting layer 17) of a set amount are obtained under a stable discharge operation by regularly discharging with the discharge nozzle 325 set in advance. ) Can be disposed in the opening 14a.
Thereafter, heat treatment is performed at 130 ° C. for about 30 minutes in a nitrogen atmosphere, and the light emitting layer 17 having a thickness of about 50 nm to 200 nm is formed in the opening 14 a formed in the partition wall 14, that is, on the pixel region A. As the solvent used in the material for forming the light emitting layer 17, a solvent that does not re-dissolve the hole injection / transport layer 16, such as xylene, is preferably used.

Next, a transparent conductive material such as MgAg is formed to cover the light emitting layer 17 and the organic partition wall 13 to form the common electrode 18. Unlike the formation of the hole injection / transport layer 16 and the light emitting layer 17, the formation of the common electrode 18 is not performed selectively only in the pixel region A by performing a vacuum deposition method or the like, A common electrode 18 is formed on almost the entire surface.
Thereafter, an adhesive layer 19 is formed on the common electrode 18 using an adhesive, and the sealing substrate 20 is further adhered by the adhesive layer 19 to perform sealing.

  According to the organic EL device 1 of the present embodiment, as described above, the inclined portion 27a is formed at the opening edge at the corner of the opening 14a (13a) formed in the partition wall 14 (organic partition wall 13). Since the inclined portion 27a is formed to have a larger inclination than the opening edge other than the corner portion, the hole injection / transport layer 16 and the light emitting layer 17 are formed by an inkjet method (droplet discharge method). At this time, even if the droplet L1 is not directly disposed in the opening 14a but is disposed on the opening edge of the corner, the droplet L1 flows down through the inclined portion 27a into the opening 14a. It becomes like this.

  Therefore, for example, as shown in FIG. 8B, the semicircular portion 14b in the oval opening portion 14a is caused to stop discharging from one of the three discharge nozzles 325 assigned to the two semicircular portions 14b. By performing regular discharge with the three discharge nozzles 325 set as shown in FIG. 8A without performing control such that discharge is performed only from the discharge nozzles 325, a stable discharge operation can be performed. Thus, the functional layer 15 can be formed. Therefore, the liquid droplet L stays on the partition wall 14 to cause the film thickness unevenness in the functional film in the opening 14a, and to ensure the disadvantage that the display quality is deteriorated without complicated discharge control. Can be prevented.

In addition, since the power supply wiring 103 provided below the partition wall 14 functions as a spacer material and the inclined portion 27a is formed reflecting the height difference formed by the power supply wiring 103, the number of steps is not increased. Therefore, the inclined portion 27a can be easily formed without reducing the productivity.
Further, since the inclined portion 27a is formed in the organic partition wall 13 made of a resin material, it is easy to form the organic partition wall 13 thick, and therefore, it is possible to form a sufficiently large slope in the inclined portion 27a. It becomes easy.

Second Embodiment
FIG. 9 is a side sectional view showing a schematic configuration of the second embodiment of the organic EL device of the present invention, and reference numeral 100 in FIG. 9 denotes the organic EL device. This organic EL device 100 is different from the organic EL device 1 shown in FIG. 1 in that an inclined portion 27a is formed at the opening edge at the corner of the opening 14a (13a) of the partition wall 14 (organic partition wall 13). In this case, an auxiliary cathode (auxiliary second electrode) 28 is used in place of the power supply wiring 13 as a spacer material.

  That is, in the organic EL device 100, the auxiliary cathode 28 is formed on the inorganic barrier 12 on the side of the pixel electrode 11, and the organic barrier 13 is formed so as to cover the auxiliary cathode 28. The auxiliary cathode 28 is formed of a conductive material having a small specific resistance such as Al, and is electrically connected to the common electrode 18 through a contact hole 13 b formed in the organic partition wall 13. Further, in the present embodiment, the auxiliary cathode 28 is formed in a lattice shape similarly to the power supply wiring 103 shown in FIGS. 2A and 2B, and a portion where the vertical and horizontal crosses is an opening. It is formed to project to the vicinity of the corner of 14a. Thereby, the inclined part 27a is formed in the opening edge part in the corner part of the opening part 14a (13a) of the partition 14 (organic partition 13) similarly to 1st Embodiment.

  Accordingly, even in such an organic EL device 100, when the hole injection / transport layer 16 and the light emitting layer 17 are formed by the inkjet method (droplet discharge method), the droplets are directly disposed in the opening 14a. Even if it is arranged on the opening edge of the corner, the liquid droplet flows down into the opening 14a through the inclined portion 27a. Therefore, regular discharge is performed with the preset discharge nozzles 325 without performing control such as stopping discharge of a part of the discharge nozzles 325 assigned according to the discharge position, thereby achieving stable discharge operation. Thus, the functional layer 15 can be formed. Therefore, the liquid droplets stay on the partition wall 14 to cause unevenness of the film thickness in the functional film in the opening 14a, and the disadvantage that the display quality deteriorates due to this is ensured without performing complicated discharge control. Can be prevented.

  Further, since the auxiliary cathode 28 provided inside the organic partition wall 13 functions as a spacer material and the height difference formed by the auxiliary cathode 28 is reflected, the inclined portion 27a is formed. The inclined portion 27a can be easily formed without increasing the number of steps and thus without reducing the productivity. Further, since the auxiliary cathode 28 as the spacer material is provided inside the organic partition wall 13, the height difference of the auxiliary cathode 28 can be more directly reflected on the surface of the organic partition wall 13. It can be formed easily.

  In FIG. 9, the power supply wiring 103 shown in FIG. 1 is not formed below the organic partition wall 13 and is therefore omitted from the illustration. However, the embodiment shown in FIG. Similarly, the power supply wiring 103 may be formed below the organic partition wall 13. In that case, both the power supply wiring 103 and the auxiliary cathode 28 can function as a spacer material for forming the inclined portion 27a.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the power supply wiring 103 and the auxiliary cathode 28 are used as the spacer material for forming the inclined portion 27a. However, a spacer material may be formed separately from these wirings. In that case, for example, it is preferable to form the maximum height of the inclined portion 27a higher than the height of the opening edge other than the corner of the opening.
Furthermore, although the opening shape of the opening 14a (13a) of the partition wall 14 (organic partition wall 13) is formed in an oval shape in the embodiment, the opening shape of the opening portion 14a (13a) may be elliptical. Even if it is elliptical in this way, the same effect as in the case of an ellipse can be obtained.
In the above embodiment, the top emission type organic EL device has been described. However, the present invention can be applied to a bottom emission type organic EL device that extracts light from the opposite side to the above embodiment.

  Moreover, the structure of the inclined part in the opening edge part of the partition of this invention is applicable also to the partition for color filter formation. In this way, when the color filter is formed by the ink jet method (droplet discharge method), a predetermined amount of the color filter material (liquid material) can be disposed in the opening of the partition wall. Therefore, it is possible to perform color discharge under a stable discharge operation by performing regular discharge with a preset discharge nozzle without performing control such as stopping discharge of a part of discharge nozzles assigned according to discharge positions. A filter can be formed.

[Electronics]
Next, an example of an electronic apparatus provided with the organic EL device of the present invention will be described. FIG. 10 is a perspective view showing a mobile phone as an example of the electronic apparatus according to the invention. A mobile phone 1300 shown in FIG. 10 includes the organic EL device of the present invention as a display unit 1301, and further includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. Therefore, the mobile phone 1300 is provided with an organic EL device that can prevent inconvenience such as a decrease in display quality as described above, and thereby can display high-quality images without unevenness. The display itself is also capable of high quality display.

  Note that the electronic device is not limited to the mobile phone described above, and can be applied to various devices. For example, a desktop computer, multimedia personal computer (PC) and engineering workstation (EWS), pager, word processor, television, viewfinder type or monitor direct view type video tape recorder, electronic notebook, electronic desk calculator, It can be suitably used as an image display means such as a car navigation device, a POS terminal, or a device provided with a touch panel. With such a configuration, an electronic device including a display unit with high display quality can be provided.

1 is a side sectional view showing a schematic configuration of a first embodiment of an organic EL device of the present invention. (A)-(c) is a schematic plan view which shows the opening shape of an opening part, power supply wiring, and the position of a corner part. (A), (b) is a sectional side view of an inclination part. It is a schematic diagram which shows the wiring structure of the organic electroluminescent apparatus of this invention. (A)-(c) is manufacturing-process explanatory drawing of the organic electroluminescent apparatus of this invention. (A)-(c) is manufacturing-process explanatory drawing of the organic electroluminescent apparatus of this invention. (A), (b) is a schematic diagram which shows schematic structure of an inkjet head. (A), (b) is a top view of the opening part for demonstrating the effect | action of this invention. It is a sectional side view which shows schematic structure of 2nd Embodiment of the organic EL apparatus of this invention. It is a perspective view which shows the electronic device which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,100 ... Organic electroluminescent apparatus (organic EL apparatus), 2 ... Board | substrate, 11 ... Pixel electrode (1st electrode), 12 ... Inorganic partition, 12a ... Opening part, 13 ... Organic partition, 13a ... Opening part, 14 ... Partition wall, 14a ... opening, 15 ... functional layer, 16 ... hole injection / transport layer, 17 ... light emitting layer (organic light emitting layer), 18 ... common electrode (second electrode), 27, 27a, 27b ... inclined portion, 28 ... auxiliary cathode (auxiliary second electrode), 30 ... organic EL element (light emitting element), 103 ... power supply wiring

Claims (10)

A light emitting element comprising a first electrode, a functional layer including at least an organic light emitting layer, and a second electrode in a region overlapping the opening of the partition wall forming the opening in a plan view, An organic electroluminescence device having at least one layer formed by a droplet discharge method,
The opening shape of the opening is formed in an ellipse or an ellipse,
The organic electroluminescence device according to claim 1, wherein the partition wall is formed with an inclined portion that descends toward the opening at an opening edge at a corner of the opening.   2. The organic electroluminescence device according to claim 1, wherein the inclined portion has a larger inclination than an opening edge portion other than a corner portion of the opening portion.   The organic electroluminescence device according to claim 1, wherein a maximum height of the inclined portion is higher than a height of an opening edge other than a corner of the opening.   The width | variety of the said inclination part is wider than the droplet diameter of the functional liquid discharged in order to form at least one layer of the said functional layer, The Claim 1 characterized by the above-mentioned. Organic electroluminescence device.   A spacer material is provided at a position corresponding to the corner of the opening in the inside of the partition wall or below the partition wall, and the inclined portion is formed reflecting the height difference due to the spacer material. The organic electroluminescence device according to any one of claims 1 to 4, wherein the organic electroluminescence device is characterized.   6. The organic electroluminescence device according to claim 5, wherein the spacer material is made of wiring.   The organic electroluminescent device according to claim 6, wherein the wiring is an auxiliary second electrode provided inside the partition wall.   The organic electroluminescence device according to claim 6, wherein the wiring is a power supply wiring provided below the partition wall.   The organic electroluminescent device according to claim 1, wherein the partition wall is made of a resin material.   The electronic device provided with the organic electroluminescent apparatus as described in any one of Claims 1-9.

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