JP2004014532A - Organic electroluminescent display panel and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display panel in which an organic electroluminescent medium layer or a cathode can be patterned in a free shape without deteriorating characteristics of an element and to provide a process for manufacturing the same. <P>SOLUTION: The organic electroluminescent display panel having an image display array made of a plurality of light emitting parts includes a substrate having a plurality of first display electrodes formed on the surface corresponding to the light emitting parts, a plurality of electric insulation barriers which project on the substrate to expose at least part of the first display electrode, a thin film of at least one layer organic electroluminescent medium formed on each part of the exposed first display electrode, and a plurality of second display electrodes formed on the thin film of the organic electroluminescent medium, and an overhanging part protruding in a direction parallel to the substrate is formed on the upper part of the barrier. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention utilizes electroluminescence (hereinafter, referred to as EL) of an organic compound material that emits light by current injection, and arranges a plurality of organic EL elements having a light emitting layer formed of a thin film of such an organic EL material in a matrix. To a manufactured organic EL display panel.

In general, micropatterning of the cathode of an organic EL element and an organic EL medium layer requires low heat resistance (generally 100 ° C. or lower), solvent resistance, and moisture resistance of an organic EL medium used for a charge injection layer and a light emitting layer. Is difficult for. For example, when a photolithography method usually used for patterning a thin film is used for an organic EL device, a solvent in a photoresist enters the device, a high-temperature atmosphere during photoresist baking, a device in a photoresist developing solution or an etching solution, or the like. There is a problem that the characteristics of the organic EL element are degraded due to intrusion into the substrate or damage due to plasma during dry etching.

There is also a method of patterning using a vapor deposition mask. However, the organic EL is formed by wraparound of the vapor due to poor adhesion of the mask between the substrate and the vapor deposition, or by contact with the mask when the substrate and the vapor deposition mask are closely adhered. Insufficient mask strength when the medium layer is damaged and the anode and the cathode made of indium tin oxide (hereinafter referred to as ITO) are short-circuited, or when the mask has a large opening such as a stripe pattern of the cathode and a thin mask. However, a fine pattern cannot be formed due to a problem such as bending of the mask.

At present, display panels using organic EL materials are disclosed in JP-A-2-66873, JP-A-5-275172, JP-A-5-258869 and JP-A-5-258860. There is something. This full color display is a light emitting device having an image display array composed of a plurality of light emitting pixels arranged in intersecting rows and columns.

In this light emitting device, each pixel is arranged on a common electrically insulating light transmitting substrate. The pixels in each row contain and are joined by a common light transmissive first electrode that extends over the substrate. The first electrodes in adjacent rows are spaced laterally on the substrate. The organic EL medium is disposed on a support surface formed by the first electrode and the substrate. The pixels in each column contain and are connected by a commonly extended second electrode disposed on the organic EL medium. The second electrodes in adjacent rows are spaced apart on the organic EL medium in the horizontal direction. In this light emitting device, a simple matrix type using first and second electrode lines that intersect with an organic EL medium interposed therebetween is employed.

方法 A method for solving the above-mentioned problem is disclosed in the above-mentioned publication. For example, the technique disclosed in JP-A-2-66873 is a method in which a photoresist using a solvent that does not dissolve the organic EL medium is patterned on the element, and the cathode is etched using dilute sulfuric acid. However, during the etching, the organic EL medium is damaged by the dilute sulfuric acid.

Further, the techniques disclosed in JP-A-5-275172, JP-A-5-258589 and JP-A-5-258860 are disclosed in Japanese Patent Application Laid-Open No. H05-258860. In this method, a partition wall having a height is formed, and an organic EL medium or a cathode material is vapor-deposited on the substrate from a direction perpendicular to the partition wall and oblique to the substrate surface. That is, a manufacturing method is adopted in which the first electrode line and the thin film of the organic EL medium are selectively obliquely vacuum-deposited to form a thin film of the organic EL medium by blocking a predetermined gas flow with a high-boundary wall provided on the substrate in advance. . However, according to this method, patterning can be performed only in a direction perpendicular to the oblique deposition direction, and only a stripe shape can be obtained. Therefore, a display panel in which RGB are arranged in a delta or a display panel in which a cathode is bent or meandering cannot be realized.

In this prior art, a high wall perpendicular to the substrate is provided and the high wall is used as a vapor deposition mask. However, especially when the pattern becomes fine, the aspect ratio (bottom / height) of the cross section is extremely large. It is difficult to form the wall with a photoresist or the like, and the reliability of the first and second electrode lines and the organic EL medium film after the formation is largely unstable. There are also problems such as the accuracy of oblique vacuum deposition and the complexity of the process.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a display in which an organic EL medium layer and a cathode can be patterned into any shape without deteriorating the characteristics of the device.

The present invention is an organic EL display panel having an image display array including a plurality of light emitting units,
A substrate having a plurality of first display electrodes corresponding to the light emitting units formed on a surface thereof;
A plurality of electrically insulating partitions projecting above the substrate exposing at least a portion of the first display electrode;
At least one organic EL medium thin film formed on each of the exposed first display electrode portions;
A plurality of second display electrodes formed on a thin film of the organic EL medium,
An overhang portion protruding in a direction parallel to the substrate above the partition wall,
The thin film of the organic EL medium and / or the second display electrode may extend below the overhang portion.

The organic EL display panel may further include an insulating film formed on at least one of the first display electrode below the overhang portion or an edge of the exposed portion of the first display electrode. Accordingly, a short circuit between the first and second display electrodes can be prevented.

In the organic EL display panel, the organic EL display panel includes the first display electrode, a thin film of the organic electroluminescence medium, and an insulating sealing film formed on the second display electrode. The two display electrodes can be completely covered, thereby preventing the panel from being deteriorated.

In the organic EL display panel, the first display electrode and the second display electrode may be a plurality of striped electrodes and may be arranged at positions orthogonal to each other.

Further, in the organic EL display panel, the substrate and the first display electrode are transparent, and the second display electrode has metallic luster, or a reflective film formed on the second display electrode is formed. It is preferred to have.

In the organic EL display panel according to still another embodiment, when the second display electrode is transparent, the first display electrode has a metallic luster or a reflective film formed outside the first display electrode. It is preferred to have.

According to the present invention, the following effects can be obtained.

(1) After forming the organic EL film, there is no need to perform a step of damaging the organic EL medium such as patterning. The partition can prevent the organic EL medium layer from being damaged, and can achieve protection of the organic functional layer.

(2) The number of steps is smaller than that of the conventional method for manufacturing an organic EL display panel, the separation of the RGB organic layers can be performed reliably, and the separation of the RGB media can be performed accurately.

(3) The electrode can be patterned into a free shape.

(4) Since the width of the thin film of the organic EL medium and / or the second display electrode can be increased, the light emitting region can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the organic EL display panel of the embodiment has an image display array including a plurality of luminescent pixels 1 arranged in a matrix and each including a red R, a green G, and a blue B light emitting unit. I have. In addition, a monochrome display panel can be formed in which all the light emitting portions emit light of a single color instead of the light emitting portions of RGB.

As shown in FIG. 2, a first display electrode line 3 made of ITO or the like is provided on a substrate 2 of the organic EL display panel. The first display electrode lines 3 are arranged in a plurality of stripes parallel to each other.

Further, a plurality of electrically insulating partition walls 7 projecting from the substrate 2 are formed over the substrate 2 and the first display electrode lines 3 so as to be orthogonal to the first display electrode lines 3 as shown in FIGS. Have been. That is, the partition 7 is formed so as to expose at least a part of the first display electrode line 3.

(4) An overhang portion 7a projecting in a direction parallel to the substrate is formed above the partition wall 7 along the direction in which the partition wall 7 extends.

{Circle around (1)} At least one layer of the organic EL medium 8 is formed on each of the exposed portions of the first display electrode lines 3. For example, the organic EL medium 8 is a single layer of an organic light emitting layer, or a medium having a three-layer structure of an organic hole transport layer, an organic light emitting layer and an organic electron transport layer, or a two-layer structure of an organic hole transport layer and an organic light emitting layer. Media.

{Circle around (2)} The second display electrode line 9 is formed on the thin film of the organic EL medium 8 along the extension direction. In this manner, the portion of the organic EL medium sandwiched by the first and second display electrode lines intersects corresponds to the light emitting portion.

保護 It is preferable that a protective film 10 or a protective substrate be provided on the second display electrode 9 of the simple matrix type panel. Further, in the organic EL display panel of the above embodiment, the substrate and the first display electrode are transparent, and light is emitted from the substrate side. Therefore, as shown in FIG. It is preferable to provide the reflective film 21 on the upper side or via a protective film. Conversely, in the organic EL display panel of another embodiment, the second display electrode may be made of a transparent material so that light is emitted from the second display electrode side. In this case, it is preferable to provide a reflective film outside the first display electrode in order to increase luminous efficiency.

Next, the manufacturing process of the organic EL display panel will be described.

As shown in FIG. 4, a plurality of conductive transparent films (for example, 0.3 mm pitch, 0.28 mm width, 0.2 μm film thickness) made of ITO or the like are formed as the first display electrodes 3 in parallel by the patterning process. A transparent substrate 2 made of glass or the like is prepared.

Next, in a partition forming step, a non-photosensitive polyimide 70 of a partition material is formed on the first display electrode 3 of the transparent substrate 2 to a thickness of 3 μm by, for example, a spin coating method, and further, an overhang portion above the partition is formed. the SiO ₂ 71 materials, is formed on the polyimide film 70 to 0.5μm thickness by a sputtering method.

Next, as shown in FIG. 5A, a photoresist is formed on the SiO ₂ film 71 by spin coating, for example, to a thickness of, for example, 1 μm, and a photoresist is usually formed to leave a photoresist of 72 μm width, for example. A photoresist pattern is formed by using a method such as photolithography.

Subsequently, as shown in FIG. 5B, the SiO ₂ film 71 is etched into the same pattern shape as that of the photoresist by using a method such as reactive ion etching, using the photoresist 72 as a mask. When performing this reactive ion etching, for example, etching is completed in 10 minutes at a gas flow rate of 100 sccm and RF power of 100 W using CF ₄ as an etching gas.

Thereafter, as shown in FIG. 5C, the dry etching or the wet etching is used to form the partition wall main body of the polyimide film 70 and the SiO ₂ film 71 of the overhang portion 7a protruding in a direction parallel to the substrate on the partition main body. A partition 7 having a substantially T-shaped cross section is formed. The height of the T-shaped partition wall 7 from the substrate is not particularly limited as long as the cathode 9 of the second display electrode formed later and the ITO anode 3 are not electrically short-circuited. Specifically, the thickness is preferably 1 μm or more and 10 μm or less. For the same reason, the T-shaped lateral overhang portion 7a only needs to have a thickness of about 0.2 μm or more with a width of about 1 μm on one side.

As shown in FIG. 6A, the T-shaped partition 7 is first subjected to reactive ion etching (anisotropic etching) using a gas such as O ₂ so that the polyimide film 70 is not undercut. 6 (b), and then wet-etching with an alkaline solution for about 30 seconds to isotropically etch the side surface 70a of the polyimide film 70, as shown in FIG. 6 (b). In this two-stage etching process, uniform side etching can be performed. FIG. 7A is a cross-sectional view of the T-shaped partition wall 7 formed in this two-step process.

Another method for etching a polyimide film 70 does not perform the anisotropic etching in advance, for 1-2 minutes with an alkaline solution is an etchant for polyimide, a SiO ₂ film 71 by performing isotropic etching as a mask The polyimide film 70 can be etched. At this time, since the polyimide is etched by wet etching, isotropic etching is performed, and an undercut state is obtained as shown in FIG.

It should be noted that what has heretofore been referred to as polyimide is a substance in a precursor state before imidization, and of course, when cured at 300 ° C. in the state of FIG. 3, becomes a real polyimide. However, as long as there is no strength or other inconvenience, the substance need not be cured. In addition, as a material instead of polyimide and SiO ₂ , any material may be used as long as the lower partition material and the material of the upper overhang portion are not etched when they are respectively etched. An electrically insulating substance which can maintain strength before film formation can be used.

Also, instead of such a two-layer structure partition, as shown in FIGS. 7C to 7H, a T-shaped cross section or an inverse tapered cross section (FIG. A partition having an upper overhang portion such as a partition having (c) and (d)) may be formed.

Then, as shown in FIGS. 8A to 8D, in the light emitting layer forming step, an organic EL medium is deposited on each of the exposed portions of the first display electrode 3, and at least one organic EL medium is deposited. A thin film of a medium is formed, and a second display electrode is formed on a plurality of thin films of the organic EL medium in the next step of forming a second display electrode. Although only two pixels of three colors R, G, and B are illustrated in the drawing, a plurality of pixels are simultaneously formed two-dimensionally.

First, in the light emitting layer forming step, as shown in FIG. 8A, each hole 31 of the film forming mask 30 is aligned with each one of the concave portions of the substrate 2 on which the partition walls 7 are formed. A mask is placed on the partition walls, and the first (for example, red) organic EL medium 8a is formed to a predetermined thickness by using, for example, a method such as evaporation. The substrate may be formed at any angle with respect to the vapor flow of the organic EL medium, but it is preferable that the vapor flow goes around the overhang portion of the partition wall.

In the step shown in FIG. 8B, for example, the film-forming mask is shifted to the left by one partition to perform alignment, and then the mask is placed on the partition to remove the second (for example, green) organic EL medium 8b. A film is formed to a predetermined thickness.

After aligning the film-forming mask with the one concave portion left in the step of FIG. 8C, the mask is placed on the partition wall and the third (for example, blue) organic EL medium 8c is formed to a predetermined thickness. Is formed. Thus, the light emitting layer forming step of sequentially moving the mask so that one opening is arranged from one first display electrode to the adjacent first display electrode is sequentially repeated. In addition, since the partition wall 7 is provided, the organic EL medium layer is not damaged by the mask during the positioning of the film-forming mask and the vapor deposition while moving.

In the second display electrode forming step of FIG. 8D, after forming three types of organic EL media of RGB at predetermined locations, the film forming mask is removed, and the metal is formed by a method without step coverage (for example, vapor deposition). The vapor is deposited to a predetermined thickness on each of the three types of organic EL media from right above, substantially perpendicular to the substrate, to form the cathode 9 of the second display electrode. The cathode 9 is divided at the overhang portion 7a of the partition by the perpendicular incidence of the metal vapor, and as a result, the cathodes 9 on both sides of the partition are electrically insulated as shown in FIG. 8D. In addition, the extent to which the metal vapor flows around the overhang portion 7a of the partition wall is smaller than the extent of the organic EL medium material particle flow, and the organic EL medium 8 protrudes from the cathode 9 as shown in FIG. It does not cause a short circuit with the ITO anode 3. The thickness of the electrically conductive cathode 9 may be large as long as there is no problem. The cathode may be made of any material as long as it is electrically conductive. Of course, a metal having a low resistivity, such as Al, Cu, or Au, is desirable.

Next, a method for manufacturing an organic EL display panel according to another embodiment will be described.

As shown in FIG. 9A, a partition 7 having an inverse tapered cross section is formed on a substrate 2 on which an ITO anode 3 has been patterned in a predetermined shape in advance, and an overhang portion 7a on the upper side is formed by metal deposition. Is formed so as to block the cathode edge portion 9a in the above.

9) As shown in FIG. 9B, RGB organic EL media are vapor-deposited on the substrate 2 using the vapor deposition mask 30 in the same manner as described above. The vapor deposition of the organic EL medium is performed by bringing the substrate and the vapor deposition mask into close contact with each other. At this time, a partition is formed as a spacer, and a gap is formed between the vapor deposition mask and the organic EL medium on ITO. No damage. Further, this vapor deposition is performed by revolving the substrate on its own axis or by using a plurality of evaporation sources from other directions so as to wrap around the base of the inversely tapered partition wall. This is to prevent the cathode from protruding from the organic EL medium layer and short-circuiting with the ITO anode when a cathode material is later deposited.

Next, as shown in FIG. 9C, a cathode material is deposited from a direction substantially perpendicular to the substrate surface. As shown in the figure, since the overhang portion 7a of the inversely tapered cross-section partition wall blocks the cathode edge 9a, the cathode is divided at the upper surface of the partition wall and the root of the partition wall, and the adjacent cathode patterns are electrically insulated.

(5) Finally, moisture-proof sealing is performed to complete the organic EL full-color display.

It is obvious that a single-color display can be obtained by forming an organic EL medium for one color instead of an organic EL medium for three colors in the steps of FIGS. 9B and 8A to 8C. is there. Further, if this one color is made white and combined with an RGB filter, a full-color display can be obtained.

有機 The organic EL display according to the present invention has high efficiency without impairing the original characteristics because there is no wet process after the organic EL medium layer is formed. Furthermore, since the cathode is formed in a substantially vertical direction, any cathode pattern shape is possible. In addition, since the inverse tapered partition is usually formed by using the photolithography technique, fine patterning of 10 μm or less is possible.

A feature of the present invention is that there is a partition having an overhang portion in which part or all of the T-shaped cross section or the cross section is reversely tapered on the substrate for an organic EL display, and the base of the reverse tapered partition. In addition, the wraparound of the particle flow of the organic EL medium material is larger than that of the cathode metal material.
(Example 1)
When an organic EL display panel was manufactured using a chemically amplified resist as a partition material, a glass substrate on which ITO was patterned in a stripe shape was sufficiently washed, and a negative photoresist LAX-1 manufactured by Zeon Corporation was spin-coated at 5.6 μm. Next, after prebaking in a hot air circulation oven, exposure was performed using a striped photomask (cathode gap: 20 μm) orthogonal to ITO. Furthermore, P.P. E. FIG. After B, development was carried out to form a partition having a width of 20 μm and a height of 5.6 μm (see a substitute photograph in FIG. 10). While rotating the substrate, 700 Å of TPD and 550 Å of Alq ₃ were evaporated, and then the rotation of the substrate was stopped, and 1000 Å of Al was evaporated from a direction perpendicular to the substrate surface (a photograph as a substitute for the drawing in FIG. 11). reference). As shown in FIG. 11, the Al film was cut off at the top and at the root of the partition, and the adjacent cathode lines were completely insulated. Further, since the edge of the organic EL medium layer protruded from the edge of Al, no short circuit occurred between A1 and ITO.
(Example 2)
When an organic EL display panel is manufactured using a C ₆ H ₅ Cl-treated resist, a glass substrate on which ITO is patterned in a stripe shape is sufficiently washed, and a positive photoresist AZ6112 made by Hoechst is spin-coated at about 1 μm, and a hot-air circulation oven is used. And then immersed in a C ₆ H ₅ Cl solution at 32 ° C. for 30 minutes. Next, exposure was performed using a striped photomask (cathode gap: 2 μm) orthogonal to ITO, followed by development to form a partition having a width of 2 μm and a height of 1 μm (see a substitute photograph in FIG. 12). . Thereafter, vapor deposition was performed in the same steps as in Example 1. As a result, the A1 film was cut off from the upper surface and the root of the partition, and the adjacent cathode lines were completely insulated. Further, since the edge of the organic EL medium layer protruded from the edge of Al, no short circuit occurred between A1 and ITO.

As described above, according to the present invention, electrical insulation between the upper portion of the partition and the portion where the organic EL medium is formed is ensured, and the patterning of the cathode is automatically completed without going through a process such as photolithography later. In addition, by forming the organic EL medium by abutting the partition against the mask, the organic EL medium is not degraded, and the organic EL medium formed on the adjacent pixels is not wrapped around because of the partition. It is possible to separately paint the area, and a high-definition full-color display can be realized.
(Example 3)
As another device for realizing a display with a fine pitch, as shown in FIG. 13, a non-linear element (for example, a thin film transistor (TFT), a capacitor, etc.) connected to a second display electrode is provided together with a data signal line and a scanning signal line. There is a full color display formed on a substrate plane. As shown, a front glass substrate 2 on which an ITO film 3, an organic EL medium layer 8, and a second display electrode 9 are formed is formed in the same manner as in the above embodiment, and a predetermined number of pixels are formed separately from the front substrate. A glass substrate 102 for the back surface is formed in which a non-linear element 101 such as a TFT to be connected to the second display electrode is formed, and both substrates are electrically connected only to the second display electrode 9 corresponding to the non-linear element 101. As described above, a display is obtained by bonding together with the anisotropic conductive adhesive 103.

デ ィ ス プ レ イ When fabricating a display by this method, an independent cathode for each pixel must be formed on the organic EL medium and insulated from the cathodes of other pixels. In order to realize this condition, the above-mentioned T-shaped partition can be formed in a two-dimensional matrix to solve the problem.

Further, the present invention solves the problem of dielectric breakdown of the first and second display electrodes and the organic EL layer, and provides a display in which the light emitting functional layer and the second electrode are patterned into a free shape without deteriorating the characteristics of the element. An element which can be produced with high yield and a method therefor are also provided. That is, a method and an element for adding an insulating film between the first and second display electrodes below the overhang portion of the partition as Example 4, and an insulating sealing film on the partition and the second display electrode as Example 5 The present invention implements the method and the device.
(Embodiment 4) Addition of an insulating film A short circuit between the first and second display electrodes, particularly a short circuit at the edge of the second display electrode is prevented.

As shown in FIG. 14A, an insulating film 40 is formed on a substrate on which a first display electrode 3 (ITO anode) is previously patterned in a predetermined shape, at least at a portion corresponding to an edge of a second display electrode pattern to be deposited later. Form.

Next, as shown in FIG. 14B, a partition wall 7 having an inverted tapered cross-sectional shape is formed. It is formed so as to block. The insulating film 40 is formed in a portion corresponding to a gap of the second display electrode pattern.

Next, as shown in FIG. 14C, RGB organic materials are vapor-deposited on the substrate 2 using the vapor-deposition mask 30 in the same manner as described above. Using the deposition mask 30, R, G and B organic EL media are deposited on the substrate. The vapor deposition of the organic EL medium is performed by bringing the substrate and the vapor deposition mask into close contact with each other. At this time, since the partition wall 7 serves as a spacer and a gap is formed between the vapor deposition mask and the organic EL medium on the first display electrode, both are in contact with each other. There is no damage to the organic EL medium.

Next, as shown in FIG. 14D, a second display electrode material is further deposited on the entire surface so as to cover at least the display area of the substrate. The deposition of the second display electrode material is performed at an angle θ (θ <θ ′) smaller than the taper angle θ ′ of the inversely tapered partition wall from the normal to the substrate. For example, as shown, a cathode material is deposited from a direction substantially perpendicular to the substrate surface. Since the cross section of the partition has an inverted tapered shape, that is, an overhang portion, the second display electrode is divided at the upper surface of the partition and the root of the partition, and the adjacent second display electrode patterns are electrically insulated. Even if the edge of the second display electrode overlaps the edge of the organic film, the second display electrode and the first display electrode are insulated by the insulating film 7 formed in the step of FIG. Does not short.

(5) Finally, sealing for moisture proof is performed, and an organic EL full-color display is completed.

It is clear that a single-color display can be obtained by forming a material of one color instead of three colors on the entire surface in the step of FIG. Further, when this one color is made white and combined with an RGB filter, a full-color display is obtained.

The formation range of the insulating film formed in the step of FIG. 14A is at least the edge portion of the second display electrode divided by the partition, and the entire surface of the substrate excluding display dots (segments) at the maximum. For example, as shown in a plan view of the substrate in this insulating film forming step, the insulating film is a pair of parallel insulating film stripes 40a and 40b extending perpendicular to the first display electrode 3, as shown in FIG. As shown in FIG. 16, it is formed so as to sandwich the root of a partition 7 to be formed later. In addition, as shown in FIG. 17, the insulating film may be formed by combining a pair of stripes shown in FIG. 15 into one stripe such that the partition wall 7 can extend on the center line as shown in FIG. it can. Furthermore, as shown in FIG. 19, the insulating film is connected in the first display electrode extending direction so as to cover the pixel 60, that is, the entire surface except for the exposed portion 50 of the first display electrode, and to cover the edge 60 of the first display electrode. In this case, a short circuit between the first display electrode edge and the second display electrode can be prevented.

The organic EL display according to the present invention has a high efficiency without impairing the original characteristics because there is no wet process after the formation of the light emitting functional layer, and has a degree of freedom in the deposition direction of the second display electrode. Two display electrode pattern shapes are possible. Further, since the insulating film is inserted between the second display electrode edge portion and the first display electrode, a short circuit does not occur at this portion. Further, since the insulating film and the reverse tapered partition are usually formed by using the photolithography technique, fine patterning of 10 μm or less is possible.

Specifically, an organic EL display was manufactured by inserting a step of forming an insulating film between the steps of forming the first display electrode and the partition as in Example 1 described above.

For example, a glass substrate on which ITO is patterned in a stripe shape as the first display electrode is sufficiently washed, and a photoresist OFPR-8000 manufactured by Tokyo Ohka is spin-coated as an insulating film by about 1 μm, pre-baked in a warm air circulation oven, and After exposure, development, and rinsing using a photomask (line width: 20 μm) in the form of orthogonal stripes, post-baking was performed in a hot-air circulation oven. The stripe insulating film 40 shown in FIG. 17 was formed. Next, a negative photoresist LAX-1 manufactured by Zeon Corporation is spin-coated at 5.6 μm and pre-baked in a hot-air circulation oven, and then a stripe pattern is formed such that the pattern of the previously formed insulating film coincides with the center line. Exposure was performed using a photomask (line width 18 μm). Furthermore, P.P. E. FIG. After B, development was performed to form an inversely tapered partition having a width of 20 μm and a height of 5.6 μm. When the taper angle θ ′ of this inverted tapered partition was measured, it was about 30 degrees.

Next, the positional relationship as shown in FIG. 20, that is, the substrate 2 is mounted on a turntable in a vacuum processing chamber of a vapor deposition apparatus, and the chamber is evacuated to -5 × 10 ^-6 torr, and the first display electrode forming surface of the substrate is evacuated. While rotating so as to rotate with respect to one normal line, by heating the resistance, the TPD having a thickness of 700 、, the Alq ₃ having a thickness of 550 、, and the Al having a thickness of 1000 に よ り as the second display electrode were formed by a resistance heating layer. Evaporated. The evaporation source 55 of various materials is arranged on the rotation center line of the substrate 2, and the evaporation is performed by forming an inverse tapered partition at an angle θ = 20 degrees between the conical generating line from the evaporation source to the edge of the rotating substrate and the substrate normal. The test was performed at an angle smaller than the taper angle θ ′ = 30 degrees. When the continuity between adjacent Al lines of the completed device was examined, it was found that the device was completely insulated. When a voltage of 10 V was applied between ITO and Al of the device, the selected portion emitted bright green light and no short circuit occurred between ITO and Al.
To increase the additional sealing effect of (Example 5) sealing the insulating film of the additional fourth embodiment of causes wrap on the back side of the reverse taper partition wall sealing film, completely covers the second display electrode pattern. Similarly to Embodiment 4, on the substrate on which the second display electrode is formed in the steps shown in FIGS. 14A to 14D, an insulating sealing film 45 having a high moisture-proof effect is deposited and sputtered by rotating the substrate on its own axis. The film is formed by a method having good wraparound, such as a CVD method.

As shown in FIG. 21, this sealing film wraps around and adheres to the back side of the reverse tapered partition wall 7, so that it reaches the insulating film 40 and completely connects the second display electrode line 9 as shown in FIG. It becomes a shape to cover. Further, as shown in FIG. 23, the sealing film 45 may have any shape as long as it completely covers the second display electrode line so as to cover the reverse tapered side wall of the insulating film 40.

Further, this sealing structure can be applied to the case of the above-mentioned embodiment having no insulating film in the fourth embodiment. As shown in FIG. The second display electrode line 9 can be completely covered by being attached on the display electrode and the substrate, or covering the reverse tapered side wall as shown in FIG.

(4) The organic EL display according to the present invention has the same effects as those of the fourth embodiment, and furthermore, since the sealing film completely covers the second display electrode pattern, the progress of the non-light emitting portion from the edge of the second display electrode can be prevented. That is, the durability is very high.

Specifically, an organic EL display was manufactured by adding a sealing film after the second display electrode forming step of Example 4 described above.

After Al was deposited in the same process as in Example 4 to produce an element, SiO ₂ was deposited to a thickness of 1 μm by sputtering. When the continuity between adjacent Al lines was examined for the device thus manufactured, it was found that the device was completely insulated. When a voltage of 10 V was applied between ITO and Al of the device, the selected portion emitted bright green light and no short circuit occurred between ITO and Al. Furthermore, when this device was left in the air, the expansion of the non-light-emitting portion from the Al edge was suppressed.

1 is a schematic partial enlarged plan view of an organic EL display panel according to the present invention. 1 is a schematic partial perspective view of an organic EL display panel according to the present invention. 1 is a schematic partial cross-sectional view of an organic EL display panel according to the present invention. 1 is a schematic perspective view of a substrate of an organic EL display panel according to an embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view of a substrate in an organic EL display panel manufacturing process according to an embodiment of the present invention. FIG. 2 is a schematic partial enlarged cross-sectional view of a substrate in an organic EL display panel manufacturing process according to an embodiment of the present invention. FIG. 2 is a schematic partial enlarged cross-sectional view of a partition wall in the organic EL display panel of the embodiment according to the present invention. FIG. 3 is a schematic partial cross-sectional view of a substrate in an organic EL display panel manufacturing process according to an embodiment of the present invention. FIG. 7 is a schematic partial cross-sectional view of a substrate in a process of manufacturing an organic EL display panel according to another embodiment of the present invention. 3 is a drawing-substituting microscope (SEM) photograph of a partition wall of the organic EL display panel of Example 1 according to the present invention. 4 is a drawing-substituting microscope (SEM) photograph of the vicinity of the partition wall in the organic EL display panel of Example 1 according to the present invention. 7 is a drawing-substituting microscope (SEM) photograph of a partition wall of the organic EL display panel of Example 2 according to the present invention. FIG. 6 is a schematic partial cross-sectional view of an organic EL display panel according to a third embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fourth embodiment of the present invention. FIG. 11 is a schematic partial plan view of a substrate in a manufacturing process of an organic EL display panel according to a fourth embodiment of the present invention. FIG. 16 is a sectional view taken along the line AA in FIG. 15. FIG. 11 is a schematic partial plan view of a substrate in a manufacturing process of an organic EL display panel according to a fourth embodiment of the present invention. FIG. 18 is a sectional view taken along the line AA in FIG. 17. FIG. 11 is a schematic partial plan view of a substrate in a manufacturing process of an organic EL display panel according to a fourth embodiment of the present invention. FIG. 9 is a schematic diagram of a substrate and an evaporation source in an evaporation apparatus in an organic EL display panel manufacturing process according to a fourth embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fifth embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fifth embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fifth embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fifth embodiment of the present invention. FIG. 13 is a schematic partial cross-sectional view of a substrate in a manufacturing process of an organic EL display panel according to a fifth embodiment of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Emission pixel 2 Substrate 3 First display electrode line 5 Non-linear element 7 Partition wall 7a Overhang portion 8 Organic EL medium 9 Second display electrode line 10 Protective film 40 Insulating film 45 Sealing film

Claims (8)

An organic electroluminescent display panel having an image display array composed of a plurality of light emitting units,
A substrate having a plurality of first display electrodes corresponding to the light emitting units formed on a surface thereof;
A plurality of electrically insulating partitions projecting above the substrate exposing at least a portion of the first display electrode;
At least one layer of an organic electroluminescent medium thin film formed on each of the exposed portions of the first display electrode;
A plurality of second display electrodes formed on a thin film of the organic electroluminescence medium,
An overhang portion protruding in a direction parallel to the substrate above the partition wall,
An organic electroluminescent display panel, wherein a thin film of the organic electroluminescent medium and / or the second display electrode extends below the overhang portion. 2. The organic electro-optical device according to claim 1, further comprising an insulating film formed on the first display electrode below the overhang portion or on at least one of the edges of the exposed portion of the first display electrode. 3. Luminescent display panel. The first display electrode, a thin film of the organic electroluminescence medium, and an insulating sealing film formed on the second display electrode, wherein the insulating sealing film completely covers at least the second display electrode. The organic electroluminescent display panel according to claim 1, wherein: The organic electroluminescent display panel according to claim 1, wherein the first display electrode and the second display electrode are a plurality of striped electrodes and are arranged at positions orthogonal to each other. The organic electroluminescent display panel according to claim 1, wherein the substrate and the first display electrode are transparent. The organic electroluminescence display panel according to claim 5, further comprising a reflection film formed on the second display electrode. The organic electroluminescent display panel according to claim 1, wherein the second display electrode is transparent. The organic electroluminescent display panel according to claim 7, further comprising a reflective film formed outside the first display electrode.

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