JP2003059661A - Manufacturing method of organic electroluminescence panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescence panel that can realize fineness by a simple patterning method by the physical evaporation method using a mask. SOLUTION: Before patterning, protrusions are formed on the face and patterning is carried out by contacting the protrusions to the mask. Thereby, the mask and the face are put together as close as possible and, thereby, entering of the evaporation material is prevented and also rubbing of the mask and the patterning face is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is useful as an exposure light source for exposing a photosensitive drum of an electrophotographic image forming apparatus such as a copying machine or a laser printer, a display device, and the like.
The present invention relates to a method of manufacturing an organic electroluminescence panel using an organic electroluminescence element, and more specifically, to a patterning method used in a manufacturing process of an organic electroluminescence panel.

[0002]

2. Description of the Related Art Conventionally, a transparent conductive film (first electrode layer) formed on the surface of a transparent substrate, and an organic layer including a light emitting layer made of an organic light emitting material formed on the first electrode layer, There is an organic electroluminescence element including at least a second electrode layer formed on an organic layer. Further, there is an organic electroluminescence panel which is used for a display device or the like by using a plurality of such organic electroluminescence elements as a light emitting source.

As an example, there is an organic electroluminescence panel as shown in FIG. FIG. 1 is a configuration diagram of an organic electroluminescence panel in which organic electroluminescence elements are arranged in a matrix. In FIG. 1, 101 is a transparent substrate and 102 is a first
Electrode layer, 103 is a light emitting layer, 104 is a second electrode layer, 105
Indicates a pixel.

In the panel shown in FIG. 1, the transparent substrate 1
On the surface of 01, dot-shaped organic electroluminescence elements are formed as pixels 105 arranged in a matrix, and each organic electroluminescence element can emit light separately. In such an organic electroluminescence panel, it is possible to display various images by appropriately selecting the organic electroluminescence element to emit light.

In the process of manufacturing an organic electroluminescence panel, when patterning an electrode or the like after at least a part of the organic layer is formed, it is not necessary to immerse the electrode in a chemical solution or the like, and the organic material susceptible to heat is not deteriorated. A physical vapor deposition method that can suppress the substrate temperature during patterning to a low level is useful, and is described in US Pat. No. 5,294,869, JP-A-5-258859, and JP-A-5-258.
As disclosed in Japanese Patent Laid-Open No. 860 and Japanese Patent Application Laid-Open No. 5-275172, a patterning method using a mask by vacuum vapor deposition is simple and common. An example of such a manufacturing process is shown below.

FIG. 2 is a perspective view schematically showing a state in which the second electrode layer of the electroluminescence element is formed by the conventional patterning method. 201 in FIG.
Is a mask, 202 is a through hole, 203 is a light emitting layer, 204 is a second electrode layer, 205 is a transparent substrate, and 206 is a first electrode layer. The first electrode layer 206 includes the transparent substrate 205 and the light emitting layer 2.
Since it is formed between No. 03 and No. 03, it is shown by a dotted line.

First, the first electrode layer 206 made of ITO or the like is formed on the transparent substrate 205. Next, a hole injection layer (not shown) and a light emitting layer 203 are formed on the entire surface thereof.
Finally, as shown in FIG. 2, a mask 201 having stripe-shaped through-holes 202 is prepared, and the light-emitting layer is formed so that these through-holes 202 are orthogonal to the first electrode layer 206 when viewed on the projection surface of the transparent substrate 205. The mask 20 above 203
1 is fixed, and the second electrode layer 204 is formed in a stripe shape by a vapor deposition method.

Thus, it is possible to obtain an organic electroluminescence panel in which the organic electroluminescence element is formed in a portion where the first electrode layer and the second electrode layer overlap with each other when viewed on the projection surface with respect to the transparent substrate. In this panel, by selecting the line of the first electrode layer and the line of the second electrode layer through which the current flows, the pixel (organic electroluminescence element) at an arbitrary portion can emit light.

However, in such a manufacturing method, when the mask having the stripe-shaped through holes is fixed on the patterning surface at the time of forming the second electrode layer, the mask itself is subject to the weight of the mask, thermal expansion due to radiant heat during vapor deposition, and the like. Even if distortion occurs, the patterning surface and the mask must be sufficiently spaced so that the mask does not rub against the patterning surface, and the wraparound of the vapor deposition material during vapor deposition has been a problem. Furthermore, in order to prevent the electrode layers of each organic electroluminescence element from short-circuiting with each other due to the wraparound of the vapor deposition material during vapor deposition, it is necessary to form the electrode layers with a sufficient line spacing. Since the electroluminescent elements are formed with a sufficient space therebetween, it has been difficult to miniaturize them.

As a method capable of solving these problems, there are conventionally known Japanese Patent Laid-Open Nos. 09-102393 and 09-161.
As disclosed in Japanese Patent Application Laid-Open No. 969 and Japanese Patent Application Laid-Open No. 09-330792, partition walls are prepared in advance before film formation.
There has been a method of preventing the electrode layers of each organic electroluminescence element from short-circuiting each other.

[0011]

However, in the method of forming the barrier ribs as described above, when the barrier ribs are formed on the substrate before vapor deposition, a film for forming the barrier ribs is formed on the entire substrate and unnecessary etching is performed. Since the part is removed, the process becomes complicated. Further, as disclosed in Japanese Patent Laid-Open No. 09-306666, there is a method in which a film is formed on a substrate without using a mask, and then unnecessary portions are removed by laser. Had the problem of being inefficient.

Therefore, from the viewpoint of cost, the physical vapor deposition method using the above-mentioned mask is preferable, but the method using the mask has problems such as difficulty in miniaturization as described above. There were merits and demerits.

The present invention has been made to solve the above problems, and provides a method of manufacturing an organic electroluminescence panel which can be miniaturized by a simple patterning method by physical vapor deposition using a mask. With the goal.

[0014]

According to the invention for solving the above-mentioned problems, at least a first electrode layer, an organic layer including a light emitting layer made of an organic light emitting material, and a second electrode layer are laminated on a substrate. In the step of manufacturing an organic electroluminescence panel, the method for manufacturing an organic electroluminescence panel, comprising the step of patterning by a physical vapor deposition method using a mask having a through hole after at least a part of the organic layer is formed. In addition, before performing the patterning, a protrusion is formed on the patterning surface,
The patterning is performed by bringing the protrusion into contact with the mask.

According to the present invention, in the above invention, "the protrusion has a height of 5 to 100 µm" and "when the mask is brought into contact with the protrusion, the mask is slid on the protrusion". , "The protrusion has a heat distortion temperature of 100 ° C.
“Forming with the above resin” is included as a preferable embodiment.

Further, the present invention according to the above-mentioned invention, "the protrusion comprises a protrusion forming member provided on the patterning surface" or "the protrusion is provided between the patterning surface and the substrate." It is formed by the provided protrusion forming member ", which is included as a preferred embodiment, and further," forming the protrusion forming member by a wet patterning method ", further,
"The wet patterning method is an ink jet printing method in which the projection forming material is made into fine liquid droplets and is ejected and fixed on the surface on which the projection forming member is provided", or "the wet patterning method has a predetermined pattern. Offset printing in which the concave portion of the intaglio plate having the concave portion is filled with the protrusion forming material, and the blanket receives the protrusion forming material, and then the protrusion forming material is transferred onto the surface on which the protrusion forming member is provided. “Being a method” is included as a preferred embodiment.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. In particular, here, a mode will be described in which a transparent first substrate is provided with a light-transmissive first electrode layer or the like, and light is extracted from the first electrode layer side. When extracting light from the second electrode layer side, the substrate does not have to be transparent, but the second electrode layer is required to have light transparency, but this form can be easily inferred from the following description. Is.

FIG. 3 is a cross-sectional view showing an intermediate structure of the organic electroluminescence panel in a state where the protrusions, which is a feature of the present invention, are formed. In FIG. 3, 301 is a transparent substrate, 302 is a first electrode layer, 303 is a hole injection layer, 304
Is a light emitting layer, and 305 is a protrusion.

The protrusion is formed in a portion unrelated to the light emitting portion of the organic electroluminescence element. Prior to performing the required patterning, such protrusions are formed, and when the patterning is performed by bringing the protrusions into contact with the mask and performing the patterning, the mask can be brought as close as possible to the patterning, thus enabling miniaturization. In addition, it is possible to prevent the patterning surface from being scratched by rubbing between the mask and the patterning surface.

The height of the protrusions allows fine patterning, and prevents the mask from rubbing the patterning surface.
It is preferably formed to a thickness of 100 μm.

Further, the protrusion may be the protrusion forming member itself provided on the patterning surface as shown in FIG. 3, or the protrusion forming member provided in any step before the patterning step. The protrusion may be formed as a result of depositing another material on the substrate, that is, formed by a protrusion forming member provided between the patterning surface and the substrate.

The protrusion forming material, which is the material of the protrusion forming member, is preferably a thermosetting resin in the process, but the present invention is not limited to this. For example, a liquid containing a cellulose derivative and other solid resin as a protrusion-forming material is
After the protrusion forming material is arranged, it is heated and dried to cure the resin. A liquid obtained by mixing an oligomer (unsaturated polyester resin type), a monomer (acrylic type), and a sensitizer (reaction initiator) as a protrusion forming material is photocured after the protrusion forming material is arranged. As described above, the resin curing method for the protrusion forming material includes heat drying and photo-curing, but the resin curing method is not limited to these.

As a method of forming the protrusion forming member, it is preferable to form it by a wet patterning method, and there are an ink jet printing method and an offset printing method, but the forming method is not limited to these. Screen printing, offset printing, inkjet printing, or the like can be used for printing, but high-precision high-definition printing is preferable in consideration of forming protrusions other than the organic electroluminescence light emitting portion. For example, offset printing is based on a sheet-fed proof printing machine, but improved so that printing position accuracy and printing conditions can be set more accurately than general waterless plate printing machines and intaglio printing machines that print on paper. What you did is good.

FIG. 4 is a process drawing of offset printing. In FIG. 4, 401 is a dispenser, 402 is a projection forming material, 403 is an intaglio, 404 is a doctor blade, 40
5 is a blanket cylinder, 406 is a blanket, and 407 is an intermediate structural plate. The intermediate structure plate refers to a structure in the process of manufacturing the organic electroluminescence panel manufactured up to the stage immediately before the step of forming the protrusion forming member.

As shown in FIG. 4, a liquid projection forming material is dropped onto the intaglio plate, and while being scraped off with a doctor blade, the recesses of the intaglio plate are filled with the projection forming material, and the blanket and the intaglio plate attached to the blanket cylinder are pressed with a constant pressure. When making contact, the projection forming material filled in the intaglio plate is received on the surface of the blanket, and this blanket and the intermediate structure plate of the organic electroluminescence panel, which is the substrate to be printed, are brought into contact with each other with a certain printing pressure, A method of printing by transferring the protrusion forming material to the surface of the structure plate is possible, but not limited to this.

FIG. 5 is a schematic side view for explaining ink jet printing. In FIG. 5, 501 is an inkjet nozzle, and 502 is an intermediate structure plate.

The ink jet printer is based on a stepper, and the protrusion forming material can be discharged to a necessary portion while precisely moving the intermediate structure plate 502. The inkjet head may be either a bubble type or a piezo type.

The form shown in FIG. 3 in which the protrusion forming member itself is used as the protrusion will be described in detail below.

A transparent first electrode layer 302 such as indium tin oxide (ITO) or tin oxide thin film is formed on a transparent substrate 301 such as glass. The first electrode layer 302 may be semitransparent. As a thin film forming method for forming the first electrode layer 302, any of a sputtering method, an electron beam method, a chemical reaction method and the like may be used.

A hole injection layer 303 is formed on the first electrode layer 302.
To form a film. As a thin film forming method of the hole injection layer 303, any of a vapor deposition method, a dipping method, and a spin coating method may be used. The thickness of the hole injection layer 303 is preferably as thin as possible in consideration of carrier mobility and light extraction from the glass substrate side. However, if it is too thin, dielectric breakdown occurs in pinholes and the like. On the other hand, when the thickness of the hole injection layer is increased, the driving voltage required for the completed organic electroluminescence panel is increased. Considering comprehensively, more preferably, the thickness of the hole injection layer 303 is 0.1 to 0.
The thickness is preferably about 5 μm.

Next, the light emitting layer 304 is formed. Light emitting layer 30
The thin film forming method of 4 may be either a vapor deposition method or a spin coating method.

Next, since the second electrode layer is formed by the physical vapor deposition method using the mask having the through holes, the mask is brought into contact with the projection 305. At this time, the mask is slid on the protrusions 305 to fix the patterning surface at a position 5 to 100 μm away from the patterning surface without rubbing. By sliding on the protrusions, the distance between the patterning surface and the mask can be narrowed to 5 to 100 μm. Further, if the protrusion is a resin having a heat distortion temperature of 100 ° C. or higher, it does not deform during vapor deposition, it is possible to prevent the vapor deposition material from getting around during vapor deposition, and a high-definition organic electroluminescence panel can be manufactured. After fixing the mask in this way, a film is formed by a physical vapor deposition method.

In the method for manufacturing an organic electroluminescence panel of the present invention, since a high quality fine structure can be manufactured by a simple method, not only a binary display panel using a monochromatic light emitting element but also a full color display panel. Needless to say, it is also useful for manufacturing the display panel, and the driving method of the display panel may be a passive matrix type or an active matrix type. Further, the present invention is not limited to display, and can be suitably used for manufacturing an exposure light source for exposing a photosensitive drum of an image forming apparatus of an electrophotographic system such as a copying machine or a laser printer.

[0034]

EXAMPLE 1 FIG. 6 is a process chart showing a first example of the method for manufacturing an organic electroluminescence panel of the present invention. In FIG. 6, 601 is a transparent substrate, 602 is a first electrode layer, 603 is a hole injection layer, 604 is a light emitting layer, 605 is a cellulose derivative, 606 is a solid resin, 607 is an inkjet nozzle, 608 is a protrusion forming member, Reference numeral 609 is a hot plate, and 610 is a mask.

As shown in FIG. 6, as a front step, (a) an ITO transparent electrode (first electrode layer) 602 is formed on a transparent substrate 601 made of glass, and (b) triphenylamine is used as a hole injection material. Hexamer (TPA-6:
A film having a molecular weight of 1461, a melting point of 277 ° C. and a Tg of 156 ° C.) was formed by a physical vapor deposition method to form a hole injection layer 603. Next, (c) a light emitting layer 604 using an 8-hydroxyquinoline metal complex represented by tris (8-quinolinol) aluminum (aluminum quinoline complex) as a light emitting material.
Was formed by a physical vapor deposition method. Next, (d) the cellulose derivative 605 is formed on the hole injection layer irrelevant to the light emitting pixel section.
And a solid resin 606 are mixed to form a protrusion forming material with an inkjet nozzle 607 having a diameter of 50 to 60 μm.
Was discharged onto the intermediate structure plate. (E) The intermediate structure plate was heated on the hot plate 609 to remove the solvent, thereby forming the solid resin protrusion forming member 608 on the intermediate structure plate. Next, (f) a mask 610 having a through hole corresponding to the pattern was used, and the patterning surface was set without sliding by sliding on the protrusion of the solid resin. Next, (g) Al-Li is formed into a film by a physical vapor deposition method as an electron injection layer, and finally Al
The electrode (second electrode layer) was formed by a physical vapor deposition method.

[0036]

[Embodiment 2] FIG. 7 is a process drawing showing a second embodiment of the method for manufacturing an organic electroluminescence panel of the present invention. In FIG. 7, 701 is a transparent substrate, 702 is a first electrode layer, 703 is a hole injection layer, 704 is an amino resin, and 70 is
5 is an inkjet nozzle, 706 is a protrusion forming member, 7
Reference numeral 07 is a vacuum heater, 708 is a light emitting layer, and 709 is a mask.

As shown in FIG. 7, as a front step, (a) an ITO transparent electrode (first electrode layer) 702 is formed on a transparent substrate 701 made of glass, and (b) triphenylamine is used as a hole injection material. Hexamer (TPA-6:
A hole injection layer 703 was formed by coating with a molecular weight of 1461, a melting point of 277 ° C., and a Tg of 156 ° C.) by spin coating and heating and drying. Next, (c) the liquid amino resin 70 is formed on the hole injection layer irrelevant to the light emitting pixel section.
No. 4 with an inkjet nozzle 705 has a diameter of 50 to 60 μm.
m droplets were discharged onto the intermediate structure plate. (D) This protrusion-forming material is condensed under a reduced pressure at 80 ° C. for 20 minutes by a deformation reaction between methylol groups of amino resin to cure, thereby forming a solid resin protrusion-forming member 706 on the intermediate structure plate. did. Next, (e) a light emitting layer 708 was formed by a physical vapor deposition method using an 8-hydroxyquinoline metal complex typified by tris (8-quinolinol) aluminum (aluminum quinoline complex) as a light emitting material. Next, (f) a mask 709 having a through hole corresponding to the pattern is provided on the solid resin protrusion forming member 70.
By sliding on the protrusion formed by 6, the patterning surface was set without rubbing. Next, (g) an Al-Li film was formed by a physical vapor deposition method as an electron injection layer, and finally an Al electrode (second electrode layer) was formed by a physical vapor deposition method.

[0038]

Third Embodiment FIG. 8 is a process chart showing a third embodiment of the method for manufacturing an organic electroluminescence panel of the present invention. In FIG. 8, 801 is a transparent substrate, 802 is a first electrode layer, 803 is a hole injection layer, 804 is a protrusion forming member, and
Reference numeral 05 is a dispenser, 806 is an intaglio, 807 is a blanket, 808 is a doctor blade, and 809 is an intermediate structural plate.

As shown in FIG. 8, in the front step, (a) an ITO transparent electrode (first electrode layer) 802 is formed on a transparent substrate 801 made of glass, and (b) triphenylamine is used as a hole injection material. Hexamer (TPA-6:
A hole injection layer 803 was formed by coating with a molecular weight of 1461, a melting point of 277 ° C., and a Tg of 156 ° C.) by a spin coating method and heating and drying. Next, (c) an oligomer (unsaturated polyester resin type), a monomer (acrylic type), and a sensitizer (reaction initiator) are mixed, and this projection forming material 804 is indented by a dispenser 805.
The ink was filled on the concave portion of the intaglio plate while being dripped on the surface and scraped off with a doctor blade 808. (D) When the blanket 807 attached to the blanket cylinder and the intaglio 806 are brought into contact with each other at a constant pressure, the projection forming material 804 filled in the intaglio is received on the surface of the blanket, and (e) and (f) this blanket and the printing target. The intermediate structure plate 809 of the organic electroluminescence display, which is the substrate, is brought into contact with a constant printing pressure, and the resin is transferred from the blanket surface to the surface of the intermediate structure plate 809 on the hole injection layer unrelated to the light emitting pixel portion. ,
The droplets having a diameter of 50 to 60 μm were arranged on the intermediate structure plate 809. An oligomer (unsaturated polyester resin system) of this protrusion forming material absorbed light and was cured by a self reaction to form a protrusion of solid resin on the substrate. Then, the light emitting layer, the electron injection layer, and the second electrode layer were formed in the same manner as in Example 2.

[0040]

EFFECTS OF THE INVENTION It is possible to prevent rubbing of a patterning surface by a simple process of forming protrusions on the patterning surface, to prevent short circuit between electrodes due to wraparound of vapor deposition material, and to form a high-definition organic electroluminescence panel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an organic electroluminescence panel in which organic electroluminescence elements are arranged in a matrix. (A) is a plan view showing an array of pixels. (B) is an AA 'sectional view.

FIG. 2 is a perspective view schematically showing a state in which a second electrode layer of an electroluminescence element is formed by a conventional patterning method.

FIG. 3 shows a state in which a protrusion, which is a feature of the present invention, is formed,
It is sectional drawing which shows the intermediate structure of an organic electroluminescent panel.

FIG. 4 is a process drawing of offset printing.

FIG. 5 is a schematic side view for explaining inkjet printing.

FIG. 6 is a process drawing showing a first embodiment of the method for manufacturing an organic electroluminescence panel of the present invention.

FIG. 7 is a process drawing showing a second embodiment of the method for manufacturing an organic electroluminescence panel of the present invention.

FIG. 8 is a process drawing showing a third embodiment of the method for manufacturing an organic electroluminescence panel of the present invention.

[Explanation of symbols]

101, 205, 301, 601, 701, 801 Transparent substrate 102, 206, 302, 602, 702, 802 First electrode layer 103, 203, 304, 604, 708 Light emitting layer 104, 204 Second electrode layer 105 Pixel 201, 610,709 mask 202 through hole 303,603,703,803 hole injection layer 305 protrusion 401,805 dispenser 402,804 protrusion forming material 403,806 intaglio 404,808 doctor blade 405 blanket cylinder 406,807 blanket 407,809, 502 Intermediate structure plates 501, 607, 704 Inkjet nozzle 605 Cellulose derivative 606 Solid resins 608, 706 Protrusion forming member 609 Hot plate 705 Amino resin 707 Vacuum heater

Continued front page    (72) Inventor Kazunari Yonemoto             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Riko Midorikawa             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 3K007 AB17 AB18 BA06 CA01 CB01                       DA01 DB03 EB00 FA01                 5C094 AA05 AA43 AA47 AA48 BA27                       CA19 DA13 DB01 DB04 EA05                       EB02 EC03 FA01 FA02 FB01                       FB20 GB10 JA08 JA20                 5G435 AA01 AA17 BB05 CC09 HH18                       KK05 KK10

Claims (9)

[Claims] 1. At least a part of a process of manufacturing an organic electroluminescence panel in which a first electrode layer, an organic layer including a light emitting layer made of an organic light emitting material, and a second electrode layer are laminated at least on a substrate. After the organic layer is formed, a method for manufacturing an organic electroluminescence panel including a step of performing patterning by a physical vapor deposition method using a mask having a through hole, wherein before the patterning, a patterning surface is formed. A method for manufacturing an organic electroluminescence panel, comprising forming protrusions and bringing the protrusions into contact with the mask to perform the patterning. 2. The method for manufacturing an organic electroluminescence panel according to claim 1, wherein the protrusion has a height of 5 to 100 μm. 3. The method for manufacturing an organic electroluminescence panel according to claim 1, wherein the mask is slid on the protrusion when the protrusion is brought into contact with the mask. 4. The method for manufacturing an organic electroluminescence panel according to claim 1, wherein the protrusion is formed of a resin having a heat distortion temperature of 100 ° C. or higher. 5. The method for manufacturing an organic electroluminescence panel according to claim 1, wherein the protrusion comprises a protrusion forming member provided on the patterning surface. 6. The protrusion according to claim 1, wherein the protrusion is formed by a protrusion forming member provided between the patterning surface and the substrate. Manufacturing method of organic electroluminescence panel. 7. The method for manufacturing an organic electroluminescence panel according to claim 5, wherein the protrusion forming member is formed by a wet patterning method. 8. The organic printing method according to claim 7, wherein the wet patterning method is an ink jet printing method in which a protrusion forming material is made into fine liquid droplets and is ejected and fixed on a surface on which the protrusion forming member is provided. Manufacturing method of electroluminescence panel. 9. The wet patterning method comprises filling a protrusion-forming material into the recess of an intaglio plate having a recess having a predetermined pattern, allowing the blanket to receive the protrusion-forming material from the intaglio plate, and then forming the protrusion. The method for manufacturing an organic electroluminescence panel according to claim 7, which is an offset printing method in which the protrusion forming material is transferred onto a surface on which a member is provided.