WO2014041614A1

WO2014041614A1 - Organic el device

Info

Publication number: WO2014041614A1
Application number: PCT/JP2012/073236
Authority: WO
Inventors: 青木　謙治; 弘務奈良
Original assignee: パイオニア株式会社; 東北パイオニア株式会社
Priority date: 2012-09-11
Filing date: 2012-09-11
Publication date: 2014-03-20

Abstract

The present invention is provided with: a substrate (10); one or more organic EL elements (1U) formed at the substrate (10); and wiring (20) formed at the outside of the region (element formation region (A)) at which the organic EL elements (1U) are formed at the substrate (10). At the region (wiring formation region (B)) at which the wiring (20) is formed of the substrate (10), a protruding section (30) is provided protruding at least to a position higher than the surface of the wiring (20).

Description

Organic EL device

The present invention relates to an organic EL device.

As a method for forming an organic layer in an organic EL device, a method for forming a desired pattern by mask vapor deposition is known. For example, in a case where a plurality of organic EL elements having different emission colors are formed on one substrate to perform color display or white illumination, a plurality of masks having an opening pattern corresponding to a deposition pattern for each emission color are used, and electrodes In addition, a deposition pattern for each emission color is sequentially formed on the substrate on which the wiring is formed. At this time, if the mask placed facing the substrate comes into contact with the previously formed vapor deposition film, the vapor deposition film may be damaged. Therefore, a spacer is interposed between the mask and the substrate so that the mask and the vapor deposition film on the substrate In general, avoiding the contact is performed (see, for example, Patent Document 1 below).

JP 2010-275598 A

In the method of interposing a spacer between the substrate and the mask as in the prior art described above, a relatively large gap is formed between the substrate and the mask. Vapor deposition blur easily occurs. When a large number of organic EL elements are formed on a substrate, a high-definition vapor deposition pattern in which vapor deposition blur is suppressed is necessary.

In order to suppress the aforementioned evaporation blur, it is necessary to arrange the substrate and the mask as close as possible. As means for arranging the substrate and the mask close to each other, it has been proposed to provide a protrusion in the vicinity of the opening of the mask or to support the mask using the cathode partition of the organic EL element. According to these means, in the organic EL element formation region (hereinafter referred to as element formation region), the mask can be disposed close to the substrate without bringing the mask into contact with the substrate surface.

However, when the mask and the substrate are arranged close to each other, the edge portion of the mask easily comes into contact with the wiring (for example, the lead wiring) formed outside the element formation region. In particular, the mask for forming a uniform vapor deposition film over the entire area of the element formation region is not supported in the element formation area because the entire area of the element formation area is opened. When such a mask is arranged close to the substrate, there is a problem that the edge portion of the mask is in contact with the wiring formed outside the element formation region and the wiring is easily damaged.

The present invention is an example of a problem to deal with such a problem. That is, in an organic EL device that forms an organic layer by mask vapor deposition, it is an object of the present invention to suppress vapor deposition blur, suppress damage to wiring on a substrate, and the like.

In order to achieve such an object, the organic EL device according to the present invention has at least the following configuration.

A substrate, one or a plurality of organic EL elements formed on the substrate, and wiring formed outside the region where the organic EL element is formed on the substrate, the wiring on the substrate being formed The organic EL device, wherein the region is provided with a protruding portion that protrudes at least to a position higher than the surface of the wiring.

It is plane explanatory drawing which showed on the board | substrate of the organic electroluminescent apparatus which concerns on embodiment of this invention. It is a section explanatory view showing a part of an organic EL device concerning an embodiment of the present invention. FIGS. 3A and 3B are explanatory views showing a specific arrangement and form of protrusions in an organic EL device according to an embodiment of the present invention (FIG. 3A is a plan view, FIG. 3B is a cross-sectional view taken along line X1-X1, FIG. 3C is a sectional view taken along line X2-X2.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory plan view showing a substrate of an organic EL device according to an embodiment of the present invention, and FIG. 2 is an explanatory sectional view showing a part of the organic EL device according to an embodiment of the present invention. is there. The organic EL device 1 is formed outside the substrate 10, one or more organic EL elements 1 </ b> U formed on the substrate 10, and a region where the organic EL element 1 </ b> U is formed on the substrate 10 (element formation region A). Wiring 20 is provided. In the region of the substrate 10 where the wiring 20 is formed (wiring formation region B), a protruding portion 30 that protrudes at least to a position higher than the surface of the wiring 20 is provided.

According to such an organic EL device 1, when the organic layer in the organic EL element 1 </ b> U is subjected to mask vapor deposition, the mask and the substrate 10 can be disposed close to each other by bringing the mask into contact with the protruding portion 30. Thereby, the vapor deposition pattern of the organic layer which suppressed vapor deposition blur can be formed. In addition, since the peripheral portion of the mask contacts the protruding portion 30, it is possible to avoid the edge portion of the mask from contacting the wiring 20. As a result, damage to the wiring 20 due to contact with the mask can be suppressed.

The wiring 20 described above includes

extraction wirings

20X and 20Y drawn from the electrodes of the organic EL element 1U. Further, the wiring 20 includes a dummy wiring 20Z formed in a region where the

lead wirings

20X and 20Y are not formed. In the example shown in FIG. 1, the protrusion 30 is provided in the region where the

lead wirings

20X and 20Y are formed and the region where the dummy wiring 20Z is formed, so that the mask can be stably supported by the protrusion 30. It is possible to prevent the edge portion of the mask from coming into contact with the lead-out

wirings

20X and 20Y and the dummy wiring Z. Further, since the protrusions 30 are provided on the outer periphery of the element formation region A, the mask and the substrate 10 can be stably disposed close to each other even if the mask has an opening corresponding to the entire region of the element formation region A. Can be made.

In the example shown in FIG. 1, a plurality of organic EL elements 1U are formed in a dot matrix in the element formation region A. However, the present invention is not limited to this, and the organic EL element 1U may be a single element or an arbitrary one. It may be arranged in segments of the pattern. 1 and 2, the organic EL element 1U includes a lower electrode 11, an organic layer 12, and an upper electrode 13. In the illustrated example, the lower electrode 11 and the upper electrode 13 are juxtaposed in a stripe shape in a direction intersecting each other, and a plurality of organic EL elements 1U are formed at positions where the lower electrode 11 and the upper electrode 13 intersect. . Here, an example in which the organic EL element 1U is passively matrix driven is shown, but the driving method of the organic EL element 1U is not limited to this, and active matrix driving may be used. In this case, the lower electrode 11 is an electrode divided for each organic EL element 1U, and the upper electrode is an electrode formed so as to be common to the plurality of organic EL elements 1U.

As shown in FIGS. 1 and 2, when the lower electrode 11 is patterned on a plurality of electrodes, an insulating film 14 is provided to ensure insulation between the electrodes. The insulating film 14 is formed so as to fill in the space between the patterns of the lower electrode 11 and partially cover the side end portion (side surface where the adjacent lower electrodes face each other), and the organic EL elements 1U are arranged in a dot matrix. In this case, the organic EL element 1U is formed in a lattice shape having openings.

In the illustrated example, the partition wall 16 is provided between the organic EL elements 1U in the element formation region A. The partition 16 is formed in a stripe shape in a direction intersecting the lower electrode 11 in order to form a pattern of the upper electrode 13 without using a mask or the like or to completely electrically insulate the adjacent upper electrode 13. ing. The protrusion 30 described above can be formed by the same material and the same process as the partition wall 16. In this case, since the partition wall 16 is formed in a reverse tapered cross-sectional shape (a shape in which the side surface has a downward tapered surface), the cross section of the protruding portion 30 is also formed in the same shape. Further, in this case, the protruding portion 30 has substantially the same height as the partition wall 16.

In the illustrated example, the organic EL element 1U is sealed by a sealing substrate 17. The substrate 10 and the sealing substrate 17 are bonded to each other through an adhesive 17A in an adhesive region S surrounding the element formation region A. And in the example of illustration, the protrusion part 30 is provided in this adhesion | attachment area | region S. FIG. As shown in FIG. 1, the protrusions 30 in the bonding region S are arranged in an annular shape. In the illustrated example, a plurality of protrusions 30 are arranged in a scattered manner, and the plurality of protrusions 30 are arranged in a staggered manner. Further, in the direction in which the partition wall 16 extends, one protrusion 30 is disposed between a pair of adjacent protrusions 30, and in the direction in which the lower electrode 11 extends, the pair of protrusions 30 are substantially the same. The protrusions 30 disposed at the same position and disposed between the pair of protrusions 30 are disposed at different positions with respect to the pair of protrusions 30. As described above, the protrusions 30 are interspersed in the bonding region, so that an effect of suppressing the spread when the adhesive 17A is applied can be obtained, and the adhesive 17A can be applied to the desired region with high accuracy. . Further, by arranging a plurality of protrusions 30 in a staggered manner so as not to form a liquid reservoir, it is possible to improve the drainage of the etching liquid when forming the partition walls 16 and the protrusions 30 in the photolithography process, and the partition walls 16 and the protrusion 30 can be formed uniformly.

FIG. 3 is an explanatory diagram showing a specific arrangement and form of protrusions in the organic EL device according to the embodiment of the present invention (FIG. 3 (a) is a plan view, and FIG. 3 (b) is X1- X1 sectional view, FIG. 3C is an X2-X2 sectional view). Also in the example shown in FIG. 3A, the protrusion 30 is formed in the formation region of the wiring 20 outside the element formation region A. Further, the protrusions 30 are arranged in a dotted manner along the application pattern of the adhesive 17A in the adhesive region S where the adhesive 17A is applied. In this case, the width of the adhesion region S is formed larger than the width of the protruding portion 30. As shown in the drawing, the protrusions 30 in the bonding region S are scattered with a sufficient interval, so that the protrusions 30 can be arranged without affecting the ultraviolet curing of the adhesive 17A.

As shown in FIG. 3A, the upper surface of the protrusion 30 has a substantially rectangular shape that is long along the direction in which the partition 16 extends (the direction of the dashed line L). When the partition 16 is formed by double exposure with the exposure mask shifted, the longitudinal section of the protrusion 30 and the cross section intersecting with it are inversely tapered as shown in FIGS. 3 (b) and 3 (c), respectively. Become a shape. At this time, the taper angle α in the longitudinal section shown in FIG. 3A is the same as or smaller than the taper angle β in the section intersecting the longitudinal section shown in FIG. By making the upper surface of the protrusion 30 longer in one direction, the protrusion 30 itself can be prevented from falling and the mask can be stably supported.

Hereinafter, specific examples of forming the constituent elements of the organic EL device 1 will be described.

The substrate 10 is light transmissive in the case of a bottom emission method in which light is extracted from the substrate 10 side, and is formed of a base material that can support the organic EL element 1U, such as glass or plastic. One of the lower electrode 11 and the upper electrode 13 functions as an anode and the other functions as a cathode. A material having a work function larger than that of the cathode is selected for the anode. The lower electrode 11 and the upper electrode 13 are formed of a transparent conductive film on the side from which light is extracted. In the case of the bottom emission method, the lower electrode 11 is a transparent conductive film, and in the case of the top emission method, the upper electrode 13 is a transparent conductive film. For the transparent conductive film, for example, a transparent metal oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), zinc oxide-based transparent conductive film, SnO ₂ -based transparent conductive film, or titanium dioxide-based transparent conductive film is used. Can do.

When the bottom electrode 11 side is used as an anode in the bottom emission method, the upper electrode 13 serves as a cathode and has a work function smaller than that of the anode (for example, 4 eV or less) (metal, metal oxide, metal fluoride, alloy, etc.) ) Is used. Specifically, metal films such as aluminum (Al), indium (In), magnesium (Mg), amorphous semiconductors such as doped polyaniline and doped polyphenylene vinylene, Cr ₂ O ₃ , NiO, Mn ₂ An oxide such as O ₅ can be used. As the structure, a single layer structure made of a metal material, a laminated structure such as LiO ₂ / Al, or the like can be adopted.

The insulating film 14 is made of a material such as polyimide resin, acrylic resin, silicon oxide, or silicon nitride. The insulating film 14 is formed by depositing the material of the insulating film 14 on the substrate 10 on which the lower electrode 11 is patterned, and then forming an opening for forming a light emitting region for each organic EL element 1U on the lower electrode 11. Patterning is performed. Specifically, an opening pattern of the organic EL element 1U is formed by forming a film on the substrate 10 on which the lower electrode 11 is formed to have a predetermined coating thickness, and performing exposure processing and development processing using an exposure mask. A layer of the insulating film 14 having a shape is formed.

The partition wall 16 is made of an insulating material such as a photosensitive resin on the insulating film 14 described above by spin coating or the like so as to be thicker than the total thickness of the organic layer 12 and the upper electrode 13 forming the organic EL element 1U. After coating and forming, the photosensitive resin film is irradiated with ultraviolet rays or the like through a photomask having a stripe pattern intersecting the lower electrode 11, and a difference in development speed caused by a difference in exposure amount in the thickness direction of the layer. Is used to form the partition wall 16 having a tapered surface with its side facing downward. The protruding portion 30 can be formed by the same material and the same process as the partition wall 16.

The organic layer 12 has a laminated structure of light emitting functional layers including a light emitting layer. When one of the lower electrode 11 and the upper electrode 13 is an anode and the other is a cathode, a hole injection layer and a hole transport are sequentially formed from the anode side. A layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like are selectively formed.

An example of forming the organic layer 12 will be described below. For example, first, NPB (N, N-di (naphtalence) -N, N-dipheneyl-benzidene) is formed as a hole transport layer. This hole transport layer has a function of transporting holes injected from the anode to the light emitting layer. The hole transport layer may be a single layer or a stack of two or more layers. In addition, the hole transport layer is not formed by a single material, but a single layer may be formed by a plurality of materials, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. Doping may be performed.

Next, a light emitting layer is formed on the hole transport layer. As an example, red (R), green (G), and blue (B) light-emitting layers are formed in respective film formation regions by using a resistance heating vapor deposition method using a coating mask. As red (R), an organic material that emits red light such as a styryl dye such as DCM1 (4- (dicyanomethylene) -2-methyl-6- (4'-dimethylaminostyryl) -4H-pyran) is used. An organic material that emits green light, such as aluminum quinolinol complex (Alq3), is used as green (G). As the blue (B), an organic material emitting blue light such as a distyryl derivative or a triazole derivative is used. Of course, other materials or a host-guest layer structure may be used, and the emission form may be a fluorescent light emitting material or a phosphorescent light emitting material.

The electron transport layer formed on the light emitting layer is formed by using various materials such as an aluminum quinolinol complex (Alq3) by various film forming methods such as resistance heating vapor deposition. The electron transport layer has a function of transporting electrons injected from the cathode to the light emitting layer. This electron transport layer may have a multilayer structure in which only one layer is stacked or two or more layers are stacked. In addition, the electron transport layer may be formed of a plurality of materials instead of a single material, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. It may be formed by doping.

The sealing member that seals the organic EL element 1U is, for example, the sealing substrate 17 bonded to the substrate 10 via the adhesive 17A, and the organic EL element is interposed between the substrate 10 and the sealing substrate 17. A sealing space for sealing 1U is formed. As the sealing substrate 17, a glass substrate or a metal substrate can be used.

Further, as the sealing member, a sealing film covering the organic EL element 1U can also be adopted. As the sealing film, a metal or silicon oxide, nitride, or acid formed by an atomic layer growth method can be used. A single layer or multilayer film of nitride can be used. By reaction of alkyl metal such as TMA (trimethylaluminum), TEA (triethylaluminum), DMAH (dimethylaluminum hydride) with water, oxygen, or alcohols. An aluminum oxide film (for example, Al ₂ O ₃ film) obtained, a silicon oxide film (for example, SiO ₂ film) obtained by a reaction between a vaporized gas of a silicon-based material and a vaporized gas of water can be used. .

Among the wirings 20 formed in the wiring forming region B, the lead-out wiring 20X is electrically connected to the lower electrode 11, and the lead-out wiring 20Y is electrically connected to the upper electrode 13. The wiring 20 is patterned in the same process as the lower electrode 11. The wiring 20 can have, for example, a multilayer structure in which metal electrodes are stacked using a transparent conductive film as a base layer.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. The embodiments described in the above drawings can be combined with each other as long as there is no particular contradiction or problem in the purpose, configuration, or the like. Moreover, the description content of each figure can become independent embodiment, respectively, and embodiment of this invention is not limited to one embodiment which combined each figure.

Claims

A substrate, one or a plurality of organic EL elements formed on the substrate, and wiring formed outside the region where the organic EL element is formed on the substrate,
In the organic EL device, a region of the substrate where the wiring is formed is provided with a protruding portion that protrudes at least to a position higher than the surface of the wiring.
2. The organic EL device according to claim 1, wherein the wiring is a lead wiring drawn from an electrode of the organic EL element.
2. The organic EL device according to claim 1, wherein a partition wall is provided between the organic EL elements in a region where the organic EL element is formed, and the protruding portion has substantially the same height as the partition wall.
4. The organic EL device according to claim 3, wherein the protrusions are arranged in a ring shape.
5. The organic EL device according to claim 4, wherein a plurality of the protrusions are scattered.
6. The organic EL device according to claim 5, wherein the plurality of protrusions are arranged in a staggered pattern.
The organic EL device according to claim 6, wherein the upper surface of the protruding portion has a substantially rectangular shape that is long along a direction in which the partition wall extends.
The substrate and a sealing substrate for sealing the organic EL element are bonded to each other in an adhesive region surrounding the region where the organic EL element is formed, and the protruding portion is provided in the adhesive region. The organic EL device according to claim 7.
9. The organic EL device according to claim 8, wherein a width of the adhesion region is larger than a width of the protruding portion.