WO2014038094A1

WO2014038094A1 - Light emitting apparatus and method for manufacturing same

Info

Publication number: WO2014038094A1
Application number: PCT/JP2012/073107
Authority: WO
Inventors: 修一関
Original assignee: パイオニア株式会社; 東北パイオニア株式会社
Priority date: 2012-09-10
Filing date: 2012-09-10
Publication date: 2014-03-13

Abstract

Provided is a technology with which reliability of a light emitting apparatus can be improved. A conductive section (CP) is provided with an auxiliary wiring line (AWL), and the auxiliary wiring line (AWL) is disposed with a separating region (space region) between the auxiliary wiring line and the anode (AE) formed on the substrate (1S). The auxiliary wiring line (AWL) extends, for instance, in the Y direction. In the conductive section (CP), an insulating film (IL1) is formed such that the auxiliary wiring line (AWL) is covered with the insulating film, and an opening (OP1) is formed in the insulating film (IL1). The auxiliary wiring line (AWL) is configured to be exposed from the bottom portion of the opening (OP1). The cathode (CE) is formed such that the opening (OP1) is fully filled with the cathode, and the cathode (CE) and the auxiliary wiring line (AWL) are electrically connected to each other.

Description

Light emitting device and manufacturing method thereof

The present invention relates to a light emitting device and a manufacturing technique thereof, and is applied to, for example, a light emitting apparatus using a light emitting element represented by an organic electroluminescence element (hereinafter referred to as an organic EL element) and a manufacturing technique thereof. It relates to effective technology.

Japanese Patent Application Publication No. 2005-521204 (Patent Document 1) describes a technique of providing a guard line below a partition formed between adjacent pixels.

In JP-A-2005-203128 (Patent Document 2), a reverse-tapered partition is provided so as to surround the organic EL element, and an auxiliary electrode for reducing the electrical resistance of the transparent electrode is provided below the partition. The technology is described.

In JP 2008-153237 A (Patent Document 3), an auxiliary electrode of an organic EL element is provided in a part of a wall-like insulating layer, and a portion of the wall-like insulating layer provided with the auxiliary electrode is provided with an auxiliary electrode. A technique is described that is wider than the unexposed portion.

JP 2005-521204 A JP-A-2005-203128 JP 2008-153237 A

Currently, light-emitting devices using light-emitting diodes (LEDs) as light-emitting devices (for example, lighting devices) that replace incandescent bulbs and fluorescent lamps are becoming widespread. This is because light-emitting diodes have energy saving characteristics that can reduce power consumption with a long lifetime, and in recent years, cost reduction has also progressed. However, since the light-emitting diode has a long life, there is a possibility that demand will stagnate in the future, and development of a new light-emitting device is underway.

For example, as an example of a new light emitting element applied to a light emitting device, attention has been focused on an organic EL element using electroluminescence. Electroluminescence is a phenomenon that emits light when a voltage is applied to a substance. In particular, an element that generates this electroluminescence with an organic substance is called an organic EL element. Since this organic EL element is a current injection type device and exhibits diode characteristics, it is also called an organic light emitting diode (OLED).

Such light-emitting devices using organic EL elements are expected to be put to practical use so as to follow light-emitting devices using light-emitting diodes that have already been commercialized. This is because a light-emitting device using an organic EL element can be made thinner than a light-emitting device using a light-emitting diode and can illuminate a wide range. That is, according to the light-emitting device using the organic EL element, there is a possibility that it can be applied to a wide range of uses that have been difficult in the past, such as lighting that shines on the entire wall and billboard lighting in a store that does not take up space. In other words, the organic EL element emits light on the surface unlike the light emitting diode that emits light in terms of the element. Therefore, according to the light emitting device using the organic EL element, the room can be illuminated in a state close to natural light without creating a shadow. it can. In particular, a light-emitting device using an organic EL element is expected for a space having high design properties such as an entrance hall and an atrium. In addition, since a light emitting device using an organic EL element is thin and light, there is an advantage that it can be easily installed on a ceiling or a wall.

As described above, light-emitting devices using light-emitting diodes are mostly point light emission, so they are suitable for miniaturization, but in contrast to the restrictions on heat generation and the need to devise light diffusion. A light-emitting device using an organic EL element has advantages such as “surface emission”, “no restriction on shape (flexible)”, and “transparent”. For this reason, the light-emitting device using an organic EL element has the possibility of spreading beyond the light-emitting device using a light emitting diode.

However, in order to promote the spread of light-emitting devices using organic EL elements, it is necessary to improve the reliability of the organic EL elements. As a result of investigation by the present inventor regarding this point, the present inventor has found that there is a cause for lowering the reliability of the organic EL element. Therefore, in the following, a typical basic configuration of the organic EL element will be described first, and then an example of factors that reduce the reliability of the organic EL element having this basic configuration will be described.

An organic EL element expected to be applied to a light emitting device has, for example, the following basic structure. That is, the organic EL element is formed, for example, such that a lower electrode is formed on a substrate and a plurality of partition walls extend in a predetermined direction (first direction) on the lower electrode. Each region sandwiched between the plurality of partition walls extending in the first direction is a cell region. In the cell region, an organic layer including a light emitting layer is formed on the lower electrode, and the upper electrode is formed on the organic layer. The upper electrode is separated for each cell region. For example, in each cell region, the upper electrode is formed to extend in the first direction. According to the organic EL element configured as described above, for example, by applying a voltage between a hole injection electrode (anode) as a lower electrode and an electron injection electrode (cathode) as an upper electrode, the anode and the cathode A current flows through the sandwiched organic layer and emits light by itself.

Here, paying attention to the step of forming the cathode in the manufacturing process of the organic EL element, the cathode is formed on the cell region after forming the organic layer including the light emitting layer in the cell region sandwiched between the plurality of partition walls. It is formed by forming a conductor film.

At this time, for example, if a conductive film is formed in a state where foreign matter (dust) is attached so as to straddle between adjacent partition walls, the conductive film is not formed in a region where the foreign matter is attached. As a result, the problem that disconnection occurs in the cathode made of the conductive film becomes apparent as an example. The disconnection of the cathode means that a defect occurs in the light emitting device, and this may cause a possibility that the reliability of the light emitting device is lowered.
The objective of this invention is providing the technique which can improve the reliability of a light-emitting device.
Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

The invention described in claim 1 includes: (a) a substrate; (b) a first electrode formed on the substrate; and (c) a partition wall portion formed on the substrate and extending in the first direction. (D) a plurality of cell regions partitioned by the partition wall, each of the plurality of cell regions being formed with (e) a light emitting unit and (f) the first electrode of the substrate. In plan view as seen from the side surface, the light emitting portion and a conducting portion sandwiched between the partition walls, and the light emitting portion includes (e1) a light emitting layer formed on the first electrode. An organic layer; and (e2) a second electrode formed on the organic layer, wherein the conductive portion is (f1) formed on the substrate and electrically separated from the first electrode. A second electrode auxiliary wiring extending in the first direction, and (f2) the conductive portion from above the organic layer of the light emitting portion. Characterized in that it comprises a second electrode formed over the second electrode for the auxiliary wire.

The invention described in claim 12 includes: (a) a step of preparing a substrate; (b) a step of forming a first conductor film on the substrate after the step (a); and (c) the ( b) After the step, the first conductive film is patterned to form the first electrode and the second electrode auxiliary wiring extending in the first direction with the first electrode interposed through the separation region. And (d) after the step (c), forming a first insulating film so as to embed the spacing region provided between the first electrode and the second electrode auxiliary wiring; e) after the step (d), forming an opening in the first insulating film and exposing the second electrode auxiliary wiring from the opening; (f) after the step (e), the substrate A partition wall extending in a first direction is formed thereon, and the light emission unit and the first electrode of the substrate are formed by the partition wall. A step of partitioning a cell region including a light-emitting portion and a conductive portion including the second electrode auxiliary wiring in a plan view as viewed from the formed surface; and (g) After the step (f), a step of forming an organic layer including a light emitting layer on the first electrode of the light emitting portion excluding the conducting portion in the cell region, and (h) after the step (g) A second electrode is formed from the organic layer formed in the light emitting portion over the second electrode auxiliary wiring exposed from the opening formed in the conducting portion, and the second electrode Electrically connecting the auxiliary wiring for use and the second electrode.

Furthermore, the invention described in claim 13 includes (a) a step of preparing a substrate, (b) a step of forming a first conductor film on the substrate after the step (a), and (c) the ( b) After the step, by patterning the first conductor film, the first electrode made of the first conductor film and the first wiring layer extending in the first direction through the separation region And (d) after the step (c), a second conductor film having a smaller resistivity than the first conductor film is formed so as to cover the first electrode and the first wiring layer. And (e) after the step (d), patterning the second conductor film to form a second wiring layer extending in the first direction on the first wiring layer, and Forming a second electrode auxiliary wiring composed of one wiring layer and the second wiring layer, and on the first electrode; A step of forming a first electrode auxiliary wiring made of the second conductor film and extending in the first direction; and (f) after the step (e), covering the first electrode auxiliary wiring, A step of forming a first insulating film so as to embed the separation region provided between the first electrode and the second electrode auxiliary wiring; and (g) after the step (f), the first insulating film Forming an opening in the opening and exposing the second electrode auxiliary wiring from the opening; and (h) a partition wall extending in the first direction on the first insulating film after the step (g) And is sandwiched between the light emitting portion and the partition portion in a plan view as viewed from the light emitting portion and the surface of the substrate on which the first electrode is formed, for the second electrode. A step of partitioning a cell region including a conductive portion including an auxiliary wiring, and (i) after the step (h), before A step of forming an organic layer including a light-emitting layer on the first electrode of the light-emitting portion excluding the conducting portion in the cell region; and (j) after the step (i), formed in the light-emitting portion. A second electrode is formed over the organic layer, and over the second electrode auxiliary wiring exposed from the opening formed in the conductive portion, and the second electrode auxiliary wiring and the second electrode are formed. And a step of electrically connecting the two.

It is a top view which shows the anode structure of the light-emitting device in related technology. In a related art light emitting device, it is a top view mainly showing the cathode composition formed on an anode. It is sectional drawing which shows one cross section of the light-emitting device in related technology. It is a flowchart which shows the flow which manufactures the light-emitting device in related technology. It is a figure which shows the state to which the foreign material adhered after forming an organic layer and before forming a cathode. It is a top view which shows one state which formed the cathode in the state which the foreign material adhered so as to straddle the mutually adjacent partition. FIG. 7 is a cross-sectional view taken along line AA in FIG. 6. FIG. 3 is a plan view showing a schematic configuration of the light emitting device in the first embodiment. 3 is a plan view mainly showing an anode configuration of the light-emitting device in Embodiment 1. FIG. 4 is a plan view mainly showing a cathode configuration formed on an anode and an auxiliary wiring in the light-emitting device of Embodiment 1. FIG. 3 is a cross-sectional view illustrating a structure of a light-emitting device in Embodiment 1. FIG. It is a figure which shows the structural example of the light emission part using the organic layer comprised from a low molecular material. It is a figure which shows the structural example of the light emission part using the organic layer comprised from a polymeric material. It is a schematic diagram which shows a mode that the electron inject | poured into the organic layer from the cathode and the hole (hole) inject | poured into the organic layer from the anode move to a counter electrode direction. It is a figure for demonstrating the light emission mechanism in an organic layer. FIG. 3 is a plan view showing a state in which a cathode is formed in a state where foreign matter adheres so as to straddle adjacent barrier ribs in the light emitting device in the first embodiment. It is sectional drawing cut | disconnected by the AA line of FIG. It is sectional drawing cut | disconnected by the BB line | wire of FIG. FIG. 17 is a diagram schematically showing a state in which electrical connection is ensured by an auxiliary wiring in the cross-sectional view taken along line AA in FIG. 16. 3 is a flowchart showing a flow of manufacturing the light emitting device in the first embodiment. 5 is a cross-sectional view showing a manufacturing process of the light-emitting device in Embodiment 1. FIG. FIG. 22 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. 21. FIG. 23 is a cross-sectional view showing a manufacturing step of the light emitting device following that of FIG. 22; FIG. 24 is a cross-sectional view showing a manufacturing step of the light-emitting device following FIG. 23. FIG. 25 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. 24. FIG. 26 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. 25. FIG. 27 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. 26. FIG. 28 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. 27. FIG. 29 is a cross-sectional view showing the manufacturing process for the light-emitting device following FIG. 28. FIG. 30 is a cross-sectional view showing a manufacturing step of the light emitting device following that of FIG. 29; 6 is a cross-sectional view illustrating a structure of a light-emitting device in Embodiment 2. FIG. 6 is a flowchart showing a flow of manufacturing the light emitting device in the second embodiment. 11 is a cross-sectional view showing a manufacturing process of the light-emitting device in Embodiment 2. FIG. FIG. 34 is a cross-sectional view showing the manufacturing process for the light-emitting device following FIG. 33. FIG. 35 is a cross-sectional view showing the manufacturing process for the light-emitting device following FIG. 34. FIG. 36 is a cross-sectional view showing a manufacturing process of the light-emitting device following FIG. FIG. 37 is a cross-sectional view showing the manufacturing process for the light-emitting device following FIG. 36. FIG. 38 is a cross-sectional view showing a manufacturing step of the light-emitting device following FIG. 7 is a cross-sectional view illustrating a structure of a light-emitting device in Embodiment 3. FIG. 10 is a flowchart showing a flow of manufacturing a light-emitting device according to Embodiment 3.

In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. There are some or all of the modifications, details, supplementary explanations, and the like.

Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say.

Similarly, in the following embodiments, when referring to the shape, positional relationship, etc., of components, etc., unless otherwise specified, and in principle, it is considered that this is not clearly the case, it is substantially the same. Including those that are approximate or similar to the shape. The same applies to the above numerical values and ranges.

In all the drawings for explaining the embodiments, the same members are, in principle, given the same reference numerals, and the repeated explanation thereof is omitted. In order to make the drawings easy to understand, even a plan view may be hatched.

(Embodiment 1)
Below, the related technique relevant to the light-emitting device in this Embodiment 1 is demonstrated first, and the room for the improvement which exists in this related technique is demonstrated after that. Then, the technical idea in the first embodiment, which is devised for the room for improvement existing in the related technology, will be described. Note that in the first embodiment, a so-called bottom emission type light-emitting device that extracts light from the back side (lower surface side) of a substrate having electrodes formed on the front surface (main surface) will be described as an example.

<Description of related technologies>
FIG. 1 is a plan view showing an anode configuration of a light emitting device LAP in the related art. As shown in FIG. 1, an anode AE having a solid pattern is formed on a rectangular substrate 1S. The term “on the substrate” here means above the substrate, and includes a case where another layer such as a protective film exists between the substrate and the anode.

A plurality of bus electrodes BE are formed on the anode AE. Specifically, the bus electrode BE formed on the anode AE is formed in a stripe shape. That is, the plurality of bus electrodes BE are arranged at a predetermined interval in the X direction, and each bus electrode BE is formed to extend in the Y direction. The bus electrode BE is electrically connected to the anode AE and is formed to reduce the resistance of the anode AE.

Next, FIG. 2 is a plan view mainly showing a cathode configuration formed on the anode AE shown in FIG. 1 in the related art light emitting device LAP. As shown in FIG. 2, the plurality of partition walls PT are arranged at predetermined intervals in the X direction, and each partition wall PT is formed to extend in the Y direction. At this time, the cell region CR is partitioned by the partition walls PT adjacent to each other. That is, the partition PT is disposed so as to sandwich the cell region CR, and the bus electrode BE shown in FIG. 1 is disposed in the lower layer overlapping the partition PT in plan view. A cathode CE is formed in the cell region CR defined by the partition walls PT. The cathode CE is separated for each cell region CR. That is, the cathode CE is provided corresponding to each of the plurality of cell regions CR.

Subsequently, FIG. 3 is a sectional view showing one section of the light emitting device LAP in the related art. As shown in FIG. 3, the anode AE is formed on the substrate 1S, and the bus electrode BE is formed in a predetermined region on the anode AE.

For example, the substrate 1S is composed of a transparent substrate such as a glass substrate or a plastic substrate, and the anode AE formed on the substrate 1S is also made of, for example, ITO (indium tin oxide) or IZO (indium zinc oxide). It is formed from a representative transparent conductor film. On the other hand, the bus electrode BE is formed of, for example, an aluminum film (Al film). Thus, since the anode AE and the bus electrode BE are both formed of a conductor film, and the bus electrode BE is directly formed on the anode AE, the anode AE and the bus electrode BE are electrically connected to each other. Will be.

Then, an insulating film IL1 made of, for example, a polyimide resin film is formed so as to cover the bus electrode BE, and a partition wall PT is formed on the insulating film IL1. This partition PT is made of, for example, a photosensitive resin. Here, if the region where the partition PT is formed is called a partition formation region, the bus electrode BE is formed below the partition PT in the partition formation region via the insulating film IL1. A region sandwiched between the partition wall formation regions is a cell region CR. In other words, the cell region CR is defined as a region sandwiched between the partition walls PT adjacent to each other. In the cell region CR, an organic layer OL including a light emitting layer is formed on the anode AE, and a cathode CE is formed on the organic layer OL. The cathode CE is formed of, for example, an aluminum film (Al film) or a silver film (Ag film).

According to the light emitting device LAP in the related art configured as described above, by generating a potential difference between the anode AE and the cathode CE, in the cell region, the anode AE passes through the organic layer OL including the light emitting layer. A current flows through the cathode CE. As a result, light based on electroluminescence (visible light) is emitted from the light emitting layer included in the organic layer OL. Light emitted from the light emitting layer passes through the anode AE that is a transparent electrode and the substrate 1S that is a transparent substrate, and is extracted from the back surface side (lower surface side) of the substrate 1S to the outside of the light emitting device LAP. As described above, the light emitting device LAP in the related art can emit light.

Here, in this specification, “transparent” used in a transparent substrate or a transparent conductor film means that it has translucency with respect to visible light, for example, it transmits with respect to incident light. It is used in a wide concept including the state where light is generated. That is, the term “transparent” in this specification refers to a state where transmitted light is generated regardless of the amount of transmitted light with respect to incident light. Therefore, there is transmitted light not only in a state where the amount of transmitted light is large, but also in a “semi-transparent” state where the amount of transmitted light with respect to incident light is about half or in a state where the amount of transmitted light is small. The state is included in “transparent” in the present specification.

The light emitting device LAP in the related art is configured as described above, and the manufacturing method thereof will be briefly described below. FIG. 4 is a flowchart showing a flow of manufacturing the light emitting device LAP in the related art. Below, based on FIG. 3 and FIG. 4, the manufacturing process of the light-emitting device LAP in related technology is demonstrated.

First, for example, a substrate 1S which is a transparent substrate is prepared (S101). Then, an anode AE made of ITO or IZO is formed on the surface (main surface) of the substrate 1S by using, for example, a sputtering method (S102). Thereafter, a metal film made of, for example, an aluminum film is formed on the anode AE, and the bus electrode BE is formed by using a photolithography technique and an etching technique on the metal film (S103).

Next, an insulating film IL1 is formed so as to cover the bus electrode BE (S104). Thereafter, a partition PT is formed on the insulating film IL1 (S105). Subsequently, an organic layer OL including a light emitting layer is formed on the anode AE of the cell region CR partitioned by the partition PT by using, for example, a vapor deposition method (S106). Thereafter, for example, by using a vapor deposition method, a cathode CE made of an aluminum film is formed on the organic layer OL (S107). In this way, the light emitting device LAP in the related art can be manufactured.

<Room for improvement in related technologies>
Here, the inventor paid attention to the point of improving the reliability of the light emitting device LAP and newly found that there is room for improvement in the cathode forming step from the viewpoint of improving the reliability. The room for improvement found by the present inventor will be described below.

For example, FIG. 5 is a diagram showing a state in which foreign matter adheres after forming the organic layer OL and before forming the cathode. In the step of forming the cathode, a conductive film made of, for example, an aluminum film is formed on the organic layer OL. Due to the cleanliness in the processing apparatus at this time, the surface of the substrate 1S is formed. Foreign matter (dust) FB may adhere to the top. Specifically, in the step of forming the cathode, since the plurality of partition walls PT are already formed, for example, when the size of the foreign matter FB is larger than the distance between the partition walls PT adjacent to each other, FIG. As shown, the foreign substance FB adheres across the partition walls PT adjacent to each other. For example, since the interval between the adjacent partition walls PT is about 100 μm to 150 μm, at least when the size of the foreign material FB is 150 μm or more, the foreign material FB adheres across the adjacent partition walls PT.

In this state, when the film forming process of the conductor film constituting the cathode is performed, it is difficult to form the cathode on the organic film OL in the cell region where the foreign substance FB adheres. become. That is, there is an increased possibility that the cathode can hardly be formed on the organic layer OL in a region overlapping the foreign matter FB in a planar manner.

FIG. 6 is a plan view showing a state in which the cathode CE is formed in a state where foreign matter adheres across the partition walls PT adjacent to each other. As shown in FIG. 6, a plurality of partition walls PT are formed at a predetermined interval in the X direction on the substrate 1S, and each partition wall PT extends in the Y direction. A plurality of cell regions are partitioned by the plurality of partition walls PT arranged in this way. For example, attention is paid to a cell region formed near the center of FIG. For example, if a foreign substance adheres so as to straddle a pair of partition walls PT that divide the cell region, a gap SP in which the cathode CE is not formed is formed in a partial region of the cell region as shown in FIG. I understand. That is, the gap SP is formed in the lower layer that overlaps with the area where the foreign matter is adhered, as a result of the conductor film constituting the cathode CE not being formed.

Therefore, as shown in FIG. 6, in the cell region to which foreign matter has adhered, the cathode CE is not formed over the entire cell region, but the cathode CE includes the first cathode portion CEP1 which is a part of the cathode CE, and the cathode It is separated from the second cathode part CEP2 which is another part of CE by the gap SP. This means that the first cathode part CEP1 and the second cathode part CEP2 are electrically separated. As a result, in the cell region to which foreign matter has adhered, the electrically integrated cathode CE is not formed, but the first cathode portion CEP1 and the second cathode portion CEP2 that are electrically separated from each other are formed. It will be. In other words, the cathode CE is disconnected in the cell region to which foreign matter has adhered.

At this time, the following disadvantages occur in the light emitting device LAP in the related art. 7 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 7, an anode AE is formed on the substrate 1S, and an organic layer OL including a light emitting layer is formed on the anode AE. Then, the first cathode part CEP1 and the second cathode part CEP2 are formed on the organic layer OL via the gap SP.

Here, let us consider a case where power is supplied to the anode AE from the left side of FIG. 7 and power is supplied to the cathode from the right side of FIG. In this case, as shown in FIG. 7, since power is supplied to the anode AE and the first cathode part CEP1, a current flows between the anode AE and the first cathode part CEP1. That is, since an electric current is supplied to the organic layer OL formed between the anode AE and the first cathode portion CEP1, the organic layer OL that planarly overlaps the first cathode portion CEP1 in the cell region Light is emitted.

On the other hand, as shown in FIG. 7, since the second cathode part CEP2 is electrically separated from the first cathode part CEP1 through the gap SP, no power is supplied to the second cathode part CEP2. As a result, no current flows between the anode AE and the second cathode part CEP2. That is, since no current is supplied to the organic layer OL formed between the anode AE and the second cathode portion CEP2, light is emitted from the organic layer OL that planarly overlaps the second cathode portion CEP2 in the cell region. Will not be ejected. From the above, in the cell region to which foreign matter has adhered, the entire cell region does not emit light, but in some regions (the organic layer OL that planarly overlaps with the second cathode portion CEP2), a light emission failure occurs. Become.

This means that a defect occurs in the light emitting device LAP in the related art. Thereby, it can be seen that the related technology has a potential to reduce the reliability of the light emitting device LAP. In other words, in the related art, when a foreign substance having a size straddling adjacent partition walls PT adheres to the cell region, the cathode is disconnected. Then, due to the disconnection of the cathode, a light emission failure of the light emitting device LAP occurs, and the reliability of the light emitting device LAP is lowered. From this, it can be seen that there is room for improvement in the related art from the viewpoint of improving the reliability of the light emitting device LAP. That is, in the current light emitting device LAP, further improvement in reliability is desired.

In this regard, first of all, it is conceivable to develop a technique for suppressing the generation of foreign substances having a size straddling adjacent partition walls PT in the step of forming the cathode as a practical problem. It is difficult to make the generation probability of foreign objects of a certain size zero. In particular, when the cell region is further miniaturized, the interval between the adjacent partition walls PT is also narrowed. As a result, the size of the foreign material straddling the adjacent partition walls PT is also reduced, and generation of such foreign material is sufficiently suppressed. It will be difficult.

Therefore, the next possibility is to develop a technology to compensate for cathode formation defects even if foreign particles of a size straddling adjacent partition walls adhere to the cell region and cause cathode formation defects. To do. For this reason, in the first embodiment, a device for improving the reliability of the light emitting device is provided by compensating for the formation failure of the cathode to prevent the light emitting failure of the light emitting device. Below, the technical idea in this Embodiment 1 which gave this device is demonstrated.

<Configuration of Light-Emitting Device in Embodiment 1>
First, a schematic configuration of the light emitting device LA1 according to the first embodiment will be described. For example, the light emitting device LA1 according to the first embodiment can be applied to the case where light of various colors is emitted. In particular, a case where a configuration for irradiating white light is employed will be described.

FIG. 8 is a plan view showing a schematic configuration of the light emitting device LA1 according to the first embodiment. As shown in FIG. 8, the light emitting device LA1 in the first embodiment includes, for example, a rectangular substrate 1S, and a plurality of cell regions CR are formed on the main surface (surface, upper surface) of the substrate 1S. Has been. Specifically, partition walls PT are arranged on the main surface of the substrate 1S so as to be arranged at predetermined intervals in the X direction, and each partition wall PT extends in the Y direction. A plurality of cell regions CR are partitioned by the partition walls PT arranged in this manner. That is, as shown in FIG. 8, a region sandwiched between adjacent partition walls PT is a cell region CR. Therefore, in the light emitting device LA1 in the first embodiment, the cell regions extending in the Y direction are arranged so as to be aligned in the X direction.

Here, as shown in FIG. 8, in the light emitting device LA1 in the first embodiment, the cell region CR that irradiates red (R), the cell region CR that irradiates green (G), and blue (B). The cell regions CR to be irradiated are periodically arranged. Thereby, according to light-emitting device LA1 in this Embodiment 1, white light can be irradiated. That is, if the physical arrangement of the cell regions CR that emit RGB light is sufficiently fine and the observer is sufficiently away from the light emitting device LA1, the RGB light beams that are incident on the human eye. Is recognized as white light. Based on such a principle, in the light emitting device LA1 according to the first embodiment, the cell regions CR that respectively emit RGB are periodically arranged. In the case of this configuration, for example, by adjusting the respective light amounts of RGB, it is possible to irradiate not only white light but also light of various colors.

However, the configuration of the light emitting device LA1 in the first embodiment is not limited to the configuration shown in FIG. 8, and white light can be irradiated by other methods. For example, white light may be obtained by periodically arranging one color of RGB and a color (cyan, yellow, magenta: CYM) complementary to the color. In this case, for example, a configuration for obtaining white light using blue (B) and its complementary color yellow (Y) is highly versatile.

Furthermore, it is possible to obtain white light by taking advantage of the characteristics of the organic EL element. That is, the organic EL element is greatly different from the inorganic LED in that RGB light emitting layers can be laminated with a thin film of the order of nm. In other words, the organic EL element can also obtain white light by single current excitation, unlike the inorganic LED that can obtain only a single color due to the structure of the device. In this case, for example, in each of the plurality of cell regions CR, the light emitting layer sandwiched between the anode and the cathode has an RGB stacked structure, whereby white light can be emitted for each cell region. As described above, in the organic EL element, white light can be obtained from a single cell region by providing a light emitting layer emitting each color of RGB between the anode and the cathode in the process of forming the element. Therefore, in the first embodiment, for example, white light can be emitted from each of the plurality of cell regions.

Next, FIG. 9 is a plan view mainly showing the anode configuration of the light emitting device LA1 in the first embodiment. As shown in FIG. 9, an anode AE is formed on a rectangular substrate 1S. The term “on the substrate” as used herein means above the substrate, and includes a case where another layer such as a protective film exists between the substrate and the substrate. Specifically, in the first embodiment, the plurality of anodes AE are arranged in a predetermined interval in the X direction, and each of the plurality of anodes AE is arranged to extend in the Y direction. This is different from the anode AE (solid pattern) shown in the related art shown in FIG.

In the first embodiment, the auxiliary wiring AWL (second electrode auxiliary wiring) is sandwiched between the anodes AE adjacent to each other in a plan view as viewed from the surface of the substrate 1S on which the first electrode is formed. ) Is formed. One feature of the first embodiment is that the auxiliary wiring AWL is provided. The auxiliary wiring AWL is provided through a separation region (space region) from the anode AE, and is arranged side by side at a predetermined interval in the X direction. Further, each auxiliary wiring AWL is configured to extend in the Y direction, like the anode AE. As described above, in the first embodiment, since the auxiliary wiring AWL is provided via the separation area from the anode AE, the anode AE is formed in a stripe shape.

Furthermore, a bus electrode BE (first electrode auxiliary wiring) is formed on each of the plurality of anodes AE. Specifically, the bus electrode BE formed on each of the plurality of anodes AE is formed in a stripe shape. That is, the plurality of bus electrodes BE are arranged at a predetermined interval in the X direction, and each bus electrode BE is formed to extend in the Y direction. The bus electrode BE is electrically connected to the anode AE and is formed to reduce the resistance of the anode AE.

Subsequently, FIG. 10 is a plan view mainly showing a cathode configuration formed on the anode AE and the auxiliary wiring AWL shown in FIG. 9 in the light emitting device LA1 of the first embodiment. As shown in FIG. 10, a plurality of partition walls PT are arranged at predetermined intervals in the X direction, and each partition wall PT is formed to extend in the Y direction. At this time, the cell region CR is partitioned by the partition walls PT adjacent to each other. That is, the partition PT is disposed so as to sandwich the cell region CR, and the bus electrode BE shown in FIG. 9 is disposed in a lower layer overlapping the partition PT in plan view. Further, the anode AE and the auxiliary wiring AWL shown in FIG. 9 are arranged in a lower layer overlapping the cell region CR in plan view. A cathode CE is formed in the cell region CR defined by the partition walls PT. The cathode CE is separated for each cell region CR. That is, the cathode CE is provided corresponding to each of the plurality of cell regions CR.

For this reason, in the light emitting device LA1 in the first embodiment, the auxiliary wiring AWL is provided, and both the anode AE and the cathode CE are separated for each cell region CR. The separated anodes AE and cathodes CE are arranged at predetermined intervals in the X direction, and the individual anodes AE and individual cathodes CE are configured to extend in the Y direction. Become.

The planar configuration of the light emitting device LA1 in the first embodiment is as described above, and the cross-sectional configuration of the light emitting device LA1 will be described below. FIG. 11 is a diagram illustrating an example of a cross-sectional configuration of the light emitting device LA1 according to the first embodiment. In FIG. 11, an area corresponding to one cell area CR is mainly illustrated.

As shown in FIG. 11, the light emitting device LA1 in the first embodiment has a substrate 1S. The type and structure of the substrate 1S are not particularly limited, and a flexible substrate, a hard material, or the like can be used depending on the application. Specifically, examples of the material of the substrate 1S include glass, quartz, polyethylene, polypropylene, polyethylene terephthalate, polymethacrylate, polymethyl methacrylate, polymethyl acrylate, polyester, polycarbonate, and the like.

The anode AE and the auxiliary wiring AWL are formed on the main surface (surface, upper surface) of the substrate 1S described above. In particular, in the first embodiment, a separation region (space region) is provided between the anode AE and the auxiliary wiring AWL, and the anode AE and the auxiliary wiring AWL are electrically separated.

Here, “main surface (front surface, upper surface)” in this specification means an element formation surface on which a light emitting element is formed, and the surface opposite to the element formation surface is “back surface (lower surface)”. It becomes.

Next, as shown in FIG. 11, a bus electrode BE is formed on the anode AE, and the bus electrode BE and the anode AE are electrically connected. Here, the reason why the bus electrode BE is provided on the anode AE will be described. For example, in the bottom emission type light emitting device LA1, the anode AE needs to be formed of a transparent electrode such as ITO or IZO. However, a transparent electrode made of ITO or IZO has a characteristic that the resistivity is relatively high. For this reason, for example, even if a positive voltage is supplied to the anode AE, there is a possibility that a uniform positive voltage cannot be supplied to the entire area of the anode AE. That is, in the region of the anode AE far from the power supply region, the voltage drop becomes significant due to the relatively high resistivity of the transparent electrode, and the applied voltage decreases as the distance from the power supply region increases. As a result, it becomes difficult to supply a uniform positive voltage to the entire area of the anode AE. In this case, the voltage applied to the cell region CR changes for each local region, and the light emission intensity in the cell region CR changes depending on the location. This increases the possibility of uneven brightness in the light emitting device.

Therefore, in the first embodiment, the bus electrode BE is formed on the anode AE. The bus electrode BE is made of a metal film such as an aluminum film having a resistivity lower than that of a transparent electrode such as ITO or IZO, and extends in the Y direction that is the extending direction of the anode AE. (See FIG. 9). Thereby, the resistivity of the electrode which integrated anode AE and bus electrode BE can be reduced. As a result, the voltage drop can be reduced even in a region away from the power supply region, and the uniformity of the positive voltage applied to the entire region of the integrated electrode can be improved. Thereby, it can suppress that the voltage applied to the cell area | region CR changes for every local area | region, and the location dependence of the emitted light intensity in the cell area | region CR can be made small. Thus, by providing the bus electrode BE so as to be integrated with the anode AE, luminance unevenness in the light emitting device can be reduced.

For example, a metal film typified by an aluminum film having a lower resistivity than the anode AE is used as the bus electrode BE. However, since this metal film is not transparent, it cannot be formed on the cell region CR. For this reason, it is provided in the lower layer of the partition PT which divides the cell region CR. As a result, the resistivity of the electrode in which the anode AE and the bus electrode BE are integrated can be reduced without blocking the light emission of the cell region CR.

Subsequently, an insulating film IL1 made of, for example, a polyimide resin film is formed so as to cover the bus electrode BE and the auxiliary wiring AWL. In this insulating film IL1, an opening OP1 reaching the surface of the auxiliary wiring AWL is formed, and a partition PT is formed on the insulating film IL1 covering the bus electrode BE. This partition PT is made of, for example, a photosensitive resin. For example, as shown in FIG. 11, the partition PT has a shape such that the width of the bottom of the partition PT is smaller than the width of the top of the partition PT. In other words, in the partition PT, the cross-sectional shape of the partition PT perpendicular to the Y direction (first direction) can be said to be an inversely tapered shape.

At this time, if the region where the partition PT is formed is referred to as a partition formation region, the bus electrode BE is formed below the partition PT in the partition formation region via the insulating film IL1. A region sandwiched between the partition wall formation regions is a cell region CR. In other words, the cell region CR is defined as a region sandwiched between the partition walls PT adjacent to each other.

Here, in the first embodiment, the cell region CR includes the light emitting part LP and the conduction part CP. Specifically, most of the cell region CR is the light emitting portion LP, and a region sandwiched between the light emitting portion LP and the partition wall PT in plan view is defined as the conduction portion CP. For example, the width of the cell region CR partitioned by the partition walls PT adjacent to each other is 100 μm to 150 μm, and the width of the conduction part CP is about 30 μm, for example.

In the light emitting unit LP, an organic layer OL including a light emitting layer is formed on the anode AE, and a cathode CE made of, for example, an aluminum film (Al film) or a silver film (Ag film) is formed on the organic layer OL. Is formed.

On the other hand, in the conductive portion CP, an auxiliary wiring AWL is formed on the substrate 1S, and an insulating film IL1 is formed so as to cover the auxiliary wiring AWL. Further, in the conduction part CP, an opening OP1 is formed in the insulating film IL1, and the opening OP1 is formed so as to reach the surface of the auxiliary wiring AWL. In the conduction part CP, the organic layer OL including the light emitting layer is not formed, and the cathode CE is formed on the insulating film IL1 including the inside of the opening OP1. That is, in the first embodiment, the cathode CE is formed from the light emitting part LP to the conduction part CP. Specifically, the cathode CE is formed so as to straddle the auxiliary wiring AWL formed on the conduction portion CP from the organic layer OL formed in the light emitting portion LP. In particular, in the conduction portion CP, the cathode CE is formed on the insulating film IL1, and the cathode CE is formed so as to fill the opening OP1 formed in the insulating film IL1. As a result, the cathode CE and the auxiliary wiring AWL are electrically connected. That is, in the light emitting device LA1 according to Embodiment 1, the cathode CE and the auxiliary wiring AWL are electrically connected.

The light emitting device LA1 according to the first embodiment is configured as described above, and a more detailed configuration of the cell region CR will be described below. Each of the plurality of cell regions CR provided in the light emitting device LA1 in the first embodiment is characterized in that it includes a light emitting part LP and a conduction part CP. In the following, first, a configuration example of the light emitting unit LP formed in the cell region CR will be described, then a light emission mechanism in the light emitting unit LP will be described, and then the conduction unit CP which is a feature of the first embodiment. Will be described.

<Configuration example of light emitting unit>
The material of the organic layer OL that is a component of the light emitting unit LP shown in FIG. 11 is roughly classified into a low molecular material and a high molecular material. Therefore, a configuration example of the light emitting unit LP using the organic layer OL made of a low molecular material and a configuration example of the light emitting unit LP using the organic layer OL made of a polymer material will be described.

FIG. 12 is a diagram showing a configuration example of the light emitting unit LP using the organic layer OL composed of a low molecular material. As shown in FIG. 12, in the light emitting unit LP in the first embodiment, for example, an anode AE (hole injection electrode) is formed on a substrate 1S. An organic layer OL is formed on the anode AE, and a cathode CE is formed on the organic layer OL. At this time, as shown in FIG. 12, for example, the organic layer OL includes a hole injection layer HIL formed on the anode AE, a hole transport layer HTL formed on the hole injection layer HIL, It has a light emitting layer LL formed on the transport layer HTL, an electron transport layer ETL formed on the light emitting layer LL, and an electron injection layer EIL formed on the electron transport layer ETL.

The hole injection layer HIL is provided in order to improve the hole injection efficiency from the anode AE. Specifically, an organic compound has a highest occupied molecular orbital (HOMO (highest occupied molecular orbital)) and a lowest unoccupied molecular orbital (LUMO (lowest unoccupied molecular orbital)). At this time, HOMO is the orbit with the highest energy among the orbits filled with electrons, and the constraint from the nucleus is the smallest. From this, it can be said that HOMO is an orbit where electrons move most easily. For example, at the interface between the anode AE and the hole transport layer HTL, electrons move from the HOMO of the hole transport layer HTL to the anode AE side. That is, the hole transport layer HTL is oxidized by supplying electrons to the anode AE. In other words, holes are injected from the anode AE into the hole transport layer HTL. This movement of electrons becomes easier as the work function of the anode AE and the HOMO level of the hole transport layer HTL are closer.

In this regard, the hole transport layer HTL mainly aims to prevent holes from moving smoothly into the light emitting layer LL and to prevent electrons injected into the light emitting layer LL from moving into the hole transport layer HTL. Selected as. Therefore, a material whose HOMO level of the hole transport layer HTL is close to the work function of the anode AE is not necessarily selected. For this reason, a hole injection layer HIL having a HOMO level close to the work function of the anode AE is inserted. Thereby, the hole injection efficiency from anode AE can be improved. That is, the hole injection layer HIL is provided in order to improve the hole injection efficiency from the anode AE.

In addition, as described above, the hole transport layer HTL has the purpose of allowing holes to move smoothly to the light emitting layer LL and that the electrons injected into the light emitting layer LL move into the hole transport layer HTL. Is provided for the purpose of preventing. Therefore, the hole transport layer HTL is made of a material having a high hole mobility.

Next, the light emitting layer LL has a function of emitting light when holes that have moved through the hole transport layer HTL and electrons that have moved through the electron transport layer ETL are recombined. For this reason, a material with high quantum efficiency of light emission is used for the light emitting layer LL.

Subsequently, the electron injection layer EIL is provided in order to improve the efficiency of electron injection from the cathode CE (electron injection electrode). Specifically, LUMO present in an organic compound is an orbit having the lowest energy among empty orbits that are not filled with electrons. For example, at the interface between the cathode CE and the electron transport layer ETL, electrons move from the cathode CE to the LUMO of the electron transport layer ETL. Thereby, the electron transport layer ETL is reduced by the electrons supplied from the cathode CE. This movement of electrons becomes easier as the work function of the cathode CE and the LUMO level of the electron transport layer ETL are closer.

In this regard, the electron transport layer ETL is selected mainly for the purpose of preventing electrons from moving smoothly into the light emitting layer LL and preventing holes injected into the light emitting layer LL from moving into the electron transport layer ETL. Is done. Therefore, a material whose LUMO level of the electron transport layer ETL is close to the work function of the cathode CE is not necessarily selected. For this reason, an electron injection layer EIL having a LUMO level close to the work function of the cathode CE is inserted. Thereby, the electron injection efficiency from the cathode CE can be improved. That is, the electron injection layer EIL is provided in order to improve the injection efficiency of electrons from the cathode CE.

The electron transport layer ETL is used for the purpose of allowing electrons to move smoothly to the light emitting layer LL and for the purpose of preventing holes injected into the light emitting layer LL from moving into the electron transport layer ETL. Is provided. Therefore, the electron transport layer ETL is made of a material having a high electron mobility.

As described above, the light emitting portion LP using the organic layer OL composed of the low molecular material is configured. Next, a configuration example of the light emitting unit LP using the organic layer OL made of a polymer material will be described.

FIG. 13 is a diagram illustrating a configuration example of the light emitting unit LP using the organic layer OL formed of a polymer material. As shown in FIG. 13, in the light emitting unit LP according to the first embodiment, for example, an anode AE is formed on a substrate 1S. An organic layer OL is formed on the anode AE, and a cathode CE is formed on the organic layer OL. At this time, for example, as shown in FIG. 13, the organic layer OL includes a hole injection layer HIL formed on the anode AE, a hole transport layer HTL formed on the hole injection layer HIL, and a hole. A light emitting layer LL formed on the transport layer HTL.

For example, as shown in FIG. 12, the light emitting part LP using the organic layer OL made of a low molecular material has a complex multilayer structure, and the vacuum evaporation method is mainly used for manufacturing. On the other hand, for example, as shown in FIG. 13, a typical light emitting portion LP using an organic layer OL made of a polymer material has a simpler structure than the case shown in FIG. For the production, a coating method or a printing method is used. Therefore, the organic layer OL composed of a high molecular weight material has a simpler structure than the organic layer OL composed of a low molecular weight material, and the coating method and the printing method can be used. There is an advantage that it can be manufactured at a lower cost than the organic layer OL composed of a low molecular material. That is, in the vacuum deposition method, the material utilization efficiency is about several percent, whereas in the coating method and the printing method, the material can be used almost without waste. It can be manufactured at a lower cost than the organic layer OL composed of a low molecular material.
Here, examples of the material of the light emitting layer LL include a dye-based light-emitting material, a metal complex-based light-emitting material, and a polymer-based light-emitting material.

Specifically, as the dye-based light emitting material, for example, cyclopentadiene derivative, tetraphenylbutadiene derivative, triphenylamine derivative, oxadiazole derivative, pyrazoloquinoline derivative, distyrylbenzene derivative, distyrylarylene derivative, silole derivative Thiophene ring compound, pyridine ring compound, perinone derivative, perylene derivative, oligothiophene derivative, trifumanylamine derivative, oxadiazole dimer, pyrazoline dimer, and the like.

Examples of the metal complex light emitting material include an aluminum quinolinol complex, a benzoquinolinol beryllium complex, a benzoxazole zinc complex, a benzothiazole zinc complex, an azomethyl zinc complex, a porphyrin zinc complex, and a europium complex.

Examples of the polymer light-emitting material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinyl carbazole, polyfluorenone derivatives, polyfluorene derivatives, polyquinoxaline derivatives, and combinations thereof. A polymer etc. can be mentioned.

As a material of the hole injection layer HIL, for example, in addition to the compounds exemplified as the light emitting material of the light emitting layer LL, phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, etc. And derivatives of oxides, amorphous carbon, polyaniline, polythiophene, and the like.

As a material of the hole transport layer HTL, phthalocyanine, naphthalocyanine, porphyrin, oxadiazole, triphenylamine, triazole, imidazole, imidazolone, pyrazoline, tetrahydroimidazole, hydrazone, stilbene, pentacene, polythiophene, butadiene, or these Derivatives and the like can be mentioned.

Materials for the electron transport layer HTL include anthraquinodimethane, fluorenylidenemethane, tetracyanoethylene, fluorenone, diphenoquinone oxadiazole, anthrone, thiopyran dioxide, diphenoquinone, benzoquinone, malononitrile, niditrobenzene, nitro Anthraquinone, maleic anhydride, perylene tetracarboxylic acid, or derivatives thereof can be exemplified.

As the material of the electron injection layer EIL, in addition to the compounds exemplified as the light emitting material of the light emitting layer LL, aluminum, lithium fluoride, strontium, magnesium oxide, magnesium fluoride, strontium fluoride, calcium fluoride, barium fluoride, and oxide Examples include aluminum, strontium oxide, calcium, sodium polymethylmethacrylate polystyrene sulfonate, lithium, cesium, cesium fluoride, and the like, alkali metals, alkali metal halides, alkali metal organic complexes, and the like.

<Light emission mechanism from light emitting part>
Next, the light emission mechanism from the light emission part LP is demonstrated, referring drawings. FIG. 14 is a schematic diagram showing how electrons injected from the cathode into the organic layer and holes injected from the anode into the organic layer move in the counter electrode direction. A and B represent molecules constituting the organic layer. First, in FIG. 14, holes injected from the anode into the organic layer and electrons injected from the cathode into the organic layer move toward the counter electrode by using an electric field gradient as a driving force. As shown in FIG. 14, it can be considered chemically about the movement of. That is, first, at the anode interface, the molecule (B) is oxidized (loses electrons) and becomes a radical cation. Molecules (B ⁺ ) with a few electrons correspond to holes in the inorganic semiconductor and become carriers. On the other hand, at the cathode interface, the molecule (A) is reduced (receives electrons) and becomes a radical anion. In this case, the molecule (A ⁻ ) in which one electron is added becomes an electron carrier.

The process in which the generated radical cation and radical anion move through the organic layer by repeating the redox reaction between adjacent molecules can be considered as carrier movement.

Thereafter, excitons are generated by recombination of holes and electrons in the light emitting layer. In current excitation, excitons are in a state where holes (radical cation) and electrons (radical anion) are bound to each other by Coulomb force, but the same as the one-electron excited state by photoexcitation due to the transfer of charge to one side. It becomes a state. The difference in energy when this exciton returns to the ground state is emitted as light.

That is, electrons are injected from the cathode into the organic layer, and holes are injected from the anode, and respective carriers (electrons and holes) are transported. And an exciton is produced | generated when an electron and a hole recombine in a light emitting layer. The light emission part LP emits light by a mechanism in which energy is released by light when the exciton returns to the ground state.

Further details will be described with reference to FIG. FIG. 15 is a diagram for explaining the light emission mechanism in the organic layer. As shown in FIG. 15, the transport state of holes can be said to be a process in which molecules constituting the hole transport layer are oxidized to form radical cations and move. Similarly, it can be said that the electron transport state is a process in which molecules constituting the electron transport layer are reduced to form radical anions and move.

Then, in the light emitting layer shown in FIG. 15, two types of radicals approach and recombine to form a hole-electron pair (exciton). The exciton then passes the charge, has two electrons in the highest occupied molecular orbital (HOMO), and has the lowest unoccupied molecular orbital (LUMO). In this case, a ground state molecule in which no electron exists and an excited state molecule having one electron each in HOMO and LUMO are generated. When the excited molecule of the excitons returns to the ground state, light corresponding to the energy difference between the excited state and the ground state is emitted. Thus, it can be seen that light is emitted from the light emitting portion LP when a current is passed between the anode and the cathode.

<Configuration of Conducting Part (Characteristics in Embodiment 1)>
Next, the conduction part CP, which is a feature of the first embodiment, will be described. For example, as shown in FIG. 11, the conduction portion CP is provided with an auxiliary wiring AWL, and the auxiliary wiring AWL is connected to the anode AE formed on the substrate 1 </ b> S via a separation region (space region). Has been placed. For example, as illustrated in FIG. 9, the auxiliary wiring AWL extends in the Y direction (first direction). Further, in the conductive portion CP, an insulating film IL1 is formed so as to cover the auxiliary wiring AWL, and this insulating film IL1 is formed so as to embed a separation region formed between the auxiliary wiring AWL and the anode AE. Has been. For this reason, the electrical isolation between the auxiliary wiring AWL and the anode AE can be reliably performed by the insulating film IL1 filling the separation region.

Subsequently, in the conduction part CP, an opening OP1 is formed in the insulating film IL1, and the auxiliary wiring AWL is exposed from the bottom of the opening OP1. The cathode CE is formed so as to fill the opening OP1, and the cathode CE and the auxiliary wiring AWL are electrically connected.

Thus, in the first embodiment, it is important that the cathode CE and the auxiliary wiring AWL are electrically connected. Thereby, even if a formation failure occurs in the cathode CE, the disconnection failure of the cathode CE can be avoided by the auxiliary wiring AWL electrically connected to the cathode CE. That is, according to the first embodiment, the formation of the auxiliary wiring AWL can compensate for the formation failure of the cathode. Therefore, according to the light emitting device LA1 in the first embodiment, it is possible to prevent the light emitting failure of the light emitting device LA1 and improve the reliability of the light emitting device LA1.

Hereinafter, it will be described in detail with reference to the drawings that the reliability of the light emitting device LA1 can be improved by providing the conductive line CP with the auxiliary wiring AWL electrically connected to the cathode CE. FIG. 16 is a plan view showing a state in which the cathode CE is formed in the light emitting device LA1 according to the first embodiment in a state where foreign matters are attached so as to straddle the adjacent partition walls PT. As shown in FIG. 16, a plurality of partition walls PT are formed at a predetermined interval in the X direction on the substrate 1S, and each partition wall PT extends in the Y direction. The plurality of cell regions CR are partitioned by the plurality of partition walls PT arranged in this manner. For example, attention is paid to the cell region CR formed near the center of FIG. For example, if a foreign substance adheres across the pair of partition walls PT that divide the cell region CR, as shown in FIG. 16, a gap SP in which the cathode CE is not formed is formed in a partial region of the cell region CR. I understand that That is, the gap SP is formed in the lower layer that overlaps with the area where the foreign matter is adhered, as a result of the conductor film constituting the cathode CE not being formed.

Accordingly, as shown in FIG. 16, in the cell region CR to which foreign matter is attached, the cathode CE is not formed over the entire cell region CR, but the cathode CE is connected to the first cathode portion CEP1 which is a part of the cathode CE. The second cathode part CEP2 which is another part of the cathode CE is separated by the gap SP. This seems that the first cathode part CEP1 and the second cathode part CEP2 are electrically separated at a glance.

However, in the light emitting device LA1 according to the first embodiment, as shown in FIG. 16, the cell region CR includes not only the light emitting portion LP but also the conduction portion CP. Therefore, as can be imagined from FIG. 16, it can be seen that the first cathode part CEP1 and the second cathode part CEP2 are electrically connected by the auxiliary wiring AWL exposed from the gap SP. That is, in the first embodiment, as a result of forming the cathode CE in a state in which foreign matter adheres across the partition walls PT adjacent to each other, even if a formation failure occurs in the cathode CE, the first cathode portion CEP1 And the second cathode portion CEP2 are electrically connected through the auxiliary wiring AWL. For this reason, according to this Embodiment 1, the disconnection of the cathode CE can be prevented and the light emission failure resulting from the disconnection of the cathode CE can be suppressed. As a result, according to the first embodiment, the reliability of the light emitting device LA1 can be dramatically improved.

Further, the advantages of the light emitting device LA1 according to the first embodiment will be described with reference to cross-sectional views. 17 is a cross-sectional view taken along line AA in FIG. That is, FIG. 17 is a cross-sectional view corresponding to the light emitting portion LP of the cell region CR. As shown in FIG. 17, it can be seen that the anode AE is formed on the substrate 1S, and the organic layer OL is formed on the anode AE. In a normal state, a cathode having no defective formation is formed on the organic layer OL. However, in the AA line in FIG. 16, there is a gap SP due to the adhesion of foreign matters. In FIG. 17, the first cathode part CEP1 and the second cathode part CEP2 are formed on the organic layer OL with a gap SP therebetween. In this case, the first cathode part CEP1 and the second cathode part CEP2 seem to be electrically separated. That is, in the light emitting part LP of the cell region CR, the first cathode part CEP1 and the second cathode part CEP2 appear to be electrically separated.

In this regard, FIG. 18 is a cross-sectional view taken along line BB in FIG. That is, FIG. 18 is a cross-sectional view corresponding to the conduction portion CP of the cell region CR. As shown in FIG. 18, the auxiliary wiring AWL is formed on the substrate 1S, and the first cathode portion CEP1 and the second cathode portion CEP2 are formed on the auxiliary wiring AWL via the gap SP. It will be. As can be seen from FIG. 18, the first cathode portion CEP1 and the auxiliary wiring AWL are electrically connected, and the second cathode portion CEP2 is also electrically connected to the auxiliary wiring AWL. From this, it can be seen that in the conduction part CP of the cell region CR, the first cathode part CEP1 and the second cathode part CEP2 are electrically connected via the auxiliary wiring AWL. Therefore, although it seems that the first cathode part CEP1 and the second cathode part CEP2 formed in the cell region CR are disconnected in the light emitting part LP, the electrical connection is actually made in the conduction part CP. It can be seen that is secured.

FIG. 19 is a diagram schematically showing a state in which electrical connection is secured by the auxiliary wiring AWL in the cross-sectional view taken along the line AA in FIG. As shown in FIG. 19, when it is assumed that anode feeding is performed from the left side of the drawing and cathode feeding is performed from the right side of the drawing, of course, the first cathode portion CEP1 is electrically connected to the cathode feeding region. Therefore, the cathode voltage is supplied to the first cathode part CEP1. Further, in the first embodiment, since the first cathode part CEP1 and the second cathode part CEP2 are electrically connected by the auxiliary wiring AWL, the cathode voltage is also supplied to the second cathode part CEP2. .

As a result, as shown in FIG. 19, since current flows from the anode AE to the second cathode portion CEP2, current is also supplied to the organic layer OL sandwiched between the anode AE and the second cathode portion CEP2, and this organic layer Light is emitted from the OL. In addition, since current flows from the anode AE to the first cathode portion CEP, current is also supplied to the organic layer OL sandwiched between the anode and the first cathode portion CEP1, and light is also emitted from the organic layer OL.

As described above, according to the light emitting device LA1 in the first embodiment, it is possible to sufficiently suppress the light emission failure caused by the adhesion of the foreign matter. This is because, according to the first embodiment, even if the formation failure of the cathode CE due to adhesion of foreign matter occurs, the effect of the light emitting device LA1 based on the formation failure of the cathode CE due to the filling effect by the auxiliary wiring AWL. It means that light emission defects can be suppressed. Thereby, according to light-emitting device LA1 in this Embodiment 1, reliability can be improved significantly.

Further, the feature of the first embodiment also exists in that the auxiliary wiring AWL is formed in the same layer as the anode AE, and that the formation material of the auxiliary wiring AWL and the formation material of the anode AE are the same. This advantage is mainly reflected in that the manufacturing process of the light emitting device LA1 can be simplified and the manufacturing cost of the light emitting device LA1 can be reduced. Therefore, these advantages will be described in a method for manufacturing the light emitting device LA1 described later.

<Method for Manufacturing Light-Emitting Device in Embodiment 1>
The light emitting device LA1 in the first embodiment is configured as described above, and the manufacturing method thereof will be described below with reference to the drawings. Specifically, first, the outline of the manufacturing process of the light emitting device LA1 will be described using the flowchart shown in FIG. 20, and then the light emitting device LA1 according to the first embodiment will be described with reference to FIGS. The manufacturing process will be described.

FIG. 20 is a flowchart showing a flow of manufacturing the light emitting device LA1 according to the first embodiment. In FIG. 20, for example, a substrate transparent to visible light typified by a glass substrate or a plastic substrate is prepared (S201). Then, a first conductor film made of, for example, ITO or IZO is formed on the main surface (element formation surface) of the substrate (S202). Next, the first conductor film is patterned by using a photolithography technique and an etching technique (S203). Thereby, the anode and auxiliary wiring which consist of a 1st conductor film can be formed. Subsequently, for example, a second conductor film having a resistivity lower than that of the first conductor film is formed on the substrate on which the anode and the auxiliary wiring are formed (S204). Specifically, the second conductor film can be formed from, for example, a metal film typified by an aluminum film.

Thereafter, the second conductor film is patterned by using a photolithography technique and an etching technique (S205). Thereby, the bus electrode made of the second conductor film can be formed on the anode.

Next, an insulating film made of, for example, a polyimide resin film is formed on the substrate on which the bus electrode is formed (S206). Then, an opening is formed in the insulating film by using a photolithography technique and an etching technique (S207). The opening is formed so as to overlap with the auxiliary wiring in a plan view, and is formed so that the surface of the auxiliary wiring is exposed at the bottom of the opening.

Subsequently, for example, a photosensitive resin film is formed on the insulating film, and a plurality of partition walls are formed by patterning the photosensitive resin film (S208). As a result, a cell region sandwiched between adjacent partition walls is partitioned. At this time, the cell region includes a light emitting portion and a conductive portion sandwiched between the light emitting portion and the partition in a plan view. This conduction part includes auxiliary wiring.

Thereafter, an organic layer including a light emitting layer is formed on the anode formed in the light emitting portion in the cell region by using a vacuum deposition method using a mask, a coating method, a printing method, or the like (S209). ). Then, a cathode made of, for example, an aluminum film or a silver film is formed from the light emitting portion in the cell region to the conducting portion (S210). At this time, the cathode is formed on the insulating film including the inside of the opening formed in the conducting portion from the organic layer formed in the light emitting portion. As a result, since the cathode fills the opening, it is electrically connected to the auxiliary wiring exposed from the bottom of the opening. In addition, a sealing process is implemented after this process in order to protect an organic EL element from air | atmosphere or a water | moisture content. As described above, the light-emitting device according to Embodiment 1 can be manufactured.

Next, the manufacturing method of the light emitting device LA1 in the first embodiment will be described in more detail with reference to the drawings. First, as shown in FIG. 21, a substrate 1S transparent to visible light is prepared. Thereafter, as shown in FIG. 22, a first conductor film CF1 is formed on the main surface (element formation surface) of the substrate 1S. The first conductor film CF1 is formed of a transparent film typified by ITO or IZO, for example, and can be formed by using, for example, a sputtering method.

Subsequently, as shown in FIG. 23, the first conductor film CF1 is patterned by using a photolithography technique and an etching technique. Thereby, the anode AE made of the first conductor film CF1 and the auxiliary wiring AWL made of the first conductor film CF1 can be formed. Specifically, the anode AE and the auxiliary wiring AWL are formed so as to be separated through a separation region. As a result, the anode AE and the auxiliary wiring AWL are electrically separated.

Here, in the first embodiment, the anode AE and the auxiliary wiring AWL are formed by patterning the common first conductor film CF1. For this reason, the auxiliary wiring AWL can be formed using the process of forming the anode AE without adding the process of forming the auxiliary wiring AWL independently. As a result, according to the first embodiment, it is possible to simplify the process and reduce the manufacturing cost.

In Embodiment 1, since the anode AE and the auxiliary wiring AWL are formed in the same process, the anode AE and the auxiliary wiring AWL are inevitably formed in the same layer, and the anode AE and the auxiliary wiring are inevitably formed. The wiring AWL is formed from the same material (first conductor film CF1).

Next, as shown in FIG. 24, the second conductor film CF2 is formed on the substrate 1S on which the anode AE and the auxiliary wiring AWL are formed. The second conductor film CF2 is formed from a film having a lower resistivity than the first conductor film CF1. For example, the second conductor film CF2 is formed of a metal film typified by an aluminum film, and can be formed by using, for example, a sputtering method.

Then, as shown in FIG. 25, the second conductor film CF2 is patterned by using a photolithography technique and an etching technique. Thereby, the bus electrode BE made of the second conductor film CF2 can be formed on the anode AE. The bus electrode BE is electrically connected to the anode AE formed in the lower layer, and has a function of reducing the resistivity of the electrode composed of the anode AE and the bus electrode BE.

Subsequently, as shown in FIG. 26, an insulating film IL1 made of, for example, a polyimide resin film is formed on the substrate 1S on which the bus electrode BE is formed. For example, the insulating film IL1 is formed so as to embed a separation region provided between the anode AE and the auxiliary wiring AWL.

Thereafter, as shown in FIG. 27, by using a photolithography technique and an etching technique, the insulating film IL1 is patterned to form an opening OP1 whose bottom reaches the auxiliary wiring AWL. As a result, the surface of the auxiliary wiring AWL is exposed. At this time, as shown in FIG. 27, the insulating film IL1 is patterned so that a partial region on the anode AE where the bus electrode BE is not formed is also exposed from the insulating film IL1.

Next, as shown in FIG. 28, a partition PT made of, for example, a photosensitive resin film is formed on the insulating film IL1. The partition PT is formed, for example, by patterning a photosensitive resin film by using a photolithography technique. At this time, for example, when an exposure process is performed on the photosensitive resin film, the intensity of the exposure light decreases downward in the photosensitive resin film. For this reason, the difference in the intensity of the exposure light causes a difference in the dissolution rate in the developer, and the inversely tapered partition wall PT is formed. That is, the partition PT is formed such that the width of the bottom of the partition PT is smaller than the width of the upper portion of the partition PT. In other words, the partition PT is formed so that the cross-sectional shape of the partition PT perpendicular to the Y direction (first direction) is an inversely tapered shape.

In this way, it is possible to form a plurality of partition walls PT arranged in the X direction at predetermined intervals and extending in the Y direction. As a result, the cell region CR is partitioned by the partition walls PT adjacent to each other. That is, the region sandwiched between the partition walls PT adjacent to each other is the cell region CR. In the cell region CR, the light emitting portion LP and the conduction portion CP sandwiched between the light emitting portion LP and the partition wall PT in plan view are formed. In particular, the auxiliary wiring AWL is formed in the conduction portion CP.

Subsequently, as shown in FIG. 29, an organic layer OL including a light emitting layer is formed on the anode AE formed in the light emitting portion LP in the cell region CR. For example, when the organic layer OL is composed of a low molecular material, the organic layer OL can be formed by a vacuum vapor deposition method using a mask. On the other hand, when the organic layer OL is composed of a polymer material, it can be formed by using a coating method or a printing method.

Here, in the first embodiment, the organic layer OL is not formed over the entire cell region CR, but the organic layer OL is formed in the light emitting portion LP in the cell region CR. In other words, the organic layer OL is not formed in the conduction part CP in the cell region CR. As a result, in the conduction part CP, the organic layer OL is not formed on the auxiliary wiring AWL and in the opening OP1.

Thereafter, as shown in FIG. 30, a cathode CE is formed from the light emitting portion LP in the cell region CR to the conducting portion CP. The cathode CE is formed of, for example, an aluminum film or a silver film, and can be formed by, for example, a vapor deposition method. At this time, the damage given to the organic layer OL can be reduced by using a vapor deposition method as a method of forming the cathode CE. Here, since the partition PT has an inversely tapered shape, the cathode CE is not formed across the plurality of cell regions CR, and the cathode CE separated for each cell region CR is automatically formed. Can do.

At this time, the cathode CE is formed on the insulating film IL1 including the inside of the opening OP1 formed in the conducting portion CP from the organic layer OL formed in the light emitting portion LP. As a result, since the cathode CE is filled in the opening OP1, the cathode CE is electrically connected to the auxiliary wiring AWL exposed from the bottom of the opening OP1.

In addition, after this process, in order to protect an organic EL element from air | atmosphere and a water | moisture content, a sealing process is implemented. As described above, the light emitting device LA1 according to Embodiment 1 can be manufactured.

<Typical effects in the first embodiment>
(1) According to the first embodiment, the auxiliary wiring AWL that is electrically connected to the cathode CE is provided. For this reason, even if formation failure occurs in the cathode CE due to adhesion of foreign matter, disconnection failure of the cathode CE can be avoided by the auxiliary wiring AWL electrically connected to the cathode CE. That is, according to the first embodiment, the formation of the auxiliary wiring AWL can compensate for the formation failure of the cathode. Therefore, according to the light emitting device LA1 in the first embodiment, it is possible to prevent the light emitting failure of the light emitting device LA1 and improve the reliability of the light emitting device LA1.

(2) In the first embodiment, the anode AE and the auxiliary wiring AWL are formed by patterning the common first conductor film CF1. For this reason, the auxiliary wiring AWL can be formed using the process of forming the anode AE without adding the process of forming the auxiliary wiring AWL independently. As a result, according to the first embodiment, it is possible to simplify the process and reduce the manufacturing cost. As described above, in the first embodiment, since the anode AE and the auxiliary wiring AWL are formed in the same process, the anode AE and the auxiliary wiring AWL are inevitably formed in the same layer. The anode AE and the auxiliary wiring AWL are formed from the same material (first conductor film CF1).

(Embodiment 2)
In the first embodiment, the example in which the auxiliary wiring AWL is composed of the first conductor film CF1 has been described. In the second embodiment, the auxiliary wiring AWL is formed by stacking the first conductor film CF1 and the second conductor film CF2. An example of forming from a film will be described.
<Characteristics in Embodiment 2>

Since the configuration of the light emitting device LA2 in the second embodiment is substantially the same as the configuration of the light emitting device LA1 in the first embodiment, the following description will focus on the differences.

FIG. 31 is a sectional view showing a section of the light emitting device LA2 in the second embodiment. As shown in FIG. 31, the light emitting device LA2 in the second embodiment is characterized in that the auxiliary wiring AWL formed in the conduction portion CP in the cell region CR is a stacked layer of the first wiring layer FWL and the second wiring layer SWL. The film is formed from a film. At this time, the first wiring layer FWL is formed in the same layer as the anode AE formed on the substrate 1S and is made of the same material. Therefore, the first wiring layer FWL is also made of a transparent material such as ITO or IZO, for example, like the anode AE. On the other hand, the second wiring layer SWL is formed in the same layer as the bus electrode BE formed on the anode AE and is made of the same material. Therefore, the second wiring layer SWL is made of, for example, a metal film typified by an aluminum film, like the bus electrode BE.

Here, since the resistivity of the bus electrode BE is smaller than the resistivity of the anode AE, the resistivity of the second wiring layer SWL is also smaller than the resistivity of the first wiring layer FWL. Become. For this reason, according to the auxiliary wiring AWL in the second embodiment, the resistivity can be reduced as compared with the auxiliary wiring AWL in the first embodiment which is made of the same material as the anode AE. That is, according to the second embodiment, as a result of forming the first wiring layer FWL and the second wiring layer FWL having a lower resistivity than the first wiring layer FWL, the auxiliary wiring AWL The resistivity can be reduced.

In this case, for example, as shown in FIG. 16, the resistivity of the auxiliary wiring AWL connecting the separated first cathode portion CEP1 and second cathode portion CEP2 is reduced in the cathode in which the formation failure has occurred. For this reason, the connection resistance between 1st cathode part CEP1 and 2nd cathode part CEP2 can be reduced. As a result, it is possible to suppress the occurrence of a potential difference between the first cathode part CEP1 and the second cathode part CEP2 due to the resistance component existing in the auxiliary wiring AWL. In other words, according to the second embodiment, the auxiliary wiring AWL that electrically connects the separated first cathode portion CEP1 and second cathode portion CEP2 even when the formation failure occurs in the cathode. The resistivity can be lowered. For this reason, the uniformity of the potential applied to the first cathode part CEP1 and the second cathode part CEP2 can be improved. Thereby, according to this Embodiment 2, the difference in the emitted light intensity in 1st cathode part CEP1 and 2nd cathode part CEP2 can be made small. As described above, the auxiliary wiring AWL is composed of the laminated film of the first wiring layer FWL and the second wiring layer SWL having a resistivity lower than that of the first wiring layer FWL. Can be avoided, and furthermore, luminance unevenness in the light emitting device LA2 can be reduced.

Further, from another viewpoint, in the auxiliary wiring AWL in the second embodiment, since the resistivity of the auxiliary wiring AWL can be reduced, the wiring width is reduced even if the wiring width of the auxiliary wiring AWL is reduced. As a result, the increase in resistance of the auxiliary wiring AWL can be mitigated. This means that according to the second embodiment, the wiring width (width in the X direction) of the auxiliary wiring AWL can be reduced without causing a significant increase in resistance of the auxiliary wiring AWL. As a result, according to the light emitting device LA2 in the second embodiment, it is possible to reduce the occupied area of the conduction part CP in the cell region CR. In other words, the area occupied by the light emitting portion LP in the cell region CR can be increased. As a result, according to the second embodiment, it is possible to improve the ratio (aperture ratio) of the area effective for light emission in the entire cell region CR.

In the second embodiment, the same effect as in the first embodiment can be obtained. That is, also in the second embodiment, the auxiliary wiring AWL that is electrically connected to the cathode CE is provided. For this reason, even if formation failure occurs in the cathode CE due to adhesion of foreign matter, disconnection failure of the cathode CE can be avoided by the auxiliary wiring AWL electrically connected to the cathode CE. That is, according to the second embodiment, the formation of the auxiliary wiring AWL can compensate for the formation failure of the cathode. Therefore, according to the light emitting device LA2 in the present second embodiment, it is possible to prevent the light emitting failure of the light emitting device LA2 and improve the reliability of the light emitting device LA2.

<Method for Manufacturing Light-Emitting Device in Embodiment 2>
The light emitting device LA2 according to the second embodiment is configured as described above, and the manufacturing method thereof will be described below with reference to the drawings. Specifically, first, an outline of the manufacturing process of the light emitting device LA2 will be described using the flowchart shown in FIG. 32, and then the light emitting device LA2 according to the second embodiment will be described with reference to FIGS. The manufacturing process will be described.

32, for example, a substrate transparent to visible light represented by a glass substrate or a plastic substrate is prepared (S301). Then, a first conductor film made of, for example, ITO or IZO is formed on the main surface (element formation surface) of the substrate (S302). Next, the first conductor film is patterned by using a photolithography technique and an etching technique (S303). Thereby, the anode and the first wiring layer made of the first conductor film can be formed. Subsequently, for example, a second conductor film having a resistivity lower than that of the first conductor film is formed on the substrate on which the anode and the first wiring layer are formed (S304). Specifically, the second conductor film can be formed from, for example, a metal film typified by an aluminum film.

Thereafter, the second conductor film is patterned by using a photolithography technique and an etching technique (S305). Thereby, the bus electrode made of the second conductor film can be formed on the anode, and the second wiring layer made of the second conductor film can be formed on the first conductor film. Thereby, an auxiliary wiring composed of a laminated film of the first wiring layer and the second wiring layer can be formed.

Next, an insulating film made of, for example, a polyimide resin film is formed on the substrate on which the bus electrode and the second wiring layer are formed (S306). Then, an opening is formed in the insulating film by using a photolithography technique and an etching technique (S307). The opening is formed so as to overlap the auxiliary wiring in a plan view, and is formed so that the surface of the auxiliary wiring (the surface of the second wiring layer) is exposed at the bottom of the opening.

Subsequently, for example, a photosensitive resin film is formed on the insulating film, and a plurality of partition walls are formed by patterning the photosensitive resin film (S308). As a result, a cell region sandwiched between adjacent partition walls is partitioned. At this time, the cell region includes a light emitting portion and a conductive portion sandwiched between the light emitting portion and the partition in a plan view. This conduction part includes auxiliary wiring.

Thereafter, an organic layer including a light emitting layer is formed on the anode formed in the light emitting portion in the cell region by using a vacuum deposition method using a mask, a coating method, a printing method, or the like (S309). ). Then, a cathode made of, for example, an aluminum film or a silver film is formed from the light emitting portion to the conducting portion in the cell region (S310). At this time, the cathode is formed on the insulating film including the inside of the opening formed in the conducting portion from the organic layer formed in the light emitting portion. As a result, since the cathode fills the opening, it is electrically connected to the auxiliary wiring exposed from the bottom of the opening. In addition, a sealing process is implemented after this process in order to protect an organic EL element from air | atmosphere or a water | moisture content. As described above, the light-emitting device in Embodiment 2 can be manufactured.

Next, the manufacturing method of the light emitting device according to the second embodiment will be described in more detail with reference to the drawings. First, the processes shown in FIGS. 21 to 24 are the same as those in the first embodiment. Note that the auxiliary wiring AWL shown in FIGS. 23 and 24 is the first wiring layer FWL in the second embodiment.

Next, as shown in FIG. 33, the second conductor film CF2 is patterned by using a photolithography technique and an etching technique. Thereby, the bus electrode BE made of the second conductor film CF2 is formed on the anode AE, and the second wiring layer SWL made of the second conductor film CF2 is formed on the first wiring layer FWL. Thereby, the auxiliary wiring AWL composed of the laminated film of the first wiring layer FWL and the second wiring layer SWL can be formed. That is, in the second embodiment, the first wiring layer FWL made of the same material and in the same layer as the anode AE and the second wiring layer SWL made of the same material and in the same layer as the bus electrode BE. The laminated film of the first wiring layer FWL and the second wiring layer SWL is used as the auxiliary wiring AWL.

Subsequently, as shown in FIG. 34, an insulating film IL1 made of, for example, a polyimide resin film is formed on the substrate 1S on which the bus electrode BE and the second wiring layer SWL are formed. For example, the insulating film IL1 is formed so as to embed a separation region provided between the anode AE and the auxiliary wiring AWL.

Thereafter, as shown in FIG. 35, by using a photolithography technique and an etching technique, the insulating film IL1 is patterned to form an opening OP1 whose bottom reaches the auxiliary wiring AWL. As a result, the surface of the auxiliary wiring AWL is exposed. At this time, as shown in FIG. 35, the insulating film IL1 is patterned so that a partial region on the anode AE where the bus electrode BE is not formed is also exposed from the insulating film IL1.

Next, as shown in FIG. 36, a partition PT made of, for example, a photosensitive resin film is formed on the insulating film IL1. The partition PT is formed, for example, by patterning a photosensitive resin film by using a photolithography technique. At this time, for example, when an exposure process is performed on the photosensitive resin film, the intensity of the exposure light decreases downward in the photosensitive resin film. For this reason, the difference in the intensity of the exposure light causes a difference in the dissolution rate in the developer, and the inversely tapered partition wall PT is formed. That is, the partition PT is formed such that the width of the bottom of the partition PT is smaller than the width of the upper portion of the partition PT. In other words, the partition PT is formed so that the cross-sectional shape of the partition PT perpendicular to the Y direction (first direction) is an inversely tapered shape.

Subsequently, as shown in FIG. 37, an organic layer OL including a light emitting layer is formed on the anode AE formed in the light emitting portion LP in the cell region CR. For example, when the organic layer OL is composed of a low molecular material, the organic layer OL can be formed by a vacuum vapor deposition method using a mask. On the other hand, when the organic layer OL is composed of a polymer material, it can be formed by using a coating method or a printing method.

Here, in the second embodiment, the organic layer OL is not formed over the entire cell region CR, but the organic layer OL is formed in the light emitting portion LP in the cell region CR. In other words, the organic layer OL is not formed in the conduction part CP in the cell region CR. As a result, in the conduction part CP, the organic layer OL is not formed on the auxiliary wiring AWL and in the opening OP1.

Thereafter, as shown in FIG. 38, a cathode CE is formed from the light emitting portion LP in the cell region CR to the conducting portion CP. The cathode CE is formed of, for example, an aluminum film or a silver film, and can be formed by, for example, a vapor deposition method. At this time, the damage given to the organic layer OL can be reduced by using a vapor deposition method as a method of forming the cathode CE. Here, since the partition PT has an inversely tapered shape, the cathode CE is not formed across the plurality of cell regions CR, and the cathode CE separated for each cell region CR is automatically formed. Can do.

In addition, after this process, in order to protect an organic EL element from air | atmosphere and a water | moisture content, a sealing process is implemented. As described above, the light emitting device LA2 according to the second embodiment can be manufactured.

(Embodiment 3)
In the first embodiment and the second embodiment, a so-called bottom emission type light emitting device that takes out light from the back side (lower surface side) of a substrate having electrodes formed on the front surface (main surface) has been described as an example. However, in the third embodiment, a so-called top emission type light emitting device that extracts light from the main surface side (front surface side, upper surface side, element forming surface side) of the substrate will be described.
<Characteristics in Embodiment 3>

Since the configuration of the light emitting device LA3 in the third embodiment is substantially the same as the configuration of the light emitting device LA1 in the first embodiment, the following description will focus on differences.

FIG. 39 is a cross-sectional view showing a cross section of the light emitting device LA3 in the third embodiment. In FIG. 39, the light emitting device LA3 according to the third embodiment is a top emission type light emitting device. For this reason, it is not necessary to use a substrate transparent to visible light as the substrate 1S, and various types of substrates that function as a support can be used. The anode AE is made of a metal film typified by an aluminum film, for example. On the other hand, in Embodiment 3, since the cathode CE needs to be transparent, it is formed from a transparent electrode such as ITO or IZO, for example. Furthermore, in the third embodiment, the auxiliary wiring AWL is made of the same material as that of the anode AE, and thus is made of, for example, a metal film typified by an aluminum film.

In the light emitting device LA3 according to the third embodiment configured as described above, the auxiliary wiring AWL that is electrically connected to the cathode CE is provided. For this reason, even if formation failure occurs in the cathode CE due to adhesion of foreign matter, disconnection failure of the cathode CE can be avoided by the auxiliary wiring AWL electrically connected to the cathode CE. That is, according to the third embodiment, the formation of the auxiliary wiring AWL can compensate for the formation failure of the cathode. For this reason, according to the light emitting device LA3 in Embodiment 3, it is possible to prevent the light emitting failure of the light emitting device LA3 and improve the reliability of the light emitting device LA3.

Furthermore, in the third embodiment, the following effects can also be obtained. That is, in the light emitting device LA3 according to Embodiment 3, since the top emission method is adopted, the cathode CE is made of a transparent material having a relatively high resistivity, such as ITO or IZO. At this time, in the third embodiment, the cathode CE is electrically connected to the auxiliary wiring AWL, and the auxiliary wiring AWL is made of a material having a low resistivity such as an aluminum film. That is, the auxiliary wiring AWL can have a lower resistivity than the cathode CE made of a transparent material.

Therefore, the auxiliary wiring AWL in the third embodiment is formed mainly for the purpose of avoiding the disconnection failure of the cathode CE. Further, in the third embodiment, the resistivity of the cathode CE is lowered. A secondary effect of being able to do so can also be obtained. That is, according to the third embodiment, since it is not necessary to use a transparent material for the auxiliary wiring AWL, the auxiliary wiring AWL can be made of a metal film such as an aluminum film having a low resistivity. For this reason, the resistivity of the cathode CE can be reduced by electrically connecting the auxiliary wiring AWL to the cathode CE made of a transparent material.

<Method for Manufacturing Light-Emitting Device in Embodiment 3>
The light emitting device LA3 according to the third embodiment is configured as described above, and the manufacturing method thereof will be described below with reference to the drawings. Specifically, the manufacturing process of the light emitting device LA3 will be described using the flowchart shown in FIG.

FIG. 40 is a flowchart showing a flow of manufacturing the light emitting device LA3 according to the third embodiment. In FIG. 40, for example, a substrate that functions as a support is prepared (S401). Then, a first conductor film made of a metal film such as an aluminum film is formed on the main surface (element formation surface) of the substrate (S402). Next, the first conductor film is patterned by using a photolithography technique and an etching technique (S403). Thereby, the anode and auxiliary wiring which consist of a 1st conductor film can be formed. Subsequently, an insulating film made of, for example, a polyimide resin film is formed on the substrate on which the anode and the auxiliary wiring are formed (S404). Then, an opening is formed in the insulating film by using a photolithography technique and an etching technique (S405). The opening is formed so as to overlap with the auxiliary wiring in a plan view, and is formed so that the surface of the auxiliary wiring is exposed at the bottom of the opening.

Subsequently, for example, a photosensitive resin film is formed on the insulating film, and a plurality of partition walls are formed by patterning the photosensitive resin film (S406). As a result, a cell region sandwiched between adjacent partition walls is partitioned. At this time, the cell region includes a light emitting portion and a conductive portion sandwiched between the light emitting portion and the partition in a plan view. This conduction part includes auxiliary wiring.

Thereafter, an organic layer including a light emitting layer is formed on the anode formed in the light emitting portion in the cell region by using a vacuum vapor deposition method using a mask, a coating method, a printing method, or the like (S407). ). Then, a cathode made of a transparent electrode such as ITO or IZO is formed from the light emitting portion to the conducting portion in the cell region (S408). At this time, the cathode is formed on the insulating film including the inside of the opening formed in the conducting portion from the organic layer formed in the light emitting portion. As a result, since the cathode fills the opening, it is electrically connected to the auxiliary wiring exposed from the bottom of the opening. In addition, a sealing process is implemented after this process in order to protect an organic EL element from air | atmosphere or a water | moisture content. As described above, the light-emitting device according to Embodiment 3 can be manufactured.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say. As an example, a light emitting device using an anode as a lower electrode and a cathode as an upper electrode is illustrated, but conversely, the light emitting device can be appropriately changed to a light emitting device having a lower electrode as a cathode and an upper electrode as an anode.

Claims

(A) a substrate;
(B) a first electrode formed on the substrate;
(C) a partition wall formed on the substrate and extending in the first direction;
(D) a plurality of cell regions partitioned by the partition wall,
Each of the plurality of cell regions is
(E) a light emitting unit;
(F) in a plan view seen from the surface of the substrate on which the first electrode is formed, the light emitting portion and a conduction portion sandwiched between the partition portions,
The light emitting unit
(E1) an organic layer including a light emitting layer formed on the first electrode;
(E2) a second electrode formed on the organic layer,
The conduction part is
(F1) A second electrode auxiliary wiring formed on the substrate and electrically separated from the first electrode and extending in the first direction;
(F2) The light emitting device including the second electrode formed from the organic layer of the light emitting unit to the second electrode auxiliary wiring of the conduction unit.
The light-emitting device according to claim 1,
The second electrode auxiliary wiring is constituted by a first wiring layer disposed in the same layer as the first electrode.
The light-emitting device according to claim 2,
The light emitting device, wherein the second electrode auxiliary wiring is formed of the first wiring layer formed on the substrate and made of the same material as the first electrode.
The light-emitting device according to claim 3,
A light-emitting device, wherein a first electrode auxiliary wiring electrically connected to the first electrode is formed.
The light-emitting device according to claim 4,
The auxiliary wiring for the second electrode is
The first wiring layer formed on the substrate and disposed in the same layer as the first electrode;
A light-emitting device comprising: a second wiring layer formed on the first wiring layer and disposed in the same layer as the first electrode auxiliary wiring.
The light-emitting device according to claim 5,
The auxiliary wiring for the second electrode is
The first wiring layer formed on the substrate and made of the same material as the first electrode;
A light emitting device comprising: the second wiring layer formed on the first wiring layer and formed of the same material as the first electrode auxiliary wiring.
The light-emitting device according to claim 6,
The light emitting device according to claim 1, wherein a resistivity of the second wiring layer is smaller than a resistivity of the first wiring layer.
The light-emitting device according to claim 1,
The first electrode is separated for each of the plurality of cell regions;
Each of the separated first electrodes extends in the first direction.
The light-emitting device according to claim 8,
The second electrode is separated for each of the plurality of cell regions,
Each of the separated second electrodes extends in the first direction.
The light-emitting device according to claim 1,
The width of the bottom of the partition wall is smaller than the width of the top of the partition wall.
The light-emitting device according to claim 10,
The light emitting device according to claim 1, wherein a cross-sectional shape of the partition wall perpendicular to the first direction is an inversely tapered shape.
(A) preparing a substrate;
(B) after the step (a), forming a first conductor film on the substrate;
(C) After the step (b), by patterning the first conductive film, the first electrode and the second electrode auxiliary wiring extending in the first direction with the first electrode interposed between the separated regions And a step of forming
(D) after the step (c), a step of forming a first insulating film so as to bury the separation region provided between the first electrode and the second electrode auxiliary wiring;
(E) after the step (d), forming an opening in the first insulating film and exposing the second electrode auxiliary wiring from the opening;
(F) After the step (e), a partition wall portion extending in the first direction is formed on the substrate, and the light emitting portion and the surface on the side where the first electrode of the substrate is formed by the partition wall portion. In a plan view as seen from the step of partitioning a cell region that is sandwiched between the light emitting portion and the partition wall and includes a conductive portion including the second electrode auxiliary wiring;
(G) After the step (f), a step of forming an organic layer including a light emitting layer on the first electrode of the light emitting unit excluding the conducting portion in the cell region;
(H) After the step (g), the second electrode extends from the organic layer formed in the light emitting section to the second electrode auxiliary wiring exposed from the opening formed in the conducting section. Forming a electrode, and electrically connecting the second electrode auxiliary wiring and the second electrode. A method for manufacturing a light emitting device, comprising:
(A) preparing a substrate;
(B) after the step (a), forming a first conductor film on the substrate;
(C) After the step (b), by patterning the first conductor film, the first electrode made of the first conductor film and the first electrode extend in the first direction through a separation region. Forming the first wiring layer,
(D) after the step (c), forming a second conductor film having a smaller resistivity than the first conductor film so as to cover the first electrode and the first wiring layer;
(E) After the step (d), by patterning the second conductor film, a second wiring layer extending in the first direction is formed on the first wiring layer, and the first wiring layer is formed. And a second electrode auxiliary wiring formed of the second wiring layer, and a first electrode auxiliary wiring formed of the second conductive film extending in the first direction on the first electrode. And a process of
(F) After the step (e), the first insulation is provided so as to cover the first electrode auxiliary wiring and to bury the separation region provided between the first electrode and the second electrode auxiliary wiring. Forming a film;
(G) after the step (f), forming an opening in the first insulating film and exposing the second electrode auxiliary wiring from the opening;
(H) After the step (g), a partition portion extending in the first direction is formed on the first insulating film, and the partition portion forms the light emitting portion and the first electrode of the substrate. In a plan view as seen from the side surface, a step of partitioning a cell region that is sandwiched between the light emitting part and the partition part and includes a conductive part including the second electrode auxiliary wiring;
(I) after the step (h), a step of forming an organic layer including a light emitting layer on the first electrode of the light emitting unit excluding the conducting portion in the cell region;
(J) After the step (i), the second electrode extends from the organic layer formed in the light emitting portion to the second electrode auxiliary wiring exposed from the opening formed in the conducting portion. Forming a electrode, and electrically connecting the second electrode auxiliary wiring and the second electrode. A method for manufacturing a light emitting device, comprising: