JP2007095733A - Electroluminescence device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an EL device in which a luminescence failure due to short-circuit of a cathode and an anode can be prevented and deterioration of a light emitting layer due to invasion of moisture is difficult to occur, and which is superior in reliability. <P>SOLUTION: A pixel region 26 and a peripheral region are formed, and the light emitting layer 20 and a second electrode 21 are continuously arranged in the whole pixel regions 26 and the peripheral regions. First electrodes 19 are arranged in the respective pixel regions 26, and are extensively arranged onto contact holes 23 corresponding to the pixel regions from the respective pixel regions 26. An insulating layer 24 is arranged on the first electrode 19 on the contact hole 23 so that the contact hole 23 is filled with the layer 24. The contact hole 23 and the insulating layer 24 are arranged in the peripheral regions detached from the pixel region 26 to constitute the EL device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  2. Description of the Related Art Conventionally, an EL device in which an EL element in which a light emitting layer made of a light emitting material such as an organic EL (Electro Luminescent) material is interposed between a cathode and an anode is arranged on a substrate has been proposed.

In such an EL device, when the light emitting layer is cut off, a short circuit occurs between the cathode and the anode, and current concentrates and flows between the cathode and the anode so that almost no current flows through the light emitting layer. Depending on the case, a light emission failure may occur.
In order to solve this problem, for example, Patent Document 1 discloses a self-luminous device in which a protective portion made of an organic resin film is provided in a gap between an electrode hole or a pixel electrode.
JP 2001-31223 A

  However, in the technique described in Patent Document 1, when the protective portion provided in the electrode hole absorbs water, there is a problem that moisture enters the EL layer and degrades the EL layer. Furthermore, in the technique described in Patent Document 1, when the protection unit provided in the gap between the pixel electrodes absorbs water, moisture enters the EL layers of the plurality of pixels through the protection unit, and the EL layers of the plurality of pixels. It has been a problem to promote the deterioration of.

  The present invention has been made in view of such circumstances, and can prevent a light emission failure due to a short circuit between a cathode and an anode, and is excellent in reliability in which a light emitting layer is not easily deteriorated due to infiltration of moisture. It is an object of the present invention to provide an electronic device that includes the device and the EL device and is less likely to cause a display defect due to a light emission failure or deterioration of the light emitting layer.

  In order to solve this problem, in an EL device according to the present invention, a first electrode, a light emitting layer, and a second electrode are sequentially arranged on a substrate, and light emitted from the light emitting layer is emitted onto the substrate. An electroluminescence device in which a plurality of pixel regions and a peripheral region surrounding each pixel region are formed, wherein the light emitting layer and the second electrode are continuously disposed in all the pixel regions and the peripheral region. The first electrode is disposed in each pixel region and extends from each pixel region to a contact hole corresponding to each pixel region, and is disposed on the contact hole, the first electrode An insulating layer is disposed thereon, and the contact hole and the insulating layer are disposed in the peripheral region apart from the pixel region.

In such an EL device, since the contact hole and the insulating layer are disposed in the peripheral region apart from the pixel region, even if the insulating layer filled in the contact hole absorbs water, It is difficult for moisture to enter the light emitting layer in the region, and there is little influence when the insulating layer absorbs water.
Further, the first electrode on the contact hole is the portion where the step on the first electrode is the largest, and the breakage of the light emitting layer disposed on the first electrode occurs as the step on the first electrode increases. Cheap. In the EL device of the present invention, since the insulating layer filling the contact hole is disposed on the first electrode on the contact hole, the portion with the largest step on the first electrode is flattened by the insulating layer. It becomes. Therefore, it is possible to effectively prevent a light emission failure due to a short circuit between the first electrode and the second electrode due to the disconnection of the light emitting layer.
Therefore, the EL device of the present invention has excellent reliability.

  In order to solve this problem, in an EL device according to the present invention, a first electrode, a light emitting layer, and a second electrode are sequentially arranged on a substrate, and light emitted from the light emitting layer is emitted onto the substrate. An electroluminescence device in which a plurality of pixel regions and a peripheral region surrounding each pixel region are formed, wherein the light emitting layer and the second electrode are continuously disposed in all the pixel regions and the peripheral region. The first electrode is disposed in each pixel region, and extends from each pixel region to a contact hole corresponding to each pixel region, and has an opening that exposes each pixel region, An edge portion is disposed in the peripheral region so as to individually surround the pixel region, and a step formed at the end portion of the first electrode by the film thickness of the first electrode and the first over the contact hole. On one electrode I, wherein the insulating layer filled in the contact hole is disposed.

In such an EL device, an insulating layer is provided that has an opening that exposes each pixel region, and an end portion is disposed in the peripheral region to separately surround the pixel region. Therefore, even if the insulating layer absorbs water, moisture does not enter the light emitting layer in the adjacent pixel region via the insulating layer, and the reliability is small and has little influence when the insulating layer absorbs water. It becomes.
Also, in such an EL device, the contact hole is filled by covering the step formed at the end of the first electrode with the film thickness of the first electrode and the first electrode on the contact hole. Since the insulating layer is arranged as described above, a portion having a large step on the first electrode is flattened by the insulating layer. Therefore, it is possible to effectively prevent a light emission failure due to a short circuit between the first electrode and the second electrode due to the disconnection of the light emitting layer, and the reliability is improved.

In the EL device of the present invention, a light reflecting layer that reflects light emitted from the light emitting layer may be disposed on the substrate side of the light emitting layer disposed in the pixel region.
By using such an EL device, a top emission type EL device that efficiently emits light emitted from the light emitting layer toward the side opposite to the substrate can be realized.

In the EL device of the present invention, the first electrode may be provided on the light reflection layer via a passivation layer.
By using such an EL device, it is possible to prevent the light reflecting layer from being exposed to the etching solution and being eroded during the patterning of the first electrode, and the reliability is improved.
In particular, when the resonant structure is formed by patterning the first electrode a plurality of times, the passivation layer functions as an indispensable element for protecting the light reflecting layer.

In the EL device of the present invention, the insulating layer may be a resin layer.
With such an EL device, the first electrode on the contact hole, which is the portion with the largest step on the first electrode, can be easily covered with high reliability.

An electronic apparatus according to the present invention includes any of the above-described EL devices.
According to such an electronic device, it is possible to realize an electronic device that includes a highly reliable EL device and is less likely to cause display defects due to light emission failure or deterioration of the light emitting layer.

  Hereinafter, an embodiment of the present invention will be described as an example. In the following description, various structures are illustrated using drawings, but the structures shown in these drawings may be shown with different dimensions from the actual structures in order to show the characteristic parts in an easy-to-understand manner. is there.

<First Embodiment>
First, the EL device according to the first embodiment of the present invention will be described.
FIG. 1 is a cross-sectional view showing a cross-sectional structure of an EL device according to this embodiment. FIG. 2 is a diagram showing a planar structure of the EL device shown in FIG. 1, and is a diagram for explaining the arrangement of the insulating layer on the substrate. 1 is a cross-sectional view taken along line AA ′ shown in FIG. Further, in FIG. 2, only the members necessary for explaining the arrangement of the insulating layer on the substrate are shown and the other members are not shown for easy understanding of the drawing.

In FIG. 1 and FIG. 2, the code | symbol 11 has shown the board | substrate. The EL device according to this embodiment is a top emission type in which light generated in the light emitting layer 20 is emitted toward the side opposite to the substrate 11. Therefore, an opaque plate material such as a ceramic or metal sheet can be used as the substrate 11 in addition to a light-transmitting plate material such as glass.
As shown in FIG. 2, a plurality of pixel regions 26 from which light emitted from the light emitting layer 20 shown in FIG. 1 is emitted are formed on the substrate 11 in a matrix. In the present embodiment, a region that overlaps the formation region of the light reflection layer 17 shown in FIG. Further, a peripheral region 28 surrounding each pixel region 26 is formed on the substrate 11. The peripheral region 28 includes an intermediate region 28 a located between adjacent pixel regions 26 and an outer peripheral region 28 b located between the pixel region 26 and the end portion 11 a of the substrate 11.

Moreover, in FIG. 1, the code | symbol 12 has shown the base layer. The underlayer 12 is a film body formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx).
On the underlayer 12, TFTs 30 and 40 are provided. The TFTs 30 and 40 include gate electrodes 31 and 41, drain wirings 32 and 42 connected to the drain electrode, source wirings 33 and 43 connected to the source electrode, and semiconductor layers 34 and 44. Reference numeral 13 denotes a gate insulating film, and reference numeral 14 denotes an interlayer insulating film.

On the TFTs 30 and 40, a first passivation layer 15 made of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx) is formed along the shape of the TFTs 30 and 40. Further, on the first passivation layer 15, a planarizing layer 16 for planarizing the substrate 11 on which the TFTs 30 and 40 are formed is provided. As the planarizing layer 16, an organic resin material such as an acrylic resin, a polyimide resin, or a polyamide resin can be used.
On the surface of the substrate 11 on which the planarizing layer 16 is formed, the light reflecting layer 17 is formed at a position corresponding to each pixel region 26. The light reflecting layer 17 reflects light emitted from the light emitting layer 20, and is made of various light reflective materials such as a single metal such as aluminum or silver, or an alloy mainly composed of aluminum or silver.

  A second passivation layer 18 is formed along the surface shape on the surface of the substrate 11 on which the planarizing layer 16 is formed. The second passivation layer 18 is formed of an insulating material having optical transparency such as silicon oxide (SiOx) or silicon nitride (SiNx).

  A pixel electrode (first electrode) 19 made of a light-transmitting conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is formed on the second passivation layer 18. As shown in FIG. 1, the pixel electrode 19 is disposed in each pixel region 26 and extends from each pixel region 26 to the contact hole 23 corresponding to each pixel region 26.

  The contact hole 23 is for electrically connecting the pixel electrode 19 and the drain wiring 42 of the TFT 40 exposed through the first passivation layer 15, the planarization layer 16, and the second passivation layer 18. is there. In the present embodiment, the contact hole 23 is formed in the intermediate region 28a or the outer peripheral region 28b so as to be separated from the pixel region 26, as shown in FIGS.

  As shown in FIGS. 1 and 2, an insulating layer 24 filling the contact hole 23 is disposed on the pixel electrode 19 on the contact hole 23. The insulating layer 24 is spaced apart from the pixel region 26 and arranged in an island shape in the plan view in the intermediate region 28a or the outer peripheral region 28b, and is independently associated with a contact hole formed in the vicinity of each pixel region 26. Is formed. As the insulating layer 24, an organic resin material such as an acrylic resin, a polyimide resin, or a polyamide resin can be used, but it is preferable to use the same material as the planarizing layer 16. When the insulating layer 24 is made of the same material as the planarizing layer 16, the material can be used efficiently. The insulating layer 24 can be formed by a photolithography technique, an etching technique, or a droplet discharge method such as an ink jet method, but when formed by a droplet discharge method such as an ink jet method, the manufacturing process is simplified. I can plan.

On the surface of the substrate 11 on which the insulating layer 24 is formed, the light emitting layer 20 and the second electrode 21 are continuously arranged in all the pixel regions 26 and the intermediate region 28a.
The light emitting layer 20 has a structure in which a plurality of functional layers including a light emitting layer made of an organic EL material are stacked. The pixel electrode 19 functions as an anode for applying electric energy to the light emitting layer 20. On the other hand, a second electrode 21 that functions as a cathode of the light emitting layer 20 is formed on the surface of each light emitting layer 20. However, the pixel electrode 19 may function as a cathode and the second electrode 21 may function as an anode.

  The light emitting layer 20 in the present embodiment has a structure in which three types of functional layers, a hole transport layer, a light emitting functional layer, and an electron transport layer, are laminated in this order from the substrate 11 side to the second electrode 21 side. . However, the structure of the light emitting layer 20 is not limited to this example. For example, a configuration in which a hole injection layer is interposed between the hole transport layer and the pixel electrode 19 or a configuration in which an electron injection layer is interposed between the electron transport layer and the second electrode 21 may be employed. In other words, a configuration in which a light emitting functional layer is interposed between the pixel electrode 19 and the second electrode 21 is sufficient.

  The second electrode 21 is formed of a light-transmitting material such as ITO (Indium Tin Oxide). A third passivation layer 22 is formed on the surface of the second electrode 21 so as to cover the entire surface. The third passivation layer 22 is formed of an insulating material having optical transparency such as silicon oxide (SiOx) or silicon nitride (SiNx).

Here, the effects of the above-described EL device according to the present embodiment will be described in detail below in proportion.
FIG. 5 is a diagram illustrating a planar structure of the EL device according to the comparative example, and corresponds to FIG. 2 in the first embodiment described above. In FIG. 5, the same parts as those in FIG. 2 are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

The EL device shown in FIG. 5 differs from the EL device shown in FIG. 2 only in the arrangement of the insulating layer on the substrate. Specifically, in the EL device shown in FIG. 2, the insulating layer 24 is arranged in an island shape in a plan view in the intermediate region 28a or the outer peripheral region 28b, and the contact hole 23 formed in the vicinity of each pixel region 26. Are formed independently of each other.
On the other hand, in the EL device shown in FIG. 5, the insulating layer 240 is disposed on the entire surface of the intermediate region 28 a and the outer peripheral region 28 b and the region overlapping the peripheral portion of the formation region of the light reflecting layer 17 in a plane. The insulating layer 240 is provided with an opening 280 that exposes only each pixel region 26 that is a region that overlaps the central portion of the light reflecting layer 17 in a planar manner.
In the EL device shown in FIG. 5, the pixel region 26 becomes the formation region of the opening 280 because the insulating layer 240 is also provided in a region overlapping the peripheral portion of the formation region of the light reflection layer 17 in a plan view. ing.

  In the EL device shown in FIG. 5, when the insulating layer 240 absorbs water, the water easily reaches the light emitting layer in the pixel region 26. In addition, even if the portion absorbed by the insulating layer 240 is not the entire insulating layer 240 but a part thereof, not only the pixel region 26 closest to the absorbed portion but also the light emission of the pixel region 26 adjacent to the pixel region 26. Water easily enters the layer through the insulating layer 240. For this reason, the influence when the insulating layer 240 absorbs water covers a wide range.

  On the other hand, in the EL device shown in FIG. 2, the insulating layer 24 is spaced apart from the pixel region 26 and arranged in the intermediate region 28 a or the outer peripheral region 28 b in an island shape in plan view, and in the vicinity of each pixel region 26. Since the contact holes 23 are formed independently of each other, even if the insulating layer 24 absorbs water, moisture does not easily enter the light emitting layer of the pixel region 26 and the insulating layer 24 is interposed. In addition, moisture does not enter the light emitting layer of the adjacent pixel region 26. Therefore, the EL device shown in FIG. 2 has excellent reliability with very little influence when the insulating layer 24 absorbs water.

  In the EL device shown in FIG. 2, since the insulating layer 24 is disposed on the contact hole 23 and on the pixel electrode 19 so as to fill the contact hole 23, as shown in FIG. The portion having the largest step on 19 is flattened by the insulating layer 24. Therefore, it is possible to effectively prevent a light emission failure due to a short circuit between the pixel electrode 19 and the second electrode 21 due to the disconnection of the light emitting layer 20.

Second Embodiment
Next, an EL device according to a second embodiment of the invention will be described.
FIG. 3 is a cross-sectional view showing a cross-sectional structure of the EL device according to this embodiment. FIG. 4 is a diagram showing a planar structure of the EL device shown in FIG. 3, and is a diagram for explaining the arrangement of the insulating layer on the substrate. 3 is a cross-sectional view taken along line BB ′ shown in FIG. Further, in FIG. 4, in order to make the drawing easier to see, only members necessary for explaining the arrangement of the insulating layer on the substrate are shown, and the description of other members is omitted.
3 and 4, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

The EL device shown in FIGS. 3 and 4 differs from the EL device shown in FIGS. 1 and 2 only in the arrangement of the insulating layer on the substrate.
In the EL device of this embodiment, as shown in FIGS. 3 and 4, the insulating layer 25 has an opening 25b that exposes each pixel region 27, and the intermediate region 28a (or the intermediate region 28a and the outer peripheral region 28b) B) by arranging the end portion 25a so as to individually surround and surround the plurality of pixel regions 27, and as shown in FIG. 3, the step formed on the end portion of the pixel electrode 19 by the film thickness of the pixel electrode 19 The step formed at the end of the light reflecting layer 17 by the film thickness of the light reflecting layer 17 and the pixel electrode 19 on the contact hole 23 are covered and filled in the contact hole 23.
As shown in FIGS. 3 and 4, in the EL device of this embodiment, the insulating layer 25 is also provided in the region overlapping the peripheral edge of the region where the light reflecting layer 17 is formed, thereby providing a pixel. The region 27 is a region where the opening 25b is formed.

In the EL device shown in FIG. 3 and FIG. 4, the insulating layer 25 has an opening 25 b that exposes each pixel region 27, and the end portion 25 a is arranged in the peripheral region 28, whereby a plurality of pixel regions 27 are individually separated. Since they are formed so as to be separated and surrounded independently, even if the insulating layer 25 absorbs water, moisture does not enter the light emitting layer of the adjacent pixel region 27 via the insulating layer 25. Therefore, the EL device is excellent in reliability with very little influence when the insulating layer 25 absorbs water.
In the EL device shown in FIGS. 3 and 4, the insulating layer 25 has a light reflecting layer formed by the step formed at the end of the pixel electrode 19 by the film thickness of the pixel electrode 19 and the film thickness of the light reflecting layer 17. 17 covers the pixel electrode 19 on the contact hole 23 and the pixel electrode 19 on the contact hole 23, and is filled in the contact hole 23, so that the large step on the pixel electrode 19 is flattened by the insulating layer 25. Is done. Therefore, it is possible to effectively prevent a light emission failure due to a short circuit between the pixel electrode 19 and the second electrode 21 due to the disconnection of the light emitting layer 20 and to have excellent reliability.

Various modifications can be made to the above-described embodiment.
For example, in the above-described embodiment, the example in which the light reflecting layer 17 is formed has been described as an example, but the light reflecting layer 17 may not be provided.

<Electronic equipment>
Next, an electronic apparatus using the light emitting device according to the present invention will be described.
FIG. 6 shows a configuration of a mobile phone to which the EL device shown in FIG. 1 is applied as a display device. A cellular phone 1000 includes a plurality of operation buttons 1001, scroll buttons 1002, and an EL device 1004 as a display device.

Note that electronic devices to which the light emitting device according to the present invention is applied include those shown in FIG. 6, personal computers, digital still cameras, televisions, video cameras, car navigation devices, pagers, electronic notebooks, electronic papers, calculators. , Word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices equipped with touch panels, and the like.
Further, the use of the light emitting device according to the present invention is not limited to the display of images. For example, the light emitting device of the present invention can be used as a backlight of a liquid crystal panel.

FIG. 1 is a cross-sectional view showing a cross-sectional structure of an EL device according to this embodiment. FIG. 2 is a diagram showing a planar structure of the EL device shown in FIG. 1, and is a diagram for explaining the arrangement of insulating layers on the substrate. FIG. 3 is a cross-sectional view showing a cross-sectional structure of the EL device according to this embodiment. FIG. 4 is a diagram showing a planar structure of the EL device shown in FIG. 3, and is a diagram for explaining the arrangement of the insulating layer on the substrate. FIG. 5 is a diagram illustrating a planar structure of the EL device according to the comparative example, and corresponds to FIG. 2 in the first embodiment described above. It is the perspective view which showed an example of the electronic device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Board | substrate, 12 ... Underlayer, 13 ... Gate insulating film, 14 ... Interlayer insulating film, 15 ... 1st passivation layer, 16 ... Planarization layer, 17 ... Light reflection layer, 18 ... 2nd passivation layer, 19 ... Pixel Electrode (first electrode), 20 ... light emitting layer, 21 ... second electrode, 22 ... third passivation layer, 23 ... contact hole, 24, 25, 240 ... insulating layer, 25a ... end, 25b, 280 ... opening, 26, 27 ... Pixel region, 28 ... Peripheral region, 28a ... Intermediate region, 28b ... Outer peripheral region, 30, 40 ... TFT, 31, 41 ... Gate electrode, 32, 42 ... Drain wiring, 33, 43 ... Source wiring.

Claims (6)

A first electrode, a light emitting layer, and a second electrode are sequentially disposed on the substrate,
An electroluminescence device in which a plurality of pixel regions from which light emitted from the light emitting layer is emitted and a peripheral region surrounding each pixel region are formed on the substrate,
The light emitting layer and the second electrode are continuously disposed in all the pixel region and the peripheral region,
The first electrode is disposed in each pixel region and extends from each pixel region to a contact hole corresponding to each pixel region,
An insulating layer is disposed on the contact hole and on the first electrode;
The electroluminescence device according to claim 1, wherein the contact hole and the insulating layer are arranged in the peripheral region apart from the pixel region. A first electrode, a light emitting layer, and a second electrode are sequentially disposed on the substrate,
An electroluminescence device in which a plurality of pixel regions from which light emitted from the light emitting layer is emitted and a peripheral region surrounding each pixel region are formed on the substrate,
The light emitting layer and the second electrode are continuously disposed in all the pixel region and the peripheral region,
The first electrode is disposed in each pixel region and extends from each pixel region to a contact hole corresponding to each pixel region,
Having an opening exposing each pixel region;
Surrounding the pixel regions separately by being arranged with an end in the peripheral region,
An insulating layer is disposed to cover the step formed at the end of the first electrode by the film thickness of the first electrode and the first electrode on the contact hole, and fill the contact hole. An electroluminescence device characterized by comprising:   3. The electro according to claim 1, wherein a light reflection layer that reflects light emitted from the light emitting layer is disposed on the substrate side of the light emitting layer disposed in the pixel region. Luminescence device.   The electroluminescent device according to claim 3, wherein the first electrode is provided on the light reflecting layer via a passivation layer.   The electroluminescent device according to any one of claims 1 to 4, wherein the insulating layer is a resin layer. An electronic apparatus comprising the electroluminescence device according to any one of claims 1 to 5.

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