JP4444042B2 - Display device - Google Patents

Description

  The present invention relates to a display device. In particular, the present invention relates to a display device that emits light from a light emitting layer by applying a voltage with the light emitting layer sandwiched between two electrodes. An example of such a display device is an organic EL (Electro Luminescence) display device.

  In a display device that emits light from a light-emitting layer by applying a voltage by sandwiching the light-emitting layer between two electrodes, the pixel electrode, the light-emitting layer, and the counter electrode are generally stacked in this order from the substrate. Yes. The pixel electrodes are arranged corresponding to the respective pixels and are controlled by TFT (Thin Film Transistor) elements. The counter electrode extends integrally in common to the plurality of pixels, and is connected to the input terminal in a region that is not the display region. There are several known structures for extracting the counter electrode and connecting it to the input terminal.

  For example, in FIG. 1 (Patent Document 1) of Japanese Patent Application Laid-Open No. 2003-229250, the third inorganic insulating layer 116 is formed on the upper surface of the first organic insulating layer 115 in the connection portion 130 that connects the cathode layer 131 to the lead wiring. A metal wiring is formed on the upper side of the metal wiring, and a cathode layer 131 corresponding to the counter electrode is connected to the metal wiring by a contact hole penetrating the second organic insulating layer 128.

  In FIGS. 17 and 18 and Japanese Patent Laid-Open No. 2001-52864, paragraphs 0185 to 0189 (Patent Document 2), an opening 1802 in which the input wiring 1709 is exposed by removing the second interlayer insulating film 347 made of an organic resin. , The protective electrode 352 corresponding to the counter electrode is electrically connected to the input wiring 1709.

In FIG. 7 (Patent Document 3) of Japanese Patent Laid-Open No. 2002-151253 (Patent Document 3), the connection from the cathode 708 corresponding to the counter electrode to the input terminal 705 is made through an opening provided in the partition 709. Is done directly through.
Japanese Patent Laying-Open No. 2003-229250 (FIG. 1) JP 2001-52864 A (FIGS. 17 and 18, paragraphs 0185 to 0189) Japanese Patent Laying-Open No. 2002-151253 (FIG. 7)

  In the case where the light emitting layer is an organic EL layer, the light emitting layer deteriorates due to the ingress of moisture. In the structure of Patent Document 1, when a defect such as a pinhole occurs in the inorganic insulating layer, there is a problem that moisture propagates from there to the pixel region and element deterioration occurs.

  In the structure of Patent Document 2, when an opening is provided in an interlayer insulating film made of an organic resin, the conductive layer on the bottom surface of the opening is removed, so that the input wiring located on the bottom surface of the opening is removed from the conductive layer. It is necessary that the material is not damaged even by etching at the time. Therefore, there is a problem in that there are restrictions on the combinations of materials that can be selected.

  Therefore, an object of the present invention is to provide a display device that can prevent deterioration due to moisture and reduce the degree to which the lower wiring is damaged by etching.

  In order to achieve the above object, a display device according to the present invention includes a substrate having a display region and a counter electrode connection region in plan view, an organic planarization film disposed on the upper side of the substrate, and the organic planarization. A pixel electrode disposed in the display region on the upper side of the film; a light emitting layer disposed to cover at least a part of the upper side of the pixel electrode; and a region in which the light emitting layer overlaps the upper side of the pixel electrode And disposed on the surface of the substrate in a state of being electrically connected to the pixel electrode, and a counter electrode extending to the counter electrode connection region. A transistor element; and an external terminal lead conductive layer formed in the counter electrode connection region using the same material as the SD wiring electrically connected to the source / drain region of the transistor element, In the counter electrode connection region, the counter electrode is electrically connected to the external terminal lead conductive layer via a mediation conductive layer covering the lower side of the counter electrode, and the organic planarization film is formed of the counter electrode. It has a part divided along at least a side near the display area of the connection area.

  According to the present invention, the display device has a structure without the organic flattening film 8 that easily contains moisture along at least the side of the counter electrode connection region 75 near the display region 73. Moisture from 75 to the light emitting layer 11 can be eliminated.

(Embodiment 1)
(Constitution)
With reference to FIG. 1 and FIG. 2, the display apparatus in Embodiment 1 based on this invention is demonstrated. This display device is an organic EL display device. As shown in FIG. 1, the display device includes a substrate 1 having a display area 73 and a counter electrode connection area 75 when viewed in a plan view. Further, this display device is disposed in the display region 73 above the organic planarization film 8, and the organic planarization film 8 disposed above the substrate 1 via the interlayer insulation film 6 and the first inorganic insulation film 7. The pixel electrode 9 formed, the light emitting layer 11 disposed so as to cover at least part of the upper side of the pixel electrode 9, and the upper side of the light emitting layer 11 in a region where the light emitting layer 11 overlaps the upper side of the pixel electrode 9 And the counter electrode 12 extending to the counter electrode connection region 75. The light emitting layer 11 is an organic EL layer.

  Further, the display device includes a transistor element 2 disposed on the surface of the substrate 1 in a state of being electrically connected to the pixel electrode 9 and an SD wiring electrically connected to a source / drain region of the transistor element 2. 32. Furthermore, the external terminal lead conductive layer 14 formed of the same material as the SD wiring 32 in the counter electrode connection region 75 is provided. The pixel electrode 9 may extend to the outside of the display area 73.

  The counter electrode connection region 75 is a region that relays electrical extraction from the counter electrode 12 to the external terminal. The external terminal leading conductive layer 14 disposed in this region is a conductor portion that is responsible for electrical connection to the external terminal. In the counter electrode connection region 75, the counter electrode 12 is electrically connected to the external terminal lead conductive layer 14 through the intermediate conductive layer 15 covering the lower side of the counter electrode 12. The counter electrode 12 and the intermediate conductive layer 15 are in direct contact. The intermediate conductive layer 15 and the external terminal lead conductive layer 14 are connected via a contact portion 21 provided so as to penetrate the first inorganic insulating film 7.

  The organic planarization film 8 has a portion divided along at least the side near the display region 73 of the counter electrode connection region 75. In the example of FIG. 1, the organic planarizing film 8 is disposed avoiding the counter electrode connection region 75. That is, not only the side of the counter electrode connection region 75 near the display region 73 but also the inside of the counter electrode connection region 75 is free of the organic planarization film 8. This corresponds to a state in which the film 8 has a portion divided along at least the side near the display region 73 of the counter electrode connection region 75.

  A part of the intermediate conductive layer 15 covers the organic planarizing film, but the overlap amount d is preferably less than the manufacturing margin in the device formation. FIG. 2 shows a plan view displaying the degree of overlap of each part in an easy-to-understand manner.

(Action / Effect)
In the display device according to the present embodiment, the organic planarizing film 8 is disposed so as to avoid the counter electrode connection region 75, that is, contains moisture from the lower side of the intermediate conductive layer 15 located in the counter electrode connection region 75. Since the organic flattening film 8 is not easily formed, moisture from the counter electrode connection region 75 to the light emitting layer 11 can be eliminated. Further, it is possible to block moisture that propagates from the periphery of the substrate 1 through the organic planarization film 8 as a path. Accordingly, a reduction in luminance due to deterioration of the light emitting layer 11 due to moisture intrusion can be prevented, so that reliability as a display device is improved.

  In addition, the external terminal lead-out conductive layer 14, which is a conductor portion responsible for electrical connection to the external terminal, is not directly connected from the counter electrode 12 but via the intermediate conductive layer 15. Therefore, the degree of freedom of the combination of materials of the external terminal leading conductive layer 14 and the intermediate conductive layer 15 is increased. In the counter electrode connection region 75, the intermediate conductive layer 15 is electrically connected to the external terminal lead conductive layer 14 at a plurality of locations. There is an advantage that the connection can be maintained as a whole even if one of the above is disconnected due to some trouble.

(Embodiment 2)
(Constitution)
With reference to FIG. 3, the display device in Embodiment 2 based on this invention is demonstrated. Like this display device, the organic planarization film 8 and the intermediate conductive layer 15 may be completely isolated without overlapping portions. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
The display device according to the present embodiment has a structure without the organic planarization film 8 that easily contains moisture from the lower side of the intermediate conductive layer 15 located in the counter electrode connection region 75. It is possible to eliminate moisture from the light emitting layer 11 to the light emitting layer 11. Accordingly, a decrease in luminance due to deterioration of the light emitting layer 11 due to moisture intrusion can be prevented, so that reliability as a display device is improved.

(Embodiment 3)
(Constitution)
With reference to FIG. 4, the display apparatus in Embodiment 3 based on this invention is demonstrated.
As in this display device, a raised layer may be disposed in a region directly below the intermediate conductive layer 15 and directly above the external terminal lead conductive layer 14. The raised layer in this case is a locally thickened first inorganic insulating film 7 and is shown as a raised portion 7a in FIG. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device according to the present embodiment, the step at the boundary between the organic planarizing film 8 and the first inorganic insulating film 7 is reduced, so that the counter electrode 12 can be prevented from being disconnected due to the step. Therefore, even better display characteristics can be obtained. In FIG. 4, the upper surfaces of the organic planarizing film 8 and the first inorganic insulating film 7 are substantially coincident with each other, but are not necessarily coincident.

  In the present embodiment, it has been explained that the raised layer is a locally thickened first inorganic insulating film 7. In this case, “the locally thickened” means the first inorganic insulating film 7. When forming the first inorganic insulating film 7, the number of locally stacked layers is not limited to the case where a locally thick structure is formed as a single layer. The thickness may be increased by increasing the thickness. In other words, in this case, the raised layer is a portion where the first inorganic insulating film 7 is locally laminated and the thickness is increased.

(Embodiment 4)
(Constitution)
With reference to FIG. 5, a display device according to Embodiment 4 of the present invention will be described. As in this display device, an insulating film thicker than the insulating films in other regions may be disposed as a raised layer in the region directly below the external terminal leading conductive layer 14. In the example of FIG. 5, a second inorganic insulating film 16 different from the first inorganic insulating film 7 is disposed as a raised layer directly below the external terminal lead conductive layer 14. The same material as the inorganic insulating film 7 or a different material may be used. Further, the interlayer insulating film 6 and the second inorganic insulating film 16 may be formed in separate steps or in the same step. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device according to the present embodiment, the step at the boundary between the organic planarizing film 8 and the first inorganic insulating film 7 is reduced, so that the counter electrode 12 can be prevented from being disconnected due to the step. Furthermore, since the height difference to which the contact portion 21 should be connected can be reduced, it is possible to prevent the intermediate conductive layer 15 from being disconnected when the contact portion 21 is formed. Therefore, even better display characteristics can be obtained. The first inorganic insulating film 7 and the interlayer insulating film 6 may be the same material or different materials. As a different material, for example, a combination of SiN and SiO ₂ may be used.

  The second inorganic insulating film 16 may be formed of the same material as the interlayer insulating film 6 in the same process. In that case, in other words, the raised layer is a portion in which the lower layer of the external terminal lead conductive layer 14 protrudes locally in the counter electrode connection region 75. Alternatively, the second inorganic insulating film 16 may be the same material as the first inorganic insulating film 7.

(Embodiment 5)
(Constitution)
With reference to FIG. 6, the display apparatus in Embodiment 5 based on this invention is demonstrated. As in this display device, a step-break prevention film 18 may be formed on the upper side of the intermediate conductive layer 15. It is advantageous if the step-break prevention film 18 is formed of the same material at the same time when the pixel separation film 17 used for separating the pixel areas in the display area 73 (see FIG. 1) is formed. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device in this embodiment mode, it is possible to prevent the counter electrode 12 from being disconnected due to the steps of the end faces of the respective layers, and thus better display characteristics can be obtained. When this structure is used, the step-break prevention film 18 itself becomes a moisture diffusion path to prevent moisture from entering the light-emitting layer 11 and the like, and then the light-emitting layer is sufficiently dehydrated. 11 and the counter electrode 12 are preferably formed.

(Embodiment 6)
(Constitution)
With reference to FIG. 7, a display device according to Embodiment 6 of the present invention will be described. Like this display device, the intermediate conductive layer 15 may be narrower than the external terminal leading conductive layer 14. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device according to the present embodiment, since the clearance of the positional relationship when viewed from above the intermediate conductive layer 15 and the organic planarizing film 8 can be ensured, manufacture becomes easy.

(Embodiment 7)
(Constitution)
With reference to FIG. 8, the display apparatus in Embodiment 7 based on this invention is demonstrated. In the embodiments described so far, the connection between the intermediate conductive layer 15 and the external terminal lead conductive layer 14 is performed such that the plurality of contact portions 21 are connected in parallel through the plurality of openings. As in the display device according to the embodiment, the intermediate conductive layer 15 and the external terminal lead conductive layer 14 have only a large opening and are collectively connected by a contact portion 21c disposed in the opening. There may be. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
Even in the case where there is anxiety in connection with a contact portion having a small-area opening, the display device in the present embodiment is surely connected by the contact portion 21c through the opening having a relatively large area, so that the intermediate conduction can be ensured. The layer 15 and the external terminal lead conductive layer 14 can be connected. In this case, it is necessary to pay attention to the stress of the intermediate conductive layer 15.

  Instead of the structure shown in FIG. 8, a structure as shown in FIG. 9 may be used. In the structure shown in FIG. 9, the intermediate conductive layer 15 is narrower than the external terminal lead conductive layer 14.

(Embodiment 8)
(Constitution)
With reference to FIG. 10, a display device according to Embodiment 8 of the present invention will be described. In this display device, the external terminal leading conductive layer 14 is connected to the gate conductive layer 33 through the contact portion 22. The gate conductive layer 33 is disposed below the interlayer insulating film 6, and the contact portion 22 is formed so as to penetrate the interlayer insulating film 6. The external terminal lead conductive layer 14 has an island shape, and the SD wiring 32 is formed between the external terminal lead conductive layers 14. The configuration of other parts is the same as that shown in the first embodiment.

(Action / Effect)
According to the display device in this embodiment, the electrical resistance from the wiring in the pixel to the circuit outside the pixel can be reduced, so that the signal delay can be reduced. In the case of this arrangement, in order to reduce the capacitance generated in the intersecting region between the wirings, in the region where the intermediate conductive layer 15 and the gate conductive layer 33 intersect with the external terminal leading conductive layer 14, a thick insulation is provided between them. It is desirable to form a film.

  In FIG. 10, the contact portion 22 appears to overlap the same position as the contact portion 21 connecting the intermediate conductive layer 15 and the external terminal lead conductive layer 14, but is not necessarily in the same position. It does not have to be.

(Embodiment 9)
(Constitution)
With reference to FIG. 11, a display device according to Embodiment 9 of the present invention will be described. In this display device, as shown in FIG. 11, the organic planarization film in the divided region 76 adjacent to the counter electrode connection region 75 is removed. In the counter electrode connection region 75, the organic flattening film is not completely removed but remains as the organic flattening film 8r. In the counter electrode connection region 75, the counter electrode 12 is formed so as to cover the upper side of the organic planarizing film 8r with the intermediate conductive layer 15 interposed therebetween. The counter electrode 12 and the intermediate conductive layer 15 are directly connected, and the intermediate conductive layer 15 and the external terminal lead conductive layer 14 are formed so as to penetrate the first inorganic insulating film 7 and the organic planarizing film 8r. It is connected through the contact portion 21d through the opening. Therefore, the counter electrode 12 is electrically connected to the external terminal leading conductive layer 14 via the intermediate conductive layer 15.

  In this display device, as shown in FIG. 11, the organic planarization film is not present in the divided region 76 surrounding the counter electrode connection region 75. However, it is not essential that the dividing region 76 surrounds the counter electrode connection region 75, and the dividing region 76 only needs to exist along at least the side near the display region 73 of the counter electrode connection region 75. In other words, in this display device, the organic planarization film 8 has a portion divided along at least the side of the counter electrode connection region 75 near the display region 73. The configuration of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device according to the present embodiment, an organic flattening film that easily contains moisture is left below the intermediate conductive layer 15 of the counter electrode 12 in the counter electrode connection region 75. Since the organic planarization film is removed in the divided region 76 that surrounds the periphery of the counter electrode connection region 75 and extends along at least the side of the counter electrode connection region 75 near the display region 73, the light emitting layer 11 (see FIG. 1) is removed. The water intrusion route leading to (see) can be blocked. Further, it is possible to block moisture that propagates from the periphery of the substrate 1 through the organic planarization film 8 as a path. Accordingly, a reduction in luminance due to deterioration of the light emitting layer 11 due to moisture intrusion can be prevented, so that reliability as a display device is improved.

(Embodiment 10)
(Constitution)
With reference to FIG. 12, the display apparatus in Embodiment 10 based on this invention is demonstrated. Like this display device, the intermediate conductive layer 15 in the counter electrode connection region 75 may be interrupted in the middle of the upper surface of the organic planarizing film 8r. The structure of other parts is the same as that shown in the first embodiment.

(Action / Effect)
In the display device according to the present embodiment, there is a margin in the arrangement of the intermediate conductive layer 15, the organic planarizing film 8r, and the organic planarizing film 8 in the display region 73 (see FIG. 1).

  In the example of FIGS. 11 and 12, a plurality of portions are removed and opened in the organic planarization film 8r for forming the contact portion 21d, but the removal region of the organic planarization film 8r is a counter electrode. The connection region 75 may be formed in any way. In other words, an opening having a large area may be provided and connected as in the contact portion 21c shown in FIGS.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the display apparatus in Embodiment 1 based on this invention. It is a top view of the display apparatus in Embodiment 1 based on this invention. It is sectional drawing of the display apparatus in Embodiment 2 based on this invention. It is sectional drawing of the display apparatus in Embodiment 3 based on this invention. It is sectional drawing of the display apparatus in Embodiment 4 based on this invention. It is sectional drawing of the display apparatus in Embodiment 5 based on this invention. It is sectional drawing of the display apparatus in Embodiment 6 based on this invention. It is sectional drawing of the display apparatus in Embodiment 7 based on this invention. It is sectional drawing of the modification of the display apparatus in Embodiment 7 based on this invention. It is a top view of the display apparatus in Embodiment 8 based on this invention. It is sectional drawing of the display apparatus in Embodiment 9 based on this invention. It is sectional drawing of the display apparatus in Embodiment 10 based on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Substrate, 2 TFT, 6 Interlayer insulation film, 7 1st inorganic insulation film, 7a Raised part, 8 Organic planarization film, 8r Organic planarization film (remaining in counter electrode connection area), 9 Pixel electrode, 11 Light emission Layer, 12 Counter electrode, 14 External terminal lead conductive layer, 15 Mediator conductive layer, 16 Second inorganic insulating film, 17 Pixel isolation film, 18 Step break prevention film, 21, 21c, 21d (Medium conductive layer and external terminal lead Contact portion (with the conductive layer), 22 contact portion (with the gate conductive layer and the external terminal leading conductive layer), 31 gate wiring, 32 SD wiring, 33 gate conductive layer, 73 display region, 75 counter electrode connection region, 76 A dividing region (in which the organic flattening film is divided).

Claims (9)

A substrate having a display area and a counter electrode connection area in plan view;
An organic planarization film disposed on the upper side of the substrate;
A pixel electrode disposed in the display region above the organic planarization film;
A light emitting layer arranged to cover at least a part of the upper side of the pixel electrode;
A counter electrode disposed to cover the upper side of the light emitting layer in a region where the light emitting layer overlaps the upper side of the pixel electrode, and further extending to the counter electrode connection region;
A transistor element disposed on a surface of the substrate in a state of being electrically connected to the pixel electrode;
An external terminal lead conductive layer formed in the counter electrode connection region with the same material as the SD wiring electrically connected to the source / drain region of the transistor element;
In the counter electrode connection region, the counter electrode is electrically connected to the external terminal lead conductive layer through an intermediate conductive layer covering the lower side of the counter electrode,
The said organic planarization film | membrane is a display apparatus which has the location divided | segmented along the edge near the said display area | region of the said counter electrode connection area | region.   The display device according to claim 1, wherein the intermediate conductive layer is electrically connected to the external terminal lead conductive layer at a plurality of locations in the counter electrode connection region.   The display device according to claim 1, wherein the organic planarization film is disposed so as to avoid the counter electrode connection region.   In the counter electrode connection region, a raised layer is disposed at a position above the substrate and below the upper surface of the intermediate conductive layer, whereby the upper surface of the organic planarization film and the upper surface of the raised layer The display device according to claim 3, wherein the heights are substantially the same.   The first inorganic insulating film is interposed between the organic planarization film and the substrate, and the raised layer is a portion where the first inorganic insulating film extends to increase the thickness. 4. The display device according to 4.   A first inorganic insulating film is interposed between the organic planarization film and the substrate, and the raised layer is a portion in which the first inorganic insulating film is locally stacked to increase the thickness. The display device according to claim 4.   5. The display device according to claim 4, wherein the raised layer is a second inorganic insulating film interposed between the external terminal extraction conductive layer and the substrate in the counter electrode connection region.   5. The display device according to claim 4, wherein the raised layer is a portion in which a lower layer of the conductive layer for extracting the external terminal protrudes locally in the counter electrode connection region.   5. The display device according to claim 1, wherein a step-break prevention film is disposed so as to continuously cover the upper side of the intermediate conductive layer and the upper side of the organic planarization film. .

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