JP2007103314A - Organic el display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display panel, equipped with a sealing structure capable of suppressing dark spot generation by reducing damages to an organic EL element caused by a load received by a sealing member receiving load. <P>SOLUTION: In the organic EL display panel 1 that has an array substrate 4, in which a display part 2 has been formed by arranging a plurality of organic EL elements 20 into a matrix form, has a sealing member 5 arranged facing the array substrate 4 at a prescribed spacing with the display panel 2, and where recessed parts 7 are installed on the inner face sides facing the display part 2, has desiccants 9 arranged at the recessed parts 7, and has sealing materials 11 for sealing the sealing member 5 to the array substrate; a thick wall part 6 to reinforce the sealing part 5 is installed in the recessed parts 7, and the desiccants 9 are arranged in hollows 8 except the thick wall part 6 in the recessed parts 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic EL display panel, and relates to a structure for preventing damage to an organic EL element by a sealing member.

  An organic EL (electroluminescence) element is a self-luminous element using an organic compound material that emits light by recombination of holes and electrons. In recent years, an organic EL display panel using the organic EL element has been used as a liquid crystal display. It attracts attention as a flat display device that replaces the device.

  An organic EL display panel is formed by arranging a plurality of pixels including an organic EL element and a TFT for driving the organic EL element in a matrix on a glass substrate. Since the organic compound material used for the organic EL element has a property that light emission characteristics are reduced due to moisture or the like, the display portion formed on the glass substrate is sealed by a sealing member provided with a desiccant. There has been proposed an organic EL display panel that employs a sealing structure that prevents intrusion and adsorbs and removes moisture in the atmosphere of the sealed space with a desiccant disposed in the sealed space (see, for example, Patent Document 1). .

As shown in FIG. 8A, the organic EL display panel 100 includes a glass substrate 102 on which a display unit 104 is formed, and a seal disposed so as to face the glass substrate 102 at a predetermined interval from the display unit 104. The stop member 106 is fixed and sealed through the sealing material 108 by applying a load to the sealing member 106, and a recess 110 that faces the display unit 104 is formed on the inner surface side of the sealing member 106. And the sealing structure which arrange | positions the desiccant 112 in the center part is employ | adopted. Thereby, moisture can be prevented from entering, and moisture in the sealed space atmosphere can be adsorbed and removed.
Japanese Patent Laid-Open No. 2000-173762

  However, since the organic EL display panel having the above-described configuration is provided with the concave portion 110 in which the desiccant 112 is disposed in the central portion of the sealing member 106, the thickness of the central portion of the sealing member 106 is thin and very flexible. It has become. For this reason, when the sealing member 106 receives a load, as shown in FIG. 8B, the edge 106a on the inner peripheral side of the recess 110 comes into contact with the display unit 104 and damages the display unit 104. There is a problem that black spots that do not emit light, so-called dark spots, occur on the display unit 104.

  Furthermore, since the sealing member 106 is bent, the pressure inside the space sealed by the sealing member 106 is increased, which causes a problem that the sealing material 108 is damaged.

  Accordingly, an object of the present invention is to provide an organic EL display panel including a sealing member that is difficult to bend even when subjected to a load, in order to solve the above-described problem.

  The organic EL display device according to the present invention includes an array substrate on which a display unit is formed by arranging a plurality of organic EL elements in a matrix, and the array substrate is disposed to face the array substrate at a predetermined interval. In an organic EL display panel having a sealing member provided with a recess on the inner surface facing the display unit, a desiccant disposed in the recess, and a sealing material for sealing the sealing member to the array substrate An organic EL display device, wherein a thick portion for reinforcing the sealing member is provided in the concave portion, and a desiccant is disposed in a recess in the concave portion other than the thick portion.

  As described above, the organic EL display panel according to the present invention can provide an organic EL display panel including a sealing member that is not easily bent even when a load is applied.

  Hereinafter, an organic EL display panel 1 according to an embodiment of the present invention will be described with reference to the drawings.

(1) Internal structure of organic EL display panel 1 First, the internal structure of the organic EL display panel 1 will be described with reference to FIG.

  FIG. 3 is a partially enlarged cross-sectional view showing the structure of the array substrate. A display unit that functions as a display region of the organic EL display panel 1 is formed on an insulating glass substrate 3 made of quartz glass or non-alkali glass. 2, and an array substrate 4 is formed. The display unit 2 is a matrix of pixels composed of a low-temperature polysilicon thin film transistor (hereinafter simply referred to as TFT) 30 and an organic EL element 20 stacked thereon. It is arranged in multiple shapes.

  Specifically, the TFT 30 disposed on the glass substrate 3 is formed by forming an amorphous silicon film on the glass substrate 3 by a CVD method or the like, and irradiating the amorphous silicon with laser light to be polycrystallized. A gate insulating film 33 and a gate electrode 35 are sequentially stacked on a semiconductor layer 31 made of crystalline silicon. The semiconductor layer 31 has a channel 31c and a source 31s and a drain 31d on both sides of the channel 31c. Is provided. Then, the first insulating film 13 is laminated so as to cover the entire upper surface of the gate electrode 35, the gate insulating film 33, and the semiconductor layer 31, and a contact hole provided corresponding to the drain 31d is filled with a metal such as aluminum, A drain electrode is formed. Similarly, a source electrode connected to the source 31s is formed. Then, a second insulating film 17 is laminated on the upper surface of the first insulating film 13 and the drain and source electrodes, and a pixel electrode 21 connected to the source electrode through a contact hole formed at a position corresponding to the source electrode, here Then, the anode of the organic EL element 20 is provided on the second insulating film 17. The pixel electrodes 21 are arranged in a matrix and are partitioned by partition walls 19 made of acrylic resin.

  On the pixel electrode 21, a hole injection layer 23, a hole transport layer 25, a light emitting layer / electron transport layer 27 (hereinafter simply referred to as a light emitting layer 27), and a counter electrode 29 are laminated in this order to form an organic EL. Element 20 is formed. In each layer, for example, an aC film having a thickness of several nm to several hundred nm as the hole injection layer 23 and a TPT film having a thickness of several tens to several hundred nm as the hole transport layer 25 emit light. The layer 27 is made of an Alq3 organic film having a thickness of several tens of nm, and the counter electrode 29 is made of a single metal material such as Al, Li, Mg, Ag, In or an alloy thereof having a thickness of several hundred to several hundred nm. Each thin film is formed. Here, the counter electrode 29 functions as a cathode, is formed on the entire surface of the display unit 2, and is an electrode common to all the organic EL elements 20 arranged for each pixel.

(2) Sealing structure of organic EL display panel 1 Next, the sealing structure of the organic EL display panel 1 will be described with reference to FIGS. FIG. 1 is a cross-sectional view of an organic EL display panel, and FIG. 2 is a plan view showing a structure of a sealing member.

  As shown in FIG. 1, an array substrate 4 on which a display unit 2 is laminated and a sealing member 5 made of a glass plate are arranged to face each other in an inert gas atmosphere from which moisture such as dry nitrogen has been removed. 4 and the outer peripheral part of the sealing member 5 are sealed with a sealing material 11.

In this case, a concave portion 7 is provided on the inner surface of the sealing member 5 facing the display portion of the array substrate 4, and a thickened portion 6 for reinforcement is provided in the concave portion 7.

  As shown in FIG. 2, the thick portion 6 is arranged in a cross shape so as to occupy other than the four corners of the recess 7, and the thickness thereof is substantially equal to the depth of the recess 7. The concave portion 7 and the thick portion 6 are formed, for example, by etching a glass plate.

  And the desiccant 9 is arrange | positioned in the hollows 8 other than the thick part 6 in the recessed part 7. FIG. As this desiccant 9, for example, a powdered body such as calcium oxide, barium oxide, magnesium oxide, and calcium chloride is dissolved in a solvent together with a resin, formed into a predetermined shape, and cured by heat treatment or the like. Then, moisture that penetrates between the array substrate 4 and the sealing member 5 or residual moisture inside the sealed space is chemically adsorbed.

  As described above, since the thick portion 6 is provided and the sealing member 5 is reinforced, the bending amount of the sealing member when receiving a load can be reduced, and therefore the edge portion 5a of the sealing member 5 can be reduced. Can be prevented from coming into contact with the display unit 2, and damage to the display unit 2 can be prevented, and an increase in pressure inside the space sealed by the sealing member 5 can be suppressed to reduce damage to the sealing material 11. Can do.

(Example of change)
The present invention is not limited to the above-described embodiment, and can be changed without departing from the spirit of the invention. Examples of the change will be described below. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

(1) Modification 1
FIG. 4 is a plan view of the sealing member 5 according to the first modification. As shown in FIG. 4, the sealing member 5 may be provided with a thick wall portion 41 having a rectangular planar shape connecting the inner peripheral side surfaces of the concave portion 7 facing each other.

(2) Modification example 2
FIG. 5 is a plan view of the sealing member 5 according to the second modification. As shown in FIG. 5, the sealing member 5 may be provided with a grid-like thick portion 42 in which a plurality of convex portions having a rectangular planar shape intersect each other.

(3) Modification 3
FIG. 6 is a plan view of the sealing member 5 according to the third modification. As shown in FIG. 6, a thick portion 43 having an island shape in plan view may be provided in the central portion of the recess 7.

(4) Modification 4
FIG. 7 is a plan view of the sealing member 5 according to the fourth modification. As shown in FIG. 7, the first thick portion 44 having a rectangular planar shape is provided at the center of the recess 7, and the second rectangular shape connecting the inner peripheral side surface of the recess 7 and the first thick portion 44. A thick part 45 may be provided.

  The present invention is useful as an organic EL display panel including a sealing member that is not easily bent.

It is sectional drawing of the organic electroluminescence display panel which concerns on one Embodiment of this invention. It is a top view of the sealing member concerning one embodiment of the present invention. 1 is a partial enlarged cross-sectional view of an organic EL display panel showing a structure of an array substrate according to an embodiment of the present invention. It is a top view of the sealing member which concerns on the modification 1 of this invention. It is a top view of the sealing member which concerns on the modification 2 of this invention. It is a top view of the sealing member which concerns on the modification 3 of this invention. It is a top view of the sealing member which concerns on the modification 4 of this invention. (A) is sectional drawing of the conventional organic electroluminescent display panel, (b) is sectional drawing which shows the state which received the load and the sealing member bent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic electroluminescent display panel 2 Display part 3 Glass substrate 4 Array substrate 5 Sealing member 6 Thick part 7 Recessed part 8 Indentation 9 Desiccant 11 Sealing material 20 Organic EL element 30 TFT

Claims (8)

An array substrate having a display unit formed by arranging a plurality of organic EL elements in a matrix, and a concave portion on the inner surface facing the display unit with a predetermined distance from the display unit. In an organic EL display panel having a sealing member provided, a desiccant disposed in the recess, and a sealing material for sealing the sealing member to the array substrate,
An organic EL display device, wherein a thick portion for reinforcing the sealing member is provided in the concave portion, and a desiccant is disposed in a recess in the concave portion other than the thick portion.   The organic EL display panel according to claim 1, wherein a planar shape of the thick portion is provided in a rectangular shape.   2. The organic EL display panel according to claim 1, wherein a planar shape of the thick portion is provided in an island shape.   2. The organic EL display panel according to claim 1, wherein the planar shape of the thick portion is provided in a cross shape.   The organic EL display panel according to claim 1, wherein the planar shape of the thick portion is provided in a lattice shape.   The organic EL display panel according to claim 2, wherein the thick portion is provided between inner peripheral side surfaces of the concave portion facing each other.   4. The organic EL display panel according to claim 3, wherein the thick portion is provided in a central portion of the concave portion.   The thick portion includes a first thick portion provided in a central portion of the recess, and a second thick portion that connects the first thick portion and an inner peripheral side surface of the recess. The organic EL display panel according to claim 1.

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