CN100377385C - Organic electroluminescence display and packaging method thereof - Google Patents

Abstract

An organic electroluminescent display comprises a substrate, an electroluminescent display element arranged on the lower surface of the substrate, a back plate and a metal pattern layer, wherein the back plate is formed on the surface opposite to the substrate and at least partially contacts with the cathode of the electroluminescent display element.

Description

Organic electroluminescence display and packaging method thereof

technical field

The invention relates to an organic electroluminescent display and a packaging method thereof, in particular to a packaging structure of an organic electroluminescent display.

Background technique

Organic Electroluminescence Display (OELD, Organic EL Display), also known as Organic Light Emitting Diode (OLED) display, has high brightness, fast screen response, thin and short, full color, and no viewing angle difference With the characteristics of low power consumption, it can replace the traditional liquid crystal display and become a display device commonly used in a new generation of portable information products, mobile phones, personal digital processors and portable computers.

The biggest difference between an organic electroluminescent display and a liquid crystal display is that the organic electroluminescent display uses a self-luminous organic light-emitting layer as a source of display illumination. Please refer to FIG. 1, which shows an existing organic light emitting diode 1 (or electroluminescent display element), at least including an anode electrode plate 12, a light emitting layer 14 and a cathode electrode plate 16; wherein, the light emitting layer 14 is sandwiched between two Between the electrode plates 12 and 16, a "hamburger" (sandwich) structure is formed. Driven by a forward voltage, the anode electrode plate 12 injects holes into the light-emitting layer 14 , and the cathode electrode plate 16 injects electrons into the light-emitting layer 14 . The injected holes and electrons meet and combine in the light-emitting layer 14, causing the electrons to drop from the excited state back to the base state, and release excess energy in the form of radiation in the form of light waves.

In general applications, the electroluminescent display element 1 will be affected by water vapor, resulting in the following conditions: 1. Water vapor easily adheres to the surface of the luminescent layer 14 and invades into the luminescent layer 14, resulting in the luminous intensity of the luminescent layer 14 There is a significant decrease in the uniformity of luminescence; 2. Water vapor invades the interface between the luminescent layer 14 and the two electrode plates, causing the luminescent layer 14 to separate from the electrode plates, resulting in dark spots. Therefore, the present invention designs a hermetically sealed package structure to protect the electroluminescent display element 1 , so as to avoid the intrusion of moisture in the external environment and affect the normal display of the organic light emitting layer 14 .

Please refer to FIG. 2 , which is a packaging structure 20 of an existing organic electroluminescent display, the packaging structure 20 includes an electroluminescent display element 1, a glass substrate 22 and a backplane 24; wherein the electroluminescent display element 1 is disposed on the lower surface of the glass substrate 22, and the back plate 24 is processed with a wide groove 241 on the upper surface by sandblasting or etching. At the same time, the glass substrate 22 is fixed on the back plate 24 by an adhesive 26, and the adhesive 26 is coated around the periphery of the groove 241 (ie, the edge of the back plate 24), so that the groove forms a closed space to accommodate the above-mentioned Electroluminescence display element 1.

At the same time, in order to reduce the existing water vapor in the above-mentioned confined space, and prevent external water vapor from penetrating into the confined space and causing damage to the electroluminescent display element 1, a dry layer 28 is arranged on the bottom surface 241a of the groove, and From the central position of the bottom surface 241a of the groove, it extends to the periphery of the groove 241 to absorb moisture in the enclosed space.

Although the above encapsulation structure 20 can effectively prevent the deterioration of the electroluminescent display element 1 due to contact with moisture, there are still the following disadvantages to be improved:

1. In order to make the enclosed space have sufficient depth to accommodate the desiccant layer 28 , the backplane 24 must have sufficient thickness to provide the space required for processing to form the groove 241 , so the thickness of the packaging structure 20 cannot be reduced.

Two, the above-mentioned groove 241 must have a uniform and wide bottom surface 241a, so it takes a long time to make the groove 241, thereby increasing the production cost, and the control of the process is also quite difficult; at the same time, the strength of the back plate 24 is also correspondingly reduced. Fragmentation easily occurs.

3. When the size of the display is large, the phenomenon of bending of the glass substrate 22 and the backplane 24 will increase relatively due to the increase of the area, and the situation that the backplane 24 is pressed against the cathode or the light-emitting layer is more serious.

4. Since the thickness of the metal electrode cannot be made very thick, its resistance will be very large in a large-sized panel, thus causing the problem of uneven voltage drop, resulting in poor performance of the panel.

In view of this, the present invention proposes a packaging structure of a high-intensity organic electroluminescent display to solve the above-mentioned shortcomings of the existing packaging structure.

Contents of the invention

An object of the present invention is to provide a high-intensity organic electroluminescent display, its packaging structure and packaging method.

Another object of the present invention is to provide an organic electroluminescent display capable of reducing the impedance of the cathode of the organic electroluminescent display element, its packaging structure and packaging method.

An organic electroluminescent display provided by the present invention at least includes a substrate; an electroluminescent display element disposed on the lower surface of the substrate; a back plate; and a metal pattern layer formed on the surface of the back plate opposite to the substrate and at least partially in contact with the cathode of the electroluminescent display element to reduce the impedance of the cathode and strengthen the backplane.

The present invention also provides a packaging method for an organic electroluminescent display, at least comprising:

Provide a backplane;

setting a metal pattern layer on the backplane;

coating an adhesive on the periphery of the upper surface of the backboard; and

Paste a substrate on the back plate, wherein the lower surface of the substrate is provided with an organic electroluminescent display element, and the cathode of the organic electroluminescent display element is at least partly in contact with the metal pattern layer.

Description of drawings

FIG. 1 is a structural diagram of an organic light emitting diode in the prior art;

FIG. 2 is a package structure diagram of an organic electroluminescent display in the prior art;

3 is a package structure diagram of an organic electroluminescent display in a preferred embodiment of the present invention;

4A is a schematic diagram of the layout of the image layer on the backplane according to an embodiment of the present invention;

4B is a schematic diagram of the layout of the image layer on the backplane according to another embodiment of the present invention;

4C is a schematic diagram of the layout of the image layer on the backplane according to another embodiment of the present invention; and

FIG. 4D is a schematic diagram of the layout of the image layer on the backplane according to another embodiment of the present invention.

simple notation

1 electroluminescent display element 12 anode electrode plate

1 4 light-emitting layer 16 cathode plate

241 backplane surface groove 241a groove bottom surface

36 metal pattern layer 20, 30 display packaging structure

22, 32 substrates 24, 34 backplanes

26, 37 Adhesive 28, 38 Desiccant

Detailed ways

Please refer to FIG. 3 , which is a schematic diagram of a preferred embodiment of a packaging structure 30 of an organic electroluminescent display according to the present invention. The packaging structure 30 includes an electroluminescent display element 1, a metal pattern layer 36, and a desiccant. 38 . A base plate 32 and a back plate 34 . Both the substrate 32 and the backplane 34 can be made of flat plates of light-transmitting materials. In the following description, glass will be used as the substrate 32 and the backplane 34 as an example for explanation.

The electroluminescent display element 1 is located on the lower surface of the glass substrate 32, the metal pattern layer 36 and the desiccant 38 are located on the upper surface of the glass backplane 34, and the desiccant 38 is located in the gap of the metal pattern layer 36 or around the glass backplane 34 (between the metal pattern layer 36 and the adhesive 37), the glass substrate 32 is fixed on the glass back plate 34 by the adhesive 37, and the adhesive 37 is coated around the edge of the glass back plate 34 (the periphery of the glass back plate 34) , make the glass substrate 32 , the glass back plate 34 , and the adhesive 37 form a closed space to accommodate the electroluminescent display element 1 , the desiccant 38 and the metal pattern layer 36 .

Please refer to Figure 4, in the present invention, the metal pattern layer on the backplane can be made into lines (Figure 4A), grids (Figure 4B), columnar arrays (Figure 4C) and thin films (Figure 4D), etc. pattern. When the metal pattern layer is a line-like, grid-like, or columnar array, it is suitable for the display element to emit light in two directions or unidirectionally; when it is a metal thin film, it is suitable for the display element to emit light in one direction and through the glass substrate Glow (Bottom Emission) mode.

The present invention uses the metal pattern layer to have the following advantages:

1. The metal pattern layer is in contact with the cathode of the display element. Due to the good conductivity of the metal, the metal pattern layer can be used as an extension of the cathode of the display element. The whole can be regarded as increasing the cross-sectional area of the cathode (that is, it is equivalent to increasing the thickness of the cathode). Therefore, the cathode impedance of the electroluminescent display element can be reduced, the problem of voltage drop can be improved, and the uniformity of the display can be optimized.

2. The metal pattern layer can increase the structural strength of the display, serve as a strengthening structure (Spacer) of the display, and improve the bending phenomenon of the glass substrate and the glass backplane. Since the metal pattern layer is in contact with the display elements, the gap between the glass substrate and the glass backplane will not be suspended. In addition, if this structure is used, the glass backplane does not necessarily need to process a groove to accommodate the desiccant, so the glass backplane The strength will not be reduced, and its production cost will be reduced.

3. If the metal pattern layer is in a line shape, grid shape, or columnar array, it can be used as a light-shielding layer (Black Matrix) of the display element, which can shield light sources other than the pixel openings, improve color contrast, and prevent adjacent red, green, and blue. Color pixels mix with each other. The position of the pixel (Pixel) circuit should be considered during design, and the aperture ratio of the pixel should not be affected as a criterion.

Generally speaking, the control circuit and other components of the electroluminescent display element are all fabricated on the lower surface of the glass substrate. Therefore, if the electroluminescent display element is in the top emission mode through the glass backplane, the electric current can be improved. The aperture ratio of the luminescent display element; combined with the design of the metal pattern layer, it can achieve improved contrast, increase the structural strength of the display, reduce the cathode impedance of the electroluminescent display element, improve the problem of voltage drop, and optimize the uniformity of the display, etc. advantage.

The above is to use the preferred embodiments to describe the present invention in detail, and its purpose is to enable those skilled in the art to better understand the content of the present invention and implement it accordingly, rather than to limit the scope of the present invention, for those skilled in the art Any equivalent modification or change made by the skilled person to the present invention without departing from the spirit and scope of the present invention shall be included in the claims of the present invention.

Claims (11)

1. An organic electroluminescence display, comprising at least: a substrate; At least one electroluminescence display element is arranged on the lower surface of the substrate; a back panel; and A metal pattern layer is arranged on the surface of the back plate facing the substrate, and is at least partially in contact with the cathode of the at least one electroluminescence display element. 2. The organic electroluminescent display as claimed in claim 1, wherein the substrate and the backplane are made of light-transmitting materials. 3. The organic electroluminescence display as claimed in claim 2, wherein the light-transmitting material is a glass plate. 4. The organic electroluminescence display as claimed in claim 1, wherein the metal pattern layer is in the shape of metal lines. 5. The organic electroluminescence display as claimed in claim 1, wherein the metal pattern layer is in the shape of a metal grid. 6. The organic electroluminescence display as claimed in claim 1, wherein the metal pattern layer is a metal pillar array. 7. The organic electroluminescence display as claimed in claim 1, further comprising a desiccant disposed around the backplane. 8 . The organic electroluminescent display as claimed in claim 1 , further comprising a desiccant in the gap between the metal pattern layers. 9. A packaging method for an organic electroluminescent display, comprising at least: Provide a backplane; setting a metal pattern layer on the backplane; coating an adhesive on the periphery of the upper surface of the backboard; and Paste a substrate on the back plate, wherein the lower surface of the substrate is provided with an organic electroluminescent display element, and the cathode of the organic electroluminescent display element is at least partly in contact with the metal pattern layer. 10. The packaging method of an organic electroluminescent display as claimed in claim 9, further comprising: disposing a desiccant around the upper surface of the backplane. 11. The packaging method of an organic electroluminescent display as claimed in claim 9, further comprising: disposing a desiccant in the gap between the metal pattern layers.

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