JP2002110349A - Manufacturing method of organic electroluminescent display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakage of cover glass when a roller or the like is used for pressing in pasting together the cover glass by deforming it in order to prevent the air bubble from remaining in the sealant. SOLUTION: When a thin plate cover glass 8 is pasted together through a sealant on the picture element forming surface of the picture element panel 1, a reinforcement sheet 10 is pasted on the one face of the cover glass 8 and then a roller 9 is applied for pressing on. Thereby, the breakage of the cover glass 8 due to its deformation (warp) is prevented by the reinforcement sheet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an organic electroluminescent display, and more particularly to a technique for sealing a pixel forming portion of a pixel panel.

[0002]

2. Description of the Related Art An organic EL display using electroluminescence (hereinafter abbreviated as EL) of an organic material is a self-luminous display device, and thus has the advantages of a wide viewing angle and no need of a backlight. It has the advantages of low drive voltage, short response time, and thin thickness, and is attracting attention as a next-generation display.

The organic EL display has a pixel panel (organic EL panel) having a plurality of pixels for displaying images. Generally, the structure of an organic EL element in a pixel panel is such that an organic EL film is formed on a transparent substrate such as a glass substrate.
It has a structure sandwiched between two electrodes. The organic EL film mainly includes an electron transporting layer, a light emitting layer, and a hole transporting layer. One of the two electrodes is an anode, and the other is a cathode.

In an organic EL display having such a pixel panel, by applying a positive voltage to the anode and a negative voltage to the cathode, holes injected from the anode into the organic EL film are transported by holes. Electrons injected into the organic EL film from the cathode through the layer and into the organic EL film reach the light emitting layer through the electron transport layer, and the electrons and holes recombine in the light emitting layer to obtain light emission. Has become.

FIG. 5 is a sectional view showing the structure of a general organic EL display. In FIG. 5, the pixel panel 1
Is composed of a transparent substrate 2 serving as a panel base material, and a pixel forming section 3 in which a plurality of organic EL elements are formed on a main surface of the transparent substrate 2 in a predetermined arrangement (for example, a matrix arrangement). I have. The pixel panel 1 is covered with a transparent cap 4. The peripheral portion of the transparent cap 4 is adhered to the peripheral portion of the main surface of the transparent substrate 2 by a sealant 5, thereby sealing the pixel forming portion 3.

[0006]

By the way, in the organic EL display having the above structure, an image displayed by the pixel forming section 3 of the pixel panel 1 is viewed through the transparent substrate 2. On the other hand, when the pixel forming portion 3 is formed on the main surface of the transparent substrate 2, an effective light emitting area in the pixel forming portion 3 is obtained in order to obtain an organic EL element by sequentially stacking thin films constituting each layer. The area is wider on the opposite side, that is, on the transparent cap 4 side, than on the side in contact with the transparent substrate 2.

Therefore, in recent years, the pixel formation surface of the pixel panel 1 (the transparent substrate
By bonding a thin plate-shaped cover glass on the main surface of the pixel via a transparent sealant, the intrusion of moisture and the like into the pixel forming portion 3 is prevented, thereby displaying from the cover glass side having a large light emitting area area. A configuration for visually observing an image has been developed. The organic EL display adopting such a configuration has the advantage that the display can be further thinned in addition to the higher brightness of the display image and the lowering of the driving voltage. However, the following problems occurred during the manufacturing process.

That is, when a cover glass is bonded to the pixel forming surface of the pixel panel 1, as shown in FIG. 6, the pixel panel 1 is placed on the bed portion 6 and the pixel forming portion 3 (see FIG. 5). ) Is covered with a sealing agent 7 on the pixel forming surface of the pixel panel 1, a cover glass 8 is put on the sealing agent 7 from above, and the sealing agent 7 is attached by a roller 9. At this time, the roller 9 is rolled from one side of the cover glass 8 to the other side while the cover glass 8 is appropriately warped (deformed) in order to release bubbles in the sealant 7, so that the cover glass 8 The pressing force is applied sequentially to the whole.

However, in the above manufacturing method, when a pressing force is applied to the cover glass 8 by the roller 9,
There was a problem that the cover glass 8 was liable to be broken, such as cracks, chips, or cracks, due to the influence of the above-described warpage. Further, if the amount of warpage (the amount of deformation) of the cover glass 8 is reduced to prevent the cover glass 8 from being damaged, there is a problem that air bubbles easily remain in the sealant 7.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a method for attaching a thin plate-shaped cover glass to a pixel forming surface of a pixel panel via a sealant. It is an object of the present invention to provide a method for manufacturing an organic EL display which can prevent both the remaining of air bubbles in the agent and the breakage of the cover glass.

[0011]

In a method of manufacturing an organic EL display according to the present invention, at least one surface of a cover member is attached when a thin plate-like cover member is bonded to a pixel forming surface of a pixel panel via a sealant. The cover member is stuck on the pixel forming surface by applying a pressing force to the reinforcing sheet for preventing the cover member from being damaged.

According to the above-described method for manufacturing an organic EL display, the reinforcing member is attached to at least one surface of the cover member and a pressing force is applied by a roller or the like. It is effectively prevented by the reinforcing sheet.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that, in the present embodiment, the same reference numerals are given to the same components as the components described in the above-described section, and the description will be made.

FIG. 1 is a view for explaining a method of manufacturing an organic EL display according to an embodiment of the present invention, in particular, a method of sealing a pixel forming portion provided in a pixel panel.

First, as shown in FIG. 1A, the pixel panel 1 is placed and set on the bed 6 and a sealing agent is formed over a predetermined area on the pixel forming surface (the upper surface in the figure) of the pixel panel 1. 7 is applied. The cover glass 8 is made of a thin plate-shaped square transparent glass so as to be easily deformed as a whole. The thickness of the cover glass 8 is set to an appropriate dimension in consideration of ease of deformation, for example, a thickness dimension of about 50 to 100 μm. The sealant 7 is applied to a substantially uniform thickness so as to cover the entire pixel forming portion of the pixel panel 1. As the sealant 7, a transparent resin of an ultraviolet curable type is preferably used so that the organic EL element is not deteriorated by a process of curing the sealant.

The sealant 7 may be applied on the pixel forming surface of the pixel panel 1 before setting the pixel panel 1 on the bed 6. The direction of the bed 6 is not limited to the upward direction as shown in the figure, but may be the horizontal direction or the downward direction.

Next, as shown in FIG. 1B, a cover glass 8 is put on the pixel forming surface of the pixel panel 1. At this time, as shown in FIG. 2, the reinforcing sheet 10 is attached to one surface of the cover glass 8. This reinforcing sheet 10
When the cover glass 8 is bonded to the pixel formation surface of the pixel panel 1 via the sealant 7, the cover glass 8 is prevented from being broken or damaged.

As shown in FIG. 3A, for example, the reinforcing sheet 10 includes a flexible plastic sheet base layer 10A and an adhesive layer 10B formed on one surface of the sheet base layer 10A. It is composed. The reinforcing sheet 10 having such a configuration can be used as a damage prevention sheet (one element of the organic EL display) for preventing damage to the cover glass 8 due to rubbing or the like in a state where the assembly of the organic EL display is completed.

Further, as one element of the organic EL display, the reinforcing sheet 10 may constitute one of a color filter, a polarizing filter, and an antireflection filter. In this case, as shown in FIG. 2B, a functional layer 1 having a color filter function, a polarizing filter function, or an antireflection function is provided on the other surface of the sheet base layer 10A.
The reinforcing sheet 10 having a structure to which 0C is added can be adopted.

Subsequently, as shown in FIG. 1 (C), a roller 9 is disposed on one side of the pixel panel 1 in parallel with the roller 9 and the roller 9 applies a pressing force to the cover glass 8 while the roller 9 is pressed. 9 is rolled in the direction of the arrow in the figure, so that the sealing glass 8 is bonded to the pixel forming surface of the pixel panel 1 via the sealing agent 7. At this time, the cover glass 8 is warped by the pressing force from the roller 9, or the cover glass 8 is warped forcibly, so that the air bubbles in the sealant 7 are surely released. Incidentally, as for applying a pressing force to the cover glass 8, for example, a squeegee or the like can be used in addition to the roller 9 described above.

At this time, although a bending stress is applied to the cover glass 8 by the pressing force from the roller 9, the bending stress is reduced by attaching the reinforcing sheet 10 to the cover glass 8. Specifically, when the reinforcing sheet 10 is not provided, as shown in FIG. 4A, the degree of application of the force (P) from the roller 9 to the cover glass 8 becomes local pressure due to line contact. On the other hand, when the reinforcing sheet 10 is provided, the force from the roller 9 is dispersed (P1, P2, P3) as shown in FIG. It is considered to be. Also, it is considered that the mechanical strength of the cover glass 8 against bending stress is increased by attaching the reinforcing sheet 10 to the cover glass 8. In particular, when the reinforcing sheet 10 is stuck on the entire surface of the cover glass 8, it is considered that the rate of increase in mechanical strength increases. As a result, even if the cover glass 8 is deformed (warped) as necessary for the purpose of preventing air bubbles from remaining in the sealant 7, it is possible to effectively prevent the cover glass 8 from being damaged (cracked, etc.). it can.

After the cover glass 8 is bonded to the pixel panel 1 in this manner, the pixel panel 1 is taken out of the bed portion 6 and transferred to the next step, where the pixel panel 1 is irradiated with ultraviolet rays from the cover glass 8 side to seal. The agent 7 is cured. Thereafter, the reinforcing sheet 10 is peeled from the cover glass 8 as necessary.

However, if the reinforcing sheet 10 is one of the elements constituting the organic EL display (for example, any one of a color filter, a polarizing filter, an antireflection filter, and a damage prevention sheet), it is peeled off. No need. By using the reinforcing sheet 10 as one element of the organic EL display in this way, it is possible to simultaneously prevent the cover glass 8 from being damaged and add the function of the organic EL display.

In the above-described embodiment, the pressing force is applied to the cover glass 8 by the roller 9 in a state where the reinforcing sheet 10 is attached to one surface of the cover glass 8 in advance, but the present invention is not limited to this. Instead, the reinforcing sheet 10 is overlaid on one surface of the cover glass 8, and from this state, the cover sheet 8 is bonded to the pixel panel 1 while the reinforcing sheet 8 is bonded to the cover glass 8 by the pressing force of the roller 9. Is also good.

In the above embodiment, the reinforcing sheet 10 is stuck on only one surface of the cover glass 8.
0 may be attached to apply a pressing force. In that case, for example, a reinforcing sheet 10 as an anti-reflection filter (or a damage prevention sheet) is provided on one surface of the cover glass 8.
Various combinations can be adopted, such as attaching a reinforcing sheet 10 as a color filter (or a polarizing filter) to the other surface of the cover glass 8 while attaching.

Further, as the cover member according to the present invention, in addition to the cover member made of glass such as the cover glass 8 described in the above-described embodiment, the pixel forming portion of the pixel panel 1 has sufficient airtightness (such as moisture). Other materials that can be sealed with the anti-permeation property of, for example, ceramics may be used. However, when the cover member is made of ceramics, the pixel forming portion of the pixel panel 1 is shielded from the outside by the cover member. The display image is viewed from the side of the substrate.

[0027]

As described above, according to the present invention, the reinforcing sheet is effectively prevented from being broken by the reinforcing sheet by applying a pressing force by attaching the reinforcing sheet to at least one surface of the cover member. Even when the cover member is warped so that air bubbles do not remain in the sealant, the cover member can be attached without being damaged.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for manufacturing an organic EL display according to an embodiment of the present invention.

FIG. 2 is a view showing a state in which a cover glass and a reinforcing sheet are attached.

FIG. 3 is a diagram showing a specific configuration example of a reinforcing sheet.

FIG. 4 is a diagram comparing the degree of pressing force exerted by a roller;

FIG. 5 is a cross-sectional view illustrating a configuration of a general organic EL display.

FIG. 6 is a diagram illustrating a conventional method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pixel panel, 2 ... Transparent substrate, 3 ... Pixel formation part, 6 ...
Bed part, 7: sealant, 8: cover glass, 9: roller, 10: reinforcing sheet

Claims (3)

[Claims] When bonding a thin plate-shaped cover member on a pixel forming surface of a pixel panel via a sealant, a reinforcing sheet for preventing damage to the cover member is attached to at least one surface of the cover member and pressed. A method for manufacturing an organic electroluminescent display, wherein the cover member is bonded to the pixel forming surface by applying pressure. 2. The method according to claim 1, wherein the reinforcing sheet constitutes one element of an organic electroluminescent display. 3. The organic electroluminescent display according to claim 1, wherein the organic electroluminescent display comprises a color filter, a polarizing filter,
3. The method according to claim 2, wherein the organic electroluminescent display is any one of an antireflection filter and a damage prevention sheet.