JP2023144578A - Image display cell manufacturing method - Google Patents

Abstract

To provide an image display cell manufacturing method capable of suppressing the deformation of substrates constituting an image display cell.SOLUTION: An image display cell manufacturing method includes: a first step of sticking a pixel substrate 101 and a counter substrate 105 together through a frame-like seal material 102 in which an opening 107 is formed; a second step of pressurizing at least one of the pixel substrate 101 and the counter substrate 105 toward the other from the outside to squash the seal material 102 between the pixel substrate 101 and the counter substrate 105 and close the opening 107 with the squashed seal material 102; a third step of releasing the pressurization to decrease the internal pressure of a cell Gap108 and deform at least one of the pixel substrate 101 and the counter substrate 105 so as to approach the other; and a fourth step of curing the seal material 102 to increase the internal pressure of the cell Gap108 and make the pixel substrate 101 and the counter substrate 105 in a flat state.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for manufacturing an image display cell.

In recent years, a wide variety of image display cells, such as organic EL elements, liquid crystal elements, and DLP (DMD) elements, have been introduced into the market.

In many image display cells, a pixel pattern is formed on a glass or silicon substrate, and in organic EL devices, the light emitted from the light emitting elements that make up the pixel pattern controls external light, and in liquid crystal and DLP devices, external light is controlled by the pixel pattern. Display the image by doing this.

However, the pixel pattern formed on the substrate is susceptible to destruction due to external stress and deterioration due to the environment such as humidity, so it is usually not possible to form the pixel pattern on a glass substrate or the like (hereinafter referred to as the counter substrate). The pixel pattern is protected and sealed.

At this time, in order to prevent the pixel pattern from being scratched due to the counter substrate touching the pixel pattern, the counter substrate must be placed on top of the pixel substrate with a certain distance between them. A resin material (hereinafter referred to as a sealing material) containing a spacer for controlling the spacing is placed on a portion of the pixel substrate other than the pixel pattern, and the pixel substrate and the counter substrate are bonded together using this sealing material. However, the spacer is not essential and may be omitted.

In addition, the pixel pattern on the pixel substrate must be sealed to prevent the effects of humidity, etc., so normally a sealing material is placed in a frame shape around the pixel pattern, and the pixel pattern is surrounded by the sealing material. By sealing the space, moisture is prevented from entering the pixel pattern forming area. (For example, see Patent Documents 1 and 2)

Japanese Patent Application Publication No. 2002-25764 Japanese Patent Application Publication No. 2005-228493

When creating an image display cell with the above structure, a sealing material is placed on the pixel substrate, and when the counter substrate is bonded together, a sealed area surrounded by the pixel substrate, counter substrate, and sealant is formed. Gas such as air may remain in the cell gap (hereinafter referred to as cell gap). Then, this remaining gas has the effect of trying to expand the cell gap, and may cause deformation (distortion, etc.) in the pixel substrate and the counter substrate.

When the pixel substrate or counter substrate is deformed in this way, the optical path length of the light incident on the image display cell or the light emitted from the image display cell partially changes, and the display quality of the image is significantly impaired. It turns out.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing an image display cell that can suppress deformation of a substrate constituting the image display cell. .

A method for manufacturing an image display cell having a pixel substrate and a counter substrate, the method comprising: a first step of bonding the pixel substrate and the counter substrate through a frame-shaped sealing material with a gap formed therein; Pressure is applied to at least one of the opposing substrates from the outside toward the other to crush the sealing material between the pixel substrate and the opposing substrate, and closing the gap with the crushed sealing material. Step 2: By releasing the pressure, the internal pressure in the space surrounded by the pixel substrate, the counter substrate, and the sealing material is lowered, and at least one of the pixel substrate and the counter substrate is transferred to the other. a third step of deforming the pixel substrate so as to approach the pixel substrate; and a fourth step of curing the sealing material to increase the internal pressure of the space and flattening the pixel substrate and the counter substrate. This is a method for manufacturing an image display cell.

In the fourth step, the method for manufacturing an image display cell may eliminate the pressure difference between the internal pressure of the space and the external pressure by increasing the internal pressure of the space.

According to the present invention, it is possible to provide a method for manufacturing an image display cell that can suppress deformation of a substrate constituting the image display cell.

FIG. 2 is a top view (a) and a cross-sectional view taken along line AA in FIG. FIG. 7 is a top view (a) and a cross-sectional view taken along line AA (b) showing a state in which a counter substrate is being bonded to a pixel substrate of an image display cell according to an embodiment of the present invention. FIG. 7A is a top view and FIG. 3B is a cross-sectional view taken along line AA, showing a state in which a counter substrate has been bonded to a pixel substrate of an image display cell according to an embodiment of the present invention. FIG. 2 is a top view (a) and a cross-sectional view taken along line AA in FIG. FIG. 2 is a top view (a) and a cross-sectional view taken along line AA in FIG.

FIG. 1 is (a) a top view and (b) a sectional view taken along line AA, showing a state in which a sealing material is arranged on a pixel substrate of an image display cell according to an embodiment of the present invention. FIG. 2 is (a) a top view and (b) a sectional view taken along the line AA, showing a state in which a counter substrate is being bonded to a pixel substrate of an image display cell according to an embodiment of the present invention. FIG. 3 is (a) a top view and (b) a cross-sectional view taken along the line AA, showing a state in which the work of bonding a counter substrate to a pixel substrate of an image display cell according to an embodiment of the present invention has been completed. FIG. 4 is (a) a top view and (b) a cross-sectional view taken along the line AA, showing the state of the image display cell according to the embodiment of the present invention after the pressure on the opposing substrate is released. FIG. 5 is (a) a top view and (b) a cross-sectional view taken along line AA, showing the state of the image display cell according to the embodiment of the present invention after the sealing material has been cured. Hereinafter, embodiments of the present invention will be described using these drawings.

In this embodiment, the image display cell is an organic EL device or a DLP device. In this example, the image display cell is manufactured by a manufacturing process including the following steps S1 to S5.

<S1>
As shown in FIG. 1, a sealing material 102 is arranged in a frame shape around a pixel pattern 103 formed on a pixel substrate 101. As shown in FIG. As a method for arranging the sealant 102, application using a dispenser, screen printing, or the like is appropriately selected. At this time, a gap (opening) 107 is provided in a part of the sealing material 102 for removing air from the space surrounded by the sealing material 102. Note that an electrode terminal 104 electrically connected to the pixel pattern 103 is formed in advance on the surface of the pixel substrate 101.

The width D of the gap 107 is set to a distance such that the gap 107 is completely filled with the sealant 102 when the bonding of the counter substrate 105 is completed in step S3, which will be described later. For example, this distance is determined by calculating or experimenting in advance the distance that the sealing material 102 will collapse and expand between the start and the end of bonding of the counter substrate 105, and the distance that is less than twice the distance that the sealant 102 will expand. is set to

<S2>
Next, as shown in FIG. 2, in an atmospheric pressure environment filled with air, the counter substrate 105 is bonded to the pixel substrate 101 via the sealant 102, and the counter substrate 105 is fixed from the outside toward the pixel substrate 101. Gradually increase the pressure to . At this time, the pixel substrate 101 is placed on, for example, a pressure stage (not shown), and the counter substrate 105 is pressed by, for example, a pressure plate (not shown). As the pressure on the opposing substrate 105 progresses, the sealing material 102 is crushed by the opposing substrate 105 and gradually expands in the width direction, and accordingly, the air 106 in the cell gap 108 passes through the gap 107 into the cell. It is pushed out of the gap 108 little by little, and at the same time, the gap 107 is gradually filled with the expanded sealing material 102. Note that during this process, the gap 107 is not completely filled with the sealing material 102, so the internal pressure of the cell Gap 108 is kept equal to the external pressure.

<S3>
Next, as shown in FIG. 3, the process of step S2 described above is continued, and this process is ended when the gap 107 is completely filled with the sealant 102. As a result, the gap 107 is completely closed with the sealing material 102, and the cell gap 108 is in a sealed state. Note that at this point, the spacer (not shown) mixed in the sealant 102 is sandwiched between the pixel substrate 101 and the counter substrate 105 to the extent that it does not deform, or it is in a state that it is not deformed to the extent that it is slightly deformed. It is in a pinched state.

<S4>
Next, as shown in FIG. 4, the pressure on the counter substrate 105 is released. As a result, the sealing material 102 is released from the pressure applied by the opposing substrate 105, and the sealing material 102 is moved in its width direction by the restoring force due to the elasticity of the sealing material 102 itself and the restoring force due to the elasticity of the spacer mixed in the sealing material 102. As it is pulled back slightly toward the center, the counter substrate 105 is slightly separated from the pixel substrate 101, and the volume of the cell gap 108 temporarily increases, but at this point, the gap 107 is already filled with the sealant 102. Therefore, no new air is supplied from the outside to the inside of the cell Gap 108, and as a result, the internal pressure of the cell Gap 108 becomes lower than the external pressure, and a pressure difference occurs between the internal pressure and the external pressure of the cell Gap 108. Due to this pressure difference, the pixel substrate 101 and the counter substrate 105 curve toward each other using the sealing material 102 as a fulcrum, and the cell gap 108 becomes concavely curved toward the center in the thickness direction. Although this embodiment shows a state in which both the pixel substrate 101 and the counter substrate 105 are curved, only one of the pixel substrate 101 and the counter substrate 105 may be curved toward the other. .

<S5>
Next, as shown in FIG. 5, the sealant 102 is cured. The method for curing the sealant 102 is selected as appropriate depending on the material of the sealant 102. For example, if the sealant 102 is an ultraviolet curable resin, the sealant 102 is cured by irradiating the sealant 102 with ultraviolet rays. The material 102 is cured. At this time, the sealing material 102 expands due to heat generated when curing the sealing material 102 (for example, heat generated by ultraviolet irradiation), and at the same time causes curing contraction, and as a result of these combined effects, the cell gap 108 The volume of the cell Gap 108 decreases, or some of the components of the sealing material 102 vaporize and gas is released from the sealing material 102. As a result, the internal pressure of the cell Gap 108 increases, and the internal and external pressures of the cell Gap 108 increase. The pressure difference between the pixel substrate 101 and the counter substrate 105, which had been curved, becomes flat, and the thickness of the cell gap 108 becomes uniform. Although it is desirable that the pressure difference between the internal pressure and the external pressure of the cell gap 108 be completely eliminated, it may be reduced only to such an extent that the curved pixel substrate 101 and counter substrate 105 become flat.

The above process was performed by experimenting with combinations of the material (viscosity and hardness), width, and thickness of the sealing material 102, the width of the gap 107, the pressure when pressurizing the opposing substrate 105 from the outside, and the width and thickness of the cell gap 108. This can be achieved by making appropriate selections based on calculations, simulations, etc.

According to the embodiment described above, deformation (distortion, etc.) of the pixel substrate 101 and the counter substrate 105 can be effectively suppressed in the manufacturing process of the image display cell.

The present invention is not limited to the above embodiments, and may take various other embodiments. For example, the gap 107 in the sealing material 102 is not limited to one location, but may be provided at several locations. Furthermore, before bonding the pixel substrate 101 and the counter substrate 105 together, the sealant 102 is not placed only on the pixel substrate 101, but only on the counter substrate 105, or on both the pixel substrate 101 and the counter substrate 105. may be done. Furthermore, when bonding the pixel substrate 101 and the counter substrate 105 together, instead of applying pressure to the counter substrate 105 from the outside toward the pixel substrate 101, pressurize the pixel substrate 101 from the outside toward the counter substrate 105, or , the pixel substrate 101 and the counter substrate 105 may be externally pressurized in the direction in which they face each other. Furthermore, the surrounding pressure environment when performing the processes of steps S2 to S5 is not limited to the atmospheric pressure environment, but also other pressure environments in which the completed image display cell is actually used (pressure environments higher or lower than atmospheric pressure). ). Further, the gas introduced into the cell gap 108 is not limited to air, but may be other gas such as nitrogen. Further, the spacer mixed into the sealing material 102 is not essential and may be omitted. Further, the image display cell is not limited to an organic EL element or a DLP element, but may be another image display cell.

101 Pixel substrate 102 Sealing material 103 Pixel pattern 104 Electrode terminal 105 Counter substrate 106 Air 107 Gap (opening)
108 Cell Gap

Claims (2)

A method for manufacturing an image display cell having a pixel substrate and a counter substrate, the method comprising:
a first step of bonding the pixel substrate and the counter substrate through a frame-shaped sealing material with a gap formed therein;
By applying external pressure to at least one of the pixel substrate and the opposing substrate toward the other, the sealing material is crushed between the pixel substrate and the opposing substrate, and the crushed sealing material is used to The second step is to close the gap,
By releasing the pressure, the internal pressure in the space surrounded by the pixel substrate, the counter substrate, and the sealing material is reduced, and at least one of the pixel substrate and the counter substrate approaches the other. A third step of transforming the
a fourth step of increasing the internal pressure of the space by curing the sealing material to flatten the pixel substrate and the counter substrate;
A method for manufacturing an image display cell, comprising: 2. The method of manufacturing an image display cell according to claim 1, wherein in the fourth step, the internal pressure of the space is increased to eliminate a pressure difference between the internal pressure of the space and the external pressure.

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