KR101881754B1 - Supporting Substrate for Flexible Display Device, Flexible Display Device Including That Supporting Substrate, and Method for Manufacturing That Flexible Display Device - Google Patents

Abstract

A flexible display device according to one aspect of the present invention, which can minimize bubbles generated when laminating a supporting substrate to a base substrate for improving impact resistance of the flexible display device, comprises a substrate including a flexible base substrate panel; And a support substrate coupled to a lower surface of the base substrate, wherein at least one first bubble outlet is formed in the support substrate in a region corresponding to a region except for a display region of the display panel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a supporting substrate for a flexible display device, a flexible display device including the same, and a manufacturing method of the flexible display device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible display device, and more particularly, to a flexible display device capable of minimizing product defects.

Due to the recent rapid development of semiconductor technology, the flat panel display device has increased in screen size and weight, and the performance of the flat panel display device has been improved, so that the demand of the flat panel display device has been explosively increased.

Such a flat panel display device includes a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), an electroluminescence display device (ELD ), An electrophoresis display device (EPD), and an organic light emitting diode (OLED).

 Such a flat panel display device is thinner and lighter than a cathode ray tube (CRT), and has advantages of being advantageous in enlargement, and its use is increasing day by day.

On the other hand, the flat panel display uses a glass substrate to withstand the high heat generated during the manufacturing process, and thus has a limitation in providing light weight, thinness and flexibility. Therefore, in recent years, a flexible display device that can maintain display performance even if bent like paper is rapidly emerging by using a substrate formed using a flexible material such as plastic or metal, instead of a conventional glass substrate having no flexibility have.

However, in the case of a flexible display device formed using a substrate formed using such a flexible material, there is a disadvantage in that the shock resistance is low, which can alleviate or absorb an impact when an external impact is applied.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a support substrate for a flexible display device for improving the impact resistance of the flexible display device, and a method of manufacturing the flexible display device and the flexible display device including the same. do.

It is another object of the present invention to provide a supporting substrate for a flexible display device capable of minimizing bubbles generated when laminating a supporting substrate to a base substrate, and a method of manufacturing a flexible display device and a flexible display device including the same. do.

Other features and advantages of the present invention, besides the above-mentioned aspects of the present invention, will be described hereinafter, or may be apparent to those skilled in the art from the description and the description.

In addition, other features and advantages of the present invention may be newly recognized through practice of the present invention.

According to an aspect of the present invention, there is provided a flexible display device including: a display panel including a base substrate made of a flexible material; And a support substrate coupled to a lower surface of the base substrate, wherein at least one first bubble outlet is formed in the support substrate in a region corresponding to a region except for a display region of the display panel.

According to another aspect of the present invention, there is provided a support substrate for a flexible display device coupled to a base substrate of a flexible display device, the display substrate including a display region of the unit display panel within a first region, At least one first bubble outlet formed to penetrate the support substrate in a second region corresponding to the excluded region; And at least one second bubble outlet formed on the support substrate to penetrate the support substrate in a third region excluding the first region.

According to another aspect of the present invention, there is provided a method of manufacturing a flexible display device coupled to a base substrate of a flexible display device, the method comprising: forming a base substrate on a carrier substrate; Forming a thin film transistor and a pixel electrode on the base substrate; Separating the base substrate and the carrier substrate; And laminating the supporting substrate on which the bubble outlet is formed to the base substrate so that bubbles are discharged through the bubble outlet.

According to the present invention, since the flexible display device includes the support substrate laminated on the plastic base substrate, the impact resistance of the flexible display device is improved.

In addition, since at least one bubble outlet is formed on the supporting substrate, bubbles generated when laminating the supporting substrate to the base substrate can be removed, thereby minimizing defects in the flexible display device due to bubbles .

Further, since the bubbles are discharged through at least one bubble outlet formed on the supporting substrate when laminating the supporting substrate to the base substrate, the time required for the auto-clave process for removing bubbles in the flexible display device is shortened I can. This has the effect of reducing the tact time of the flexible display device.

1 is a sectional view of a supporting substrate for a flexible display device according to an embodiment of the present invention;
Fig. 2 is a view showing the structure of the bubble outlet shown in Fig. 1; Fig.
3 is a cross-sectional view schematically showing a configuration of a flexible display device according to an embodiment of the present invention.
4 is a flowchart illustrating a method of manufacturing a flexible display device according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing an embodiment of the present invention, when a structure is described as being "on" or "under" another structure, such a substrate is not limited to the case where these structures are in contact with each other, It should be interpreted to include the case where the structure is interposed. However, if the terms "directly above" or "directly below" are used, these structures should be construed as limited to being in contact with each other.

1 is a schematic cross-sectional view of a flexible display device according to an embodiment of the present invention. In the following description, it is assumed that the flexible display device is an electrophoretic display device. However, the present invention is not limited to this, and a display device including a base substrate formed of a flexible material such as an organic light emitting display (OLED) And may be applied to a display device such as a display device (LCD).

1, a flexible display device 100 according to an exemplary embodiment of the present invention includes a base substrate 110, an electrophoretic film 120, a protective sheet 130, and a supporting substrate 140 .

The base substrate 110 may be a flexible plastic substrate or a metal substrate as the base substrate 110 in order to impart flexibility to the flexible display device 100. In one embodiment, the base substrate 110 may be a film formed of polyimide. At this time, since the base substrate 110 is located on the side opposite to the side where the image is displayed, it is not necessary to have transparency. The base substrate 110 may be formed as a rectangular plate as a whole.

A thin film transistor (TFT) (not shown) and a pixel electrode are formed on the base substrate 110. The thin film transistor TFT includes a gate electrode (not shown) protruded from a gate line (not shown), a source electrode (not shown) protruded from a data line (not shown) And a drain electrode (not shown), and the pixel electrode is connected to the drain electrode through the contact hole.

Next, the electrophoretic film 120 is bonded onto the base substrate 110. As shown in FIG. 1, the electrophoretic film 120 may be attached to and bonded to the upper surface 110 a of the base substrate 100.

The electrophoretic film 120 according to the present invention includes a plurality of microcapsules 200 having an electrophoretic dispersion 210, as shown in FIG. The electrophoretic dispersion 210 includes a dielectric solvent 212 and positive and negative charged particles 214 and 216, respectively, dispersed in the dielectric solvent.

The dielectric solvent 212 is preferably transparent so as to secure the reflection luminance. Examples thereof include water, an alcohol solvent, an ester solvent, a ketone solvent, an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, a halogenated solvent, etc. These materials may be used alone or as a mixture. The dielectric solvent 212 may further comprise a surfactant. The dielectric solvent 212 may be selected to have a low viscosity in terms of ensuring high mobility of the charged particles 214 and 216.

The black particles 214 are, for example, polymers or colloids colored with black dyes such as aniline black and carbon black, and can be positively charged. The white particles 216 are, for example, polymers or colloids colored with white dyes such as titanium dioxide, antimony trioxide, etc., and can be used by being negatively charged. In addition to these dyes, a charge control agent, a dispersant, a lubricant, and the like may be further added, if necessary.

In the present specification and the drawings, the electrophoretic dispersion liquid 210 in which positively charged black particles 214 and negatively charged white particles 216 are dispersed in a colorless dielectric solvent is taken as an example for convenience of explanation, The electrophoretic dispersion 210 of the invention is not limited thereto, and an electrophoretic dispersion in which charged white particles are dispersed in a dielectric solvent containing a black dye may be used.

Meanwhile, the electrophoretic film 120 according to the present invention may further include a base film (not shown), a common electrode (not shown), and an adhesive layer (not shown). At this time, the electrophoretic film 120 has a structure in which a base film, a common electrode, a plurality of microcapsules, and an adhesive layer are sequentially laminated. The adhesive layer 640 of the electrophoretic film 120 is attached to the base substrate 110 by a laminating process.

The base film is made of glass or plastic, and the common electrode is formed of ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The base film and the common electrode must be transparent for image display.

The electrophoretic film 120 as described above may be a front-plane laminate (FPL). Although not shown, the electrophoretic display device 100 according to the present invention may use a microcup electrophoretic film 120.

Referring again to FIG. 1, the protective sheet 130 is bonded onto the electrophoretic film 120. As shown in FIG. 1, the protective sheet 130 may be attached to and bonded to the upper surface of the electrophoretic film 120. The protective sheet 130 may be formed as a rectangular plate as a whole.

Next, the supporting substrate 140 is coupled to the lower surface of the base substrate 110. [ At this time, the supporting substrate 140 may be coupled to the lower surface of the base substrate 110 using an adhesive (not shown). In addition, the supporting substrate 140 may be formed using a material having flexibility to make the flexible display device 100 flexible.

In one embodiment, the support substrate 140 may be formed using a material including CHO, such as polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), or polycarbonate (PC). In another embodiment, the support substrate 140 may be formed using a material such as Rubber or Olefin.

As described above, since the flexible display device 100 according to the present invention further includes the support substrate 140 for supporting the flexible base substrate 110, the flexible display device 100 can be formed into a desired shape And the impact resistance of the flexible display device 100 can be improved.

In one embodiment, at least one first bubble outlet 142 may be formed in the support substrate 140 according to the present invention, as shown in FIG.

At least one first bubble outlet 142 is formed in the support substrate 140 to discharge bubbles generated in the process of laminating the support substrate 140 to the base substrate 110.

In the process of manufacturing the flexible display device 100, when the supporting substrate 140 in the original state is laminated to the base substrate 110, air bubbles are only generated. In order to remove such air bubbles, an auto- Even if the process is applied, the generated bubbles can not be completely removed. Accordingly, in the case of the present invention, bubbles are removed by forming at least one first bubble outlet 142 for discharging bubbles in the supporting substrate 140.

The at least one first bubble outlet 142 may be formed in the region 170 corresponding to the region 160 excluding the display region 150 of the flexible display device 100. In this case, For example, at least one first bubble outlet 142 is formed in a region corresponding to the link region 162 between the pad region 164 where the driver circuit portion 180 and the printed circuit board 182 are mounted and the display region 150, (Not shown).

As described above, in the present invention, at least one first bubble outlet 142 is formed on the support substrate 140, so that the bubble generated in the process of laminating the support substrate 140 to the base substrate 110 Can be discharged through the at least one first bubble outlet (142), thereby minimizing product defects.

Hereinafter, the structure of the supporting substrate used in such a flexible display device will be described in more detail with reference to Fig. Hereinafter, the base substrate 110, the electrophoretic film 120, and the protective sheet 130 constituting the flexible display device are defined as constituting a unit display panel for convenience of explanation.

2 is a plan view of a supporting substrate for a flexible display device according to an embodiment of the present invention. 2, the supporting substrate 140 includes a first region 200 where the display panel is disposed and a second region 210 excluding the first region, and the supporting substrate 140 is provided with the above- At least one first bubble outlet 142 is formed.

At this time, as shown in the enlarged view of FIG. 2A, at least one first bubble outlet 142 is formed in the first region 200 where the unit display panel is disposed on the support substrate 140, And is formed in the corresponding region 170. Specifically, the first bubble outlet 142 may be formed in the region 172 corresponding to the link region between the pad region and the display region.

In one embodiment, at least one second bubble outlet 144 may be additionally formed in the support substrate 140 according to the present invention to further facilitate discharge of bubbles.

At this time, the second bubble outlet 144 may be formed in the second region 210 in the supporting substrate 140, as shown in FIG. 2A. For example, the second bubble outlet 144 may be formed between the first region 200 and the first region 200 where the unit display panel is disposed within the second region of the support substrate 140, or between the first region 200 and the support substrate 140, As shown in Fig.

In the above-described embodiment, the first and second bubble outlets 142 and 144 may be formed in a plurality of holes passing through the support substrate 140 as shown in FIG.

In the modified embodiment, the first and second bubble outlets 142 and 144 may be formed in the shape of a dot line passing through the support substrate 140, as shown in FIG. 3A, And the supporting substrate 140, as shown in FIG.

2B, when the bubbles 230 are generated during the process of laminating the supporting substrate 140 to the base substrate 110, when the bubbles 230 are generated in the process of laminating the supporting substrate 140 to the base substrate 110, (230) can be discharged to the outside through the at least one first bubble outlet (142) or the at least one second bubble outlet (144), thereby minimizing product defects.

Hereinafter, a manufacturing method of a flexible display device according to the present invention will be described with reference to FIG.

4 is a flowchart illustrating a method of manufacturing a flexible display device according to an embodiment of the present invention. 4, it is assumed that the flexible display device is an electrophoretic display device. However, the present invention is not limited to this, and a flexible display device in which a supporting substrate is attached to a base substrate made of a flexible material It will be possible to apply them all regardless

First, a base substrate is formed on a glass substrate (Carrier Substrate) (S400). In one embodiment, such a base substrate may be formed using a material having flexibility such as polyimide.

Specifically, the base substrate is formed by coating a polymeric material layer such as polyimide on a carrier substrate using a slit coating, a spin coating, or a bar coating technique, and curing the carrier substrate having the polymeric material layer formed thereon by an oven or a furnace And the polymeric material layer is cured by being placed inside the device.

Although not shown, the present invention can further include a step of forming an adhesive layer on the carrier substrate in order to facilitate peeling between the base substrate and the carrier substrate, which will be described later. Such an adhesive layer may be formed using an inorganic material such as amorphous silicon (a-Si) or silicon nitride (SiNx).

Next, a thin film transistor and a pixel electrode are formed on the base substrate (S410). The thin film transistor includes a gate electrode protruding from the gate line, a source electrode protruded from the data line, and a drain electrode spaced apart from the source electrode by a predetermined distance, and the pixel electrode is connected to the drain electrode through the contact hole.

Next, the base substrate and the carrier substrate are separated (S420). In one embodiment, the base substrate and the carrier substrate can be separated by irradiating a laser beam to the back surface of the carrier substrate.

Next, the supporting substrate is laminated on the lower surface of the base substrate (S430). In one embodiment, at least one first bubble outlet and at least one second bubble outlet are formed in the support substrate to remove bubbles generated during laminating of the support substrate.

At this time, the first bubble outlet is formed in a region corresponding to a region except for the display region in the first region where the unit display panel is disposed on the support substrate, as shown in an enlarged view of FIG. 1 and FIG. Specifically, the first bubble outlet may be formed in a region corresponding to a link region between the pad region and the display region.

On the other hand, the second bubble outlet may be formed in the second region except for the first region where the unit display panel is disposed on the support substrate as shown in FIG. 2A. More specifically, the second bubble outlet may be formed in a region between first regions where the unit display panel is disposed on the support substrate, or in a region between the first region and the support substrate.

In the above-described embodiment, it is described that at least one first bubble outlet and at least one second bubble outlet are formed on the support substrate. However, in the modified embodiment, the first bubble outlet and the second bubble outlet Only one of them may be formed on the supporting substrate.

As described above, in the process of laminating the support substrate to the base substrate, the bubbles generated during laminating through the first bubble outlet and the second bubble outlet formed on the support substrate can be discharged to the outside, .

In addition, the present invention can discharge bubbles generated during laminating through the first and second bubble outlets to the outside, thereby shortening the time required for an auto-clave process for removing bubbles. As a result, the tact time of the flexible display device can be reduced.

On the other hand, in the above-described embodiment, the supporting substrate can be formed using a material having ductility so that the flexible display device has ductility. In one embodiment, the support substrate may be formed using a material including CHO, such as polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), or polycarbonate, or formed using a material such as rubber or olefin have.

Such a supporting substrate can be laminated to a base substrate using an adhesive.

Next, the electrophoretic film and the protective sheet are attached on the pixel electrodes formed on the base substrate (S440). As described above, the electrophoretic film includes a base film, a common electrode, a plurality of microcapsules, and an adhesive layer, and the microcapsules contain a dielectric solvent and a positive and negative charged And an electrophoretic dispersion composed of particles.

In one embodiment, the electrophoretic film may be attached to the base substrate using a laminating technique. At this time, the adhesive layer included in the electrophoretic film is attached to the base substrate, so that the electrophoretic film can be bonded onto the base substrate. In one embodiment, the electrophoretic film may be a FPL.

On the other hand, the protective sheet to be attached on the electrophoretic film may be formed in a rectangular plate as a whole.

Next, the base substrate is scribed to form a unit display panel (S450), and the driving circuit and the printed circuit board are attached to each unit display panel (S460). Thereafter, the unit display panel is sealed by applying silicon to the region where the driving circuit portion and the printed circuit board are attached (S470).

On the other hand, in the above-described embodiment, the electrophoretic film and the protective sheet are attached after separating the carrier substrate from the base substrate. However, in the modified embodiment, the electrophoretic display film and the protective sheet are attached The carrier substrate may be separated from the base substrate. That is, S440 in FIG. 4 may be performed between S410 and S420.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

For example, while the present invention is described as being applied to an electrophoretic display device using microcapsules in the above-described embodiments, the present invention may be applied to an electrophoretic display device using a barrier rib in a modified embodiment.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Flexible display device 110: Base substrate
120: electrophoretic film 130: protective sheet
140: support substrate 142: first bubble outlet
144: Second bubble outlet

Claims (10)

A display panel including a base substrate made of a material having flexibility; And
And a support substrate coupled to a lower surface of the base substrate,
Wherein at least one first bubble discharge port is formed in the support substrate in an area corresponding to an area excluding the display area of the display panel. The method according to claim 1,
Wherein the at least one bubble outlet is formed in an area corresponding to a link area between the display area and the pad area. The display device according to claim 1,
The base substrate on which the thin film transistor and the pixel electrode are formed;
An electrophoretic film bonded onto the base substrate; And
And a protective sheet bonded on the electrophoretic film. A supporting substrate for a flexible display device coupled to a base substrate of a flexible display device,
At least one first bubble outlet formed to penetrate the support substrate in a second region corresponding to a region except a display region of the unit display panel within a first region in which the unit display panel is disposed; And at least one second bubble outlet formed on the support substrate to penetrate the support substrate in a third region excluding the first region. 5. The method of claim 4,
Wherein the first and second bubble outlets are formed of a plurality of holes, dot lines, or one connected line. 5. The method of claim 4,
And the second bubble outlet is formed to surround the first region. Forming a base substrate on the carrier substrate;
Forming a thin film transistor and a pixel electrode on the base substrate;
Separating the base substrate and the carrier substrate; And
And laminating the supporting substrate on which the bubble outlet is formed to the base substrate so that bubbles are discharged through the bubble outlet. 8. The method of claim 7,
The bubbles are discharged through the first bubble outlet formed in the second region corresponding to the region excluding the display region of the display panel in the first region in which the display panel is disposed on the support substrate in the laminating step Of the flexible display device. 9. The method of claim 8,
Wherein the bubble is discharged through a second bubble outlet formed to penetrate the supporting substrate in a third region except for a first region in which the display panel is disposed on the supporting substrate in the laminating step, ≪ / RTI > 8. The method of claim 7,
Attaching an electrophoretic film on the pixel electrode; And
And bonding the protective sheet on the electrophoretic film. ≪ RTI ID = 0.0 > 21. < / RTI >

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