KR20150075604A - Flexible display device and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a flexible display device and, more specifically, to a flexible display device capable of preventing deterioration in the quality of an image caused by static electricity and damage to pixels and a panel-driving part and to a manufacturing method thereof. For the purpose, the flexible display device according to the present invention comprises: a display panel including a first substrate having a plurality of pixels and a second substrate bonded to face the first substrate; a static electricity-absorbing substrate for supporting the first substrate and absorbing static electricity generated in the vicinity of the display panel; and a conductive adhesive layer placed between the first substrate and the static electricity-absorbing substrate to attach the same to each other.

Description

[0001] FLEXIBLE DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly, to a flexible display device and a method of manufacturing the same, which can prevent deterioration of image quality due to static electricity and damage of a pixel or a panel driving part.

In general, a flexible display device has advantages in that a pixel cell is implemented on a thin flexible substrate such as a plastic substrate, so that an image desired to be folded or rolled up like paper can be displayed. And research and development thereof is proceeding. Such a flexible display device may be a flexible liquid crystal display device, a flexible plasma display device, a flexible organic light emitting display device, a flexible electrophoretic display device flexible electrophoretic display device, or a flexible electro-wetting display device.

1 is a cross-sectional view schematically showing a general flexible display device.

Referring to FIG. 1, a typical flexible display device includes a display panel 10, a support member 40, and a panel driver 20.

The display panel 10 includes a lower substrate 11 and an upper substrate 12 which are adhered to each other.

The lower substrate 11 is made of a thin flexible substrate such as plastic. The lower substrate 11 includes a display region composed of a plurality of pixels for displaying an image, a non-display region surrounding the display region, and a pad portion provided on one side of the non-display region.

For example, a gate line and a data line defining a pixel region are formed in a crossing manner in a display region, a thin film transistor is formed in a region where a gate line and a data line cross each other, As shown in Fig. The pad portion is formed on one side non-display region of the lower substrate 11 so as to be connected to each of the gate line and the data line, and is connected to the panel driving portion 20. [

The upper substrate 12 is made of a thin and transparent flexible substrate such as plastic or the like and is formed to have a smaller area than the lower substrate 11. The upper substrate 12 is adhered to the lower substrate 11 except for the pad portion of the lower substrate 11 by a joining member (not shown) formed in a non-display region of the lower substrate 11 in the form of a closed loop.

The panel driver 20 is connected to the pad portion of the lower substrate 11 and supplies signals to the gate lines and the data lines. For this, the panel driving unit 20 may be formed of a flexible circuit board, a driving circuit unit, and the like.

A support member 40 made of a plastic material for supporting the display panel 10 is formed on the lower surface of the display panel 10. The support member 40 may be made of a plastic substrate such as PET.

An adhesive layer 41 is present between the display panel 10 and the support member 40 to attach the display panel 10 and the support member 40 to each other.

The support member 40 is attached to the adhesive layer 41 to prevent foreign matter from adhering to the adhesive layer 41 before being attached to the display panel 10.

The adhesive layer 41 is exposed to the outside and attached to the lower surface of the display panel 10 when the film attached to one surface of the supporting member 40 is peeled to attach the supporting member 40 to the display panel 10 do..

However, in the conventional flexible display device, in order to adhere the supporting member 40 to the display panel 10, the film adhered to the film when peeling off the film is separated to cause charge separation, and static electricity is generated. When static electricity accumulation occurs in a direction perpendicular to the stripping direction of the film and the support member 40 is attached to the display panel 10 in this state to drive the display image, there is a problem that the electrostatic band unevenness occurs as shown in FIG.

In addition, when static electricity is generated in the surroundings after the display device is completed, the static electricity flows into the first substrate 11 along the support member 40, thereby damaging the circuit parts for pixel and panel driving.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flexible display device and a method of manufacturing the same that can prevent deterioration of image quality due to static electricity and damage of a pixel or a panel driving part.

According to an aspect of the present invention, there is provided a flexible display device including: a display panel including a first substrate including a plurality of pixels and a second substrate facing the first substrate; An electrostatic absorption substrate for supporting the first substrate and absorbing static electricity generated around the display panel; And a conductive adhesive layer positioned between the first substrate and the electrostatic absorption substrate and adhered to each other.

According to another aspect of the present invention, there is provided a method of manufacturing a flexible display, comprising: forming a first substrate including a plurality of pixels; bonding a second substrate to one surface of the first substrate by facing the first substrate; Removing the support substrate supporting one surface of the display panel, preparing a static-absorbing substrate, removing the film adhered to the electrostatic-absorption substrate to expose the conductive adhesive layer, and removing the conductive adhesive layer And attaching the display panel to one surface of the display panel.

According to the present invention, the conductive adhesive layer between the supporting member and the film absorbs static electricity generated when the film is peeled off, thereby preventing electrostatic aggregation. Therefore, when an image is displayed, a stain defect due to static electricity aggregation is prevented.

Further, according to the present invention, when an external static electricity is generated, the electrostatic absorption substrate absorbs static electricity and prevents the pixel and the panel driving unit from being damaged by static electricity.

1 is a cross-sectional view schematically showing a general flexible display device;
Fig. 2 is a plan view showing a defective electrostatic stain occurring in a general flexible display device. Fig.
3 is a cross-sectional view showing a flexible display device according to the present invention.
4 is a cross-sectional view of a conductive adhesive layer and an electrostatic absorption substrate applied to a flexible display device according to the present invention.
5 is a flowchart showing a manufacturing step of a flexible display device according to the present invention.

Hereinafter, a flexible display device and a method of manufacturing the same according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a perspective view illustrating a support member applied to the flexible display device according to the present invention, and FIG. 4 is a cross-sectional view illustrating a support member applied to the flexible display device according to the present invention.

3, the flexible display device according to the present invention includes a first substrate 110 including a plurality of pixels and a second substrate 120 which is adhered to the first substrate 110 so as to face each other A display device includes a display panel 100, an electrostatic absorption substrate 400 supporting the second substrate 120 and absorbing static electricity generated around the display panel 100, And a conductive adhesive layer 410 positioned between and adhering to each other.

First, the display panel 100 will be described as follows.

The display panel 100 may be a flexible flat panel display device. In the following description, it is assumed that the display panel 100 is an organic light emitting display panel that is applied to a flexible organic light emitting display device among flexible flat panel display devices. The display panel 100 includes a first substrate 110 and a second substrate 120 which are bonded to each other.

First, the first substrate 110 is a flexible substrate, and may be made of a plastic material or a metal foil. That is, since the first substrate 110 is formed of a flexible material, it can be bent.

For example, the first substrate 110 made of a plastic material may be made of any one material selected from polyimide (PI), polycarbonate (PC), polynorbornene (PNB), polyethyleneterephthalate (PET), polyethylenepthanate (PEN), and polyethersulfone Lt; / RTI > The first substrate 110 includes a display unit, a non-display unit, and a pad unit.

The display portion of the first substrate 110 includes a plurality of gate lines (not shown), a plurality of data lines (not shown), a plurality of driving power lines (not shown), a plurality of pixels (not shown) Not shown).

Each of the plurality of gate lines is formed at regular intervals so as to intersect with each of the plurality of data lines, and each of the plurality of driving power supply lines is formed to be in parallel with each of the plurality of gate lines or each of the plurality of data lines.

Each of the plurality of pixels is formed in a pixel region defined by the gate line and the data line intersecting to display an image in accordance with a gate signal from the gate line and a data signal from the data line. To this end, each of the plurality of pixels includes a pixel driving circuit (not shown) connected to the gate line and the data line, and an organic light emitting element (not shown) connected to the pixel driving circuit and connected to the cathode power line .

The pixel driving circuit includes a switching transistor (not shown) connected to the gate line and the data line, a driving transistor (not shown) connected to the switching transistor, a capacitor connected to the gate electrode and the source electrode of the driving transistor Time).

Wherein the pixel driving circuit supplies a data signal supplied to the data line to the driving transistor in accordance with switching of the switching transistor according to a gate signal supplied to the gate line, The gate-source voltage of the capacitor is stored in the capacitor.

By turning on the driving transistor with the voltage stored in the capacitor, a data current corresponding to the data signal is supplied to the organic light emitting element. Here, the transistor may be an a-Si TFT (thin film transistor), a poly-Si TFT, an oxide TFT, an organic TFT, or the like.

The pixel driving circuit may further include at least one compensation transistor and at least one compensation capacitor for compensating a threshold voltage of the driving transistor.

The organic light emitting device includes a pixel electrode (or an anode electrode) connected to the driving transistor, an organic light emitting layer (not shown) formed on the pixel electrode, and a cathode electrode (not shown) formed on the organic light emitting layer. The organic light emitting diode emits light of a luminance corresponding to the data current by the current flowing from the pixel electrode to the cathode electrode by the turn-on of the driving transistor, Lt; / RTI >

The cathode power supply line may be formed on the entire surface of the display unit so as to be electrically connected to the cathode electrodes of the pixels or may be electrically connected to the cathode electrodes of the pixels formed on the vertical or horizontal line of the display unit. . The cathode power supply line may be formed to be electrically connected to the organic light emitting layer of each pixel, in which case the cathode electrode is omitted.

The non-display portion is provided in a peripheral region of the display portion so as to surround the display portion. Here, the non-display portion may be defined as an area overlapping an edge portion of the second substrate 120.

And a plurality of pad portions electrically connected to the plurality of gate lines, the plurality of data lines, the plurality of driving power supply lines, and the cathode power supply line formed in the display portion are formed on one side of the non-display portion.

And a panel driving unit 200 for driving the display panel 100 is connected to the pad unit. The panel driver 200 may include a flexible circuit board and a drive integrated circuit.

Second, the second substrate 120 is made of a transparent plastic material and has a relatively smaller area than the first substrate 110. The second substrate 120 is adhered to the first substrate 110 by a joining member (not shown) formed in a closed loop shape on a non-display portion of the first substrate 110.

The first and second substrates 110 and 120 are bonded to each other and the first substrate 110 and the second substrate 120 are bonded to each other to protect the organic light emitting device from external moisture or oxygen. 2 substrates 120. [0034] FIG.

That is, the second substrate 120 may function as an encapsulating substrate for sealing the first substrate 110.

3, the conductive adhesive layer 410 and the electrostatic absorption substrate 400 are formed on the lower surface of the first substrate 110 of the display panel 100

First, the electrostatic absorption substrate 400 is formed on the lower surface of the first substrate 110 to prevent foreign matter from adhering to the bottom surface of the first substrate 110, It is possible to prevent the light emitted from the first substrate 110 from traveling in the downward direction of the first substrate 110.

When the static electricity is generated outside the display device, the static electricity absorbing substrate 400 absorbs the static electricity to prevent the static electricity from damaging the pixels and the panel driving part 200 in the display area of the first substrate 110.

In addition, the display panel 100 also radiates heat generated by the heat generated in the display panel 100 to the outside.

Here, the electrostatic absorption substrate 400 can be made of a metal material having electrical conductivity, but SUS foil, copper foil, and aluminum foil can be mainly used.

Second, the display panel 100 and the electrostatic absorption substrate 400 are attached to each other by the conductive adhesive layer 410 as shown in FIG. The conductive adhesive layer 410 serves to prevent the generation of static electricity and the accumulation of static electricity before the electrostatic absorption substrate 400 is attached to the display panel 100. The conductive adhesive layer may be formed of a polyacetylene (PA) derivative, a polyaniline (PANI) derivative, a polythiophene (PT) derivative, a polypyrrole (PPy) derivative, a poly (phenylenevinylene) PPV) derivatives and the like can be applied. The present invention describes the synthesis of a PEDOT material, one of the polythiophene derivatives, and a sticky solution composed of acrylic or silicone. The present invention is not limited to the PEDOT material but may be applied to any conductive polymer material.

Before the electrostatic absorption substrate 400 is attached to the display panel 100, the film is attached by a conductive adhesive layer as shown in Fig. Here, the film serves to prevent foreign matter from adhering to the conductive adhesive layer 410 until just before the electrostatic absorption substrate 400 is attached to the display panel 100.

When the film 420 is peeled off for attaching the electrostatic-absorption substrate 400 to the display panel 100, the two objects that are in close contact with each other are separated from each other, causing charge separation, and static electricity is generated on the conductive adhesive layer 410 . Then, static electricity is accumulated between the regions to be peeled, and an electrostatic band can be formed in the direction perpendicular to the peeling direction. The conductive adhesive layer 410 absorbs and neutralizes the static electricity accumulated in a strip shape, thereby eliminating banding unevenness caused during image driving.

The manufacturing steps of the flexible display device according to the present invention will be described with reference to FIG.

First, it is the glass substrate backside cleaning step shown in Fig. 5 (a). When the display panel 100 is completed by reversing the first substrate 110 and the second substrate 120 so that the glass substrate 500 supporting the first substrate is positioned at the upper portion do.

Then, the upper surface of the glass substrate 500 is cleaned with the polishing cloth 600 to remove foreign matter.

Second, the laser irradiation step shown in Fig. 5 (b). When the cleaning of the glass substrate 500 is completed, the entire surface of the glass substrate 500 is irradiated with laser 700 starting from one end of the glass substrate 500 to remove the sacrificial layer (not shown) formed between the glass substrate 500 and the first substrate 110 Weakens the binding force. The sacrificial layer (not shown) is made of amorphous-silicon and absorbs the energy of the laser 700 to be crystallized into poly-silicon so that the gap between the glass substrate 500 and the first substrate 110 .

Third, it is a glass substrate peeling step shown in Fig. 5 (c). The glass substrate 500 with reduced bonding force is removed from the display panel 100. [

Next, the preparation step of the electrostatic absorption substrate 400 will be described.

First, the electrostatic absorption substrate 400 processes SUS, copper, and aluminum materials into a thin film form.

Secondly, a conductive polymer solution is conventionally mixed with a viscous solution composed of silicon or an acrylic component and applied on one side of the electrostatic absorption substrate 400. As the conductive polymer solution, a PEDOT material, which is one of the polythiophene derivatives, can be used.

Third, the applied mixed liquid is photo-cured to form a conductive adhesive layer 410 on the electrostatic absorption substrate 400.

Fourth, when the conductive adhesive layer 410 is formed, the film is attached to the conductive adhesive layer 410 so that the conductive adhesive layer 410 adheres to the conductive adhesive layer 410 until the electrostatic-absorption substrate 400 is bonded to the display panel 100 ≪ / RTI >

4, the electrostatic absorption substrate 400 and the film 420 are attached to each other by the conductive adhesive layer 410. In this case,

5 (c), when the glass substrate 500 located on the inverted display panel 100 is stripped, the film 420 located on the electrostatic absorption substrate 400 is peeled at the same time to form a conductive adhesive layer (Not shown).

In this case, when the film 420 on the electrostatic absorption substrate 400 is peeled off, when two objects in contact with each other are separated and charge separation occurs and static electricity is generated on the conductive adhesive layer 410, the conductive adhesive layer 410 is gathered Absorbs and neutralizes the static electricity.

Finally, it is a step of attaching the electrostatic absorption substrate shown in Fig. 5 (d). The one side of the display panel 100 on which the glass substrate 500 is peeled and the electrostatic absorption substrate 400 are attached through the conductive adhesive layer 410.

As a result, when the electrostatic absorption substrate 400 is attached to the display panel 100, even if static electricity is generated outside the product, the static electricity is absorbed to prevent the static electricity from flowing into the display panel 100 and damaging the pixels and the panel driving circuit .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of.

100: display panel 110: first substrate
120: second substrate 200: panel driver
400: electrostatic absorption substrate 410: conductive adhesive layer
420: film 500: glass substrate
600: polishing cloth 700: laser

Claims (7)

A display panel including a first substrate including a plurality of pixels, and a second substrate facing the first substrate;
An electrostatic absorption substrate for supporting the first substrate and absorbing static electricity generated around the display panel; And
And a conductive adhesive layer positioned between the first substrate and the electrostatic absorption substrate and adhered to each other. The method according to claim 1,
Wherein the electrostatic absorption substrate comprises one of an SUS foil, a copper foil, and an aluminum foil. The method according to claim 1,
Wherein the conductive adhesive layer comprises a polythiophene derivative material. Forming a first substrate including a plurality of pixels;
Preparing a display panel by facing a second substrate to one surface of the first substrate;
Removing a supporting substrate supporting one surface of the display panel;
Preparing a static-absorbing substrate;
Removing the film attached to the electrostatic absorption substrate to expose the conductive adhesive layer; And
And attaching the conductive adhesive layer to one surface of the display panel. 5. The method of claim 4,
Wherein the step of preparing the electrostatic absorption substrate comprises:
Applying a conductive adhesive solution to one surface of the electrostatic absorption substrate;
Curing the conductive adhesive solution to form the conductive adhesive layer; And
And adhering the film to the conductive adhesive layer,
Wherein the conductive adhesive solution is formed by mixing a conductive polymer material and an adhesive material. The method of claim 4,
Wherein the electrostatic absorption substrate is formed of any one of an SUS foil, a copper foil, and an aluminum foil. 6. The method of claim 5,
The conductive polymer solution may contain,
Wherein the polythiophene derivative material is a polythiophene derivative material.

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