KR20160038959A - Flexible display apparatus and method for manufacturing thereof - Google Patents

Abstract

The present invention provides a flexible display apparatus with a thin bezel width and a method for manufacturing the same. The flexible display apparatus according to the present invention may include a flexible substrate including a pixel and a hole pattern; a back contact electrode which is embedded in the hole pattern and is connected to the signal lien of the pixel; and a pad part which is prepared on the lower surface of the flexible substrate to be connected to the back contact electrode.

Description

[0001] FLEXIBLE DISPLAY APPARATUS AND METHOD FOR MANUFACTURING THEREOF [0002]

The present invention relates to a display device, and more particularly, to a flexible display device having a thin bezel width and a method of manufacturing the same.

Flat panel display devices are becoming increasingly important with the development of multimedia. In response to this, flat panel display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting display device have been commercialized. Among such flat panel display devices, organic light emitting display devices are attracting attention as a next generation flat panel display device because they have a high response speed, low power consumption, and self-luminescence, so that there is no problem in viewing angle.

Among the flat panel display devices, the organic light emitting display device and the electrophoretic display device can also be realized as a flexible display device using a flexible substrate.

1 is a cross-sectional view schematically showing the configuration of a conventional flexible display device.

1, a conventional flexible display device includes a flexible substrate 10 having a display area AA and a non-display area NA, a pixel 11 provided in a display area AA of the flexible substrate 10, A pad portion 12 provided in a non-display area NA of the flexible substrate 10, a routing line 13 connecting a signal line of the pixel 11 and the pad portion 12, and a pixel 11 A sealing layer 14 covering the display area AA and the peripheral area of the display area AA, a flexible circuit film 15 attached to the pad part 12, and a driving integrated Circuitry 16.

The pixel 11 includes a thin film transistor provided in a pixel region defined by intersection of a data line and a gate line, a data line DL and a gate line GL, and an anode electrode connected to the thin film transistor. An organic light emitting element having an organic light emitting layer, and a cathode electrode connected to the organic light emitting element.

Each of the plurality of data lines and the plurality of gate lines is connected to the pad portion 12 through the corresponding routing line 13.

The sealing layer 14 serves to protect the organic light emitting element from oxygen and moisture and is formed on the flexible substrate 10 so as to cover the pixels 11 except for the pad portions 12. [ Here, the sealing layer 14 may be formed of an AlOx material by a sputtering process.

The pad portion 12 includes a plurality of pads formed simultaneously with the anode electrode and exposed to the outside.

Such a conventional flexible display device has the following problems.

First, since a plurality of data lines provided in the pixel 11 are connected to the pad unit 12 through the plurality of routing lines 13, the area of the non-display area NA is increased by the routing line 13 , Which results in an increase in the width of the bezel.

Secondly, since the pad portion 12 is exposed to the outside, the pad is corroded.

Third, it is preferable that the sealing layer 14 is formed by an atomic layer deposition process rather than the sputtering process for improvement of the film quality and high moisture permeability. However, when the sealing layer 14 is formed by an atomic layer deposition process, An additional process of exposing the pad portion 12 after the process becomes necessary.

SUMMARY OF THE INVENTION The present invention provides a flexible display device having a thin bezel width and a method of manufacturing the flexible display device.

According to an aspect of the present invention, there is provided a flexible display device including: a flexible substrate including pixels and a hole pattern; A back contact electrode embedded in the hole pattern and connected to a signal line of the pixel; And a pad portion provided on a lower surface of the flexible substrate to be connected to the back contact electrode.

According to a preferred embodiment of the present invention, a pad portion connected to a signal line of a pixel is formed on a lower surface (or a back surface) of a flexible substrate to form a routing line connecting a signal line of the pixel and a pad portion, It is possible to reduce the width of the bezel of the flexible display device.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention will be described below, or may be apparent to those skilled in the art from the description and the description.

1 is a cross-sectional view schematically showing the configuration of a conventional flexible display device.
2 is a cross-sectional view schematically showing a configuration of a flexible display device according to an exemplary embodiment of the present invention.
3 is a cross-sectional view schematically showing a cross section taken along the line I-I 'shown in FIG.
4 is a view for explaining a first example of the plurality of first and second pad portions shown in FIG.
5 is a view for explaining a second example of the plurality of first and second pad portions shown in FIG.
FIG. 6 is a view for explaining a third example of the plurality of first and second pad portions shown in FIG. 3. FIG.
7A to 7K are process sectional views schematically showing a manufacturing method of a flexible display device according to an exemplary embodiment of the present invention, which is a process sectional view of the line I-I 'shown in FIG.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms. It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one. The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

Hereinafter, preferred embodiments of a flexible display device and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 2 is a cross-sectional view schematically showing a configuration of a flexible display device according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view schematically showing a cross section taken along a line I-I 'shown in FIG.

2 and 3, a flexible display device according to an exemplary embodiment of the present invention includes a flexible substrate 100, a pixel P, a plurality of first and second hole patterns 200 and 300, And second back contact electrodes 210 and 310, and first and second pad units 250 and 350.

The flexible substrate 100 may be made of a flexible plastic material, for example, an opaque or colored polyimide (PI) material. The flexible substrate 100 according to an exemplary embodiment may be formed by curing a plastic material coated on a top surface of a lower release layer formed on a relatively thick lower carrier substrate (not shown) with a predetermined thickness. Here, the lower carrier substrate is separated from the flexible substrate 100 by the release of the lower release layer using a laser-releasing process.

The flexible substrate 100 has a display area AA and a peripheral area. The peripheral area is a border area surrounding the display area AA and is defined by a first peripheral area PA parallel to the longitudinal direction X of the long side of the flexible substrate 100 and a longitudinal direction Y of the short side of the flexible substrate 100 And a second peripheral area PA in parallel with the first peripheral area PA. Each of the first and second peripheral areas PA1 and PA2 is preferably formed to have a width BW of several hundreds of micrometers or less in order to minimize the bezel width BW of the flexible display device.

The display area AA of the flexible substrate 100 is divided into a plurality of gate lines GL, a plurality of data lines DL crossing the plurality of gate lines GL, and a plurality of And a power supply line PL. In addition, a plurality of auxiliary power lines may be additionally formed in the display area AA of the flexible substrate 100 according to the driving method of the pixels P.

The pixel P is formed for each pixel region defined on the display region AA by the gate line GL and the data line DL. The pixel P according to one example includes a thin film transistor 110, an anode electrode 130, an organic light emitting element 150, and a cathode electrode 170.

The thin film transistor 110 includes an active layer 111, a gate electrode 113, a drain electrode 115d, and a source electrode 115s.

The active layer 111 is patterned on the flexible substrate 100. The active layer 111 may be formed of an oxide such as Zinc Oxide, Tin Oxide, Ga-In-Zn Oxide, In-Zn Oxide, or In- However, the present invention is not limited thereto, and may be made of a silicon-based semiconductor. As an example, the active layer 111 includes a drain region and a source region by a conducting process, and a channel region that is not conducted in the conducting process. Here, the drain region and the source region are formed in parallel with each other with the channel region therebetween. On the channel region of the active layer 111, a gate insulating film 112 is formed.

The gate electrode 113 is formed together with the gate line GL. The gate electrode 113 is formed in a pattern on the gate insulating film 112 so as to overlap with the channel region of the active layer 111. The gate electrode 112 serves as a mask to prevent the channel region of the active layer 111 from becoming conductive by the dry etching gas during the patterning process of the gate insulating layer 112 using the dry etching process. The gate electrode 113 may be formed of at least one selected from the group consisting of Mo, Al, Cr, Au, Ti, Ni, Alloy, and may be composed of a single layer of the metal or alloy or multiple layers of two or more layers.

An interlayer insulating film 114 is formed on the drain region and the source region of the gate electrode 113 and the active layer 111.

The drain electrode 115d and the source electrode 115s are formed together with the data line DL and the power supply line PL. The drain electrode 115d is formed on the upper surface of the interlayer insulating film 114 which overlaps the drain region of the active layer 111 and is connected to the drain region of the active layer 111. [ The source electrode 115s is patterned on the upper surface of the interlayer insulating film 114 overlapping the source region of the active layer 111 and connected to the source region of the active layer 111. [ The interlayer insulating layer 114 may include a first contact hole for connecting the drain electrode 115d and a drain region of the active layer 111 and a source electrode 115s and a source region of the active layer 111 And a second contact hole for allowing the second contact hole to be formed. The drain electrode 115d and the source electrode 115s are made of the same metal and are made of a metal such as Mo, Al, Cr, Au, Ti, Ni, (Nd), copper (Cu), or an alloy thereof, and may be formed of a single layer of the metal or alloy, or multiple layers of two or more layers.

A protective film 116 is formed on the drain electrode 115d and the source electrode 115s. The protective film 116 may be made of an insulating material such as silicon oxide or silicon nitride, but not limited thereto, and may be made of an insulating material such as photo acryl or benzocyclobutene (BCB).

The anode electrode 130 is patterned on the passivation layer 116 so as to be connected to the source electrode 115s of the thin film transistor 110. The anode electrode 130 may be connected to the source electrode 115s of the thin film transistor 110 through the auxiliary electrode 120 in order to increase the opening area of the pixel P. [ The anode electrode 130 is made of a conductive metal having a high reflectivity to reflect light emitted from the organic light emitting diode 150. For example, the anode electrode 130 may be formed of indium-tin-oxide (ITO) : Cu) / ITO. ≪ / RTI >

The auxiliary electrode 120 is formed in an island shape on the protection film 116 so as to cover the top of the TFT 110 and connected to the source electrode 115s of the TFT 110. The passivation layer 116 includes a third contact hole for connecting the auxiliary electrode 120 to the source electrode 115s of the thin film transistor 110. [

A planarization layer 125 is formed on the auxiliary electrode 120 and the protective layer 116.

The anode electrode 130 is patterned on the planarization layer 125 of the pixel region and connected to the auxiliary electrode 120. For this purpose, the planarization layer 125 includes a fourth contact hole for connecting the anode electrode 130 and the auxiliary electrode 120.

The organic light emitting device 150 is formed on the light emitting region of each pixel P defined on the anode electrode 130. The light emitting region of each pixel P is defined by the bank layer 140 formed on the protective film 116 as a remaining portion excluding the edge portion of the anode electrode 130. [ That is, the bank layer 140 is formed so as to cover the edge portion of the anode electrode 130 and the thin film transistor (TFT), thereby exposing the remaining portion except the edge portion of the anode electrode 130. Accordingly, the organic light emitting element 150 is formed on the upper surface of the anode electrode 130 of the light emitting region defined by the bank layer 140. Although not shown, the organic light emitting diode 150 may have a structure in which a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer are sequentially stacked. However, the hole injection layer and / or the electron injection layer may be omitted. The organic light emitting layer may be formed to emit light of the same color, for example white, for each pixel P, and may emit light of different colors, for example, red, green, or blue, .

The cathode electrode 170 is formed on the bank layer 140 and connected to the organic light emitting diode 150. The cathode electrode 170 may be formed in an electrode shape common to all the pixels P and may be connected to the OLED 150 formed in each pixel P without being divided into the pixels P. [ The cathode electrode 170 is made of a transparent conductive material for emitting light emitted from the organic light emitting diode 150 to the outside.

A sealing layer 190 is formed on the upper surface of the cathode electrode 170 and the bank layer 140 to prevent penetration of oxygen, moisture, and the like. Materials and methods for forming such a sealing layer 190 can be applied without any particular limitation as long as they are well known in the art. However, since the sealing layer 190 according to the present invention can be formed on the entire upper surface of the flexible substrate 100, it is more preferable to form the sealing layer 190 by an atomic layer deposition process, rather than a sputtering process, in order to improve film quality and prevent moisture permeation.

The plurality of first hole patterns 200 are formed in the first peripheral area PA1 of the flexible substrate 100 so as to penetrate the flexible substrate 100 up and down. A plurality of first hole patterns 200 according to an example are formed in the first peripheral area PA1 of the flexible substrate 100 adjacent to one end of each of the plurality of data lines DL.

The plurality of second hole patterns 300 are formed in the second peripheral area PA2 of the flexible substrate 100 so as to penetrate the flexible substrate 100 up and down. A plurality of second hole patterns 300 according to an example are formed in the second peripheral area PA2 of the flexible substrate 100 adjacent to one end of each of the plurality of gate lines GL.

Each of the plurality of first and second hole patterns 200 and 300 may be formed by a laser process or a wet etching process, but is preferably formed by a laser process for productivity and process simplification. Since the flexible substrate 100 is made of a plastic material, cracks are not generated around the hole patterns 200 and 300 formed by the laser, and the reliability of the flexible substrate 100 can be improved have. On the other hand, when the flexible substrate 100 is made of a thin glass material and the hole patterns 200 and 300 are formed by laser, a crack is generated around the hole patterns 200 and 300, 100 may be deteriorated. Therefore, the flexible substrate 100 according to the present invention is made of a plastic material rather than a glass material, so that the hole patterns 200 and 300 can be formed without cracking using a laser.

Each of the plurality of first back contact electrodes 210 is embedded in each of the plurality of first hole patterns 200 to cover the first hole pattern 200 and the first peripheral area PA1 of the flexible substrate 100, And may be made of a metal material. Each of the plurality of first back contact electrodes 210 is individually connected to one end of each of a plurality of data lines DL and a plurality of power supply lines PL. To this end, a plurality of first and second back contact patterns 220 and 230 connected to the plurality of first back contact electrodes 210 are formed in the first peripheral area PA1. The plurality of first and second back contact patterns 220 and 230 may be arranged in a lattice form or zigzag form in at least two rows in the first peripheral area PA1.

Each of the plurality of first back contact patterns 220 is electrically connected to a corresponding first back contact electrode 210 through a first via hole 222 formed in the interlayer insulating layer 114 and a data extension line DLe To one end of the corresponding data line DL. The data extension line DLe and the first back contact pattern 220 extend from one end of the data line DL to the first peripheral area PA1, Is formed to have an area overlapping with the corresponding first hole pattern (200) within a range smaller than the short side length of the first hole pattern (P).

Each of the plurality of second back contact patterns 230 is electrically connected to the corresponding first back contact electrode 210 through a second via hole 232 formed in the interlayer insulating layer 114 so as to be adjacent to the first via hole 222 And is connected to one end of the corresponding power supply line PL through a power extension line PLe. The power extension line PLe and the second back contact pattern 230 extend from one end of the power supply line PL to the first peripheral area PA1 and the second back contact pattern 230 extends The first hole pattern 200 is formed to have the same area as that of the first back contact pattern 220 while overlapping with the corresponding first hole pattern 200.

Each of the plurality of second back contact electrodes 310 is embedded in each of the plurality of second hole patterns 300 and covers the second peripheral area PA2 of the flexible substrate 100 so as to cover the second hole pattern 300. [ And may be made of a metal material. Each of the plurality of second back contact electrodes 310 is individually connected to one end of the plurality of gate lines GL. To this end, a plurality of third back contact patterns 320 connected to the plurality of third back contact electrodes 310 are formed in the second peripheral area PA2. The plurality of third back contact patterns 320 may be disposed in at least one row in the first peripheral area PA1.

Each of the plurality of third back contact patterns 320 is electrically connected to a corresponding second back contact electrode 310 through a third via hole 322 formed in the gate insulating layer 112 and a gate extension line GLe To the one end of the corresponding gate line GL. Here, the gate extension line GLe and the third back contact pattern 320 extend from one end of the gate line GL to the second peripheral area PA2, and the third back contact pattern 320 is formed to extend from the pixel The first hole pattern 300 may be formed so as to have an area overlapping the second hole pattern 300 within a range shorter than the short side length of the first back contact pattern 220 or to be overlapped with the second hole pattern 300, May be formed to have an area.

Each of the plurality of first and second back contact electrodes 210 and 310 may be formed of a metal material formed on the flexible substrate 100 in order to shield light emitted to the active layer 111 of the thin film transistor 110 (Not shown) of the flexible substrate 100 or an alignment mark of a metal material formed on the flexible substrate 100 for substrate alignment in the manufacturing process.

In addition, a buffer layer 102 is formed on the upper surface of the flexible substrate 100. The buffer layer 102 may include first and second inorganic films 102a and 102b.

The first inorganic film 102a is formed of the same material as the lower release layer and is formed to have a constant thickness over the entire upper surface of the flexible substrate 100 including the first and second hole patterns 200 and 300 do. When the flexible substrate 100 and the lower carrier substrate are separated from each other through the laser-releasing process, the first inorganic film 102a is formed on the lower release layer formed in the first and second hole patterns 200 and 300, This is to make it possible to remove it completely. Accordingly, each of the plurality of back contact electrodes 210 and 310 is formed on the upper surface of the first inorganic film 102a formed in the corresponding hole pattern 200. [ For example, the first inorganic film 102a may be formed of silicon oxide or silicon nitride.

The second inorganic film 102b is buried in each of the plurality of hole patterns 200 and 300 and the upper surface of the first inorganic film 102a except the plurality of white contact electrodes 210 and 310 formed in the periphery thereof . The second inorganic film 102b serves to prevent the material contained in the flexible substrate 100 from diffusing into the thin film transistor 100 during the high temperature process during the manufacturing process of the thin film transistor 110, And also prevents moisture from penetrating into the organic light emitting element 150. The second inorganic film 102b may be formed of the same material as the first inorganic film 102a or may be formed of silicon oxide and silicon nitride other than the first inorganic film 102a.

On the upper surface of the buffer layer 102, an interlayer insulating film 114 covering the thin film transistor 110 and the thin film transistor 110 is formed.

The first pad unit 250 is formed on the lower surface of the first peripheral area PA1 of the flexible substrate 100 and is connected to the plurality of first back contact electrodes 210 so that the corresponding first back contact electrode 210, Are individually connected to the corresponding data line DL and the power supply line PL through the back contact patterns 220 and 230 and the extension lines DLe and PLe. Each of the first pad units 250 is connected to each of a plurality of data drivers (not shown), and a data signal and a driving voltage supplied from the corresponding data driver are supplied to the corresponding first back contact electrode 210 .

Each of the second pad portions 350 is formed on the lower surface of the second peripheral region PA2 of the flexible substrate 100 and is connected to the plurality of second back contact electrodes 310 to form a corresponding second back contact electrode 310, The back contact pattern 320, and the gate extension line DGe to the corresponding gate line GL. Each of the second pad portions 350 is individually connected to each of a plurality of gate drivers (not shown), and transmits a gate signal supplied from the corresponding gate driver to the corresponding second back contact electrode 310.

Unlike the anode electrode 130, each of the first and second pad portions 250 and 350 may be formed of a metal material that does not corrode due to moisture, Do.

In addition, the flexible display device according to an exemplary embodiment of the present invention further includes a transparent substrate 500 attached to the upper surface of the sealing layer 190.

The transparent substrate 500 is attached to the upper surface of the sealing layer 190 by the substrate bonding member 410.

The transparent substrate 500 according to an exemplary embodiment may be made of a transparent and flexible engineering plastic material, for example, a PET (polyethyleneterephthalate) material. The transparent substrate 500 according to this example is attached to the upper surface of the sealing layer 190 by the substrate bonding member 410 to form the pad portions 250 and 350 on the lower surface of the flexible substrate 100 And serves as a support substrate. After the process of forming the pads 250 and 350 is completed on the lower surface of the flexible substrate 100, the upper surface of the sealing layer 190 remains attached.

The transparent substrate 500 according to another example may be made of a flexible plastic material, for example, a transparent polyimide (PI) material. In this case, the transparent substrate 500 according to another example may be formed by curing the polyimide material coated on the upper surface of the upper release layer formed on the relatively lower lower carrier substrate (not shown) with a predetermined thickness. The transparent substrate 500 according to this another example is attached to the upper surface of the sealing layer 190 by the substrate bonding member 410 to form the pad portions 250 and 350 on the lower surface of the flexible substrate 100 And serves as a support substrate. When the process of forming the pad portions 250 and 350 is completed on the lower surface of the flexible substrate 100, the upper release layer is separated from the upper carrier substrate by using the laser release process, As shown in Fig.

4 is a view for explaining a first example of the plurality of first and second pad portions shown in FIG.

Referring to FIG. 4, the first pad unit 250 according to the first example includes a plurality of first back contact pads 251, a plurality of first back pad units 253, And a routing line 255.

Each of the plurality of first back contact pads 251 is electrically connected to a first back contact electrode 210 formed in each of a plurality of first hole patterns 200 formed in a first peripheral region PA1 of the flexible substrate 100 A pattern is formed on the lower surface of the first peripheral area PA1.

Each of the plurality of first rear pad units 253 is provided at a predetermined interval on the lower surface of the first peripheral area PA1 adjacent to the plurality of first rear contact pads 251 and is connected to the data driver 500 individually do. Each of the plurality of first back pad units 253 includes a plurality of back pads including the number of channels of the data driver 500.

Each of the plurality of first backside routing lines 255 is pattern-formed on the lower surface of the flexible substrate 100 so as to be positioned between the first backside contact pad 251 and the first backside pad portion 253, And electrically connects each of the rear contact pads 251 to the first rear pad of the corresponding first rear pad portion 253. The plurality of first rear contact pads 251 are grouped so as to correspond to the number of channels of the data driver 500 and connected to the corresponding first back pad 253 through the first back routing line 255, It is very connected.

The data driver 500 is individually connected to each of the plurality of first back pad units 253 and includes a first signal transmission film 510 and a data driving integrated circuit (520). The first signal transfer film 510 is attached to the first rear pad unit 253 by a TAB (Tape Automated Bonding) process and is made of a TCP (Tape Carrier Package), a COF (Chip On Flexible Board or Chip On Film) ≪ / RTI > The first signal transfer film 510 transfers a data signal output from the data driving integrated circuit 520 to the corresponding first backside pad unit 253, (253).

The first pad unit 250 according to the first example transmits the data signal and the driving voltage supplied from the first signal transmission film 510 to the corresponding first back contact electrode 210, Voltage is supplied to the corresponding data line DL and the power supply line PL through the first back contact electrode 210 and the back contact patterns 220 and 230, respectively.

The second pad portion 350 according to the second example includes a plurality of second backside contact pads 351, a plurality of second backside pad portions 353, and a plurality of second backside routing lines 355.

Each of the plurality of second back contact pads 351 is electrically connected to a second back contact electrode 210 formed in each of the plurality of second hole patterns 300 formed in the second peripheral area PA2 of the flexible substrate 100 A pattern is formed on the lower surface of the second peripheral area PA2.

Each of the plurality of second rear pad portions 353 is provided at a predetermined interval on the lower surface of the second peripheral area PA2 adjacent to the plurality of second rear contact pads 351 and connected to the gate driver 600 individually do. Each of the plurality of second rear pad portions 353 includes a plurality of second rear pads including the number of channels of the gate driver 600.

Each of the plurality of second backside routing lines 355 is pattern-formed on the lower surface of the flexible substrate 100 so as to be positioned between the second backside contact pad 351 and the second backside pad portion 353, And electrically connects each of the rear contact pads 351 to the second rear pad of the corresponding second rear pad portion 353. The plurality of second rear contact pads 351 are grouped so as to correspond to the number of channels of the gate driver 600 and connected to the corresponding second rear pad 353 through the second rear routing line 355 It is very connected.

The gate driver 600 is individually connected to each of the plurality of second back pad units 353 and includes a second signal transfer film 610 and a gate driver IC 620 mounted on the second signal transfer film 610. [ (620). The second signal transmission film 620 is attached to the second rear pad part 353 by a TAB process, and may be made of TCP or COF. The second signal transfer film 620 transfers a gate signal output from the gate drive integrated circuit 620 to the second rear pad unit 353.

The second pad unit 350 according to the first example transfers the gate signal supplied through the second signal transfer film 610 to the corresponding second back contact electrode 310, Contact electrode 220 and the back contact pattern 320 to the corresponding gate line GL.

In addition, a back insulating film (not shown) may be additionally formed on the lower surface of the flexible substrate 100. The back insulating film may be formed of a flexible material, And may be formed on the entire lower surface of the substrate 100.

5 is a view for explaining a second example of the plurality of first and second pad portions shown in FIG.

Referring to FIG. 5, the first pad portion 250 according to the second example includes a plurality of first back contact pads 251, a plurality of first back pad portions 253 ', and a plurality of first And a backside routing line 255 '.

Each of the plurality of first back contact pads 251 is electrically connected to a first back contact electrode 210 formed in each of a plurality of first hole patterns 200 formed in a first peripheral region PA1 of the flexible substrate 100 A pattern is formed on the lower surface of the first peripheral area PA1.

Each of the plurality of first back pad units 253 'is provided at regular intervals on the bottom edge of the third peripheral area PA3 of the flexible substrate 100 parallel to the first peripheral area PA1, And is connected to the driving unit 500 separately. Each of the plurality of first back pad units 253 'includes a plurality of first back pad units including the number of channels of the data driver unit 500. When each of the plurality of first back surface pad portions 253 'is provided at a lower edge portion of the third peripheral area PA3 of the flexible substrate 100, The bonding process of attaching to the first back pad portion 253 'can proceed more easily.

Each of the plurality of first backside routing lines 255 'is pattern-formed on the lower surface of the flexible substrate 100 so as to be positioned between the first backside contact pad 251 and the first backside pad portion 253' And electrically connects each of the first backside contact pads 251 to the first backside pad of the corresponding first backside pad portion 253 '. Accordingly, the plurality of first rear contact pads 251 are grouped so as to correspond to the number of channels of the data driver 500 and connected to the first rear pad unit 253 'through the first rear routing line 255' ).

The second pad portion 350 according to the second example includes a plurality of second backside contact pads 351, a plurality of second backside pad portions 353 ', and a plurality of second backside routing lines 355' do.

Each of the plurality of second back contact pads 351 is electrically connected to a second back contact electrode 210 formed in each of the plurality of second hole patterns 300 formed in the second peripheral area PA2 of the flexible substrate 100 A pattern is formed on the lower surface of the second peripheral area PA2.

Each of the plurality of second back pad units 353 'is provided at a predetermined interval on the bottom edge of the fourth peripheral area PA4 of the flexible substrate 100 parallel to the second peripheral area PA2, And is connected to the driving unit 600 separately. Each of the plurality of second rear pad portions 353 includes a plurality of second rear pads including the number of channels of the gate driver 600. When each of the plurality of second rear pad portions 353 'is provided at the lower edge portion of the fourth peripheral region PA4 of the flexible substrate 100, So that the bonding process of attaching to the two-sided pad portion 353 'can proceed more easily.

Each of the plurality of second backside routing lines 355 'is pattern-formed on the lower surface of the flexible substrate 100 so as to be positioned between the second backside contact pad 351 and the second backside pad portion 353' And electrically connects each of the second backside contact pads 351 to the second backside pad of the corresponding second backside pad portion 353 '. The plurality of second rear contact pads 351 are grouped so as to correspond to the number of channels of the gate driver 600 and connected to the corresponding second rear pad 353 through the second rear routing line 355 It is very connected.

Each of the first and second pad portions according to the first and second embodiments of the present invention includes the routing lines 255, 255 ', 355, and 355' and the back pad portions 253 and 353, Can be used as it is without changing the structure of the general data driver 510 and the gate driver 610.

FIG. 6 is a view for explaining a third example of the plurality of first and second pad portions shown in FIG. 3. FIG.

Referring to FIG. 6, the first pad unit 250 according to the third example includes a plurality of first backside contact pads 251 and a plurality of first backside pad units 255.

Each of the plurality of first back contact pads 251 is electrically connected to a first back contact electrode 210 formed in each of a plurality of first hole patterns 200 formed in a first peripheral region PA1 of the flexible substrate 100 A pattern is formed on the lower surface of the first peripheral area PA1. The plurality of first back surface contact pads 251 are grouped into a plurality of first back surface pad parts 255.

Each of the plurality of first back pad units 255 includes first back contact pads 251 corresponding to the number of channels of the data driver 500, Lt; RTI ID = 0.0 > 510 < / RTI > Here, the first signal transmission film 510 includes a plurality of signal transmission pads (not shown) individually connected to each of the plurality of first rear contact pads 251 included in the corresponding first rear pad unit 255, .

The second pad portion 350 according to the third example includes a plurality of second backside contact pads 351 and a plurality of second backside pad portions 355.

Each of the plurality of second back contact pads 351 electrically connects the second back contact electrode 310 formed in each of the plurality of second hole patterns 200 formed in the second peripheral area PA2 of the flexible substrate 100 A pattern is formed on the lower surface of the second peripheral area PA2. The plurality of second rear contact pads 351 are grouped into a plurality of second rear pad portions 355.

Each of the plurality of second back pad units 355 includes second back contact pads 351 corresponding to the number of channels of the gate driver 600, Lt; RTI ID = 0.0 > 610 < / RTI > The second signal transmission film 610 is provided with a plurality of signal transmission pads (not shown) individually connected to each of a plurality of second rear contact pads 351 included in the corresponding second rear pad unit 355, .

4 and 5, each of the first and second pad units 250 and 350 according to the third embodiment of the present invention may include data without data lines 255, 255 ', 355, and 355' And may be connected to the general data driver 510 and the gate driver 610 because it is connected to the driver 510 and the gate driver 610. The signal transmission pads included in the signal transmission films 510 and 610 of the data driver 510 and the gate driver 610 are structurally changed in accordance with the pad structures of the corresponding pads 250 and 350. However, in the present invention, it is necessary to change the structure of the signal transmission pads of the general data driver 510 and the gate driver 610, but it is not necessary to form the routing lines 255, 255 ', 355 and 355'.

In the flexible display device according to the present invention as described above, the pad portions 250 and 350 connected to the signal lines DL, GL and PL of the pixel P are formed on the lower surface (or the back surface) of the flexible substrate 100, It is not necessary to form a routing line connecting the signal lines DL, GL and PL of the pixel P and the pad units 250 and 350 in the peripheral region of the upper surface of the flexible substrate 100, Width (BW).

7A to 7K are process sectional views schematically showing a manufacturing method of a flexible display device according to an exemplary embodiment of the present invention, which is a process sectional view of the line I-I 'shown in FIG.

Hereinafter, a method of manufacturing a flexible display device according to an exemplary embodiment of the present invention will be described.

First, as shown in FIG. 7A, a lower release layer 710 is formed on the upper surface of the lower carrier substrate 700. The lower release layer 710 may be formed of an insulating material such as silicon oxide or silicon nitride.

7B, a flexible substrate 100 is formed on the upper surface of the lower release layer 710 by applying a plastic material to the upper surface of the lower release layer 710 and then curing the plastic material. Here, the flexible substrate 100 may be made of a flexible plastic material, for example, an opaque or colored polyimide (PI) material.

7C, a plurality of first hole patterns 200 (see FIG. 7C) passing through the flexible substrate 100 by irradiating a laser to the first peripheral area PA1 of the flexible substrate 100, ). A plurality of second hole patterns 300 passing through the flexible substrate 100 are formed by irradiating a laser to the second peripheral area PA2 of the flexible substrate 100. [

7D, a first inorganic film 102a is formed on the entire upper surface of the flexible substrate 100 on which the first and second hole patterns 200 and 300 are formed. It is preferable that the first inorganic film 102a is made of the same material as the lower lower release layer 710. This is because the hole patterns 200 and 300 are formed on the flexible substrate 100 as shown in FIG. The lower release layer 710 overlapped with the hole patterns 200 and 300 may be damaged 710a by the laser. In this case, the flexible substrate 100 and the lower carrier substrate 700 There is a problem that the damaged portion 710a of the lower release layer 710 overlapping with the hole patterns 200 and 300 is not removed during the laser release process. The first inorganic film 102a may be formed of the same material as the lower lower release layer 710 and may be formed on the lower substrate 200 when the flexible substrate 100 and the lower carrier substrate 700 are separated from each other. And is further formed to completely remove the release layer 710.

7E, after depositing a metal material on the first inorganic film 102a, a metal material is deposited on the first inorganic film 102a except for the metal material overlapping each of the first and second hole patterns 200 and 300 And the remaining metallic material is removed to form a plurality of first and second back contact electrodes 210 and 310, respectively. At this time, each of the plurality of first and second back contact electrodes 210 and 310 is patterned on the first inorganic film 102a around the hole pattern 200 and 300, respectively.

Next, a second inorganic film 102b is formed on each of the first and second back contact electrodes 210 and 310 and the first inorganic film 102a. Then, a plurality of first and second back contact electrodes The second inorganic film 102b formed on each of the first and second back contact electrodes 210 and 310 is removed to expose the upper surfaces of the plurality of first and second back contact electrodes 210 and 310 to the outside. Here, the second inorganic film 102b constitutes the buffer layer 102 together with the first inorganic film 102a, and serves as hydrogen and a moisture-barrier film.

Subsequently, as shown in FIG. 7F, the thin film transistor 110 is formed in the display area AA of the flexible sub-substrate 100.

A method of forming the thin film transistor 110 according to an example is as follows.

The active layer 111 is pattern-formed for each pixel region defined on the display region AA of the flexible substrate 100 and the gate insulating film 112 covering the active layer 111 is formed.

Next, a third via hole 322 is formed in the gate insulating film 112 overlapping each of the plurality of second back contact electrodes 310, and then a third via hole 322 is formed on the gate insulating film 112 including the third via hole 322 A gate electrode 113 is formed on the gate insulating film 112 which overlaps the active layer 111 and a plurality of gate electrodes GL are formed through the third via hole 322 A plurality of third back contact patterns 320 connected to each of the second back contact electrodes 310 are simultaneously formed.

Next, the drain region and the source region of the active layer 111 are made conductive while the gate insulating film 112 is removed using the third plurality of contact patterns 320 and the gate electrode 113 as masks.

Next, an interlayer insulating film 114 is formed on the entire surface of the flexible substrate 100 and the first and second contact holes CH1 (CH1) and CH1 (second contact holes) are formed in the interlayer insulating film 114, which overlaps the drain region and the source region of the active layer 111, And the first and second via holes 222 and 232 are formed in the interlayer insulating film 114 overlapping each of the plurality of first back contact electrodes 210.

Next, a drain / source electrode material is formed on the interlayer insulating layer 114 and then patterned to form active / inactive regions through a plurality of data lines DL, a plurality of power supply lines PL and a first contact hole CH1, A drain electrode 115d connected to the drain region of the layer 111, a source electrode 115d connected to the source region of the active layer 111 through the second contact hole CH2, The first and second back contact patterns 220 and 230 connected to the plurality of first back contact electrodes 210 are formed at the same time.

7G, the anode electrode 130 connected to the source electrode 115s of the thin film transistor 110, the organic light emitting element 150 on the anode electrode 130, and the organic light emitting element And a cathode electrode 170 connected to the cathode electrode 150. This will be described in more detail as follows.

A protective film 116 is formed on the flexible substrate 110 on which the thin film transistor 110 and the first and second back contact patterns 220 and 230 are formed and the protective film 116 overlapped with the source electrode 115d, The third contact hole CH3 is formed in the second interlayer insulating film 116.

Next, a metal material is formed on the upper surface of the passivation layer 116 including the third contact hole CH3 and is patterned to be connected to the source electrode 115s of the thin film transistor 110 through the third contact hole CH3 The auxiliary electrode 120 to be connected is pattern-formed.

Next, the planarization layer 125 is formed on the protective layer 116 on which the auxiliary electrode 120 is formed, and the fourth contact hole CH4 (not shown) is formed on the planarization layer 125, ).

An anode electrode material is formed on the top surface of the planarization layer 125 including the fourth contact hole CH4 and is patterned to be connected to the anode electrode 120 through the fourth contact hole CH4. 130 are pattern-formed. Here, the anode electrode 130 may be formed as a multi-layer structure in which a metal layer of indium-tin-oxide (ITO) / APC (Ag: Pb: Cu) / ITO is stacked. In addition, the auxiliary electrode 120 may be omitted. When the auxiliary electrode 120 is omitted, the anode electrode 130 is electrically connected to the source electrode (not shown) of the thin film transistor 110 through the third contact hole CH3 115s. The protective film 116 or the planarization film 125 may be omitted.

Next, a bank layer 140 is formed on the planarization film 125 to expose portions of the anode electrode 130 other than the edge portions thereof. The bank layer 140 is formed so as to cover the edge portions of the thin film transistor (TFT) and the anode electrode 130, thereby defining the light emitting region of each pixel P.

Next, the organic light emitting element 150 is formed on the anode electrode 130 exposed by the bank layer 140. The organic light emitting device 150 may have a structure in which a hole injecting layer, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and an electron injecting layer are sequentially stacked. However, the hole injection layer and / or the electron injection layer may be omitted. The organic light emitting layer may be formed to emit light of the same color, for example white, for each pixel P, and may emit light of different colors, for example, red, green, or blue, .

Next, the pixel P is formed in the display area AA of the flexible substrate 100 by forming the cathode electrode 170 on the organic light emitting element 150 and the bank layer 140. Next, The cathode electrode 170 may be formed in an electrode shape common to all the pixels P and may be connected to the organic light emitting diode 150 formed in each pixel P,

Next, the sealing layer 190 is formed on the entire surface of the flexible substrate 100 so as to cover the pixel P. At this time, it is more preferable that the sealing layer 190 is formed by an atomic layer deposition process rather than a sputtering process in order to improve film quality and prevent moisture permeation.

7H, the upper carrier substrate 800 is bonded to the upper surface of the sealing layer 190 through the substrate bonding member 410. [ At this time, the upper carrier substrate 800 is formed with a transparent substrate 500 coated on the upper release layer 810 and the upper release layer 810. The transparent substrate 500 is adhered to the sealing layer 190 by the substrate bonding member 410. Here, the upper release layer 810 may be made of the same material as the lower release layer 710.

Then, the lower release layer is irradiated with a laser through a laser release process in which the lower carrier substrate 700 and the upper carrier substrate 800 are inverted with each other and the upper carrier substrate 800 is used as a support, Thereby releasing the lower release layer, thereby separating the lower carrier substrate and the flexible substrate 100 from each other. The lower surfaces 210a and 310a of the plurality of first and second back contact electrodes 210 and 310 formed in the plurality of first and second hole patterns 200 and 300 formed on the flexible substrate 100, Is exposed to the back surface of the flexible substrate 100 through the corresponding hole patterns 200 and 300. [ The lower release layer formed in each of the first and second hole patterns 200 and 300 may include a first inorganic film 102a formed on the first and second hole patterns 200 and 300, The lower surfaces 210a and 310a of the plurality of first and second back contact electrodes 210 and 310 can be exposed to the back surface of the flexible substrate 100. [

Then, as shown in FIG. 7J, a first pad unit 250 connected to the plurality of first back contact electrodes 210 exposed at the back surface of the flexible substrate 100, and a plurality of second back contact electrodes And a second pad portion 350 connected to the first pad portion 310 are pattern-formed on the lower surface of the flexible substrate 100, respectively. 4 and 5, the first and second pad portions 250 and 350 may include a plurality of back contact pads 251 and 351, a plurality of back pad portions 253, 253 ', 353, and 353 And the first and second peripheral areas PA1 and PA2 or the third and fourth peripheral areas PA1 and PA2 of the flexible substrate 100 so as to have the same shape as the plurality of backside routing lines 255, 255 ', 355 and 355' Are pattern-formed in the regions PA3 and PA4.

7K, the upper release layer is released by irradiating a laser to the upper release layer through a laser release process using the flexible substrate 100 as a support, thereby separating the upper carrier substrate from the transparent substrate 500 do. Accordingly, the transparent substrate 500 remains attached to the sealing layer 190 by the substrate bonding member 410.

Although the thin film transistor 110 has been described as having a top gate structure in the present invention as described above, the present invention is not limited thereto and the thin film transistor 110 may include a bottom gate transistor. Further, in the present invention, when the gate drive circuit for driving the gate line is directly embedded in one side of the flexible substrate together with the thin film transistor, the second pad portion connected to the aforementioned gate line may be omitted, And may be driven by receiving a gate control signal and a clock signal through one pad portion.

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. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

100: Flexible substrate 102a: First inorganic film
102b: second inorganic film 110: thin film transistor
130: anode electrode 150: organic light emitting element
170: cathode electrode 190: sealing layer
200, 300: hole pattern 210, 310: back contact electrode
220, 230, 320: a back contact pattern 250, 350:
400: transparent substrate 500: data driver
600: gate driver 700: lower carrier substrate
800: upper carrier substrate

Claims (13)

A flexible substrate including pixels and a hole pattern;
A back contact electrode embedded in the hole pattern and connected to a signal line of the pixel; And
And a pad portion provided on a lower surface of the flexible substrate to be connected to the back contact electrode. The method according to claim 1,
A first inorganic film covering the upper surface of the flexible substrate including the inner surface of the hole pattern; And
And a second inorganic film that covers an upper surface of the first inorganic film except for the white contact electrode,
And the back contact electrode is formed on the first inorganic film. The method according to claim 1,
And a back contact pattern extending from a data line connected to the pixel and connected to the back contact electrode. The method according to claim 1,
The pad unit includes:
A back contact pad formed on a lower surface of the flexible substrate so as to overlap with the hole pattern and connected to the back contact electrode;
A back pad spaced apart from the contact pad; And
And a backside routing line connecting the backside contact pad and the backside pad portion. 5. The method of claim 4,
Wherein the back contact pad is provided in a first peripheral region of the flexible substrate,
And the rear pad portion is provided in a second peripheral region of the flexible substrate parallel to the first peripheral region. 6. The method according to any one of claims 1 to 5,
A sealing layer covering the entire upper surface of the flexible substrate including a display region where the pixel is formed and a peripheral region where the hole pattern is formed; And
And a transparent substrate attached to the sealing layer. (A) forming a hole pattern vertically passing through the flexible substrate;
A step (B) of embedding a white contact electrode in the hole pattern;
(C) forming a pixel having a signal line connected to the white contact electrode on the flexible substrate; And
(D) forming a pad portion connected to the back contact electrode on the lower surface of the flexible substrate. 8. The method of claim 7,
The step (A)
Forming a lower release layer on the upper surface of the lower carrier substrate;
Applying a plastic material on the lower release layer and curing the flexible material to form the flexible substrate; And
And a step of irradiating a laser beam onto the flexible substrate to form the hole pattern. 9. The method of claim 8,
The step (B)
Forming a first inorganic film on an upper surface of the flexible substrate including the hole pattern;
Forming the back contact electrode on the first inorganic film formed on the hole pattern; And
And forming a second inorganic film covering the upper surface of the first inorganic film except for the white contact electrode,
Wherein the first inorganic film covers the lower release layer formed inside the hole pattern. 10. The method of claim 9,
The step (C)
A step of providing a transparent substrate;
Forming a sealing layer on the entire upper surface of the flexible substrate including a display region where the pixel is formed and a peripheral region where the hole pattern is formed; And
Further comprising the step of bonding the transparent substrate to the upper surface of the sealing layer. 11. The method of claim 10,
The step (D)
Separating the lower carrier substrate and the flexible substrate by using the transparent substrate as a support and irradiating a laser to the lower release layer; And
And forming the pad portion connected to the white contact electrode through the hole pattern on the lower surface of the flexible substrate using the transparent substrate as a support base. 11. The method of claim 10,
Wherein the step of forming the transparent substrate comprises:
Forming an upper release layer on the upper surface of the upper carrier substrate; And
And a step of applying and curing a plastic material on the upper release layer to form the transparent substrate. 13. The method of claim 12,
Further comprising the step (E) of irradiating the upper release layer with a laser to separate the upper carrier substrate and the transparent substrate after the step (D).

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