U.S. patent application number 14/534954 was filed with the patent office on 2015-03-05 for organic light emitting diode display device having built-in touch panel and method of manufacturing the same.
This patent application is currently assigned to LG Display Co. Ltd.. The applicant listed for this patent is LG DISPLAY CO., LTD.. Invention is credited to Moo-Chan Kang, SANG-KYU LEE.
Application Number | 20150060838 14/534954 |
Document ID | / |
Family ID | 50910438 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150060838 |
Kind Code |
A1 |
LEE; SANG-KYU ; et
al. |
March 5, 2015 |
ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE HAVING BUILT-IN TOUCH
PANEL AND METHOD OF MANUFACTURING THE SAME
Abstract
An organic light emitting diode (OLED) display device having a
built-in touch panel and a manufacturing method thereof in which an
OLED array and a touch array are formed on a flexible substrate and
thus the OLED display device has flexibility, and a flexible
printed circuit board for driving the touch array is integrally
formed with a printed circuit board for driving the OLED array and
thus manufacturing costs are reduced are disclosed. The OLED
display device includes an OLED array formed on a lower flexible
substrate, a touch array formed on an upper flexible substrate, and
an adhesive layer adhering the upper flexible substrate to the
lower flexible substrate such that the touch array and the OLED
array face each other.
Inventors: |
LEE; SANG-KYU; (Daejeon,
KR) ; Kang; Moo-Chan; (Gwangju, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG DISPLAY CO., LTD. |
Seoul |
|
KR |
|
|
Assignee: |
LG Display Co. Ltd.
|
Family ID: |
50910438 |
Appl. No.: |
14/534954 |
Filed: |
November 6, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13943149 |
Jul 16, 2013 |
8906717 |
|
|
14534954 |
|
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|
Current U.S.
Class: |
257/40 |
Current CPC
Class: |
H01L 27/3276 20130101;
H01L 27/323 20130101 |
Class at
Publication: |
257/40 |
International
Class: |
H01L 27/32 20060101
H01L027/32 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2012 |
KR |
10-2012-0147137 |
Claims
1. An organic light emitting diode (OLED) display device
comprising: an OLED array on a lower flexible substrate; a touch
array on an upper flexible substrate; and an adhesive layer
adhering the upper flexible substrate to the lower flexible
substrate such that the touch array and the OLED array face each
other.
2. The OLED display device according to claim 1, wherein the touch
array comprises X and Y electrodes crossing each other, a pad part,
and a routing line connecting the pad part to the X and Y
electrodes, wherein the pad part is connected to the OLED array via
an anisotropic conductive paste.
3. The OLED display device according to claim 2, wherein the
anisotropic conductive paste has a first end connected to the pad
part and a second end on the lower flexible substrate and connected
to a flexible printed circuit board for driving the touch
array.
4. The OLED display device according to claim 3, wherein the
flexible printed circuit board is integrally formed with a printed
circuit board electrically connected to the OLED array to drive the
OLED array.
Description
[0001] This present patent document is a divisional of U.S. patent
application Ser. No. 13/943,149, filed Jul. 16, 2013 which claims
the benefit of priority of Korean Patent Application No.
10-2012-0147137, filed on Dec. 17, 2012, which is hereby
incorporated by reference as if fully set forth herein.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to an organic light emitting
diode (OLED) display device having a built-in touch panel, and more
particularly, to an OLED display device having a built-in touch
panel in which an OLED array and a touch array are formed on
respective flexible substrates and thus the OLED display device has
a decreased thickness and improved flexibility and a manufacturing
method thereof.
DISCUSSION OF THE RELATED ART
[0003] Image display devices, which display a variety of
information on a screen, are a core technology of information and
communication and are developed towards a trend of thinner,
lighter, portable, and high performance. Thus, organic light
emitting diode (OLED) display devices, which display an image by
controlling emission amount of an organic emission layer (EML),
have received attention as a flat panel display device that may
address problems in terms of weight and volume which occur in
cathode ray tubes (CRTs).
[0004] An OLED display device includes an OLED, which is
self-emissive and emits light using a thin EML between electrodes,
and thus may be realized as a thin film such as paper.
[0005] An OLED array includes a thin film transistor (TFT) formed
in each subpixel region of a substrate and the OLED connected to
the TFT and including a first electrode (i.e., anode), an EML, and
a second electrode (i.e., cathode) which are sequentially formed.
When a voltage is applied between the first and second electrodes,
holes and electrons are recombined in the EML to form excitons and,
when the excitons drop to a ground state, light is emitted.
[0006] In particular, the OLED array is formed on a flexible
substrate and thus an OLED display device having flexibility may be
manufactured. More particularly, an exfoliation layer is formed on
a rigid substrate formed of, for example, glass, the flexible
substrate is formed on the exfoliation layer, and the OLED array is
formed on the flexible substrate. Subsequently, the exfoliation
layer is separated from the flexible substrate.
[0007] Meanwhile, to manufacture a flexible OLED display device, an
encapsulation substrate covering an OLED array is also formed of a
plastic film. However, it is impossible to perform a manufacturing
process such as chemical vapor deposition (CVD), sputtering, or the
like on the film. Thus, only an add-on type in which a touch array
is attached to a film may be applied to the flexible OLED display
device.
SUMMARY
[0008] An OLED display device includes an OLED array formed on a
lower flexible substrate, a touch array formed on an upper flexible
substrate, and an adhesive layer adhering the upper flexible
substrate to the lower flexible substrate such that the touch array
and the OLED array face each other.
[0009] The touch array may include X and Y electrodes crossing each
other, a pad part, and a routing line connecting the pad part to
the X and Y electrodes, wherein the pad part is connected to the
OLED array via an anisotropic conductive paste.
[0010] In another aspect of the present invention, a method of
manufacturing an OLED display device having a built-in touch panel
includes forming a lower flexible substrate on a lower rigid
substrate with a lower exfoliation layer positioned therebetween
and forming an OLED array on the lower flexible substrate, forming
an upper flexible substrate on an upper rigid substrate with an
upper exfoliation layer positioned therebetween and forming a touch
array on the upper flexible substrate, adhering the upper rigid
substrate to the lower rigid substrate using an adhesive layer such
that the touch array and the OLED array face each other, separating
the upper exfoliation layer from the upper flexible substrate,
cutting the lower rigid substrate on a unit panel basis, and
separating the lower exfoliation layer from the lower flexible
layer.
[0011] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0013] FIG. 1 is a sectional view of an organic light emitting
diode (OLED) display device having a built-in touch panel,
according to an embodiment of the present invention;
[0014] FIG. 2A is a sectional view of an OLED array of the OLED
display device of FIG. 1;
[0015] FIG. 2B is a sectional view of a touch array of the OLED
display device of FIG. 1;
[0016] FIGS. 3A through 3H are sectional views sequentially
illustrating a method of manufacturing the OLED display device
having a built-in touch panel, according to a first embodiment of
the present invention;
[0017] FIG. 4A is a photograph of an upper flexible substrate from
which an upper exfoliation layer is separated using ultraviolet
irradiation;
[0018] FIGS. 4B and 4C are photographs showing a case in which
wiring defects of the touch array do not occur when the upper
exfoliation layer is separated upon ultraviolet irradiation;
[0019] FIGS. 5A through 5F are sectional views sequentially
illustrating a method of manufacturing the OLED display device
having a built-in touch panel, according to a second embodiment of
the present invention;
[0020] FIG. 6A is a photograph of an upper flexible substrate from
which an upper exfoliation layer is separated by application of a
certain voltage; and
[0021] FIGS. 6B and 6C are photographs showing a case in which
wiring defects of a touch array do not occur when the upper
exfoliation layer is separated by application of a voltage.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0022] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers will be used throughout the drawings to
refer to the same or like parts.
[0023] Hereinafter, embodiments of an organic light emitting diode
display device having a built-in touch panel will be described in
detail with reference to the accompanying drawings.
[0024] FIG. 1 is a sectional view of an organic light emitting
diode (OLED) display device having a built-in touch panel,
according to an embodiment of the present invention. FIG. 2A is a
sectional view of an OLED array 140 of the OLED display device of
FIG. 1. FIG. 2B is a sectional view of a touch array 160 of the
OLED display device of FIG. 1.
[0025] As illustrated in FIG. 1, the OLED display device having a
built-in touch panel includes the OLED array 140 formed on a lower
flexible substrate 120a and the touch array 160 formed on an upper
flexible substrate 120b. The lower and upper flexible substrates
120a and 120b are adhered to each other by an adhesive layer 170
such that the touch array 160 and the OLED array 140 face each
other.
[0026] In particular, the lower flexible substrate 120a is a
plastic film formed of at least one organic material selected from
among polyethylene naphthalate (PEN), polyethylene terephthalate
(PET), polyethylene ether phthalate, polycarbonate, polyarylate,
polyether imide, polyether sulfonate, polyimide, and
polyacrylate.
[0027] A buffer layer 130 is formed between the lower flexible
substrate 120a and the OLED array 140. The buffer layer 130
improves adhesion between the OLED array 140 and the lower flexible
substrate 120a and prevents moisture or impurities from diffusing
into the OLED array 140 from the lower flexible substrate 120a. The
buffer layer 130 may be a single layer structure of an inorganic
insulator such as silicon oxide (SiO.sub.x), silicon nitride
(SiN.sub.x), or the like or a double-layered structure of SiO.sub.x
and SiN.sub.x.
[0028] The OLED array 140 is formed on the lower flexible substrate
120a with the buffer layer 130 positioned therebetween. As
illustrated in FIG. 2A, the OLED array 140 includes a thin film
transistor (TFT) including a gate electrode 140a, a gate insulating
layer 141, a semiconductor layer 142, a source electrode 143a, and
a drain electrode 143b and an OLED including a first electrode 145,
an organic emission layer (EML) 147, and a second electrode
148.
[0029] In particular, the gate electrode 140a is formed on the
buffer layer 130, and the gate insulating layer 141 is formed to
cover the gate electrode 140a. The semiconductor layer 142 is
formed on the gate insulating layer 141 to overlap with the gate
electrode 140a. The source and drain electrodes 143a and 143b are
formed on the semiconductor layer 142 to be spaced apart from each
other.
[0030] An organic layer 144 formed of an acryl-based resin or the
like is formed to cover the TFT. The organic layer 144 planarizes
the lower flexible substrate 120a on which the TFT is formed.
Although not shown, an inorganic layer (not shown) formed of
SiO.sub.x, SiN.sub.x, or the like is formed between the gate
insulating layer 141 and the organic layer 144. The inorganic layer
may improve the stability of an interface between the organic layer
144 and each of the gate insulating layer 141, the source electrode
143a, and the drain electrode 143b.
[0031] The second electrode 148 is formed on the organic layer 144
to cover the first electrode 145 connected to the drain electrode
143b, a bank insulating layer 146 that partially exposes the first
electrode 145, and the organic EML 147 formed on the exposed
portion of the first electrode 145. The bank insulating layer 146
defines a light-emitting region of the OLED array 140 and prevents
light leakage of a non-light-emitting region.
[0032] Referring back to FIG. 1, a passivation layer 150 is formed
to cover the OLED array 140. The passivation layer 150 may have a
single layer structure of an inorganic insulator, such as aluminum
oxide (AlO.sub.x), silicon oxynitride (SiON), silicon nitride
(SiN.sub.x), or silicon oxide (SiO.sub.x) or an organic insulator
such as benzocyclobutene or photoacryl. Alternatively, the
passivation layer 150 may have a structure in which layers
respectively formed of the inorganic insulator and the organic
insulator are stacked one upon another.
[0033] Although not shown, a drive IC is formed at one side of the
lower flexible substrate 120a, and the drive IC is connected to a
printed circuit board (PCB). The PCB includes a timing control unit
(not shown) for supplying various control signals to drive the OLED
array 140 and a power supply (not shown) to supply a driving
voltage. A signal of the PCB is applied to the OLED array 120a via
the drive IC.
[0034] In particular, the PCB is integrally formed with a flexible
PCB (FPCB) including a touch controller to drive the touch array
160. The FPCB is electrically connected to the touch array 160 via
an anisotropic conductive paste (ACP), which will be described
below.
[0035] The touch array 160 formed on the upper flexible substrate
120b is adhered to the passivation layer 150 by an adhesive layer
170 so that the touch array 160 and the OLED array 140 face each
other. In this regard, the upper flexible substrate 120b is a
plastic film formed of at least one organic material selected from
PEN, PET, polyethylene ether phthalate, polycarbonate, polyarylate,
polyether imide, polyether sulfonate, polyimide, and polyacrylate,
like the lower flexible substrate 120a.
[0036] In particular, as illustrated in FIG. 2B, the touch array
160 formed on the upper flexible substrate 120b includes a
plurality of X electrodes 161a and a plurality of Y electrodes 161b
that cross each other with a first insulating layer 162a positioned
therebetween and take the form of a bar and a second insulating
layer 162b to cover the Y electrodes 161b.
[0037] The X and Y electrodes 161a and 161b of the touch array 160
are connected to pad parts by routing lines. In this regard, the
pad parts are voltage applying pads or voltage detection pads. The
touch array 160 is of a mutual capacitive type in which a driving
voltage is applied to the X electrodes 161a and the Y electrodes
161b sense voltage drop according to whether touch is performed or
not.
[0038] In some embodiments, the touch array 160 may include bridge
electrodes formed on the upper flexible substrate 120b, a first
insulating layer covering the bridge electrodes, X electrodes
formed on the first insulating layer and electrically connected via
the bridge electrodes, Y electrodes formed at the same layer level
as the X electrodes, and a second insulating layer covering the X
and Y electrodes.
[0039] Referring back to FIG. 1, the adhesive layer 170 is formed
on the touch array 160. In addition, the adhesive layer 170 is
attached to the passivation layer 150. In such a manner, the upper
and lower flexible substrates 120b and 120a are adhered such that
the touch array 160 and the OLED array 140 face each other.
[0040] Although not shown, the touch array 160 and the OLED array
140 are electrically connected to each other via an ACP. The ACP
has a structure in which conductive balls coated with a metal such
as gold (Au), silver (Ag), copper (Cu), molybdenum (Mo), or the
like are dispersed in a sealant.
[0041] The ACP connects the pad parts of the touch array 160 to the
FPCB. The pad parts are connected to X and Y electrodes 161a and
161b of the touch array 160 via routing lines.
[0042] In general, an FPCB to drive a touch array is separately
formed from a PCB to drive an OLED array. However, in embodiments,
the PCB to drive the OLED array 130 is integrally formed with the
FPCB to drive the touch array 160, and the FPCB and the touch array
160 are connected to each other using an ACP.
[0043] Therefore, in the OLED display device having a built-in
touch panel, manufacturing costs may be reduced by integrating the
FPCB to drive the touch array 160 with the PCB to drive the OLED
array 140.
[0044] In addition, a top cover 180 is attached to a rear surface
of the upper flexible substrate 120b on which the touch array 160
is formed. The top cover 180 is formed of a material having high
transmittance and flexibility, such as polymethylmethacrylate
(PMMA), polyurethane (PU), acryl, cyclo olefin polymer (COP),
polyethylene terephthalate (PET), polyethylene naphthalate (PEN),
polyimide, or the like.
[0045] In addition, although not shown, a bottom cover formed of a
material, such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the
like may be formed on a rear surface of the lower flexible
substrate 120a.
[0046] As described above, the OLED array 140 and the touch array
160 are respectively formed on the lower flexible substrate 120a
and the upper flexible substrate 120b, and thus the OLED display
device having a built-in touch panel has flexibility. In
particular, a flexible substrate has a smaller thickness than a
general rigid substrate and thus may enable reduction in display
device thickness.
[0047] Moreover, the FPCB for driving the touch array 160 is formde
on the PCB for driving the OLED array 140 and the FPCB is
electrically connected to the touch array 160 via an ACP, and thus
manufacturing costs may be reduced.
[0048] Hereinafter, a method of manufacturing the OLED display
device having a built-in touch panel will be described in detail
with reference to the accompanying drawings.
First Embodiment
[0049] FIGS. 3A through 3H are sectional views sequentially
illustrating a method of manufacturing the OLED display device
having a built-in touch panel, according to a first embodiment of
the present invention. FIG. 4A is a photograph of the upper
flexible substrate 120b from which an upper exfoliation layer 110b
is separated upon ultraviolet irradiation. FIGS. 4B and 4C are
photographs showing a case in which wiring defects of the touch
array 160 do not occur when the upper exfoliation layer is
separated using ultraviolet irradiation.
[0050] As illustrated in FIG. 3A, a lower exfoliation layer 110a is
formed on a lower rigid substrate 100a such as a glass substrate,
and the lower flexible substrate 120a is formed on the lower
exfoliation layer 110a. The lower flexible substrate 120a is a
plastic film formed by coating the lower exfoliation layer 110a
with a polymer solution by slit coating, spin coating, or the like
and curing the polymer solution coated thereon.
[0051] The plastic film is formed of at least one organic material
selected from PEN, PET, polyethylene ether phthalate,
polycarbonate, polyarylate, polyether imide, polyether sulfonate,
polyimide, and polyacrylate.
[0052] As illustrated in FIG. 3B, the buffer layer 130 is formed on
the lower flexible substrate 120a. The buffer layer 130 improves
adhesion between the lower flexible substrate 120a and the OLED
array 140, which will be described below and prevents moisture or
impurities from diffusing into the OLED array 140 from the lower
flexible substrate 120a. The buffer layer 130 may have a single
layer structure of an inorganic insulator such as SiO.sub.x,
SiN.sub.x, or the like or a double-layered structure including two
layers of SiO.sub.x and SiN.sub.x.
[0053] Subsequently, as illustrated in FIG. 3C, the OLED array 140
is formed on the buffer layer 130, and the passivation layer 150 is
formed on the OLED array 140. In particular, the OLED array 140
includes a TFT including a gate electrode, a gate insulating layer,
a semiconductor layer, and source and drain electrodes and an OLED
including a first electrode, an organic EML, and a second
electrode.
[0054] First, the gate electrode is formed on the buffer layer 130,
and the gate insulating layer is formed to cover the gate
electrode. In addition, the semiconductor layer is formed on the
gate insulating layer to overlap with the gate electrode, and the
source and drain electrodes spaced apart from each other are formed
on the semiconductor layer.
[0055] The organic layer 144 formed of an acryl-based resin or the
like is formed to cover the TFT. The organic layer 144 planarizes
the lower flexible substrate 120a on which the TFT is formed.
Although not shown, an inorganic layer formed of SiO.sub.x,
SiN.sub.x, or the like is formed between the gate insulating layer
and the organic layer 144 and thus may improve the stability of an
interface between the organic layer 144 and each of the gate
insulating layer, the source electrode, and the drain
electrode.
[0056] The second electrode is formed on the organic layer 144 to
cover the first electrode connected to the drain electrode, a bank
insulating layer that partially exposes the first electrode, and
the organic EML formed on the exposed portion of the first
electrode. The bank insulating layer defines a light-emitting
region of the OLED array 140 and prevents light leakage of a
non-light-emitting region.
[0057] Next, the passivation layer 150 is formed on the OLED array
140. The passivation layer 150 may have a single layer structure of
an inorganic insulator, such as AlO.sub.x, SiON, SiN.sub.x, or
SiO.sub.x or an organic insulator such as benzocyclobutene or
photoacryl. Alternatively, the passivation layer 150 may have a
structure in which layers respectively formed of the inorganic
insulator and the organic insulator are stacked one upon
another.
[0058] Subsequently, as illustrated in FIG. 3D, the touch array 160
is formed on the upper flexible substrate 120b. In this regard, the
upper flexible substrate 120b is a plastic film formed by coating
the upper exfoliation layer 110b formed on an upper rigid substrate
100b formed of glass with the above-described polymer by slit
coating, spin coating, or the like and curing the polymer coated on
the upper exfoliation layer 110b.
[0059] Next, the touch array 160 is formed on the upper flexible
substrate 120b. The touch array 160 is formed such that a plurality
of X electrodes and a plurality of Y electrodes that cross each
other with a lower insulating layer positioned therebetween and
take the form of a bar are formed on the upper flexible substrate
120b and an upper insulating layer is formed to cover the Y
electrodes. The X and Y electrodes are connected to pad parts by
routing lines, and the pad parts are voltage applying pads or
voltage detection pads.
[0060] The touch array 160 is of a mutual capacitive type in which
a driving voltage is applied to the X electrodes and the Y
electrodes sense voltage drop according to whether touch is
performed or not.
[0061] In some embodiments, the touch array 160 may include bridge
electrodes formed on the upper flexible substrate 120b, an
insulating layer covering the bridge electrodes, X electrodes
formed on the insulating layer and electrically connected via the
bridge electrodes, and Y electrodes formed at the same layer level
as the X electrodes.
[0062] Next, as illustrated in FIG. 3E, the adhesive layer 170 is
formed on the touch array 160, and the adhesive layer 170 is
attached to the passivation layer 150. The lower and upper rigid
substrates 100a and 100b are adhered by curing the adhesive layer
170 so that the touch array 160 and the OLED array 140 face each
other.
[0063] Subsequently, as illustrated in FIG. 3F, an ultraviolet
irradiator is positioned above the upper rigid substrate 100b, and
the upper rigid substrate 100b is irradiated with ultraviolet
light. The upper exfoliation layer 110b loses adhesive strength
upon ultraviolet irradiation and thus, as illustrated in FIG. 4A,
the upper exfoliation layer 110b is separated from a rear surface
of the upper flexible substrate 120b via ultraviolet irradiation.
In this regard, as illustrated in FIGS. 4B and 4C, routing lines of
the touch array 160 are not disconnected.
[0064] Although not shown, the lower rigid substrate 100a is cut on
a unit panel basis, and then the PCB for driving the OLED array 140
is integrally formed with the FPCB for driving the touch array 160.
In addition, the FPCB is connected to the touch array 160 using an
ACP. In this regard, the ACP has a structure in which conductive
balls coated with a metal such as Au, Ag, Cu, Mo, or the like are
dispersed in a sealant.
[0065] Subsequently, as illustrated in FIG. 3G, an ultraviolet
irradiator is positioned below the lower rigid substrate 100a, and
then the lower rigid substrate 100a is irradiated with ultraviolet
light. As with the upper exfoliation layer 110b, the lower
exfoliation layer 110a also loses adhesive strength upon
ultraviolet irradiation and thus is separated from a rear surface
of the lower flexible substrate 120a by the irradiated ultraviolet
light.
[0066] That is, in the OLED display device having a built-in touch
panel described above, after removal of the upper rigid substrate
100b, the OLED array 140 and the touch array 160 are cut on a unit
panel basis and then the lower rigid substrate 100a is removed. In
another embodiment, however, after removal of the lower rigid
substrate 100a, the OLED array 140 and the touch array 160 may be
cut on a unit panel basis and then the upper rigid substrate 100b
may be removed.
[0067] As described above, the lower and upper rigid substrates
100a and 100b are separately removed. This is because when the PCB
for driving the OLED array 140, the ACP, and the like are attached
to the lower and upper flexible substrates 120a and 120b in a case
in which only the lower and upper flexible substrates 120a and 120b
remain, the lower and upper flexible substrates 120a and 120b may
bend, resulting in poor attachment.
[0068] Lastly, as illustrated in FIG. 3H, the top cover 180 is
attached to the rear surface of the upper flexible substrate 120b.
The top cover 180 is formed of a material having high transmittance
and flexibility, such as PMMA, PU, acryl, COP, PET, PEN, polyimide,
or the like.
[0069] In addition, although not shown, a bottom cover may be
formed on a rear surface of the lower flexible substrate 120a. The
bottom cover is formed of a material such as PMMA, PU, acryl, COP,
PET, PEN, polyimide, or the like.
Second Embodiment
[0070] In a manufacturing method of the OLED display device having
a built-in touch panel, according to a second embodiment of the
present invention, an exfoliation layer formed between a rigid
substrate and a flexible substrate is formed of a metal or a
transparent conductive oxide and thus, when a high voltage is
applied to the exfoliation layer, the exfoliation layer is
separated from the flexible substrate.
[0071] FIGS. 5A through 5F are sectional views sequentially
illustrating a method of manufacturing the OLED display device
having a built-in touch panel, according to a second embodiment of
the present invention. FIG. 6A is a photograph of an upper flexible
substrate 200b from which an upper exfoliation layer 210b is
separated by application of a certain voltage. FIGS. 6B and 6C are
photographs showing a case in which wiring defects of the touch
array 160 do not occur when the upper exfoliation layer 210b is
separated by application of a certain voltage.
[0072] As illustrated in FIG. 5A, a lower exfoliation layer 210a is
formed on a lower rigid substrate 200a formed of, for example,
glass, and a lower flexible substrate 220a is formed on the lower
exfoliation layer 210a. In this regard, the lower exfoliation layer
210a is formed of a metal such as molybdenum (Mo), aluminum (Al),
or the like, or a transparent conductive oxide such as indium tin
oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO),
or the like.
[0073] The lower exfoliation layer 210a is used to separate the
lower rigid substrate 200a from the lower flexible substrate 220a.
In this regard, when the thickness of the lower exfoliation layer
210a is too small or too large, separation characteristics
deteriorate when the lower exfoliation layer 210a is separated from
the lower flexible substrate 220a. Thus, the thickness of the lower
exfoliation layer 210a may range from 1,000 .ANG. to 3,000
.ANG..
[0074] The lower flexible substrate 220a is formed on the lower
exfoliation layer 210a, and an OLED array 240 is formed on the
lower flexible substrate 220a, with a buffer layer 230 positioned
therebetween.
[0075] The OLED array 240 includes a TFT and an OLED connected to
the TFT. The TFT includes a gate electrode, a gate insulating
layer, a semiconductor layer, and source and drain electrodes, and
the OLED includes a first electrode, an organic EML, and a second
electrode. A passivation layer 250 is formed on the OLED array
240.
[0076] Subsequently, as illustrated in FIG. 5B, a touch array 260
is formed on the upper flexible substrate 220b. In this regard, as
with the lower flexible substrate 220a, an upper exfoliation layer
210b is formed on an upper rigid substrate 200b formed of, for
example, glass. The upper exfoliation layer 210b is also formed of
a metal such as Mo, Al, or the like, or a transparent conductive
oxide such as ITO, IZO, ITZO, or the like. The thickness of the
upper exfoliation layer 210b ranges from 1,000 .ANG. to 3,000
.ANG..
[0077] Next, the upper exfoliation layer 210b is coated with the
above-described polymer using a method such as slit coating, spin
coating, or the like and the polymer coated on the upper
exfoliation layer 210b is cured, to form the upper flexible
substrate 220b. Subsequently, the touch array 260 is formed on the
upper flexible substrate 220b. The touch array 260 includes a
plurality of X electrodes and a plurality of Y electrodes that
cross each other with a lower insulating layer positioned
therebetween and take the form of a bar, and an upper insulating
layer to cover the Y electrodes. The X and Y electrodes are
connected to pad parts, such as voltage applying pads or voltage
detection pads, by routing lines.
[0078] In some embodiments, the touch array 260 may include bridge
electrodes formed on the upper flexible substrate 220b, an
insulating layer to cover the bridge electrodes, X electrodes
formed on the insulating layer and electrically connected via the
bridge electrodes, and Y electrodes formed at the same layer level
as the X electrodes.
[0079] Next, as illustrated in FIG. 5C, an adhesive layer 270 is
formed on the touch array 260, and the adhesive layer 270 is
attached to the passivation layer 250. Then, the lower and upper
rigid substrates 200a and 200b are adhered by curing the adhesive
layer 270 so that the touch array 260 and the OLED array 240 face
each other.
[0080] Subsequently, a high voltage, i.e., 3 kV to 5 kV, is applied
to the upper exfoliation layer 210b using a voltage applying
device. In this regard, the voltage is applied for a period on the
order of a microsecond, and thus the high voltage applied to the
upper exfoliation layer 210b is a pulse type voltage. Due to this,
as illustrated in FIG. 5D, a gap is formed between the upper
exfoliation layer 210b formed of a metal or a transparent
conductive oxide and the upper flexible substrate 220b formed of a
plastic film. Thus, as illustrated in FIG. 6A, the upper
exfoliation layer 210b is separated from a rear surface of the
upper flexible substrate 220b. In this regard, as illustrated in
FIGS. 6B and 6C, routing lines of the touch array 260 are not
disconnected.
[0081] Although not shown, the lower rigid substrate 200a is cut on
a unit panel basis, a PCB for driving the OLED array 240 is
integrally formed with an FPCB for driving the touch array 260, and
the FPCB is connected to the touch array 260 using an ACP.
[0082] Subsequently, a pulse type high voltage ranging from 3 kV to
5 kV is also applied to the lower exfoliation layer 210a. As
illustrated in FIG. 5E, when the voltage is applied to the lower
exfoliation layer 210a, a gap is formed between the lower
exfoliation layer 210a formed of a metal or a transparent
conductive oxide and the lower flexible substrate 220a formed of a
plastic film. Accordingly, the lower exfoliation layer 210a is
separated from the lower flexible substrate 220a.
[0083] Next, as illustrated in FIG. 5F, a top cover 280 is attached
to a rear surface of the upper flexible substrate 220b from which
the upper exfoliation layer 210a has been separated. The top cover
280 is formed of a material such as PMMA, PU, acryl, COP, PET, PEN,
polyimide, or the like. Although not shown, a bottom cover may be
formed on a rear surface of the lower flexible substrate 220a.
[0084] According to the manufacturing method of the OLED display
device having a built-in touch panel, a flexible substrate is
formed on a rigid substrate with an exfoliation layer positioned
therebetween, and an OLED array or a touch array is formed on the
flexible substrate. In addition, the rigid substrate is separated
from the flexible substrate using ultraviolet light. Therefore, an
OLED display device including a built-in touch panel and having
flexibility may be manufactured.
[0085] In particular, the OLED display device may be manufactured
by integrating a PCB for driving the OLED array with an FPCB for
driving the touch array, and thus manufacturing costs may be
reduced.
[0086] As is apparent from the above description, the OLED display
device having a built-in touch panel and the manufacturing method
thereof have the following effects.
[0087] First, an OLED array and a touch array are formed on
respective flexible substrates, and thus the OLED display device
having a built-in touch panel has flexibility and decreased
thickness.
[0088] Second, an FPCB for driving the touch array and a PCB for
driving the OLED array are integrally installed, and thus
manufacturing costs may be reduced.
[0089] 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 inventions. Thus,
it is intended that the present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *