U.S. patent application number 15/595434 was filed with the patent office on 2018-07-26 for conductive layer structures for substrates.
The applicant listed for this patent is Innolux Corporation. Invention is credited to Yuan-Lin WU.
Application Number | 20180212051 15/595434 |
Document ID | / |
Family ID | 62906366 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180212051 |
Kind Code |
A1 |
WU; Yuan-Lin |
July 26, 2018 |
CONDUCTIVE LAYER STRUCTURES FOR SUBSTRATES
Abstract
An example substrate includes a surface, a plurality of thin
film layers disposed on the surface, and a conductive layer
disposed on the surface. The conductive layer includes a bending
structure. The bending structure includes a plurality of openings,
where a shape of at least one opening of the plurality of openings
has a first curved portion.
Inventors: |
WU; Yuan-Lin; (Miao-Lin
County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Innolux Corporation |
Miao-Li County |
|
TW |
|
|
Family ID: |
62906366 |
Appl. No.: |
15/595434 |
Filed: |
May 15, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62450106 |
Jan 25, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/1343 20130101;
H01L 29/786 20130101; Y02E 10/549 20130101; H01L 27/3244 20130101;
H01L 27/1251 20130101; G02F 1/13306 20130101; H01L 27/0218
20130101; G02F 1/133305 20130101; G02F 1/1347 20130101; G02F
1/133308 20130101; H01L 29/0653 20130101; H01L 29/41733 20130101;
C09K 2323/00 20200801; H01L 27/32 20130101; H01L 2251/5338
20130101; G02F 1/1533 20130101; H01L 27/016 20130101; H01L 51/5256
20130101; H01L 51/0097 20130101 |
International
Class: |
H01L 29/786 20060101
H01L029/786; H01L 29/417 20060101 H01L029/417; H01L 29/06 20060101
H01L029/06; H01L 27/01 20060101 H01L027/01; H01L 27/02 20060101
H01L027/02; H01L 27/12 20060101 H01L027/12 |
Claims
1. A display device, comprising: a substrate including a surface; a
thin film transistor layer disposed on the surface; a light
emitting unit disposed on the surface and electrically connected to
the thin film transistor layer; and a conductive layer disposed on
the surface, the conductive layer including a bending structure,
the bending structure including a plurality of openings, where a
shape of at least one opening of the plurality of openings has a
first curved portion, wherein the conductive layer includes a first
layer and a second layer disposed on the first layer, and a
thickness of the first layer is different than a thickness of the
second layer.
2. The display device of claim 1, wherein the at least one opening
has an area between 5 .mu.m.sup.2 and 500 .mu.m.sup.2.
3. The display device of claim 1, wherein the at least one opening
further includes a second curved portion, where a curvature of the
first curved portion is different than a curvature of the second
curved portion.
4. The display device of claim 1, wherein the bending structure
further includes an undulating edge.
5. The display device of claim 1, wherein the conductive layer
further includes: a conductive line extending along a first
direction, the conductive line including a wiring portion, a
connecting portion, and the bending structure, the connecting
portion disposed between the bending structure and the wiring
portion, the connecting portion having a first width along a second
direction substantially perpendicular to the first direction, the
wiring portion having a second width along the second direction,
and the first width being greater than the second width.
6. The display device of claim 5, wherein the thin film transistor
layer includes a thin film transistor having a source contact and a
drain contact, where a material of the conductive line, and a
material of at least one of the source contact and the drain
contact, are the same.
7. The display device of claim 5, wherein the thin film transistor
layer includes a thin film transistor having a gate electrode,
where a material of the conductive line and a material of the gate
electrode are the same.
8. The display device of claim 1, wherein the conductive layer
includes a first layer and a second layer disposed on the first
layer, a material of the first layer being different than a
material of the second layer.
9. (canceled)
10. The display device of claim 1, wherein the conductive layer
includes a touch signal line, the touch signal line including the
bending structure.
11. The display device of claim 1, wherein the conductive layer
includes a touch electrode, the touch electrode including the
bending structure.
12. A substrate, comprising: a surface; a plurality of thin film
layers disposed on the surface; and a conductive layer disposed on
the surface, the conductive layer including a bending structure,
the bending structure including a plurality of openings, where a
shape of at least one opening of the plurality of openings has a
first curved portion, wherein the conductive layer includes a first
layer and a second layer disposed on the first layer, and a
thickness of the first layer is different than a thickness of the
second layer.
13. The substrate of claim 12, wherein the at least one opening has
an area between 5 .mu.m.sup.2 and 500 .mu.m.sup.2.
14. The substrate of claim 12, wherein the at least one opening
further includes a second curved portion, where a curvature of the
first curved portion is different than a curvature of the second
curved portion.
15. The substrate of claim 12, wherein the bending structure
further includes an undulating edge.
16. The substrate of claim 12, wherein the conductive layer further
includes: a conductive line extending along a first direction, the
conductive line including a wiring portion, a connecting portion,
and the bending structure, the connecting portion disposed between
the bending structure and the wiring portion, the connecting
portion having a first width along a second direction substantially
perpendicular to the first direction, the wiring portion having a
second width along the second direction, and the first width being
greater than the second width.
17. The substrate of claim 16, wherein the plurality of thin film
layers includes a first patterned metal layer, where a material of
the conductive line and a material of the first patterned metal
layer are the same.
18. The substrate of claim 12, wherein the conductive layer
includes a first layer and a second layer disposed on the first
layer, a material of the first layer being different than a
material of the second layer.
19. (canceled)
20. The substrate of claim 12, wherein the conductive layer
includes an electrode, the electrode including the bending
structure.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 62/450,106, filed Jan. 25, 2017, the
contents of which is incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] Examples of the present disclosure relate to conductive
layer structures for substrates.
BACKGROUND
[0003] Electronic devices, such as portable computers, typically
include rigid displays made of rigid display structures. For
example, a liquid crystal display (LCD) can be formed from a stack
of rigid display structures. It may be challenging to include a
rigid display into the housing of some devices, such as mobile
devices (e.g., mobile telephones, watches, etc.). It is desirable
to include flexible displays in such devices. A flexible display
typically includes organic layers (e.g., organic light emitting
layer, organic passivation layer, etc.), a thin semiconductor
layer, and conductive layers all formed on a flexible substrate
(e.g., a polymer substrate). A conductive layer includes metal
conductive lines electrically coupled to circuitry in the thin
semiconductor layer. Such a flexible display can be curved, folded,
stretched, or the like (generally referred to as "flexed").
However, in some cases, the metal conductive lines in a conductive
layer can be damaged when the displayed is flexed. For example,
when the display is flexed, the metal conductive lines can be
cracked, causing a disconnection therein.
SUMMARY
[0004] Conductive layer structures for substrates are described. In
an embodiment, a display device comprises a substrate including a
surface, a thin film transistor layer disposed on the surface, and
a light emitting unit disposed on the surface and electrically
connected to the thin film transistor layer. The display device
further includes a conductive layer disposed on the surface. The
conductive layer includes a bending structure. The bending
structure includes a plurality of openings, where a shape of at
least one opening of the plurality of openings has a first curved
portion.
[0005] In another embodiment, a flexible substrate includes a
surface, a plurality of thin film layers disposed on the surface,
and a conductive layer disposed on the surface. The conductive
layer includes a bending structure. The bending structure includes
a plurality of openings, where a shape of at least one opening of
the plurality of openings has a first curved portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] So that the manner in which the above recited features can
be understood in detail, a more particular description, briefly
summarized above, may be had by reference to example
implementations, some of which are illustrated in the appended
drawings. It is to be noted, however, that the appended drawings
illustrate only typical example implementations and are therefore
not to be considered limiting of its scope.
[0007] FIG. 1A is a schematic top view of a display device
according to an embodiment.
[0008] FIG. 1B is an exploded side view showing a portion of a
display device according to an embodiment.
[0009] FIG. 2 is a circuit diagram showing a portion of a pixel
array of a display device according to an embodiment.
[0010] FIG. 3A is a cross-sectional view showing a portion of a
pixel of a display device according to an embodiment.
[0011] FIG. 3B is a cross-sectional view showing a portion of a
pixel of a display device according to another embodiment.
[0012] FIGS. 4A-4D are top views showing bending structures for
conductive lines according to embodiments.
[0013] FIG. 5 shows top views of various arrangements of openings
in bending structures according to embodiments.
[0014] FIGS. 6A-6C are top views showing connecting portions of
conductive lines according to embodiments.
[0015] FIGS. 7A-7B are schematic top views showing placements of
conductive lines on display devices according to embodiments.
[0016] FIGS. 8A-8B are cross-sectional views of display device
portions having conductive layers with bending structures according
to embodiments.
[0017] FIGS. 9A-9D are cross-sectional views of conductive lines
having multilayer structures according to embodiments.
[0018] FIGS. 10A-B are top views showing touch electrode layers
having bending structures according to embodiments.
[0019] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements of
one example may be beneficially incorporated in other examples.
DETAILED DESCRIPTION
[0020] FIG. 1A is a schematic top view of a display device 100
according to an embodiment. The display device 100 includes a
substrate 102 having a gate driver region 104, an active area
region 108, and an inactive area region 110. An integrated circuit
(IC) 106 is disposed in the inactive area region 110. The active
area region 108 includes a pixel array (FIG. 2), which is described
further below. The gate driver region 104 includes circuitry (e.g.,
gate drivers) configured to drive gates of thin-film transistors
(TFTs) formed in the active area region 108. The gate drivers
select rows of pixels in the pixel array for updating. The IC 106
includes circuitry (e.g., source drivers) configured to drive
sources of the TFTs formed in the active area region 108. The
source drivers supply display data to selected pixel rows.
[0021] Conductive lines 114, 116, and 118 are formed on the
substrate 102. The conductive lines 114, 116, and 118 are formed of
metal, an oxide semiconductor, or a metal oxide. In embodiments,
metal can be Ti, Pt, Au, Ni, AI, Mo, Cu, and the like, as well as
alloys of such elements. In embodiments, an oxide semiconductor can
be a material having at least one kind of element selected from
among In, Ga, Zn, and Sn. In embodiments, the metal oxide can be
ITO (indium tin oxide) or IZO (indium zinc oxide). The conductive
lines 114, 116, and 118 can be on a plurality of conductive layers
disposed on the substrate 102. The conductive lines 114 are coupled
between gate drivers in the gate driver region 104 and TFTs in the
active area region 108. The conductive lines 114 are also referred
to herein as "gate lines 114." The conductive lines 116 are coupled
between source drivers in the IC 106 and TFTs in the active area
region 108. The conductive lines 116 are also referred to herein as
"source lines 116." The conductive lines 118 are coupled between
control circuitry in the IC 106 and the gate drivers in gate driver
region 104. For purposes of clarity by example, FIG. 1A shows only
the conductive lines 114, 116, and 118 having the functions
described above. The substrate 102 can include other conductive
lines formed thereon, including conductive lines to supply anode or
cathode voltage to light-emitting diode (LED) elements in the pixel
array, as well as conductive lines coupled to touch sensing
electrodes integrated with the display device 100 (if present).
[0022] The substrate 102 can be flexible and can be a polymer
layer, such as a thin plastic film formed from polyimide,
polyethylene naphthalate (PEN), polyethylene terephthalate (PET),
or other suitable polymers or combination of such polymers. The
substrate 102 can include other suitable materials, such as a metal
foil covered with a dielectric, a multi-layer polymer stack, a thin
glass film bonded to a thin polymer, a polymer composite film
comprising a polymer material combined with nanoparticles or
microparticles dispersed therein, and the like. In some
embodiments, the substrate 102 can be a rigid substrate, such as
glass. The IC 106 comprises an application specific integrated
circuit (ASIC) or the like that is mechanically mounted to the
substrate 102 and electrically coupled to the conductive lines 116
and 118. The IC 106 can include other contacts or pins that are
coupled to a flexible printed circuit board (PCB) or the like (not
shown).
[0023] A fan-out region 112 is a portion of the inactive region
110. The conductive lines 116 and 118 are coupled to pins of the IC
106 in the fan-out region 112. In an embodiment, conductive lines
disposed on the substrate 102 include bending structures that
improve stability and reliability thereof when the substrate 102 is
flexed (e.g., bent, curved, folded, stretched, etc.). Various
embodiments of the bending structure are described below.
[0024] In the embodiment shown, the display device 100 is a
gate-in-panel (GIP) device, where the gate drivers are formed using
thin-films on the substrate 102 in the gate driver region 104. In
other embodiments, the gate drivers can be integrated on the IC
106, rather than formed directly on the substrate 102. In such
case, the gate driving region 104 is omitted and replaced with a
wiring region having conductive lines that electrically couple gate
drivers in the IC 106 with the gate lines 114. Also, in the
embodiment shown in FIG. 1A, the gate driver region 104 is disposed
on both sides of the active area region 108. In another embodiment,
the gate driver region 104 is disposed on a single side of the
active area region 108.
[0025] FIG. 1B is an exploded side view 150 showing a portion of
the display device 100 according to an embodiment. The display
device 100 generally includes multiple layers, including a cover
layer 120, a light emitting layer 121, a TFT layer 122, conductive
layers 124, and a substrate layer (e.g., the substrate 102). The
display device 100 can include other layers, such as a carrier
layer (not shown) that supports the substrate 102 and the layers
disposed thereon. Further, some or all of the layers 120, 121, 122,
and 124 can be further divided into a plurality of sublayers.
[0026] The TFT layer 122 is disposed on the surface of the
substrate 102 in the active area region 108. The light emitting
layer 121 is disposed on the surface of the substrate 102 in the
active area region 108 and is electrically connected to the TFT
layer 122. In general, the conductive layers 124 are disposed on
the surface of the substrate 102. Some of the conductive layers 124
are sublayers of the TFT layer 122. For example, the TFT layer 122
can include a conductive layer 124-1 that is patterned into at
least the gate lines 114, and a conductive layer 124-2 that is
patterned into at least the source lines 116. The TFT layer 122 can
include more than two conductive layers (not shown).
[0027] One or more other conductive layers 124 are disposed on the
surface of the substrate 102 in the inactive area region 110. For
example, a conductive layer 124-4 can be patterned into conductive
lines, pads, etc. in the inactive area region 110 (e.g., the
fan-out region 112 and the gate driver region 104). A given
conductive layer 124 includes one or more bending structures formed
therein. As described further herein, each bending structure
includes a plurality of openings, where a shape of at least one
opening thereof has at least one curved portion. Various
embodiments of the bending structure are described below.
[0028] In some embodiments, the conductive layers 124 include a
touch electrode layer 124-3. The touch electrode layer 124-3 is
disposed on the surface of the substrate 102. The touch electrode
layer 124-3 includes one or more conductive layers patterned to
include electrodes and conductive lines for the purpose of touch or
proximity sensing of input object(s). As shown, the touch electrode
layer 124-3 can be formed on an inner surface of the cover layer
120 or on an additional substrate attached to the cover layer 120.
Alternatively, at least a portion of the touch electrode layer
124-3 can be formed in the TFT layer 122 or between the TFT layer
122 and the light emitting layer 121. The touch electrodes and/or
conductive lines coupled thereto in the touch electrode layer 124-3
can include bending structures, as described further herein.
[0029] FIG. 2 is a circuit diagram showing a portion of a pixel
array 200 of the display device 100 according to an embodiment. The
pixel array 200 is formed in the active area region 108 of the
display device 100. The pixel array 200 includes pixels 202
arranged into rows and columns. The pixels 202 are controlled using
a pattern of gate lines 114 and source lines 116. Each pixel 202
includes an LED element 206, such as an organic LED (OLED) or micro
LED or the like, as well as an associated control circuit 204. The
control circuit 204 can include TFT(s) and capacitor(s). The
control circuit 204 is coupled to a source line 116 and a gate line
114 to control the LED element 206. The control circuit 204 is
formed in the TFT layer 122. The LED element 206 is formed in the
light-emitting layer 121. The gate lines 114 and the source lines
116 are formed in the TFT layer 122, as described above.
[0030] FIG. 3A is a cross-sectional view showing a portion of a
pixel 202 of the display device 100 according to an embodiment. The
pixel 202 includes multiple layers formed on the substrate 102. In
the embodiment, the layers include a buffer layer 302, a
semiconductor layer 303, a dielectric layer 304, a conductive layer
having a gate electrode 316, a dielectric layer 306, a conductive
layer having a drain contact 312 and a source contact 314, a
dielectric layer 308, a conductive layer having a first electrode
322, an organic layer 323, a pixel define layer 310, and a
conductive layer having a second electrode 324. The second
electrode 324, the organic layer 323, the pixel define layer 310,
and the first electrode 322 are part of the light-emitting layer
121. The dielectric layer 308, the source contact 314, the drain
contact 312, the gate electrode 316, the dielectric layer 306, the
dielectric layer 304, the semiconductor layer 303, and the buffer
layer 302 are part of the TFT layer 122. The first electrode 322
can be an anode and the second electrode 324 can be a cathode, and
vice versa. The first electrode 322 can be electrically connected
to the drain contact 312 through the via hole 322a in the
dielectric layer 308.
[0031] In the embodiment of FIG. 3A, the second electrode 324, the
organic layer 323, the pixel define layer 310, and the first
electrode 322 form an OLED (e.g., LED element 206, FIG. 2). While
FIG. 3A shows an OLED structure, LED element 206 can be implemented
using other structures. For example, LED element 206 can be a micro
LED element, and will be described in FIG. 3B below. The organic
layer 323 includes one or more layers of organic emissive material.
The anode electrode 322 can be metal or a transparent conductive
material. The cathode electrode 324 can be metal or a transparent
conductive material. Suitable metal can be Mg, Ca, Al, Ag, W, Cu,
Ni, Cr, or an alloy thereof. Suitable transparent conductive
material can be ITO (indium tin oxide), IZO (indium zinc oxide),
zinc oxide, or indium oxide.
[0032] The semiconductor layer 303 is formed of a semiconductor
material, such as silicon or an organic semiconductor material. For
example, the semiconductor layer 303 can be amorphous silicon,
polysilicon, or metal oxide such as IGZO. The semiconductor layer
303 can include a source region 318 and a drain region 320 formed
therein through diffusion. The source contact 314 is electrically
coupled to the source region 318 through a via in the dielectric
layer 306 and the dielectric layer 304. The drain contact 312 is
electrically coupled to the drain region 320 through another via in
the dielectric layer 306 and the dielectric layer 304. The gate
electrode 316 is separated from a channel between the source region
318 and the drain region 320 by the dielectric layer 304 (e.g., a
gate dielectric). The gate electrode 316 can be formed of metal or
an oxide semiconductor. The source contact 314 and the drain
contact 312 can be formed of metal. The gate electrode 316, the
dielectric layer 304, the source region 318, and the drain region
320 implement a TFT used in the control circuit 204 (FIG. 2) that
drives the LED element 206. While an example TFT structure is shown
in FIG. 2A, other TFT structures can be used. For example, the
source region 318 and the drain region 320 can be formed of metal,
rather than diffusion regions in the semiconductor layer 303. The
source contact 314, the gate electrode 316, and the drain contact
312 are coupled to conductive lines having bending structures, as
described further herein.
[0033] FIG. 3B is a cross-sectional view showing a portion of a
pixel 202 of the display device 100 according to an embodiment. In
the present embodiment, the LED element 206 is a micro LED element.
Elements of FIG. 3B that are the same or similar to those of FIG.
3A are designated with identical reference numerals and are
described in detail above. At least one micro LED element 206 can
be disposed in one pixel. The micro LED element can include a p-n
diode 350, a first contact electrode 361 located at one side of the
p-n diode 350, and a second contact electrode 362 located at
another side of the p-n diode 350. The p-n diode 350 can include a
first semiconductor layer 351, a second semiconductor layer 353,
and multi quantum well (MQW) structure 352 disposed between the
first semiconductor layer 351 and the second semiconductor layer
353. The first semiconductor layer 351 can be a p-type
semiconductor layer and the second semiconductor layer 353 can be
an n-type semiconductor layer, and vice versa.
[0034] FIGS. 4A-4D are top views showing bending structures for
conductive lines according to embodiments. FIG. 4A is a top view
showing a bending structure 402-1 according to an embodiment. The
bending structure 402-1 comprises a conductive line having a
plurality of openings 404 therein. The bending structure 402-1
includes a width along the Y-direction and a length along the
X-direction. Each opening 404 is generally rectangular, but having
rounded corners. Thus, each opening 404 includes a curved portion
406. In an embodiment, as shown in detail 407A, the curved portion
406 includes a radius R and is disposed in each corner of the
opening 404. In another embodiment, as shown in detail 407B, the
curved portion 406 includes a radius R and is disposed on each side
of the opening 404. In general, each opening 404 includes a curved
portion having a single radius of curvature. The openings 404 can
have other shapes, including polygons other than rectangles or a
circle.
[0035] The bending structure 402-1 can include any number of the
openings 404 in various arrangements. In the example of FIG. 4A,
the bending structure 402-1 includes three rows of openings 404
that extend along the length, but the bending structure 402-1 can
include more or less than three rows of openings 404. The length of
each opening 404 along a given row can varying from one opening to
the next according to a pattern, which may be repeated along the
length. The patterns of openings between the rows can be staggered
from one row to the next.
[0036] In the present disclosure, the bending structure can be
formed by bending the conductive layer. According to some
embodiments, the bending process can be conducted before the
display device is presented to the consumers (or users).
Alternatively, according to some embodiments, when a flexible
substrate is used, the bending process can be conducted by the
consumer. That is, originally, the substrate and the conductive
layer can be flat, and then the consumer can bend the substrate and
the conductive layer to have the bending structure according to
requirement. In the disclosure, the bending structure can mean a
structure that has been bent, or a structure that will be bent by
the consumers.
[0037] FIG. 4B is a top view showing a bending structure 402-2
according to an embodiment. The bending structure 402-2 comprises a
conductive line having a plurality of openings 408 therein. The
bending structure 402-2 includes a width along the Y-direction and
a length along the X-direction. As shown in detail 409, each
opening 408 is elliptical in shape having a first curved portion
410 and a second curved portion 412. The first curved portion 410
includes a curvature radius R1, and the second curved portion 412
includes a radius R2. The bending structure 402-2 can include any
number of the openings 408 in various arrangements. In the example
of FIG. 4B, the bending structure 402-2 includes three rows of
openings 408, but the bending structure 402-2 can include more or
less than three rows of openings 408. In the present example of
FIG. 4B, each opening 408 is the same or similar in size, but in
other examples the openings 408 can have different sizes from one
opening to another. Further, while a staggered pattern of openings
408 is shown, the bending structure 402-2 can have other patterns
of the openings 408.
[0038] FIG. 4C is a top view showing a bending structure 402-3
according to an embodiment. The bending structure 402-3 comprises a
conductive line having a plurality of openings 408 similar to those
of the bending structure 402-2 shown in FIG. 4B. The bending
structure 402-3 includes a width along the Y-direction and a length
along the X-direction. The bending structure 402-3 differs from the
bending structure 402-2 by having undulating edges 430 (e.g.,
serpentine edges) along at least a portion of the length thereof.
While the openings 408 are shown in the example, the bending
structure 402-3 can have openings 404 as shown in FIG. 4A (i.e.,
the bending structure 402-1 can be configured with undulating edges
430).
[0039] FIG. 4D is a top view showing a bending structure 402-4
according to an embodiment. The bending structure 402-4 comprises a
conductive line having a plurality of openings 414 therein. The
bending structure 402-4 includes a width along the Y-direction and
a length along the X-direction. As shown in detail 416, each
opening 414 includes a first curved portion 418 and a second curved
portion 420. The first curved portion 418 includes a curvature
radius R1, and the second curved portion 420 includes a radius R2.
The bending structure 402-4 can include any number of the openings
414 in various arrangements. In the example of FIG. 4D, the bending
structure 402-4 includes one row of openings 414, but the bending
structure 402-4 can include more than one row of openings 414. In
the present example of FIG. 4D, each opening 414 is the same or
similar in size, but in other examples the openings 414 can have
different sizes from one opening to another.
[0040] There are numerous other types of bending structures that
can be formed having different opening shapes and arrangements than
shown in the examples of FIGS. 4A-4D. In general, each bending
structure includes a plurality of openings, where a shape of at
least one of the plurality of openings has a first curved portion.
Each opening can have additional curved portions that have
curvatures that are the same or similar to the curvature of the
first curved portion. In an embodiment, the at least one opening
further includes a second curved portion. In an embodiment, the
curvature of the first curved portion is different than a curvature
of the second curved portion. Each opening can have additional
curved portions that have curvatures that are the same or similar
to either the first or second curved portion. In an embodiment,
each opening in a bending structure has an area between 5
.mu.m.sup.2 and 500 .mu.m.sup.2. In an embodiment, the bending
structure can include at least one undulating edge.
[0041] The openings in the bending structure of a conductive line
reduce the stress when the flexible substrate is bent or otherwise
flexed. Further, the curved shape of each opening reduces the
probability of a crack in the conductive line when the flexible
substrate is bent or otherwise flexed. This is opposed to cases
where the conductive line includes no openings or includes openings
that have right-angles, where the probability of cracking is
higher.
[0042] FIG. 5 shows top views of various arrangements of openings
in bending structures according to embodiments. The bending
structures shown in FIG. 5 each include a plurality of elliptical
openings similar to those shown in FIGS. 4B and 4C, but disposed in
different patterns. A bending structure 502 includes a single row
of elliptical openings, where the openings are rotated by some
angle. The bending structure 504 includes a single row of
elliptical openings. The bending structure 506 includes a single
row of openings that are rotated 90 degrees with respect to the
openings in FIGS. 4B and 4C. The bending structure 508 includes a
single row of elliptical openings, where each opening has an angle
of rotation that alternates between two different angles. The
bending structure 510 includes two rows of elliptical openings,
where the openings in the first row are rotated by a first angle
and the openings in the second row are rotated by a second angle
different than the first angle. The bending structure 512 includes
a repeating pattern of four openings rotated by four different
angles and one opening rotated 90 degrees with respect to the
openings in FIGS. 4B and 4C. The bending structure 514 includes two
rows of elliptical openings that are aligned instead of staggered.
Each of the bending structures 502 . . . 514 includes undulating
edges along the lengths thereof. In other embodiments, the bending
structures 502 . . . 514 can include straight edges along the
length thereof.
[0043] FIGS. 6A-6C are top views showing connecting portions of
conductive lines according to embodiments. FIG. 6A shows a portion
of a conductive line 601 (e.g., gate line, source line, or any
other conductive line disposed on a substrate). The conductive line
601 includes a wiring portion 602 and a bending structure 606A. The
wiring portion 602 has a width 608 along the Y-direction and a
length along the X-direction. The wiring portion 602 does not
include openings or other features of the bending structure 606.
The wiring portion 602 can be, for example, a rectangular trace.
The bending structure 606A includes a plurality of openings and
undulating edges according to example bending structures described
above. While a specific bending structure is shown in FIG. 6A, the
bending structure 606A can have any of the structures discussed
above. The wiring portion 602 is connected to the bending structure
606A by a connecting portion 604A. In the embodiment, the
connecting portion 604A is generally rectangular and includes a
width 610 along the Y-direction and a length along the X-direction.
The width 610 is greater than the width 608 of the wiring portion
602. The bending structure 606A includes a width along the
Y-direction and a length along the X-direction. The width of the
bending structure 606A can be as wide as the width 610 of the
connecting portion 604A or can be less than the width 610.
[0044] FIG. 6B shows a portion of a conductive line 603 (e.g., gate
line, source line, or any other conductive line disposed on a
flexible substrate). The conductive line 603 includes the wiring
portion 602 connected to a bending structure 606B by a connecting
portion 604B. While a specific bending structure is shown in FIG.
6B, the bending structure 606B can have any of the structures
discussed above. As shown in detail 611, the connecting portion
604B includes a sub-portion 604B-1 and a sub-portion 604B-2. The
sub-portion 604B-1 is generally rectangular, similar to the
connecting portion 604A in FIG. 6A. The width 620 of the
sub-portion 604B-1 along the Y-direction is greater than the width
608 of the wiring portion 602. The sub-portion 604B-2 is generally
trapezoidal in shape having a first width 614 and a second width
616 along the Y-direction. The sub-portion 604B-1 is connected to
the sub-portion 604B-2 at the side of the sub-portion 604B-2 having
the width 614. The sub-portion 604B-2 is connected to the bending
structure 606B at the side having the width 616. The first width
614 can be greater than the second width 616.
[0045] FIG. 6C shows a portion of a conductive line 605 (e.g., gate
line, source line, or any other conductive line disposed on a
flexible substrate). The conductive line 605 includes the wiring
portion 602 connected to a bending structure 606C by a connecting
portion 604C. While a specific bending structure is shown in FIG.
6C, the bending structure 606C can have any of the structures
discussed above. In FIG. 6C, the connecting portion 604C is similar
to the connecting portion 604B, but includes a plurality of the
trapezoidal sub-portions connected to the bending structure 606C.
While three of the trapezoidal sub-portions are shown, the bending
structure 606C can include a plurality of trapezoidal
sub-portions.
[0046] FIGS. 7A-7B are schematic top views showing placements of
conductive lines on display devices according to embodiments. FIG.
7A is a schematic top view showing a conductive line 702 according
to an embodiment. The conductive line 702 is disposed on the
substrate 102 within both the active area region 108 and the
inactive area region 110. The conductive line 702 includes wiring
portions 704, connecting portions 706, and bending structures 708.
Similar to the embodiments of FIGS. 6A-6C, the wiring portions 704
are connected to the bending structures 708 by the connecting
portions 706. While specific connecting portions and bending
structures are shown in FIG. 7A, the connecting portions 706 and
bending structures 708 can have any structure described in the
various embodiments herein. The bending structure 708 includes a
plurality of openings 718. While the schematic shows the conductive
line 702 as having three bending structures 708, the conductive
line 702 generally includes at least one bending structure 708. The
conductive line 702 can be a source line, gate line, or any other
conductive line disposed on the substrate 102 discussed herein.
While only a single conductive line 702 is shown in the schematic,
the substrate 102 can include a plurality of the same or similar
conductive lines. While the conductive line 702 includes bending
structures 708 in both the active area region 108 and the inactive
area region 110, the conductive line 702 can include bending
structures 708 in only the active area region 108 or only the
inactive area region 110.
[0047] FIG. 7B is a schematic top view showing a plurality of
conductive lines 712 according to an embodiment. The conductive
lines 712 (e.g., three are shown) are disposed on the substrate 102
within both the active area region 108 and the fan-out region 112.
The conductive lines 712 includes the wiring portions 704, the
connecting portions 706, and the bending structures 708. Similar to
the embodiments of FIGS. 6A-6C, the wiring portions 704 are
connected to the bending portions 708 by the connecting portions
706. While specific connecting portions and bending structures are
shown in FIG. 7B, the connecting portions 706 and bending
structures 708 can have any structure described in the various
embodiments herein. The conductive lines 712 include bending
structures 708 disposed in the fan-out region 112. The conductive
lines 712' are coupled to pads 714, which are in turn coupled to
pins of the IC 106. Only a portion of the conductive lines 712 in
the active area region 108 are shown. Similar to the embodiment of
FIG. 7A, the conductive lines 712 can include bending structures
708 in the active area region 108.
[0048] FIGS. 8A-8B are cross-sectional views of display device
portions having conductive layers with bending structures according
to embodiments. FIG. 8A is a cross-sectional view of a portion of
the display device 100 taken along the line A-A' in FIG. 7A
according to an embodiment. As shown, the conductive line 702
includes a portion that is patterned on the conductive layer 124-2
of the TFT layer 122. For example, the conductive line 702 can
include a source line 116 coupled to source contacts of TFTs. The
conductive line 702 also includes a portion that is patterned on
the conductive layer 124-4 disposed in the inactive area region 110
on the substrate 102. The conductive layer 124-2 and the conductive
layer 124-4 can be electrically connected (not shown) to form the
conductive line 702. In the example, the substrate 102 is shown as
being curved in the inactive area region 110 having the portion of
the conductive line 702 on the conductive layer 124-4. In other
examples, the substrate 102 can be curved, bent, stretched, or the
like in other ways. In an embodiment, both portions of the
conductive line 702 are made of the same material as the source and
drain contacts in the TFT layer 122. In some embodiments, the
conductive layer 124-2 forming the source and drain contacts in the
active area region 108 and the conductive layer 124-4 including the
bending structure in the inactive active region 110 can be of the
same material, and specifically, can be the same layer and formed
by the same process.
[0049] In some embodiments, referring to FIG. 8A, the TFT layer 122
can include a TFT as shown in FIG. 3 (not shown in FIG. 8A), and
the TFT includes a source contact 314 and a drain contact 312. A
material of the conductive line including the bending structure,
and a material of at least one of the source contact and the drain
contact, are the same. For example, a conductive layer can be
formed on the substrate 102, and then the conductive layer can be
patterned by photolithography in the same process to form the
source line, the source contact, the drain contact, and the
conductive line including the bending structure. The conductive
line including the bending structure can be disposed in the
inactive area region 110, in the active area region 108, or both in
the inactive area region 110 and the active area region 108.
[0050] FIG. 8B is a cross-sectional view of a portion of the
display device 100 taken along the line A-A' in FIG. 7A according
to another embodiment. As shown, the conductive line 702 includes a
portion that is patterned on the conductive layer 124-1 of the TFT
layer 122. For example, the conductive line 702 can be a gate line
114 coupled to gate electrodes of TFTs. The conductive line 702
also includes a portion that is patterned on the conductive layer
124-4 disposed in the inactive area region 110 on the substrate
102. The conductive layer 124-1 and the conductive layer 124-4 can
be electrically connected (not shown) to form the conductive line
702. In the example, the substrate 102 is shown as being curved in
the inactive area region 110 having the portion of the conductive
line 702 on the conductive layer 124-4. In other examples, the
substrate 102 can be curved, bent, stretched, or the like in other
ways. In an embodiment, both portions of the conductive line 702
are made of the same material as the gate electrodes in the TFT
layer 122. In some embodiments, the conductive layer 124-1 forming
the gate electrode in the active area region 108 and the conductive
layer 124-4 including the bending structure in the inactive active
region 110 can be of the same material, and specifically, can be
the same layer and formed by the same process.
[0051] In some embodiments, referring to FIG. 8B, the TFT layer 122
can include a TFT as shown in FIG. 3 (not shown in FIG. 8B), and
the TFT includes a gate electrode 316. A material of the conductive
line including the bending structure, and a material of the gate
electrode are the same. For example, a conductive layer can be
formed on the substrate 102, and then the conductive layer can be
patterned by photolithography in the same process to form the gate
line, the gate electrode, and the conductive line including the
bending structure. The conductive line including the bending
structure can be disposed in the inactive area region 110, in the
active area region 108, or both in the inactive area region 110 and
the active area region 108.
[0052] FIGS. 9A-9D are cross-sectional views of conductive lines
having multilayer structures according to embodiments. FIG. 9A is a
cross-sectional view of a conductive line 902A disposed on a layer
901 according to an embodiment. The layer 901 can be the substrate
or some other layer (e.g., a layer in the TFT layer 122). The
conductive line 902A includes openings 904 in bending structures
thereof, as discussed in the various embodiments above. In the
present embodiment, the conductive line 902A includes two layers
906 and 908. The layer 908 is disposed on the layer 901, and the
layer 906 is disposed on the layer 908. The layer 906 has a
thickness 910, and the layer 908 has a thickness 912. In an
embodiment, the thickness 910 of the layer 906 is greater than the
thickness 912 of the layer 908. In an embodiment, the conductive
material of the layer 906 is different than the conductive material
of the layer 908. The layer 908 can be a conductive material that
provides increased adhesion to the layer 901, whereas the layer 906
can be a material that provides for increased toughness.
[0053] FIG. 9B is a cross-sectional view of a conductive line 902B
disposed on a layer 901 according to an embodiment. The conductive
line 902B is configured similar to the conductive line 902A, with
the exception of the layer 908. In the embodiment of FIG. 9A, the
openings 904 of the bending structures are in both of the layers
906 and 908. In the embodiment of FIG. 9B, the openings 904 are
only in the layer 906. The layer 908 does not include openings.
[0054] FIG. 9C is a cross-sectional view of a conductive line 902C
disposed on a layer 901 according to an embodiment. In the
embodiment of FIG. 9C, the conductive line 902C includes three
layers 914, 916, and 918. The layer 918 is disposed on the layer
901; the layer 916 is disposed on the layer 918; and the layer 914
is disposed on the layer 916. The openings 914 are through all
layers 914 . . . 918. The thicknesses 920, 922, and 924 of the
layers 914, 916, and 918 can be different. For example, the
thickness 922 of the layer 916 can be greater than the thicknesses
920 and 924 of the layers 914 and 918, respectively. The thickness
920 of the layer 914 can be more, less, or the same as the
thickness 924 of the layer 918. In an embodiment, the conductive
material of the layer 916 is different than the conductive material
of the layers 914 and 918. The layer 918 can be a conductive
material that provides increased adhesion to the layer 901, whereas
the layer 916 can be a material that provides for increased
toughness. In some embodiments, the layer 914 and the layer 918 can
be of the same material, and the layer 916 can be a different
material from the layer 914. For example, the layer 914 and 918 can
be Mo, and the layer 916 can be Al.
[0055] FIG. 9D is a cross-sectional view of a conductive line 902D
disposed on a layer 901 according to an embodiment. In the
embodiment of FIG. 9D, the conductive line 902D includes three
layers 914, 916, and 918, similar to the conductive line 902C in
FIG. 9C. However, in the embodiment of FIG. 9D, the layer 918 does
not include the openings 904. That is, the openings 904 are only
through the layers 914 and 916.
[0056] FIGS. 10A-B are schematic top views showing touch electrode
layers having bending structures according to embodiments. FIG. 10A
is a schematic top view showing a touch electrode layer 1002
according to an embodiment. The touch electrode layer 1002 is
disposed on the substrate 102 in the active area region 108 (e.g.,
on a layer above the light-emitting layer 121 or between the TFT
layer 122 and the light-emitting layer 121). The touch electrode
layer 1002 can include a plurality columns of electrodes 1004 and a
plurality rows of electrodes 1204. For one column of touch
electrodes, two adjacent touch electrodes 1004 are electrically
connected by the connecting structure 1006. For one row of touch
electrodes, two adjacent touch electrodes 1204 are electrically
connected by the connecting structure 1206. The touch electrode
layer 1002 further includes a plurality of conductive lines 1008
disposed on the substrate 102 in both the active area region 108
and the inactive area region 110. The conductive lines 1008 can be
coupled to pins of the IC 106. Some of the conductive lines 1008
are coupled to columns of the touch electrodes 1004, and others of
the conductive lines 1008 are coupled to rows of the touch
electrodes 1204. The columns of the touch electrodes 1004 are
ohmically isolated (or electrically insulated) from each other and
from the rows of the touch electrodes 1204. The conductive lines
1008 include bending structures that can be in the active area
region 108, the inactive area region 110, or both.
[0057] FIG. 10B is a schematic top view showing a touch electrode
layer 1003 according to an embodiment. The touch electrode layer
1003 is configured similarly to the touch electrode layer 1002
shown in FIG. 10A. In the embodiment of FIG. 10A, the touch
electrodes 1004 and 1204 do not include openings therein. In the
embodiment of FIG. 10B, each of the touch electrodes 1004 includes
one or more openings 1012, and each of the touch electrodes 1204
includes one or more openings 1012. In some embodiments, at least
one of the touch electrodes in the active area region 108 includes
the bending structure. In the example shown, each touch electrode
1004 (or touch electrodes 1204) includes four elliptical openings.
In general, one or more of the touch electrodes 1004 (or touch
electrodes 1204) can include one or more openings, and the openings
can have various shapes and arrangements, similar to the openings
in the bending structures described above for the conductive
lines.
[0058] In the various embodiments described above, conductive lines
and/or touch electrodes are described as having bending structures
to reduce strain when a flexible substrate is flexed in some
manner. The embodiments are described with respect to a flexible
substrate of a display device. However, the embodiments are
applicable to flexible substrates in general and can be used in
other types of devices having flexible substrates and circuitry
requiring conductive lines and/or electrodes.
[0059] While the foregoing is directed to specific examples, other
and further examples may be devised without departing from the
basic scope thereof, and the scope thereof is determined by the
claims that follow.
* * * * *