JP2022062080A - Element substrate having flexible base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable display device hardly causing disconnection of wiring at the time of bending.

SOLUTION: A display device includes: a flexible base material; a display region including a plurality of pixels on a first surface of the base material; a peripheral region outside the display region on the base material; first wiring extending in a first direction disposed in the peripheral region; a first insulation layer on the first wiring; and second wiring extending in a second direction intersecting with the first direction on the first insulation layer. The first wiring has a first bent portion. The second wiring has a second bent portion. In an area where the first wiring and the second intersect with each other, the first bent portion overlaps with the second wiring and the second bent portion overlaps with the first wiring.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

One embodiment of the present invention relates to a display device. In particular, it relates to the wiring configuration of the display device.

The organic electroluminescence (hereinafter referred to as organic EL) display device is provided with a light emitting element in each pixel and displays an image by individually controlling the light emission. The light emitting device has a structure in which a layer containing an organic EL material (hereinafter, also referred to as “light emitting layer”) is sandwiched between a pair of electrodes distinguished by using one as an anode and the other as a cathode. When electrons are injected from the cathode and holes are injected from the anode into the light emitting layer, the electrons and holes are recombined. The surplus energy emitted by this excites the luminescent molecules in the light emitting layer, and then deexcites to emit light.

In the organic EL display device, each anode of the light emitting element is provided as a pixel electrode for each pixel, and the cathode is provided as a common electrode to which a common potential is applied across a plurality of pixels. The organic EL display device controls the light emission of the pixel by applying the potential of the pixel electrode to the potential of the common electrode for each pixel.

In recent years, flexible display devices having a foldable display area have been actively developed. The wiring formed in the display area of the flexible display device has a problem that stress is concentrated when the display device is bent and the wiring is easily broken.

To solve such a problem, for example, in Patent Document 1, when the flexible display device is curved in one direction, the data line extending in one direction is not a straight line but a crank-shaped or S-shaped wiring. Is disclosed.

Japanese Unexamined Patent Publication No. 2009-48007

In the configuration of Patent Document 1, the data line extending in one direction is not a straight line but a crank shape or an S shape, but the select line (also referred to as a gate line) extending intersecting the one direction is a straight line. That is, a crank-shaped or S-shaped data line is provided on the straight select line via the interlayer insulating film.

When the flexible display device is curved in one direction, stress is concentrated in the region where the select line and the data line intersect. In particular, stress is concentrated on the stepped portion of the upper data line that crosses the select line. Therefore, there is a problem that the data line is likely to be broken along the end of the select line.

One of the objects of the present invention is to provide a highly reliable display device in which wiring is less likely to be broken when bent.

The display device according to an embodiment of the present invention includes a flexible base material, a display region including a plurality of pixels on the base material, a peripheral region outside the display region on the base material, and a peripheral region. It has a first wiring extending in a first direction arranged, a first insulating layer on the first wiring, and a second wiring extending in a second direction intersecting the first direction on the first insulating layer. The first wiring has a first bending portion, the second wiring has a second bending portion, and the first bending portion overlaps with the second wiring in the region where the first wiring and the second wiring intersect. However, the second bent portion overlaps with the first wiring.

A display device according to an embodiment of the present invention includes a flexible base material, a display area including a plurality of pixels on the base material, a peripheral area outside the display area on the base material, and a display area. It has a first wiring extending in a first direction, a first insulating layer on the first wiring, and a second wiring extending in a second direction intersecting the first direction on the first insulating layer. The wiring has a first bent portion, the second wiring has a second bent portion, and the first bent portion overlaps with the second wiring in the region where the first wiring and the second wiring intersect. The second bent portion overlaps with the first wiring.

It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the structure of the display device which concerns on one Embodiment of this invention. It is a top view of the intersection of two wirings in a conventional display device. It is sectional drawing which follows the B1-B2 line shown in FIG. 4A. It is an enlarged view of a part of the display device which concerns on one Embodiment of this invention. It is an enlarged view of a part of the display device which concerns on one Embodiment of this invention. It is an enlarged view of a part of the display device which concerns on one Embodiment of this invention. It is an enlarged view of a part of the display device which concerns on one Embodiment of this invention. It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is an enlarged view of a part of the display device which concerns on one Embodiment of this invention. It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is a perspective view explaining the structure of the display device which concerns on one Embodiment of this invention. It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is a top view explaining the structure of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the structure of the display device which concerns on one Embodiment of this invention. It is a circuit diagram of the display device which concerns on one Embodiment of this invention. It is a timing chart of the display device which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

<First Embodiment>
The display device according to this embodiment will be described with reference to FIGS. 1 to 6.

[Display device configuration]
FIG. 1 is a plan view showing the configuration of the display device 100 according to the present embodiment. The display device 100 includes a base material 101, a display area 102, and a peripheral area 110. The base material 101 has flexibility. The display area 102 is provided on the base material 101. Further, the display area 102 includes a plurality of pixels 103. The plurality of pixels 103 are arranged in a matrix.

The peripheral area 110 is provided so as to surround the display area 102. The peripheral region 110 refers to a region from the display region 102 to the end of the base material 101. In other words, the peripheral region 110 refers to a region other than the display region 102 provided on the base material 101 (that is, a region outside the display region 102). The peripheral region 110 includes a drive circuit 104 and a terminal 106. The drive circuit 104 is provided so as to sandwich the display area 102. Further, the driver IC 105 may be provided in the peripheral region 110. The driver IC is connected to the terminal 106. The terminal 106 is connected to the flexible printed circuit 107.

The drive circuit 104 is connected to a scan line connected to the pixel 103 and functions as a scan line drive circuit. Further, the driver IC 105 is connected to a signal line connected to the pixel 103, and a signal line drive circuit is incorporated. Although FIG. 1 shows an example in which the signal line drive circuit is incorporated in the driver IC 105, the signal line drive circuit may be provided on the base material 101 separately from the driver IC 105.

The driver IC 105 may be arranged on the base material 101 in the form of an IC chip. Further, although not shown, the driver IC 105 may be provided on the flexible printed circuit 107.

A video signal is given to each pixel 103 from the driver IC 105 via a signal line. Further, each pixel 103 is given a signal from the driver IC 105 to select each pixel 103 via the drive circuit 104 and the scanning line. With these signals, the transistor included in the pixel 103 can be driven to display the screen according to the video signal.

In the peripheral area 110, a bent area 120 of the display device 100 is provided between the display area 102 and the driver IC 105. Wiring 111 and wiring 112 are provided in the bent region 120. The wiring 111 connects the plurality of pixels 103 and the driver IC 105. Similarly, the wiring 112 connects the plurality of pixels 103 and the driver IC. An insulating layer (not shown) is provided on the wiring 111, and the wiring 112 is provided on the insulating layer.

In the bent region 120, the wiring 111 has a portion extending in the first direction (x direction in FIG. 1). A part of the wiring 111 may extend in the second direction. Further, in the bent region 120, the wiring 112 has a portion extending in the second direction (y direction in FIG. 1). As shown in FIG. 1, the wiring 111 and the wiring 112 intersect with each other, but may not be orthogonal to each other. The first direction may be, for example, offset by ± 30 ° with respect to the x-axis. Further, the second direction may be deviated by, for example, ± 30 ° with respect to the y-axis.

FIG. 2 is a diagram showing a state in which the display device 100 is bent in the bent region 120. Further, FIG. 3 is a cross-sectional view taken along the line A1-A2 shown in FIG.

As shown in FIGS. 2 and 3, in the bending region 120 provided between the display region 102 and the driver IC 105, the base material 101 is bent in the direction of the arrow 301. As shown in FIG. 3, the base material 101 is bent so that the driver IC 105 and the flexible print circuit 107 are superimposed on the back surface side of the display area 102. Thereby, when the display device 100 is applied to an electronic device such as a smartphone, the width 302 of the peripheral region 110 can be reduced.

By bending the base material 101 in the direction of the arrow 301, stress is generated in the bent region 120. At this time, the stress due to the bending of the base material 101 is concentrated in the region where the wiring 111 extending in the first direction and the wiring 112 extending in the second direction intersect.

4A and 4B are enlarged views of an area where two wirings provided in a conventional display device intersect. 4A is a plan view of the intersection of the two wirings, and FIG. 4B is a cross-sectional view taken along the line B1-B2 shown in FIG. 4A.

As shown in FIG. 4A, the wiring 411 extends in the first direction and the wiring 412 extends in the second direction. Further, as shown in FIG. 4B, the wiring 411 is provided on the base material 401, the insulating layer 413 is provided on the wiring 411, and the wiring 412 is provided on the insulating layer.

When the base material of the display device is bent, stress is concentrated in the region where the wiring 411 and the wiring 412 intersect. In particular, stress is concentrated on the stepped portion of the wiring 412 on the upper layer that crosses the end of the wiring 411. Therefore, there is a problem that the wiring 412 is likely to be broken along the end portion of the wiring 411.

Therefore, in one embodiment of the present invention, a bent portion is provided in each of the wiring extending in the first direction and the wiring extending in the second direction. Then, in the region where the wiring extending in the first direction and the wiring extending in the second direction intersect, the bent portion of one wiring is superimposed on the other wiring in a plan view.

FIG. 5 is an enlarged view of the region 130 shown in FIG. As shown in FIG. 5, wirings 111a and 111b are provided in the first direction, and wirings 112a to 112c are provided in the second direction. An insulating layer is provided between the wirings 111a and 111b and the wirings 112a to 112c. The illustration of the insulating layer is omitted.

The wirings 111a and 111b each have at least one bent portion. Further, the wirings 112a to 112c each have at least one bent portion. Further, in the region 140 where the wiring 111a and the wiring 112a intersect, the bending portion of the wiring 112a overlaps with the wiring 111a.

FIG. 6 is an enlarged view of the region 140 shown in FIG. The wiring 111a overlaps with the corner portions 122a to 122d of the bent portion of the wiring 112a. Further, the wiring 112a overlaps with the corner portions 121a to 121d of the bent portion of the wiring 111. That is, the wiring 112a does not overlap with the straight line region of the wiring 111a, and the wiring 111a does not overlap with the straight line region of the wiring 112a. In the present specification and the like, the corner portion of the bent portion means that the two lines are bent and have an angle when viewed in a plan view.

As described above, in the region where the wiring extending in the first direction and the wiring extending in the second direction intersect, the bent portion of one wiring and the other wiring are superimposed. As a result, even if the base material 101 is bent in the bent region 120, the stress applied to the wiring 112a can be dispersed in the region where the wiring 111a and the wiring 112a intersect. Therefore, the disconnection of the wiring 112a due to the wiring 111a is less likely to occur. Further, since the wiring 112a is less likely to be broken, the reliability of the display device 100 can be improved.

<Second Embodiment>
In the present embodiment, the configuration of the region 140A, which is partially different from the configuration of the region 140 shown in FIG. 6, will be described with reference to FIG. 7.

FIG. 7 is a diagram showing a region 140A in which the configuration of the region 140 shown in FIG. 6 is partially modified. As shown in FIG. 7, the wiring 131a is provided in the first direction, and the wiring 132a is provided in the second direction. An insulating layer is provided between the wiring 131a and the wiring 132a. Further, in the region 140A where the wiring 131a and the wiring 132a intersect, the wiring 132a overlaps with the bent portion of the wiring 131a. Further, the wiring 131a overlaps with the bent portion of the wiring 132a.

The wiring 131a overlaps with the corner portions 142a to 142d of the bent portion of the wiring 132a. Further, the wiring 132a overlaps with the corner portions 141a to 141d of the bent portion of the wiring 131. Here, the corner portions 141a to 141d of the bent portion of the wiring 131a are rounded. Further, the corner portions 142a to 142d of the bent portion of the wiring 132a are rounded. In FIG. 7, the two-dot chain line indicates the corner portion of the bent portion, and the solid line and the dotted line indicate the actual shapes of the wiring 131a and the wiring 132a.

Therefore, even if the base material 101 is bent in the bent region 120, the stress is concentrated on the apex portion by forming the shape so that the apex is not provided at the corner portion of the bent portion in the region where the wiring 131a and the wiring 132a intersect. Is avoided, and the stress applied to the wiring 132a can be more dispersed. Therefore, the disconnection of the wiring 132a due to the wiring 131a is less likely to occur. Further, since the wiring 132a is less likely to be disconnected, the reliability of the display device 100 can be improved.

<Third Embodiment>
In the present embodiment, the configuration of the region 140B, which is partially different from the configuration of the region 140 shown in FIG. 6, will be described with reference to FIG.

FIG. 8 is a diagram showing a region 140B in which the configuration of the region 140 shown in FIG. 6 is partially modified. As shown in FIG. 8, the wiring 151a is provided in the first direction, and the wiring 152a is provided in the second direction. An insulating layer is provided between the wiring 151a and the wiring 152a. Further, in the region 140A where the wiring 151a and the wiring 152a intersect, the bending portion of the wiring 152a overlaps with the bending portion of the wiring 151a.

The wiring 151a overlaps with the corner portions 162a to 162d of the bent portion of the wiring 152a. Further, the wiring 152a overlaps with the corner portions 161a to 161d of the bent portion of the wiring 151. Here, the corner portions 161a to 161d of the bent portion of the wiring 151a are chamfered. Further, the corner portions 162a to 162d of the bent portion of the wiring 152a are chamfered. In FIG. 8, the two-dot chain line indicates the corner portion of the bent portion, and the solid line and the dotted line indicate the shapes of the actual wiring 151a and wiring 152a.

Therefore, even if the base material 101 is bent in the bent region 120, the stress concentration on the apex portion is concentrated by forming the apex of the corner portion of the bent portion into an obtuse angle shape in the region where the wiring 151a and the wiring 152a intersect. This can be avoided and the stress applied to the wiring 152a can be more dispersed. Therefore, the disconnection of the wiring 152a due to the wiring 151a is less likely to occur. Further, since the wiring 152a is less likely to be broken, the reliability of the display device 100 can be improved.

<Fourth Embodiment>
In the present embodiment, the display device 100A having a configuration partially different from the display device 100 shown in the first embodiment will be described with reference to FIGS. 9 and 10. The description of the same configuration as that of the display device 100 shown in FIG. 1 will be omitted.

FIG. 9 is a plan view showing the configuration of the display device 100A according to the present embodiment. In the display device 100A shown in FIG. 9, the configuration of the folding region 120A is partially different from the configuration of the folding region 120 of the display device 100 shown in FIG. Specifically, the configurations of the wiring 181 and the wiring 182 are different from the configurations of the wiring 111 and the wiring 112 shown in FIG.

FIG. 10 is an enlarged view of the region 130A shown in FIG. As shown in FIG. 10, the wiring 181a is provided in the first direction, and the wirings 182a to 182e are provided in the second direction. An insulating layer is provided between the wiring 181a and the wirings 182a to 182e. Further, the width m of the wiring 181a is larger than the width n of the wiring 182a. As described above, the width m of the wiring 181 extending in the first direction and the width n of the wirings 182a to 182e extending in the second direction may be different.

The wiring 181 has at least one bent portion. Further, the wirings 182a to 182e each have at least one bent portion. Further, in the region where the wiring 181a and the wiring 182a intersect, the wiring 181 overlaps with, for example, the bent portion of the wiring 182a.

As shown in FIG. 10, the wiring 181a overlaps with at least the corner portions 184a and 184b of the bent portion of the wiring 182a. Further, the wiring 182a overlaps with the corner portions 183a and 183b of the bent portion of the wiring 181a. Here, the corner portions 183a and 183b of the bent portion of the wiring 181a are rounded. Further, the corner portions 184a and 184b of the bent portion of the wiring 182a are rounded. That is, the wiring 181a does not overlap with the straight line region of the wiring 182a, and the wiring 182a does not overlap with the straight line region of the wiring 181a.

Therefore, even if the base material 101 is bent in the bent region 120A shown in FIG. 9, in the region where the wiring 181a and the wiring 182a intersect, the apex portion is formed by forming a shape in which no apex is provided at the corner portion of the bent portion. The stress concentration on the wiring 182a is avoided, and the stress applied to the wiring 182a can be dispersed. Therefore, the disconnection of the wiring 182a due to the wiring 181a is less likely to occur. Further, since the wiring 182a is less likely to be broken, the reliability of the display device 100A can be improved.

<Fifth Embodiment>
In the present embodiment, the display device 100B having a configuration partially different from the display device 100 shown in the first embodiment will be described with reference to FIGS. 11 to 15. The description of the same configuration as that of the display device 100 shown in FIG. 1 will be omitted.

In the display device 100 shown in FIG. 1, an example in which the driver IC 105 is provided in the peripheral region 110 is shown, but in FIG. 11, an example in which the driver IC 105 is provided on the flexible printed circuit 107 is shown. In FIG. 11, the display area 102 and the flexible print circuit 107 are electrically connected by a plurality of wirings.

In this embodiment, a configuration in which the base material 101 is curved in the display region 102 will be described. FIG. 12 is a perspective view showing a state in which the display device 100B is curved in one direction. The display device 100B is bent in the bending region 120B in the same manner as the display device 100 shown in FIG. As a result, the base material 101 is bent so that the driver IC 105 and the flexible print circuit 107 are superimposed on the back surface side of the display area 102. In addition, the display area 102 is curved in the direction of arrow 303.

By bending the display device 100B in the direction of the arrow 303, stress is generated in the display area 102. At this time, the stress due to bending is concentrated in the region where the wiring extending in the first direction and the wiring extending in the second direction intersect in the display area 102.

FIG. 13 is an enlarged view of the region 150 shown in FIG. The area 150 is provided with 2 rows × 3 columns of pixels 103a to 103f. FIG. 13 shows the conductive layer and the semiconductor layer constituting the pixels 103a to 103f, and the insulating film is not shown.

In FIG. 13, the pixel 103a has a semiconductor layer 211, a semiconductor layer 212, a wiring layer 213, 215, a conductive layer 214, a wiring layer 216, 217, a conductive layer 218, 219, and a pixel electrode 227.

A wiring layer 213 and a conductive layer 214 are provided on the semiconductor layer 211 and the semiconductor layer 212. Further, the wiring layers 216 and 217 and the conductive layers 218 and 219 are provided on the wiring layers 213 and 215 and the conductive layer 214. Further, a wiring layer 215 is provided on the wiring layers 216 and 217. Further, pixel electrodes 227 are provided in the wiring layers 216 and 217 and the conductive layers 218 and 219.

The semiconductor layer 211 is connected to the wiring layer 217 and the conductive layer 218. The conductive layer 218 is connected to the conductive layer 214. The semiconductor layer 212 is connected to the wiring layer 215 and the conductive layer 219. The wiring layer 215 is connected to the wiring layer 217. The conductive layer 219 is connected to the pixel electrode 227.

The transistor 210 functions as a switching transistor. The wiring layer 213 functions as a gate and a scanning line of the transistor 210. In the semiconductor layer 211, the region where the wiring layers 213 overlap functions as a channel region of the transistor 210. The wiring layer 217 functions as a source or drain of the transistor 210 and a signal line. The conductive layer 218 functions as a source or drain.

The transistor 220 functions as a drive transistor. The conductive layer 214 functions as a gate for the transistor 220. In the semiconductor layer 212, the region where the conductive layer 214 overlaps functions as a channel region of the transistor 220. The wiring layer 215 functions as a power line connected to either the source or the drain of the transistor 220. The conductive layer 219 is connected to the other of the transistor source and the drain and functions as a connection wiring to and from the pixel electrode.

In FIG. 13, the wiring layer 213 and the wiring layer 215 are arranged with respect to the first direction (x direction) of the display area 102, and are arranged in the second direction (y direction) intersecting the first direction of the display area 102. , Wiring layer 216 and wiring layer 217 are arranged. That is, the wiring layer 213 and the wiring layer 217 intersect, and the wiring layer 213 and the wiring layer 216 intersect. The wiring layer 215 and the wiring layer 217 intersect, and the wiring layer 215 and the wiring layer 216 intersect.

FIG. 14 is an enlarged view of a region 160 where the wiring layers 213 and 215 extending in the first direction and the wiring layers 216 and 217 extending in the second direction intersect. An interlayer insulating film (not shown) is provided between the wiring layer 213 and the wiring layers 216 and 217. Further, an interlayer insulating film is also provided between the wiring layers 216 and 217 and the wiring layer 215. The wiring layer 215 is connected to the wiring layer 216 via an opening 237 provided in the interlayer insulating film.

The wiring layers 213, 215, 216, and 217 each have two bent portions. The first bent portion of the wiring layer 213 overlaps with the first bent portion of the wiring layer 216, and the second bent portion of the wiring layer 213 overlaps with the first bent portion of the wiring layer 217. Further, the first bent portion of the wiring layer 215 overlaps with the second bent portion of the wiring layer 216, and the second bent portion of the wiring layer 215 overlaps with the second bent portion of the wiring layer 217.

In the area where the two wiring layers intersect in the display area 102 shown in FIG. 14, the stress applied to the wiring layer provided on the upper layer can be dispersed. Therefore, even if the base material 101 is curved or bent in the display region 102, it is possible to suppress the concentration of stress on the upper wiring layer due to the lower wiring layer. As a result, disconnection of the wiring layer is less likely to occur, so that the reliability of the display device 100B can be improved.

Further, in FIG. 14, for example, in the region where the wiring layer 213 extending in the first direction and the wiring layer 216 extending in the second direction intersect, the corner portion of the first bending portion of the wiring layer 213 and the wiring layer 216. Are superimposed. As a result, even if the base material 101 is bent in the display region 102, the stress applied to the wiring layer 216 can be further dispersed in the region where the wiring layer 213 and the wiring layer 216 intersect. Therefore, the disconnection of the wiring layer 216 due to the wiring layer 213 is less likely to occur. Further, since the wiring layer 216 is less likely to be disconnected, the reliability of the display device 100B can be improved. Although the description is omitted, the same applies to the region where the wiring layer 213 and the wiring layer 217 overlap, the region where the wiring layer 215 and the wiring layer 216 overlap, and the region where the wiring layer 215 and the wiring layer 217 overlap.

Further, as shown in FIG. 7 of the second embodiment, the corners of the bent portions of the wiring layers 213, 215, 216, and 217 may be rounded. Further, as shown in FIG. 8 of the third embodiment, the corners of the bent portions of the wiring layers 213, 215, 216, and 217 may be chamfered. As a result, even if the base material 101 is bent in the display region 102, the stress applied to the wiring layer 216 can be further dispersed, for example, in the region where the wiring layer 213 and the wiring layer 216 intersect. Therefore, the disconnection of the wiring layer 216 due to the wiring layer 213 is less likely to occur. Further, since the wiring layer 216 is less likely to be disconnected, the reliability of the display device 100B can be improved. Although the description is omitted, the same applies to the region where the wiring layer 213 and the wiring layer 217 overlap, the region where the wiring layer 215 and the wiring layer 216 overlap, and the region where the wiring layer 215, the wiring layer 215, and the wiring layer 217 overlap. be.

FIG. 15 shows a cross-sectional view of each of the display area 102 and the peripheral area 110 in the display device 100B shown in FIG.

A flexible substrate such as polyimide can be used as the base material 101 and the facing base material 202. However, as a foldable sheet display, another resin material may be used as long as it is a base material having sufficient flexibility.

An undercoat layer 203 is provided on the base material 101. For the undercoat layer 203, for example, a silicon oxide film and a silicon nitride film can be used. The undercoat layer 203 is provided with, for example, a three-layer structure of a silicon oxide film, a silicon nitride film, and a silicon oxide film. The silicon oxide film of the lowermost layer can improve the adhesion with the base material 101. In addition, the silicon nitride film in the middle layer can suppress the intrusion of moisture and impurities from the outside. Further, the silicon oxide film on the uppermost layer can suppress the diffusion of hydrogen atoms contained in the silicon nitride film into the semiconductor layer 211. The undercoat layer 203 is not limited to the above-mentioned three-layer structure. It may have a laminated structure of four or more layers, or may have a single-layer structure or a two-layer structure.

In FIG. 15, a part of the pixel 103 is shown as the display area 102. The pixel 103 has a transistor 220 provided on the undercoat layer 203, and a light emitting element 250 electrically connected to the transistor 220.

In the present embodiment, the transistor 220 includes a semiconductor layer 211 provided on the undercoat layer 203, a gate insulating film 221 covering the semiconductor layer 211, and a conductive layer 214 provided on the gate insulating film 221. The conductive layer 214 functions as a gate electrode. An interlayer insulating film 122 that covers the conductive layer 214 is provided on the transistor 220. A wiring layer 215 and a conductive layer 219 are provided on the interlayer insulating film 122. Further, the wiring layer 215 and the conductive layer 219 are connected to the semiconductor layer 211 via an opening provided in the interlayer insulating film 122.

The material of each layer constituting the transistor 220 may be a known material and is not particularly limited. Polysilicon, amorphous silicon, or an oxide semiconductor can be used as the semiconductor layer 211. Silicon oxide or silicon nitride can be used as the gate insulating film 221. Further, the conductive layer 214 is made of a metal material such as copper, molybdenum, tantalum, tungsten, and aluminum. Silicon oxide or silicon nitride can be used as the interlayer insulating film 122. The wiring layer 215 and the conductive layer 219 are each made of a metal material such as copper, titanium, molybdenum, or aluminum.

As the transistor 220, a thin film transistor (TFT) is shown. However, the device is not limited to the thin film transistor, and any device may be used as long as it has a current control function. In FIG. 14, the transistor 220 shows an example in which an n-channel transistor is used, but a p-channel transistor may be used.

A flattening film 223 is provided on the interlayer insulating film 222, the wiring layer 215, and the conductive layer 219. The flattening film 223 is formed using an organic resin material. As the organic resin material, for example, polyimide, polyamide, acrylic, epoxy or the like can be used. These materials can form a film by a solution coating method and have a high flattening effect. The flattening film 223 is not provided in the peripheral region 110.

The flattening film 223 is provided with an opening. The conductive layer 219 is connected to the conductive layer 224 via the opening of the flattening film 223. Further, a conductive layer 225 is provided on the flattening film 223. For the conductive layer 224 and the conductive layer 225, for example, an indium oxide-based transparent conductive film (for example, ITO) or a zinc oxide-based transparent conductive film (for example, IZO, ZnO) can be used as the transparent conductive film.

An insulating layer 226 is provided on the flattening film 223 and the conductive layers 224 and 225. The insulating layer 226 is formed by using, for example, a silicon nitride film or a silicon oxide film. A pixel electrode 227 is provided on the insulating layer 226. The pixel electrode 227 is connected to the conductive layer 224 via an opening provided in the insulating layer 226. An insulating layer 235 is provided so as to cover the end portion of the pixel electrode 227. The insulating layer 235 is also referred to as a partition wall or a bank. As the insulating layer 235, photosensitive acrylic can be used as in the flattening film 223. It is preferable that the insulating layer 235 is opened so that the pixel electrode 227 is exposed, and the end portion of the opening has a gently tapered shape. If the end of the opening has a steep shape, poor coverage of the organic layer 228 formed later occurs.

Further, the insulating layer 226 is provided with an opening 230, and the flattening film 223 and the insulating layer 235 are in contact with the opening 230. As a result, the moisture and gas desorbed from the flattening film 223 by the heat treatment after the formation of the insulating layer 235 can be released through the insulating layer 235.

After forming the insulating layer 235, a plurality of organic materials constituting the organic layer 228 are laminated. The organic layer 228 is formed by laminating a hole transport layer, a light emitting layer, and an electron transport layer in order from the pixel electrode 227 side. These layers may be formed by thin film deposition or may be formed by coating on solvent dispersion. Further, it may be selectively formed for each sub-pixel, or may be formed on the entire surface of the display area 102. When the organic layer 228 is formed on the front surface, white light can be emitted from all the pixels, and a desired color wavelength portion can be extracted by a color filter (not shown).

After the formation of the organic layer 228, the counter electrode 229 is formed. In the present embodiment, since the top emission structure is used, the counter electrode 229 needs to have translucency. When MgAg is used as the counter electrode 229, it is formed of a thin film that allows the emitted light from the organic layer 228 to pass through. The light emitting element 250 is composed of the pixel electrode 227, the organic layer 228, and the counter electrode 229. In the case of the top emission structure, the pixel electrode 227 serves as an anode and the counter electrode 229 serves as a cathode. The counter electrode 229 is formed on the display region 102 and over the cathode contact portion provided in the peripheral region 110. In the cathode contact portion, the counter electrode 229 is connected to the wiring layer 252 via the conductive layer 254 and the conductive layer 253, and is electrically connected to the terminal 106.

A sealing film 240 is provided on the counter electrode 229. The sealing film 240 is provided in order to prevent moisture that has entered from the outside from entering the organic layer 228. Therefore, as the sealing film 240, a material having a high gas barrier property is preferable. FIG. 14 shows an example in which the sealing film 240 is formed by a three-layer structure of an inorganic insulating layer 231, an organic insulating layer 232, and an inorganic insulating layer 233. It is preferable to use silicon nitride as the inorganic insulating layer 231 and 233 and an organic resin as the organic insulating layer 232. A silicon oxide film or an amorphous silicon film may be provided between the silicon nitride and the organic resin. Thereby, the adhesion can be improved.

A filler 234 is provided on the inorganic insulating layer 233. As the filler 234, for example, an acrylic-based, rubber-based, silicone-based, or urethane-based adhesive material can be used. Further, the filler 234 may be provided with a spacer in order to secure a gap between the base material 101 and the facing base material 202. Such a spacer may be mixed with the filler 234, or may be formed on the base material 101 with a resin or the like.

The facing base material 202 may be provided with an overcoat layer, for example, for flattening. When the organic layer 228 emits white light, the facing base material 202 has a color filter corresponding to each color of RGB on the main surface (the surface facing the base material 101) and a black matrix provided between the color filters. May be provided. When the color filter is not formed on the facing base material 202 side, for example, the color filter may be formed directly on the inorganic insulating layer 233, and the filler 234 may be formed on the color filter. The organic insulating layer 232 has a flattening effect, and each layer above the organic insulating layer 232 is formed flat. Therefore, the organic insulating layer 232 is thick on the light emitting element 250 and thin on the insulating layer 235.

In FIG. 14, the terminal 106 is configured by the wiring layer 252 and the conductive layer 255. The conductive layer 255 is, for example, a film formed in the same process as the counter electrode 229.

In the display device 100B shown in the present embodiment, the bent portions are superimposed on each other in the region where the two wiring layers intersect. Thereby, even if the base material 101 is curved or bent in the display region 102, it is possible to suppress the concentration of stress on the upper wiring layer due to the lower wiring layer. As a result, disconnection of the wiring layer is less likely to occur, so that the reliability of the display device 100B can be improved.

Further, as shown in FIGS. 11 and 15, the wiring layer 251 and the wiring layer 252 intersect in the bent region 120B. Similar to the previous embodiment, the bent portions are overlapped with each other in the region where the wiring layer 251 and the wiring layer 252 intersect. Thereby, even if the base material 101 is bent or bent in the bent region 120B, it is possible to suppress the concentration of stress on the wiring layer 252 due to the wiring layer 251. As a result, disconnection of the wiring layer is less likely to occur, so that the reliability of the bent region 120B can be improved.

As described in the present embodiment, the display device 100B improves the resistance to bending or bending of the base material 101 not only in the bending region 120B but also in the display region 102.

<Sixth Embodiment>
In the present embodiment, pixels that are partially different from the pixels shown in the fifth embodiment will be described with reference to FIGS. 16 and 17.

FIG. 16 is an equivalent circuit diagram of pixels. As shown in FIG. 16, the pixel 103 and the drive circuit 104 are connected by a plurality of wirings. Signals are transmitted from the drive circuit 104 to the pixel 103 via the gate emission control scan line BG, the reset control scan line RG, the correction control scan line CG, the initialization control scan line IG, and the write control scan line SG, respectively. Given. Further, the pixel 103 is provided with a light emission control transistor BCT, a correction transistor CCT, an initialization transistor IST, a write transistor SST, and a drive transistor DRT. Some transistors may be shared between a plurality of adjacent pixels. One reset transistor RST is provided in the peripheral region 110, for example, in each row. A holding capacitance Cs may be provided between the gate and the source of the drive transistor DRT. The capacitance Cel is a parasitic capacitance between the anode and the cathode of the light emitting element OLED.

The anode of the light emitting element OLED is provided with a high potential side power supply P VDD via a light emission control transistor BCT, a correction transistor CCT, and a drive transistor DRT. Further, a low potential side power supply PVSS is provided to the cathode of the light emitting element OLED. The light emission control transistor BCT, the correction transistor CCT, the initialization transistor IST, and the write transistor SST function as a switching element for selecting conduction or non-conduction between two nodes. The drive transistor DRT functions as a current control element that controls the current value flowing through the light emitting element OLED according to the voltage between the gate and the source. The light emission control transistor BCT, the correction transistor CCT, the initialization transistor IST, and the write transistor SST are formed by using a thin film transistor (TFT). Further, although the plurality of TFTs used for the pixels are all formed by using the n-channel type transistor, they may be formed by using the p-channel type transistor. When a p-channel transistor is used, it is advisable to appropriately adjust the connection of the power supply potential and the holding capacity.

FIG. 17 is a timing chart of the drive circuit 104 for driving the pixels shown in FIG. Each period indicated by the periods G1 to G4 is one horizontal period, and although omitted thereafter, it continues until the last line. The period represented by T0 to T6 in FIG. 17 will be described in detail with reference to FIG.

<T0: Front frame emission>
In the period T0, the light emitting element OLED continues the light emitting state of the previous frame until the processing in a certain frame period is started.

<T1: Drive transistor DTR source initialization>
In the period T1, the potential of the gate emission control scanning line BG is Low level (hereinafter, L level), the potential of the reset control scanning line RG is High level (hereinafter, H level), and the potential of the correction control scanning line CG is H level. Become. As a result, the light emission control transistor BCT is turned off, the correction transistor CCT is turned on, and the reset transistor RST is turned on. In each pixel of the row, the current from the high potential side power supply P VDD is cut off by the light emission control transistor BCT. Further, the light emission of the light emitting element OLED is stopped, and the electric charge remaining in the pixel 103 is extracted through the reset transistor RST. As a result, the source of the drive transistor DRT is fixed to the reset potential Vrst. The reset potential Vrst is set to a potential lower than the issuance start voltage of the light emitting element OLED with respect to the low potential side power supply PVSS.

<T2: Drive transistor DTR gate initialization>
In the period T2, the potential of the initialization control scanning line IG becomes H level, and the initialization transistor IST is turned on. At each pixel in the row, the gate of the DRT is fixed to the initialization potential Vini via the initialization transistor IST. The initialization potential Vini is set to a potential larger than the threshold value of the drive transistor DRT with respect to the reset potential Vrst. That is, by this operation, the drive transistor DRT is turned on. However, since the light emission control transistor BCT is turned off, no current flows through the drive transistor DRT yet.

<T3: Offset cancel operation>
In the period T3, the potential of the gate emission control scanning line BG becomes the H level, and the potential of the reset control scanning line RG becomes the L level. As a result, the light emission control transistor BCT is turned on and the reset transistor RST is turned off. Since the drive transistor DRT is turned on by the previous operation, a current is supplied to the drive transistor DRT from the light emission control transistor BCT and the high potential side power supply P VDD through the correction transistor CCT. At this stage, the voltage between the anode and the cathode of the light emitting element OLED does not exceed the light emission start voltage, so no current flows. Therefore, the source of the drive transistor DRT is charged by the current supplied from the high potential side power supply P VDD, and its potential rises. At this time, the gate potential of the drive transistor DRT is the initialization potential Vini. Therefore, when the potential of the source of the drive transistor DRT becomes (Vini-Vth), the drive transistor DRT is turned off and the increase of the potential is stopped. Since the threshold voltage Vth of the drive transistor DRT varies depending on the pixel, the potential of the source of the drive transistor DRT when the increase in potential is stopped differs depending on the pixel. That is, by this operation, a voltage corresponding to the threshold voltage Vth of the drive transistor DRT is acquired in each pixel. At this time, a voltage of {(Vini-Vth) -PVSS} is applied between the anode and the cathode of the light emitting element OLED, but since this voltage still does not exceed the light emission start voltage, the light emitting element OLED is used. No current flows.

In the timing chart of FIG. 17, the operations of the period T1 to the period T3 are performed in parallel for two lines, but the operation is not limited to this. It may be carried out sequentially for each line, or three or more lines may be carried out in parallel.

<T4, T5: Video signal writing operation>
In the period T3 and the period T4, the potential of the correction control scan line CG is L level, the potential of the initialization control scan line IG is L level, and the potential of the write control scan line SG is H level. As a result, the correction transistor CCT is turned off, the initialization transistor IST is turned off, and the write transistor SST is turned on. In each pixel of the line, the potential of the video signal line Vsig is input to the gate of the drive transistor DRT. The gate potential of the drive transistor DRT changes from the initialization potential Vini to the potential of the video signal Vsig. On the other hand, the source potential of the drive transistor DRT is still (Vini-Vth), and as a result, the gate-source voltage of the drive transistor DRT becomes {Vsig- (Vini-Vth)}, and the threshold value varies between pixels. Will be reflected.

Since the video signal line Vsig is common to the pixels of a plurality of lines belonging to the same column, the video signal writing operation is sequentially performed line by line.

<T6: Light emission operation>
In the period T6, the potential of the correction control scanning line CG becomes the H level, and the potential of the writing control scanning line SG becomes the L level. As a result, the correction transistor CCT is turned on and the writing transistor SST is turned off. A current is supplied to the drive transistor DRT from the high potential side power supply P VDD through the light emission control transistor BCT and the correction transistor CCT. The drive transistor DRT causes a current corresponding to the gate-source voltage set up to the previous stage to flow through the light emitting element OLED, and the light emitting element OLED emits light with brightness corresponding to the current. At this time, the voltage between the anode and the cathode of the light emitting element OLED becomes a voltage corresponding to the current, so that the potential on the anode side rises, but the voltage between the gate and the source of the drive transistor DRT is maintained by the capacitance Cs. Therefore, as the potential on the anode side rises, the gate potential of the drive transistor DRT also rises due to the coupling of the capacitance Cs. Actually, not only the capacitance Cs but also the additional capacitance CAD and other parasitic capacitances are attached to the gate of the drive transistor DRT. Therefore, the increase in the gate potential of the drive transistor DRT is slightly smaller than the increase in the potential on the anode side, but since this value is known, the desired current at the gate-source voltage of the final drive transistor DRT. The potential of the video signal line Vsig may be determined so as to be a value.

This completes a series of pixel operations. When the operation is completed from the first line to the last line, one screen is displayed within one frame period. After that, the operation is repeated to display the image.

Based on the display device described as the embodiment and the embodiment of the present invention, those skilled in the art appropriately add, delete, or change the design, or add, omit, or change the conditions of the process. Also, as long as it has the gist of the present invention, it is included in the scope of the present invention. Further, the above-described embodiments can be combined with each other as long as technical inconsistencies do not occur.

In addition, even if the action / effect is different from the action / effect brought about by the above-described embodiment, those that are clear from the description of the present specification or those that can be easily predicted by those skilled in the art are of course. Is understood to be brought about by the present invention.

100: Display device, 101: Substrate, 102: Display area, 103: Pixel, 104: Drive circuit, 106: Terminal, 107: Flexible print circuit, 110: Peripheral area, 111: Wiring, 112: Wiring, 120: Area 122: Interlayer insulating film, 130: Area, 131: Wiring, 140: Area, 150: Area, 151: Wiring, 160: Area, 181: Wiring, 182: Wiring, 201: Base material, 202: Opposing base material, 203: Undercoat layer, 210: Transistor, 211: Semiconductor layer, 212: Semiconductor layer, 213: Wiring layer, 214: Conductive layer, 215: Wiring layer, 216: Wiring layer, 217: Wiring layer, 218: Conductive layer, 219: Conductive layer, 220: Transistor, 221: Gate insulating film, 222: Interlayer insulating film, 223: Flattening film, 224: Conductive layer, 225: Conductive layer, 226: Insulating layer, 227: Pixel electrode, 228: Organic Layer, 229: counter electrode, 230: opening, 231: inorganic insulating layer, 232: organic insulating layer, 233: inorganic insulating layer, 234: filler, 235: insulating layer, 237: opening, 240: sealing film , 250: light emitting element, 251: wiring layer, 252: wiring layer, 253: conductive layer, 254: conductive layer, 255: conductive layer, 301: arrow, 302: width, 303: arrow, 401: base material, 411: Wiring, 412: Wiring, 413: Insulation layer

Claims (6)

With a flexible substrate,
The first wiring extending in the first direction arranged on the base material and
The first insulating layer on the first wiring and
It has a second wiring extending in a second direction intersecting the first direction on the first insulating layer.
The first wiring has a first bent portion whose extending direction changes in a plan view.
The second wiring has a second bent portion whose extending direction changes in a plan view.
An element substrate in which the first bent portion is superimposed on the second wiring and the second bent portion is superimposed on the first wiring in a region where the first wiring and the second wiring intersect. The first bending portion includes at least one first bending angle portion.
The second bent portion includes at least one second bent angle portion.
The first wiring overlaps with the second bending angle portion,
The element substrate according to claim 1, wherein the second wiring is superimposed on the first bending angle portion. The at least one first bending angle portion is composed of four bending corner portions.
The at least one second bending angle portion is composed of four bending corner portions.
The first wiring overlaps with the four bending corners of the second bending corner, and the first wiring is overlapped with the four bending corners.
The element substrate according to claim 2, wherein the second wiring overlaps with the four bending corners of the first bending corner. The element substrate according to claim 2 or 3, wherein the first bending corner portion and the second bending corner portion are rounded, respectively. The element substrate according to claim 2 or 3, wherein the first bending corner portion and the second bending corner portion are chamfered, respectively. The element substrate according to claim 1, wherein the width of the first wiring is larger than the width of the second wiring.

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