KR102650335B1 - Foldable display device - Google Patents

Abstract

The present invention relates to a foldable display device. The foldable display device according to the present invention includes a first flexible substrate, a second flexible substrate on the first flexible substrate, a plurality of transistors on the second flexible substrate, a second flexible substrate and a plurality of transistors. It includes a plurality of barrier metal layers disposed between the transistors to overlap the plurality of transistors, and a conductive pattern disposed between the first flexible substrate and the second flexible substrate and overlapping the area excluding the barrier metal layer. Accordingly, there is an effect of reducing damage to the internal components of the foldable display device due to static electricity generated during the process of removing the glass substrate during the manufacturing process of the foldable display device.

Description

Foldable display device {FOLDABLE DISPLAY DEVICE}

The present invention relates to a foldable display device, and more specifically, to a foldable display device with improved heat dissipation function and folding characteristics, and reduced defects during the manufacturing process.

Recently, as we entered the full-fledged information age, the field of displays that visually express electrical information signals has developed rapidly, and in response to this, a variety of flat display devices with excellent performance such as thinness, lightness, and low power consumption have been developed. Device) has been developed and is rapidly replacing the existing cathode ray tube (CRT).

Specific examples of such flat panel displays include liquid crystal displays (LCDs), organic light emitting displays (OLEDs), electrophoretic displays (EPDs), plasma displays (PDPs), and electrowetting displays (EWDs). there is.

Display devices may have defects in internal elements due to static electricity generated during the manufacturing process, and internal elements of a display device that has been manufactured may be damaged after manufacturing due to heat generated inside the display device.

Additionally, the display device includes a substrate made of a material with flexibility and can be folded. However, as the display device is folded, there is a problem that cracks and other damage may occur in components inside the display device.

The inventors of the present invention believe that elements inside the display device may be damaged by static electricity that may be generated during the manufacturing process of the display device, and that heat may be generated inside the display device when the display device is driven even after the manufacturing process is completed. It was recognized that there is a problem that components inside the display device may be damaged by heat generated internally.

Accordingly, the inventors of the present invention considered including components with a heat dissipation function or anti-static function in the display device. However, when the display device is a foldable display device, the components inside the display device due to the additional components The problem that cracks may occur was recognized.

Accordingly, the inventors of the present invention invented a foldable display device with a new structure to minimize damage due to static electricity and heat and improve folding characteristics.

The problem to be solved by the present invention is to provide a foldable display device that can minimize damage caused by static electricity during the manufacturing process of the foldable display device, minimize damage caused by heat to the foldable display device, and enhance folding characteristics. .

Another problem to be solved by the present invention is to provide a foldable display device in which moisture penetration from the bottom of the foldable display device can be suppressed.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to solve the problems described above, a foldable display device according to an embodiment of the present invention includes a first flexible substrate, a second flexible substrate on the first flexible substrate, a plurality of transistors on the second flexible substrate, and a second flexible substrate. and a plurality of barrier metal layers disposed between the plurality of transistors to overlap the plurality of transistors, and a conductive pattern disposed between the first flexible substrate and the second flexible substrate and overlapping the area excluding the barrier metal layer. Accordingly, during the manufacturing process of the foldable display device, the internal components of the foldable display device are damaged by static electricity generated in the process of transporting the foldable display device after removing the glass substrate disposed under the first and second flexible substrates. It has the effect of reducing damage.

In order to solve the above-described problem, a foldable display device according to another embodiment of the present invention includes a plurality of flexible substrates overlapped to correspond to each other, a plurality of transistors disposed on the plurality of flexible substrates, a plurality of flexible substrates, and a plurality of flexible substrates. It may include a plurality of barrier metal layers disposed between the transistors, and a heat dissipation pattern disposed to overlap an area excluding the plurality of barrier metal layers between the plurality of flexible substrates to perform a heat dissipation function. Accordingly, the heat generated from the foldable display device is effectively discharged to the outside, thereby reducing damage to the foldable display device due to heat.

Specific details of other embodiments are included in the detailed description and drawings.

The present invention has the effect of reducing damage to internal components of a foldable display device due to static electricity generated during the manufacturing process of the foldable display device.

In addition, the present invention has the effect of reducing damage to the foldable display device due to heat by effectively dissipating heat generated from the foldable display device to the outside.

In addition, the present invention has the effect of strengthening the folding characteristics of the foldable display device and suppressing damage such as cracking of the conductive pattern due to folding by arranging the conductive pattern to overlap the area excluding the barrier metal layer.

The effects according to the present invention are not limited to the contents exemplified above, and further various effects are included in the present specification.

1 is a plan view of a foldable display device according to an embodiment of the present invention.
Figure 2 is a schematic cross-sectional view of one pixel of a foldable display device according to an embodiment of the present invention.
Figure 3 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention.
Figure 4 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention.
Figure 5 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

When an element or layer is referred to as “on” another element or layer, it includes instances where the other layer or other element is directly on top of or interposed between the other elements.

Although first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Like reference numerals refer to like elements throughout the specification.

The size and thickness of each component shown in the drawings are shown for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the components shown.

Each feature of the various embodiments of the present invention can be partially or fully combined or combined with each other, and as can be fully understood by those skilled in the art, various technical interconnections and operations are possible, and each embodiment may be implemented independently of each other. It may be possible to conduct them together due to a related relationship.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

1 is a plan view of a foldable display device according to an embodiment of the present invention. In FIG. 1 , for convenience of explanation, only the first flexible substrate 111 and a plurality of pixels (PX) of the foldable display device 100 are shown.

Referring to FIG. 1, the first flexible substrate 111 supports various components of the foldable display device 100. The first flexible substrate 111 may be made of an insulating material with flexibility. For example, the substrate may be made of plastic such as polyimide, but is not limited thereto.

The first flexible substrate 111 includes a display area (AA) and a non-display area (NA). The display area AA is an area where an image is displayed in the foldable display device 100, and a display element and various driving elements for driving the display element are disposed in the display area AA.

Referring to FIG. 1, a plurality of pixels (PX) are defined in the display area (AA). The plurality of pixels (PX) are individual units that emit light, and the plurality of pixels (PX) may include, but are not limited to, red pixels, green pixels, and blue pixels. A transistor and an organic light emitting element are formed in each of the plurality of pixels (PX). A more detailed description of the transistor and the organic light emitting device will be described later with reference to FIG. 2.

Referring to FIG. 1, the non-display area (NA) is an area surrounding the display area (AA). The non-display area (NA) is an area where images of the foldable display device 100 are not displayed, and wiring or circuit parts are formed. An external module, for example, a chip on film (COF), may be placed in the non-display area (NA). The COF may include a base film made of an insulating material and a driver IC formed on the base film. The COF can supply power voltage and data voltage to the display area (AA) through the pad.

Some of the display area (AA) and the non-display area (NA) may be folded. Accordingly, part of the display area AA and the non-display area NA may include a folding area, which is an area that is folded. Areas other than the folding area are not folded and remain flat, and only the folding area can be folded. However, the present invention is not limited thereto, and the entire display area AA and non-display area NA may be freely folded as a folding area.

Figure 2 is a schematic cross-sectional view of one pixel of a foldable display device according to an embodiment of the present invention. The cross-sectional view of FIG. 2 is a schematic cross-sectional view of one pixel (PX) of the foldable display device 100 of FIG. 1. For convenience of explanation, description will be made with reference to FIG. 1.

Referring to FIG. 2 , a second flexible substrate 112 is disposed on the first flexible substrate 111 to correspond to the first flexible substrate 111 . The second flexible substrate 112 is a substrate that supports various components of the foldable display device 100. The second flexible substrate 112 may be made of the same material as the first flexible substrate 111, for example, a plastic such as polyimide, but is not limited thereto.

Referring to FIG. 2, a buffer layer 113 is disposed on the second flexible substrate 112. The buffer layer 113 is a layer that improves the adhesion between the layers formed on the buffer layer 113 and the second flexible substrate 112 and blocks alkaline components leaking from the lower part of the buffer layer 113. The buffer layer 113 may be made of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx), or a multiple layer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. However, the buffer layer 113 is not an essential component and may be omitted based on the type and material of the second flexible substrate 112, the structure and type of the transistor 140, etc.

Referring to FIG. 2, a plurality of barrier metal layers 130 are disposed on the buffer layer 113. The plurality of barrier metal layers 130 are layers that serve to protect the active layer 141 of the plurality of transistors 140. Each of the plurality of barrier metal layers 130 may be arranged to overlap each of the active layers 141 of the plurality of transistors 140 on the buffer layer 113, and the width of each of the plurality of barrier metal layers 130 in the cross section is The width of each transistor 140 may be greater than or equal to the width of the active layer 141 .

The plurality of barrier metal layers 130 may be made of various metal materials and may be in a floating state where no voltage is applied. Alternatively, a constant voltage may be applied.

The plurality of barrier metal layers 130 may serve to protect the active layer 141. Specifically, when the first flexible substrate 111 and the second flexible substrate 112 are made of a plastic material and the buffer layer 113 includes silicon nitride (SiNx), the first flexible substrate 111 and the second flexible substrate 112 Hydrogen or moisture may move upward from the flexible substrate 112 or the buffer layer 113 and damage the active layer 141 of the transistor 140. Additionally, during the manufacturing process of the foldable display device 100, the active layer 141 may be damaged by the laser when the glass substrate below the first flexible substrate 111 is removed through a laser process. In addition, a sacrificial layer disposed between the glass substrate and the first flexible substrate 111 to help remove the glass substrate by the laser process, and the current generated by the first flexible substrate 111 and the second flexible substrate 112. The threshold voltage (Vth) of the transistor 140 may change due to the drop phenomenon, and thus, the reliability of the foldable display device 100 may decrease. At this time, the plurality of barrier metal layers 130 are disposed under the active layer 141 overlapping with the active layer 141 to block hydrogen or moisture flowing in from the bottom, block the laser irradiated during the laser process, and transistor ( 140), the shift phenomenon of the threshold voltage (Vth) can also be suppressed.

Referring to FIG. 2, an active buffer 114 is disposed on the plurality of barrier metal layers 130 and the buffer layer 113. The active buffer 114 is an insulating layer that insulates the plurality of barrier metal layers 130 and the active layer 141 of the transistor 140. The active buffer 114 may be formed of the same material as the buffer layer 113, for example, a single layer of silicon nitride (SiNx) or silicon oxide (SiOx), or a single layer of silicon nitride (SiNx) and silicon oxide (SiOx). It may be comprised of multiple layers, but is not limited thereto.

Referring to FIG. 2, a transistor 140 is disposed on the active buffer 114. Specifically, the transistor 140 may be a top gate type coplanar structure. However, it is not limited to this.

Specifically, the active layer 141 of the transistor 140 is disposed on the active buffer 114. The active layer 141 may be made of low temperature poly-silicon (LTPS) or an oxide semiconductor, but is not limited thereto. The active layer 141 includes a channel region 141a where a channel is formed, a source region 141b connected to the source electrode 142, and a drain region 141c connected to the drain electrode 143.

Referring to FIG. 2, a gate insulating layer 115 is formed on the active layer 141. The gate insulating layer 115 may be composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx) or a multiple layer of silicon nitride (SiNx) or silicon oxide (SiOx). In the gate insulating layer 115, the source electrode 142 and the drain electrode 143 of the transistor 140 each contact the source region 141b and the drain region 141c of the active layer 141 of the transistor 140. A contact hole is formed for

Referring to FIG. 2, the gate electrode 144 of the transistor 140 is formed on the gate insulating layer 115. The gate electrode 144 may be made of a metal layer such as molybdenum (Mo). Additionally, the gate electrode 144 is disposed on the gate insulating layer 115 to overlap the channel region 141a of the active layer 141 of the transistor 140.

Referring to FIG. 2, an interlayer insulating layer 116 is disposed on the gate electrode 144 and the gate insulating layer 115. The interlayer insulating layer 116 is made of an inorganic material such as silicon nitride (SiNx) or silicon oxide (SiOx), and may be a single layer or a plurality of layers, but is not limited thereto.

Referring to FIG. 2, the source electrode 142 and drain electrode 143 of the transistor 140 are formed on the interlayer insulating layer 116. The source electrode 142 and the drain electrode 143 are electrically connected to the active layer 141 through contact holes formed in the gate insulating layer 115 and the interlayer insulating layer 116. The source electrode 142 and the drain electrode 143 may be made of a conductive material, and the source electrode 142 and the drain electrode 143 may be made of the same material through the same process, but are not limited thereto.

Referring to FIG. 2, a planarization layer 117 is disposed on the source electrode 142, the drain electrode 143, and the interlayer insulating layer 116. The planarization layer 117 is a layer for planarizing the upper part of the transistor 140. The planarization layer 117 may be a single layer as shown in FIG. 2, but alternatively, it may be composed of multiple layers. The planarization layer 117 may be made of an acryl-based organic material, but is not limited thereto. The planarization layer 117 includes a contact hole for electrically connecting the transistor 140 and the anode 151.

In some embodiments, a passivation layer may be formed between the transistor 140 and the planarization layer 117. That is, in order to protect the transistor 140 from penetration of moisture and oxygen, a passivation layer may be formed to cover the transistor 140. The passivation layer may be made of an inorganic material and may be made of a single layer or a double layer, but is not limited thereto.

Referring to FIG. 2, an organic light emitting device 150 is disposed on the planarization layer 117. The organic light-emitting device 150 includes an anode 151 electrically connected to the drain electrode 143 of the transistor 140, an organic light-emitting layer 152 disposed on the anode 151, and a cathode formed on the organic light-emitting layer 152 ( 153). When the foldable display device 100 is a top-emission organic light emitting display device, the anode 151 is a reflective layer for reflecting the emitted light toward the cathode 153 and a reflective layer for supplying holes to the organic light emitting layer 152. It may further include a transparent conductive layer.

Referring to FIG. 2, a bank 118 is disposed on the anode 151 and the planarization layer 117. The bank 118 is a structure for distinguishing adjacent pixels PX from each other in the display area AA, and may define a plurality of pixels PX. The bank 118 may be made of an organic material, but is not limited thereto.

Referring to FIG. 2, a conductive pattern 120 is disposed between the first flexible substrate 111 and the second flexible substrate 112. The conductive pattern 120 is a component that protects other components of the foldable display device 100 from static electricity and heat. Specifically, the conductive pattern 120 can protect internal components of the foldable display device 100 from static electricity during the manufacturing process of the foldable display device 100. Additionally, the conductive pattern 120 may be a heat dissipation pattern that performs a heat dissipation function to radiate heat generated inside the foldable display device 100 to the outside.

Specifically, the conductive pattern 120 is arranged to overlap the remaining area between the first flexible substrate 111 and the second flexible substrate 112 excluding the area where the barrier metal layer 130, which will be described later, is disposed. Accordingly, the conductive pattern 120 may have an open pattern in an area corresponding to the barrier metal layer 130. That is, the conductive pattern 120 may be formed in the entire area of the foldable display device 100 excluding the barrier metal layer 130, and may not be formed in the area corresponding to the barrier metal layer 130. Accordingly, the area between the conductive patterns 120 that overlaps the plurality of barrier metal layers 130 may be empty space.

Additionally, the conductive pattern 120 may have conductivity. Specifically, the conductive pattern 120 may have a dielectric constant of 6C ² /Nm ² or more and 28C ² /Nm ² or less and may have conductivity. The conductive pattern 120 has a dielectric constant of 6C ² /Nm ² or more and 28C ² /Nm ^{2 or} less, thereby effectively protecting other components of the foldable display device 100 from electric fields.

Additionally, the conductive pattern 120 may be a heat dissipation pattern capable of performing a heat dissipation function. Specifically, the conductive pattern 120 may have a thermal conductivity of 5 W/mk or more and 50 W/mk or less. The conductive pattern 120 has a thermal conductivity of 5 W/mk or more and 50 W/mk or less, and thus can effectively radiate heat generated from the foldable display device 100 to the outside.

Additionally, the conductive pattern 120 may be made of at least one of graphene, graphene oxide, and carbon nanotubes. However, it is not limited thereto, and the conductive pattern 120 may be made of another material having a dielectric constant of 5 W/mk to 50 W/mk and a thermal conductivity of 5 W/mk to 50 W/mk.

During the manufacturing process of a foldable display device, a glass substrate that supports the flexible substrate and various upper components may be disposed on the bottom of the flexible substrate. The glass substrate can be removed from the flexible substrate by a laser process, and during the process of removing the glass substrate, static electricity may be generated on the contact surface between the glass substrate and the flexible substrate.

In the case of a conventional foldable display device, static electricity generated may cause damage to components of the foldable display device, such as black spots on the flexible substrate or defects in transistors and various wiring lines.

Additionally, some components of the foldable display device may generate heat while the foldable display device is operating. For example, a foldable display device may include a battery, and heat may be generated from the battery while the foldable display device is operating.

Accordingly, in the case of a conventional foldable display device, various components of the foldable display device may be deformed or damaged due to the generated heat, and the defect rate of the foldable display device may increase.

In contrast, in the case of the foldable display device 100 according to an embodiment of the present invention, a conductive pattern 120 is disposed between the first flexible substrate 111 and the second flexible substrate 112, and the conductive pattern ( 120) may have a dielectric constant of 6C ² /Nm ² or more and 28C ² /Nm ² or less, and may have conductivity. Accordingly, various components on the upper part of the conductive pattern 120 can be protected from static electricity generated during the process of transporting the foldable display device 100 after removing the glass substrate during the manufacturing process of the foldable display device 100, Configuration of the foldable display device 100, such as black spots occurring on the first flexible substrate 111 and the second flexible substrate 112 or defects occurring in the transistor 140 and various wiring due to the generated static electricity. Damage to elements can be reduced.

And, in the case of the foldable display device 100 according to an embodiment of the present invention, the conductive pattern 120 may be a heat dissipation pattern with a heat dissipation function, and the thermal conductivity may be 5 W/mk or more and 50 W/mk or less. As described above, the foldable display device 100 may generate heat while operating, and various components of the foldable display device 100 may be deformed or damaged due to the heat. At this time, the conductive pattern 120 is a heat dissipation pattern and can effectively radiate heat generated from the foldable display device 100 to the outside. In addition, the area between the conductive patterns 120 and overlapping with the plurality of barrier metal layers 130 may remain empty, and thus the heat generated by the foldable display device 100 in the empty space may be It can be released to the outside more effectively through convection of the air in the space. Accordingly, damage such as deformation of various components of the foldable display device 100 due to heat can be effectively reduced.

In addition, in the case of the foldable display device 100 according to an embodiment of the present invention, the conductive pattern 120 is formed to overlap the area excluding the area where the plurality of barrier metal layers 130 are disposed, and the plurality of barrier metal layers 130 are formed. It is not formed in the area where (130) is placed. Accordingly, the conductive pattern 120 may include an opening area corresponding to an area where the plurality of barrier metal layers 130 are disposed. Accordingly, the stress applied to the conductive pattern 120, which is deformed as the foldable display device 100 is folded, may be distributed. Accordingly, even when the foldable display device 100 is folded, damage such as cracks may not easily occur in the conductive pattern 120.

And, in the case of the foldable display device 100 according to an embodiment of the present invention, the conductive pattern 120 is made of at least graphene, graphene oxide, and carbon nanotube. By forming one, the flexibility of the conductive pattern 120 can be increased. When the conductive pattern 120 is made of a material such as graphite other than at least one of graphene, graphene oxide, and carbon nanotube, the conductive pattern 120 is As the foldable display device 100 is folded, it may be easily damaged, such as by generating cracks. Accordingly, the conductive pattern 120 can have increased flexibility by being made of at least one of graphene, graphene oxide, and carbon nanotube, and thus is easily damaged even when folded. It may not work. Accordingly, durability due to folding of the foldable display device 100 can be further improved.

Additionally, according to some embodiments, the conductive pattern 120 may have a thickness of 1 μm or more and 7 μm or less. If the thickness of the conductive pattern 120 is less than 1 μm, the conductive pattern 120 may be so thin that it cannot sufficiently perform the heat dissipation function and the function of reducing damage to components due to static electricity as described above. Accordingly, the thickness of the conductive pattern 120 may be 1 μm or more. Accordingly, the conductive pattern 120 protects various components of the foldable display device 100 from static electricity generated during the manufacturing process of the foldable display device 100. Damage can be effectively reduced, and heat generated during operation of the foldable display device 100 can be effectively dissipated to the outside.

Additionally, if the thickness of the conductive pattern 120 is greater than 7 μm, the folding characteristics of the conductive pattern 120 may deteriorate. Specifically, if the thickness of the conductive pattern 120 is greater than 7 μm, the conductive pattern 120 may be damaged, such as cracks, as the foldable display device 100 is folded. Accordingly, the thickness of the conductive pattern 120 may be 7 μm or less, and thus, the conductive pattern 120 may not be damaged even when the foldable display device 100 is folded and folding characteristics may be improved.

Figure 3 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention. The foldable display device 300 of FIG. 3 is substantially the same as the foldable display device 100 of FIGS. 1 and 2 except that it includes a plurality of inorganic patterns 360, and redundant description will be omitted. . For convenience of explanation, description will be made with reference to FIGS. 1 and 2.

Referring to FIG. 3, a plurality of inorganic patterns 360 are disposed between the plurality of conductive patterns 120 between the first flexible substrate 111 and the second flexible substrate 112. The plurality of inorganic patterns 360 are components that prevent moisture penetration into the interior of the foldable display device 300. Specifically, the plurality of inorganic patterns 360 may be disposed on the same plane as the conductive pattern 120 to fill the area between the conductive patterns 120 . The plurality of inorganic patterns 360 will be disposed between the first flexible substrate 111 and the second flexible substrate 112 so as to overlap the area where the plurality of barrier metal layers 130 where the conductive pattern 120 is not disposed. You can. Accordingly, the side surfaces of the plurality of inorganic patterns 360 may contact the side surfaces of the conductive pattern 120 . Additionally, the lower surface of the plurality of inorganic patterns 360 may be in contact with the upper surface of the first flexible substrate 111, and the upper surface of the plurality of inorganic patterns 360 may be in contact with the lower surface of the second flexible substrate 112.

The plurality of inorganic patterns 360 may be made of an inorganic material. For example, the plurality of inorganic patterns 360 may be made of silicon nitride (SiNx) or silicon oxide (SiOx), but are not limited thereto.

The foldable display device 300 according to another embodiment of the present invention is disposed between the first flexible substrate 111 and the second flexible substrate 112 and the conductive pattern 120 and includes a plurality of inorganic patterns made of an inorganic material. Includes (360). If moisture or the like flows into the lower surface of the first flexible substrate 111 of the foldable display device 300, various components of the foldable display device 300 may be damaged, and thus the foldable display device ( The defect rate of 300) can be increased. At this time, a plurality of inorganic patterns 360 made of an inorganic material may be disposed between the conductive patterns 120, and the plurality of inorganic patterns 360 block moisture flowing into the interior of the foldable display device 300. It can perform the function of preventing moisture penetration. Accordingly, moisture penetration into the inside of the foldable display device 300 can be suppressed, and the defect rate of the foldable display device 300 can be reduced.

Figure 4 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention. The foldable display device 400 of FIG. 4 is substantially different from the foldable display device 300 of FIG. 3 except that the conductive pattern 420, the plurality of inorganic patterns 460, and the inorganic layer 470 are different. Since it is the same, duplicate description will be omitted.

Referring to FIG. 4, a plurality of conductive patterns 420 are disposed on the first flexible substrate 111. The conductive pattern 420 is arranged to overlap the remaining area of the first flexible substrate 111 except for the area where the barrier metal layer 130 is disposed. Accordingly, the conductive pattern 420 may have an open pattern in an area corresponding to the barrier metal layer 130. The conductive pattern 420 is substantially the same as the conductive pattern 120 of FIGS. 1 and 2 and may have conductive and heat dissipation functions. Additionally, the conductive pattern 420 may be made of at least one of graphene, graphene oxide, and carbon nanotubes. However, it is not limited to this.

Referring to FIG. 4, a plurality of inorganic patterns 460 are disposed on the first flexible substrate 111. The plurality of inorganic patterns 460 are components that prevent moisture penetration into the interior of the foldable display device 400, and may be substantially the same as the plurality of inorganic patterns 460 of FIG. 3 . The plurality of inorganic patterns 460 may be disposed on the same plane as the conductive pattern 420 to fill the area between the conductive patterns 420 . The plurality of inorganic patterns 460 may be disposed on the first flexible substrate 111 to overlap areas where the plurality of barrier metal layers 130 where the conductive patterns 420 are not disposed. Accordingly, the side surfaces of the plurality of inorganic patterns 460 may contact the side surfaces of the conductive patterns 420 . Additionally, the lower surfaces of the plurality of inorganic patterns 460 may be in contact with the first flexible substrate 111 . Additionally, the plurality of inorganic patterns 460 may be made of an inorganic material, for example, silicon nitride (SiNx) or silicon oxide (SiOx), but are not limited thereto.

Referring to FIG. 4 , an inorganic layer 470 is disposed between the conductive pattern 420 and the plurality of inorganic patterns 460 and the second flexible substrate 112 . The inorganic layer 470 is a component that prevents moisture penetration into the interior of the foldable display device 400. Specifically, the inorganic layer 470 is disposed to overlap the entire first flexible substrate 111 on the conductive pattern 420 and the plurality of inorganic patterns 460. And, the upper surface of the inorganic layer 470 is in contact with the lower surface of the second flexible substrate 112.

And, the inorganic layer 470 may be made of an inorganic material. For example, the inorganic layer 470 may be made of the same material as the plurality of inorganic patterns 460, for example, silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto. . When the inorganic layer 470 is made of the same material as the plurality of inorganic patterns 460, the inorganic layer 470 and the plurality of inorganic patterns 460 can be formed simultaneously through the same process. Accordingly, the inorganic layer 470 and the plurality of inorganic patterns 460 may be formed as one component.

In the case of the foldable display device 400 according to another embodiment of the present invention, the inorganic layer 470 is disposed between the conductive pattern 420 and the plurality of inorganic patterns 460 and the second flexible substrate 112. do. As described above, moisture may infiltrate from the bottom of the foldable display device 400, and components of the foldable display device 400 may be damaged by the moisture. In the foldable display device 400 according to another embodiment of the present invention, an inorganic layer 470 made of an inorganic material is formed on the lower part of the second flexible substrate 112 to correspond to the entire second flexible substrate 112. Therefore, lower moisture permeation can be more effectively suppressed. Accordingly, the defect rate due to moisture infiltration of the foldable display device 400 can be suppressed.

In addition, in the case of the foldable display device 400 according to another embodiment of the present invention, an inorganic layer 470 is formed between the conductive pattern 420 and the plurality of inorganic patterns 460 and the second flexible substrate 112. By this arrangement, the adhesion between the conductive pattern 420 and the plurality of inorganic patterns 460 and the second flexible substrate 112 can be further improved. Specifically, the inorganic layer 470 covers both the upper surface of the conductive pattern 420 and the upper surface of the plurality of inorganic patterns 460, and the upper surface of the inorganic layer 470 is the entire lower surface of the second flexible substrate 112. come into contact with Accordingly, the conductive pattern 420 and the plurality of inorganic patterns 460 and the second flexible substrate 112 can be more firmly coupled by the inorganic layer 470. In addition, when the inorganic layer 470 and the plurality of inorganic patterns 460 are made of the same material and are made of one component, the conductive pattern 420 is formed of a plurality of inorganic patterns 460 and a single component. It may be covered by the layer 470, and the bonding strength of the conductive pattern 420, the plurality of inorganic patterns 460 and the inorganic layer 470 made of one component, and the second flexible substrate 112 is further improved. can be increased. Accordingly, the foldable display device 400 can be effectively prevented from being damaged by external impacts, and its folding characteristics can be enhanced.

Figure 5 is a schematic cross-sectional view of one pixel of a foldable display device according to another embodiment of the present invention. The foldable display device 500 of FIG. 5 is substantially different from the foldable display device 400 of FIG. 4 except that the conductive pattern 520, the plurality of inorganic patterns 560, and the inorganic layer 570 are different. Since it is the same, duplicate description will be omitted.

Referring to FIG. 5, an inorganic layer 570 is disposed on the first flexible substrate 111. The inorganic layer 570 is a component that prevents moisture penetration into the interior of the foldable display device 500. Specifically, the inorganic layer 570 is disposed on the first flexible substrate 111, and the lower surface of the inorganic layer 570 is in contact with the lower surface of the first flexible substrate 111 and overlaps the front surface of the first flexible substrate 111. and is placed.

And, the inorganic layer 570 may be made of an inorganic material. For example, the inorganic layer 570 may be made of silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

Referring to FIG. 5 , a conductive pattern 520 is disposed between the inorganic layer 570 and the second flexible substrate 112 . The conductive pattern 520 is arranged to overlap the remaining area of the inorganic layer 570 except for the area where the barrier metal layer 130 is disposed. Accordingly, the conductive pattern 520 may have an open pattern in an area corresponding to the barrier metal layer 130. The conductive pattern 520 is substantially the same as the conductive pattern 520 of FIG. 4 and may have conductive and heat dissipation functions. Additionally, the conductive pattern 520 may be made of at least one of graphene, graphene oxide, and carbon nanotubes. However, it is not limited to this.

Referring to FIG. 5 , a plurality of inorganic patterns 560 are disposed between the inorganic layer 570 and the second flexible substrate 112 . The plurality of inorganic patterns 560 are components that prevent moisture penetration into the interior of the foldable display device 500, and may be substantially the same as the plurality of inorganic patterns 460 of FIG. 4 . The plurality of inorganic patterns 560 may be disposed on the same plane as the conductive pattern 520 to fill the area between the conductive patterns 520 . The plurality of inorganic patterns 560 may be disposed on the inorganic layer 570 to overlap the area where the plurality of barrier metal layers 130 where the conductive pattern 520 is not disposed. Accordingly, the side surfaces of the plurality of inorganic patterns 560 may contact the side surfaces of the conductive pattern 520 . Additionally, the lower surface of the plurality of inorganic patterns 560 may be in contact with the inorganic layer 570, and the upper surface of the plurality of inorganic patterns 560 may be in contact with the lower surface of the second flexible substrate 112.

Additionally, the plurality of inorganic patterns 560 may be made of an inorganic material and may be made of the same material as the inorganic layer 570. The plurality of inorganic patterns 560 may be made of, for example, silicon nitride (SiNx) or silicon oxide (SiOx), but are not limited thereto. When the plurality of inorganic patterns 560 are made of the same material as the inorganic layer 570, the plurality of inorganic patterns 560 and the inorganic layer 570 can be formed simultaneously through the same process. Accordingly, the plurality of inorganic patterns 560 and the inorganic layer 570 may be formed as one component.

In the case of the foldable display device 500 according to another embodiment of the present invention, the inorganic layer 570 is disposed between the first flexible substrate 111, the conductive pattern 520, and the plurality of inorganic patterns 560. do. As described above, moisture may infiltrate from the bottom of the foldable display device 500, and components of the foldable display device 500 may be damaged by the moisture. In the foldable display device 500 according to another embodiment of the present invention, an inorganic layer 570 made of an inorganic material is formed on the first flexible substrate 111 to correspond to the entire first flexible substrate 111. Therefore, lower moisture permeation can be more effectively suppressed. Accordingly, the defect rate due to moisture infiltration of the foldable display device 500 can be suppressed.

Additionally, in the case of the foldable display device 500 according to another embodiment of the present invention, an inorganic layer 570 is formed between the first flexible substrate 111, the conductive pattern 520, and the plurality of inorganic patterns 560. By this arrangement, the adhesion between the conductive pattern 520 and the plurality of inorganic patterns 560 and the first flexible substrate 111 can be further improved. Specifically, the inorganic layer 570 is in contact with both the lower surface of the conductive pattern 520 and the lower surface of the plurality of inorganic patterns 560, and the lower surface of the inorganic layer 570 is in contact with the entire upper surface of the first flexible substrate 111. . Accordingly, the conductive pattern 520 and the plurality of inorganic patterns 560 and the first flexible substrate 111 can be more firmly coupled by the inorganic layer 570. In addition, when the inorganic layer 570 and the plurality of inorganic patterns 560 are made of the same material and are made of one component, the side and bottom surfaces of the conductive pattern 520 are formed of a plurality of inorganic patterns ( 560) and the inorganic layer 570, and thus the conductive pattern 520, the plurality of inorganic patterns 560 and the inorganic layer 570 composed of one component, and the first flexible substrate 111. The binding force can be further increased. Accordingly, the foldable display device 500 can be effectively prevented from being damaged by external impacts, and its folding characteristics can be enhanced.

A foldable display device according to embodiments of the present invention may be described as follows.

A foldable display device according to an embodiment of the present invention includes a first flexible substrate, a second flexible substrate on the first flexible substrate, a plurality of transistors on the second flexible substrate, and a plurality of transistors between the second flexible substrate and the plurality of transistors. It may include a plurality of barrier metal layers disposed to overlap the transistor, and a conductive pattern disposed between the first flexible substrate and the second flexible substrate and overlapping an area excluding the barrier metal layer.

According to another feature of the present invention, the dielectric constant of the conductive pattern may be 6C ² /Nm ² or more and 28C ² /Nm ² or less.

According to another feature of the present invention, the thermal conductivity of the conductive pattern may be 5 W/mk or more and 50 W/mk or less.

According to another feature of the present invention, the conductive pattern may be made of at least one of graphene, graphene oxide, and carbon nanotubes.

According to another feature of the present invention, the thickness of the conductive pattern may be 1 μm or more and 7 μm or less.

According to another feature of the present invention, the foldable display device may further include a plurality of inorganic patterns disposed between conductive patterns between the first flexible substrate and the second flexible substrate.

According to another feature of the present invention, the foldable display device further includes an inorganic layer disposed between a conductive pattern and a first flexible substrate or between a conductive pattern and a second flexible substrate, wherein the inorganic layer is integrated with the plurality of inorganic patterns. It can be done with

According to another feature of the present invention, the plurality of transistors may be transistors with a top gate structure.

A foldable display device according to another embodiment of the present invention includes a plurality of flexible substrates overlapped to correspond to each other, a plurality of transistors disposed on the plurality of flexible substrates, and a plurality of transistors disposed between the plurality of flexible substrates and the plurality of transistors. It may include a barrier metal layer and a heat dissipation pattern disposed to overlap an area excluding the plurality of barrier metal layers between the plurality of flexible substrates to perform a heat dissipation function.

According to another feature of the present invention, the heat dissipation pattern may be made of at least one of graphene, graphene oxide, and carbon nanotubes to increase flexibility.

According to another feature of the present invention, the foldable display device may further include a plurality of inorganic patterns disposed between the heat dissipation patterns between the plurality of flexible substrates to reduce moisture penetration into the interior of the foldable display device.

According to another feature of the present invention, the foldable display device further includes an inorganic layer disposed between the heat dissipation pattern and at least one of the plurality of flexible substrates to improve adhesion between the heat dissipation pattern and at least one of the plurality of flexible substrates. The inorganic layer may be composed of multiple inorganic patterns and one component.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

100, 300, 400, 500: Foldable display device
111: first flexible substrate
112: Second flexible substrate
113: buffer layer
114: Active buffer
115: Gate insulating layer
116: Interlayer insulation layer
117: Flattening layer
118: bank
120, 420, 520: Challenge Pattern
130: barrier metal layer
140: transistor
141: active layer
141a: Channel area
141b: Source area
141c: drain area
142: source electrode
143: drain electrode
144: Gate electrode
150: Organic light emitting device
151: anode
152: Organic light emitting layer
153: cathode
360, 460, 560: Weapon Pattern
470, 570: Inorganic layer
PX: pixel
AA: display area
NA: Non-display area

Claims (12)

first flexible substrate;
a second flexible substrate on the first flexible substrate;
a buffer layer on the second flexible substrate;
a plurality of transistors on the buffer layer;
a plurality of barrier metal layers disposed between the buffer layer and the plurality of transistors to overlap the plurality of transistors;
a conductive pattern disposed between the first flexible substrate and the second flexible substrate and overlapping an area excluding the barrier metal layer; and
A plurality of inorganic patterns disposed between the first flexible substrate and the second flexible substrate to overlap the plurality of barrier metal layers,
The plurality of inorganic patterns are disposed on the same surface as the conductive pattern to fill the area between the conductive patterns, and the side surfaces of the plurality of inorganic patterns are arranged to contact the side surfaces of the conductive patterns. According to paragraph 1,
A foldable display device wherein the conductive pattern has a dielectric constant of 6C ² /Nm ² or more and 28C ² /Nm ^{2 or} less. According to paragraph 1,
A foldable display device wherein the thermal conductivity of the conductive pattern is 5W/mk or more and 50W/mk or less. According to paragraph 1,
The conductive pattern is a foldable display device made of at least one of graphene, graphene oxide, and carbon nanotube. According to paragraph 1,
A foldable display device wherein the thickness of the conductive pattern is 1 μm or more and 7 μm or less. delete According to paragraph 1,
It further includes an inorganic layer disposed between the conductive pattern and the first flexible substrate or between the conductive pattern and the second flexible substrate,
A foldable display device, wherein the inorganic layer is integrated with the plurality of inorganic patterns. According to paragraph 1,
A foldable display device in which the plurality of transistors are transistors with a top gate structure. In the foldable display device,
A plurality of flexible substrates overlapped to correspond to each other;
a buffer layer disposed on the plurality of flexible substrates;
a plurality of transistors disposed on the buffer layer;
a plurality of barrier metal layers disposed between the buffer layer and the plurality of transistors;
a heat dissipation pattern disposed between the plurality of flexible substrates to overlap a region excluding the plurality of barrier metal layers to perform a heat dissipation function; and
A plurality of inorganic patterns arranged to overlap the plurality of barrier metal layers between the plurality of flexible substrates to reduce moisture penetration into the interior of the foldable display device,
The plurality of inorganic patterns are disposed on the same surface as the heat dissipation pattern to fill the area between the heat dissipation patterns, and the side surfaces of the plurality of inorganic patterns are arranged to contact the side surfaces of the heat dissipation pattern. According to clause 9,
A foldable display device, wherein the heat dissipation pattern is made of at least one of graphene, graphene oxide, and carbon nanotube to increase flexibility. delete According to clause 9,
Further comprising an inorganic layer disposed between the heat dissipation pattern and at least one of the plurality of flexible substrates to improve adhesion between the heat dissipation pattern and at least one of the plurality of flexible substrates,
The inorganic layer is comprised of the plurality of inorganic patterns and one component.

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