Display device and method of manufacturing for display device

Abstract

A display device and a method for manufacturing a display device are provided. A method for manufacturing a display device according to one embodiment includes the steps of: preparing a carrier substrate and forming a sacrificial layer on one surface of the carrier substrate, the sacrificial layer including a cover area and an exposed area on at least one side of the cover area; forming a first flexible material on one surface of the cover area of ​​the sacrificial layer, the first surface of which contacts the sacrificial layer, thereby exposing the exposed area of ​​the sacrificial layer; and removing the exposed area of ​​the sacrificial layer.

Description

Technology Field

[0001] The present invention relates to a display device and a method for manufacturing a display device. Background Technology

[0002] Electronic devices that provide video to users, such as smartphones, tablet PCs, digital cameras, laptop computers, navigation systems, and smart televisions, include a display device for displaying video. The display device includes a display device that generates and displays video and various input devices.

[0003] A display device may refer to any electronic device that provides a display screen. For example, portable electronic devices that provide a display screen, such as mobile phones, smartphones, tablet PCs (Personal Computers), electronic watches, smartwatches, watch phones, mobile communication terminals, electronic notebooks, e-books, PMPs (Portable Multimedia Players), navigation systems, game consoles, digital cameras, etc., as well as televisions, laptops, monitors, billboards, and the Internet of Things, may be included in a display device.

[0004] Recently, flexible display devices including flexible substrates among display devices are being widely studied. Flexible display devices are deposited on a rigid carrier substrate. After the deposition of the flexible display device on the carrier substrate is completed, the carrier substrate must be detached from the flexible display device. For example, the detachment process may include a process of removing the adhesive force by irradiating the flexible substrate of the flexible display device with a laser and removing the carrier substrate by a mechanical detachment method.

[0005] However, in the case of the above process, a residual film of the flexible substrate may remain on the surface of the carrier substrate, making it difficult to recycle the carrier substrate. The problem to be solved

[0006] The problem that the present invention aims to solve is to provide a method for manufacturing a display device in which the carrier substrate can be recycled after a flexible display device is deposited on the carrier substrate.

[0007] Another problem that the present invention aims to solve is to provide a display device manufactured by the above-described manufacturing method.

[0008] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0009] A method for manufacturing a display device according to one embodiment for solving the above problem comprises: preparing a carrier substrate and forming a sacrificial layer on one surface of the carrier substrate, the sacrificial layer including a cover area and an exposed area on at least one side of the cover area; forming a first flexible material on one surface of the cover area of ​​the sacrificial layer, the first surface of which is in contact with the sacrificial layer, thereby exposing the exposed area of ​​the sacrificial layer; and removing the exposed area of ​​the sacrificial layer.

[0010] The step of preparing the carrier substrate may further include the step of charging one surface of the carrier substrate with a negative charge.

[0011] The step of charging one side of the carrier substrate with a negative charge can be performed using an atmospheric-pressure plasma device.

[0012] The step of forming the sacrificial layer may include the step of repeatedly forming a first coating film charged with a first charge and a second coating film charged with a second charge having a polarity different from the first charge.

[0013] The first charge above may be a positive charge and the second charge above may be a negative charge.

[0014] The first coating film and the second coating film may each be made of graphene oxide (GO).

[0015] The step of removing the exposed area of ​​the sacrificial layer can be performed through the atmospheric pressure plasma device or water washing.

[0016] After the step of removing the exposed area of ​​the sacrificial layer, the sides of the sacrificial layer and the flexible material can be aligned.

[0017] After the step of removing the exposed area of ​​the sacrificial layer, the method may further include the step of forming a first barrier layer on the first flexible material.

[0018] After the step of forming a first barrier layer, the method may further include the step of sequentially forming a second flexible material on the first barrier layer, a circuit driving layer on the second flexible material, a light-emitting layer on the circuit driving layer, and an encapsulation layer on the light-emitting layer.

[0019] After the step of removing the exposed area of ​​the sacrificial layer, the method may include the step of removing the carrier substrate from the first flexible material.

[0020] In the step of removing the carrier substrate from the first flexible material, the sacrificial layer may remain on one side of the carrier substrate and on one side of the first flexible material, respectively.

[0021] The thickness of the sacrificial layer remaining on one side of the carrier substrate may be smaller than the thickness of the sacrificial layer remaining on one side of the first flexible material.

[0022] After removing the carrier substrate from the first flexible material, the method may further include the step of removing the sacrificial layer remaining on one side of the carrier substrate.

[0023] The step of removing the sacrificial layer remaining on one side of the carrier substrate can be performed through the atmospheric pressure plasma device or water washing.

[0024] A method for manufacturing a display device according to another embodiment for solving the above problem comprises the steps of: preparing a carrier substrate and forming a sacrificial layer on one side of the carrier substrate; forming a first flexible material on one side of the sacrificial layer, the first side of which is in contact with the sacrificial layer; removing the carrier substrate from the first flexible material, wherein the sacrificial layer remains on one side of the carrier substrate; and removing the sacrificial layer remaining on one side of the carrier substrate to recycle the carrier substrate.

[0025] The step of removing the sacrificial layer remaining on one side of the carrier substrate can be performed through the atmospheric pressure plasma device or water washing.

[0026] In the step of removing the carrier substrate from the first flexible material, the sacrificial layer may remain on one side of the first flexible material.

[0027] The thickness of the sacrificial layer remaining on one side of the carrier substrate may be smaller than the thickness of the sacrificial layer remaining on one side of the first flexible material.

[0028] A display device according to one embodiment for solving the above other problems comprises: a first flexible substrate; a first barrier layer disposed on one side of the first flexible substrate; a second flexible substrate disposed on the first barrier layer; a circuit driving layer disposed on the second flexible substrate; and a residue disposed on the other side opposite to one side of the first flexible substrate, wherein one side of the residue is aligned with one side of the first flexible substrate.

[0029] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0030] According to a display device and a method for manufacturing the same according to one embodiment, after a flexible display device is deposited on a carrier substrate, the carrier substrate can be recycled.

[0031] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0032] FIG. 1 is a flowchart of a method for manufacturing a display device according to one embodiment. FIG. 2 is a plan view of a carrier substrate according to one embodiment. Figure 3 is a cross-sectional view taken along the line III-III' of Figure 2. FIGS. 4 to 10, FIGS. 12 to 16, and FIG. 18 are cross-sectional views of process steps of a manufacturing method according to one embodiment. FIGS. 11 and FIGS. 17 are plan views of the process steps of a manufacturing method according to one embodiment. FIG. 19 is a perspective view of one process step of a manufacturing method according to one embodiment. FIG. 20 is a cross-sectional view of one process step of a manufacturing method according to another embodiment. Specific details for implementing the invention

[0033] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0034] When elements or layers are referred to as being on another element or layer, this includes cases where another layer or element is interposed directly on or in the middle of another element. Throughout the specification, the same reference numerals refer to the same components.

[0035] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may also be the second component within the technical scope of the present invention.

[0036] Specific embodiments will be described below with reference to the attached drawings.

[0037] FIG. 1 is a flowchart of a method for manufacturing a display device according to one embodiment, FIG. 2 is a plan view of a carrier substrate according to one embodiment, FIG. 3 is a cross-sectional view taken along the line III-III' of FIG. 2, FIG. 4 to 10, FIG. 12 to 16, and FIG. 18 are cross-sectional views of process steps of a method for manufacturing according to one embodiment, FIG. 11 and FIG. 17 are plan views of process steps of a method for manufacturing according to one embodiment, and FIG. 19 is a perspective view of one process step of a method for manufacturing according to one embodiment.

[0038] In the embodiments, the first direction (DR1) and the second direction (DR2) intersect each other in different directions. In the plan view of FIG. 1, for convenience of explanation, the first direction (DR1), which is the vertical direction, and the second direction (DR2), which is the horizontal direction, are defined. Furthermore, a third direction (DR3), which is the thickness direction intersecting the first direction (DR1) and the second direction (DR2), is defined. In the following embodiments, one side of the first direction (DR1) is referred to as the upper direction in the plan view, the other side of the first direction (DR1) is referred to as the lower direction in the plan view, one side of the second direction (DR2) is referred to as the right direction in the plan view, and the other side of the second direction (DR2) is referred to as the left direction in the plan view. Additionally, one side of the third direction (DR3) is referred to as the upper direction in the cross-sectional view (the display direction in the case of a front light-emitting display device), and the other side of the third direction (DR3) is referred to as the lower direction in the cross-sectional view (the direction opposite to the display direction in the case of a front light-emitting display device). However, the directions mentioned in the embodiments should be understood as referring to relative directions, and the embodiments are not limited to the mentioned directions.

[0039] Referring to FIGS. 1 to 19, the display device (10) may be a cell-unit display device in which a display device (11) manufactured in units of a mother board as described below is separated into each cell.

[0040] The display device (10) can provide a display screen. Examples of the display device (10) include an organic light-emitting display device, a micro LED display device, a nano LED display device, a quantum dot light-emitting display device, a liquid crystal display device, a plasma display device, a field emission display device, an electrophoretic display device, an electrowetting display device, etc. In the following, an example of the display device (10) is given in which an organic light-emitting display device is applied, but it is not limited thereto, and if the same technical concept is applicable, it can be applied to other display devices.

[0041] The display device (10) may include a flexible display device comprising a flexible material or a flexible substrate including a flexible polymer material such as polyimide. Accordingly, the display device (10) may be bent, folded, folded, or rolled.

[0042] Referring to FIGS. 1 to 3, a carrier substrate (20) is prepared (S10).

[0043] A rectangular shape having a short side extended along the first direction (DR1) and a long side extended along the second direction (DR2) may be applied as the planar shape of the carrier substrate (20). However, the planar shape of the carrier substrate (20) is not limited thereto and may be various shapes such as a rectangular shape with a short side extended along the second direction (DR2) and a long side extended along the first direction (DR1), a square, other polygons, a circle, an ellipse, etc.

[0044] The carrier substrate (20) may have a rigid material such as glass or quartz applied thereto and may provide a space for a display device to be deposited. That is, a plurality of components of the display device may be sequentially stacked on the upper surface (20t) of the carrier substrate (20).

[0045] Referring to FIG. 4, the step of preparing (S10) the carrier substrate (20) may further include the step of charging the upper surface (20t) of the carrier substrate (20) with a negative charge. The upper surface (20t) of the carrier substrate (20) may be one side of the third direction (DR3) of the carrier substrate (20).

[0046] The step of charging the upper surface (20t) of the carrier substrate (20) with a negative charge can be performed by surface treating the upper surface (20t) of the carrier substrate (20). The surface treatment can be performed using an atmospheric-pressure plasma device, but is not limited thereto and can also be performed by methods widely known in the art.

[0047] After charging the upper surface (20t) of the carrier substrate (20) with a negative charge, the upper surface (20t) of the carrier substrate (21) may be in a state where it is entirely charged with a negative charge.

[0048] Next, referring to FIGS. 5 to 10, a sacrificial layer (30) is formed (S20) on the upper surface (20t) of a carrier substrate (21) that is charged with a negative charge.

[0049] The sacrificial layer (30) may be a de-bonding layer that weakens the adhesion between the first flexible substrate (60) and the carrier substrate (21) to facilitate separation of the carrier substrate (21) from the first flexible material (61) deposited on one side of the sacrificial layer (30). The de-bonding layer may be made of graphene oxide (GO). The de-bonding layer may include a first coating film charged with a first charge and another coating film charged with a second charge having a polarity different from the first charge. The first coating film and the other coating film may be directly coated on the upper surface (20t) of the carrier substrate (21) which is charged with a negative charge. The first coating film and the other coating film may be repeatedly arranged along a third direction (DR3).

[0050] The step of forming the sacrifice layer (30) is described below in detail.

[0051] First, as shown in FIG. 5, a carrier substrate (21) charged with a negative charge is placed in a first aqueous solution (40).

[0052] The first aqueous solution (40) may have a first substance (41) that is positively charged dispersed therein. The first substance (41) may include positively charged graphene oxide.

[0053] The first material (41) can be primarily coated on the upper surface (20t) of a carrier substrate (21) charged with a negative charge to form a first coating film (41L) as shown in FIG. 6. That is, one positive charge of the first material (41) can be mutually coupled through electrostatic attraction with a negative charge charged on the upper surface (20t) of the carrier substrate (21) on the other side of the third direction (DR3).

[0054] The first coating film (41L) may be a film formed by a layer of first materials (41) over the front surface of the carrier substrate (21). The first coating film (41L) may be formed over the front surface of the carrier substrate (20).

[0055] A positive charge located on one side facing the upper surface (20t) of the carrier substrate (21) of the first coating film (41L) is combined with a negative charge charged on the upper surface (20t) of the carrier substrate (21), and a positive charge located on the other side opposite to the one side may be exposed to the outside. That is, the surface of the first coating film (41L) may be in a state where it is charged with a positive charge.

[0056] Next, as shown in FIG. 7, a first coating film (41L) charged with a positive charge and a carrier substrate (20) are placed in a second aqueous solution (50).

[0057] The second aqueous solution (50) may have a second material (51) that is negatively charged dispersed therein. The second material (51) may include negatively charged graphene oxide.

[0058] The second material (51) can be secondarily coated on one side of the first coating film (41L) charged with a positive charge to form the second coating film (51L) as shown in FIG. 8. That is, one negative charge of the second material (51) can be mutually coupled through electrostatic attraction with the positive charge charged on the other side of the first coating film (41L) in the third direction (DR3).

[0059] The second coating film (51L) may be a film formed by a layer of second materials (51) over the front surface of the first coating film (41L). The second coating film (51L) may be formed over the front surface of the carrier substrate (21).

[0060] The negative charge located on one side of the first coating film (41L) of the second coating film (51L) is combined with the positive charge charged on one side of the first coating film (41L), and the negative charge located on the other side opposite to one side of the second coating film (51L) may be exposed to the outside.

[0061] Next, when the negatively charged second coating film (51L), the first coating film (41L), and the carrier substrate (20) are immersed in the first aqueous solution (40), as shown in FIG. 9, the first material (41) can be tertiarily coated on one side of the negatively charged second coating film (51L) to form a third coating film (42L). The process of immersing the negatively charged second coating film (51L), the first coating film (41L), and the carrier substrate (21) in the first aqueous solution (40) is different only in the composition of the immersed material compared to the process of immersing the negatively charged carrier substrate (21) in the first aqueous solution (40) of FIG. 5, and the material of the first aqueous solution (40) is the same, so a redundant description of the process steps will be omitted.

[0062] One positive charge of the first material (41) can be combined with a negative charge charged on the other side of the second coating film (51L) in the third direction (DR3) through electrostatic attraction.

[0063] The third coating film (42L) may be a film formed by a layer of the first material (41) over the front surface of the second coating film (51L). The third coating film (42L) may be formed over the front surface of the carrier substrate (21).

[0064] A positive charge located on one side of the second coating film (51L) of the third coating film (42L) is combined with a negative charge charged on one side of the second coating film (51L), and a positive charge located on the other side opposite to one side of the third coating film (42L) may be exposed to the outside.

[0065] Subsequently, when the positively charged third coating film (42L), the second coating film (51L), the first coating film (41L), and the carrier substrate (21) are immersed in the second aqueous solution (50), as shown in FIG. 10, the second material (51) can be coated a fourth time on one side of the positively charged third coating film (42L) to form the fourth coating film (52L). The process of immersing the positively charged third coating film (42L), the second coating film (51L), the first coating film (41L), and the carrier substrate (21) in the second aqueous solution (50) is different only in the composition of the immersed parts compared to the process of immersing the positively charged first coating film (41L) and the carrier substrate (21) in the second aqueous solution (50) in FIG. 7, but the material of the second aqueous solution (50) is the same, so a redundant description of the process steps is omitted.

[0066] One negative charge of the second material (51) can be combined with a positive charge charged on the other side of the third coating film (42L) in the third direction (DR3) through electrostatic attraction.

[0067] The fourth coating film (52L) may be a film formed by a layer of second materials (51) over the front surface of the third coating film (42L). The fourth coating film (52L) may be formed over the front surface of the carrier substrate (20).

[0068] A negative charge located on one side of the third coating film (42L) of the fourth coating film (52L) is combined with a positive charge charged on one side of the third coating film (42L), and a negative charge located on the other side opposite to one side of the fourth coating film (52L) may be exposed to the outside.

[0069] The sacrificial layer (30) may include a first coating film (41L), a second coating film (51L), a third coating film (42L), and a fourth coating film (52L) sequentially stacked along a third direction (DR3) from the upper surface (20t) of the carrier substrate (21). Here, the other coating film charged with a negative charge adjacent to the first coating film charged with a positive charge may form a bi-layer. That is, the first coating film (41L) charged with a positive charge and the second coating film (51L) charged with a negative charge may form a first bi-layer, and the third coating film (42L) charged with a positive charge and the fourth coating film (52L) charged with a negative charge may form a second bi-layer. That is, the sacrifice layer (30) may include a dyad bi-layer in which a first bi-layer (1 bi-layer) and a second bi-layer (2 bi-layer) are sequentially stacked.

[0070] However, not limited thereto, the sacrifice layer (30) may include other bi-layers sequentially stacked on the second bi-layer, so that the number of bi-layers is three or more, or the number of bi-layers is one.

[0071] Hereinafter, the configuration will be described with a focus on the number of bi-layers being two, that is, a first coating film (41L), a second coating film (51L), a third coating film (42L), and a fourth coating film (52L) sequentially stacked along the third direction (DR3) from the upper surface (20t) of the carrier substrate (21).

[0072] The upper surface of the sacrificial layer (30) (see '30t' in FIG. 12) may be formed from one side or the upper surface of the fourth coating film (52L), and the lower surface of the sacrificial layer (30) (see '30u' in FIG. 12) may be formed from the other side or the lower surface of the first coating film (41L).

[0073] As described above, the sequentially stacked first coating film (41L), second coating film (51L), third coating film (42L), and fourth coating film (52L) of the sacrificial layer (30) can be formed across the front surface of the carrier substrate (20). That is, one side and the other side of the sacrificial layer (30) can be aligned along the third direction (DR3) on one side and the other side of the corresponding carrier substrate (21), respectively.

[0074] When the first flexible material (61) described later comes into direct contact with the carrier substrate (21), the first flexible material (61) and the like remain on the carrier substrate (21) after the separation process of the carrier substrate, and it may be difficult to remove the remaining first flexible material (61) and the like from the carrier substrate (21). That is, when removing the remaining first flexible material (61) and the like from the carrier substrate (21), a polishing process is used, and if polishing proceeds, scratches and sludge may occur on the surface of the carrier substrate (21). That is, even if a sacrificial layer is formed between the carrier substrate (21) and the first flexible material (61), if the placement area of ​​the first flexible material (61) is larger than the placement area of ​​the sacrificial layer, the first flexible material (61) comes into direct contact with the upper surface (20t) of the carrier substrate (21), making it difficult to recycle the carrier substrate (21).

[0075] According to a method for manufacturing a display device according to one embodiment, by forming a sacrificial layer (30) on the front surface of a carrier substrate (21), the first flexible material (61) can be fundamentally prevented from coming into contact with the upper surface (20t) of the carrier substrate (21).

[0076] Furthermore, after the first flexible material (61) and a plurality of members formed thereon are formed, the first flexible material (61) and the plurality of members can be cut into individual cell units. As described above, if a sacrificial layer (30) is formed on the front surface of the carrier substrate (21), the placement area of ​​the first flexible material (61) and the plurality of members can be made larger. As a result, when a display device is manufactured in cell units from a mother substrate unit, not only is material not wasted, but more cell-unit display devices can be formed from a single mother substrate unit.

[0077] In some embodiments, the sequentially stacked first coating film (41L), second coating film (51L), third coating film (42L), and fourth coating film (52L) of the sacrificial layer (30) may not be formed across the front surface of the carrier substrate (20) but may be formed on one side of the carrier substrate (21) and on the inner side of the other side.

[0078] The sacrificial layer (30) may have a first thickness (t1) from the upper surface (20t) of the carrier substrate (21). The first thickness (t1) may be, for example, about 50 μm to about 60 μm, but the thickness is not limited to the above example.

[0079] Next, referring to FIGS. 1, FIGS. 11, and FIGS. 12, a first flexible material (61) is formed (S30) on the upper surface (30t) of the sacrificial layer (30).

[0080] The first flexible material (61) may include a flexible material such as polyimide (PI).

[0081] The lower surface (61u) of the first flexible material (61) can be formed to be in contact with the upper surface (30t) of the sacrificial layer (30).

[0082] The step (S30) of forming the first flexible material (61) may include the step of forming the first flexible material (61) on the upper surface (30t) of the sacrificial layer (30) in a slit coating manner. When forming the first flexible material (61) on the upper surface (30t) of the sacrificial layer (30) in a slit coating manner, the end of the first flexible material (61) where the slit coating begins may have a shape that rises toward one side of the third direction (DR3), so that the thickness in that area may be greater than the thickness in the remaining area, but is not limited thereto, and the thickness of the first flexible material (61) may be uniform overall.

[0083] The step (S30) of forming the first flexible material (61) may include forming the first flexible material (61) on one side and the other side of the sacrificial layer (30), respectively. That is, the sacrificial layer (30) may include a cover area (30a) that overlaps the first flexible material (61) along the third direction (DR3) as shown in FIG. 12, and an exposed area (30b, 30c) that does not overlap the first flexible material (61) along the third direction (DR3).

[0084] The cover area (30a) of the sacrificial layer (30) is in direct contact with the first flexible material (61) on one side of the third direction (DR3) and can be covered by the first flexible material (61), and the upper surface (30t) of the exposed area (30b, 30c) of the sacrificial layer (30) is not in contact with the first flexible material (61) and the upper surface (30t) can be exposed by the first flexible material (61).

[0085] The step (S30) of forming the first flexible material (61) can prevent the first flexible material (61) from overflowing to the outside of the carrier substrate (21) and coming into contact with the one side and the other side of the carrier substrate (20) by forming the first flexible material (61) on the inner side of the sacrificial layer (30) and the other side, respectively.

[0086] A method for manufacturing a display device according to one embodiment may form the first flexible material (61) in the step (S30) of forming the first flexible material (61) so that the first flexible material (61) does not come into contact with the carrier substrate (21). That is, by forming the sacrificial layer (30) on the front surface of the carrier substrate (21) as described above, and forming the first flexible material (61) on the inner side of one side and the other side of the sacrificial layer (30), respectively, the first flexible material (61) may not come into contact with the upper surface (20t) of the carrier substrate (21).

[0087] In an embodiment where the first coating film (41L), second coating film (51L), third coating film (42L), and fourth coating film (52L) sequentially stacked on the sacrificial layer (30) are not formed across the front surface of the carrier substrate (20) but are formed on one side and the other side of the carrier substrate (21), the first flexible material (61) can be formed on one side and the other side of the sacrificial layer (30), respectively.

[0088] Next, referring to FIG. 1 and FIG. 13, the exposed areas (30b, 30c) of the sacrifice layer (30) are removed to form a sacrifice layer (31) (S40).

[0089] More specifically, in one embodiment, the step (S40) of removing the exposed areas (30b, 30c) of the sacrificial layer (30) may include removing the exposed areas (30b, 30c) of the sacrificial layer (30) through the surface treatment described above in FIG. 4. The surface treatment may be performed using an atmospheric-pressure plasma device, but is not limited thereto and may also be performed by methods widely known in the art.

[0090] When the above surface treatment is performed using an atmospheric-pressure plasma device, the gas having the form of plasma of the atmospheric-pressure plasma device may have different selectivity ratios for the first flexible material (61) and the sacrificial layer (30). That is, when the gas comes into contact, the first flexible material (61) does not undergo substantial surface treatment, but the sacrificial layer (30) can undergo relatively more surface treatment. The fact that the surface treatment of the first flexible material (61) does not undergo substantial treatment means that some of the surface of the first flexible material (61) may be treated by the gas, but the degree of surface treatment can be seen as almost negligible compared to the sacrificial layer (30).

[0091] As illustrated in FIG. 13, the cover area (30a) of the sacrificial layer (30) that is overlapped with the first flexible material (61) along the third direction (DR3) remains untreated and is not surface treated because the gas is not reached by the first flexible material (61), but the exposed area (30b, 30c) of the sacrificial layer (30) that is not overlapped with the first flexible material (61) can be removed by the gas reaching it and surface treatment proceeding.

[0092] Accordingly, one side and the other side of the cover area (30a) of the sacrificial layer (31) can be aligned along the third direction (DR3) with one side and the other side of the corresponding first flexible material (61), respectively.

[0093] The exposed areas (30b, 30c) of the sacrificial layer (30) may be subjected to physical and / or chemical damage during the formation process (deposition and etching processes, etc.) of the inorganic films of the first barrier layer (62), the second barrier layer (64), the buffer layer (65), the circuit driving layer (66), and the thin film encapsulation layer (68). The exposed areas (30b, 30c) that have been subjected to physical and / or chemical damage may peel off from the carrier substrate (21), thereby reducing the efficiency of subsequent processes, and may cause self-cracks to be transmitted to multiple members formed in subsequent processes.

[0094] However, the manufacturing method of a display device according to one embodiment can prevent the exposed areas (30b, 30c) of the sacrificial layer (30) from being physically and / or chemically damaged during the formation process (deposition and etching processes, etc.) of the inorganic films of the first barrier layer (62), the second barrier layer (64), the buffer layer (65), the circuit driving layer (66), and the thin film encapsulation layer (68) by removing (S40) the exposed areas (30b, 30c) of the sacrificial layer (30), thereby preventing the sacrificial layer (30) from being peeled off from the carrier substrate (21) due to the exposed areas (30b, 30c) being physically and / or chemically damaged, which reduces the efficiency of the subsequent process, and prevent the occurrence of self-cracking and transmission of said cracks to the plurality of members formed in the subsequent process.

[0095] As another example, the step (S40) of removing the exposed area (30b, 30c) of the sacrifice layer (30) may include removing the exposed area (30b, 30c) of the sacrifice layer (30) through washing.

[0096] When the step (S40) of removing the exposed areas (30b, 30c) of the sacrificial layer (30) is performed through water washing, the cleaning solution may have different selectivity ratios for the first flexible material (61) and the sacrificial layer (30). That is, when the cleaning solution comes into contact, the first flexible material (61) is not substantially cleaned, but the sacrificial layer (30) may be relatively cleaned. The fact that the first flexible material (61) is not substantially cleaned means that some of the first flexible material (61) may be cleaned by the cleaning solution, but the degree of cleaning is almost negligible compared to the sacrificial layer (30).

[0097] Accordingly, the cover area (30a) of the sacrificial layer (30) overlapped along the first flexible material (61) and the third direction (DR3) remains almost uncleaned and is almost as it is because the cleaning solution is hardly reached by the first flexible material (61), but the exposed area (30b, 30c) of the sacrificial layer (30) non-overlapping with the first flexible material (61) can be removed by the cleaning solution reaching it and cleaning proceeding.

[0098] The cleaning agent used for the above water washing can remove the exposed areas (30b, 30c) of the sacrificial layer (30) through a chemical action. The cleaning agent may be a basic cleaning agent containing (Tetramethylammonium hydroxide).

[0099] Next, a first barrier layer (62) is formed (S50) on the first flexible material (61).

[0100] The first barrier layer (62) may include an inorganic material such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0101] The first barrier layer (62) can be formed through deposition and etching processes of the inorganic material.

[0102] One side and the other side of the first barrier layer (62) may be aligned along the third direction (DR3) with the one side and the other side of the corresponding first flexible material (61), respectively. However, not limited thereto, the one side and the other side of the first barrier layer (62) may be protruded further outward or inwardly more than the one side and the other side of the corresponding first flexible material (61), respectively.

[0103] Next, a second flexible material (63), a second barrier layer (64), a buffer layer (65), a circuit driving layer (66), a light-emitting layer (67), and a thin film encapsulation layer (68) are sequentially stacked.

[0104] The second flexible material (63) may be formed by including the same material as the constituent material of the first flexible material (61). One side and the other side of the second flexible material (63) may be formed to be more indented inward than the corresponding one side and the other side of the first flexible material (61). As a result, the second flexible material (63) may be prevented from overflowing outward beyond the sides of the first barrier layer (62) and the first flexible material (61).

[0105] The second flexible material (63) can be formed through a slit coating that is substantially the same as the method of forming the first flexible material (61), and the end at which the slit coating begins may have a shape that protrudes along the third direction (DR3). A redundant description of this is omitted.

[0106] A second barrier layer (64) can be formed on the second flexible material (63). The second barrier layer (64) can extend outward from one side and the other side of the second flexible material (63) to cover and protect one side and the other side of the second flexible material (63).

[0107] One side and the other side of the second barrier layer (64) can be aligned along the third direction (DR3) with the corresponding one side and the other side of the first barrier layer (62).

[0108] A buffer layer (65) can be formed on the second barrier layer (64).

[0109] The buffer layer (65) may include an inorganic material such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

[0110] The buffer layer (65) can be formed through deposition and etching processes of the inorganic material.

[0111] A circuit driving layer (66) can be formed on the buffer layer (65). The circuit driving layer (66) may include a circuit that drives the light-emitting layer (67) of the pixel. The circuit driving layer (66) may include a plurality of thin-film transistors.

[0112] A light-emitting layer (67) may be disposed on top of the circuit driving layer (66). The light-emitting layer (67) may include an organic light-emitting layer. The light-emitting layer (67) may emit light with various brightness levels depending on the driving signal transmitted from the circuit driving layer (66).

[0113] A thin film encapsulation layer (68) may be disposed on the upper portion of the light-emitting layer (67). The thin film encapsulation layer (68) may include an inorganic film or a laminate of an inorganic film and an organic film. As another example, glass or an encapsulation film may be applied as the thin film encapsulation layer (68).

[0114] One side and the other side of the buffer layer (65), circuit driving layer (66), light-emitting layer (67), and thin film encapsulation layer (68) may be formed inwardly from one side and the other side of the corresponding second barrier layer (64), and at least one side of the buffer layer (65), circuit driving layer (66), light-emitting layer (67), and thin film encapsulation layer (68) may be aligned along the third direction (DR3), but is not limited thereto.

[0115] Next, referring to FIGS. 1, FIGS. 15, and FIGS. 16, the carrier substrate (21) is removed (S60) from the first flexible material (61).

[0116] More specifically, the step (S60) of removing the carrier substrate (21) from the first flexible material (61) can be performed through mechanical detachment.

[0117] The above mechanical detachment can be achieved through a glass removal machine (GRM) including a vacuum pad. That is, by placing the glass removal machine on the lower surface of the carrier substrate (21) and using the vacuum pad to adsorb the lower surface of the carrier substrate (21), the carrier substrate (21) is pulled toward the other side in the third direction (DR3), thereby physically separating the carrier substrate (21) from the first flexible material (61).

[0118] As described above, a sacrificial layer (31) that weakens the bonding force between the carrier substrate (21) and the first flexible material (61) may be disposed between the carrier substrate (21) and the first flexible material (61). For example, by disposing of the sacrificial layer (31), the bonding force between the first flexible material (61) and the carrier substrate (21) can be reduced to a level of about 3 gf / in or less.

[0119] In the step (S60) of removing the carrier substrate (21) from the first flexible material (61), the sacrificial layer (31) disposed therein may remain on the lower surface (61u) of the first flexible material (61) and the upper surface (21t) of the carrier substrate (21), respectively.

[0120] The sacrificial layer (32) remaining on the lower surface (61u) of the first flexible material (61) has a second thickness (t2), and the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21) may have a third thickness (t3) smaller than the second thickness (t2).

[0121] The sum of the second thickness (t2) and the third thickness (t3) may be equal to the first thickness (t1). The second thickness (t2) may be, for example, about four times the third thickness (t3). For example, the second thickness (t2) may be about 40 μm, and the third thickness (t3) may be about 10 μm.

[0122] However, not limited thereto, the sacrificial layers (32, 33) remaining on the lower surface (61u) of the first flexible material (61) and the upper surface (21t) of the carrier substrate (21), respectively, may be further partially removed in the step (S60) of removing the carrier substrate (21) from the first flexible material (61), and the sum of the second thickness (t2) and the third thickness (t3) may be smaller than the first thickness (t1).

[0123] As shown in FIGS. 15, 17, and 18, the sacrificial layer (32), the first flexible material (61), and a plurality of members disposed on top thereof can constitute a display device (11) of a mosquito board unit.

[0124] In some embodiments, a touch layer may be placed directly above the thin film encapsulation layer (68).

[0125] A display device (11) in a mother substrate unit may include a plurality of cell unit display devices (10). Each display device (10) may be formed by cutting from a display device (11) in a mother substrate unit after the carrier substrate (21) is removed from the first flexible material (61) and a release film is placed on the thin film encapsulation layer (68) (if a touch layer is included, the release film is placed on the touch film).

[0126] In FIG. 17, a display device (11) in a mosquito board unit is illustrated as comprising a total of 10 cell unit display devices (10) arranged in 2 rows along the first direction (DR1) and 5 columns along the second direction (DR2), but it is obvious that the number and arrangement of cell unit display devices (10) included in one display device (11) in a mosquito board unit are not limited to what is illustrated.

[0127] As illustrated in FIG. 18, the cell-cut cell unit display device (10) may have corresponding sides and other sides of a sacrificial layer (33'), a first flexible material (61'), a first barrier layer (62'), a second flexible material (63'), a second barrier layer (64'), a buffer layer (65'), a circuit driving layer (66'), a light-emitting layer (67'), and a thin film encapsulation layer (68') aligned along a third direction (DR3). The sacrificial layer (33'), first flexible material (61'), first barrier layer (62'), second flexible material (63'), second barrier layer (64'), buffer layer (65'), circuit driving layer (66'), light-emitting layer (67'), and thin film encapsulation layer (68') of the display device (10) of FIG. 18 each perform substantially the same function as the sacrificial layer (33), first flexible material (61), first barrier layer (62), second flexible material (63), second barrier layer (64), buffer layer (65), circuit driving layer (66), light-emitting layer (67), and thin film encapsulation layer (68) of FIG. 14 and FIG. 15, differing only in planar size, so a detailed description is omitted.

[0128] Referring to FIGS. 1, FIGS. 15, and FIGS. 19, after the step (S60) of removing the carrier substrate (21) from the first flexible material (61), the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21) is removed (S70).

[0129] The step of removing (S70) the remaining sacrificial layer (33) on the upper surface (21t) of the carrier substrate (21) may be performed before the step of manufacturing each cell unit display device (10) from the mother substrate unit display device (11), and may be performed later or simultaneously.

[0130] The step (S70) of removing the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21) can be performed through the surface treatment or water washing described above in FIG. 13.

[0131] More specifically, when using surface treatment, the step (S70) of removing the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21) can be performed using an atmospheric-pressure plasma device as illustrated in FIG. 19. The atmospheric-pressure plasma device (70) may include a main body (71) and a plurality of nozzles (72) connected to the main body (71). Plasma gas described above in FIG. 13 can be ejected through the nozzles (72).

[0132] When the atmospheric pressure plasma device (70) moves along the second direction (DR2), plasma gas ejected from nozzles (72) connected to the main body (71) comes into contact with the sacrificial layer (33), and the sacrificial layer (33) can be removed.

[0133] In FIG. 19, the atmospheric pressure plasma device (70) is illustrated as moving along the second direction (DR2), but the direction of movement of the atmospheric pressure plasma device (70) can be varied.

[0134] The above surface treatment and the above water washing are explained in detail in FIG. 13, and then redundant explanations are omitted below.

[0135] Subsequently, after the step (S70) of removing the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21), the carrier substrate (21) can be recycled again. That is, the processes of FIGS. 5 to 19 can be performed again on the carrier substrate (21).

[0136] As described above, if the first flexible material (61) comes into direct contact with the carrier substrate (21), the first flexible material (61) and the like may remain on the carrier substrate (21) after the separation process of the carrier substrate, and it may be difficult to remove the remaining first flexible material (61) and the like from the carrier substrate (21). That is, when removing the remaining first flexible material (61) and the like from the carrier substrate (21), a polishing process is used, and if polishing proceeds, scratches and sludge may occur on the surface of the carrier substrate (21). That is, even if a sacrificial layer is formed between the carrier substrate (21) and the first flexible material (61), if the placement area of ​​the first flexible material (61) is larger than the placement area of ​​the sacrificial layer, the first flexible material (61) may come into direct contact with the upper surface (20t) of the carrier substrate (21), making it difficult to recycle the carrier substrate (21).

[0137] However, according to the manufacturing method of one embodiment, by forming a sacrificial layer (30) on the front surface of the carrier substrate (21), the first flexible material (61) is fundamentally prevented from coming into contact with the upper surface (20t) of the carrier substrate (21), and after separating the carrier substrate (21), the carrier substrate (21) can be recycled by easily removing the sacrificial layer (33) remaining on the upper surface (21t) of the carrier substrate (21).

[0138] Other embodiments are described below. In the following embodiments, components identical to those already described are referred to by the same reference numerals, and their descriptions are omitted or simplified.

[0139] FIG. 20 is a cross-sectional view of one process step of a manufacturing method according to another embodiment.

[0140] Referring to FIG. 20, the method of manufacturing a display device according to one embodiment differs in that a step of forming a first barrier layer (62) is performed between the step of forming a first flexible material (61) on the upper surface (30t) of the sacrificial layer (30) according to FIG. 12 and the step of forming a sacrificial layer (31) by removing the exposed areas (30b, 30c) of the sacrificial layer (30) according to FIG. 13 (S40).

[0141] To explain more specifically, the selectivity of the first barrier layer (62) and the selectivity of the sacrificial layer (30) for the plasma gas described above in FIG. 13 may be different. That is, like the first flexible material (61), the first barrier layer (62) may hardly react with the plasma gas.

[0142] One side and the other side of the first barrier layer (62) may be aligned along the third direction (DR3) with one side and the other side of the first flexible material (61). In this case, the area to be removed of the sacrificial layer (30) is the same as in the step (S40) of forming the sacrificial layer (31) by removing the exposed area (30b, 30c) of the sacrificial layer (30). The same applies even if one side and the other side of the first barrier layer (62) are formed inwardly from one side and the other side of the first flexible material (61).

[0143] However, if one side and the other side of the first barrier layer (62) protrude outwardly more than one side and the other side of the first flexible material (61), the area to be removed of the sacrificial layer (30) may be smaller than in the step (S40) of forming the sacrificial layer (31) by removing the exposed area (30b, 30c) of the sacrificial layer (30) by the protruding first barrier layer (62).

[0144] When the washing process described above in FIG. 13 is applied, if one side and the other side of the first barrier layer (62) protrude outwardly more than one side and the other side of the first flexible material (61), the area of ​​the sacrificial layer (30) to be removed may be smaller than in the step (S40) of forming the sacrificial layer (31) by removing the exposed area (30b, 30c) of the sacrificial layer (30) by the protruding first barrier layer (62). However, if the cleaning liquid flows down below the protruding part of the first barrier layer (62) and comes into contact with the upper surface (30t) of the sacrificial layer (30) to perform cleaning, the area of ​​the sacrificial layer (30) to be removed may be substantially the same as in the step (S40) of forming the sacrificial layer (31) by removing the exposed area (30b, 30c) of the sacrificial layer (30).

[0145] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0146] 10, 11: Display device 20: Carrier substrate 30: Sacrifice Layer 61: First flexible substance 62: First barrier layer

Claims

Claim 1 A method for manufacturing a display device comprising: preparing a carrier substrate and forming a sacrificial layer on one side of the carrier substrate, the sacrificial layer including a cover area and an exposed area on at least one side of the cover area; forming a first flexible material on one side of the cover area of ​​the sacrificial layer, the first side of which is in contact with the sacrificial layer, thereby exposing the exposed area of ​​the sacrificial layer; and removing the exposed area of ​​the sacrificial layer that is not covered by the first flexible material, wherein after the step of removing the exposed area, the side of the sacrificial layer is aligned with the side of the first flexible material. Claim 2 A method for manufacturing a display device according to claim 1, wherein the step of preparing the carrier substrate further comprises the step of charging one surface of the carrier substrate with a negative charge. Claim 3 In claim 2, the step of charging one surface of the carrier substrate with a negative charge is performed using an atmospheric-pressure plasma device in a method for manufacturing a display device. Claim 4 A method for manufacturing a display device according to claim 3, wherein the step of forming the sacrificial layer comprises the step of repeatedly forming a first coating film charged with a first charge and a second coating film charged with a second charge having a polarity different from the first charge. Claim 5 A method for manufacturing a display device according to claim 4, wherein the first charge is a positive charge and the second charge is a negative charge. Claim 6 A method for manufacturing a display device according to claim 4, wherein the first coating film and the second coating film are each made of graphene oxide (GO). Claim 7 In claim 4, the step of removing the exposed area of ​​the sacrificial layer is performed through the atmospheric pressure plasma device or water washing in a method for manufacturing a display device. Claim 8 delete Claim 9 A method for manufacturing a display device according to claim 1, further comprising the step of forming a first barrier layer on the first flexible material after the step of removing the exposed area of ​​the sacrificial layer. Claim 10 A method for manufacturing a display device according to claim 9, further comprising the step of sequentially forming a second flexible material on the first barrier layer, a circuit driving layer on the second flexible material, a light-emitting layer on the circuit driving layer, and an encapsulation layer on the light-emitting layer after the step of forming a first barrier layer. Claim 11 A method for manufacturing a display device according to claim 1, comprising the step of removing the carrier substrate from the first flexible material after the step of removing the exposed area of ​​the sacrificial layer. Claim 12 A method for manufacturing a display device according to claim 11, wherein, in the step of removing the carrier substrate from the first flexible material, the sacrificial layer remains on one side of the carrier substrate and on one side of the first flexible material, respectively. Claim 13 A method for manufacturing a display device according to claim 12, wherein the thickness of the sacrificial layer remaining on one side of the carrier substrate is smaller than the thickness of the sacrificial layer remaining on one side of the first flexible material. Claim 14 A method for manufacturing a display device according to claim 12, further comprising the step of removing the sacrificial layer remaining on one surface of the carrier substrate after removing the carrier substrate from the first flexible material. Claim 15 In claim 14, the step of removing the sacrificial layer remaining on one surface of the carrier substrate is performed through an atmospheric pressure plasma device or water washing. Claim 16 A method for manufacturing a display device comprising: preparing a carrier substrate and forming a sacrificial layer on one side of the carrier substrate; forming a first flexible material on one side of the sacrificial layer, wherein one side of the first flexible material is in contact with the sacrificial layer and exposes a portion of the sacrificial layer; removing the portion of the sacrificial layer that is exposed and not covered by the first flexible material; removing the carrier substrate from the first flexible material, wherein the sacrificial layer remains on one side of the carrier substrate; and removing the sacrificial layer remaining on one side of the carrier substrate to recycle the carrier substrate. Claim 17 In claim 16, the step of removing the sacrificial layer remaining on one surface of the carrier substrate is performed through an atmospheric pressure plasma device or water washing, in a method for manufacturing a display device. Claim 18 A method for manufacturing a display device according to claim 16, wherein, in the step of removing the carrier substrate from the first flexible material, the sacrificial layer remains on one side of the first flexible material. Claim 19 A method for manufacturing a display device according to claim 18, wherein the thickness of the sacrificial layer remaining on one side of the carrier substrate is smaller than the thickness of the sacrificial layer remaining on one side of the first flexible material. Claim 20 delete

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