Patent ID: 12256627

DETAILED DESCRIPTION

Example embodiments of the inventions will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. Example embodiments of the inventions may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those of ordinary skill in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like reference numerals in the drawings denote like elements, and thus their description will be omitted.

It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Like numbers indicate like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items. Other words used to describe the relationship between elements or layers should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” “on” versus “directly on”).

It will be understood that, although the terms “first”, “second”, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of example embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes” and/or “including,” if used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments of the inventions belong. It will be further understood that terms, such as those defined in commonly-used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

FIG.1is a conceptual diagram illustrating a bonding device according to an embodiment of the invention.

Referring toFIG.1, a bonding device CD according to an embodiment of the invention may include a stage STG, a pressing part UPP1disposed over the stage STG, and a plurality of pressing rollers ROL, which are disposed over the stage STG and are spaced apart from the pressing part UPP1.FIG.1illustrates a cross-section of the bonding device CD, when viewed in a first direction DR1.

The stage STG may include an upper surface US facing the pressing part UPP1.

The upper surface US of the stage STG may include a first plane PL1and first curved surfaces CU1, which are extended from opposite side portions of the first plane PL1in outward and downward directions and have a convexly curved shape.

The first plane PL1may have a plane that is defined by two different directions (e.g., first and second directions DR1and DR2). When viewed in the first direction DR1, each of the first curved surfaces CU1may be a surface that is curved with a specific curvature.

Hereinafter, a direction, which is normal to the plane defined by the first and second direction DR1and DR2, may be defined as a third direction DR3. In the present specification, the expression “when viewed in a plan view” in the present specification will be used to describe a structure viewed in the third direction DR3. Furthermore, directions indicated by terms “upward direction”, “downward direction”, and “vertical direction” may be defined based on the third direction DR3.

The pressing part UPP1may have a flat shape. For example, the pressing part UPP1may have a plane defined by the first and second direction DR1and DR2.

The pressing part UPP1may be configured to reciprocally move in the third direction DR3. For example, the pressing part UPP1may be configured to move toward the stage STG (i.e., in the downward direction) or to move away from the stage STG (e.g., in the upward direction).

Each of the pressing rollers ROL may have a circular shape, when viewed in the first direction DR1. The pressing part UPP1may be disposed between the pressing rollers ROL. Each of the pressing rollers ROL may be configured to rotate about its rotation axis parallel to the first direction DR1. The pressing rollers ROL will be described in more detail with reference to a fabricating method of a display device DD.

FIG.2is a diagram illustrating a display device fabricated by a bonding device.

Referring toFIG.2, a display device DD may be more lengthily extended in the first direction DR1than in the second direction DR2. The display device DD may include a folding region FA and a plurality of non-folding regions NFA1and NFA2. The non-folding regions NFA1and NFA2may include a first non-folding region NFA1and a second non-folding region NFA2. The folding region FA may be disposed between the first non-folding region NFA1and the second non-folding region NFA2. The first non-folding region NFA1, the folding region FA, and the second non-folding region NFA2may be arranged in the first direction DR1.

Although one folding region FA and two non-folding regions NFA1and NFA2are illustrated, the numbers of the folding and non-folding regions are not limited to this example. For example, the display device DD may include three or more non-folding regions and a plurality of folding regions, which are disposed between the non-folding regions.

An upper surface of the display device DD may be defined as a display surface DS and may have a plane (i.e., flat surface) defined by the first and second directions DR1and DR2. Images IM generated by the display device DD may be provided to a user through the display surface DS.

The display surface DS may include a display region DA and a non-display region NDA around or near the display region DA. The display region DA may be used to display an image, and the non-display region NDA may not be used to display an image. The non-display region NDA may be disposed to enclose the display region DA and to define an edge of the display device DD, which is printed with a specific color.

The display device DD may include a flat portion FL, which has a flat shape, and curved surface portions EG, and here, the curved surface portions EG may be curvedly extended from side portions of the flat portion FL, which are opposite to each other in the second direction DR2, in outward and downward directions.

The curved surface portions EG may be curved with a specific curvature in the second direction DR2.

Grooves GR may be defined in side portions of the display device DD, which are opposite to each other in the second direction DR2. The grooves GR may be overlapped with the folding region FA. The grooves GR may be formed defined in the display device DD by partially removing the curved surface portions EG overlapped with the folding region FA.

FIG.3is a diagram illustrating a folding state of the display device ofFIG.2.

Referring toFIG.3, the display device DD may be a foldable display device that can be folded and unfolded. For example, the folding region FA may be bent along a folding axis FX parallel to the first direction DR1, when the display device DD is folded.

In an embodiment, the display device DD may be folded in such an in-folding manner that the first and second non-folding regions NFA1and NFA2face each other and the display surface DS is not exposed to the outside. However, the invention is not limited to this example. For example, the display device DD may be folded along the folding axis FX in an out-folding manner such that the display surface DS is exposed to the outside.

FIG.4is an exploded perspective view illustrating the display device shown inFIG.2.

Referring toFIG.4the display device DD may include a display module DM and a supporting plate PLT, which is disposed below the display module DM. The supporting plate PLT may be provided under the display module DM to support the display module DM. The supporting plate PLT may be more lengthily extended in the first direction DR1than in the second direction DR2.

The supporting plate PLT may be disposed below the display module DM to support the display module DM. The supporting plate PLT may have stiffness higher than the display module DM. The supporting plate PLT may be formed of or include at least one of metallic materials (e.g., stainless steel). For example, the supporting plate PLT may be formed of or include SUS 304, but in an embodiment, the metallic material in the supporting plate PLT may be variously changed. Furthermore, in an embodiment, the supporting plate PLT may be formed of or include at least one of nonmetallic materials (e.g., glass or plastic materials).

A plurality of openings OP may be defined in a region of the supporting plate PLT overlapped with the folding region FA. The openings OP may be formed to penetrate the region of the supporting plate PLT in the third direction DR3.

Since the openings OP are defined in the region of the supporting plate PLT overlapped with the folding region FA, the region of the supporting plate PLT overlapped with the folding region FA may have high flexibility. As a result, the supporting plate PLT may be easily folded along the folding region FA.

The supporting plate PLT may include a first flat portion FL1and first bending portions EG1, which are curvedly extended from opposite side portions of the first flat portion FL1in outward and downward directions. The opposite side portions of the first flat portion FL1may be opposite to each other in the second direction DR2. The first flat portion FL1may have a plane (i.e., a flat surface) defined by the first and second direction DR1and DR2. The first bending portions EG1may have a shape that is curved with a specific curvature, when viewed in the first direction DR1.

First grooves GR1may be defined in opposite side portions of the supporting plate PLT, which are opposite to each other in the second direction DR2. The first grooves GR1may be overlapped with the folding region FA. Portions of the first bending portions EG1, which are overlapped with the folding region FA, may be removed, and thus, the first grooves GR1may be defined in the supporting plate PLT.

The display module DM may include a window WIN and a display panel DP disposed below the window WIN. The window WIN and the display panel DP may be more lengthily extended in the first direction DR1than in the second direction DR2. The display panel DP may be used to display an image. The window WIN may protect the display panel DP from an external scratch or impact. The supporting plate PLT may be disposed below the display panel DP to support the display panel DP.

In an embodiment, the display panel DP may be a light-emitting type display panel, but the invention is not limited to a specific type of the display panel DP. For example, the display panel DP may be an organic light-emitting display panel or a quantum dot light-emitting display panel. A light-emitting layer of the organic light-emitting display panel DP may be formed of or include an organic light-emitting material. A light-emitting layer of the quantum dot light-emitting display panel may include quantum dots and/or quantum rods.

The display panel DP may be a flexible display panel. For example, the display panel DP may include a plurality of electronic devices disposed on a flexible substrate.

The display panel DP may include a second flat portion FL2and second bending portions EG2, which are curvedly extended from opposite side portions of the second flat portion FL2in outward and downward directions. The opposite side portions of the second flat portion FL2may be opposite to each other in the second direction DR2. The second flat portion FL2may have a plane (i.e., a flat surface) defined by the first and second direction DR1and DR2. The second bending portions EG2may have a shape that is curved with a specific curvature, when viewed in the first direction DR1.

Second grooves GR2may be defined in opposite side portions of the display panel DP, which are opposite to each other in the second direction DR2. The second grooves GR2may be overlapped with the folding region FA. Portions of the second bending portions EG2, which are overlapped with the folding region FA, may be removed, and thus, the second grooves GR2may be defined in the display panel DP.

The bonding device CD ofFIG.1may be used to bond the display panel DP to the supporting plate PLT. The bonding operation will be described in more detail with reference toFIGS.6A to6I.

The window WIN may be disposed on the display panel DP. The window WIN may have an optically transparent property. The window WIN may be formed of or include glass. However, the invention is not limited to this example, and in an embodiment, the window WIN may include a synthetic resin film.

The window WIN may have a multi-layered structure or a single-layered structure. For example, the window WIN may include a plurality of synthetic resin films, which are combined to each other by an adhesive material, or a glass substrate and a synthetic resin film, which are combined to each other by an adhesive material.

The window WIN may include a third flat portion FL3and third bending portions EG3, which are curvedly extended from opposite side portions of the third flat portion FL3in outward and downward directions. The opposite side portions of the third flat portion FL3may be opposite to each other in the second direction DR2. The third flat portion FL3may have a plane defined by the first and second direction DR1and DR2. The third bending portions EG3may have a shape that is curved with a specific curvature, when viewed in the first direction DR1.

Third grooves GR3may be defined in opposite side portions of the window WIN, which are opposite to each other in the second direction DR2. The third grooves GR3may be overlapped with the folding region FA. Portions of the third bending portions EG3, which are overlapped with the folding region FA, may be removed, and thus, the third grooves GR3may be defined in the window WIN.

The bonding device CD ofFIG.1may be used to bond the window WIN to the display panel DP. The bonding process will be described in more detail with reference toFIGS.6A to6I.

FIG.5is a sectional view exemplarily illustrating a display panel.

Referring toFIG.5, the display panel DP may include a substrate SUB, a circuit device layer DP-CL disposed on the substrate SUB, a display element layer DP-OLED disposed on the circuit device layer DP-CL, and a thin encapsulation layer TFE disposed on the display element layer DP-OLED.

The substrate SUB may include the display region DA and the non-display region NDA around the display region DA. The substrate SUB may be formed of or include at least one of glass or flexible plastic materials (e.g., poly imide (“PI”)). The display element layer DP-OLED may be disposed on the display region DA.

The circuit device layer DP-CL and the display element layer DP-OLED may be provided to have a plurality of pixels. Each of the pixels may include a transistor, which is disposed in the circuit device layer DP-CL, and a light-emitting device, which is disposed in the display element layer DP-OLED and is connected to the transistor.

The thin encapsulation layer TFE may be disposed on the circuit device layer DP-CL to cover the display element layer DP-OLED. The thin encapsulation layer TFE may protect pixels from moisture, oxygen, and external contamination materials.

FIGS.6A to6Iare diagrams illustrating a method of bonding a display device using the bonding device ofFIG.1.

Referring toFIG.6A, when a bonding process of the display device DD using a bonding device CD1is performed, a first layer LY1and a second layer LY2may be disposed between the stage STG and the pressing part UPP1. The first layer LY1may be disposed on the stage STG, the second layer LY2may be disposed over the first layer LY1, and the pressing part UPP1may be disposed on the second layer LY2. The second layer LY2may face the first layer LY1.

The first layer LY1may be substantially the supporting plate PLT ofFIG.4. Thus, similar to the supporting plate PLT, the first layer LY1may include the first flat portion FL1and the first bending portions EG1, which are curvedly extended from the opposite side portions of the first flat portion FL1in outward and downward directions. The first bending portions EG1may be bent with a specific curvature and may be placed on the upper surface US of the stage STG, when viewed in the first direction DR1. A lower surface of the first layer LY1may have the same shape as the upper surface of the stage STG.

The first flat portion FL1may be disposed to be in contact with the first plane PL1of the stage STG. The first bending portions EG1may be disposed to be in contact with the first curved surfaces CU1, respectively. Lower surfaces of the first bending portions EG1may be bent to have the same curvature as the first curved surfaces CU1.

The second layer LY2may be substantially the display panel DP ofFIG.4. Thus, the second layer LY2may include the second flat portion FL2and the second bending portions EG2, which are curvedly extended from the opposite side portions of the second flat portion FL2in outward and downward directions, like the display panel DP.

The second flat portion FL2may be disposed below a lower surface of the pressing part UPP1. The second flat portion FL2may be disposed to be in contact with the lower surface of the pressing part UPP1. The second bending portions EG2may be bent with a specific curvature and may be placed below the pressing part UPP1, when viewed in the first direction DR1. The second bending portions EG2may be disposed outside the pressing part UPP1such that they are not in contact with the lower surface of the pressing part UPP1. The first and second bending portions EG1and EG2may be placed between the stage STG and the pressing part UPP1, in a state bent with a specific curvature.

A curvature CR2_1of a lower surface of each of the second bending portions EG2may be smaller than a curvature CR1of an upper surface of each of the first bending portions EG1. This structure will be described in more detail with reference toFIG.6C.

Referring toFIG.6B, the pressing part UPP1may be moved toward the stage STG or in the downward direction to bond the second layer LY2to the first layer LY1.

The second flat portion FL2may be bonded to the first flat portion FL1by the pressing part UPP1moving in the downward direction. Although not shown, an adhesive layer may be disposed between the first and second layers LY1and LY2to attach the second layer LY2to the first layer LY1. The adhesive layer may be attached to an upper surface of the first layer LY1in advance, or the adhesive layer, which is attached to a lower surface of the second layer LY2, may be disposed between the first and second layers LY1and LY2. The second bending portions EG2and the first bending portions EG1may be spaced apart from each other, when the second flat portion FL2is bonded to the first flat portion FL1.

The second bending portions EG2and the first bending portions EG1may be spaced apart from each other, because the curvature CR2_1of the lower surface of the second bending portion EG2is smaller than the curvature CR1of the upper surface of the first bending portion EG1when the second flat portion FL2is bonded to the first flat portion FL1.

FIG.6Cis an enlarged view of the first and second bending portions shown inFIG.6B.

Referring toFIG.6C, the curvature CR2_1of the lower surface of the second bending portion EG2may be smaller than the curvature CR1of the upper surface of the first bending portion EG1. The lower surface of the second bending portion EG2may have a concavely curved surface. The upper surface of the first bending portion EG1may have a convexly curved surface.

The curvature radius R2of the lower surface of the second bending portion EG2may be set to a value that is larger than a sum of a curvature radius R1of a lower surface of the first bending portion EG1and a thickness TH1of the first bending portion EG1.

Thus, the curvature radius R2of the lower surface of the second bending portion EG2may be greater than the curvature radius R1of the lower surface of the first bending portion EG1. The thickness TH1may be defined as a length measured in a direction perpendicular to a tangential surface of the curved upper surface of the first bending portion EG1. For example, the thickness TH1may be a value measured in the direction normal to the upper surface of the first bending portion EG1.

The curvature and the curvature radius are concepts that are opposite to each other. Thus, the curvature CR2_1of the lower surface of the second bending portion EG2may be smaller than the curvature CR1of the upper surface of the first bending portion EG1. In other words, the second bending portion EG2may be bent less than the first bending portion EG1, and the first bending portion EG1may be bent more than the second bending portion EG2. Due to this structure, the second bending portion EG2may have a curvature smaller than a curvature of the first bending portion EG1, and thus, the second bending portions EG2may be spaced apart from the first bending portions EG1, when the first flat portion FL1is bonded to the second flat portion FL2.

Referring toFIGS.6D and6E, when the first and second flat portions FL1and FL2are bonded to each other, the pressing rollers ROL may be placed on the second bending portions EG2. The pressing rollers ROL may press the second bending portions EG2toward the first bending portions EG1. The second bending portions EG2may be pressed by the pressing rollers ROL and may be bonded to the first bending portions EG1. For example, in the case where the second bending portions EG2are pressed by the pressing rollers ROL, the second bending portions EG2may be moved toward the first bending portions EG1and may be bonded to the first bending portions EG1.

If the second bending portions EG2have the same curvature as the first bending portions EG1before pressed by the pressing rollers ROL, the second bending portions EG2may be in contact with the first bending portions EG1in advance before the bonding of the first and second flat portions FL1and FL2. For example, lower portions of the second bending portions EG2may be previously bonded to the first bending portions EG1before the bonding of the first and second flat portions FL1and FL2.

In this case, the second flat portion FL2may not be normally in contact with the first flat portion FL1, or portions of the second bending portions EG2adjacent to the second flat portion FL2may not be normally in contact with the first bending portions EG1. As a result, a bonding failure may occur; for example, an air layer may be formed between the first and second layers LY1and LY2.

According to an embodiment of the invention, the first and second flat portions FL1and FL2may be previously bonded to each other, and then, the first and second bending portions EG1and EG2may be bonded to each other. That is, the first and second flat portions FL1and FL2and the first and second bending portions EG1and EG2may be sequentially bonded to each other, and in this case, the afore-described bonding failure may not occur.

Referring toFIG.6F, in a bonding process of the display device DD using the stage STG, a third layer LY3may be further disposed between the stage STG and the pressing part UPP1. The third layer LY3may be provided on the second layer LY2after the second layer LY2is bonded on the first layer LY1. The pressing part UPP1may be disposed on the third layer LY3. The third layer LY3may face the second layer LY2.

The third layer LY3may be substantially the window WIN ofFIG.4. Thus, the third layer LY3may include the third flat portion FL3and the third bending portions EG3, which are curvedly extended from the opposite side portions of the third flat portion FL3in outward and downward directions, like the window WIN.

The third flat portion FL3may be disposed below the lower surface of the pressing part UPP1. The third flat portion FL3may be disposed to be in contact with the lower surface of the pressing part UPP1. The third bending portions EG3may be bent with a specific curvature and may be placed below the pressing part UPP1, when viewed in the first direction DR1. The third bending portions EG3may be placed between the stage STG and the pressing part UPP1, in a state bent with a specific curvature.

A curvature CR3of a lower surface of the third bending portions EG3may be smaller than a curvature CR2_2of an upper surface of the second bending portion EG2, which is a curvature of the upper surface of the second bending portion EG2after pressed by the pressing rollers ROL. This structure will be described in more detail with reference toFIG.6H.

Referring toFIG.6G, the pressing part UPP1may be moved toward the stage STG or in the downward direction to bond the third layer LY3to the second layer LY2.

The third flat portion FL3may be bonded to the second flat portion FL2by the pressing part UPP1moving in the downward direction. Although not shown, an adhesive layer may be disposed between the second and third layers LY2and LY3to attach the third layer LY3to the second layer LY2. The adhesive layer may be attached to an upper surface of the second layer LY2in advance, or the adhesive layer, which is attached to a lower surface of the third layer LY3, may be disposed between the second and third layers LY2and LY3. When the third flat portion FL3is bonded to the second flat portion FL2, the third bending portions EG3may be spaced apart from the second bending portions EG2.

The third bending portions EG3and the second bending portions EG2may be spaced apart from each other, because the curvature CR3of the lower surface of the third bending portion EG3is smaller than the curvature CR2_2of the upper surface of the second bending portion EG2when the third flat portion FL3is bonded to the second flat portion FL2.

FIG.6His an enlarged view of the first, second, and third bending portions shown inFIG.6G.

Referring toFIG.6H, the curvature CR3of the lower surface of the third bending portion EG3may be smaller than the curvature CR2_2of the upper surface of the second bending portion EG2. The lower surface of the third bending portion EG3may have a concavely curved surface. The upper surface of the second bending portion EG2may have a convexly curved surface.

A curvature radius R3of the lower surface of the third bending portion EG3may be set to a value that is larger than a sum of a curvature radius R2of the lower surface of the second bending portion EG2and a thickness TH2of the second bending portion EG2.

Thus, the curvature radius R3of the lower surface of the third bending portion EG3may be larger than the curvature radius R2of the lower surface of the second bending portion EG2. The thickness TH2may be defined as a length measured in a direction perpendicular to a tangential surface of the curved upper surface of the second bending portion EG2. For example, the thickness TH2may be a value measured in the direction normal to the upper surface of the second bending portion EG2.

The curvature and the curvature radius are concepts that are opposite to each other. Thus, the curvature CR3of the lower surface of the third bending portion EG3may be smaller than the curvature CR2_2of the upper surface of the second bending portion EG2. In other words, the third bending portion EG3may be bent less than the second bending portion EG2, and the second bending portion EG2may be bent more than the third bending portion EG3.

Due to this structure, the third bending portion EG3may have a curvature smaller than a curvature of the second bending portion EG2, and thus, the third bending portions EG3may be spaced apart from the second bending portions EG2, when the second flat portion FL2is bonded to the third flat portion FL3.

Referring toFIG.6I, if the second and third flat portions FL2and FL3are bonded, the pressing rollers ROL may be disposed on the third bending portions EG3. The pressing rollers ROL may press the third bending portions EG3toward the second bending portions EG2. The third bending portions EG3may be pressed by the pressing rollers ROL and may be bonded to the second bending portions EG2. For example, in the case where the third bending portions EG3are pressed by the pressing rollers ROL, the third bending portions EG3may be moved toward the second bending portions EG2and may be bonded to the second bending portions EG2.

The process described with reference toFIGS.6A to6Emay be repeated to bond the third layer LY3to the second layer LY2.

If the third bending portions EG3have the same curvature as the second bending portions EG2before pressed by the pressing rollers ROL, the third bending portions EG3may be in contact with the second bending portions EG2in advance before the bonding of the second and third flat portions FL2and FL3. For example, lower portions of the third bending portions EG3may be previously bonded to the second bending portions EG2before pressed by the pressing rollers ROL.

In this case, the third flat portion FL3may not be normally in contact with the second flat portion FL2, or portions of the third bending portions EG3adjacent to the third flat portion FL3may not be normally in contact with the second bending portions EG2. As a result, a bonding failure may occur; for example, an air layer may be formed between the second and third layers LY2and LY3.

According to an embodiment of the invention, the second and third flat portions FL2and FL3may be previously bonded to each other, and then, the second and third bending portions EG2and EG3may be bonded to each other. Thus, the second and third flat portions FL2and FL3and the second and third bending portions EG2and EG3may be sequentially bonded to each other, and in this case, the afore-described bonding failure may not occur.

FIG.7is a diagram illustrating a structure of a bonding device according to another embodiment of the invention.

Referring toFIG.7, a bonding device CD2may include the stage STG and a pressing part UPP2, which is disposed over the stage STG.FIG.7illustrates a cross-section of the bonding device CD2, when viewed in the first direction DR1. For concise description, an element previously described with reference toFIG.1may be identified by the same reference number without repeating an overlapping description thereof.

The pressing part UPP2may include a guide film GF and fastening parts FP, which are connected to opposite side portions of the guide film GF. The fastening parts FP may be disposed to be symmetric with respect to each other in the second direction DR2. The guide film GF and the fastening parts FP may be disposed over the stage STG.

The guide film GF may include a flat portion GF_PL, which is provided to face the first plane PL1of the stage STG, and bending portions GF_CU, which are extended from opposite side portions of the flat portion GF_PL in outward and downward directions and have a curved shape. The flat portion GF_PL may have a plane (i.e., flat surface) defined by the first and second directions DR1and DR2. The bending portions GF_CU may have a shape that is curved with a specific curvature, when viewed in the first direction DR1.

The bending portions GF_CU may have a curvature different from the first curved surfaces CU1of the stage STG. For example, the bending portions GF_CU may have a curvature smaller than a curvature of the first curved surfaces CU1. In other words, the bending portions GF_CU may be bent less than the first curved surfaces CU1.

FIG.8A to8Dare diagrams illustrating a method of bonding a display device using the bonding device ofFIG.7.

Referring toFIG.8A, when a bonding process of the display device DD using the bonding device CD2is performed, the first and second layers LY1and LY2may be disposed between the stage STG and the guide film GF. The first layer LY1may be disposed on the stage STG, the second layer LY2may be disposed over the first layer LY1, and the guide film GF may be disposed on the second layer LY2. The second layer LY2may face the first layer LY1.

The first layer LY1may be substantially the supporting plate PLT ofFIG.6A. Thus, the first layer LY1may include the first flat portion FL1and the first bending portions EG1, like the first layer LY1ofFIG.6A.

The second layer LY2may be substantially the display panel DP ofFIG.6A. Thus, the second layer LY2may include the second flat portion FL2and the second bending portions EG2, like the second layer LY2ofFIG.6A.

The second flat portion FL2may be disposed below the flat portion GF_PL of the guide film GF. The second flat portion FL2may be disposed to be in contact with a lower surface of the flat portion GF_PL of the guide film GF.

The second bending portions EG2may be bent with specific curvatures and may be placed below a lower surface of the bending portion GF_CU of the guide film GF, when viewed in the first direction DR1. The second bending portions EG2and the bending portions GF_CU may have a curved shape of the same curvature. For example, the upper surface of the second bending portion EG2and the lower surface of the bending portion GF_CU may have the same curvature.

The first and second bending portions EG1and EG2may be disposed between the stage STG and the guide film GF, in a state bent with a specific curvature.

In the embodiment ofFIG.8A, the curvature CR2_1of the lower surface of the second bending portion EG2may be smaller than the curvature CR1of the upper surface of the first bending portion EG1, as described inFIGS.6A to6C.

Referring toFIG.8B, the guide film GF may be moved toward the stage STG or in the downward direction to bond the second layer LY2to the first layer LY1.

The second flat portion FL2may be bonded to the first flat portion FL1by the guide film GF moving in the downward direction. When the second flat portion FL2is bonded to the first flat portion FL1, the second bending portions EG2may be spaced apart from the first bending portions EG1.

The second bending portions EG2and the first bending portions EG1may be spaced apart from each other, because the curvature CR2_1of the lower surface of the second bending portion EG2is smaller than the curvature CR1of the upper surface of the first bending portion EG1when the second flat portion FL2is bonded to the first flat portion FL1.

The fastening parts FP may be disposed at a level lower than the first and second layers LY1and LY2. The fastening parts FP may be disposed on side surfaces of the stage STG, which are opposite to each other in the second direction DR2.

Referring toFIGS.8C and8D, the fastening parts FP may be moved toward a side surface of the stage STG, after the bonding of the first and second flat portions FL1and FL2using the guide film GF moving in the downward direction. As a result of the motion of the fastening parts FP toward the side surface of the stage STG, the second bending portions EG2may be bonded to the first bending portions EG1. For example, the fastening parts FP may be moved toward the stage STG to reduce a distance therebetween, and in this case, the fastening parts FP may exert a pressure on the second bending portions EG2. The second bending portions EG2may be moved toward the first bending portions EG1by such a pressure, and as a result, the second bending portions EG2may be bonded to the first bending portions EG1.

According to this sequential bonding process using the bonding device CD2, the second flat portion FL2may be previously bonded to the first flat portion FL1, and then, the second bending portions EG2may be bonded to the first bending portions EG1. Thus, the afore-described bonding failure may not occur.

Although not shown, the third layer LY3may be bonded to the second layer LY2in a similar manner to the process described with reference toFIG.6F to6I. For example, the process ofFIGS.8A to8Dmay be repeated to attach the third layer LY3to the second layer LY2. After the bonding of the second layer LY2to the first layer LY1, the third layer LY3may be disposed on the second layer LY2. The third layer LY3may be disposed below the guide film GF. The guide film GF may be moved in the downward direction such that the third layer LY3is bonded to the second layer LY2in the same manner as the method of bonding the second layer LY2to the first layer LY1.

FIG.9is a diagram illustrating a structure of a bonding device according to still another embodiment of the invention.

Referring toFIG.9, a bonding device CD3may include the stage STG and a pressing part UPP3, which is disposed over the stage STG.FIG.9illustrates a cross-section of the bonding device CD3, when viewed in the first direction DR1. For concise description, an element previously described with reference toFIG.1may be identified by the same reference number without repeating an overlapping description thereof.

The pressing part UPP3may be formed of or include a material having an elastic property. For example, the pressing part UPP3may be formed of or include an elastic material (e.g., rubber), but the invention is not limited to this example.

The pressing part UPP3may include a recessed portion RES facing the upper surface US of the stage STG. The recessed portion RES may include a second plane PL2facing the first plane PL1. The second plane PL2may have a plane (i.e., a flat surface) defined by the first and second directions DR1and DR2. The second plane PL2may be disposed on the first plane PL1. The recessed portion RES may include second curved surfaces CU2, which are provided to face the first curved surfaces CU1and are extended downward from opposite side portions of the second plane PL2to have a concavely curved shape. The second curved surfaces CU2may have a shape that is curved with a specific curvature, when viewed in the first direction DR1.

The second curved surfaces CU2may have a curvature different from the first curved surfaces CU1of the stage STG. For example, the second curved surfaces CU2may have a curvature smaller than a curvature of the first curved surfaces CU1. That is, the second curved surfaces CU2may be bent less than the first curved surfaces CU1.

Air injection holes AR, which are recessed toward the second curved surfaces CU2, may be defined in an outer surface of the pressing part UPP3. The air injection holes AR may be extended along the second curved surfaces CU2. The air injection holes AR may not be disposed on the second plane PL2. In the case where the air is injected or supplied into the air injection holes AR, the second curved surfaces CU2may be expanded.

FIG.10A to10Dare diagrams illustrating a method of bonding a display device using the bonding device ofFIG.9.

Referring toFIG.10A, when a bonding process of the display device DD using the bonding device CD3is performed, the first and second layers LY1and LY2may be disposed between the stage STG and the pressing part UPP3. The first layer LY1may be disposed on the stage STG, the second layer LY2may be disposed over the first layer LY1, and the pressing part UPP3may be disposed on the second layer LY2. The second layer LY2may face the first layer LY1.

The first layer LY1may be substantially the supporting plate PLT ofFIG.6A. Thus, the first layer LY1may include the first flat portion FL1and the first bending portions EG1, like the first layer LY1ofFIG.6A.

The second layer LY2may be substantially the display panel DP ofFIG.6A. Thus, the second layer LY2may include the second flat portion FL2and the second bending portions EG2, like the second layer LY2ofFIG.6A.

The second flat portion FL2may be disposed below the second plane PL2of the pressing part UPP3. The second flat portion FL2may be disposed to be in contact with a lower surface of the second plane PL2of the pressing part UPP3.

The second bending portions EG2may be bent with specific curvatures and may be placed below the second curved surfaces CU2of the pressing part UPP3, when viewed in the first direction DR1. The second bending portions EG2and the second curved surfaces CU2may have a curved shape of the same curvature. For example, the upper surface of the second bending portion EG2and the lower surface of the second curved surface CU2may have the same curvature.

The first and second bending portions EG1and EG2may be disposed between the stage STG and the pressing part UPP3, in a state bent with a specific curvature.

In the embodiment ofFIG.10A, the curvature CR2_1of the lower surface of the second bending portion EG2may be smaller than the curvature CR1of the upper surface of the first bending portion EG1, as described inFIGS.6A to6C.

Referring toFIG.10B, the pressing part UPP3may be moved toward the stage STG or in the downward direction to bond the second layer LY2to the first layer LY1.

The second flat portion FL2may be bonded to the first flat portion FL1by the pressing part UPP3moving in the downward direction. When the second flat portion FL2is bonded to the first flat portion FL1, the second bending portions EG2may be spaced apart from the first bending portions EG1.

The second bending portions EG2and the first bending portions EG1may be spaced apart from each other, because the curvature CR2_1of the lower surface of the second bending portion EG2is smaller than the curvature CR1of the upper surface of the first bending portion EG1when the second flat portion FL2is bonded to the first flat portion FL1.

Referring toFIGS.10C and10D, the air may be injected into the air injection holes AR of the pressing part UPP3, after the bonding of the first and second flat portions FL1and FL2using the pressing part UPP3moving in the downward direction. As a result of the injection of the air, the second curved surfaces CU2may be expanded and may be moved toward the stage STG. Since the second curved surfaces CU2are moved toward the first curved surfaces CU1of the stage STG, the second bending portions EG2may be bonded to the first bending portions EG1. Since the second curved surfaces CU2are moved toward the first curved surfaces CU1of the stage STG, the second curved surfaces CU2may exert a pressure on the second bending portions EG2. The second bending portions EG2may be moved toward the first bending portions EG1by such a pressure, and as a result, the second bending portions EG2may be bonded to the first bending portions EG1.

According to this sequential bonding process using the bonding device CD3, the second flat portion FL2may be previously bonded to the first flat portion FL1, and then, the second bending portions EG2may be bonded to the first bending portions EG1. Thus, the afore-described bonding failure may not occur.

Although not shown, the third layer LY3may be bonded to the second layer LY2in a similar manner to the process described with reference toFIG.6F to6I. For example, the process ofFIGS.10A to10Dmay be repeated to attach the third layer LY3to the second layer LY2. After the bonding of the second layer LY2to the first layer LY1, the third layer LY3may be disposed on the second layer LY2. The third layer LY3may be disposed below the pressing part UPP3. The pressing part UPP3may be moved in the downward direction such that the third layer LY3is bonded to the second layer LY2in the same manner as the method of bonding the second layer LY2to the first layer LY1.

In a bonding device according to an embodiment of the invention and a method of fabricating a display device using the same, a bonding process may be first performed on flat portions of each layer and then on bending portions of the layer. Accordingly, it may be possible to prevent a bonding failure from occurring in the layers.

While example embodiments of the invention have been particularly shown and described, it will be understood by one of ordinary skill in the art that variations in form and detail may be made therein without departing from the spirit and scope of the attached claims.