Patent Publication Number: US-2016247981-A1

Title: Display device and manufacturing method of the same

Description:
This application claims the benefit of Taiwan application Serial No. 104106026, filed Feb. 25, 2015, the subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure is related in general to a display device and a manufacturing method thereof, and particularly to a display device having excellent durability and stability and a manufacturing method thereof. 
     2. Description of the Related Art 
     In the mass production of display devices, display elements are usually disposed on a mother board, and after components are assembled, a cutting process is performed on the mother board for manufacturing the display devices. In the cutting process by cutting knives, cracks may occur and remain on where the cutting process is performed, and such cracks may cause instability issue of the structures of the display devices. 
     In order to solve this issue, the industry has applied chemical etching processes on the cutting processes. However, cutting processes performed by chemical etching processes may raise other different issues, resulting in poor stability or short lives of the display devices. 
     SUMMARY OF THE INVENTION 
     The present disclosure is directed to a display device and a manufacturing method thereof. In the embodiments, the etching stop layer surrounds the encapsulation layer and contacts the first substrate and the second substrate, such that the encapsulation layer can be effectively protected from the damage of the chemical etching solution in the manufacturing process, the encapsulation layer can achieve the effect of excellent resistance to water and oxygen, and the life of the display device can be further extended. 
     According to an embodiment of the present disclosure, a display device is provided. The display device includes a first substrate, a second substrate, a display element, an encapsulation layer, and an etching stop layer. The display element is located between the first substrate and the second substrate. The encapsulation layer surrounds the display element and contacts the first substrate and the second substrate. The etching stop layer surrounds the encapsulation layer and contacts the first substrate and the second substrate. The etching stop layer has at least a sidewall having an arc-shaped protruded surface. 
     According to another embodiment of the present disclosure, a manufacturing method of a display device is provided. The manufacturing method includes the following steps: providing a first base; disposing a plurality of display elements on the first base; disposing a plurality of encapsulation layers on the first base, each of the encapsulation layers surrounding each of the display elements; disposing a plurality of etching stop layers on the first base, wherein each of the etching stop layers surrounds each of the encapsulation layers, and the etching stop layers are separated from each other by a plurality of gaps; providing a second base to be assembled to the first base, wherein the encapsulation layers and the etching stop layers contact the first base and the second base; and performing a chemical etching process on the first base and the second base along the gaps between the etching stop layers for forming a plurality of the display devices separated from each other, wherein each of the display devices comprises one of the display elements, one of the encapsulation layers, and one of the etching stop layers. 
     The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment(s). The following description is made with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a top view of a display device according to an embodiment of the present disclosure; 
         FIG. 1B  shows a cross-sectional view along the section line  1 B- 1 B′ in  FIG. 1A ; 
         FIG. 1C  shows a cross-sectional view of a display device according to another embodiment of the present disclosure; 
         FIG. 1D  shows a cross-sectional view of a display device according to a further embodiment of the present disclosure; 
         FIGS. 2A-2D  illustrate a manufacturing method of a display device according to an embodiment of the present disclosure; 
         FIGS. 3A-3D  illustrate a manufacturing method of a display device according to another embodiment of the present disclosure; 
         FIGS. 4A-4D  illustrate a manufacturing method of a display device according to a further embodiment of the present disclosure; and 
         FIGS. 5A-5C  illustrate a manufacturing method of a display device according to a still further embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     According to the embodiments of the present disclosure, a display device and a manufacturing method thereof are provided. In the embodiments, the etching stop layer surrounds the encapsulation layer and contacts the first substrate and the second substrate, such that the encapsulation layer can be effectively protected from the damage of the chemical etching solution in the manufacturing process, the encapsulation layer can achieve the effect of excellent resistance to water and oxygen, and the life of the display device can be further extended. The embodiments are described in details with reference to the accompanying drawings. However, the embodiments are for exemplification only, not for limiting the scope of protection of the disclosure. Besides, some of the secondary elements are omitted in the drawings accompanying the following embodiments to highlight the technical features of the invention. 
       FIG. 1A  shows a top view of a display device according to an embodiment of the present disclosure, and  FIG. 1B  shows a cross-sectional view along the section line  1 B- 1 B′ in  FIG. 1A . As shown in  FIGS. 1A-1B , the display device  100  includes a first substrate  110 , a second substrate  120 , a display element  130 , an encapsulation layer  140 , and an etching stop layer  150 . The second substrate  120  is assembled to the first substrate  110 . The display element  130  is located between the first substrate  110  and the second substrate  120 . The encapsulation layer  140  surrounds the display element  130 , and the encapsulation layer  140  contacts the first substrate  110  and the second substrate  120 . The etching stop layer  150  surrounds the encapsulation layer  140 , and the etching stop layer  150  contacts the first substrate  110  and the second substrate  120 . The etching stop layer  150  has at least a sidewall  150   s  having an arc-shaped protruded surface. In the embodiment, the display element  130  may include, for example, a liquid crystal layer, an organic light emitting diode layer, or an inorganic light emitting diode layer. 
     In the embodiment, the encapsulation layer  140  surrounds the display element  130  and contacts the first substrate  110  and the second substrate  120 , such that the display element  130  can be sealed between the first substrate  110  and the second substrate  120 ; accordingly, the damage of water and oxygen from external environment can be effectively blocked, and the life of the display device  100  can be further extended. In the embodiment, the encapsulation layer  140  may include, for example, frit, UV curable resin or thermosetting resin. However, the selections of the encapsulation layer  140  may depend on actual needs and are not limited to the above-mentioned examples. 
     In the embodiment, the etching stop layer  150  surrounds the encapsulation layer  140  and contacts the first substrate  110  and the second substrate  120 , such that the encapsulation layer  140  can be sealed between the first substrate  110  and the second substrate  120 . Accordingly, the etching stop layer  150  can effectively protect the encapsulation layer  140  from the damage of the chemical etching solution in the manufacturing process, the consistency of the structure of the encapsulation layer  140  as well as the sealing ability of the encapsulation layer  140  regarding resistance to water and oxygen can be maintained, and hence the encapsulation layer  140  can achieve the effect of excellent resistance to water and oxygen, the durability and stability of the display device  100  can be increased, and the life of the display device  100  can be further extended. 
     As shown in  FIGS. 1A-1B , in the embodiment, the etching stop layer  150  directly contacts the encapsulation layer  140 . As such, the size of the border area around the display surface can be reduced, and hence the area of the display device  100  is further reduced. 
     In the present embodiment, as shown in  FIG. 1B , the etching stop layer  150  is located between the first substrate  110  and the second substrate  120 . That is, the etching stop layer  150  is fully located in a space between the first substrate  110  and the second substrate  120 . The etching stop layer  150  includes at least one sidewall  150   s  having an arc-shaped protruded surface. 
     In the embodiment, the etching stop layer  150  includes at least two sidewalls  150   s  each having an arc-shaped protruded surface. The outer edge  110   s  of the first substrate  110  and the outer edge  120   s  of the second substrate  120  are substantially aligned with each other and define a boundary of the space wherein the etching stop layer  150  is located. And the arc-shaped protruded surface of the sidewall  150   s  is located within the space. 
     In the embodiment, the etching stop layer  150  may include such as a thermoplastic resin, a thermosetting resin, and/or rubber. The thermoplastic resin may be, for example, polyvinyl chloride (PVC) resin, acrylonitrile-butadiene-styrene (ABS) resin, polyethylene (PE) resin, polypropylene (PP) resin, poly(methyl methacrylate) (PMMA) resin, polytetrafluoroethene (PTFE) resin, ethylene tetrafluoroethylene (ETFE) resin, polycarbonate (PC) resin, polymethylpentene (PMP) resin, or any combination thereof. The thermosetting resin may be, for example, paraformaldehyde (PF) resin, epoxide (EP) resin, or a combination thereof. The rubber may be, for example, fluoroelastomer polymer (FPM). In some examples, when the chemical etching solution used in the manufacturing process is a hydrofluoric acid series etching solution for etching glass materials, and the material of the etching stop layer  150  is preferably selected from a material which is not etched by a hydrofluoric acid series etching solution, such as polytetrafluoroethene (PTFE) resin. However, the selections of the etching stop layer  150  may depend on actual needs and are not limited to the above-mentioned example. 
     In some embodiments, the first substrate  110  and the second substrate  120  are such as glass substrates. 
     In some embodiments, at least one of the first substrate  110  and the second substrate  120  may be a flexible substrate. In one embodiment, the first substrate  110  is such as a glass substrate, and the second substrate  120  is such as a flexible substrate made of an organic material. In another embodiment, the second substrate  120  is such as a glass substrate, and the first substrate  110  is such as a flexible substrate made of an organic material. In another embodiment, the first substrate  110  and the second substrate  120  are such as flexible substrates. 
     In some embodiments, at least one of the first substrate  110  and the second substrate  120  includes an anti-etching material; that is, at least one of the first substrate  110  and the second substrate  120  may be an anti-etching substrate. In one embodiment, the first substrate  110  is such as a glass substrate, and the second substrate  120  is an anti-etching substrate. In another embodiment, the second substrate  120  is such as a glass substrate, and the first substrate  110  is an anti-etching substrate. In another embodiment, the first substrate  110  and the second substrate  120  are such as anti-etching substrates. 
       FIG. 10  shows a cross-sectional view of a display device according to another embodiment of the present disclosure. The elements in the present embodiment sharing similar or the same labels with those in the previous embodiment are similar or the same elements, and the description of which is omitted. 
     As shown in  FIG. 1C , in the embodiment, in the display device  200 , the etching stop layer  150  is partially located in a space between the first substrate  110  and the second substrate  120 . The outer edge  110   s  of the first substrate  110  and the outer edge  120   s  of the second substrate  120  are substantially aligned with each other and define a boundary of the space wherein the etching stop layer  150  is located. And the arc-shaped protruded surface of the sidewall  150   s  is located outside the space. 
       FIG. 1D  shows a cross-sectional view of a display device according to a further embodiment of the present disclosure. The elements in the present embodiment sharing similar or the same labels with those in the previous embodiments are similar or the same elements, and the description of which is omitted. 
     In the present embodiment, in the display device  300 , the encapsulation layer  140  is such as a frit layer. As shown in  FIG. 1D , the etching stop layer  150  and the encapsulation layer  140  may be separated by a spacing S 1 , and the encapsulation layer  140  and the display element  130  may be separated by a spacing S 2  as well. Since a high temperature heating treatment is required in the manufacturing process of the frit layer (encapsulation layer  140 ), the spacing S 1  between the etching stop layer  150  and the encapsulation layer  140  can prevent the damage of the etching stop layer  150  from the high temperature manufacturing process of the frit layer (encapsulation layer  140 ). Moreover, the spacing S 2  between the encapsulation layer  140  and the display element  130  can prevent the damage of the display element  130  from the high temperature manufacturing process of the frit layer (encapsulation layer  140 ) as well. 
     In the present embodiment, as shown in  FIG. 1D , the two opposite sidewall  150   s   1  and sidewall  150   s   2  both have arc-shaped protruded surfaces. 
       FIGS. 2A-2D  illustrate a manufacturing method of a display device according to an embodiment of the present disclosure, wherein  FIG. 2A  shows a top view, and  FIG. 2B  shows a cross-sectional view along the section line  2 B- 2 B′ in  FIG. 2A . The elements in the present embodiment sharing similar or the same labels with those in the previous embodiments are similar or the same elements, and the description of which is omitted. 
     Please refer to  FIGS. 2A-2B . A first base  110 A is provided. The display elements  130  are disposed on the first base  110 A. A plurality of the encapsulation layers  140  are disposed on the first base  110 A, each of the encapsulation layers  140  correspondingly surrounding each of the display elements  130 . A plurality of the etching stop layers  150  are disposed on the first base  110 A, wherein each of the etching stop layers  150  correspondingly surrounds each of the encapsulation layers  140 , and the etching stop layers  150  are separated from each other by a plurality of gap G, wherein the manufacturing method of disposing the encapsulation layers  140  and the etching stop layers  150  on the first base  110 A may be selected from any one of a coating process, a printing process, a dispensing process, or photolithography, according to the properties of the materials. A second base  120 A is provided to be assembled to the first base  110 A; since the encapsulation layers  140  and the etching stop layers  150  on the first base  110 A are pressed by the second base  120 A, at least one sidewall  150   s  of each of the etching stop layers  150  forms an arc-shaped protruded surface. The second base  120 A is tightly assembled to the first base  110 A via the encapsulation layers  140  and the etching stop layers  150  by a UV irradiation process or a thermal baking process. 
     Next, as shown in  FIGS. 2C-2D , a chemical etching process is performed along the gaps G between the etching stop layers  150  for separating at least one of the first base  110 A and the second base  120 A, thereby forming a plurality of the display devices  100  separated from each other. 
     In the display devices manufactured by mechanical cutting processes, micro cracks may be formed around the cutting cross-sectional edges of the substrate surfaces. In contrast, according to the embodiments of the present disclosure, the display devices are manufactured by a chemical etching process along the gaps G between the etching stop layers  150 , such that no micro crack would be formed on the surfaces of the substrates, and hence the issues of the structure strength of the display devices being damaged due to micro cracks suffering from applied forces in the subsequent manufacturing processes or uses can be effectively prevented. In addition, the encapsulation layers  140  can be effectively protected by the etching stop layers  150 , as such, the encapsulation layer  140  can maintain excellent resistance to water and oxygen, and the durability and stability of the display device can be further increased. 
     In the present embodiment, the first base  110 A and the second base  120 A are both glass substrates. As shown in  FIG. 2C , prior to the chemical etching process, a plurality of masks  160  are disposed on the first base  110 A and the second base  120 A to expose the gaps G. The masks  160  are preferably anti-etching masks. The positions and the covering areas of the masks  160  substantially define the predetermined positions and areas of the display devices  100  to be made. 
     In the embodiment, the chemical etching process may include etching the first base  110 A and/or the second base  120 A according to the masks  160 . For example, a hydrofluoric acid series etching solution may be used as a chemical etching solution, and the first base  110 A and/or the second base  120 A having glass material are etched along the gaps G exposed between the masks  160 . 
     In the embodiment, prior to the chemical etching process, a mechanical process may be optionally performed along the gaps G to form a plurality of cutting grooves on at least one of the first base  110 A and the second base  120 A, which are predetermined to be separated. These cutting grooves are merely formed on the surface, where an etching solution is predetermined to apply on, of the first base  110 A and/or the second base  120 A, and the depths of these cutting grooves are smaller than the thickness of the first base  110 A and/or the second base  120 A, and thus the cutting grooves do not penetrate through the first base  110 A and/or the second base  120 A. 
     In the present embodiment, as shown in  FIG. 2C , the first base  110 A and the second base  120 A are etched along the gaps G. Prior to the etching process, a mechanical process is performed along the gaps G to form cutting grooves at the positions C on the surfaces of the first base  110 A and the second base  120 A. For example, the cutting grooves are formed by such as cutting the positions C along the middle of the gaps G by a diamond knife or a metal knife. In the present embodiment, the thicknesses of the first base  110 A and the second base  120 A are about 100-1000 micrometers (μm), and the depths of the cutting grooves are about 10-100 μm, which may vary depending on the thickness of the bases. Next, the chemical etching process is performed at the positions C where the cutting grooves are formed. 
     The cutting grooves can increase the etching rate; thereby the cutting step by the chemical etching process can be speeded up. In addition, although micro cracks may be formed around the cutting grooves after the cutting grooves are formed by cutting the substrates by a mechanical process, the region having the micro cracks will then be removed along with the removal of portions of the substrates by the chemical etching process. In such case, after the cutting step by the chemical etching process, no micro crack would remain on the substrates of the as-made display devices, and thus the issues of the structure strength of the display devices being damaged due to the existence of micro cracks can be effectively prevented, even when the devices are suffered from bending forces in the subsequent manufacturing processes or uses. 
     In the present embodiment, in the chemical etching process, the first base  110 A and the second base  120 A of glass materials are etched by such as a hydrofluoric acid series etching solution for separating the first base  110 A and the second base  120 A into a plurality of the first substrates  110  and a plurality of the second substrates  120 . After the masks  160  are removed, the display devices  100  separated from each other are formed. As shown in  FIG. 2D , each of the display devices includes a first substrate  110 , a second substrate  120 , a display element  130 , an encapsulation layer  140 , and an etching stop layer  150 . 
       FIGS. 3A-3D  illustrate a manufacturing method of a display device according to another embodiment of the present disclosure. The elements in the present embodiment sharing similar or the same labels with those in the previous embodiments are similar or the same elements, and the description of which is omitted. 
     As shown in  FIG. 3A , the present embodiment is similar to the embodiment as shown in  FIGS. 2A-2B  except that the second base  120 A is an anti-etching substrate. The first base  110 A is provided, the display elements  130  are disposed, the encapsulation layers  140  and the etching stop layers  150  are formed on the first base  110 A, and the second base  120 A is provided to be assembled to the first base  110 A. Since the encapsulation layers  140  and the etching stop layers  150  on the first base  110 A are pressed by the second base  120 A, at least one sidewall  150   s  of each of the etching stop layers  150  forms an arc-shaped protruded surface. The second base  120 A is tightly assembled to the first base  110 A via the encapsulation layers  140  and the etching stop layers  150  by a UV irradiation process or a thermal baking process. 
     Next, as shown in  FIGS. 3B-3D , the chemical etching process is performed along the gaps G between the etching stop layers  150  for separating at least one of the first base  110 A and the second base  120 A, thereby forming a plurality of the display devices  200 . 
     In the present embodiment, the first base  110 A is such as a glass substrate, and the second base  120 A is an anti-etching substrate. Since the second base  120 A is anti-etching, the second base  120 A would not be damaged by the etching solution in the subsequent chemical etching process. 
     As shown in  FIG. 3B , prior to the chemical etching process, a plurality of masks  160  are disposed on the first base  110 A to expose the gaps G. The positions and the covering areas of the masks  160  substantially define the predetermined positions and areas of the display devices  200  to be made. 
     In the present embodiment, prior to the chemical etching process, a mechanical process may be optionally performed along the gaps G to form a plurality of cutting grooves on the first base  110 A, which is predetermined to be separated. That is, these cutting grooves are formed on the surface, where an etching solution is predetermined to apply on, of the first base  110 A. For example, the cutting grooves are formed by such as cutting the positions C along the middle of the gaps G by a diamond knife or a metal knife, and the depths of these cutting grooves are smaller than the thickness of the first base  110 A. Next, the chemical etching process is performed at the positions C where the cutting grooves are formed. 
     In the present embodiment, as shown in  FIG. 3C , the chemical etching process may include etching the first base  110 A according to the masks  160 . For example, a hydrofluoric acid series etching solution may be used as a chemical etching solution, and the first base  110 A having glass material is etched along the gaps G exposed between the masks  160  for separating the first base  110 A into a plurality of the first substrates  110 . 
     Next, as shown in  FIG. 3C , the masks  160  are removed. 
     Next, a mechanical process is performed along the gaps G to separate the second base  120 A. For example, the second base  120 A is cut along the gaps G by a diamond knife or a metal knife for separating the second base  120 A into a plurality of the second substrates  120 . As such, the display devices  200  as shown in  FIG. 3D  are formed. 
       FIGS. 4A-4D  illustrate a manufacturing method of a display device according to a further embodiment of the present disclosure. The elements in the present embodiment sharing similar or the same labels with those in the previous embodiments are similar or the same elements, and the description of which is omitted. 
     As shown in  FIG. 4A , the present embodiment is similar to the previous embodiment except that the first base  110 A is a flexible substrate. The first base  110 A is provided, the display elements  130  are disposed, the encapsulation layers  140  and the etching stop layers  150  are formed on the first base  110 A, and the second base  120 A is provided to be assembled to the first base  110 A. Since the encapsulation layers  140  and the etching stop layers  150  on the first base  110 A are pressed by the second base  120 A, at least one sidewall  150   s  of each of the etching stop layers  150  forms an arc-shaped protruded surface. The second base  120 A is tightly assembled to the first base  110 A via the encapsulation layers  140  and the etching stop layers  150  by a UV irradiation process or a thermal baking process. 
     Next, as shown in  FIGS. 4B-4D , the chemical etching process is performed along the gaps G between the etching stop layers  150  for separating at least one of the first base  110 A and the second base  120 A, thereby forming a plurality of the display devices  200 . 
     In the present embodiment, the first base  110 A is a flexible substrate. In the embodiment, the flexible substrate may have an organic material or an inorganic material. In the present embodiment, the second base  120 A is such as a glass substrate. 
     As shown in  FIG. 4B , an anti-etching material layer  170  is disposed covering the first base  110 A for protecting the first base  110 A from the damage by the subsequent chemical etching process. 
     As shown in  FIG. 4B , prior to the chemical etching process, a plurality of masks  160  are disposed on the second base  120 A to expose the gaps G. The positions and the covering areas of the masks  160  substantially define the predetermined positions and areas of the display devices  200  to be made. 
     In the present embodiment, prior to the chemical etching process, a mechanical process may be optionally performed along the gaps G to form a plurality of cutting grooves on the second base  120 A, which is predetermined to be separated. That is, these cutting grooves are formed on the surface, where an etching solution is predetermined to apply on, of the second base  120 A. For example, the cutting grooves are formed by such as cutting the positions C along the middle of the gaps G by a diamond knife or a metal knife, and the depths of these cutting grooves are smaller than the thickness of the second base  120 A. Next, the chemical etching process is performed at the positions C where the cutting grooves are formed. 
     In the present embodiment, as shown in  FIG. 4C , the chemical etching process may include etching the first base  110 A according to the masks  160 . For example, a hydrofluoric acid series etching solution may be used as a chemical etching solution, and the second base  120 A having glass material is etched along the gaps G exposed between the masks  160  for separating the second base  120 A into a plurality of the second substrates  120 . 
     In the present embodiment, as shown in  FIG. 4C , after the chemical etching process, the anti-etching material layer  170  and the masks  160  are removed. 
     Next, a mechanical process is performed along the gaps G to separate the first base  110 A. For example, the first base  110 A is cut along the gaps G by a diamond knife or a metal knife for separating the first base  110 A into a plurality of the first substrates  110 . As such, the display devices  200  as shown in  FIG. 4D  are formed. 
       FIGS. 5A-5C  illustrate a manufacturing method of a display device according to a still further embodiment of the present disclosure. The elements in the present embodiment sharing similar or the same labels with those in the previous embodiments are similar or the same elements, and the description of which is omitted. 
     As shown in  FIG. 5A , the present embodiment is similar to the previous embodiment except that the encapsulation layer  140  and the etching stop layer  150  is separated by a spacing. The first base  110 A is provided, the display elements  130  are disposed, the encapsulation layers  140  and the etching stop layers  150  are formed on the first base  110 A, and the second base  120 A is provided to be assembled to the first base  110 A. 
     Next, as shown in  FIGS. 5B-5C , the chemical etching process is performed along the gaps G between the etching stop layers  150  for separating at least one of the first base  110 A and the second base  120 A, thereby forming a plurality of the display devices  300 . 
     In the present embodiment, the encapsulation layer  140  is a frit layer, each of the etching stop layers  150  and each of the corresponding encapsulation layers  140  are separated by a spacing S 1 , and each of the encapsulation layers  140  and each of the corresponding display element  130  may also be separated by a spacing S 2 . 
     In the present embodiment, after the first base  120 A is assembled to the first base  110 A, the encapsulation is melted and then cooled down, such that the second bass  120 A is adhered to and tightly assembled to the first base  110 A. 
     In the present embodiment, the first base  110 A and the second base  120 A are both glass substrates. As shown in  FIG. 5B , prior to the chemical etching process, a plurality of masks  160  are disposed on the first base  110 A and the second base  120 A to expose the gaps G. The positions and the covering areas of the masks  160  substantially define the predetermined positions and areas of the display devices  100  to be made. 
     In the embodiment, prior to the chemical etching process, a mechanical process may be optionally performed along the gaps G to form a plurality of cutting grooves on the first base  110 A and the second base  120 A, which are predetermined to be separated. For example, the cutting grooves are formed by such as cutting the positions C along the middle of the gaps G by a diamond knife or a metal knife. These cutting grooves are merely formed on the surface, where an etching solution is predetermined to apply on, of the first base  110 A and the second base  120 A, and the depths of these cutting grooves are smaller than the thicknesses of the first base  110 A and the second base  120 A. 
     In the present embodiment, in the chemical etching process, the first base  110 A and the second base  120 A of glass materials are etched by such as a hydrofluoric acid series etching solution for separating the first base  110 A and the second base  120 A into a plurality of the first substrates  110  and a plurality of the second substrates  120 . After the masks  160  are removed, the display devices  300  are formed. As shown in  FIG. 5C , each of the display devices includes a first substrate  110 , a second substrate  120 , a display element  130 , an encapsulation layer  140 , and an etching stop layer  150 . 
     While the invention has been described by way of example and in terms of the preferred embodiment(s), it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.