Abstract:
An organic light emitting diode display includes a display substrate including an organic light emitting element and a driving circuit part, an encapsulation substrate sealing the display substrate, and a sealing portion between the display substrate and the encapsulation substrate, the sealing portion including a plurality of sealing frame portions around the display substrate, and a first sealing frame portion of the plurality of sealing frame portions being adjacent to a pad portion, wherein at least one of a width of an edge of the sealing portion and a width of the first sealing frame portion is wider than a width of a sealing frame portion other than the first sealing frame portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a divisional application based on pending application Ser. No. 14/074,919, filed Nov. 8, 2013, the entire contents of which is hereby incorporated by reference. 
         [0002]    The present application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2013-0043752, filed on Apr. 19, 2013, in the Korean Intellectual Property Office, and entitled: “Organic Light Emitting Diode Display,” which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0003]    1. Field 
         [0004]    The present disclosure relates to an organic light emitting diode display. More particularly, the present disclosure relates to an organic light emitting diode display which partially reinforces a width of a sealing material formed in an area except for a display area and a non-display area. 
         [0005]    2. Description of the Related Art 
         [0006]    A conventional organic light emitting diode display may include two electrodes and an organic emission layer positioned between the two electrodes. An electron injected from one electrode and a hole injected from the other electrode are coupled with each other in the organic emission layer to form an exciton, and the exciton emits energy to display light. 
         [0007]    The conventional organic light emitting diode display may also include a display substrate with the organic emission layer, and an encapsulation substrate covering and sealing the display substrate. In addition, a sealant may be formed between the display substrate and the encapsulation substrate to seal and attach the display substrate and the encapsulation substrate. 
       SUMMARY 
       [0008]    The present disclosure has been made in an effort to provide an organic light emitting diode display capable of preventing deformation of a cell seal structure. 
         [0009]    An exemplary embodiment provides an organic light emitting diode display, including a display substrate including an organic light emitting element and a driving circuit part, an encapsulation substrate sealing the display substrate, and a sealing portion between the display substrate and the encapsulation substrate, the sealing portion including a plurality of sealing frame portions around the display substrate, and a first sealing frame portion of the plurality of sealing frame portions being adjacent to a pad portion, wherein at least one of a width of an edge of the sealing portion and a width of the first sealing frame portion is wider than a width of a sealing frame portion other than the first sealing frame portion. 
         [0010]    The organic light emitting diode display may further include a sealing material at least at one inner edge of the sealing portion, the sealing material having a triangular shape. 
         [0011]    The sealing material may be reinforced at two or more edges among inner edges of the sealing portion. 
         [0012]    The sealing material may have a right-triangular shape, the sealing material fitting into an inner right-triangular shape of the inner edge of the sealing portion. 
         [0013]    The sealing material may be only at edges of the sealing portion among all portions of the sealing portion, the sealing material being in direct contact with the inner edges of the sealing portion. 
         [0014]    The width of the first sealing frame portion may be wider than the width sealing frame portions other than the first sealing frame portion by about 10% or more. 
         [0015]    The organic light emitting diode display may further include a protruding portion on and protruding away from at least one of the sealing frame portions, a width of the protruding portion being wider than the sealing frame portions. 
         [0016]    The protruding portion may have a semicircular shape. 
         [0017]    The protruding portion may be at an opposite side. 
         [0018]    The width of the edge of the sealing portion may be measured along a direction that is oblique with respect to a direction of the width of any adjacent sealing frame portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Features will become apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which: 
           [0020]      FIG. 1  illustrates a plan view of a unit cell of an organic light emitting diode display according to a first exemplary embodiment. 
           [0021]      FIG. 2  illustrates a cross-sectional view taken along line II-II of  FIG. 1 . 
           [0022]      FIG. 3  illustrates a partially enlarged view of a portion A of  FIG. 1 . 
           [0023]      FIG. 4  illustrates a plan view of a unit cell of an organic light emitting diode display according to a second exemplary embodiment. 
           [0024]      FIG. 5  illustrates a cross-sectional view taken along line V-V of  FIG. 4 . 
           [0025]      FIG. 6  illustrates a plan view of a unit cell of an organic light emitting diode display according to a third exemplary embodiment. 
           [0026]      FIG. 7  illustrates a plan view of a unit cell of an organic light emitting diode display according to a fourth exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
         [0028]    Hereinafter, a configuration of an organic light emitting diode display according to an exemplary embodiment will be described in more detail with reference to the accompanying drawings. 
         [0029]      FIG. 1  illustrates a plan view of a unit cell of an organic light emitting diode display according to a first exemplary embodiment.  FIG. 2  is a cross-sectional view along line II-II of  FIG. 1 .  FIG. 3  is a partially enlarged view of portion A in  FIG. 1 . 
         [0030]    An organic light emitting diode display according to an exemplary embodiment is designed such that a width of a sealing portion is larger in an area to which increased stress is applied. That is, a sealing portion in a pad area or at an edge may have a larger width than in other regions for structural reinforcement. As a result, it may be possible to prevent releasing or rupturing of a cell seal structure, i.e., of the sealing portion. 
         [0031]    Referring to  FIGS. 1 and 2 , a unit cell of an organic light emitting diode display according to a first exemplary embodiment may include a display substrate  10  and an encapsulation substrate  20  facing each other, and a sealing portion  15 . The sealing portion  15  may be formed between the display substrate  10  and the encapsulation substrate  20 . 
         [0032]    The display substrate  10  may include an organic light emitting element and a driving circuit part. In this case, the organic light emitting element may include an anode, an organic emission layer, and a cathode, and the driving circuit part may include at least two thin film transistors T 1  and T 2 , and at least one storage capacitor CAP 1 . 
         [0033]    The encapsulation substrate  20 , as illustrated in  FIG. 2 , may be installed at an upper portion and at a side of the display substrate  10 . The encapsulation substrate  20  serves to protect the organic light emitting elements and the driving circuit parts of the display substrate  10  from the outside by sealing the display substrate  10 . 
         [0034]    The sealing portion  15  may include a sealing frame  11  and a reinforced sealing material  12  reinforcing the sealing frame  11 . The sealing frame  11  and the reinforced sealing material  12  will be separately described below. 
         [0035]    The sealing frame  11  is formed to adhere along edges of the display substrate  10  and the encapsulation substrate  20 , and to seal the display substrate  10  and the encapsulation substrate  20 , as illustrated in  FIG. 1 . For example, the sealing frame  11  may extend continuously along an entire peripheral edge, e.g., en entire perimeter, of the display substrate  10  and/or the encapsulation substrate  20 . 
         [0036]    For example, the sealing frame  11  may have a quadrangular frame, so each edge of the sealing frame  11  may be configured at a right angle. In other words, as illustrated in  FIGS. 1 and 3 , two portions of the sealing frame  11  may be configured perpendicularly to each other to define a corner at a right angle, such that a surface contact between the two perpendicular portions is at an oblique angle to a side surface of each of the perpendicular portions that faces a center of the sealing frame  11 . As a result, a width W 1  ( FIG. 3 ) of the corner, i.e., the surface contact, is larger than a width W 2  of either of the two perpendicular portions of the sealing frame defining the corner. In other words, the width W 1  can be defined as a diagonal of a square having a side that equals the width W 2 , so the width W 1  equals W 2 *(√{square root over ( )}2), i.e., W 1 =W 2 *1.41421. As the width W 1  is larger than the width W 2 , corners, i.e., edges, of the sealing frame  11  are reinforced to provide increased support against potential stress. In contrast, if an entire sealing frame has a uniform width, e.g., if edges of the frame are curved to have a same width as side portions of the frame, when a relatively large stress is concentrated at edges of the sealing frame, a cell rupturing phenomenon may occur. 
         [0037]    In addition, as illustrated in  FIGS. 1 and 3 , the reinforced sealing material  12  may be closely installed at an edge of the sealing frame  11  to further increase the width W 1 . For example, the reinforced sealing material  12  may have a right triangular shape. For example, the reinforced sealing material  12  may fit into, e.g., and contact, an inner edge of sealing frame  11 . For example, when the sealing frame  11  has a shape of a quadrangular frame, e.g., a rectangular frame, the right-triangular reinforced sealing material  12  may fit into the right-angled inner edge of sealing frame  11  to further increase a total width of the sealing material  12  at the edge of the sealing frame  11 . As the reinforced sealing material  12  has a right-triangular shape that, e.g., directly, contacts portions of perpendicular sides of the sealing frame  11 , e.g., portions of the sealing frame that define the edge, a relatively large stress amount concentrated at the edge may be dispersed. However, embodiments are not limited to the shape of the reinforced sealing material  12  described above. 
         [0038]    The reinforced sealing material  12  may be installed at two or more edges among the four edges. The reinforced sealing material  12  may be integrally configured, e.g., formed, with the sealing frame  11  or may be separately configured, e.g., formed, from the sealing frame  11  to be fastened with, e.g., physically attached to, the sealing frame  11 . 
         [0039]    Hereinafter, various exemplary embodiments and modified embodiments of the sealing portion  15  for preventing releasing or rupturing of the cell seal structure will be described. 
         [0040]      FIG. 4  illustrates a plan view of a unit cell of an organic light emitting diode display according to a second exemplary embodiment.  FIG. 5  is a cross-sectional view taken along line V-V of  FIG. 4 . 
         [0041]    Referring to  FIGS. 4 and 5 , a unit cell of the organic light emitting diode display according to the second exemplary embodiment may include the display substrate  10 , the encapsulation substrate  20 , and a sealing portion  15 ′. In this case, since the display substrate  10  and the encapsulation substrate  20  are the same as the configuration of the first exemplary embodiment described above, the same reference numerals are used and a duplicate description is omitted. 
         [0042]    The sealing portion  15 ′, which is different from the configuration of the first exemplary embodiment, will be mainly described. The sealing portion  15 ′ of the second exemplary embodiment may include the sealing frame  11  and a reinforced sealing material  13  reinforcing the sealing frame  11 . 
         [0043]    In detail, the sealing frame  11  is the same as in the first exemplary embodiment. In  FIG. 4 , sealing frame portions positioned in a counter clockwise (CCW) direction from a sealing frame portion positioned at a lower side are illustrated as first to fourth sealing frames  11   a ,  11   b ,  11   c , and  11   d , respectively. 
         [0044]    Meanwhile, the reinforced sealing material  13  is formed at the lower side of the first sealing frame portion  11   a , among the first to fourth sealing frame portions  11   a ,  11   b ,  11   c , and  11   d , as illustrated in  FIGS. 4 and 5 . 
         [0045]    In more detail, GATE/SD wires are concentrated in a pad area, e.g., in a region of the organic light emitting diode display overlapping the first sealing frame portion  11   a , so a step is non-uniformly formed in the pad area. As a result, the cell seal structure may be relatively unstable in the pad area, and releasing or rupturing may easily occur. 
         [0046]    However, according to embodiments, the reinforced sealing material  13  is added in the pad area positioned at the lower side. For example, as illustrated in  FIGS. 4-5 , the reinforced sealing material  13  may contact, e.g., directly contact, and extend along, e.g., an entire length of, the first sealing frame portion  11   a . As a result, a combined width PA of the first sealing frame portion  11  with the reinforced sealing material  13  is larger than a width L of each of the second through fourth sealing frame portions  11   b ,  11   c , and  11   d . For example, the combined width PA of the first sealing frame portion  11   a  with the reinforced sealing material  13  may be larger than the width L of each of the second through fourth sealing frame portions  11   b ,  11   c , and  11   d  by about 10% or more. 
         [0047]    It is noted that in  FIGS. 4 and 5  the size of the sealing material  13  is not to scale. That is, in order to emphasize the reinforced sealing material  13 , the width of the reinforced sealing material  13  is exaggerated. 
         [0048]      FIG. 6  is a plan view of a unit cell of an organic light emitting diode display according to a third exemplary embodiment. 
         [0049]    Referring to  FIG. 6 , a unit cell of an organic light emitting diode display according to the third exemplary embodiment may include the display substrate, the encapsulation substrate, and a sealing portion  15 ″. The sealing portion  15 ″ may include the sealing frame  11  and the reinforced sealing materials  12  and  13  reinforcing the sealing frame  11 . The sealing frame  11  may include first to fourth sealing frame portions  11   a ,  11   b ,  11   c , and  11   d.    
         [0050]    In this case, since the display substrate, the encapsulation substrate, and the sealing frame  11  are the same as those described previously with respect to  FIGS. 1-5  above, duplicate description thereof is omitted. 
         [0051]    The reinforced sealing materials  12  and  13  in  FIG. 6  include the reinforced sealing material  12  of the first exemplary embodiment and the reinforced sealing material  13  of the second exemplary embodiment. For example, as illustrated in  FIG. 6 , at an upper side of the sealing frame  11 , the reinforced sealing material  12  according to the first exemplary embodiment may be closely installed at each upper edge to disperse stress concentrated at the edges. For example, as further illustrated in  FIG. 6 , at a lower side of the sealing frame  11 , the reinforced sealing material  13  may be formed in the pad area according to the second exemplary embodiment. 
         [0052]    In the exemplary embodiment, the reinforced sealing material  12  has a right triangular shape and is installed only at the upper side, but embodiments are not limited thereto. In addition, the reinforced sealing material  12  may be integrally configured with the sealing frame  11  or may be separately configured from the sealing frame  11  to be fastened with the sealing frame  11 . 
         [0053]    In the exemplary embodiment, a width of the first sealing frame portion  11   a , to which the reinforced sealing material  13  is added, is larger than corresponding widths of the other second to fourth sealing frame portions  11   b ,  11   c , and  11   d . As a result, it may be possible to prevent cell releasing or rupturing. As described above, the combined width of the first sealing frame portion  11   a  with the reinforced sealing material  13  may be larger than the widths of the second to fourth sealing frame portions  11   b ,  11   c , and  11   d  by about 10% or more. 
         [0054]      FIG. 7  is a plan view of a unit cell of an organic light emitting diode display according to a fourth exemplary embodiment. 
         [0055]    Referring to  FIG. 7 , a unit cell of an organic light emitting diode display according to the fourth exemplary embodiment may include the display substrate, the encapsulation substrate, the sealing portion  15 ″, and a protruding portion  14 . Further, the sealing portion  15 ″ may include the sealing frame  11  and reinforced sealing materials  12  and  13  reinforcing the sealing frame  11 , and the sealing frame  11  may include first to fourth sealing frame portions  11   a ,  11   b ,  11   c , and  11   d.    
         [0056]    In this case, since the display substrate, the encapsulation substrate, the sealing frame  11 , and the reinforced sealing materials  12  and  13  are the same as the configurations of the first to third exemplary embodiments described above, a duplicate description is omitted. 
         [0057]    The protruding portion  14 , as illustrated in  FIG. 7 , may be installed on at least one sealing frame portion among sealing frame portions of the sealing frame  11  where the reinforced sealing material  13  is not formed, e.g., on the second to fourth sealing frame portions  11   b  through  11   d . The protruding portion  14  may protrude from the sealing frame  11  in an outer direction and may have a larger width than a width of the sealing frame  11 . As a result, since the reinforced sealing materials  12  and  13  and the protruding portion  14  selectively, e.g., locally, increase a width of the sealing frame  11 , a place where stress is concentrated may be reinforced. 
         [0058]    In  FIG. 7 , the protruding portion  14  is formed only at the second and fourth sealing frame portions  11   b  and  11   d , but is not limited thereto. Further, in  FIG. 7 , the protruding portion  14  is illustrated as a semicircular shape, but so long as the width of the protruding portion  14  extends in the outer direction, e.g., convex, the shape of the protruding portion is not limited thereto. Further, exemplary embodiments may include the display substrate, the encapsulation substrate, and the protruding portion  14 , without configuring the sealing portion  15 ″. 
         [0059]    According to the exemplary embodiment, a width of a sealing portion may be non-uniform, i.e., may be designed to be larger in a partial area to which a lot of stress is applied. As a result, it may be possible to prevent releasing or rupturing of the sealing portion. 
         [0060]    In contrast, a conventional organic light emitting diode display may include a sealing portion with a uniform width along an entire circumference of the display substrate, while four edges of the sealing portion may be curved to have a radius of R and a width of L, i.e., four sides and the widths L are the same as each other. However, as stress may be concentrated in a pad area, i.e., where a step is non-uniform, or at an edge, i.e., including a curved portion R of the edge, the conventional sealing portion may rupture. Further, when implementing a large size, the problem is further increased. 
         [0061]    Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.