Patent Application
20150102300
Korean Patent Application No. 10-2013-0121503, filed on Oct. 11, 2013, in the Korean Intellectual Property Office, and entitled: “Organic Light Emitting Display Apparatus And Method Of Manufacturing The Same,” is incorporated by reference herein in its entirety.
1. Field
One or more embodiments relate to organic light-emitting display apparatuses and methods of manufacturing the same.
2. Description of the Related Art
A display apparatus provides visual information such as images or videos and can be manufactured in various ways.
More particularly, an organic light-emitting display apparatus is a self-light-emitting display apparatus that emits light by electrical excitation of organic compounds. Thus, organic light-emitting display apparatuses may be drivable at low voltages, may be easily thinned, may have wide viewing angles, and may have short response times. Accordingly, organic light-emitting display apparatuses have received much attention as next generation displays.
Exemplary embodiments may provide an organic light-emitting display apparatus including a first substrate including a display portion, a second substrate opposite the first substrate, a sealing line enclosing the display portion and binding the first substrate to the second substrate, and a plurality of sealing branches binding the first substrate to the second substrate. The plurality of sealing branches may each include a first end and a second end. Each first end may contact the sealing line, and each second end may not contact the sealing line. In exemplary embodiments, each second end is externally exposed.
The plurality of sealing branches may be separated from each other.
The organic light-emitting apparatus may include a stiffener between two neighboring sealing branches of the plurality of sealing branches and the stiffener may supplement binding between the sealing branches. The stiffener may include a polymer resin.
At least one sealing branch of the plurality of sealing branches may perpendicularly contact the sealing line.
At least one of the plurality of sealing branches may have a uniform width or at least one of the plurality of sealing branches may have a non-uniform width.
At least one of the plurality of sealing branches may include a crack preventing portion configured to prevent a crack generated in the first end from spreading to the second end.
At least one of the plurality of sealing branches may include a first sealing branch that may contact the sealing line at a first end of the first sealing branch and may contact the crack preventing portion at a second end of the first sealing branch. At least one of the plurality of sealing branches may also include a second sealing branch that may contact the crack preventing portion at a first end of the second sealing branch and may be externally exposed at a second end of the second sealing branch.
At least one of the first and the second sealing branches may include an area that has a narrower width than a maximum width of the crack preventing portion. At least one of the first and the second sealing branches may have the narrowest width in an area that contacts the crack preventing portion.
The sealing line and the plurality of sealing branches may include the same material, and the materials may include glass frit.
The first substrate may further include a peripheral area that may enclose the display portion. An insulating layer may be over the display portion and the peripheral area on the first substrate, and the insulating layer may include at least one through-hole corresponding to the peripheral area.
The sealing line may fill inside a first through-hole.
The display portion may include a buffer layer, a gate insulating film, and an interlayer insulating layer. The insulating layer may include at least one of the buffer layer, the gate insulating film, and the interlayer insulating layer.
A metal layer may be in the insulating layer and may include at least one second through-hole on the first substrate. The first through-hole may be in the second through-hole.
Exemplary embodiments also provide a method of manufacturing an organic light-emitting display apparatus including providing a first mother substrate comprising a plurality of display portions, forming a plurality of sealing lines respectively enclosing a plurality of display portions and a plurality of sealing bridges connecting neighboring sealing lines among the plurality of sealing lines, binding the first mother substrate to the second mother substrate with the plurality of sealing lines and the plurality of sealing bridges; and cutting the plurality of sealing bridges to separate the plurality of display portions.
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:
Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as 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 exemplary implementations to those skilled in the art.
In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present.
The sizes of all elements shown in the drawings are randomly chosen, and thus, the lengths, widths, thickness, and all other dimensions of the elements shown in the drawings are not limited thereto. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes of a rectangular coordinate system, and may be construed broadly as meaning three random axes. For example, the x-axis, the y-axis, and the z-axis may be perpendicular to each other. However, they may have other directions without necessarily being perpendicular to each other.
The terms, first and second, as used herein, may be used to explain various features. However, the features are not limited by the terms used, and these terms are only used to distinguish one feature from another feature.
The terms as used herein are only used to explain specific embodiments and thus are not limiting. A singular expression includes a plural expression, unless clearly stated otherwise. In the present application, terms such as “including” or “having” are only used to specify the existence of characteristics, numbers, processes, operations, features, components, or a combination thereof, and should not be construed as to exclude the existence of one or more of other characteristics, numbers, processes, operations, features, components, or a combination thereof.
Referring to
The first substrate 10 may be divided into a display area DA and a peripheral area PA enclosing the display area DA. The substrate 10 may be made of a transparent glass material including SiO2 as a main material. However, the substrate 10 is not limited thereto and may be made of a transparent plastic material. The substrate 10 may be a flexible substrate that may be manufactured by using a material that is lightweight due to smaller specific gravity than the glass substrate, does not break easily, and is bendable. For example, the material may be a polymer material such as a flexible plastic film.
The display portion 40 of the first substrate 10 may include a transistor TR, which is a thin film transistor for driving, a capacitor Cst, an organic light-emitting device OLED, or the like on the first substrate 10. The display portion 40 is described below in detail.
The second substrate 20 may be disposed opposite the first substrate 10, and the second substrate 20 may be made of various materials such as a glass material, a metal material, a plastic material, or the like. The first substrate 10 may be attached to the second substrate 20 with the sealing line 32 and the plurality of sealing branches 34. The sealing line 32 and the plurality of sealing branches 34 may be made of the same material. For example, the sealing line 32 and the plurality of sealing branches 34 may include glass frit or the like.
In greater detail, sealing line 32 may enclose the display portion 40 to separate the display area DA from the peripheral area PA. The sealing line 32 may seal the display portion 40 to protect the display portion 40 from outside. Also, one end 34E1 of the sealing branch 34 may contact the sealing line 32 and other end 34E2 may not contact the sealing line 32. For example, the other end 34E2 of the sealing line 32 may be exposed externally. When a display area DA is defined as an inner portion of the sealing line 32 and a peripheral area PA as an outer portion of the sealing line 32, the sealing branch 34 may be located at the outer portion of the sealing line 32 and the one end 34E1 may contact the sealing line 32.
An organic light-emitting display apparatus according to an embodiment may include the sealing branch 34 therein in addition to the sealing line 32 to broaden a contact area of the sealing line 32 with respect to the first and the second substrates. Furthermore, due to a broader contact area, adhesiveness between the first substrate 10 and the second substrate 20 may be increased. Although the sealing line 32 may be located in all areas except for a pad portion 50 to maximize the contact area, a crack may occur. As a result, the organic light-emitting display apparatus according to an embodiment may include the sealing branch 34 to broaden the contact area and prevent the occurrence of a crack.
The plurality of the sealing branches 34 may be separated from each other. Also, at least one of the plurality of sealing branches 34 may perpendicularly contact the sealing line 32. For example, a lengthwise direction of at least one of the plurality of sealing branches 34 may be perpendicular to a sealing line 32.
A stiffener 60 that may supplement binding between the sealing branches 34 may be filled between two neighboring sealing branches 34 of the plurality of sealing branches 34. The stiffener 60 may include a resin, for example, a polymer resin. The stiffener 60 may supplement mechanical strength that has been deteriorated due to thermal shock and stress generated from a thermal mismatch between the glass fit of the sealing line 32 and glass of the first and the second substrates 10 and 20.
As illustrated in
As described below, the second sealing branch 34c may be produced by cutting. A crack may be generated in the second sealing branch 34c due to the cutting. However, most of the cracks generated in the second sealing branch 34c may disappear in the crack preventing portion 34a having a large volume. Even when the crack passes through the crack preventing portion 34a, the crack may not pass through an area that has a narrow width in the first sealing branch 34b, thereby reducing the possibility of spreading of the crack to the sealing line 32. As a result, the crack produced from the cutting may not spread to the sealing line 32, and thus, the sealing line 32 may stably protect the display portion 40 from external environment.
As illustrated in
Also, the display portion 40 of the first substrate 10 may include a transistor TR, a capacitor Cst, and an organic light-emitting device OLED on the substrate 10. In greater detail, the transistor TR may be formed on the buffer layer 11. The present embodiments illustrate a thin film transistor having a bottom gate form, but the thin film transistor may have another structure such as a top gate form or the like.
An active layer 212 may be formed on the buffer layer 11. When the active layer 212 is formed of polysilicon, the active layer 212 may be first formed of amorphous silicon, which is then crystallized into the polysilicon.
Methods of crystallizing the amorphous silicon include rapid thermal annealing (RTA), solid phase crystalization (SPC), eximer laser annealing (ELA), metal induced crystallization (MIC), metal induced lateral crystallization (MILC), and sequential lateral solidification (SLS). Methods may be used that do not require a high temperature heating process to use the substrate according to embodiments.
For example, during crystallization by using a low temperature poly-silicon (LTPS) process, the active layer 212 may be activated by irradiating a laser beam for a short period of time so as to prevent the first substrate 10 from being exposed to a high temperature equal to or higher than 300° C., and thus the entire processes may be performed at a temperature equal to or less than 300° C. Accordingly, the transistor TR may be formed by applying a substrate formed of a polymer material.
An N-type or a P-type impurity ion may be doped on the active layer 212 to form a source area 212b and a drain area 212a. An area between the source area 212b and the drain area 212a may be a channel area 212c on which the impurities are not doped.
A gate insulating film 13 may be formed on the active layer 212. The gate insulating film 13 may be formed as a single layer structure of SiO2 or as a double layer structure of SiO2 and SiNx.
A gate electrode 214 may be formed on a predetermined area of the gate insulating film 13. The gate electrode 214 may be connected to a gate line (not shown) which transmits a transistor on/off signal. The gate electrode 214 may be formed as a single layer or a plurality of conductive layers.
A drain electrode 216a and a source electrode 216b, which respectively connect to the drain area 212a source area 212b, may be formed on the gate electrode 214 with an interlayer insulating layer 15 disposed therebetween. The interlayer insulating layer 15 may be formed of an insulating material such as SiO2 or SiNx, and may be formed of an insulating organic material.
A pixel defining layer 18 may be formed on the interlayer insulating layer 15 to cover the drain electrode 216a and the source electrode 216b. However, a pixel electrode 114 including the same transparent conductive material as the gate electrode 214 may be formed on the buffer layer 11 and the gate insulating film 13. A resistance of the drain electrode 216a and the source electrode 216b may be smaller than that of the gate electrode 214.
A metal having a low work function, in other words, Li, Ca, LiF/Ca, LiF/Al, Al, Mg, or a compound thereof, may be deposited on an intermediate layer 119, and then an auxiliary electrode including a material for forming a transparent electrode such as ITO, IZO, ZnO, or In2O3 may be formed thereon to manufacture the pixel electrode. However, the pixel electrode 114 is not limited thereto and may be a reflective electrode.
On the pixel electrode 114, a portion of the pixel defining layer 18 may be etched to form an intermediate layer 119. The intermediate layer 119 may include an emissive layer that may emit visible rays.
A counter electrode 19 may be formed as a common electrode on the intermediate layer 119. On the intermediate layer 119, voltages of different polarities may be applied such that light is emitted from the intermediate layer 119.
The emissive layer of the intermediate layer 119 may include a low molecular weight organic material or a high molecular weight organic material.
When a low molecular weight organic material is used for the emissive layer in the intermediate layer 119, the intermediate layer 119 may be formed as a single layer or a plurality of layers of hole injection layer (HIL), hole transport layer (HTL), emissive layer (EML), electron transport layer (ETL), and electron injection layer (EIL).
Also, an organic material that may be used for the intermediate layer 119 may include copper phthalocyanine (CuPc), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine, NPB), tris-8-hydroxyquinoline aluminum (Alq3), and the like. The low molecular weight material may be formed by using vacuum deposition or the like by using masks.
When the emissive layer of the intermediate layer 119 includes the high molecular weight organic material, the intermediate layer 119 may have a structure including the HTL and the EML. In this regard, PEDOT may be used for the HTL and poly-phenylenevinylene-based or polyfluorene-based high molecular weight organic material may be used for the EML. The high molecular weight organic material may be formed by a screen printing method or an inkjet printing method. However, the intermediate layer 119 is not limited thereto, and the intermediate layer 119 may have other structures.
The counter electrode 19 may be made of a transparent electrode or a reflective electrode as in the case of the pixel electrode 114. When the counter electrode 19 is used as a transparent electrode, a metal having a low work function, such as Li, Ca, LiF/Ca, LiF/Al, Al, Mg, or a compound thereof, may be deposited on an intermediate layer 119, and then an auxiliary electrode made of a material for forming a transparent electrode such as ITO, IZO, ZnO, or In2O3 may be formed thereon to manufacture the counter electrode 19.
When the counter electrode 19 is used as a reflective electrode, the counter electrode 19 may be formed by depositing Li, Ca, LiF/Ca, LiF/Al, Al, Mg, or a combination thereof on the intermediate layer 119.
Also, the pixel electrode 114 may be formed in a shape that corresponds to a shape of an opening of each sub pixel when the pixel electrode 114 is formed as a transparent electrode or a reflective electrode. The counter electrode 19 may be formed by depositing a transparent electrode or a reflective electrode throughout the display area DA. Alternatively, the counter electrode 19 may not be formed throughout the display area DA but may be patterned in any shape. In this regard, the pixel electrode 114 and the counter electrode 19 may be layered in opposite directions.
In the case of the organic light-emitting display apparatus according to embodiments, the pixel electrode 114 may be an anode, and the counter electrode 19 may be a cathode. The polarities of the electrodes may be reversed.
Also, the buffer layer 11, the gate insulating film 13, and the interlayer insulating layer 15, as a whole, may be referred to as an insulating layer IL. The insulating layer IL may be disposed on the display portion 40 of the first substrate 10 and peripheral area PA, for example, as illustrated in the drawings. Furthermore, the sealing line 32 may be disposed on the insulating layer IL to attach the first substrate 10 to the second substrate 20. Although not shown in the drawings, the sealing branch 34 may be disposed on the insulating layer IL to bind the first and the second substrates 10 and 20.
When the sealing line 32 attaches the first substrate 10 to the second substrate 20, a contact area may have a sufficient binding force. However, the greater the width 32A occupied by the sealing line 32, the greater the peripheral area PA, which is a dead space. As a result, to reduce the dead space, an area occupied by the sealing line 32, that is, the width 32A, may be reduced.
Also, the insulating layer IL may include at least one first through-hole TH1. Accordingly, the area of the sealing line 32 on a surface area that is parallel to the first substrate 10 (xy surface area) may be reduced while the sealing line 32 increases a contact area between components on the first substrate 10 and the insulating layer IL. Accordingly, the area occupied by the sealing line 32, that is, the width 32A may be reduced so as to reduce the dead space and maintain or increase the binding force between the sealing line 32 and the first substrate 10.
Also, as illustrated in
When the sealing line 32 is used to bind the first substrate 10 and the second substrate 20, UV light, laser beam, or the like may be irradiated to cure the sealing line 32. In greater detail, UV light or laser beam may be irradiated to the sealing line 32 through the second substrate 20, and an irradiation efficiency of the UV light or laser beam may be increased by reflecting the UV light or the laser beam that passes through to the sealing line 32 by using the metal layer 70 located at the bottom of the sealing line 32, such that the UV light or the laser beam is directed back to the sealing line 32, thereby increasing the irradiation efficiency of the UV light or the laser beam.
Also, the area in which the sealing line 32 contacts the second substrate 20 may be easily observable through the second substrate 20 made of a transparent material. However, the area in which the sealing line 32 contacts the first substrate 10 may not be observable because of the metal layer 70, which is not transparent. Accordingly, as the sealing line 32 may include at least one second through-hole TH2, the contact area between the sealing line 32 and the first substrate 10 may be observable through the second through-hole TH2 of the metal layer 70. As a result, it may determined whether the contact area between the sealing line 32 and the second substrate 20 and/or the first substrate 10 is greater than a predetermined minimum area to easily observe the presence of sealing defects. Thus, an inner portion 70a of each second through-hole TH2 may be covered by the insulating layer IL, such that the second through-hole TH2 does not contact the sealing line 32. In
Also, the first through-hole TH1 may be formed inside the second through-hole TH2. For example, when at least one first through-hole TH1 is formed in the insulating layer IL, the buffer layer 11, the gate insulating film 13, and the interlayer insulating layer 15 may be simultaneously etched to form at least one first through-hole TH1. During this process, if the inner portion 70a of the second through-hole TH2 of the metal layer 70 is exposed by at least one first through-hole TH1, the metal layer 70 in which the second through-hole TH2 is already formed may be additionally etched, which may increase the surface area of the second through-hole TH2 of the metal layer 70. In order to prevent such an increase in surface area, insulating layer IL may cover the inner portion 70a of at least one second through-hole TH2 of the metal layer 70, thereby preventing contact between metal layer 70 and the sealing line 32.
In
A method of manufacturing an organic light-emitting display apparatus according to an embodiment will be described.
To manufacture an organic light-emitting display apparatus, first, a plurality of display portions 40 and a plurality of pad portions 50 may be formed on a first mother substrate 1000, as shown in
Furthermore, as illustrated in
Thereafter, as illustrated in
As illustrated in
By way of summation and review, an organic light-emitting display apparatus may be manufactured by forming a plurality of organic light-emitting devices and pads on a first mother substrate, attaching a second mother substrate to the first mother substrate with a sealing material, and then cutting the resultant structure. During the cutting operation, cracks may be generated in the first and second mother substrates.
In contrast, according to the one or more of the above embodiments, the organic light-emitting display apparatus may prevent spreading of a crack. Also, a contact area between the sealing line and the substrate may be enlarged to improve a binding force.
One or more embodiments include an organic light-emitting display apparatus having strong adhesiveness and a method of manufacturing the same. In addition, one or more embodiments include an organic light-emitting display apparatus that may prevent spreading of a crack that may occur in a cutting operation.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2013-0121503 | Oct 2013 | KR | national |
