KR101600816B1 - Organic Light Emitting Diode Display and Manufacturing Method thereof - Google Patents

Abstract

An OLED display according to an exemplary embodiment of the present invention includes a light emitting member having an expanded area, the spacer serving as a dam, and the reflective film may be positioned under the extended light emitting member. Therefore, the aperture ratio, the luminance, and the luminous efficiency of the organic light emitting display device are improved, and the process cost is reduced.

An organic light emitting display, a spacer, a pixel defining layer,

Description

[0001] The present invention relates to an organic light emitting display and a method of manufacturing the same,

The present invention relates to an organic light emitting display and a method of manufacturing the same.

An organic light emitting diode display (OLED display) has an organic light emitting layer formed between two electrodes, and electrons and holes are injected from the two electrodes into an organic light emitting layer, Is an apparatus using the principle that excitons due to coupling are generated and light is generated when the excitons fall from the excited state to the ground state.

Since the organic light emitting display device is a self light emitting type, a separate light source is not required, so that it is advantageous not only in power consumption but also in response speed, viewing angle, and contrast ratio.

It is an object of the present invention to improve the aperture ratio, the luminance, and the luminous efficiency of an organic light emitting display device, and to reduce a process cost.

The above and other objects of the present invention can be achieved by the present invention described below.

The OLED display according to an embodiment of the present invention includes a first thin film transistor connected to a first signal line and a second signal line crossing each other, a first signal line and a second signal line, A protective film formed on the first thin film transistor, the first signal line, the second signal line, the switching thin film transistor, and the driving thin film transistor, a reflective film formed on the protective film and connected to the driving thin film transistor, A pixel defining layer formed on the pixel defining layer, a pixel electrode formed inside the opening of the pixel defining layer and extending on an inclined surface around the opening, a spacer formed on the pixel electrode and surrounding the pixel electrode, Emitting portion , And it includes a common electrode formed on the light emitting member.

The boundary portion of the light emitting member may contact the boundary portion of the opening portion of the spacer.

The area of the opening of the spacer may be wider than the area of the opening of the pixel defining layer.

The reflective layer may be formed on the pixel defining layer.

The planar shape of the reflective film and the pixel electrode may be substantially the same.

The pixel electrode may be in contact with the reflective film.

The reflective layer may be connected to the driving thin film transistor through a contact hole passing through the protective layer and the pixel defining layer.

The reflective film may be connected to the driving thin film transistor through a contact hole passing through the protective film.

And a part of the pixel electrode may contact a part of the reflective film.

The common electrode may be formed on the spacer.

A method of manufacturing an organic light emitting display according to another embodiment of the present invention includes forming a switching thin film transistor on a substrate and a driving thin film transistor connected to the switching thin film transistor, forming a protective film on the switching thin film transistor and the driving thin film transistor Forming a reflective layer on the protective layer, the reflective layer being connected to the driving thin film transistor, forming a pixel defining layer surrounding the reflective layer on the reflective layer, forming a pixel electrode on the pixel defining layer and the reflective layer, Forming a spacer surrounding the pixel electrode, forming a light emitting member on the pixel electrode, and forming a common electrode on the light emitting member.

A method of fabricating an organic light emitting display according to another embodiment of the present invention includes forming a switching thin film transistor on a substrate and a driving thin film transistor connected to the switching thin film transistor and forming a protective film on the switching thin film transistor and the driving thin film transistor Forming a pixel defining layer including an opening on the passivation layer, forming a reflective layer on the pixel defining layer and connected to the driving thin film transistor, forming a pixel electrode on the reflective layer, Forming a spacer surrounding the pixel electrode, forming a light emitting member on the pixel electrode, and forming a common electrode on the light emitting member.

The reflective film and the pixel electrode can be formed simultaneously through an etching process.

The OLED display according to an embodiment of the present invention and the method of manufacturing the OLED display according to the present invention can improve the luminous efficiency by increasing the light emitting area of the light emitting member and improving the light emission brightness, And the process cost is reduced by using a spacer process or etching the reflective film and the pixel electrode at the same time.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are used for the same or similar components throughout the specification. In the case of publicly known technologies, a detailed description thereof will be omitted.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, On the other hand, when a part is "directly on" another part, it means that there is no other part in the middle. On the contrary, when a portion such as a layer, film, region, plate, or the like is referred to as being "under" another portion, this includes not only the case where the other portion is "directly underneath" On the other hand, when a part is "directly beneath" another part, it means that there is no other part in the middle.

An organic light emitting display according to an embodiment of the present invention will now be described in detail with reference to FIG.

1 is an equivalent circuit diagram of an OLED display according to an embodiment of the present invention.

1, the OLED display includes a plurality of signal lines 121, 171, and 172 and a plurality of pixels PX connected to the plurality of signal lines 121, 171, and 172 and arranged in the form of a matrix. do.

The signal line includes a plurality of gate lines 121 for transmitting gate signals (or scanning signals), a plurality of data lines 171 for transmitting data signals, and a plurality of driving voltage lines 172 for transmitting driving voltages. The gate lines 121 extend substantially in the row direction, are substantially parallel to each other, and the data lines 171 and the driving voltage lines 172 extend substantially in the column direction and are substantially parallel to each other.

Each pixel PX includes a switching thin film transistor Qs, a driving thin film transistor Qd, a storage capacitor Cst, and an organic light emitting diode , OLED (LD).

The switching thin film transistor Qs has a control terminal, an input terminal and an output terminal. The control terminal is connected to the gate line 121, the input terminal is connected to the data line 171, And is connected to the transistor Qd. The switching thin film transistor Qs transfers a data signal applied to the data line 171 to the driving thin film transistor Qd in response to a scanning signal applied to the gate line 121. [

The driving thin film transistor Qd also has a control terminal, an input terminal and an output terminal. The control terminal is connected to the switching thin film transistor Qs, the input terminal is connected to the driving voltage line 172, And is connected to the light emitting diode (LD). The driving thin film transistor Qd delivers an output current ILD whose magnitude varies according to the voltage applied between the control terminal and the output terminal.

The capacitor Cst is connected between the control terminal and the input terminal of the driving thin film transistor Qd. The capacitor Cst charges the data signal applied to the control terminal of the driving thin film transistor Qd and maintains the data signal even after the switching thin film transistor Qs is turned off.

The organic light emitting diode LD has an anode connected to the output terminal of the driving thin film transistor Qd and a cathode connected to the common voltage Vss. The organic light emitting diode LD emits light with different intensity according to the output current ILD of the driving thin film transistor Qd to display an image.

The switching thin film transistor Qs and the driving thin film transistor Qd are n-channel field effect transistors (FETs). However, at least one of the switching thin film transistor Qs and the driving thin film transistor Qd may be a p-channel field effect transistor. Also, the connection relationship between the thin film transistors Qs and Qd, the capacitor Cst, and the organic light emitting diode LD can be changed.

The detailed structure of the organic light emitting display shown in FIG. 1 will now be described in detail with reference to FIG. 2 and FIG. 3 together with FIG.

FIG. 2 is a layout diagram of an organic light emitting display according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along a line III-III of the organic light emitting display of FIG.

An insulating substrate 110 made of transparent glass or plastic is prepared.

A first interlayer insulating film 120 made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the substrate 110. [ The first interlayer insulating film 120 serves as a buffer for separating the semiconductor layer 151 from the substrate 110.

A driving semiconductor 154b is formed on the first interlayer insulating film 120. [ The driving semiconductor 154b is island-like and can be made of crystalline silicon, such as microcrystalline silicon or polycrystalline silicon.

The driving semiconductor 154b includes a doped region and a non-doped region. The doping region is located on both sides of the non-doped region, and the crystalline silicon is doped with a p-type impurity such as boron (B) or an n-type impurity such as phosphorous (P). The non-doped region is made of an intrinsic semiconductor not doped with an impurity, and a channel of the driving thin film transistor is formed.

A gate insulating film 140 made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the driving semiconductor 154b.

A gate line 121 including a switching control electrode 124a and a driving control gate 124b are formed on the gate insulating layer 140. [ The gate line 121 extends along one direction of the substrate and includes a switching control electrode 124a extending upward and an end portion (not shown) for connecting to an external driving circuit. The driving control electrode 124b is separated from the gate line 121 and includes a sustaining electrode 127 extending upwardly.

The gate line 121 and the drive control electrode 124b may include a chromium-containing metal, a titanium (Ti), or a titanium alloy including molybdenum-containing metal, chromium (Cr), or a chromium alloy including molybdenum (Mo) Containing tantalum (Ta) or tantalum alloy and a refractory metal such as a tungsten-containing metal containing tungsten (W) or a tungsten alloy, aluminum (Al), copper (Cu) Or silver (Ag).

A second interlayer insulating film 160 made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the gate line 121 and the driving control electrode 124b.

On the second interlayer insulating film 160, a driving voltage line 172 including a driving input electrode 173b and a driving output electrode 175b are formed.

The driving voltage line 172 extends mainly in the longitudinal direction and crosses the gate line 121 to transmit the driving voltage. The driving voltage line 172 includes a driving input electrode 173b extending over the driving semiconductor 154b and a part of the driving voltage line 172 overlaps with the sustaining electrode 127 of the driving control electrode 124b, storage capacitor, Cst).

The driving output electrode 175b is separated from the driving voltage line 172 and is island-shaped. The driving input electrode 173b and the driving output electrode 175b are electrically connected to the doped region of the driving semiconductor 154b through the contact holes 183a and 183b, respectively. The driving voltage line 172 and the driving output electrode 175b may be made of the above-described refractory metal or a low-resistance metal such as aluminum (Al), copper (Cu), or silver (Ag) / Aluminum (Al) / molybdenum (Mo) or the like.

The description of the data line 171 and the switching output electrode 175a including the switching semiconductor 154a, the switching control electrode 124a and the switching input electrode 173a constituting the switching thin film transistor is the same as that of the above- Can be applied equally or similarly.

Protective films 180p and 180q are formed on the driving voltage line 172, the driving output electrode 175b, and the switching output electrode 175a. The protective films 180p and 180q may be made of an inorganic insulating material or an organic material such as a polyacrylic material having excellent planarization characteristics.

A reflective film 192 is formed on the passivation film 180q and the reflective film is electrically connected to the driving output electrode 175b through the contact hole 181. [ The reflective film 192 includes an opaque conductive material such as Al and reflects light emitted downward through the light emitting member 370, thereby enhancing the luminous efficiency.

A pixel defining layer 361 made of an organic insulating material is formed on the reflective film 192. The pixel defining layer 361 surrounds the reflective film 192 like a bank. Accordingly, the pixel defining layer 361 is formed with an opening for each pixel, and an inclined surface 365 is formed around the opening.

On the pixel defining layer 361, a pixel electrode 191 and a connecting member 85 are formed. At this time, the opening of the pixel defining layer 361 and its inclined surface 365 are covered with the pixel electrode 191, and the area of the pixel electrode 191 can be appropriately adjusted as needed. The pixel electrode 191 is in contact with the reflective film 192 through the opening of the pixel defining layer 361. However, a layer including a conductive material may be further formed between the pixel electrode 191 and the reflective film 192. The pixel electrode 191 and the connecting member 85 may be made of a transparent conductor such as ITO or IZO. The connecting member 85 electrically connects the switching output electrode 175a and the driving control electrode 124b through the contact hole.

On the pixel electrode 191, a spacer 362 surrounds the pixel electrode 191 like a bank. Therefore, the spacer 362 is also provided with an opening for each pixel, and an inclined surface 366 is formed around the opening. The opening of the spacer 362 is wider than the opening of the pixel defining layer 361. The opening of the spacer 362 is wide enough to expose the inclined plane 365 of the pixel defining layer 361. The opening of the spacer 362 is wide enough to expose the inclined plane 365 of the pixel defining layer 361. The opening of the spacer 362 exposes the inclined plane 365 of the pixel defining layer 361 is formed by inclining the inclined plane 365 of the pixel electrode 191 inclined along the inclined plane 365 of the pixel defining layer 361, The inclined plane 365 of the pixel defining layer 361 is indirectly exposed. When the spacer 362 is formed, the height of the pixel defining layer 361 may be reduced as necessary.

A light emitting member 370 is formed on the pixel defining layer 361 and the light emitting member 370 covers the entire pixel electrode 191 excluding the boundary of the pixel electrode 191. The boundary portion of the light emitting member 370 and the boundary portion of the opening portion of the spacer 362 are in contact with each other. At this time, the light emitting member 370 may be formed through a fine metal mask (FMM) deposition process. Meanwhile, in the deposition process of the light emitting member 370 using the fine metal mask, scratches may be generated on the surface of the pixel electrode 191 on the substrate on which the fine metal mask is loaded. The spacer 362 serves to prevent such scratches and serves to maintain a gap between the fine metal mask and the surface of the pixel electrode 191. It also serves as a dam for forming the light emitting member 370. As a result, the light emitting member 370 defined by the opening of the spacer 362 is formed on the pixel electrode 191 covering the opening portion of the pixel defining layer 361 and the entire inclined surface in the vicinity thereof, Efficiency increases. In addition, the width of the opening of the spacer 362 defining the width of the region where the light emitting member 370 is formed can be appropriately adjusted as needed.

The light emitting member 370 may have a multi-layer structure including an auxiliary layer (not shown) for improving light emission efficiency of the light emitting layer in addition to a light emitting layer (not shown).

The light emitting layer is formed to emit white light by forming red, green, and blue light emitting layers vertically or horizontally in one pixel. The light emitting layer may be made of a polymer material or a low molecular material, or a mixture thereof, which uniquely emits any one of primary colors such as red, green, and blue primary colors.

The sub-layer includes an electron transport layer (not shown) and a hole transport layer (not shown) for balancing electrons and holes and an electron injection layer (not shown) for enhancing the injection of electrons and holes an electron injecting layer (not shown), and a hole injecting layer (not shown).

A common electrode 270 is formed on the light emitting member 370. The common electrode 270 is formed on the entire surface of the substrate and may be formed of an opaque conductor such as gold (Au), platinum (Pt), nickel (Ni), copper (Cu), tungsten Can be made.

The common electrode 270 is paired with the pixel electrode 191 to allow current to flow through the light emitting member 370. The pixel electrode 191, the organic light emitting member 370 and the common electrode 270 constitute a light emitting diode LD. When the pixel electrode 191 is an anode and the common electrode 270 is a cathode Conversely, the pixel electrode 191 serves as a cathode and the common electrode 270 serves as an anode.

On the other hand, the interlayer structure and the arrangement structure of the switching thin film transistor and the driving thin film transistor can be modified into various forms in addition to those exemplified above. That is, in the organic light emitting display according to the embodiment of the present invention, the top gate structure in which the gate electrode 124b formed to correspond to the driving semiconductor 154b is formed on the driving semiconductor 154b has been described, May be formed using amorphous silicon rather than polycrystalline silicon. In this case, the gate electrode may have a bottom gate structure formed below the semiconductor layer. In addition, any one of the semiconductors 154a and 154b included in the driving thin film transistor and the switching thin film transistor described above may be formed of polycrystalline silicon and the other may be formed of amorphous silicon.

An OLED display according to another embodiment of the present invention will now be described in detail with reference to FIG.

4 is a cross-sectional view of an OLED display according to another embodiment of the present invention.

The reflective film 192 is formed on the pixel defining layer 361 and the reflective film 192 is formed on the driving output electrode 175b by the contact hole 181 passing through the pixel defining layer 361 and the protective films 180p, Is distinguished from the organic light emitting display device of FIG. 3 described above. At this time, in order to prevent a part of the reflection film 192 inside the contact hole 181 from being cut off, the slope of the contact hole 181 may be made moderately or stepwise. In addition, the reflective film 192 and the pixel electrode 191 may be etched at the same time to have substantially the same planar shape, and in this case, the process cost is reduced. 4, since the reflective film 192 is in contact with the front surface excluding the boundary portion of the pixel electrode 191, the light emitted from the center of the light emitting member 370 in the left and right direction is reflected upward, The light emitted from the light emitting member 370 located on the inclined plane 365 of the opening of the defining layer 361 is also reflected to the upper portion, thereby improving the luminous efficiency.

Hereinafter, a method of manufacturing an OLED display according to another embodiment of the present invention will be described. The description of the organic light emitting diode display of FIGS. 2 to 3 will be omitted.

A switching thin film transistor and a driving thin film transistor connected to the switching thin film transistor are formed on the substrate 110. As a method for forming the thin film transistor and the electrode, a conventional thin film forming method such as thin film deposition or photolithography can be used. At this time, the gate insulating film 140, the first interlayer insulating film 120, and the second interlayer insulating film 160 may be stacked between the elements of the thin film transistor as described above.

The protective films 180p and 180q are formed on the switching thin film transistor and the driving thin film transistor.

A reflective film 192 connected to the driving thin film transistor is formed on the protective films 180p and 180q. The reflective film 192 can be formed by the conventional thin film forming method described above.

A pixel defining layer 361 surrounding the reflective film 192 is formed on the reflective film 192. At this time, the pixel defining layer 361 forms an opening through photolithography.

A pixel electrode 191 is formed on the pixel defining layer 361 and the reflective film 192. The pixel electrode 191 can use the conventional thin film forming method described above

A spacer 362 surrounding the pixel electrode 191 is formed on the pixel electrode 191. At this time, the spacer 362 forms an opening through the photolithography process.

A light emitting member 370 is formed on the pixel electrode 191. At this time, it can be formed using the above-described fine metal mask (FMM) deposition process.

A common electrode 270 is formed on the light emitting member 370. The common electrode 270 may be stacked on the front surface of the substrate.

Hereinafter, a method of manufacturing an OLED display according to another embodiment of the present invention will be described in detail. The overlapping description with the OLED display of FIG. 4 will be omitted.

4, a pixel defining layer 361 including an opening is formed on the passivation layers 180p and 180q, a reflective layer 192 is formed on the pixel defining layer 361 and connected to the driving thin film transistor, 192 are formed in the pixel electrode in the method of manufacturing the organic light emitting display device. At this time, since the reflective film 192 and the pixel electrode 191 can be sequentially formed and then formed through the etching process, the process cost can be reduced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

1 is an equivalent circuit diagram of an OLED display according to an embodiment of the present invention.

2 is a layout diagram of an OLED display according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the organic light emitting diode display of FIG. 2 taken along line III-III.

4 is a cross-sectional view of an OLED display according to another embodiment of the present invention.

Description of the Related Art [0002]

181, 183a, 183b: contact hole 191: pixel electrode

192: reflective film 361: pixel defining layer

362: Spacer

365: an inclined surface around the opening of the pixel defining layer

366: an inclined surface around the spacer opening

370: organic light emitting member

Claims (17)

A first signal line and a second signal line crossing each other, A switching thin film transistor connected to the first signal line and the second signal line, A driving thin film transistor connected to the switching thin film transistor, A protective film formed on the first signal line, the second signal line, the switching thin film transistor, and the driving thin film transistor, A reflective film formed on the protective film and connected to the driving thin film transistor, A pixel defining layer formed on the passivation layer and including an opening, A pixel electrode formed in the opening of the pixel defining layer and extending over an inclined surface around the opening, A spacer having a larger area than the opening of the pixel defining layer and having an opening exposing an inclined surface of the pixel defining layer opening, A light emitting member formed on the pixel electrode and formed inside the opening of the spacer, And a common electrode formed on the light emitting member and the spacer, And an organic light emitting diode. The method of claim 1, Wherein a boundary portion of the light emitting member is in contact with a boundary portion of an opening portion of the spacer. delete The method of claim 1, Wherein the reflective layer is formed on the pixel defining layer. 5. The method of claim 4, Wherein the reflective film and the pixel electrode have the same planar shape. 5. The method of claim 4, And the pixel electrode is in contact with the reflective film. 5. The method of claim 4, Wherein the reflective film is connected to the driving thin film transistor through a contact hole penetrating the protective film and the pixel defining layer. The method of claim 1, Wherein the reflective film is connected to the driving thin film transistor through a contact hole penetrating the protective film. The method of claim 1, And a part of the pixel electrode is in contact with a part of the reflective film. delete A switching thin film transistor and a driving thin film transistor connected to the switching thin film transistor are formed on a substrate, Forming a protective film on the switching thin film transistor and the driving thin film transistor, A reflective film connected to the driving thin film transistor is formed on the protective film, Forming a pixel defining layer having an opening portion surrounding the reflective film on the reflective film, Forming a pixel electrode on the pixel defining layer and the reflective film, A spacer having an opening larger than an opening of the pixel defining layer is formed on the pixel electrode, Forming a light emitting member on the pixel electrode, and And a common electrode is formed on the light emitting member and the spacer Wherein the organic light emitting display device comprises: 12. The method of claim 11, Wherein a boundary portion of the light emitting member is in contact with a boundary portion of an opening portion of the spacer. delete A switching thin film transistor and a driving thin film transistor connected to the switching thin film transistor are formed on a substrate, Forming a protective film on the switching thin film transistor and the driving thin film transistor, Forming a pixel defining layer including an opening on the protective film, Forming a reflective layer on the pixel defining layer, the reflective layer being connected to the driving thin film transistor, A pixel electrode is formed on the reflective film, Forming a spacer on the pixel electrode, the spacer having an area wider than the opening of the pixel defining layer and having an opening exposing an inclined surface of the pixel defining layer opening; Forming a light emitting member on the pixel electrode, and And a common electrode is formed on the light emitting member and the spacer Wherein the organic light emitting display device comprises: The method of claim 14, Wherein the reflective film and the pixel electrode are simultaneously formed through an etching process. The method of claim 14, Wherein a boundary portion of the light emitting member is in contact with a boundary portion of an opening portion of the spacer. delete

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