KR20160083449A - Organic Light Emitting Display Device - Google Patents

Abstract

The present invention relates to an organic light emitting display device capable of preventing a dim spot malfunction, which is caused by erosion of an active layer, by separating an interlayer insulating film hole from a protective film hole. A plurality of pixels arranged in the organic light emitting display device is defined by a data line, a driving power line, and a reference voltage line which are arranged in a first direction; and a scan signal line, and a sense signal line which are arranged in a second direction. An organic light emitting diode and a pixel circuit for driving the organic light emitting diode are arranged in each of pixels. The pixel circuit includes: a scan thin film transistor (TFT), a driving TFT, a sense TFT, and a storage capacitor. A first insulating layer hole, which connects the sense TFT and the storage capacitor, is separated from a second insulating layer hole.

Description

[0001] The present invention relates to an organic light emitting display device,

The present invention relates to an organic light emitting display device that prevents a defect in a dark spot caused by erosion of an active layer.

An organic light emitting display device which displays an image by emitting an organic light emitting diode (OLED) can be divided into a passive matrix method and an active matrix method according to a driving method.

The passive matrix method includes a configuration in which pixels are arranged in a matrix form without a separate thin film transistor (hereinafter referred to as a TFT), and power consumption is increased and resolution is also limited.

On the other hand, the active matrix method includes a configuration in which TFTs are formed in each of the pixels arranged in a matrix form, and drives each pixel by the switching operation of the TFT and the voltage charging of the storage capacitor Cst.

Therefore, power consumption is low and resolution is advantageous compared with the passive matrix method. An organic light emitting element of the active matrix type is suitable for a display element requiring a high resolution and a large area. Hereinafter, an active matrix organic light emitting display device will be briefly referred to as an organic light emitting display device in the present specification.

1 is a view for explaining a pixel structure of an organic light emitting display device according to the related art. 1 shows one pixel among all the pixels of the organic light emitting display device.

1, each pixel of the display panel includes a light emitting portion EA in which an organic light emitting diode (OLED) emitting light by an input data current Ioled is disposed, and a light emitting portion EA for driving the organic light emitting diode OLED And a drive circuit unit (CA) in which a circuit is disposed.

In the display panel, a plurality of lines for supplying driving power and signals to the organic light emitting diode (OLED) and the pixel circuit are connected to the data line 10, the VDD line 20, the reference voltage line 30, (40), and a sense signal line (50).

FIG. 1 shows a pixel circuit of an internal compensation system composed of 3Tr-1 Cap. The pixel circuit includes a driving TFT 60, a scan TFT 70, a sense TFT 80, and a storage capacitor 90.

Here, the gate electrode of the sense TFT 80 is connected to the sense signal line 50, the first electrode of the sense TFT 80 is connected to the storage capacitor 80, and the second electrode of the sense TFT 80 The electrodes are connected to the reference voltage line 30.

Fig. 2 is an enlarged view of a portion A shown in Fig. 1 and a sectional view of a portion A of Fig.

Referring to FIG. 2, a line extending from the first electrode of the sense TFT 80 to the ITO and a portion where the storage capacitor 90 is connected are shown.

An active layer 92 is disposed on the buffer layer 91 and an interlayer insulating film 93 (ILD: Interlayer Dielectric) is disposed to cover the active layer 92. A source / drain metal layer 94 is disposed on the interlayer insulating film 93 and a protective film 95 is disposed to cover the source / drain metal layer 94.

An ILD hole is formed by removing the interlayer insulating film 93 which overlaps the active layer 92 in order to connect the storage capacitor 90 to the first electrode of the sense TFT 80. [ Then, a protective film 95 overlying the interlayer insulating film hole (ILD hole) is removed to form a PAS hole.

In this manner, the interlayer insulating film hole (ILD hole) and the PAS hole are arranged so as to overlap with each other. There is a problem that erosion occurs in the active layer 92 disposed below when an interlayer insulating film hole (ILD hole) is formed in a manufacturing process and a PAS hole is formed.

In the structure in which the ILD hole and the PAS hole are overlapped with each other, etchant used for forming the PAS hole penetrates the ILD hole under the interlayer insulating film hole The interlayer insulating film 93 is lost and the active layer 92 is eroded.

The pixels in which the interlayer insulating film hole (ILD hole) is leaked and the active layer 92 is eroded have a problem that the organic light emitting diode OLED can not normally emit light, resulting in a defective pixel.

The pixel structure and the arrangement structure of the interlayer insulating film hole (ILD hole) and the PAS hole described in the background art described above can be obtained by the inventors of the present application for the purpose of deriving the present invention, As a technical information, it is not necessarily a known technology disclosed to the general public before the application of the present invention.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an organic light emitting display device which prevents erosion of an active layer to prevent a defect in a dark spot.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an embodiment of the present invention, a plurality of pixels arranged in an OLED display device includes a data line arranged in a first direction, a driving power line, a reference voltage line, Signal lines, and sense signal lines. Each of the plurality of pixels is provided with an organic light emitting diode and a pixel circuit for driving the organic light emitting diode, and the pixel circuit includes a thin film transistor (TFT), a driving TFT, a sense TFT and a storage capacitor. The first insulating layer hole and the second insulating layer hole for connecting the sense TFT and the storage capacitor are spaced apart from each other.

The organic light emitting display device according to the embodiment of the present invention can arrange the interlayer insulating film hole and the protective film hole so as to be spaced apart from each other to prevent the defect of the dark spot due to the erosion of the active layer.

The organic light emitting display device according to the embodiment of the present invention can prevent the loss of the interlayer insulating layer by disposing the interlayer insulating layer hole and the protective layer hole apart from each other.

Other features and effects of the present invention may be newly understood through the embodiments of the present invention in addition to the features and effects of the present invention mentioned above.

1 is a view for explaining a pixel structure of an organic light emitting display device according to the related art.
Fig. 2 is an enlarged view of a portion A shown in Fig. 1 and a sectional view of a portion A of Fig.
3 is a diagram illustrating a pixel structure of an organic light emitting display device according to an embodiment of the present invention.
4 is an enlarged view of a portion B shown in Fig.
5 is a cross-sectional view taken along the line B1-B2 shown in Fig.

Like reference numerals throughout the specification denote substantially identical components. In the following description, detailed descriptions of configurations and functions known in the technical field of the present invention and those not related to the core configuration of the present invention can be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is only defined by the scope of the claims.

It should be noted that, in the specification of the present invention, the same reference numerals as in the drawings denote the same elements, but they are numbered as much as possible even if they are shown in different drawings.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can be added unless '~ only' is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

The term " at least one " should be understood to include all possible combinations from one or more related items. For example, the meaning of 'at least one of the first item, the second item and the third item' means not only the first item, the second item or the third item, but also the second item, the second item and the third item, Means any combination of items that can be presented from more than one.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

Before describing the drawings, an organic light emitting display device according to an embodiment of the present invention includes a display panel and a driving circuit.

The driving circuit unit includes a data driver, a gate driver, a timing controller, a memory, and a power supply unit, and is formed on a printed circuit board and a chip on film (COF) on which a plurality of driving ICs are mounted. And supplies power and driving signals to the display panel using FOG (Film on Glass).

The display panel includes an active area in which a plurality of pixels are arranged in a matrix form to display an image, and a non-display area in which a plurality of link lines and log lines are formed.

Hereinafter, an organic light emitting display device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a diagram illustrating a pixel structure of an organic light emitting display device according to an embodiment of the present invention.

Although not shown in the figure, one unit pixel may be composed of four color RWBG pixels, and FIG. 3 illustrates one pixel structure among all the pixels of the organic light emitting display device according to the embodiment of the present invention.

Referring to FIG. 3, each pixel of the organic light emitting display device 100 according to the embodiment of the present invention includes a light emitting portion EA having an organic light emitting diode (OLED) emitting light by an input data current Ioled, And a driving circuit unit (CA) having a pixel circuit for driving the organic light emitting diode (OLED).

A plurality of lines for supplying driving power and signals to the organic light emitting diode (OLED) and the pixel circuit are disposed on the TFT array substrate of the display panel.

 The plurality of lines includes a data line 110, a VDD line 120, a reference voltage line 130, a scan signal line 140, and a sense signal line 150.

Here, the data line 110, the scan signal line 140, and the sense signal line 150 may be formed for each pixel. On the other hand, the VDD line 120 and the reference voltage line 130 may be formed for one unit pixel or for a plurality of unit pixels.

One unit pixel is composed of red, white, blue and green (RWBG) pixels of four colors, and the data line 110 of each pixel is arranged in the vertical direction.

The VDD line 120 is arranged in the vertical direction in common between the two unit pixels, and is branched in the horizontal direction so that the VDD voltage is supplied to each pixel. In FIG. 3, one pixel is shown, and the portion where the VDD line 120 is arranged in the vertical direction is not shown.

The vertically formed VDD line 120 is branched in the horizontal direction to be connected to the driving TFT 160 and the driving power supply VDD is supplied to the driving TFT 160. [

The reference voltage line 130 is arranged in the vertical direction, and the reference voltage line 130 may be disposed in common to one unit pixel. The reference voltage line 130 may be disposed at the center of the unit pixel.

The scan signal lines 140 are arranged in the horizontal direction and disposed under the storage capacitor 190. The sense signal lines 150 are arranged in the horizontal direction and are arranged below the scan signal lines 140.

A data voltage is applied to the data line 110 from the data driver. The data voltage Vdata may include a compensation voltage for compensating for a change in the threshold voltage Vth and the mobility k of the driving TFT 160 of the pixel.

The reference voltage line 130 may be selectively supplied with a display reference voltage or a sensing reference voltage from the data driver. The display reference voltage is supplied to each reference voltage line 130 during the data charging period of each pixel. The sensing reference voltage may be supplied to the reference voltage line 130 in the sensing period for sensing the threshold voltage Vth and mobility k of the driving TFT 160 of each pixel.

A scan signal (gate drive signal) is applied to the scan signal line 140 from a gate driver. A sense signal (sense) is applied to the sense signal line 150 from the gate driver.

FIG. 3 shows an internal compensation type pixel circuit composed of 3Tr-1 Cap. The pixel circuit includes a driving TFT 160, a scan TFT 170, a sense TFT 180, and a storage capacitor 190.

The driving TFT 160, the scan TFT 170 and the sense TFT 180 may be formed of an amorphous silicon (a-Si), a low-temperature poly-silicon (LTPSL) (N-type) or P-type (P-type).

The scan TFT 170 is switched in accordance with a scan signal (gate drive signal) supplied to the scan signal line 140. The scan TFT 170 is turned on by the scan signal and the data voltage Vdata supplied to the data line 110 is supplied to the driving TFT 160. [

The driving TFT 160 is switched according to the data voltage Vdata supplied from the scan TFT 170 to control the data current Ioled flowing to the organic light emitting diode OLED. When the driving TFT 160 is turned on, the driving current applied through the VDD line 120 is input to the organic light emitting diode OLED, and the organic light emitting diode OLED emits light.

A gate electrode of the sense TFT 180 is connected to a sense signal line 150. A first electrode (for example, a source electrode) of the sense TFT 80 is connected to the storage capacitor 180, (For example, a drain electrode) of the second transistor 80 is connected to the reference voltage line 130. [

The sense TFT 180 is switched by the sense signal sense applied to the sense signal line 150. [ The voltage of the anode electrode of the organic light emitting diode OLED is initialized to the reference voltage by the switching of the sense TFT 180. [

However, in the case of the external compensation method, the data current Ioled supplied to the anode electrode of the organic light emitting diode OLED is sensed by the switching of the sense TFT 180, The data voltage supplied to each pixel can be compensated to compensate for the change in the threshold voltage (Vth) and the mobility characteristic of the driving TFT (160).

Fig. 4 is an enlarged view of part B shown in Fig. 3, and Fig. 5 is a sectional view taken along the line B1-B2 shown in Fig.

Referring to FIGS. 4 and 5, a line extending from the first electrode of the sense TFT 180 to the ITO and a portion where the storage capacitor 190 is connected are shown.

An active layer 192 is disposed on the buffer layer 191 and an interlayer insulating layer 193 (ILD: Interlayer Dielectric) is disposed to cover the active layer 192. The interlayer insulating film 193 is a second layer formed of a first film and a silicon nitride (SiNx) can be formed as a single film formed of a silicon oxide (SiO ₂₎ of silicon oxide (SiO ₂₎ or silicon nitride (SiNx) .

A source / drain metal layer 194 is disposed on the interlayer insulating film 193 and a protective film 195 is disposed to cover the source / drain metal layer 194. A protective film 195 is formed in a second film formed of a silicon oxide (SiO ₂₎ or silicon nitride first layer and a silicon nitride (SiNx) can be formed as a single film formed of a silicon oxide (SiO ₂₎ a (SiNx) .

The source / drain metal layer 194 may be formed of a single layer structure using molybdenum (Mo), titanium (Ti), aluminum (Al), or copper (Cu) As another example, the source / drain metal layer 194 may be formed in a multi-layer structure using at least two materials selected from the group consisting of molybdenum (Mo), titanium (Ti), aluminum (Al) It is possible.

In the OLED display device according to the embodiment of the present invention, the connection structure of the sense TFT 180 and the storage capacitor 190 is arranged in a double contact structure, and an interlayer insulating film hole (ILD hole) and a PAS hole And are arranged so as to be spaced apart with an insulating layer therebetween.

Specifically, in order to connect the first electrode of the sense TFT 180 and the storage capacitor 190, an ILD hole is formed by removing the interlayer insulating film 13 overlapping the active layer 92 Respectively.

The active layer 192 is exposed by the ILD hole and the active layer 192 and the source / drain metal layer 193 are connected in the interlayer insulating film hole (ILD hole).

Then, a part of the protective film 195 is removed at a portion spaced apart by a predetermined distance so as not to overlap the interlayer insulating film hole (ILD hole) to form a PAS hole.

The upper surface of the source / drain metal layer 193 is exposed by the PAS hole and the transparent line extending from the first electrode of the sense TFT 180 to the ITO is disposed inside the PAS hole, / Drain metal layer 194, respectively. Thus, the first electrode of the sense TFT 180 and the storage capacitor 190 are connected.

The interlayer insulating layer 193 and the passivation layer 195 are disposed between the ILD hole and the PAS hole and the interlayer insulating layer hole and the PAS hole are overlapped with each other. .

(ILD) hole and a PAS hole are not overlapped with each other. Therefore, when an ILD hole is formed in a manufacturing process and a PAS hole is formed, a protective film 195 The erosion of the active layer 192 due to the etchant can be prevented.

It is also possible to prevent the etchant of the protective film 195 from penetrating into the lower portion of the interlayer insulating film 193 and thereby preventing the interlayer insulating film 193 from being lost.

It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Display panel
110: Data line
120: VDD line
140: scan signal line
150: sense signal line
160: Driving TFT
170: scan TFT
180: Sense TFT
190: storage capacitor
191: buffer layer
192: active layer
193: Interlayer insulating film
194: Source / drain metal layer
195: Shield
PAS hole: Shield hole
ILD hole: Interlayer insulating film hole

Claims (4)

A plurality of pixels defined by a data line arranged in a first direction, a driving power supply line, a reference voltage line and a scan signal line arranged in a second direction, and a sense signal line; And
An organic light emitting diode disposed in each of the plurality of pixels, and a pixel circuit for driving the organic light emitting diode,
The pixel circuit includes a thin film transistor (TFT), a driving TFT, a sense TFT, and a storage capacitor,
Wherein the first insulating layer hole and the second insulating layer hole for connecting the sense TFT and the storage capacitor are spaced apart from each other. The method according to claim 1,
Wherein the first insulating layer hole and the second insulating layer hole are not overlapped with each other. 3. The method of claim 2,
The interlayer insulating film disposed to cover the active layer is removed and the first insulating layer hole is disposed,
A source / drain metal layer is disposed to be in contact with the active layer,
And the second insulation layer hole is disposed by removing the protective film disposed to cover the source / drain metal layer. The method of claim 3,
And a transparent line extending from the first electrode of the sense TFT is arranged so as to be connected to the source / drain metal layer in the second insulating layer hole, and the first electrode of the sense TFT and the storage capacitor are connected to each other. .

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