KR20080001263A - Dual plate organic electro-luminescence device and method for manufacturing the same - Google Patents

Abstract

A dual plate organic electro-luminescence device and a method for manufacturing the same are provided to adjust the height of a separator according to the condition of a process. First and second substrates(501) define a plurality of pixel areas(P), and face each other. A thin film transistor is formed on the first substrate in correspondence to each pixel region. Bus lines(503) are formed at predetermined intervals on the second substrate between the pixel regions. A first electrode(502) is formed at the front side of the second substrate. A buffer layer(504) is formed on the first electrode at the upper part of the bus line except the pixel region. Separators(505) are formed on the buffer layer in the shape of undercut. An organic light emitting layer(506) is formed on the first electrode in correspondence to the pixel region. A second electrode(507) is formed on the light emitting layer. A connection pattern connects the thin film transistor and the second electrode.

Description

Dual plate organic electroluminescent device and method for manufacturing the same

1 is a cross-sectional view showing a general dual plate organic electroluminescent device.

2 is a cross-sectional view illustrating a top substrate of a general dual plate organic electroluminescent device.

3A to 3D are cross-sectional views illustrating a method of manufacturing an upper substrate of a general dual plate organic electroluminescent device.

Figure 4 is a cross-sectional view showing a top substrate of the dual plate organic electroluminescent device of the present invention.

5A to 5E are cross-sectional views illustrating a method of manufacturing the upper substrate of the dual plate organic electroluminescent device of the present invention.

* Description of the Signs of the Major Parts of the Drawings *

501: upper substrate 502: gate insulating film

503: bus film 504: buffer film

505: partition 506: organic light emitting layer

507: second electrode layer

The present invention relates to an organic electroluminescent device, and more particularly, to a dual plate organic electroluminescent device through a double-sided undercut and a manufacturing method thereof.

In general, a liquid crystal display device (LCD) has a light weight and low power consumption, and thus is most commonly used as a flat panel display (FPD). However, since LCDs are not self-light emitting devices, there are technical limitations in brightness, contrast, viewing angle, and large area, and efforts to develop a flat panel display that can overcome these disadvantages have been actively developed. One is a self-luminous organic light emitting display device.

When an organic light emitting diode is supplied with current in a forward direction, a P-positive-N junction is formed between an anode electrode, which is a hole providing layer, and a cathode electrode, which is an electron providing layer. Electrons and holes recombine with each other as they move through the part, and thus have a smaller energy than when the electrons and holes are separated, thereby utilizing the principle of emitting light due to the energy difference generated.

Since the organic light emitting diode display is self-luminous, the viewing angle, contrast, etc. are superior to the liquid crystal display, and since the backlight is not required, the organic light emitting diode display can be light and thin, and thus, low voltage driving can be realized, which is advantageous in terms of power consumption.

Meanwhile, the organic electroluminescent device is classified into a bottom emission method or a top emission method according to where the light emitting layer is positioned in the upper and lower substrates, and in the case of the upper emission method, the thin film transistor array is disposed on the lower substrate when the active matrix type is implemented. When the light emitting layer is positioned on the upper substrate, this is called a dual plate organic electroluminescence device (DOD).

Hereinafter, a conventional dual plate organic electroluminescent device will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view illustrating a general dual plate organic electroluminescent device.

As shown in FIG. 1, a general dual plate organic electroluminescent device corresponds to a first substrate 10 and a second substrate 20 which are largely spaced apart from each other by a predetermined distance, and correspond to each sub-pixel on the first substrate 10. A thin film transistor array including a thin film transistor (TFT), an organic light emitting diode device formed on the second substrate, and a seal pattern 30 formed at edges of the first and second substrates 10 and 20. It is made to include. In addition, in order to supply a current to the organic light emitting diode E, a connector 17 and a transparent electrode 16 connecting the second electrode 25 and the thin film transistor TFT in subpixel units are formed.

The organic EL device E may include a first electrode 21 used as a common electrode and a plurality of partition walls 26 positioned at boundary portions of subpixels on the first electrode 21. ) And organic electroluminescent layers 22, 23, 24 and second electrodes 25 which are sequentially stacked for each pixel defined by the partition walls 26.

Here, the organic electroluminescent layer has a structure in which the first carrier transport layer 22, the light emitting layer 23, and the second carrier transport layer 24 are sequentially stacked, and the first and second carrier transport layers 22 are formed. , 24 serves to inject and transport electrons or holes into the light emitting layer 23.

Here, the thin film transistor TFT corresponds to a driving thin film transistor connected to the organic light emitting diode E. The thin film transistor TFT may include a gate electrode 11 formed at a predetermined portion on the first substrate 10, a gate insulating layer 12 formed on the entire surface of the first substrate 10 including the gate electrode 11, and The semiconductor layer 13 formed on the gate insulating layer 12 above the gate electrode 11, the source / drain electrodes 14a and 14b formed on both sides of the semiconductor layer 13, and the source / drain electrodes 14a and 14b. The protective layer 15 is selectively removed to expose the drain electrode 14b and the protective layer 15 formed on the entire surface of the first substrate including a contact hole, and a contact hole is formed, and the drain electrode 14b is formed through the contact hole. The transparent electrode 16 is formed on the passivation layer 15 so as to be connected to the protective layer 15. The upper side of the transparent electrode 16 is in contact with the conductive spacer 17.

The conductive spacer 17 electrically connects the drain electrode 14b of the thin film transistor T provided in the sub-pixel unit on the first substrate 10 and the second electrode 25 provided in the second substrate 20. In this case, metal is coated on a columnar spacer formed of an organic insulating layer or the like, which serves to connect the subpixels of the first and second substrates 10 and 20 one-to-one to pass current. .

In addition, the separation space between the first and second substrates 10 and 20 may be filled with an inert gas or an insulating liquid.

Although not shown in the drawings, the first substrate 10 further includes a scan line, a signal line and a power supply line crossing the scan line and spaced apart from each other by a predetermined distance, and a storage capacitor.

2 is a cross-sectional view illustrating a top substrate of a general dual plate organic electroluminescent device.

Referring to FIG. 2, an upper substrate (second substrate) 401 of a general dual plate organic light emitting display device is defined as a plurality of pixel regions P arranged in a matrix form, and the pixel region P The first electrode layer 402 is formed on the front surface of the upper substrate 401 including the substrate. The first electrode layer 402 is a hole injection electrode for injecting holes into the organic emission layer 406.

In addition, a bus line 403 is arranged in one direction on the first electrode layer 402 at regular intervals, and an insulating film 408 is formed on the bus line 403 to cover the bus line 403. A partition wall 405 is formed on the insulating film 408 to isolate the pixel areas P from each other.

An organic emission layer 406 is formed on the first electrode layer 402 of the pixel region P, and a second electrode layer 407 is formed on the organic emission layer 406. The second electrode layer 407 is an electron injection electrode for injecting electrons into the organic emission layer 406. Although not shown below and above the organic light emitting layer 406, first and second carrier transfer layers (not shown) may be provided, and the organic light emitting layer may be formed from the first electrode 402 and the second electrode 407. 406 is responsible for the injection and transport of electrons and holes to.

Referring to the manufacturing method of such a general dual plate organic electroluminescent device is as follows.

3A to 3D are cross-sectional views illustrating a method of manufacturing an upper substrate of a general dual plate organic electroluminescent device.

First, as shown in FIG. 3A, a substrate 401 having a plurality of pixel regions P arranged in a matrix form is prepared, and a transparent conductive surface is formed on the entire surface of the substrate 401 including the pixel regions P. FIG. Indium Tin Oxide (ITO) is deposited to form a first electrode layer 402.

Subsequently, as illustrated in FIG. 3B, a metal having excellent electrical conductivity, such as copper, is deposited on the entire surface of the substrate 401 including the first electrode layer 402, and patterned through a photo and etching process. The bus lines 403 are formed at regular intervals on the first electrode layer 402. In this case, the bus line 403 is formed on the first electrode layer 402 except for the pixel region P. FIG.

Subsequently, as illustrated in FIG. 3C, an insulating material is deposited on the entire surface of the substrate 401 including the bus line 403 and an insulating material of the pixel area is removed through an etching process to remove the pixel area P. An insulating film 408 is formed to cover the bus line 403 in the excluded portion.

Subsequently, as shown in FIG. 3D, a polyimide-based material is deposited on the entire surface of the substrate 401 including the insulating film 408, and patterned through a photo and etching process to form the insulating film 408. The partition wall 405 is formed on it. In this case, the barrier rib 405 is formed on the insulating layer 408 on the upper side of the bus line 403 to surround the edge of the pixel region P.

Next, a light emitting solution is coated on the first electrode layer 402 located in each pixel region P using an inkjet coating apparatus (not shown) to form an organic light emitting layer 406. The color of the light emitting solution represents any one of R, G, and B.

Subsequently, as shown in FIG. 3E, titanium (Ti), molybdenum (Mo), potassium (Ca), magnesium (Mg), and barium (Ba) are formed on the entire surface of the substrate 401 including the organic light emitting layer 406. Alternatively, a metal layer such as aluminum (Al) is deposited to form a second electrode layer 407, which is a cathode electrode (S7). In this case, the second electrode layer 407 is separated between the pixel regions P. FIG.

Thus, each pixel region P has an independent second electrode layer 407.

Although not shown in the drawings, first and second carrier transfer layers (not shown) are provided on the lower and upper portions of the organic light emitting layer 406, respectively, so that the first electrode 402 and the second electrode 407 are provided. It is responsible for injecting and transporting holes and electrons into the organic light emitting layer 406.

However, a general dual plate organic electroluminescent device and a method of manufacturing the same have a negative effect on the lifespan of the organic light emitting layer due to out gassing of organic barriers made of organic materials. It is difficult to apply.

Therefore, the sequential deposition of the organic light emitting layer is difficult because the flexible structure is not applicable to the entire structure and the lower portion of the partition wall must maintain a high slope.

An object of the present invention is to provide a dual plate organic electroluminescent device and a method of manufacturing the same in an organic electroluminescent device, through both sides undercut.

The dual plate organic electroluminescent device according to the present invention defines a plurality of pixel regions, the first substrate and the second substrate formed to face each other; A thin film transistor formed on the first substrate corresponding to each pixel area; Bus lines formed at regular intervals on a second substrate between the pixel regions; A first electrode formed on the front surface of the second substrate including the bus line; A buffer film formed on the first electrode above the bus line except for the pixel area; Barrier ribs formed on the buffer layer to have a double-sided undercut phenomenon; An organic electroluminescent layer formed on the first electrode corresponding to the pixel region; A second electrode formed on the organic electroluminescent layer; And a connection pattern connecting the thin film transistor and the second electrode.

A method for manufacturing a dual plate organic electroluminescent device according to the present invention may include: preparing a first substrate and a second substrate that define a plurality of pixel regions and are formed to face each other; Forming a thin film transistor corresponding to each pixel area on the first substrate; Forming bus lines at regular intervals on a second substrate between the pixel regions; Forming a first electrode on the front surface of the second substrate including the bus line; Forming a buffer film on the first electrode above the bus line; Forming a sacrificial layer on the entire surface of the first electrode including the buffer layer; Selectively removing the sacrificial layer above the buffer layer; Forming a partition on a portion where the sacrificial layer has been removed and an adjacent portion thereof; Removing all of the sacrificial film; Forming an organic EL layer on the first electrode corresponding to each pixel area; Forming a second electrode on the organic electroluminescent layer; And forming a seal pattern on the outer periphery of the first and second substrates, and electrically connecting the second electrode and the thin film transistor through a conductive spacer between the drain electrode and the second electrode of the thin film transistor. And bonding the first and second substrates together.

Hereinafter, the dual plate organic electroluminescent device of the present invention will be described in detail with reference to the accompanying drawings.

4 is a structural cross-sectional view showing an upper substrate of the dual plate organic electroluminescent device of the present invention.

Referring to FIG. 4, the upper substrate (second substrate) 501 of the dual plate organic electroluminescent display of the present invention is defined as a plurality of pixel regions P arranged in a matrix form. The bus line 503 is formed in one direction at regular intervals on the upper substrate 501 except P).

The first electrode layer is formed of a transparent conductive material including any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO) on the entire surface of the upper substrate 501 including the bus line 503. 502 is formed. The first electrode layer 502 is a hole injection electrode for injecting holes into the organic emission layer to be formed later.

A buffer layer 504 is formed on the first electrode layer 502 above the bus line 503, and partition walls 505 are formed on the buffer layer 504. Each of the partitions 505 separates the pixel areas P from each other, and for this purpose, the partitions 505 surround the periphery of the pixel areas P.

The bus line 503 is made of a light-shielding metal having high conductivity compared to at least the first electrode 502 having good conductivity. The light-shielding metal is made of at least one of titanium (Ti), molybdenum (Mo), potassium (Ca), magnesium (Mg), barium (Ba), copper (Cu) and aluminum (Al).

An organic emission layer 506 is formed on the first electrode layer 502 of the pixel region P, and a second electrode layer 507 is formed on the organic emission layer 506. The second electrode layer 507 is an electron injection electrode for injecting electrons into the organic emission layer 506. Although not shown below and above the organic light emitting layer 506, first and second carrier transfer layers (not shown) may be provided to form the organic light emitting layer 506 from the first electrode 502 and the second electrode 507. It is in charge of the injection and transport of electrons and holes to).

The lower substrate facing the upper substrate is also defined as a plurality of pixel regions P, and thin film transistors (switching elements and driving elements) are provided in each pixel region. Here, as the upper substrate 501 and the lower substrate are bonded by a seal pattern, the drain electrode of the driving element provided in the lower substrate is connected to the second electrode layer 507 of the upper substrate 501. .

The thin film transistor may include a gate electrode formed on a predetermined portion on the lower substrate, a gate insulating film formed on the entire surface of the substrate including the gate electrode, a semiconductor layer formed on the gate insulating film above the gate electrode, and formed on both sides of the semiconductor layer. And source / drain electrodes. The drain electrode is connected to the second electrode 507 through a connection pattern to apply a signal according to driving of the thin film transistor.

The connection pattern may include a transparent electrode electrically connected to the thin film transistor and a conductive spacer connecting and supporting the second electrode and the pixel electrode.

Referring to the method of manufacturing a dual plate organic electroluminescent device according to the present invention as follows.

5A to 5D are cross-sectional views illustrating a method of manufacturing the upper substrate of the dual plate organic electroluminescent device according to the present invention.

First, as shown in FIG. 5A, a substrate 501 having a plurality of pixel regions P arranged in a matrix form is prepared, and a metal having excellent electrical conductivity such as copper is deposited on the entire surface of the substrate 501. Then, this is patterned through a photo and etching process, thereby forming a bus line 403 on the substrate 501 between the pixel region (P).

As shown in FIG. 5B, a transparent conductive metal (ITO; Indium Tin Oxide) is deposited on the entire surface of the upper substrate 501 including the bus line 503 to form a first electrode layer 502.

Subsequently, a buffer layer 504 is formed on the first electrode layer 502 except for the pixel region P. Referring to FIG.

As illustrated in FIG. 5C, a sacrificial layer 508 such as SIO 2 is deposited on the entire surface of the upper substrate 501 including the buffer layer 504, and the sacrificial layer 508 above the buffer layer 504. ) Is removed through the photo and etching process in a narrower width than the buffer layer 504.

Subsequently, as illustrated in FIG. 5D, a material such as SINx is deposited on the entire surface of the sacrificial layer 508 including the patterned portion of the sacrificial layer 508, and patterned through a photo and etching process. The partition wall 505 is formed on the sacrificial layer 508 above the buffer layer 504.

As shown in FIG. 5D, the sacrificial layer 508 is removed through wet etching, thereby leaving a partition 505 having an undercut shape. At this time, there is no damage to the partition.

Each of the partitions 505 separates the pixel areas P from each other, and for this purpose, the partitions 505 surround the periphery of the pixel areas P.

Next, a light emitting solution is applied onto the first electrode layer 502 located in each pixel region P using an inkjet coating device (not shown) to form the organic light emitting layer 506. The color of the light emitting solution represents any one of R, G, and B.

Subsequently, as shown in FIG. 5E, titanium (Ti), molybdenum (Mo), potassium (Ca), magnesium (Mg), and barium (Ba) are formed on the entire surface of the substrate 401 including the organic light emitting layer 506. Alternatively, a metal layer such as aluminum (Al) is deposited to form a second electrode layer 507 that is a cathode electrode. In this case, the second electrode layer 507 is separated between the pixel areas P. FIG. Therefore, each pixel area P has an independent second electrode layer 507.

Although not shown in the drawings, first and second carrier transfer layers (not shown) are provided on the lower and upper portions of the organic light emitting layer 506, respectively, so that the first electrode 502 and the second electrode 507 are provided. It is responsible for injecting and transporting holes and electrons into the organic light emitting layer 506.

 Such a dual plate organic electroluminescent device and a method of manufacturing the same according to the present invention can be applied to a large area compared to the general dual plate organic electroluminescent device according to the undercut structure, and the life of the organic light emitting layer is increased by replacing the existing organic partition with an inorganic partition. Increases.

In addition, it is possible to adjust the height of the partition wall according to the process conditions, it is possible to apply flexibly to the entire structure and to maintain a low taper lower partition wall is possible to sequentially deposit the organic light-emitting film after.

Therefore, partition wall formation through undercuts on both sides enables more accurate separation than cross-sectional undercut formation.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention It will be apparent to those skilled in the art.

The dual plate organic electroluminescent device through the double-sided undercut and the manufacturing method thereof as described above can simplify the process and apply a large area, and the height of the partition wall can be adjusted according to the process conditions so that the entire structure can be flexibly applied and the bottom of the partition wall It is possible to maintain a low taper allows subsequent deposition of the organic light emitting film. In addition, the lifespan of the organic light emitting layer is increased by replacing the organic barrier with an inorganic barrier.

Claims (10)

A first substrate and a second substrate defining a plurality of pixel regions and formed to face each other; A thin film transistor formed on the first substrate corresponding to each pixel area; Bus lines formed at regular intervals on a second substrate between the pixel regions; A first electrode formed on the front surface of the second substrate including the bus line; A buffer film formed on the first electrode above the bus line except for the pixel area; Barrier ribs formed on the buffer layer to have a double-sided undercut shape; An organic electroluminescent layer formed on the first electrode corresponding to the pixel region; A second electrode formed on the organic electroluminescent layer; And And a connection pattern connecting the thin film transistor and the second electrode. The method of claim 1, The partition wall is a dual plate organic electroluminescent device characterized in that it comprises a SINx-based material. The method of claim 1, And the first electrode is a transparent electrode. The method of claim 3, wherein The first electrode is a dual plate organic electroluminescent device comprising any one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). The method of claim 1, The bus line is a dual plate organic electroluminescent device, characterized in that the light-shielding metal. The method of claim 5, The light-shielding metal is a dual plate comprising at least one of titanium (Ti), molybdenum (Mo), potassium (Ca), magnesium (Mg), barium (Ba), copper (Cu) and aluminum (Al). Organic electroluminescent device. Defining a plurality of pixel regions and preparing a first substrate and a second substrate formed to face each other; Forming a thin film transistor corresponding to each pixel area on the first substrate; Forming bus lines at regular intervals on a second substrate between the pixel regions; Forming a first electrode on the front surface of the second substrate including the bus line; Forming a buffer film on the first electrode above the bus line; Forming a sacrificial layer on the entire surface of the first electrode including the buffer layer; Selectively removing the sacrificial layer above the buffer layer; Forming a partition on a portion where the sacrificial layer has been removed and an adjacent portion thereof; Removing all of the sacrificial film; Forming an organic EL layer on the first electrode corresponding to each pixel area; Forming a second electrode on the organic electroluminescent layer; And The first and second substrates may include a seal pattern, and the second electrode and the thin film transistor may be electrically connected to each other through a conductive spacer between the drain electrode and the second electrode of the thin film transistor. 1, the method of manufacturing a dual plate organic electroluminescent device comprising the step of bonding the second substrate. The method of claim 7, wherein The partition wall is a manufacturing method of a dual plate organic electroluminescent device, characterized in that it comprises a SINx-based material. The method of claim 7, wherein The sacrificial layer is a method of manufacturing a dual plate organic electroluminescent device, characterized in that it comprises a SIO₂ series material. The method of claim 9, The sacrificial layer is removed by a wet etching method of manufacturing a dual plate organic electroluminescent device.

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