KR100581099B1 - Organic electroluminescent device and manufacturing method thereof - Google Patents

Abstract

An organic electroluminescent device according to the present invention comprises: first and second substrates disposed to face each other; An array region defined by an array element having a thin film transistor formed on an inner surface of the first substrate, and an organic light emitting diode element formed on an inner surface of a second substrate corresponding to each array element; A plurality of conductive spacers positioned in the array region and connecting the array elements and the organic light emitting diode elements and maintaining the gap between the first and second substrates; Seal patterns formed at edges of the first and second substrates to bond the first and second substrates together; A plurality of first dummy pattern spacers formed in an area from outside the array area to a seal pattern; The second dummy pattern spacers formed inside the seal pattern may be included.

Description

Organic electroluminescent device and method of manufacturing the same {Organic Electro luminescence Device and fabrication method

1 is a view showing a basic pixel structure of a general active matrix organic electroluminescent device.

Figure 2 is a schematic cross-sectional view of a conventional bottom emission organic electroluminescent device.

3 is a plan view of an organic light emitting display device of a dual panel type.

4 is a cross-sectional view of a specific region I-I 'of FIG.

5 is a plan view of an organic light emitting display device of a dual panel type according to the present invention;

FIG. 6 is a cross-sectional view of a specific region II-II ′ of FIG. 5.

Figure 7 is a process flow diagram for one embodiment of an organic electroluminescent device manufacturing process according to the present invention.

<Explanation of symbols for the main parts of the drawings>

500: seal pattern 510: first dummy pattern spacer

520: second dummy pattern spacer

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device of a dual panel type and a method of manufacturing the same.

One of the new flat panel displays (FPDs), organic light emitting diodes are self-luminous, so they have better viewing angles, contrast, etc. than liquid crystal displays. Do.

In addition, since it is possible to drive DC low voltage, fast response speed, and all solid, it is strong against external shock, wide use temperature range, and especially inexpensive in terms of manufacturing cost.

In particular, unlike the liquid crystal display device or the plasma display panel (PDP), the deposition and encapsulation equipments can be referred to in the manufacturing process of the organic light emitting device, and the process is very simple.

In the related art, a passive matrix having no separate switching device has been mainly used as a driving method of the organic light emitting device.

However, in the passive matrix method, since the gate lines (scan lines) and data lines (signal lines) cross each other to form a device in a matrix form, the gate lines are sequentially driven over time to drive each pixel. In order to represent the average luminance, the instantaneous luminance must be equal to the average luminance multiplied by the number of lines.

However, in the active matrix method, a thin film transistor, which is a switching element for turning on / off a pixel, is positioned for each subpixel, and the first electrode connected to the thin film transistor is The second electrode, which is turned on / off in subpixel units and faces the first electrode, becomes a common electrode.

In the active matrix method, a voltage applied to a pixel is charged in a storage capacitor (C _ST ), and the power is applied until the next frame signal is applied to the number of gate lines. Run continuously for one screen regardless.

Therefore, according to the active matrix method, since the same luminance is applied even when a low current is applied, it has the advantage of low power consumption, high definition, and large size.

Hereinafter, the basic structure and operation characteristics of the active matrix organic electroluminescent device will be described in detail with reference to the accompanying drawings.

1 is a view showing a basic pixel structure of a general active matrix organic electroluminescent device.

As shown, the gate lines GL 2 are formed in a first direction, are formed in a second direction crossing the first direction, and are spaced apart from each other by a predetermined distance. A power supply line (VDD) 4 is formed to define one subpixel region.

At the intersection of the gate line 2 and the data line 3, a switching TFT 5, which is an addressing element, is formed, and the switching TFT 5 and the power supply line 4 are formed. ) and which is the storage capacitor (C _ST) 6 are formed connection, the storage capacitor of the driving TFT (C _ST) associated with a 6 and a power supply line (4), a current source element (current source element) ( 7) is formed, and is connected to the driving thin film transistor 7 to form an organic luminescent diode 8.

When the organic light emitting diode 8 supplies current to the organic light emitting material in a forward direction, a P (positive) -N (negative) junction between an anode electrode, which is a hole providing layer, and a cathode electrode, which is an electron providing layer, is applied. Since the electron and the hole move and recombine with each other through the junction, they have less energy than when the electron and the hole are separated, and thus, the principle of emitting light due to the difference in energy generated at this time is used.

The organic light emitting diode is classified into a top emission type and a bottom emission type according to a traveling direction of light emitted from the organic light emitting diode.

FIG. 2 is a schematic cross-sectional view of a conventional bottom emission type organic electroluminescent device, and is illustrated based on one pixel area including red, green, and blue subpixels.

As illustrated, the first and second substrates 10 and 30 are disposed to face each other, and the edge portions of the first and second substrates 10 and 30 are sealed by a seal pattern 40. The thin film transistor T is formed on the transparent substrate 1 of the first substrate 10 for each subpixel, is connected to the thin film transistor T, and the first electrode 12 is formed. Red, green, and blue colors are disposed on the transistor T and the first electrode 12 to be connected to the thin film transistor T so as to correspond to the first electrode 12. An organic light emitting layer 14 including a light emitting material is formed, and a second electrode 16 is formed on the organic light emitting layer 14.

The first and second electrodes 12 and 16 serve to apply an electric field to the organic light emitting layer 14.

The second electrode 16 and the second substrate 30 are spaced apart from each other by the seal pattern 40 described above, and although not shown in the drawing, the inner surface of the second substrate 30 may be formed from the outside. A moisture absorbent (not shown) that absorbs the incoming moisture and a semipermeable tape (not shown) for adhesion between the moisture absorbent and the second substrate 30 are included.

For example, when the first electrode 12 is an anode and the second electrode 16 is a cathode in a bottom emission structure, the first electrode 12 is selected from a transparent conductive material, and the second electrode 16 is formed. ) Is selected from a metal material having a low work function, and under these conditions, the organic light emitting layer 14 is formed from a layer in contact with the first electrode 12, a hole injection layer 14a, a hole transport layer 14b; A transporting layer), an emission layer 14c, and an electron transporting layer 14d are formed in this order.

In this case, the light emitting layer 14c has a structure in which light emitting materials for implementing red, green, and blue colors are sequentially disposed for each subpixel.

In the conventional bottom emission type organic light emitting device as described above, the device is manufactured by bonding the first substrate 10 having the array element and the organic light emitting diode and the second substrate 30 for encapsulation.

In this case, since the product of the yield of the array device and the yield of the organic light emitting diode determines the yield of the organic light emitting device, the conventional organic electroluminescent device structure has a total process yield by the organic electroluminescent diode process, which is a late step. There was a problem that is greatly limited. For example, even if the array element is satisfactorily formed, if a defect occurs due to foreign matter or other elements in forming the organic electroluminescent layer using a thin film of about 1000 mW, the organic electroluminescent element is determined to be a poor grade.

This results in a loss of overall costs and material costs that were required to manufacture the array device of good quality, there was a problem that the production yield is lowered.

In addition, the bottom emission method has a high degree of freedom and stability due to the encapsulation process, and has a problem in that it is difficult to be applied to a high-resolution product due to the limitation of the aperture ratio. It is advantageous in terms of product life, but in the conventional top emission type structure, since the material selection range is narrow as the cathode is normally positioned on the organic light emitting layer, the transmittance is limited and the light efficiency is reduced, and the light transmittance is minimized. In order to configure a thin film type protective film, there is a problem that does not sufficiently block the outside air.

According to an embodiment of the present invention, first dummy pattern spacers are formed in an area from an outside of an array region to a seal pattern, second dummy pattern spacers are formed in the seal pattern, and the first dummy pattern spacers and the second dummy pattern spacer are formed. By differentiating the density of these, the purpose of maintaining the gap between the upper and lower plates almost similar to the inside of the array region, and the second dummy pattern spacer to provide an organic electroluminescent device that serves as a reinforcement of the seal pattern.

In order to achieve the above object, the organic electroluminescent device according to the present invention comprises: first and second substrates disposed to face each other; An array region defined by an array element having a thin film transistor formed on an inner surface of the first substrate, and an organic light emitting diode element formed on an inner surface of a second substrate corresponding to each array element; A plurality of conductive spacers positioned in the array region and connecting the array elements and the organic light emitting diode elements and maintaining the gap between the first and second substrates; Seal patterns formed at edges of the first and second substrates to bond the first and second substrates together; A plurality of first dummy pattern spacers formed in an area from outside the array area to a seal pattern; The second dummy pattern spacers formed inside the seal pattern may be included.

Here, the first and second substrates are defined as subpixels, which are the smallest unit areas for implementing a screen, and the thin film transistors are positioned in units of the subpixels, and the organic light emitting diode device includes a first electrode and an organic light emitting layer. And a second electrode patterned in units of the subpixels, and the conductive spacer electrically connects the thin film transistor and the second electrode in each subpixel unit.

The first dummy pattern spacers and the second dummy pattern spacers may have different densities, respectively, and the second dummy pattern spacers may be formed more densely than the first dummy pattern spacers. It is characterized in that it is formed more densely than the first and second dummy pattern spacers.

In addition, the fail turn is characterized in that the sealant is made of a glass fiber-free.

In addition, the method of manufacturing an organic light emitting display device according to the present invention includes the steps of: providing first and second substrates on which pixels composed of red, green, and blue subpixels are defined; Forming an array device having switching elements for each subpixel on an upper array area of the first substrate; Forming a first electrode made of a transparent material having transparency on the second substrate; Forming an organic light emitting layer on the first electrode; Forming a second electrode on the organic light emitting layer in units of subpixels; Connecting the first and second substrates to conductive spacers; Forming a seal pattern at an edge portion of one of the first and second substrates to form first dummy pattern spacers in a region from the outside of the array region to the seal pattern in bonding the first and second substrates; And forming second dummy pattern spacers inside the seal pattern. Prior to the description of the present invention, a dual panel type organic light emitting display device will be described.

FIG. 3 is a plan view of an organic light emitting display device of a dual panel type, and FIG. 4 is a cross-sectional view of a specific region I-I 'of FIG. 3. However, in FIG. 4, for convenience of description, only one pixel area is illustrated.

As illustrated, the first and second substrates 110 and 130 are disposed to face each other, and the edge portions of the first and second substrates 110 and 130 are sealed by the seal pattern 140.

An array element 120 is formed on the transparent substrate 100 of the first substrate 110, and an organic light emitting diode E is formed below the transparent substrate 101 of the second substrate 130. .

The array element 120 includes a thin film transistor positioned at a point where a gate line (not shown), a data line (not shown) and a power supply line (not shown) intersecting the gate line, and the gate line and the data line cross each other. (T) and a storage capacitor (not shown) are included, which is provided in a matrix form, and is formed by the array element 120 and the organic light emitting diode E corresponding thereto. 300) is formed.

In addition, the gate line and the data line are respectively connected to the gate pad 310 and the data pad 320 shown in FIG. 3.

The organic light emitting diode (E) is positioned under the first electrode 132 used as a common electrode, the organic light emitting layer 134 disposed under the first electrode 132, and the organic light emitting layer 134. And a second electrode 136 patterned for each subpixel.

The organic light emitting layer 134 may include a light emitting layer 134b in which red, green, and blue light emitting materials are arranged for each subpixel, and a first organic material layer disposed above and below the light emitting layer 134b, respectively. 134a) and the second organic material layer 134c.

The organic electroluminescent material constituting the first organic material layer 134a and the second organic material layer 134c is determined according to the arrangement of the anode and the cathode. For example, the first electrode 132 may be an anode, a second electrode. When the second electrode 136 is configured as a cathode, the first organic material layer 134a may include a hole injection layer and a hole transport layer, and the second organic material layer 134c may include an electron injection layer and an electron transport layer. have.

The array element 120 includes a thin film transistor T and a second electrode connection pattern 112 connected to the thin film transistor T. The second electrode connection pattern 112 is formed of a thin film transistor T. The electrode pattern may be formed as an extension pattern or may be formed by patterning a separate metal material. The thin film transistor T corresponds to a driving thin film transistor connected to the organic light emitting diode E.

In addition, the section between the second electrode 136 and the second electrode connection pattern 112 electrically connects the second electrode 136 and the thin film transistor T in a direction parallel to the seal pattern 140 described above. Conductive spacers 114 are formed.

In addition, the conductive spacer 114 serves to maintain a cell gap in the array region.

In addition, the light emission from the organic light emitting layer 134 is characterized in that the upper light emitting method for emitting the light toward the second substrate 130.

Accordingly, the first electrode 132 is selected from a light-transmitting conductive material, and the material layer of the second electrode 136 for the cathode in contact with the organic light emitting layer 134 is an electrode located on the rear side of the emission direction. Therefore , it is desirable to form an opaque metal material having a low work function value into a thin film.

The opaque metal material is selected from any one of aluminum (Al), magnesium (Mg) and an alloy of aluminum (hereinafter referred to as magnesium: aluminum), aluminum: lithium (Li), and aluminum: benzonate. It is preferable.

In addition, the first electrode 132 serves as a common electrode, and a constant voltage should always be applied from the electrode pad 330 provided on one surface of the first substrate 110.

That is, the voltage applied from the electrode pad 330 is applied to the first electrode through the contact portion 332 formed at the end of the first electrode 132.

In addition, the space I between the first and second substrates 110 and 130 preferably forms a nitrogen (N ₂ ) atmosphere.

Such a dual panel type organic electroluminescent device comprises an array element and an organic electroluminescent diode element on different substrates, so that the conventional array element and organic electroluminescent diode element shown in FIG. 1 are placed on the same substrate. As compared with the case of forming, the organic electroluminescent diode device is not affected by the yield of the array device, and thus can exhibit good characteristics in terms of production management of each device.

 In addition, if the screen is implemented using the top emission method under the above-described conditions, the thin film transistor can be designed without minding the aperture ratio, thereby increasing the array process efficiency, and providing a high aperture ratio / high resolution product, and dual panel. Since the organic light emitting diode device is formed as a dual panel type, it is possible to effectively block outside air than the conventional top emitting method, thereby increasing the stability of the product.

In addition, since the thin film transistor design generated in the conventional lower light emitting device product is configured on a substrate separate from the organic light emitting diode device, the degree of freedom in the arrangement of the thin film transistor can be obtained sufficiently, and the first of the organic light emitting diode device can be obtained. Since the electrode is formed on the transparent substrate, compared with the structure of forming the first electrode on the existing array element, there is an advantage that can increase the degree of freedom for the first electrode.

In the above-described dual panel type organic light emitting display device, the conductive spacer 114 is formed in each subpixel region with respect to the array region 300 to form a constant gap, and formed at the edges of both substrates. A glass fiber is provided in the seal pattern 140 to maintain a predetermined gap.

However, in this case, the outside of the array region 300, that is, the region from the outside of the array region 300 to the failure turn 140 is not provided with a means for maintaining the gap between the two substrates, and the seal The glass fiber provided in the pattern 140 has a disadvantage in that it is difficult to maintain a constant gap at all times.

As a result, when such a dual panel type organic electroluminescent device is applied to a large area panel, the gap between the two substrates may become inconsistent in the bonding process. In this case, the conductive spacer 114 and the second electrode 136 may be used. This poor contact can occur which may appear in the form of point defects on the display.

The present invention was created to overcome the above problems and will be described in more detail with reference to the accompanying drawings.

5 is a plan view of a dual panel type organic light emitting display device according to the present invention, and FIG. 6 is a cross-sectional view of a specific region II-II ′ of FIG. 5.

However, the same reference numerals are used for the same components as in FIG. 3, and description thereof will be omitted.

Although not shown, the structure in the array region of the first and second substrates of the dual panel type organic light emitting display device according to the present invention is the same as that described with reference to FIG.

Referring to FIG. 5, in the dual panel type organic light emitting display device according to the present invention, first dummy pattern spacers 510 are formed in an area from the outside of the array area 300 to the seal pattern 500. Second dummy pattern spacers (not shown) are formed in the seal pattern 500.

In addition, the dummy pattern spacers may be provided in various arrangements on the region. That is, it may be provided in an aligned form as shown, may also be provided in a zigzag form.

FIG. 6 is a cross-sectional view of a region from the outside of the specific region II-II ′ of FIG. 5, that is, the seal pattern 500 and the array region 300 of FIG. 5 to FIG. 6. As illustrated, second dummy pattern spacers 520 are formed in the seal pattern 500, and first dummy pattern spacers are formed in an area from the outside of the array region 300 to the seal pattern 500. 510 is formed.

At this time, the density of the first dummy pattern spacers 510 and the density of the second dummy pattern spacers 520 are different from each other, and the density of the second dummy pattern spacers 520 is different from the first density. Larger than the dummy pattern spacers 510.

That is, the dummy pattern spacer 520 formed inside the seal pattern 500 is denser than the dummy pattern spacer 510 formed in the area from the outside of the array region 300 to the seal pattern 500. will be.

However, the second dummy pattern spacer 520 is less dense than the conductive spacer 114 formed on the array region.

In addition, as the second dummy pattern spacer 520 is formed inside the seal pattern 500, in the case of the seal pattern 500 according to the present invention, glass fibers are included in the seal pattern 500, unlike the conventional art. Not.

At this time, the second dummy pattern spacer 520 performs a role of a reinforcement for the seal pattern 500 more efficiently than conventional glass fibers.

As described above, dummy pattern spacers are formed in the seal pattern 500 and in the region from the outside of the array region 300 to the seal pattern 500, thereby forming the first and second substrates 110 and 130. The spacing of the lower substrate can be maintained to be almost similar to the inside of the array region 300.

That is, even if a large area organic electroluminescent device panel is formed, display defects as in the prior art do not occur.

In addition, as the second dummy pattern spacer 520 is formed inside the seal pattern 500, a water blocking effect from the outside may also be obtained.

7 is a flowchart illustrating one embodiment of an organic electroluminescent device manufacturing process according to the present invention.

Referring to FIGS. 4 to 7, in ST1, an array element is formed on the first substrate 110. In this step, a buffer layer is formed on a transparent substrate, a semiconductor layer and an upper portion of the buffer layer. Forming a capacitor electrode, forming a gate electrode, a source and a drain electrode on the semiconductor layer, and forming a power electrode on the capacitor electrode and connected to the source electrode. In this case, the array element is formed in a matrix form in the array region 300.

In this step, a conductive spacer 114 for electrical connection between the first and second substrates 110 and 130 may be formed in a subsequent process. In ST2, the first electrode 132 is formed on the second substrate 130, and is formed on a substrate different from the array element formed in the ST1.

In the present invention, in forming the first electrode for an organic light emitting diode, since it is formed directly on the transparent substrate, unlike the conventional one, the material selection range can be widened and the process becomes much easier. The first electrode is selected from a conductive material having transparency.

In ST3, the organic electroluminescent layer 134 is formed on the first electrode 130, and the organic electroluminescent layer is injected with electrons or holes and a light emitting layer made of a light emitting material having a red, green, and blue color. It is selected from the low molecular or high molecular material layer to transport.

In ST4, the second electrode 136 is formed on the organic light emitting layer 134.

In ST5, the first and second substrates are electrically connected to each other using the conductive spacers 114, and more specifically, the thin film transistors or the second electrode connection patterns 112 connected to the thin film transistors on the first substrate 110. ) To electrically connect the first and second substrates 110 and 130. That is, it serves to connect the driving thin film transistor formed on the first substrate and the organic light emitting diode of the second substrate.

In ST6, as a step of encapsulating the first and second substrates 110 and 130, a seal pattern 500 is formed at an edge of one of the first and second substrates to bond the first and second substrates together. This step includes the step of making a space between the first and second substrates in a nitrogen atmosphere.

In the present invention, the first dummy pattern spacers 510 are formed in an area from the outside of the array region 300 to the seal pattern 500, and the second dummy pattern spacers ( 520 is formed.

In this case, the densities of the first dummy pattern spacers 510 and the densities of the second dummy pattern spacers 520 are different from each other, and the densities of the second dummy pattern spacers 520 are different from each other. Larger than the dummy pattern spacers 510.

That is, the dummy pattern spacer 520 formed inside the seal pattern 500 is denser than the dummy pattern spacer 510 formed in the area from the outside of the array region 300 to the seal pattern 500. will be.

As described above, in the conventional organic light emitting diode, the entire organic light emitting diode panel is poorly treated even if a defect occurs in any of the steps of manufacturing the array device and manufacturing the organic light emitting diode. However, in the present invention, the array substrate and the organic light emitting diode By inspecting each board, the two boards of good products can be bonded together to reduce product defect rate and improve production management efficiency.

According to the organic light emitting display device and a method of manufacturing the same, the first dummy pattern spacers are formed in the region from the outside of the array region to the seal pattern, and the second dummy pattern spacers are formed in the seal pattern, By differentiating the density of the first dummy pattern spacers and the second dummy pattern spacers, there is an advantage that the gap between the upper and lower plates can be maintained almost similar to the inside of the array region.

In addition, by forming the second dummy pattern spacer inside the seal pattern, it is possible to reduce the process deviation by using a sealant without glass fiber, it has the advantage that the effect of blocking the water from the outside.

Claims (11)

First and second substrates disposed to face each other; An array region in a matrix form having a thin film transistor formed on an inner surface of the first substrate, an array region defined by an organic light emitting diode element formed on an inner surface of a second substrate corresponding to each of the array elements; A conductive spacer disposed in the array region and connecting the array elements and the organic light emitting diode elements to maintain the distance between the first and second substrates; Seal patterns formed at edges of the first and second substrates to bond the first and second substrates; A plurality of first dummy pattern spacers formed in an area from outside the array area to a seal pattern; Organic light emitting device, characterized in that the second dummy pattern spacers formed inside the seal pattern. The method of claim 1, Subpixels, which are the smallest unit areas for implementing a screen, are defined in the first and second substrates, and the thin film transistor is positioned in units of the subpixels, and the organic light emitting diode device includes a first electrode, an organic light emitting layer, and the And a second electrode patterned in units of subpixels, and the conductive spacers electrically connect the thin film transistor and the second electrode to each subpixel unit. The method of claim 1, The first dummy pattern spacer and the second dummy pattern spacer are formed with different densities, respectively. The method of claim 3, wherein The second dummy pattern spacers are formed more densely than the first dummy pattern spacers. The method of claim 1, The conductive spacers are formed more densely than the first and second dummy pattern spacers. The method of claim 1, The failed turn is an organic electroluminescent device, characterized in that made of a sealant material that does not contain glass fibers. Providing first and second substrates defining pixels consisting of red, green, and blue subpixels; Forming an array device having switching elements for each subpixel on an upper array area of the first substrate; Forming a first electrode made of a transparent material having transparency on the second substrate; Forming an organic light emitting layer on the first electrode; Forming a second electrode on the organic light emitting layer in units of subpixels; Connecting the first and second substrates to conductive spacers; Forming a seal pattern at an edge portion of one of the first and second substrates to form first dummy pattern spacers in a region from the outside of the array region to the seal pattern in bonding the first and second substrates; And forming second dummy pattern spacers inside the seal pattern. The method of claim 7, wherein The first dummy pattern spacers and the second dummy pattern spacers are formed with different densities, respectively. The method of claim 8, The second dummy pattern spacers are formed more densely than the first dummy pattern spacers. The method of claim 7, wherein The conductive spacers are more densely formed than the first and second dummy pattern spacers. The method of claim 7, wherein The failed turn is an organic electroluminescent device manufacturing method, characterized in that made of a sealant material does not contain glass fibers.

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