KR20100013533A - Light emitting diode display device and method for driving the same - Google Patents

Abstract

PURPOSE: A luminescent display device and a method of manufacturing thereof are provided to improve adhesiveness between a luminescent display device and a buffer layer, and to minimize the manufacturing inferiority. CONSTITUTION: A luminescent display device comprises: a gate electrode(11) formed on a pixel region of a lower substrate(10); a gate insulating layer(12) formed in the front of the lower substrate; a semiconductor layer(13) formed on the gate insulating layer; an ohmic contact layer(14) overlapped in both edge of the semiconductor layer; source/drain electrodes(15,16) formed on the ohmic contact layer; a protective film(17) formed in the front of the lower substrate; a contact hole(18) formed on the protective film; and a contact electrode(19) formed in each contact hole. An upper substrate(30) includes an auxiliary electrode(31), a separator(32), a contact spacer(33), a first electrode(34), a buffer layer(35), an organic luminescent layer(36), and a second electrode(37).

Description

LIGHT EMITTING DIODE DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting display device, and more particularly, to a light emitting display device and a method of manufacturing the same, which minimize the defects generated during manufacturing of the light emitting display device to increase the display efficiency of an image.

Video display device that realizes a variety of information as a video is the core technology of the information and communication era, and is developing in a direction of thinner, lighter, portable and high performance.

Recently, research on active matrix organic light emitting diode (AMOLED) panels has been actively conducted. Since the AMOLED panel is a self-luminous type that emits light by itself, high contrast ratio and ultra-thin display are realized. It is possible to implement a moving picture with a response time of several microseconds. In addition, there is no restriction on the viewing angle, it is stable even at low temperatures, and it is easy to manufacture and design a driving circuit because it is driven at a low voltage of 5V to 15V. In addition, the manufacturing process of the AMOLED panel is very simple because the deposition process and the encapsulation (encapsulation) process is all.

In the conventional AMOLED panel, a plurality of pixels consisting of three color (R, G, B) sub-pixels are arranged in a matrix form on one substrate, and the other substrate is formed in a form in which the sub-pixels are encapsulated. . Here, each sub-pixel consists of an organic electroluminescent cell and a cell driver for independently driving the light emitting cell. In the conventional AMOLED panel, since the light emitting cells and the cell driver of each sub-pixel are formed together, when a failure occurs in any one of the light emitting cell and the cell driver, the panel itself is judged to be defective and the defective rate increases.

Accordingly, recently, a dual panel type AMOLED panel, in which a light emitting cell and a cell driver are formed on different substrates and then coupled to face each other, has emerged. However, in the case of the dual panel type, a plurality of spacers are formed to allow the light emitting cells to contact the cell driving unit when the substrates are bonded together. Since the spacers are formed of a transparent organic material, problems such as poor adhesive strength during the light emitting cell process are eliminated. Occurs. In other words, the light emitting cell includes a spacer formed of an organic material on a substrate, an organic light emitting layer formed to cover the spacer, and at least one electrode. However, since the spacer is formed of a transparent organic material, there is a problem that the surface is uneven or the height is different from each other because the exposure dose is not uniformly received during the patterning process. As a result, the contact force between the non-uniform spacer and the organic light emitting layer is reduced, thereby weakening the impact, and the contact resistance is nonuniform, resulting in a decrease in display efficiency of an image. In addition, the spacer and the organic light emitting layer made of an organic material are very vulnerable to thermal evaporation, which shows that the contact force is further decreased due to different elastic modulus when forming a metal electrode.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a light emitting display device and a method of manufacturing the same, which can increase display efficiency of an image by minimizing defects generated during manufacturing of the light emitting display device.

A light emitting display device according to an embodiment of the present invention for achieving the above object includes a lower light emitting region and a plurality of light emitting regions, the lower and upper substrates facing each other; A plurality of switching elements formed in the non-light emitting area of the lower substrate; A contact electrode electrically connected to the drain electrode of each switching element; An auxiliary electrode formed in the non-light emitting area of the upper substrate; A contact spacer formed in the non-light emitting area of the upper substrate to correspond to the contact electrode of the lower substrate; A separator formed on the auxiliary electrode of the non-light emitting area to divide the light emitting area into sub pixel units; A first electrode formed on the lower front surface of the upper substrate to cover both the separator and the contact spacer; A buffer layer formed of an inorganic insulating material under the first electrode so as to correspond to a non-light emitting area of the upper substrate; An organic emission layer formed on an entire lower surface of the upper substrate including the buffer layer; And a second electrode formed on the entire surface of the organic light emitting layer and electrically contacting the contact electrode of the lower substrate.

The first electrode is formed of at least one of indium tin oxide (ITO), indium zinc oxide (IZO), and Al- dopped zinc oxide (AZO), and is formed on the lower front surface of the upper substrate to be in electrical contact with the auxiliary electrode. It is characterized by.

The first electrode may be formed before the separator and the contact spacer to receive common power from the common power line in the non-light emitting area together with the auxiliary electrode.

The buffer layer is formed of an inorganic insulating material of any one of SiNx, SiOx, SiON, SiOy by PECVD or sputtering.

The organic light emitting layer is formed to cover the entire surface of the first electrode including the buffer layer with an organic material through a thermal transfer method.

Further, a method of manufacturing a light emitting display device according to an embodiment of the present invention for achieving the above object comprises the steps of forming an auxiliary electrode in a non-light emitting region of the upper substrate; Forming a contact spacer in a non-light emitting area of the upper substrate; Forming a separator on the auxiliary electrode of the non-light emitting area to divide the light emitting area of the upper substrate into sub pixel units; Forming a first electrode on an entire surface of the upper substrate to cover both the separator and the contact spacer; Forming a buffer layer of an inorganic insulating material on the first electrode so as to correspond to a non-light emitting area of the upper substrate; Forming an organic light emitting layer on an entire surface of the upper substrate including the buffer layer; And forming a second electrode on the entire surface of the organic light emitting layer.

The first electrode forming step is formed on the front surface of the upper substrate to be in electrical contact with the auxiliary electrode with at least one of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and Al-dopped Zinc Oxide (AZO). It is characterized by one.

The first electrode forming step is performed before the separator and contact spacer forming step to form the first electrode such that the first electrode is in electrical contact with the common power wiring of the non-light emitting region together with the auxiliary electrode. do.

The buffer layer forming step is characterized in that the buffer layer is formed of an inorganic insulating material of any one of SiNx, SiOx, SiON, SiOy by PECVD or sputtering.

The organic light emitting layer forming step is characterized in that the organic light emitting layer is formed to cover the entire surface of the first electrode including the buffer layer with an organic material through a thermal transfer method.

The light emitting display device and the method of manufacturing the same of the present invention as described above have a first electrode made of a metal material so as to be in contact with a contact spacer of an organic material formed in a non-display area, and then a first electrode of a non-display area. The buffer layer of the inorganic material is formed to be connected. Thus, the adhesion between the organic light emitting layer and the buffer layer formed thereafter may be improved, thereby minimizing manufacturing defects of the light emitting display device and increasing display efficiency of an image.

Hereinafter, a light emitting display device and a method of manufacturing the same according to an exemplary embodiment of the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

1 is an equivalent circuit diagram illustrating one sub-pixel of a light emitting display according to an exemplary embodiment of the present invention.

One sub-pixel illustrated in FIG. 1 includes a cell driver DRV, a cell driver DRV, and a second power signal GND connected to a gate line GL, a data line DL, and a power line PL. And a light emitting cell OEL equivalently represented by a diode.

The cell driver DRV is connected between the first switching element T1, the first switching element T1, the power supply line PL, and the light emitting cell OEL connected to the gate line GL and the data line DL. And a storage capacitor C connected between the second switching element T2, the power supply line PL, and the first switching element T1.

The gate electrode of the first switching element T1 is connected to the gate line GL, the source electrode is connected to the data line DL, and the drain electrode is connected to the gate electrode of the second switching element T2. When the gate-on signal is supplied to the gate line GL, the first switching element T1 turns on and supplies the data signal supplied to the data line DL to the storage capacitor C and the second switching element T2. It is supplied to the gate electrode of.

The source electrode of the second switching element T2 is connected to the power supply line PL and the drain electrode is connected to the light emitting cell OEL. The second switching element T2 controls the amount of light emitted from the light emitting cell OEL by controlling the current I supplied from the power supply line PL to the light emitting cell OEL in response to a data signal from the first switching element. Will be adjusted.

The storage capacitor C is connected between the power supply line PL and the gate electrode of the second switching element T2. The second switching element T2 remains on by the voltage charged in the storage capacitor C even when the first switching element T1 is turned off, until the data signal of the next frame is supplied. The emission of (OEL) is maintained. Here, the PMOS or the NMOS transistor may be used as the first and second switching elements T1 and T2, but only the case where the NMOS transistor is used will be described below.

2 is a cross-sectional view illustrating a sub pixel of a light emitting display device according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the light emitting display device of the present invention includes a light emitting display panel including lower and upper substrates 10 and 30 bonded to face each other.

The lower and upper substrates 10 and 30 are composed of a plurality of light emitting regions in which an image is displayed and a non-light emitting region in which an image is not displayed. A cell driver DRV is provided to provide a signal. These lower and upper substrates 10 and 30 are bonded to each other by sealants, which are formed at the periphery of the lower and upper substrates 10 and 30.

The non-light emitting area may form a grid to expose the light emitting areas. Here, the light emitting area means a pixel area where light from the light emitting cells OEL is emitted, and the non-light emitting area is an area where switching elements T1 and T2 for operating the light emitting cells OEL are formed. Means.

The switching element of the lower substrate 10 shown in FIG. 2 may have a bottom gate structure using amorphous silicon (a-Si), and although not shown, the switching element may have a top gate structure using polysilicon.

Here, the structure of the lower substrate 10 will be described in detail.

The lower substrate 10 includes a gate electrode 11 formed in the pixel region of the lower substrate 10, a gate insulating film 12 formed on the entire surface of the lower substrate 10 including the gate electrode 11, and a gate electrode 11. The semiconductor layer 13 formed on the gate insulating layer 12 so as to overlap the semiconductor insulating layer 12, the ohmic contact layer 14 formed so as to be centered at both edges of the semiconductor layer 13, and the source / drain electrode formed on the ohmic contact layer 14. 15 and 16 and a passivation layer 17 formed on the entire surface of the lower substrate 10 including the source / drain electrodes 15 and 16. Here, the gate electrode 11, the source / drain electrodes 15 and 16, the semiconductor layer 13, the ohmic contact layer 14, the gate insulating film 12, and the protective film 17 form one switching element. . In the passivation layer 17, a contact hole 18 penetrating the passivation layer 17 is formed in each sub-pixel region to expose a part of the drain electrode 16, and the contact electrode 19 is formed in each contact hole 18. And is in electrical contact with the drain electrode.

Although not shown in the drawings, a power line PL is formed on the gate insulating layer positioned in the outer non-display area of the lower substrate 10. The power line PL is a line for transmitting a first voltage source or a second voltage source, and the first voltage source or the second voltage source applied through the power line PL is each of the first or second electrodes of the light emitting cells OEL. Means the power applied to. The power line PL is formed of the same material as the source / drain electrodes 15 and 16. In other words, the power line PL and the source / drain electrodes 15 and 16 may be simultaneously manufactured through the same mask process. As such, the power line PL is electrically connected to each first or second electrode of the light emitting cells OEL through a pad electrode, which is not shown. Therefore, in addition to the contact hole 18 connected to the drain electrode 16, the contact layer connected to the power line PL may be further formed in the passivation layer 17.

Next, the structure of the upper substrate 30 in which the light emitting cells OEL are formed will be described in detail as follows.

The upper substrate 30 has an auxiliary electrode 31 formed in the non-light emitting area and a contact spacer 33 formed in the non-light emitting area of the upper substrate 30 so as to correspond to the contact electrode 19 of the lower substrate 10. The separator 32 formed on the auxiliary electrode 31 of the non-emission area, the auxiliary electrode 31 and the separator 32, and the contact spacer 33 may be covered to divide the light emitting area into sub pixel units. Lower portion of the first electrode 32 to correspond to a non-emission region in which the first electrode 32, the auxiliary electrode 31, the separator 32, and the contact spacer 33 are formed on the lower front surface of the upper substrate 30. A buffer layer 35 formed of an inorganic insulating material on the organic light emitting layer 36 formed on the lower front surface of the upper substrate 30 including the buffer layer 35 and the first electrode 32, and on the front surface of the organic light emitting layer 36. A second electrode formed in electrical contact with the contact electrode 19 of the lower substrate 10 The pole 37 is formed.

The auxiliary electrode 31 is formed of a low resistance metal material to compensate for the resistance of the first electrode 202 and apply a more effective voltage. The auxiliary electrode 31 is formed in the non-light emitting region of the upper substrate 30. Is formed. As the low resistance metal material constituting the auxiliary electrode 31, at least one metal material of aluminum (Al), aluminum alloy (AlNd), copper (Cu), silver (Ag), or a copper alloy may be used.

The contact spacers 33 are formed in a columnar shape by being aligned in an area requiring electrical contact between the second electrode 37 of the upper substrate 30 and the contact electrode 19 of the lower substrate 10. ) May be formed in an inverted taper, ie inverted trapezoidal shape. The contact spacer 33 is to allow the second electrode 37 formed on the bottom surface of the second substrate 30 to contact the contact electrode 19 of the first substrate 10. It is formed in an inverted trapezoidal shape at a position corresponding to a part of the contact electrode 19 forming region of (10). The contact spacer 33 is formed by patterning a transparent organic material having a refractive index of the visible light band, for example, at least one of poly styrenr, poly 2-vinylthiophene, and poly vinylcarbazole.

The separator 32 is formed on the lower surface of the auxiliary electrode 32 in the form of a partition wall surrounding each sub-pixel. The gate line GL or the data line of the first substrate 10 depends on the position of the auxiliary electrode 32. It may be formed to correspond to the DL. Unlike the contact spacer 33, the separator 32 has a tapered shape with respect to the auxiliary electrode 31. Specifically, when the separator 32 is vertically cut with respect to the auxiliary electrode 31, the cross-sectional structure of the separator 32 is different from that of the auxiliary spacer 31. The contact surface is formed in a trapezoidal shape that is narrow and widens downwardly. The taper structure separator 32 separates the organic light emitting layer 36, the second electrode 37, and the like into units of each sub pixel region. The separator 32 may be formed by applying a photosensitive organic material, for example, photoresist (PR), photo acryl, or benzocyclobutene (BCB), and then patterning the photoresist. The height of the separator 32 should be lower than the height of the contact spacer 33 and preferably formed to be 2/1 to 2/3 of the height of the contact spacer 33. This is because if the separator 32 is formed too low, the organic light emitting layer 36 and the second electrode 37 may not be separated for each sub pixel by the separator 32, and the contact spacer 33 may be formed too high. This is because it may come into contact with the protective film 17 of the first substrate 10, or the like.

The first electrode 34 is formed on the lower front surface of the upper substrate 30 to cover all of the auxiliary electrode 31, the separator 32, and the contact spacer 33. The first electrode 32 may be an anode electrode and may be formed of at least one material of indium tin oxide (ITO), indium zinc oxide (IZO), and al- dopped zinc oxide (AZO). Here, ITO is a transparent conductive film having a relatively uniform work function and a small hole injection barrier for the organic light emitting layer 36. In FIG. 2, only the structure in which the first electrode 34 is formed to cover all of the auxiliary electrode 31, the separator 32, and the contact spacer 33 is illustrated, but the first electrode 34 is the separator 32 and the contact spacer. It may be formed earlier than the reference numeral 33 to cover the auxiliary electrode 31 and the lower front surface of the upper substrate 30 (not shown). In this case, the separator 32 and the contact spacer 33 are formed on the lower surface of the first electrode 34. As described above, since one side of the first electrode 34 is connected to the common power line through a pad electrode (not shown) in the non-light emitting area, the first electrode 34 and the auxiliary electrode 31 are separated from the common power line. It is supplied with common power.

Although not shown in the drawing, since the above-described contact spacer 33 is patterned with a transparent photosensitive organic material, the exposure amount may be uneven due to the upper substrate 30 or the self-reflected light during the exposure process. If the exposure amount is uneven, the surface of the contact spacer 33 is unevenly formed during the etching process. In addition, since the contact spacer 33 itself is an organic material, when the contact spacer 33 is in contact with another organic material that is thermally deposited, adhesion failure occurs, thereby weakening the external impact. Accordingly, when the first electrode 34 of the metallic conductive material is formed on the lower front surface of the upper substrate 30 including the contact spacer 33 by a deposition method such as sputtering, the contact spacer 33 may be first planarized. The adhesive force with the contact spacer 33 can be improved.

The buffer layer 35 is formed of an inorganic insulating material in a non-light emitting region in which the auxiliary electrode 31, the separator 32, and the contact spacer 33 are formed. The buffer layer 35 is to compensate for a bad state of the contact spacer 33 and may be made of any one inorganic insulating material of SiNx, SiOx, SiON, or SiOy. In other words, the surface of the first electrode 34 covering the contact spacer 33 may also be somewhat uneven by the contact spacer 33 having an uneven surface. By forming the buffer layer 35 made of an inorganic insulating material, The organic light emitting layer 36 formed after this can be formed in a more flat shape. In addition, the adhesion between the organic light emitting layer 36 and the buffer layer 35 formed by a laser induced thermal imaging may be further improved.

Although not shown in detail in the drawings, the organic emission layer 36 includes a hole injection layer HIL, a hole transport layer HTL, an emission layer OEL, an electron injection layer EIL, and an electron transport layer ETL. The hole injection layer HIL is formed on the entire surface of the upper substrate 30 including the first electrode 34, for example, the anode electrode and the buffer layer 35, and the hole transport layer HTL forms the hole injection layer HIL. It is formed on the front surface of the upper substrate 30 including. In addition, the emission layer OEL is formed on the hole transport layer HTL of the emission region, and the electron injection layer EIL is formed on the entire surface of the upper substrate 30 including the emission layer OEL and the hole transport layer HTL. The electron transport layer ETL is formed on the entire surface of the upper substrate 30 including the electron injection layer EIL.

The light emitting layer OEL includes a red light emitting layer for displaying red, a green light emitting layer for displaying green, and a blue light emitting layer for displaying blue in unit pixel units. The light emitting layer OEL formed in each light emitting area is any one of the red light emitting layer, the green light emitting layer, and the blue light emitting layer. That is, the red light emitting layer, the green light emitting layer, and the blue light emitting layer form one unit pixel. The unit pixel may further include a white light emitting layer, in which one unit pixel includes a red light emitting layer, a green light emitting layer, a blue light emitting layer, and a white light emitting layer.

The light emitting layer (OEL) is patterned to be selectively formed only in the light emitting region. As a method for patterning the light emitting layer, a method using a shadow mask may be used when the light emitting layer is a low molecular organic material. In the case of the polymer material, inkjet printing or thermal transfer by laser may be used. Among these, the thermal transfer method using a laser has a merit that the light emitting layer can be finely patterned, can be used for a large area, and is advantageous for high resolution, and inkjet printing is a wet process, whereas it has a merit of a dry process.

The second electrode 37 is formed so as to cover the organic light emitting layer 36 separated in sub pixel units by the separator 32 or the like. The second electrode 32 may be a cathode electrode, and aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, ITO / Ag, ITO / Ag / ITO having a relatively small work function value. It may be formed of at least one material of ITO / Ag / IZO (Indium Zinc Oxide), silver alloy (ITO / Ag alloy / ITO) and the equivalents thereof. Here, Ag is a film which reflects light from the organic light emitting layer 36 to the top surface in the top emission method. The second electrode 37 is separated in each sub pixel unit by the separator 32 or the like, and each of the separated second electrodes 37 is formed by the height or thickness of the contact spacer 33. Is in electrical contact with the contact electrode 19.

3 is a cross-sectional view illustrating a method of manufacturing a lower substrate of the light emitting display device illustrated in FIG. 2. 4A through 4C are cross-sectional views illustrating a method of manufacturing an upper substrate of the light emitting display device of FIG. 2, and FIG. 5 is a cross-sectional view of a process in which the lower substrate of FIG. 3 and the upper substrate of FIG. 4C are bonded to each other. to be.

First, the lower substrate manufacturing method of the present invention will be described with reference to FIG. 3.

Referring to FIG. 3, first, a gate metal material is deposited and patterned on a glass substrate used as the lower substrate 10 to form a gate electrode 11. After the gate insulating film 12 is deposited on the entire surface of the lower substrate 10 including the gate electrode 11, the semiconductor layer forming material, the ohmic contact layer forming material, and the source / drain forming material on the gate insulating film 12. Are deposited sequentially. Thereafter, the semiconductor layer 13 and the ohmic contact layer 14 and the source / drain electrodes 15 and 16 are patterned by simultaneously or sequentially patterning the semiconductor layer forming material, the ohmic contact layer forming material, and the source / drain forming material. To form a switching element. Next, the protective layer 12 is formed on the entire surface of the lower substrate 12 including the switching element and the gate insulating layer 12, and then patterned, thereby contacting the contact hole 18 to expose the drain electrode 16 of the switching element. To form. Then, a metal material such as ITO is deposited and patterned to form the contact electrode 19. Here, the lower substrate 10 may be a silicon substrate, a magnetic thin film substrate, or a magnetic support substrate in addition to the glass substrate.

Next, the upper substrate manufacturing method of the present invention will be described with reference to FIGS. 4A to 4C.

Referring to FIG. 4A, aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, titanium (Ti) may be deposited on the upper substrate 30 by a deposition enhanced method such as plasma enhanced chemical vapor deposition (PPECVD) or sputtering. ) And at least one low resistance metal material of chromium (Cr). The deposited low resistance metal material layer is patterned by a photolithography process or an etching process to form the auxiliary electrode 31 in the non-light emitting region.

Thereafter, at least one material of a transparent organic material, for example, poly styrenr, poly 2-vinylthiophene, and poly vinylcarbazole, is deposited and patterned on the front surface of the upper substrate 30 including the auxiliary electrode 31 to contact the contact spacer 33. To form. In this case, the height of the contact spacer 33 may be set by the thickness of the deposited organic material. When the wet etching process is performed in the process of forming the contact spacer 33, an area adjacent to the formation pattern of the contact spacer 33 is formed. Since the etching time is longer than other portions, the contact spacer 33 is patterned in a trapezoidal shape.

Next, a photosensitive organic insulating material different from an organic material constituting the contact spacer 33 is formed on the entire surface of the upper substrate 30 including the auxiliary electrode 31 and the contact spacer 33. PR and photo acryl or benzocyclobutene (BCB) and the like are deposited and patterned to form an inverted trapezoid-shaped separator 32 on the auxiliary electrode 31. The separator 32 is formed on the upper surface of the auxiliary electrode 32 in the form of a partition wall surrounding each sub-pixel, and according to the position of the auxiliary electrode 32, the gate line GL or the data of the first substrate 10. It may be formed to correspond to the line DL. At this time, the height of the separator 32 should be lower than the height of the contact spacer 33 and preferably formed to be 2/1 to 2/3 of the height of the contact spacer 33.

As shown in FIG. 4B, indium tin oxide (ITO) and indium zinc oxide (IZO) are deposited on the entire surface of the upper substrate 30 on which the separator 32 and the contact spacer 33 are formed, such as PECVD or sputtering. , AZO (Al- dopped Zinc Oxide) or an equivalent material is deposited to form the first electrode 34. The first electrode 34 is in electrical contact with the auxiliary electrode 31 and the like. In addition, an inorganic insulating material made of SiNx, SiOx, SiON, or SiOy by PECVD, spin coating, or spinless coating on the entire surface of the upper substrate 30 including the first electrode 34. After the deposition, the buffer layer 35 is formed in the non-light emitting region in which the auxiliary electrode 31, the separator 32, and the contact spacer 33 are formed. The buffer layer 35 may also have a somewhat uneven surface of the first electrode 34 covering the contact spacer 33 by the contact spacer 33 having a non-uniform surface. The buffer layer 35 may be formed of an inorganic insulating material. By forming 35, the organic light emitting layer 36 to be formed later may be formed in a more flat shape. In addition, the adhesion between the organic light emitting layer 36 and the buffer layer 35 formed by a laser induced thermal imaging may be further improved.

Next, as shown in FIG. 4C, the organic light emitting layer 36 is formed on the entire surface of the upper substrate 30 on which the buffer layer 35 and the first electrode 34 are formed using a printing method, a shadow mask method, a thermal transfer method, or the like. To form. That is, although not shown in detail in the drawings, the organic light emitting layer 36 is sequentially formed of a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (OEL), an electron injection layer (EIL) and an electron transport layer (ETL) by a thermal transfer method. It is formed by vapor deposition. In particular, in the case of forming the light emitting layer (OEL) by a thermal transfer method using a laser, it can be finely patterned than other methods described above, can be used in a large area, it is advantageous in high resolution, inkjet printing While this is a wet process, it can take advantage of the dry process. As described above, the organic light emitting layer 36 formed on the buffer layer 35 made of the inorganic material may be formed to be stronger and more flat against impact due to enhanced adhesion of the buffer layer 35, thereby improving current transfer efficiency and the like.

Thereafter, PECVD or sputtering is performed on the entire surface of the upper substrate 30 on which the organic light emitting layer 36 is formed, and among the aluminum (Al), aluminum alloy (AlNd), copper (Cu), and copper alloy having a relatively small work function value, A second electrode 37 having a structure in which silver / calcium (Ag / Ca) or the like is stacked on at least one metal material is formed. The second electrode 37 is formed to cover the organic light emitting layer 36 separated by the sub-pixel unit by the separator 32 or the like.

Finally, as shown in FIG. 5, the organic light emitting layer 36 and the upper substrate 30 having the second electrode 37, etc. are formed on the lower substrate 10 on which the switching element and the contact electrode 19 are formed. Squeeze face to face. In this case, the second electrode 37 of the upper substrate 30 is in electrical contact with the contact electrode 19 of the lower substrate 10 by the height or thickness of the contact spacer 33.

Although the detailed description of the present invention described above has been described with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art have ordinary skill in the art. It is apparent that the present invention can be variously modified and changed without departing from the spirit and technical scope.

1 is an equivalent circuit diagram illustrating one sub-pixel of a light emitting display according to an exemplary embodiment of the present invention.

2 is a cross-sectional view illustrating a sub-pixel of a light emitting display device according to an exemplary embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing a lower substrate of the light emitting display device illustrated in FIG. 2.

4A to 4C are cross-sectional views illustrating a method of manufacturing an upper substrate of the light emitting display device illustrated in FIG. 2.

5 is a cross-sectional view of a process in which the lower substrate of FIG. 3 and the upper substrate of FIG. 4C are bonded to each other.

<Simple explanation of the code | symbol about the main part of drawing>

10 lower substrate 11 gate electrode

12: gate insulating film 15, 16: source / drain electrode

30: upper substrate 31: auxiliary electrode

32: separator 33: contact spacer

34: first electrode 35: buffer layer

36 organic light emitting layer 37 second electrode

Claims (10)

A lower and an upper substrate including a non-light emitting area and a plurality of light emitting areas and facing each other; A plurality of switching elements formed in the non-light emitting area of the lower substrate; A contact electrode electrically connected to the drain electrode of each switching element; An auxiliary electrode formed in the non-light emitting area of the upper substrate; A contact spacer formed in the non-light emitting area of the upper substrate to correspond to the contact electrode of the lower substrate; A separator formed on the auxiliary electrode of the non-light emitting area to divide the light emitting area into sub pixel units; A first electrode formed on the lower front surface of the upper substrate to cover both the separator and the contact spacer; A buffer layer formed of an inorganic insulating material under the first electrode so as to correspond to a non-light emitting area of the upper substrate; An organic emission layer formed on an entire lower surface of the upper substrate including the buffer layer; And And a second electrode formed on an entire surface of the organic light emitting layer and electrically contacting a contact electrode of the lower substrate. The method of claim 1, The first electrode is At least one of indium tin oxide (ITO), indium zinc oxide (IZO) and al-dopped zinc oxide (AZO), and is formed on the lower front surface of the upper substrate to be in electrical contact with the auxiliary electrode. Light emitting display. The method of claim 1, The first electrode is And a common power source formed before the separator and the contact spacer to receive common power from the common power line of the non-light emitting area together with the auxiliary electrode. The method of claim 1, The buffer layer A light emitting display device comprising: an inorganic insulating material of any one of SiNx, SiOx, SiON, and SiOy by PECVD or sputtering. The method of claim 1, The organic light emitting layer is And a light emitting display device covering the entire surface of the first electrode including the buffer layer with an organic material by thermal transfer. Forming an auxiliary electrode in a non-light emitting area of the upper substrate; Forming a contact spacer in a non-light emitting area of the upper substrate; Forming a separator on the auxiliary electrode of the non-light emitting area to divide the light emitting area of the upper substrate into sub pixel units; Forming a first electrode on an entire surface of the upper substrate to cover both the separator and the contact spacer; Forming a buffer layer of an inorganic insulating material on the first electrode so as to correspond to a non-light emitting area of the upper substrate; Forming an organic light emitting layer on an entire surface of the upper substrate including the buffer layer; And And forming a second electrode on the entire surface of the organic light emitting layer. The method of claim 6, The first electrode forming step A light emitting display comprising at least one of indium tin oxide (ITO), indium zinc oxide (IZO), and aluminum doped zinc oxide (AZO) formed on an entire surface of the upper substrate to be in electrical contact with the auxiliary electrode. Method of manufacturing the device. The method of claim 6, The first electrode forming step Wherein the first electrode is formed before the separator and contact spacers are formed so that the first electrode is in electrical contact with the common power wiring of the non-light emitting area together with the auxiliary electrode. . The method of claim 6, The buffer layer forming step A method of manufacturing a light emitting display device, wherein the buffer layer is formed of any one of an inorganic insulating material of SiNx, SiOx, SiON, and SiOy by PECVD or sputtering. The method of claim 6, The organic light emitting layer forming step And manufacturing the organic light emitting layer so as to cover the entire surface of the first electrode including the buffer layer by an organic material by thermal transfer.

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