KR100873031B1 - Formation method of large area oled substrate - Google Patents

Abstract

A method for forming an OLED substrate is provided to remove a sealant coating process of a sealing process by coating the sealant on the film and performing the masking. A stack file with a sealant is attached to one side of an OLED substrate(S10). At least one electrode material and one organic thin film material are deposited on one surface of the OLED substrate with the film(S20). The film is peeled off according to the progressing state of the deposition. After the deposition is completed, the film is peeled off so that the sealant remains on the one side of the OLED substrate(S30).

Description

Formation method of large area OLED substrate

The present invention relates to a method for forming a large area OLED substrate, and more particularly, to a method for forming a large area OLED substrate using a film.

Recently, with the rapid development of information and communication technology and the expansion of the market, flat panel displays have been in the spotlight as display devices. Such flat panel displays include liquid crystal displays, plasma display panels, and organic light emitting diodes.

Among them, the organic light emitting device has very good advantages such as fast response speed, lower power consumption than conventional liquid crystal display device, light weight, ultra thin because no separate back light device is required, and high brightness. It is attracting attention as a next generation display device.

In the organic light emitting device, an anode film, an organic thin film, and a cathode film are sequentially coated on a substrate, and an appropriate energy difference is formed in the organic film by emitting a voltage between the anode and the cathode. That is, the excitation energy left by recombination of injected electrons and holes is generated as light. In this case, since the wavelength of light generated according to the amount of the dopant of the organic material may be adjusted, full color may be realized.

Although the detailed structure of the organic light emitting diode is not shown in the drawings, an anode, a hole injection layer, a hole transport layer, an emission layer, and an electron transport layer are deposited on a substrate. A layer, an electron injection layer, and a cathode are stacked in this order. As the anode, indium tin oxide (ITO) having a small sheet resistance and good permeability is mainly used. The organic thin film is composed of a multilayer of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer in order to increase luminous efficiency. Organic materials used as the light emitting layer are Alq3, TPD, PBD, m-MTDATA, TCTA and the like. As the cathode, a LiF-Al metal film is used. Since the organic thin film is very weak against moisture and oxygen in the air, an encapsulation film is formed on the top to increase the life time of the device.

Therefore, the competition for the development of organic light emitting diodes is fiercely developed not only in academia but also in research and development in general industries.

In general, organic materials have many advantages, such as small driving voltage and high brightness, as display devices, compared to inorganic materials. Therefore, the organic materials have a global recognition of the possibility and applicability as next-generation display devices.

Meanwhile, organic thin film formation methods developed to date include vacuum deposition method, sputtering method, ion-beam deposition method, pulsed-laser deposition method, molecular beam deposition method, chemical vapor deposition method, spin coater ( spin coater). Among these, currently commercially available technology is vacuum deposition.

The vacuum deposition method is to form a thin film by installing a thermal evaporation source on the lower part of the vacuum chamber and a substrate for film formation on the upper part.

Looking at the schematic configuration of the organic thin film forming apparatus using a vacuum deposition method as follows. First, there is a vacuum exhaust machine connected to the vacuum chamber, by using it to maintain a constant vacuum of the vacuum chamber, and then evaporate the organic material of the organic thin film material from the thermal evaporation source of one or more organic thin film materials disposed under the vacuum chamber.

The thermal evaporation source of the organic thin film material is a cylindrical or rectangular container in which an organic material for film formation is placed. As the container material, quartz, ceramic, or the like is used. The heating heater of a certain pattern is wound around the container part. When a certain amount of power is applied, the temperature around the vessel rises and the vessel heats up. At this temperature, organic matter begins to evaporate. The temperature is detected by a thermocouple for temperature control installed at the bottom or top of the vessel to maintain the organic evaporation material at a constant concentration to achieve the desired evaporation rate. The evaporated organic matter is solidified on the substrate through a continuous process such as adsorption, vapor deposition, re-evaporation, etc. on the surface of the substrate made of glass or wafer material placed a certain distance away from the top of the vessel to form a thin film.

Here, the organic compound of the organic thin film material has a high vapor pressure to vaporize. In addition, since the pyrolysis temperature by heating is close to the evaporation temperature, it is difficult to control the stable organic evaporation rate for a long time, making it difficult to deposit a high-speed thin film. The vaporized organic thin film material discharged from the thermal evaporation source in the vacuum chamber has a directivity corresponding to the shape of the opening of the upper portion of the thermal evaporation source. This property causes the vaporized organic thin film material to be reached within a limited narrow range within the substrate, which makes it difficult to obtain a uniform thin film formed on a large area substrate.

In addition, film formation may be performed while rotating the substrate at a constant speed by means of directivity correction means to form a uniform thin film of the organic thin film. In this case, due to the rotation radius of the substrate, the deposition equipment must be enlarged to a corresponding size. Therefore, since the organic thin film is formed up to the unnecessary effective area of the vacuum equipment, the use efficiency of expensive organic materials is very low. In addition, since the performance of the vacuum equipment must be increased, the productivity is lowered and the cost of the equipment is increased.

As described above, in the conventional vacuum deposition technique, in forming a product using an organic light emitting device and a functional thin film using an organic thin film, a low film forming speed, low organic material use efficiency, non-uniformity of the organic thin film layer, a main material (host material) and a coloring material (Dopant) It is difficult to manufacture and produce high quality devices at low cost due to various problems such as difficulty in fine-tuning the mixing amount of the material), controlling the temperature of the thermal evaporation source, and difficulty in forming a uniform organic thin film due to the enlargement of the substrate.

In particular, prior to such deposition, an electrode and an organic light emitting layer should be deposited on a substrate according to a predetermined pattern, and a mask for metal is used as a shielding means for this purpose. In other words, if a desired pattern pattern mask is contacted on a substrate and then vapor deposition is performed, an electrode or a light emitting layer having a desired pattern may be formed. At this time, the mask and the substrate should be aligned to match the predesigned pattern. For this purpose, the mask is moved to match the alignment marks formed on the glass substrate and the mask while observing with a CCD camera, and then the mask is moved to the substrate. It adheres to a phase.

On the other hand, the organic light emitting device needs a method for efficiently forming a light emitting layer of R (Red), G (Green), B (Blue) for full color display. Current methods are Side-By-Side method using each emitting layer, using color filter on white emitting layer, using color converting material, using optical mechanism of color spectrum, through sub-pixel Selective generation methods.

The deposition of the conventional organic light emitting device is carried out inside the deposition equipment (not shown in the figure) as shown in FIG. R, G, and B pattern deposition is performed to implement full color on the substrate 10 brought into the deposition equipment. The substrate 10 may be vaporized by vaporizing respective organic materials emitting R, G, and B in a thermal evaporation source (not shown) through the respective masks 20a, 20b, and 20c used to deposit R, G, and B patterns. Evaporate to face.

The masks 20a, 20b, and 20c are provided with holes arranged at appropriate intervals. The holes penetrate at different positions according to the R, G, and B pattern formation.

In the organic light emitting device deposition process, first, the large area substrate 10 carried into the deposition equipment is fixed.

Then, the R pattern mask 20a is brought into the deposition apparatus, and then the organic material corresponding to R is evaporated from the thermal evaporation source to deposit from one end of the substrate 10 to the other end, and the R pattern mask 20a is taken out. do.

Then, the G pattern mask 20b is brought into the deposition apparatus, and the organic material corresponding to G is evaporated at a position spaced apart from the R pattern position in the thermal evaporation source to deposit from one end to the other end of the substrate 10 and the G pattern. The mask 20b for carrying out is carried out.

Finally, the B pattern mask 20c is brought into the deposition apparatus, and then the organic material corresponding to B is evaporated at a position spaced apart from the G pattern position in the thermal evaporation source to deposit from one end to the other end of the substrate 10 and B By carrying out the pattern mask 20c outside the vapor deposition apparatus, vapor deposition of the R, G, and B patterns was performed.

On the other hand, in recent years, large areas of the substrate are required in accordance with industrial demand. To this end, the substrate and the mask must be in close contact with each other in order to pattern from one end to the other end of the large-area substrate, as described above. At this time, as the substrate becomes larger, a phenomenon in which the center portion of the substrate sags appears. This entails damaging the substrate or damaging the light emitting layer that is already patterned in the process of adhering the mask.

In addition, as described above, since the organic thin film is very weak to moisture and oxygen in the air, an encapsulation film that is sealed to increase the life time of the device is required. Frit glass and various kinds of sealants are used to adhere the encapsulation film and the substrate during the sealing process. Such a material is applied onto the encapsulation film using a screen printer or a dispenser, and ultraviolet rays (UV) or heat are applied to the process of attaching the upper and lower plates to achieve a perfect sealing effect.

In the related art, as described above, the mask alignment problem and the weight of the substrate increases as the size of the substrate increases, so that the weight of the substrate 10 is reduced. It has been realized the limitations of the use of large substrates such as abutment.

In addition, in order to solve these problems, there have been attempts to erect a substrate or to place the substrate under a mask and to deposit it from the above, but the technology is limited to be realized. To date, how to make a large size mask remains a challenge.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-described problems, and an object thereof is to provide a method for forming a large-area OLD substrate, which enables the production of a flat white large area OLED substrate using a film.

In order to achieve the above object, a large-area OLD substrate forming method according to a preferred embodiment of the present invention, the film attaching step of attaching a laminated film having a sealant formed on one surface of the OLD substrate; A deposition step of depositing at least one electrode material and at least one organic thin film material on one surface of an OLD substrate having a film attached thereto; And peeling the film layer by layer according to the progress of deposition, and after the deposition is completed, peeling off the film so that the sealant remains on one surface of the OLED substrate.

In the film attaching step, a sealant is formed along the sealing line of the upper surface of the film.

During the deposition by the deposition step, the film covers a portion of one surface of the OLED substrate except for the effective screen region.

An adhesive with different adhesive strengths is formed on the upper and lower surfaces of the sealant. Preferably, the adhesive force of the adhesive formed in the upper surface of a sealing agent shall be strong compared with the adhesive force formed in the lower surface of a sealing agent.

The film includes a first film for an organic mask and a second film for a metal mask laminated on the first film, and in the deposition step, the first film is peeled from the OLED substrate with respect to the second film.

In the film peeling step, after the deposition is completed, the second film is peeled off against the sealant.

The sealant comprises one of a sealant and frit glass.

On the other hand, a large-area OLD substrate forming method according to another embodiment of the present invention, the film adhesion step of attaching a laminated film to the one surface of the OLD substrate through the adhesive; A deposition step of depositing at least one electrode material and at least one organic thin film material on one surface of an OLD substrate having a film attached thereto; And peeling the film layer by layer according to the progress of deposition, and after the deposition is completed, peeling off the film so that a part of the adhesive remains on one surface of the OLED substrate.

During the deposition by the deposition step, the film covers a portion of one surface of the OLED substrate except for the effective screen region.

Some of the adhesive remaining by the film peeling step includes a component similar to the sealant.

The film includes a first film for an organic mask and a second film for a metal mask laminated on the first film, and in the deposition step, the first film is peeled from the OLED substrate with respect to the second film.

In the film peeling step, after the deposition is completed, the second film is peeled off against one surface of the OLED substrate.

According to the present invention having such a configuration, a large area OLD substrate is formed by attaching and depositing a film (including an organic mask thin film and a metal mask thin film) on which a sealing sealant is formed (coated) on a large area OLD substrate on which a photo process is completed. The flatness is maintained to eliminate sagging of the large-area OLD substrate.

It is possible to overcome the limitation of the large-area deposition of the OLED (to date, it is difficult to exceed the size of 730mm * 460).

Not only is the substrate slightly bent, it is easy to unfold the substrate and eliminates the risk of scratching the substrate.

This solves many other time and money wastes that do not resolve this phenomenon (i.e., research on how to lay the substrate sideways during deposition, research on placing the substrate underneath and depositing from top to bottom).

In the future, as the substrate grows, the production cost of the device may be lowered, and the overall tact time may be reduced to reduce the production cost by eliminating the alignment time during deposition.

In addition, the process of applying a sealant (eg, sealant, frit glass, etc.) during the encapsulation process can be eliminated, thereby lowering the process cost and device cost, and freeing space due to the process removal. The advantage arises.

Hereinafter, a large area OLD substrate forming method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a plan view showing the shape of a large area OLED substrate to be employed in the description of the present invention, and FIG. 4 is an enlarged view of portion A of FIG.

The OLED substrate 30 includes a plurality of cells 32. In the following description, the OLED substrate 30 means a large area (eg, a size of 730 mm * 460 mm) white OLED substrate. Each cell 32 has a plurality of valid screen areas 32a. An encapsulant (eg, sealant, frit glass, etc.) 34 for adhering to an encapsulation portion (not shown) is disposed around the effective screen area 32a. The effective screen area 32a is an area where R, G, and B are implemented. In the effective screen area 32a, R, G, and B are implemented later using a color filter (not shown). The sealant is an adhesive for bonding the upper plate and the lower plate. The sealant includes a resin (UV) adhesive (resin) including resins, which are conventionally used, including sealant and frit glass. Of course, the sealing agent should just be able to adhere | attach an upper board and a lower board other than those illustrated above.

5 is a plan view of a film to be employed in the embodiment of the present invention, Figure 6 is a cross-sectional view of the line AA of Figure 5, Figure 7 is a large-area OLD substrate when the film is attached and deposited in the embodiment of the present invention It is a figure which shows the cross section of.

The film 50 is attached to the OLED substrate 30 on which the photo process is completed. The film 50 may or may not be transparent. The film 50 has a plurality of openings (or through holes) 52 corresponding to the size of the effective screen area 32a of the OLED substrate 30. A sealant (eg, sealant, frit glass, etc.) 34 is formed along the periphery of each opening 52. The perimeter of each opening 52 is a sealing line. That is, the sealant 34 is formed along the sealing line of the upper surface of the film 50.

The film 50 includes a first film 50a for an organic mask and a second film 50b for a metal mask laminated on the first film 50a. In general, the OLED is disposed at the bottom of the substrate, and a transparent electrode (anode) is stacked on the upper surface of the substrate, and an organic multilayer film made of a plurality of organic materials for forming an organic thin film is stacked on the upper surface of the transparent electrode. The metal cathode electrode is laminated on the upper surface of the organic multilayer film, and sealing glass or metal is formed on the upper surface of the cathode electrode. The OLD substrate 30 having the photo process completed as described above is deposited in the order of a transparent electrode, an organic multilayer film, a metal cathode electrode, an encapsulating glass, or a metal. At this time, since the sizes of the organic material and the metal are different from each other, in the embodiment of the present invention, the film 50 has at least an organic mask film 50a and a metal mask film 50b. Of course, the number of the organic mask film 50a may vary depending on the type of the organic material, and if necessary, the organic material and the metal may be combined to form a single film. Therefore, in the embodiment of the present invention, it is assumed that the film 50 includes the first film 50a and the second film 50b comprehensively, which does not mean only two films. As described above, the film 50 may be three or more films or one film.

The film 50 is an example of the laminated film described in the claims of the present invention, which means that a plurality of films are formed in a laminated form.

What is necessary is just to determine the size of the sealing agent 34 in the range which does not disturb the function of an element after sealing.

An adhesive 36 is formed (coated) on the upper and lower surfaces of the sealant 34 formed to a predetermined thickness along the sealing line of the upper surface of the film 50 (that is, the upper surface of the second film 50b). Here, the thickness of the film 50 is determined in a range that does not interfere with the deposition during deposition. It is preferable that the thickness of the film 50 is as thin as possible, but it may have a certain thickness as long as it does not interfere with deposition and does not affect properties.

It is preferable to make the adhesive force of the adhesive 36a formed on the upper surface of the sealing agent 34 stronger than the adhesive force of the adhesive 36b formed on the lower surface. In other words, after the film deposition is finished, the film (before the OLD substrate 30) and the lower plate (i.e., glass and other plates or films to protect the deposition material) (not shown) before entering the process of entering the film ( 50). At this time, the sealant 34 is to be left on the substrate 30. To this end, the pressure-sensitive adhesive 36a on the upper surface of the sealant 34 and the pressure-sensitive adhesive 36b on the lower surface have different adhesive strengths (that is, the adhesive strength of the adhesive 36a is stronger).

Align film (not shown) is located in the film 50. The alignment mark is used when pasting the OLED substrate 30 and the film 50. The position and shape of the alignment mark can be free and should be at the same position as the alignment mark of the OLED substrate 30.

8 is a flowchart for explaining a method for forming a large area OLED substrate according to an embodiment of the present invention.

First, the film 50 including the first film 50a for the organic mask and the second film 50b for the metal mask is attached to one surface (eg, the bottom) of the OLD substrate 30 having completed the photo process (S10). ). Of course, the sealant 34 is formed to a predetermined thickness along the sealing line on the upper surface of the film 50. Accordingly, the upper surface of the film 50 is not attached to one surface (eg, the bottom surface) of the OLED substrate 30, but the sealant 34 is attached to one surface of the OLED substrate 30 as shown in FIG. 7. The film 50 is spaced apart from the one surface of the OLED substrate 30 by a sealant 34 at a predetermined interval and is horizontally attached thereto. That is, in the related art, the limitation of the use of a large substrate, such as the problem of alignment of the mask, the weight of the substrate increases as the size of the substrate increases, and when the deposition occurs, the center portion of the OLD substrate comes into contact with the mask and the glass. Has come. However, according to the present invention, since the film 50 is attached to the one surface of the OLED substrate 30 at a predetermined interval and is horizontally attached by the sealant 34, even if the OLED substrate 30 is enlarged, the flatness of the OLED substrate 30 is increased. This maintains the deflection of the large-area OLD substrate.

Thereafter, at least one electrode material and at least one organic thin film material are deposited on one surface of the OLED substrate 30 to which the film 50 is attached (S20). Here, since the thickness of the film 50 is determined in a range that does not interfere with the deposition during deposition, it is to be understood that the film 50 is in close contact with one surface of the OLED substrate 30 by deposition. The film 50 covers a portion excluding the effective screen area 32a on one surface of the OLED substrate 30 during deposition. The OLD substrate 30 on which the photo process is completed is deposited in the order of a transparent electrode, an organic multilayer film, a metal cathode electrode, a sealing glass or a metal.

Thereafter, according to the progress of the deposition peels the film 50 for each layer (S30). When peeling the film 50 layer by layer, the corresponding film is peeled off in the reverse order of deposition. That is, according to the progress of the deposition, the first film 50a for organic mask 50a of the film 50 is first removed (peeled), and when the deposition is completed, the second film 50b for metal mask is removed. Referring to FIG. 9, the pressure-sensitive adhesive 60 is applied between the first film 50a and the second film 50b, and the pressure-sensitive adhesive 36b is applied and sealed between the second film 50b and the sealant 34. An adhesive 36a is applied between the agent 34 and the OLD substrate 30. Here, the adhesive force of the adhesive 36a is the strongest, the adhesive force of the adhesive 60 is the weakest, and the adhesive force of the adhesive 36b is medium.

In this way, only one sealant 34 remains on one surface of the OLED substrate 30 along the sealing line. This makes a white OLD substrate using a blank mask without the need for a full color mask. Although not shown in the drawings, since R, G, and B can be implemented by using color filters later, there is no need to use a metal mask. By using a film as a blank mask, alignment problems can be solved. Do. In particular, by applying and masking a sealant on the film, the sealant coating step in the sealing step can be eliminated.

10 is a diagram for explaining a modification of the embodiment of the present invention.

In the examples, a sealant was formed on the upper surface of the film, but in the modification, the sealant was removed.

In the case of a modification, the film 50 contains the 1st film 50a for organic masks, and the 2nd film 50b for metal masks laminated | stacked on the 1st film 50a. There is no sealant on the top surface of the film 50.

The adhesive 72 is applied between the first film 50a and the second film 50b, and the adhesive 70 is coated on the upper surface of the second film 50b. The adhesive force of the adhesive 70 is stronger than the adhesive force of the adhesive 72. Both ends of the upper surface of the pressure-sensitive adhesive 70 become sealing lines. Preferably, a sealant or sealant similar to a sealant is applied flat along the sealing line of the upper surface of the pressure-sensitive adhesive 70.

In this case, when the second film 50b is removed from the OLED substrate 30, a sealant similar to a sealant or sealant remains on one surface of the OLED substrate 30 along the sealing line.

According to this modification, the film 50 is attached to one surface of the OLED substrate 30 through an adhesive as in the previous embodiment, and the attached film 50 is deposited on one surface of the OLED substrate 30. . The first film 50a of the film 50 is removed during the deposition process, and the second film 50b of the film 50 is removed after the deposition is completed. In this way, a part of the adhesive 70 (that is, the adhesive (similar to the sealant or the sealant) applied to the sealing line on the upper surface of the adhesive 70) remains on one surface of the OLED substrate 30.

Such modifications also have the same effects as the above-described embodiments.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, the technical idea to which such modifications and variations are also applied to the claims Must see

1 is a view for explaining the deposition of a conventional organic light emitting device.

2 is a view employed to explain a conventional problem.

3 is a plan view showing the shape of a large-area OLD substrate to be employed in the description of the present invention.

4 is an enlarged view of a portion A of FIG. 3.

5 is a plan view of a film to be employed in the embodiment of the present invention.

6 is a cross-sectional view taken along the line A-A of FIG.

FIG. 7 is a view showing a cross section of a large-area OLD substrate in the case of attaching and depositing a film to be employed in an embodiment of the present invention.

8 is a flowchart for explaining a method for forming a large area OLED substrate according to an embodiment of the present invention.

9 is a diagram employed in describing an embodiment of the present invention.

10 is a diagram for explaining a modification of the embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

30 OLD board 34 Sealant

36: adhesive 50: film

Claims (13)

A film attaching step of attaching a laminated film having a sealant formed on one surface of the OLED substrate; Depositing at least one electrode material and at least one organic thin film material on one surface of the OLD substrate to which the film is attached; And A peeling step of peeling the film layer by layer according to the progress of the deposition, and after the deposition is completed, peeling the film so that the sealant remains on one surface of the OLED substrate. Substrate Formation Method. The method according to claim 1, In the film attaching step, the sealant is formed along a sealing line on the upper surface of the film. The method according to claim 1, And the film covers the portion of one surface of the OLED substrate, except for the effective screen region, during the deposition by the deposition step. The method according to claim 1, A method for forming a large area OLED board, wherein an adhesive having different adhesive strengths is formed on the upper and lower surfaces of the sealant. The method according to claim 4, A method for forming a large-area OLED board, wherein the adhesive force of the pressure-sensitive adhesive formed on the upper surface of the sealant is stronger than the pressure-sensitive adhesive force formed on the lower surface of the sealant. The method according to claim 1, The film includes a first film used as a mask for forming an organic multilayer film, and a second film laminated on the first film and used as a mask for forming an electrode of metal. And in the deposition step, the first film is peeled off from the second substrate with respect to the second film. The method according to claim 6, In the film peeling step, after the deposition is completed, the second film is peeled off against the sealant. The method according to claim 1, And the sealant comprises one of a sealant and a frit glass. A film attaching step of attaching the laminated film to the one surface of the OLED substrate through an adhesive; Depositing at least one electrode material and at least one organic thin film material on one surface of the OLD substrate to which the film is attached; And And peeling the film layer by layer according to the progress of the deposition, and after the deposition is completed, peeling the film so that a part of the adhesive remains on one side of the OLED substrate. A method of forming an area OLD substrate. The method according to claim 9, And the film covers the portion of one surface of the OLED substrate, except for the effective screen region, during the deposition by the deposition step. delete The method according to claim 9, The film includes a first film used as a mask for forming an organic multilayer film, and a second film laminated on the first film and used as a mask for forming an electrode of metal. And in the deposition step, the first film is peeled off from the second substrate with respect to the second film. The method according to claim 12, In the film peeling step, after the deposition is completed, the second film is peeled off with respect to one surface of the OLED substrate.

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