Organic light-emitting apparatus fabricated using a fluoropolymer and method of manufacturing the same

A method of manufacturing an organic light-emitting display apparatus includes: forming a lift-off layer on a substrate including a first electrode, the lift-off layer including a fluoropolymer; forming a pattern layer on the lift-off layer; etching the lift-off layer between patterns of the pattern layer by utilizing a first solvent to expose the first electrode; forming an organic functional layer on the first electrode and the pattern layer, the organic functional layer including an emission layer; removing remaining portions of the lift-off layer by utilizing a second solvent; and forming a second electrode on the organic functional layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0012908, filed on Feb. 2, 2016, and No. 10-2017-0002068, filed on Jan. 5, 2017, in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more aspects of example embodiments relate to an organic light-emitting display apparatus and a method of manufacturing an organic light-emitting display apparatus.

2. Description of the Related Art

An organic light-emitting display apparatus includes a hole injection electrode, an electron injection electrode, and an organic emission layer between the hole injection electrode and the electron injection electrode. The organic light-emitting display apparatus is a self-emissive display apparatus, in which holes injected from the hole injection electrode and electrons injected from the electron injection electrode recombine in the organic emission layer and extinguish to emit light. The organic light-emitting display apparatus is considered as the next generation display apparatus owing to its high quality characteristics, such as low power consumption, high brightness, and fast response speeds.

SUMMARY

One or more aspects of example embodiments are directed toward an organic light-emitting display apparatus and a method of manufacturing the organic light-emitting display apparatus, capable of reducing defects and manufacturing costs.

According to one or more embodiments of the inventive concept, a method of manufacturing an organic light-emitting display apparatus includes: forming a lift-off layer on a substrate including a first electrode, the lift-off layer including a fluoropolymer; forming a pattern layer on the lift-off layer; etching the lift-off layer between patterns of the pattern layer by utilizing a first solvent to expose the first electrode; forming an organic functional layer on the first electrode and the pattern layer, the organic functional layer including an emission layer; removing remaining portions of the lift-off layer by utilizing a second solvent; and forming a second electrode on the organic functional layer.

The fluoropolymer may include fluorine of about 20 wt % to about 76 wt %.

The pattern layer may be formed by a printing method.

The pattern layer may include a material having a surface energy that is greater than a surface energy of the lift-off layer.

The pattern layer may include a non-fluorine based polymer material.

The pattern layer may include a fluorine-based polymer containing less than 20 wt % of fluorine.

The pattern layer may include: a first pattern layer including a material having a surface energy that is greater than a surface energy of the lift-off layer; and a second pattern layer including a material having a surface energy that is less than the surface energy of the first pattern layer.

The first pattern layer may include a non-fluorine based polymer material, and the second pattern layer may include a surfactant containing fluorine.

The first pattern layer may surround the second pattern layer.

The organic functional layer may further include a hole injection layer, a hole transport layer, an electron transport layer, and/or an electron injection layer.

The organic functional layer may be formed by a deposition process.

The first solvent may include fluorine.

The second solvent may include fluorine.

When the lift-off layer between patterns of the pattern layer is etched, the lift-off layer may form an undercut profile under the pattern layer.

The method may further include: forming a pixel defining layer surrounding edges of the first electrode.

According to one or more embodiments of the inventive concept, a method of manufacturing an organic light-emitting display apparatus includes: forming a plurality of first electrodes on a substrate; performing a first unit process, the performing of the first unit process including: forming a lift-off layer on the substrate including the plurality of first electrodes, the lift-off layer including a fluoropolymer; forming a pattern layer having a set shape on the lift-off layer; etching the lift-off layer between patterns of the pattern layer by utilizing a first solvent to expose first first electrodes from among the plurality of first electrodes; forming a first organic functional layer on the first first electrodes and the pattern layer, the first organic functional layer including an emission layer; and removing remaining portions of the lift-off layer by utilizing a second solvent; performing a second unit process at least once for forming a second organic functional layer on second first electrodes from among the first electrodes that are different from the first first electrodes after the performing of the first unit process, the second organic functional layer being configured to emit light of a different color from that of the first organic function layer; and forming a second electrode after the performing of each of the first unit process and the second unit process.

The light emitted from the first organic functional layer formed through the first unit process and the light emitted from the second organic functional layer formed through the second unit process may be mixed to generate white light.

The forming of the second electrode may include integrally forming the second electrode as a common electrode on a plurality of organic functional layers.

The method may further include forming an auxiliary cathode on each of the first and second organic functional layers respectively formed in each of the first and second unit processes, before the forming of the second electrode.

According to one or more embodiments of the inventive concept, an organic light-emitting display apparatus includes: a substrate; a first electrode on the substrate; an organic functional layer on the first electrode, the organic functional layer including an emission layer; and a second electrode on the organic functional layer. An unevenness of boundary lines of the organic functional layer is greater than an unevenness of boundary lines of the first electrode.

DETAILED DESCRIPTION

FIG. 1is a schematic flowchart of a method of manufacturing an organic light-emitting display apparatus, according to an embodiment.

Referring toFIG. 1, the method of manufacturing the organic light-emitting display apparatus includes forming a lift-off layer on a substrate including a first electrode, the lift-off layer including a fluorine polymer (e.g., a fluoropolymer) (S10), forming a pattern layer of a certain shape on the lift-off layer (S20), exposing the first electrode by etching the lift-off layer between the pattern layer by using a first solvent (S30), forming an organic functional layer on upper portions of the first electrode and the pattern layer, the organic functional layer including an emission layer (S40), removing the remaining lift-off layer by using a second solvent (S50), and forming a second electrode on the organic functional layer (S60).

The method of manufacturing the organic light-emitting display apparatus and the organic light-emitting display apparatus1manufactured by the method according to an embodiment will be described in more detail below with reference toFIGS. 2 through 6E.

FIG. 2is a schematic cross-sectional view of the organic light-emitting display apparatus1manufactured by the method ofFIG. 1.FIG. 3is a schematic cross-sectional view of a process of forming a plurality of anodes on a substrate, in the method ofFIG. 1according to an embodiment,FIGS. 4A to 4Eare schematic cross-sectional views of a first unit process in the method ofFIG. 1according to an embodiment,FIGS. 5A to 5Eare schematic cross-sectional views of a second unit process in the method ofFIG. 1according to an embodiment, andFIGS. 6A to 6Eare schematic cross-sectional views of a third unit process in the method ofFIG. 1according to an embodiment.

Referring toFIG. 2, the organic light-emitting display apparatus1manufactured by the method ofFIG. 1includes a plurality of anodes including a first anode101, a second anode102, and a third anode103, on a substrate100. First to third organic functional layers151,152, and153, each including an emission layer, are located respectively on the first to third anodes101,102, and103. A cathode180is disposed on the first to third organic functional layers151,152, and153.

As will be described later, during the process of forming the first to third organic functional layers151,152, and153on the first to third anodes101,102, and103, a pattern layer130(e.g., seeFIG. 4D) including a non-fluorine based resin and formed by a printing method on a lift-off layer120(e.g., seeFIG. 4D) including a fluoropolymer having a low surface energy may function as a deposition mask. In addition, a boundary of the pattern layer130(e.g., seeFIG. 4D) having poor spreadability may not be uniform, but may be rough. Because the pattern layer130(e.g., seeFIG. 4D) functions as a deposition mask, a rough shape of the boundary of the pattern layer130may affect patterns of the first to third organic functional layers151,152, and153. Consequently, the boundaries of the first to third organic functional layers151,152, and153may be formed to be rougher than those of the first to third anodes101,102, and103.

Referring toFIG. 3, the plurality of anodes including the first to third anodes101,102, and103are formed on the substrate100.

The substrate100may include various materials. For example, the substrate100may include a glass material or a plastic material. The plastic material may include a material having excellent heat-resisting property and durability, such as polyimide, polyethylenenaphthalate, polyethyleneterephthalate, polyarylate, polycarbonate, polyetherimide, and/or polyethersulfone.

Although not shown inFIG. 3, a buffer layer for providing a flat surface on the substrate100and for preventing impurity elements from infiltrating into the substrate100may be further provided. The buffer layer may have a single-layered structure or a multi-layered structure including silicon nitride and/or silicon oxide.

The first to third anodes101,102, and103are hole injection electrodes, and may include a material having a large work function. The first to third anodes101,102, and103may each include at least one selected from the group consisting of indium tin oxide, indium zinc oxide, zinc oxide, indium oxide, indium gallium oxide, and aluminium zinc oxide.

Although not shown inFIG. 3, the first to third anodes101,102, and103may be electrically connected to first to third thin film transistors located between the substrate100and the first to third anodes101,102, and103, respectively.

Referring toFIG. 4A, a lift-off layer120including a fluoropolymer is formed over the substrate100, on which the first to third anodes101,102, and103are formed.

The fluoropolymer included in the lift-off layer120may include a polymer containing fluorine of about 20 wt % to about 76 wt %. For example, the fluoropolymer included in the lift-off layer120may include polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, a copolymer of tetrafluoroethylene and perfluoroalkylvinylether, a copolymer of chlorotrifluoroethylene and perfluoroalkylvinylether, a copolymer of tetrafluoroethylene and perfluoroalkylvinylether, and/or a copolymer of chlorotrifluoroethylene and perfluoroalkylvinylether.

If an amount of fluorine in the fluoropolymer is less than 20 wt %, the fluoropolymer is not soluble in a fluorine-based solvent, and thus, a fluorine-based resin for forming the lift-off layer120may not be fabricated. In addition, the amount of fluorine in the fluoropolymer may not exceed 76 wt %, because an amount of fluorine in Teflon that has the largest amount of fluorine among fluoropolymers is not greater than 76 wt %. In the embodiment, the lift-off layer120shows excellent tolerance with respect to an organic solvent and excellent solubility with respect to the fluorine-based solvent, when the fluoropolymer contains fluorine within a range of about 60 wt % to about 70 wt %.

The lift-off layer120may be formed on the substrate100by using an application method, a printing method, or a deposition method. When the lift-off layer120is formed by the application method or the printing method, a patterning process may be performed after performing a hardening process and a polymerization process, if desired.

The lift-off layer120may be formed to a thickness of 0.2 μm to 5 μm. If the lift-off layer120is too thick, a time taken to melt the lift-off layer120for performing the patterning increases, thereby increasing a time for performing the manufacturing processes. If the lift-off layer120is too thin, it is difficult to lift off the lift-off layer120.

Referring toFIG. 4B, a pattern layer130having a shape (e.g., a set or predetermined shape) is formed on the lift-off layer120.

The pattern layer130may not be formed at (e.g., on) a first region131corresponding to the first anode101, but may be formed at (e.g., on) a remaining region136except the first region131.

The pattern layer130may include a material having a greater surface energy than that of the lift-off layer120.

In an embodiment, the pattern layer130may include a non-fluorine based polymer. For example, the pattern layer130may include a composite in which a binder material not containing fluorine, such as an acryl-based resin, a styrene-based resin, a novolac resin, and/or a silicon resin, is melted in a non-fluorine based general organic solvent.

In another embodiment, the pattern layer130may include a material containing a small amount of fluorine. For example, the pattern layer130may include a composite, in which a fluorine-based polymer containing less than 20 wt % of fluorine is melted in a non-fluorine based general organic solvent.

The pattern layer130may be formed by a printing method.

FIG. 4Bshows an example in which the pattern layer130is printed on the lift-off layer120by directly dropping droplets J1, J2, and J3from an inkjet printing device S including a plurality of nozzles N1, N2, and N3.

FIG. 4Billustrates that the droplets J1, J2, and J3are concurrently (e.g., simultaneously) dropped onto first and second pixel regions PX1and PX2from the inkjet printing device S to form the pattern layer130, but the inventive concept is not limited thereto. For example, the inkjet printing device S may form the pattern layer130first on the first pixel region PX1, and then may move to the second pixel region PX2to form the pattern layer130. Also, the number, size, and shape of the nozzles provided in the inkjet printing device S may be varied, and an injecting speed of the droplets dropped from the nozzles may be adjusted.

In a case where the pattern layer130of the set or predetermined shape is directly formed on the lift-off layer120by the printing method, because the lift-off layer120including the fluoropolymer has low surface energy, the pattern layer130does not spread over the lift-off layer120but maintains or substantially maintains a set or predetermined pattern, even when the pattern layer130including the non-fluorine based resin or the polymer containing a small amount of fluorine is directly printed on the lift-off layer120.

If the pattern layer130is formed by a photolithography method, a photoresist is applied on the lift-off layer120, the photoresist is exposed via a photomask by using an exposure device, and the exposed photoresist is developed and stripped. Accordingly, when using the photolithography method, complicated manufacturing processes are performed. However, according to an embodiment, the non-fluorine based polymer may be a general polymer that is not expensive, and thus, may cost less than the photoresist. In addition, when the photolithography method is performed, an expensive apparatus is used and complicated manufacturing processes are performed. However, the printing method according to an embodiment may use a simplified device and may perform straightforward manufacturing processes, and accordingly, equipment investment costs and processing costs may be reduced. Also, when the photolithography process is performed, the pattern layer130may be partially lost through the exposure, developing, and stripping processes, whereas the printing method according to an embodiment may directly form the pattern layer130on a region where the pattern is to be formed (e.g., the region136, except the first region131), and thus, loss of material may be prevented or reduced, and manufacturing costs may be reduced.

Although not shown inFIG. 4B, after performing the printing process of the pattern layer130, a process of drying the pattern layer130may be performed. After printing the pattern layer130, a temperature and a time for drying the pattern layer130may be dependent upon a glass transition temperature Tg of the fluoropolymer included in the lift-off layer120, a boiling point of the solvent included in the lift-off layer120, and/or a wet film thickness. In an embodiment, under a condition where the glass transition temperature Tg of the fluoropolymer is about 75° C., the boiling point of the solvent (e.g., PGMEA) is about 150° C., and the wet film thickness after the printing process is about 10 μm, the pattern layer130is dried for about 3 to 6 minutes at a temperature of about 70° C. to about 80° C.

Referring toFIG. 4C, the lift-off layer120is etched by using the pattern layer130formed by the process illustrated inFIG. 4Bas an etching mask.

An etchant may be a first solvent including fluorine. Because the lift-off layer120includes the fluoropolymer and the pattern layer130includes the non-fluorine based polymer, the pattern layer130may function as the etching mask during the etching process using the first solvent including the fluorine.

The first solvent may include hydrofluoroether. The hydrofluoroether is an electrochemically stabilized material that rarely interacts with other materials, and is also an eco-friendly material having a low global warming potential (GWP) and a low toxicity.

Through the etching process, the lift-off layer120formed on a location corresponding to the first region131, that is, on the first anode101, is etched.

When the lift-off layer120is etched, the first solvent including the fluorine forms a first undercut profile UC1in the lift-off layer120under an interface between the pattern layer130and the first region131.

The first undercut profile UC1may allow a first organic functional layer151to be precisely deposited in a deposition process that will be described later, and may remove the lift-off layer120remaining on the substrate100clearly in a lift-off process that will be described later.

Referring toFIG. 4D, the first organic functional layer151including a first organic emission layer is formed on the structure shown inFIG. 4C.

The first organic functional layer151may further include a hole injection layer, a hole transport layer, an electron transport layer, and/or an electron injection layer.

In an embodiment, the first organic emission layer is used as an example of the first organic function layer151. Hereinafter, the first organic functional layer and the first organic emission layer may be denoted by the same reference numeral.

The first organic functional layer151may be formed by a vacuum deposition process. In the deposition process, the lift-off layer120and the pattern layer130function as a mask. A part of the first organic emission layer151is formed over the first anode101, and another part of the first organic emission layer151is formed on the other region136of the pattern layer130, except the first region131.

Referring toFIG. 4E, a lift-off process is performed on the structure shown inFIG. 4D.

Because the lift-off layer120includes the fluoropolymer, a second solvent including fluorine is used in the lift-off process. In addition, because the lift-off process is performed after forming the first organic emission layer151, the second solvent may include a material having a low degree of reactivity with the first organic emission layer151. The second solvent may include, for example, hydrofluoroether like the first solvent.

By lifting off the lift-off layer120formed under the region136(seeFIG. 4D) of the pattern layer130, the first organic layer151formed on the region136(seeFIG. 4D) of the pattern layer130is removed, and the first organic emission layer151formed on the first anode101remains as a pattern.

FIG. 11Ais a schematic diagram of boundary lines L151of the first organic emission layer, which are irregularly formed, after finishing a first unit process. The pattern layer130(seeFIG. 4D) formed on the lift-off layer120(seeFIG. 4D) having a low surface energy has poor spreadability, and thus, boundary lines of the pattern layer130(seeFIG. 4D) are not uniform, but irregularly formed. Because the pattern layer130(seeFIG. 4D) functions as a deposition mask, the irregular shape of the boundary lines of the pattern layer130may affect the pattern of the first organic emission layer151. Therefore, the boundary lines L151of the first organic emission layer151are irregularly formed while generating fine waves. The boundary lines L151of the first organic emission layer151may be more irregular than the boundary lines L101of the first anode101formed by the photolithography method.

According to an embodiment, in the process of forming the first organic emission layer151, a metal mask having openings is not used, but the lift-off process is performed. Thus, misalignment between the substrate100and the metal mask may be prevented.

After performing the first unit process, a second unit process for forming a second organic emission layer152(e.g., seeFIG. 5E) for emitting light of a different color from that of the first organic emission layer151is performed on a region where the second anode102is located. Hereinafter, the second unit process will be described in more detail below with reference toFIGS. 5A to 5E.

Referring toFIG. 5A, the lift-off layer120including fluoropolymer is formed over the substrate100, on which the first to third anodes101,102, and103are formed.

The lift-off layer120may include a material that is the same as or different from the fluoropolymer used in the first unit process. The lift-off layer120may be formed on the substrate100by an application method, a printing method, or a deposition method.

Referring toFIG. 5B, the pattern layer130is formed on the lift-off layer120.

The pattern layer130including a non-fluorine based polymer is not formed at (e.g., on) a second region132corresponding to the second anode102, but is directly formed at (e.g., on) a region137other than the second region132by dropping droplets J1, J2, and J3from an inkjet printing device S including the plurality of nozzles N1, N2, and N3.

A process of drying the pattern layer130may be further performed after the printing process of the pattern layer130.

Referring toFIG. 5C, the lift-off layer120is etched by using the pattern layer130of a set or predetermined shape formed by the printing process illustrated with reference toFIG. 5Bas an etching mask.

An etchant may be the first solvent including fluorine. Because the lift-off layer120includes the fluoropolymer and the pattern layer130includes the non-fluorine based polymer, the pattern layer130may function as an etching mask in the etching process using the first solvent including the fluorine.

The first solvent may include hydrofluoroether. Otherwise, the first solvent may include a different material from that of the first unit process described above.

According to the etching process, the lift-off layer120corresponding to the second region132, that is, the lift-off layer120formed on the second anode102, is etched.

In addition, when the lift-off layer120is etched, the first solvent including the fluorine forms a second undercut profile UC2in the lift-off layer120under a boundary of the second region132.

Referring toFIG. 5D, a second organic functional layer152including a second organic emission layer is formed over a structure shown inFIG. 5C.

The second organic functional layer152may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

In an embodiment, the second organic emission layer is described as an example of the second organic functional layer152. Hereinafter, the second organic functional layer and the second organic emission layer may be denoted by the same reference numeral.

The second organic emission layer152may be formed by a vacuum deposition process. In the deposition process, the lift-off layer120and the pattern layer130may function as a mask. A part of the second organic emission layer152is formed on the second anode102, and another part of the second organic emission layer152is formed on the region137other than the second region132in the pattern layer130.

Referring toFIG. 5E, a lift-off process is performed on the structure shown inFIG. 5D.

Because the lift-off layer120includes the fluoropolymer, a second solvent including fluorine is used in the lift-off process. In addition, because the lift-off process is performed after forming the second organic emission layer152, the second solvent may include a material having a low degree of reactivity with the second organic emission layer152. The second solvent may include, for example, hydrofluoroether like the first solvent.

By lifting off the lift-off layer120formed under the region137(seeFIG. 5D) of the pattern layer130, the second organic emission layer152formed on the region137(seeFIG. 5D) of the pattern layer130is removed, and the second organic emission layer152formed on the second anode102remains as a pattern.

FIG. 11Bis a schematic diagram showing a state, in which boundary lines L152of the second organic emission layer152are irregularly formed after finishing the second unit process. Because the pattern layer130(seeFIG. 5D) formed on the lift-off layer120(seeFIG. 5D) having a low surface energy has poor spreadability, boundary lines of the pattern layer130(seeFIG. 5D) are not uniform, but are irregularly formed. Because the pattern layer130(seeFIG. 5D) functions as a deposition mask, the irregular shape of the boundary lines of the pattern layer130affects the pattern of the second organic emission layer152. Therefore, boundary lines L152of the second organic emission layer152are irregularly formed as, for example, fine waves. The boundary lines L152of the second organic emission layer152may be formed to be more irregular than the boundary lines L102of the second anode102that is formed by the photolithography method.

After performing the second unit process described above, a third unit process for forming a third organic emission layer153(e.g., seeFIG. 6E) for emitting light of a different color from those of the first and second organic emission layers152and152is performed. Hereinafter, the third unit process will be described below with reference toFIGS. 6A through 6E.

Referring toFIG. 6A, the lift-off layer120including fluoropolymer is formed over the substrate100on which the first to third anodes101,102, and103are formed.

The lift-off layer120may include a material that is the same as or different from the fluoropolymer used in the first unit process and/or the second unit process. The lift-off layer120may be formed on the substrate100by an application method, a printing method, or a deposition method.

Referring toFIG. 6B, the pattern layer130is formed on the lift-off layer120.

The pattern layer130including a non-fluorine based polymer is not formed at (e.g., on) a third region133corresponding to the third anode103, but is directly formed at (e.g., on) a region138other than the third region133, by dropping droplets J1, J2, and J3from the inkjet printing device S including the plurality of nozzles N1, N2, and N3.

A process for drying the pattern layer130may be further performed after the printing process of the pattern layer130.

Referring toFIG. 6C, the lift-off layer120is etched by using the pattern layer130having a set or predetermined shape formed by the printing method illustrated inFIG. 6Bas an etching mask.

An etchant may include the first solvent including fluorine. Because the lift-off layer120includes the fluoropolymer and the pattern layer130includes the non-fluorine based polymer, the pattern layer130may function as the etching mask in the etching process using the first solvent including the fluorine.

The first solvent may include hydrofluoroether, like in the first unit process and/or the second unit process. The first solvent may include a material different from those of the first unit process and the second unit process.

Due to the etching process, the lift-off layer120corresponding to the third region133, that is, the lift-off layer120formed on the third anode103, is etched.

In addition, when the lift-off layer120is etched, the first solvent including the fluorine forms a third undercut profile UC3in the lift-off layer120under a boundary surface of the third region133in the pattern layer130.

Referring toFIG. 6D, a third organic functional layer153including a third organic emission layer is formed on the structure shown inFIG. 6C.

The third organic functional layer153may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

In an embodiment, the third organic emission layer is described as an example of the third organic functional layer153. Hereinafter, the third organic functional layer and the third organic emission layer may be denoted by the same reference numeral.

The third organic emission layer153may be formed by a vacuum deposition process. In the deposition process, the lift-off layer120and the pattern layer130may function as a mask. A part of the third organic emission layer153is formed on the third anode103, and another part of the third organic emission layer153is formed on a region138other than the third region133in the pattern layer130.

Referring toFIG. 6E, a lift-off process is performed on the structure shown inFIG. 6D.

Because the lift-off layer120includes the fluoropolymer, the second solvent including the fluorine is used in the lift-off process. In addition, since the lift-off process is performed after forming the third organic emission layer153, the second solvent may include a material having a low degree of reactivity with the third organic emission layer153. The second solvent may include hydrofluoroether, like the first solvent.

By lifting off the lift-off layer120formed under the region138(seeFIG. 6D) of the pattern layer130, the third organic emission layer153formed on the region138(seeFIG. 6D) of the pattern layer130is removed, and the third organic emission layer153formed on the third anode103remains as a pattern.

FIG. 11Cis a schematic diagram showing a state in which boundary lines L153of the third organic emission layer153are irregularly formed after finishing the third unit process. Because the pattern layer130(seeFIG. 6D) formed on the lift-off layer120(seeFIG. 6D) having a low surface energy has poor spreadability, boundary lines of the pattern layer130(seeFIG. 6D) are not uniform, but are irregularly formed. Because the pattern layer130(seeFIG. 6D) functions as a deposition mask, the irregular shape of the boundary lines of the pattern layer130affects the pattern of the third organic emission layer153. Therefore, boundary lines L153of the third organic emission layer153are irregularly formed as, for example, fine waves. The boundary lines L153of the third organic emission layer153may be formed to be more irregular than the boundary lines L103of the third anode103that is formed by the photolithography method.

Referring back toFIG. 2, the first to third organic functional layers151,152, and153are formed through the first to third unit processes described above, respectively, and then, a cathode180is formed as a common layer.

InFIG. 2, the cathode180is shown as not integrally formed, but separately formed on the first to third anodes101,102, and103. However, the inventive concept is not limited thereto, and in some embodiments, the cathode180may be integrally formed.

In an embodiment, the first to third anodes101,102, and103are described as hole injection electrodes, and the cathode180is described as an electron injection electrode, but the inventive concept is not limited thereto. That is, the electron injection electrodes may be formed on regions where the first to third anodes101,102, and103are located, and the hole injection electrode may be formed on a region where the cathode180is located.

The first to third organic emission layers151,152, and153may emit light of different colors from each other. The light emitted from the first to third organic emission layers151,152, and153may be mixed with each other to form white light. For example, the first to third organic emission layers151,152, and153may respectively emit red light, green light, and blue light. For example, the first to third organic emission layers151,152, and153may be sub-pixels configuring a unit pixel in the organic light-emitting display apparatus1.

The organic light-emitting display apparatus1shown inFIG. 2may denote one unit pixel (e.g., two one unit pixels). Also, the above described methods may be applied to an organic light-emitting display apparatus including a plurality of unit pixels as shown inFIG. 2. That is, a plurality of first organic emission layers151for emitting first color light may be formed concurrently (e.g., simultaneously) through the first unit process. A plurality of second organic emission layers152for emitting second color light may be concurrently (e.g., simultaneously) formed through the second unit process. A plurality of third organic emission layers153for emitting third color light may be concurrently (e.g., simultaneously) formed through the third unit process. Full-color light may be implemented through the first to third unit processes.

FIG. 7is a schematic cross-sectional view of an organic light-emitting display apparatus2manufactured by a manufacturing method according to an embodiment.

The organic light-emitting display apparatus2illustrated with reference toFIG. 7may be manufactured in a similar manner to that of the organic light-emitting display apparatus1ofFIG. 2. Hereinafter, differences between the method for manufacturing the organic light-emitting display apparatus1ofFIG. 2and the method for manufacturing the organic light-emitting display apparatus2ofFIG. 7will be described in more detail below.

Referring toFIG. 7, a plurality of anodes including first to third anodes101,102, and103are formed on the substrate100, and a pixel defining layer110is formed on the substrate100to surround edges of the first to third anodes101,102, and103. The pixel defining layer110defines an emission area, and prevents or substantially prevents short-circuit between each of the first to third anodes101,102, and103and the cathode180.

In an embodiment, first to third unit processes are performed after forming the first to third anodes101,102, and103and the pixel defining layer110.

Through the first to third unit processes, the first to third organic emission layers151,152, and153are formed on the first to third anodes101,102, and103, respectively. After performing the first to third unit processes, the cathode180is formed as a common layer.

The pixel defining layer180may be formed by a photolithography process. As in the above-described embodiments, because the pattern layer130(e.g., seeFIGS. 4D, 5D, and 6D) functions as the deposition mask, the irregular shape at the boundary of the pattern layer130affects the patterns of the first to third organic functional layers151,152, and153. Therefore, the boundary lines of the first to third organic functional layers151,152, and153may be more irregular than those of the first to third anodes101,102, and103and the pixel defining layer110.

FIG. 8is a schematic cross-sectional view of an organic light-emitting display apparatus3manufactured by a manufacturing method according to an embodiment.

The organic light-emitting display apparatus3ofFIG. 8may be manufactured in a similar manner to that of the organic light-emitting display apparatus2shown inFIG. 7described above. Hereinafter, differences between the method of manufacturing the organic light-emitting display apparatus2illustrated with reference toFIG. 7and the method of manufacturing the organic light-emitting display apparatus3illustrated with reference toFIG. 8will be described below.

Referring toFIG. 8, a plurality of anodes including first to third anodes101,102, and103are formed on the substrate100, and a pixel defining layer110is formed on the substrate100to surround edges of the first to third anodes101,102, and103. The pixel defining layer110defines an emission area, and prevents or substantially prevents short-circuit between each of the first to third anodes101,102, and103and the cathode180.

In an embodiment, first to third unit processes are performed after forming the first to third anodes101,102, and103and the pixel defining layer110.

In the first unit process, the lift-off layer120(e.g., seeFIG. 4D) formed on the first anode101is etched by using the printing method and the etching process. Next, the first organic emission layer151is formed on the first anode101by a deposition process. When the first organic emission layer151is formed, a first auxiliary cathode181is formed successively on the first organic emission layer151, and then, a lift-off process is performed.

In the lift-off process, a second solvent including fluorine is used. The second solvent including the fluorine may break the first organic emission layer151. The first auxiliary cathode181functions as a barrier for protecting the first organic emission layer151during the lift-off process.

After performing the first unit process, the second unit process is performed. The lift-off layer120(e.g., seeFIG. 5D) on the second anode102is etched by using the printing method and the etching process. Next, the second organic emission layer152is formed on the second anode102by a deposition process. When the second organic emission layer152is formed, a second auxiliary cathode182is successively formed on the second organic emission layer152, and the lift-off process is performed.

In the lift-off process, the second solvent including fluorine is used. The second solvent may break the second organic emission layer152. The second auxiliary cathode182functions as a barrier for protecting the second organic emission layer152during the lift-off process.

After the second unit process, the third unit process is performed. The lift-off layer120(e.g., seeFIG. 6D) on the third anode103is etched by using the printing method and the etching process. Next, the third organic emission layer153is formed on the third anode103by a deposition process. When the third organic emission layer153is formed, a third auxiliary cathode183is successively formed on the third organic emission layer153, and the lift-off process is performed.

In the lift-off process, a second solvent including fluorine is used. The second solvent including the fluorine may damage the third organic emission layer153. The third auxiliary cathode183functions as a barrier for protecting the third organic emission layer183during the lift-off process.

After performing the first to third unit processes, the cathode180is formed as a common layer.

According to a manufacturing method illustrated with reference toFIG. 8, when the first to third organic emission layers151,152, and153are formed, the first to third auxiliary cathodes181,182, and183are successively formed on the first to third organic emission layers151,152, and153, respectively, in order to prevent or reduce damage to the first to third organic emission layers151,152, and153in the post lift-off process. Thereafter, the first to third auxiliary cathodes181,182, and183are electrically connected to the cathode180that is commonly formed throughout the plurality of pixels after the first to third unit processes, in order to prevent or reduce a voltage dropping of the cathode180.

FIGS. 9A and 9Bare schematic cross-sectional views of a method of forming a pattern layer according to an embodiment.

InFIG. 9A, a first pattern layer131is formed on the lift-off layer120by dropping droplets J1and J3including a material having a greater surface energy than that of the lift-off layer120from the inkjet printing device S including the plurality of nozzles N1, N2, and N3.

InFIG. 9B, a second pattern layer132is formed on the lift-off layer120by dropping a droplet J2including a material having a smaller surface energy than that of the first pattern layer131from the inkjet printing device S including the plurality of nozzles N1, N2, and N3.

Referring toFIGS. 9A and 9B, the first pattern layer131including the material having the greater surface energy than that of the lift-off layer120is formed first, and then the second pattern layer132including the material having the smaller surface energy than that of the first pattern layer131is formed thereafter.

The first pattern layer131includes a non-fluorine based polymer, and the second pattern layer132may include a material, in which a fluorine-based surfactant is added to the non-fluorine based polymer material of the first pattern layer131. For example, the second pattern layer132may include non-ionic polymeric fluorosurfactant.

The first pattern layer131having the greater surface energy may surround the second pattern layer132having the smaller surface energy.

As in one or more of the above-described embodiments, when the pattern layer130(e.g., seeFIG. 4B) of a set or predetermined shape is directly formed on the lift-off layer120by the printing method, even if the pattern layer130including the non-fluorine based resin or the polymer having a small amount of fluorine is directly printed on the lift-off layer120, the pattern layer130does not spread over the lift-off layer120, but maintains or substantially maintains a set or predetermined pattern, because the lift-off layer120including the fluoropolymer has a low surface energy. However, because the pattern layer130does not spread, uniformity of the pattern layer130degrades.

However, since the first pattern layer131having a high surface energy is formed according to the method illustrated inFIGS. 9A and 9C, the uniformity of the pattern layer may be improved, and a pin hole defect that may occur in a surface of the pattern layer may be prevented or reduced.

FIG. 10is a schematic cross-sectional view of a method of forming a pattern layer according to an embodiment.

FIG. 10illustrates that the first pattern layer131and the second pattern layer132are concurrently (e.g., simultaneously) formed on the lift-off layer120by using the inkjet printing device S including the plurality of nozzles N1, N2, and N3. For example, droplets J1and J3including a material having a large surface energy are dropped via the nozzles N1and N3to form the first pattern layer131, and concurrently (e.g., simultaneously or at the same time), a droplet J2including a material having a small surface energy is dropped via the nozzle N2to form the second pattern layer132. Thus, processing speed may be faster than that of the method illustrated inFIGS. 9A and 9B.

In addition, although not shown in the drawings, one or more of the organic light-emitting display apparatuses described above may further include an encapsulation member for encapsulating the organic emission layer. The encapsulation member may include a glass substrate, a metal foil, or a thin film encapsulation layer in which an inorganic layer and an organic layer are mixed.

According to the one or more embodiments, an organic light-emitting display apparatus may be manufactured through straightforward manufacturing processes, and a misalignment between the patterns may be prevented or substantially prevented. Also, costs for providing equipment and performing manufacturing processes, and material costs, may be reduced, and thus, manufacturing costs may be reduced.

It should be understood that embodiments described herein should be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features and/or aspects within each embodiment should typically be considered as available for other similar features and/or aspects in other embodiments.