KR100770273B1 - Donor substrate and method of fabricating thereof - Google Patents

Abstract

A donor substrate and a manufacturing method thereof are provided to reduce an edge open error by forming a protrusion portion on a substrate layer of the donor substrate. A donor substrate includes a base substrate(21), a photothermal conversion layer(22), a buffer layer(23) and a transfer layer(24). The photothermal conversion layer is formed on the base substrate. The buffer layer is arranged on the photothermal conversion layer and includes a protrusion portion. The transfer layer is formed on the protrusion portion of the buffer layer and includes an OLED(Organic Light Emitting Display) layer. The buffer layer includes a metal layer, a first polymer thin film layer and a second polymer thin film layer. The first polymer thin film layer is formed on a portion of the metal layer. The second polymer thin film layer is formed outside the first polymer thin film layer.

Description

Donor substrate and its manufacturing method

1A and 1B are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using a conventional laser thermal transfer method.

2A to 2E are cross-sectional views illustrating a method of manufacturing a donor substrate according to a first embodiment of the present invention.

3A to 3B are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a second embodiment of the present invention.

<Brief Description of Drawings>

10,20: donor substrate 11,21: base material layer

12,22: light-to-heat conversion layer 13,23: first buffer layer

14,24: transfer layer 14 ', 24': transfer layer pattern

231: metal layer 232: first molecular thin film layer

233: second molecular thin film layer

100,200: substrate 110,210: second buffer layer

115,215: semiconductor layer 120,220: gate insulating film

125,225: gate electrode 130,230: interlayer insulating film

135,235 source / drain electrodes 140,240 planarization film

145,245: via hole 155,255: first electrode

150,250: pixel defining layer 165,265: opening

The present invention relates to a donor substrate and a method for manufacturing the same, and more particularly, to a donor substrate including a buffer layer including a protrusion and a method for manufacturing the same.

Among the flat panel display devices, organic light emitting display devices are self-luminous, having a wide viewing angle, fast response speed, thin thickness, low manufacturing cost, and high contrast. It is attracting attention as a next-generation flat panel display device in the future.

In general, the organic light emitting device is composed of several layers such as a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer and an electron injection layer between the anode and the cathode, the three primary colors of R, G and B in the organic light emitting device The full color can be realized by patterning the light emitting layer.

The multilayer organic film may be formed using a vacuum deposition method or a conventional optical etching method using a shadow mask, but in the case of the vacuum deposition method, it is difficult to form a perfect full color display because it is difficult to form the organic film in a fine pattern. In the case of the photoetching method, there is a problem in that light emission characteristics such as lifetime and efficiency are deteriorated due to damage of the organic layer by the developer or the etchant.

Accordingly, a method of patterning an organic film using laser induced thermal imaging (LITI) has been introduced as a method to solve this problem.

The laser thermal transfer method is a method in which light is emitted from a light source and absorbed by a light-to-heat conversion layer of a donor substrate to convert light into thermal energy, and the organic material formed on the transfer layer is transferred to a substrate by the converted thermal energy.

1A and 1B are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using a conventional donor substrate.

Referring to FIG. 1A, first, a semiconductor layer 115, a gate insulating layer 120, a gate electrode 125, and an interlayer insulating layer 130 are formed on a substrate 100 on which a second buffer layer 110 is formed. A thin film transistor having a source / drain electrode 135 is formed.

A planarization layer 140 is formed on the source / drain electrode 135 over the entire surface of the substrate including the thin film transistor, and a via hole 145 is formed to expose the source or drain electrode 135.

The first electrode 155 is formed to be connected to the source or drain electrode 135 through the via hole 145 formed in the planarization layer 140.

In this case, after forming the pixel defining layer 150 covering the first electrode 155 having the curved shape of the via hole 145, the pixel defining layer 150 is patterned to form the first electrode ( An opening 165 is formed that exposes a portion of 155.

As a result, a substrate having the thin film transistor and having the first electrode 155 formed thereon is manufactured.

Meanwhile, a donor substrate 10 having a structure in which a base layer 11, a light-to-heat conversion layer 12, a first buffer layer 13, and a transfer layer 14 are sequentially stacked is provided separately from the substrate.

Subsequently, the first electrode 155 of the substrate and the transfer layer 14 of the donor substrate 10 are disposed to face each other, and then a portion of the base layer 11 of the donor substrate 10 is irradiated with a laser. do.

Thereafter, as illustrated in FIG. 1B, the transfer layer 14 is transferred from the donor substrate on the first electrode 155 of the substrate to form an organic layer pattern 14 ′.

However, in the organic electroluminescent device, since the edge portion of the pixel region has a step due to the pixel defining layer, when the organic light emitting layer is formed by using the laser thermal transfer method, the transfer layer is cut off at the stepped portion so that the transfer layer is not transferred. Done. This is referred to as edge open failure (E). Such a defect may reduce the efficiency and lifespan of the organic light emitting display device, and may cause a problem in that a full color cannot be realized.

In addition, in the case of performing the laser thermal transfer method using a conventional donor substrate, the donor substrate is lightly applied to the donor substrate using a roller or a soft bar to closely adhere the transfer layer of the donor substrate to the substrate on which the first electrode is formed. This causes a problem that additional equipment or processes are added.

Accordingly, the present invention provides a donor substrate including a buffer layer including a protrusion, a method of manufacturing the same, and a method of manufacturing an organic light emitting device using the same.

In order to achieve the above object, the present invention is a substrate layer; A photo-thermal conversion layer on the base layer; A buffer layer on the photo-thermal conversion layer, the buffer layer including a protrusion; A donor substrate is provided on the buffer layer and includes a transfer layer including an organic light emitting layer.

The present invention also provides a substrate layer; Forming a photo-thermal conversion layer on the substrate layer; Forming a buffer layer including a protrusion on the photo-thermal conversion layer; It provides a method for producing a donor substrate comprising forming a transfer layer comprising an organic light emitting layer on the buffer layer.

The present invention also provides a substrate on which a first electrode is formed; A donor substrate including a substrate layer, a photo-thermal conversion layer, a buffer layer including protrusions, and a transfer layer, spaced apart from each other such that the transfer layer faces the substrate; A method of manufacturing an organic light emitting display device, the method comprising: irradiating a portion of a base layer of a donor substrate with a laser to transfer the transfer layer to form a transfer layer pattern on the first electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. In the figures, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout the specification.

2A through 2E are cross-sectional views illustrating a method of manufacturing a donor substrate according to an embodiment of the present invention.

Referring to FIG. 2A, a substrate layer 21 and a light-to-heat conversion layer 22 formed on the substrate layer 21 are provided.

In this case, the base layer 21 should have transparency in order to transmit light to the light-heat conversion layer 22, and may be made of a material having suitable optical properties and sufficient mechanical stability. For example, it may be made of glass or one or more polymeric materials selected from the group consisting of polyester, polyacrylic, polyepoxy, polyethylene and polystyrene. More preferably, the base layer 21 may be polyethylene terephthalate. The base layer 21 serves as a support substrate, and complex multiple systems may also be used.

The light-to-heat conversion layer 22 formed on the base layer 21 is a layer for absorbing light in the infrared-visible light region and converting a portion of the light into heat, and a light absorbing material for absorbing light. It is preferable to include. Here, the light-to-heat conversion layer 22 may be a metal film made of Al, Ag, oxides and sulfides thereof, or an organic film made of a polymer including carbon black, graphite, or infrared dye. Here, the metal film may be formed by vacuum deposition, electron beam deposition, or sputtering, and the organic film is a conventional film coating method, and includes gravure, extrusion, spin, and knife coating. It can be formed by one of the methods.

Next, referring to FIG. 2B, a metal layer 231 is formed on the light-to-heat conversion layer 22, and a first molecular thin film layer 232a is formed on the metal layer 231 by using a self-assembly method.

Here, in order to perform the self-assembly method, the metal layer 231 is preferably any one of gold (Au) and an alloy thereof. The thickness of the metal layer 231 does not need to be particularly limited, but in order to uniformly form the light-to-heat conversion layer 22, the thickness of the metal layer 231 should be at least 5 nm and preferably 300 nm or less in consideration of manufacturing time. In addition, the metal layer 231 may be formed using a vacuum deposition method, an electron beam deposition method, or a sputtering method.

Here, the first molecular thin film layer 232 preferably includes any one of a mercapto group (-SH) and an alkane chain, ethylene oxide, ethylene oxide, and amide. If the first molecular thin film layer 232 includes an alkane chain, the number of the alkane chains is limited in thickness so that the number of carbon atoms is 6-20. When the number of carbon atoms is 6 or less, the metal layer 231 may not be uniformly formed, and thus, an area where the metal layer 231 is exposed may occur. When the number of carbon atoms is 20 or more, van der Waals forces between molecules ) May cause the first molecular thin film layer 232 not to be uniformly formed on the surface of the metal layer 231 but excessively formed in a predetermined region.

Referring to the process of performing the self-assembly, the mercapto group (-SH) and the alkane chain, including the group having a strong interaction with the gold (Au) or the alloy of the gold (Au), ethylene oxide (ethylene oxide ), A molecule containing any one of ester and amide is dissolved in the solution. Subsequently, when the substrate containing the gold (Au) or the alloy of the gold (Au) is left in the solution for a predetermined time and taken out, a self-assembled monolayer is formed. Because the mercapto group (-SH) and alkane chain, ethylene oxide, ester and amide on the surface of the gold (Au) or the alloy of gold (Au) exposed to the solution This is because the reaction does not proceed any further if it is covered with a molecule containing any one of Since the self-assembled monomolecular film formed as described above acts as a strong attraction force with the surface of the substrate, post-treatment is possible by a method such as washing after manufacturing the thin film and can be performed without expensive equipment.

Next, referring to FIG. 2C, a partial laser beam is irradiated to a partial region of the base layer 21 to remove a partial region of the first molecular thin film layer 232. The first molecular thin film layer 232 may be easily removed because the first molecular thin film layer 232 is vertically bonded to the metal layer 231.

Subsequently, referring to FIG. 2D, the second molecular thin film layer 233 is formed in a region where the first molecular thin film layer 232 is removed by performing a surface initiated polymerization method.

In the surface-initiated polymerization method, the second molecular thin film layer 233 is added to any one selected from styrene-based monomers as an initiator, and in particular, nitrooxide-mediated polymerization. Can be formed by performing the method

In addition, the second molecular thin film layer 233 may be added to any one selected from acrylic monomers, and any one selected from 3-azahexane group as an initiator may be added. It can be formed by going through an oxide mediated polymerization method.

In addition, the second molecular thin film layer 233 is an atomic transfer radical polymerization in which a polymer is grown while being transferred from a halogen valence initiator to a methacrylic acid monomer and a growing polymer by a potential metal catalyst. It can be formed by performing the method.

The thickness of the second molecular thin film layer 233 is preferably 200 nm to 1 μm thicker than the thickness of the first molecular thin film layer. This is because the organic electroluminescent device is manufactured using the donor substrate of the present invention, and the thickness is varied in consideration of the step difference of the pixel definition layer of the organic electroluminescent device.

As a result, the first buffer layer 23 including the metal layer 231, the first molecular thin film layer 232, and the second molecular thin film layer 233 is completed.

Subsequently, referring to FIG. 2E, the donor substrate 20 is completed by forming a transfer layer 24 including an organic light emitting layer on the second molecular thin film layer 233.

Here, the transfer layer 24 may be formed of one single layer film or one or more multilayer films selected from the group consisting of a hole injection layer, a hole transport layer, an organic light emitting layer, a hole suppression layer, an electron transport layer and an electron injection layer.

The hole injection layer facilitates hole injection into the organic light emitting layer of the organic light emitting diode and serves to increase the life of the device. The hole injection layer may be formed of an aryl amine compound, starburst amines, and the like. More specifically, 4,4 ', 4 "-tris (3-methylphenylamino) triphenylamino (m-MTDATA), 1,3,5-tris [4- (3-methylphenylamino) phenyl] benzene (m- MTDATB) and phthalocyanine copper (CuPc) and the like.

The hole transport layer may be made of an arylene diamine derivative, a starburst compound, a biphenyldiamine derivative having a spiro group, a ladder compound, and the like. More specifically N, N-diphenyl-N, N'-bis (4-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD) or 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB).

The organic light emitting layer is a low molecular material such as Alq3 (host) / DCJTB (fluorescent dopant), Alq3 (host) / DCM (fluorescent dopant), CBP (host) / PtOEP (phosphorescent organometallic complex), which is a red light emitting material, and a PFO-based polymer. High molecular weight materials such as Alq3, Alq3 (host) / C545t (dopant), CBP (host) / IrPPY (phosphorescent organic complex) which are green light emitting materials, and PFO polymer, Polymeric materials, such as a PPV polymer, can be used. In addition, low molecular weight materials such as DPVBi, Spiro-DPVBi, Spiro-6P, Distylbenzene (DSB), and Distriarylene (DSA), which are blue light emitting materials, and polymer materials such as PFO polymer and PPV polymer can be used. .

The hole suppression layer serves to prevent the hole from moving to the electron injection layer when the hole mobility is greater than the electron mobility in the organic light emitting layer. Wherein the hole suppression layer is 2-biphenyl-4-yl-5- (4-t-butylphenyl) -1,3,4-oxydiazole (PBD), spiro-PBD and 3- (4'-t -Butylphenyl) -4-phenyl-5- (4'-biphenyl) -1,2,4-triazole (TAZ).

The electron transport layer may be made of a metal compound that can accept electrons well, and may be made of 8-hydroquinoline aluminum salt (Alq3) having excellent properties of stably transporting electrons supplied from the cathode electrode.

The electron injection layer may be made of one or more materials selected from the group consisting of 1,3,4-oxydiazole derivatives, 1,2,4-triazole derivatives, and LiF.

In addition, such an organic film may be formed by a method such as extrusion, spin, knife coating, vacuum deposition, or CVD.

3A and 3B are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a second embodiment of the present invention.

3A and 3B, a second buffer layer 210 is formed on a substrate 200 formed of glass, stainless steel, plastic, or the like. The second buffer layer 210 may be formed of a silicon nitride film, a silicon oxide film, a silicon oxynitride film, or multiple layers thereof.

Subsequently, amorphous silicon is deposited on the second buffer layer 210 to be patterned and then crystallized to form a semiconductor layer 215. A gate insulating layer 220 is formed on the semiconductor layer 215, and a gate electrode 225 is formed on the gate insulating layer 220 in a region corresponding to the semiconductor layer 215. The gate insulating film 220 may be a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a multilayer thereof.

Subsequently, a conductive impurity is implanted into the semiconductor layer 215 using the gate electrode 225 as a mask to form a source region and a drain region 215a. In this case, a channel region 215c is defined between the source / drain regions 215a. An interlayer insulating layer 230 is formed on the gate electrode 225 over the entire substrate. The interlayer insulating film 230 may be a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a multilayer thereof.

Subsequently, contact holes 235a exposing the source / drain regions 215a are formed in the interlayer insulating layer 230. A conductive film is stacked on the substrate on which the contact holes 235a are formed, and then patterned to form a source electrode 235 and a drain electrode 235. The source / drain electrodes 235 are connected to the source / drain regions 215a through the contact holes 235a. The semiconductor layer 215, the gate electrode 225, and the source / drain electrodes 235 form a thin film transistor. The thin film transistor is not limited to the above-described thin film transistor and can be applied to all kinds of thin film transistors.

The planarization layer 240 is formed on the source / drain electrode 235 over the entire substrate. The planarization layer 240 may be formed of one material selected from the group consisting of polyimide, benzocyclobutene series resin, and acrylate.

Subsequently, a via hole 245 exposing the source / drain electrodes 235 is formed in the planarization layer 240. One of the source / drain electrodes 235 exposed by the via hole 245 is connected to the first electrode 255 formed on the planarization layer 240.

The first electrode 255 is made of ITO or IZO having a high work function, and may include a reflective film made of a metal having high reflectivity such as Al, Al-Nd, and Ag in the lower layer. In the case of the bottom emission, it does not include the reflective film and may be formed of one of ITO and IZO, which are transparent conductive films.

Subsequently, the pixel defining layer 250 is formed and patterned on the first electrode 255 to form the opening 265. The pixel definition layer 250 may be formed of one material selected from the group consisting of polyimide, benzocyclobutene series resin, and acrylate.

Meanwhile, a donor substrate 20 is provided separately from the substrate. The donor substrate 20 includes a substrate layer 21, a photo-thermal conversion layer 22 on the substrate layer 21, and a first buffer layer 23 including protrusions on the photo-thermal conversion layer 22. ), A transfer layer 24 including an organic light emitting layer is sequentially stacked on the first buffer layer 23.

Here, the first buffer layer 23 includes a metal layer 231, a first molecular thin film layer 232, and a second molecular thin film layer 233, and the second molecular thin film layer 233 is positioned in the protrusion region.

Since the detailed description of the first buffer layer 23 has been described above, it will be omitted here to avoid duplication.

Subsequently, the first electrode 255 of the substrate and the transfer layer 24 of the donor substrate are spaced apart from each other to face each other.

Subsequently, a portion of the base layer 21 of the donor substrate is irradiated with a laser to transfer the transfer layer 24 onto the first electrode 255 to form a transfer layer pattern 24 ′. .

Subsequently, a second electrode (not shown) is formed on the transfer layer pattern 24 ′ over the entire surface of the substrate on which the first electrode 255 is formed, and then encapsulated to complete the organic light emitting diode.

The present invention can significantly reduce the edge open defects generated when the laser thermal transfer method is performed using the donor substrate, and the organic electroluminescent device can be manufactured without any additional equipment due to the protrusion of the buffer layer of the donor substrate. have.

While the invention has been shown and described with reference to certain preferred embodiments, the invention is not so limited, and the invention is not limited to the spirit and scope of the invention as set forth in the claims below. It will be readily apparent to one of ordinary skill in the art that various modifications and variations can be made.

As described above, the present invention includes the protrusions in the buffer layer of the donor substrate, which significantly reduces edge open defects and does not require separate manufacturing equipment, thereby manufacturing an organic light emitting display device, thereby reducing manufacturing costs. .

Claims (24)

Base layer; A photo-thermal conversion layer on the base layer; A buffer layer on the photo-thermal conversion layer, the buffer layer including a protrusion; And A donor substrate, wherein the donor substrate is positioned on a protrusion of the buffer layer and includes a transfer layer including an organic light emitting layer, wherein the buffer layer includes a metal layer, a first molecular thin film layer, and a second molecular thin film layer. The method of claim 1 The donor substrate of claim 1, wherein the first molecular thin film layer is positioned on a portion of the metal layer, and the second molecular thin film layer is located in a region where the first molecular thin film layer is not located on the metal layer. The method of claim 1, The transfer layer is a donor substrate comprising a single layer or a multilayer film selected from the group consisting of an organic light emitting layer, an electron injection layer, an electron transport layer, a hole injection layer and a hole transport layer. The method of claim 2, The donor substrate, characterized in that the metal layer comprises any one of gold (Au) or an alloy thereof. The method of claim 2, The first molecular thin film layer is mercapto group (-SH); And A donor substrate comprising any one of an alkane chain, ethylene oxide, ester and amide. The method of claim 2, The donor substrate, wherein the second molecular thin film layer includes any one selected from a styrene monomer and an alkoxyamine living group. The method of claim 2, The donor substrate, wherein the second molecular thin film layer includes any one selected from acrylic monomers and one selected from 3-azahexane group. The method of claim 2, The donor substrate, wherein the second molecular thin film layer includes any one of a halogen atom and a methacrylic acid monomer. The method of claim 2, The second molecular thin film layer The donor substrate, characterized in that about 200nm ~ 1㎛ thicker than the first molecular thin film layer. The method of claim 5, A donor substrate, characterized in that the carbon number of the alkane chain is 6-20. Providing a base layer; Forming a photo-thermal conversion layer on the substrate layer; Forming a buffer layer including a protrusion on the photo-thermal conversion layer; And forming a transfer layer including an organic light emitting layer on the buffer layer, wherein the buffer layer is formed to include a metal layer, a first molecular thin film layer, and a second molecular thin film layer. The method of claim 11, Forming the metal layer on the photo-thermal conversion layer; Forming the first molecular thin film layer on the metal layer; Irradiating a portion of the substrate layer with a laser to remove a portion of the first molecular thin film layer; And forming the second molecular thin film layer in the region where the first molecular thin film layer is removed. The method of claim 12, The metal layer is a manufacturing method of a donor substrate, characterized in that any one of gold (Au) or an alloy thereof. The method of claim 12, A method of manufacturing a donor substrate, characterized in that to form the first molecular thin film layer using a self-assembly method. The method of claim 12, The first molecular thin film layer is mercapto group (-SH); And Method of producing a donor substrate, characterized in that it comprises any one of an alkane chain, ethylene oxide (ethylene oxide), ester (ester) and amide (amide). The method of claim 12, Forming the second molecular thin film layer is a method of producing a donor substrate, characterized in that using the surface initiated polymerization (surface initiated polymerization) method. The method of claim 12, The second molecular thin film layer is a method of manufacturing a donor substrate, characterized in that it comprises any one selected from styrene-based monomers and any one selected from the alkoxyamine living group (alkoxyamine living group). The method of claim 12, The second molecular thin film layer is a method of manufacturing a donor substrate, characterized in that it comprises any one selected from acrylic monomers and one selected from 3-azahexane group (3-azahexane group). The method of claim 12, The second molecular thin film layer is a method for producing a donor substrate, characterized in that it comprises any one of a halogen atom and a methacrylic acid monomer (methacylate monomer). The method of claim 12, The second molecular thin film layer The method of manufacturing a donor substrate, characterized in that formed in about 200nm ~ 1㎛ thicker than the first molecular thin film layer. The method of claim 15, Method of producing a donor substrate, characterized in that 6 to 20 carbon atoms of the alkane chain. The method of claim 16, The surface-initiated polymerization method is a nitroxide-mediated polymerization (NMP) method or a method for producing a donor substrate, characterized in that the atom-transfer radical polymerization (ATRP: atom-transfer radical polymerization). Providing a substrate on which a first electrode is formed; A donor substrate including a substrate layer, a photo-thermal conversion layer, a buffer layer including protrusions, and a transfer layer, spaced apart from each other such that the transfer layer faces the substrate; A method of manufacturing an organic light emitting display device, the method comprising: irradiating a laser to a portion of the base layer of the donor substrate to transfer the transfer layer to form a transfer layer pattern on the first electrode. The method of claim 23, The buffer layer is a metal layer; A first molecular thin film layer on a portion of the metal layer; And a second molecular thin film layer on the region where the first molecular thin film layer of the metal layer is not located, the second molecular thin film layer including the protrusion.

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