KR20080004120A - Donor substrate and method of fabricating thereof, and method of fabricating oled using the same - Google Patents

Abstract

A donor substrate and a method of fabricating the same, and a method of fabricating an OLED(Organic Light Emitting Display) using the same are provided to remarkably reduce a defective rate by improving an imaging characteristic of the donor substrate. A donor substrate(20) includes a base layer(21), a photothermal conversion layer(22), and a buffer layer, and an imaging layer(24). The buffer layer includes a block copolymer. The buffer layer is positioned on the photothermal conversion layer and prevents a thermal damage of the imaging layer by diffusing thermal energy converted by the photothermal conversion layer. The buffer layer controls an adhesion force with the imaging layer so as to improve an imaging pattern characteristic. The base layer serves as a support substrate of the donor substrate. The photothermal conversion layer positioned on the base layer absorbs light in infrared-visible ray area and converts a part of the light to a heat. The photothermal conversion layer includes an optical absorption material.

Description

Donor substrate, its manufacturing method and manufacturing method of organic electroluminescent device using same {Don substrate and method of fabricating young, and method of fabricating OLED using the same}

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

2 is a cross-sectional view showing the structure of a donor substrate according to a first embodiment of the present invention.

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.

<Brief Description of Drawings>

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

12,22: photo-thermal conversion layer 13,23: buffer layer

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

100,200: substrate 110,210: 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, a method for manufacturing the same, and a method for manufacturing an organic light emitting device using the same, and specifically, a buffer layer including a block copolymer capable of improving surface characteristics with a light-to-heat conversion layer and a transfer layer. It relates to a donor substrate, a manufacturing method thereof and a method of manufacturing an organic light emitting device using 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, and the three primary colors of R, G and B in the organic light emitting device Full color can be implemented by patterning the light emitting layer shown.

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 a corporation, there is a problem in that light emission characteristics such as lifespan and efficiency are deteriorated due to damage of the organic layer by the developer or etching solution.

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, an interlayer insulating layer 130, and a source are disposed on a substrate 100 on which a buffer layer 110 is formed. A thin film transistor having a / drain electrode 135 is formed.

A passivation 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 on the passivation layer 140 to be connected to the source or drain electrode 135 through the via hole 145.

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 a thin film transistor and having the first electrode 155 formed thereon is manufactured.

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

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

Thereafter, as illustrated in FIG. 1B, the transfer layer 14 is transferred from the donor substrate to the first electrode 155 of the substrate to form an organic layer pattern 14 ′. Subsequently, a second electrode (not shown) is formed on the entire surface of the substrate including the organic layer pattern 14 ′ to manufacture an organic light emitting diode.

However, when the laser thermal transfer method is performed using a donor substrate including a conventional buffer layer, there is a problem that the transfer layer is not separated from the buffer layer so that the transfer is not performed efficiently. In order to overcome this problem, a donor substrate including a buffer layer containing a material having a glass transition temperature of 25 ° C. or lower has been proposed. However, since the buffer layer including a material having a glass transition temperature of 25 ° C. or lower has a low surface energy, not only a transfer layer but also an optical-thermal layer Since the separation layer is also well separated, the buffer layer is transferred together with the transfer layer. As a result, a separate process of removing the buffer layer is required, which causes a problem in that the process becomes complicated.

Accordingly, the present invention is to solve the above problems, a donor substrate including a buffer layer to improve the surface properties of the transfer layer and the light-to-heat conversion layer of the donor substrate, a method of manufacturing the same and the manufacturing of an organic light emitting device using the same Provide a method.

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 comprising a block copolymer positioned on the photo-thermal conversion layer; And it provides a donor substrate comprising a transfer layer located on the buffer 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 block copolymer on the light-to-heat conversion layer; It provides a method for producing a donor substrate comprising forming a transfer layer on the buffer layer.

The present invention also provides a substrate; A donor substrate including a substrate layer, a photo-thermal conversion layer, a buffer layer including a block copolymer, and a transfer layer, spaced apart from each other such that the transfer layer faces the substrate; It provides a method of manufacturing an organic light emitting device comprising irradiating a laser to a portion of the donor substrate to perform the transfer of the transfer layer to form a transfer layer pattern on the substrate.

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.

2 is a cross-sectional view of the structure of the donor substrate according to the first embodiment of the present invention.

Referring to FIG. 2, the donor substrate 20 includes a substrate layer 21, a photo-thermal conversion layer 22, a buffer layer 23 including a block copolymer, and a transfer layer 24.

The base layer 21 is a layer serving as a supporting substrate of the donor substrate 20, and may be used as a complex multi-system. In addition, in order to transmit light to the light-to-heat conversion layer 22, it must have transparency, 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 a plurality of polymer materials selected from the group consisting of polyester, polyacrylic, polyepoxy, polyethylene and polystyrene. More preferably, the base layer 21 may be polyethylene terephthalate.

The light-heat conversion layer 22 disposed 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.

The buffer layer 23 disposed on the light-to-heat conversion layer 22 is a layer that prevents thermal damage of the transfer layer 24 by dispersing the heat energy converted by the light-to-heat conversion layer 22. . It also serves to control the adhesive force with the transfer layer 24 so that the characteristics of the transfer pattern can be improved.

Here, the buffer layer 23 includes a block copolymer, and the block copolymer is represented by Equation 1 below.

Here, R is hydrogen, a methyl group or a phenyl group, R 'is any one selected from the group consisting of a phenyl group or an alkyl group having 1 to 3 carbon atoms, m and p is a natural number of 10 to 500. If the carbon number of R and R 'is too large, the problem of phase separation, which is a characteristic of the present invention, becomes difficult, and if the values of m and p are less than 10, phase separation equal to the limiting reason of R and R' becomes difficult, and exceeds 500. This causes a problem of poor solubility of the molecules. The block copolymer is preferably-[-C (CH ₃ ) ₂ ] ₂₀₀ -[-SiO (C ₆ H ₅ ) ₂ ] ₃₀₀ .

The reason for including the block copolymer is that the force for causing the phase separation in the post-process is due to the difference in physical properties, that is, the surface energy difference between the inorganic polymer silicon block and the organic polymer block.

The buffer layer 23 including the block copolymer having a-(-CR _2- ) m-(-OSiR ' _2- ) p- structure is first variously coated on the photo-thermal conversion layer 22, such as spin coating. It is formed using the method and left for a certain time.

Here, generally, in a block copolymer containing Si, blocks containing Si are arranged in a direction in which the surface energy is small so that they are always exposed, and the enthalpy gain obtained when the block containing Si faces outward is This is because phase separation is larger than entropy loss due to separation. Because of this, the time required for spontaneous phase separation is to be left for a certain time. The-(-CR2-) m (23a) is thus arranged towards the photo-thermal conversion layer 22, and the-(-OSiR'2-) p- (23b) is directed towards the surface, i.e. in a later process It is arranged toward the direction of the transfer layer 24 to be formed.

Subsequently, the solvent is removed by heating in a hot plate to fix the phase-separated block copolymer. Here, the removal of the solvent is because when the solvent is removed from the beginning, the block copolymer becomes a solid state, and thus the spontaneous phase separation is impossible because the polymer chain cannot move. In addition, since this is a physical fixation, a post-process is required in order to obtain an irreversible, robust phase-separated structure, which is preferably cured by chemical crosslinking using UV or heat. In particular, it is more preferable to apply photocuring which does not involve heat such as UV. This is because there is a possibility of deformation of the donor substrate when using thermal curing. Curing using UV may be performed only in the-(-CR2-) m (203a) or the-(-OSiR'2-) p- (23b) or the-(-CR2-) m (203a) and the Both-(-OSiR'2-) p- (23b) can be implemented.

It is preferable that the thickness of the said buffer layer 23 is 0.5-3 micrometers. When the buffer layer 23 has a thickness of 0.5 μm, the buffer layer 23 may not be uniformly formed on the light-to-heat conversion layer 22, resulting in incomplete surface coverage. When the thickness of the buffer layer 23 is 3 μm or more, the light- There is a problem that prevents the transfer of the thermal energy converted in the heat conversion layer 202 to the transfer layer 24.

The transfer layer 24 may be an organic layer or a conductive material including an organic light emitting layer.

Here, the organic film layer 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 formed 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 polymer High molecular weight materials such as Alq3, Alq3 (host) / C545t (dopant), CBP (host) / IrPPY (phosphorescent organic complex), green light emitting materials and PFO polymer, PPV Polymeric materials, such as system type polymers, 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.

Subsequently, the conductive material is Al, Al-alloy, Mg, MgAg, Ca, Ca-alloy or ITO, IZO.

3A and 3B are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using the donor substrate of the present invention.

3A and 3B, a buffer layer 210 is formed on a substrate 200 formed of glass, stainless steel, plastic, or the like. The 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 buffer layer 210, 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, first 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 first contact hole 235a is 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 first contact hole 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 first via hole 245 exposing the source / drain electrode 235 is formed in the planarization layer 240. One of the source / drain electrodes 235 exposed by the first 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 base layer 21, a light-to-heat conversion layer 22 on the base layer 21, and a buffer layer 23 including a block copolymer on the light-to-heat conversion layer 22. ), The transfer layer 24 is sequentially stacked on the buffer layer 23.

Here, the buffer layer 23 includes a block copolymer, and the block copolymer is represented by Equation 1 below.

[Equation 1]

Here, R is hydrogen, a methyl group or a phenyl group, R 'is any one selected from the group consisting of a phenyl group or an alkyl group having 1 to 3 carbon atoms, m and p is a natural number of 10 to 500. Further, the-(-CR _2- ) m- (23a) is arranged toward the photo-thermal conversion layer 22, the-(-OSiR ' _2- ) p- (23b) is the transfer layer ( It is arranged toward 24). In addition, the thickness of the buffer layer 23 is preferably 0.5 ~ 3㎛.

Since a detailed description of the 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 ′. . In the present embodiment, the transfer layer 24 is an organic film layer, but is not limited to the organic film layer, and a conductive material can be formed.

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 provides a donor substrate including a buffer layer including a block copolymer having a good adhesion with the light-to-heat conversion layer and a weak surface energy from the transfer layer, thereby improving the transfer characteristics of the donor substrate, thereby reducing the defective rate. There is a significant reduction effect.

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 scope and spirit of the invention as defined by the following claims. 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 provides a donor substrate including a buffer layer including a block copolymer having a good adhesion to the light-to-heat conversion layer and a weak surface energy from the transfer layer, so that the transfer characteristics of the donor substrate are improved. There is an effect that the defect rate is remarkably reduced.

Claims (19)

Base layer; A photo-thermal conversion layer on the base layer; A buffer layer comprising a block copolymer positioned on the photo-thermal conversion layer; And A donor substrate, characterized in that it comprises a transfer layer located on the buffer layer. The method of claim 1, The block copolymer is a donor substrate, characterized in that any one of the compounds represented by the following formula 1: [Equation 1]

R is hydrogen, a methyl group or a phenyl group, R 'is any one selected from the group consisting of a phenyl group or an alkyl group having 1 to 3 carbon atoms, m and p is a natural number of 10 to 500. The method of claim 1, The donor substrate, characterized in that the thickness of the buffer layer is 0.5 ~ 3㎛. The method of claim 1, The transfer layer is a donor substrate, characterized in that the organic layer or conductive material including an organic light emitting layer. The method of claim 2, And the-(-CR2-) m- is arranged toward the light-to-heat conversion layer. The method of claim 2, And-(-OSiR'2-) p- is arranged toward the transfer layer. Providing a base layer; Forming a photo-thermal conversion layer on the substrate layer; Forming a buffer layer including a block copolymer on the light-to-heat conversion layer; Method of manufacturing a donor substrate comprising forming a transfer layer on the buffer layer. The method of claim 7, wherein The block copolymer is a method of producing a donor substrate, characterized in that any one of the compounds represented by the following formula 1: [Equation 1]

R is hydrogen, a methyl group or a phenyl group, R 'is any one selected from the group consisting of a phenyl group or an alkyl group having 1 to 3 carbon atoms, m and p is a natural number of 10 to 500. The method of claim 7, wherein The buffer layer is a manufacturing method of the donor substrate, characterized in that formed to a thickness of 0.5 ~ 3㎛. The method of claim 7, wherein Forming the buffer layer forms the block copolymer on the photo-thermal conversion layer; Leaving the block copolymer for a certain time; Removing the solvent of the block copolymer left for the predetermined time; A method of manufacturing a donor substrate, comprising curing the block copolymer from which the solvent is removed. The method of claim 10, Forming the block copolymer is a method of manufacturing a donor substrate comprising performing by using a spin coating method. The method of claim 10, Removing the solvent of the block copolymer left for a predetermined time comprises the step of performing a heating process using a donor substrate. The method of claim 10, Curing the block copolymer from which the solvent is removed comprises the step of performing using a UV or heat. Providing a substrate; A donor substrate including a substrate layer, a photo-thermal conversion layer, a buffer layer including a block copolymer, and a transfer layer, spaced apart from each other such that the transfer layer faces the substrate; And forming a transfer layer pattern on the substrate by irradiating a laser to a portion of the donor substrate to transfer the transfer layer. The method of claim 14, The block copolymer is a method of manufacturing an organic light emitting device, characterized in that any one of the compounds represented by the following formula 1: [Equation 1]

R is hydrogen, a methyl group or a phenyl group, R 'is any one selected from the group consisting of a phenyl group or an alkyl group having 1 to 3 carbon atoms, m and p is a natural number of 10 to 500. The method of claim 14, The buffer layer forms the block copolymer on the light-to-heat conversion layer; Leaving the block copolymer for a certain time; Removing the solvent of the block copolymer left for the predetermined time; And forming the block copolymer from which the solvent has been removed, to form the organic electroluminescent device. The method of claim 16, Forming the block copolymer is a method of manufacturing an organic electroluminescent device comprising performing by using a spin coating method. The method of claim 16, Removing the solvent of the block copolymer is a method of manufacturing an organic electroluminescent device comprising performing using a heating process. The method of claim 16, Curing the block copolymer from which the solvent is removed is a method of manufacturing an organic light emitting device comprising performing by using UV or heat.

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