JP4707996B2 - Flexible display and manufacturing method thereof - Google Patents

Description

  The present invention relates to a flexible display and a manufacturing method thereof, and more particularly to a flexible display applicable to an organic EL display or a liquid crystal display using a plastic film as a substrate and a manufacturing method thereof.

  Display devices such as organic EL (Electroluminescence) displays and liquid crystal displays are rapidly expanding their applications to information equipment. In recent years, a flexible display using a plastic film as a substrate has attracted attention. Such flexible displays can be used not only for ultra-thin and lightweight mobile devices that can be rolled up and stored, but also for large displays.

  However, the plastic film has a low rigidity and a low thermal deformation temperature, and thus is likely to undergo thermal deformation such as warping and expansion / contraction in a manufacturing process involving heat treatment. For this reason, in a manufacturing method in which various elements are formed directly on a plastic film, conditions such as a manufacturing process involving heat treatment are limited, and high-precision alignment becomes difficult, so that an element substrate having desired characteristics is manufactured. It may not be possible.

  In order to avoid such problems, a transparent electrode, a color filter layer, and the like are aligned and formed with high accuracy on a heat-resistant and rigid glass substrate without restricting manufacturing conditions, There is a method of manufacturing an element substrate for a liquid crystal device by transferring and forming this transfer layer on a plastic film (Patent Document 1).

  In addition, in order to obtain a display having excellent display characteristics, active driving in which a driving transistor is incorporated for each pixel is required. The flexible display requires a flexible TFT element that can follow the bending, and there is a possibility that sufficient reliability cannot be obtained with a low-temperature polysilicon TFT or an amorphous silicon TFT as a conventional driving transistor. For this reason, organic TFTs that use a flexible organic semiconductor layer that can follow bending as an active layer have attracted attention as driving transistors for flexible displays.

  In Patent Document 2, a gate electrode, a gate insulating film, an organic semiconductor layer, and a source / drain electrode are sequentially formed on a substrate, and an organic EL element is formed on an anode connected to the drain electrode. A method of manufacturing an EL display is described.

In Patent Document 3, an isolation layer is formed on a heat-resistant substrate, an organic TFT composed of a gate electrode, a gate insulating film, an organic semiconductor layer, and a source / drain is formed thereon, and then an organic TFT is formed. A method of transferring from a heat-resistant substrate to a surface substrate (plastic substrate) is described.
JP 2003-131199 A JP 2003-255857 A JP 2003-318195 A

  By the way, the organic semiconductor layer and the organic EL layer have a problem in that their performance deteriorates or eventually becomes nonfunctional in a photolithography and etching process that involves processing such as an organic solvent, water, plasma, electron beam, or heat treatment. .

  In Patent Documents 2 and 3 described above, since it is necessary to pattern the source / drain after forming the organic semiconductor layer, there is a possibility that performance degradation of the organic semiconductor layer in the photolithography process may become a problem.

  Thus, a manufacturing method of a flexible display using an organic TFT using a plastic film as a substrate has not been sufficiently established, and a desired organic TFT or organic EL element can be stably provided on a plastic film with a high yield. A method of forming is eagerly desired.

  The present invention has been created in view of the above-described problems, and is manufactured at a high yield without causing any problems. A flexible display using a plastic film as a substrate and having an organic TFT and a method for manufacturing the same The purpose is to provide.

  In order to solve the above problems, the present invention relates to a flexible display, which is an active matrix type flexible display in which a TFT is provided for each of a plurality of pixels, and includes a plastic film and an adhesive layer formed on the plastic film. A protective layer formed on the adhesive layer; a gate electrode for the TFT embedded in the protective layer; a gate insulating layer for the TFT covering the gate electrode; and the gate insulating layer A source electrode and a drain electrode for the TFT formed and arranged on the gate electrode at a predetermined interval; a pixel electrode formed on the gate insulating layer and electrically connected to the drain electrode; and the source electrode Between the source electrode and the drain electrode, and electrically connected to the source electrode and the drain electrode. An organic active layer for the TFT, an organic EL layer including a light emitting layer formed on each of the pixel electrodes of the plurality of pixels, a metal electrode formed on the organic EL layer, and covering the metal electrode And a sealing layer.

  In order to obtain the flexible display of the present invention, first, a release layer, a source electrode, a drain electrode, a pixel electrode, a gate insulating layer, a gate electrode, and a protective layer are formed on a temporary substrate (such as a glass substrate) having heat resistance and rigidity. The transfer layer is formed with desired film characteristics without restricting the production conditions. Thereafter, the transfer layer is transferred and formed in a state of being inverted upside down on the plastic film via the adhesive layer. Next, after the release layer is removed, an organic active layer electrically connected to the source electrode and the drain electrode exposed on the upper side is formed by mask vapor deposition or an inkjet method.

  Subsequently, an organic EL layer including a light emitting layer is formed on the pixel electrode 26 of each pixel by mask vapor deposition, an inkjet method, or the like. Furthermore, after metal electrodes are formed on the organic EL layer, they are covered with a sealing layer.

  In the above-described invention, the light emitting layer may be composed of a red (R) light emitting layer, a green (G) light emitting layer, and a blue (B) light emitting layer, and a white light emitting layer is used as the light emitting layer. A color filter layer embedded in the adhesive layer may be formed between the adhesive layer and the protective layer. Alternatively, in order to improve the color saturation, the light emitting layer is composed of the light emitting layers of the three primary colors, and further, the color filter layer is formed between the adhesive layer and the protective layer, so that the color filter layer and the three primary colors are formed. Full color may be achieved by combining with EL emission.

  Unlike the present invention, in a structure in which a TFT having an organic active layer, a pixel electrode, and an organic EL layer are directly formed on a plastic film, a photolithography process is required after the organic active layer is formed. Not only is the performance of the active layer deteriorated, but when a low-resistance pixel electrode (ITO) is formed, there is a problem that the plastic film is thermally deformed due to heat treatment at a high temperature.

  However, in the present invention, a photolithography patterning step (a step of forming a source electrode, a drain electrode, a pixel electrode, and a gate electrode) that adversely affects the organic active layer or the organic EL layer, or a step involving a high-temperature heat treatment (pixel electrode) Are formed on a temporary substrate, and after transferring them onto a plastic film, an organic active layer and an organic EL layer are formed by mask vapor deposition or an inkjet method. Thereby, there is no possibility that the performance of the organic active layer or the organic EL layer may be deteriorated by various processes in the photolithography process.

  As described above, in the flexible display of the present invention, the organic active layer and the organic EL layer for TFT are formed on the plastic film at a high yield without causing any problems, thereby reducing the manufacturing cost and improving the reliability. be able to.

  The flexible display of the present invention can be applied to an active matrix liquid crystal display by omitting the organic EL layer and the like.

  In order to solve the above-described problems, the present invention relates to a method for manufacturing a flexible display, which is a method for manufacturing an active matrix flexible display in which a TFT is provided for each of a plurality of pixels, and is peeled off on a temporary substrate. Forming a layer, forming a source electrode and a drain electrode for the TFT on the release layer, and forming a pixel electrode electrically connected to the drain electrode, the source electrode, A step of forming a gate insulating layer for the TFT covering the drain electrode and the pixel electrode, and a gate electrode for the TFT is formed on the gate insulating layer between the source electrode and the drain electrode A step of forming a protective layer covering the gate electrode, and a plastic film on the protective layer via an adhesive layer. Bonding the temporary substrate from the interface with the release layer, the release layer, the source electrode, the drain electrode, the pixel electrode, the gate insulating layer, the gate electrode, and the protective layer. A step of transferring onto the plastic film; a step of exposing upper surfaces of the source electrode, the drain electrode and the pixel electrode by removing the release layer; and between the source electrode and the drain electrode. The pixel electrodes of the plurality of pixels before or after the step of forming an organic active layer for the TFT electrically connected to the source electrode and the drain electrode and the step of forming the organic EL layer Forming an organic EL layer including a light emitting layer thereon, forming a metal electrode on the organic EL layer, and forming a sealing layer covering the metal electrode Characterized by a step.

  By using the manufacturing method of the present invention, a flexible display having the above-described configuration can be easily manufactured.

  In the above-described invention, the organic active layer and the organic EL layer for TFT are formed by mask vapor deposition, an inkjet method, or printing. When the inkjet method or printing is employed, an organic insulating layer pattern in which openings are provided between the source electrode and the drain electrode and on the pixel electrode is formed before the organic active layer and the organic EL layer are formed. The organic active layer and the organic EL layer are aligned and formed in the openings in a state where the organic insulating layer pattern is formed as a partition.

  As described above, according to the present invention, an active matrix type organic EL display or liquid crystal display including an organic TFT using a plastic film as a substrate is manufactured with a high yield without causing any problems.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
1 to 4 are cross-sectional views sequentially illustrating a method for manufacturing a flexible display according to the first embodiment of the present invention, and FIG. 5 is a cross-sectional view illustrating the flexible display (organic EL display) according to the first embodiment of the present invention. In the first embodiment, an example in which the present invention is applied to an organic EL display will be described. As shown in FIG. 1A, the flexible display manufacturing method according to the first embodiment of the present invention first prepares a glass substrate 20 as a temporary substrate, and peels the polyimide substrate or the like on the glass substrate 20. Layer 22 is formed.

  Thereafter, as shown in FIG. 1B, a conductive layer made of gold (Au) having a thickness of, for example, 100 nm is formed on the release layer 22, and the conductive layer is patterned by photolithography and etching. Thus, the source electrode 24a and the drain electrode 24b of the switching TFT (Thin Film Transistor) (hereinafter referred to as Sw-TFT) and the source electrode 24x and the drain electrode 24y of the driving TFT (hereinafter referred to as Dr-TFT) are provided. And are formed.

Subsequently, a transparent conductive layer such as an ITO (Indium Tin Oxide) layer having a film thickness of, for example, 150 nm is formed on the release layer 22, the source electrodes 24 a and 24 x, and the drain electrodes 24 b and 24 y by a sputtering method. The transparent conductive layer is patterned by lithography and etching. Thereby, as shown in FIG. 1C, the pixel electrode 26 electrically connected to the drain electrode 24y for the Dr-TFT is formed on the peeling layer 22. Note that the pixel electrode 26 may be formed so as to overlap the end portion of the drain electrode 24y for the Dr-TFT. In this embodiment, since the ITO layer to be the pixel electrode 26 is formed on the heat-resistant glass substrate 20, a sputtering method with a film forming temperature of about 200 ° C. can be employed. Thus, the pixel electrode 26 (ITO) is formed with low resistance (specific resistance value: 3 × 10 ⁻⁴ Ω · cm or less) electrical characteristics.

Next, as shown in FIG. 1D, a gate insulating layer 28 that covers the source electrodes 24a and 24x, the drain electrodes 24b and 24y, and the pixel electrode 26 is formed. As the gate insulating layer 28, a silicon oxide layer (SiO _x layer) or a tantalum oxide layer (Ta ₂ O ₅ layer) having a film thickness of 200 nm, for example, is used, and these insulating layers are formed by CVD or sputtering. The

Next, after a conductive layer made of tantalum (Ta), aluminum (Al), ITO, or the like is formed on the gate insulating layer 28 by vapor deposition or sputtering, the conductive layer is patterned by photolithography and etching.
As a result, as shown in FIG. 2 (a), the gate electrode 30a for the Sw-TFT is overlying the end portions of the source electrode 24a and the drain electrode 24b for the Sw-TFT, respectively, so that the gates above them. It is formed on the insulating layer 28. At the same time, the gate electrode 30b for the Dr-TFT is formed on the portion on the gate insulating layer 28 above the end of the source electrode 24x and the drain electrode 24y for the Dr-TFT so as to overlap each other. .

  As described above, the source electrodes 24a and 24x, the drain electrodes 24b and 24y, the pixel electrode 26, and the gate electrodes 30a and 30b are formed on the glass substrate 20 with high precision and miniaturized by photolithography.

  Subsequently, as shown in FIG. 2B, a protective layer 32 made of an acrylic resin or the like that covers the gate electrodes 30a and 30b is formed. As a result, the step between the gate electrodes 30a and 30b is buried and flattened by the protective layer 30.

  Next, as shown in FIG. 2C, the plastic film 40 is disposed on the upper surface of the structure of FIG. Further, the adhesive layer 34 is cured by heat treatment, and the plastic film 40 is bonded onto the structure shown in FIG. As the plastic film 40, a polyethersulfone film or a polycarbonate film having a film thickness of 100 to 200 μm is preferably used.

  Subsequently, as shown in FIG. 2C, a roll 29 is fixed to one end of the plastic film 40, and the glass substrate 20 is peeled while the roll 29 is rotated. At this time, it peels along the interface (A part of FIG.2 (c)) of the glass substrate 20 and the peeling layer 22, and the glass substrate 20 is discarded.

  As a result, as shown in FIG. 2D, the adhesive layer 34, the protective layer 32, the gate electrodes 30a and 30b, the gate insulating layer 28, the source electrodes 24a and 24x, and the drain electrode are formed on the plastic film 40 in this order from the bottom. 24b and 24y, the pixel electrode 26, and the release layer 22 are transferred and formed.

  Thereafter, as shown in FIG. 3A, the release layer 22 is removed by plasma of oxygen gas. Thereby, the upper surfaces of the source electrodes 24a and 24x, the drain electrodes 24b and 24y, and the pixel electrode 26 are exposed.

  Next, as shown in FIG. 3B, the gate insulating layer above the Sw-TFT organic active layer 36a so as to overlap the ends of the Sw-TFT source electrode 24a and the drain electrode 24b, respectively. 28 is formed in the upper part. At the same time, the organic active layer 36b for the Dr-TFT is formed on the portion on the gate insulating layer 28 between them so as to overlap the end portions of the source electrode 24x and the drain electrode 24y for the Dr-TFT. . As a material of each organic active layer 36a, 36b, an organic semiconductor such as pentacene, sexithiophene, or polythiophene is used. The organic active layers 36a and 36b are formed by mask vapor deposition, and the film thickness thereof is, for example, 50 nm. Mask vapor deposition is a method of forming a pattern simultaneously with film formation by moving a shadow mask with high accuracy in a vacuum vapor deposition apparatus. Patterned organic active layers 36a and 36b are used without using photolithography. Can be formed. Therefore, the performance of the organic active layers 36a and 36b is not deteriorated by wet processing or plasma in the photolithography process.

  In this way, the Sw-TFT 5 including the gate electrode 30a, the gate insulating layer 28, the source electrode 24a, the drain electrode 24b, and the organic active layer 36a is obtained. At the same time, the Dr-TFT 6 including the gate electrode 30b, the gate insulating layer 28, the source electrode 24x, the drain electrode 24y, and the organic active layer 36b is obtained.

  As described above, in the present embodiment, the source electrodes 24a and 24x, the drain electrodes 24b and 24y, the pixel electrode 26, and the gate electrode having the desired film characteristics on the heat-resistant glass substrate 20 without being limited in manufacturing conditions. The organic active layers 36a and 36b are formed after the patterns 30a and 30b are accurately patterned by photolithography and transferred onto the plastic film 40. Therefore, there is no possibility that the performance of the organic active layers 36a and 36b is deteriorated in the photolithography process for forming the pixel electrode 26 and the like.

  Subsequently, as shown in FIG. 3C, a hole transport layer 38 having a film thickness of, for example, 30 nm is selectively formed on the pixel electrode 26 by mask vapor deposition. As the hole transport layer 38, α-NPD, which is an aromatic tertiary amine derivative, is preferably used.

  Further, as shown in FIG. 3C, a low molecular light emitting layer 42 having a film thickness of, for example, 70 nm is selectively formed on the hole transport layer 38 by mask vapor deposition. In the present embodiment, an example in which the light emitting layers of the three primary colors are separately formed to form a full color is illustrated, so that the three primary colors (red (R), green (G), blue ( A red light emitting layer, a green light emitting layer, and a blue light emitting layer are formed on the hole transport layer 34 of each pixel portion in B)). A pixel portion (sub-pixel) of three primary colors constitutes a pixel as a display unit.

  As the low molecular light emitting layer 42, a host material mixed with a doping material is used, and the doping material (molecule) emits light. Examples of the host material include Alq3 and a distyrylarylene derivative (DPVBi), and examples of the doping material include green-emitting coumarin 6 and red-emitting DCJTB.

  Subsequently, as shown in FIG. 3C, an electron transport layer 44 is formed on the light emitting layer 42 by mask vapor deposition. As the electron transport layer 44, quinolinol aluminum complex (Alq3) or the like is preferably used.

  Thereby, the organic EL layer 3 comprised by the positive hole transport layer 38, the light emitting layer 42, and the electron carrying layer 44 is obtained.

  Note that only one of the hole transport layer 38 and the electron transport layer 44 may be formed, or both the hole transport layer 38 and the electron transport layer 44 may be omitted.

  Alternatively, after removing the release layer 22 (FIG. 3A), the organic EL layer 3 may be formed first, and then the organic active layers 36a and 36b for TFT may be formed.

  Further, as shown in FIG. 3D, a metal electrode 46 is selectively formed on the electron transport layer 44 by mask vapor deposition. As the metal electrode 46, a lithium fluoride / aluminum (LiF / Al) laminated film or the like is preferably used. The film thickness of the LiF layer is set to 0.2 to 1 nm, and the film thickness of the Al layer is set to 100 to 200 nm. .

  When the organic active layers 36a and 36b are selectively covered with an insulating layer by mask vapor deposition or printing, the metal electrode 46 may be formed on the entire top surface of the structure shown in FIG.

  Thereby, the organic EL element 2 comprised by the pixel electrode 26, the organic EL layer 3, and the metal electrode 46 is obtained.

  Thus, in this embodiment, since the process of forming the organic active layers 36a and 36b and the organic EL layer 3 and the subsequent processes do not use photolithography, the organic active layers 36a and 36b and the organic EL layer 3 can be There is no possibility that the performance deteriorates due to various processes in the lithography process.

Thereafter, as shown in FIG. 4, a sealing layer 48 that covers the organic EL element 2, the Sw-TFT 5, and the Dr-TFT 6 is formed. As the sealing layer 48, a silicon oxide layer (SiO _x ), a silicon nitride layer (SiN _x ), or the like is used. Or it is good also as the sealing layer 48 by sticking the resin film in which the moisture-proof layer was formed.

  Thus, the flexible organic EL display 1 according to the first embodiment of the present invention is completed.

  As described above, in the flexible display manufacturing method according to the first embodiment, first, the manufacturing conditions are not limited on the heat-resistant glass substrate 20, and the release layer 22, the source electrodes 24a and 24x, and the drain electrode 24b. 24y and the pixel electrode 26, the gate insulating layer 28, the gate electrodes 30a and 30b, and the protective layer 32 are formed with high accuracy. Thereafter, the transfer layer is transferred and formed on the plastic film 40 through the adhesive layer 32 in an inverted state. Next, after the release layer 22 is removed, organic active layers 36a and 36b for TFT are formed by mask vapor deposition between the source electrodes 24a and 24x and the drain electrodes 24b and 24y.

  Further, the hole transport layer 38, the light emitting layer 42 of primary colors, and the electron transport layer 44 are sequentially formed on the pixel electrode 26 by mask vapor deposition to obtain the organic EL layer 3. Subsequently, after the metal electrodes 42 are formed on the organic EL layer 3, they are covered with the sealing layer 48.

  In the present embodiment, a photolithography patterning process (source electrodes 24a and 24x, drain electrodes 24b and 24y, pixel electrodes 26, and gate electrodes 30a and 30b are formed, which adversely affects the organic active layers 36a and 36b and the light emitting layer 42. Step) is performed on the glass substrate 20, and after transferring them onto the plastic film 40, the organic active layers 36a and 36b and the light emitting layer 42 are formed by mask deposition. Therefore, there is no possibility that the characteristics of the organic active layers 36a and 36b and the light emitting layer 42 are deteriorated by various processes in the photolithography process.

  As described above, in the present embodiment, an organic EL display including an organic TFT using a plastic film as a substrate can be stably manufactured with a high yield.

  FIG. 5 illustrates the three primary color pixel portions (red pixel portion (R), green pixel portion (G), and blue pixel portion (B)) of the flexible display of the first embodiment. As shown in FIG. 5, in the flexible organic EL display 1 of the first embodiment, a plastic film 40 is used as a substrate, and a protective film 32 is formed thereon via an adhesive layer 34. A gate electrode 30a of the Sw-TFT 5 and a gate electrode 30b of the Dr-TFT 6 are embedded in the protective film 32 of the pixel portions (R), (G), and (B) of the three primary colors. A gate insulating layer 28 is formed on each gate electrode 30a, 30b.

  Further, on the gate insulating layer 28 of the pixel portions (R), (G), and (B) of the three primary colors, the source electrode 24a and the drain electrode 24b for the Sw-TFT 5 and the source electrode 24x for the Dr-TFT 6 are provided. A drain electrode 24y and a pixel electrode 26 electrically connected to the drain electrode 24y for the Dr-TFT 6 are formed.

  Further, an organic layer composed of a hole transport layer 38, light emitting layers 42R, 42G, and 42B and an electron transport layer 44 is formed on each pixel electrode 26 of each of the three primary color pixel portions (R), (G), and (B). Each EL layer 3 is formed. A red light-emitting layer 42R, a green light-emitting layer 42G, and a blue light-emitting layer 42B are provided corresponding to the three primary color pixel portions (R), (G), and (B), respectively.

  Further, metal electrodes 46 are respectively formed on the organic EL layers 3 of the three primary color pixel portions (R), (G), and (B), and the pixel portions (R), (G), and (B) are formed. The organic EL element 2 constituted by the pixel electrode 26, the organic EL layer 3 and the metal electrode 46 is provided. On the organic EL element 2, the Dr-TFT 6, and the Sw-TFT 5, a sealing layer 48 that covers them is formed.

  FIG. 6 is a diagram showing an equivalent circuit of one pixel portion of the flexible display according to the first embodiment of the present invention. FIG. 7 is a plan view of one pixel portion of the flexible display according to the first embodiment of the present invention as seen from the plane direction. It is.

  As shown in FIGS. 6 and 7, in the flexible organic EL display 1 of the first embodiment, the metal electrode 46 (cathode) of the organic EL element 2 is connected to the ground (GND) 66, and the pixel electrode of the organic EL element 2 26 (anode) is connected to the drain electrode 24 y of the Dr-TFT 6. The source electrode 24 x of the Dr-TFT 6 is connected to a power supply (Vdd) line 60. Further, a storage capacitor Cs is formed between the gate electrode 30 b of the Dr-TFT 6 and the power supply (Vdd) line 60. Further, the drain electrode 24 b of the Sw-TFT 5 is connected to the gate electrode 30 b of the Dr-TFT 6, and the source electrode 24 a of the Sw-TFT 5 is connected to the data line 62. Further, the gate electrode 30 a of the Sw-TFT 5 is connected to the scanning line 64.

  The equivalent circuit of FIG. 6 operates as follows. First, when the potential of the scanning line 64 is selected and a writing potential is applied to the scanning line 64, the Sw-TFT 5 is turned on to charge or discharge the storage capacitor Cs, and the gate potential of the Dr-TFT 6 becomes the writing potential. Next, when the potential of the scanning line 64 is set to a non-selected state, the scanning line 64 and the Dr-TFT 6 are electrically disconnected, but the gate potential of the Dr-TFT 6 is stably held by the storage capacitor Cs.

  Then, the current flowing through the Dr-TFT 6 and the organic EL element 2 has a value corresponding to the gate-source voltage of the Dr-TFT 6, and the organic EL element 2 continues to emit light with the luminance corresponding to the current value.

  An active matrix organic EL display can be configured by arranging a plurality of pixels having such a configuration in a matrix and repeating writing through the data lines 62 while sequentially selecting the scanning lines 64. In this manner, light of a predetermined color is emitted to the outside from the light emitting layers 42R, 42G, and 42B of the pixel portions (R), (G), and (B) to obtain a color image (FIG. 5). Arrow direction).

  In addition, the problem which organic TFT has is the dispersion | variation in the characteristic of organic TFT. In particular, if the threshold voltage (Vth) of the Dr-TFT 6 varies, the illuminance varies within the display screen. Accordingly, a countermeasure is taken to compensate for variations in the threshold voltage (Vth) of the Dr-TFT 6 by providing a compensation circuit in the equivalent circuit of FIG. As such a compensation circuit, there are a current programming method and a voltage programming method in which two transistors are added (reference material: 2003 FPD technology, Electronic Journal Publishing (2003)).

  Although a technique for adding a compensation circuit to a circuit using a low-temperature polysilicon TFT or an amorphous silicon TFT has been developed, the same effect can be obtained by adding a compensation circuit to a circuit using an organic TFT as in this embodiment. can get.

  In the first embodiment described above, the color filter layer is formed on the protective layer 32 and then the plastic film 40 is bonded via the adhesive layer 34 as in the second embodiment described below. A color filter layer embedded in the adhesive layer 34 may be further provided. In the case of this embodiment, since the color filter layer is combined with the red (R), green (G), and blue (B) EL light emission, the color saturation can be improved.

(Second Embodiment)
FIG. 8 is a sectional view showing a flexible display (organic EL display) according to the second embodiment of the present invention. In the second embodiment, a white light emitting layer is used as the light emitting layer of the organic EL layer, and a color filter layer is combined to achieve full color. In FIG. 8, the same elements as those in FIG. 5 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 8, in the flexible organic EL display 1a of the second embodiment, the red light emitting layer 42R, the green light emitting layer 42G, and the blue light emitting layer 42B are all replaced with the white light emitting layer 42 in FIG. 5 of the first embodiment. It is a form. The color filter layers 52R, 52G, and 52B are formed between the protective layer 32 and the adhesive layer 34 so as to be embedded in the adhesive layer 34, and the red color filter layer formed in the red pixel portion (R). 52R, a green color filter layer 52G formed in the green pixel portion (G), and a blue color filter layer 52B formed in the blue pixel portion (B). In the second embodiment, white light is emitted from the white light emitting layer 42 of each pixel unit (R), (G), and (B), and a color image passes through the three primary color filter layers 52R, 52G, and 52B. Is obtained (in the direction of the arrow in FIG. 8).

  In the flexible display manufacturing method of the second embodiment, the color filter layers 52R, 52G, and 52B are formed on the protective layer 32 after the step of FIG. 2B of the first embodiment. That is, the red color filter layer 52R, the green color filter layer 52G, and the blue color filter layer 52B are formed on the protective layer 30 on each pixel electrode 26 corresponding to the pixel portions (R), (G), and (B) of the three primary colors. Are sequentially formed. Each of the color filter layers 52R, 52G, and 52B is formed by patterning, for example, a pigment dispersion type photosensitive coating film by photolithography. Then, the plastic film 40 is bonded onto the color filter layers 52R, 52G, and 52B via the adhesive layer 32, and the transfer layer is transferred and formed on the plastic film 40 as in the first embodiment.

  Thereafter, the organic active layers 36a and 36b and the organic EL element 2 are formed by the same method as in the first embodiment, and then the sealing layer 48 is formed.

  The flexible organic EL display 1a of the second embodiment has the same effects as those of the first embodiment.

(Third embodiment)
9-12 is sectional drawing which shows the manufacturing method of the flexible display of 3rd Embodiment of this invention in order. In the first embodiment, the organic active layer and the organic EL layer for the TFT are formed by mask vapor deposition. In the third embodiment, the organic active layer and the organic EL layer of the TFT are formed by an inkjet method or printing. In the third embodiment, detailed description of the same steps as those in the first embodiment is omitted.

  First, as shown in FIG. 9A, after the release layer 22 is formed on the glass substrate 20 in the same manner as in the first embodiment, the mask metal layer 25 having an opening 25x provided in a required portion is formed as the release layer 22. Pattern on top. As a material of the mask metal layer 25, aluminum (Al), silver (Ag), or the like is used. The opening 25x of the mask metal layer 25 is formed in a portion corresponding to a region where an organic active layer for TFT and a pixel electrode (light emitting layer) to be formed later are formed.

  Next, as shown in FIG. 9B, after a coating film such as polyimide resin is formed on the release layer 22 and the mask metal layer 25 by spin coating or printing, heat treatment is performed at a temperature of 200 to 300 ° C. By curing the coating film, an organic insulating layer 27a having a film thickness of, for example, 2 to 5 μm is obtained. As the organic insulating layer 27a, a material that can be etched by plasma of a gas mainly containing oxygen gas such as PMMA (polymethyl methacrylate) resin and acrylic resin is used in addition to polyimide resin. In this embodiment, since the organic insulating layer 27a accompanied by the heat treatment is formed on the glass substrate 20, thermal deformation does not occur in the plastic film that finally becomes the substrate.

  Subsequently, as shown in FIG. 9C, the Sw-TFT source electrode 24a and the drain electrode 24b and the Dr-TFT source are formed on the organic insulating layer 27a by the same method as in the first embodiment. After the electrode 24x and the drain electrode 24y are formed, the pixel electrode 26 that is electrically connected to the drain electrode 24y for the Dr-TFT is formed.

  Further, as shown in FIG. 9D, after forming the gate insulating layer 28 covering the source electrodes 24a and 24x, the drain electrodes 24b and 24y, and the pixel electrode 26 by the same method as in the first embodiment, A gate electrode 30a for Sw-TFT and a gate electrode 30b for Dr-TFT are formed on the insulating layer 28. Further, a protective layer 32 that covers the gate electrodes 30a and 30b is formed.

  Next, as shown in FIG. 10A, after the plastic film 40 is bonded to the upper surface of the structure of FIG. 9D via the adhesive layer 34 by the same method as in the first embodiment, The glass substrate 20 is peeled off while rotating a roll 29 fixed to one end of the glass substrate 20. At this time, it peels along the interface (A part of Fig.10 (a)) of the glass substrate 20 and the peeling layer 22, and the glass substrate 20 is discarded.

  Thus, as shown in FIG. 10B, the adhesive layer 34, the protective layer 32, the gate electrodes 30a and 30b, the gate insulating layer 28, the source electrodes 24a and 24x, and the drain electrode are sequentially formed on the plastic film 40 from the bottom. 24b and 24y, the pixel electrode 26, the organic insulating layer 27a, the mask metal layer 25, and the peeling layer 22 are transferred and formed.

  Thereafter, as shown in FIG. 10C, the peeling layer 22 is removed by oxygen gas plasma, and the organic insulating layer 27a is etched by oxygen gas plasma using the exposed mask metal layer 25 as a mask. An organic insulating layer pattern 27 is obtained. By using oxygen gas plasma in an isotropic etching apparatus, the organic insulating layer 27a (polyimide resin or PMMA resin) is isotropically etched from the mask metal layer 25 to form a forward tapered shape (from the upper side to the lower side). As a result, the organic insulating layer pattern 27 having a shape in which the width becomes thicker is obtained. In the present embodiment, the organic insulating layer pattern 27 having a forward taper shape with a taper angle θ (FIG. 10C) of 60 ° or less (preferably 60 ° to 30 °) can be obtained.

When an acrylic resin is used as the organic insulating layer 27a, the organic insulating layer 27a is etched by plasma of a mixed gas obtained by adding 2 to 5% of a gas containing fluorine atoms such as CF _{4 to} oxygen gas.

  Subsequently, as shown in FIG. 11A, the mask metal layer 25 is selectively removed with respect to the base layer. For example, when an Al layer is used as the mask metal layer 25, wet etching using a solution containing phosphoric acid is employed without damaging the pixel electrode 26, the source electrodes 24a and 24x, the drain electrodes 24b and 24y, and the like. The mask metal layer 25 is removed.

  As a result, a forward tapered organic insulating layer pattern 27 is exposed, and the organic insulating layer pattern 27 has openings 27x on the pixel electrode 26 and between the source electrodes 24a and 24x and the drain electrodes 24b and 24y. It is formed in the provided state.

After that, the upper surface of the structure in FIG. 11A is exposed to plasma of a gas containing fluorine atoms (such as CF ₄ , SF _6, or CHF ₃ ). As a result, the fluorine atoms adhere to the upper and side surfaces of the organic insulating layer pattern 27 so that the organic insulating layer pattern 27 exhibits water repellency that repels liquid, and at the same time, the exposed surface of the pixel electrode 26 becomes hydrophilic.

  Next, as shown in FIG. 11B, a coating liquid 33 for forming the organic active layer of the TFT is applied from the nozzle 31 of the ink jet apparatus (not shown) to the source electrodes 24a and 24x and the drain electrodes 24b and 24y. A coating film is formed by coating each inside the opening 27x of the organic insulating layer pattern 27 above. Further, the coating film is baked at a temperature of 100 to 200 ° C. and dried to form the organic active layer 36 a for Sw-TFT and the organic active layer 36 b for Dr-TFT. As the coating liquid 33 for forming the organic active layers 36a and 36b, a liquid containing an organic semiconductor material such as pentacene, sexithiophene, or polythiophene described in the first embodiment is used. At this time, since the surface of the organic insulating layer pattern 27 is water-repellent, even if the nozzle 31 of the ink jet apparatus is slightly displaced from the opening 27x of the organic insulating layer pattern 27, the coating liquid 33 is left in the opening 27x. It flows to the side and accumulates in the opening 26x. In this way, the Sw-TFT 5 and the Dr-TFT 6 having the same structure as that of the first embodiment are obtained.

  Subsequently, as shown in FIG. 11B, a thiophene conductive polymer (PEDOT / PSS) coating solution is applied to the opening 27x of the organic insulating layer pattern 27 on the pixel electrode 26 by a similar ink jet method. The hole transport layer 38 is formed by applying (not shown), baking at a temperature of 100 to 200 ° C., and drying.

  Further, as shown in FIG. 11B, a coating liquid for forming a light emitting layer is applied onto the hole transport layer 38 in the opening 27x of the organic insulating layer 27 by a similar ink jet method. The light emitting layer 42 is formed by baking at a temperature of ˜200 ° C. and drying. Although only one pixel portion is shown in FIG. 11B, as in the first embodiment, the hole transport layer 38 of each of the three primary color pixel portions (R), (G), and (B). A red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer are formed on each of them.

  Examples of the light emitting layer material for forming the light emitting layer of the three primary colors include a π-conjugated polymer light emitting material and a dye-containing polymer light emitting material. More specifically, the π-conjugated polymer-based light emitting material includes polyfluorene (PF) dielectric (red, green, blue), poly-Spiro dielectric (red, green, blue), polyparaphenylene dielectric, or Examples include polythiophene dielectrics.

On the other hand, as a dye-containing polymer-based light emitting material, a dye dispersed PVK (red, green, blue) which is a light emitting material in which a phosphorescent or fluorescent low molecular weight dye is dispersed in polyvinyl carbazole (PVK), Ir (ppy) ₃ or the like There are side chain-incorporated PVKs (red, green, and blue), which are phosphorescent polymers in which the phosphor group is incorporated into the side chain of PVK.

  The above-described materials are dissolved in a solvent such as xylene, toluene, chloroform, anisole, tetradecane, dichloroethane, chlorobenzene, benzene, dichlorobenzene, and the coating liquid (ink) for forming each color light emitting layer is prepared.

  In this way, the organic EL layer 3a composed of the hole transport layer 38 and the light emitting layer 42 is obtained. As in the first embodiment, the electron transport layer may be further formed on the light emitting layer 42, or only one of the hole transport layer 38 and the electron transport layer may be formed. It is good. Alternatively, both the hole transport layer 38 and the electron transport layer may be omitted.

  In the third embodiment, since the organic active layers 36a and 36b for TFT and the organic EL layer 3a are formed by an ink jet method, as in the first embodiment, the organic active layers 36a and 36b and the organic EL layer 3a There is no possibility that the performance is deteriorated by various processes in the lithography process.

  In addition, when the hole transport layer 38 and the light emitting layer 42 are formed by the ink jet method, the surface of the organic insulating layer pattern 27 is water repellent, so that the hole transport layer 38 and the light emitting layer 42 are formed of the organic insulating layer. 27 is formed in alignment within the opening 27x.

  Note that the organic EL layer 3a may be formed first, and then the organic active layers 36a and 36b may be formed. Further, the organic active layers 36a and 36b and the organic EL layer 3a may be formed by screen printing instead of the ink jet method.

  Next, as shown in FIG. 11C, a calcium / aluminum (Ca / Al) laminated film, a barium (Ba) film, or a barium / aluminum (Ba / Al) laminated film is formed on the light emitting layer 42 by mask vapor deposition. A metal electrode 46 is formed. Thereby, the organic EL element 2a comprised by the pixel electrode 26, the organic EL layer 3a, and the metal electrode 46 is obtained.

  After that, as shown in FIG. 12, the sealing layer 48 that covers the organic EL element 2a, the Sw-TFT 5, and the Dr-TFT 6 is formed as in the first embodiment.

  Thus, the flexible organic EL display 1b according to the third embodiment is completed.

  As shown in FIG. 12, in the flexible organic EL display 1b of the third embodiment, a plastic film 40 is used as a substrate, and a protective film 32 is formed thereon with an adhesive layer 34 interposed therebetween. In the protective film 32, a gate electrode 30a of the Sw-TFT 5 and a gate electrode 30b of the Dr-TFT 6 are embedded. A gate insulating layer 28 is formed on the gate electrodes 30a and 30b.

  On the gate insulating layer 28, the source electrode 24a and the drain electrode 24b for the Sw-TFT 5, the source electrode 24x and the drain electrode 24y for the Dr-TFT 6, and the drain electrode 24y for the Dr-TFT 6 are electrically connected. A connected pixel electrode 26 is formed.

  Further, an organic insulating layer pattern 27 having openings 27x provided on the pixel electrode 26 and between the source electrodes 24a and 24x and the drain electrodes 24b and 24y is formed. The organic insulating layer pattern 27 is formed in a forward tapered shape with a taper angle of 60 ° or less, and the surface thereof is water repellent.

  In addition, organic active layers 36a and 36b for the Sw-TFT 5 and the Dr-TFT 6 are formed in the openings 27x of the organic insulating layer pattern 27 between the source electrodes 24a and 24x and the drain electrodes 24b and 24y, respectively. In the opening 27x on the pixel electrode 26 of the organic insulating layer pattern 27, a hole transport layer 38 and a light emitting layer 42 are formed. As in FIG. 5 of the first embodiment, the plurality of pixel electrodes 26 are defined by a red (R) pixel portion, a green (G) pixel portion, and a blue (B) pixel portion, and correspond to the pixel portions of each color. Thus, a red light emitting layer, a green light emitting layer, and a blue light emitting layer (not shown) are formed. The hole transport layer 38 and the light emitting layer 42 constitute the organic EL layer 3a. The organic EL layer 3 is accurately formed in each pixel portion of the three primary colors in a state defined by the organic insulating layer pattern 27 that functions as a partition when formed by the ink jet method.

  Furthermore, a metal electrode 46 is formed on the organic EL layer 3a, and the organic EL element 2a is configured by the pixel electrode 26, the organic EL layer 3a, and the metal electrode 46. A sealing layer 48 is formed on the organic EL element 2a, the Sw-TFT 5 and the Dr-TFT 6 to cover them.

  The flexible organic EL display 1b of the third embodiment has such a configuration, and similarly to the first embodiment, light of a predetermined color is emitted from the light emitting layer 42 of each color to the outside to obtain a color image ( The direction of the arrow in FIG.

  In the flexible display manufacturing method of the third embodiment, first, the manufacturing conditions are not limited on the heat-resistant glass substrate 20, and the release layer 22, the mask metal layer 25, the organic insulating layer 27a, and the source electrodes 24a and 24x. In addition, a transfer layer including the drain electrodes 24b and 24y, the pixel electrode 26, the gate insulating layer 28, the gate electrodes 30a and 30b, and the protective layer 32 is formed with high accuracy.

Thereafter, the transfer layer is transferred and formed on the plastic film 40 through the adhesive layer 32 in an inverted state. Next, after the peeling layer 22 is removed by oxygen plasma, the mask metal layer 25 is removed after the organic insulating layer 27a is continuously etched by oxygen plasma using the exposed mask metal layer 25 as a mask.
In this manner, the organic insulating layer pattern 27 having the openings 27x provided on the pixel electrode 26 on the plastic film 40 and between the source electrodes 24a and 24x and the drain electrodes 24b and 24y is formed. Thereafter, the surface of the organic insulating layer pattern 27 is made water-repellent and the surface of the pixel electrode 26 is made hydrophilic by performing a surface treatment with a plasma of a gas containing fluorine atoms.

  Further, organic active layers 36a and 36b are formed by an inkjet method in the opening 27x of the organic insulating layer 27 between the source electrodes 24a and 24x and the drain electrodes 24b and 24y. Subsequently, in the opening 27x of the organic insulating layer 27 on the pixel electrode 26, the hole transport layer 38 and the light emitting layer 42 of the three primary colors are sequentially formed by the ink jet method to obtain the organic EL layer 3a. At this time, since the organic insulating layer pattern 27 has a forward taper shape and the surface thereof is water-repellent, each coating solution is poured into the opening 27x with high accuracy, with the organic insulating layer pattern 27 serving as a partition. Thereby, the organic active layers 36a and 36b and the organic EL layer 3a are formed with high positional accuracy. Then, after forming the metal electrode 46 on the organic EL layer 3a to obtain the organic EL element 2a, a sealing layer 48 for covering them is formed.

  In the third embodiment, similarly to the first embodiment, a photolithography patterning process (source electrodes 24a and 24x, drain electrodes 24b and 24y, pixel electrodes 26, which adversely affect the organic active layers 36a and 36b and the organic EL layer 3a). And the step of forming the gate electrodes 30a and 30b) are performed on the glass substrate 20, and after they are transferred onto the plastic film 40, the organic active layers 36a and 36b and the organic EL layer 3a are formed by the inkjet method. Is done. Therefore, there is no possibility that the organic active layers 36a and 36b and the organic EL layer 3a are deteriorated by various processes in the photolithography process.

  As described above, in the third embodiment, similarly to the first embodiment, a flexible organic EL display including an organic TFT using a plastic film as a substrate can be stably manufactured with a high yield.

(Fourth embodiment)
13 to 15 are cross-sectional views sequentially illustrating a method for manufacturing a flexible display according to the fourth embodiment of the present invention, and FIG. 16 is a cross-sectional view illustrating a flexible display (liquid crystal display) according to the fourth embodiment of the present invention. In the fourth embodiment, a mode in which the present invention is applied to a liquid crystal display is illustrated. In the fourth embodiment, detailed description of the same steps as those in the first embodiment is omitted. Moreover, the same code | symbol is attached | subjected to the same element and the description is abbreviate | omitted.

  As shown in FIG. 13A, the flexible display manufacturing method according to the fourth embodiment of the present invention first forms a release layer 22 on a glass substrate 20 as a temporary substrate, and then the source of a switching TFT. Electrode 24a and drain electrode 24b are formed. Subsequently, a pixel electrode 26 made of ITO or the like electrically connected to the drain electrode 24 b is formed on the peeling layer 22.

  Next, as shown in FIG. 13B, a gate insulating layer 28 covering the source electrode 24a, the drain electrode 24b, and the pixel electrode 26 is formed. Thereafter, as shown in FIG. 13C, a TFT gate electrode 30 is formed on the gate insulating layer 28 between the source electrode 24a and the drain electrode 24b so as to overlap the end portions of the source electrode 24a and the drain electrode 24b. .

  Subsequently, as illustrated in FIG. 13D, after forming the protective layer 32 covering the gate electrode 30, the color filter layer 50 is formed on the portion on the gate insulating layer 28 corresponding to the pixel electrode 26. In the present embodiment, an example of full colorization by the color filter layer 50 is illustrated. Although only one pixel portion is shown in FIG. 13D, each pixel electrode 26 of the three primary color pixel portions (R), (G), and (B) as shown in FIG. 5 of the first embodiment. A red (R) color filter layer, a green (G) color filter layer, and a blue (B) color filter layer are formed thereon. A pixel portion (sub-pixel) of three primary colors constitutes a pixel as a display unit. The color filter layers 50 of the three primary colors are formed by sequentially patterning, for example, a pigment dispersion type photosensitive coating film by photolithography.

  Subsequently, as shown in FIG. 14A, the first plastic film 40 is bonded onto the structure of FIG. 13D via the adhesive layer 34, and then fixed to one end of the first plastic film 40. The glass substrate 20 is peeled off while rotating the rolled roll 29. At this time, it peels along the interface (A part of Fig.14 (a)) of the glass substrate 20 and the peeling layer 22, and the glass substrate 20 is discarded.

  Accordingly, as shown in FIG. 14B, the adhesive layer 34, the color filter layer 50, the protective layer 32, the gate electrode 30, the source electrode 24a and the drain electrode 24b are sequentially formed on the first plastic film 40 from the bottom. The pixel electrode 26 and the release layer 22 are transferred and formed.

  Next, as shown in FIG. 14C, the upper surface of the source electrode 24a, the drain electrode 24b, and the pixel electrode 26 is exposed by removing the peeling layer 22.

  Thereafter, as shown in FIG. 15, an organic active layer 36 for TFT is formed between the source electrode 24a and the drain electrode 24b by mask vapor deposition. As a result, the switching TFT 7 including the gate electrode 30, the gate insulating layer 28, the source electrode 24a, the drain electrode 24b, and the organic active layer 36 is obtained.

  As in the third embodiment, an organic insulating layer pattern in which an opening is provided between the source electrode 24a and the drain electrode 24b is formed, and an organic active layer is formed in the opening by an inkjet method or screen printing. Layer 36 may be formed.

  Subsequently, a resin layer 52 that covers the organic active layer 36 is formed by a photocurable resin such as PVA (polyvinyl alcohol) resin, and the step of the organic active layer 36 is flattened. Thereafter, a first alignment film 54 a for aligning liquid crystals is formed on the resin layer 52. Note that the resin layer 52 may be omitted when no problem occurs due to the step of the organic active layer 36.

  Thereby, the TFT substrate 8 for liquid crystal displays is obtained.

  As shown in FIG. 15, in the TFT substrate 8 for a liquid crystal display, a first plastic film 40 is used as a substrate, an adhesive layer 34 is formed thereon, and a color filter layer 50 is embedded in the adhesive layer 34. ing. A protective layer 32 is formed on the color filter layer 50, and the gate electrode 30 is embedded in the protective layer 32. A gate insulating layer 28 is formed on the gate electrode 30.

  Further, on the gate insulating layer 28, a source electrode 24a and a drain electrode 24b for the TFT 7 and a pixel electrode 26 electrically connected to the drain electrode 24b are formed. An organic active layer 36 for the TFT 7 is formed between the source electrode 24a and the drain electrode 24b, and both ends of the organic active layer 30 are electrically connected to the source electrode 24a and the drain electrode 24b, respectively.

  The organic active layer 36 is covered with a resin layer 52 and the level difference is flattened, and a first alignment film 54 a is formed on the resin layer 52.

  Next, as shown in FIG. 16, a counter substrate 9 of the TFT substrate 8 is prepared. The counter substrate 9 is basically composed of a second plastic film 40a, a common electrode 58 made of ITO or the like formed thereon, and a second alignment film 54b formed thereon. Then, the TFT substrate 8 and the counter substrate 9 are bonded to each other with a sealant (not shown) provided at the periphery in a state where a predetermined interval is secured by the spacer, and the TFT substrate 8 and the counter substrate 9 are further bonded. Liquid crystal 60 is sealed in the gap.

  Thus, the flexible liquid crystal display 1c according to the fourth embodiment is completed. Instead of providing the color filter layer 50 on the TFT substrate 8, the color filter layer 50 may be provided on the counter substrate 9.

  Although not particularly illustrated, a data bus line is connected to the source electrode 24 a of the TFT 7, and a gate bus line is connected to the gate electrode 30 of the TFT 7. Then, gradation voltages are sequentially applied from the gate bus line and the data bus line to the pixel electrode 26 of each pixel via the TFT 7 at a predetermined timing, and an image is displayed.

  Also in the fourth embodiment, as in the first embodiment, it is not necessary to perform a photolithography process after forming the organic active layer 36 of the TFT substrate 8, so that the organic active layer 36 is formed by various processes in the photolithography process. There is no possibility that the performance will deteriorate.

  As described above, in the fourth embodiment, an active matrix type flexible liquid crystal display using an element substrate in which an organic TFT is formed on a plastic film can be stably manufactured with a high yield.

  The present invention can also be applied to a flexible type electrophoretic display in addition to a flexible type organic EL display and a liquid crystal display.

1A to 1D are cross-sectional views (part 1) showing the method for manufacturing the flexible display according to the first embodiment of the present invention. 2A to 2D are cross-sectional views (part 2) illustrating the method for manufacturing the flexible display according to the first embodiment of the present invention. 3A to 3D are cross-sectional views (part 3) illustrating the method for manufacturing the flexible display according to the first embodiment of the present invention. FIG. 4 is a sectional view (No. 4) showing the method for manufacturing the flexible display according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing the flexible display (organic EL display) of the first embodiment of the present invention. FIG. 6 is a diagram showing an equivalent circuit of one pixel portion of the flexible display according to the first embodiment of the present invention. FIG. 7 is a plan view of one pixel portion of the flexible display according to the first embodiment of the present invention as seen from the plane direction. FIG. 8 is a sectional view showing a flexible display (organic EL display) according to the second embodiment of the present invention. 9A to 9D are cross-sectional views (part 1) showing the method for manufacturing the flexible display according to the third embodiment of the present invention. 10A to 10C are cross-sectional views (part 2) showing the method for manufacturing the flexible display according to the third embodiment of the present invention. 11A to 11C are cross-sectional views (part 3) illustrating the method for manufacturing the flexible display according to the third embodiment of the present invention. FIG. 12: is sectional drawing (the 4) which shows the manufacturing method of the flexible display of 3rd Embodiment of this invention. FIGS. 13A to 13D are sectional views (No. 1) showing the method for manufacturing the flexible display according to the fourth embodiment of the present invention. 14A to 14C are sectional views (No. 2) showing the method for manufacturing the flexible display according to the fourth embodiment of the present invention. FIG. 15: is sectional drawing (the 3) which shows the manufacturing method of the flexible display of 4th Embodiment of this invention. FIG. 15 is a sectional view showing a flexible display (liquid crystal display) according to a fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Flexible organic EL display, 1c ... Flexible liquid crystal display, 2, 2a ... Organic EL element, 3, 3a ... Organic EL layer, 5 ... Sw-TFT, 6 ... Dr-TFT, 7 ... TFT, 8 ... TFT substrate, 9 ... Counter substrate, 20 ... Glass substrate, 22 ... Release layer, 24a, 24x ... Source electrode, 24b, 24y ... Drain electrode, 25 ... Mask metal layer, 25x, 27x ... Opening, 26 ... Pixel electrode 27a ... organic insulating layer, 27 ... organic insulating layer pattern, 28 ... gate insulating layer, 29 ... roll, 30a, 30b ... gate electrode, 31 ... nozzle, 32 ... protective layer, 33 ... coating solution, 34 ... adhesive layer, 36a, 36b ... organic active layer, 38 ... hole transport layer, 40, 40a ... plastic film, 42 ... light emitting layer, 42R ... red light emitting layer, 42G ... green light emitting layer, 42B Blue light emitting layer, 44 ... electron transport layer, 46 ... metal electrode, 48 ... sealing layer, 50, 52R, 52G, 52B ... color filter layer, 52 ... resin layer, 54a, 54b ... alignment film, 58 ... common electrode, 60 ... Liquid crystal.

Claims (19)

An active matrix flexible display in which a TFT is provided for each of a plurality of pixels,
Plastic film,
An adhesive layer formed on the plastic film;
A protective layer formed on the adhesive layer;
A gate electrode for the TFT embedded in the protective layer;
A gate insulating layer for the TFT covering the gate electrode;
A source electrode and a drain electrode for the TFT formed on the gate insulating layer and disposed on the gate electrode at a predetermined interval;
A pixel electrode formed on the gate insulating layer and electrically connected to the drain electrode;
An organic active layer for the TFT formed between the source electrode and the drain electrode and electrically connected to the source electrode and the drain electrode;
An organic EL layer including a light-emitting layer formed on each of the pixel electrodes of the plurality of pixels;
A metal electrode formed on the organic EL layer;
A flexible display comprising a sealing layer covering the metal electrode.   The plurality of pixels are defined in a red pixel portion, a green pixel portion, and a blue pixel portion, and the light emitting layer is formed in a red (R) light emitting layer formed in the red pixel portion and the green pixel portion. The flexible display according to claim 1, comprising a green (G) light emitting layer formed and a blue (B) light emitting layer formed in the blue pixel portion.   The flexible display according to claim 1, wherein the light emitting layer is a white light emitting layer, and a color filter layer embedded in the adhesive layer is formed between the adhesive layer and the protective layer.   The flexible display according to claim 1, wherein upper surfaces of the source electrode and the drain electrode are formed to be flush with an upper surface of the gate insulating layer. An organic insulating layer pattern formed on the source electrode and the drain electrode, provided with openings on the source electrode and the drain electrode, and on the pixel electrode;
The organic active layer is formed in the opening between the source electrode and the drain electrode of the organic insulating layer pattern, and the organic EL layer is formed on the pixel electrode of the organic insulating layer pattern. The flexible display according to claim 1, wherein the flexible display is formed in the opening.   The flexible display according to claim 5, wherein the organic insulating layer pattern is made of any one of a polyimide resin, a PMMA resin, and an acrylic resin.   2. The TFT according to claim 1, wherein the TFT includes a switching TFT and a driving TFT connected to the switching TFT, and the drain electrode of the driving TFT is connected to the pixel electrode. The flexible display as described in any one of thru | or 3. The organic EL layer is
The light emitting layer;
It is constituted by at least one of a hole transport layer formed between the pixel electrode and the light emitting layer and an electron transport layer formed between the light emitting layer and the metal electrode. The flexible display according to any one of claims 1 to 3. An active matrix flexible display in which a TFT is provided for each of a plurality of pixels,
A first plastic film; an adhesive layer formed on the first plastic film; a protective layer formed above the adhesive layer; a gate electrode for the TFT embedded in the protective layer; A gate insulating layer for the TFT covering the gate electrode; a source electrode and a drain electrode for the TFT formed on the gate insulating layer and arranged at a predetermined interval on the gate electrode; and on the gate insulating layer And the pixel electrode electrically connected to the drain electrode and the TFT electrode formed between the source electrode and the drain electrode and electrically connected to the source electrode and the drain electrode. A TFT substrate comprising: an organic active layer; and a first alignment film formed above the pixel electrode and the organic active layer;
A counter substrate comprising a second plastic film, a common electrode formed on the second plastic film, and a second alignment film formed on the common electrode;
A flexible display comprising: a liquid crystal sealed between the TFT substrate and the counter substrate.   The flexible display according to claim 9, further comprising a color filter layer formed between the adhesive layer and the protective layer.   The flexible display according to any one of claims 1 to 10, wherein the organic active layer is made of pentacene, sexithiophene, or polythiophene. An active matrix flexible display manufacturing method in which a TFT is provided for each of a plurality of pixels,
Forming a release layer on the temporary substrate;
Forming a source electrode and a drain electrode for the TFT on the release layer, and forming a pixel electrode electrically connected to the drain electrode;
Forming a gate insulating layer for the TFT that covers the source electrode, the drain electrode, and the pixel electrode;
Forming a gate electrode for the TFT in a portion on the gate insulating layer between the source electrode and the drain electrode;
Forming a protective layer covering the gate electrode;
Adhering a plastic film on the protective layer via an adhesive layer;
The temporary substrate is peeled from the interface with the peeling layer, and the peeling layer, the source electrode, the drain electrode, the pixel electrode, the gate insulating layer, the gate electrode, and the protective layer are transferred onto the plastic film. And a process of
Removing the release layer to expose upper surfaces of the source electrode, the drain electrode, and the pixel electrode;
Forming an organic active layer for the TFT electrically connected to the source electrode and the drain electrode between the source electrode and the drain electrode;
Forming an organic EL layer including a light emitting layer on the pixel electrodes of the plurality of pixels, respectively, before or after the step of forming the organic active layer;
Forming a metal electrode on the organic EL layer;
And a step of forming a sealing layer covering the metal electrode.   The plurality of pixels are defined by a red pixel portion, a green pixel portion, and a blue pixel portion. In the step of forming the light emitting layer, a red (R) light emitting layer is formed in the red pixel portion, and the green pixel The method for manufacturing a flexible display according to claim 12, wherein a green (G) light emitting layer is formed on the portion, and a blue (B) light emitting layer is formed on the blue pixel portion. After the step of forming the protective layer, further comprising a step of forming a color filter layer on the protective layer,
The method for manufacturing a flexible display according to claim 12, wherein a white light emitting layer is formed as the light emitting layer.   15. The organic active layer and the organic EL layer are formed by mask vapor deposition in the step of forming the organic active layer and the step of forming the organic EL layer, respectively. The manufacturing method of the flexible display of claim | item. Before the step of forming the pixel electrode,
Patterning a mask layer on the release layer;
Further comprising forming an organic insulating layer on the release layer and the mask layer,
The step of removing the release layer is performed by etching the organic insulating layer using the mask layer as a mask after removing the release layer, and between the source electrode and the drain electrode, and the pixel electrode. Forming an organic insulating layer pattern each having an opening thereon,
In the step of forming the organic active layer, the organic active layer is formed by an inkjet method or printing in the opening above the source electrode and the drain electrode of the organic insulating layer pattern,
13. The flexible display according to claim 12, wherein, in the step of forming the organic EL layer, the organic EL layer is formed in the opening on the pixel electrode of the organic insulating layer pattern by an ink-jet method or printing. Production method. An active matrix flexible display manufacturing method in which a TFT is provided for each of a plurality of pixels,
Forming a release layer on the temporary substrate;
Forming a source electrode and a drain electrode for the TFT on the release layer, and forming a pixel electrode electrically connected to the drain electrode;
Forming a gate insulating layer for the TFT that covers the source electrode, the drain electrode, and the pixel electrode;
Forming a gate electrode for the TFT in a portion on the gate insulating layer between the source electrode and the drain electrode;
Forming a protective layer covering the gate electrode;
Adhering the first plastic film on the protective layer via an adhesive layer;
The temporary substrate is peeled from the interface with the peeling layer, and the peeling layer, the source electrode, the drain electrode, the pixel electrode, the gate insulating layer, the gate electrode, and the protective layer are peeled off from the first plastic film. A process of transferring to the top;
Removing the release layer to expose upper surfaces of the source electrode, the drain electrode, and the pixel electrode;
Forming an organic active layer for the TFT electrically connected to the source electrode and the drain electrode between the source electrode and the drain electrode;
A TFT substrate is created by a manufacturing method including a step of forming an alignment film above the organic EL layer and the organic active layer,
The TFT substrate and a counter substrate having a structure in which a common electrode and an alignment film are formed on the second plastic film are bonded to each other at a predetermined interval, and liquid crystal is sealed between the TFT substrate and the counter substrate. A method for manufacturing a flexible display.   18. The method of claim 17, further comprising a step of forming a color filter layer on the protective layer after the step of forming the protective layer and before the step of bonding the first plastic film. The manufacturing method of the flexible display as described in any one of.   The method for manufacturing a flexible display according to claim 12, wherein the organic active layer is made of pentacene, sexithiophene, or polythiophene.

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